summaryrefslogblamecommitdiff
path: root/nuttx/arch/arm/src/samv7/sam_emac.c
blob: 4ee2e37094b09d0b82baa9ee9fd847de4766dce9 (plain) (tree)
1
2
3
4
5
6
7
8
9
2933
2934
2935
2936
2937
2938
2939
2940
2941
2942
2943
2944
2945
2946
2947
2948
2949
2950
2951
2952
2953
2954
2955
2956
2957
2958
2959
2960
2961
2962
2963
2964
2965
2966
2967
2968
2969
2970
2971
2972
2973
2974
2975
2976
2977
2978
2979
2980
2981
2982
2983
2984
2985
2986
2987
2988
2989
2990
2991
2992
2993
2994
2995
2996
2997
2998
2999
3000
3001
3002
3003
3004
3005
3006
3007
3008
3009
3010
3011
3012
3013
3014
3015
3016
3017
3018
3019
3020
3021
3022
3023
3024
3025
3026
3027
3028
3029
3030
3031
3032
3033
3034
3035
3036
3037
3038
3039
3040
3041
3042
3043
3044
3045
3046
3047
3048
3049
3050
3051
3052
3053
3054
3055
3056
3057
3058
3059
3060
3061
3062
3063
3064
3065
3066
3067
3068
3069
3070
3071
3072
3073
3074
3075
3076
3077
3078
3079
3080
3081
3082
3083
3084
3085
3086
3087
3088
3089
3090
3091
3092
3093
3094
3095
3096
3097
3098
3099
3100
3101
3102
3103
3104
3105
3106
3107
3108
3109
3110
3111
3112
3113
3114
3115
3116
3117
3118
3119
3120
3121
3122
3123
3124
3125
3126
3127
3128
3129
3130
3131
3132
3133
3134
3135
3136
3137
3138
3139
3140
3141
3142
3143
3144
3145
3146
3147
3148
3149
3150
3151
3152
3153
3154
3155
3156
3157
3158
3159
3160
3161
3162
3163
3164
3165
3166
3167
3168
3169
3170
3171
3172
3173
3174
3175
3176
3177
3178
3179
3180
3181
3182
3183
3184
3185
3186
3187
3188
3189
3190
3191
3192
3193
3194
3195
3196
3197
3198
3199
3200
3201
3202
3203
3204
3205
3206
3207
3208
3209
3210
3211
3212
3213
3214
3215
3216
3217
3218
3219
3220
3221
3222
3223
3224
3225
3226
3227
3228
3229
3230
3231
3232
3233
3234
3235
3236
3237
3238
3239
3240
3241
3242
3243
3244
3245
3246
3247
3248
3249
3250
3251
3252
3253
3254
3255
3256
3257
3258
3259
3260
3261
3262
3263
3264
3265
3266
3267
3268
3269
3270
3271
3272
3273
3274
3275
3276
3277
3278
3279
3280
3281
3282
3283
3284
3285
3286
3287
3288
3289
3290
3291
3292
3293
3294
3295
3296
3297
3298
3299
3300
3301
3302
3303
3304
3305
3306
3307
3308
3309
3310
3311
3312
3313
3314
3315
3316
3317
3318
3319
3320
3321
3322
3323
3324
3325
3326
3327
3328
3329
3330
3331
3332
3333
3334
3335
3336
3337
3338
3339
3340
3341
3342
3343
3344
3345
3346
3347
3348
3349
3350
3351
3352
3353
3354
3355
3356
3357
3358
3359
3360
3361
3362
3363
3364
3365
3366
3367
3368
3369
3370
3371
3372
3373
3374
3375
3376
3377
3378
3379
3380
3381
3382
3383
3384
3385
3386
3387
3388
3389
3390
3391
3392
3393
3394
3395
3396
3397
3398
3399
3400
3401
3402
3403
3404
3405
3406
3407
3408
3409
3410
3411
3412
3413
3414
3415
3416
3417
3418
3419
3420
3421
3422
3423
3424
3425
3426
3427
3428
3429
3430
3431
3432
3433
3434
3435
3436
3437
3438
3439
3440
3441
3442
3443
3444
3445
3446
3447
3448
3449
3450
3451
3452
3453
3454
3455
3456
3457
3458
3459
3460
3461
3462
3463
3464
3465
3466
3467
3468
3469
3470
3471
3472
3473
3474
3475
3476
3477
3478
3479
3480
3481
3482
3483
3484
3485
3486
3487
3488
3489
3490
3491
3492
3493
3494
3495
3496
3497
3498
3499
3500
3501
3502
3503
3504
3505
3506
3507
3508
3509
3510
3511
3512
3513
3514
3515
3516
3517
3518
3519
3520
3521
3522
3523
3524
3525
3526
3527
3528
3529
3530
3531
3532
3533
3534
3535
3536
3537
3538
3539
3540
3541
3542
3543
3544
3545
3546
3547
3548
3549
3550
3551
3552
3553
3554
3555
3556
3557
3558
3559
3560
3561
3562
3563
3564
3565
3566
3567
3568
3569
3570
3571
3572
3573
3574
3575
3576
3577
3578
3579
3580
3581
3582
3583
3584
3585
3586
3587
3588
3589
3590
3591
3592
3593
3594
3595
3596
3597
3598
3599
3600
3601
3602
3603
3604
3605
3606
3607
3608
3609
3610
3611
3612
3613
3614
3615
3616
3617
3618
3619
3620
3621
3622
3623
3624
3625
3626
3627
3628
3629
3630
3631
3632
3633
3634
3635
3636
3637
3638
3639
3640
3641
3642
3643
3644
3645
3646
3647
3648
3649
3650
3651
3652
3653
3654
3655
3656
3657
3658
3659
3660
3661
3662
3663
3664
3665
3666
3667
3668
3669
3670
3671
3672
3673
3674
3675
3676
3677
3678
3679
3680
3681
3682
3683
3684
3685
3686
3687
3688
3689
3690
3691
3692
3693
3694
3695
3696
3697
3698
3699
3700
3701
3702
3703
3704
3705
3706
3707
3708
3709
3710
3711
3712
3713
3714
3715
3716
3717
3718
3719
3720
3721
3722
3723
3724
3725
3726
3727
3728
3729
3730
3731
3732
3733
3734
3735
3736
3737
3738
3739
3740
3741
3742
3743
3744
3745
3746
3747
3748
3749
3750
3751
3752
3753
3754
3755
3756
3757
3758
3759
3760
3761
3762
3763
3764
3765
3766
3767
3768
3769
3770
3771
3772
3773
3774
3775
3776
3777
3778
3779
3780
3781
3782
3783
3784
3785
3786
3787
3788
3789
3790
3791
3792
3793
3794
3795
3796
3797
3798
3799
3800
3801
3802
3803
3804
3805
3806
3807
3808
3809
3810
3811
3812
3813
3814
3815
3816
3817
3818
3819
3820
3821
3822
3823
3824
3825
3826
3827
3828
3829
3830
3831
3832
3833
3834
3835
3836
3837
3838
3839
3840
3841
3842
3843
3844
3845
3846
3847
3848
3849
3850
3851
3852
3853
3854
3855
3856
3857
3858
3859
3860
3861
3862
3863
3864
3865
3866
3867
3868
3869
3870
3871
3872
3873
3874
3875
3876
3877
3878
3879
3880
3881
3882
3883
3884
3885
3886
3887
3888
3889
3890
3891
3892
3893
3894
3895
3896
3897
3898
3899
3900
3901
3902
3903
3904
3905
3906
3907
3908
3909
3910
3911
3912
3913
3914
3915
3916
3917
3918
3919
3920
3921
3922
3923
3924
3925
3926
3927
3928
3929
3930
3931
3932
3933
3934
3935
3936
3937
3938
3939
3940
3941
3942
3943
3944
3945
3946
3947
3948
3949
3950
3951
3952
3953
3954








                                                                             


                                                                            













































































































                                                                              



                                                





                                            



                                                















































































                                                                                               



                                                





                                            



                                                
























































































                                                                                               
                                                                              











                                                                             

                               



                             


                        






























































                                                                                          
 




                                                                              

                                       


                           
                                        


                                          
                                   



































































                                                                              









                                                                                


      
















                                                                    
























                                                                                     
 
                       
 


                                           























                                                                               


                                                              



                                                     
                                                           
                                                 
                                                         


                        





                                                                      














































































                                                                          

                                                          








                                                         


                                                                  











                                                                              
                                                                          




                                                                       

                                                           
                                                   


                               
                                                                          




                                                                       

                                                           
                                                   







                                                                                  

                                                   

                                                                 
                                                   


                           

                                                    
 
                                                              
                                                   
 




                               





                                                                          

                                                           
                                                   


                               





                                                                          

                                                           
                                                   







                                                                                  

                                                   

                                                                 
                                                   


                           

                                                    
 
                                                                 
                                                   
 






























































                                                                                   



                                    































































                                                                                   


                                    






















































































































                                                                              
                                         





                                                                              
                                                             
 



                                              
     
                                   

     
                                                       









                                                                             
                                         





                                                                              
                                                            





                                                                            
                                                                   


                                                                             
                                


                                                                         
                                                                             











                                                                              
                                                       

                                    
                           

          

                                 


                                                        
                                                        





                                                       


                                          
     










                                               
     

     
                           
                   
          
 
                                
 

                                                                                     
                            




                                                           

                                                    
 

                                                                                     
                            





                                                           

                                                    

                                                        
                                                                          
                              





                                                      

                                             
                                                        
                                                                          
                              





                                                      



                                             

                                                                                     








                                                           

                                                                                     










                                                           
                                                                          









                                                      
                                                                          








                                                      
                                                                           


                                          
                                          
 

                                              
 

                                                
 




                                        

     

      

                        








                                                                           




















                                                                              
                           

          

                              
                                          
     
                              

                  
                           
             

                                     
             
 
                           
             

                                     
             
 
                             
             

                                       
             
 
                             
             

                                       


             



                            










                                                                             

                                                                       

                                                    
                                        










                                                                              
                                                         


                                        
                           

                  
                  
 









                                                        





                                                                        


                                                      
                                








                                                



                                                                          

                                                           

                                                             

     
                                                  

                                         
                                     






                                                                       

                                                                     


                                
                                   
     
                 

     
                        
 





                                                          






                                                                       

















                                                                          
                                

































































                                                                                 
                                       




                                                                           
                                              























                                                                              
                                                 








                                                                              
                                                        






                                                                           
                                

















                                                                             
                                                    











                                                                              
                                                          
 
                                        
                           

















                                                                          


                                    

                     
                                                                   
 

                                                                           
 
                                               








                                                                            


                                                                            
 
                                      


                                                   
                                                  

                                                    




                                                              
 
                                                                
 
                                                    
                 
                                  












                                                               



                                                                          
 
                                      







                                            
                                   
             
                                                                        



                                                       
                                                      

                                                        




                                                                  


                                              
                                                        
                     
                                      

                     
                                           
 















                                                                         
                                                                           
 



                                                                            











                                                                      
                                                                             

                                                                           

                                                                          

                 
                                          


                                                       
                                                      

                                                        




                                                                  
 


                                                                           
 
                                                        
                     
                                      






                                                                             
                                              
                                               










                                                                  


                                                                           







                                                




                                                          




                                                                      
                              

         
                                                                  

                                         
 
                                  
 
                                                                    


                                                                             



                           

                                                    











                                                                             
                                                                








                                                                              
                                                         






                                                                  
                                        























































                                                                               
                                      



































                                                                               
                                      


















                                                                               
                                      


















                                                                             
                                                            








                                                                              
                                                        

                               
                           
                





                                                                           



                              


                                                               
                                   

                                                                               
 



                                                                        

         
                                                   
         
                                                                           
 

                
 

                                                                
                                    



                                                      
                                         

                       
             
 
                                          
 
                                       


                                                                                   
 
                                                
 

                                     
         
                   






                                                                           
                                                          

     

                               
                      
 

                                       
                        


                                                                             
                                

               
                                   


                                                   
                                                                   








                                                                              
                                                                     
 
                               
                           
                  
                
 




                                                                       
 


                                                  
 






                                                                         
    


                                                                            

     






                                                                          



                              
     
                                   
 
                                                                     
 

                                                                               
 

                                                         
                                    
                                                      
         
                                        
 
                                         


                       
 
                                          
 
                                       

                                                                                   

         
                                                
 

                                     
         
                   
         
     
 
                               
 
                      
 
                      
 
                         
 
                    
 































































                                                                              








                                                                             
                                                                 









































                                                                             


























































                                                                                   


                       






                                      
















































                                                                              
                                            

































































                                                                              
                                            


































































                                                                              
                                 








































































































                                                                              
                                         
































































































































                                                                              

                                          
                             
























































































































                                                                                
                                     





























































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































                                                                                     
               






























































































































































































                                                                         



                                                     
                                                
                                             
 
                        
     
                                




                                               
                                             




































































































































                                                                              
                            



                                                




                                                                                 


                                                                                 



                                                                                 



















































































































































                                                                                    
                                            







                                                                              
                                                         
 


                               
                    
                    


                  





                                     







                                                 

                   
 
                                              
     
                                                            
 
                                                                                 
 


                                            


                                             
                                       

                                        



                                                   
                                                                     


                                                      

                                                                            









                                                                             
                                          







                                                                              
                                                         
 


                               

                    


                  





                                     







                                                  
                  



                                                            
 


                                                                 
 


                                   


                                             
                                                         
 



                                                   
                                                                     


                                                     

                                                                            





















































































































                                                                              






                                  













                                                               






                                  





























































































































                                                                              














                                                                              
                                                        










                                                                     
                                                 

     

                                                                                     


























































                                                                              




























                                                                              

                                                                   


                                                             
                                                                         



                                                             

                                                                        




                                                

                                                         




                                                                         

                                                                       


                             



                            


                                                  













                                                                              

                                                                           


























































































                                                                                    
                                  

              
                                                           














































                                                                                  









                                                                             

                                                                          
























































                                                                              
                                            
/****************************************************************************
 * arch/arm/src/samv7/sam_emac.c
 * 10/100 Base-T Ethernet driver for the SAMV71.
 *
 *   Copyright (C) 2015 Gregory Nutt. All rights reserved.
 *   Author: Gregory Nutt <gnutt@nuttx.org>
 *
 * This logic derives from the SAMA5 Ethernet driver which, in turn, derived
 * from the SAM4E Ethernet driver which used Atmel NoOS sample code for
 * reference (only).  Updates for SAMV7 queue logic derive Atmel sample code
 * for the SAMV7-XULT evaluation board.  The Atmel sample code has a BSD
 * compatible license that requires this copyright notice:
 *
 *   Copyright (c) 2012, Atmel Corporation
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in
 *    the documentation and/or other materials provided with the
 *    distribution.
 * 3. Neither the names NuttX nor Atmel nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
 * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
 * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
 * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 *
 ****************************************************************************/

/****************************************************************************
 * Included Files
 ****************************************************************************/

#include <nuttx/config.h>

#if defined(CONFIG_DEBUG) && defined(CONFIG_SAMV7_EMAC_DEBUG)
  /* Force debug output (from this file only) */

#  undef  CONFIG_DEBUG_NET
#  define CONFIG_DEBUG_NET 1
#endif

#include <stdint.h>
#include <stdbool.h>
#include <time.h>
#include <string.h>
#include <debug.h>
#include <queue.h>
#include <errno.h>

#include <arpa/inet.h>

#include <nuttx/arch.h>
#include <nuttx/irq.h>
#include <nuttx/wdog.h>
#include <nuttx/kmalloc.h>

#ifdef CONFIG_NET_NOINTS
#  include <nuttx/wqueue.h>
#endif

#include <nuttx/net/mii.h>
#include <nuttx/net/arp.h>
#include <nuttx/net/netdev.h>
#include <nuttx/net/phy.h>

#ifdef CONFIG_NET_PKT
#  include <nuttx/net/pkt.h>
#endif

#include <arch/samv7/chip.h>

#include "up_arch.h"
#include "up_internal.h"
#include "cache.h"

#include "chip/sam_pinmap.h"
#include "sam_gpio.h"
#include "sam_periphclks.h"
#include "sam_ethernet.h"

#include <arch/board/board.h>

#if defined(CONFIG_NET) && defined(CONFIG_SAMV7_EMAC)

/****************************************************************************
 * Pre-processor Definitions
 ****************************************************************************/
/* Configuration ************************************************************/

/* If processing is not done at the interrupt level, then high priority
 * work queue support is required.
 */

#if defined(CONFIG_NET_NOINTS) && !defined(CONFIG_SCHED_HPWORK)
#  error High priority work queue support is required
#endif

/* EMAC0 Configuration ******************************************************/

#ifdef CONFIG_SAMV7_EMAC0
  /* Number of buffers for RX */

#  ifndef CONFIG_SAMV7_EMAC0_NRXBUFFERS
#    define CONFIG_SAMV7_EMAC0_NRXBUFFERS  16
#  endif

#  if CONFIG_SAMV7_EMAC0_NRXBUFFERS <= 1
#    error CONFIG_SAMV7_EMAC0_NRXBUFFERS invalid
#  endif

  /* Number of buffers for TX */

#  ifndef CONFIG_SAMV7_EMAC0_NTXBUFFERS
#    define CONFIG_SAMV7_EMAC0_NTXBUFFERS  8
#  endif

#  if CONFIG_SAMV7_EMAC0_NTXBUFFERS <= 1
#    error CONFIG_SAMV7_EMAC0_NTXBUFFERS invalid
#  endif

#  ifndef CONFIG_SAMV7_EMAC0_PHYADDR
#    error "CONFIG_SAMV7_EMAC0_PHYADDR must be defined in the NuttX configuration"
#  endif

#  if !defined(CONFIG_SAMV7_EMAC0_MII) && !defined(CONFIG_SAMV7_EMAC0_RMII)
#    warning "Neither CONFIG_SAMV7_EMAC0_MII nor CONFIG_SAMV7_EMAC0_RMII defined"
#  endif

#  if defined(CONFIG_SAMV7_EMAC0_MII) && defined(CONFIG_SAMV7_EMAC0_RMII)
#    error "Both CONFIG_SAMV7_EMAC0_MII and CONFIG_SAMV7_EMAC0_RMII defined"
#  endif

#  ifndef CONFIG_SAMV7_EMAC0_PHYSR
#    error "CONFIG_SAMV7_EMAC0_PHYSR must be defined in the NuttX configuration"
#  endif

#  ifdef CONFIG_SAMV7_EMAC0_AUTONEG
#    ifdef CONFIG_SAMV7_EMAC0_PHYSR_ALTCONFIG
#      ifndef CONFIG_SAMV7_EMAC0_PHYSR_ALTMODE
#        error "CONFIG_SAMV7_EMAC0_PHYSR_ALTMODE must be defined in the NuttX configuration"
#      endif
#      ifndef CONFIG_SAMV7_EMAC0_PHYSR_10HD
#        error "CONFIG_SAMV7_EMAC0_PHYSR_10HD must be defined in the NuttX configuration"
#      endif
#      ifndef CONFIG_SAMV7_EMAC0_PHYSR_100HD
#        error "CONFIG_SAMV7_EMAC0_PHYSR_100HD must be defined in the NuttX configuration"
#      endif
#      ifndef CONFIG_SAMV7_EMAC0_PHYSR_10FD
#        error "CONFIG_SAMV7_EMAC0_PHYSR_10FD must be defined in the NuttX configuration"
#      endif
#      ifndef CONFIG_SAMV7_EMAC0_PHYSR_100FD
#        error "CONFIG_SAMV7_EMAC0_PHYSR_100FD must be defined in the NuttX configuration"
#      endif
#    else
#      ifndef CONFIG_SAMV7_EMAC0_PHYSR_SPEED
#        error "CONFIG_SAMV7_EMAC0_PHYSR_SPEED must be defined in the NuttX configuration"
#      endif
#      ifndef CONFIG_SAMV7_EMAC0_PHYSR_100MBPS
#        error "CONFIG_SAMV7_EMAC0_PHYSR_100MBPS must be defined in the NuttX configuration"
#      endif
#      ifndef CONFIG_SAMV7_EMAC0_PHYSR_MODE
#        error "CONFIG_SAMV7_EMAC0_PHYSR_MODE must be defined in the NuttX configuration"
#      endif
#      ifndef CONFIG_SAMV7_EMAC0_PHYSR_FULLDUPLEX
#        error "CONFIG_SAMV7_EMAC0_PHYSR_FULLDUPLEX must be defined in the NuttX configuration"
#      endif
#    endif
#  endif

  /* PHY definitions */

#  if defined(SAMV7_EMAC0_PHY_DM9161)
#    define EMAC0_MII_OUI_MSB    0x0181
#    define EMAC0_MII_OUI_LSB    0x2e
#  elif defined(SAMV7_EMAC0_PHY_LAN8700)
#    define EMAC0_MII_OUI_MSB    0x0007
#    define EMAC0_MII_OUI_LSB    0x30
#  elif defined(SAMV7_EMAC0_PHY_KSZ8051)
#    define EMAC0_MII_OUI_MSB    0x0022
#    define EMAC0_MII_OUI_LSB    0x05
#  elif defined(SAMV7_EMAC0_PHY_KSZ8061)
#    define EMAC0_MII_OUI_MSB    0x0022
#    define EMAC0_MII_OUI_LSB    0x05
#  elif defined(SAMV7_EMAC0_PHY_KSZ8081)
#    define EMAC0_MII_OUI_MSB    0x0022
#    define EMAC0_MII_OUI_LSB    0x05
#  else
#    error EMAC PHY unrecognized
#  endif
#endif /* CONFIG_SAMV7_EMAC0 */

/* EMAC1 Configuration ******************************************************/

#ifdef CONFIG_SAMV7_EMAC1
  /* Number of buffers for RX */

#  ifndef CONFIG_SAMV7_EMAC1_NRXBUFFERS
#    define CONFIG_SAMV7_EMAC1_NRXBUFFERS  16
#  endif

#  if CONFIG_SAMV7_EMAC1_NRXBUFFERS <= 1
#    error CONFIG_SAMV7_EMAC1_NRXBUFFERS invalid
#  endif

  /* Number of buffers for TX */

#  ifndef CONFIG_SAMV7_EMAC1_NTXBUFFERS
#    define CONFIG_SAMV7_EMAC1_NTXBUFFERS  8
#  endif

#  if CONFIG_SAMV7_EMAC1_NTXBUFFERS <= 1
#    error CONFIG_SAMV7_EMAC1_NTXBUFFERS invalid
#  endif

#  ifndef CONFIG_SAMV7_EMAC1_PHYADDR
#    error "CONFIG_SAMV7_EMAC1_PHYADDR must be defined in the NuttX configuration"
#  endif

#  if !defined(CONFIG_SAMV7_EMAC1_MII) && !defined(CONFIG_SAMV7_EMAC1_RMII)
#    warning "Neither CONFIG_SAMV7_EMAC1_MII nor CONFIG_SAMV7_EMAC1_RMII defined"
#  endif

#  if defined(CONFIG_SAMV7_EMAC1_MII) && defined(CONFIG_SAMV7_EMAC1_RMII)
#    error "Both CONFIG_SAMV7_EMAC1_MII and CONFIG_SAMV7_EMAC1_RMII defined"
#  endif

#  ifndef CONFIG_SAMV7_EMAC1_PHYSR
#    error "CONFIG_SAMV7_EMAC1_PHYSR must be defined in the NuttX configuration"
#  endif

