[PATCH 0/2] Add Mediatek watchdog suspend resume and shutdown

[PATCH 0/2] Add Mediatek watchdog suspend resume and shutdown

[Eddie Huang]

This series add Mediatek watchdog suspend, resume and shutdown support.
These patches are based on v4.2-rc1

Greta Zhang (2):
  watchdog: add wdt suspend/resume support
  watchdog: add wdt shutdown callback to disable wdt if enabled

 drivers/watchdog/mtk_wdt.c | 47 ++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 47 insertions(+)

-- 
1.8.1.1.dirty

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[PATCH 1/2] watchdog: add wdt suspend/resume support

[Eddie Huang]

From: Greta Zhang <greta.zhang@mediatek.com>

add wdt driver suspend/resume support

Signed-off-by: Greta Zhang <greta.zhang@mediatek.com>
Signed-off-by: Roger Lu <roger.lu@mediatek.com>
Signed-off-by: Eddie Huang <eddie.huang@mediatek.com>
---
 drivers/watchdog/mtk_wdt.c | 38 ++++++++++++++++++++++++++++++++++++++
 1 file changed, 38 insertions(+)

diff --git a/drivers/watchdog/mtk_wdt.c b/drivers/watchdog/mtk_wdt.c
index 938b987..5ef3910 100644
--- a/drivers/watchdog/mtk_wdt.c
+++ b/drivers/watchdog/mtk_wdt.c
@@ -65,6 +65,7 @@ struct mtk_wdt_dev {
 	struct watchdog_device wdt_dev;
 	void __iomem *wdt_base;
 	struct notifier_block restart_handler;
+	bool started;
 };
 
 static int mtk_reset_handler(struct notifier_block *this, unsigned long mode,
@@ -125,6 +126,8 @@ static int mtk_wdt_stop(struct watchdog_device *wdt_dev)
 	reg &= ~WDT_MODE_EN;
 	iowrite32(reg, wdt_base + WDT_MODE);
 
+	mtk_wdt->started = false;
+
 	return 0;
 }
 
@@ -135,6 +138,8 @@ static int mtk_wdt_start(struct watchdog_device *wdt_dev)
 	void __iomem *wdt_base = mtk_wdt->wdt_base;
 	int ret;
 
+	mtk_wdt->started = true;
+
 	ret = mtk_wdt_set_timeout(wdt_dev, wdt_dev->timeout);
 	if (ret < 0)
 		return ret;
@@ -174,6 +179,8 @@ static int mtk_wdt_probe(struct platform_device *pdev)
 
 	platform_set_drvdata(pdev, mtk_wdt);
 
+	mtk_wdt->started = false;
+
 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 	mtk_wdt->wdt_base = devm_ioremap_resource(&pdev->dev, res);
 	if (IS_ERR(mtk_wdt->wdt_base))
@@ -221,6 +228,35 @@ static int mtk_wdt_remove(struct platform_device *pdev)
 	return 0;
 }
 
+#ifdef CONFIG_PM
+static int mtk_wdt_suspend(struct platform_device *pdev, pm_message_t state)
+{
+	struct mtk_wdt_dev *mtk_wdt = platform_get_drvdata(pdev);
+
+	if (mtk_wdt->started) {
+		mtk_wdt_stop(&mtk_wdt->wdt_dev);
+		mtk_wdt->started = true;
+	}
+
+	return 0;
+}
+
+static int mtk_wdt_resume(struct platform_device *pdev)
+{
+	struct mtk_wdt_dev *mtk_wdt = platform_get_drvdata(pdev);
+
+	if (mtk_wdt->started) {
+		mtk_wdt_start(&mtk_wdt->wdt_dev);
+		mtk_wdt_ping(&mtk_wdt->wdt_dev);
+	}
+
+	return 0;
+}
+#else
+#define	mtk_wdt_suspend	NULL
+#define	mtk_wdt_resume	NULL
+#endif
+
 static const struct of_device_id mtk_wdt_dt_ids[] = {
 	{ .compatible = "mediatek,mt6589-wdt" },
 	{ /* sentinel */ }
@@ -230,6 +266,8 @@ MODULE_DEVICE_TABLE(of, mtk_wdt_dt_ids);
 static struct platform_driver mtk_wdt_driver = {
 	.probe		= mtk_wdt_probe,
 	.remove		= mtk_wdt_remove,
+	.suspend	= mtk_wdt_suspend,
+	.resume		= mtk_wdt_resume,
 	.driver		= {
 		.name		= DRV_NAME,
 		.of_match_table	= mtk_wdt_dt_ids,
-- 
1.8.1.1.dirty

