[PATCH V5 0/3] Add watchdog DT nodes and use syscon regmap interfac to configure pmu registers

[PATCH V5 0/3] Add watchdog DT nodes and use syscon regmap interfac to configure pmu registers

[Leela Krishna Amudala]

This patchset does the following things
	- Adds pmusysreg device node to exynos5.dtsi file
	- Adds watchdog DT nodes to Exynos5250 and 5420
	- Uses syscon regmap interface to configure pmu registers
	  to mask/unmask enable/disable of watchdog.
	
This patch set is rebased on Kgene's for-next branch and tested on SMDK5420

Changes since V4:
	- changed the node name from pmusysreg to syscon and node label from pmu_sys_reg to pmu_syscon
	- changed the property name from samsung,pmusysreg to samsung,syscon-phandle
	- used regmap_update_bits instead of remap_read/regmap_write
	- Addressed other comments given by Tomasz Figa <t.figa@samsung.com>

Changes since V3:
	- changed the compatible strings for watchdog node
	- splitted up adding pmusysreg node and made it separate patch
	- Addressed comments given by Sachin Kamat <sachin.kamat@linaro.org>

Changes since V2:
	- used syscon regmap interface to configure pmu registers in WDT driver
	  (suggested by Tomasz Figa <t.figa@samsung.com>)

Changes since V1:
        - Added new compatible string for Exynos5 SoCs
        - Introduced quirk mechanism to program PMU registers
        - Addressed comments given by Tomasz Figa <t.figa@samsung.com>

Leela Krishna Amudala (3):
  ARM: dts: Add pmu sysreg node to Exynos5 dtsi file
  ARM: dts: add watchdog device nodes for Exynos5250 and Exynos5420
  watchdog: s3c2410_wdt: use syscon regmap interface to configure pmu
    register

 .../devicetree/bindings/watchdog/samsung-wdt.txt   |   22 ++-
 arch/arm/boot/dts/exynos5.dtsi                     |   12 +-
 arch/arm/boot/dts/exynos5250.dtsi                  |    7 +-
 arch/arm/boot/dts/exynos5420.dtsi                  |   10 ++
 drivers/watchdog/s3c2410_wdt.c                     |  150 +++++++++++++++++---
 5 files changed, 175 insertions(+), 26 deletions(-)

-- 
1.7.10.4

[PATCH V5 1/3] ARM: dts: Add pmu sysreg node to Exynos5 dtsi file

[Leela Krishna Amudala]

This patch adds pmusysreg node to Exynos5 dtsi file to handle PMU
register accesses in a centralized way using syscon driver

Signed-off-by: Leela Krishna Amudala <l.krishna@samsung.com>
---
 arch/arm/boot/dts/exynos5.dtsi |    5 +++++
 1 file changed, 5 insertions(+)

diff --git a/arch/arm/boot/dts/exynos5.dtsi b/arch/arm/boot/dts/exynos5.dtsi
index e52b038..ad6e47c9 100644
--- a/arch/arm/boot/dts/exynos5.dtsi
+++ b/arch/arm/boot/dts/exynos5.dtsi
@@ -106,4 +106,9 @@
 		#size-cells = <0>;
 		status = "disabled";
 	};
+
+	pmu_syscon: syscon@10040000 {
+		compatible = "syscon";
+		reg = <0x10040000 0x5000>;
+	};
 };
-- 
1.7.10.4

Re: [PATCH V5 1/3] ARM: dts: Add pmu sysreg node to Exynos5 dtsi file

[Tomasz Figa]

Hi Leela,

On Thursday 31 of October 2013 11:30:48 Leela Krishna Amudala wrote:
> This patch adds pmusysreg node to Exynos5 dtsi file to handle PMU
> register accesses in a centralized way using syscon driver
> 
> Signed-off-by: Leela Krishna Amudala <l.krishna@samsung.com>
> ---
>  arch/arm/boot/dts/exynos5.dtsi |    5 +++++
>  1 file changed, 5 insertions(+)

Reviewed-by: Tomasz Figa <t.figa@samsung.com>

Best regards,
Tomasz

[PATCH V5 2/3] ARM: dts: add watchdog device nodes for Exynos5250 and Exynos5420

[Leela Krishna Amudala]

Adds watchdog device nodes to the DT device list for Exynos5250 and Exynos5420

Signed-off-by: Leela Krishna Amudala <l.krishna@samsung.com>
---
 arch/arm/boot/dts/exynos5.dtsi    |    7 -------
 arch/arm/boot/dts/exynos5250.dtsi |    7 ++++++-
 arch/arm/boot/dts/exynos5420.dtsi |   10 ++++++++++
 3 files changed, 16 insertions(+), 8 deletions(-)

diff --git a/arch/arm/boot/dts/exynos5.dtsi b/arch/arm/boot/dts/exynos5.dtsi
index ad6e47c9..e6ab5d9 100644
--- a/arch/arm/boot/dts/exynos5.dtsi
+++ b/arch/arm/boot/dts/exynos5.dtsi
@@ -81,13 +81,6 @@
 		status = "disabled";
 	};
 
-	watchdog {
-		compatible = "samsung,s3c2410-wdt";
-		reg = <0x101D0000 0x100>;
-		interrupts = <0 42 0>;
-		status = "disabled";
-	};
-
 	fimd@14400000 {
 		compatible = "samsung,exynos5250-fimd";
 		interrupt-parent = <&combiner>;
diff --git a/arch/arm/boot/dts/exynos5250.dtsi b/arch/arm/boot/dts/exynos5250.dtsi
index c4a8662..7e4867f 100644
--- a/arch/arm/boot/dts/exynos5250.dtsi
+++ b/arch/arm/boot/dts/exynos5250.dtsi
@@ -158,9 +158,14 @@
 		interrupts = <0 47 0>;
 	};
 
-	watchdog {
+	watchdog@101D0000 {
+		compatible = "samsung,exynos5250-wdt";
+		reg = <0x101D0000 0x100>;
+		interrupts = <0 42 0>;
 		clocks = <&clock 336>;
 		clock-names = "watchdog";
+		samsung,syscon-phandle = <&pmu_syscon>;
+		status = "okay";
 	};
 
 	g2d@10850000 {
diff --git a/arch/arm/boot/dts/exynos5420.dtsi b/arch/arm/boot/dts/exynos5420.dtsi
index 6ffefd1..8585fe7 100644
--- a/arch/arm/boot/dts/exynos5420.dtsi
+++ b/arch/arm/boot/dts/exynos5420.dtsi
@@ -369,4 +369,14 @@
 		clock-names = "gscl";
 		samsung,power-domain = <&gsc_pd>;
 	};
+
+        watchdog@101D0000 {
+		compatible = "samsung,exynos5420-wdt";
+		reg = <0x101D0000 0x100>;
+		interrupts = <0 42 0>;
+		clocks = <&clock 316>;
+		clock-names = "watchdog";
+		samsung,syscon-phandle = <&pmu_syscon>;
+		status = "okay";
+        };
 };
-- 
1.7.10.4

Re: [PATCH V5 2/3] ARM: dts: add watchdog device nodes for Exynos5250 and Exynos5420