#  ifdef CONFIG_SAMV7_EMAC1_AUTONEG
#    ifdef CONFIG_SAMV7_EMAC1_PHYSR_ALTCONFIG
#      ifndef CONFIG_SAMV7_EMAC1_PHYSR_ALTMODE
#        error "CONFIG_SAMV7_EMAC1_PHYSR_ALTMODE must be defined in the NuttX configuration"
#      endif
#      ifndef CONFIG_SAMV7_EMAC1_PHYSR_10HD
#        error "CONFIG_SAMV7_EMAC1_PHYSR_10HD must be defined in the NuttX configuration"
#      endif
#      ifndef CONFIG_SAMV7_EMAC1_PHYSR_100HD
#        error "CONFIG_SAMV7_EMAC1_PHYSR_100HD must be defined in the NuttX configuration"
#      endif
#      ifndef CONFIG_SAMV7_EMAC1_PHYSR_10FD
#        error "CONFIG_SAMV7_EMAC1_PHYSR_10FD must be defined in the NuttX configuration"
#      endif
#      ifndef CONFIG_SAMV7_EMAC1_PHYSR_100FD
#        error "CONFIG_SAMV7_EMAC1_PHYSR_100FD must be defined in the NuttX configuration"
#      endif
#    else
#      ifndef CONFIG_SAMV7_EMAC1_PHYSR_SPEED
#        error "CONFIG_SAMV7_EMAC1_PHYSR_SPEED must be defined in the NuttX configuration"
#      endif
#      ifndef CONFIG_SAMV7_EMAC1_PHYSR_100MBPS
#        error "CONFIG_SAMV7_EMAC1_PHYSR_100MBPS must be defined in the NuttX configuration"
#      endif
#      ifndef CONFIG_SAMV7_EMAC1_PHYSR_MODE
#        error "CONFIG_SAMV7_EMAC1_PHYSR_MODE must be defined in the NuttX configuration"
#      endif
#      ifndef CONFIG_SAMV7_EMAC1_PHYSR_FULLDUPLEX
#        error "CONFIG_SAMV7_EMAC1_PHYSR_FULLDUPLEX must be defined in the NuttX configuration"
#      endif
#    endif
#  endif

  /* PHY definitions */

#  if defined(SAMV7_EMAC1_PHY_DM9161)
#    define EMAC1_MII_OUI_MSB    0x0181
#    define EMAC1_MII_OUI_LSB    0x2e
#  elif defined(SAMV7_EMAC1_PHY_LAN8700)
#    define EMAC1_MII_OUI_MSB    0x0007
#    define EMAC1_MII_OUI_LSB    0x30
#  elif defined(SAMV7_EMAC1_PHY_KSZ8051)
#    define EMAC1_MII_OUI_MSB    0x0022
#    define EMAC1_MII_OUI_LSB    0x05
#  elif defined(SAMV7_EMAC1_PHY_KSZ8061)
#    define EMAC1_MII_OUI_MSB    0x0022
#    define EMAC1_MII_OUI_LSB    0x05
#  elif defined(SAMV7_EMAC1_PHY_KSZ8081)
#    define EMAC1_MII_OUI_MSB    0x0022
#    define EMAC1_MII_OUI_LSB    0x05
#  else
#    error EMAC PHY unrecognized
#  endif
#endif /* CONFIG_SAMV7_EMAC1 */

/* Common Configuration *****************************************************/

#undef CONFIG_SAMV7_EMAC_NBC

/* Extremely detailed register debug that you would normally never want
 * enabled.
 */

#ifndef CONFIG_DEBUG
#  undef CONFIG_SAMV7_EMAC_REGDEBUG
#endif

#ifdef CONFIG_NET_DUMPPACKET
#  define sam_dumppacket(m,a,n) lib_dumpbuffer(m,a,n)
#else
#  define sam_dumppacket(m,a,n)
#endif

/* EMAC buffer sizes, number of buffers, and number of descriptors ***********
 *
 * REVISIT: The CONFIG_NET_MULTIBUFFER might be useful.  It might be possible
 * to use this option to send and receive messages directly into the DMA
 * buffers, saving a copy.  There might be complications on the receiving
 * side, however, where buffers may wrap and where the size of the received
 * frame will typically be smaller than a full packet.
 */

#ifdef CONFIG_NET_MULTIBUFFER
#  error CONFIG_NET_MULTIBUFFER must not be set
#endif

/* Queue identifiers/indices */

#define EMAC_QUEUE_0        0
#define EMAC_QUEUE_1        1
#define EMAC_QUEUE_2        2
#define EMAC_NQUEUES        3

/* Interrupt settings */

#define EMAC_RX_INTS        (EMAC_INT_RCOMP | EMAC_INT_RXUBR | EMAC_INT_ROVR)
#define EMAC_TXERR_INTS     (EMAC_INT_TUR | EMAC_INT_RLEX | EMAC_INT_TFC | \
                             EMAC_INT_HRESP)
#define EMAC_TX_INTS        (EMAC_TXERR_INTS | EMAC_INT_TCOMP)

/* Buffer Alignment.
 *
 * The EMAC peripheral requires that descriptors and buffers be aligned
 * the 8-byte (2 word boundaries).  However, if the data cache is enabled
 * the a higher level of alignment is required.  That is because the data
 * will need to be invalidated and that cache invalidation will occur in
 * multiples of full change lines.
 *
 * In addition, padding may be required at the ends of the descriptors and
 * buffers to protect data after the end of from invalidation.
 */

#ifdef CONFIG_ARMV7M_DCACHE
/* Align to the cache line size which we assume is >= 8 */

#  define EMAC_ALIGN        ARMV7M_DCACHE_LINESIZE
#  define EMAC_ALIGN_MASK   (EMAC_ALIGN-1)
#  define EMAC_ALIGN_UP(n)  (((n) + EMAC_ALIGN_MASK) & ~EMAC_ALIGN_MASK)

#  define EMAC0_RX_DPADSIZE (EMAC0_RX_DESCSIZE & EMAC_ALIGN_MASK)
#  define EMAC0_TX_DPADSIZE (EMAC0_TX_DESCSIZE & EMAC_ALIGN_MASK)
#  define EMAC1_RX_DPADSIZE (EMAC1_RX_DESCSIZE & EMAC_ALIGN_MASK)
#  define EMAC1_TX_DPADSIZE (EMAC1_TX_DESCSIZE & EMAC_ALIGN_MASK)

#else
/* Use the minimum alignment requirement */

#  define EMAC_ALIGN        8
#  define EMAC_ALIGN_MASK   7
#  define EMAC_ALIGN_UP(n)  (((n) + 7) & ~7)

#  define EMAC0_RX_DPADSIZE 0
#  define EMAC0_TX_DPADSIZE 0
#  define EMAC1_RX_DPADSIZE 0
#  define EMAC1_TX_DPADSIZE 0

#endif

/* Buffer sizes.
 *
 * RX buffer size if fixed at 128 bytes since fragmented incoming packets
 * are handled.
 */

#define EMAC_RX_UNITSIZE    EMAC_ALIGN_UP(128)
#define EMAC_TX_UNITSIZE    EMAC_ALIGN_UP(CONFIG_NET_ETH_MTU)
#define DUMMY_BUFSIZE       EMAC_ALIGN_UP(128)
#define DUMMY_NBUFFERS      2

#define EMAC0_RX_DESCSIZE   (CONFIG_SAMV7_EMAC0_NRXBUFFERS * sizeof(struct emac_rxdesc_s))
#define EMAC0_TX_DESCSIZE   (CONFIG_SAMV7_EMAC0_NTXBUFFERS * sizeof(struct emac_txdesc_s))
#define EMAC0_RX_BUFSIZE    (CONFIG_SAMV7_EMAC0_NRXBUFFERS * EMAC_RX_UNITSIZE)
#define EMAC0_TX_BUFSIZE    (CONFIG_SAMV7_EMAC0_NTXBUFFERS * EMAC_TX_UNITSIZE)

#define EMAC1_RX_DESCSIZE   (CONFIG_SAMV7_EMAC1_NRXBUFFERS * sizeof(struct emac_rxdesc_s))
#define EMAC1_TX_DESCSIZE   (CONFIG_SAMV7_EMAC1_NTXBUFFERS * sizeof(struct emac_txdesc_s))
#define EMAC1_RX_BUFSIZE    (CONFIG_SAMV7_EMAC1_NRXBUFFERS * EMAC_RX_UNITSIZE)
#define EMAC1_TX_BUFSIZE    (CONFIG_SAMV7_EMAC1_NTXBUFFERS * EMAC_TX_UNITSIZE)

/* Timing *******************************************************************/
/* TX poll delay = 1 seconds. CLK_TCK is the number of clock ticks per
 * second
 */

#define SAM_WDDELAY         (1*CLK_TCK)
#define SAM_POLLHSEC        (1*2)

/* TX timeout = 1 minute */

#define SAM_TXTIMEOUT       (60*CLK_TCK)

/* PHY read/write delays in loop counts */

#define PHY_RETRY_MAX       1000000

/* Helpers ******************************************************************/
/* This is a helper pointer for accessing the contents of the EMAC
 * header
 */

#define BUF ((struct eth_hdr_s *)priv->dev.d_buf)

/****************************************************************************
 * Private Types
 ****************************************************************************/
/* This structure defines the constant an configured attributes of an EMAC */

struct sam_emacattr_s
{
  /* Basic hardware information */

  uint32_t             base;         /* EMAC Register base address */
  xcpt_t               handler;      /* EMAC interrupt handler */
  uint8_t              emac;         /* EMACn, n=0 or 1 */
  uint8_t              irq;          /* EMAC interrupt number */

  /* PHY Configuration */

  uint8_t              phyaddr;      /* PHY address */
  uint8_t              physr;        /* PHY status register address */
  uint16_t             msoui;        /* MS 16 bits of the 18-bit OUI */
  uint8_t              lsoui;        /* LS 2 bits of the 18-bit OUI */
  bool                 rmii;         /* True: RMII vs. False: MII */
  bool                 clause45;     /* True: Clause 45 behavior */
//bool                 autoneg;      /* True: Autonegotiate rate and *plex */
  bool                 sralt;        /* True: Alternate PHYSR bit access */

  union
  {
    /* "Standard" form:  Individual bits determine speed and half/full
     * duplex.
     */

    struct
    {
      uint16_t stdmask;             /* Mask for speed and *plex mode bits */
      uint16_t speed100;            /* 100Base_t bit */
      uint16_t fduplex;             /* Full duplex bit */
    } std;

    /* Alternative form:  Speed and duplex are encoded in a single,
     * multi-bit field.
     */

    struct
    {
      uint16_t altmask;             /* Mask speed for mode bits */
      uint16_t hdx10;               /* 10Base_T Half Duplex bit pattern */
      uint16_t hdx100;              /* 100Base_T Half Duplex bit pattern */
      uint16_t fdx10;               /* 10Base_T Half Duplex bit pattern */
      uint16_t fdx100;              /* 100Base_T Half Duplex bit pattern */
    } alt;
  } u;

  /* Buffer and descriptor configuration */

  uint8_t              ntxbuffers;   /* Number of TX buffers */
  uint8_t              nrxbuffers;   /* Number of RX buffers */

#ifdef CONFIG_SAMV7_EMAC_PREALLOCATE
  /* Attributes and addresses of preallocated buffers */

  struct emac_txdesc_s *tx0desc;     /* Preallocated TX descriptor list */
  struct emac_rxdesc_s *rx0desc;     /* Preallocated RX descriptor list */
  uint8_t              *tx0buffer;   /* Preallocated TX buffers */
  uint8_t              *rx0buffer;   /* Preallocated RX buffers */

  struct emac_txdesc_s *tx1desc;     /* Preallocated TX dummy descriptor list */
  struct emac_rxdesc_s *rx1desc;     /* Preallocated RX dummy descriptor list */
  uint8_t              *tx1buffer;   /* Preallocated TX dummy buffers */
  uint8_t              *rx1buffer;   /* Preallocated RX dummy buffers */

#endif
};

/* This structure describes one transfer queue */

struct sam_queue_s
{
  struct emac_rxdesc_s *rxdesc;      /* Allocated RX descriptors */
  struct emac_txdesc_s *txdesc;      /* Allocated TX descriptors */
  uint8_t              *rxbuffer;    /* Allocated RX buffers */
  uint8_t              *txbuffer;    /* Allocated TX buffers */
  uint16_t              rxbufsize;   /* Size of one RX buffer */
  uint16_t              txbufsize;   /* Size of one TX buffer */
  uint8_t               nrxbuffers;  /* Number of RX buffers/TDs  */
  uint8_t               rxndx;       /* Current RX TD index */
  uint8_t               ntxbuffers;  /* Number of TX buffers/TDs */
  uint16_t              txhead;      /* Buffer head pointer */
  uint16_t              txtail;      /* Buffer tail pointer */
};

/* The sam_emac_s encapsulates all state information for the EMAC peripheral */

struct sam_emac_s
{
  uint8_t               ifup    : 1; /* true:ifup false:ifdown */
  WDOG_ID               txpoll;      /* TX poll timer */
  WDOG_ID               txtimeout;   /* TX timeout timer */
#ifdef CONFIG_NET_NOINTS
  struct work_s         work;        /* For deferring work to the work queue */
#endif

  /* This holds the information visible to uIP/NuttX */

  struct net_driver_s   dev;         /* Interface understood by uIP */

  /* Constant and configured attributes of the EMAC */

  const struct sam_emacattr_s *attr;

  /* Used to track transmit and receive descriptors */

  uint8_t               phyaddr;     /* PHY address (pre-defined by pins on reset) */
#if defined(CONFIG_NETDEV_PHY_IOCTL) && defined(CONFIG_ARCH_PHY_INTERRUPT)
  uint8_t               phytype;     /* See SAMV7_EMAC0/1_PHY_TYPE definitions */
#endif

  /* Transfer queues */

  struct sam_queue_s    xfrq[EMAC_NQUEUES];

    /* Debug stuff */

#ifdef CONFIG_SAMV7_EMAC_REGDEBUG
   bool               wrlast;     /* Last was a write */
   uintptr_t          addrlast;   /* Last address */
   uint32_t           vallast;    /* Last value */
   int                ntimes;     /* Number of times */
#endif
};

/****************************************************************************
 * Private Function Prototypes
 ****************************************************************************/
/* Register operations ******************************************************/

#if defined(CONFIG_SAMV7_EMAC_REGDEBUG) && defined(CONFIG_DEBUG)
static bool sam_checkreg(struct sam_emac_s *priv, bool wr,
                         uint32_t regval, uintptr_t address);
#endif

static uint32_t sam_getreg(struct sam_emac_s *priv, uint16_t offset);
static void sam_putreg(struct sam_emac_s *priv, uint16_t offset, uint32_t val);

/* Buffer management */

static uint16_t sam_txinuse(struct sam_emac_s *priv, int qid);
static uint16_t sam_txfree(struct sam_emac_s *priv, int qid);
static int  sam_buffer_allocate(struct sam_emac_s *priv);
static void sam_buffer_free(struct sam_emac_s *priv);

/* Common TX logic */

static int  sam_transmit(struct sam_emac_s *priv, int qid);
static int  sam_txpoll(struct net_driver_s *dev);
static void sam_dopoll(struct sam_emac_s *priv, int qid);

/* Interrupt handling */

static int  sam_recvframe(struct sam_emac_s *priv, int qid);
static void sam_receive(struct sam_emac_s *priv, int qid);
static void sam_txdone(struct sam_emac_s *priv, int qid);
static void sam_txerr_interrupt(FAR struct sam_emac_s *priv, int qid);
static inline void sam_interrupt_process(FAR struct sam_emac_s *priv,
                                         int qid);
#ifdef CONFIG_NET_NOINTS
static void sam_interrupt_work(FAR void *arg);
#endif
static int  sam_emac_interrupt(struct sam_emac_s *priv);
#ifdef CONFIG_SAMV7_EMAC0
static int sam_emac0_interrupt(int irq, void *context);
#endif
#ifdef CONFIG_SAMV7_EMAC1
static int sam_emac1_interrupt(int irq, void *context);
#endif

/* Watchdog timer expirations */

static inline void sam_txtimeout_process(FAR struct sam_emac_s *priv);
#ifdef CONFIG_NET_NOINTS
static void sam_txtimeout_work(FAR void *arg);
#endif
static void sam_txtimeout_expiry(int argc, uint32_t arg, ...);

static inline void sam_poll_process(FAR struct sam_emac_s *priv);
#ifdef CONFIG_NET_NOINTS
static void sam_poll_work(FAR void *arg);
#endif
static void sam_poll_expiry(int argc, uint32_t arg, ...);

/* NuttX callback functions */

static int  sam_ifup(struct net_driver_s *dev);
static int  sam_ifdown(struct net_driver_s *dev);

static inline void sam_txavail_process(FAR struct sam_emac_s *priv);
#ifdef CONFIG_NET_NOINTS
static void sam_txavail_work(FAR void *arg);
#endif
static int  sam_txavail(struct net_driver_s *dev);

#if defined(CONFIG_NET_IGMP) || defined(CONFIG_NET_ICMPv6)
static unsigned int sam_hashindx(const uint8_t *mac);
static int  sam_addmac(struct net_driver_s *dev, const uint8_t *mac);
#endif
#ifdef CONFIG_NET_IGMP
static int  sam_rmmac(struct net_driver_s *dev, const uint8_t *mac);
#endif

#ifdef CONFIG_NETDEV_PHY_IOCTL
static int  sam_ioctl(struct net_driver_s *dev, int cmd, long arg);
#endif

/* PHY Initialization */

#if defined(CONFIG_DEBUG_NET) && defined(CONFIG_DEBUG_VERBOSE)
static void sam_phydump(struct sam_emac_s *priv);
#else
#  define sam_phydump(priv)
#endif

#if 0 /* Not used */
static bool sam_is10hdx(struct sam_emac_s *priv, uint16_t physr);
#endif
static bool sam_is100hdx(struct sam_emac_s *priv, uint16_t physr);
static bool sam_is10fdx(struct sam_emac_s *priv, uint16_t physr);
static bool sam_is100fdx(struct sam_emac_s *priv, uint16_t physr);

#if defined(CONFIG_NETDEV_PHY_IOCTL) && defined(CONFIG_ARCH_PHY_INTERRUPT)
static int  sam_phyintenable(struct sam_emac_s *priv);
#endif
static int  sam_phywait(struct sam_emac_s *priv);
static int  sam_phyreset(struct sam_emac_s *priv);
static int  sam_phyfind(struct sam_emac_s *priv, uint8_t *phyaddr);
static int  sam_phyread(struct sam_emac_s *priv, uint8_t phyaddr,
                        uint8_t regaddr, uint16_t *phyval);
static int  sam_phywrite(struct sam_emac_s *priv, uint8_t phyaddr,
                         uint8_t regaddr, uint16_t phyval);
static int  sam_autonegotiate(struct sam_emac_s *priv);
static bool sam_linkup(struct sam_emac_s *priv);
static int  sam_phyinit(struct sam_emac_s *priv);

/* EMAC Initialization */

static void sam_txreset(struct sam_emac_s *priv, int qid);
static void sam_rxreset(struct sam_emac_s *priv, int qid);
static void sam_emac_enableclk(struct sam_emac_s *priv);
#ifndef CONFIG_NETDEV_PHY_IOCTL
static void sam_emac_disableclk(struct sam_emac_s *priv);
#endif
static void sam_emac_reset(struct sam_emac_s *priv);
static void sam_macaddress(struct sam_emac_s *priv);
#ifdef CONFIG_NET_ICMPv6
static void sam_ipv6multicast(struct sam_emac_s *priv);
#endif

static int  sam_queue0_configure(struct sam_emac_s *priv);
static int  sam_queue_configure(struct sam_emac_s *priv, int qid);
static int  sam_emac_configure(struct sam_emac_s *priv);

/****************************************************************************
 * Private Data
 ****************************************************************************/

#ifdef CONFIG_SAMV7_EMAC_PREALLOCATE
/* Preallocated data */

#ifdef CONFIG_SAMV7_EMAC0
/* EMAC0 TX descriptors list */

static struct emac_txdesc_s g_emac0_tx0desc[CONFIG_SAMV7_EMAC0_NTXBUFFERS]
              __attribute__((aligned(EMAC_ALIGN)));

#if EMAC0_TX_DPADSIZE > 0
static uint8_t g_emac0_txdpad[EMAC0_TX_DPADSIZE] __atrribute__((used));
#endif

static struct emac_txdesc_s g_emac0_tx1desc[DUMMY_NBUFFERS]
              __attribute__((aligned(EMAC_ALIGN)));

/* EMAC0 RX descriptors list */

static struct emac_rxdesc_s g_emac0_rx0desc[CONFIG_SAMV7_EMAC0_NRXBUFFERS]
              __attribute__((aligned(EMAC_ALIGN)));

#if EMAC0_RX_DPADSIZE > 0
static uint8_t g_emac0_rxdpad[EMAC0_RX_DPADSIZE] __atrribute__((used));
#endif

static struct emac_rxdesc_s g_emac0_rx1desc[DUMMY_NBUFFERS]
              __attribute__((aligned(EMAC_ALIGN)));

/* EMAC0 Transmit Buffers
 *
 * Section 3.6 of AMBA 2.0 spec states that burst should not cross 1K Boundaries.
 * Receive buffer manager writes are burst of 2 words => 3 lsb bits of the address
 * shall be set to 0
 */

static uint8_t g_emac0_tx0buffer[EMAC0_TX_BUFSIZE];
               __attribute__((aligned(EMAC_ALIGN)))

static uint8_t g_emac0_tx1buffer[DUMMY_NBUFFERS * DUMMY_BUFSIZE];
               __attribute__((aligned(EMAC_ALIGN)))

/* EMAC0 Receive Buffers */

static uint8_t g_emac0_rx0buffer[EMAC0_RX_BUFSIZE]
               __attribute__((aligned(EMAC_ALIGN)));

static uint8_t pRxDummyBuffer[DUMMY_NBUFFERS * DUMMY_BUFSIZE];
               __attribute__((aligned(EMAC_ALIGN)))

#endif

#ifdef CONFIG_SAMV7_EMAC1
/* EMAC1 TX descriptors list */

static struct emac_txdesc_s g_emac1_tx1desc[CONFIG_SAMV7_EMAC1_NTXBUFFERS]
              __attribute__((aligned(EMAC_ALIGN)));

#if EMAC1_TX_DPADSIZE > 0
static uint8_t g_emac1_txdpad[EMAC1_TX_DPADSIZE] __atrribute__((used));
#endif

static struct emac_txdesc_s g_emac1_tx1desc[DUMMY_NBUFFERS]
              __attribute__((aligned(EMAC_ALIGN)));

/* EMAC1 RX descriptors list */

static struct emac_rxdesc_s g_emac1_rx1desc[CONFIG_SAMV7_EMAC1_NRXBUFFERS]
              __attribute__((aligned(EMAC_ALIGN)));

#if EMAC1_RX_DPADSIZE > 0
static uint8_t g_emac1_rxdpad[EMAC1_RX_DPADSIZE] __atrribute__((used));
#endif

static struct emac_rxdesc_s g_emac1_rx1desc[DUMMY_NBUFFERS]
              __attribute__((aligned(EMAC_ALIGN)));

