Merge tag 'linux-watchdog-5.17-rc1' of git://www.linux-watchdog.org/linux-watchdog

Pull watchdog updates from Wim Van Sebroeck:

 - New device support:
     - Watchdog Timer driver for RZ/G2L
     - Realtek Otto watchdog timer
     - Apple SoC watchdog driver
     - Fintek F81966

 - Remove BCM63XX_WDT after support for this SoC was added to
   BCM7038_WDT

 - Improvements of the BCM7038_WDT and s3c2410_wdt code

 - Several other fixes and improvements

* tag 'linux-watchdog-5.17-rc1' of git://www.linux-watchdog.org/linux-watchdog: (38 commits)
  watchdog: msc313e: Check if the WDT was running at boot
  watchdog: Add Apple SoC watchdog driver
  dt-bindings: watchdog: Add SM6350 and SM8250 compatible
  watchdog: s3c2410: Fix getting the optional clock
  watchdog: s3c2410: Use platform_get_irq() to get the interrupt
  dt-bindings: watchdog: atmel: Add missing 'interrupts' property
  watchdog: mtk_wdt: use platform_get_irq_optional
  watchdog: Add Watchdog Timer driver for RZ/G2L
  dt-bindings: watchdog: renesas,wdt: Add support for RZ/G2L
  watchdog: da9063: Add hard dependency on I2C
  watchdog: Add Realtek Otto watchdog timer
  dt-bindings: watchdog: Realtek Otto WDT binding
  watchdog: s3c2410: Add Exynos850 support
  watchdog: da9063: use atomic safe i2c transfer in reset handler
  watchdog: davinci: Use div64_ul instead of do_div
  watchdog: Remove BCM63XX_WDT
  MIPS: BCM63XX: Provide platform data to watchdog device
  watchdog: bcm7038_wdt: Add platform device id for bcm63xx-wdt
  watchdog: Allow building BCM7038_WDT for BCM63XX
  watchdog: bcm7038_wdt: Support platform data configuration
  ...

14 files changed, 1228 insertions, 448 deletions

diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig
index 1dc86eb1361a..c8fa79da23b3 100644
--- a/drivers/watchdog/Kconfig
+++ b/drivers/watchdog/Kconfig
@@ -207,6 +207,7 @@ config DA9055_WATCHDOG
 config DA9063_WATCHDOG
 	tristate "Dialog DA9063 Watchdog"
 	depends on MFD_DA9063 || COMPILE_TEST
+	depends on I2C
 	select WATCHDOG_CORE
 	help
 	  Support for the watchdog in the DA9063 PMIC.
@@ -680,10 +681,10 @@ config MAX77620_WATCHDOG
 	depends on MFD_MAX77620 || COMPILE_TEST
 	select WATCHDOG_CORE
 	help
-	 This is the driver for the Max77620 watchdog timer.
-	 Say 'Y' here to enable the watchdog timer support for
-	 MAX77620 chips. To compile this driver as a module,
-	 choose M here: the module will be called max77620_wdt.
+	  This is the driver for the Max77620 watchdog timer.
+	  Say 'Y' here to enable the watchdog timer support for
+	  MAX77620 chips. To compile this driver as a module,
+	  choose M here: the module will be called max77620_wdt.
 
 config IMX2_WDT
 	tristate "IMX2+ Watchdog"
@@ -822,6 +823,7 @@ config MESON_WATCHDOG
 config MEDIATEK_WATCHDOG
 	tristate "Mediatek SoCs watchdog support"
 	depends on ARCH_MEDIATEK || COMPILE_TEST
+	default ARCH_MEDIATEK
 	select WATCHDOG_CORE
 	select RESET_CONTROLLER
 	help
@@ -881,6 +883,14 @@ config RENESAS_RZAWDT
 	  This driver adds watchdog support for the integrated watchdogs in the
 	  Renesas RZ/A SoCs. These watchdogs can be used to reset a system.
 
+config RENESAS_RZG2LWDT
+	tristate "Renesas RZ/G2L WDT Watchdog"
+	depends on ARCH_RENESAS || COMPILE_TEST
+	select WATCHDOG_CORE
+	help
+	  This driver adds watchdog support for the integrated watchdogs in the
+	  Renesas RZ/G2L SoCs. These watchdogs can be used to reset a system.
+
 config ASPEED_WATCHDOG
 	tristate "Aspeed BMC watchdog support"
 	depends on ARCH_ASPEED || COMPILE_TEST
@@ -940,6 +950,19 @@ config RTD119X_WATCHDOG
 	  Say Y here to include support for the watchdog timer in
 	  Realtek RTD1295 SoCs.
 
+config REALTEK_OTTO_WDT
+	tristate "Realtek Otto MIPS watchdog support"
+	depends on MACH_REALTEK_RTL || COMPILE_TEST
+	depends on COMMON_CLK
+	select WATCHDOG_CORE
+	default MACH_REALTEK_RTL
+	help
+	  Say Y here to include support for the watchdog timer on Realtek
+	  RTL838x, RTL839x, RTL930x SoCs. This watchdog has pretimeout
+	  notifications and system reset on timeout.
+
+	  When built as a module this will be called realtek_otto_wdt.
+
 config SPRD_WATCHDOG
 	tristate "Spreadtrum watchdog support"
 	depends on ARCH_SPRD || COMPILE_TEST
@@ -976,6 +999,18 @@ config MSC313E_WATCHDOG
 	  To compile this driver as a module, choose M here: the
 	  module will be called msc313e_wdt.
 
+config APPLE_WATCHDOG
+	tristate "Apple SoC watchdog"
+	depends on ARCH_APPLE || COMPILE_TEST
+	select WATCHDOG_CORE
+	help
+	  Say Y here to include support for the Watchdog found in Apple
+	  SoCs such as the M1. Next to the common watchdog features this
+	  driver is also required in order to reboot these SoCs.
+
+	  To compile this driver as a module, choose M here: the
+	  module will be called apple_wdt.
+
 # X86 (i386 + ia64 + x86_64) Architecture
 
 config ACQUIRE_WDT
@@ -1440,26 +1475,26 @@ config TQMX86_WDT
 	depends on X86
 	select WATCHDOG_CORE
 	help
-	This is the driver for the hardware watchdog timer in the TQMX86 IO
-	controller found on some of their ComExpress Modules.
+	  This is the driver for the hardware watchdog timer in the TQMX86 IO
+	  controller found on some of their ComExpress Modules.
 
-	To compile this driver as a module, choose M here; the module
-	will be called tqmx86_wdt.
+	  To compile this driver as a module, choose M here; the module
+	  will be called tqmx86_wdt.
 
-	Most people will say N.
+	  Most people will say N.
 
 config VIA_WDT
 	tristate "VIA Watchdog Timer"
 	depends on X86 && PCI
 	select WATCHDOG_CORE
 	help
-	This is the driver for the hardware watchdog timer on VIA
-	southbridge chipset CX700, VX800/VX820 or VX855/VX875.
+	  This is the driver for the hardware watchdog timer on VIA
+	  southbridge chipset CX700, VX800/VX820 or VX855/VX875.
 
-	To compile this driver as a module, choose M here; the module
-	will be called via_wdt.
+	  To compile this driver as a module, choose M here; the module
+	  will be called via_wdt.
 
-	Most people will say N.
+	  Most people will say N.
 
 config W83627HF_WDT
 	tristate "Watchdog timer for W83627HF/W83627DHG and compatibles"
@@ -1707,16 +1742,6 @@ config OCTEON_WDT
 	  from the first interrupt, it is then only poked when the
 	  device is written.
 
-config BCM63XX_WDT
-	tristate "Broadcom BCM63xx hardware watchdog"
-	depends on BCM63XX
-	help
-	  Watchdog driver for the built in watchdog hardware in Broadcom
-	  BCM63xx SoC.
-
-	  To compile this driver as a loadable module, choose M here.
-	  The module will be called bcm63xx_wdt.
-
 config BCM2835_WDT
 	tristate "Broadcom BCM2835 hardware watchdog"
 	depends on ARCH_BCM2835 || (OF && COMPILE_TEST)
@@ -1751,15 +1776,16 @@ config BCM_KONA_WDT_DEBUG
 	  If in doubt, say 'N'.
 
 config BCM7038_WDT
-	tristate "BCM7038 Watchdog"
+	tristate "BCM63xx/BCM7038 Watchdog"
 	select WATCHDOG_CORE
 	depends on HAS_IOMEM
-	depends on ARCH_BRCMSTB || BMIPS_GENERIC || COMPILE_TEST
+	depends on ARCH_BRCMSTB || BMIPS_GENERIC || BCM63XX || COMPILE_TEST
 	help
-	 Watchdog driver for the built-in hardware in Broadcom 7038 and
-	 later SoCs used in set-top boxes.  BCM7038 was made public
-	 during the 2004 CES, and since then, many Broadcom chips use this
-	 watchdog block, including some cable modem chips.
+	  Watchdog driver for the built-in hardware in Broadcom 7038 and
+	  later SoCs used in set-top boxes.  BCM7038 was made public
+	  during the 2004 CES, and since then, many Broadcom chips use this
+	  watchdog block, including some cable modem chips and DSL (63xx)
+	  chips.
 
 config IMGPDC_WDT
 	tristate "Imagination Technologies PDC Watchdog Timer"
@@ -2120,12 +2146,12 @@ config KEEMBAY_WATCHDOG
 	depends on ARCH_KEEMBAY || (ARM64 && COMPILE_TEST)
 	select WATCHDOG_CORE
 	help
-	 This option enable support for an In-secure watchdog timer driver for
-	 Intel Keem Bay SoC. This WDT has a 32 bit timer and decrements in every
-	 count unit. An interrupt will be triggered, when the count crosses
-	 the threshold configured in the register.
+	  This option enable support for an In-secure watchdog timer driver for
+	  Intel Keem Bay SoC. This WDT has a 32 bit timer and decrements in every
+	  count unit. An interrupt will be triggered, when the count crosses
+	  the threshold configured in the register.
 
-	 To compile this driver as a module, choose M here: the
-	 module will be called keembay_wdt.
+	  To compile this driver as a module, choose M here: the
+	  module will be called keembay_wdt.
 
 endif # WATCHDOG
diff --git a/drivers/watchdog/Makefile b/drivers/watchdog/Makefile
index 31b931846e32..f7da867e8782 100644
--- a/drivers/watchdog/Makefile
+++ b/drivers/watchdog/Makefile
@@ -84,6 +84,7 @@ obj-$(CONFIG_LPC18XX_WATCHDOG) += lpc18xx_wdt.o
 obj-$(CONFIG_BCM7038_WDT) += bcm7038_wdt.o
 obj-$(CONFIG_RENESAS_WDT) += renesas_wdt.o
 obj-$(CONFIG_RENESAS_RZAWDT) += rza_wdt.o
+obj-$(CONFIG_RENESAS_RZG2LWDT) += rzg2l_wdt.o
 obj-$(CONFIG_ASPEED_WATCHDOG) += aspeed_wdt.o
 obj-$(CONFIG_STM32_WATCHDOG) += stm32_iwdg.o
 obj-$(CONFIG_UNIPHIER_WATCHDOG) += uniphier_wdt.o
@@ -93,6 +94,7 @@ obj-$(CONFIG_PM8916_WATCHDOG) += pm8916_wdt.o
 obj-$(CONFIG_ARM_SMC_WATCHDOG) += arm_smc_wdt.o
 obj-$(CONFIG_VISCONTI_WATCHDOG) += visconti_wdt.o
 obj-$(CONFIG_MSC313E_WATCHDOG) += msc313e_wdt.o
+obj-$(CONFIG_APPLE_WATCHDOG) += apple_wdt.o
 