Re: [PATCH 1/2] watchdog: add wdt suspend/resume support

[Guenter Roeck]

On 07/21/2015 08:26 PM, Eddie Huang wrote:
> From: Greta Zhang <greta.zhang-NuS5LvNUpcJWk0Htik3J/w@public.gmane.org>
>
> add wdt driver suspend/resume support
>
> Signed-off-by: Greta Zhang <greta.zhang-NuS5LvNUpcJWk0Htik3J/w@public.gmane.org>
> Signed-off-by: Roger Lu <roger.lu-NuS5LvNUpcJWk0Htik3J/w@public.gmane.org>
> Signed-off-by: Eddie Huang <eddie.huang-NuS5LvNUpcJWk0Htik3J/w@public.gmane.org>
> ---
>   drivers/watchdog/mtk_wdt.c | 38 ++++++++++++++++++++++++++++++++++++++
>   1 file changed, 38 insertions(+)
>
> diff --git a/drivers/watchdog/mtk_wdt.c b/drivers/watchdog/mtk_wdt.c
> index 938b987..5ef3910 100644
> --- a/drivers/watchdog/mtk_wdt.c
> +++ b/drivers/watchdog/mtk_wdt.c
> @@ -65,6 +65,7 @@ struct mtk_wdt_dev {
>   	struct watchdog_device wdt_dev;
>   	void __iomem *wdt_base;
>   	struct notifier_block restart_handler;
> +	bool started;

Any reason why you can not use watchdog_active() ?

>   };
>
>   static int mtk_reset_handler(struct notifier_block *this, unsigned long mode,
> @@ -125,6 +126,8 @@ static int mtk_wdt_stop(struct watchdog_device *wdt_dev)
>   	reg &= ~WDT_MODE_EN;
>   	iowrite32(reg, wdt_base + WDT_MODE);
>
> +	mtk_wdt->started = false;
> +
>   	return 0;
>   }
>
> @@ -135,6 +138,8 @@ static int mtk_wdt_start(struct watchdog_device *wdt_dev)
>   	void __iomem *wdt_base = mtk_wdt->wdt_base;
>   	int ret;
>
> +	mtk_wdt->started = true;
> +
>   	ret = mtk_wdt_set_timeout(wdt_dev, wdt_dev->timeout);
>   	if (ret < 0)
>   		return ret;
> @@ -174,6 +179,8 @@ static int mtk_wdt_probe(struct platform_device *pdev)
>
>   	platform_set_drvdata(pdev, mtk_wdt);
>
> +	mtk_wdt->started = false;
> +
>   	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
>   	mtk_wdt->wdt_base = devm_ioremap_resource(&pdev->dev, res);
>   	if (IS_ERR(mtk_wdt->wdt_base))
> @@ -221,6 +228,35 @@ static int mtk_wdt_remove(struct platform_device *pdev)
>   	return 0;
>   }
>
> +#ifdef CONFIG_PM
> +static int mtk_wdt_suspend(struct platform_device *pdev, pm_message_t state)
> +{
> +	struct mtk_wdt_dev *mtk_wdt = platform_get_drvdata(pdev);
> +
> +	if (mtk_wdt->started) {
> +		mtk_wdt_stop(&mtk_wdt->wdt_dev);
> +		mtk_wdt->started = true;

?????

