Merge git://www.linux-watchdog.org/linux-watchdog

Pull watchdog updates from Wim Van Sebroeck:
 "This adds the following new drivers:

   - ImgTec PDC Watchdog Timer Driver,
   - Mediatek SoC integrated watchdog

  Add support for BCM5301X, IT8783, NCT6791 and NCT6792 WDT's

  Add bcm47xx_wdt and da9063 restart handlers and contains overall
  improvements and fixes"

* git://www.linux-watchdog.org/linux-watchdog:
  watchdog: bcm47xx_wdt.c: allow enabling on BCM5301X arch
  watchdog: jz4740: Add DT support
  dt: watchdog: Add DT binding documentation for jz4740 watchdog timer
  watchdog: dw_wdt: Try to get a 30 second watchdog by default
  watchdog: dw_wdt: pat the watchdog before enabling it
  watchdog: w83627hf_wdt: Add support for NCT6791 and NCT6792
  watchdog: bcm47xx_wdt.c: add restart handler support
  watchdog: gpio_wdt: Add "always_running" feature to GPIO watchdog
  watchdog: da9063: Add restart handler support
  ARM: mediatek: dts: Add bindings for watchdog
  watchdog: Add driver for Mediatek watchdog
  watchdog: Fix omap watchdogs to enable the magic close bit
  watchdog: rt2880_wdt: minor clean up
  watchdog: hpwdt: Fix initialization message in hpwdt.c
  watchdog: it87_wdt: add IT8783 ID
  watchdog: imx2: Constify struct regmap_config and watchdog_ops
  DT: watchdog: Add ImgTec PDC Watchdog Timer binding documentation
  watchdog: ImgTec PDC Watchdog Timer Driver

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

@@ -13,6 +13,11 @@ Required Properties:
     by the GPIO flags.
 - hw_margin_ms: Maximum time to reset watchdog circuit (milliseconds).
 
+Optional Properties:
+- always-running: If the watchdog timer cannot be disabled, add this flag to
+  have the driver keep toggling the signal without a client. It will only cease
+  to toggle the signal when the device is open and the timeout elapsed.
+
 Example:
 	watchdog: watchdog {
 		/* ADM706 */

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

@@ -0,0 +1,19 @@
+*ImgTec PowerDown Controller (PDC) Watchdog Timer (WDT)
+
+Required properties:
+- compatible : Should be "img,pdc-wdt"
+- reg : Should contain WDT registers location and length
+- clocks: Must contain an entry for each entry in clock-names.
+- clock-names: Should contain "wdt" and "sys"; the watchdog counter
+               clock and register interface clock respectively.
+- interrupts : Should contain WDT interrupt
+
+Examples:
+
+watchdog@18102100 {
+	compatible = "img,pdc-wdt";
+	reg = <0x18102100 0x100>;
+	clocks = <&pdc_wdt_clk>, <&sys_clk>;
+	clock-names = "wdt", "sys";
+	interrupts = <0 52 IRQ_TYPE_LEVEL_HIGH>;
+};

Documentation/devicetree/bindings/watchdog/ingenic,jz4740-wdt.txt

@@ -0,0 +1,12 @@
+Ingenic Watchdog Timer (WDT) Controller for JZ4740
+
+Required properties:
+compatible: "ingenic,jz4740-watchdog"
+reg: Register address and length for watchdog registers
+
+Example:
+
+watchdog: jz4740-watchdog@0x10002000 {
+	compatible = "ingenic,jz4740-watchdog";
+	reg = <0x10002000 0x100>;
+};

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

@@ -0,0 +1,13 @@
+Mediatek SoCs Watchdog timer
+
+Required properties:
+
+- compatible : should be "mediatek,mt6589-wdt"
+- reg : Specifies base physical address and size of the registers.
+
+Example:
+
+wdt: watchdog@010000000 {
+	compatible = "mediatek,mt6589-wdt";
+	reg = <0x10000000 0x18>;
+};

drivers/watchdog/Kconfig

@@ -505,6 +505,16 @@ config MESON_WATCHDOG
 	  To compile this driver as a module, choose M here: the
 	  module will be called meson_wdt.
 
