reset.c

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/*
 * Copyright (C) 2009 Michal Simek <[email protected]>
 * 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)) {
        pr_info("Skipping unavailable RESET gpio %d (%s)\n",
                handle, "reset");
        return;
    }

    ret = gpio_request(handle, "reset");
    if (ret < 0) {
        pr_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);

    pr_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)
{
    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)
        ;
}