Merge tag 'linux-watchdog-5.10-rc1' of git://www.linux-watchdog.org/linux-watchdog

Pull watchdog updates from Wim Van Sebroeck:

- Add Toshiba Visconti watchdog driver

- it87_wdt: add IT8772 + IT8784

- several fixes and improvements

* tag 'linux-watchdog-5.10-rc1' of git://www.linux-watchdog.org/linux-watchdog:
watchdog: Add Toshiba Visconti watchdog driver
watchdog: bindings: Add binding documentation for Toshiba Visconti watchdog device
watchdog: it87_wdt: add IT8784 ID
watchdog: sp5100_tco: Enable watchdog on Family 17h devices if disabled
watchdog: sp5100: Fix definition of EFCH_PM_DECODEEN3
watchdog: renesas_wdt: support handover from bootloader
watchdog: imx7ulp: Watchdog should continue running for wait/stop mode
watchdog: rti: Simplify with dev_err_probe()
watchdog: davinci: Simplify with dev_err_probe()
watchdog: cadence: Simplify with dev_err_probe()
watchdog: remove unneeded inclusion of <uapi/linux/sched/types.h>
watchdog: Use put_device on error
watchdog: Fix memleak in watchdog_cdev_register
watchdog: imx7ulp: Strictly follow the sequence for wdog operations
watchdog: it87_wdt: add IT8772 ID
watchdog: pcwd_usb: Avoid GFP_ATOMIC where it is not needed
drivers: watchdog: rdc321x_wdt: Fix race condition bugs

Documentation/devicetree/bindings/watchdog/toshiba,visconti-wdt.yaml

···
+# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
+# Copyright 2020 Toshiba Electronic Devices & Storage Corporation
+%YAML 1.2
+---
+$id: "http://devicetree.org/schemas/watchdog/toshiba,visconti-wdt.yaml#"
+$schema: "http://devicetree.org/meta-schemas/core.yaml#"
+
+title: Toshiba Visconti SoCs PIUWDT Watchdog timer
+
+maintainers:
+  - Nobuhiro Iwamatsu <[e-mail]>
+
+allOf:
+  - $ref: watchdog.yaml#
+
+properties:
+  compatible:
+    enum:
+      - toshiba,visconti-wdt
+
+  reg:
+    maxItems: 1
+
+  clocks:
+    maxItems: 1
+
+  timeout-sec: true
+
+required:
+  - compatible
+  - reg
+  - clocks
+
+additionalProperties: false
+
+examples:
+  - |
+    soc {
+        #address-cells = <2>;
+        #size-cells = <2>;
+
+        wdt_clk: wdt-clk {
+            compatible = "fixed-clock";
+            clock-frequency = <150000000>;
+            #clock-cells = <0>;
+        };
+
+        watchdog@28330000 {
+            compatible = "toshiba,visconti-wdt";
+            reg = <0 0x28330000 0 0x1000>;
+            clocks = <&wdt_clk>;
+            timeout-sec = <20>;
+        };
+    };

drivers/watchdog/Kconfig

···
 	  Say Y here to include support watchdog timer embedded into the
 	  pm8916 module.
 
+config VISCONTI_WATCHDOG
+	tristate "Toshiba Visconti series watchdog support"
+	depends on ARCH_VISCONTI || COMPILE_TEST
+	select WATCHDOG_CORE
+	help
+	  Say Y here to include support for the watchdog timer in Toshiba
+	  Visconti SoCs.
+
 # X86 (i386 + ia64 + x86_64) Architecture
 
 config ACQUIRE_WDT

drivers/watchdog/Makefile

···
 obj-$(CONFIG_SPRD_WATCHDOG) += sprd_wdt.o
 obj-$(CONFIG_PM8916_WATCHDOG) += pm8916_wdt.o
 obj-$(CONFIG_ARM_SMC_WATCHDOG) += arm_smc_wdt.o
+obj-$(CONFIG_VISCONTI_WATCHDOG) += visconti_wdt.o
 
