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
|
/****************************************************************************
* arch/arm/src/imx/imx_timerisr.c
* arch/arm/src/chip/imx_timerisr.c
*
* Copyright (C) 2009 Gregory 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 <debug.h>
#include <errno.h>
#include <nuttx/arch.h>
#include "clock_internal.h"
#include "up_internal.h"
#include "up_arch.h"
/****************************************************************************
* Definitions
****************************************************************************/
/****************************************************************************
* Private Types
****************************************************************************/
/****************************************************************************
* Private Function Prototypes
****************************************************************************/
/****************************************************************************
* Global Functions
****************************************************************************/
/****************************************************************************
* Function: up_timerisr
*
* Description:
* The timer ISR will perform a variety of services for various portions
* of the systems.
*
****************************************************************************/
int up_timerisr(int irq, uint32 *regs)
{
uint32 tstat;
int ret = -EIO;
/* Get and clear the interrupt status */
tstat = getreg32(IMX_TIMER1_TSTAT);
putreg32(0, IMX_TIMER1_TSTAT);
/* Verify that this is a timer interrupt */
if ((tstat & TIMER_TSTAT_COMP) != 0)
{
/* Process timer interrupt */
sched_process_timer();
ret = OK;
}
return ret;
}
/****************************************************************************
* Function: up_timerinit
*
* Description:
* This function is called during start-up to initialize the timer
* interrupt.
*
****************************************************************************/
void up_timerinit(void)
{
uint32 tctl;
/* Make sure the timer interrupts are disabled */
up_disable_irq(IMX_IRQ_SYSTIMER);
/* Make sure that timer1 is disabled */
putreg32(0, IMX_TIMER1_TCTL);
putreg32(0, IMX_TIMER1_TPRER);
/* Select restart mode with source = PERCLK1. In restart mode, after
* the compare value is reached, the counter resets to 0x00000000, the
* compare event (COMP) bit of the timer status register is set, an
* interrupt is issued if the interrupt request enable (IRQEN) bit of
* the corresponding TCTL register is set, and the counter resumes
* counting.
*/
tctl = TCTL_CLKSOURCE_PERCLK1;
putreg32(tctl, IMX_TIMER1_TCTL);
/* The timer is driven by PERCLK1. Set prescaler for division by one
* so that the clock is driven at PERCLK1.
*
* putreg(0, IMX_TIMER1_TPRER); -- already the case
*
* Set the compare register so that the COMP interrupt is generated
* with a period of MSEC_PER_TICK. The value IMX_PERCLK1_FREQ/1000
* (defined in board.h) is the number of counts in millisecond, so:
*/
putreg32((IMX_PERCLK1_FREQ / 1000) * MSEC_PER_TICK, IMX_TIMER1_TCMP);
/* Configure to provide timer COMP interrupts when TCN increments
* to TCMP.
*/
tctl |= TIMER_TCTL_IRQEN;
putreg32(tctl, IMX_TIMER1_TCTL);
/* Finally, enable the timer (be be the last operation on TCTL) */
tctl |= TIMER_TCTL_TEN;
putreg32(tctl, IMX_TIMER1_TCTL);
/* Attach and enable the timer interrupt */
irq_attach(IMX_IRQ_SYSTIMER, (xcpt_t)up_timerisr);
up_enable_irq(IMX_IRQ_SYSTIMER);
}
|
