alistair23-linux/arch/microblaze/kernel/reset.c
Stephan Linz 191d5eca24 microblaze: Improve failure handling for GPIO reset
Early exit from of_platform_reset_gpio_probe() if there
was no GPIO reset line configured.

Avoid kernel oops in gpio_system_reset():

[   27.413294] Restarting system.
[   27.415674] Machine restart...
[   27.418787] Oops: kernel access of bad area, sig: 11
[   27.423252]  Registers dump: mode=83871D1C
[   27.427428]  r1=00000000, r2=00000000, r3=FFFFFEF8, r4=00000000
[   27.433310]  r5=C026AED0, r6=00000001, r7=00000068, r8=00000000
[   27.439189]  r9=C3871DAC, r10=000011A5, r11=00000000, r12=0000000A
[   27.445318]  r13=00000000, r14=0000000F, r15=C00029BC, r16=00000000
[   27.451558]  r17=C011DE8C, r18=80000115, r19=0000000F, r20=48184ED8
[   27.457770]  r21=00000000, r22=FFFFFFEA, r23=00000001, r24=FEE1DEAD
[   27.463982]  r25=00000054, r26=1000B1C8, r27=00000000, r28=00000000
[   27.470208]  r29=00000000, r30=00000000, r31=C32D30C0, rPC=C011DE8C
[   27.476433]  msr=000042A2, ear=0000004B, esr=00000872, fsr=342E3732

And remove useless dump_stack from machine_restart.

Signed-off-by: Stephan Linz <linz@li-pro.net>
Signed-off-by: Michal Simek <monstr@monstr.eu>
2012-10-04 14:23:42 +02:00

105 lines
2 KiB
C

/*
* Copyright (C) 2009 Michal Simek <monstr@monstr.eu>
* Copyright (C) 2009 PetaLogix
*
* This file is subject to the terms and conditions of the GNU General Public
* License. See the file "COPYING" in the main directory of this archive
* for more details.
*/
#include <linux/init.h>
#include <linux/of_platform.h>
#include <asm/prom.h>
/* Trigger specific functions */
#ifdef CONFIG_GPIOLIB
#include <linux/of_gpio.h>
static int handle; /* reset pin handle */
static unsigned int reset_val;
void of_platform_reset_gpio_probe(void)
{
int ret;
handle = of_get_named_gpio(of_find_node_by_path("/"),
"hard-reset-gpios", 0);
if (!gpio_is_valid(handle)) {
printk(KERN_INFO "Skipping unavailable RESET gpio %d (%s)\n",
handle, "reset");
return;
}
ret = gpio_request(handle, "reset");
if (ret < 0) {
printk(KERN_INFO "GPIO pin is already allocated\n");
return;
}
/* get current setup value */
reset_val = gpio_get_value(handle);
/* FIXME maybe worth to perform any action */
pr_debug("Reset: Gpio output state: 0x%x\n", reset_val);
/* Setup GPIO as output */
ret = gpio_direction_output(handle, 0);
if (ret < 0)
goto err;
/* Setup output direction */
gpio_set_value(handle, 0);
printk(KERN_INFO "RESET: Registered gpio device: %d, current val: %d\n",
handle, reset_val);
return;
err:
gpio_free(handle);
return;
}
static void gpio_system_reset(void)
{
if (gpio_is_valid(handle))
gpio_set_value(handle, 1 - reset_val);
else
pr_notice("Reset GPIO unavailable - halting!\n");
}
#else
#define gpio_system_reset() do {} while (0)
void of_platform_reset_gpio_probe(void)
{
return;
}
#endif
void machine_restart(char *cmd)
{
printk(KERN_NOTICE "Machine restart...\n");
gpio_system_reset();
while (1)
;
}
void machine_shutdown(void)
{
printk(KERN_NOTICE "Machine shutdown...\n");
while (1)
;
}
void machine_halt(void)
{
printk(KERN_NOTICE "Machine halt...\n");
while (1)
;
}
void machine_power_off(void)
{
printk(KERN_NOTICE "Machine power off...\n");
while (1)
;
}