> +	}
> +
> +	return 0;
> +}
> +
> +static int mtk_wdt_resume(struct platform_device *pdev)
> +{
> +	struct mtk_wdt_dev *mtk_wdt = platform_get_drvdata(pdev);
> +
> +	if (mtk_wdt->started) {
> +		mtk_wdt_start(&mtk_wdt->wdt_dev);
> +		mtk_wdt_ping(&mtk_wdt->wdt_dev);
> +	}
> +
> +	return 0;
> +}
> +#else
> +#define	mtk_wdt_suspend	NULL
> +#define	mtk_wdt_resume	NULL
> +#endif
> +
>   static const struct of_device_id mtk_wdt_dt_ids[] = {
>   	{ .compatible = "mediatek,mt6589-wdt" },
>   	{ /* sentinel */ }
> @@ -230,6 +266,8 @@ MODULE_DEVICE_TABLE(of, mtk_wdt_dt_ids);
>   static struct platform_driver mtk_wdt_driver = {
>   	.probe		= mtk_wdt_probe,
>   	.remove		= mtk_wdt_remove,
> +	.suspend	= mtk_wdt_suspend,
> +	.resume		= mtk_wdt_resume,
>   	.driver		= {
>   		.name		= DRV_NAME,
>   		.of_match_table	= mtk_wdt_dt_ids,

Typically drivers would use struct dev_pm_ops and
                 .pm = &mtk_wdt_pm_ops,

Any reason for not using the same mechanism ?

Thanks,
Guenter

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Re: [PATCH 1/2] watchdog: add wdt suspend/resume support

[Eddie Huang]

On Tue, 2015-07-21 at 20:45 -0700, Guenter Roeck wrote:
> On 07/21/2015 08:26 PM, Eddie Huang wrote:
> > From: Greta Zhang <greta.zhang-NuS5LvNUpcJWk0Htik3J/w@public.gmane.org>
> >
> > add wdt driver suspend/resume support
> >
> > Signed-off-by: Greta Zhang <greta.zhang-NuS5LvNUpcJWk0Htik3J/w@public.gmane.org>
> > Signed-off-by: Roger Lu <roger.lu-NuS5LvNUpcJWk0Htik3J/w@public.gmane.org>
> > Signed-off-by: Eddie Huang <eddie.huang-NuS5LvNUpcJWk0Htik3J/w@public.gmane.org>
> > ---
> >   drivers/watchdog/mtk_wdt.c | 38 ++++++++++++++++++++++++++++++++++++++
> >   1 file changed, 38 insertions(+)
> >
> > diff --git a/drivers/watchdog/mtk_wdt.c b/drivers/watchdog/mtk_wdt.c
> > index 938b987..5ef3910 100644
> > --- a/drivers/watchdog/mtk_wdt.c
> > +++ b/drivers/watchdog/mtk_wdt.c
> > @@ -65,6 +65,7 @@ struct mtk_wdt_dev {
> >   	struct watchdog_device wdt_dev;
> >   	void __iomem *wdt_base;
> >   	struct notifier_block restart_handler;
> > +	bool started;
> 
> Any reason why you can not use watchdog_active() ?

Will change to use watchdog_active()