+config MEDIATEK_WATCHDOG
+	tristate "Mediatek SoCs watchdog support"
+	depends on ARCH_MEDIATEK
+	select WATCHDOG_CORE
+	help
+	  Say Y here to include support for the watchdog timer
+	  in Mediatek SoCs.
+	  To compile this driver as a module, choose M here: the
+	  module will be called mtk_wdt.
+
 # AVR32 Architecture
 
 config AT32AP700X_WDT
@@ -1005,6 +1015,8 @@ config W83627HF_WDT
 		NCT6775
 		NCT6776
 		NCT6779
+		NCT6791
+		NCT6792
 
 	  This watchdog simply watches your kernel to make sure it doesn't
 	  freeze, and if it does, it reboots your computer after a certain
@@ -1101,7 +1113,7 @@ config ATH79_WDT
 
 config BCM47XX_WDT
 	tristate "Broadcom BCM47xx Watchdog Timer"
-	depends on BCM47XX
+	depends on BCM47XX || ARCH_BCM_5301X
 	select WATCHDOG_CORE
 	help
 	  Hardware driver for the Broadcom BCM47xx Watchdog Timer.
@@ -1235,6 +1247,17 @@ config BCM_KONA_WDT_DEBUG
 
 	  If in doubt, say 'N'.
 
+config IMGPDC_WDT
+	tristate "Imagination Technologies PDC Watchdog Timer"
+	depends on HAS_IOMEM
+	depends on METAG || MIPS || COMPILE_TEST
+	help
+	  Driver for Imagination Technologies PowerDown Controller
+	  Watchdog Timer.
+
+	  To compile this driver as a loadable module, choose M here.
+	  The module will be called imgpdc_wdt.
+
 config LANTIQ_WDT
 	tristate "Lantiq SoC watchdog"
 	depends on LANTIQ

drivers/watchdog/Makefile

@@ -63,6 +63,7 @@ obj-$(CONFIG_QCOM_WDT) += qcom-wdt.o
 obj-$(CONFIG_BCM_KONA_WDT) += bcm_kona_wdt.o
 obj-$(CONFIG_TEGRA_WATCHDOG) += tegra_wdt.o
 obj-$(CONFIG_MESON_WATCHDOG) += meson_wdt.o
+obj-$(CONFIG_MEDIATEK_WATCHDOG) += mtk_wdt.o
 
 # AVR32 Architecture
 obj-$(CONFIG_AT32AP700X_WDT) += at32ap700x_wdt.o
@@ -142,6 +143,7 @@ obj-$(CONFIG_OCTEON_WDT) += octeon-wdt.o
 octeon-wdt-y := octeon-wdt-main.o octeon-wdt-nmi.o
 obj-$(CONFIG_LANTIQ_WDT) += lantiq_wdt.o
 obj-$(CONFIG_RALINK_WDT) += rt2880_wdt.o
+obj-$(CONFIG_IMGPDC_WDT) += imgpdc_wdt.o
 
 # PARISC Architecture
 

drivers/watchdog/bcm47xx_wdt.c

@@ -169,6 +169,17 @@ static int bcm47xx_wdt_notify_sys(struct notifier_block *this,
 	return NOTIFY_DONE;
 }
 
+static int bcm47xx_wdt_restart(struct notifier_block *this, unsigned long mode,
+			       void *cmd)
+{
+	struct bcm47xx_wdt *wdt;
+
+	wdt = container_of(this, struct bcm47xx_wdt, restart_handler);
+	wdt->timer_set(wdt, 1);
+
+	return NOTIFY_DONE;
+}
+
 static struct watchdog_ops bcm47xx_wdt_soft_ops = {
 	.owner		= THIS_MODULE,
 	.start		= bcm47xx_wdt_soft_start,
@@ -209,15 +220,23 @@ static int bcm47xx_wdt_probe(struct platform_device *pdev)
 	if (ret)
 		goto err_timer;
 
-	ret = watchdog_register_device(&wdt->wdd);
+	wdt->restart_handler.notifier_call = &bcm47xx_wdt_restart;
+	wdt->restart_handler.priority = 64;
+	ret = register_restart_handler(&wdt->restart_handler);
 	if (ret)
 		goto err_notifier;
 
+	ret = watchdog_register_device(&wdt->wdd);
+	if (ret)
+		goto err_handler;
+
 	dev_info(&pdev->dev, "BCM47xx Watchdog Timer enabled (%d seconds%s%s)\n",
 		timeout, nowayout ? ", nowayout" : "",
 		soft ? ", Software Timer" : "");
 	return 0;
 
+err_handler:
+	unregister_restart_handler(&wdt->restart_handler);
 err_notifier:
 	unregister_reboot_notifier(&wdt->notifier);
 err_timer:

drivers/watchdog/da9063_wdt.c

@@ -20,6 +20,7 @@
 #include <linux/delay.h>
 #include <linux/mfd/da9063/registers.h>
 #include <linux/mfd/da9063/core.h>
+#include <linux/reboot.h>
 #include <linux/regmap.h>
 
