linux-arkmicro/linux/arch/microblaze/kernel/reset.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>

/* Trigger specific functions */
#ifdef CONFIG_GPIOLIB

#include <linux/of_gpio.h>

static int handle; /* reset pin handle */
static unsigned int reset_val;

static int 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)) {
		pr_info("Skipping unavailable RESET gpio %d (%s)\n",
				handle, "reset");
		return -ENODEV;
	}

	ret = gpio_request(handle, "reset");
	if (ret < 0) {
		pr_info("GPIO pin is already allocated\n");
		return ret;
	}

	/* 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);

	pr_info("RESET: Registered gpio device: %d, current val: %d\n",
							handle, reset_val);
	return 0;
err:
	gpio_free(handle);
	return ret;
}
device_initcall(of_platform_reset_gpio_probe);


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
static void gpio_system_reset(void)
{
	pr_notice("No reset GPIO present - halting!\n");
}

void of_platform_reset_gpio_probe(void)
{
	return;
}
#endif

void machine_restart(char *cmd)
{
	pr_notice("Machine restart...\n");
	gpio_system_reset();
	while (1)
		;
}

void machine_shutdown(void)
{
	pr_notice("Machine shutdown...\n");
	while (1)
		;
}

void machine_halt(void)
{
	pr_notice("Machine halt...\n");
	while (1)
		;
}

void machine_power_off(void)
{
	pr_notice("Machine power off...\n");
	while (1)
		;
}