[PATCH v2 0/4] watchdog: Introduce new driver to support ST's Watchdog

[PATCH v2 0/4] watchdog: Introduce new driver to support ST's Watchdog

[Lee Jones]

Hi Wim,

Basic driver to support ST's LPC Watchdog device.

Kind regards,
Lee

v1 => v2:
 - Fixed reset enable masks
 - Fixed DT documentation

Lee Jones (4):
  ARM: STi: DT: STiH407: Add Device Tree node for LPC Watchdog
  ARM: multi_v7_defconfig: Enable support for ST's LPC Watchdog
  watchdog: st_wdt: Provide binding documentation for ST's LPC Watchdog
    driver
  watchdog: st_wdt: Add new driver for ST's LPC Watchdog

 .../devicetree/bindings/watchdog/st-lpc-wdt.txt    |  30 ++
 arch/arm/boot/dts/stih407.dtsi                     |  10 +
 arch/arm/configs/multi_v7_defconfig                |   1 +
 drivers/watchdog/Kconfig                           |  16 +
 drivers/watchdog/Makefile                          |   1 +
 drivers/watchdog/st_wdt.c                          | 325 +++++++++++++++++++++
 6 files changed, 383 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/watchdog/st-lpc-wdt.txt
 create mode 100644 drivers/watchdog/st_wdt.c

-- 
1.9.1

[PATCH 1/4] ARM: STi: DT: STiH407: Add Device Tree node for LPC Watchdog

[Lee Jones]

Signed-off-by: David Paris <david.paris@st.com>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
---
 arch/arm/boot/dts/stih407.dtsi | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/arch/arm/boot/dts/stih407.dtsi b/arch/arm/boot/dts/stih407.dtsi
index f539627a..303df6c 100644
--- a/arch/arm/boot/dts/stih407.dtsi
+++ b/arch/arm/boot/dts/stih407.dtsi
@@ -259,5 +259,15 @@
 
 			status = "disabled";
 		};
+
+		watchdog at 0x8787000 {
+			compatible = "st,stih407-watchdog";
+			reg = <0x8787000 0x1000>, <0x204 0x4>;
+			reg-names = "base", "syscfg-en";
+			clock-names = "st_wdog";
+			clocks = <&clk_s_d3_flexgen CLK_LPC_0>;
+			timeout-sec = <600>;
+			st,syscfg = <&syscfg_core>;
+		};
 	};
 };
-- 
1.9.1

[PATCH 2/4] ARM: multi_v7_defconfig: Enable support for ST's LPC Watchdog

[Lee Jones]

Signed-off-by: Lee Jones <lee.jones@linaro.org>
---
 arch/arm/configs/multi_v7_defconfig | 1 +
 1 file changed, 1 insertion(+)

diff --git a/arch/arm/configs/multi_v7_defconfig b/arch/arm/configs/multi_v7_defconfig
index 5fb95fb..034aeab 100644
--- a/arch/arm/configs/multi_v7_defconfig
+++ b/arch/arm/configs/multi_v7_defconfig
@@ -238,6 +238,7 @@ CONFIG_ST_THERMAL_SYSCFG=y
 CONFIG_ST_THERMAL_MEMMAP=y
 CONFIG_WATCHDOG=y
 CONFIG_ORION_WATCHDOG=y
+CONFIG_ST_WATCHDOG=y
 CONFIG_SUNXI_WATCHDOG=y
 CONFIG_MFD_AS3722=y
 CONFIG_MFD_BCM590XX=y
-- 
1.9.1

[PATCH 3/4] watchdog: st_wdt: Provide binding documentation for ST's LPC Watchdog driver

[Lee Jones]

Cc: devicetree at vger.kernel.org
Signed-off-by: David Paris <david.paris@st.com>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
---
 .../devicetree/bindings/watchdog/st-lpc-wdt.txt    | 30 ++++++++++++++++++++++
 1 file changed, 30 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/watchdog/st-lpc-wdt.txt

