Commit bbc88a0e authored by Matti Vaittinen's avatar Matti Vaittinen Committed by Wim Van Sebroeck
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watchdog: bd70528: Initial support for ROHM BD70528 watchdog block 



Initial support for watchdog block included in ROHM BD70528
power management IC.

Configurations for low power states are still to be checked.

Signed-off-by: default avatarMatti Vaittinen <matti.vaittinen@fi.rohmeurope.com>
Acked-by: default avatarGuenter Roeck <linux@roeck-us.net>
Signed-off-by: default avatarGuenter Roeck <linux@roeck-us.net>
Signed-off-by: default avatarWim Van Sebroeck <wim@linux-watchdog.org>
parent e347afa5

drivers/watchdog/Kconfig

+12 −0
Original line number Diff line number Diff line
@@ -90,6 +90,18 @@ config SOFT_WATCHDOG_PRETIMEOUT 
	  watchdog. Be aware that governors might affect the watchdog because it

	  is purely software, e.g. the panic governor will stall it!



config BD70528_WATCHDOG

	tristate "ROHM BD70528 PMIC Watchdog"

	depends on MFD_ROHM_BD70528

	select WATCHDOG_CORE

	help

	  Support for the watchdog in the ROHM BD70528 PMIC. Watchdog trigger

	  cause system reset.



	  Say Y here to include support for the ROHM BD70528 watchdog.

	  Alternatively say M to compile the driver as a module,

	  which will be called bd70528_wdt.



config DA9052_WATCHDOG

	tristate "Dialog DA9052 Watchdog"

	depends on PMIC_DA9052 || COMPILE_TEST

drivers/watchdog/Makefile

+1 −0
Original line number Diff line number Diff line
@@ -205,6 +205,7 @@ obj-$(CONFIG_WATCHDOG_SUN4V) += sun4v_wdt.o 
obj-$(CONFIG_XEN_WDT) += xen_wdt.o



# Architecture Independent

obj-$(CONFIG_BD70528_WATCHDOG) += bd70528_wdt.o

obj-$(CONFIG_DA9052_WATCHDOG) += da9052_wdt.o

obj-$(CONFIG_DA9055_WATCHDOG) += da9055_wdt.o

obj-$(CONFIG_DA9062_WATCHDOG) += da9062_wdt.o

drivers/watchdog/bd70528_wdt.c

0 → 100644
+290 −0
Original line number Diff line number Diff line 
// SPDX-License-Identifier: GPL-2.0

// Copyright (C) 2018 ROHM Semiconductors

// ROHM BD70528MWV watchdog driver



#include <linux/bcd.h>

#include <linux/kernel.h>

#include <linux/mfd/rohm-bd70528.h>

#include <linux/module.h>

#include <linux/of.h>

#include <linux/platform_device.h>

#include <linux/regmap.h>

#include <linux/watchdog.h>



/*

 * Max time we can set is 1 hour, 59 minutes and 59 seconds

 * and Minimum time is 1 second

 */

#define WDT_MAX_MS	((2 * 60 * 60 - 1) * 1000)

#define WDT_MIN_MS	1000

#define DEFAULT_TIMEOUT	60



#define WD_CTRL_MAGIC1 0x55

#define WD_CTRL_MAGIC2 0xAA



struct wdtbd70528 {

	struct device *dev;

	struct regmap *regmap;

	struct rohm_regmap_dev *mfd;

	struct watchdog_device wdt;

};



/**

 * bd70528_wdt_set - arm or disarm watchdog timer

 *

 * @data:	device data for the PMIC instance we want to operate on

 * @enable:	new state of WDT. zero to disable, non zero to enable

 * @old_state:	previous state of WDT will be filled here

 *

 * Arm or disarm WDT on BD70528 PMIC. Expected to be called only by

 * BD70528 RTC and BD70528 WDT drivers. The rtc_timer_lock must be taken

 * by calling bd70528_wdt_lock before calling bd70528_wdt_set.

