1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
|
/****************************************************************************
* drivers/analog/dac.c
*
* Copyright (C) 2011 Li Zhuoyi. All rights reserved.
* Author: Li Zhuoyi <lzyy.cn@gmail.com>
* History: 0.1 2011-08-04 initial version
*
* Derived from drivers/can.c
*
* Copyright (C) 2008-2009Gregory Nutt. All rights reserved.
* Author: Gregory Nutt <spudmonkey@racsa.co.cr>
*
* 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 name NuttX 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>
#include <sys/types.h>
#include <stdint.h>
#include <stdbool.h>
#include <unistd.h>
#include <string.h>
#include <semaphore.h>
#include <fcntl.h>
#include <errno.h>
#include <debug.h>
#include <nuttx/fs.h>
#include <nuttx/arch.h>
#include <nuttx/analog/dac.h>
#include <arch/irq.h>
/****************************************************************************
* Pre-processor Definitions
****************************************************************************/
#define HALF_SECOND_MSEC 500
#define HALF_SECOND_USEC 500000L
/****************************************************************************
* Private Function Prototypes
****************************************************************************/
static int dac_open(FAR struct file *filep);
static int dac_close(FAR struct file *filep);
static ssize_t dac_read(FAR struct file *, FAR char *, size_t);
static ssize_t dac_write(FAR struct file *filep, FAR const char *buffer, size_t buflen);
static int dac_ioctl(FAR struct file *filep,int cmd,unsigned long arg);
/****************************************************************************
* Private Data
****************************************************************************/
static const struct file_operations dac_fops =
{
dac_open,
dac_close,
dac_read,
dac_write,
0,
dac_ioctl
#ifndef CONFIG_DISABLE_POLL
, 0
#endif
};
/****************************************************************************
* Private Functions
****************************************************************************/
/************************************************************************************
* Name: dac_open
*
* Description:
* This function is called whenever the DAC device is opened.
*
************************************************************************************/
static int dac_open(FAR struct file *filep)
{
FAR struct inode *inode = filep->f_inode;
FAR struct dac_dev_s *dev = inode->i_private;
uint8_t tmp;
int ret = OK;
/* If the port is the middle of closing, wait until the close is finished */
if (sem_wait(&dev->ad_closesem) != OK)
{
ret = -errno;
}
else
{
/* Increment the count of references to the device. If this the first
* time that the driver has been opened for this device, then initialize
* the device.
*/
tmp = dev->ad_ocount + 1;
if (tmp == 0)
{
/* More than 255 opens; uint8_t overflows to zero */
ret = -EMFILE;
}
else
{
/* Check if this is the first time that the driver has been opened. */
if (tmp == 1)
{
/* Yes.. perform one time hardware initialization. */
irqstate_t flags = irqsave();
ret = dev->ad_ops->ao_setup(dev);
if (ret == OK)
{
/* Mark the FIFOs empty */
dev->ad_xmit.af_head = 0;
dev->ad_xmit.af_tail = 0;
/* Save the new open count on success */
dev->ad_ocount = tmp;
}
irqrestore(flags);
}
}
sem_post(&dev->ad_closesem);
}
return ret;
}
/************************************************************************************
* Name: dac_close
*
* Description:
* This routine is called when the DAC device is closed.
* It waits for the last remaining data to be sent.
*
************************************************************************************/
static int dac_close(FAR struct file *filep)
{
FAR struct inode *inode = filep->f_inode;
FAR struct dac_dev_s *dev = inode->i_private;
irqstate_t flags;
int ret = OK;
if (sem_wait(&dev->ad_closesem) != OK)
{
ret = -errno;
}
else
{
/* Decrement the references to the driver. If the reference count will
* decrement to 0, then uninitialize the driver.
*/
if (dev->ad_ocount > 1)
{
dev->ad_ocount--;
sem_post(&dev->ad_closesem);
}
else
{
/* There are no more references to the port */
dev->ad_ocount = 0;
/* Now we wait for the transmit FIFO to clear */
while (dev->ad_xmit.af_head != dev->ad_xmit.af_tail)
{
#ifndef CONFIG_DISABLE_SIGNALS
usleep(HALF_SECOND_USEC);
#else
up_mdelay(HALF_SECOND_MSEC);
#endif
}
/* Free the IRQ and disable the DAC device */
flags = irqsave(); /* Disable interrupts */
dev->ad_ops->ao_shutdown(dev); /* Disable the DAC */
irqrestore(flags);
sem_post(&dev->ad_closesem);
}
}
return ret;
}
/****************************************************************************
* Name: dac_read
****************************************************************************/
static ssize_t dac_read(FAR struct file *filep, FAR char *buffer, size_t buflen)
{
return 0;
}
/************************************************************************************
* Name: dac_xmit
*
* Description:
* Send the message at the head of the ad_xmit FIFO
*
* Assumptions:
* Called with interrupts disabled
*
************************************************************************************/
static int dac_xmit(FAR struct dac_dev_s *dev)
{
bool enable = false;
int ret = OK;
/* Check if the xmit FIFO is empty */
if (dev->ad_xmit.af_head != dev->ad_xmit.af_tail)
{
/* Send the next message at the head of the FIFO */
ret = dev->ad_ops->ao_send(dev, &dev->ad_xmit.af_buffer[dev->ad_xmit.af_head]);
/* Make sure the TX done interrupts are enabled */
enable = (ret == OK ? true : false);
}
dev->ad_ops->ao_txint(dev, enable);
return ret;
}
/************************************************************************************
* Name: dac_write
************************************************************************************/
static ssize_t dac_write(FAR struct file *filep, FAR const char *buffer, size_t buflen)
{
FAR struct inode *inode = filep->f_inode;
FAR struct dac_dev_s *dev = inode->i_private;
FAR struct dac_fifo_s *fifo = &dev->ad_xmit;
FAR struct dac_msg_s *msg;
bool empty = false;
ssize_t nsent = 0;
irqstate_t flags;
int nexttail;
int msglen;
int ret = 0;
/* Interrupts must disabled throughout the following */
flags = irqsave();
/* Check if the TX FIFO was empty when we started. That is a clue that we have
* to kick off a new TX sequence.