 # X86 (i386 + ia64 + x86_64) Architecture
 obj-$(CONFIG_ACQUIRE_WDT) += acquirewdt.o
@@ -154,7 +156,6 @@ obj-$(CONFIG_XILINX_WATCHDOG) += of_xilinx_wdt.o
 # MIPS Architecture
 obj-$(CONFIG_ATH79_WDT) += ath79_wdt.o
 obj-$(CONFIG_BCM47XX_WDT) += bcm47xx_wdt.o
-obj-$(CONFIG_BCM63XX_WDT) += bcm63xx_wdt.o
 obj-$(CONFIG_RC32434_WDT) += rc32434_wdt.o
 obj-$(CONFIG_INDYDOG) += indydog.o
 obj-$(CONFIG_JZ4740_WDT) += jz4740_wdt.o
@@ -171,6 +172,7 @@ obj-$(CONFIG_IMGPDC_WDT) += imgpdc_wdt.o
 obj-$(CONFIG_MT7621_WDT) += mt7621_wdt.o
 obj-$(CONFIG_PIC32_WDT) += pic32-wdt.o
 obj-$(CONFIG_PIC32_DMT) += pic32-dmt.o
+obj-$(CONFIG_REALTEK_OTTO_WDT) += realtek_otto_wdt.o
 
 # PARISC Architecture
 
diff --git a/drivers/watchdog/apple_wdt.c b/drivers/watchdog/apple_wdt.c
new file mode 100644
index 000000000000..16aca21f13d6
--- /dev/null
+++ b/drivers/watchdog/apple_wdt.c
@@ -0,0 +1,226 @@
+// SPDX-License-Identifier: GPL-2.0-only OR MIT
+/*
+ * Apple SoC Watchdog driver
+ *
+ * Copyright (C) The Asahi Linux Contributors
+ */
+
+#include <linux/bits.h>
+#include <linux/clk.h>
+#include <linux/delay.h>
+#include <linux/io.h>
+#include <linux/kernel.h>
+#include <linux/limits.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/watchdog.h>
+
+/*
+ * Apple Watchdog MMIO registers
+ *
+ * This HW block has three separate watchdogs. WD0 resets the machine
+ * to recovery mode and is not very useful for us. WD1 and WD2 trigger a normal
+ * machine reset. WD0 additionally supports a configurable interrupt.
+ * This information can be used to implement pretimeout support at a later time.
+ *
+ * APPLE_WDT_WDx_CUR_TIME is a simple counter incremented for each tick of the
+ * reference clock. It can also be overwritten to any value.
+ * Whenever APPLE_WDT_CTRL_RESET_EN is set in APPLE_WDT_WDx_CTRL and
+ * APPLE_WDT_WDx_CUR_TIME >= APPLE_WDT_WDx_BITE_TIME the entire machine is
+ * reset.
+ * Whenever APPLE_WDT_CTRL_IRQ_EN is set and APPLE_WDTx_WD1_CUR_TIME >=
+ * APPLE_WDTx_WD1_BARK_TIME an interrupt is triggered and
+ * APPLE_WDT_CTRL_IRQ_STATUS is set. The interrupt can be cleared by writing
+ * 1 to APPLE_WDT_CTRL_IRQ_STATUS.
+ */
+#define APPLE_WDT_WD0_CUR_TIME		0x00
+#define APPLE_WDT_WD0_BITE_TIME		0x04
+#define APPLE_WDT_WD0_BARK_TIME		0x08
+#define APPLE_WDT_WD0_CTRL		0x0c
+
+#define APPLE_WDT_WD1_CUR_TIME		0x10
+#define APPLE_WDT_WD1_BITE_TIME		0x14
+#define APPLE_WDT_WD1_CTRL		0x1c
+
+#define APPLE_WDT_WD2_CUR_TIME		0x20
+#define APPLE_WDT_WD2_BITE_TIME		0x24
+#define APPLE_WDT_WD2_CTRL		0x2c
+
+#define APPLE_WDT_CTRL_IRQ_EN		BIT(0)
+#define APPLE_WDT_CTRL_IRQ_STATUS	BIT(1)
+#define APPLE_WDT_CTRL_RESET_EN		BIT(2)
+
+#define APPLE_WDT_TIMEOUT_DEFAULT	30
+
+struct apple_wdt {
+	struct watchdog_device wdd;
+	void __iomem *regs;
+	unsigned long clk_rate;
+};
+
+static struct apple_wdt *to_apple_wdt(struct watchdog_device *wdd)
+{
+	return container_of(wdd, struct apple_wdt, wdd);
+}
+
+static int apple_wdt_start(struct watchdog_device *wdd)
+{
+	struct apple_wdt *wdt = to_apple_wdt(wdd);
+
+	writel_relaxed(0, wdt->regs + APPLE_WDT_WD1_CUR_TIME);
+	writel_relaxed(APPLE_WDT_CTRL_RESET_EN, wdt->regs + APPLE_WDT_WD1_CTRL);
+
+	return 0;
+}
+
+static int apple_wdt_stop(struct watchdog_device *wdd)
+{
+	struct apple_wdt *wdt = to_apple_wdt(wdd);
+
+	writel_relaxed(0, wdt->regs + APPLE_WDT_WD1_CTRL);
+
+	return 0;
+}
+
+static int apple_wdt_ping(struct watchdog_device *wdd)
+{
+	struct apple_wdt *wdt = to_apple_wdt(wdd);
+
+	writel_relaxed(0, wdt->regs + APPLE_WDT_WD1_CUR_TIME);
+
+	return 0;
+}
+
+static int apple_wdt_set_timeout(struct watchdog_device *wdd, unsigned int s)
+{
+	struct apple_wdt *wdt = to_apple_wdt(wdd);
+
+	writel_relaxed(0, wdt->regs + APPLE_WDT_WD1_CUR_TIME);
+	writel_relaxed(wdt->clk_rate * s, wdt->regs + APPLE_WDT_WD1_BITE_TIME);
+
+	wdd->timeout = s;
+
+	return 0;
+}
+
+static unsigned int apple_wdt_get_timeleft(struct watchdog_device *wdd)
+{
+	struct apple_wdt *wdt = to_apple_wdt(wdd);
+	u32 cur_time, reset_time;
+
+	cur_time = readl_relaxed(wdt->regs + APPLE_WDT_WD1_CUR_TIME);
+	reset_time = readl_relaxed(wdt->regs + APPLE_WDT_WD1_BITE_TIME);
+
+	return (reset_time - cur_time) / wdt->clk_rate;
+}
+
+static int apple_wdt_restart(struct watchdog_device *wdd, unsigned long mode,
+			     void *cmd)
+{
+	struct apple_wdt *wdt = to_apple_wdt(wdd);
+
+	writel_relaxed(APPLE_WDT_CTRL_RESET_EN, wdt->regs + APPLE_WDT_WD1_CTRL);
+	writel_relaxed(0, wdt->regs + APPLE_WDT_WD1_BITE_TIME);
+	writel_relaxed(0, wdt->regs + APPLE_WDT_WD1_CUR_TIME);
+
+	/*
+	 * Flush writes and then wait for the SoC to reset. Even though the
+	 * reset is queued almost immediately experiments have shown that it
+	 * can take up to ~20-25ms until the SoC is actually reset. Just wait
+	 * 50ms here to be safe.
+	 */
+	(void)readl_relaxed(wdt->regs + APPLE_WDT_WD1_CUR_TIME);
+	mdelay(50);
+
+	return 0;
+}
+
+static void apple_wdt_clk_disable_unprepare(void *data)
+{
+	clk_disable_unprepare(data);
+}
+
+static struct watchdog_ops apple_wdt_ops = {
+	.owner = THIS_MODULE,
+	.start = apple_wdt_start,
+	.stop = apple_wdt_stop,
+	.ping = apple_wdt_ping,
+	.set_timeout = apple_wdt_set_timeout,
+	.get_timeleft = apple_wdt_get_timeleft,
+	.restart = apple_wdt_restart,
+};
+
+static struct watchdog_info apple_wdt_info = {
+	.identity = "Apple SoC Watchdog",
+	.options = WDIOF_MAGICCLOSE | WDIOF_KEEPALIVEPING | WDIOF_SETTIMEOUT,
+};
+
+static int apple_wdt_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct apple_wdt *wdt;
+	struct clk *clk;
+	u32 wdt_ctrl;
+	int ret;
+
+	wdt = devm_kzalloc(dev, sizeof(*wdt), GFP_KERNEL);
+	if (!wdt)
+		return -ENOMEM;
+
+	wdt->regs = devm_platform_ioremap_resource(pdev, 0);
+	if (IS_ERR(wdt->regs))
+		return PTR_ERR(wdt->regs);
+
+	clk = devm_clk_get(dev, NULL);
+	if (IS_ERR(clk))
+		return PTR_ERR(clk);
+
+	ret = clk_prepare_enable(clk);
+	if (ret)
+		return ret;
+
+	ret = devm_add_action_or_reset(dev, apple_wdt_clk_disable_unprepare,
+				       clk);
+	if (ret)
+		return ret;
+
+	wdt->clk_rate = clk_get_rate(clk);
+	if (!wdt->clk_rate)
+		return -EINVAL;
+
+	wdt->wdd.ops = &apple_wdt_ops;
+	wdt->wdd.info = &apple_wdt_info;
+	wdt->wdd.max_timeout = U32_MAX / wdt->clk_rate;
+	wdt->wdd.timeout = APPLE_WDT_TIMEOUT_DEFAULT;
+
+	wdt_ctrl = readl_relaxed(wdt->regs + APPLE_WDT_WD1_CTRL);
+	if (wdt_ctrl & APPLE_WDT_CTRL_RESET_EN)
+		set_bit(WDOG_HW_RUNNING, &wdt->wdd.status);
+
+	watchdog_init_timeout(&wdt->wdd, 0, dev);
+	apple_wdt_set_timeout(&wdt->wdd, wdt->wdd.timeout);
+	watchdog_stop_on_unregister(&wdt->wdd);
+	watchdog_set_restart_priority(&wdt->wdd, 128);
+
+	return devm_watchdog_register_device(dev, &wdt->wdd);
+}
+
+static const struct of_device_id apple_wdt_of_match[] = {
+	{ .compatible = "apple,wdt" },
+	{},
+};
+MODULE_DEVICE_TABLE(of, apple_wdt_of_match);
+
+static struct platform_driver apple_wdt_driver = {
+	.driver = {
+		.name = "apple-watchdog",
+		.of_match_table = apple_wdt_of_match,
+	},
+	.probe = apple_wdt_probe,
+};
+module_platform_driver(apple_wdt_driver);
+
+MODULE_DESCRIPTION("Apple SoC watchdog driver");
+MODULE_AUTHOR("Sven Peter <sven@svenpeter.dev>");
+MODULE_LICENSE("Dual MIT/GPL");
diff --git a/drivers/watchdog/bcm63xx_wdt.c b/drivers/watchdog/bcm63xx_wdt.c
deleted file mode 100644
index 56cc262571a5..000000000000
--- a/drivers/watchdog/bcm63xx_wdt.c
+++ /dev/null
@@ -1,317 +0,0 @@
-// SPDX-License-Identifier: GPL-2.0+
-/*
- *  Broadcom BCM63xx SoC watchdog driver
- *
- *  Copyright (C) 2007, Miguel Gaio <miguel.gaio@efixo.com>
- *  Copyright (C) 2008, Florian Fainelli <florian@openwrt.org>
- *
- */
-
-#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
-
-#include <linux/bitops.h>
-#include <linux/errno.h>
-#include <linux/fs.h>
-#include <linux/io.h>
-#include <linux/kernel.h>
-#include <linux/miscdevice.h>
-#include <linux/module.h>
-#include <linux/moduleparam.h>
-#include <linux/types.h>
-#include <linux/uaccess.h>
-#include <linux/watchdog.h>
-#include <linux/timer.h>
-#include <linux/jiffies.h>
-#include <linux/interrupt.h>
-#include <linux/ptrace.h>
-#include <linux/resource.h>
-#include <linux/platform_device.h>
-
-#include <bcm63xx_cpu.h>
-#include <bcm63xx_io.h>
-#include <bcm63xx_regs.h>
-#include <bcm63xx_timer.h>
-
-#define PFX KBUILD_MODNAME
-
-#define WDT_HZ		50000000 /* Fclk */
-#define WDT_DEFAULT_TIME	30      /* seconds */
-#define WDT_MAX_TIME		256     /* seconds */
-
-static struct {
-	void __iomem *regs;
-	struct timer_list timer;
-	unsigned long inuse;
-	atomic_t ticks;
-} bcm63xx_wdt_device;
-
-static int expect_close;
-
-static int wdt_time = WDT_DEFAULT_TIME;
-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) ")");
-
-/* HW functions */
-static void bcm63xx_wdt_hw_start(void)
-{
-	bcm_writel(0xfffffffe, bcm63xx_wdt_device.regs + WDT_DEFVAL_REG);
-	bcm_writel(WDT_START_1, bcm63xx_wdt_device.regs + WDT_CTL_REG);
-	bcm_writel(WDT_START_2, bcm63xx_wdt_device.regs + WDT_CTL_REG);
-}
-
-static void bcm63xx_wdt_hw_stop(void)
-{
-	bcm_writel(WDT_STOP_1, bcm63xx_wdt_device.regs + WDT_CTL_REG);
-	bcm_writel(WDT_STOP_2, bcm63xx_wdt_device.regs + WDT_CTL_REG);
-}
-
-static void bcm63xx_wdt_isr(void *data)
-{
-	struct pt_regs *regs = get_irq_regs();
-
-	die(PFX " fire", regs);
-}
-
-static void bcm63xx_timer_tick(struct timer_list *unused)
-{
-	if (!atomic_dec_and_test(&bcm63xx_wdt_device.ticks)) {
-		bcm63xx_wdt_hw_start();
-		mod_timer(&bcm63xx_wdt_device.timer, jiffies + HZ);
-	} else
-		pr_crit("watchdog will restart system\n");
-}
-
-static void bcm63xx_wdt_pet(void)
-{
-	atomic_set(&bcm63xx_wdt_device.ticks, wdt_time);
-}
-
-static void bcm63xx_wdt_start(void)
-{
-	bcm63xx_wdt_pet();
-	bcm63xx_timer_tick(0);
-}
-
-static void bcm63xx_wdt_pause(void)
-{
-	del_timer_sync(&bcm63xx_wdt_device.timer);
-	bcm63xx_wdt_hw_stop();
-}
-
-static int bcm63xx_wdt_settimeout(int new_time)
-{
-	if ((new_time <= 0) || (new_time > WDT_MAX_TIME))
-		return -EINVAL;
-
-	wdt_time = new_time;
-
-	return 0;
-}
-
-static int bcm63xx_wdt_open(struct inode *inode, struct file *file)
-{
-	if (test_and_set_bit(0, &bcm63xx_wdt_device.inuse))
-		return -EBUSY;
-
-	bcm63xx_wdt_start();
-	return stream_open(inode, file);
-}
-
-static int bcm63xx_wdt_release(struct inode *inode, struct file *file)
-{
-	if (expect_close == 42)
-		bcm63xx_wdt_pause();
-	else {
-		pr_crit("Unexpected close, not stopping watchdog!\n");
-		bcm63xx_wdt_start();
-	}
-	clear_bit(0, &bcm63xx_wdt_device.inuse);
-	expect_close = 0;
-	return 0;
-}
-
-static ssize_t bcm63xx_wdt_write(struct file *file, const char *data,
-				size_t len, loff_t *ppos)
-{
-	if (len) {
-		if (!nowayout) {
-			size_t i;
-
-			/* In case it was set long ago */
-			expect_close = 0;
-
-			for (i = 0; i != len; i++) {
-				char c;
-				if (get_user(c, data + i))
-					return -EFAULT;
-				if (c == 'V')
-					expect_close = 42;
-			}
-		}
-		bcm63xx_wdt_pet();
-	}
-	return len;
-}
-
-static struct watchdog_info bcm63xx_wdt_info = {
-	.identity       = PFX,
-	.options        = WDIOF_SETTIMEOUT |
-				WDIOF_KEEPALIVEPING |
-				WDIOF_MAGICCLOSE,
-};
-
-
-static long bcm63xx_wdt_ioctl(struct file *file, unsigned int cmd,
-				unsigned long arg)
-{
-	void __user *argp = (void __user *)arg;
-	int __user *p = argp;
-	int new_value, retval = -EINVAL;
-
-	switch (cmd) {
-	case WDIOC_GETSUPPORT:
-		return copy_to_user(argp, &bcm63xx_wdt_info,
-			sizeof(bcm63xx_wdt_info)) ? -EFAULT : 0;
-
-	case WDIOC_GETSTATUS:
-	case WDIOC_GETBOOTSTATUS:
-		return put_user(0, p);
-
-	case WDIOC_SETOPTIONS:
-		if (get_user(new_value, p))
-			return -EFAULT;
-
-		if (new_value & WDIOS_DISABLECARD) {
-			bcm63xx_wdt_pause();
-			retval = 0;
-		}
-		if (new_value & WDIOS_ENABLECARD) {
-			bcm63xx_wdt_start();
-			retval = 0;
-		}
-
-		return retval;
-
-	case WDIOC_KEEPALIVE:
-		bcm63xx_wdt_pet();
-		return 0;
-
-	case WDIOC_SETTIMEOUT:
-		if (get_user(new_value, p))
-			return -EFAULT;
-
-		if (bcm63xx_wdt_settimeout(new_value))
-			return -EINVAL;
-
-		bcm63xx_wdt_pet();
-
-		fallthrough;
-
-	case WDIOC_GETTIMEOUT:
-		return put_user(wdt_time, p);
-
-	default:
-		return -ENOTTY;
-
-	}
-}
-
-static const struct file_operations bcm63xx_wdt_fops = {
-	.owner		= THIS_MODULE,
-	.llseek		= no_llseek,
-	.write		= bcm63xx_wdt_write,
-	.unlocked_ioctl	= bcm63xx_wdt_ioctl,
-	.compat_ioctl	= compat_ptr_ioctl,
-	.open		= bcm63xx_wdt_open,
-	.release	= bcm63xx_wdt_release,
-};
-
-static struct miscdevice bcm63xx_wdt_miscdev = {
-	.minor	= WATCHDOG_MINOR,
-	.name	= "watchdog",
-	.fops	= &bcm63xx_wdt_fops,
-};
-
-
-static int bcm63xx_wdt_probe(struct platform_device *pdev)
-{
-	int ret;
-	struct resource *r;
-
-	timer_setup(&bcm63xx_wdt_device.timer, bcm63xx_timer_tick, 0);
-
-	r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
-	if (!r) {
-		dev_err(&pdev->dev, "failed to get resources\n");
-		return -ENODEV;
-	}
-
-	bcm63xx_wdt_device.regs = devm_ioremap(&pdev->dev, r->start,
-							resource_size(r));
-	if (!bcm63xx_wdt_device.regs) {
-		dev_err(&pdev->dev, "failed to remap I/O resources\n");
-		return -ENXIO;
-	}
-
-	ret = bcm63xx_timer_register(TIMER_WDT_ID, bcm63xx_wdt_isr, NULL);
-	if (ret < 0) {
-		dev_err(&pdev->dev, "failed to register wdt timer isr\n");
-		return ret;
-	}
-
-	if (bcm63xx_wdt_settimeout(wdt_time)) {
-		bcm63xx_wdt_settimeout(WDT_DEFAULT_TIME);
-		dev_info(&pdev->dev,
-			": wdt_time value must be 1 <= wdt_time <= 256, using %d\n",
-			wdt_time);
-	}
-
-	ret = misc_register(&bcm63xx_wdt_miscdev);
-	if (ret < 0) {
-		dev_err(&pdev->dev, "failed to register watchdog device\n");
-		goto unregister_timer;
-	}
-
-	dev_info(&pdev->dev, " started, timer margin: %d sec\n",
-						WDT_DEFAULT_TIME);
-
-	return 0;
-
-unregister_timer:
-	bcm63xx_timer_unregister(TIMER_WDT_ID);
-	return ret;
-}
-
-static int bcm63xx_wdt_remove(struct platform_device *pdev)
-{
-	if (!nowayout)
-		bcm63xx_wdt_pause();
-
-	misc_deregister(&bcm63xx_wdt_miscdev);
-	bcm63xx_timer_unregister(TIMER_WDT_ID);
-	return 0;
-}
-
-static void bcm63xx_wdt_shutdown(struct platform_device *pdev)
-{
-	bcm63xx_wdt_pause();
-}
-
-static struct platform_driver bcm63xx_wdt_driver = {
-	.probe	= bcm63xx_wdt_probe,
-	.remove = bcm63xx_wdt_remove,
-	.shutdown = bcm63xx_wdt_shutdown,
-	.driver = {
-		.name = "bcm63xx-wdt",
-	}
-};
-
-module_platform_driver(bcm63xx_wdt_driver);
-
-MODULE_AUTHOR("Miguel Gaio <miguel.gaio@efixo.com>");
-MODULE_AUTHOR("Florian Fainelli <florian@openwrt.org>");
-MODULE_DESCRIPTION("Driver for the Broadcom BCM63xx SoC watchdog");
-MODULE_LICENSE("GPL");
-MODULE_ALIAS("platform:bcm63xx-wdt");
diff --git a/drivers/watchdog/bcm7038_wdt.c b/drivers/watchdog/bcm7038_wdt.c
index acaaa0005d5b..8656a137e9a4 100644
--- a/drivers/watchdog/bcm7038_wdt.c
+++ b/drivers/watchdog/bcm7038_wdt.c
@@ -10,6 +10,7 @@
 #include <linux/module.h>
 #include <linux/of.h>
 #include <linux/platform_device.h>
+#include <linux/platform_data/bcm7038_wdt.h>
 #include <linux/pm.h>
 #include <linux/watchdog.h>
 
