Merge tag 'linux-watchdog-5.15-rc1' of git://www.linux-watchdog.org/linux-watchdog

Pull watchdog updates from Wim Van Sebroeck:

 - add Mediatek MT7986 & MT8195 wdt support

 - add Maxim MAX63xx

 - drop bd70528 support

 - rewrite ixp4xx to watchdog framework

 - constify static struct watchdog_ops for sl28cpld_wdt, mpc8xxx_wdt and
   tqmx86

 - introduce watchdog_dev_suspend/resume

 - several fixes and improvements

* tag 'linux-watchdog-5.15-rc1' of git://www.linux-watchdog.org/linux-watchdog:
  dt-bindings: watchdog: Add compatible for Mediatek MT7986
  watchdog: ixp4xx: Rewrite driver to use core
  watchdog: Start watchdog in watchdog_set_last_hw_keepalive only if appropriate
  watchdog: max63xx_wdt: Add device tree probing
  dt-bindings: watchdog: Add Maxim MAX63xx bindings
  watchdog: mediatek: mt8195: add wdt support
  dt-bindings: reset: mt8195: add toprgu reset-controller header file
  watchdog: tqmx86: Constify static struct watchdog_ops
  watchdog: mpc8xxx_wdt: Constify static struct watchdog_ops
  watchdog: sl28cpld_wdt: Constify static struct watchdog_ops
  watchdog: iTCO_wdt: Fix detection of SMI-off case
  watchdog: bcm2835_wdt: consider system-power-controller property
  watchdog: imx2_wdg: notify wdog core to stop ping worker on suspend
  watchdog: introduce watchdog_dev_suspend/resume
  watchdog: Fix NULL pointer dereference when releasing cdev
  watchdog: only run driver set_pretimeout op if device supports it
  watchdog: bd70528 drop bd70528 support

Documentation/devicetree/bindings/watchdog/maxim,max63xx.yaml

+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/watchdog/maxim,max63xx.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Maxim 63xx Watchdog Timers
+
+allOf:
+  - $ref: "watchdog.yaml#"
+
+maintainers:
+  - Marc Zyngier <maz@kernel.org>
+  - Linus Walleij <linus.walleij@linaro.org>
+
+properties:
+  compatible:
+    oneOf:
+      - const: maxim,max6369
+      - const: maxim,max6370
+      - const: maxim,max6371
+      - const: maxim,max6372
+      - const: maxim,max6373
+      - const: maxim,max6374
+
+  reg:
+    description: This is a 1-byte memory-mapped address
+    maxItems: 1
+
+required:
+  - compatible
+  - reg
+
+unevaluatedProperties: false
+
+examples:
+  - |
+    wdt: watchdog@50000000 {
+        compatible = "maxim,max6369";
+        reg = <0x50000000 0x1>;
+        timeout-sec = <10>;
+    };
+
+...

Documentation/devicetree/bindings/watchdog/mtk-wdt.txt

@@ -13,6 +13,7 @@ Required properties:
 	"mediatek,mt7622-wdt", "mediatek,mt6589-wdt": for MT7622
 	"mediatek,mt7623-wdt", "mediatek,mt6589-wdt": for MT7623
 	"mediatek,mt7629-wdt", "mediatek,mt6589-wdt": for MT7629
+	"mediatek,mt7986-wdt", "mediatek,mt6589-wdt": for MT7986
 	"mediatek,mt8183-wdt": for MT8183
 	"mediatek,mt8516-wdt", "mediatek,mt6589-wdt": for MT8516
 	"mediatek,mt8192-wdt": for MT8192

drivers/watchdog/Kconfig

@@ -168,18 +168,6 @@ 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 BD957XMUF_WATCHDOG
 	tristate "ROHM BD9576MUF and BD9573MUF PMIC Watchdog"
 	depends on MFD_ROHM_BD957XMUF

drivers/watchdog/Makefile

@@ -204,7 +204,6 @@ 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_BD957XMUF_WATCHDOG) += bd9576_wdt.o
 obj-$(CONFIG_DA9052_WATCHDOG) += da9052_wdt.o
 obj-$(CONFIG_DA9055_WATCHDOG) += da9055_wdt.o

drivers/watchdog/bcm2835_wdt.c

@@ -205,9 +205,13 @@ static int bcm2835_wdt_probe(struct platform_device *pdev)
 	if (err)
 		return err;
 
