[PATCH V2 0/3] add UniPhier watchdog support

[PATCH V2 0/3] add UniPhier watchdog support

[Keiji Hayashibara]

This series adds support for watchdog timer implemented on UniPhier LD11 and
LD20 SoCs. This driver supports watchdog and system reset for SoCs.

patch V1
http://www.spinics.net/lists/linux-watchdog/msg11782.html

Changes between V2 and V1
=========================
1. Add barrier code in uniphier_watchdog_ping() and __uniphier_watchdog_start().

 When writing WDTCTRL_CLEAR to WDTCTRL register, WDTCTRL_STATUS is updated
 about 62.5usec(2cycle of 32kHz) later. However, if WDTCTRL_CLEAR is written
 before WDTCTRL_STATUS is updated, it can't reboot as SoC specification.
 Therefore, I added barrier code, it waits until WDTCTRL_STATUS is updated.
   
2. Fix issues according to review comments.

 * Use WDOG_STOP_ON_REBOOT instead of shutdown method of struct platform_driver.
 * Separate uniphier-wdt bindings documentation as a patch.
 * Remove delay.h and add bitops.h header file.
 * Use devm_watchdog_register_device().
 * Remove unnecessary code.

Keiji Hayashibara (3):
  devicetree: add UniPhier WDT devicetree bindings documentation
  watchdog: uniphier: add UniPhier watchdog driver
  arm64: dts: uniphier: add watchdog node for LD11 and LD20

 .../devicetree/bindings/watchdog/uniphier-wdt.txt  |  20 ++
 Documentation/watchdog/watchdog-parameters.txt     |   6 +
 arch/arm64/boot/dts/socionext/uniphier-ld11.dtsi   |   4 +
 arch/arm64/boot/dts/socionext/uniphier-ld20.dtsi   |   4 +
 drivers/watchdog/Kconfig                           |  11 +
 drivers/watchdog/Makefile                          |   1 +
 drivers/watchdog/uniphier_wdt.c                    | 275 +++++++++++++++++++++
 7 files changed, 321 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/watchdog/uniphier-wdt.txt
 create mode 100644 drivers/watchdog/uniphier_wdt.c

-- 
2.7.4

[PATCH V2 1/3] devicetree: add UniPhier WDT devicetree bindings documentation

[Keiji Hayashibara]

Add uniphier-wdt bindings documentation.

Signed-off-by: Keiji Hayashibara <hayashibara.keiji@socionext.com>
---
 .../devicetree/bindings/watchdog/uniphier-wdt.txt    | 20 ++++++++++++++++++++
 1 file changed, 20 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/watchdog/uniphier-wdt.txt

diff --git a/Documentation/devicetree/bindings/watchdog/uniphier-wdt.txt b/Documentation/devicetree/bindings/watchdog/uniphier-wdt.txt
new file mode 100644
index 0000000..a59d1ba
--- /dev/null
+++ b/Documentation/devicetree/bindings/watchdog/uniphier-wdt.txt
@@ -0,0 +1,20 @@
+UniPhier watchdog timer controller
+
+This UniPhier watchdog timer controller must be under sysctrl compatible node.
+
+Required properties:
+- compatible: should be "socionext,uniphier-wdt"
+
+Example:
+
+	sysctrl@61840000 {
+		compatible = "socionext,uniphier-ld11-sysctrl",
+			     "simple-mfd", "syscon";
+		reg = <0x61840000 0x4000>;
+
+		sys_wdt: watchdog {
+			compatible = "socionext,uniphier-wdt";
+		}
+
+		other nodes ...
+	};
-- 
2.7.4

[PATCH V2 2/3] watchdog: uniphier: add UniPhier watchdog driver

[Keiji Hayashibara]

Add a watchdog driver for Socionext UniPhier series SoC.
Note that the timeout value for this device must be a power
of 2 because of the specification.

Signed-off-by: Keiji Hayashibara <hayashibara.keiji@socionext.com>
---
 Documentation/watchdog/watchdog-parameters.txt |   6 +
 drivers/watchdog/Kconfig                       |  11 +
 drivers/watchdog/Makefile                      |   1 +
 drivers/watchdog/uniphier_wdt.c                | 275 +++++++++++++++++++++++++
 4 files changed, 293 insertions(+)
 create mode 100644 drivers/watchdog/uniphier_wdt.c

diff --git a/Documentation/watchdog/watchdog-parameters.txt b/Documentation/watchdog/watchdog-parameters.txt
index 4f7d86d..6f9d7b4 100644
--- a/Documentation/watchdog/watchdog-parameters.txt
+++ b/Documentation/watchdog/watchdog-parameters.txt
@@ -369,6 +369,12 @@ timeout: Watchdog timeout in seconds. (0<timeout<N, default=60)
 nowayout: Watchdog cannot be stopped once started
 	(default=kernel config parameter)
 -------------------------------------------------
+uniphier_wdt:
+timeout: Watchdog timeout in power of two seconds.
+	(1 <= timeout <= 128, default=64)
+nowayout: Watchdog cannot be stopped once started
+	(default=kernel config parameter)
+-------------------------------------------------
 w83627hf_wdt:
 wdt_io: w83627hf/thf WDT io port (default 0x2E)
 timeout: Watchdog timeout in seconds. 1 <= timeout <= 255, default=60.
diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig
index 52a70ee..2a9d9a6 100644
--- a/drivers/watchdog/Kconfig
+++ b/drivers/watchdog/Kconfig
@@ -744,6 +744,17 @@ config ZX2967_WATCHDOG
 	  To compile this driver as a module, choose M here: the
 	  module will be called zx2967_wdt.
 
+config UNIPHIER_WATCHDOG
+	tristate "UniPhier watchdog support"
+	depends on ARCH_UNIPHIER || COMPILE_TEST
+	select WATCHDOG_CORE
+	help
+	  Say Y here to include support watchdog timer embedded
+	  into the UniPhier system.
+
+	  To compile this driver as a module, choose M here: the
+	  module will be called uniphier_wdt.
+
 # AVR32 Architecture
 
 config AT32AP700X_WDT
diff --git a/drivers/watchdog/Makefile b/drivers/watchdog/Makefile
index a2126e2..0928dac 100644
--- a/drivers/watchdog/Makefile
+++ b/drivers/watchdog/Makefile
@@ -84,6 +84,7 @@ obj-$(CONFIG_ATLAS7_WATCHDOG) += atlas7_wdt.o
 obj-$(CONFIG_RENESAS_WDT) += renesas_wdt.o
 obj-$(CONFIG_ASPEED_WATCHDOG) += aspeed_wdt.o
 obj-$(CONFIG_ZX2967_WATCHDOG) += zx2967_wdt.o
+obj-$(CONFIG_UNIPHIER_WATCHDOG) += uniphier_wdt.o
 