 # X86 (i386 + ia64 + x86_64) Architecture
 obj-$(CONFIG_ACQUIRE_WDT) += acquirewdt.o

drivers/watchdog/cadence_wdt.c

···
 	watchdog_set_drvdata(cdns_wdt_device, wdt);
 
 	wdt->clk = devm_clk_get(dev, NULL);
-	if (IS_ERR(wdt->clk)) {
-		ret = PTR_ERR(wdt->clk);
-		if (ret != -EPROBE_DEFER)
-			dev_err(dev, "input clock not found\n");
-		return ret;
-	}
+	if (IS_ERR(wdt->clk))
+		return dev_err_probe(dev, PTR_ERR(wdt->clk),
+				     "input clock not found\n");
 
 	ret = clk_prepare_enable(wdt->clk);
 	if (ret) {

drivers/watchdog/davinci_wdt.c

···
 		return -ENOMEM;
 
 	davinci_wdt->clk = devm_clk_get(dev, NULL);
-
-	if (IS_ERR(davinci_wdt->clk)) {
-		if (PTR_ERR(davinci_wdt->clk) != -EPROBE_DEFER)
-			dev_err(dev, "failed to get clock node\n");
-		return PTR_ERR(davinci_wdt->clk);
-	}
+	if (IS_ERR(davinci_wdt->clk))
+		return dev_err_probe(dev, PTR_ERR(davinci_wdt->clk),
+				     "failed to get clock node\n");
 
 	ret = clk_prepare_enable(davinci_wdt->clk);
 	if (ret) {

drivers/watchdog/imx7ulp_wdt.c

···
 
 #include <linux/clk.h>
 #include <linux/io.h>
+#include <linux/iopoll.h>
 #include <linux/kernel.h>
 #include <linux/module.h>
 #include <linux/of.h>
···
 #define WDOG_CS_CLK		(LPO_CLK << LPO_CLK_SHIFT)
 #define WDOG_CS_EN		BIT(7)
 #define WDOG_CS_UPDATE		BIT(5)
+#define WDOG_CS_WAIT		BIT(1)
+#define WDOG_CS_STOP		BIT(0)
 
 #define WDOG_CNT	0x4
 #define WDOG_TOVAL	0x8
···
 #define DEFAULT_TIMEOUT	60
 #define MAX_TIMEOUT	128
 #define WDOG_CLOCK_RATE	1000
+#define WDOG_WAIT_TIMEOUT	20
 
 static bool nowayout = WATCHDOG_NOWAYOUT;
 module_param(nowayout, bool, 0000);
···
 	struct clk *clk;
 };
 
-static void imx7ulp_wdt_enable(struct watchdog_device *wdog, bool enable)
+static int imx7ulp_wdt_wait(void __iomem *base, u32 mask)
+{
+	u32 val = readl(base + WDOG_CS);
+
+	if (!(val & mask) && readl_poll_timeout_atomic(base + WDOG_CS, val,
+						       val & mask, 0,
+						       WDOG_WAIT_TIMEOUT))
+		return -ETIMEDOUT;
+
+	return 0;
+}
+
+static int imx7ulp_wdt_enable(struct watchdog_device *wdog, bool enable)
 {
 	struct imx7ulp_wdt_device *wdt = watchdog_get_drvdata(wdog);
 
 	u32 val = readl(wdt->base + WDOG_CS);
+	int ret;
 
+	local_irq_disable();
 	writel(UNLOCK, wdt->base + WDOG_CNT);
+	ret = imx7ulp_wdt_wait(wdt->base, WDOG_CS_ULK);
+	if (ret)
+		goto enable_out;
 	if (enable)
 		writel(val | WDOG_CS_EN, wdt->base + WDOG_CS);
 	else
 		writel(val & ~WDOG_CS_EN, wdt->base + WDOG_CS);
+	imx7ulp_wdt_wait(wdt->base, WDOG_CS_RCS);
+
+enable_out:
+	local_irq_enable();
+
+	return ret;
 }
 
 static bool imx7ulp_wdt_is_enabled(void __iomem *base)
···
 
 static int imx7ulp_wdt_start(struct watchdog_device *wdog)
 {
-
-	imx7ulp_wdt_enable(wdog, true);
-
-	return 0;
+	return imx7ulp_wdt_enable(wdog, true);
 }
 
 static int imx7ulp_wdt_stop(struct watchdog_device *wdog)
 {
-	imx7ulp_wdt_enable(wdog, false);
-
-	return 0;
+	return imx7ulp_wdt_enable(wdog, false);
 }
 
 static int imx7ulp_wdt_set_timeout(struct watchdog_device *wdog,
···
 {
 	struct imx7ulp_wdt_device *wdt = watchdog_get_drvdata(wdog);
 	u32 val = WDOG_CLOCK_RATE * timeout;
+	int ret;
 