/* EMAC1 Transmit Buffers
 *
 * Section 3.6 of AMBA 2.0 spec states that burst should not cross 1K Boundaries.
 * Receive buffer manager writes are burst of 2 words => 3 lsb bits of the address
 * shall be set to 0
 */

static uint8_t g_emac1_tx1buffer[EMAC1_TX_BUFSIZE];
               __attribute__((aligned(EMAC_ALIGN)))

static uint8_t g_emac1_tx1buffer[DUMMY_NBUFFERS * DUMMY_BUFSIZE];
               __attribute__((aligned(EMAC_ALIGN)))

/* EMAC1 Receive Buffers */

static uint8_t g_emac1_rxbuffer[EMAC1_RX_BUFSIZE]
               __attribute__((aligned(EMAC_ALIGN)));

static uint8_t g_emac1_rx1buffer[DUMMY_NBUFFERS * DUMMY_BUFSIZE];
               __attribute__((aligned(EMAC_ALIGN)))

#endif
#endif

/* The driver state singletons */

#ifdef CONFIG_SAMV7_EMAC0
static const struct sam_emacattr_s g_emac0_attr =
{
  /* Basic hardware information */

  .base         = SAM_EMAC0_BASE,
  .handler      = sam_emac0_interrupt,
  .emac         = EMAC0_INTF,
  .irq          = SAM_IRQ_EMAC0,

  /* PHY Configuration */

  .phyaddr      = CONFIG_SAMV7_EMAC0_PHYADDR,
  .physr        = CONFIG_SAMV7_EMAC0_PHYSR,
  .msoui        = EMAC0_MII_OUI_MSB,
  .lsoui        = EMAC0_MII_OUI_LSB,
#ifdef CONFIG_SAMV7_EMAC0_RMII
  .rmii         = true,
#endif
#ifdef CONFIG_SAMV7_EMAC0_CLAUSE45
  .clause45     = true,
#endif
#ifdef CONFIG_SAMV7_EMAC0_AUTONEG
//.autoneg      = true,
#endif
#ifdef CONFIG_SAMV7_EMAC0_PHYSR_ALTCONFIG
  .sralt        = true,
#endif

  .u            =
  {
#ifdef CONFIG_SAMV7_EMAC0_PHYSR_ALTCONFIG
    .alt        =
    {
      .altmask  = CONFIG_SAMV7_EMAC0_PHYSR_ALTMODE,
      .hdx10    = CONFIG_SAMV7_EMAC0_PHYSR_10HD,
      .hdx100   = CONFIG_SAMV7_EMAC0_PHYSR_100HD,
      .fdx10    = CONFIG_SAMV7_EMAC0_PHYSR_10FD,
      .fdx100   = CONFIG_SAMV7_EMAC0_PHYSR_100FD,
    },
#else
    .std        =
    {
      .stdmask  = (CONFIG_SAMV7_EMAC0_PHYSR_SPEED | CONFIG_SAMV7_EMAC0_PHYSR_MODE),
      .speed100 = CONFIG_SAMV7_EMAC0_PHYSR_100MBPS,
      .fduplex  = CONFIG_SAMV7_EMAC0_PHYSR_FULLDUPLEX,
    },
#endif
  },

  /* Buffer and descriptor configuration */

  .ntxbuffers   = CONFIG_SAMV7_EMAC0_NTXBUFFERS,
  .nrxbuffers   = CONFIG_SAMV7_EMAC0_NRXBUFFERS,

#ifdef CONFIG_SAMV7_EMAC_PREALLOCATE
  /* Addresses of preallocated buffers */

  .tx0desc      = g_emac0_tx0desc,
  .rx0desc      = g_emac0_rx0desc,
  .tx0buffer    = g_emac0_tx0buffer,
  .rx0buffer    = g_emac0_rx0buffer,
#endif
};

static struct sam_emac_s g_emac0;
#endif

#ifdef CONFIG_SAMV7_EMAC1
static const struct sam_emacattr_s g_emac1_attr =
{
  /* Basic hardware information */

  .base         = SAM_EMAC1_BASE,
  .handler      = sam_emac1_interrupt,
  .emac         = EMAC1_INTF,
  .irq          = SAM_IRQ_EMAC1,

  /* PHY Configuration */

  .phyaddr      = CONFIG_SAMV7_EMAC1_PHYADDR,
  .physr        = CONFIG_SAMV7_EMAC1_PHYSR,
  .msoui        = EMAC1_MII_OUI_MSB,
  .lsoui        = EMAC1_MII_OUI_LSB,
#ifdef CONFIG_SAMV7_EMAC1_RMII
  .rmii         = true,
#endif
#ifdef CONFIG_SAMV7_EMAC1_CLAUSE45
  .clause45     = true,
#endif
#ifdef CONFIG_SAMV7_EMAC1_AUTONEG
//.autoneg      = true,
#endif
#ifdef CONFIG_SAMV7_EMAC1_PHYSR_ALTCONFIG
  .sralt        = true,
#endif

  .u            =
  {
#ifdef CONFIG_SAMV7_EMAC1_PHYSR_ALTCONFIG
    .alt        =
    {
      .altmask  = CONFIG_SAMV7_EMAC1_PHYSR_ALTMODE,
      .hdx10    = CONFIG_SAMV7_EMAC1_PHYSR_10HD,
      .hdx100   = CONFIG_SAMV7_EMAC1_PHYSR_100HD,
      .fdx10    = CONFIG_SAMV7_EMAC1_PHYSR_10FD,
      .fdx100   = CONFIG_SAMV7_EMAC1_PHYSR_100FD,
    },
#else
    .std        =
    {
      .stdmask  = (CONFIG_SAMV7_EMAC1_PHYSR_SPEED | CONFIG_SAMV7_EMAC1_PHYSR_MODE),
      .speed100 = CONFIG_SAMV7_EMAC1_PHYSR_100MBPS,
      .fduplex  = CONFIG_SAMV7_EMAC1_PHYSR_FULLDUPLEX,
    },
#endif
  },

  /* Buffer and descriptor configuration */

  .ntxbuffers   = CONFIG_SAMV7_EMAC1_NTXBUFFERS,
  .nrxbuffers   = CONFIG_SAMV7_EMAC1_NRXBUFFERS,

#ifdef CONFIG_SAMV7_EMAC_PREALLOCATE
  /* Attributes and addresses of preallocated buffers */

  .txdesc       = g_emac1_tx0desc,
  .rxdesc       = g_emac1_rx0desc,
  .txbuffer     = g_emac1_tx0buffer,
  .rxbuffer     = g_emac1_rxbuffer,
#endif
};

static struct sam_emac_s g_emac1;
#endif

/****************************************************************************
 * Private Functions
 ****************************************************************************/
/****************************************************************************
 * Name: sam_checkreg
 *
 * Description:
 *   Check if the current register access is a duplicate of the preceding.
 *
 * Input Parameters:
 *   regval  - The value to be written
 *   address - The address of the register to write to
 *
 * Returned Value:
 *   true:  This is the first register access of this type.
 *   flase: This is the same as the preceding register access.
 *
 ****************************************************************************/

#ifdef CONFIG_SAMV7_EMAC_REGDEBUG
static bool sam_checkreg(struct sam_emac_s *priv, bool wr, uint32_t regval,
                         uintptr_t regaddr)
{
  if (wr      == priv->wrlast &&   /* Same kind of access? */
      regval  == priv->vallast &&  /* Same value? */
      regaddr == priv->addrlast)   /* Same address? */
    {
      /* Yes, then just keep a count of the number of times we did this. */

      priv->ntimes++;
      return false;
    }
  else
    {
      /* Did we do the previous operation more than once? */

      if (priv->ntimes > 0)
        {
          /* Yes... show how many times we did it */

          lldbg("...[Repeats %d times]...\n", priv->ntimes);
        }

      /* Save information about the new access */

      priv->wrlast   = wr;
      priv->vallast  = regval;
      priv->addrlast = regaddr;
      priv->ntimes   = 0;
    }

  /* Return true if this is the first time that we have done this operation */

  return true;
}
#endif

/****************************************************************************
 * Name: sam_getreg
 *
 * Description:
 *  Read a 32-bit EMAC register using an offset from the EMAC base address
 *
 ****************************************************************************/

static uint32_t sam_getreg(struct sam_emac_s *priv, uint16_t offset)
{
  uintptr_t regaddr = priv->attr->base + (uintptr_t)offset;
  uint32_t regval = getreg32(regaddr);

#ifdef CONFIG_SAMV7_EMAC_REGDEBUG
  if (sam_checkreg(priv, false, regval, regaddr))
    {
      lldbg("%08x->%08x\n", regaddr, regval);
    }
#endif

  return regval;
}

/****************************************************************************
 * Name: sam_putreg
 *
 * Description:
 *  Write to a 32-bit EMAC register using an offset from the EMAC base
 *  address
 *
 ****************************************************************************/

static void sam_putreg(struct sam_emac_s *priv, uint16_t offset,
                       uint32_t regval)
{
  uintptr_t regaddr = priv->attr->base + (uintptr_t)offset;

#ifdef CONFIG_SAMV7_EMAC_REGDEBUG
  if (sam_checkreg(priv, true, regval, regaddr))
    {
      lldbg("%08x<-%08x\n", regaddr, regval);
    }
#endif

  putreg32(regval, regaddr);
}

/****************************************************************************
 * Function: sam_txinuse
 *
 * Description:
 *   Return the number of TX buffers in-use
 *
 * Input Parameters:
 *   priv - The EMAC driver state
 *   quid - The transfer queue to examine
 *
 * Returned Value:
 *   The number of TX buffers in-use
 *
 ****************************************************************************/

static uint16_t sam_txinuse(struct sam_emac_s *priv, int qid)
{
  struct sam_queue_s *xfrq = &priv->xfrq[qid];

  uint32_t txhead32 = (uint32_t)xfrq->txhead;
  if ((uint32_t)xfrq->txtail > txhead32)
    {
      txhead32 += xfrq->ntxbuffers;
    }

  return (uint16_t)(txhead32 - (uint32_t)xfrq->txtail);
}

/****************************************************************************
 * Function: sam_txfree
 *
 * Description:
 *   Return the number of TX buffers available
 *
 * Input Parameters:
 *   priv - The EMAC driver state
 *   qid  - The transfer queue to examine
 *
 * Returned Value:
 *   The number of TX buffers available
 *
 ****************************************************************************/

static uint16_t sam_txfree(struct sam_emac_s *priv, int qid)
{
  /* The number available is equal to the total number of buffers, minus the
   * number of buffers in use.  Notice that that actual number of buffers is
   * the configured size minus 1.
   */

  return (priv->xfrq[qid].ntxbuffers - 1) - sam_txinuse(priv, qid);
}

/****************************************************************************
 * Function: sam_buffer_allocate
 *
 * Description:
 *   Allocate aligned TX and RX descriptors and buffers.  For the case of
 *   pre-allocated structures, the function degenerates to a few assignments.
 *
 * Input Parameters:
 *   priv - The EMAC driver state
 *
 * Returned Value:
 *   OK on success; Negated errno on failure.
 *
 * Assumptions:
 *   Called very early in the initialization sequence.
 *
 ****************************************************************************/

static int sam_buffer_allocate(struct sam_emac_s *priv)
{
#ifdef CONFIG_SAMV7_EMAC_PREALLOCATE
  struct sam_queue_s *xfrq;
  int qid;

  /* Use pre-allocated buffers */

  priv->xfrq[0].txdesc         = priv->attr->tx0desc;
  priv->xfrq[0].ntxbuffers     = priv->attr->ntxbuffers;
  priv->xfrq[0].rxdesc         = priv->attr->rx0desc;
  priv->xfrq[0].nrxbuffers     = priv->attr->nrxbuffers;

  priv->xfrq[0].txbuffer       = priv->attr->tx0buffer;
  priv->xfrq[0].txbufsize      = EMAC_TX_UNITSIZE;
  priv->xfrq[0].rxbuffer       = priv->attr->rx0buffer;
  priv->xfrq[0].rxbufsize      = EMAC_RX_UNITSIZE;

  /* Priority queues */

  for (qid = 1; qid < EMAC_NQUEUES; qid++)
    {
      xfrq             = &priv->xfrq[qid];

      xfrq->txdesc     = priv->attr->tx1desc;
      xfrq->ntxbuffers = DUMMY_NBUFFERS;
      xfrq->rxdesc     = priv->attr->rx1desc;
      xfrq->nrxbuffers = DUMMY_NBUFFERS;

      xfrq->txbuffer   = priv->attr->tx1buffer;
      xfrq->txbufsize  = DUMMY_BUFSIZE;
      xfrq->rxbuffer   = priv->attr->rx1buffer;
      xfrq->rxbufsize  = DUMMY_BUFSIZE;
    }

#else
  struct sam_queue_s *xfrq;
  size_t allocsize;
  int qid;

  /* Allocate Queue 0 buffers */

  allocsize = EMAC_ALIGN_UP(priv->attr->ntxbuffers * sizeof(struct emac_txdesc_s));
  priv->xfrq[0].txdesc = (struct emac_txdesc_s *)kmm_memalign(EMAC_ALIGN, allocsize);
  if (!priv->xfrq[0].txdesc)
    {
      nlldbg("ERROR: Failed to allocate TX descriptors\n");
      return -ENOMEM;
    }

  memset(priv->xfrq[0].txdesc, 0, allocsize);
  priv->xfrq[0].ntxbuffers = priv->attr->ntxbuffers;

  allocsize = EMAC_ALIGN_UP(priv->attr->nrxbuffers * sizeof(struct emac_rxdesc_s));
  priv->xfrq[0].rxdesc = (struct emac_rxdesc_s *)kmm_memalign(EMAC_ALIGN, allocsize);
  if (!priv->xfrq[0].rxdesc)
    {
      nlldbg("ERROR: Failed to allocate RX descriptors\n");
      sam_buffer_free(priv);
      return -ENOMEM;
    }

  memset(priv->xfrq[0].rxdesc, 0, allocsize);
  priv->xfrq[0].nrxbuffers = priv->attr->nrxbuffers;

  allocsize = priv->attr->ntxbuffers * EMAC_TX_UNITSIZE;
  priv->xfrq[0].txbuffer = (uint8_t *)kmm_memalign(EMAC_ALIGN, allocsize);
  if (!priv->xfrq[0].txbuffer)
    {
      nlldbg("ERROR: Failed to allocate TX buffer\n");
      sam_buffer_free(priv);
      return -ENOMEM;
    }

  priv->xfrq[0].txbufsize = EMAC_TX_UNITSIZE;

  allocsize = priv->attr->nrxbuffers * EMAC_RX_UNITSIZE;
  priv->xfrq[0].rxbuffer = (uint8_t *)kmm_memalign(EMAC_ALIGN, allocsize);
  if (!priv->xfrq[0].rxbuffer)
    {
      nlldbg("ERROR: Failed to allocate RX buffer\n");
      sam_buffer_free(priv);
      return -ENOMEM;
    }

  priv->xfrq[0].rxbufsize = EMAC_RX_UNITSIZE;

  /* Allocate Queue 1 buffers */

  allocsize = EMAC_ALIGN_UP(DUMMY_NBUFFERS * sizeof(struct emac_txdesc_s));
  priv->xfrq[1].txdesc = (struct emac_txdesc_s *)kmm_memalign(EMAC_ALIGN, allocsize);
  if (!priv->xfrq[1].txdesc)
    {
      nlldbg("ERROR: Failed to allocate TX descriptors\n");
      return -ENOMEM;
    }

  memset(priv->xfrq[1].txdesc, 0, allocsize);
  priv->xfrq[1].ntxbuffers = DUMMY_NBUFFERS;

  allocsize = EMAC_ALIGN_UP(DUMMY_NBUFFERS * sizeof(struct emac_rxdesc_s));
  priv->xfrq[1].rxdesc = (struct emac_rxdesc_s *)kmm_memalign(EMAC_ALIGN, allocsize);
  if (!priv->xfrq[1].rxdesc)
    {
      nlldbg("ERROR: Failed to allocate RX descriptors\n");
      sam_buffer_free(priv);
      return -ENOMEM;
    }

  memset(priv->xfrq[1].rxdesc, 0, allocsize);
  priv->xfrq[1].nrxbuffers = DUMMY_NBUFFERS;

  allocsize = DUMMY_NBUFFERS * DUMMY_BUFSIZE;
  priv->xfrq[1].txbuffer = (uint8_t *)kmm_memalign(EMAC_ALIGN, allocsize);
  if (!priv->xfrq[1].txbuffer)
    {
      nlldbg("ERROR: Failed to allocate TX buffer\n");
      sam_buffer_free(priv);
      return -ENOMEM;
    }

  priv->xfrq[1].txbufsize = DUMMY_BUFSIZE;

  allocsize = DUMMY_NBUFFERS * DUMMY_BUFSIZE;
  priv->xfrq[1].rxbuffer = (uint8_t *)kmm_memalign(EMAC_ALIGN, allocsize);
  if (!priv->xfrq[1].rxbuffer)
    {
      nlldbg("ERROR: Failed to allocate RX buffer\n");
      sam_buffer_free(priv);
      return -ENOMEM;
    }

  priv->xfrq[1].rxbufsize = DUMMY_BUFSIZE;

  /* Clone the Priority Queue 1 allocations to the other priority queues */

  for (qid = 2; qid < EMAC_NQUEUES; qid++)
    {
      xfrq             = &priv->xfrq[qid];

      xfrq->txdesc     = priv->xfrq[1].txdesc;
      xfrq->rxdesc     = priv->xfrq[1].rxdesc;

      xfrq->txbuffer   = priv->xfrq[1].txbuffer;
      xfrq->rxbuffer   = priv->xfrq[1].rxbuffer;

      xfrq->ntxbuffers = DUMMY_NBUFFERS;
      xfrq->nrxbuffers = DUMMY_NBUFFERS;

      xfrq->txbufsize  = DUMMY_BUFSIZE;
      xfrq->rxbufsize  = DUMMY_BUFSIZE;
    }

#endif

  /* Verify Alignment */

  DEBUGASSERT(((uintptr_t)priv->xfrq[0].rxdesc   & EMAC_ALIGN_MASK) == 0 &&
              ((uintptr_t)priv->xfrq[0].rxbuffer & EMAC_ALIGN_MASK) == 0 &&
              ((uintptr_t)priv->xfrq[0].txdesc   & EMAC_ALIGN_MASK) == 0 &&
              ((uintptr_t)priv->xfrq[0].txbuffer & EMAC_ALIGN_MASK) == 0);
  DEBUGASSERT(((uintptr_t)priv->xfrq[1].rxdesc   & EMAC_ALIGN_MASK) == 0 &&
              ((uintptr_t)priv->xfrq[1].rxbuffer & EMAC_ALIGN_MASK) == 0 &&
              ((uintptr_t)priv->xfrq[1].txdesc   & EMAC_ALIGN_MASK) == 0 &&
              ((uintptr_t)priv->xfrq[1].txbuffer & EMAC_ALIGN_MASK) == 0);

  return OK;
}

/****************************************************************************
 * Function: sam_buffer_free
 *
 * Description:
 *   Free aligned TX and RX descriptors and buffers.  For the case of
 *   pre-allocated structures, the function does nothing.
 *
 * Input Parameters:
 *   priv - The EMAC driver state
 *
 * Returned Value:
 *   None
 *
 ****************************************************************************/

static void sam_buffer_free(struct sam_emac_s *priv)
{
#ifndef CONFIG_SAMV7_EMAC_PREALLOCATE
  struct sam_queue_s *xfrq;
  int qid;

  /* Free allocated buffers */

  for (qid = 0; qid < EMAC_NQUEUES; qid++)
    {
      xfrq = &priv->xfrq[qid];
      if (qid < 2)
        {
          if (xfrq->txdesc)
            {
              kmm_free(xfrq->txdesc);
              xfrq->txdesc = NULL;
            }

          if (xfrq->rxdesc)
            {
              kmm_free(xfrq->rxdesc);
              xfrq->rxdesc = NULL;
            }

          if (xfrq->txbuffer)
            {
              kmm_free(xfrq->txbuffer);
              xfrq->txbuffer = NULL;
            }

          if (xfrq->rxbuffer)
            {
              kmm_free(xfrq->rxbuffer);
              xfrq->rxbuffer = NULL;
            }
        }

      xfrq->txdesc = NULL;
      xfrq->rxdesc = NULL;
      xfrq->txbuffer = NULL;
      xfrq->rxbuffer = NULL;
    }
#endif
}

/****************************************************************************
 * Function: sam_transmit
 *
 * Description:
 *   Start hardware transmission.  Called either from the txdone interrupt
 *   handling or from watchdog based polling.
 *
 *   REVISIT:  This implementation does not support scatter-gather DMA.
 *
 * Parameters:
 *   priv  - Reference to the driver state structure
 *   qid   - The queue to send the frame
 *
 * Returned Value:
 *   OK on success; a negated errno on failure
 *
 * Assumptions:
 *   May or may not be called from an interrupt handler.  In either case,
 *   global interrupts are disabled, either explicitly or indirectly through
 *   interrupt handling logic.
 *
 ****************************************************************************/

static int sam_transmit(struct sam_emac_s *priv, int qid)
{
  struct net_driver_s *dev = &priv->dev;
  volatile struct emac_txdesc_s *txdesc;
  struct sam_queue_s *xfrq;
  uint32_t regval;
  uint32_t status;
  uint16_t txhead;

  /* Check parameter */

  if (dev->d_len > EMAC_TX_UNITSIZE)
    {
      nlldbg("ERROR: Packet too big: %d\n", dev->d_len);
      return -EINVAL;
    }

  /* Pointer to the current TX descriptor */

  xfrq   = &priv->xfrq[qid];
  txhead = xfrq->txhead;
  txdesc = &xfrq->txdesc[txhead];

  nllvdbg("d_len: %d txhead[%d]: %d\n",  dev->d_len, qid, xfrq->txhead);
  sam_dumppacket("Transmit packet", dev->d_buf, dev->d_len);

  /* If no free TX descriptor, buffer can't be sent */

  if (sam_txfree(priv, qid) < 1)
    {
      nlldbg("ERROR: No free TX descriptors\n");
      return -EBUSY;
    }

  /* Setup/Copy data to transmission buffer */

  if (dev->d_len > 0)
    {
      /* Copy the data into the driver managed the ring buffer.  If we
       * wanted to support zero copy transfers, we would need to make sure
       * that dev->d_buf and txdesc->addr refer to the same memory.
       */

      memcpy((void *)txdesc->addr, dev->d_buf, dev->d_len);
      arch_clean_dcache((uint32_t)txdesc->addr,
                        (uint32_t)txdesc->addr + dev->d_len);
    }

  /* Update TX descriptor status (with USED=0). */

  status = dev->d_len | EMACTXD_STA_LAST;
  if (txhead == xfrq->ntxbuffers - 1)
    {
      status |= EMACTXD_STA_WRAP;
    }

  /* Update the descriptor status and flush the updated value to RAM */

  txdesc->status = status;
  arch_clean_dcache((uint32_t)txdesc,
                    (uint32_t)txdesc + sizeof(struct emac_txdesc_s));

  /* Increment the head index */

  if (++txhead >= xfrq->ntxbuffers)
    {
      txhead = 0;
    }

  xfrq->txhead = txhead;

  /* Now start transmission (if it is not already done) */

  regval  = sam_getreg(priv, SAM_EMAC_NCR_OFFSET);
  regval |= EMAC_NCR_TSTART;
  sam_putreg(priv, SAM_EMAC_NCR_OFFSET, regval);