 # AVR32 Architecture
 obj-$(CONFIG_AT32AP700X_WDT) += at32ap700x_wdt.o
diff --git a/drivers/watchdog/uniphier_wdt.c b/drivers/watchdog/uniphier_wdt.c
new file mode 100644
index 0000000..75862a0
--- /dev/null
+++ b/drivers/watchdog/uniphier_wdt.c
@@ -0,0 +1,275 @@
+/*
+ * Watchdog driver for the UniPhier watchdog timer
+ *
+ * (c) Copyright 2014 Panasonic Corporation
+ * (c) Copyright 2016 Socionext Inc.
+ * All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+#include <linux/module.h>
+#include <linux/mfd/syscon.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/regmap.h>
+#include <linux/watchdog.h>
+#include <linux/bitops.h>
+
+/* WDT timer setting register */
+#define WDTTIMSET			0x3004
+#define   WDTTIMSET_PERIOD_MASK		(0xf << 0)
+#define   WDTTIMSET_PERIOD_1_SEC	(0x3 << 0)
+#define   WDTTIMSET_PERIOD_2_SEC	(0x4 << 0)
+#define   WDTTIMSET_PERIOD_4_SEC	(0x5 << 0)
+#define   WDTTIMSET_PERIOD_8_SEC	(0x6 << 0)
+#define   WDTTIMSET_PERIOD_16_SEC	(0x7 << 0)
+#define   WDTTIMSET_PERIOD_32_SEC	(0x8 << 0)
+#define   WDTTIMSET_PERIOD_64_SEC	(0x9 << 0)
+#define   WDTTIMSET_PERIOD_128_SEC	(0xa << 0)
+
+/* WDT reset selection register */
+#define WDTRSTSEL			0x3008
+#define   WDTRSTSEL_RSTSEL_MASK		(0x3 << 0)
+#define   WDTRSTSEL_RSTSEL_BOTH		(0x0 << 0)
+#define   WDTRSTSEL_RSTSEL_IRQ_ONLY	(0x2 << 0)
+
+/* WDT control register */
+#define WDTCTRL				0x300c
+#define   WDTCTRL_STATUS		BIT(8)
+#define   WDTCTRL_CLEAR			BIT(1)
+#define   WDTCTRL_ENABLE		BIT(0)
+
+#define SEC_TO_WDTTIMSET_PRD(sec) \
+		(ilog2(sec) + WDTTIMSET_PERIOD_1_SEC)
+
+#define WDTST_TIMEOUT			1000 /* usec */
+
+#define WDT_DEFAULT_TIMEOUT		64   /* Default is 64 seconds */
+#define WDT_PERIOD_MIN			1
+#define WDT_PERIOD_MAX			128
+
+static unsigned int timeout = WDT_DEFAULT_TIMEOUT;
+static bool nowayout = WATCHDOG_NOWAYOUT;
+
+struct uniphier_wdt_dev {
+	struct watchdog_device wdt_dev;
+	struct regmap	*regmap;
+};
+
+/*
+ * UniPhier Watchdog operations
+ */
+static int uniphier_watchdog_ping(struct watchdog_device *w)
+{
+	struct uniphier_wdt_dev *wdev = watchdog_get_drvdata(w);
+	unsigned int val;
+	int ret;
+
+	/* Clear counter */
+	ret = regmap_write_bits(wdev->regmap, WDTCTRL,
+				WDTCTRL_CLEAR, WDTCTRL_CLEAR);
+	if (!ret)
+		/*
+		 * As SoC specification, after clear counter,
+		 * it needs to wait until counter status is 1.
+		 */
+		ret = regmap_read_poll_timeout(wdev->regmap, WDTCTRL, val,
+					       (val & WDTCTRL_STATUS),
+					       0, WDTST_TIMEOUT);
+
+	return ret;
+}
+
+static int __uniphier_watchdog_start(struct regmap *regmap, unsigned int sec)
+{
+	unsigned int val;
+	int ret;
+
+	ret = regmap_read_poll_timeout(regmap, WDTCTRL, val,
+				       !(val & WDTCTRL_STATUS),
+				       0, WDTST_TIMEOUT);
+	if (ret)
+		return ret;
+
+	/* Setup period */
+	ret = regmap_write(regmap, WDTTIMSET,
+			   SEC_TO_WDTTIMSET_PRD(sec));
+	if (ret)
+		return ret;
+
+	/* Enable and clear watchdog */
+	ret = regmap_write(regmap, WDTCTRL, WDTCTRL_ENABLE | WDTCTRL_CLEAR);
+	if (!ret)
+		/*
+		 * As SoC specification, after clear counter,
+		 * it needs to wait until counter status is 1.
+		 */
+		ret = regmap_read_poll_timeout(regmap, WDTCTRL, val,
+					       (val & WDTCTRL_STATUS),
+					       0, WDTST_TIMEOUT);
+
+	return ret;
+}
+
+static int __uniphier_watchdog_stop(struct regmap *regmap)
+{
+	/* Disable and stop watchdog */
+	return regmap_write_bits(regmap, WDTCTRL, WDTCTRL_ENABLE, 0);
+}
+
+static int __uniphier_watchdog_restart(struct regmap *regmap, unsigned int sec)
+{
+	int ret;
+
+	ret = __uniphier_watchdog_stop(regmap);
+	if (ret)
+		return ret;
+
+	return __uniphier_watchdog_start(regmap, sec);
+}
+
+static int uniphier_watchdog_start(struct watchdog_device *w)
+{
+	struct uniphier_wdt_dev *wdev = watchdog_get_drvdata(w);
+	unsigned int tmp_timeout;
+
+	tmp_timeout = roundup_pow_of_two(w->timeout);
+
+	return __uniphier_watchdog_start(wdev->regmap, tmp_timeout);
+}
+
+static int uniphier_watchdog_stop(struct watchdog_device *w)
+{
+	struct uniphier_wdt_dev *wdev = watchdog_get_drvdata(w);
+
+	return __uniphier_watchdog_stop(wdev->regmap);
+}
+
+static int uniphier_watchdog_set_timeout(struct watchdog_device *w,
+					 unsigned int t)
+{
+	struct uniphier_wdt_dev *wdev = watchdog_get_drvdata(w);
+	unsigned int tmp_timeout;
+	int ret;
+
+	tmp_timeout = roundup_pow_of_two(t);
+	if (tmp_timeout == w->timeout)
+		return 0;
+
+	if (watchdog_active(w)) {
+		ret = __uniphier_watchdog_restart(wdev->regmap, tmp_timeout);
+		if (ret)
+			return ret;
+	}
+
+	w->timeout = tmp_timeout;
+
+	return 0;
+}
+
+/*
+ * Kernel Interfaces
+ */
+static const struct watchdog_info uniphier_wdt_info = {
+	.identity	= "uniphier-wdt",
+	.options	= WDIOF_SETTIMEOUT |
+			  WDIOF_KEEPALIVEPING |
+			  WDIOF_MAGICCLOSE |
+			  WDIOF_OVERHEAT,
+};
+
+static const struct watchdog_ops uniphier_wdt_ops = {
+	.owner		= THIS_MODULE,
+	.start		= uniphier_watchdog_start,
+	.stop		= uniphier_watchdog_stop,
+	.ping		= uniphier_watchdog_ping,
+	.set_timeout	= uniphier_watchdog_set_timeout,
+};
+
+static int uniphier_wdt_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct uniphier_wdt_dev *wdev;
+	struct regmap *regmap;
+	struct device_node *parent;
+	int ret;
+
+	wdev = devm_kzalloc(dev, sizeof(*wdev), GFP_KERNEL);
+	if (!wdev)
+		return -ENOMEM;
+
+	platform_set_drvdata(pdev, wdev);
+
+	parent = of_get_parent(dev->of_node); /* parent should be syscon node */
+	regmap = syscon_node_to_regmap(parent);
+	of_node_put(parent);
+	if (IS_ERR(regmap))
+		return PTR_ERR(regmap);
+
+	wdev->regmap = regmap;
+	wdev->wdt_dev.info = &uniphier_wdt_info;
+	wdev->wdt_dev.ops = &uniphier_wdt_ops;
+	wdev->wdt_dev.timeout = WDT_DEFAULT_TIMEOUT;
+	wdev->wdt_dev.max_timeout = WDT_PERIOD_MAX;
+	wdev->wdt_dev.min_timeout = WDT_PERIOD_MIN;
+	wdev->wdt_dev.parent = dev;
+
+	watchdog_init_timeout(&wdev->wdt_dev, timeout, dev);
+	watchdog_set_nowayout(&wdev->wdt_dev, nowayout);
+	watchdog_stop_on_reboot(&wdev->wdt_dev);
+
+	watchdog_set_drvdata(&wdev->wdt_dev, wdev);
+
+	uniphier_watchdog_stop(&wdev->wdt_dev);
+	ret = regmap_write(wdev->regmap, WDTRSTSEL, WDTRSTSEL_RSTSEL_BOTH);
+	if (ret)
+		return ret;
+
+	ret = devm_watchdog_register_device(dev, &wdev->wdt_dev);
+	if (ret)
+		return ret;
+
+	dev_info(dev, "watchdog driver (timeout=%d sec, nowayout=%d)\n",
+		 wdev->wdt_dev.timeout, nowayout);
+
+	return 0;
+}
+
+static const struct of_device_id uniphier_wdt_dt_ids[] = {
+	{ .compatible = "socionext,uniphier-wdt" },
+	{ /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(of, uniphier_wdt_dt_ids);
+
+static struct platform_driver uniphier_wdt_driver = {
+	.probe		= uniphier_wdt_probe,
+	.driver		= {
+		.name		= "uniphier-wdt",
+		.of_match_table	= uniphier_wdt_dt_ids,
+	},
+};
+
+module_platform_driver(uniphier_wdt_driver);
+
+module_param(timeout, uint, 0000);
+MODULE_PARM_DESC(timeout,
+	"Watchdog timeout seconds in power of 2. (0 < timeout < 128, default="
+				__MODULE_STRING(WDT_DEFAULT_TIMEOUT) ")");
+
+module_param(nowayout, bool, 0000);
+MODULE_PARM_DESC(nowayout,
+	"Watchdog cannot be stopped once started (default="
+				__MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
+
+MODULE_AUTHOR("Socionext Inc.");
+MODULE_DESCRIPTION("UniPhier Watchdog Device Driver");
+MODULE_LICENSE("GPL v2");
-- 
2.7.4