+	local_irq_disable();
 	writel(UNLOCK, wdt->base + WDOG_CNT);
+	ret = imx7ulp_wdt_wait(wdt->base, WDOG_CS_ULK);
+	if (ret)
+		goto timeout_out;
 	writel(val, wdt->base + WDOG_TOVAL);
+	imx7ulp_wdt_wait(wdt->base, WDOG_CS_RCS);
 
 	wdog->timeout = timeout;
 
-	return 0;
+timeout_out:
+	local_irq_enable();
+
+	return ret;
 }
 
 static int imx7ulp_wdt_restart(struct watchdog_device *wdog,
 			       unsigned long action, void *data)
 {
 	struct imx7ulp_wdt_device *wdt = watchdog_get_drvdata(wdog);
+	int ret;
 
-	imx7ulp_wdt_enable(wdog, true);
-	imx7ulp_wdt_set_timeout(&wdt->wdd, 1);
+	ret = imx7ulp_wdt_enable(wdog, true);
+	if (ret)
+		return ret;
+
+	ret = imx7ulp_wdt_set_timeout(&wdt->wdd, 1);
+	if (ret)
+		return ret;
 
 	/* wait for wdog to fire */
 	while (true)
···
 		    WDIOF_MAGICCLOSE,
 };
 
-static void imx7ulp_wdt_init(void __iomem *base, unsigned int timeout)
+static int imx7ulp_wdt_init(void __iomem *base, unsigned int timeout)
 {
 	u32 val;
+	int ret;
 
+	local_irq_disable();
 	/* unlock the wdog for reconfiguration */
 	writel_relaxed(UNLOCK_SEQ0, base + WDOG_CNT);
 	writel_relaxed(UNLOCK_SEQ1, base + WDOG_CNT);
+	ret = imx7ulp_wdt_wait(base, WDOG_CS_ULK);
+	if (ret)
+		goto init_out;
 
 	/* set an initial timeout value in TOVAL */
 	writel(timeout, base + WDOG_TOVAL);
 	/* enable 32bit command sequence and reconfigure */
-	val = WDOG_CS_CMD32EN | WDOG_CS_CLK | WDOG_CS_UPDATE;
+	val = WDOG_CS_CMD32EN | WDOG_CS_CLK | WDOG_CS_UPDATE |
+	      WDOG_CS_WAIT | WDOG_CS_STOP;
 	writel(val, base + WDOG_CS);
+	imx7ulp_wdt_wait(base, WDOG_CS_RCS);
+
+init_out:
+	local_irq_enable();
+
+	return ret;
 }
 
 static void imx7ulp_wdt_action(void *data)
···
 	watchdog_stop_on_reboot(wdog);
 	watchdog_stop_on_unregister(wdog);
 	watchdog_set_drvdata(wdog, imx7ulp_wdt);
-	imx7ulp_wdt_init(imx7ulp_wdt->base, wdog->timeout * WDOG_CLOCK_RATE);
+	ret = imx7ulp_wdt_init(imx7ulp_wdt->base, wdog->timeout * WDOG_CLOCK_RATE);
+	if (ret)
+		return ret;
 
 	return devm_watchdog_register_device(dev, wdog);
 }

drivers/watchdog/it87_wdt.c

···
  *	Support of the watchdog timers, which are available on
  *	IT8607, IT8620, IT8622, IT8625, IT8628, IT8655, IT8665, IT8686,
  *	IT8702, IT8712, IT8716, IT8718, IT8720, IT8721, IT8726, IT8728,
- *	and IT8783.
+ *	IT8772, IT8783 and IT8784.
  */
 
 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
···
 #define IT8721_ID	0x8721
 #define IT8726_ID	0x8726	/* the data sheet suggest wrongly 0x8716 */
 #define IT8728_ID	0x8728
+#define IT8772_ID	0x8772
 #define IT8783_ID	0x8783
+#define IT8784_ID	0x8784
 #define IT8786_ID	0x8786
 
 /* GPIO Configuration Registers LDN=0x07 */
···
 	case IT8720_ID:
 	case IT8721_ID:
 	case IT8728_ID:
+	case IT8772_ID:
 	case IT8783_ID:
+	case IT8784_ID:
 	case IT8786_ID:
 		max_units = 65535;
 		break;

drivers/watchdog/pcwd_usb.c

···
 
 	/* set up the memory buffer's */
 	usb_pcwd->intr_buffer = usb_alloc_coherent(udev, usb_pcwd->intr_size,
-					GFP_ATOMIC, &usb_pcwd->intr_dma);
+					GFP_KERNEL, &usb_pcwd->intr_dma);
 	if (!usb_pcwd->intr_buffer) {
 		pr_err("Out of memory\n");
 		goto error;