@@ -133,8 +134,10 @@ static void bcm7038_clk_disable_unprepare(void *data)
 
 static int bcm7038_wdt_probe(struct platform_device *pdev)
 {
+	struct bcm7038_wdt_platform_data *pdata = pdev->dev.platform_data;
 	struct device *dev = &pdev->dev;
 	struct bcm7038_watchdog *wdt;
+	const char *clk_name = NULL;
 	int err;
 
 	wdt = devm_kzalloc(dev, sizeof(*wdt), GFP_KERNEL);
@@ -147,7 +150,10 @@ static int bcm7038_wdt_probe(struct platform_device *pdev)
 	if (IS_ERR(wdt->base))
 		return PTR_ERR(wdt->base);
 
-	wdt->clk = devm_clk_get(dev, NULL);
+	if (pdata && pdata->clk_name)
+		clk_name = pdata->clk_name;
+
+	wdt->clk = devm_clk_get(dev, clk_name);
 	/* If unable to get clock, use default frequency */
 	if (!IS_ERR(wdt->clk)) {
 		err = clk_prepare_enable(wdt->clk);
@@ -217,8 +223,15 @@ static const struct of_device_id bcm7038_wdt_match[] = {
 };
 MODULE_DEVICE_TABLE(of, bcm7038_wdt_match);
 
+static const struct platform_device_id bcm7038_wdt_devtype[] = {
+	{ .name = "bcm63xx-wdt" },
+	{ /* sentinel */ },
+};
+MODULE_DEVICE_TABLE(platform, bcm7038_wdt_devtype);
+
 static struct platform_driver bcm7038_wdt_driver = {
 	.probe		= bcm7038_wdt_probe,
+	.id_table	= bcm7038_wdt_devtype,
 	.driver		= {
 		.name		= "bcm7038-wdt",
 		.of_match_table	= bcm7038_wdt_match,
diff --git a/drivers/watchdog/da9063_wdt.c b/drivers/watchdog/da9063_wdt.c
index d79ce64e26a9..9adad1862bbd 100644
--- a/drivers/watchdog/da9063_wdt.c
+++ b/drivers/watchdog/da9063_wdt.c
@@ -14,6 +14,7 @@
 #include <linux/platform_device.h>
 #include <linux/uaccess.h>
 #include <linux/slab.h>
+#include <linux/i2c.h>
 #include <linux/delay.h>
 #include <linux/mfd/da9063/registers.h>
 #include <linux/mfd/da9063/core.h>
@@ -169,14 +170,19 @@ static int da9063_wdt_restart(struct watchdog_device *wdd, unsigned long action,
 			      void *data)
 {
 	struct da9063 *da9063 = watchdog_get_drvdata(wdd);
+	struct i2c_client *client = to_i2c_client(da9063->dev);
 	int ret;
 