[PATCH V2 3/3] arm64: dts: uniphier: add watchdog node for LD11 and LD20

[Keiji Hayashibara]

Add nodes of watchdog timer for UniPhier LD11 and LD20 SoC.
The watchdog timer is included in sysctrl.

Signed-off-by: Keiji Hayashibara <hayashibara.keiji@socionext.com>
---
 arch/arm64/boot/dts/socionext/uniphier-ld11.dtsi | 4 ++++
 arch/arm64/boot/dts/socionext/uniphier-ld20.dtsi | 4 ++++
 2 files changed, 8 insertions(+)

diff --git a/arch/arm64/boot/dts/socionext/uniphier-ld11.dtsi b/arch/arm64/boot/dts/socionext/uniphier-ld11.dtsi
index da881f5..5fee3e3 100644
--- a/arch/arm64/boot/dts/socionext/uniphier-ld11.dtsi
+++ b/arch/arm64/boot/dts/socionext/uniphier-ld11.dtsi
@@ -393,6 +393,10 @@
 				compatible = "socionext,uniphier-ld11-reset";
 				#reset-cells = <1>;
 			};
+
+			watchdog {
+				compatible = "socionext,uniphier-wdt";
+			};
 		};
 	};
 };
diff --git a/arch/arm64/boot/dts/socionext/uniphier-ld20.dtsi b/arch/arm64/boot/dts/socionext/uniphier-ld20.dtsi
index a6b3a70..d4d82c8 100644
--- a/arch/arm64/boot/dts/socionext/uniphier-ld20.dtsi
+++ b/arch/arm64/boot/dts/socionext/uniphier-ld20.dtsi
@@ -417,6 +417,10 @@
 				compatible = "socionext,uniphier-ld20-reset";
 				#reset-cells = <1>;
 			};
+
+			watchdog {
+				compatible = "socionext,uniphier-wdt";
+			};
 		};
 	};
 };
-- 
2.7.4

Re: [PATCH V2 2/3] watchdog: uniphier: add UniPhier watchdog driver

[Masahiro Yamada]

Hayashibara-san

Just a nit.


> +
> +#include <linux/module.h>
> +#include <linux/mfd/syscon.h>
> +#include <linux/of.h>
> +#include <linux/platform_device.h>
> +#include <linux/regmap.h>
> +#include <linux/watchdog.h>
> +#include <linux/bitops.h>

I think you should have added <linux/bitops.h> on the top
to keep the includes alphabetically sorted.


-- 
Best Regards
Masahiro Yamada

Re: [PATCH V2 1/3] devicetree: add UniPhier WDT devicetree bindings documentation

[Masahiro Yamada]

Hayashibara-san


Just nitpicking.


2017-06-06 18:11 GMT+09:00 Keiji Hayashibara <hayashibara.keiji@socionext.com>:
> Add uniphier-wdt bindings documentation.
>
> Signed-off-by: Keiji Hayashibara <hayashibara.keiji@socionext.com>


Maybe "dt-bindings: watchdog: ..." for the subject.

This seems what Rob prefers.

For example,
https://patchwork.kernel.org/patch/9606365/



> ---
>  .../devicetree/bindings/watchdog/uniphier-wdt.txt    | 20 ++++++++++++++++++++
>  1 file changed, 20 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/watchdog/uniphier-wdt.txt
>
> diff --git a/Documentation/devicetree/bindings/watchdog/uniphier-wdt.txt b/Documentation/devicetree/bindings/watchdog/uniphier-wdt.txt
> new file mode 100644
> index 0000000..a59d1ba
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/watchdog/uniphier-wdt.txt
> @@ -0,0 +1,20 @@
> +UniPhier watchdog timer controller
> +
> +This UniPhier watchdog timer controller must be under sysctrl compatible node.

Do you mean "syscon compatible" ?


> +Required properties:
> +- compatible: should be "socionext,uniphier-wdt"
> +
> +Example:
> +
> +       sysctrl@61840000 {
> +               compatible = "socionext,uniphier-ld11-sysctrl",
> +                            "simple-mfd", "syscon";
> +               reg = <0x61840000 0x4000>;
> +
> +               sys_wdt: watchdog {
> +                       compatible = "socionext,uniphier-wdt";
> +               }

Could you remove the "sys_dwt: " label?
I'd like the example matched with actual DT files.