[Tomasz Figa]

Hi Leela,

On Thursday 31 of October 2013 11:30:49 Leela Krishna Amudala wrote:
> Adds watchdog device nodes to the DT device list for Exynos5250 and Exynos5420
> 
> Signed-off-by: Leela Krishna Amudala <l.krishna@samsung.com>
> ---
>  arch/arm/boot/dts/exynos5.dtsi    |    7 -------
>  arch/arm/boot/dts/exynos5250.dtsi |    7 ++++++-
>  arch/arm/boot/dts/exynos5420.dtsi |   10 ++++++++++
>  3 files changed, 16 insertions(+), 8 deletions(-)
[snip]
> diff --git a/arch/arm/boot/dts/exynos5250.dtsi b/arch/arm/boot/dts/exynos5250.dtsi
> index c4a8662..7e4867f 100644
> --- a/arch/arm/boot/dts/exynos5250.dtsi
> +++ b/arch/arm/boot/dts/exynos5250.dtsi
> @@ -158,9 +158,14 @@
>  		interrupts = <0 47 0>;
>  	};
>  
> -	watchdog {
> +	watchdog@101D0000 {
> +		compatible = "samsung,exynos5250-wdt";
> +		reg = <0x101D0000 0x100>;
> +		interrupts = <0 42 0>;
>  		clocks = <&clock 336>;
>  		clock-names = "watchdog";
> +		samsung,syscon-phandle = <&pmu_syscon>;
> +		status = "okay";

You can drop the status property here, as it's "okay" by default.

>  	};
>  
>  	g2d@10850000 {
> diff --git a/arch/arm/boot/dts/exynos5420.dtsi b/arch/arm/boot/dts/exynos5420.dtsi
> index 6ffefd1..8585fe7 100644
> --- a/arch/arm/boot/dts/exynos5420.dtsi
> +++ b/arch/arm/boot/dts/exynos5420.dtsi
> @@ -369,4 +369,14 @@
>  		clock-names = "gscl";
>  		samsung,power-domain = <&gsc_pd>;
>  	};
> +
> +        watchdog@101D0000 {

Is it just my mail client or there is an indentation issue here?

> +		compatible = "samsung,exynos5420-wdt";
> +		reg = <0x101D0000 0x100>;
> +		interrupts = <0 42 0>;
> +		clocks = <&clock 316>;
> +		clock-names = "watchdog";
> +		samsung,syscon-phandle = <&pmu_syscon>;
> +		status = "okay";

Status property can be dropped.

> +        };

Wrong indentation?

Best regards,
Tomasz

[PATCH V5 3/3] watchdog: s3c2410_wdt: use syscon regmap interface to configure pmu register

[Leela Krishna Amudala]

The syscon regmap interface is used to configure AUTOMATIC_WDT_RESET_DISABLE
and MASK_WDT_RESET_REQUEST registers of PMU to mask/unmask enable/disable of
watchdog in probe and s2r scenarios.

Signed-off-by: Leela Krishna Amudala <l.krishna@samsung.com>
---
 .../devicetree/bindings/watchdog/samsung-wdt.txt   |   22 ++-
 drivers/watchdog/s3c2410_wdt.c                     |  150 +++++++++++++++++---
 2 files changed, 154 insertions(+), 18 deletions(-)

diff --git a/Documentation/devicetree/bindings/watchdog/samsung-wdt.txt b/Documentation/devicetree/bindings/watchdog/samsung-wdt.txt
index 2aa486c..0b8aa4b 100644
--- a/Documentation/devicetree/bindings/watchdog/samsung-wdt.txt
+++ b/Documentation/devicetree/bindings/watchdog/samsung-wdt.txt
@@ -5,10 +5,30 @@ after a preset amount of time during which the WDT reset event has not
 occurred.
 
 Required properties:
-- compatible : should be "samsung,s3c2410-wdt"
+- compatible : should be one among the following
+	(a) "samsung,s3c2410-wdt" for Exynos4 and previous SoCs
+	(b) "samsung,exynos5250-wdt" for Exynos5250
+	(c) "samsung,exynos5420-wdt" for Exynos5420
+
 - reg : base physical address of the controller and length of memory mapped
 	region.
 - interrupts : interrupt number to the cpu.
+- samsung,syscon-phandle : reference to syscon node (This property required only
+	in case of compatible being "samsung,exynos5250-wdt" or "samsung,exynos5420-wdt".
+	In case of Exynos5250 and 5420 this property points to syscon node holding the PMU
+	base address)
 
 Optional properties:
 - timeout-sec : contains the watchdog timeout in seconds.
+
+Example:
+
+watchdog@101D0000 {
+	compatible = "samsung,exynos5250-wdt";
+	reg = <0x101D0000 0x100>;
+	interrupts = <0 42 0>;
+	clocks = <&clock 336>;
+	clock-names = "watchdog";
+	samsung,sysreg = <&pmu_sys_reg>;
+	status = "okay";
+};
diff --git a/drivers/watchdog/s3c2410_wdt.c b/drivers/watchdog/s3c2410_wdt.c
index 23aad7c..235d160 100644
--- a/drivers/watchdog/s3c2410_wdt.c
+++ b/drivers/watchdog/s3c2410_wdt.c
@@ -41,6 +41,8 @@
 #include <linux/slab.h>
 #include <linux/err.h>
 #include <linux/of.h>
+#include <linux/mfd/syscon.h>
+#include <linux/regmap.h>
 
 #define S3C2410_WTCON		0x00
 #define S3C2410_WTDAT		0x04
@@ -61,6 +63,10 @@
 #define CONFIG_S3C2410_WATCHDOG_ATBOOT		(0)
 #define CONFIG_S3C2410_WATCHDOG_DEFAULT_TIME	(15)
 
+#define WDT_DISABLE_REG_OFFSET		0x0408
+#define WDT_MASK_RESET_REG_OFFSET	0x040c
+#define QUIRK_NEEDS_PMU_CONFIG		(1 << 0)
+
 static bool nowayout	= WATCHDOG_NOWAYOUT;
 static int tmr_margin;
 static int tmr_atboot	= CONFIG_S3C2410_WATCHDOG_ATBOOT;
@@ -84,18 +90,61 @@ MODULE_PARM_DESC(soft_noboot, "Watchdog action, set to 1 to ignore reboots, "
 			"0 to reboot (default 0)");
 MODULE_PARM_DESC(debug, "Watchdog debug, set to >1 for debug (default 0)");
 
+struct s3c2410_wdt_variant {
+	int	disable_reg;
+	int	mask_reset_reg;
+	int	mask_bit;
+	u32	quirks;
+};
+
 struct s3c2410_wdt {
-	struct device		*dev;
-	struct clk		*clock;
-	void __iomem		*reg_base;
-	unsigned int		count;
-	spinlock_t		lock;
-	unsigned long		wtcon_save;
-	unsigned long		wtdat_save;
-	struct watchdog_device	wdt_device;
-	struct notifier_block	freq_transition;
+	struct device			*dev;
+	struct clk			*clock;
+	void __iomem			*reg_base;
+	unsigned int			count;
+	spinlock_t			lock;
+	unsigned long			wtcon_save;
+	unsigned long			wtdat_save;
+	struct watchdog_device		wdt_device;
+	struct notifier_block		freq_transition;
+	struct s3c2410_wdt_variant	*pmu_config;
+	struct regmap			*pmureg;
+};
+
+#ifdef CONFIG_OF
+static struct s3c2410_wdt_variant pmu_config_s3c2410 = {
+	.disable_reg = 0x0,
+	.mask_reset_reg = 0x0,
+	.mask_bit = 0,
+	.quirks = 0
 };
 