*/
empty = (fifo->af_head == fifo->af_tail);
/* Add the messages to the FIFO. Ignore any trailing messages that are
* shorter than the minimum.
*/
if (buflen % 5 ==0 )
msglen=5;
else if (buflen % 4 ==0 )
msglen=4;
else if (buflen % 3 ==0 )
msglen=3;
else if (buflen % 2 ==0 )
msglen=2;
else if (buflen == 1)
msglen=1;
else
msglen=5;
while ((buflen - nsent) >= msglen )
{
/* Check if adding this new message would over-run the drivers ability to enqueue
* xmit data.
*/
nexttail = fifo->af_tail + 1;
if (nexttail >= CONFIG_DAC_FIFOSIZE)
{
nexttail = 0;
}
/* If the XMIT fifo becomes full, then wait for space to become available */
while (nexttail == fifo->af_head)
{
/* The transmit FIFO is full -- was non-blocking mode selected? */
if (filep->f_oflags & O_NONBLOCK)
{
if (nsent == 0)
{
ret = -EAGAIN;
}
else
{
ret = nsent;
}
goto return_with_irqdisabled;
}
/* If the FIFO was empty when we started, then we will have
* start the XMIT sequence to clear the FIFO.
*/
if (empty)
{
dac_xmit(dev);
}
/* Wait for a message to be sent */
do
{
ret = sem_wait(&fifo->af_sem);
if (ret < 0 && errno != EINTR)
{
ret = -errno;
goto return_with_irqdisabled;
}
}
while (ret < 0);
/* Re-check the FIFO state */
empty = (fifo->af_head == fifo->af_tail);
}
/* We get here if there is space at the end of the FIFO. Add the new
* CAN message at the tail of the FIFO.
*/
if (msglen==5)
{
msg = (FAR struct dac_msg_s *)&buffer[nsent];
memcpy(&fifo->af_buffer[fifo->af_tail], msg, msglen);
}
else if(msglen == 4)
{
fifo->af_buffer[fifo->af_tail].am_channel=buffer[nsent];
fifo->af_buffer[fifo->af_tail].am_data=*(uint32_t *)&buffer[nsent];
fifo->af_buffer[fifo->af_tail].am_data&=0xffffff00;
}
else if(msglen == 3)
{
fifo->af_buffer[fifo->af_tail].am_channel=buffer[nsent];
fifo->af_buffer[fifo->af_tail].am_data=(*(uint16_t *)&buffer[nsent+1]);
fifo->af_buffer[fifo->af_tail].am_data<<=16;
}
else if(msglen == 2)
{
fifo->af_buffer[fifo->af_tail].am_channel=0;
fifo->af_buffer[fifo->af_tail].am_data=(*(uint16_t *)&buffer[nsent]);
fifo->af_buffer[fifo->af_tail].am_data<<=16;
}
else if(msglen == 1)
{
fifo->af_buffer[fifo->af_tail].am_channel=0;
fifo->af_buffer[fifo->af_tail].am_data=buffer[nsent];
fifo->af_buffer[fifo->af_tail].am_data<<=24;
}
/* Increment the tail of the circular buffer */
fifo->af_tail = nexttail;
/* Increment the number of bytes that were sent */
nsent += msglen;
}
/* We get here after all messages have been added to the FIFO. Check if
* we need to kick of the XMIT sequence.
*/
if (empty)
{
dac_xmit(dev);
}
/* Return the number of bytes that were sent */
ret = nsent;
return_with_irqdisabled:
irqrestore(flags);
return ret;
}
/************************************************************************************
* Name: dac_ioctl
************************************************************************************/
static int dac_ioctl(FAR struct file *filep, int cmd, unsigned long arg)
{
FAR struct inode *inode = filep->f_inode;
FAR struct dac_dev_s *dev = inode->i_private;
int ret = OK;
ret = dev->ad_ops->ao_ioctl(dev, cmd, arg);
return ret;
}
/****************************************************************************
* Public Functions
****************************************************************************/
/************************************************************************************
* Name: dac_txdone
*
* Description:
* Called from the DAC interrupt handler at the completion of a send operation.
*
* Return:
* OK on success; a negated errno on failure.
*
************************************************************************************/
int dac_txdone(FAR struct dac_dev_s *dev)
{
int ret = -ENOENT;
/* Verify that the xmit FIFO is not empty */
if (dev->ad_xmit.af_head != dev->ad_xmit.af_tail)
{
/* Remove the message at the head of the xmit FIFO */
if (++dev->ad_xmit.af_head >= CONFIG_DAC_FIFOSIZE)
{
dev->ad_xmit.af_head = 0;
}
/* Send the next message in the FIFO */
ret = dac_xmit(dev);
if (ret == OK)
{
/* Inform any waiting threads that new xmit space is available */
ret = sem_post(&dev->ad_xmit.af_sem);
}
}
return ret;
}
int dac_register(FAR const char *path, FAR struct dac_dev_s *dev)
{
/* Initialize the DAC device structure */
dev->ad_ocount = 0;
sem_init(&dev->ad_xmit.af_sem, 0, 0);
sem_init(&dev->ad_closesem, 0, 1);
dev->ad_ops->ao_reset(dev);
return register_driver(path, &dac_fops, 0555, dev);
}
|