drivers/watchdog/rdc321x_wdt.c

···
 
 	rdc321x_wdt_device.sb_pdev = pdata->sb_pdev;
 	rdc321x_wdt_device.base_reg = r->start;
+	rdc321x_wdt_device.queue = 0;
+	rdc321x_wdt_device.default_ticks = ticks;
 
 	err = misc_register(&rdc321x_wdt_misc);
 	if (err < 0) {
···
 				rdc321x_wdt_device.base_reg, RDC_WDT_RST);
 
 	init_completion(&rdc321x_wdt_device.stop);
-	rdc321x_wdt_device.queue = 0;
 
 	clear_bit(0, &rdc321x_wdt_device.inuse);
 
 	timer_setup(&rdc321x_wdt_device.timer, rdc321x_wdt_trigger, 0);
-
-	rdc321x_wdt_device.default_ticks = ticks;
 
 	dev_info(&pdev->dev, "watchdog init success\n");
 

drivers/watchdog/renesas_wdt.c

···
 	struct clk *clk;
 	unsigned long clks_per_sec;
 	int ret, i;
+	u8 csra;
 
 	if (rwdt_blacklisted(dev))
 		return -ENODEV;
···
 	pm_runtime_enable(dev);
 	pm_runtime_get_sync(dev);
 	priv->clk_rate = clk_get_rate(clk);
-	priv->wdev.bootstatus = (readb_relaxed(priv->base + RWTCSRA) &
-				RWTCSRA_WOVF) ? WDIOF_CARDRESET : 0;
+	csra = readb_relaxed(priv->base + RWTCSRA);
+	priv->wdev.bootstatus = csra & RWTCSRA_WOVF ? WDIOF_CARDRESET : 0;
 	pm_runtime_put(dev);
 
 	if (!priv->clk_rate) {
···
 
 	/* This overrides the default timeout only if DT configuration was found */
 	watchdog_init_timeout(&priv->wdev, 0, dev);
+
+	/* Check if FW enabled the watchdog */
+	if (csra & RWTCSRA_TME) {
+		/* Ensure properly initialized dividers */
+		rwdt_start(&priv->wdev);
+		set_bit(WDOG_HW_RUNNING, &priv->wdev.status);
+	}
 
 	ret = watchdog_register_device(&priv->wdev);
 	if (ret < 0)

drivers/watchdog/rti_wdt.c

···
 		return -ENOMEM;
 
 	clk = clk_get(dev, NULL);
-	if (IS_ERR(clk)) {
-		if (PTR_ERR(clk) != -EPROBE_DEFER)
-			dev_err(dev, "failed to get clock\n");
-		return PTR_ERR(clk);
-	}
+	if (IS_ERR(clk))
+		return dev_err_probe(dev, PTR_ERR(clk), "failed to get clock\n");
 
 	wdt->freq = clk_get_rate(clk);
 
···
 
 	pm_runtime_enable(dev);
 	ret = pm_runtime_get_sync(dev);
-	if (ret) {
-		if (ret != -EPROBE_DEFER)
-			dev_err(&pdev->dev, "runtime pm failed\n");
-		return ret;
-	}
+	if (ret)
+		return dev_err_probe(dev, ret, "runtime pm failed\n");
 
 	platform_set_drvdata(pdev, wdt);
 

drivers/watchdog/sp5100_tco.c

···
  *	    AMD Publication 51192 "AMD Bolton FCH Register Reference Guide"
  *	    AMD Publication 52740 "BIOS and Kernel Developer’s Guide (BKDG)
  *				for AMD Family 16h Models 30h-3Fh Processors"
+ *	    AMD Publication 55570-B1-PUB "Processor Programming Reference (PPR)
+ *				for AMD Family 17h Model 18h, Revision B1
+ *				Processors (PUB)
+ *	    AMD Publication 55772-A1-PUB "Processor Programming Reference (PPR)
+ *				for AMD Family 17h Model 20h, Revision A1
+ *				Processors (PUB)
  */
 