Thanks.


> +               other nodes ...
> +       };
> --
> 2.7.4
>
> --
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> the body of a message to majordomo@vger.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html



-- 
Best Regards
Masahiro Yamada

RE: [PATCH V2 2/3] watchdog: uniphier: add UniPhier watchdog driver

[Keiji Hayashibara]

Hello Yamada-san,

> > +
> > +#include <linux/module.h>
> > +#include <linux/mfd/syscon.h>
> > +#include <linux/of.h>
> > +#include <linux/platform_device.h>
> > +#include <linux/regmap.h>
> > +#include <linux/watchdog.h>
> > +#include <linux/bitops.h>
> 
> I think you should have added <linux/bitops.h> on the top
> to keep the includes alphabetically sorted.

Sorry, I will fix in v3 patch.

----------
Best Regards,
Keiji Hayashibara

RE: [PATCH V2 1/3] devicetree: add UniPhier WDT devicetree bindings documentation

[Keiji Hayashibara]

Hello Yamada-san

Thank you for your comment.

> > Add uniphier-wdt bindings documentation.
> >
> > Signed-off-by: Keiji Hayashibara <hayashibara.keiji@socionext.com>
> 
> 
> Maybe "dt-bindings: watchdog: ..." for the subject.
> 
> This seems what Rob prefers.
> 
> For example,
> https://patchwork.kernel.org/patch/9606365/

OK. I will change the subject in v3 patch.

> 
> > ---
> >  .../devicetree/bindings/watchdog/uniphier-wdt.txt    | 20 ++++++++++++++++++++
> >  1 file changed, 20 insertions(+)
> >  create mode 100644 Documentation/devicetree/bindings/watchdog/uniphier-wdt.txt
> >
> > diff --git a/Documentation/devicetree/bindings/watchdog/uniphier-wdt.txt
> b/Documentation/devicetree/bindings/watchdog/uniphier-wdt.txt
> > new file mode 100644
> > index 0000000..a59d1ba
> > --- /dev/null
> > +++ b/Documentation/devicetree/bindings/watchdog/uniphier-wdt.txt
> > @@ -0,0 +1,20 @@
> > +UniPhier watchdog timer controller
> > +
> > +This UniPhier watchdog timer controller must be under sysctrl compatible node.
> 
> Do you mean "syscon compatible" ?

The "compatible" word is inappropriate.
I will remove it in v3 patch.

> 
> > +Required properties:
> > +- compatible: should be "socionext,uniphier-wdt"
> > +
> > +Example:
> > +
> > +       sysctrl@61840000 {
> > +               compatible = "socionext,uniphier-ld11-sysctrl",
> > +                            "simple-mfd", "syscon";
> > +               reg = <0x61840000 0x4000>;
> > +
> > +               sys_wdt: watchdog {
> > +                       compatible = "socionext,uniphier-wdt";
> > +               }
> 
> Could you remove the "sys_dwt: " label?
> I'd like the example matched with actual DT files.

I will remove it.

> 
> Thanks.
> 
> 
> > +               other nodes ...
> > +       };
> > --
> > 2.7.4
> >
> > --
> > To unsubscribe from this list: send the line "unsubscribe linux-watchdog" in
> > the body of a message to majordomo@vger.kernel.org
> > More majordomo info at  http://vger.kernel.org/majordomo-info.html

----------
Best Regards,
Keiji Hayashibara

Re: [PATCH V2 2/3] watchdog: uniphier: add UniPhier watchdog driver

[Guenter Roeck]

On 06/06/2017 02:11 AM, Keiji Hayashibara wrote:
> Add a watchdog driver for Socionext UniPhier series SoC.
> Note that the timeout value for this device must be a power
> of 2 because of the specification.
> 
> Signed-off-by: Keiji Hayashibara <hayashibara.keiji@socionext.com>
> ---
>   Documentation/watchdog/watchdog-parameters.txt |   6 +
>   drivers/watchdog/Kconfig                       |  11 +
>   drivers/watchdog/Makefile                      |   1 +
>   drivers/watchdog/uniphier_wdt.c                | 275 +++++++++++++++++++++++++
>   4 files changed, 293 insertions(+)
>   create mode 100644 drivers/watchdog/uniphier_wdt.c
> 
> diff --git a/Documentation/watchdog/watchdog-parameters.txt b/Documentation/watchdog/watchdog-parameters.txt
> index 4f7d86d..6f9d7b4 100644
> --- a/Documentation/watchdog/watchdog-parameters.txt
> +++ b/Documentation/watchdog/watchdog-parameters.txt
> @@ -369,6 +369,12 @@ timeout: Watchdog timeout in seconds. (0<timeout<N, default=60)
>   nowayout: Watchdog cannot be stopped once started
>   	(default=kernel config parameter)
>   -------------------------------------------------
> +uniphier_wdt:
> +timeout: Watchdog timeout in power of two seconds.
> +	(1 <= timeout <= 128, default=64)
> +nowayout: Watchdog cannot be stopped once started
> +	(default=kernel config parameter)
> +-------------------------------------------------
>   w83627hf_wdt:
>   wdt_io: w83627hf/thf WDT io port (default 0x2E)
>   timeout: Watchdog timeout in seconds. 1 <= timeout <= 255, default=60.
> diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig
> index 52a70ee..2a9d9a6 100644
> --- a/drivers/watchdog/Kconfig
> +++ b/drivers/watchdog/Kconfig
> @@ -744,6 +744,17 @@ config ZX2967_WATCHDOG
>   	  To compile this driver as a module, choose M here: the
>   	  module will be called zx2967_wdt.
>   
> +config UNIPHIER_WATCHDOG
> +	tristate "UniPhier watchdog support"
> +	depends on ARCH_UNIPHIER || COMPILE_TEST
> +	select WATCHDOG_CORE
> +	help
> +	  Say Y here to include support watchdog timer embedded
> +	  into the UniPhier system.
> +
> +	  To compile this driver as a module, choose M here: the
> +	  module will be called uniphier_wdt.
> +
>   # AVR32 Architecture
>   
>   config AT32AP700X_WDT
> diff --git a/drivers/watchdog/Makefile b/drivers/watchdog/Makefile
> index a2126e2..0928dac 100644
> --- a/drivers/watchdog/Makefile
> +++ b/drivers/watchdog/Makefile
> @@ -84,6 +84,7 @@ obj-$(CONFIG_ATLAS7_WATCHDOG) += atlas7_wdt.o
>   obj-$(CONFIG_RENESAS_WDT) += renesas_wdt.o
>   obj-$(CONFIG_ASPEED_WATCHDOG) += aspeed_wdt.o
>   obj-$(CONFIG_ZX2967_WATCHDOG) += zx2967_wdt.o
> +obj-$(CONFIG_UNIPHIER_WATCHDOG) += uniphier_wdt.o
>   
>   # AVR32 Architecture
>   obj-$(CONFIG_AT32AP700X_WDT) += at32ap700x_wdt.o
> diff --git a/drivers/watchdog/uniphier_wdt.c b/drivers/watchdog/uniphier_wdt.c
> new file mode 100644
> index 0000000..75862a0
> --- /dev/null
> +++ b/drivers/watchdog/uniphier_wdt.c
> @@ -0,0 +1,275 @@
> +/*
> + * Watchdog driver for the UniPhier watchdog timer
> + *
> + * (c) Copyright 2014 Panasonic Corporation
> + * (c) Copyright 2016 Socionext Inc.
> + * All rights reserved.
> + *
> + * This program is free software; you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License as published by
> + * the Free Software Foundation; either version 2 of the License, or
> + * (at your option) any later version.
> + *
> + * This program is distributed in the hope that it will be useful,
> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
> + * GNU General Public License for more details.
> + */
> +
> +#include <linux/module.h>
> +#include <linux/mfd/syscon.h>
> +#include <linux/of.h>
> +#include <linux/platform_device.h>
> +#include <linux/regmap.h>
> +#include <linux/watchdog.h>
> +#include <linux/bitops.h>
> +
> +/* WDT timer setting register */
> +#define WDTTIMSET			0x3004
> +#define   WDTTIMSET_PERIOD_MASK		(0xf << 0)
> +#define   WDTTIMSET_PERIOD_1_SEC	(0x3 << 0)
> +#define   WDTTIMSET_PERIOD_2_SEC	(0x4 << 0)
> +#define   WDTTIMSET_PERIOD_4_SEC	(0x5 << 0)
> +#define   WDTTIMSET_PERIOD_8_SEC	(0x6 << 0)
> +#define   WDTTIMSET_PERIOD_16_SEC	(0x7 << 0)
> +#define   WDTTIMSET_PERIOD_32_SEC	(0x8 << 0)
> +#define   WDTTIMSET_PERIOD_64_SEC	(0x9 << 0)
> +#define   WDTTIMSET_PERIOD_128_SEC	(0xa << 0)
> +
> +/* WDT reset selection register */
> +#define WDTRSTSEL			0x3008
> +#define   WDTRSTSEL_RSTSEL_MASK		(0x3 << 0)
> +#define   WDTRSTSEL_RSTSEL_BOTH		(0x0 << 0)
> +#define   WDTRSTSEL_RSTSEL_IRQ_ONLY	(0x2 << 0)
> +
> +/* WDT control register */
> +#define WDTCTRL				0x300c
> +#define   WDTCTRL_STATUS		BIT(8)
> +#define   WDTCTRL_CLEAR			BIT(1)
> +#define   WDTCTRL_ENABLE		BIT(0)
> +
> +#define SEC_TO_WDTTIMSET_PRD(sec) \
> +		(ilog2(sec) + WDTTIMSET_PERIOD_1_SEC)
> +
> +#define WDTST_TIMEOUT			1000 /* usec */
> +
> +#define WDT_DEFAULT_TIMEOUT		64   /* Default is 64 seconds */
> +#define WDT_PERIOD_MIN			1
> +#define WDT_PERIOD_MAX			128
> +
> +static unsigned int timeout = WDT_DEFAULT_TIMEOUT;