diff --git a/Documentation/devicetree/bindings/watchdog/st-lpc-wdt.txt b/Documentation/devicetree/bindings/watchdog/st-lpc-wdt.txt
new file mode 100644
index 0000000..520ce90
--- /dev/null
+++ b/Documentation/devicetree/bindings/watchdog/st-lpc-wdt.txt
@@ -0,0 +1,30 @@
+STMicroelectronics LPC Watchdog
+===============================
+
+Required properties
+
+- compatible 	: Must be one of:
+			"st,stih407-watchdog"
+			"st,stih416-watchdog"
+			"st,stih415-watchdog"
+			"st,stid127-watchdog"
+- reg		: LPC registers base address + range
+- reg-names	: Register map "base" and "syscfg-en" are compulsory. "type" is
+		  platform dependent and not required for the STiH407
+- clock-names 	: Should be "lpc_wdt"
+- clocks	: Clock used by LPC device
+- timeout-sec	: Watchdog timeout in seconds
+- st,syscfg	: Syscfg node used to configure CPU reset type and mask
+- st,warm_reset	: If present, reset type will be 'warm'. If not, it will be cold
+
+Example:
+	watchdog at fde05000 {
+		compatible	= "st,stih416-lpc-watchdog";
+		reg		= <0xfde05000 0x1000> <0x204 0x4>;
+		reg-names	= "base", "syscfg-en"
+		clock-names	= "lpc_wdt";
+		clocks 		= <&clk_s_d3_flexgen CLK_LPC_0>;
+		timeout-sec	= <600>;
+		st,syscfg	= <&syscfg_core>;
+		st,warm_reset;
+	};
-- 
1.9.1

[PATCH 4/4] watchdog: st_wdt: Add new driver for ST's LPC Watchdog

[Lee Jones]

Signed-off-by: David Paris <david.paris@st.com>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
---
 drivers/watchdog/Kconfig  |  16 +++
 drivers/watchdog/Makefile |   1 +
 drivers/watchdog/st_wdt.c | 325 ++++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 342 insertions(+)
 create mode 100644 drivers/watchdog/st_wdt.c

diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig
index f57312f..c8abf57 100644
--- a/drivers/watchdog/Kconfig
+++ b/drivers/watchdog/Kconfig
@@ -432,6 +432,22 @@ config SIRFSOC_WATCHDOG
 	  Support for CSR SiRFprimaII and SiRFatlasVI watchdog. When
 	  the watchdog triggers the system will be reset.
 
+config ST_WATCHDOG
+       tristate "STMicroelectronics LPC Watchdog"
+       depends on ARCH_STI && OF
+       depends on !RTC_DRV_ST_LPC
+       select WATCHDOG_CORE
+       help
+	 Say Y here to include Watchdog timer support for the watchdog
+	 existing in the LPC of STMicroelectronics SOCs.
+	 !!! BE CARREFUL !!!
+	 This driver shares hardware resources with RTC Alarm part of the
+	 LPC. Both LPC Watchdog driver and LPC RTC driver cannot be
+	 used together.
+
+	 To compile this driver as a module, choose M here: the
+	 module will be called st-wdt.
+
 config TEGRA_WATCHDOG
 	tristate "Tegra watchdog"
 	depends on ARCH_TEGRA || COMPILE_TEST
diff --git a/drivers/watchdog/Makefile b/drivers/watchdog/Makefile
index 468c320..eb19937 100644
--- a/drivers/watchdog/Makefile
+++ b/drivers/watchdog/Makefile
@@ -57,6 +57,7 @@ obj-$(CONFIG_RETU_WATCHDOG) += retu_wdt.o
 obj-$(CONFIG_BCM2835_WDT) += bcm2835_wdt.o
 obj-$(CONFIG_MOXART_WDT) += moxart_wdt.o
 obj-$(CONFIG_SIRFSOC_WATCHDOG) += sirfsoc_wdt.o
+obj-$(CONFIG_ST_WATCHDOG) += st_wdt.o
 obj-$(CONFIG_BCM_KONA_WDT) += bcm_kona_wdt.o
 obj-$(CONFIG_TEGRA_WATCHDOG) += tegra_wdt.o
 