+static struct s3c2410_wdt_variant pmu_config_5250  = {
+	.disable_reg = WDT_DISABLE_REG_OFFSET,
+	.mask_reset_reg = WDT_MASK_RESET_REG_OFFSET,
+	.mask_bit = 20,
+	.quirks = QUIRK_NEEDS_PMU_CONFIG
+};
+
+static struct s3c2410_wdt_variant pmu_config_5420 = {
+	.disable_reg = WDT_DISABLE_REG_OFFSET,
+	.mask_reset_reg = WDT_MASK_RESET_REG_OFFSET,
+	.mask_bit = 0,
+	.quirks = QUIRK_NEEDS_PMU_CONFIG
+};
+
+static const struct of_device_id s3c2410_wdt_match[] = {
+	{ .compatible = "samsung,s3c2410-wdt",
+	  .data = (struct s3c2410_wdt_variant *) &pmu_config_s3c2410 },
+	{ .compatible = "samsung,exynos5250-wdt",
+	  .data = (struct s3c2410_wdt_variant *) &pmu_config_5250 },
+	{ .compatible = "samsung,exynos5420-wdt",
+	  .data = (struct s3c2410_wdt_variant *) &pmu_config_5420 },
+	{},
+};
+MODULE_DEVICE_TABLE(of, s3c2410_wdt_match);
+#endif
+
 /* watchdog control routines */
 
 #define DBG(fmt, ...)					\
@@ -111,6 +160,47 @@ static inline struct s3c2410_wdt *freq_to_wdt(struct notifier_block *nb)
 	return container_of(nb, struct s3c2410_wdt, freq_transition);
 }
 
+static void s3c2410wdt_mask_and_disable_reset(int mask, struct s3c2410_wdt *wdt)
+{
+	int ret;
+
+	if (mask) {
+		ret = regmap_update_bits(wdt->pmureg,
+					wdt->pmu_config->disable_reg,
+					(1 << wdt->pmu_config->mask_bit),
+					(1 << wdt->pmu_config->mask_bit));
+		if (ret < 0) {
+			dev_err(wdt->dev, "failed to update reg(%d)\n", ret);
+			return;
+		}
+		ret = regmap_update_bits(wdt->pmureg,
+					wdt->pmu_config->mask_reset_reg,
+					(1 << wdt->pmu_config->mask_bit),
+					(1 << wdt->pmu_config->mask_bit));
+		if (ret < 0) {
+			dev_err(wdt->dev, "failed to update reg(%d)\n", ret);
+			return;
+		}
+	} else {
+		ret = regmap_update_bits(wdt->pmureg,
+					wdt->pmu_config->disable_reg,
+					(1 << wdt->pmu_config->mask_bit),
+					(0 << wdt->pmu_config->mask_bit));
+		if (ret < 0) {
+			dev_err(wdt->dev, "failed to update reg(%d)\n", ret);
+			return;
+		}
+		ret = regmap_update_bits(wdt->pmureg,
+					wdt->pmu_config->mask_reset_reg,
+					(1 << wdt->pmu_config->mask_bit),
+					(0 << wdt->pmu_config->mask_bit));
+		if (ret < 0) {
+			dev_err(wdt->dev, "failed to update reg(%d)\n", ret);
+			return;
+		}
+	}
+}
+
 static int s3c2410wdt_keepalive(struct watchdog_device *wdd)
 {
 	struct s3c2410_wdt *wdt = watchdog_get_drvdata(wdd);
@@ -332,6 +422,15 @@ static inline void s3c2410wdt_cpufreq_deregister(struct s3c2410_wdt *wdt)
 }
 #endif
 
+/* s3c2410_get_wdt_driver_data */
+static inline struct s3c2410_wdt_variant *
+get_wdt_drv_data(struct platform_device *pdev)
+{
+	const struct of_device_id *match;
+	match = of_match_node(s3c2410_wdt_match, pdev->dev.of_node);
+	return (struct s3c2410_wdt_variant *)match->data;
+}
+
 static int s3c2410wdt_probe(struct platform_device *pdev)
 {
 	struct device *dev;
@@ -354,6 +453,16 @@ static int s3c2410wdt_probe(struct platform_device *pdev)
 	spin_lock_init(&wdt->lock);
 	wdt->wdt_device = s3c2410_wdd;
 
+	wdt->pmu_config = (struct s3c2410_wdt_variant *) get_wdt_drv_data(pdev);
+	if (wdt->pmu_config->quirks & QUIRK_NEEDS_PMU_CONFIG) {
+		wdt->pmureg = syscon_regmap_lookup_by_phandle(dev->of_node,
+							"samsung,syscon-phandle");
+		if (IS_ERR(wdt->pmureg)) {
+			dev_err(dev, "syscon regmap lookup failed.\n");
+			return PTR_ERR(wdt->pmureg);
+		}
+	}
+
 	wdt_irq = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
 	if (wdt_irq == NULL) {
 		dev_err(dev, "no irq resource specified\n");
@@ -444,6 +553,9 @@ static int s3c2410wdt_probe(struct platform_device *pdev)
 		 (wtcon & S3C2410_WTCON_RSTEN) ? "en" : "dis",
 		 (wtcon & S3C2410_WTCON_INTEN) ? "en" : "dis");
 
+	if (wdt->pmu_config->quirks & QUIRK_NEEDS_PMU_CONFIG)
+		s3c2410wdt_mask_and_disable_reset(0, wdt);
+
 	return 0;
 
  err_cpufreq:
@@ -461,6 +573,9 @@ static int s3c2410wdt_remove(struct platform_device *dev)
 {
 	struct s3c2410_wdt *wdt = platform_get_drvdata(dev);
 
+	if (wdt->pmu_config->quirks & QUIRK_NEEDS_PMU_CONFIG)
+		s3c2410wdt_mask_and_disable_reset(1, wdt);
+
 	watchdog_unregister_device(&wdt->wdt_device);
 
 	s3c2410wdt_cpufreq_deregister(wdt);
@@ -475,6 +590,9 @@ static void s3c2410wdt_shutdown(struct platform_device *dev)
 {
 	struct s3c2410_wdt *wdt = platform_get_drvdata(dev);
 
+	if (wdt->pmu_config->quirks & QUIRK_NEEDS_PMU_CONFIG)
+		s3c2410wdt_mask_and_disable_reset(1, wdt);
+
 	s3c2410wdt_stop(&wdt->wdt_device);
 }
 
@@ -488,6 +606,9 @@ 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);
 
+	if (wdt->pmu_config->quirks & QUIRK_NEEDS_PMU_CONFIG)
+		s3c2410wdt_mask_and_disable_reset(1, wdt);
+
 	/* Note that WTCNT doesn't need to be saved. */
 	s3c2410wdt_stop(&wdt->wdt_device);
 