  /* REVISIT: Sometimes TSTART is missed?  In this case, the symptom is
   * that the packet is not sent until the next transfer when TXSTART
   * is set again.
   */

  sam_putreg(priv, SAM_EMAC_NCR_OFFSET, regval);

  /* Setup the TX timeout watchdog (perhaps restarting the timer) */

  (void)wd_start(priv->txtimeout, SAM_TXTIMEOUT, sam_txtimeout_expiry, 1,
                 (uint32_t)priv);

  /* Set d_len to zero meaning that the d_buf[] packet buffer is again
   * available.
   */

  dev->d_len = 0;

  /* If we have no more available TX descriptors, then we must disable the
   * RCOMP interrupt to stop further RX processing.  Why?  Because EACH RX
   * packet that is dispatched is also an opportunity to replay with a TX
   * packet.  So, if we cannot handle an RX packet reply, then we disable
   * all RX packet processing.
   */

  if (sam_txfree(priv, qid) < 1)
    {
      nllvdbg("Disabling RX interrupts\n");
      sam_putreg(priv, SAM_EMAC_IDR_OFFSET, EMAC_INT_RCOMP);
    }

  return OK;
}

/****************************************************************************
 * Function: sam_txpoll
 *
 * Description:
 *   The transmitter is available, check if uIP has any outgoing packets ready
 *   to send.  This is a callback from devif_poll().  devif_poll() may be called:
 *
 *   1. When the preceding TX packet send is complete,
 *   2. When the preceding TX packet send timesout and the interface is reset
 *   3. During normal TX polling
 *
 * Parameters:
 *   dev  - Reference to the NuttX driver state structure
 *
 * Returned Value:
 *   OK on success; a negated errno on failure
 *
 * Assumptions:
 *   May or may not be called from an interrupt handler.  In either case,
 *   global interrupts are disabled, either explicitly or indirectly through
 *   interrupt handling logic.
 *
 ****************************************************************************/

static int sam_txpoll(struct net_driver_s *dev)
{
  struct sam_emac_s *priv = (struct sam_emac_s *)dev->d_private;

  /* If the polling resulted in data that should be sent out on the network,
   * the field d_len is set to a value > 0.
   */

  if (priv->dev.d_len > 0)
    {
      /* Look up the destination MAC address and add it to the Ethernet
       * header.
       */

#ifdef CONFIG_NET_IPv4
#ifdef CONFIG_NET_IPv6
      if (IFF_IS_IPv4(priv->dev.d_flags))
#endif
        {
          arp_out(&priv->dev);
        }
#endif /* CONFIG_NET_IPv4 */

#ifdef CONFIG_NET_IPv6
#ifdef CONFIG_NET_IPv4
      else
#endif
        {
          neighbor_out(&priv->dev);
        }
#endif /* CONFIG_NET_IPv6 */

      /* Send the packet */

      sam_transmit(priv, EMAC_QUEUE_0);

      /* Check if the there are any free TX descriptors.  We cannot perform
       * the TX poll if we do not have buffering for another packet.
       */

      if (sam_txfree(priv, EMAC_QUEUE_0) == 0)
        {
          /* We have to terminate the poll if we have no more descriptors
           * available for another transfer.
           */

          return -EBUSY;
        }
    }

  /* If zero is returned, the polling will continue until all connections have
   * been examined.
   */

  return 0;
}

/****************************************************************************
 * Function: sam_dopoll
 *
 * Description:
 *   Perform the uIP poll.
 *
 * Parameters:
 *   priv - Reference to the driver state structure
 *   qid  - The transfer queue to send packets on
 *
 * Returned Value:
 *   None
 *
 * Assumptions:
 *   Global interrupts are disabled by interrupt handling logic.
 *
 ****************************************************************************/

static void sam_dopoll(struct sam_emac_s *priv, int qid)
{
  struct net_driver_s *dev = &priv->dev;

  /* Check if the there are any free TX descriptors.  We cannot perform the
   * TX poll if we do not have buffering for another packet.
   */

  if (sam_txfree(priv, qid) > 0)
    {
      /* If we have the descriptor, then poll uIP for new XMIT data. */

      (void)devif_poll(dev, sam_txpoll);
    }
}

/****************************************************************************
 * Function: sam_recvframe
 *
 * Description:
 *   The function is called when a frame is received. It scans the RX
 *   descriptors of the received frame and assembles the full packet/
 *
 *   NOTE: This function will silently discard any packets containing errors.
 *
 * Parameters:
 *   priv  - Reference to the driver state structure
 *   qid   - The transfer queue to receive the frame
 *
 * Returned Value:
 *   OK if a packet was successfully returned; -EAGAIN if there are no
 *   further packets available
 *
 * Assumptions:
 *   - Global interrupts are disabled by interrupt handling logic.
 *   - The RX descriptor D-cache list has been invalided to force fetching
 *     from RAM.
 *
 ****************************************************************************/

static int sam_recvframe(struct sam_emac_s *priv, int qid)
{
  volatile struct emac_rxdesc_s *rxdesc;
  struct sam_queue_s *xfrq;
  struct net_driver_s *dev;
  const uint8_t *src;
  uint8_t  *dest;
  uint32_t rxndx;
  uint32_t pktlen;
  uint16_t copylen;
  bool isframe;

  /* Process received RX descriptor.  The ownership bit is set by the EMAC
   * once it has successfully written a frame to memory.
   */

  dev        = &priv->dev;
  dev->d_len = 0;

  dest       = dev->d_buf;
  pktlen     = 0;

  xfrq       = &priv->xfrq[qid];
  rxndx      = xfrq->rxndx;
  rxdesc     = &xfrq->rxdesc[rxndx];
  isframe    = false;

  /* Invalidate the RX descriptor to force re-fetching from RAM. */

  arch_invalidate_dcache((uintptr_t)rxdesc,
                         (uintptr_t)rxdesc + sizeof(struct emac_rxdesc_s));

  nllvdbg("Entry rxndx[%d]: %d\n", qid, rxndx);

  while ((rxdesc->addr & EMACRXD_ADDR_OWNER) != 0)
    {
      /* The start of frame bit indicates the beginning of a frame.  Discard
       * any previous fragments.
       */

      if ((rxdesc->status & EMACRXD_STA_SOF) != 0)
        {
          /* Skip previous fragments.  Loop incrementing the index to the
           * start fragment until it is equal to the index with the SOF mark
           */

          while (rxndx != xfrq->rxndx)
            {
              /* Give ownership back to the EMAC */

              rxdesc = &xfrq->rxdesc[xfrq->rxndx];
              rxdesc->addr &= ~(EMACRXD_ADDR_OWNER);

              /* Flush the modified RX descriptor to RAM */

              arch_clean_dcache((uintptr_t)rxdesc,
                                (uintptr_t)rxdesc +
                                sizeof(struct emac_rxdesc_s));

              /* Increment the RX index to the start fragment */

              if (++xfrq->rxndx >= xfrq->nrxbuffers)
                {
                  xfrq->rxndx = 0;
                }
            }

          /* Reset the packet data pointer and packet length */

          dest   = dev->d_buf;
          pktlen = 0;

          /* Start to gather buffers into the packet buffer */

          isframe = true;
        }

      /* Increment the working index. rxndx points to the next fragment
       * in this frame (or, if the LAST bit was set, to the first fragment
       * of the next frame).
       */

      if (++rxndx >= xfrq->nrxbuffers)
        {
          rxndx = 0;
        }

      /* Copy data into the packet buffer */

      if (isframe)
        {
          if (rxndx == xfrq->rxndx)
            {
              nllvdbg("ERROR: No EOF (Invalid or buffers too small)\n");
              do
                {
                  /* Give ownership back to the EMAC */

                  rxdesc = &xfrq->rxdesc[xfrq->rxndx];
                  rxdesc->addr &= ~(EMACRXD_ADDR_OWNER);

                  /* Flush the modified RX descriptor to RAM */

                  arch_clean_dcache((uintptr_t)rxdesc,
                                    (uintptr_t)rxdesc +
                                    sizeof(struct emac_rxdesc_s));

                  /* Increment the RX index */

                  if (++xfrq->rxndx >= xfrq->nrxbuffers)
                    {
                      xfrq->rxndx = 0;
                    }
                }
              while (rxndx != xfrq->rxndx);

              return -EIO;
            }

          /* Get the number of bytes to copy from the buffer */

          copylen = EMAC_RX_UNITSIZE;
          if ((pktlen + copylen) > CONFIG_NET_ETH_MTU)
            {
              copylen = CONFIG_NET_ETH_MTU - pktlen;
            }

          /* Get the data source.  Invalidate the source memory region to
           * force reload from RAM.
           */

          src = (const uint8_t *)(rxdesc->addr & EMACRXD_ADDR_MASK);
          arch_invalidate_dcache((uintptr_t)src, (uintptr_t)src + copylen);

          /* Copy the data from the driver managed the ring buffer.  If we
           * wanted to support zero copy transfers, we would need to make
           * sure that dev->d_buf and rxdesc->addr refer to the same memory.
           */

          memcpy(dest, src, copylen);
          dest   += copylen;
          pktlen += copylen;

          /* If the end of frame has been received, return the data */

          if ((rxdesc->status & EMACRXD_STA_EOF) != 0)
            {
              /* Frame size from the EMAC */

              dev->d_len = (rxdesc->status & EMACRXD_STA_FRLEN_MASK);
              nllvdbg("packet %d-%d (%d)\n", xfrq->rxndx, rxndx, dev->d_len);

              /* All data have been copied in the application frame buffer,
               * release the RX descriptor(s).  Loop until all descriptors
               * have been released up to the start of the next frame.
               */

              while (xfrq->rxndx != rxndx)
                {
                  /* Give ownership back to the EMAC */

                  rxdesc = &xfrq->rxdesc[xfrq->rxndx];
                  rxdesc->addr &= ~(EMACRXD_ADDR_OWNER);

                  /* Flush the modified RX descriptor to RAM */

                  arch_clean_dcache((uintptr_t)rxdesc,
                                    (uintptr_t)rxdesc +
                                    sizeof(struct emac_rxdesc_s));

                  /* Increment the RX index of the descriptor that was just
                   * released.
                   */

                  if (++xfrq->rxndx >= xfrq->nrxbuffers)
                    {
                      xfrq->rxndx = 0;
                    }
                }

              /* Check if the device packet buffer was large enough to accept
               * all of the data.
               */

              nllvdbg("rxndx: %d d_len: %d\n",
                      xfrq->rxndx, dev->d_len);
              if (pktlen < dev->d_len)
                {
                  nlldbg("ERROR: Buffer size %d; frame size %d\n",
                         dev->d_len, pktlen);
                  return -E2BIG;
                }

              return OK;
            }
        }

      /* We found a descriptor that we own, but we have not encountered the
       * SOF yet... discard this fragment and keep looking starting at the
       * next fragment.
       */

      else
        {
          /* Give ownership back to the EMAC */

          rxdesc->addr &= ~(EMACRXD_ADDR_OWNER);

          /* Flush the modified RX descriptor to RAM */

          arch_clean_dcache((uintptr_t)rxdesc,
                            (uintptr_t)rxdesc +
                            sizeof(struct emac_rxdesc_s));

          /* rxndx already points to the next fragment to be examined.
           * Use it to update the candidate Start-of-Frame.
           */

          xfrq->rxndx = rxndx;
        }

    /* Set-up to process the next fragment.  Get the RX descriptor
     * associated with the next fragment.
     */

    rxdesc = &xfrq->rxdesc[rxndx];

    /* Invalidate the RX descriptor to force re-fetching from RAM */

    arch_invalidate_dcache((uintptr_t)rxdesc,
                           (uintptr_t)rxdesc + sizeof(struct emac_rxdesc_s));
  }

  /* No packet was found */

  xfrq->rxndx = rxndx;
  nllvdbg("Exit rxndx[%d]: %d\n", qid, xfrq->rxndx);
  return -EAGAIN;
}

/****************************************************************************
 * Function: sam_receive
 *
 * Description:
 *   An interrupt was received indicating the availability of one or more
 *   new RX packets in FIFO memory.
 *
 * Parameters:
 *   priv  - Reference to the driver state structure
 *   qid   - The transfer queue on which the packet was recieved
 *
 * Returned Value:
 *   None
 *
 * Assumptions:
 *   Global interrupts are disabled by interrupt handling logic.
 *
 ****************************************************************************/

static void sam_receive(struct sam_emac_s *priv, int qid)
{
  struct net_driver_s *dev = &priv->dev;

  /* Loop while while sam_recvframe() successfully retrieves valid
   * EMAC frames.
   */

  while (sam_recvframe(priv, qid) == OK)
    {
      sam_dumppacket("Received packet", dev->d_buf, dev->d_len);

      /* Check if the packet is a valid size for the uIP buffer configuration
       * (this should not happen)
       */

      if (dev->d_len > CONFIG_NET_ETH_MTU)
        {
          nlldbg("DROPPED: Too big: %d\n", dev->d_len);
          continue;
        }

#ifdef CONFIG_NET_PKT
      /* When packet sockets are enabled, feed the frame into the packet tap */

      pkt_input(&priv->dev);
#endif

      /* We only accept IP packets of the configured type and ARP packets */

#ifdef CONFIG_NET_IPv4
      if (BUF->type == HTONS(ETHTYPE_IP))
        {
          nllvdbg("IPv4 frame\n");

          /* Handle ARP on input then give the IPv4 packet to the network
           * layer
           */

          arp_ipin(&priv->dev);
          ipv4_input(&priv->dev);

          /* If the above function invocation resulted in data that should be
           * sent out on the network, the field  d_len will set to a value > 0.
           */

          if (priv->dev.d_len > 0)
            {
              /* Update the Ethernet header with the correct MAC address */

#ifdef CONFIG_NET_IPv6
              if (IFF_IS_IPv4(priv->dev.d_flags))
#endif
                {
                  arp_out(&priv->dev);
                }
#ifdef CONFIG_NET_IPv6
              else
                {
                  neighbor_out(&priv->dev);
                }
#endif

              /* And send the packet */

              sam_transmit(priv, qid);
            }
        }
      else
#endif
#ifdef CONFIG_NET_IPv6
      if (BUF->type == HTONS(ETHTYPE_IP6))
        {
          nllvdbg("Iv6 frame\n");

          /* Give the IPv6 packet to the network layer */

          ipv6_input(&priv->dev);

          /* If the above function invocation resulted in data that should be
           * sent out on the network, the field  d_len will set to a value > 0.
           */

          if (priv->dev.d_len > 0)
           {
              /* Update the Ethernet header with the correct MAC address */

#ifdef CONFIG_NET_IPv4
              if (IFF_IS_IPv4(priv->dev.d_flags))
                {
                  arp_out(&priv->dev);
                }
              else
#endif
#ifdef CONFIG_NET_IPv6
                {
                  neighbor_out(&priv->dev);
                }
#endif

              /* And send the packet */

              sam_transmit(priv, qid);
            }
        }
      else
#endif
#ifdef CONFIG_NET_ARP
      if (BUF->type == htons(ETHTYPE_ARP))
        {
          nllvdbg("ARP frame\n");

          /* Handle ARP packet */

          arp_arpin(&priv->dev);

          /* If the above function invocation resulted in data that should be
           * sent out on the network, the field  d_len will set to a value > 0.
           */

          if (priv->dev.d_len > 0)
            {
              sam_transmit(priv, qid);
            }
        }
      else
#endif
        {
          nlldbg("DROPPED: Unknown type: %04x\n", BUF->type);
        }
    }
}

/****************************************************************************
 * Function: sam_txdone
 *
 * Description:
 *   An interrupt was received indicating that one or more frames have
 *   completed transmission.
 *
 * Parameters:
 *   priv  - Reference to the driver state structure
 *   qid   - The transfer queue on which the packet was sent
 *
 * Returned Value:
 *   None
 *
 * Assumptions:
 *   Global interrupts are disabled by the watchdog logic.
 *
 ****************************************************************************/

static void sam_txdone(struct sam_emac_s *priv, int qid)
{
  struct emac_txdesc_s *txdesc;
  struct sam_queue_s *xfrq;
  uint16_t tail;

  /* Are there any outstanding transmissions?  Loop until either (1) all of
   * the TX descriptors have been examined, or (2) until we encounter the
   * first descriptor that is still in use by the hardware.
   */

  xfrq = &priv->xfrq[qid];
  tail = xfrq->txtail;

  while (tail != xfrq->txhead)
    {
      /* Yes.. check the next buffer at the tail of the list */

      txdesc = &xfrq->txdesc[tail];
      arch_invalidate_dcache((uintptr_t)txdesc,
                             (uintptr_t)txdesc + sizeof(struct emac_txdesc_s));

      /* Break out of the loop if frame has not yet been sent.  On TX
       * completion, the GMAC sets the USED bit only into the very first
       * buffer descriptor of the sent frame.  Otherwise it updates this
       * descriptor with status error bits.
       */

      if ((txdesc->status & EMACTXD_STA_USED) == 0)
        {
          /* The descriptor is still in use.  Break out of the loop now. */

          break;
        }

      /* Process all buffers of the current transmitted frame */

      while (tail != xfrq->txhead &&
             (txdesc->status & EMACTXD_STA_LAST) == 0)
        {
          /* Increment the tail index */

          if (++tail >= xfrq->ntxbuffers)
            {
              tail = 0;
            }

          /* Get the next TX descriptor */

          txdesc = &xfrq->txdesc[tail];
          arch_invalidate_dcache((uintptr_t)txdesc,
                                 (uintptr_t)txdesc + sizeof(struct emac_txdesc_s));
        }

      /* Go to first buffer of the next frame */

      if (tail != xfrq->txhead &&
          ++tail >= xfrq->ntxbuffers)
        {
          tail = 0;
        }

      /* At least one TX descriptor is available.  Re-enable RX interrupts.
       * RX interrupts may previously have been disabled when we ran out of
       * TX descriptors (see comments in sam_transmit()).
       */

      sam_putreg(priv, SAM_EMAC_IER_OFFSET, EMAC_RX_INTS);
    }

  /* Save the new tail index */

  xfrq->txtail = tail;

  /* Then poll uIP for new XMIT data */

  sam_dopoll(priv, qid);
}

/****************************************************************************
 * Function: sam_txerr_interrupt
 *
 * Description:
 *   TX error interrupt processing.
 *
 * Parameters:
 *   priv - Reference to the driver state structure
 *   quid - Index of the tranfer queue that generated the interrupt
 *
 * Returned Value:
 *   None
 *
 * Assumptions:
 *   Ethernet interrupts are disabled
 *
 ****************************************************************************/

static void sam_txerr_interrupt(FAR struct sam_emac_s *priv, int qid)
{
  struct emac_txdesc_s *txdesc;
  struct sam_queue_s *xfrq;
  uint32_t regval;
  uint16_t tail;

  /* Clear TXEN bit into the Network Configuration Register.  This is a
   * workaround to recover from TX lockups that occur on sama5d3 gmac
   * (r1p24f2) when using  scatter-gather.   This issue has never been
   * seen on sama5d4 gmac (r1p31).
   */

  regval  = sam_getreg(priv, SAM_EMAC_NCR_OFFSET);
  regval &= ~EMAC_NCR_TXEN;
  sam_putreg(priv, SAM_EMAC_NCR_OFFSET, regval);

  /* The following step should be optional since this function is called
   * directly by the IRQ handler. Indeed, according to Cadence
   * documentation, the transmission is halted on errors such as
   * too many retries or transmit under run.  However it would becom
   * mandatory if the call of this function were scheduled as a task by
   * the IRQ handler (this is how Linux driver works). Then this function
   * might compete with GMACD_Send().
   *
   * Setting bit 10, tx_halt, of the Network Control Register is not enough:
   * We should wait for bit 3, tx_go, of the Transmit Status Register to
   * be cleared at transmit completion if a frame is being transmitted.
   */

  regval |= EMAC_NCR_THALT;
  sam_putreg(priv, SAM_EMAC_NCR_OFFSET, regval);

  while ((sam_getreg(priv, SAM_EMAC_TSR_OFFSET) & EMAC_TSR_TXGO) != 0);

  /* Treat frames in TX queue including the ones that caused the error. */

  xfrq = &priv->xfrq[qid];
  tail = xfrq->txtail;

  while (tail != xfrq->txhead)
    {
      txdesc = &xfrq->txdesc[tail];

      /* Make H/W updates to the TX descriptor visible to the CPU. */

      arch_invalidate_dcache((uintptr_t)txdesc,
                             (uintptr_t)txdesc + sizeof(struct emac_txdesc_s));

      /* Go to the last buffer descriptor of the frame */

      while (tail != xfrq->txhead &&
             (txdesc->status & EMACTXD_STA_LAST) == 0)
        {
          /* Increment the tail index */

          if (++tail >= xfrq->ntxbuffers)
            {
              tail = 0;
            }

          /* Get the next TX descriptor */

          txdesc = &xfrq->txdesc[tail];
          arch_invalidate_dcache((uintptr_t)txdesc,
                                 (uintptr_t)txdesc + sizeof(struct emac_txdesc_s));
        }

      /* Go to first buffer of the next frame */

      if (tail != xfrq->txhead &&
          ++tail >= xfrq->ntxbuffers)
        {
          tail = 0;
        }
    }

  /* Save the new tail index */

  xfrq->txtail = tail;

  /* Reset TX queue */

  sam_txreset(priv, qid);

  /* Clear status */

  regval = sam_getreg(priv, SAM_EMAC_TSR_OFFSET);
  sam_putreg(priv, SAM_EMAC_TSR_OFFSET, regval);

  /* Now we are ready to start transmission again */

  regval  = sam_getreg(priv, SAM_EMAC_NCR_OFFSET);
  regval &= ~EMAC_NCR_TXEN;
  sam_putreg(priv, SAM_EMAC_NCR_OFFSET, regval);

  /* At least one TX descriptor is available.  Re-enable RX interrupts.
   * RX interrupts may previously have been disabled when we ran out of
   * TX descriptors (see comments in sam_transmit()).
   */

  sam_putreg(priv, SAM_EMAC_IER_OFFSET, EMAC_RX_INTS);

  /* Then poll uIP for new XMIT data */

  sam_dopoll(priv, qid);
}

/****************************************************************************
 * Function: sam_interrupt_process
 *
 * Description:
 *   Interrupt processing.  This may be performed either within the interrupt
 *   handler or on the worker thread, depending upon the configuration
 *
 * Parameters:
 *   priv - Reference to the driver state structure
 *   quid - Index of the tranfer queue that generated the interrupt
 *
 * Returned Value:
 *   None
 *
 * Assumptions:
 *   Ethernet interrupts are disabled
 *
 ****************************************************************************/

static inline void sam_interrupt_process(FAR struct sam_emac_s *priv, int qid)
{
  uint32_t isr;
  uint32_t rsr;
  uint32_t tsr;
  uint32_t imr;
  uint32_t regval;
  uint32_t pending;
  uint32_t clrbits;

  /* Read the interrupt status, RX status, and TX status registers.
   * NOTE that the interrupt status register is cleared by this read.
   */

  isr = sam_getreg(priv, SAM_EMAC_ISR_OFFSET);
  rsr = sam_getreg(priv, SAM_EMAC_RSR_OFFSET);
  tsr = sam_getreg(priv, SAM_EMAC_TSR_OFFSET);

  /* Make the pending interrupt status (probably not necessary) */

  imr = sam_getreg(priv, SAM_EMAC_IMR_OFFSET);
  pending = isr & ~(imr | EMAC_INT_UNUSED);

  nllvdbg("isr: %08x pending: %08x\n", isr, pending);