diff --git a/drivers/watchdog/st_wdt.c b/drivers/watchdog/st_wdt.c
new file mode 100644
index 0000000..97ead2b
--- /dev/null
+++ b/drivers/watchdog/st_wdt.c
@@ -0,0 +1,325 @@
+/*
+ * st-wdt.c -- ST's LPC Watchdog
+ *
+ * Copyright (C) 2014 STMicroelectronics -- All Rights Reserved
+ *
+ * Author: David Paris <david.paris@st.com> for STMicroelectronics
+ * Contributor: Lee Jones <lee.jones@linaro.org> for STMicroelectronics
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public Licence
+ * as published by the Free Software Foundation; either version
+ * 2 of the Licence, or (at your option) any later version.
+ */
+
+#include <linux/clk.h>
+#include <linux/init.h>
+#include <linux/io.h>
+#include <linux/kernel.h>
+#include <linux/mfd/syscon.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_platform.h>
+#include <linux/platform_device.h>
+#include <linux/regmap.h>
+#include <linux/watchdog.h>
+
+/* Low Power Alarm */
+#define LPC_LPA_LSB_OFF			0x410
+#define LPC_LPA_START_OFF		0x418
+
+/* LPC as WDT */
+#define LPC_WDT_OFF			0x510
+
+#define WATCHDOG_MIN			1
+#define WATCHDOG_MAX32			4294967 /* 32bit resolution */
+
+#define WDT_ENABLE			1
+#define WDT_DISABLE			0
+
+struct st_wdog_syscfg {
+	struct regmap *regmap;
+	unsigned int type_reg;
+	unsigned int type_mask;
+	unsigned int enable_reg;
+	unsigned int enable_mask;
+};
+
+struct st_wdog {
+	void __iomem *base;
+	struct device *dev;
+	struct st_wdog_syscfg *syscfg;
+	struct clk *clk;
+	int warm_reset;
+};
+
+static struct st_wdog_syscfg stid127_syscfg = {
+	.type_mask	= BIT(2),
+	.enable_mask	= BIT(2),
+};
+
+static struct st_wdog_syscfg stih415_syscfg = {
+	.type_mask	= BIT(6),
+	.enable_mask	= BIT(7),
+};
+
+static struct st_wdog_syscfg stih416_syscfg = {
+	.type_mask	= BIT(6),
+	.enable_mask	= BIT(7),
+};
+
+static struct st_wdog_syscfg stih407_syscfg = {
+	.enable_mask	= BIT(19),
+};
+
+static struct of_device_id st_wdog_match[] = {
+	{
+		.compatible = "st,stih407-watchdog",
+		.data = (void *)&stih407_syscfg,
+	},
+	{
+		.compatible = "st,stih416-watchdog",
+		.data = (void *)&stih416_syscfg,
+	},
+	{
+		.compatible = "st,stih415-watchdog",
+		.data = (void *)&stih415_syscfg,
+	},
+	{
+		.compatible = "st,stid127-watchdog",
+		.data = (void *)&stid127_syscfg,
+	},
+	{},
+};
+MODULE_DEVICE_TABLE(of, st_wdog_match);
+
+static void st_wdog_setup(struct st_wdog *st_wdog, bool enable)
+{
+	/* Type of watchdog reset - 0: Cold 1: Warm */
+	if (st_wdog->syscfg->type_reg)
+		regmap_update_bits(st_wdog->syscfg->regmap,
+				   st_wdog->syscfg->type_reg,
+				   st_wdog->syscfg->type_mask,
+				   st_wdog->warm_reset);
+
+	/* Mask/unmask watchdog reset */
+	regmap_update_bits(st_wdog->syscfg->regmap,
+			   st_wdog->syscfg->enable_reg,
+			   st_wdog->syscfg->enable_mask,
+			   enable ? 0 : st_wdog->syscfg->enable_mask);
+}
+
+static void st_wdog_load_timer(struct st_wdog *st_wdog, unsigned int timeout)
+{
+	unsigned long clkrate = clk_get_rate(st_wdog->clk);
+	int maxtimeout = 0xFFFFFFFF / clkrate;
+
+	if (timeout > maxtimeout) {
+		dev_warn(st_wdog->dev,
+			 "timer overrun detected at current freq (%dHz)\n"
+			 "wdog timeout set for %ds instead of requested %ds",
+			 clkrate, maxtimeout, timeout);
+		timeout = maxtimeout;
+	}
+	timeout *= clkrate;
+
+	writel_relaxed(timeout, st_wdog->base + LPC_LPA_LSB_OFF);
+	writel_relaxed(1, st_wdog->base + LPC_LPA_START_OFF);
+}
+
+static int st_wdog_start(struct watchdog_device *wdd)
+{
+	struct st_wdog *st_wdog = watchdog_get_drvdata(wdd);
+
+	writel_relaxed(1, st_wdog->base + LPC_WDT_OFF);
+
+	return 0;
+}
+
+static int st_wdog_stop(struct watchdog_device *wdd)
+{
+	struct st_wdog *st_wdog = watchdog_get_drvdata(wdd);
+
+	writel_relaxed(0, st_wdog->base + LPC_WDT_OFF);
+
+	return 0;
+}
+
+static int st_wdog_set_timeout(struct watchdog_device *wdd,
+			       unsigned int timeout)
+{
+	struct st_wdog *st_wdog = watchdog_get_drvdata(wdd);
+
+	wdd->timeout = timeout;
+	st_wdog_load_timer(st_wdog, timeout);
+
+	return 0;
+}
+
+static int st_wdog_keepalive(struct watchdog_device *wdd)
+{
+	struct st_wdog *st_wdog = watchdog_get_drvdata(wdd);
+