@@ -503,6 +624,9 @@ 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);
 
+	if (wdt->pmu_config->quirks & QUIRK_NEEDS_PMU_CONFIG)
+		s3c2410wdt_mask_and_disable_reset(0, wdt);
+
 	dev_info(dev, "watchdog %sabled\n",
 		(wdt->wtcon_save & S3C2410_WTCON_ENABLE) ? "en" : "dis");
 
@@ -513,14 +637,6 @@ static int s3c2410wdt_resume(struct device *dev)
 static SIMPLE_DEV_PM_OPS(s3c2410wdt_pm_ops, s3c2410wdt_suspend,
 			s3c2410wdt_resume);
 
-#ifdef CONFIG_OF
-static const struct of_device_id s3c2410_wdt_match[] = {
-	{ .compatible = "samsung,s3c2410-wdt" },
-	{},
-};
-MODULE_DEVICE_TABLE(of, s3c2410_wdt_match);
-#endif
-
 static struct platform_driver s3c2410wdt_driver = {
 	.probe		= s3c2410wdt_probe,
 	.remove		= s3c2410wdt_remove,
-- 
1.7.10.4

Re: [PATCH V5 3/3] watchdog: s3c2410_wdt: use syscon regmap interface to configure pmu register

[Tomasz Figa]

Hi Leela,

On Thursday 31 of October 2013 11:30:50 Leela Krishna Amudala wrote:
> The syscon regmap interface is used to configure AUTOMATIC_WDT_RESET_DISABLE
> and MASK_WDT_RESET_REQUEST registers of PMU to mask/unmask enable/disable of
> watchdog in probe and s2r scenarios.
> 
> Signed-off-by: Leela Krishna Amudala <l.krishna@samsung.com>
> ---
>  .../devicetree/bindings/watchdog/samsung-wdt.txt   |   22 ++-
>  drivers/watchdog/s3c2410_wdt.c                     |  150 +++++++++++++++++---
>  2 files changed, 154 insertions(+), 18 deletions(-)

This patch looks better now, but there are still several issues remaining.
Please see my comments inline.

> diff --git a/Documentation/devicetree/bindings/watchdog/samsung-wdt.txt b/Documentation/devicetree/bindings/watchdog/samsung-wdt.txt
> index 2aa486c..0b8aa4b 100644
> --- a/Documentation/devicetree/bindings/watchdog/samsung-wdt.txt
> +++ b/Documentation/devicetree/bindings/watchdog/samsung-wdt.txt
> @@ -5,10 +5,30 @@ after a preset amount of time during which the WDT reset event has not
>  occurred.
>  
>  Required properties:
> -- compatible : should be "samsung,s3c2410-wdt"
> +- compatible : should be one among the following
> +	(a) "samsung,s3c2410-wdt" for Exynos4 and previous SoCs
> +	(b) "samsung,exynos5250-wdt" for Exynos5250
> +	(c) "samsung,exynos5420-wdt" for Exynos5420
> +
>  - reg : base physical address of the controller and length of memory mapped
>  	region.
>  - interrupts : interrupt number to the cpu.
> +- samsung,syscon-phandle : reference to syscon node (This property required only
> +	in case of compatible being "samsung,exynos5250-wdt" or "samsung,exynos5420-wdt".
> +	In case of Exynos5250 and 5420 this property points to syscon node holding the PMU
> +	base address)
>  
>  Optional properties:
>  - timeout-sec : contains the watchdog timeout in seconds.
> +
> +Example:
> +
> +watchdog@101D0000 {
> +	compatible = "samsung,exynos5250-wdt";
> +	reg = <0x101D0000 0x100>;
> +	interrupts = <0 42 0>;
> +	clocks = <&clock 336>;
> +	clock-names = "watchdog";
> +	samsung,sysreg = <&pmu_sys_reg>;

Shouldn't it be samsung,syscon-phandle?

> +	status = "okay";

The status property is not a part of this binding, so can be dropped
from the example.

> +};
> diff --git a/drivers/watchdog/s3c2410_wdt.c b/drivers/watchdog/s3c2410_wdt.c
> index 23aad7c..235d160 100644
> --- a/drivers/watchdog/s3c2410_wdt.c
> +++ b/drivers/watchdog/s3c2410_wdt.c
> @@ -41,6 +41,8 @@
>  #include <linux/slab.h>
>  #include <linux/err.h>
>  #include <linux/of.h>
> +#include <linux/mfd/syscon.h>
> +#include <linux/regmap.h>
>  
>  #define S3C2410_WTCON		0x00
>  #define S3C2410_WTDAT		0x04
> @@ -61,6 +63,10 @@
>  #define CONFIG_S3C2410_WATCHDOG_ATBOOT		(0)
>  #define CONFIG_S3C2410_WATCHDOG_DEFAULT_TIME	(15)
>  
> +#define WDT_DISABLE_REG_OFFSET		0x0408
> +#define WDT_MASK_RESET_REG_OFFSET	0x040c
> +#define QUIRK_NEEDS_PMU_CONFIG		(1 << 0)
> +
>  static bool nowayout	= WATCHDOG_NOWAYOUT;
>  static int tmr_margin;
>  static int tmr_atboot	= CONFIG_S3C2410_WATCHDOG_ATBOOT;
> @@ -84,18 +90,61 @@ MODULE_PARM_DESC(soft_noboot, "Watchdog action, set to 1 to ignore reboots, "
>  			"0 to reboot (default 0)");
>  MODULE_PARM_DESC(debug, "Watchdog debug, set to >1 for debug (default 0)");
>  
> +struct s3c2410_wdt_variant {
> +	int	disable_reg;
> +	int	mask_reset_reg;
> +	int	mask_bit;
> +	u32	quirks;

nit: To avoid the need of changing the indentation in future, if fields
with longer types gets added, I would simply separate type name from field
name using a single space.

> +};
> +
>  struct s3c2410_wdt {
> -	struct device		*dev;
> -	struct clk		*clock;
> -	void __iomem		*reg_base;
> -	unsigned int		count;
> -	spinlock_t		lock;
> -	unsigned long		wtcon_save;
> -	unsigned long		wtdat_save;
> -	struct watchdog_device	wdt_device;
> -	struct notifier_block	freq_transition;
> +	struct device			*dev;
> +	struct clk			*clock;
> +	void __iomem			*reg_base;
> +	unsigned int			count;
> +	spinlock_t			lock;
> +	unsigned long			wtcon_save;
> +	unsigned long			wtdat_save;
> +	struct watchdog_device		wdt_device;
> +	struct notifier_block		freq_transition;
> +	struct s3c2410_wdt_variant	*pmu_config;
> +	struct regmap			*pmureg;

And here's an example of such (unnecessary) change. I believe it would
be better to keep indendation of other fields as is, use single space for
the new field and then change remaining fields in a separate patch,
outside of this series.

