blob: 01e9d643394a9d28160a98ccaee118761d8fb75f [file] [log] [blame]
Dmitry Baryshkov75f10b42008-05-22 16:20:18 +01001/*
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>
Russell Kingfced80c2008-09-06 12:10:45 +010010#include <linux/io.h>
Dmitry Baryshkov75f10b42008-05-22 16:20:18 +010011#include <asm/proc-fns.h>
12
Eric Miao5bf3df32009-01-20 11:04:16 +080013#include <mach/regs-ost.h>
Russell Kingafd2fc02008-08-07 11:05:25 +010014#include <mach/reset.h>
Dmitry Baryshkov75f10b42008-05-22 16:20:18 +010015
Eric Miao04fef222008-07-29 14:26:00 +080016unsigned int reset_status;
17EXPORT_SYMBOL(reset_status);
Dmitry Baryshkov75f10b42008-05-22 16:20:18 +010018
19static void do_hw_reset(void);
20
21static int reset_gpio = -1;
22
Daniel Ribeiro216e3b72009-05-05 22:43:18 -030023int init_gpio_reset(int gpio, int output, int level)
Dmitry Baryshkov75f10b42008-05-22 16:20:18 +010024{
25 int rc;
26
27 rc = gpio_request(gpio, "reset generator");
28 if (rc) {
29 printk(KERN_ERR "Can't request reset_gpio\n");
30 goto out;
31 }
32
Dmitry Baryshkov69fc7ee2008-10-09 16:58:13 +010033 if (output)
Daniel Ribeiro216e3b72009-05-05 22:43:18 -030034 rc = gpio_direction_output(gpio, level);
Dmitry Baryshkov69fc7ee2008-10-09 16:58:13 +010035 else
36 rc = gpio_direction_input(gpio);
Dmitry Baryshkov75f10b42008-05-22 16:20:18 +010037 if (rc) {
Dmitry Baryshkov69fc7ee2008-10-09 16:58:13 +010038 printk(KERN_ERR "Can't configure reset_gpio\n");
Dmitry Baryshkov75f10b42008-05-22 16:20:18 +010039 gpio_free(gpio);
40 goto out;
41 }
42
43out:
44 if (!rc)
45 reset_gpio = gpio;
46
47 return rc;
48}
49
50/*
51 * Trigger GPIO reset.
52 * This covers various types of logic connecting gpio pin
53 * to RESET pins (nRESET or GPIO_RESET):
54 */
55static void do_gpio_reset(void)
56{
57 BUG_ON(reset_gpio == -1);
58
59 /* drive it low */
60 gpio_direction_output(reset_gpio, 0);
61 mdelay(2);
62 /* rising edge or drive high */
63 gpio_set_value(reset_gpio, 1);
64 mdelay(2);
65 /* falling edge */
66 gpio_set_value(reset_gpio, 0);
67
68 /* give it some time */
69 mdelay(10);
70
71 WARN_ON(1);
72 /* fallback */
73 do_hw_reset();
74}
75
76static void do_hw_reset(void)
77{
78 /* Initialize the watchdog and let it fire */
79 OWER = OWER_WME;
80 OSSR = OSSR_M3;
81 OSMR3 = OSCR + 368640; /* ... in 100 ms */
82}
83
Russell Kingbe093be2009-03-19 16:20:24 +000084void arch_reset(char mode, const char *cmd)
Dmitry Baryshkov75f10b42008-05-22 16:20:18 +010085{
Eric Miao04fef222008-07-29 14:26:00 +080086 clear_reset_status(RESET_STATUS_ALL);
Dmitry Baryshkov75f10b42008-05-22 16:20:18 +010087
88 switch (mode) {
89 case 's':
90 /* Jump into ROM at address 0 */
91 cpu_reset(0);
92 break;
Dmitry Baryshkov75f10b42008-05-22 16:20:18 +010093 case 'g':
94 do_gpio_reset();
95 break;
Jaya Kumar28105fd2008-11-11 12:17:05 +010096 case 'h':
97 default:
98 do_hw_reset();
99 break;
Dmitry Baryshkov75f10b42008-05-22 16:20:18 +0100100 }
101}
102