This should be initialized to 0 (see below).

> +static bool nowayout = WATCHDOG_NOWAYOUT;
> +
> +struct uniphier_wdt_dev {
> +	struct watchdog_device wdt_dev;
> +	struct regmap	*regmap;
> +};
> +
> +/*
> + * UniPhier Watchdog operations
> + */
> +static int uniphier_watchdog_ping(struct watchdog_device *w)
> +{
> +	struct uniphier_wdt_dev *wdev = watchdog_get_drvdata(w);
> +	unsigned int val;
> +	int ret;
> +
> +	/* Clear counter */
> +	ret = regmap_write_bits(wdev->regmap, WDTCTRL,
> +				WDTCTRL_CLEAR, WDTCTRL_CLEAR);
> +	if (!ret)
> +		/*
> +		 * As SoC specification, after clear counter,
> +		 * it needs to wait until counter status is 1.
> +		 */
> +		ret = regmap_read_poll_timeout(wdev->regmap, WDTCTRL, val,
> +					       (val & WDTCTRL_STATUS),
> +					       0, WDTST_TIMEOUT);
> +
> +	return ret;
> +}
> +
> +static int __uniphier_watchdog_start(struct regmap *regmap, unsigned int sec)
> +{
> +	unsigned int val;
> +	int ret;
> +
> +	ret = regmap_read_poll_timeout(regmap, WDTCTRL, val,
> +				       !(val & WDTCTRL_STATUS),
> +				       0, WDTST_TIMEOUT);
> +	if (ret)
> +		return ret;
> +
> +	/* Setup period */
> +	ret = regmap_write(regmap, WDTTIMSET,
> +			   SEC_TO_WDTTIMSET_PRD(sec));
> +	if (ret)
> +		return ret;
> +
> +	/* Enable and clear watchdog */
> +	ret = regmap_write(regmap, WDTCTRL, WDTCTRL_ENABLE | WDTCTRL_CLEAR);
> +	if (!ret)
> +		/*
> +		 * As SoC specification, after clear counter,
> +		 * it needs to wait until counter status is 1.
> +		 */
> +		ret = regmap_read_poll_timeout(regmap, WDTCTRL, val,
> +					       (val & WDTCTRL_STATUS),
> +					       0, WDTST_TIMEOUT);
> +
> +	return ret;
> +}
> +
> +static int __uniphier_watchdog_stop(struct regmap *regmap)
> +{
> +	/* Disable and stop watchdog */
> +	return regmap_write_bits(regmap, WDTCTRL, WDTCTRL_ENABLE, 0);
> +}
> +
> +static int __uniphier_watchdog_restart(struct regmap *regmap, unsigned int sec)
> +{
> +	int ret;
> +
> +	ret = __uniphier_watchdog_stop(regmap);
> +	if (ret)
> +		return ret;
> +
> +	return __uniphier_watchdog_start(regmap, sec);
> +}
> +
> +static int uniphier_watchdog_start(struct watchdog_device *w)
> +{
> +	struct uniphier_wdt_dev *wdev = watchdog_get_drvdata(w);
> +	unsigned int tmp_timeout;
> +
> +	tmp_timeout = roundup_pow_of_two(w->timeout);
> +
> +	return __uniphier_watchdog_start(wdev->regmap, tmp_timeout);
> +}
> +
> +static int uniphier_watchdog_stop(struct watchdog_device *w)
> +{
> +	struct uniphier_wdt_dev *wdev = watchdog_get_drvdata(w);
> +
> +	return __uniphier_watchdog_stop(wdev->regmap);
> +}
> +
> +static int uniphier_watchdog_set_timeout(struct watchdog_device *w,
> +					 unsigned int t)
> +{
> +	struct uniphier_wdt_dev *wdev = watchdog_get_drvdata(w);
> +	unsigned int tmp_timeout;
> +	int ret;
> +
> +	tmp_timeout = roundup_pow_of_two(t);
> +	if (tmp_timeout == w->timeout)
> +		return 0;
> +
> +	if (watchdog_active(w)) {
> +		ret = __uniphier_watchdog_restart(wdev->regmap, tmp_timeout);
> +		if (ret)
> +			return ret;
> +	}
> +
> +	w->timeout = tmp_timeout;
> +
> +	return 0;
> +}
> +
> +/*
> + * Kernel Interfaces
> + */
> +static const struct watchdog_info uniphier_wdt_info = {
> +	.identity	= "uniphier-wdt",
> +	.options	= WDIOF_SETTIMEOUT |
> +			  WDIOF_KEEPALIVEPING |
> +			  WDIOF_MAGICCLOSE |
> +			  WDIOF_OVERHEAT,
> +};
> +
> +static const struct watchdog_ops uniphier_wdt_ops = {
> +	.owner		= THIS_MODULE,
> +	.start		= uniphier_watchdog_start,
> +	.stop		= uniphier_watchdog_stop,
> +	.ping		= uniphier_watchdog_ping,
> +	.set_timeout	= uniphier_watchdog_set_timeout,
> +};
> +
> +static int uniphier_wdt_probe(struct platform_device *pdev)
> +{
> +	struct device *dev = &pdev->dev;
> +	struct uniphier_wdt_dev *wdev;
> +	struct regmap *regmap;
> +	struct device_node *parent;
> +	int ret;
> +
> +	wdev = devm_kzalloc(dev, sizeof(*wdev), GFP_KERNEL);
> +	if (!wdev)
> +		return -ENOMEM;
> +
> +	platform_set_drvdata(pdev, wdev);
> +
> +	parent = of_get_parent(dev->of_node); /* parent should be syscon node */
> +	regmap = syscon_node_to_regmap(parent);
> +	of_node_put(parent);
> +	if (IS_ERR(regmap))
> +		return PTR_ERR(regmap);
> +
> +	wdev->regmap = regmap;
> +	wdev->wdt_dev.info = &uniphier_wdt_info;
> +	wdev->wdt_dev.ops = &uniphier_wdt_ops;
> +	wdev->wdt_dev.timeout = WDT_DEFAULT_TIMEOUT;
> +	wdev->wdt_dev.max_timeout = WDT_PERIOD_MAX;
> +	wdev->wdt_dev.min_timeout = WDT_PERIOD_MIN;
> +	wdev->wdt_dev.parent = dev;
> +
> +	watchdog_init_timeout(&wdev->wdt_dev, timeout, dev);

