Commit ec66096b authored by Michael Klein's avatar Michael Klein Committed by Sebastian Reichel
Browse files

power: reset: new driver regulator-poweroff 



This driver registers a pm_power_off function to turn off the board
by force-disabling a devicetree-defined regulator.

Signed-off-by: default avatarMichael Klein <michael@fossekall.de>
Signed-off-by: default avatarSebastian Reichel <sebastian.reichel@collabora.com>
parent 36f1de0d

drivers/power/reset/Kconfig

+7 −0
Original line number Diff line number Diff line
@@ -177,6 +177,13 @@ config POWER_RESET_QNAP 


	  Say Y if you have a QNAP NAS.



config POWER_RESET_REGULATOR

	bool "Regulator subsystem power-off driver"

	depends on OF && REGULATOR

	help

	  This driver supports turning off your board by disabling a

	  power regulator defined in the devicetree.



config POWER_RESET_RESTART

	bool "Restart power-off driver"

	help

drivers/power/reset/Makefile

+1 −0
Original line number Diff line number Diff line
@@ -19,6 +19,7 @@ obj-$(CONFIG_POWER_RESET_OCELOT_RESET) += ocelot-reset.o 
obj-$(CONFIG_POWER_RESET_PIIX4_POWEROFF) += piix4-poweroff.o

obj-$(CONFIG_POWER_RESET_LTC2952) += ltc2952-poweroff.o

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

obj-$(CONFIG_POWER_RESET_REGULATOR) += regulator-poweroff.o

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

obj-$(CONFIG_POWER_RESET_ST) += st-poweroff.o

obj-$(CONFIG_POWER_RESET_VERSATILE) += arm-versatile-reboot.o

drivers/power/reset/regulator-poweroff.c

0 → 100644
+82 −0
Original line number Diff line number Diff line 
// SPDX-License-Identifier: GPL-2.0-only

/*

 * Force-disables a regulator to power down a device

 *

 * Michael Klein <michael@fossekall.de>

 *

 * Copyright (C) 2020 Michael Klein

 *

 * Based on the gpio-poweroff driver.

 */

#include <linux/delay.h>

#include <linux/module.h>

#include <linux/of.h>

#include <linux/platform_device.h>

#include <linux/pm.h>

#include <linux/regulator/consumer.h>



#define TIMEOUT_MS 3000



/*

 * Hold configuration here, cannot be more than one instance of the driver

 * since pm_power_off itself is global.

 */

static struct regulator *cpu_regulator;



static void regulator_poweroff_do_poweroff(void)

{

	if (cpu_regulator && regulator_is_enabled(cpu_regulator))

		regulator_force_disable(cpu_regulator);



	/* give it some time */

	mdelay(TIMEOUT_MS);



	WARN_ON(1);

}



static int regulator_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,

			"%s: pm_power_off function already registered\n",

			__func__);

		return -EBUSY;

	}



	cpu_regulator = devm_regulator_get(&pdev->dev, "cpu");

	if (IS_ERR(cpu_regulator))

		return PTR_ERR(cpu_regulator);



	pm_power_off = &regulator_poweroff_do_poweroff;

	return 0;

}



static int regulator_poweroff_remove(__maybe_unused struct platform_device *pdev)

{

	if (pm_power_off == &regulator_poweroff_do_poweroff)

		pm_power_off = NULL;



	return 0;

}



static const struct of_device_id of_regulator_poweroff_match[] = {

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

	{},

};



static struct platform_driver regulator_poweroff_driver = {

	.probe = regulator_poweroff_probe,

	.remove = regulator_poweroff_remove,

	.driver = {

		.name = "poweroff-regulator",

		.of_match_table = of_regulator_poweroff_match,

	},

};



module_platform_driver(regulator_poweroff_driver);



MODULE_AUTHOR("Michael Klein <michael@fossekall.de>");

MODULE_DESCRIPTION("Regulator poweroff driver");

MODULE_LICENSE("GPL v2");

MODULE_ALIAS("platform:poweroff-regulator");