+	st_wdog_load_timer(st_wdog, wdd->timeout);
+
+	return 0;
+}
+
+static const struct watchdog_info st_wdog_info = {
+	.options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE,
+	.identity = "ST LPC WDT",
+};
+
+static const struct watchdog_ops st_wdog_ops = {
+	.owner		= THIS_MODULE,
+	.start		= st_wdog_start,
+	.stop		= st_wdog_stop,
+	.ping		= st_wdog_keepalive,
+	.set_timeout	= st_wdog_set_timeout,
+};
+
+static struct watchdog_device st_wdog_dev = {
+	.info		= &st_wdog_info,
+	.ops		= &st_wdog_ops,
+	.min_timeout	= WATCHDOG_MIN,
+	.max_timeout	= WATCHDOG_MAX32,
+};
+
+static int st_wdog_probe(struct platform_device *pdev)
+{
+	const struct of_device_id *match;
+	struct device_node *np = pdev->dev.of_node;
+	struct st_wdog *st_wdog;
+	struct regmap *regmap;
+	struct resource *res;
+	struct clk *clk;
+	void __iomem *base;
+	int ret;
+
+	st_wdog = devm_kzalloc(&pdev->dev, sizeof(*st_wdog), GFP_KERNEL);
+	if (!st_wdog)
+		return -ENOMEM;
+
+	match = of_match_device(st_wdog_match, &pdev->dev);
+	if (!match) {
+		dev_err(&pdev->dev, "Couldn't match device\n");
+		return -ENODEV;
+	}
+	st_wdog->syscfg	= (struct st_wdog_syscfg *)match->data;
+
+	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "base");
+	base = devm_ioremap_resource(&pdev->dev, res);
+	if (IS_ERR(base)) {
+		dev_err(&pdev->dev, "Failed to ioremap base\n");
+		return PTR_ERR(base);
+	}
+
+	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "syscfg-en");
+	if (!res) {
+		dev_err(&pdev->dev, "Failed to get enable register address\n");
+		return -EINVAL;
+	}
+	st_wdog->syscfg->enable_reg = res->start;
+
+	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "syscfg-type");
+	if (res)
+		st_wdog->syscfg->type_reg = res->start;
+
+	regmap = syscon_regmap_lookup_by_phandle(np, "st,syscfg");
+	if (IS_ERR(regmap)) {
+		dev_err(&pdev->dev, "No syscfg phandle specified\n");
+		return PTR_ERR(regmap);
+	}
+
+	clk = of_clk_get_by_name(np, "st_wdog");
+	if (IS_ERR(clk)) {
+		dev_err(&pdev->dev, "Unable to request clock\n");
+		return PTR_ERR(clk);
+	}
+	clk_prepare_enable(st_wdog->clk);
+
+	st_wdog->dev 		= &pdev->dev;
+	st_wdog->base 		= base;
+	st_wdog->clk		= clk;
+	st_wdog->warm_reset 	= of_property_read_bool(np, "st,warm_reset");
+	st_wdog->syscfg->regmap = regmap;
+
+	watchdog_set_drvdata(&st_wdog_dev, st_wdog);
+	watchdog_set_nowayout(&st_wdog_dev, WATCHDOG_NOWAYOUT);
+
+	ret = watchdog_register_device(&st_wdog_dev);
+	if (ret) {
+		dev_err(&pdev->dev, "Unable to register watchdog\n");
+		clk_disable_unprepare(clk);
+		return ret;
+	}
+
+	/* Init Watchdog timeout with value in DT */
+	ret = watchdog_init_timeout(&st_wdog_dev, 0, &pdev->dev);
+	if (ret) {
+		dev_err(&pdev->dev, "Unable to initialise watchdog timeout\n");
+		return ret;
+	}
+
+	st_wdog_setup(st_wdog, WDT_ENABLE);
+
+	dev_info(&pdev->dev, "LPC Watchdog driver registered, reset type is %s",
+		 st_wdog->warm_reset ? "warm" : "cold");
+
+	return ret;
+}
+
+static int st_wdog_remove(struct platform_device *pdev)
+{
+	struct st_wdog *st_wdog = watchdog_get_drvdata(&st_wdog_dev);
+
+	if (watchdog_active(&st_wdog_dev))
+		st_wdog_stop(&st_wdog_dev);
+
+	st_wdog_setup(st_wdog, WDT_DISABLE);
+
+	watchdog_unregister_device(&st_wdog_dev);
+
+	return 0;
+}
+
+#ifdef CONFIG_PM
+static int st_wdog_suspend(struct device *dev)
+{
+	if (watchdog_active(&st_wdog_dev))
+		st_wdog_stop(&st_wdog_dev);
+
+	return 0;
+}
+
+static int st_wdog_resume(struct device *dev)
+{
+	struct st_wdog *st_wdog = watchdog_get_drvdata(&st_wdog_dev);
+
+	if (watchdog_active(&st_wdog_dev)) {
+		st_wdog_load_timer(st_wdog, st_wdog_dev.timeout);
+		st_wdog_start(&st_wdog_dev);
+	}
+
+	return 0;
+}
+#endif
+
+static SIMPLE_DEV_PM_OPS(st_wdog_pm_ops,
+			 st_wdog_suspend,
+			 st_wdog_resume);
+
+static struct platform_driver st_wdog_driver = {
+	.driver	= {
+		.name = "st-wdt",
+		.pm = &st_wdog_pm_ops,
+		.of_match_table = st_wdog_match,
+	},
+	.probe = st_wdog_probe,
+	.remove = st_wdog_remove,
+};
+module_platform_driver(st_wdog_driver);
+
+MODULE_AUTHOR("David PARIS <david.paris@st.com>");
+MODULE_DESCRIPTION("ST LPC Watchdog Driver");
+MODULE_LICENSE("GPL v2");
-- 
1.9.1