This only really makes sense if the default for 'timeout' is 0.
Otherwise it will never take a timeout from devicetree unless timeout is
explicitly set to 0 as module parameter, which does not make much sense.

> +	watchdog_set_nowayout(&wdev->wdt_dev, nowayout);
> +	watchdog_stop_on_reboot(&wdev->wdt_dev);
> +
> +	watchdog_set_drvdata(&wdev->wdt_dev, wdev);
> +
> +	uniphier_watchdog_stop(&wdev->wdt_dev);
> +	ret = regmap_write(wdev->regmap, WDTRSTSEL, WDTRSTSEL_RSTSEL_BOTH);
> +	if (ret)
> +		return ret;
> +
> +	ret = devm_watchdog_register_device(dev, &wdev->wdt_dev);
> +	if (ret)
> +		return ret;
> +
> +	dev_info(dev, "watchdog driver (timeout=%d sec, nowayout=%d)\n",
> +		 wdev->wdt_dev.timeout, nowayout);
> +
> +	return 0;
> +}
> +
> +static const struct of_device_id uniphier_wdt_dt_ids[] = {
> +	{ .compatible = "socionext,uniphier-wdt" },
> +	{ /* sentinel */ }
> +};
> +MODULE_DEVICE_TABLE(of, uniphier_wdt_dt_ids);
> +
> +static struct platform_driver uniphier_wdt_driver = {
> +	.probe		= uniphier_wdt_probe,
> +	.driver		= {
> +		.name		= "uniphier-wdt",
> +		.of_match_table	= uniphier_wdt_dt_ids,
> +	},
> +};
> +
> +module_platform_driver(uniphier_wdt_driver);
> +
> +module_param(timeout, uint, 0000);
> +MODULE_PARM_DESC(timeout,
> +	"Watchdog timeout seconds in power of 2. (0 < timeout < 128, default="
> +				__MODULE_STRING(WDT_DEFAULT_TIMEOUT) ")");
> +
> +module_param(nowayout, bool, 0000);
> +MODULE_PARM_DESC(nowayout,
> +	"Watchdog cannot be stopped once started (default="
> +				__MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
> +
> +MODULE_AUTHOR("Socionext Inc.");
> +MODULE_DESCRIPTION("UniPhier Watchdog Device Driver");
> +MODULE_LICENSE("GPL v2");
> 

The license here does not match the license in the header (which states GPL2+).

RE: [PATCH V2 2/3] watchdog: uniphier: add UniPhier watchdog driver

[Keiji Hayashibara]

Hi Guenter,

Thank you for your comment.