-	ret = regmap_write(da9063->regmap, DA9063_REG_CONTROL_F,
-			   DA9063_SHUTDOWN);
-	if (ret)
+	/* Don't use regmap because it is not atomic safe */
+	ret = i2c_smbus_write_byte_data(client, DA9063_REG_CONTROL_F,
+					DA9063_SHUTDOWN);
+	if (ret < 0)
 		dev_alert(da9063->dev, "Failed to shutdown (err = %d)\n",
 			  ret);
 
+	/* wait for reset to assert... */
+	mdelay(500);
+
 	return ret;
 }
 
diff --git a/drivers/watchdog/davinci_wdt.c b/drivers/watchdog/davinci_wdt.c
index e6eaba6bae5b..584a56893b81 100644
--- a/drivers/watchdog/davinci_wdt.c
+++ b/drivers/watchdog/davinci_wdt.c
@@ -134,7 +134,7 @@ static unsigned int davinci_wdt_get_timeleft(struct watchdog_device *wdd)
 	timer_counter = ioread32(davinci_wdt->base + TIM12);
 	timer_counter |= ((u64)ioread32(davinci_wdt->base + TIM34) << 32);
 
-	do_div(timer_counter, freq);
+	timer_counter = div64_ul(timer_counter, freq);
 
 	return wdd->timeout - timer_counter;
 }
diff --git a/drivers/watchdog/f71808e_wdt.c b/drivers/watchdog/f71808e_wdt.c
index ee90c5f943f9..7f59c680de25 100644
--- a/drivers/watchdog/f71808e_wdt.c
+++ b/drivers/watchdog/f71808e_wdt.c
@@ -49,6 +49,7 @@
 #define SIO_F81803_ID		0x1210	/* Chipset ID */
 #define SIO_F81865_ID		0x0704	/* Chipset ID */
 #define SIO_F81866_ID		0x1010	/* Chipset ID */
+#define SIO_F81966_ID		0x1502  /* F81804 chipset ID, same for f81966 */
 
 #define F71808FG_REG_WDO_CONF		0xf0
 #define F71808FG_REG_WDT_CONF		0xf5
@@ -105,7 +106,7 @@ MODULE_PARM_DESC(start_withtimeout, "Start watchdog timer on module load with"
 	" given initial timeout. Zero (default) disables this feature.");
 
 enum chips { f71808fg, f71858fg, f71862fg, f71868, f71869, f71882fg, f71889fg,
-	     f81803, f81865, f81866};
+	     f81803, f81865, f81866, f81966};
 
 static const char * const fintek_wdt_names[] = {
 	"f71808fg",
@@ -118,6 +119,7 @@ static const char * const fintek_wdt_names[] = {
 	"f81803",
 	"f81865",
 	"f81866",
+	"f81966"
 };
 
 /* Super-I/O Function prototypes */
@@ -347,6 +349,7 @@ static int fintek_wdt_start(struct watchdog_device *wdd)
 		break;
 
 	case f81866:
+	case f81966:
 		/*
 		 * GPIO1 Control Register when 27h BIT3:2 = 01 & BIT0 = 0.
 		 * The PIN 70(GPIO15/WDTRST) is controlled by 2Ch:
@@ -373,7 +376,7 @@ static int fintek_wdt_start(struct watchdog_device *wdd)
 	superio_select(wd->sioaddr, SIO_F71808FG_LD_WDT);
 	superio_set_bit(wd->sioaddr, SIO_REG_ENABLE, 0);
 
-	if (wd->type == f81865 || wd->type == f81866)
+	if (wd->type == f81865 || wd->type == f81866 || wd->type == f81966)
 		superio_set_bit(wd->sioaddr, F81865_REG_WDO_CONF,
 				F81865_FLAG_WDOUT_EN);
 	else
@@ -580,6 +583,9 @@ static int __init fintek_wdt_find(int sioaddr)
 	case SIO_F81866_ID:
 		type = f81866;
 		break;
+	case SIO_F81966_ID:
+		type = f81966;
+		break;
 	default:
 		pr_info("Unrecognized Fintek device: %04x\n",
 			(unsigned int)devid);
diff --git a/drivers/watchdog/meson_gxbb_wdt.c b/drivers/watchdog/meson_gxbb_wdt.c
index 945f5e65db57..d3c9e2f6e63b 100644
--- a/drivers/watchdog/meson_gxbb_wdt.c
+++ b/drivers/watchdog/meson_gxbb_wdt.c
@@ -198,7 +198,6 @@ static int meson_gxbb_wdt_probe(struct platform_device *pdev)
 
 	meson_gxbb_wdt_set_timeout(&data->wdt_dev, data->wdt_dev.timeout);
 
-	watchdog_stop_on_reboot(&data->wdt_dev);
 	return devm_watchdog_register_device(dev, &data->wdt_dev);
 }
 
diff --git a/drivers/watchdog/msc313e_wdt.c b/drivers/watchdog/msc313e_wdt.c
index 0d497aa0fb7d..90171431fc59 100644
--- a/drivers/watchdog/msc313e_wdt.c
+++ b/drivers/watchdog/msc313e_wdt.c
@@ -120,6 +120,10 @@ static int msc313e_wdt_probe(struct platform_device *pdev)
 	priv->wdev.max_timeout = U32_MAX / clk_get_rate(priv->clk);
 	priv->wdev.timeout = MSC313E_WDT_DEFAULT_TIMEOUT;
 
+	/* If the period is non-zero the WDT is running */
+	if (readw(priv->base + REG_WDT_MAX_PRD_L) | (readw(priv->base + REG_WDT_MAX_PRD_H) << 16))
+		set_bit(WDOG_HW_RUNNING, &priv->wdev.status);
+
 	watchdog_set_drvdata(&priv->wdev, priv);
 
 	watchdog_init_timeout(&priv->wdev, timeout, dev);
diff --git a/drivers/watchdog/mtk_wdt.c b/drivers/watchdog/mtk_wdt.c
index 543cf38bd04e..4577a76dd464 100644
--- a/drivers/watchdog/mtk_wdt.c
+++ b/drivers/watchdog/mtk_wdt.c
@@ -339,7 +339,7 @@ static int mtk_wdt_probe(struct platform_device *pdev)
 	if (IS_ERR(mtk_wdt->wdt_base))
 		return PTR_ERR(mtk_wdt->wdt_base);
 