 /*
@@ -38,6 +39,7 @@ static const unsigned int wdt_timeout[] = { 0, 2, 4, 8, 16, 32, 65, 131 };
 struct da9063_watchdog {
 	struct da9063 *da9063;
 	struct watchdog_device wdtdev;
+	struct notifier_block restart_handler;
 };
 
 static unsigned int da9063_wdt_timeout_to_sel(unsigned int secs)
@@ -119,6 +121,23 @@ static int da9063_wdt_set_timeout(struct watchdog_device *wdd,
 	return ret;
 }
 
+static int da9063_wdt_restart_handler(struct notifier_block *this,
+				      unsigned long mode, void *cmd)
+{
+	struct da9063_watchdog *wdt = container_of(this,
+						   struct da9063_watchdog,
+						   restart_handler);
+	int ret;
+
+	ret = regmap_write(wdt->da9063->regmap, DA9063_REG_CONTROL_F,
+			   DA9063_SHUTDOWN);
+	if (ret)
+		dev_alert(wdt->da9063->dev, "Failed to shutdown (err = %d)\n",
+			  ret);
+
+	return NOTIFY_DONE;
+}
+
 static const struct watchdog_info da9063_watchdog_info = {
 	.options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING,
 	.identity = "DA9063 Watchdog",
@@ -163,14 +182,25 @@ static int da9063_wdt_probe(struct platform_device *pdev)
 	dev_set_drvdata(&pdev->dev, wdt);
 
 	ret = watchdog_register_device(&wdt->wdtdev);
+	if (ret)
+		return ret;
 
-	return ret;
+	wdt->restart_handler.notifier_call = da9063_wdt_restart_handler;
+	wdt->restart_handler.priority = 128;
+	ret = register_restart_handler(&wdt->restart_handler);
+	if (ret)
+		dev_err(wdt->da9063->dev,
+			"Failed to register restart handler (err = %d)\n", ret);
+
+	return 0;
 }
 
 static int da9063_wdt_remove(struct platform_device *pdev)
 {
 	struct da9063_watchdog *wdt = dev_get_drvdata(&pdev->dev);
 
+	unregister_restart_handler(&wdt->restart_handler);
+
 	watchdog_unregister_device(&wdt->wdtdev);
 
 	return 0;

drivers/watchdog/dw_wdt.c

@@ -51,6 +51,8 @@
 /* The maximum TOP (timeout period) value that can be set in the watchdog. */
 #define DW_WDT_MAX_TOP		15
 
+#define DW_WDT_DEFAULT_SECONDS	30
+
 static bool nowayout = WATCHDOG_NOWAYOUT;
 module_param(nowayout, bool, 0);
 MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started "
@@ -96,6 +98,12 @@ static inline void dw_wdt_set_next_heartbeat(void)
 	dw_wdt.next_heartbeat = jiffies + dw_wdt_get_top() * HZ;
 }
 
+static void dw_wdt_keepalive(void)
+{
+	writel(WDOG_COUNTER_RESTART_KICK_VALUE, dw_wdt.regs +
+	       WDOG_COUNTER_RESTART_REG_OFFSET);
+}
+
 static int dw_wdt_set_top(unsigned top_s)
 {
 	int i, top_val = DW_WDT_MAX_TOP;
@@ -110,21 +118,27 @@ static int dw_wdt_set_top(unsigned top_s)
 			break;
 		}
 
-	/* Set the new value in the watchdog. */
+	/*
+	 * Set the new value in the watchdog.  Some versions of dw_wdt
+	 * have have TOPINIT in the TIMEOUT_RANGE register (as per
+	 * CP_WDT_DUAL_TOP in WDT_COMP_PARAMS_1).  On those we
+	 * effectively get a pat of the watchdog right here.
+	 */
 	writel(top_val | top_val << WDOG_TIMEOUT_RANGE_TOPINIT_SHIFT,
 		dw_wdt.regs + WDOG_TIMEOUT_RANGE_REG_OFFSET);
 
