Commit 80698507 authored by Emil Renner Berthing's avatar Emil Renner Berthing Committed by Sebastian Reichel
Browse files

power: reset: Add TPS65086 restart driver 

The only way to reset the BeagleV Starlight v0.9 board[1] properly is to
tell the PMIC to reset itself which will then assert the external reset
lines of the SoC, USB hub and ethernet phy.

This adds a driver to register a reset handler to do just that.

[1] https://github.com/beagleboard/beaglev-starlight



Signed-off-by: default avatarEmil Renner Berthing <kernel@esmil.dk>
Signed-off-by: default avatarSebastian Reichel <sebastian.reichel@collabora.com>
parent 9c425fa3

drivers/power/reset/Kconfig

+6 −0
Original line number Diff line number Diff line
@@ -204,6 +204,12 @@ config POWER_RESET_ST 
	help

	  Reset support for STMicroelectronics boards.



config POWER_RESET_TPS65086

	bool "TPS65086 restart driver"

	depends on MFD_TPS65086

	help

	  This driver adds support for resetting the TPS65086 PMIC on restart.



config POWER_RESET_VERSATILE

	bool "ARM Versatile family reboot driver"

	depends on ARM

drivers/power/reset/Makefile

+1 −0
Original line number Diff line number Diff line
@@ -23,6 +23,7 @@ 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_TPS65086) += tps65086-restart.o

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

obj-$(CONFIG_POWER_RESET_VEXPRESS) += vexpress-poweroff.o

obj-$(CONFIG_POWER_RESET_XGENE) += xgene-reboot.o

drivers/power/reset/tps65086-restart.c

0 → 100644
+98 −0
Original line number Diff line number Diff line 
// SPDX-License-Identifier: GPL-2.0

/*

 * Copyright (C) 2021 Emil Renner Berthing

 */



#include <linux/mfd/tps65086.h>

#include <linux/mod_devicetable.h>

#include <linux/module.h>

#include <linux/platform_device.h>

#include <linux/reboot.h>



struct tps65086_restart {

	struct notifier_block handler;

	struct device *dev;

};



static int tps65086_restart_notify(struct notifier_block *this,

				   unsigned long mode, void *cmd)

{

	struct tps65086_restart *tps65086_restart =

		container_of(this, struct tps65086_restart, handler);

	struct tps65086 *tps65086 = dev_get_drvdata(tps65086_restart->dev->parent);

	int ret;



	ret = regmap_write(tps65086->regmap, TPS65086_FORCESHUTDN, 1);

	if (ret) {

		dev_err(tps65086_restart->dev, "%s: error writing to tps65086 pmic: %d\n",

			__func__, ret);

		return NOTIFY_DONE;

	}



	/* give it a little time */

	mdelay(200);



	WARN_ON(1);



	return NOTIFY_DONE;

}



static int tps65086_restart_probe(struct platform_device *pdev)

{

	struct tps65086_restart *tps65086_restart;

	int ret;



	tps65086_restart = devm_kzalloc(&pdev->dev, sizeof(*tps65086_restart), GFP_KERNEL);

	if (!tps65086_restart)

		return -ENOMEM;



	platform_set_drvdata(pdev, tps65086_restart);



	tps65086_restart->handler.notifier_call = tps65086_restart_notify;

	tps65086_restart->handler.priority = 192;

	tps65086_restart->dev = &pdev->dev;



	ret = register_restart_handler(&tps65086_restart->handler);

	if (ret) {

		dev_err(&pdev->dev, "%s: cannot register restart handler: %d\n",

			__func__, ret);

		return -ENODEV;

	}



	return 0;

}



static int tps65086_restart_remove(struct platform_device *pdev)

{

	struct tps65086_restart *tps65086_restart = platform_get_drvdata(pdev);

	int ret;



	ret = unregister_restart_handler(&tps65086_restart->handler);

	if (ret) {

		dev_err(&pdev->dev, "%s: cannot unregister restart handler: %d\n",

			__func__, ret);

		return -ENODEV;

	}



	return 0;

}



static const struct platform_device_id tps65086_restart_id_table[] = {

	{ "tps65086-reset", },

	{ /* sentinel */ }

};

MODULE_DEVICE_TABLE(platform, tps65086_restart_id_table);



static struct platform_driver tps65086_restart_driver = {

	.driver = {

		.name = "tps65086-restart",

	},

	.probe = tps65086_restart_probe,

	.remove = tps65086_restart_remove,

	.id_table = tps65086_restart_id_table,

};

module_platform_driver(tps65086_restart_driver);



MODULE_AUTHOR("Emil Renner Berthing <kernel@esmil.dk>");

MODULE_DESCRIPTION("TPS65086 restart driver");

MODULE_LICENSE("GPL v2");