[PATCH 4/4] watchdog: st_wdt: Add new driver for ST's LPC Watchdog

[Guenter Roeck]

On Tue, Oct 07, 2014 at 03:36:12PM +0100, Lee Jones wrote:
> Signed-off-by: David Paris <david.paris@st.com>
> Signed-off-by: Lee Jones <lee.jones@linaro.org>
> ---
>  drivers/watchdog/Kconfig  |  16 +++
>  drivers/watchdog/Makefile |   1 +
>  drivers/watchdog/st_wdt.c | 325 ++++++++++++++++++++++++++++++++++++++++++++++
>  3 files changed, 342 insertions(+)
>  create mode 100644 drivers/watchdog/st_wdt.c
> 
> diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig
> index f57312f..c8abf57 100644
> --- a/drivers/watchdog/Kconfig
> +++ b/drivers/watchdog/Kconfig
> @@ -432,6 +432,22 @@ config SIRFSOC_WATCHDOG
>  	  Support for CSR SiRFprimaII and SiRFatlasVI watchdog. When
>  	  the watchdog triggers the system will be reset.
>  
> +config ST_WATCHDOG
> +       tristate "STMicroelectronics LPC Watchdog"
> +       depends on ARCH_STI && OF
> +       depends on !RTC_DRV_ST_LPC
> +       select WATCHDOG_CORE
> +       help
> +	 Say Y here to include Watchdog timer support for the watchdog
> +	 existing in the LPC of STMicroelectronics SOCs.
> +	 !!! BE CARREFUL !!!
> +	 This driver shares hardware resources with RTC Alarm part of the
> +	 LPC. Both LPC Watchdog driver and LPC RTC driver cannot be
> +	 used together.
> +
> +	 To compile this driver as a module, choose M here: the
> +	 module will be called st-wdt.
> +
>  config TEGRA_WATCHDOG
>  	tristate "Tegra watchdog"
>  	depends on ARCH_TEGRA || COMPILE_TEST
> diff --git a/drivers/watchdog/Makefile b/drivers/watchdog/Makefile
> index 468c320..eb19937 100644
> --- a/drivers/watchdog/Makefile
> +++ b/drivers/watchdog/Makefile
> @@ -57,6 +57,7 @@ obj-$(CONFIG_RETU_WATCHDOG) += retu_wdt.o
>  obj-$(CONFIG_BCM2835_WDT) += bcm2835_wdt.o
>  obj-$(CONFIG_MOXART_WDT) += moxart_wdt.o
>  obj-$(CONFIG_SIRFSOC_WATCHDOG) += sirfsoc_wdt.o
> +obj-$(CONFIG_ST_WATCHDOG) += st_wdt.o
>  obj-$(CONFIG_BCM_KONA_WDT) += bcm_kona_wdt.o
>  obj-$(CONFIG_TEGRA_WATCHDOG) += tegra_wdt.o
>  
> diff --git a/drivers/watchdog/st_wdt.c b/drivers/watchdog/st_wdt.c
> new file mode 100644
> index 0000000..97ead2b
> --- /dev/null
> +++ b/drivers/watchdog/st_wdt.c
> @@ -0,0 +1,325 @@
> +/*
> + * st-wdt.c -- ST's LPC Watchdog
> + *
> + * Copyright (C) 2014 STMicroelectronics -- All Rights Reserved
> + *
> + * Author: David Paris <david.paris@st.com> for STMicroelectronics
> + * Contributor: Lee Jones <lee.jones@linaro.org> for STMicroelectronics
> + *
> + * This program is free software; you can redistribute it and/or
> + * modify it under the terms of the GNU General Public Licence
> + * as published by the Free Software Foundation; either version
> + * 2 of the Licence, or (at your option) any later version.
> + */
> +
> +#include <linux/clk.h>
> +#include <linux/init.h>
> +#include <linux/io.h>
> +#include <linux/kernel.h>
> +#include <linux/mfd/syscon.h>
> +#include <linux/module.h>
> +#include <linux/of.h>
> +#include <linux/of_platform.h>
> +#include <linux/platform_device.h>
> +#include <linux/regmap.h>
> +#include <linux/watchdog.h>
> +
> +/* Low Power Alarm */
> +#define LPC_LPA_LSB_OFF			0x410
> +#define LPC_LPA_START_OFF		0x418
> +
> +/* LPC as WDT */
> +#define LPC_WDT_OFF			0x510
> +
> +#define WATCHDOG_MIN			1
> +#define WATCHDOG_MAX32			4294967 /* 32bit resolution */
> +
> +#define WDT_ENABLE			1
> +#define WDT_DISABLE			0