 /*
···
 		break;
 	case efch:
 		dev_name = SB800_DEVNAME;
+		/*
+		 * On Family 17h devices, the EFCH_PM_DECODEEN_WDT_TMREN bit of
+		 * EFCH_PM_DECODEEN not only enables the EFCH_PM_WDT_ADDR memory
+		 * region, it also enables the watchdog itself.
+		 */
+		if (boot_cpu_data.x86 == 0x17) {
+			val = sp5100_tco_read_pm_reg8(EFCH_PM_DECODEEN);
+			if (!(val & EFCH_PM_DECODEEN_WDT_TMREN)) {
+				sp5100_tco_update_pm_reg8(EFCH_PM_DECODEEN, 0xff,
+							  EFCH_PM_DECODEEN_WDT_TMREN);
+			}
+		}
 		val = sp5100_tco_read_pm_reg8(EFCH_PM_DECODEEN);
 		if (val & EFCH_PM_DECODEEN_WDT_TMREN)
 			mmio_addr = EFCH_PM_WDT_ADDR;

drivers/watchdog/sp5100_tco.h

···
 #define EFCH_PM_DECODEEN_WDT_TMREN	BIT(7)
 
 
-#define EFCH_PM_DECODEEN3		0x00
+#define EFCH_PM_DECODEEN3		0x03
 #define EFCH_PM_DECODEEN_SECOND_RES	GENMASK(1, 0)
 #define EFCH_PM_WATCHDOG_DISABLE	((u8)GENMASK(3, 2))
 