-	irq = platform_get_irq(pdev, 0);
+	irq = platform_get_irq_optional(pdev, 0);
 	if (irq > 0) {
 		err = devm_request_irq(&pdev->dev, irq, mtk_wdt_isr, 0, "wdt_bark",
 				       &mtk_wdt->wdt_dev);
diff --git a/drivers/watchdog/realtek_otto_wdt.c b/drivers/watchdog/realtek_otto_wdt.c
new file mode 100644
index 000000000000..60058a0c3ec4
--- /dev/null
+++ b/drivers/watchdog/realtek_otto_wdt.c
@@ -0,0 +1,384 @@
+// SPDX-License-Identifier: GPL-2.0-only
+
+/*
+ * Realtek Otto MIPS platform watchdog
+ *
+ * Watchdog timer that will reset the system after timeout, using the selected
+ * reset mode.
+ *
+ * Counter scaling and timeouts:
+ * - Base prescale of (2 << 25), providing tick duration T_0: 168ms @ 200MHz
+ * - PRESCALE: logarithmic prescaler adding a factor of {1, 2, 4, 8}
+ * - Phase 1: Times out after (PHASE1 + 1) × PRESCALE × T_0
+ *   Generates an interrupt, WDT cannot be stopped after phase 1
+ * - Phase 2: starts after phase 1, times out after (PHASE2 + 1) × PRESCALE × T_0
+ *   Resets the system according to RST_MODE
+ */
+
+#include <linux/bits.h>
+#include <linux/bitfield.h>
+#include <linux/clk.h>
+#include <linux/delay.h>
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/math.h>
+#include <linux/minmax.h>
+#include <linux/module.h>
+#include <linux/mod_devicetable.h>
+#include <linux/platform_device.h>
+#include <linux/property.h>
+#include <linux/reboot.h>
+#include <linux/watchdog.h>
+
+#define OTTO_WDT_REG_CNTR		0x0
+#define OTTO_WDT_CNTR_PING		BIT(31)
+
+#define OTTO_WDT_REG_INTR		0x4
+#define OTTO_WDT_INTR_PHASE_1		BIT(31)
+#define OTTO_WDT_INTR_PHASE_2		BIT(30)
+
+#define OTTO_WDT_REG_CTRL		0x8
+#define OTTO_WDT_CTRL_ENABLE		BIT(31)
+#define OTTO_WDT_CTRL_PRESCALE		GENMASK(30, 29)
+#define OTTO_WDT_CTRL_PHASE1		GENMASK(26, 22)
+#define OTTO_WDT_CTRL_PHASE2		GENMASK(19, 15)
+#define OTTO_WDT_CTRL_RST_MODE		GENMASK(1, 0)
+#define OTTO_WDT_MODE_SOC		0
+#define OTTO_WDT_MODE_CPU		1
+#define OTTO_WDT_MODE_SOFTWARE		2
+#define OTTO_WDT_CTRL_DEFAULT		OTTO_WDT_MODE_CPU
+
+#define OTTO_WDT_PRESCALE_MAX		3
+
+/*
+ * One higher than the max values contained in PHASE{1,2}, since a value of 0
+ * corresponds to one tick.
+ */
+#define OTTO_WDT_PHASE_TICKS_MAX	32
+
+/*
+ * The maximum reset delay is actually 2×32 ticks, but that would require large
+ * pretimeout values for timeouts longer than 32 ticks. Limit the maximum timeout
+ * to 32 + 1 to ensure small pretimeout values can be configured as expected.
+ */
+#define OTTO_WDT_TIMEOUT_TICKS_MAX	(OTTO_WDT_PHASE_TICKS_MAX + 1)
+
+struct otto_wdt_ctrl {
+	struct watchdog_device wdev;
+	struct device *dev;
+	void __iomem *base;
+	unsigned int clk_rate_khz;
+	int irq_phase1;
+};
+
+static int otto_wdt_start(struct watchdog_device *wdev)
+{
+	struct otto_wdt_ctrl *ctrl = watchdog_get_drvdata(wdev);
+	u32 v;
+
+	v = ioread32(ctrl->base + OTTO_WDT_REG_CTRL);
+	v |= OTTO_WDT_CTRL_ENABLE;
+	iowrite32(v, ctrl->base + OTTO_WDT_REG_CTRL);
+
+	return 0;
+}
+
+static int otto_wdt_stop(struct watchdog_device *wdev)
+{
+	struct otto_wdt_ctrl *ctrl = watchdog_get_drvdata(wdev);
+	u32 v;
+
+	v = ioread32(ctrl->base + OTTO_WDT_REG_CTRL);
+	v &= ~OTTO_WDT_CTRL_ENABLE;
+	iowrite32(v, ctrl->base + OTTO_WDT_REG_CTRL);
+
+	return 0;
+}
+
+static int otto_wdt_ping(struct watchdog_device *wdev)
+{
+	struct otto_wdt_ctrl *ctrl = watchdog_get_drvdata(wdev);
+
+	iowrite32(OTTO_WDT_CNTR_PING, ctrl->base + OTTO_WDT_REG_CNTR);
+
+	return 0;
+}
+
+static int otto_wdt_tick_ms(struct otto_wdt_ctrl *ctrl, int prescale)
+{
+	return DIV_ROUND_CLOSEST(1 << (25 + prescale), ctrl->clk_rate_khz);
+}
+
+/*
+ * The timer asserts the PHASE1/PHASE2 IRQs when the number of ticks exceeds
+ * the value stored in those fields. This means each phase will run for at least
+ * one tick, so small values need to be clamped to correctly reflect the timeout.
+ */
+static inline unsigned int div_round_ticks(unsigned int val, unsigned int tick_duration,
+		unsigned int min_ticks)
+{
+	return max(min_ticks, DIV_ROUND_UP(val, tick_duration));
+}
+
+static int otto_wdt_determine_timeouts(struct watchdog_device *wdev, unsigned int timeout,
+		unsigned int pretimeout)
+{
+	struct otto_wdt_ctrl *ctrl = watchdog_get_drvdata(wdev);
+	unsigned int pretimeout_ms = pretimeout * 1000;
+	unsigned int timeout_ms = timeout * 1000;
+	unsigned int prescale_next = 0;
+	unsigned int phase1_ticks;
+	unsigned int phase2_ticks;
+	unsigned int total_ticks;
+	unsigned int prescale;
+	unsigned int tick_ms;
+	u32 v;
+
+	do {
+		prescale = prescale_next;
+		if (prescale > OTTO_WDT_PRESCALE_MAX)
+			return -EINVAL;
+
+		tick_ms = otto_wdt_tick_ms(ctrl, prescale);
+		total_ticks = div_round_ticks(timeout_ms, tick_ms, 2);
+		phase1_ticks = div_round_ticks(timeout_ms - pretimeout_ms, tick_ms, 1);
+		phase2_ticks = total_ticks - phase1_ticks;
+
+		prescale_next++;
+	} while (phase1_ticks > OTTO_WDT_PHASE_TICKS_MAX
+		|| phase2_ticks > OTTO_WDT_PHASE_TICKS_MAX);
+
+	v = ioread32(ctrl->base + OTTO_WDT_REG_CTRL);
+
+	v &= ~(OTTO_WDT_CTRL_PRESCALE | OTTO_WDT_CTRL_PHASE1 | OTTO_WDT_CTRL_PHASE2);
+	v |= FIELD_PREP(OTTO_WDT_CTRL_PHASE1, phase1_ticks - 1);
+	v |= FIELD_PREP(OTTO_WDT_CTRL_PHASE2, phase2_ticks - 1);
+	v |= FIELD_PREP(OTTO_WDT_CTRL_PRESCALE, prescale);
+
+	iowrite32(v, ctrl->base + OTTO_WDT_REG_CTRL);
+
+	timeout_ms = total_ticks * tick_ms;
+	ctrl->wdev.timeout = timeout_ms / 1000;
+
+	pretimeout_ms = phase2_ticks * tick_ms;
+	ctrl->wdev.pretimeout = pretimeout_ms / 1000;
+
+	return 0;
+}
+
+static int otto_wdt_set_timeout(struct watchdog_device *wdev, unsigned int val)
+{
+	return otto_wdt_determine_timeouts(wdev, val, min(wdev->pretimeout, val - 1));
+}
+
+static int otto_wdt_set_pretimeout(struct watchdog_device *wdev, unsigned int val)
+{
+	return otto_wdt_determine_timeouts(wdev, wdev->timeout, val);
+}
+
+static int otto_wdt_restart(struct watchdog_device *wdev, unsigned long reboot_mode,
+		void *data)
+{
+	struct otto_wdt_ctrl *ctrl = watchdog_get_drvdata(wdev);
+	u32 reset_mode;
+	u32 v;
+
+	disable_irq(ctrl->irq_phase1);
+
+	switch (reboot_mode) {
+	case REBOOT_SOFT:
+		reset_mode = OTTO_WDT_MODE_SOFTWARE;
+		break;
+	case REBOOT_WARM:
+		reset_mode = OTTO_WDT_MODE_CPU;
+		break;
+	default:
+		reset_mode = OTTO_WDT_MODE_SOC;
+		break;
+	}
+
+	/* Configure for shortest timeout and wait for reset to occur */
+	v = FIELD_PREP(OTTO_WDT_CTRL_RST_MODE, reset_mode) | OTTO_WDT_CTRL_ENABLE;
+	iowrite32(v, ctrl->base + OTTO_WDT_REG_CTRL);
+
+	mdelay(3 * otto_wdt_tick_ms(ctrl, 0));
+
+	return 0;
+}
+
+static irqreturn_t otto_wdt_phase1_isr(int irq, void *dev_id)
+{
+	struct otto_wdt_ctrl *ctrl = dev_id;
+
+	iowrite32(OTTO_WDT_INTR_PHASE_1, ctrl->base + OTTO_WDT_REG_INTR);
+	dev_crit(ctrl->dev, "phase 1 timeout\n");
+	watchdog_notify_pretimeout(&ctrl->wdev);
+
+	return IRQ_HANDLED;
+}
+
+static const struct watchdog_ops otto_wdt_ops = {
+	.owner = THIS_MODULE,
+	.start = otto_wdt_start,
+	.stop = otto_wdt_stop,
+	.ping = otto_wdt_ping,
+	.set_timeout = otto_wdt_set_timeout,
+	.set_pretimeout = otto_wdt_set_pretimeout,
+	.restart = otto_wdt_restart,
+};
+
+static const struct watchdog_info otto_wdt_info = {
+	.identity = "Realtek Otto watchdog timer",
+	.options = WDIOF_KEEPALIVEPING |
+		WDIOF_MAGICCLOSE |
+		WDIOF_SETTIMEOUT |
+		WDIOF_PRETIMEOUT,
+};
+
+static void otto_wdt_clock_action(void *data)
+{
+	clk_disable_unprepare(data);
+}
+
+static int otto_wdt_probe_clk(struct otto_wdt_ctrl *ctrl)
+{
+	struct clk *clk = devm_clk_get(ctrl->dev, NULL);
+	int ret;
+
+	if (IS_ERR(clk))
+		return dev_err_probe(ctrl->dev, PTR_ERR(clk), "Failed to get clock\n");
+
+	ret = clk_prepare_enable(clk);
+	if (ret)
+		return dev_err_probe(ctrl->dev, ret, "Failed to enable clock\n");
+
+	ret = devm_add_action_or_reset(ctrl->dev, otto_wdt_clock_action, clk);
+	if (ret)
+		return ret;
+
+	ctrl->clk_rate_khz = clk_get_rate(clk) / 1000;
+	if (ctrl->clk_rate_khz == 0)
+		return dev_err_probe(ctrl->dev, -ENXIO, "Failed to get clock rate\n");
+
+	return 0;
+}
+
+static int otto_wdt_probe_reset_mode(struct otto_wdt_ctrl *ctrl)
+{
+	static const char *mode_property = "realtek,reset-mode";
+	const struct fwnode_handle *node = ctrl->dev->fwnode;
+	int mode_count;
+	u32 mode;
+	u32 v;
+
+	if (!node)
+		return -ENXIO;
+
+	mode_count = fwnode_property_string_array_count(node, mode_property);
+	if (mode_count < 0)
+		return mode_count;
+	else if (mode_count == 0)
+		return 0;
+	else if (mode_count != 1)
+		return -EINVAL;
+
+	if (fwnode_property_match_string(node, mode_property, "soc") == 0)
+		mode = OTTO_WDT_MODE_SOC;
+	else if (fwnode_property_match_string(node, mode_property, "cpu") == 0)
+		mode = OTTO_WDT_MODE_CPU;
+	else if (fwnode_property_match_string(node, mode_property, "software") == 0)
+		mode = OTTO_WDT_MODE_SOFTWARE;
+	else
+		return -EINVAL;
+
+	v = ioread32(ctrl->base + OTTO_WDT_REG_CTRL);
+	v &= ~OTTO_WDT_CTRL_RST_MODE;
+	v |= FIELD_PREP(OTTO_WDT_CTRL_RST_MODE, mode);
+	iowrite32(v, ctrl->base + OTTO_WDT_REG_CTRL);
+
+	return 0;
+}
+
+static int otto_wdt_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct otto_wdt_ctrl *ctrl;
+	unsigned int max_tick_ms;
+	int ret;
+
+	ctrl = devm_kzalloc(dev, sizeof(*ctrl), GFP_KERNEL);
+	if (!ctrl)
+		return -ENOMEM;
+
+	ctrl->dev = dev;
+	ctrl->base = devm_platform_ioremap_resource(pdev, 0);
+	if (IS_ERR(ctrl->base))
+		return PTR_ERR(ctrl->base);
+
+	/* Clear any old interrupts and reset initial state */
+	iowrite32(OTTO_WDT_INTR_PHASE_1 | OTTO_WDT_INTR_PHASE_2,
+			ctrl->base + OTTO_WDT_REG_INTR);
+	iowrite32(OTTO_WDT_CTRL_DEFAULT, ctrl->base + OTTO_WDT_REG_CTRL);
+
+	ret = otto_wdt_probe_clk(ctrl);
+	if (ret)
+		return ret;
+
+	ctrl->irq_phase1 = platform_get_irq_byname(pdev, "phase1");
+	if (ctrl->irq_phase1 < 0)
+		return ctrl->irq_phase1;
+
+	ret = devm_request_irq(dev, ctrl->irq_phase1, otto_wdt_phase1_isr, 0,
+			"realtek-otto-wdt", ctrl);
+	if (ret)
+		return dev_err_probe(dev, ret, "Failed to get IRQ for phase1\n");
+
+	ret = otto_wdt_probe_reset_mode(ctrl);
+	if (ret)
+		return dev_err_probe(dev, ret, "Invalid reset mode specified\n");
+
+	ctrl->wdev.parent = dev;
+	ctrl->wdev.info = &otto_wdt_info;
+	ctrl->wdev.ops = &otto_wdt_ops;
+
+	/*
+	 * Since pretimeout cannot be disabled, min. timeout is twice the
+	 * subsystem resolution. Max. timeout is ca. 43s at a bus clock of 200MHz.
+	 */
+	ctrl->wdev.min_timeout = 2;
+	max_tick_ms = otto_wdt_tick_ms(ctrl, OTTO_WDT_PRESCALE_MAX);
+	ctrl->wdev.max_hw_heartbeat_ms = max_tick_ms * OTTO_WDT_TIMEOUT_TICKS_MAX;
+	ctrl->wdev.timeout = min(30U, ctrl->wdev.max_hw_heartbeat_ms / 1000);
+
+	watchdog_set_drvdata(&ctrl->wdev, ctrl);
+	watchdog_init_timeout(&ctrl->wdev, 0, dev);
+	watchdog_stop_on_reboot(&ctrl->wdev);
+	watchdog_set_restart_priority(&ctrl->wdev, 128);
+