Used as bool, so maybe should be true / false (though I am not sure if
those defines are really needed)

> +
> +struct st_wdog_syscfg {
> +	struct regmap *regmap;
> +	unsigned int type_reg;
> +	unsigned int type_mask;
> +	unsigned int enable_reg;
> +	unsigned int enable_mask;
> +};
> +
> +struct st_wdog {
> +	void __iomem *base;
> +	struct device *dev;
> +	struct st_wdog_syscfg *syscfg;
> +	struct clk *clk;
> +	int warm_reset;
> +};
> +
> +static struct st_wdog_syscfg stid127_syscfg = {
> +	.type_mask	= BIT(2),
> +	.enable_mask	= BIT(2),
> +};
> +
> +static struct st_wdog_syscfg stih415_syscfg = {
> +	.type_mask	= BIT(6),
> +	.enable_mask	= BIT(7),
> +};
> +
> +static struct st_wdog_syscfg stih416_syscfg = {
> +	.type_mask	= BIT(6),
> +	.enable_mask	= BIT(7),
> +};
> +
> +static struct st_wdog_syscfg stih407_syscfg = {
> +	.enable_mask	= BIT(19),
> +};
> +
> +static struct of_device_id st_wdog_match[] = {
> +	{
> +		.compatible = "st,stih407-watchdog",
> +		.data = (void *)&stih407_syscfg,
> +	},
> +	{
> +		.compatible = "st,stih416-watchdog",
> +		.data = (void *)&stih416_syscfg,
> +	},
> +	{
> +		.compatible = "st,stih415-watchdog",
> +		.data = (void *)&stih415_syscfg,
> +	},
> +	{
> +		.compatible = "st,stid127-watchdog",
> +		.data = (void *)&stid127_syscfg,
> +	},
> +	{},
> +};
> +MODULE_DEVICE_TABLE(of, st_wdog_match);
> +
> +static void st_wdog_setup(struct st_wdog *st_wdog, bool enable)
> +{
> +	/* Type of watchdog reset - 0: Cold 1: Warm */
> +	if (st_wdog->syscfg->type_reg)
> +		regmap_update_bits(st_wdog->syscfg->regmap,
> +				   st_wdog->syscfg->type_reg,
> +				   st_wdog->syscfg->type_mask,
> +				   st_wdog->warm_reset);
> +
> +	/* Mask/unmask watchdog reset */
> +	regmap_update_bits(st_wdog->syscfg->regmap,
> +			   st_wdog->syscfg->enable_reg,
> +			   st_wdog->syscfg->enable_mask,
> +			   enable ? 0 : st_wdog->syscfg->enable_mask);
> +}
> +
> +static void st_wdog_load_timer(struct st_wdog *st_wdog, unsigned int timeout)
> +{
> +	unsigned long clkrate = clk_get_rate(st_wdog->clk);
> +	int maxtimeout = 0xFFFFFFFF / clkrate;
> +
> +	if (timeout > maxtimeout) {
> +		dev_warn(st_wdog->dev,
> +			 "timer overrun detected at current freq (%dHz)\n"
> +			 "wdog timeout set for %ds instead of requested %ds",
> +			 clkrate, maxtimeout, timeout);
> +		timeout = maxtimeout;
> +	}
> +	timeout *= clkrate;
> +
> +	writel_relaxed(timeout, st_wdog->base + LPC_LPA_LSB_OFF);
> +	writel_relaxed(1, st_wdog->base + LPC_LPA_START_OFF);
> +}
> +
> +static int st_wdog_start(struct watchdog_device *wdd)
> +{
> +	struct st_wdog *st_wdog = watchdog_get_drvdata(wdd);
> +
> +	writel_relaxed(1, st_wdog->base + LPC_WDT_OFF);
> +
> +	return 0;
> +}
> +
> +static int st_wdog_stop(struct watchdog_device *wdd)
> +{
> +	struct st_wdog *st_wdog = watchdog_get_drvdata(wdd);
> +
> +	writel_relaxed(0, st_wdog->base + LPC_WDT_OFF);
> +
> +	return 0;
> +}
> +
> +static int st_wdog_set_timeout(struct watchdog_device *wdd,
> +			       unsigned int timeout)
> +{
> +	struct st_wdog *st_wdog = watchdog_get_drvdata(wdd);
> +
> +	wdd->timeout = timeout;
> +	st_wdog_load_timer(st_wdog, timeout);