> 
> >   };
> >
> >   static int mtk_reset_handler(struct notifier_block *this, unsigned long mode,
> > @@ -125,6 +126,8 @@ static int mtk_wdt_stop(struct watchdog_device *wdt_dev)
> >   	reg &= ~WDT_MODE_EN;
> >   	iowrite32(reg, wdt_base + WDT_MODE);
> >
> > +	mtk_wdt->started = false;
> > +
> >   	return 0;
> >   }
> >
> > @@ -135,6 +138,8 @@ static int mtk_wdt_start(struct watchdog_device *wdt_dev)
> >   	void __iomem *wdt_base = mtk_wdt->wdt_base;
> >   	int ret;
> >
> > +	mtk_wdt->started = true;
> > +
> >   	ret = mtk_wdt_set_timeout(wdt_dev, wdt_dev->timeout);
> >   	if (ret < 0)
> >   		return ret;
> > @@ -174,6 +179,8 @@ static int mtk_wdt_probe(struct platform_device *pdev)
> >
> >   	platform_set_drvdata(pdev, mtk_wdt);
> >
> > +	mtk_wdt->started = false;
> > +
> >   	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> >   	mtk_wdt->wdt_base = devm_ioremap_resource(&pdev->dev, res);
> >   	if (IS_ERR(mtk_wdt->wdt_base))
> > @@ -221,6 +228,35 @@ static int mtk_wdt_remove(struct platform_device *pdev)
> >   	return 0;
> >   }
> >
> > +#ifdef CONFIG_PM
> > +static int mtk_wdt_suspend(struct platform_device *pdev, pm_message_t state)
> > +{
> > +	struct mtk_wdt_dev *mtk_wdt = platform_get_drvdata(pdev);
> > +
> > +	if (mtk_wdt->started) {
> > +		mtk_wdt_stop(&mtk_wdt->wdt_dev);
> > +		mtk_wdt->started = true;
> 
> ?????
> 
Because mtk_wdt_stop() change mtk_wdt->started to false, so set
mtk_wdt->started back to true here. This code is not necessary if use
watchdog_active()

> > +	}
> > +
> > +	return 0;
> > +}
> > +
> > +static int mtk_wdt_resume(struct platform_device *pdev)
> > +{
> > +	struct mtk_wdt_dev *mtk_wdt = platform_get_drvdata(pdev);
> > +
> > +	if (mtk_wdt->started) {
> > +		mtk_wdt_start(&mtk_wdt->wdt_dev);
> > +		mtk_wdt_ping(&mtk_wdt->wdt_dev);
> > +	}
> > +
> > +	return 0;
> > +}
> > +#else
> > +#define	mtk_wdt_suspend	NULL
> > +#define	mtk_wdt_resume	NULL
> > +#endif
> > +
> >   static const struct of_device_id mtk_wdt_dt_ids[] = {
> >   	{ .compatible = "mediatek,mt6589-wdt" },
> >   	{ /* sentinel */ }
> > @@ -230,6 +266,8 @@ MODULE_DEVICE_TABLE(of, mtk_wdt_dt_ids);
> >   static struct platform_driver mtk_wdt_driver = {
> >   	.probe		= mtk_wdt_probe,
> >   	.remove		= mtk_wdt_remove,
> > +	.suspend	= mtk_wdt_suspend,
> > +	.resume		= mtk_wdt_resume,
> >   	.driver		= {
> >   		.name		= DRV_NAME,
> >   		.of_match_table	= mtk_wdt_dt_ids,
> 
> Typically drivers would use struct dev_pm_ops and
>                  .pm = &mtk_wdt_pm_ops,
> 
> Any reason for not using the same mechanism ?
> 
Will change to use dev_pm_ops

Eddie
Thanks

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[PATCH 2/2] watchdog: add wdt shutdown callback to disable wdt if enabled

[Eddie Huang]

From: Greta Zhang <greta.zhang-NuS5LvNUpcJWk0Htik3J/w@public.gmane.org>

Without .shutdown(), watchdog might reset the system during power off.
For example, if watchdog's timeout is set to 30s, then it is reset to
zero by mtk_wdt_ping(). During power off, no app will ping watchdog,
but watchdog is still running and may trigger reset.