+	ret = otto_wdt_determine_timeouts(&ctrl->wdev, ctrl->wdev.timeout, 1);
+	if (ret)
+		return dev_err_probe(dev, ret, "Failed to set timeout\n");
+
+	return devm_watchdog_register_device(dev, &ctrl->wdev);
+}
+
+static const struct of_device_id otto_wdt_ids[] = {
+	{ .compatible = "realtek,rtl8380-wdt" },
+	{ .compatible = "realtek,rtl8390-wdt" },
+	{ .compatible = "realtek,rtl9300-wdt" },
+	{ }
+};
+MODULE_DEVICE_TABLE(of, otto_wdt_ids);
+
+static struct platform_driver otto_wdt_driver = {
+	.probe = otto_wdt_probe,
+	.driver = {
+		.name = "realtek-otto-watchdog",
+		.of_match_table	= otto_wdt_ids,
+	},
+};
+module_platform_driver(otto_wdt_driver);
+
+MODULE_LICENSE("GPL v2");
+MODULE_AUTHOR("Sander Vanheule <sander@svanheule.net>");
+MODULE_DESCRIPTION("Realtek Otto watchdog timer driver");
diff --git a/drivers/watchdog/rzg2l_wdt.c b/drivers/watchdog/rzg2l_wdt.c
new file mode 100644
index 000000000000..6b426df34fd6
--- /dev/null
+++ b/drivers/watchdog/rzg2l_wdt.c
@@ -0,0 +1,263 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Renesas RZ/G2L WDT Watchdog Driver
+ *
+ * Copyright (C) 2021 Renesas Electronics Corporation
+ */
+#include <linux/bitops.h>
+#include <linux/clk.h>
+#include <linux/delay.h>
+#include <linux/io.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/pm_runtime.h>
+#include <linux/reset.h>
+#include <linux/units.h>
+#include <linux/watchdog.h>
+
+#define WDTCNT		0x00
+#define WDTSET		0x04
+#define WDTTIM		0x08
+#define WDTINT		0x0C
+#define WDTCNT_WDTEN	BIT(0)
+#define WDTINT_INTDISP	BIT(0)
+
+#define WDT_DEFAULT_TIMEOUT		60U
+
+/* Setting period time register only 12 bit set in WDTSET[31:20] */
+#define WDTSET_COUNTER_MASK		(0xFFF00000)
+#define WDTSET_COUNTER_VAL(f)		((f) << 20)
+
+#define F2CYCLE_NSEC(f)			(1000000000 / (f))
+
+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 rzg2l_wdt_priv {
+	void __iomem *base;
+	struct watchdog_device wdev;
+	struct reset_control *rstc;
+	unsigned long osc_clk_rate;
+	unsigned long delay;
+};
+
+static void rzg2l_wdt_wait_delay(struct rzg2l_wdt_priv *priv)
+{
+	/* delay timer when change the setting register */
+	ndelay(priv->delay);
+}
+
+static u32 rzg2l_wdt_get_cycle_usec(unsigned long cycle, u32 wdttime)
+{
+	u64 timer_cycle_us = 1024 * 1024 * (wdttime + 1) * MICRO;
+
+	return div64_ul(timer_cycle_us, cycle);
+}
+
+static void rzg2l_wdt_write(struct rzg2l_wdt_priv *priv, u32 val, unsigned int reg)
+{
+	if (reg == WDTSET)
+		val &= WDTSET_COUNTER_MASK;
+
+	writel_relaxed(val, priv->base + reg);
+	/* Registers other than the WDTINT is always synchronized with WDT_CLK */
+	if (reg != WDTINT)
+		rzg2l_wdt_wait_delay(priv);
+}
+
+static void rzg2l_wdt_init_timeout(struct watchdog_device *wdev)
+{
+	struct rzg2l_wdt_priv *priv = watchdog_get_drvdata(wdev);
+	u32 time_out;
+
+	/* Clear Lapsed Time Register and clear Interrupt */
+	rzg2l_wdt_write(priv, WDTINT_INTDISP, WDTINT);
+	/* 2 consecutive overflow cycle needed to trigger reset */
+	time_out = (wdev->timeout * (MICRO / 2)) /
+		   rzg2l_wdt_get_cycle_usec(priv->osc_clk_rate, 0);
+	rzg2l_wdt_write(priv, WDTSET_COUNTER_VAL(time_out), WDTSET);
+}
+
+static int rzg2l_wdt_start(struct watchdog_device *wdev)
+{
+	struct rzg2l_wdt_priv *priv = watchdog_get_drvdata(wdev);
+
+	reset_control_deassert(priv->rstc);
+	pm_runtime_get_sync(wdev->parent);
+
+	/* Initialize time out */
+	rzg2l_wdt_init_timeout(wdev);
+
+	/* Initialize watchdog counter register */
+	rzg2l_wdt_write(priv, 0, WDTTIM);
+
+	/* Enable watchdog timer*/
+	rzg2l_wdt_write(priv, WDTCNT_WDTEN, WDTCNT);
+
+	return 0;
+}
+
+static int rzg2l_wdt_stop(struct watchdog_device *wdev)
+{
+	struct rzg2l_wdt_priv *priv = watchdog_get_drvdata(wdev);
+
+	pm_runtime_put(wdev->parent);
+	reset_control_assert(priv->rstc);
+
+	return 0;
+}
+
+static int rzg2l_wdt_restart(struct watchdog_device *wdev,
+			     unsigned long action, void *data)
+{
+	struct rzg2l_wdt_priv *priv = watchdog_get_drvdata(wdev);
+
+	/* Reset the module before we modify any register */
+	reset_control_reset(priv->rstc);
+	pm_runtime_get_sync(wdev->parent);
+
+	/* smallest counter value to reboot soon */
+	rzg2l_wdt_write(priv, WDTSET_COUNTER_VAL(1), WDTSET);
+
+	/* Enable watchdog timer*/
+	rzg2l_wdt_write(priv, WDTCNT_WDTEN, WDTCNT);
+
+	return 0;
+}
+
+static const struct watchdog_info rzg2l_wdt_ident = {
+	.options = WDIOF_MAGICCLOSE | WDIOF_KEEPALIVEPING | WDIOF_SETTIMEOUT,
+	.identity = "Renesas RZ/G2L WDT Watchdog",
+};
+
+static int rzg2l_wdt_ping(struct watchdog_device *wdev)
+{
+	struct rzg2l_wdt_priv *priv = watchdog_get_drvdata(wdev);
+
+	rzg2l_wdt_write(priv, WDTINT_INTDISP, WDTINT);
+
+	return 0;
+}
+
+static const struct watchdog_ops rzg2l_wdt_ops = {
+	.owner = THIS_MODULE,
+	.start = rzg2l_wdt_start,
+	.stop = rzg2l_wdt_stop,
+	.ping = rzg2l_wdt_ping,
+	.restart = rzg2l_wdt_restart,
+};
+
+static void rzg2l_wdt_reset_assert_pm_disable_put(void *data)
+{
+	struct watchdog_device *wdev = data;
+	struct rzg2l_wdt_priv *priv = watchdog_get_drvdata(wdev);
+
+	pm_runtime_put(wdev->parent);
+	pm_runtime_disable(wdev->parent);
+	reset_control_assert(priv->rstc);
+}
+
+static int rzg2l_wdt_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct rzg2l_wdt_priv *priv;
+	unsigned long pclk_rate;
+	struct clk *wdt_clk;
+	int ret;
+
+	priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
+	if (!priv)
+		return -ENOMEM;
+
+	priv->base = devm_platform_ioremap_resource(pdev, 0);
+	if (IS_ERR(priv->base))
+		return PTR_ERR(priv->base);
+
+	/* Get watchdog main clock */
+	wdt_clk = clk_get(&pdev->dev, "oscclk");
+	if (IS_ERR(wdt_clk))
+		return dev_err_probe(&pdev->dev, PTR_ERR(wdt_clk), "no oscclk");
+
+	priv->osc_clk_rate = clk_get_rate(wdt_clk);
+	clk_put(wdt_clk);
+	if (!priv->osc_clk_rate)
+		return dev_err_probe(&pdev->dev, -EINVAL, "oscclk rate is 0");
+
+	/* Get Peripheral clock */
+	wdt_clk = clk_get(&pdev->dev, "pclk");
+	if (IS_ERR(wdt_clk))
+		return dev_err_probe(&pdev->dev, PTR_ERR(wdt_clk), "no pclk");
+
+	pclk_rate = clk_get_rate(wdt_clk);
+	clk_put(wdt_clk);
+	if (!pclk_rate)
+		return dev_err_probe(&pdev->dev, -EINVAL, "pclk rate is 0");
+
+	priv->delay = F2CYCLE_NSEC(priv->osc_clk_rate) * 6 + F2CYCLE_NSEC(pclk_rate) * 9;
+
+	priv->rstc = devm_reset_control_get_exclusive(&pdev->dev, NULL);
+	if (IS_ERR(priv->rstc))
+		return dev_err_probe(&pdev->dev, PTR_ERR(priv->rstc),
+				     "failed to get cpg reset");
+
+	reset_control_deassert(priv->rstc);
+	pm_runtime_enable(&pdev->dev);
+	ret = pm_runtime_resume_and_get(&pdev->dev);
+	if (ret < 0) {
+		dev_err(dev, "pm_runtime_resume_and_get failed ret=%pe", ERR_PTR(ret));
+		goto out_pm_get;
+	}
+
+	priv->wdev.info = &rzg2l_wdt_ident;
+	priv->wdev.ops = &rzg2l_wdt_ops;
+	priv->wdev.parent = dev;
+	priv->wdev.min_timeout = 1;
+	priv->wdev.max_timeout = rzg2l_wdt_get_cycle_usec(priv->osc_clk_rate, 0xfff) /
+				 USEC_PER_SEC;
+	priv->wdev.timeout = WDT_DEFAULT_TIMEOUT;
+
+	watchdog_set_drvdata(&priv->wdev, priv);
+	ret = devm_add_action_or_reset(&pdev->dev,
+				       rzg2l_wdt_reset_assert_pm_disable_put,
+				       &priv->wdev);
+	if (ret < 0)
+		return ret;
+
+	watchdog_set_nowayout(&priv->wdev, nowayout);
+	watchdog_stop_on_unregister(&priv->wdev);
+
+	ret = watchdog_init_timeout(&priv->wdev, 0, dev);
+	if (ret)
+		dev_warn(dev, "Specified timeout invalid, using default");
+
+	return devm_watchdog_register_device(&pdev->dev, &priv->wdev);
+
+out_pm_get:
+	pm_runtime_disable(dev);
+	reset_control_assert(priv->rstc);
+
+	return ret;
+}
+
+static const struct of_device_id rzg2l_wdt_ids[] = {
+	{ .compatible = "renesas,rzg2l-wdt", },
+	{ /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(of, rzg2l_wdt_ids);
+
+static struct platform_driver rzg2l_wdt_driver = {
+	.driver = {
+		.name = "rzg2l_wdt",
+		.of_match_table = rzg2l_wdt_ids,
+	},
+	.probe = rzg2l_wdt_probe,
+};
+module_platform_driver(rzg2l_wdt_driver);
+
+MODULE_DESCRIPTION("Renesas RZ/G2L WDT Watchdog Driver");
+MODULE_AUTHOR("Biju Das <biju.das.jz@bp.renesas.com>");
+MODULE_LICENSE("GPL v2");
diff --git a/drivers/watchdog/s3c2410_wdt.c b/drivers/watchdog/s3c2410_wdt.c
index 2395f353e52d..6db22f2e3a4f 100644
--- a/drivers/watchdog/s3c2410_wdt.c
+++ b/drivers/watchdog/s3c2410_wdt.c
@@ -56,13 +56,58 @@
 #define EXYNOS5_RST_STAT_REG_OFFSET		0x0404
 #define EXYNOS5_WDT_DISABLE_REG_OFFSET		0x0408
 #define EXYNOS5_WDT_MASK_RESET_REG_OFFSET	0x040c
-#define QUIRK_HAS_PMU_CONFIG			(1 << 0)
-#define QUIRK_HAS_RST_STAT			(1 << 1)
-#define QUIRK_HAS_WTCLRINT_REG			(1 << 2)
+#define EXYNOS850_CLUSTER0_NONCPU_OUT		0x1220
+#define EXYNOS850_CLUSTER0_NONCPU_INT_EN	0x1244
+#define EXYNOS850_CLUSTER1_NONCPU_OUT		0x1620
+#define EXYNOS850_CLUSTER1_NONCPU_INT_EN	0x1644
+
+#define EXYNOS850_CLUSTER0_WDTRESET_BIT		24
+#define EXYNOS850_CLUSTER1_WDTRESET_BIT		23
+
+/**
+ * DOC: Quirk flags for different Samsung watchdog IP-cores
+ *
+ * This driver supports multiple Samsung SoCs, each of which might have
+ * different set of registers and features supported. As watchdog block
+ * sometimes requires modifying PMU registers for proper functioning, register
+ * differences in both watchdog and PMU IP-cores should be accounted for. Quirk
+ * flags described below serve the purpose of telling the driver about mentioned
+ * SoC traits, and can be specified in driver data for each particular supported
+ * device.
+ *
+ * %QUIRK_HAS_WTCLRINT_REG: Watchdog block has WTCLRINT register. It's used to
+ * clear the interrupt once the interrupt service routine is complete. It's
+ * write-only, writing any values to this register clears the interrupt, but
+ * reading is not permitted.
+ *
+ * %QUIRK_HAS_PMU_MASK_RESET: PMU block has the register for disabling/enabling
+ * WDT reset request. On old SoCs it's usually called MASK_WDT_RESET_REQUEST,
+ * new SoCs have CLUSTERx_NONCPU_INT_EN register, which 'mask_bit' value is
+ * inverted compared to the former one.
+ *
+ * %QUIRK_HAS_PMU_RST_STAT: PMU block has RST_STAT (reset status) register,
+ * which contains bits indicating the reason for most recent CPU reset. If
+ * present, driver will use this register to check if previous reboot was due to
+ * watchdog timer reset.
+ *
+ * %QUIRK_HAS_PMU_AUTO_DISABLE: PMU block has AUTOMATIC_WDT_RESET_DISABLE
+ * register. If 'mask_bit' bit is set, PMU will disable WDT reset when
+ * corresponding processor is in reset state.
+ *
+ * %QUIRK_HAS_PMU_CNT_EN: PMU block has some register (e.g. CLUSTERx_NONCPU_OUT)
+ * with "watchdog counter enable" bit. That bit should be set to make watchdog
+ * counter running.
+ */
+#define QUIRK_HAS_WTCLRINT_REG			(1 << 0)
+#define QUIRK_HAS_PMU_MASK_RESET		(1 << 1)
+#define QUIRK_HAS_PMU_RST_STAT			(1 << 2)
+#define QUIRK_HAS_PMU_AUTO_DISABLE		(1 << 3)
+#define QUIRK_HAS_PMU_CNT_EN			(1 << 4)
 