-	if (pm_power_off == NULL) {
-		pm_power_off = bcm2835_power_off;
-		bcm2835_power_off_wdt = wdt;
+	if (of_device_is_system_power_controller(pdev->dev.parent->of_node)) {
+		if (!pm_power_off) {
+			pm_power_off = bcm2835_power_off;
+			bcm2835_power_off_wdt = wdt;
+		} else {
+			dev_info(dev, "Poweroff handler already present!\n");
+		}
 	}
 
 	dev_info(dev, "Broadcom BCM2835 watchdog timer");

drivers/watchdog/bd70528_wdt.c

-// 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
- *
- * @data:	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
- *
- * @data:	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");
-MODULE_ALIAS("platform:bd70528-wdt");

drivers/watchdog/iTCO_wdt.c

@@ -362,7 +362,7 @@ static int iTCO_wdt_set_timeout(struct watchdog_device *wd_dev, unsigned int t)
 	 * Otherwise, the BIOS generally reboots when the SMI triggers.
 	 */
 	if (p->smi_res &&
-	    (SMI_EN(p) & (TCO_EN | GBL_SMI_EN)) != (TCO_EN | GBL_SMI_EN))
+	    (inl(SMI_EN(p)) & (TCO_EN | GBL_SMI_EN)) != (TCO_EN | GBL_SMI_EN))
 		tmrval /= 2;
 
 	/* from the specs: */

drivers/watchdog/imx2_wdt.c

@@ -317,6 +317,7 @@ static int __init imx2_wdt_probe(struct platform_device *pdev)
 	watchdog_set_nowayout(wdog, nowayout);
 	watchdog_set_restart_priority(wdog, 128);
 	watchdog_init_timeout(wdog, timeout, dev);
+	watchdog_stop_ping_on_suspend(wdog);
 
 	if (imx2_wdt_is_running(wdev)) {
 		imx2_wdt_set_timeout(wdog, wdog->timeout);

drivers/watchdog/max63xx_wdt.c

@@ -26,6 +26,7 @@
 #include <linux/spinlock.h>
 #include <linux/io.h>
 #include <linux/slab.h>
+#include <linux/property.h>
 
 #define DEFAULT_HEARTBEAT 60
 #define MAX_HEARTBEAT     60
@@ -99,8 +100,8 @@ static const struct max63xx_timeout max6373_table[] = {
 	{ },
 };
 
-static struct max63xx_timeout *
-max63xx_select_timeout(struct max63xx_timeout *table, int value)
+static const struct max63xx_timeout *
+max63xx_select_timeout(const struct max63xx_timeout *table, int value)
 {
 	while (table->twd) {
 		if (value <= table->twd) {
@@ -202,14 +203,17 @@ static int max63xx_wdt_probe(struct platform_device *pdev)
 {
 	struct device *dev = &pdev->dev;
 	struct max63xx_wdt *wdt;
-	struct max63xx_timeout *table;
+	const struct max63xx_timeout *table;
 	int err;
 
 	wdt = devm_kzalloc(dev, sizeof(*wdt), GFP_KERNEL);
 	if (!wdt)
 		return -ENOMEM;
 
-	table = (struct max63xx_timeout *)pdev->id_entry->driver_data;
+	/* Attempt to use fwnode first */
+	table = device_get_match_data(dev);
+	if (!table)
+		table = (struct max63xx_timeout *)pdev->id_entry->driver_data;
 
 	if (heartbeat < 1 || heartbeat > MAX_HEARTBEAT)
 		heartbeat = DEFAULT_HEARTBEAT;
@@ -255,11 +259,23 @@ static const struct platform_device_id max63xx_id_table[] = {
 };
 MODULE_DEVICE_TABLE(platform, max63xx_id_table);
 
