1 /*
2 * This program is free software; you can redistribute it and/or modify
3 * it under the terms of the GNU General Public License version 2 as
4 * published by the Free Software Foundation.
5 */
6 #include <linux/kernel.h>
7 #include <linux/module.h>
8 #include <linux/delay.h>
9 #include <linux/gpio.h>
10 #include <linux/io.h>
11 #include <asm/proc-fns.h>
12 #include <asm/system_misc.h>
13
14 #include <mach/regs-ost.h>
15 #include <mach/reset.h>
16
17 unsigned int reset_status;
18 EXPORT_SYMBOL(reset_status);
19
20 static void do_hw_reset(void);
21
22 static int reset_gpio = -1;
23
init_gpio_reset(int gpio,int output,int level)24 int init_gpio_reset(int gpio, int output, int level)
25 {
26 int rc;
27
28 rc = gpio_request(gpio, "reset generator");
29 if (rc) {
30 printk(KERN_ERR "Can't request reset_gpio\n");
31 goto out;
32 }
33
34 if (output)
35 rc = gpio_direction_output(gpio, level);
36 else
37 rc = gpio_direction_input(gpio);
38 if (rc) {
39 printk(KERN_ERR "Can't configure reset_gpio\n");
40 gpio_free(gpio);
41 goto out;
42 }
43
44 out:
45 if (!rc)
46 reset_gpio = gpio;
47
48 return rc;
49 }
50
51 /*
52 * Trigger GPIO reset.
53 * This covers various types of logic connecting gpio pin
54 * to RESET pins (nRESET or GPIO_RESET):
55 */
do_gpio_reset(void)56 static void do_gpio_reset(void)
57 {
58 BUG_ON(reset_gpio == -1);
59
60 /* drive it low */
61 gpio_direction_output(reset_gpio, 0);
62 mdelay(2);
63 /* rising edge or drive high */
64 gpio_set_value(reset_gpio, 1);
65 mdelay(2);
66 /* falling edge */
67 gpio_set_value(reset_gpio, 0);
68
69 /* give it some time */
70 mdelay(10);
71
72 WARN_ON(1);
73 /* fallback */
74 do_hw_reset();
75 }
76
do_hw_reset(void)77 static void do_hw_reset(void)
78 {
79 /* Initialize the watchdog and let it fire */
80 OWER = OWER_WME;
81 OSSR = OSSR_M3;
82 OSMR3 = OSCR + 368640; /* ... in 100 ms */
83 }
84
pxa_restart(char mode,const char * cmd)85 void pxa_restart(char mode, const char *cmd)
86 {
87 local_irq_disable();
88 local_fiq_disable();
89
90 clear_reset_status(RESET_STATUS_ALL);
91
92 switch (mode) {
93 case 's':
94 /* Jump into ROM at address 0 */
95 soft_restart(0);
96 break;
97 case 'g':
98 do_gpio_reset();
99 break;
100 case 'h':
101 default:
102 do_hw_reset();
103 break;
104 }
105 }
106
107