> +};
> +
> +#ifdef CONFIG_OF
> +static struct s3c2410_wdt_variant pmu_config_s3c2410 = {

static const struct

> +	.disable_reg = 0x0,
> +	.mask_reset_reg = 0x0,
> +	.mask_bit = 0,

nit: I would simply omit the three fields above, since they are irrelevant
when QUIRK_NEEDS_PMU_CONFIG flag is not set. Not even saying that when
unspecified, they default to zero.

> +	.quirks = 0
>  };
>  
> +static struct s3c2410_wdt_variant pmu_config_5250  = {

static const struct

> +	.disable_reg = WDT_DISABLE_REG_OFFSET,
> +	.mask_reset_reg = WDT_MASK_RESET_REG_OFFSET,
> +	.mask_bit = 20,
> +	.quirks = QUIRK_NEEDS_PMU_CONFIG
> +};
> +
> +static struct s3c2410_wdt_variant pmu_config_5420 = {

static const struct

> +	.disable_reg = WDT_DISABLE_REG_OFFSET,
> +	.mask_reset_reg = WDT_MASK_RESET_REG_OFFSET,
> +	.mask_bit = 0,
> +	.quirks = QUIRK_NEEDS_PMU_CONFIG
> +};
> +
> +static const struct of_device_id s3c2410_wdt_match[] = {
> +	{ .compatible = "samsung,s3c2410-wdt",
> +	  .data = (struct s3c2410_wdt_variant *) &pmu_config_s3c2410 },

No need for the cast.

> +	{ .compatible = "samsung,exynos5250-wdt",
> +	  .data = (struct s3c2410_wdt_variant *) &pmu_config_5250 },

Ditto.

> +	{ .compatible = "samsung,exynos5420-wdt",
> +	  .data = (struct s3c2410_wdt_variant *) &pmu_config_5420 },

Ditto.

> +	{},
> +};
> +MODULE_DEVICE_TABLE(of, s3c2410_wdt_match);
> +#endif
> +
>  /* watchdog control routines */
>  
>  #define DBG(fmt, ...)					\
> @@ -111,6 +160,47 @@ static inline struct s3c2410_wdt *freq_to_wdt(struct notifier_block *nb)
>  	return container_of(nb, struct s3c2410_wdt, freq_transition);
>  }
>  
> +static void s3c2410wdt_mask_and_disable_reset(int mask, struct s3c2410_wdt *wdt)

This function should return int and propagate possible errors to the caller.

Also the order of arguments is rather strange. The main context structure
is usually passed as first argument.

In addition, bool probably would make more sense for mask argument than int.

> +{
> +	int ret;
> +
> +	if (mask) {
> +		ret = regmap_update_bits(wdt->pmureg,
> +					wdt->pmu_config->disable_reg,
> +					(1 << wdt->pmu_config->mask_bit),
> +					(1 << wdt->pmu_config->mask_bit));
> +		if (ret < 0) {
> +			dev_err(wdt->dev, "failed to update reg(%d)\n", ret);
> +			return;
> +		}
> +		ret = regmap_update_bits(wdt->pmureg,
> +					wdt->pmu_config->mask_reset_reg,
> +					(1 << wdt->pmu_config->mask_bit),
> +					(1 << wdt->pmu_config->mask_bit));
> +		if (ret < 0) {
> +			dev_err(wdt->dev, "failed to update reg(%d)\n", ret);
> +			return;
> +		}
> +	} else {
> +		ret = regmap_update_bits(wdt->pmureg,
> +					wdt->pmu_config->disable_reg,
> +					(1 << wdt->pmu_config->mask_bit),
> +					(0 << wdt->pmu_config->mask_bit));
> +		if (ret < 0) {
> +			dev_err(wdt->dev, "failed to update reg(%d)\n", ret);
> +			return;
> +		}
> +		ret = regmap_update_bits(wdt->pmureg,
> +					wdt->pmu_config->mask_reset_reg,
> +					(1 << wdt->pmu_config->mask_bit),
> +					(0 << wdt->pmu_config->mask_bit));
> +		if (ret < 0) {
> +			dev_err(wdt->dev, "failed to update reg(%d)\n", ret);
> +			return;
> +		}
> +	}

This is not really what I imagined. You can greatly simplify this code
by refactoring it as follows:

static int s3c2410wdt_mask_and_disable_reset(struct s3c2410_wdt *wdt, bool mask)
{
	int ret;
	u32 mask_val = 1 << wdt->pmu_config->mask_bit;
	u32 val = 0;

	if (mask)
		val = mask_val;

	ret = regmap_update_bits(wdt->pmureg,
				wdt->pmu_config->disable_reg,
				mask_val, val);
	if (ret < 0) {
		dev_err(wdt->dev, "failed to update reg(%d)\n", ret);
		return ret;
	}

	ret = regmap_update_bits(wdt->pmureg,
				wdt->pmu_config->mask_reset_reg,
				mask_val, val);
	if (ret < 0) {
		dev_err(wdt->dev, "failed to update reg(%d)\n", ret);
		return ret;
	}

	return 0;
}

> +}
> +
>  static int s3c2410wdt_keepalive(struct watchdog_device *wdd)
>  {
>  	struct s3c2410_wdt *wdt = watchdog_get_drvdata(wdd);
> @@ -332,6 +422,15 @@ static inline void s3c2410wdt_cpufreq_deregister(struct s3c2410_wdt *wdt)
>  }
>  #endif
>  
> +/* s3c2410_get_wdt_driver_data */
> +static inline struct s3c2410_wdt_variant *

const struct

> +get_wdt_drv_data(struct platform_device *pdev)
> +{
> +	const struct of_device_id *match;
> +	match = of_match_node(s3c2410_wdt_match, pdev->dev.of_node);
> +	return (struct s3c2410_wdt_variant *)match->data;

This function does not handle non-DT cases, which will cause a NULL pointer
dereference when the device is instantiated from a board file.

> +}
> +
>  static int s3c2410wdt_probe(struct platform_device *pdev)
>  {
>  	struct device *dev;
> @@ -354,6 +453,16 @@ static int s3c2410wdt_probe(struct platform_device *pdev)
>  	spin_lock_init(&wdt->lock);
>  	wdt->wdt_device = s3c2410_wdd;
>  
> +	wdt->pmu_config = (struct s3c2410_wdt_variant *) get_wdt_drv_data(pdev);

No need for type cast here.

> +	if (wdt->pmu_config->quirks & QUIRK_NEEDS_PMU_CONFIG) {
> +		wdt->pmureg = syscon_regmap_lookup_by_phandle(dev->of_node,
> +							"samsung,syscon-phandle");
> +		if (IS_ERR(wdt->pmureg)) {
> +			dev_err(dev, "syscon regmap lookup failed.\n");
> +			return PTR_ERR(wdt->pmureg);
> +		}
> +	}
> +
>  	wdt_irq = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
>  	if (wdt_irq == NULL) {
>  		dev_err(dev, "no irq resource specified\n");
> @@ -444,6 +553,9 @@ static int s3c2410wdt_probe(struct platform_device *pdev)
>  		 (wtcon & S3C2410_WTCON_RSTEN) ? "en" : "dis",
>  		 (wtcon & S3C2410_WTCON_INTEN) ? "en" : "dis");
>  
> +	if (wdt->pmu_config->quirks & QUIRK_NEEDS_PMU_CONFIG)
> +		s3c2410wdt_mask_and_disable_reset(0, wdt);

Error should be handled here. Also false would be better than 0 here.