+static const struct of_device_id max63xx_dt_id_table[] = {
+	{ .compatible = "maxim,max6369", .data = max6369_table, },
+	{ .compatible = "maxim,max6370", .data = max6369_table, },
+	{ .compatible = "maxim,max6371", .data = max6371_table, },
+	{ .compatible = "maxim,max6372", .data = max6371_table, },
+	{ .compatible = "maxim,max6373", .data = max6373_table, },
+	{ .compatible = "maxim,max6374", .data = max6373_table, },
+	{ }
+};
+MODULE_DEVICE_TABLE(of, max63xx_dt_id_table);
+
 static struct platform_driver max63xx_wdt_driver = {
 	.probe		= max63xx_wdt_probe,
 	.id_table	= max63xx_id_table,
 	.driver		= {
 		.name	= "max63xx_wdt",
+		.of_match_table = max63xx_dt_id_table,
 	},
 };
 

drivers/watchdog/mpc8xxx_wdt.c

@@ -118,7 +118,7 @@ static struct watchdog_info mpc8xxx_wdt_info = {
 	.identity = "MPC8xxx",
 };
 
-static struct watchdog_ops mpc8xxx_wdt_ops = {
+static const struct watchdog_ops mpc8xxx_wdt_ops = {
 	.owner = THIS_MODULE,
 	.start = mpc8xxx_wdt_start,
 	.ping = mpc8xxx_wdt_ping,

drivers/watchdog/mtk_wdt.c

@@ -12,6 +12,7 @@
 #include <dt-bindings/reset-controller/mt2712-resets.h>
 #include <dt-bindings/reset-controller/mt8183-resets.h>
 #include <dt-bindings/reset-controller/mt8192-resets.h>
+#include <dt-bindings/reset/mt8195-resets.h>
 #include <linux/delay.h>
 #include <linux/err.h>
 #include <linux/init.h>
@@ -82,6 +83,10 @@ static const struct mtk_wdt_data mt8192_data = {
 	.toprgu_sw_rst_num = MT8192_TOPRGU_SW_RST_NUM,
 };
 
+static const struct mtk_wdt_data mt8195_data = {
+	.toprgu_sw_rst_num = MT8195_TOPRGU_SW_RST_NUM,
+};
+
 static int toprgu_reset_update(struct reset_controller_dev *rcdev,
 			       unsigned long id, bool assert)
 {
@@ -408,6 +413,7 @@ static const struct of_device_id mtk_wdt_dt_ids[] = {
 	{ .compatible = "mediatek,mt6589-wdt" },
 	{ .compatible = "mediatek,mt8183-wdt", .data = &mt8183_data },
 	{ .compatible = "mediatek,mt8192-wdt", .data = &mt8192_data },
+	{ .compatible = "mediatek,mt8195-wdt", .data = &mt8195_data },
 	{ /* sentinel */ }
 };
 MODULE_DEVICE_TABLE(of, mtk_wdt_dt_ids);

drivers/watchdog/sl28cpld_wdt.c

@@ -108,7 +108,7 @@ static const struct watchdog_info sl28cpld_wdt_info = {
 	.identity = "sl28cpld watchdog",
 };
 
-static struct watchdog_ops sl28cpld_wdt_ops = {
+static const struct watchdog_ops sl28cpld_wdt_ops = {
 	.owner = THIS_MODULE,
 	.start = sl28cpld_wdt_start,
 	.stop = sl28cpld_wdt_stop,

drivers/watchdog/tqmx86_wdt.c

@@ -62,7 +62,7 @@ static const struct watchdog_info tqmx86_wdt_info = {
 	.identity	= "TQMx86 Watchdog",
 };
 
-static struct watchdog_ops tqmx86_wdt_ops = {
+static const struct watchdog_ops tqmx86_wdt_ops = {
 	.owner		= THIS_MODULE,
 	.start		= tqmx86_wdt_start,
 	.set_timeout	= tqmx86_wdt_set_timeout,

drivers/watchdog/watchdog_core.c

@@ -34,6 +34,7 @@
 #include <linux/idr.h>		/* For ida_* macros */
 #include <linux/err.h>		/* For IS_ERR macros */
 #include <linux/of.h>		/* For of_get_timeout_sec */
+#include <linux/suspend.h>
 
 #include "watchdog_core.h"	/* For watchdog_dev_register/... */
 
@@ -185,6 +186,33 @@ static int watchdog_restart_notifier(struct notifier_block *nb,
 	return NOTIFY_DONE;
 }
 