> +
> +	return 0;
> +}
> +
> +static int st_wdog_keepalive(struct watchdog_device *wdd)
> +{
> +	struct st_wdog *st_wdog = watchdog_get_drvdata(wdd);
> +
> +	st_wdog_load_timer(st_wdog, wdd->timeout);
> +
> +	return 0;
> +}
> +
> +static const struct watchdog_info st_wdog_info = {
> +	.options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE,
> +	.identity = "ST LPC WDT",
> +};
> +
> +static const struct watchdog_ops st_wdog_ops = {
> +	.owner		= THIS_MODULE,
> +	.start		= st_wdog_start,
> +	.stop		= st_wdog_stop,
> +	.ping		= st_wdog_keepalive,
> +	.set_timeout	= st_wdog_set_timeout,
> +};
> +
> +static struct watchdog_device st_wdog_dev = {
> +	.info		= &st_wdog_info,
> +	.ops		= &st_wdog_ops,
> +	.min_timeout	= WATCHDOG_MIN,
> +	.max_timeout	= WATCHDOG_MAX32,
> +};
> +
> +static int st_wdog_probe(struct platform_device *pdev)
> +{
> +	const struct of_device_id *match;
> +	struct device_node *np = pdev->dev.of_node;
> +	struct st_wdog *st_wdog;
> +	struct regmap *regmap;
> +	struct resource *res;
> +	struct clk *clk;
> +	void __iomem *base;
> +	int ret;
> +
> +	st_wdog = devm_kzalloc(&pdev->dev, sizeof(*st_wdog), GFP_KERNEL);
> +	if (!st_wdog)
> +		return -ENOMEM;
> +
> +	match = of_match_device(st_wdog_match, &pdev->dev);
> +	if (!match) {
> +		dev_err(&pdev->dev, "Couldn't match device\n");
> +		return -ENODEV;
> +	}
> +	st_wdog->syscfg	= (struct st_wdog_syscfg *)match->data;
> +
> +	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "base");
> +	base = devm_ioremap_resource(&pdev->dev, res);
> +	if (IS_ERR(base)) {
> +		dev_err(&pdev->dev, "Failed to ioremap base\n");
> +		return PTR_ERR(base);
> +	}
> +
> +	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "syscfg-en");
> +	if (!res) {
> +		dev_err(&pdev->dev, "Failed to get enable register address\n");
> +		return -EINVAL;
> +	}
> +	st_wdog->syscfg->enable_reg = res->start;
> +
> +	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "syscfg-type");
> +	if (res)
> +		st_wdog->syscfg->type_reg = res->start;
> +
> +	regmap = syscon_regmap_lookup_by_phandle(np, "st,syscfg");
> +	if (IS_ERR(regmap)) {
> +		dev_err(&pdev->dev, "No syscfg phandle specified\n");
> +		return PTR_ERR(regmap);
> +	}
> +
> +	clk = of_clk_get_by_name(np, "st_wdog");
> +	if (IS_ERR(clk)) {
> +		dev_err(&pdev->dev, "Unable to request clock\n");
> +		return PTR_ERR(clk);
> +	}
> +	clk_prepare_enable(st_wdog->clk);
> +
> +	st_wdog->dev 		= &pdev->dev;
> +	st_wdog->base 		= base;
> +	st_wdog->clk		= clk;
> +	st_wdog->warm_reset 	= of_property_read_bool(np, "st,warm_reset");
> +	st_wdog->syscfg->regmap = regmap;
> +
> +	watchdog_set_drvdata(&st_wdog_dev, st_wdog);
> +	watchdog_set_nowayout(&st_wdog_dev, WATCHDOG_NOWAYOUT);
> +
> +	ret = watchdog_register_device(&st_wdog_dev);
> +	if (ret) {
> +		dev_err(&pdev->dev, "Unable to register watchdog\n");
> +		clk_disable_unprepare(clk);
> +		return ret;
> +	}
> +
> +	/* Init Watchdog timeout with value in DT */
> +	ret = watchdog_init_timeout(&st_wdog_dev, 0, &pdev->dev);
> +	if (ret) {
> +		dev_err(&pdev->dev, "Unable to initialise watchdog timeout\n");
> +		return ret;
> +	}

