power/reset: Add a new driver implementing 'power off by restarting'

* Restart Power Off

Buffalo Linkstation LS-XHL and LS-CHLv2, and other devices power off

by restarting and letting u-boot keep hold of the machine until the

user presses a button.

Required Properties:

- compatible: Should be "restart-poweroff"

	  commands to the microcontroller which controls the main power.

	  Say Y if you have a QNAP NAS.

config POWER_RESET_RESTART

	bool "Restart power-off driver"

	depends on ARM

	help

	  Some boards don't actually have the ability to power off.

	  Instead they restart, and u-boot holds the SoC until the

	  user presses a key. u-boot then boots into Linux.

obj-$(CONFIG_POWER_RESET_GPIO) += gpio-poweroff.o

obj-$(CONFIG_POWER_RESET_QNAP) += qnap-poweroff.o

obj-$(CONFIG_POWER_RESET_RESTART) += restart-poweroff.o

 No newline at end of file

/*

 * Power off by restarting and let u-boot keep hold of the machine

 * until the user presses a button for example.

 *

 * Andrew Lunn <andrew@lunn.ch>

 *

 * Copyright (C) 2012 Andrew Lunn

 *

 * This program is free software; you can redistribute it and/or modify

 * it under the terms of the GNU General Public License version 2 as

 * published by the Free Software Foundation.

 */

#include <linux/kernel.h>

#include <linux/init.h>

#include <linux/platform_device.h>

#include <linux/of_platform.h>

#include <linux/module.h>

#include <asm/system_misc.h>

static void restart_poweroff_do_poweroff(void)

{

	arm_pm_restart('h', NULL);

}

static int __devinit restart_poweroff_probe(struct platform_device *pdev)

{

	/* If a pm_power_off function has already been added, leave it alone */

	if (pm_power_off != NULL) {

		dev_err(&pdev->dev,

			"pm_power_off function already registered");

		return -EBUSY;

	}

	pm_power_off = &restart_poweroff_do_poweroff;

	return 0;

}

static int __devexit restart_poweroff_remove(struct platform_device *pdev)

{

	if (pm_power_off == &restart_poweroff_do_poweroff)

		pm_power_off = NULL;

	return 0;

}

static const struct of_device_id of_restart_poweroff_match[] = {

	{ .compatible = "restart-poweroff", },

	{},

};

static struct platform_driver restart_poweroff_driver = {

	.probe = restart_poweroff_probe,

	.remove = __devexit_p(restart_poweroff_remove),

	.driver = {

		.name = "poweroff-restart",

		.owner = THIS_MODULE,

		.of_match_table = of_restart_poweroff_match,

	},

};

module_platform_driver(restart_poweroff_driver);

MODULE_AUTHOR("Andrew Lunn <andrew@lunn.ch");

MODULE_DESCRIPTION("restart poweroff driver");

MODULE_LICENSE("GPLv2");

MODULE_ALIAS("platform:poweroff-restart");