+static int watchdog_pm_notifier(struct notifier_block *nb, unsigned long mode,
+				void *data)
+{
+	struct watchdog_device *wdd;
+	int ret = 0;
+
+	wdd = container_of(nb, struct watchdog_device, pm_nb);
+
+	switch (mode) {
+	case PM_HIBERNATION_PREPARE:
+	case PM_RESTORE_PREPARE:
+	case PM_SUSPEND_PREPARE:
+		ret = watchdog_dev_suspend(wdd);
+		break;
+	case PM_POST_HIBERNATION:
+	case PM_POST_RESTORE:
+	case PM_POST_SUSPEND:
+		ret = watchdog_dev_resume(wdd);
+		break;
+	}
+
+	if (ret)
+		return NOTIFY_BAD;
+
+	return NOTIFY_DONE;
+}
+
 /**
  * watchdog_set_restart_priority - Change priority of restart handler
  * @wdd: watchdog device
@@ -292,6 +320,15 @@ static int __watchdog_register_device(struct watchdog_device *wdd)
 				wdd->id, ret);
 	}
 
+	if (test_bit(WDOG_NO_PING_ON_SUSPEND, &wdd->status)) {
+		wdd->pm_nb.notifier_call = watchdog_pm_notifier;
+
+		ret = register_pm_notifier(&wdd->pm_nb);
+		if (ret)
+			pr_warn("watchdog%d: Cannot register pm handler (%d)\n",
+				wdd->id, ret);
+	}
+
 	return 0;
 }
 

drivers/watchdog/watchdog_dev.c

@@ -401,7 +401,7 @@ static int watchdog_set_pretimeout(struct watchdog_device *wdd,
 	if (watchdog_pretimeout_invalid(wdd, timeout))
 		return -EINVAL;
 
-	if (wdd->ops->set_pretimeout)
+	if (wdd->ops->set_pretimeout && (wdd->info->options & WDIOF_PRETIMEOUT))
 		err = wdd->ops->set_pretimeout(wdd, timeout);
 	else
 		wdd->pretimeout = timeout;
@@ -1096,6 +1096,8 @@ static void watchdog_cdev_unregister(struct watchdog_device *wdd)
 		watchdog_stop(wdd);
 	}
 
+	watchdog_hrtimer_pretimeout_stop(wdd);
+
 	mutex_lock(&wd_data->lock);
 	wd_data->wdd = NULL;
 	wdd->wd_data = NULL;
@@ -1103,7 +1105,6 @@ static void watchdog_cdev_unregister(struct watchdog_device *wdd)
 
 	hrtimer_cancel(&wd_data->timer);
 	kthread_cancel_work_sync(&wd_data->work);
-	watchdog_hrtimer_pretimeout_stop(wdd);
 
 	put_device(&wd_data->dev);
 }
@@ -1172,7 +1173,10 @@ int watchdog_set_last_hw_keepalive(struct watchdog_device *wdd,
 
 	wd_data->last_hw_keepalive = ktime_sub(now, ms_to_ktime(last_ping_ms));
 
-	return __watchdog_ping(wdd);
+	if (watchdog_hw_running(wdd) && handle_boot_enabled)
+		return __watchdog_ping(wdd);
+
+	return 0;
 }
 EXPORT_SYMBOL_GPL(watchdog_set_last_hw_keepalive);
 
@@ -1227,6 +1231,53 @@ void __exit watchdog_dev_exit(void)
 	kthread_destroy_worker(watchdog_kworker);
 }
 
+int watchdog_dev_suspend(struct watchdog_device *wdd)
+{
+	struct watchdog_core_data *wd_data = wdd->wd_data;
+	int ret = 0;
+
+	if (!wdd->wd_data)
+		return -ENODEV;
+
+	/* ping for the last time before suspend */
+	mutex_lock(&wd_data->lock);
+	if (watchdog_worker_should_ping(wd_data))
+		ret = __watchdog_ping(wd_data->wdd);
+	mutex_unlock(&wd_data->lock);
+
+	if (ret)
+		return ret;
+
+	/*
+	 * make sure that watchdog worker will not kick in when the wdog is
+	 * suspended
+	 */
+	hrtimer_cancel(&wd_data->timer);
+	kthread_cancel_work_sync(&wd_data->work);
+
+	return 0;
+}
+
+int watchdog_dev_resume(struct watchdog_device *wdd)
+{
+	struct watchdog_core_data *wd_data = wdd->wd_data;
+	int ret = 0;
+
+	if (!wdd->wd_data)
+		return -ENODEV;
+
+	/*
+	 * __watchdog_ping will also retrigger hrtimer and therefore restore the
+	 * ping worker if needed.
+	 */
+	mutex_lock(&wd_data->lock);
+	if (watchdog_worker_should_ping(wd_data))
+		ret = __watchdog_ping(wd_data->wdd);
+	mutex_unlock(&wd_data->lock);
+
+	return ret;
+}
+
 module_param(handle_boot_enabled, bool, 0444);
 MODULE_PARM_DESC(handle_boot_enabled,
 	"Watchdog core auto-updates boot enabled watchdogs before userspace takes over (default="