> On 06/06/2017 02:11 AM, Keiji Hayashibara wrote:
> > Add a watchdog driver for Socionext UniPhier series SoC.
> > Note that the timeout value for this device must be a power
> > of 2 because of the specification.
> >
> > Signed-off-by: Keiji Hayashibara <hayashibara.keiji@socionext.com>
> > ---
> >   Documentation/watchdog/watchdog-parameters.txt |   6 +
> >   drivers/watchdog/Kconfig                       |  11 +
> >   drivers/watchdog/Makefile                      |   1 +
> >   drivers/watchdog/uniphier_wdt.c                | 275 +++++++++++++++++++++++++
> >   4 files changed, 293 insertions(+)
> >   create mode 100644 drivers/watchdog/uniphier_wdt.c
> >
> > diff --git a/Documentation/watchdog/watchdog-parameters.txt b/Documentation/watchdog/watchdog-parameters.txt
> > index 4f7d86d..6f9d7b4 100644
> > --- a/Documentation/watchdog/watchdog-parameters.txt
> > +++ b/Documentation/watchdog/watchdog-parameters.txt
> > @@ -369,6 +369,12 @@ timeout: Watchdog timeout in seconds. (0<timeout<N, default=60)
> >   nowayout: Watchdog cannot be stopped once started
> >   	(default=kernel config parameter)
> >   -------------------------------------------------
> > +uniphier_wdt:
> > +timeout: Watchdog timeout in power of two seconds.
> > +	(1 <= timeout <= 128, default=64)
> > +nowayout: Watchdog cannot be stopped once started
> > +	(default=kernel config parameter)
> > +-------------------------------------------------
> >   w83627hf_wdt:
> >   wdt_io: w83627hf/thf WDT io port (default 0x2E)
> >   timeout: Watchdog timeout in seconds. 1 <= timeout <= 255, default=60.
> > diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig
> > index 52a70ee..2a9d9a6 100644
> > --- a/drivers/watchdog/Kconfig
> > +++ b/drivers/watchdog/Kconfig
> > @@ -744,6 +744,17 @@ config ZX2967_WATCHDOG
> >   	  To compile this driver as a module, choose M here: the
> >   	  module will be called zx2967_wdt.
> >
> > +config UNIPHIER_WATCHDOG
> > +	tristate "UniPhier watchdog support"
> > +	depends on ARCH_UNIPHIER || COMPILE_TEST
> > +	select WATCHDOG_CORE
> > +	help
> > +	  Say Y here to include support watchdog timer embedded
> > +	  into the UniPhier system.
> > +
> > +	  To compile this driver as a module, choose M here: the
> > +	  module will be called uniphier_wdt.
> > +
> >   # AVR32 Architecture
> >
> >   config AT32AP700X_WDT
> > diff --git a/drivers/watchdog/Makefile b/drivers/watchdog/Makefile
> > index a2126e2..0928dac 100644
> > --- a/drivers/watchdog/Makefile
> > +++ b/drivers/watchdog/Makefile
> > @@ -84,6 +84,7 @@ obj-$(CONFIG_ATLAS7_WATCHDOG) += atlas7_wdt.o
> >   obj-$(CONFIG_RENESAS_WDT) += renesas_wdt.o
> >   obj-$(CONFIG_ASPEED_WATCHDOG) += aspeed_wdt.o
> >   obj-$(CONFIG_ZX2967_WATCHDOG) += zx2967_wdt.o
> > +obj-$(CONFIG_UNIPHIER_WATCHDOG) += uniphier_wdt.o
> >
> >   # AVR32 Architecture
> >   obj-$(CONFIG_AT32AP700X_WDT) += at32ap700x_wdt.o
> > diff --git a/drivers/watchdog/uniphier_wdt.c b/drivers/watchdog/uniphier_wdt.c
> > new file mode 100644
> > index 0000000..75862a0
> > --- /dev/null
> > +++ b/drivers/watchdog/uniphier_wdt.c
> > @@ -0,0 +1,275 @@
> > +/*
> > + * Watchdog driver for the UniPhier watchdog timer
> > + *
> > + * (c) Copyright 2014 Panasonic Corporation
> > + * (c) Copyright 2016 Socionext Inc.
> > + * All rights reserved.
> > + *
> > + * This program is free software; you can redistribute it and/or modify
> > + * it under the terms of the GNU General Public License as published by
> > + * the Free Software Foundation; either version 2 of the License, or
> > + * (at your option) any later version.
> > + *
> > + * This program is distributed in the hope that it will be useful,
> > + * but WITHOUT ANY WARRANTY; without even the implied warranty of
> > + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
> > + * GNU General Public License for more details.
> > + */
> > +
> > +#include <linux/module.h>
> > +#include <linux/mfd/syscon.h>
> > +#include <linux/of.h>
> > +#include <linux/platform_device.h>
> > +#include <linux/regmap.h>
> > +#include <linux/watchdog.h>
> > +#include <linux/bitops.h>
> > +
> > +/* WDT timer setting register */
> > +#define WDTTIMSET			0x3004
> > +#define   WDTTIMSET_PERIOD_MASK		(0xf << 0)
> > +#define   WDTTIMSET_PERIOD_1_SEC	(0x3 << 0)
> > +#define   WDTTIMSET_PERIOD_2_SEC	(0x4 << 0)
> > +#define   WDTTIMSET_PERIOD_4_SEC	(0x5 << 0)
> > +#define   WDTTIMSET_PERIOD_8_SEC	(0x6 << 0)
> > +#define   WDTTIMSET_PERIOD_16_SEC	(0x7 << 0)
> > +#define   WDTTIMSET_PERIOD_32_SEC	(0x8 << 0)
> > +#define   WDTTIMSET_PERIOD_64_SEC	(0x9 << 0)
> > +#define   WDTTIMSET_PERIOD_128_SEC	(0xa << 0)
> > +
> > +/* WDT reset selection register */
> > +#define WDTRSTSEL			0x3008
> > +#define   WDTRSTSEL_RSTSEL_MASK		(0x3 << 0)
> > +#define   WDTRSTSEL_RSTSEL_BOTH		(0x0 << 0)
> > +#define   WDTRSTSEL_RSTSEL_IRQ_ONLY	(0x2 << 0)
> > +
> > +/* WDT control register */
> > +#define WDTCTRL				0x300c
> > +#define   WDTCTRL_STATUS		BIT(8)
> > +#define   WDTCTRL_CLEAR			BIT(1)
> > +#define   WDTCTRL_ENABLE		BIT(0)
> > +
> > +#define SEC_TO_WDTTIMSET_PRD(sec) \
> > +		(ilog2(sec) + WDTTIMSET_PERIOD_1_SEC)
> > +
> > +#define WDTST_TIMEOUT			1000 /* usec */
> > +
> > +#define WDT_DEFAULT_TIMEOUT		64   /* Default is 64 seconds */
> > +#define WDT_PERIOD_MIN			1
> > +#define WDT_PERIOD_MAX			128
> > +
> > +static unsigned int timeout = WDT_DEFAULT_TIMEOUT;
> 
> This should be initialized to 0 (see below).

OK. I fix it.