+	/*
+	 * Add an explicit pat to handle versions of the watchdog that
+	 * don't have TOPINIT.  This won't hurt on versions that have
+	 * it.
+	 */
+	dw_wdt_keepalive();
+
 	dw_wdt_set_next_heartbeat();
 
 	return dw_wdt_top_in_seconds(top_val);
 }
 
-static void dw_wdt_keepalive(void)
-{
-	writel(WDOG_COUNTER_RESTART_KICK_VALUE, dw_wdt.regs +
-	       WDOG_COUNTER_RESTART_REG_OFFSET);
-}
-
 static int dw_wdt_restart_handle(struct notifier_block *this,
 				unsigned long mode, void *cmd)
 {
@@ -167,9 +181,9 @@ static int dw_wdt_open(struct inode *inode, struct file *filp)
 	if (!dw_wdt_is_enabled()) {
 		/*
 		 * The watchdog is not currently enabled. Set the timeout to
-		 * the maximum and then start it.
+		 * something reasonable and then start it.
 		 */
-		dw_wdt_set_top(DW_WDT_MAX_TOP);
+		dw_wdt_set_top(DW_WDT_DEFAULT_SECONDS);
 		writel(WDOG_CONTROL_REG_WDT_EN_MASK,
 		       dw_wdt.regs + WDOG_CONTROL_REG_OFFSET);
 	}

drivers/watchdog/gpio_wdt.c

@@ -31,6 +31,8 @@ struct gpio_wdt_priv {
 	int			gpio;
 	bool			active_low;
 	bool			state;
+	bool			always_running;
+	bool			armed;
 	unsigned int		hw_algo;
 	unsigned int		hw_margin;
 	unsigned long		last_jiffies;
@@ -48,14 +50,20 @@ static void gpio_wdt_disable(struct gpio_wdt_priv *priv)
 		gpio_direction_input(priv->gpio);
 }
 
-static int gpio_wdt_start(struct watchdog_device *wdd)
+static void gpio_wdt_start_impl(struct gpio_wdt_priv *priv)
 {
-	struct gpio_wdt_priv *priv = watchdog_get_drvdata(wdd);
-
 	priv->state = priv->active_low;
 	gpio_direction_output(priv->gpio, priv->state);
 	priv->last_jiffies = jiffies;
 	mod_timer(&priv->timer, priv->last_jiffies + priv->hw_margin);
+}
+
+static int gpio_wdt_start(struct watchdog_device *wdd)
+{
+	struct gpio_wdt_priv *priv = watchdog_get_drvdata(wdd);
+
+	gpio_wdt_start_impl(priv);
+	priv->armed = true;
 
 	return 0;
 }
@@ -64,8 +72,11 @@ static int gpio_wdt_stop(struct watchdog_device *wdd)
 {
 	struct gpio_wdt_priv *priv = watchdog_get_drvdata(wdd);
 
-	mod_timer(&priv->timer, 0);
-	gpio_wdt_disable(priv);
+	priv->armed = false;
+	if (!priv->always_running) {
+		mod_timer(&priv->timer, 0);
+		gpio_wdt_disable(priv);
+	}
 
 	return 0;
 }
@@ -91,8 +102,8 @@ static void gpio_wdt_hwping(unsigned long data)
 	struct watchdog_device *wdd = (struct watchdog_device *)data;
 	struct gpio_wdt_priv *priv = watchdog_get_drvdata(wdd);
 
-	if (time_after(jiffies, priv->last_jiffies +
-		       msecs_to_jiffies(wdd->timeout * 1000))) {
+	if (priv->armed && time_after(jiffies, priv->last_jiffies +
+				      msecs_to_jiffies(wdd->timeout * 1000))) {
 		dev_crit(wdd->dev, "Timer expired. System will reboot soon!\n");
 		return;
 	}
@@ -197,6 +208,9 @@ static int gpio_wdt_probe(struct platform_device *pdev)
 	/* Use safe value (1/2 of real timeout) */
 	priv->hw_margin = msecs_to_jiffies(hw_margin / 2);
 
+	priv->always_running = of_property_read_bool(pdev->dev.of_node,
+						     "always-running");
+
 	watchdog_set_drvdata(&priv->wdd, priv);
 
 	priv->wdd.info		= &gpio_wdt_ident;
@@ -216,8 +230,15 @@ static int gpio_wdt_probe(struct platform_device *pdev)
 	priv->notifier.notifier_call = gpio_wdt_notify_sys;
 	ret = register_reboot_notifier(&priv->notifier);
 	if (ret)
-		watchdog_unregister_device(&priv->wdd);
+		goto error_unregister;
 
+	if (priv->always_running)
+		gpio_wdt_start_impl(priv);
+
+	return 0;
+
+error_unregister:
+	watchdog_unregister_device(&priv->wdd);
 	return ret;
 }