> +
>  	return 0;
>  
>   err_cpufreq:
> @@ -461,6 +573,9 @@ static int s3c2410wdt_remove(struct platform_device *dev)
>  {
>  	struct s3c2410_wdt *wdt = platform_get_drvdata(dev);
>  
> +	if (wdt->pmu_config->quirks & QUIRK_NEEDS_PMU_CONFIG)
> +		s3c2410wdt_mask_and_disable_reset(1, wdt);

Error should be handled here. Also true would be better than 1 here.

> +
>  	watchdog_unregister_device(&wdt->wdt_device);
>  
>  	s3c2410wdt_cpufreq_deregister(wdt);
> @@ -475,6 +590,9 @@ static void s3c2410wdt_shutdown(struct platform_device *dev)
>  {
>  	struct s3c2410_wdt *wdt = platform_get_drvdata(dev);
>  
> +	if (wdt->pmu_config->quirks & QUIRK_NEEDS_PMU_CONFIG)
> +		s3c2410wdt_mask_and_disable_reset(1, wdt);

Error should be handled here. Also true would be better than 1 here.

> +
>  	s3c2410wdt_stop(&wdt->wdt_device);
>  }
>  
> @@ -488,6 +606,9 @@ 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);
>  
> +	if (wdt->pmu_config->quirks & QUIRK_NEEDS_PMU_CONFIG)
> +		s3c2410wdt_mask_and_disable_reset(1, wdt);

Error should be handled here. Also true would be better than 1 here.

> +
>  	/* Note that WTCNT doesn't need to be saved. */
>  	s3c2410wdt_stop(&wdt->wdt_device);
>  
> @@ -503,6 +624,9 @@ 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);
>  
> +	if (wdt->pmu_config->quirks & QUIRK_NEEDS_PMU_CONFIG)
> +		s3c2410wdt_mask_and_disable_reset(0, wdt);

Error should be handled here. Also false would be better than 0 here.

Best regards,
Tomasz

Re: [PATCH V5 3/3] watchdog: s3c2410_wdt: use syscon regmap interface to configure pmu register

[Guenter Roeck]

On 10/31/2013 05:29 AM, Tomasz Figa wrote:
> Hi Leela,
>
> On Thursday 31 of October 2013 11:30:50 Leela Krishna Amudala wrote:
>> The syscon regmap interface is used to configure AUTOMATIC_WDT_RESET_DISABLE
>> and MASK_WDT_RESET_REQUEST registers of PMU to mask/unmask enable/disable of
>> watchdog in probe and s2r scenarios.
>>
>> Signed-off-by: Leela Krishna Amudala <l.krishna@samsung.com>
>> ---
>>   .../devicetree/bindings/watchdog/samsung-wdt.txt   |   22 ++-
>>   drivers/watchdog/s3c2410_wdt.c                     |  150 +++++++++++++++++---
>>   2 files changed, 154 insertions(+), 18 deletions(-)
>
> This patch looks better now, but there are still several issues remaining.
> Please see my comments inline.
>
>> diff --git a/Documentation/devicetree/bindings/watchdog/samsung-wdt.txt b/Documentation/devicetree/bindings/watchdog/samsung-wdt.txt
>> index 2aa486c..0b8aa4b 100644
>> --- a/Documentation/devicetree/bindings/watchdog/samsung-wdt.txt
>> +++ b/Documentation/devicetree/bindings/watchdog/samsung-wdt.txt
>> @@ -5,10 +5,30 @@ after a preset amount of time during which the WDT reset event has not
>>   occurred.
>>
>>   Required properties:
>> -- compatible : should be "samsung,s3c2410-wdt"
>> +- compatible : should be one among the following
>> +	(a) "samsung,s3c2410-wdt" for Exynos4 and previous SoCs
>> +	(b) "samsung,exynos5250-wdt" for Exynos5250
>> +	(c) "samsung,exynos5420-wdt" for Exynos5420
>> +
>>   - reg : base physical address of the controller and length of memory mapped
>>   	region.
>>   - interrupts : interrupt number to the cpu.
>> +- samsung,syscon-phandle : reference to syscon node (This property required only
>> +	in case of compatible being "samsung,exynos5250-wdt" or "samsung,exynos5420-wdt".
>> +	In case of Exynos5250 and 5420 this property points to syscon node holding the PMU
>> +	base address)
>>
>>   Optional properties:
>>   - timeout-sec : contains the watchdog timeout in seconds.
>> +
>> +Example:
>> +
>> +watchdog@101D0000 {
>> +	compatible = "samsung,exynos5250-wdt";
>> +	reg = <0x101D0000 0x100>;
>> +	interrupts = <0 42 0>;
>> +	clocks = <&clock 336>;
>> +	clock-names = "watchdog";
>> +	samsung,sysreg = <&pmu_sys_reg>;
>
> Shouldn't it be samsung,syscon-phandle?
>
>> +	status = "okay";
>
> The status property is not a part of this binding, so can be dropped
> from the example.
>
>> +};
>> diff --git a/drivers/watchdog/s3c2410_wdt.c b/drivers/watchdog/s3c2410_wdt.c
>> index 23aad7c..235d160 100644
>> --- a/drivers/watchdog/s3c2410_wdt.c
>> +++ b/drivers/watchdog/s3c2410_wdt.c
>> @@ -41,6 +41,8 @@
>>   #include <linux/slab.h>
>>   #include <linux/err.h>
>>   #include <linux/of.h>
>> +#include <linux/mfd/syscon.h>
>> +#include <linux/regmap.h>
>>
>>   #define S3C2410_WTCON		0x00
>>   #define S3C2410_WTDAT		0x04
>> @@ -61,6 +63,10 @@
>>   #define CONFIG_S3C2410_WATCHDOG_ATBOOT		(0)
>>   #define CONFIG_S3C2410_WATCHDOG_DEFAULT_TIME	(15)
>>
>> +#define WDT_DISABLE_REG_OFFSET		0x0408
>> +#define WDT_MASK_RESET_REG_OFFSET	0x040c
>> +#define QUIRK_NEEDS_PMU_CONFIG		(1 << 0)
>> +
>>   static bool nowayout	= WATCHDOG_NOWAYOUT;
>>   static int tmr_margin;
>>   static int tmr_atboot	= CONFIG_S3C2410_WATCHDOG_ATBOOT;
>> @@ -84,18 +90,61 @@ MODULE_PARM_DESC(soft_noboot, "Watchdog action, set to 1 to ignore reboots, "
>>   			"0 to reboot (default 0)");
>>   MODULE_PARM_DESC(debug, "Watchdog debug, set to >1 for debug (default 0)");
>>
>> +struct s3c2410_wdt_variant {
>> +	int	disable_reg;
>> +	int	mask_reset_reg;
>> +	int	mask_bit;
>> +	u32	quirks;
>
> nit: To avoid the need of changing the indentation in future, if fields
> with longer types gets added, I would simply separate type name from field
> name using a single space.
>
>> +};
>> +
>>   struct s3c2410_wdt {
>> -	struct device		*dev;
>> -	struct clk		*clock;
>> -	void __iomem		*reg_base;
>> -	unsigned int		count;
>> -	spinlock_t		lock;
>> -	unsigned long		wtcon_save;
>> -	unsigned long		wtdat_save;
>> -	struct watchdog_device	wdt_device;
>> -	struct notifier_block	freq_transition;
>> +	struct device			*dev;
>> +	struct clk			*clock;
>> +	void __iomem			*reg_base;
>> +	unsigned int			count;
>> +	spinlock_t			lock;
>> +	unsigned long			wtcon_save;
>> +	unsigned long			wtdat_save;
>> +	struct watchdog_device		wdt_device;
>> +	struct notifier_block		freq_transition;
>> +	struct s3c2410_wdt_variant	*pmu_config;
>> +	struct regmap			*pmureg;
>
> And here's an example of such (unnecessary) change. I believe it would
> be better to keep indendation of other fields as is, use single space for
> the new field and then change remaining fields in a separate patch,
> outside of this series.
>
>> +};
>> +
>> +#ifdef CONFIG_OF
>> +static struct s3c2410_wdt_variant pmu_config_s3c2410 = {
>
> static const struct
>
>> +	.disable_reg = 0x0,
>> +	.mask_reset_reg = 0x0,
>> +	.mask_bit = 0,
>
> nit: I would simply omit the three fields above, since they are irrelevant
> when QUIRK_NEEDS_PMU_CONFIG flag is not set. Not even saying that when
> unspecified, they default to zero.
>
checkpatch used to complain about that ... in general, static variables
should not be initialized to 0. That is just unnecessary extra code.