  /* Check for the receipt of an RX packet.
   *
   * RXCOMP indicates that a packet has been received and stored in memory.
   *   The RXCOMP bit is cleared when the interrupt status register was read.
   * RSR:REC indicates that one or more frames have been received and placed
   *   in memory. This indication is cleared by writing a one to this bit.
   */

  if ((pending & EMAC_RX_INTS) != 0 || (rsr & EMAC_RSR_REC) != 0)
    {
      clrbits = EMAC_RSR_REC;

      /* Check for Receive Overrun.
       *
       * RSR:RXOVR will be set if the RX FIFO is not able to store the
       *   receive frame due to a FIFO overflow, or if the receive status
       *   was not taken at the end of the frame. This bit is also set in
       *   DMA packet buffer mode if the packet buffer overflows. For DMA
       *   operation, the buffer will be recovered if an overrun occurs. This
       *   bit is cleared when set to 1.
       */

      if ((rsr & EMAC_RSR_RXOVR) != 0)
        {
          nlldbg("ERROR: Receiver overrun RSR: %08x\n", rsr);
          clrbits |= EMAC_RSR_RXOVR;
        }

      /* Check for buffer not available (BNA)
       *
       * RSR:BNA means that an attempt was made to get a new buffer and the
       *   pointer indicated that it was owned by the processor. The DMA will
       *   reread the pointer each time an end of frame is received until a
       *   valid pointer is found. This bit is set following each descriptor
       *   read attempt that fails, even if consecutive pointers are
       *   unsuccessful and software has in the mean time cleared the status
       *   flag. Cleared by writing a one to this bit.
       */

      if ((rsr & EMAC_RSR_BNA) != 0)
        {
          nlldbg("ERROR: Buffer not available RSR: %08x\n", rsr);
          clrbits |= EMAC_RSR_BNA;
        }

      /* Clear status */

      sam_putreg(priv, SAM_EMAC_RSR_OFFSET, clrbits);

      /* Handle the received packet */

       sam_receive(priv, qid);
    }

  /* Check for TX errors */

  if ((pending & EMAC_TXERR_INTS) != 0)
    {
      sam_txerr_interrupt(priv, qid);
    }

  /* Check for the completion of a transmission.  This should be done before
   * checking for received data (because receiving can cause another transmission
   * before we had a chance to handle the last one).
   *
   * ISR:TCOMP is set when a frame has been transmitted. Cleared on read.
   * TSR:TXCOMP is set when a frame has been transmitted. Cleared by writing a
   *   one to this bit.
   */

  if ((pending & EMAC_INT_TCOMP) != 0 || (tsr & EMAC_TSR_TXCOMP) != 0)
    {
      /* A frame has been transmitted */
      /* Check for Retry Limit Exceeded (RLE) */

      if ((tsr & EMAC_TSR_RLE) != 0)
        {
          /* Status RLE & Number of discarded buffers */

          clrbits = EMAC_TSR_RLE | sam_txinuse(priv, qid);
          sam_txreset(priv, qid);

          nlldbg("ERROR: Retry Limit Exceeded TSR: %08x\n", tsr);

          regval  = sam_getreg(priv, SAM_EMAC_NCR_OFFSET);
          regval |= EMAC_NCR_TXEN;
          sam_putreg(priv, SAM_EMAC_NCR_OFFSET, regval);
        }

      /* Check Collision Occurred (COL) */

      if ((tsr & EMAC_TSR_COL) != 0)
        {
          nlldbg("ERROR: Collision occurred TSR: %08x\n", tsr);
        }

      /* Check Transmit Frame Corruption due to AHB error (TFC) */

      if ((tsr & EMAC_TSR_TFC) != 0)
        {
          nlldbg("ERROR: Transmit Frame Corruption due to AHB error: %08x\n", tsr);
        }

      /* Clear status */

      sam_putreg(priv, SAM_EMAC_TSR_OFFSET, tsr);

      /* And handle the TX done event */

      sam_txdone(priv, qid);
    }

#ifdef CONFIG_DEBUG_NET
  /* Check for response not OK */

  if ((pending & EMAC_INT_HRESP) != 0)
    {
      nlldbg("ERROR: Hresp not OK\n");
    }

  /* Check for PAUSE Frame received (PFRE).
   *
   * ISR:PFRE indicates that a pause frame has been received with non-zero
   * pause quantum.  Cleared on a read.
   */

  if ((pending & EMAC_INT_PFNZ) != 0)
    {
      nlldbg("Pause frame received\n");
    }

  /* Check for Pause Time Zero (PTZ)
   *
   * ISR:PTZ is set Pause Time Zero
   */

  if ((pending & EMAC_INT_PTZ) != 0)
    {
      nlldbg("Pause TO!\n");
    }
#endif
}

/****************************************************************************
 * Function: sam_interrupt_work
 *
 * Description:
 *   Perform interrupt related work from the worker thread
 *
 * Parameters:
 *   arg - The argument passed when work_queue() was called.
 *
 * Returned Value:
 *   OK on success
 *
 * Assumptions:
 *   Ethernet interrupts are disabled
 *
 ****************************************************************************/

#ifdef CONFIG_NET_NOINTS
static void sam_interrupt_work(FAR void *arg)
{
  FAR struct sam_emac_s *priv = (FAR struct sam_emac_s *)arg;
  net_lock_t state;

  /* Process pending Ethernet interrupts */

  state = net_lock();
  sam_interrupt_process(priv, EMAC_QUEUE_0);
  net_unlock(state);

  /* Re-enable Ethernet interrupts */

  up_enable_irq(priv->attr->irq);
}
#endif

/****************************************************************************
 * Function: sam_emac_interrupt
 *
 * Description:
 *   Common hardware interrupt handler
 *
 * Parameters:
 *   priv    - Reference to the EMAC private state structure
 *
 * Returned Value:
 *   OK on success
 *
 * Assumptions:
 *
 ****************************************************************************/

static int sam_emac_interrupt(struct sam_emac_s *priv)
{
#ifdef CONFIG_NET_NOINTS
  uint32_t tsr;

  /* Disable further Ethernet interrupts.  Because Ethernet interrupts are
   * also disabled if the TX timeout event occurs, there can be no race
   * condition here.
   */

  up_disable_irq(priv->attr->irq);

  /* Check for the completion of a transmission.  Careful:
   *
   * ISR:TCOMP is set when a frame has been transmitted. Cleared on read (so
   *   we cannot read it here).
   * TSR:TXCOMP is set when a frame has been transmitted. Cleared by writing a
   *   one to this bit.
   */

  tsr = sam_getreg(priv, SAM_EMAC_TSR_OFFSET);
  if ((tsr & EMAC_TSR_TXCOMP) != 0)
    {
      /* If a TX transfer just completed, then cancel the TX timeout so
       * there will be do race condition between any subsequent timeout
       * expiration and the deferred interrupt processing.
       */

       wd_cancel(priv->txtimeout);
    }

  /* Cancel any pending poll work */

  work_cancel(HPWORK, &priv->work);

  /* Schedule to perform the interrupt processing on the worker thread. */

  work_queue(HPWORK, &priv->work, sam_interrupt_work, priv, 0);

#else
  /* Process the interrupt now */

  sam_interrupt_process(priv, EMAC_QUEUE_0);
#endif

  return OK;
}

/****************************************************************************
 * Function: sam_emac0/1_interrupt
 *
 * Description:
 *   EMAC hardware interrupt handler
 *
 * Parameters:
 *   irq     - Number of the IRQ that generated the interrupt
 *   context - Interrupt register state save info (architecture-specific)
 *
 * Returned Value:
 *   OK on success
 *
 * Assumptions:
 *
 ****************************************************************************/

#ifdef CONFIG_SAMV7_EMAC0
static int sam_emac0_interrupt(int irq, void *context)
{
  return sam_emac_interrupt(&g_emac0);
}
#endif

#ifdef CONFIG_SAMV7_EMAC1
static int sam_emac1_interrupt(int irq, void *context)
{
  return sam_emac_interrupt(&g_emac1);
}
#endif

/****************************************************************************
 * Function: sam_txtimeout_process
 *
 * Description:
 *   Process a TX timeout.  Called from the either the watchdog timer
 *   expiration logic or from the worker thread, depending upon the
 *   configuration.  The timeout means that the last TX never completed.
 *   Reset the hardware and start again.
 *
 * Parameters:
 *   priv - Reference to the driver state structure
 *
 * Returned Value:
 *   None
 *
 * Assumptions:
 *   Global interrupts are disabled by the watchdog logic.
 *
 ****************************************************************************/

static inline void sam_txtimeout_process(FAR struct sam_emac_s *priv)
{
  nlldbg("Timeout!\n");

  /* Reset the hardware.  Just take the interface down, then back up again. */

  sam_ifdown(&priv->dev);
  sam_ifup(&priv->dev);

  /* Then poll uIP for new XMIT data */

  sam_dopoll(priv, EMAC_QUEUE_0);
}

/****************************************************************************
 * Function: sam_txtimeout_work
 *
 * Description:
 *   Perform TX timeout related work from the worker thread
 *
 * Parameters:
 *   arg - The argument passed when work_queue() as called.
 *
 * Returned Value:
 *   OK on success
 *
 * Assumptions:
 *   Ethernet interrupts are disabled
 *
 ****************************************************************************/

#ifdef CONFIG_NET_NOINTS
static void sam_txtimeout_work(FAR void *arg)
{
  FAR struct sam_emac_s *priv = (FAR struct sam_emac_s *)arg;
  net_lock_t state;

  /* Process pending Ethernet interrupts */

  state = net_lock();
  sam_txtimeout_process(priv);
  net_unlock(state);
}
#endif

/****************************************************************************
 * Function: sam_txtimeout_expiry
 *
 * Description:
 *   Our TX watchdog timed out.  Called from the timer interrupt handler.
 *   The last TX never completed.  Reset the hardware and start again.
 *
 * Parameters:
 *   argc - The number of available arguments
 *   arg  - The first argument
 *
 * Returned Value:
 *   None
 *
 * Assumptions:
 *   Global interrupts are disabled by the watchdog logic.
 *
 ****************************************************************************/

static void sam_txtimeout_expiry(int argc, uint32_t arg, ...)
{
  FAR struct sam_emac_s *priv = (FAR struct sam_emac_s *)arg;

#ifdef CONFIG_NET_NOINTS
  /* Disable further Ethernet interrupts.  This will prevent some race
   * conditions with interrupt work.  There is still a potential race
   * condition with interrupt work that is already queued and in progress.
   */

  up_disable_irq(priv->attr->irq);

  /* Cancel any pending poll or interrupt work.  This will have no effect
   * on work that has already been started.
   */

  work_cancel(HPWORK, &priv->work);

  /* Schedule to perform the TX timeout processing on the worker thread. */

  work_queue(HPWORK, &priv->work, sam_txtimeout_work, priv, 0);
#else
  /* Process the timeout now */

  sam_txtimeout_process(priv);
#endif
}

/****************************************************************************
 * Function: sam_poll_process
 *
 * Description:
 *   Perform the periodic poll.  This may be called either from watchdog
 *   timer logic or from the worker thread, depending upon the configuration.
 *
 * Parameters:
 *   priv - Reference to the driver state structure
 *
 * Returned Value:
 *   None
 *
 * Assumptions:
 *
 ****************************************************************************/

static inline void sam_poll_process(FAR struct sam_emac_s *priv)
{
  struct net_driver_s *dev  = &priv->dev;

  /* Check if the there are any free TX descriptors.  We cannot perform the
   * TX poll if we do not have buffering for another packet.
   */

  if (sam_txfree(priv, EMAC_QUEUE_0) > 0)
    {
      /* Update TCP timing states and poll uIP for new XMIT data. */

      (void)devif_timer(dev, sam_txpoll, SAM_POLLHSEC);
    }

  /* Setup the watchdog poll timer again */

  (void)wd_start(priv->txpoll, SAM_WDDELAY, sam_poll_expiry, 1, priv);
}

/****************************************************************************
 * Function: sam_poll_work
 *
 * Description:
 *   Perform periodic polling from the worker thread
 *
 * Parameters:
 *   arg - The argument passed when work_queue() as called.
 *
 * Returned Value:
 *   OK on success
 *
 * Assumptions:
 *   Ethernet interrupts are disabled
 *
 ****************************************************************************/

#ifdef CONFIG_NET_NOINTS
static void sam_poll_work(FAR void *arg)
{
  FAR struct sam_emac_s *priv = (FAR struct sam_emac_s *)arg;
  net_lock_t state;

  /* Perform the poll */

  state = net_lock();
  sam_poll_process(priv);
  net_unlock(state);
}
#endif

/****************************************************************************
 * Function: sam_poll_expiry
 *
 * Description:
 *   Periodic timer handler.  Called from the timer interrupt handler.
 *
 * Parameters:
 *   argc - The number of available arguments
 *   arg  - The first argument
 *
 * Returned Value:
 *   None
 *
 * Assumptions:
 *   Global interrupts are disabled by the watchdog logic.
 *
 ****************************************************************************/

static void sam_poll_expiry(int argc, uint32_t arg, ...)
{
  FAR struct sam_emac_s *priv = (FAR struct sam_emac_s *)arg;

#ifdef CONFIG_NET_NOINTS
  /* Is our single work structure available?  It may not be if there are
   * pending interrupt actions.
   */

  if (work_available(&priv->work))
    {
      /* Schedule to perform the interrupt processing on the worker thread. */

      work_queue(HPWORK, &priv->work, sam_poll_work, priv, 0);
    }
  else
    {
      /* No.. Just re-start the watchdog poll timer, missing one polling
       * cycle.
       */

      (void)wd_start(priv->txpoll, SAM_WDDELAY, sam_poll_expiry, 1, arg);
    }

#else
  /* Process the interrupt now */

  sam_poll_process(priv);
#endif
}

/****************************************************************************
 * Function: sam_ifup
 *
 * Description:
 *   NuttX Callback: Bring up the EMAC interface when an IP address is
 *   provided
 *
 * Parameters:
 *   dev  - Reference to the NuttX driver state structure
 *
 * Returned Value:
 *   None
 *
 * Assumptions:
 *
 ****************************************************************************/

static int sam_ifup(struct net_driver_s *dev)
{
  struct sam_emac_s *priv = (struct sam_emac_s *)dev->d_private;
  int ret;

#ifdef CONFIG_NET_IPv4
  ndbg("Bringing up: %d.%d.%d.%d\n",
       dev->d_ipaddr & 0xff, (dev->d_ipaddr >> 8) & 0xff,
       (dev->d_ipaddr >> 16) & 0xff, dev->d_ipaddr >> 24);
#endif
#ifdef CONFIG_NET_IPv6
  ndbg("Bringing up: %04x:%04x:%04x:%04x:%04x:%04x:%04x:%04x\n",
       dev->d_ipv6addr[0], dev->d_ipv6addr[1], dev->d_ipv6addr[2],
       dev->d_ipv6addr[3], dev->d_ipv6addr[4], dev->d_ipv6addr[5],
       dev->d_ipv6addr[6], dev->d_ipv6addr[7]);
#endif

  /* Configure the EMAC interface for normal operation. */

  nllvdbg("Initialize the EMAC\n");
  sam_emac_configure(priv);
  sam_queue_configure(priv, EMAC_QUEUE_1);
  sam_queue_configure(priv, EMAC_QUEUE_2);
  sam_queue0_configure(priv);

  /* Set the MAC address (should have been configured while we were down) */

  sam_macaddress(priv);

#ifdef CONFIG_NET_ICMPv6
  /* Set up IPv6 multicast address filtering */

  sam_ipv6multicast(priv);
#endif

  /* Initialize for PHY access */

  ret = sam_phyinit(priv);
  if (ret < 0)
    {
      nlldbg("ERROR: sam_phyinit failed: %d\n", ret);
      return ret;
    }

  /* Auto Negotiate, working in RMII mode */

  ret = sam_autonegotiate(priv);
  if (ret < 0)
    {
      nlldbg("ERROR: sam_autonegotiate failed: %d\n", ret);
      return ret;
    }

  while (sam_linkup(priv) == 0);
  nllvdbg("Link detected \n");

  /* Enable normal MAC operation */

  nllvdbg("Enable normal operation\n");

  /* Set and activate a timer process */

  (void)wd_start(priv->txpoll, SAM_WDDELAY, sam_poll_expiry, 1, (uint32_t)priv);

  /* Enable the EMAC interrupt */

  priv->ifup = true;
  up_enable_irq(priv->attr->irq);
  return OK;
}

/****************************************************************************
 * Function: sam_ifdown
 *
 * Description:
 *   NuttX Callback: Stop the interface.
 *
 * Parameters:
 *   dev  - Reference to the NuttX driver state structure
 *
 * Returned Value:
 *   None
 *
 * Assumptions:
 *
 ****************************************************************************/

static int sam_ifdown(struct net_driver_s *dev)
{
  struct sam_emac_s *priv = (struct sam_emac_s *)dev->d_private;
  irqstate_t flags;

  nlldbg("Taking the network down\n");

  /* Disable the EMAC interrupt */

  flags = irqsave();
  up_disable_irq(priv->attr->irq);

  /* Cancel the TX poll timer and TX timeout timers */

  wd_cancel(priv->txpoll);
  wd_cancel(priv->txtimeout);

  /* Put the EMAC in its reset, non-operational state.  This should be
   * a known configuration that will guarantee the sam_ifup() always
   * successfully brings the interface back up.
   */

  sam_emac_reset(priv);

  /* Mark the device "down" */

  priv->ifup = false;
  irqrestore(flags);
  return OK;
}

/****************************************************************************
 * Function: sam_txavail_process
 *
 * Description:
 *   Perform an out-of-cycle poll.
 *
 * Parameters:
 *   dev - Reference to the NuttX driver state structure
 *
 * Returned Value:
 *   None
 *
 * Assumptions:
 *   Called in normal user mode
 *
 ****************************************************************************/

static inline void sam_txavail_process(FAR struct sam_emac_s *priv)
{
  nllvdbg("ifup: %d\n", priv->ifup);

  /* Ignore the notification if the interface is not yet up */

  if (priv->ifup)
    {
      /* Poll uIP for new XMIT data */

      sam_dopoll(priv, EMAC_QUEUE_0);
    }
}

/****************************************************************************
 * Function: sam_txavail_work
 *
 * Description:
 *   Perform an out-of-cycle poll on the worker thread.
 *
 * Parameters:
 *   arg - Reference to the NuttX driver state structure (cast to void*)
 *
 * Returned Value:
 *   None
 *
 * Assumptions:
 *   Called on the higher priority worker thread.
 *
 ****************************************************************************/

#ifdef CONFIG_NET_NOINTS
static void sam_txavail_work(FAR void *arg)
{
  FAR struct sam_emac_s *priv = (FAR struct sam_emac_s *)arg;
  net_lock_t state;

  /* Perform the poll */

  state = net_lock();
  sam_txavail_process(priv);
  net_unlock(state);
}
#endif

/****************************************************************************
 * Function: sam_txavail
 *
 * Description:
 *   Driver callback invoked when new TX data is available.  This is a
 *   stimulus perform an out-of-cycle poll and, thereby, reduce the TX
 *   latency.
 *
 * Parameters:
 *   dev - Reference to the NuttX driver state structure
 *
 * Returned Value:
 *   None
 *
 * Assumptions:
 *   Called in normal user mode
 *
 ****************************************************************************/

static int sam_txavail(struct net_driver_s *dev)
{
  FAR struct sam_emac_s *priv = (FAR struct sam_emac_s *)dev->d_private;

#ifdef CONFIG_NET_NOINTS
  /* Is our single work structure available?  It may not be if there are
   * pending interrupt actions and we will have to ignore the Tx
   * availability action.
   */

  if (work_available(&priv->work))
    {
      /* Schedule to serialize the poll on the worker thread. */

      work_queue(HPWORK, &priv->work, sam_txavail_work, priv, 0);
    }

#else
  irqstate_t flags;

  /* Disable interrupts because this function may be called from interrupt
   * level processing.
   */

  flags = irqsave();

  /* Perform the out-of-cycle poll now */

  sam_txavail_process(priv);
  irqrestore(flags);
#endif

  return OK;
}

/****************************************************************************
 * Name: sam_hashindx
 *
 * Description:
 *   Cacuclate the hash address register index.  The hash address register
 *   is 64 bits long and takes up two locations in the memory map. The
 *   destination address is reduced to a 6-bit index into the 64-bit Hash
 *   Register using the following hash function: The hash function is an XOR
 *   of every sixth bit of the destination address.
 *
 *   ndx:05 = da:05 ^ da:11 ^ da:17 ^ da:23 ^ da:29 ^ da:35 ^ da:41 ^ da:47
 *   ndx:04 = da:04 ^ da:10 ^ da:16 ^ da:22 ^ da:28 ^ da:34 ^ da:40 ^ da:46
 *   ndx:03 = da:03 ^ da:09 ^ da:15 ^ da:21 ^ da:27 ^ da:33 ^ da:39 ^ da:45
 *   ndx:02 = da:02 ^ da:08 ^ da:14 ^ da:20 ^ da:26 ^ da:32 ^ da:38 ^ da:44
 *   ndx:01 = da:01 ^ da:07 ^ da:13 ^ da:19 ^ da:25 ^ da:31 ^ da:37 ^ da:43
 *   ndx:00 = da:00 ^ da:06 ^ da:12 ^ da:18 ^ da:24 ^ da:30 ^ da:36 ^ da:42
 *
 *   Where da:00 represents the least significant bit of the first byte
 *   received and da:47 represents the most significant bit of the last byte
 *   received.
 *
 * Input Parameters:
 *   mac - The multicast address to be hashed
 *
 * Returned Value:
 *   The 6-bit hash table index
 *
 ****************************************************************************/

#if defined(CONFIG_NET_IGMP) || defined(CONFIG_NET_ICMPv6)
static unsigned int sam_hashindx(const uint8_t *mac)
{
  unsigned int ndx;

  /* Isolate: mac[0]
  *           ... 05 04 03 02 01 00] */

  ndx = mac[0];

  /* Isolate: mac[1]           mac[0]
   *          ...11 10 09 08] [07 06 ...
   *
   * Accumulate: 05 04 03 02 01 00
   *        XOR: 11 10 09 08 07 06
   */

  ndx ^= (mac[1] << 2) | (mac[0] >> 6);

  /* Isolate: mac[2]      mac[1]
   *          ... 17 16] [15 14 13 12 ...
   *
   * Accumulate: 05 04 03 02 01 00
   *        XOR: 11 10 09 08 07 06
   *        XOR: 17 16 15 14 13 12
   */

  ndx ^= (mac[2] << 4) | (mac[1] >> 4);

  /* Isolate:  mac[2]
   *          [23 22 21 20 19 18 ...
   *
   * Accumulate: 05 04 03 02 01 00
   *        XOR: 11 10 09 08 07 06
   *        XOR: 17 16 15 14 13 12
   *        XOR: 23 22 21 20 19 18
   */

  ndx ^= (mac[2] >> 2);

  /* Isolate:     mac[3]
   *          ... 29 28 27 26 25 24]
   *
   * Accumulate: 05 04 03 02 01 00
   *        XOR: 11 10 09 08 07 06
   *        XOR: 17 16 15 14 13 12
   *        XOR: 23 22 21 20 19 18
   *        XOR: 29 28 27 26 25 24
   */

  ndx ^= mac[3];