You should make that call prior to calling watchdog_register_device,
and clk_disable_unprepare is missing.

> +
> +	st_wdog_setup(st_wdog, WDT_ENABLE);
> +
> +	dev_info(&pdev->dev, "LPC Watchdog driver registered, reset type is %s",
> +		 st_wdog->warm_reset ? "warm" : "cold");
> +
> +	return ret;
> +}
> +
> +static int st_wdog_remove(struct platform_device *pdev)
> +{
> +	struct st_wdog *st_wdog = watchdog_get_drvdata(&st_wdog_dev);
> +
> +	if (watchdog_active(&st_wdog_dev))
> +		st_wdog_stop(&st_wdog_dev);
> +
I think this effectively defeats nowayout, since that is the only time
where the function can return true at this point. Are you sure you want
to do this here ?

> +	st_wdog_setup(st_wdog, WDT_DISABLE);
> +
> +	watchdog_unregister_device(&st_wdog_dev);
> +
clk_disable_unprepare ?

Thanks,
Guenter

> +	return 0;
> +}
> +
> +#ifdef CONFIG_PM
> +static int st_wdog_suspend(struct device *dev)
> +{
> +	if (watchdog_active(&st_wdog_dev))
> +		st_wdog_stop(&st_wdog_dev);
> +
> +	return 0;
> +}
> +
> +static int st_wdog_resume(struct device *dev)
> +{
> +	struct st_wdog *st_wdog = watchdog_get_drvdata(&st_wdog_dev);
> +
> +	if (watchdog_active(&st_wdog_dev)) {
> +		st_wdog_load_timer(st_wdog, st_wdog_dev.timeout);
> +		st_wdog_start(&st_wdog_dev);
> +	}
> +
> +	return 0;
> +}
> +#endif
> +
> +static SIMPLE_DEV_PM_OPS(st_wdog_pm_ops,
> +			 st_wdog_suspend,
> +			 st_wdog_resume);
> +
> +static struct platform_driver st_wdog_driver = {
> +	.driver	= {
> +		.name = "st-wdt",
> +		.pm = &st_wdog_pm_ops,
> +		.of_match_table = st_wdog_match,
> +	},
> +	.probe = st_wdog_probe,
> +	.remove = st_wdog_remove,
> +};
> +module_platform_driver(st_wdog_driver);
> +
> +MODULE_AUTHOR("David PARIS <david.paris@st.com>");
> +MODULE_DESCRIPTION("ST LPC Watchdog Driver");
> +MODULE_LICENSE("GPL v2");
> -- 
> 1.9.1
>