Guenter

>> +	.quirks = 0
>>   };
>>
>> +static struct s3c2410_wdt_variant pmu_config_5250  = {
>
> static const struct
>
>> +	.disable_reg = WDT_DISABLE_REG_OFFSET,
>> +	.mask_reset_reg = WDT_MASK_RESET_REG_OFFSET,
>> +	.mask_bit = 20,
>> +	.quirks = QUIRK_NEEDS_PMU_CONFIG
>> +};
>> +
>> +static struct s3c2410_wdt_variant pmu_config_5420 = {
>
> static const struct
>
>> +	.disable_reg = WDT_DISABLE_REG_OFFSET,
>> +	.mask_reset_reg = WDT_MASK_RESET_REG_OFFSET,
>> +	.mask_bit = 0,
>> +	.quirks = QUIRK_NEEDS_PMU_CONFIG
>> +};
>> +
>> +static const struct of_device_id s3c2410_wdt_match[] = {
>> +	{ .compatible = "samsung,s3c2410-wdt",
>> +	  .data = (struct s3c2410_wdt_variant *) &pmu_config_s3c2410 },
>
> No need for the cast.
>
>> +	{ .compatible = "samsung,exynos5250-wdt",
>> +	  .data = (struct s3c2410_wdt_variant *) &pmu_config_5250 },
>
> Ditto.
>
>> +	{ .compatible = "samsung,exynos5420-wdt",
>> +	  .data = (struct s3c2410_wdt_variant *) &pmu_config_5420 },
>
> Ditto.
>
>> +	{},
>> +};
>> +MODULE_DEVICE_TABLE(of, s3c2410_wdt_match);
>> +#endif
>> +
>>   /* watchdog control routines */
>>
>>   #define DBG(fmt, ...)					\
>> @@ -111,6 +160,47 @@ static inline struct s3c2410_wdt *freq_to_wdt(struct notifier_block *nb)
>>   	return container_of(nb, struct s3c2410_wdt, freq_transition);
>>   }
>>
>> +static void s3c2410wdt_mask_and_disable_reset(int mask, struct s3c2410_wdt *wdt)
>
> This function should return int and propagate possible errors to the caller.
>
> Also the order of arguments is rather strange. The main context structure
> is usually passed as first argument.
>
> In addition, bool probably would make more sense for mask argument than int.
>
>> +{
>> +	int ret;
>> +
>> +	if (mask) {
>> +		ret = regmap_update_bits(wdt->pmureg,
>> +					wdt->pmu_config->disable_reg,
>> +					(1 << wdt->pmu_config->mask_bit),
>> +					(1 << wdt->pmu_config->mask_bit));
>> +		if (ret < 0) {
>> +			dev_err(wdt->dev, "failed to update reg(%d)\n", ret);
>> +			return;
>> +		}
>> +		ret = regmap_update_bits(wdt->pmureg,
>> +					wdt->pmu_config->mask_reset_reg,
>> +					(1 << wdt->pmu_config->mask_bit),
>> +					(1 << wdt->pmu_config->mask_bit));
>> +		if (ret < 0) {
>> +			dev_err(wdt->dev, "failed to update reg(%d)\n", ret);
>> +			return;
>> +		}
>> +	} else {
>> +		ret = regmap_update_bits(wdt->pmureg,
>> +					wdt->pmu_config->disable_reg,
>> +					(1 << wdt->pmu_config->mask_bit),
>> +					(0 << wdt->pmu_config->mask_bit));
>> +		if (ret < 0) {
>> +			dev_err(wdt->dev, "failed to update reg(%d)\n", ret);
>> +			return;
>> +		}
>> +		ret = regmap_update_bits(wdt->pmureg,
>> +					wdt->pmu_config->mask_reset_reg,
>> +					(1 << wdt->pmu_config->mask_bit),
>> +					(0 << wdt->pmu_config->mask_bit));
>> +		if (ret < 0) {
>> +			dev_err(wdt->dev, "failed to update reg(%d)\n", ret);
>> +			return;
>> +		}
>> +	}
>
> This is not really what I imagined. You can greatly simplify this code
> by refactoring it as follows:
>
> static int s3c2410wdt_mask_and_disable_reset(struct s3c2410_wdt *wdt, bool mask)
> {
> 	int ret;
> 	u32 mask_val = 1 << wdt->pmu_config->mask_bit;
> 	u32 val = 0;
>
> 	if (mask)
> 		val = mask_val;
>
> 	ret = regmap_update_bits(wdt->pmureg,
> 				wdt->pmu_config->disable_reg,
> 				mask_val, val);
> 	if (ret < 0) {
> 		dev_err(wdt->dev, "failed to update reg(%d)\n", ret);
> 		return ret;
> 	}
>
> 	ret = regmap_update_bits(wdt->pmureg,
> 				wdt->pmu_config->mask_reset_reg,
> 				mask_val, val);
> 	if (ret < 0) {
> 		dev_err(wdt->dev, "failed to update reg(%d)\n", ret);
> 		return ret;
> 	}
>
> 	return 0;
> }
>
>> +}
>> +
>>   static int s3c2410wdt_keepalive(struct watchdog_device *wdd)
>>   {
>>   	struct s3c2410_wdt *wdt = watchdog_get_drvdata(wdd);
>> @@ -332,6 +422,15 @@ static inline void s3c2410wdt_cpufreq_deregister(struct s3c2410_wdt *wdt)
>>   }
>>   #endif
>>
>> +/* s3c2410_get_wdt_driver_data */
>> +static inline struct s3c2410_wdt_variant *
>
> const struct
>
>> +get_wdt_drv_data(struct platform_device *pdev)
>> +{
>> +	const struct of_device_id *match;
>> +	match = of_match_node(s3c2410_wdt_match, pdev->dev.of_node);
>> +	return (struct s3c2410_wdt_variant *)match->data;
>
> This function does not handle non-DT cases, which will cause a NULL pointer
> dereference when the device is instantiated from a board file.
>
>> +}
>> +
>>   static int s3c2410wdt_probe(struct platform_device *pdev)
>>   {
>>   	struct device *dev;
>> @@ -354,6 +453,16 @@ static int s3c2410wdt_probe(struct platform_device *pdev)
>>   	spin_lock_init(&wdt->lock);
>>   	wdt->wdt_device = s3c2410_wdd;
>>
>> +	wdt->pmu_config = (struct s3c2410_wdt_variant *) get_wdt_drv_data(pdev);
>
> No need for type cast here.
>
>> +	if (wdt->pmu_config->quirks & QUIRK_NEEDS_PMU_CONFIG) {
>> +		wdt->pmureg = syscon_regmap_lookup_by_phandle(dev->of_node,
>> +							"samsung,syscon-phandle");
>> +		if (IS_ERR(wdt->pmureg)) {
>> +			dev_err(dev, "syscon regmap lookup failed.\n");
>> +			return PTR_ERR(wdt->pmureg);
>> +		}
>> +	}
>> +
>>   	wdt_irq = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
>>   	if (wdt_irq == NULL) {
>>   		dev_err(dev, "no irq resource specified\n");
>> @@ -444,6 +553,9 @@ static int s3c2410wdt_probe(struct platform_device *pdev)
>>   		 (wtcon & S3C2410_WTCON_RSTEN) ? "en" : "dis",
>>   		 (wtcon & S3C2410_WTCON_INTEN) ? "en" : "dis");
>>
>> +	if (wdt->pmu_config->quirks & QUIRK_NEEDS_PMU_CONFIG)
>> +		s3c2410wdt_mask_and_disable_reset(0, wdt);
>
> Error should be handled here. Also false would be better than 0 here.
>
>> +
>>   	return 0;
>>
>>    err_cpufreq:
>> @@ -461,6 +573,9 @@ static int s3c2410wdt_remove(struct platform_device *dev)
>>   {
>>   	struct s3c2410_wdt *wdt = platform_get_drvdata(dev);
>>
>> +	if (wdt->pmu_config->quirks & QUIRK_NEEDS_PMU_CONFIG)
>> +		s3c2410wdt_mask_and_disable_reset(1, wdt);
>
> Error should be handled here. Also true would be better than 1 here.
>
>> +
>>   	watchdog_unregister_device(&wdt->wdt_device);
>>
>>   	s3c2410wdt_cpufreq_deregister(wdt);
>> @@ -475,6 +590,9 @@ static void s3c2410wdt_shutdown(struct platform_device *dev)
>>   {
>>   	struct s3c2410_wdt *wdt = platform_get_drvdata(dev);
>>
>> +	if (wdt->pmu_config->quirks & QUIRK_NEEDS_PMU_CONFIG)
>> +		s3c2410wdt_mask_and_disable_reset(1, wdt);
>
> Error should be handled here. Also true would be better than 1 here.
>
>> +
>>   	s3c2410wdt_stop(&wdt->wdt_device);
>>   }
>>
>> @@ -488,6 +606,9 @@ 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);
>>
>> +	if (wdt->pmu_config->quirks & QUIRK_NEEDS_PMU_CONFIG)
>> +		s3c2410wdt_mask_and_disable_reset(1, wdt);
>
> Error should be handled here. Also true would be better than 1 here.
>
>> +
>>   	/* Note that WTCNT doesn't need to be saved. */
>>   	s3c2410wdt_stop(&wdt->wdt_device);
>>
>> @@ -503,6 +624,9 @@ 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);
>>
>> +	if (wdt->pmu_config->quirks & QUIRK_NEEDS_PMU_CONFIG)
>> +		s3c2410wdt_mask_and_disable_reset(0, wdt);
>
> Error should be handled here. Also false would be better than 0 here.
>
> Best regards,
> Tomasz
>
> --
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> More majordomo info at  http://vger.kernel.org/majordomo-info.html
>
>