drivers/watchdog/visconti_wdt.c

···
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (c) 2020 TOSHIBA CORPORATION
+ * Copyright (c) 2020 Toshiba Electronic Devices & Storage Corporation
+ * Copyright (c) 2020 Nobuhiro Iwamatsu <[e-mail]>
+ */
+
+#include <linux/clk.h>
+#include <linux/io.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/watchdog.h>
+
+#define WDT_CNT			0x00
+#define WDT_MIN			0x04
+#define WDT_MAX			0x08
+#define WDT_CTL			0x0c
+#define WDT_CMD			0x10
+#define WDT_CMD_CLEAR		0x4352
+#define WDT_CMD_START_STOP	0x5354
+#define WDT_DIV			0x30
+
+#define VISCONTI_WDT_FREQ	2000000 /* 2MHz */
+#define WDT_DEFAULT_TIMEOUT	10U /* in seconds */
+
+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 visconti_wdt_priv {
+	struct watchdog_device wdev;
+	void __iomem *base;
+	u32 div;
+};
+
+static int visconti_wdt_start(struct watchdog_device *wdev)
+{
+	struct visconti_wdt_priv *priv = watchdog_get_drvdata(wdev);
+	u32 timeout = wdev->timeout * VISCONTI_WDT_FREQ;
+
+	writel(priv->div, priv->base + WDT_DIV);
+	writel(0, priv->base + WDT_MIN);
+	writel(timeout, priv->base + WDT_MAX);
+	writel(0, priv->base + WDT_CTL);
+	writel(WDT_CMD_START_STOP, priv->base + WDT_CMD);
+
+	return 0;
+}
+
+static int visconti_wdt_stop(struct watchdog_device *wdev)
+{
+	struct visconti_wdt_priv *priv = watchdog_get_drvdata(wdev);
+
+	writel(1, priv->base + WDT_CTL);
+	writel(WDT_CMD_START_STOP, priv->base + WDT_CMD);
+
+	return 0;
+}
+
+static int visconti_wdt_ping(struct watchdog_device *wdd)
+{
+	struct visconti_wdt_priv *priv = watchdog_get_drvdata(wdd);
+
+	writel(WDT_CMD_CLEAR, priv->base + WDT_CMD);
+
+	return 0;
+}
+
+static unsigned int visconti_wdt_get_timeleft(struct watchdog_device *wdev)
+{
+	struct visconti_wdt_priv *priv = watchdog_get_drvdata(wdev);
+	u32 timeout = wdev->timeout * VISCONTI_WDT_FREQ;
+	u32 cnt = readl(priv->base + WDT_CNT);
+
+	if (timeout <= cnt)
+		return 0;
+	timeout -= cnt;
+
+	return timeout / VISCONTI_WDT_FREQ;
+}
+
+static int visconti_wdt_set_timeout(struct watchdog_device *wdev, unsigned int timeout)
+{
+	u32 val;
+	struct visconti_wdt_priv *priv = watchdog_get_drvdata(wdev);
+
+	wdev->timeout = timeout;
+	val = wdev->timeout * VISCONTI_WDT_FREQ;
+
+	/* Clear counter before setting timeout because WDT expires */
+	writel(WDT_CMD_CLEAR, priv->base + WDT_CMD);
+	writel(val, priv->base + WDT_MAX);
+
+	return 0;
+}
+
+static const struct watchdog_info visconti_wdt_info = {
+	.options = WDIOF_SETTIMEOUT | WDIOF_MAGICCLOSE | WDIOF_KEEPALIVEPING,
+	.identity = "Visconti Watchdog",
+};
+
+static const struct watchdog_ops visconti_wdt_ops = {
+	.owner		= THIS_MODULE,
+	.start		= visconti_wdt_start,
+	.stop		= visconti_wdt_stop,
+	.ping		= visconti_wdt_ping,
+	.get_timeleft	= visconti_wdt_get_timeleft,
+	.set_timeout	= visconti_wdt_set_timeout,
+};
+
+static void visconti_clk_disable_unprepare(void *data)
+{
+	clk_disable_unprepare(data);
+}
+
+static int visconti_wdt_probe(struct platform_device *pdev)
+{
+	struct watchdog_device *wdev;
+	struct visconti_wdt_priv *priv;
+	struct device *dev = &pdev->dev;
+	struct clk *clk;
+	int ret;
+	unsigned long clk_freq;
+
+	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);
+
+	clk = devm_clk_get(dev, NULL);
+	if (IS_ERR(clk))
+		return dev_err_probe(dev, PTR_ERR(clk), "Could not get clock\n");
+
+	ret = clk_prepare_enable(clk);
+	if (ret) {
+		dev_err(dev, "Could not enable clock\n");
+		return ret;
+	}
+
+	ret = devm_add_action_or_reset(dev, visconti_clk_disable_unprepare, clk);
+	if (ret)
+		return ret;
+
+	clk_freq = clk_get_rate(clk);
+	if (!clk_freq)
+		return -EINVAL;
+
+	priv->div = clk_freq / VISCONTI_WDT_FREQ;
+
+	/* Initialize struct watchdog_device. */
+	wdev = &priv->wdev;
+	wdev->info = &visconti_wdt_info;
+	wdev->ops = &visconti_wdt_ops;
+	wdev->parent = dev;
+	wdev->min_timeout = 1;
+	wdev->max_timeout = 0xffffffff / VISCONTI_WDT_FREQ;
+	wdev->timeout = min(wdev->max_timeout, WDT_DEFAULT_TIMEOUT);
+
+	watchdog_set_drvdata(wdev, priv);
+	watchdog_set_nowayout(wdev, nowayout);
+	watchdog_stop_on_unregister(wdev);
+
+	/* This overrides the default timeout only if DT configuration was found */
+	ret = watchdog_init_timeout(wdev, 0, dev);
+	if (ret)
+		dev_warn(dev, "Specified timeout value invalid, using default\n");
+
+	return devm_watchdog_register_device(dev, wdev);
+}
+
+static const struct of_device_id visconti_wdt_of_match[] = {
+	{ .compatible = "toshiba,visconti-wdt", },
+	{}
+};
+MODULE_DEVICE_TABLE(of, visconti_wdt_of_match);
+
+static struct platform_driver visconti_wdt_driver = {
+	.driver = {
+			.name = "visconti_wdt",
+			.of_match_table = visconti_wdt_of_match,
+		},
+	.probe = visconti_wdt_probe,
+};
+module_platform_driver(visconti_wdt_driver);
+
+MODULE_DESCRIPTION("TOSHIBA Visconti Watchdog Driver");
+MODULE_AUTHOR("Nobuhiro Iwamatsu <[e-mail]");
+MODULE_LICENSE("GPL v2");

drivers/watchdog/watchdog_dev.c

···
 #include <linux/watchdog.h>	/* For watchdog specific items */
 #include <linux/uaccess.h>	/* For copy_to_user/put_user/... */
 
-#include <uapi/linux/sched/types.h>	/* For struct sched_param */
-
 #include "watchdog_core.h"
 #include "watchdog_pretimeout.h"
 
···
 	wd_data->wdd = wdd;
 	wdd->wd_data = wd_data;
 
-	if (IS_ERR_OR_NULL(watchdog_kworker))
+	if (IS_ERR_OR_NULL(watchdog_kworker)) {
+		kfree(wd_data);
 		return -ENODEV;
+	}
 
 	device_initialize(&wd_data->dev);
 	wd_data->dev.devt = MKDEV(MAJOR(watchdog_devt), wdd->id);
···
 				pr_err("%s: a legacy watchdog module is probably present.\n",
 					wdd->info->identity);
 			old_wd_data = NULL;
-			kfree(wd_data);
+			put_device(&wd_data->dev);
 			return err;
 		}
 	}