 */

int bd70528_wdt_set(struct rohm_regmap_dev *data, int enable, int *old_state)

{

	int ret, i;

	unsigned int tmp;

	struct bd70528_data *bd70528 = container_of(data, struct bd70528_data,

						 chip);

	u8 wd_ctrl_arr[3] = { WD_CTRL_MAGIC1, WD_CTRL_MAGIC2, 0 };

	u8 *wd_ctrl = &wd_ctrl_arr[2];



	ret = regmap_read(bd70528->chip.regmap, BD70528_REG_WDT_CTRL, &tmp);

	if (ret)

		return ret;



	*wd_ctrl = (u8)tmp;



	if (old_state) {

		if (*wd_ctrl & BD70528_MASK_WDT_EN)

			*old_state |= BD70528_WDT_STATE_BIT;

		else

			*old_state &= ~BD70528_WDT_STATE_BIT;

		if ((!enable) == (!(*old_state & BD70528_WDT_STATE_BIT)))

			return 0;

	}



	if (enable) {

		if (*wd_ctrl & BD70528_MASK_WDT_EN)

			return 0;

		*wd_ctrl |= BD70528_MASK_WDT_EN;

	} else {

		if (*wd_ctrl & BD70528_MASK_WDT_EN)

			*wd_ctrl &= ~BD70528_MASK_WDT_EN;

		else

			return 0;

	}



	for (i = 0; i < 3; i++) {

		ret = regmap_write(bd70528->chip.regmap, BD70528_REG_WDT_CTRL,

				   wd_ctrl_arr[i]);

		if (ret)

			return ret;

	}



	ret = regmap_read(bd70528->chip.regmap, BD70528_REG_WDT_CTRL, &tmp);

	if ((tmp & BD70528_MASK_WDT_EN) != (*wd_ctrl & BD70528_MASK_WDT_EN)) {

		dev_err(bd70528->chip.dev,

			"Watchdog ctrl mismatch (hw) 0x%x (set) 0x%x\n",

			tmp, *wd_ctrl);

		ret = -EIO;

	}



	return ret;

}

EXPORT_SYMBOL(bd70528_wdt_set);



/**

 * bd70528_wdt_lock - take WDT lock

 *

 * @bd70528:	device data for the PMIC instance we want to operate on

 *

 * Lock WDT for arming/disarming in order to avoid race condition caused

 * by WDT state changes initiated by WDT and RTC drivers.

 */

void bd70528_wdt_lock(struct rohm_regmap_dev *data)

{

	struct bd70528_data *bd70528 = container_of(data, struct bd70528_data,

						 chip);



	mutex_lock(&bd70528->rtc_timer_lock);

}

EXPORT_SYMBOL(bd70528_wdt_lock);



/**

 * bd70528_wdt_unlock - unlock WDT lock

 *

 * @bd70528:	device data for the PMIC instance we want to operate on

 *

 * Unlock WDT lock which has previously been taken by call to

 * bd70528_wdt_lock.

 */

void bd70528_wdt_unlock(struct rohm_regmap_dev *data)

{

	struct bd70528_data *bd70528 = container_of(data, struct bd70528_data,

						 chip);



	mutex_unlock(&bd70528->rtc_timer_lock);

}

EXPORT_SYMBOL(bd70528_wdt_unlock);



static int bd70528_wdt_set_locked(struct wdtbd70528 *w, int enable)

{

	return bd70528_wdt_set(w->mfd, enable, NULL);

}



static int bd70528_wdt_change(struct wdtbd70528 *w, int enable)

{

	int ret;



	bd70528_wdt_lock(w->mfd);

	ret = bd70528_wdt_set_locked(w, enable);

	bd70528_wdt_unlock(w->mfd);



	return ret;

}



static int bd70528_wdt_start(struct watchdog_device *wdt)

{

	struct wdtbd70528 *w = watchdog_get_drvdata(wdt);



	dev_dbg(w->dev, "WDT ping...\n");

	return bd70528_wdt_change(w, 1);

}



static int bd70528_wdt_stop(struct watchdog_device *wdt)

{

	struct wdtbd70528 *w = watchdog_get_drvdata(wdt);



	dev_dbg(w->dev, "WDT stopping...\n");

	return bd70528_wdt_change(w, 0);

}



static int bd70528_wdt_set_timeout(struct watchdog_device *wdt,

				   unsigned int timeout)

{

	unsigned int hours;

	unsigned int minutes;

	unsigned int seconds;

	int ret;

	struct wdtbd70528 *w = watchdog_get_drvdata(wdt);



	seconds = timeout;

	hours = timeout / (60 * 60);