Re: [PATCH V5 0/3] Add watchdog DT nodes and use syscon regmap interfac to configure pmu registers

[Sachin Kamat]

Hi Leela,

On 31 October 2013 11:30, Leela Krishna Amudala <l.krishna@samsung.com> wrote:
> This patchset does the following things
>         - Adds pmusysreg device node to exynos5.dtsi file
>         - Adds watchdog DT nodes to Exynos5250 and 5420
>         - Uses syscon regmap interface to configure pmu registers
>           to mask/unmask enable/disable of watchdog.
>
> This patch set is rebased on Kgene's for-next branch and tested on SMDK5420
>
> Changes since V4:
>         - changed the node name from pmusysreg to syscon and node label from pmu_sys_reg to pmu_syscon
>         - changed the property name from samsung,pmusysreg to samsung,syscon-phandle
>         - used regmap_update_bits instead of remap_read/regmap_write
>         - Addressed other comments given by Tomasz Figa <t.figa@samsung.com>
>
> Changes since V3:
>         - changed the compatible strings for watchdog node
>         - splitted up adding pmusysreg node and made it separate patch
>         - Addressed comments given by Sachin Kamat <sachin.kamat@linaro.org>
>
> Changes since V2:
>         - used syscon regmap interface to configure pmu registers in WDT driver
>           (suggested by Tomasz Figa <t.figa@samsung.com>)
>
> Changes since V1:
>         - Added new compatible string for Exynos5 SoCs
>         - Introduced quirk mechanism to program PMU registers
>         - Addressed comments given by Tomasz Figa <t.figa@samsung.com>
>
> Leela Krishna Amudala (3):
>   ARM: dts: Add pmu sysreg node to Exynos5 dtsi file
>   ARM: dts: add watchdog device nodes for Exynos5250 and Exynos5420
>   watchdog: s3c2410_wdt: use syscon regmap interface to configure pmu
>     register
>
>  .../devicetree/bindings/watchdog/samsung-wdt.txt   |   22 ++-
>  arch/arm/boot/dts/exynos5.dtsi                     |   12 +-
>  arch/arm/boot/dts/exynos5250.dtsi                  |    7 +-
>  arch/arm/boot/dts/exynos5420.dtsi                  |   10 ++
>  drivers/watchdog/s3c2410_wdt.c                     |  150 +++++++++++++++++---
>  5 files changed, 175 insertions(+), 26 deletions(-)
>
> --
> 1.7.10.4
>

Series looks good. However, you would need to add select MFD_SYSCON option to
watchdog Kconfig for ARCH_EXYNOS5.

Tested this series on Origen (4210), Arndale (5250) and SMDK5420 boards.

Tested-by: Sachin Kamat <sachin.kamat@linaro.org>
Reviewed-by: Sachin Kamat <sachin.kamat@linaro.org>

-- 
With warm regards,
Sachin