  /* Isolate:     mac[4]        mac[3]
   *          ... 35 34 33 32] [31 30 ...
   *
   * Accumulate: 05 04 03 02 01 00
   *        XOR: 11 10 09 08 07 06
   *        XOR: 17 16 15 14 13 12
   *        XOR: 23 22 21 20 19 18
   *        XOR: 29 28 27 26 25 24
   *        XOR: 35 34 33 32 31 30
   */

  ndx ^= (mac[4] << 2) | (mac[3] >> 6);

  /* Isolate:     mac[5]  mac[4]
   *          ... 41 40] [39 38 37 36 ...
   *
   * Accumulate: 05 04 03 02 01 00
   *        XOR: 11 10 09 08 07 06
   *        XOR: 17 16 15 14 13 12
   *        XOR: 23 22 21 20 19 18
   *        XOR: 29 28 27 26 25 24
   *        XOR: 35 34 33 32 31 30
   *        XOR: 41 40 39 38 37 36
   */

  ndx ^= (mac[5] << 4) | (mac[4] >> 4);

  /* Isolate:  mac[5]
   *          [47 46 45 44 43 42 ...
   *
   * Accumulate: 05 04 03 02 01 00
   *        XOR: 11 10 09 08 07 06
   *        XOR: 17 16 15 14 13 12
   *        XOR: 23 22 21 20 19 18
   *        XOR: 29 28 27 26 25 24
   *        XOR: 35 34 33 32 31 30
   *        XOR: 41 40 39 38 37 36
   *        XOR: 47 46 45 44 43 42
   */

  ndx ^= (mac[5] >> 2);

  /* Mask out the garbage bits and return the 6-bit index */

  return ndx & 0x3f;
}
#endif /* CONFIG_NET_IGMP || CONFIG_NET_ICMPv6 */

/****************************************************************************
 * Function: sam_addmac
 *
 * Description:
 *   NuttX Callback: Add the specified MAC address to the hardware multicast
 *   address filtering
 *
 * Parameters:
 *   dev  - Reference to the NuttX driver state structure
 *   mac  - The MAC address to be added
 *
 * Returned Value:
 *   None
 *
 * Assumptions:
 *
 ****************************************************************************/

#if defined(CONFIG_NET_IGMP) || defined(CONFIG_NET_ICMPv6)
static int sam_addmac(struct net_driver_s *dev, const uint8_t *mac)
{
  struct sam_emac_s *priv = (struct sam_emac_s *)dev->d_private;
  uint32_t regval;
  unsigned int regoffset;
  unsigned int ndx;
  unsigned int bit;

  nllvdbg("MAC: %02x:%02x:%02x:%02x:%02x:%02x\n",
          mac[0], mac[1], mac[2], mac[3], mac[4], mac[5]);

  /* Calculate the 6-bit has table index */

  ndx = sam_hashindx(mac);

  /* Add the multicast address to the hardware multicast hash table */

  if (ndx >= 32)
    {
      regoffset = SAM_EMAC_HRT_OFFSET;  /* Hash Register Top [63:32] Register */
      bit       = 1 << (ndx - 32);      /* Bit 0-31 */
    }
  else
    {
      regoffset = SAM_EMAC_HRB_OFFSET;  /* Hash Register Bottom [31:0] Register */
      bit       = 1 << ndx;             /* Bit 0-31 */
    }

  regval = sam_getreg(priv, regoffset);
  regval |= bit;
  sam_putreg(priv, regoffset, regval);

  /* The unicast hash enable and the multicast hash enable bits in the
   * Network Configuration Register enable the reception of hash matched
   * frames:
   *
   * - A multicast match will be signalled if the multicast hash enable bit
   *   is set, da:00 is logic 1 and the hash index points to a bit set in
   *   the Hash Register.
   * - A unicast match will be signalled if the unicast hash enable bit is
   *   set, da:00 is logic 0 and the hash index points to a bit set in the
   *   Hash Register.
   */

  regval  = sam_getreg(priv, SAM_EMAC_NCFGR_OFFSET);
  regval &= ~EMAC_NCFGR_UNIHEN;  /* Disable unicast matching */
  regval |= EMAC_NCFGR_MTIHEN;   /* Enable multicast matching */
  sam_putreg(priv, SAM_EMAC_NCFGR_OFFSET, regval);

  return OK;
}
#endif

/****************************************************************************
 * Function: sam_rmmac
 *
 * Description:
 *   NuttX Callback: Remove the specified MAC address from the hardware multicast
 *   address filtering
 *
 * Parameters:
 *   dev  - Reference to the NuttX driver state structure
 *   mac  - The MAC address to be removed
 *
 * Returned Value:
 *   None
 *
 * Assumptions:
 *
 ****************************************************************************/

#ifdef CONFIG_NET_IGMP
static int sam_rmmac(struct net_driver_s *dev, const uint8_t *mac)
{
  struct sam_emac_s *priv = (struct sam_emac_s *)dev->d_private;
  uint32_t regval;
  unsigned int regoffset1;
  unsigned int regoffset2;
  unsigned int ndx;
  unsigned int bit;

  nllvdbg("MAC: %02x:%02x:%02x:%02x:%02x:%02x\n",
          mac[0], mac[1], mac[2], mac[3], mac[4], mac[5]);

  /* Calculate the 6-bit has table index */

  ndx = sam_hashindx(mac);

  /* Remove the multicast address to the hardware multicast hast table */

  if (ndx >= 32)
    {
      regoffset1 = SAM_EMAC_HRT_OFFSET;  /* Hash Register Top [63:32] Register */
      regoffset2 = SAM_EMAC_HRB_OFFSET;  /* Hash Register Bottom [31:0] Register */
      bit        = 1 << (ndx - 32);      /* Bit 0-31 */
    }
  else
    {
      regoffset1 = SAM_EMAC_HRB_OFFSET;  /* Hash Register Bottom [31:0] Register */
      regoffset2 = SAM_EMAC_HRT_OFFSET;  /* Hash Register Top [63:32] Register */
      bit        = 1 << ndx;             /* Bit 0-31 */
    }

  regval  = sam_getreg(priv, regoffset1);
  regval &= ~bit;
  sam_putreg(priv, regoffset1, regval);

  /* The unicast hash enable and the multicast hash enable bits in the
   * Network Configuration Register enable the reception of hash matched
   * frames:
   *
   * - A multicast match will be signalled if the multicast hash enable bit
   *   is set, da:00 is logic 1 and the hash index points to a bit set in
   *   the Hash Register.
   * - A unicast match will be signalled if the unicast hash enable bit is
   *   set, da:00 is logic 0 and the hash index points to a bit set in the
   *   Hash Register.
   */

  /* Are all multicast address matches disabled? */

  if (regval == 0 && sam_getreg(priv, regoffset2) == 0)
    {
       /* Yes.. disable all address matching */

      regval  = sam_getreg(priv, SAM_EMAC_NCFGR_OFFSET);
      regval &= ~(EMAC_NCFGR_UNIHEN | EMAC_NCFGR_MTIHEN);
      sam_putreg(priv, SAM_EMAC_NCFGR_OFFSET, regval);
    }

  return OK;
}
#endif

/****************************************************************************
 * Function: sam_ioctl
 *
 * Description:
 *  Handles driver ioctl calls:
 *
 *  SIOCMIINOTIFY - Set up to received notifications from PHY interrupting
 *    events.
 *
 *  SIOCGMIIPHY, SIOCGMIIREG, and SIOCSMIIREG:
 *    Executes the SIOCxMIIxxx command and responds using the request struct
 *    that must be provided as its 2nd parameter.
 *
 *    When called with SIOCGMIIPHY it will get the PHY address for the device
 *    and write it to the req->phy_id field of the request struct.
 *
 *    When called with SIOCGMIIREG it will read a register of the PHY that is
 *    specified using the req->reg_no struct field and then write its output
 *    to the req->val_out field.
 *
 *    When called with SIOCSMIIREG it will write to a register of the PHY that
 *    is specified using the req->reg_no struct field and use req->val_in as
 *    its input.
 *
 * Parameters:
 *   dev - Ethernet device structure
 *   cmd - SIOCxMIIxxx command code
 *   arg - Request structure also used to return values
 *
 * Returned Value: Negated errno on failure.
 *
 * Assumptions:
 *
 ****************************************************************************/

#ifdef CONFIG_NETDEV_PHY_IOCTL
static int sam_ioctl(struct net_driver_s *dev, int cmd, long arg)
{
  struct sam_emac_s *priv = (struct sam_emac_s *)dev->d_private;
  int ret;

  switch (cmd)
  {
#ifdef CONFIG_ARCH_PHY_INTERRUPT
  case SIOCMIINOTIFY: /* Set up for PHY event notifications */
    {
      struct mii_iotcl_notify_s *req = (struct mii_iotcl_notify_s *)((uintptr_t)arg);

      ret = phy_notify_subscribe(dev->d_ifname, req->pid, req->signo, req->arg);
      if (ret == OK)
        {
          /* Enable PHY link up/down interrupts */

          ret = sam_phyintenable(priv);
        }
    }
    break;
#endif

  case SIOCGMIIPHY: /* Get MII PHY address */
    {
      struct mii_ioctl_data_s *req = (struct mii_ioctl_data_s *)((uintptr_t)arg);
      req->phy_id = priv->phyaddr;
      ret = OK;
    }
    break;

  case SIOCGMIIREG: /* Get register from MII PHY */
    {
      struct mii_ioctl_data_s *req = (struct mii_ioctl_data_s *)((uintptr_t)arg);
      uint32_t regval;

      /* Enable management port */

      regval = sam_getreg(priv, SAM_EMAC_NCR_OFFSET);
      sam_putreg(priv, SAM_EMAC_NCR_OFFSET, regval | EMAC_NCR_MPE);

      /* Read from the requested register */

      ret = sam_phyread(priv, req->phy_id, req->reg_num, &req->val_out);

      /* Disable management port (probably) */

      sam_putreg(priv, SAM_EMAC_NCR_OFFSET, regval);
    }
    break;

  case SIOCSMIIREG: /* Set register in MII PHY */
    {
      struct mii_ioctl_data_s *req = (struct mii_ioctl_data_s *)((uintptr_t)arg);
      uint32_t regval;

      /* Enable management port */

      regval = sam_getreg(priv, SAM_EMAC_NCR_OFFSET);
      sam_putreg(priv, SAM_EMAC_NCR_OFFSET, regval | EMAC_NCR_MPE);

      /* Write to the requested register */

      ret = sam_phywrite(priv, req->phy_id, req->reg_num, req->val_in);

      /* Disable management port (probably) */

      sam_putreg(priv, SAM_EMAC_NCR_OFFSET, regval);
    }
    break;

  default:
    ret = -ENOTTY;
    break;
  }

  return ret;
}
#endif /* CONFIG_NETDEV_PHY_IOCTL */

/****************************************************************************
 * Function: sam_phydump
 *
 * Description:
 *   Dump the contents of PHY registers
 *
 * Parameters:
 *   priv - A reference to the private driver state structure
 *
 * Returned Value:
 *   None
 *
 ****************************************************************************/

#if defined(CONFIG_DEBUG_NET) && defined(CONFIG_DEBUG_VERBOSE)
static void sam_phydump(struct sam_emac_s *priv)
{
  uint32_t regval;
  uint16_t phyval;

  /* Enable management port */

  regval  = sam_getreg(priv, SAM_EMAC_NCR_OFFSET);
  regval |= EMAC_NCR_MPE;
  sam_putreg(priv, SAM_EMAC_NCR_OFFSET, regval);

  nllvdbg("%s Registers (Address %02x)\n",
          priv->attr->rmii ? "RMII" : "MII", priv->phyaddr);

  sam_phyread(priv, priv->phyaddr, MII_MCR, &phyval);
  nllvdbg("  MCR:       %04x\n", phyval);
  sam_phyread(priv, priv->phyaddr, MII_MSR, &phyval);
  nllvdbg("  MSR:       %04x\n", phyval);
  sam_phyread(priv, priv->phyaddr, MII_ADVERTISE, &phyval);
  nllvdbg("  ADVERTISE: %04x\n", phyval);
  sam_phyread(priv, priv->phyaddr, MII_LPA, &phyval);
  nllvdbg("  LPR:       %04x\n", phyval);
  sam_phyread(priv, priv->phyaddr, priv->attr->physr, &phyval);
  nllvdbg("  PHYSR:     %04x\n", phyval);

  /* Disable management port */

  regval  = sam_getreg(priv, SAM_EMAC_NCR_OFFSET);
  regval &= ~EMAC_NCR_MPE;
  sam_putreg(priv, SAM_EMAC_NCR_OFFSET, regval);
}
#endif

/****************************************************************************
 * Function: sam_is*
 *
 * Description:
 *   Helpers to simplify decoding PHY status register bits
 *
 * Parameters:
 *   physr - The value of the PHY status register
 *
 * Returned Value:
 *   True: The PHY configuration is selected; False; some other PHY
 *   configuration is selected.
 *
 ****************************************************************************/

#if 0 /* Not used */
static bool sam_is10hdx(struct sam_emac_s *priv, uint16_t physr)
{
  uint16_t mask;
  uint16_t match;

  if (priv->attr->sralt)
    {
      mask  = priv->attr->u.alt.altmask;
      match = priv->attr->u.alt.hdx10;
    }
  else
    {
      mask  = priv->attr->u.std.stdmask;
      match = 0;
    }

  return (physr & mask) == match;
}
#endif

static bool sam_is100hdx(struct sam_emac_s *priv, uint16_t physr)
{
  uint16_t mask;
  uint16_t match;

  if (priv->attr->sralt)
    {
      mask  = priv->attr->u.alt.altmask;
      match = priv->attr->u.alt.hdx100;
    }
  else
    {
      mask  = priv->attr->u.std.stdmask;
      match = priv->attr->u.std.speed100;
    }

  return (physr & mask) == match;
}

static bool sam_is10fdx(struct sam_emac_s *priv, uint16_t physr)
{
  uint16_t mask;
  uint16_t match;

  if (priv->attr->sralt)
    {
      mask  = priv->attr->u.alt.altmask;
      match = priv->attr->u.alt.fdx10;
    }
  else
    {
      mask  = priv->attr->u.std.stdmask;
      match = priv->attr->u.std.fduplex;
    }

  return (physr & mask) == match;
}

static bool sam_is100fdx(struct sam_emac_s *priv, uint16_t physr)
{
  uint16_t mask;
  uint16_t match;

  if (priv->attr->sralt)
    {
      mask  = priv->attr->u.alt.altmask;
      match = priv->attr->u.alt.fdx100;
    }
  else
    {
      mask  = priv->attr->u.std.stdmask;
      match = (priv->attr->u.std.fduplex | priv->attr->u.std.speed100);
    }

  return (physr & mask) == match;
}

/****************************************************************************
 * Function: sam_phyintenable
 *
 * Description:
 *  Enable link up/down PHY interrupts.  The interrupt protocol is like this:
 *
 *  - Interrupt status is cleared when the interrupt is enabled.
 *  - Interrupt occurs.  Interrupt is disabled (at the processor level) when
 *    is received.
 *  - Interrupt status is cleared when the interrupt is re-enabled.
 *
 * Parameters:
 *   priv - A reference to the private driver state structure
 *
 * Returned Value:
 *   OK on success; Negated errno (-ETIMEDOUT) on failure.
 *
 ****************************************************************************/

#if defined(CONFIG_NETDEV_PHY_IOCTL) && defined(CONFIG_ARCH_PHY_INTERRUPT)
static int sam_phyintenable(struct sam_emac_s *priv)
{
#if defined(SAMV7_EMAC0_PHY_KSZ8051) || defined(SAMV7_EMAC0_PHY_KSZ8061) || \
    defined(SAMV7_EMAC0_PHY_KSZ8081) || \
    defined(SAMV7_EMAC1_PHY_KSZ8051) || defined(SAMV7_EMAC1_PHY_KSZ8061) || \
    defined(SAMV7_EMAC1_PHY_KSZ8081)
  uint32_t regval;
  uint16_t phyval;
  int ret;

  /* Does this MAC support a KSZ80x1 PHY? */

  if (priv->phytype == SAMV7_PHY_KSZ8051 ||
      priv->phytype == SAMV7_PHY_KSZ8061 ||
      priv->phytype == SAMV7_PHY_KSZ8081)
    {
      /* Enable management port */

      regval = sam_getreg(priv, SAM_EMAC_NCR_OFFSET);
      sam_putreg(priv, SAM_EMAC_NCR_OFFSET, regval | EMAC_NCR_MPE);

      /* Read the interrupt status register in order to clear any pending
       * interrupts
       */

      ret = sam_phyread(priv, priv->phyaddr, MII_KSZ8081_INT, &phyval);
      if (ret == OK)
        {
          /* Enable link up/down interrupts */

          ret = sam_phywrite(priv, priv->phyaddr, MII_KSZ8081_INT,
                            (MII_KSZ80x1_INT_LDEN | MII_KSZ80x1_INT_LUEN));
        }

      /* Disable management port (probably) */

      sam_putreg(priv, SAM_EMAC_NCR_OFFSET, regval);
    }
  else
#endif
    {
      ndbg("ERROR: Unsupported PHY type: %d\n", priv->phytype);
      ret = -ENOSYS;
    }

  return ret;
}
#endif

/****************************************************************************
 * Function: sam_phywait
 *
 * Description:
 *   Wait for the PHY to become IDLE
 *
 * Parameters:
 *   priv - A reference to the private driver state structure
 *
 * Returned Value:
 *   OK on success; Negated errno (-ETIMEDOUT) on failure.
 *
 ****************************************************************************/

static int sam_phywait(struct sam_emac_s *priv)
{
  volatile unsigned int retries;

  /* Loop for the configured number of attempts */

  for (retries = 0; retries < PHY_RETRY_MAX; retries++)
    {
      /* Is the PHY IDLE */

      if ((sam_getreg(priv, SAM_EMAC_NSR_OFFSET) & EMAC_NSR_IDLE) != 0)
        {
          return OK;
        }
    }

  return -ETIMEDOUT;
}

/****************************************************************************
 * Function: sam_phyreset
 *
 * Description:
 *  Reset the PHY
 *
 * Parameters:
 *   priv - A reference to the private driver state structure
 *
 * Returned Value:
 *   OK on success; Negated errno on failure.
 *
 * Assumptions:
 *
 ****************************************************************************/

static int sam_phyreset(struct sam_emac_s *priv)
{
  uint32_t regval;
  uint16_t mcr;
  int timeout;
  int ret;

  nllvdbg(" sam_phyreset\n");

  /* Enable management port */

  regval  = sam_getreg(priv, SAM_EMAC_NCR_OFFSET);
  regval |= EMAC_NCR_MPE;
  sam_putreg(priv, SAM_EMAC_NCR_OFFSET, regval);

  /* Reset the PHY */

  ret = sam_phywrite(priv, priv->phyaddr, MII_MCR, MII_MCR_RESET);
  if (ret < 0)
    {
      nlldbg("ERROR: sam_phywrite failed: %d\n", ret);
    }

  /* Wait for the PHY reset to complete */

  ret = -ETIMEDOUT;
  for (timeout = 0; timeout < 10; timeout++)
    {
      mcr = MII_MCR_RESET;
      int result = sam_phyread(priv, priv->phyaddr, MII_MCR, &mcr);
      if (result < 0)
        {
          nlldbg("ERROR: Failed to read the MCR register: %d\n", ret);
          ret = result;
        }
      else if ((mcr & MII_MCR_RESET) == 0)
        {
          ret = OK;
          break;
        }
    }

  /* Disable management port */

  regval  = sam_getreg(priv, SAM_EMAC_NCR_OFFSET);
  regval &= ~EMAC_NCR_MPE;
  sam_putreg(priv, SAM_EMAC_NCR_OFFSET, regval);
  return ret;
}

/****************************************************************************
 * Function: sam_phyfind
 *
 * Description:
 *  Verify the PHY address and, if it is bad, try to one that works.
 *
 * Parameters:
 *   priv - A reference to the private driver state structure
 *
 * Returned Value:
 *   OK on success; Negated errno on failure.
 *
 * Assumptions:
 *
 ****************************************************************************/

static int sam_phyfind(struct sam_emac_s *priv, uint8_t *phyaddr)
{
  uint32_t regval;
  uint16_t phyval;
  uint8_t candidate;
  unsigned int offset;
  int ret = -ESRCH;

  nllvdbg("Find a valid PHY address\n");

  /* Enable management port */

  regval  = sam_getreg(priv, SAM_EMAC_NCR_OFFSET);
  regval |= EMAC_NCR_MPE;
  sam_putreg(priv, SAM_EMAC_NCR_OFFSET, regval);

  candidate = *phyaddr;

  /* Check current candidate address */

  ret = sam_phyread(priv, candidate, MII_PHYID1, &phyval);
  if (ret == OK && phyval == priv->attr->msoui)
    {
      *phyaddr = candidate;
      ret = OK;
    }

  /* The current address does not work... try another */

  else
    {
      nlldbg("ERROR: sam_phyread failed for PHY address %02x: %d\n",
             candidate, ret);

      for (offset = 0; offset < 32; offset++)
        {
          /* Get the next candidate PHY address */

          candidate = (candidate + 1) & 0x1f;

          /* Try reading the PHY ID from the candidate PHY address */

          ret = sam_phyread(priv, candidate, MII_PHYID1, &phyval);
          if (ret == OK && phyval == priv->attr->msoui)
            {
              ret = OK;
              break;
            }
        }
    }

  if (ret == OK)
    {
      nllvdbg("  PHYID1: %04x PHY addr: %d\n", phyval, candidate);
      *phyaddr = candidate;
      sam_phyread(priv, candidate, priv->attr->physr, &phyval);
      nllvdbg("  PHYSR:  %04x PHY addr: %d\n", phyval, candidate);
    }

  /* Disable management port */

  regval  = sam_getreg(priv, SAM_EMAC_NCR_OFFSET);
  regval &= ~EMAC_NCR_MPE;
  sam_putreg(priv, SAM_EMAC_NCR_OFFSET, regval);
  return ret;
}

/****************************************************************************
 * Function: sam_phyread
 *
 * Description:
 *  Read a PHY register.
 *
 * Parameters:
 *   priv - A reference to the private driver state structure
 *   phyaddr - The PHY device address
 *   regaddr - The PHY register address
 *   phyval - The location to return the 16-bit PHY register value.
 *
 * Returned Value:
 *   OK on success; Negated errno on failure.
 *
 * Assumptions:
 *
 ****************************************************************************/

static int sam_phyread(struct sam_emac_s *priv, uint8_t phyaddr,
                       uint8_t regaddr, uint16_t *phyval)
{
  uint32_t regval;
  int ret;

  /* Make sure that the PHY is idle */

  ret = sam_phywait(priv);
  if (ret < 0)
    {
      nlldbg("ERROR: sam_phywait failed: %d\n", ret);
      return ret;
    }

  /* Write the PHY Maintenance register */

  regval = EMAC_MAN_DATA(0)       | EMAC_MAN_WTN  | EMAC_MAN_REGA(regaddr) |
           EMAC_MAN_PHYA(phyaddr) | EMAC_MAN_READ | EMAC_MAN_WZO;

  if (!priv->attr->clause45)
    {
      /* CLTTO must be set for Clause 22 operation. To read clause 45 PHYs,
       * bit 30 should be written with a 0 rather than a 1.
       */

      regval |= EMAC_MAN_CLTTO;
    }

  sam_putreg(priv, SAM_EMAC_MAN_OFFSET, regval);