	/* Maximum timeout is 1h 59m 59s => hours is 1 or 0 */

	if (hours)

		seconds -= (60 * 60);

	minutes = seconds / 60;

	seconds = seconds % 60;



	bd70528_wdt_lock(w->mfd);



	ret = bd70528_wdt_set_locked(w, 0);

	if (ret)

		goto out_unlock;



	ret = regmap_update_bits(w->regmap, BD70528_REG_WDT_HOUR,

				 BD70528_MASK_WDT_HOUR, hours);

	if (ret) {

		dev_err(w->dev, "Failed to set WDT hours\n");

		goto out_en_unlock;

	}

	ret = regmap_update_bits(w->regmap, BD70528_REG_WDT_MINUTE,

				 BD70528_MASK_WDT_MINUTE, bin2bcd(minutes));

	if (ret) {

		dev_err(w->dev, "Failed to set WDT minutes\n");

		goto out_en_unlock;

	}

	ret = regmap_update_bits(w->regmap, BD70528_REG_WDT_SEC,

				 BD70528_MASK_WDT_SEC, bin2bcd(seconds));

	if (ret)

		dev_err(w->dev, "Failed to set WDT seconds\n");

	else

		dev_dbg(w->dev, "WDT tmo set to %u\n", timeout);



out_en_unlock:

	ret = bd70528_wdt_set_locked(w, 1);

out_unlock:

	bd70528_wdt_unlock(w->mfd);



	return ret;

}



static const struct watchdog_info bd70528_wdt_info = {

	.identity = "bd70528-wdt",

	.options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE,

};



static const struct watchdog_ops bd70528_wdt_ops = {

	.start		= bd70528_wdt_start,

	.stop		= bd70528_wdt_stop,

	.set_timeout	= bd70528_wdt_set_timeout,

};



static int bd70528_wdt_probe(struct platform_device *pdev)

{

	struct rohm_regmap_dev *bd70528;

	struct wdtbd70528 *w;

	int ret;

	unsigned int reg;



	bd70528 = dev_get_drvdata(pdev->dev.parent);

	if (!bd70528) {

		dev_err(&pdev->dev, "No MFD driver data\n");

		return -EINVAL;

	}

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

	if (!w)

		return -ENOMEM;



	w->regmap = bd70528->regmap;

	w->mfd = bd70528;

	w->dev = &pdev->dev;



	w->wdt.info = &bd70528_wdt_info;

	w->wdt.ops =  &bd70528_wdt_ops;

	w->wdt.min_hw_heartbeat_ms = WDT_MIN_MS;

	w->wdt.max_hw_heartbeat_ms = WDT_MAX_MS;

	w->wdt.parent = pdev->dev.parent;

	w->wdt.timeout = DEFAULT_TIMEOUT;

	watchdog_set_drvdata(&w->wdt, w);

	watchdog_init_timeout(&w->wdt, 0, pdev->dev.parent);



	ret = bd70528_wdt_set_timeout(&w->wdt, w->wdt.timeout);

	if (ret) {

		dev_err(&pdev->dev, "Failed to set the watchdog timeout\n");

		return ret;

	}



	bd70528_wdt_lock(w->mfd);

	ret = regmap_read(w->regmap, BD70528_REG_WDT_CTRL, &reg);

	bd70528_wdt_unlock(w->mfd);



	if (ret) {

		dev_err(&pdev->dev, "Failed to get the watchdog state\n");

		return ret;

	}

	if (reg & BD70528_MASK_WDT_EN) {

		dev_dbg(&pdev->dev, "watchdog was running during probe\n");

		set_bit(WDOG_HW_RUNNING, &w->wdt.status);

	}



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

	if (ret < 0)

		dev_err(&pdev->dev, "watchdog registration failed: %d\n", ret);



	return ret;

}



static struct platform_driver bd70528_wdt = {

	.driver = {

		.name = "bd70528-wdt"

	},

	.probe = bd70528_wdt_probe,

};



module_platform_driver(bd70528_wdt);



MODULE_AUTHOR("Matti Vaittinen <matti.vaittinen@fi.rohmeurope.com>");

MODULE_DESCRIPTION("BD70528 watchdog driver");

MODULE_LICENSE("GPL");