> > +static bool nowayout = WATCHDOG_NOWAYOUT;
> > +
> > +struct uniphier_wdt_dev {
> > +	struct watchdog_device wdt_dev;
> > +	struct regmap	*regmap;
> > +};
> > +
> > +/*
> > + * UniPhier Watchdog operations
> > + */
> > +static int uniphier_watchdog_ping(struct watchdog_device *w)
> > +{
> > +	struct uniphier_wdt_dev *wdev = watchdog_get_drvdata(w);
> > +	unsigned int val;
> > +	int ret;
> > +
> > +	/* Clear counter */
> > +	ret = regmap_write_bits(wdev->regmap, WDTCTRL,
> > +				WDTCTRL_CLEAR, WDTCTRL_CLEAR);
> > +	if (!ret)
> > +		/*
> > +		 * As SoC specification, after clear counter,
> > +		 * it needs to wait until counter status is 1.
> > +		 */
> > +		ret = regmap_read_poll_timeout(wdev->regmap, WDTCTRL, val,
> > +					       (val & WDTCTRL_STATUS),
> > +					       0, WDTST_TIMEOUT);
> > +
> > +	return ret;
> > +}
> > +
> > +static int __uniphier_watchdog_start(struct regmap *regmap, unsigned int sec)
> > +{
> > +	unsigned int val;
> > +	int ret;
> > +
> > +	ret = regmap_read_poll_timeout(regmap, WDTCTRL, val,
> > +				       !(val & WDTCTRL_STATUS),
> > +				       0, WDTST_TIMEOUT);
> > +	if (ret)
> > +		return ret;
> > +
> > +	/* Setup period */
> > +	ret = regmap_write(regmap, WDTTIMSET,
> > +			   SEC_TO_WDTTIMSET_PRD(sec));
> > +	if (ret)
> > +		return ret;
> > +
> > +	/* Enable and clear watchdog */
> > +	ret = regmap_write(regmap, WDTCTRL, WDTCTRL_ENABLE | WDTCTRL_CLEAR);
> > +	if (!ret)
> > +		/*
> > +		 * As SoC specification, after clear counter,
> > +		 * it needs to wait until counter status is 1.
> > +		 */
> > +		ret = regmap_read_poll_timeout(regmap, WDTCTRL, val,
> > +					       (val & WDTCTRL_STATUS),
> > +					       0, WDTST_TIMEOUT);
> > +
> > +	return ret;
> > +}
> > +
> > +static int __uniphier_watchdog_stop(struct regmap *regmap)
> > +{
> > +	/* Disable and stop watchdog */
> > +	return regmap_write_bits(regmap, WDTCTRL, WDTCTRL_ENABLE, 0);
> > +}
> > +
> > +static int __uniphier_watchdog_restart(struct regmap *regmap, unsigned int sec)
> > +{
> > +	int ret;
> > +
> > +	ret = __uniphier_watchdog_stop(regmap);
> > +	if (ret)
> > +		return ret;
> > +
> > +	return __uniphier_watchdog_start(regmap, sec);
> > +}
> > +
> > +static int uniphier_watchdog_start(struct watchdog_device *w)
> > +{
> > +	struct uniphier_wdt_dev *wdev = watchdog_get_drvdata(w);
> > +	unsigned int tmp_timeout;
> > +
> > +	tmp_timeout = roundup_pow_of_two(w->timeout);
> > +
> > +	return __uniphier_watchdog_start(wdev->regmap, tmp_timeout);
> > +}
> > +
> > +static int uniphier_watchdog_stop(struct watchdog_device *w)
> > +{
> > +	struct uniphier_wdt_dev *wdev = watchdog_get_drvdata(w);
> > +
> > +	return __uniphier_watchdog_stop(wdev->regmap);
> > +}
> > +
> > +static int uniphier_watchdog_set_timeout(struct watchdog_device *w,
> > +					 unsigned int t)
> > +{
> > +	struct uniphier_wdt_dev *wdev = watchdog_get_drvdata(w);
> > +	unsigned int tmp_timeout;
> > +	int ret;
> > +
> > +	tmp_timeout = roundup_pow_of_two(t);
> > +	if (tmp_timeout == w->timeout)
> > +		return 0;
> > +
> > +	if (watchdog_active(w)) {
> > +		ret = __uniphier_watchdog_restart(wdev->regmap, tmp_timeout);
> > +		if (ret)
> > +			return ret;
> > +	}
> > +
> > +	w->timeout = tmp_timeout;
> > +
> > +	return 0;
> > +}
> > +
> > +/*
> > + * Kernel Interfaces
> > + */
> > +static const struct watchdog_info uniphier_wdt_info = {
> > +	.identity	= "uniphier-wdt",
> > +	.options	= WDIOF_SETTIMEOUT |
> > +			  WDIOF_KEEPALIVEPING |
> > +			  WDIOF_MAGICCLOSE |
> > +			  WDIOF_OVERHEAT,
> > +};
> > +
> > +static const struct watchdog_ops uniphier_wdt_ops = {
> > +	.owner		= THIS_MODULE,
> > +	.start		= uniphier_watchdog_start,
> > +	.stop		= uniphier_watchdog_stop,
> > +	.ping		= uniphier_watchdog_ping,
> > +	.set_timeout	= uniphier_watchdog_set_timeout,
> > +};
> > +
> > +static int uniphier_wdt_probe(struct platform_device *pdev)
> > +{
> > +	struct device *dev = &pdev->dev;
> > +	struct uniphier_wdt_dev *wdev;
> > +	struct regmap *regmap;
> > +	struct device_node *parent;
> > +	int ret;
> > +
> > +	wdev = devm_kzalloc(dev, sizeof(*wdev), GFP_KERNEL);
> > +	if (!wdev)
> > +		return -ENOMEM;
> > +
> > +	platform_set_drvdata(pdev, wdev);
> > +
> > +	parent = of_get_parent(dev->of_node); /* parent should be syscon node */
> > +	regmap = syscon_node_to_regmap(parent);
> > +	of_node_put(parent);
> > +	if (IS_ERR(regmap))
> > +		return PTR_ERR(regmap);
> > +
> > +	wdev->regmap = regmap;
> > +	wdev->wdt_dev.info = &uniphier_wdt_info;
> > +	wdev->wdt_dev.ops = &uniphier_wdt_ops;
> > +	wdev->wdt_dev.timeout = WDT_DEFAULT_TIMEOUT;
> > +	wdev->wdt_dev.max_timeout = WDT_PERIOD_MAX;
> > +	wdev->wdt_dev.min_timeout = WDT_PERIOD_MIN;
> > +	wdev->wdt_dev.parent = dev;
> > +
> > +	watchdog_init_timeout(&wdev->wdt_dev, timeout, dev);
> 
> This only really makes sense if the default for 'timeout' is 0.
> Otherwise it will never take a timeout from devicetree unless timeout is
> explicitly set to 0 as module parameter, which does not make much sense.

It is certainly so.
I will fix it in next v3 patch.


> > +	watchdog_set_nowayout(&wdev->wdt_dev, nowayout);
> > +	watchdog_stop_on_reboot(&wdev->wdt_dev);
> > +
> > +	watchdog_set_drvdata(&wdev->wdt_dev, wdev);
> > +
> > +	uniphier_watchdog_stop(&wdev->wdt_dev);
> > +	ret = regmap_write(wdev->regmap, WDTRSTSEL, WDTRSTSEL_RSTSEL_BOTH);
> > +	if (ret)
> > +		return ret;
> > +
> > +	ret = devm_watchdog_register_device(dev, &wdev->wdt_dev);
> > +	if (ret)
> > +		return ret;
> > +
> > +	dev_info(dev, "watchdog driver (timeout=%d sec, nowayout=%d)\n",
> > +		 wdev->wdt_dev.timeout, nowayout);
> > +
> > +	return 0;
> > +}
> > +
> > +static const struct of_device_id uniphier_wdt_dt_ids[] = {
> > +	{ .compatible = "socionext,uniphier-wdt" },
> > +	{ /* sentinel */ }
> > +};
> > +MODULE_DEVICE_TABLE(of, uniphier_wdt_dt_ids);
> > +
> > +static struct platform_driver uniphier_wdt_driver = {
> > +	.probe		= uniphier_wdt_probe,
> > +	.driver		= {
> > +		.name		= "uniphier-wdt",
> > +		.of_match_table	= uniphier_wdt_dt_ids,
> > +	},
> > +};
> > +
> > +module_platform_driver(uniphier_wdt_driver);
> > +
> > +module_param(timeout, uint, 0000);
> > +MODULE_PARM_DESC(timeout,
> > +	"Watchdog timeout seconds in power of 2. (0 < timeout < 128, default="
> > +				__MODULE_STRING(WDT_DEFAULT_TIMEOUT) ")");
> > +
> > +module_param(nowayout, bool, 0000);
> > +MODULE_PARM_DESC(nowayout,
> > +	"Watchdog cannot be stopped once started (default="
> > +				__MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
> > +
> > +MODULE_AUTHOR("Socionext Inc.");
> > +MODULE_DESCRIPTION("UniPhier Watchdog Device Driver");
> > +MODULE_LICENSE("GPL v2");
> >
> 
> The license here does not match the license in the header (which states GPL2+).

I will modify in next v3 patch.

----------
Best Regards,
Keiji Hayashibara