Signed-off-by: Greta Zhang <greta.zhang-NuS5LvNUpcJWk0Htik3J/w@public.gmane.org>
Signed-off-by: Eddie Huang <eddie.huang-NuS5LvNUpcJWk0Htik3J/w@public.gmane.org>
---
 drivers/watchdog/mtk_wdt.c | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/drivers/watchdog/mtk_wdt.c b/drivers/watchdog/mtk_wdt.c
index 5ef3910..c6741a5 100644
--- a/drivers/watchdog/mtk_wdt.c
+++ b/drivers/watchdog/mtk_wdt.c
@@ -217,6 +217,14 @@ static int mtk_wdt_probe(struct platform_device *pdev)
 	return 0;
 }
 
+static void mtk_wdt_shutdown(struct platform_device *pdev)
+{
+	struct mtk_wdt_dev *mtk_wdt = platform_get_drvdata(pdev);
+
+	if (mtk_wdt->started)
+		mtk_wdt_stop(&mtk_wdt->wdt_dev);
+}
+
 static int mtk_wdt_remove(struct platform_device *pdev)
 {
 	struct mtk_wdt_dev *mtk_wdt = platform_get_drvdata(pdev);
@@ -266,6 +274,7 @@ MODULE_DEVICE_TABLE(of, mtk_wdt_dt_ids);
 static struct platform_driver mtk_wdt_driver = {
 	.probe		= mtk_wdt_probe,
 	.remove		= mtk_wdt_remove,
+	.shutdown	= mtk_wdt_shutdown,
 	.suspend	= mtk_wdt_suspend,
 	.resume		= mtk_wdt_resume,
 	.driver		= {
-- 
1.8.1.1.dirty

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Re: [PATCH 2/2] watchdog: add wdt shutdown callback to disable wdt if enabled

[Guenter Roeck]

On 07/21/2015 08:26 PM, Eddie Huang wrote:
> From: Greta Zhang <greta.zhang-NuS5LvNUpcJWk0Htik3J/w@public.gmane.org>
>
> Without .shutdown(), watchdog might reset the system during power off.
> For example, if watchdog's timeout is set to 30s, then it is reset to
> zero by mtk_wdt_ping(). During power off, no app will ping watchdog,
> but watchdog is still running and may trigger reset.
>
> Signed-off-by: Greta Zhang <greta.zhang-NuS5LvNUpcJWk0Htik3J/w@public.gmane.org>
> Signed-off-by: Eddie Huang <eddie.huang-NuS5LvNUpcJWk0Htik3J/w@public.gmane.org>
> ---
>   drivers/watchdog/mtk_wdt.c | 9 +++++++++
>   1 file changed, 9 insertions(+)
>
> diff --git a/drivers/watchdog/mtk_wdt.c b/drivers/watchdog/mtk_wdt.c
> index 5ef3910..c6741a5 100644
> --- a/drivers/watchdog/mtk_wdt.c
> +++ b/drivers/watchdog/mtk_wdt.c
> @@ -217,6 +217,14 @@ static int mtk_wdt_probe(struct platform_device *pdev)
>   	return 0;
>   }
>
> +static void mtk_wdt_shutdown(struct platform_device *pdev)
> +{
> +	struct mtk_wdt_dev *mtk_wdt = platform_get_drvdata(pdev);
> +
> +	if (mtk_wdt->started)

watchdog_active() ?

> +		mtk_wdt_stop(&mtk_wdt->wdt_dev);
> +}
> +
>   static int mtk_wdt_remove(struct platform_device *pdev)
>   {
>   	struct mtk_wdt_dev *mtk_wdt = platform_get_drvdata(pdev);
> @@ -266,6 +274,7 @@ MODULE_DEVICE_TABLE(of, mtk_wdt_dt_ids);
>   static struct platform_driver mtk_wdt_driver = {
>   	.probe		= mtk_wdt_probe,
>   	.remove		= mtk_wdt_remove,
> +	.shutdown	= mtk_wdt_shutdown,
>   	.suspend	= mtk_wdt_suspend,
>   	.resume		= mtk_wdt_resume,
>   	.driver		= {
>

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