 /* These quirks require that we have a PMU register map */
-#define QUIRKS_HAVE_PMUREG			(QUIRK_HAS_PMU_CONFIG | \
-						 QUIRK_HAS_RST_STAT)
+#define QUIRKS_HAVE_PMUREG \
+	(QUIRK_HAS_PMU_MASK_RESET | QUIRK_HAS_PMU_RST_STAT | \
+	 QUIRK_HAS_PMU_AUTO_DISABLE | QUIRK_HAS_PMU_CNT_EN)
 
 static bool nowayout	= WATCHDOG_NOWAYOUT;
 static int tmr_margin;
@@ -90,26 +135,33 @@ MODULE_PARM_DESC(soft_noboot, "Watchdog action, set to 1 to ignore reboots, 0 to
  * timer reset functionality.
  * @mask_reset_reg: Offset in pmureg for the register that masks the watchdog
  * timer reset functionality.
+ * @mask_reset_inv: If set, mask_reset_reg value will have inverted meaning.
  * @mask_bit: Bit number for the watchdog timer in the disable register and the
  * mask reset register.
  * @rst_stat_reg: Offset in pmureg for the register that has the reset status.
  * @rst_stat_bit: Bit number in the rst_stat register indicating a watchdog
  * reset.
+ * @cnt_en_reg: Offset in pmureg for the register that enables WDT counter.
+ * @cnt_en_bit: Bit number for "watchdog counter enable" in cnt_en register.
  * @quirks: A bitfield of quirks.
  */
 
 struct s3c2410_wdt_variant {
 	int disable_reg;
 	int mask_reset_reg;
+	bool mask_reset_inv;
 	int mask_bit;
 	int rst_stat_reg;
 	int rst_stat_bit;
+	int cnt_en_reg;
+	int cnt_en_bit;
 	u32 quirks;
 };
 
 struct s3c2410_wdt {
 	struct device		*dev;
-	struct clk		*clock;
+	struct clk		*bus_clk; /* for register interface (PCLK) */
+	struct clk		*src_clk; /* for WDT counter */
 	void __iomem		*reg_base;
 	unsigned int		count;
 	spinlock_t		lock;
@@ -136,8 +188,8 @@ static const struct s3c2410_wdt_variant drv_data_exynos5250  = {
 	.mask_bit = 20,
 	.rst_stat_reg = EXYNOS5_RST_STAT_REG_OFFSET,
 	.rst_stat_bit = 20,
-	.quirks = QUIRK_HAS_PMU_CONFIG | QUIRK_HAS_RST_STAT \
-		  | QUIRK_HAS_WTCLRINT_REG,
+	.quirks = QUIRK_HAS_WTCLRINT_REG | QUIRK_HAS_PMU_MASK_RESET | \
+		  QUIRK_HAS_PMU_RST_STAT | QUIRK_HAS_PMU_AUTO_DISABLE,
 };
 
 static const struct s3c2410_wdt_variant drv_data_exynos5420 = {
@@ -146,8 +198,8 @@ static const struct s3c2410_wdt_variant drv_data_exynos5420 = {
 	.mask_bit = 0,
 	.rst_stat_reg = EXYNOS5_RST_STAT_REG_OFFSET,
 	.rst_stat_bit = 9,
-	.quirks = QUIRK_HAS_PMU_CONFIG | QUIRK_HAS_RST_STAT \
-		  | QUIRK_HAS_WTCLRINT_REG,
+	.quirks = QUIRK_HAS_WTCLRINT_REG | QUIRK_HAS_PMU_MASK_RESET | \
+		  QUIRK_HAS_PMU_RST_STAT | QUIRK_HAS_PMU_AUTO_DISABLE,
 };
 
 static const struct s3c2410_wdt_variant drv_data_exynos7 = {
@@ -156,8 +208,32 @@ static const struct s3c2410_wdt_variant drv_data_exynos7 = {
 	.mask_bit = 23,
 	.rst_stat_reg = EXYNOS5_RST_STAT_REG_OFFSET,
 	.rst_stat_bit = 23,	/* A57 WDTRESET */
-	.quirks = QUIRK_HAS_PMU_CONFIG | QUIRK_HAS_RST_STAT \
-		  | QUIRK_HAS_WTCLRINT_REG,
+	.quirks = QUIRK_HAS_WTCLRINT_REG | QUIRK_HAS_PMU_MASK_RESET | \
+		  QUIRK_HAS_PMU_RST_STAT | QUIRK_HAS_PMU_AUTO_DISABLE,
+};
+
+static const struct s3c2410_wdt_variant drv_data_exynos850_cl0 = {
+	.mask_reset_reg = EXYNOS850_CLUSTER0_NONCPU_INT_EN,
+	.mask_bit = 2,
+	.mask_reset_inv = true,
+	.rst_stat_reg = EXYNOS5_RST_STAT_REG_OFFSET,
+	.rst_stat_bit = EXYNOS850_CLUSTER0_WDTRESET_BIT,
+	.cnt_en_reg = EXYNOS850_CLUSTER0_NONCPU_OUT,
+	.cnt_en_bit = 7,
+	.quirks = QUIRK_HAS_WTCLRINT_REG | QUIRK_HAS_PMU_MASK_RESET | \
+		  QUIRK_HAS_PMU_RST_STAT | QUIRK_HAS_PMU_CNT_EN,
+};
+
+static const struct s3c2410_wdt_variant drv_data_exynos850_cl1 = {
+	.mask_reset_reg = EXYNOS850_CLUSTER1_NONCPU_INT_EN,
+	.mask_bit = 2,
+	.mask_reset_inv = true,
+	.rst_stat_reg = EXYNOS5_RST_STAT_REG_OFFSET,
+	.rst_stat_bit = EXYNOS850_CLUSTER1_WDTRESET_BIT,
+	.cnt_en_reg = EXYNOS850_CLUSTER1_NONCPU_OUT,
+	.cnt_en_bit = 7,
+	.quirks = QUIRK_HAS_WTCLRINT_REG | QUIRK_HAS_PMU_MASK_RESET | \
+		  QUIRK_HAS_PMU_RST_STAT | QUIRK_HAS_PMU_CNT_EN,
 };
 
 static const struct of_device_id s3c2410_wdt_match[] = {
@@ -171,6 +247,8 @@ static const struct of_device_id s3c2410_wdt_match[] = {
 	  .data = &drv_data_exynos5420 },
 	{ .compatible = "samsung,exynos7-wdt",
 	  .data = &drv_data_exynos7 },
+	{ .compatible = "samsung,exynos850-wdt",
+	  .data = &drv_data_exynos850_cl0 },
 	{},
 };
 MODULE_DEVICE_TABLE(of, s3c2410_wdt_match);
@@ -187,9 +265,14 @@ MODULE_DEVICE_TABLE(platform, s3c2410_wdt_ids);
 
 /* functions */
 
-static inline unsigned int s3c2410wdt_max_timeout(struct clk *clock)
+static inline unsigned long s3c2410wdt_get_freq(struct s3c2410_wdt *wdt)
 {
-	unsigned long freq = clk_get_rate(clock);
+	return clk_get_rate(wdt->src_clk ? wdt->src_clk : wdt->bus_clk);
+}
+
+static inline unsigned int s3c2410wdt_max_timeout(struct s3c2410_wdt *wdt)
+{
+	const unsigned long freq = s3c2410wdt_get_freq(wdt);
 
 	return S3C2410_WTCNT_MAXCNT / (freq / (S3C2410_WTCON_PRESCALE_MAX + 1)
 				       / S3C2410_WTCON_MAXDIV);
@@ -200,35 +283,74 @@ static inline struct s3c2410_wdt *freq_to_wdt(struct notifier_block *nb)
 	return container_of(nb, struct s3c2410_wdt, freq_transition);
 }
 
-static int s3c2410wdt_mask_and_disable_reset(struct s3c2410_wdt *wdt, bool mask)
+static int s3c2410wdt_disable_wdt_reset(struct s3c2410_wdt *wdt, bool mask)
 {
+	const u32 mask_val = BIT(wdt->drv_data->mask_bit);
+	const u32 val = mask ? mask_val : 0;
 	int ret;
-	u32 mask_val = 1 << wdt->drv_data->mask_bit;
-	u32 val = 0;
 
-	/* No need to do anything if no PMU CONFIG needed */
-	if (!(wdt->drv_data->quirks & QUIRK_HAS_PMU_CONFIG))
-		return 0;
+	ret = regmap_update_bits(wdt->pmureg, wdt->drv_data->disable_reg,
+				 mask_val, val);
+	if (ret < 0)
+		dev_err(wdt->dev, "failed to update reg(%d)\n", ret);
 
-	if (mask)
-		val = mask_val;
+	return ret;
+}
+
+static int s3c2410wdt_mask_wdt_reset(struct s3c2410_wdt *wdt, bool mask)
+{
+	const u32 mask_val = BIT(wdt->drv_data->mask_bit);
+	const bool val_inv = wdt->drv_data->mask_reset_inv;
+	const u32 val = (mask ^ val_inv) ? mask_val : 0;
+	int ret;
 
-	ret = regmap_update_bits(wdt->pmureg,
-			wdt->drv_data->disable_reg,
-			mask_val, val);
+	ret = regmap_update_bits(wdt->pmureg, wdt->drv_data->mask_reset_reg,
+				 mask_val, val);
 	if (ret < 0)
-		goto error;
+		dev_err(wdt->dev, "failed to update reg(%d)\n", ret);
+
+	return ret;
+}
 
-	ret = regmap_update_bits(wdt->pmureg,
-			wdt->drv_data->mask_reset_reg,
-			mask_val, val);
- error:
+static int s3c2410wdt_enable_counter(struct s3c2410_wdt *wdt, bool en)
+{
+	const u32 mask_val = BIT(wdt->drv_data->cnt_en_bit);
+	const u32 val = en ? mask_val : 0;
+	int ret;
+
+	ret = regmap_update_bits(wdt->pmureg, wdt->drv_data->cnt_en_reg,
+				 mask_val, val);
 	if (ret < 0)
 		dev_err(wdt->dev, "failed to update reg(%d)\n", ret);
 
 	return ret;
 }
 
+static int s3c2410wdt_enable(struct s3c2410_wdt *wdt, bool en)
+{
+	int ret;
+
+	if (wdt->drv_data->quirks & QUIRK_HAS_PMU_AUTO_DISABLE) {
+		ret = s3c2410wdt_disable_wdt_reset(wdt, !en);
+		if (ret < 0)
+			return ret;
+	}
+
+	if (wdt->drv_data->quirks & QUIRK_HAS_PMU_MASK_RESET) {
+		ret = s3c2410wdt_mask_wdt_reset(wdt, !en);
+		if (ret < 0)
+			return ret;
+	}
+
+	if (wdt->drv_data->quirks & QUIRK_HAS_PMU_CNT_EN) {
+		ret = s3c2410wdt_enable_counter(wdt, en);
+		if (ret < 0)
+			return ret;
+	}
+
+	return 0;
+}
+
 static int s3c2410wdt_keepalive(struct watchdog_device *wdd)
 {
 	struct s3c2410_wdt *wdt = watchdog_get_drvdata(wdd);
@@ -300,7 +422,7 @@ static int s3c2410wdt_set_heartbeat(struct watchdog_device *wdd,
 				    unsigned int timeout)
 {
 	struct s3c2410_wdt *wdt = watchdog_get_drvdata(wdd);
-	unsigned long freq = clk_get_rate(wdt->clock);
+	unsigned long freq = s3c2410wdt_get_freq(wdt);
 	unsigned int count;
 	unsigned int divisor = 1;
 	unsigned long wtcon;
@@ -482,7 +604,7 @@ static inline unsigned int s3c2410wdt_get_bootstatus(struct s3c2410_wdt *wdt)
 	unsigned int rst_stat;
 	int ret;
 
