Commit 28804c2c authored by Pascal PAILLET-LME's avatar Pascal PAILLET-LME Committed by Lee Jones
Browse files

watchdog: stpmic1: Add STPMIC1 watchdog driver 



The STPMIC1 PMIC embeds a watchdog which is disabled by default. As soon
as the watchdog is started, it must be refreshed periodically otherwise
the PMIC goes off.

Signed-off-by: default avatarPascal Paillet <p.paillet@st.com>
Reviewed-by: default avatarGuenter Roeck <linux@roeck-us.net>
Signed-off-by: default avatarLee Jones <lee.jones@linaro.org>
parent 6e453109

drivers/watchdog/Kconfig

+12 −0
Original line number Diff line number Diff line
@@ -817,6 +817,18 @@ config STM32_WATCHDOG 
	  To compile this driver as a module, choose M here: the

	  module will be called stm32_iwdg.



config STPMIC1_WATCHDOG

	tristate "STPMIC1 PMIC watchdog support"

	depends on MFD_STPMIC1

	select WATCHDOG_CORE

	help

	  Say Y here to include watchdog support embedded into STPMIC1 PMIC.

	  If the watchdog timer expires, stpmic1 will shut down all its power

	  supplies.



	  To compile this driver as a module, choose M here: the

	  module will be called spmic1_wdt.



config UNIPHIER_WATCHDOG

	tristate "UniPhier watchdog support"

	depends on ARCH_UNIPHIER || COMPILE_TEST

drivers/watchdog/Makefile

+1 −0
Original line number Diff line number Diff line
@@ -220,3 +220,4 @@ obj-$(CONFIG_SOFT_WATCHDOG) += softdog.o 
obj-$(CONFIG_MENF21BMC_WATCHDOG) += menf21bmc_wdt.o

obj-$(CONFIG_MENZ069_WATCHDOG) += menz69_wdt.o

obj-$(CONFIG_RAVE_SP_WATCHDOG) += rave-sp-wdt.o

obj-$(CONFIG_STPMIC1_WATCHDOG) += stpmic1_wdt.o

drivers/watchdog/stpmic1_wdt.c

0 → 100644
+139 −0
Original line number Diff line number Diff line 
// SPDX-License-Identifier: GPL-2.0

// Copyright (C) STMicroelectronics 2018

// Author: Pascal Paillet <p.paillet@st.com> for STMicroelectronics.



#include <linux/kernel.h>

#include <linux/mfd/stpmic1.h>

#include <linux/module.h>

#include <linux/platform_device.h>

#include <linux/of.h>

#include <linux/regmap.h>

#include <linux/slab.h>

#include <linux/watchdog.h>



/* WATCHDOG CONTROL REGISTER bit */

#define WDT_START		BIT(0)

#define WDT_PING		BIT(1)

#define WDT_START_MASK		BIT(0)

#define WDT_PING_MASK		BIT(1)

#define WDT_STOP		0



#define PMIC_WDT_MIN_TIMEOUT 1

#define PMIC_WDT_MAX_TIMEOUT 256

#define PMIC_WDT_DEFAULT_TIMEOUT 30



static bool nowayout = WATCHDOG_NOWAYOUT;

module_param(nowayout, bool, 0);

MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default="

		 __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");



struct stpmic1_wdt {

	struct stpmic1 *pmic;

	struct watchdog_device wdtdev;

};



static int pmic_wdt_start(struct watchdog_device *wdd)

{

	struct stpmic1_wdt *wdt = watchdog_get_drvdata(wdd);



	return regmap_update_bits(wdt->pmic->regmap,

				  WCHDG_CR, WDT_START_MASK, WDT_START);

}



static int pmic_wdt_stop(struct watchdog_device *wdd)

{

	struct stpmic1_wdt *wdt = watchdog_get_drvdata(wdd);



	return regmap_update_bits(wdt->pmic->regmap,

				  WCHDG_CR, WDT_START_MASK, WDT_STOP);

}



static int pmic_wdt_ping(struct watchdog_device *wdd)

{

	struct stpmic1_wdt *wdt = watchdog_get_drvdata(wdd);



	return regmap_update_bits(wdt->pmic->regmap,

				  WCHDG_CR, WDT_PING_MASK, WDT_PING);

}



static int pmic_wdt_set_timeout(struct watchdog_device *wdd,

				unsigned int timeout)

{

	struct stpmic1_wdt *wdt = watchdog_get_drvdata(wdd);



	wdd->timeout = timeout;

	/* timeout is equal to register value + 1 */

	return regmap_write(wdt->pmic->regmap, WCHDG_TIMER_CR, timeout - 1);

}



static const struct watchdog_info pmic_watchdog_info = {

	.options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE,

	.identity = "STPMIC1 PMIC Watchdog",

};



static const struct watchdog_ops pmic_watchdog_ops = {

	.owner = THIS_MODULE,

	.start = pmic_wdt_start,

	.stop = pmic_wdt_stop,

	.ping = pmic_wdt_ping,

	.set_timeout = pmic_wdt_set_timeout,

};



static int pmic_wdt_probe(struct platform_device *pdev)

{

	int ret;

	struct stpmic1 *pmic;

	struct stpmic1_wdt *wdt;



	if (!pdev->dev.parent)

		return -EINVAL;



	pmic = dev_get_drvdata(pdev->dev.parent);

	if (!pmic)

		return -EINVAL;



	wdt = devm_kzalloc(&pdev->dev, sizeof(struct stpmic1_wdt), GFP_KERNEL);

	if (!wdt)

		return -ENOMEM;



	wdt->pmic = pmic;



	wdt->wdtdev.info = &pmic_watchdog_info;

	wdt->wdtdev.ops = &pmic_watchdog_ops;

	wdt->wdtdev.min_timeout = PMIC_WDT_MIN_TIMEOUT;

	wdt->wdtdev.max_timeout = PMIC_WDT_MAX_TIMEOUT;

	wdt->wdtdev.parent = &pdev->dev;



	wdt->wdtdev.timeout = PMIC_WDT_DEFAULT_TIMEOUT;

	watchdog_init_timeout(&wdt->wdtdev, 0, &pdev->dev);



	watchdog_set_nowayout(&wdt->wdtdev, nowayout);

	watchdog_set_drvdata(&wdt->wdtdev, wdt);



	ret = devm_watchdog_register_device(&pdev->dev, &wdt->wdtdev);

	if (ret)

		return ret;



	dev_dbg(wdt->pmic->dev, "PMIC Watchdog driver probed\n");

	return 0;

}



static const struct of_device_id of_pmic_wdt_match[] = {

	{ .compatible = "st,stpmic1-wdt" },

	{ },

};



MODULE_DEVICE_TABLE(of, of_pmic_wdt_match);



static struct platform_driver stpmic1_wdt_driver = {

	.probe = pmic_wdt_probe,

	.driver = {

		.name = "stpmic1-wdt",

		.of_match_table = of_pmic_wdt_match,

	},

};

module_platform_driver(stpmic1_wdt_driver);



MODULE_DESCRIPTION("Watchdog driver for STPMIC1 device");

MODULE_AUTHOR("Pascal Paillet <p.paillet@st.com>");

MODULE_LICENSE("GPL v2");