  /* Wait until the PHY is again idle */

  ret = sam_phywait(priv);
  if (ret < 0)
    {
      nlldbg("ERROR: sam_phywait failed: %d\n", ret);
      return ret;
    }

  /* Return data */

  *phyval = (uint16_t)(sam_getreg(priv, SAM_EMAC_MAN_OFFSET) & EMAC_MAN_DATA_MASK);
  return OK;
}

/****************************************************************************
 * Function: sam_phywrite
 *
 * Description:
 *  Write to a PHY register.
 *
 * Parameters:
 *   priv - A reference to the private driver state structure
 *   phyaddr - The PHY device address
 *   regaddr - The PHY register address
 *   phyval - The 16-bit value to write to the PHY register.
 *
 * Returned Value:
 *   OK on success; Negated errno on failure.
 *
 * Assumptions:
 *
 ****************************************************************************/

static int sam_phywrite(struct sam_emac_s *priv, uint8_t phyaddr,
                        uint8_t regaddr, uint16_t phyval)
{
  uint32_t regval;
  int ret;

  /* Make sure that the PHY is idle */

  ret = sam_phywait(priv);
  if (ret < 0)
    {
      nlldbg("ERROR: sam_phywait failed: %d\n", ret);
      return ret;
    }

  /* Write the PHY Maintenance register */

  regval = EMAC_MAN_DATA(phyval)  | EMAC_MAN_WTN   | EMAC_MAN_REGA(regaddr) |
           EMAC_MAN_PHYA(phyaddr) | EMAC_MAN_WRITE | EMAC_MAN_WZO;

  if (!priv->attr->clause45)
    {
      /* CLTTO must be set for Clause 22 operation. To read clause 45 PHYs,
       * bit 30 should be written with a 0 rather than a 1.
       */

      regval |= EMAC_MAN_CLTTO;
    }

  sam_putreg(priv, SAM_EMAC_MAN_OFFSET, regval);

  /* Wait until the PHY is again IDLE */

  ret = sam_phywait(priv);
  if (ret < 0)
    {
      nlldbg("ERROR: sam_phywait failed: %d\n", ret);
      return ret;
    }

  return OK;
}

/****************************************************************************
 * Function: sam_autonegotiate
 *
 * Description:
 *  Autonegotiate speed and duplex.
 *
 * Parameters:
 *   priv - A reference to the private driver state structure
 *
 * Returned Value:
 *   OK on success; Negated errno on failure.
 *
 ****************************************************************************/

static int sam_autonegotiate(struct sam_emac_s *priv)
{
  uint32_t regval;
  uint32_t ncr;
  uint16_t phyid1;
  uint16_t phyid2;
  uint16_t mcr;
  uint16_t msr;
  uint16_t advertise;
  uint16_t lpa;
  int timeout;
  int ret;

  /* Enable management port */

  regval  = sam_getreg(priv, SAM_EMAC_NCR_OFFSET);
  regval |= EMAC_NCR_MPE;
  sam_putreg(priv, SAM_EMAC_NCR_OFFSET, regval);

  /* Verify tht we can read the PHYID register */

  ret = sam_phyread(priv, priv->phyaddr, MII_PHYID1, &phyid1);
  if (ret < 0)
    {
      nlldbg("ERROR: Failed to read PHYID1\n");
      goto errout;
    }

  nllvdbg("PHYID1: %04x PHY address: %02x\n", phyid1, priv->phyaddr);

  ret = sam_phyread(priv, priv->phyaddr, MII_PHYID2, &phyid2);
  if (ret < 0)
    {
      nlldbg("ERROR: Failed to read PHYID2\n");
      goto errout;
    }

  nllvdbg("PHYID2: %04x PHY address: %02x\n", phyid2, priv->phyaddr);

  if (phyid1 == priv->attr->msoui &&
     ((phyid2 & MII_PHYID2_OUI_MASK) >> MII_PHYID2_OUI_SHIFT) ==
      (uint16_t)priv->attr->lsoui)
    {
      nllvdbg("  Vendor Model Number:   %04x\n",
             (phyid2 & MII_PHYID2_MODEL_MASK) >> MII_PHYID2_MODEL_SHIFT);
      nllvdbg("  Model Revision Number: %04x\n",
             (phyid2 & MII_PHYID2_REV_MASK) >> MII_PHYID2_REV_SHIFT);
    }
  else
    {
      nlldbg("ERROR: PHY not recognized\n");
    }

  /* Setup control register */

  ret = sam_phyread(priv, priv->phyaddr, MII_MCR, &mcr);
  if (ret < 0)
    {
      nlldbg("ERROR: Failed to read MCR\n");
      goto errout;
    }

  mcr &= ~MII_MCR_ANENABLE;  /* Remove autonegotiation enable */
  mcr &= ~(MII_MCR_LOOPBACK | MII_MCR_PDOWN);
  mcr |= MII_MCR_ISOLATE;    /* Electrically isolate PHY */

  ret = sam_phywrite(priv, priv->phyaddr, MII_MCR, mcr);
  if (ret < 0)
    {
      nlldbg("ERROR: Failed to write MCR\n");
      goto errout;
    }

  /* Set the Auto_negotiation Advertisement Register MII advertising for
   * Next page 100BaseTxFD and HD, 10BaseTFD and HD, IEEE 802.3
   */

  advertise = MII_ADVERTISE_100BASETXFULL | MII_ADVERTISE_100BASETXHALF |
              MII_ADVERTISE_10BASETXFULL | MII_ADVERTISE_10BASETXHALF |
              MII_ADVERTISE_8023;

  ret = sam_phywrite(priv, priv->phyaddr, MII_ADVERTISE, advertise);
  if (ret < 0)
    {
      nlldbg("ERROR: Failed to write ANAR\n");
      goto errout;
    }

  /* Read and modify control register */

  ret = sam_phyread(priv, priv->phyaddr, MII_MCR, &mcr);
  if (ret < 0)
    {
      nlldbg("ERROR: Failed to read MCR\n");
      goto errout;
    }

  mcr |= (MII_MCR_SPEED100 | MII_MCR_ANENABLE | MII_MCR_FULLDPLX);
  ret = sam_phywrite(priv, priv->phyaddr, MII_MCR, mcr);
  if (ret < 0)
    {
      nlldbg("ERROR: Failed to write MCR\n");
      goto errout;
    }

  /* Restart Auto_negotiation */

  mcr |=  MII_MCR_ANRESTART;
  mcr &= ~MII_MCR_ISOLATE;

  ret = sam_phywrite(priv, priv->phyaddr, MII_MCR, mcr);
  if (ret < 0)
    {
      nlldbg("ERROR: Failed to write MCR\n");
      goto errout;
    }

  nllvdbg("  MCR: %04x\n", mcr);

  /* Check AutoNegotiate complete */

  timeout = 0;
  for (;;)
    {
      ret = sam_phyread(priv, priv->phyaddr, MII_MSR, &msr);
      if (ret < 0)
        {
          nlldbg("ERROR: Failed to read MSR\n");
          goto errout;
        }

      /* Completed successfully? */

      if ((msr & MII_MSR_ANEGCOMPLETE) != 0)
        {
          /* Yes.. break out of the loop */

          nllvdbg("AutoNegotiate complete\n");
          break;
        }

      /* No.. check for a timeout */

      if (++timeout >= PHY_RETRY_MAX)
        {
          nlldbg("ERROR: TimeOut\n");
          sam_phydump(priv);
          ret = -ETIMEDOUT;
          goto errout;
        }
    }

  /* Get the AutoNeg Link partner base page */

  ret = sam_phyread(priv, priv->phyaddr, MII_LPA, &lpa);
  if (ret < 0)
    {
      nlldbg("ERROR: Failed to read ANLPAR\n");
      goto errout;
    }

  /* Setup the EMAC link speed */

  regval  = sam_getreg(priv, SAM_EMAC_NCFGR_OFFSET);
  regval &= ~(EMAC_NCFGR_SPD | EMAC_NCFGR_FD);

  if (((advertise & lpa) & MII_ADVERTISE_100BASETXFULL) != 0)
    {
      /* Set MII for 100BaseTX and Full Duplex */

      regval |= (EMAC_NCFGR_SPD | EMAC_NCFGR_FD);
    }
  else if (((advertise & lpa) & MII_ADVERTISE_10BASETXFULL) != 0)
    {
      /* Set MII for 10BaseT and Full Duplex */

      regval |= EMAC_NCFGR_FD;
    }
  else if (((advertise & lpa) & MII_ADVERTISE_100BASETXHALF) != 0)
    {
      /* Set MII for 100BaseTX and half Duplex */

      regval |= EMAC_NCFGR_SPD;
    }
#if 0
  else if (((advertise & lpa) & MII_ADVERTISE_10BASETXHALF) != 0)
    {
      /* set MII for 10BaseT and half Duplex */
    }
#endif

  sam_putreg(priv, SAM_EMAC_NCFGR_OFFSET, regval);

  /* Select RMII/MII */

  ncr = sam_getreg(priv, SAM_EMAC_NCR_OFFSET);
  sam_putreg(priv, SAM_EMAC_NCR_OFFSET,
             ncr & ~(EMAC_NCR_TXEN | EMAC_NCR_RXEN));

  regval = sam_getreg(priv, SAM_EMAC_UR_OFFSET);
  regval &= ~EMAC_UR_RMII;  /* Assume RMII */

  if (!priv->attr->rmii)
    {
      /* Not RMII, select MII */

      regval |= EMAC_UR_RMII;
    }

  sam_putreg(priv, SAM_EMAC_UR_OFFSET, regval);
  sam_putreg(priv, SAM_EMAC_NCR_OFFSET, ncr);

errout:
  /* Disable management port */

  regval  = sam_getreg(priv, SAM_EMAC_NCR_OFFSET);
  regval &= ~EMAC_NCR_MPE;
  sam_putreg(priv, SAM_EMAC_NCR_OFFSET, regval);
  return ret;
}

/****************************************************************************
 * Function: sam_linkup
 *
 * Description:
 *   Check if the link is up
 *
 * Parameters:
 *   priv - A reference to the private driver state structure
 *
 * Returned Value:
 *   true: The link is up
 *
 ****************************************************************************/

static bool sam_linkup(struct sam_emac_s *priv)
{
  uint32_t regval;
  uint16_t msr;
  uint16_t physr;
  bool linkup = false;
  int ret;

  /* Enable management port */

  regval  = sam_getreg(priv, SAM_EMAC_NCR_OFFSET);
  regval |= EMAC_NCR_MPE;
  sam_putreg(priv, SAM_EMAC_NCR_OFFSET, regval);

  ret = sam_phyread(priv, priv->phyaddr, MII_MSR, &msr);
  if (ret < 0)
    {
      nlldbg("ERROR: Failed to read MSR: %d\n", ret);
      goto errout;
    }

  if ((msr & MII_MSR_LINKSTATUS) == 0)
    {
      nlldbg("ERROR: MSR LinkStatus: %04x\n", msr);
      goto errout;
    }

  /* Re-configure Link speed */

  ret = sam_phyread(priv, priv->phyaddr, priv->attr->physr, &physr);
  if (ret < 0)
    {
      nlldbg("ERROR: Failed to read PHYSR: %d\n", ret);
      goto errout;
    }

  regval = sam_getreg(priv, SAM_EMAC_NCFGR_OFFSET);
  regval &= ~(EMAC_NCFGR_SPD | EMAC_NCFGR_FD);

  if ((msr & MII_MSR_100BASETXFULL) != 0 && sam_is100fdx(priv, physr))
    {
      /* Set EMAC for 100BaseTX and Full Duplex */

      regval |= (EMAC_NCFGR_SPD | EMAC_NCFGR_FD);
    }
  else if ((msr & MII_MSR_10BASETXFULL) != 0  && sam_is10fdx(priv, physr))
    {
      /* Set MII for 10BaseT and Full Duplex */

      regval |= EMAC_NCFGR_FD;
    }

  else if ((msr & MII_MSR_100BASETXHALF) != 0  && sam_is100hdx(priv, physr))
    {
      /* Set MII for 100BaseTX and Half Duplex */

      regval |= EMAC_NCFGR_SPD;
    }

#if 0
  else if ((msr & MII_MSR_10BASETXHALF) != 0  && sam_is10hdx(priv, physr))
    {
      /* Set MII for 10BaseT and Half Duplex */
    }
#endif

  sam_putreg(priv, SAM_EMAC_NCFGR_OFFSET, regval);

  /* Start the EMAC transfers */

  nllvdbg("Link is up\n");
  linkup = true;

errout:
  /* Disable management port */

  regval  = sam_getreg(priv, SAM_EMAC_NCR_OFFSET);
  regval &= ~EMAC_NCR_MPE;
  sam_putreg(priv, SAM_EMAC_NCR_OFFSET, regval);

  return linkup;
}

/****************************************************************************
 * Function: sam_phyinit
 *
 * Description:
 *  Configure the PHY and determine the link speed/duplex.
 *
 * Parameters:
 *   priv - A reference to the private driver state structure
 *
 * Returned Value:
 *   OK on success; Negated errno on failure.
 *
 ****************************************************************************/

static int sam_phyinit(struct sam_emac_s *priv)
{
  uint32_t regval;
  uint32_t mck;
  int ret;

  /* Configure PHY clocking */

  regval = sam_getreg(priv, SAM_EMAC_NCFGR_OFFSET);
  regval &= ~EMAC_NCFGR_CLK_MASK;

  mck = BOARD_MCK_FREQUENCY;
  if (mck > (240*1000*1000))
    {
      ndbg("ERROR: Cannot realize PHY clock\n");
      return -EINVAL;
    }
  else if (mck > (160*1000*1000))
    {
      regval |= EMAC_NCFGR_CLK_DIV96; /* MCK divided by 64 (MCK up to 240 MHz) */
    }
  else if (mck > (120*1000*1000))
    {
      regval |= EMAC_NCFGR_CLK_DIV64; /* MCK divided by 64 (MCK up to 160 MHz) */
    }
  else if (mck > (80*1000*1000))
    {
      regval |= EMAC_NCFGR_CLK_DIV48; /* MCK divided by 64 (MCK up to 120 MHz) */
    }
  else if (mck > (40*1000*1000))
    {
      regval |= EMAC_NCFGR_CLK_DIV32; /* MCK divided by 32 (MCK up to 80 MHz) */
    }
  else if (mck > (20*1000*1000))
    {
      regval |= EMAC_NCFGR_CLK_DIV16; /* MCK divided by 16 (MCK up to 40 MHz) */
    }
  else
    {
      regval |= EMAC_NCFGR_CLK_DIV8;  /* MCK divided by 8 (MCK up to 20 MHz) */
    }

  sam_putreg(priv, SAM_EMAC_NCFGR_OFFSET, regval);

  /* Check the PHY Address */

  priv->phyaddr = priv->attr->phyaddr;
  ret = sam_phyfind(priv, &priv->phyaddr);
  if (ret < 0)
    {
      nlldbg("ERROR: sam_phyfind failed: %d\n", ret);
      return ret;
    }

  if (priv->phyaddr != priv->attr->phyaddr)
    {
      sam_phyreset(priv);
    }

  return OK;
}

/****************************************************************************
 * Function: sam_ethgpioconfig
 *
 * Description:
 *   Configure PIOs for the EMAC0/1 RMII/MII interface.
 *
 *   Signal   Name Function                     MII      RMII
 *   -------- --------------------------------- -------- -----------
 *   TXCK     Transmit Clock or Reference Clock TXCK     REFCK
 *   TXEN     Transmit Enable                   TXEN     TXEN
 *   TX[3..0] Transmit Data                     TXD[3:0] TXD[1:0]
 *   TXER     Transmit Coding Error             TXER     Not Used
 *   RXCK     Receive Clock                     RXCK     Not Used
 *   RXDV     Receive Data Valid                RXDV     CRSDV
 *   RX[3..0] Receive Data                      RXD[3:0] RXD[1:0]
 *   RXER     Receive Error                     RXER     RXER
 *   CRS      Carrier Sense and Data Valid      CRS      Not Used
 *   COL      Collision Detect                  COL      Not Used
 *   MDC      Management Data Clock             MDC      MDC
 *   MDIO     Management Data Input/Output      MDIO     MDIO
 *
 * Parameters:
 *   priv - A reference to the private driver state structure
 *
 * Returned Value:
 *   None.
 *
 * Assumptions:
 *
 ****************************************************************************/

static inline void sam_ethgpioconfig(struct sam_emac_s *priv)
{
#if defined(CONFIG_SAMV7_EMAC0)
  /* Configure EMAC0 PIO pins */

  if (priv->attr->emac == EMAC0_INTF)
    {
      /* Configure PIO pins common to RMII and MII mode*/

       sam_configgpio(GPIO_EMAC0_TXCK);    /* Transmit Clock (or Reference Clock) */
       sam_configgpio(GPIO_EMAC0_TXEN);    /* Transmit Enable */
       sam_configgpio(GPIO_EMAC0_TX0);     /* Transmit data TXD0 */
       sam_configgpio(GPIO_EMAC0_TX1);     /* Transmit data TXD1 */
       sam_configgpio(GPIO_EMAC0_RXDV);    /* Receive Data Valid */
       sam_configgpio(GPIO_EMAC0_RX0);     /* Receive data RXD0 */
       sam_configgpio(GPIO_EMAC0_RX1);     /* Receive data RXD0 */
       sam_configgpio(GPIO_EMAC0_RXER);    /* Receive Error */
       sam_configgpio(GPIO_EMAC0_MDC);     /* Management Data Clock */
       sam_configgpio(GPIO_EMAC0_MDIO);    /* Management Data Input/Output */

      /* Configure additional PIO pins to support EMAC in MII mode*/

      if (!priv->attr->rmii)
        {
          sam_configgpio(GPIO_EMAC0_TX2);  /* Transmit data TXD2 */
          sam_configgpio(GPIO_EMAC0_TX3);  /* Transmit data TXD3 */
          sam_configgpio(GPIO_EMAC0_TXER); /* Transmit Coding Error */
          sam_configgpio(GPIO_EMAC0_RXCK); /* Receive Clock */
          sam_configgpio(GPIO_EMAC0_RX2);  /* Receive data RXD2 */
          sam_configgpio(GPIO_EMAC0_RX3);  /* Receive data RXD3 */
          sam_configgpio(GPIO_EMAC0_CRS);  /* Carrier Sense and Data Valid */
          sam_configgpio(GPIO_EMAC0_COL);  /* Collision Detect */
        }
    }
 else
#endif

#if defined(CONFIG_SAMV7_EMAC1)
  /* Configure EMAC0 PIO pins */

  if (priv->attr->emac == EMAC1_INTF)
    {
      /* Configure PIO pins common to RMII and MII mode*/

       sam_configgpio(GPIO_EMAC1_TXCK);    /* Transmit Clock (or Reference Clock) */
       sam_configgpio(GPIO_EMAC1_TXEN);    /* Transmit Enable */
       sam_configgpio(GPIO_EMAC1_TX0);     /* Transmit data TXD0 */
       sam_configgpio(GPIO_EMAC1_TX1);     /* Transmit data TXD1 */
       sam_configgpio(GPIO_EMAC1_RXDV);    /* Receive Data Valid */
       sam_configgpio(GPIO_EMAC1_RX0);     /* Receive data RXD0 */
       sam_configgpio(GPIO_EMAC1_RX1);     /* Receive data RXD0 */
       sam_configgpio(GPIO_EMAC1_RXER);    /* Receive Error */
       sam_configgpio(GPIO_EMAC1_MDC);     /* Management Data Clock */
       sam_configgpio(GPIO_EMAC1_MDIO);    /* Management Data Input/Output */

      /* Configure additional PIO pins to support EMAC in MII mode*/

      if (!priv->attr->rmii)
        {
          sam_configgpio(GPIO_EMAC1_TX2);  /* Transmit data TXD2 */
          sam_configgpio(GPIO_EMAC1_TX3);  /* Transmit data TXD3 */
          sam_configgpio(GPIO_EMAC1_TXER); /* Transmit Coding Error */
          sam_configgpio(GPIO_EMAC1_RXCK); /* Receive Clock */
          sam_configgpio(GPIO_EMAC1_RX2);  /* Receive data RXD2 */
          sam_configgpio(GPIO_EMAC1_RX3);  /* Receive data RXD3 */
          sam_configgpio(GPIO_EMAC1_CRS);  /* Carrier Sense and Data Valid */
          sam_configgpio(GPIO_EMAC1_COL);  /* Collision Detect */
        }
    }
  else
#endif
   {
     nvdbg("ERROR: emac=%d\n", priv->attr->emac);
   }
}

/****************************************************************************
 * Function: sam_txreset
 *
 * Description:
 *  Reset the transmit logic
 *
 * Parameters:
 *   priv - A reference to the private driver state structure
 *   qid  - Identifies the queue to be reset
 *
 * Returned Value:
 *   None.
 *
 * Assumptions:
 *
 ****************************************************************************/

static void sam_txreset(struct sam_emac_s *priv, int qid)
{
  struct emac_txdesc_s *txdesc;
  struct sam_queue_s *xfrq;
  uint8_t *txbuffer;
  uintptr_t bufaddr;
  uintptr_t regaddr;
  uint32_t regval;
  int ndx;

  /* Get some convenience pointers */

  xfrq     = &priv->xfrq[qid];
  txdesc   = xfrq->txdesc;
  txbuffer = xfrq->txbuffer;

  /* Disable TX */

  regval = sam_getreg(priv, SAM_EMAC_NCR_OFFSET);
  regval &= ~EMAC_NCR_TXEN;
  sam_putreg(priv, SAM_EMAC_NCR_OFFSET, regval);

  /* Configure the TX descriptors. */

  xfrq->txhead = 0;
  xfrq->txtail = 0;

  for (ndx = 0; ndx < xfrq->ntxbuffers; ndx++)
    {
      bufaddr = (uintptr_t)&txbuffer[ndx * xfrq->txbufsize];

      /* Set the buffer address and mark the descriptor as in used by firmware */

      txdesc[ndx].addr   = bufaddr;
      txdesc[ndx].status = EMACTXD_STA_USED;
    }

  /* Mark the final descriptor in the list */

  txdesc[xfrq->ntxbuffers - 1].status =
    EMACTXD_STA_USED | EMACTXD_STA_WRAP;

  /* Flush the entire TX descriptor table to RAM */

  arch_clean_dcache((uintptr_t)txdesc,
                    (uintptr_t)txdesc +
                    xfrq->ntxbuffers * sizeof(struct emac_txdesc_s));

  /* Set the Transmit Buffer Queue Pointer Register */

  regaddr = qid ? SAM_EMAC_ISRPQ_TBQBAPQ_OFFSET(qid) : SAM_EMAC_TBQB_OFFSET;
  sam_putreg(priv, regaddr, (uint32_t)txdesc);
}

/****************************************************************************
 * Function: sam_rxreset
 *
 * Description:
 *  Reset the receive logic
 *
 * Parameters:
 *   priv - A reference to the private driver state structure
 *   qid  - The transfer queue to be reset
 *
 * Returned Value:
 *   None.
 *
 * Assumptions:
 *
 ****************************************************************************/

static void sam_rxreset(struct sam_emac_s *priv, int qid)
{
  struct emac_rxdesc_s *rxdesc;
  struct sam_queue_s *xfrq;
  uint8_t *rxbuffer;
  uintptr_t bufaddr;
  uintptr_t regaddr;
  uint32_t regval;
  int ndx;