-	if (!(wdt->drv_data->quirks & QUIRK_HAS_RST_STAT))
+	if (!(wdt->drv_data->quirks & QUIRK_HAS_PMU_RST_STAT))
 		return 0;
 
 	ret = regmap_read(wdt->pmureg, wdt->drv_data->rst_stat_reg, &rst_stat);
@@ -498,14 +620,40 @@ static inline const struct s3c2410_wdt_variant *
 s3c2410_get_wdt_drv_data(struct platform_device *pdev)
 {
 	const struct s3c2410_wdt_variant *variant;
+	struct device *dev = &pdev->dev;
 
-	variant = of_device_get_match_data(&pdev->dev);
+	variant = of_device_get_match_data(dev);
 	if (!variant) {
 		/* Device matched by platform_device_id */
 		variant = (struct s3c2410_wdt_variant *)
 			   platform_get_device_id(pdev)->driver_data;
 	}
 
+#ifdef CONFIG_OF
+	/* Choose Exynos850 driver data w.r.t. cluster index */
+	if (variant == &drv_data_exynos850_cl0) {
+		u32 index;
+		int err;
+
+		err = of_property_read_u32(dev->of_node,
+					   "samsung,cluster-index", &index);
+		if (err) {
+			dev_err(dev, "failed to get cluster index\n");
+			return NULL;
+		}
+
+		switch (index) {
+		case 0:
+			return &drv_data_exynos850_cl0;
+		case 1:
+			return &drv_data_exynos850_cl1;
+		default:
+			dev_err(dev, "wrong cluster index: %u\n", index);
+			return NULL;
+		}
+	}
+#endif
+
 	return variant;
 }
 
@@ -513,9 +661,8 @@ static int s3c2410wdt_probe(struct platform_device *pdev)
 {
 	struct device *dev = &pdev->dev;
 	struct s3c2410_wdt *wdt;
-	struct resource *wdt_irq;
 	unsigned int wtcon;
-	int started = 0;
+	int wdt_irq;
 	int ret;
 
 	wdt = devm_kzalloc(dev, sizeof(*wdt), GFP_KERNEL);
@@ -527,6 +674,9 @@ static int s3c2410wdt_probe(struct platform_device *pdev)
 	wdt->wdt_device = s3c2410_wdd;
 
 	wdt->drv_data = s3c2410_get_wdt_drv_data(pdev);
+	if (!wdt->drv_data)
+		return -EINVAL;
+
 	if (wdt->drv_data->quirks & QUIRKS_HAVE_PMUREG) {
 		wdt->pmureg = syscon_regmap_lookup_by_phandle(dev->of_node,
 						"samsung,syscon-phandle");
@@ -536,40 +686,52 @@ static int s3c2410wdt_probe(struct platform_device *pdev)
 		}
 	}
 
-	wdt_irq = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
-	if (wdt_irq == NULL) {
-		dev_err(dev, "no irq resource specified\n");
-		ret = -ENOENT;
-		goto err;
-	}
+	wdt_irq = platform_get_irq(pdev, 0);
+	if (wdt_irq < 0)
+		return wdt_irq;
 
 	/* get the memory region for the watchdog timer */
 	wdt->reg_base = devm_platform_ioremap_resource(pdev, 0);
-	if (IS_ERR(wdt->reg_base)) {
-		ret = PTR_ERR(wdt->reg_base);
-		goto err;
-	}
+	if (IS_ERR(wdt->reg_base))
+		return PTR_ERR(wdt->reg_base);
 
-	wdt->clock = devm_clk_get(dev, "watchdog");
-	if (IS_ERR(wdt->clock)) {
-		dev_err(dev, "failed to find watchdog clock source\n");
-		ret = PTR_ERR(wdt->clock);
-		goto err;
+	wdt->bus_clk = devm_clk_get(dev, "watchdog");
+	if (IS_ERR(wdt->bus_clk)) {
+		dev_err(dev, "failed to find bus clock\n");
+		return PTR_ERR(wdt->bus_clk);
 	}
 
-	ret = clk_prepare_enable(wdt->clock);
+	ret = clk_prepare_enable(wdt->bus_clk);
 	if (ret < 0) {
-		dev_err(dev, "failed to enable clock\n");
+		dev_err(dev, "failed to enable bus clock\n");
 		return ret;
 	}
 
+	/*
+	 * "watchdog_src" clock is optional; if it's not present -- just skip it
+	 * and use "watchdog" clock as both bus and source clock.
+	 */
+	wdt->src_clk = devm_clk_get_optional(dev, "watchdog_src");
+	if (IS_ERR(wdt->src_clk)) {
+		dev_err_probe(dev, PTR_ERR(wdt->src_clk),
+			      "failed to get source clock\n");
+		ret = PTR_ERR(wdt->src_clk);
+		goto err_bus_clk;
+	}
+
+	ret = clk_prepare_enable(wdt->src_clk);
+	if (ret) {
+		dev_err(dev, "failed to enable source clock\n");
+		goto err_bus_clk;
+	}
+
 	wdt->wdt_device.min_timeout = 1;
-	wdt->wdt_device.max_timeout = s3c2410wdt_max_timeout(wdt->clock);
+	wdt->wdt_device.max_timeout = s3c2410wdt_max_timeout(wdt);
 
 	ret = s3c2410wdt_cpufreq_register(wdt);
 	if (ret < 0) {
 		dev_err(dev, "failed to register cpufreq\n");
-		goto err_clk;
+		goto err_src_clk;
 	}
 
 	watchdog_set_drvdata(&wdt->wdt_device, wdt);
@@ -581,19 +743,19 @@ static int s3c2410wdt_probe(struct platform_device *pdev)
 	ret = s3c2410wdt_set_heartbeat(&wdt->wdt_device,
 					wdt->wdt_device.timeout);
 	if (ret) {
-		started = s3c2410wdt_set_heartbeat(&wdt->wdt_device,
-					S3C2410_WATCHDOG_DEFAULT_TIME);
-
-		if (started == 0)
-			dev_info(dev,
-				 "tmr_margin value out of range, default %d used\n",
+		ret = s3c2410wdt_set_heartbeat(&wdt->wdt_device,
+					       S3C2410_WATCHDOG_DEFAULT_TIME);
+		if (ret == 0) {
+			dev_warn(dev, "tmr_margin value out of range, default %d used\n",
 				 S3C2410_WATCHDOG_DEFAULT_TIME);
-		else
-			dev_info(dev, "default timer value is out of range, cannot start\n");
+		} else {
+			dev_err(dev, "failed to use default timeout\n");
+			goto err_cpufreq;
+		}
 	}
 
-	ret = devm_request_irq(dev, wdt_irq->start, s3c2410wdt_irq, 0,
-				pdev->name, pdev);
+	ret = devm_request_irq(dev, wdt_irq, s3c2410wdt_irq, 0,
+			       pdev->name, pdev);
 	if (ret != 0) {
 		dev_err(dev, "failed to install irq (%d)\n", ret);
 		goto err_cpufreq;
@@ -605,25 +767,29 @@ static int s3c2410wdt_probe(struct platform_device *pdev)
 	wdt->wdt_device.bootstatus = s3c2410wdt_get_bootstatus(wdt);
 	wdt->wdt_device.parent = dev;
 
+	/*
+	 * If "tmr_atboot" param is non-zero, start the watchdog right now. Also
+	 * set WDOG_HW_RUNNING bit, so that watchdog core can kick the watchdog.
+	 *
+	 * If we're not enabling the watchdog, then ensure it is disabled if it
+	 * has been left running from the bootloader or other source.
+	 */
+	if (tmr_atboot) {
+		dev_info(dev, "starting watchdog timer\n");
+		s3c2410wdt_start(&wdt->wdt_device);
+		set_bit(WDOG_HW_RUNNING, &wdt->wdt_device.status);
+	} else {
+		s3c2410wdt_stop(&wdt->wdt_device);
+	}
+
 	ret = watchdog_register_device(&wdt->wdt_device);
 	if (ret)
 		goto err_cpufreq;
 
-	ret = s3c2410wdt_mask_and_disable_reset(wdt, false);
+	ret = s3c2410wdt_enable(wdt, true);
 	if (ret < 0)
 		goto err_unregister;
 
-	if (tmr_atboot && started == 0) {
-		dev_info(dev, "starting watchdog timer\n");
-		s3c2410wdt_start(&wdt->wdt_device);
-	} else if (!tmr_atboot) {
-		/* if we're not enabling the watchdog, then ensure it is
-		 * disabled if it has been left running from the bootloader
-		 * or other source */
-
-		s3c2410wdt_stop(&wdt->wdt_device);
-	}
-
 	platform_set_drvdata(pdev, wdt);
 
 	/* print out a statement of readiness */
@@ -643,10 +809,12 @@ static int s3c2410wdt_probe(struct platform_device *pdev)
  err_cpufreq:
 	s3c2410wdt_cpufreq_deregister(wdt);
 
- err_clk:
-	clk_disable_unprepare(wdt->clock);
+ err_src_clk:
+	clk_disable_unprepare(wdt->src_clk);
+
+ err_bus_clk:
+	clk_disable_unprepare(wdt->bus_clk);
 
- err:
 	return ret;
 }
 
@@ -655,7 +823,7 @@ static int s3c2410wdt_remove(struct platform_device *dev)
 	int ret;
 	struct s3c2410_wdt *wdt = platform_get_drvdata(dev);
 
-	ret = s3c2410wdt_mask_and_disable_reset(wdt, true);
+	ret = s3c2410wdt_enable(wdt, false);
 	if (ret < 0)
 		return ret;
 
@@ -663,7 +831,8 @@ static int s3c2410wdt_remove(struct platform_device *dev)
 
 	s3c2410wdt_cpufreq_deregister(wdt);
 
-	clk_disable_unprepare(wdt->clock);
+	clk_disable_unprepare(wdt->src_clk);
+	clk_disable_unprepare(wdt->bus_clk);
 
 	return 0;
 }
@@ -672,8 +841,7 @@ static void s3c2410wdt_shutdown(struct platform_device *dev)
 {
 	struct s3c2410_wdt *wdt = platform_get_drvdata(dev);
 
-	s3c2410wdt_mask_and_disable_reset(wdt, true);
-
+	s3c2410wdt_enable(wdt, false);
 	s3c2410wdt_stop(&wdt->wdt_device);
 }
 
@@ -688,7 +856,7 @@ static int s3c2410wdt_suspend(struct device *dev)
 	wdt->wtcon_save = readl(wdt->reg_base + S3C2410_WTCON);
 	wdt->wtdat_save = readl(wdt->reg_base + S3C2410_WTDAT);
 
-	ret = s3c2410wdt_mask_and_disable_reset(wdt, true);
+	ret = s3c2410wdt_enable(wdt, false);
 	if (ret < 0)
 		return ret;
 
@@ -708,7 +876,7 @@ static int s3c2410wdt_resume(struct device *dev)
 	writel(wdt->wtdat_save, wdt->reg_base + S3C2410_WTCNT);/* Reset count */
 	writel(wdt->wtcon_save, wdt->reg_base + S3C2410_WTCON);
 
-	ret = s3c2410wdt_mask_and_disable_reset(wdt, false);
+	ret = s3c2410wdt_enable(wdt, true);
 	if (ret < 0)
 		return ret;