include/dt-bindings/reset/mt8195-resets.h

+/* SPDX-License-Identifier: (GPL-2.0+ OR BSD-3-Clause)*/
+/*
+ * Copyright (c) 2021 MediaTek Inc.
+ * Author: Christine Zhu <christine.zhu@mediatek.com>
+ */
+
+#ifndef _DT_BINDINGS_RESET_CONTROLLER_MT8195
+#define _DT_BINDINGS_RESET_CONTROLLER_MT8195
+
+#define MT8195_TOPRGU_CONN_MCU_SW_RST          0
+#define MT8195_TOPRGU_INFRA_GRST_SW_RST        1
+#define MT8195_TOPRGU_APU_SW_RST               2
+#define MT8195_TOPRGU_INFRA_AO_GRST_SW_RST     6
+#define MT8195_TOPRGU_MMSYS_SW_RST             7
+#define MT8195_TOPRGU_MFG_SW_RST               8
+#define MT8195_TOPRGU_VENC_SW_RST              9
+#define MT8195_TOPRGU_VDEC_SW_RST              10
+#define MT8195_TOPRGU_IMG_SW_RST               11
+#define MT8195_TOPRGU_APMIXEDSYS_SW_RST        13
+#define MT8195_TOPRGU_AUDIO_SW_RST             14
+#define MT8195_TOPRGU_CAMSYS_SW_RST            15
+#define MT8195_TOPRGU_EDPTX_SW_RST             16
+#define MT8195_TOPRGU_ADSPSYS_SW_RST           21
+#define MT8195_TOPRGU_DPTX_SW_RST              22
+#define MT8195_TOPRGU_SPMI_MST_SW_RST          23
+
+#define MT8195_TOPRGU_SW_RST_NUM               16
+
+#endif  /* _DT_BINDINGS_RESET_CONTROLLER_MT8195 */

include/linux/watchdog.h

@@ -107,6 +107,7 @@ struct watchdog_device {
 	unsigned int max_hw_heartbeat_ms;
 	struct notifier_block reboot_nb;
 	struct notifier_block restart_nb;
+	struct notifier_block pm_nb;
 	void *driver_data;
 	struct watchdog_core_data *wd_data;
 	unsigned long status;
@@ -116,6 +117,7 @@ struct watchdog_device {
 #define WDOG_STOP_ON_REBOOT	2	/* Should be stopped on reboot */
 #define WDOG_HW_RUNNING		3	/* True if HW watchdog running */
 #define WDOG_STOP_ON_UNREGISTER	4	/* Should be stopped on unregister */
+#define WDOG_NO_PING_ON_SUSPEND	5	/* Ping worker should be stopped on suspend */
 	struct list_head deferred;
 };
 
@@ -156,6 +158,12 @@ static inline void watchdog_stop_on_unregister(struct watchdog_device *wdd)
 	set_bit(WDOG_STOP_ON_UNREGISTER, &wdd->status);
 }
 
+/* Use the following function to stop the wdog ping worker when suspending */
+static inline void watchdog_stop_ping_on_suspend(struct watchdog_device *wdd)
+{
+	set_bit(WDOG_NO_PING_ON_SUSPEND, &wdd->status);
+}
+
 /* Use the following function to check if a timeout value is invalid */
 static inline bool watchdog_timeout_invalid(struct watchdog_device *wdd, unsigned int t)
 {
@@ -209,6 +217,8 @@ extern int watchdog_init_timeout(struct watchdog_device *wdd,
 				  unsigned int timeout_parm, struct device *dev);
 extern int watchdog_register_device(struct watchdog_device *);
 extern void watchdog_unregister_device(struct watchdog_device *);
+int watchdog_dev_suspend(struct watchdog_device *wdd);
+int watchdog_dev_resume(struct watchdog_device *wdd);
 
 int watchdog_set_last_hw_keepalive(struct watchdog_device *, unsigned int);