Cubieboard2裸机开发之（五）看门狗操作

1 /*
2 * (C) Copyright 2014 conan liang
3 *
4 */
5
6
7 /* global entry point */
8 .global _start
9 _start:
10 b reset
11
12
13 reset:
14 /* disable IRQ & FIQ, set the cpu to SVC32 mode */
15 mrs r0, cpsr
16 and r1, r0, #0x1f
17 teq r1, #0x1a
18 bicne r0, r0, #0x1f
19 orrne r0, r0, #0x13
20 orr r0, r0, #0xc0
21 msr cpsr, r0
22
23 /* set exception vector table */
24 ldr r0, =_start
25 mcr p15, 0, r0, c12, c0, 0
26
27 /* setup stack, so we can call C code */
28 ldr sp, =(1024 * 10)
29
30 /* jump to main function */
31 bl main
32 loop:
33 b loop

1 #include "io.h"
2 #include "watchdog.h"
3
4
5 #define SUNXI_PIO_BASE (0x01C20800)
6 #define PH_CFG2 (SUNXI_PIO_BASE + 0x104)
7 #define PH_DAT (SUNXI_PIO_BASE + 0x10C)
8
9
10 /* set two LEDs on */
11 static void set_led_on(void)
12 {
13 unsigned int tmp;
14
15 /* PH20 and PH21 output 1 */
16 tmp = readl(PH_DAT);
17 tmp |= (0x1 <<20);
18 tmp |= (0x1 <<21);
19 writel(tmp, PH_DAT);
20 }
21
22 /* init two PIOs */
23 static void led_init(void)
24 {
25 unsigned int tmp;
26
27 /* configure PH20 and PH21 output */
28 tmp = readl(PH_CFG2);
29 tmp &= ~(0x7 <<16);
30 tmp &= ~(0x7 <<20);
31 tmp |= (0x1 <<16);
32 tmp |= (0x1 <<20);
33 writel(tmp, PH_CFG2);
34 /* PH20 and PH21 output 0 */
35 tmp = readl(PH_DAT);
36 tmp &= ~(0x1 <<20);
37 tmp &= ~(0x1 <<21);
38 writel(tmp, PH_DAT);
39 }
40
41
42 int main(void)
43 {
44 int i;
45
46 /* let watchdog reset the system after 3 second */
47 sunxi_watchdog_init(3);
48 /* init LEDs */
49 led_init();
50 /* some delay, so we can see two LEDs off a while */
51 for (i = 0; i <50000; i++);
52 /* set two LEDs on */
53 set_led_on();
54 while (1);
55
56 return 0;
57 }

1 #include "watchdog.h"
2 #include "io.h"
3
4 /* watchdog interval value */
5 static unsigned int watchdog_intv_val [] = {
6 0b0000, // 0.5s
7 0b0001, // 1s
8 0b0010, // 2s
9 0b0011, // 3s
10 0b0100, // 4s
11 0b0101, // 5s
12 0b0110, // 6s
13 0b0111, // 8s
14 0b0111, // 8s
15 0b1000, // 10s
16 0b1000, // 10s
17 0b1001, // 12s
18 0b1001, // 12s
19 0b1010, // 14s
20 0b1010, // 14s
21 0b1011, // 16s
22 0b1011 // 16s
23 };
24
25 /* reg bits */
26 #define WDOG_OFF (-1)
27 #define WDOG_RST_EN (1)
28 #define WDOG_EN (0)
29 #define WDOG_RSTART (0)
30
31 static void sunxi_watchdog_set(int time)
32 {
33 if (time >= 0) {
34 /* should not larger than 16 seconds */
35 if(time > 16)
36 time = 16;
37 writel((watchdog_intv_val[time] <<3) | (1 <1 << WDOG_EN), SUNXI_WDOG_MODE_REG);
38 } else {
39 /* disable watchdog */
40 writel(0, SUNXI_WDOG_MODE_REG);
41 }
42 /* restart watchdog */
43 writel(1 << WDOG_RSTART, SUNXI_WDOG_CTRL_REG);
44 }
45
46 int sunxi_watchdog_init(int val)
47 {
48 sunxi_watchdog_set(val);
49
50 return 0;
51 }