  /* Get some convenience pointers */

  xfrq     = &priv->xfrq[qid];
  rxdesc   = xfrq->rxdesc;
  rxbuffer = xfrq->rxbuffer;

  /* Disable RX */

  regval  = sam_getreg(priv, SAM_EMAC_NCR_OFFSET);
  regval &= ~EMAC_NCR_RXEN;
  sam_putreg(priv, SAM_EMAC_NCR_OFFSET, regval);

  /* Configure the RX descriptors. */

  xfrq->rxndx = 0;
  for (ndx = 0; ndx < xfrq->nrxbuffers; ndx++)
    {
      bufaddr = (uintptr_t)&rxbuffer[ndx * xfrq->rxbufsize];
      DEBUGASSERT((bufaddr & ~EMACRXD_ADDR_MASK) == 0);

      /* Set the buffer address and remove EMACRXD_ADDR_OWNER and
       * EMACRXD_ADDR_WRAP.
       */

      rxdesc[ndx].addr   = bufaddr;
      rxdesc[ndx].status = 0;
    }

  /* Mark the final descriptor in the list */

  rxdesc[xfrq->nrxbuffers - 1].addr |= EMACRXD_ADDR_WRAP;

  /* Flush the entire RX descriptor table to RAM */

  arch_clean_dcache((uintptr_t)rxdesc,
                    (uintptr_t)rxdesc +
                    xfrq->nrxbuffers * sizeof(struct emac_rxdesc_s));

  /* Set the Receive Buffer Queue Pointer Register */

  regaddr = qid ? SAM_EMAC_ISRPQ_RBQBAPQ_OFFSET(qid) : SAM_EMAC_RBQB_OFFSET;
  sam_putreg(priv, regaddr, (uint32_t)rxdesc);
}

/****************************************************************************
 * Function: sam_emac_enableclk
 *
 * Description:
 *  Enable clocking to the EMAC block
 *
 * Parameters:
 *   priv - A reference to the private driver state structure
 *
 * Returned Value:
 *   None.
 *
 * Assumptions:
 *
 ****************************************************************************/

static void sam_emac_enableclk(struct sam_emac_s *priv)
{
#if defined(CONFIG_SAMV7_EMAC0) && defined(CONFIG_SAMV7_EMAC1)
  /* Both EMAC blocks are selected, which are we enabling? */

  if (priv->attr->emac == EMAC0_INTF)
    {
      sam_emac0_enableclk();
    }
  else
    {
      sam_emac1_enableclk();
    }

#elif defined(CONFIG_SAMV7_EMAC0)
  /* Only EMAC0 is selected */

  sam_emac0_enableclk();

#else
  /* Only EMAC1 is selected */

  sam_emac1_enableclk();
#endif
}

/****************************************************************************
 * Function: sam_emac_disableclk
 *
 * Description:
 *  Disable clocking to the EMAC block
 *
 * Parameters:
 *   priv - A reference to the private driver state structure
 *
 * Returned Value:
 *   None.
 *
 * Assumptions:
 *
 ****************************************************************************/

#ifndef CONFIG_NETDEV_PHY_IOCTL
static void sam_emac_disableclk(struct sam_emac_s *priv)
{
#if defined(CONFIG_SAMV7_EMAC0) && defined(CONFIG_SAMV7_EMAC1)
  /* Both EMAC blocks are selected, which are we disabling? */

  if (priv->attr->emac == EMAC0_INTF)
    {
      sam_emac0_disableclk();
    }
  else
    {
      sam_emac1_disableclk();
    }

#elif defined(CONFIG_SAMV7_EMAC0)
  /* Only EMAC0 is selected */

  sam_emac0_disableclk();

#else
  /* Only EMAC1 is selected */

  sam_emac1_disableclk();
#endif
}
#endif

/****************************************************************************
 * Function: sam_emac_reset
 *
 * Description:
 *  Reset the EMAC block.
 *
 * Parameters:
 *   priv - A reference to the private driver state structure
 *
 * Returned Value:
 *   None.
 *
 * Assumptions:
 *
 ****************************************************************************/

static void sam_emac_reset(struct sam_emac_s *priv)
{
#ifdef CONFIG_NETDEV_PHY_IOCTL
  uint32_t regval;

  /* We are supporting PHY IOCTLs, then do not reset the MAC.  If we do,
   * then we cannot communicate with the PHY.  So, instead, just disable
   * interrupts, cancel timers, and disable TX and RX.
   */

  sam_putreg(priv, SAM_EMAC_IDR_OFFSET, EMAC_INT_ALL);

  /* Reset RX and TX logic */

  sam_rxreset(priv, EMAC_QUEUE_0);
  sam_rxreset(priv, EMAC_QUEUE_1);
  sam_rxreset(priv, EMAC_QUEUE_2);

  sam_txreset(priv, EMAC_QUEUE_0);
  sam_txreset(priv, EMAC_QUEUE_1);
  sam_txreset(priv, EMAC_QUEUE_2);

  /* Disable Rx and Tx, plus the statistics registers. */

  regval  = sam_getreg(priv, SAM_EMAC_NCR_OFFSET);
  regval &= ~(EMAC_NCR_RXEN | EMAC_NCR_TXEN | EMAC_NCR_WESTAT);
  sam_putreg(priv, SAM_EMAC_NCR_OFFSET, regval);

#else
  /* Disable all EMAC interrupts */

  sam_putreg(priv, SAM_EMAC_IDR_OFFSET, EMAC_INT_ALL);

  /* Reset RX and TX logic */

  sam_rxreset(priv, EMAC_QUEUE_0);
  sam_rxreset(priv, EMAC_QUEUE_1);
  sam_rxreset(priv, EMAC_QUEUE_2);

  sam_txreset(priv, EMAC_QUEUE_0);
  sam_txreset(priv, EMAC_QUEUE_1);
  sam_txreset(priv, EMAC_QUEUE_2);

  /* Make sure that RX and TX are disabled; clear statistics registers */

  sam_putreg(priv, SAM_EMAC_NCR_OFFSET, EMAC_NCR_CLRSTAT);

  /* Disable clocking to the EMAC peripheral */

  sam_emac_disableclk(priv);

#endif
}

/****************************************************************************
 * Function: sam_macaddress
 *
 * Description:
 *   Configure the selected MAC address.
 *
 * Parameters:
 *   priv - A reference to the private driver state structure
 *
 * Returned Value:
 *   OK on success; Negated errno on failure.
 *
 * Assumptions:
 *
 ****************************************************************************/

static void sam_macaddress(struct sam_emac_s *priv)
{
  struct net_driver_s *dev = &priv->dev;
  uint32_t regval;

  nllvdbg("%s MAC: %02x:%02x:%02x:%02x:%02x:%02x\n",
          dev->d_ifname,
          dev->d_mac.ether_addr_octet[0], dev->d_mac.ether_addr_octet[1],
          dev->d_mac.ether_addr_octet[2], dev->d_mac.ether_addr_octet[3],
          dev->d_mac.ether_addr_octet[4], dev->d_mac.ether_addr_octet[5]);

  /* Set the MAC address */

  regval = (uint32_t)dev->d_mac.ether_addr_octet[0] |
           (uint32_t)dev->d_mac.ether_addr_octet[1] << 8 |
           (uint32_t)dev->d_mac.ether_addr_octet[2] << 16 |
           (uint32_t)dev->d_mac.ether_addr_octet[3] << 24;
  sam_putreg(priv, SAM_EMAC_SAB1_OFFSET, regval);

  regval = (uint32_t)dev->d_mac.ether_addr_octet[4] |
           (uint32_t)dev->d_mac.ether_addr_octet[5] << 8;
  sam_putreg(priv, SAM_EMAC_SAT1_OFFSET, regval);
}

/****************************************************************************
 * Function: sam_ipv6multicast
 *
 * Description:
 *   Configure the IPv6 multicast MAC address.
 *
 * Parameters:
 *   priv - A reference to the private driver state structure
 *
 * Returned Value:
 *   OK on success; Negated errno on failure.
 *
 * Assumptions:
 *
 ****************************************************************************/

#ifdef CONFIG_NET_ICMPv6
static void sam_ipv6multicast(struct sam_emac_s *priv)
{
  struct net_driver_s *dev;
  uint16_t tmp16;
  uint8_t mac[6];

  /* For ICMPv6, we need to add the IPv6 multicast address
   *
   * For IPv6 multicast addresses, the Ethernet MAC is derived by
   * the four low-order octets OR'ed with the MAC 33:33:00:00:00:00,
   * so for example the IPv6 address FF02:DEAD:BEEF::1:3 would map
   * to the Ethernet MAC address 33:33:00:01:00:03.
   *
   * NOTES:  This appears correct for the ICMPv6 Router Solicitation
   * Message, but the ICMPv6 Neighbor Solicitation message seems to
   * use 33:33:ff:01:00:03.
   */

  mac[0] = 0x33;
  mac[1] = 0x33;

  dev    = &priv->dev;
  tmp16  = dev->d_ipv6addr[6];
  mac[2] = 0xff;
  mac[3] = tmp16 >> 8;

  tmp16  = dev->d_ipv6addr[7];
  mac[4] = tmp16 & 0xff;
  mac[5] = tmp16 >> 8;

  nvdbg("IPv6 Multicast: %02x:%02x:%02x:%02x:%02x:%02x\n",
        mac[0], mac[1], mac[2], mac[3], mac[4], mac[5]);

  (void)sam_addmac(dev, mac);

#ifdef CONFIG_NET_ICMPv6_AUTOCONF
  /* Add the IPv6 all link-local nodes Ethernet address.  This is the
   * address that we expect to receive ICMPv6 Router Advertisement
   * packets.
   */

  (void)sam_addmac(dev, g_ipv6_ethallnodes.ether_addr_octet);

#endif /* CONFIG_NET_ICMPv6_AUTOCONF */
#ifdef CONFIG_NET_ICMPv6_ROUTER
  /* Add the IPv6 all link-local routers Ethernet address.  This is the
   * address that we expect to receive ICMPv6 Router Solicitation
   * packets.
   */

  (void)sam_addmac(dev, g_ipv6_ethallrouters.ether_addr_octet);

#endif /* CONFIG_NET_ICMPv6_ROUTER */
}
#endif /* CONFIG_NET_ICMPv6 */

/****************************************************************************
 * Function: sam_queue0_configure
 *
 * Description:
 *  Put transfer queue 0 in the operational state
 *
 * Parameters:
 *   priv - A reference to the private driver state structure
 *
 * Returned Value:
 *   OK on success; Negated errno on failure.
 *
 * Assumptions:
 *
 ****************************************************************************/

static int sam_queue0_configure(struct sam_emac_s *priv)
{
  uint32_t regval;

  /* Set up the DMA configuration register
   *
   * EMAC_DCFGR_FBLDO_INCR4 - Attempt to use INCR8 AHB bursts
   *                        - No endian swap mode
   * EMAC_DCFGR_RXBMS_FULL  - 4 Kbytes Memory Size
   * EMAC_DCFGR_TXPBMS      - Full configured address space (4Kbytes)
   *                        - No Checksum generation offload enable
   * EMAC_DCFGR_DRBS        - Set configured receive buffer size
   *                          (units of 64 bytes)
   */

  regval = EMAC_DCFGR_FBLDO_INCR4 | EMAC_DCFGR_RXBMS_FULL | /* EMAC_DCFGR_TXPBMS | */
           EMAC_DCFGR_DRBS(priv->xfrq[0].rxbufsize >> 6);
  sam_putreg(priv, SAM_EMAC_DCFGR_OFFSET, regval);

  /* Reset RX and TX */

  sam_rxreset(priv, EMAC_QUEUE_0);
  sam_txreset(priv, EMAC_QUEUE_0);

  /* Enable Rx and Tx, plus the statistics registers. */

  regval  = sam_getreg(priv, SAM_EMAC_NCR_OFFSET);
  regval |= EMAC_NCR_RXEN | EMAC_NCR_TXEN | EMAC_NCR_WESTAT;
  sam_putreg(priv, SAM_EMAC_NCR_OFFSET, regval);

  /* Setup the interrupts for TX events, RX events, and error events */

  regval = EMAC_RX_INTS | EMAC_TX_INTS;
  sam_putreg(priv, SAM_EMAC_IER_OFFSET, regval);
  return OK;
}

/****************************************************************************
 * Function: sam_queue_configure
 *
 * Description:
 *  Put transfer queue n, n=1..(EMAC_NQUEUES-1), in the operational state
 *
 * Parameters:
 *   priv - A reference to the private driver state structure
 *   qid  - Identifies the transfer queue to be configured
 *
 * Returned Value:
 *   OK on success; Negated errno on failure.
 *
 * Assumptions:
 *
 ****************************************************************************/

static int sam_queue_configure(struct sam_emac_s *priv, int qid)
{
  uint32_t regval;

  /* Set the receive buffer size */

  regval = (uint32_t)priv->xfrq[qid].rxbufsize >> 6;
  sam_putreg(priv, SAM_EMAC_ISRPQ_RBSRPQ_OFFSET(qid), regval);

  /* Reset RX and TX */

  sam_rxreset(priv, qid);
  sam_txreset(priv, qid);

  /* Setup interrupts for RX/TX completion events */

  regval = EMAC_RX_INTS | EMAC_TX_INTS;
  sam_putreg(priv, SAM_EMAC_ISRPQ_IERPQ_OFFSET(qid), regval);
  return OK;
}

/****************************************************************************
 * Function: sam_emac_configure
 *
 * Description:
 *  Configure the EMAC interface for normal operation.
 *
 * Parameters:
 *   priv - A reference to the private driver state structure
 *
 * Returned Value:
 *   OK on success; Negated errno on failure.
 *
 * Assumptions:
 *
 ****************************************************************************/

static int sam_emac_configure(struct sam_emac_s *priv)
{
  uint32_t regval;

  nllvdbg("Entry\n");

  /* Enable clocking to the EMAC peripheral */

  sam_emac_enableclk(priv);

  /* Disable TX, RX, clear statistics.  Disable all interrupts. */

  sam_putreg(priv, SAM_EMAC_NCR_OFFSET, EMAC_NCR_CLRSTAT);
  sam_putreg(priv, SAM_EMAC_IDR_OFFSET, EMAC_INT_ALL);
  sam_putreg(priv, SAM_EMAC_ISRPQ_IDRPQ_OFFSET(1), EMAC_INTPQ_ALL);
  sam_putreg(priv, SAM_EMAC_ISRPQ_IDRPQ_OFFSET(2), EMAC_INTPQ_ALL);

  /* Clear all status bits in the receive status register. */

  regval = (EMAC_RSR_RXOVR | EMAC_RSR_REC | EMAC_RSR_BNA | EMAC_RSR_HNO);
  sam_putreg(priv, SAM_EMAC_RSR_OFFSET, regval);

  /* Clear all status bits in the transmit status register */

  regval = (EMAC_TSR_UBR | EMAC_TSR_COL | EMAC_TSR_RLE | EMAC_TSR_TXGO |
            EMAC_TSR_TFC | EMAC_TSR_TXCOMP | EMAC_TSR_HRESP);
  sam_putreg(priv, SAM_EMAC_TSR_OFFSET, regval);

  /* Clear any pending interrupts */

  (void)sam_getreg(priv, SAM_EMAC_ISR_OFFSET);
  (void)sam_getreg(priv, SAM_EMAC_ISRPQ_ISRPQ_OFFSET(1));
  (void)sam_getreg(priv, SAM_EMAC_ISRPQ_ISRPQ_OFFSET(2));

  /* Enable/disable the copy of data into the buffers, ignore broadcasts.
   * Don't copy FCS.
   */

  regval = EMAC_NCFGR_FD | EMAC_NCFGR_DBW_ZERO | EMAC_NCFGR_CLK_DIV64 |
           EMAC_NCFGR_MAXFS | EMAC_NCFGR_PEN | EMAC_NCFGR_RFCS;

#ifdef CONFIG_NET_PROMISCUOUS
  regval |=  EMAC_NCFGR_CAF;
#endif

#ifdef CONFIG_SAMV7_EMAC_NBC
  regval |=  EMAC_NCFGR_NBC;
#endif

  sam_putreg(priv, SAM_EMAC_NCFGR_OFFSET, regval);
  return OK;
}

/****************************************************************************
 * Public Functions
 ****************************************************************************/

/****************************************************************************
 * Function: sam_emac_initialize
 *
 * Description:
 *   Initialize the EMAC driver.
 *
 * Input Parameters:
 *   intf - If multiple EMAC peripherals are supported, this identifies the
 *     the EMAC peripheral being initialized.
 *
 * Returned Value:
 *   OK on success; Negated errno on failure.
 *
 * Assumptions:
 *   Called very early in the initialization sequence.
 *
 ****************************************************************************/

int sam_emac_initialize(int intf)
{
  struct sam_emac_s *priv;
  const struct sam_emacattr_s *attr;
#if defined(CONFIG_NETDEV_PHY_IOCTL) && defined(CONFIG_ARCH_PHY_INTERRUPT)
  uint8_t phytype;
#endif
  int ret;

#if defined(CONFIG_SAMV7_EMAC0)
  if (intf == EMAC0_INTF)
    {
      priv    = &g_emac0;
      attr    = &g_emac0_attr;

#if defined(CONFIG_NETDEV_PHY_IOCTL) && defined(CONFIG_ARCH_PHY_INTERRUPT)
      phytype = SAMV7_EMAC0_PHY_TYPE;
#endif
    }
  else
#endif
#if defined(CONFIG_SAMV7_EMAC1)
  if (intf == EMAC1_INTF)
    {
      priv    = &g_emac1;
      attr    = &g_emac1_attr;

#if defined(CONFIG_NETDEV_PHY_IOCTL) && defined(CONFIG_ARCH_PHY_INTERRUPT)
      phytype = SAMV7_EMAC1_PHY_TYPE;
#endif
    }
  else
#endif
    {
      ndbg("ERROR:  Interface %d not supported\n", intf);
      return -EINVAL;
    }

  /* Initialize the driver structure */

  memset(priv, 0, sizeof(struct sam_emac_s));
  priv->attr          = attr;           /* Save the constant attributes */
  priv->dev.d_ifup    = sam_ifup;       /* I/F up (new IP address) callback */
  priv->dev.d_ifdown  = sam_ifdown;     /* I/F down callback */
  priv->dev.d_txavail = sam_txavail;    /* New TX data callback */
#ifdef CONFIG_NET_IGMP
  priv->dev.d_addmac  = sam_addmac;     /* Add multicast MAC address */
  priv->dev.d_rmmac   = sam_rmmac;      /* Remove multicast MAC address */
#endif
#ifdef CONFIG_NETDEV_PHY_IOCTL
  priv->dev.d_ioctl   = sam_ioctl;      /* Support PHY ioctl() calls */
#ifdef CONFIG_ARCH_PHY_INTERRUPT
  priv->phytype       = phytype;        /* Type of PHY on port */
#endif
#endif

  priv->dev.d_private = priv;           /* Used to recover private state from dev */

  /* Create a watchdog for timing polling for and timing of transmissions */

  priv->txpoll = wd_create();
  if (!priv->txpoll)
    {
      ndbg("ERROR: Failed to create periodic poll timer\n");
      ret = -EAGAIN;
      goto errout;
    }

  priv->txtimeout = wd_create();     /* Create TX timeout timer */
  if (!priv->txtimeout)
    {
      ndbg("ERROR: Failed to create periodic poll timer\n");
      ret = -EAGAIN;
      goto errout_with_txpoll;
    }

  /* Configure PIO pins to support EMAC */

  sam_ethgpioconfig(priv);

  /* Allocate buffers */

  ret = sam_buffer_allocate(priv);
  if (ret < 0)
    {
      ndbg("ERROR: sam_buffer_allocate failed: %d\n", ret);
      goto errout_with_txtimeout;
    }

  /* Attach the IRQ to the driver.  It will not be enabled at the AIC until
   * the interface is in the 'up' state.
   */

  ret = irq_attach(priv->attr->irq, priv->attr->handler);
  if (ret < 0)
    {
      ndbg("ERROR: Failed to attach the handler to the IRQ%d\n", priv->attr->irq);
      goto errout_with_buffers;
    }

  /* Enable clocking to the EMAC peripheral (just for sam_ifdown()) */

  sam_emac_enableclk(priv);

  /* Put the interface in the down state (disabling clocking again). */

  ret = sam_ifdown(&priv->dev);
  if (ret < 0)
    {
      ndbg("ERROR: Failed to put the interface in the down state: %d\n", ret);
      goto errout_with_buffers;
    }

  /* Register the device with the OS so that socket IOCTLs can be performed */

  ret = netdev_register(&priv->dev, NET_LL_ETHERNET);
  if (ret >= 0)
    {
      return ret;
    }

  ndbg("ERROR: netdev_register() failed: %d\n", ret);

errout_with_buffers:
  sam_buffer_free(priv);
errout_with_txtimeout:
  wd_delete(priv->txtimeout);
errout_with_txpoll:
  wd_delete(priv->txpoll);
errout:
  return ret;
}

/****************************************************************************
 * Function: sam_emac_setmacaddr
 *
 * Description:
 *   There are two ways that the Ethernet MAC address can be set:
 *
 *   1) Application level code can set the Ethernet MAC address using a
 *      netdev ioctl.  The application level code have gotten the MAC
 *      address from some configuration parameter or by accessing some
 *      non-volatile storage containing the address.  This is the
 *      "canonically correct" way to set the MAC address.
 *   2) Alternatively, the board logic may support some other less obvious
 *      non-volatile storage and the board-level boot-up code may access
 *      this and use this interface to set the Ethernet MAC address more
 *      directly.  This is mostly a kludge for the case where you just don't
 *      want to expose a application level storage interface.
 *
 * Input Parameters:
 *   intf - If multiple EMAC peripherals are supported, this identifies the
 *     the EMAC peripheral being initialized.
 *
 * Returned Value:
 *   OK on success; Negated errno on failure.
 *
 * Assumptions:
 *   Called very early in the initialization sequence.
 *
 ****************************************************************************/

int sam_emac_setmacaddr(int intf, uint8_t mac[6])
{
  struct sam_emac_s *priv;
  struct net_driver_s *dev;

  /* Get the driver state structure */

#if defined(CONFIG_SAMV7_EMAC0)
  if (intf == EMAC0_INTF)
    {
      priv = &g_emac0;
    }
  else
#endif
#if defined(CONFIG_SAMV7_EMAC1)
  if (intf == EMAC1_INTF)
    {
      priv = &g_emac1;
    }
  else
#endif
    {
      ndbg("ERROR:  Interface %d not supported\n", intf);
      return -EINVAL;
    }

  /* Copy the MAC address into the device structure */

  dev = &priv->dev;
  memcpy(dev->d_mac.ether_addr_octet, mac, 6);

  nvdbg("%s MAC: %02x:%02x:%02x:%02x:%02x:%02x\n",
        dev->d_ifname,
        dev->d_mac.ether_addr_octet[0], dev->d_mac.ether_addr_octet[1],
        dev->d_mac.ether_addr_octet[2], dev->d_mac.ether_addr_octet[3],
        dev->d_mac.ether_addr_octet[4], dev->d_mac.ether_addr_octet[5]);

  return OK;
}

#endif /* CONFIG_NET && CONFIG_SAMV7_EMAC */