Linux 3.11-rc3
[cris-mirror.git] / arch / arm / mach-pxa / reset.c
blob0d5dd646f61fa7d5aa743d4c68f162a2453d00e0
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>
14 #include <mach/regs-ost.h>
15 #include <mach/reset.h>
17 unsigned int reset_status;
18 EXPORT_SYMBOL(reset_status);
20 static void do_hw_reset(void);
22 static int reset_gpio = -1;
24 int init_gpio_reset(int gpio, int output, int level)
26 int rc;
28 rc = gpio_request(gpio, "reset generator");
29 if (rc) {
30 printk(KERN_ERR "Can't request reset_gpio\n");
31 goto out;
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;
44 out:
45 if (!rc)
46 reset_gpio = gpio;
48 return rc;
52 * Trigger GPIO reset.
53 * This covers various types of logic connecting gpio pin
54 * to RESET pins (nRESET or GPIO_RESET):
56 static void do_gpio_reset(void)
58 BUG_ON(reset_gpio == -1);
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);
69 /* give it some time */
70 mdelay(10);
72 WARN_ON(1);
73 /* fallback */
74 do_hw_reset();
77 static void do_hw_reset(void)
79 /* Initialize the watchdog and let it fire */
80 writel_relaxed(OWER_WME, OWER);
81 writel_relaxed(OSSR_M3, OSSR);
82 /* ... in 100 ms */
83 writel_relaxed(readl_relaxed(OSCR) + 368640, OSMR3);
86 void pxa_restart(enum reboot_mode mode, const char *cmd)
88 local_irq_disable();
89 local_fiq_disable();
91 clear_reset_status(RESET_STATUS_ALL);
93 switch (mode) {
94 case REBOOT_SOFT:
95 /* Jump into ROM at address 0 */
96 soft_restart(0);
97 break;
98 case REBOOT_GPIO:
99 do_gpio_reset();
100 break;
101 case REBOOT_HARD:
102 default:
103 do_hw_reset();
104 break;