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[PATCH v2] watchdog: sunxi_wdt: Allow watchdog to remain enabled after probe

Regis Dargent posted 1 patch 3 weeks, 5 days ago
There is a newer version of this series
drivers/watchdog/sunxi_wdt.c | 48 +++++++++++++++++++++++++++++++++---
1 file changed, 45 insertions(+), 3 deletions(-)
[PATCH v2] watchdog: sunxi_wdt: Allow watchdog to remain enabled after probe
Posted by Regis Dargent 3 weeks, 5 days ago 
If the watchdog is already running during probe, let it run on, read its
configured timeout, and set its status so that it is correctly handled by the
kernel.

Signed-off-by: Regis Dargent <regis.dargent@gmail.com>
---
 drivers/watchdog/sunxi_wdt.c | 48 +++++++++++++++++++++++++++++++++---
 1 file changed, 45 insertions(+), 3 deletions(-)

diff --git a/drivers/watchdog/sunxi_wdt.c b/drivers/watchdog/sunxi_wdt.c
index b85354a99582..0094bcd063c5 100644
--- a/drivers/watchdog/sunxi_wdt.c
+++ b/drivers/watchdog/sunxi_wdt.c
@@ -140,6 +140,7 @@ static int sunxi_wdt_set_timeout(struct watchdog_device *wdt_dev,
 		timeout++;
 
 	sunxi_wdt->wdt_dev.timeout = timeout;
+	sunxi_wdt->wdt_dev.max_hw_heartbeat_ms = 0;
 
 	reg = readl(wdt_base + regs->wdt_mode);
 	reg &= ~(WDT_TIMEOUT_MASK << regs->wdt_timeout_shift);
@@ -152,6 +153,32 @@ static int sunxi_wdt_set_timeout(struct watchdog_device *wdt_dev,
 	return 0;
 }
 
+static int sunxi_wdt_read_timeout(struct watchdog_device *wdt_dev)
+{
+	struct sunxi_wdt_dev *sunxi_wdt = watchdog_get_drvdata(wdt_dev);
+	void __iomem *wdt_base = sunxi_wdt->wdt_base;
+	const struct sunxi_wdt_reg *regs = sunxi_wdt->wdt_regs;
+	int i;
+	u32 reg;
+
+	reg = readl(wdt_base + regs->wdt_mode);
+	reg >>= regs->wdt_timeout_shift;
+	reg &= WDT_TIMEOUT_MASK;
+
+	/* Start at 0 which actually means 0.5s */
+	for (i = 0; ((i < WDT_MAX_TIMEOUT) && (wdt_timeout_map[i] != reg)); i++)
+		;
+	if (i == 0) {
+		wdt_dev->timeout = 1;
+		wdt_dev->max_hw_heartbeat_ms = 500;
+	} else {
+		wdt_dev->timeout = i;
+		wdt_dev->max_hw_heartbeat_ms = 0;
+	}
+
+	return 0;
+}
+
 static int sunxi_wdt_stop(struct watchdog_device *wdt_dev)
 {
 	struct sunxi_wdt_dev *sunxi_wdt = watchdog_get_drvdata(wdt_dev);
@@ -192,11 +219,22 @@ static int sunxi_wdt_start(struct watchdog_device *wdt_dev)
 	return 0;
 }
 
+static bool sunxi_wdt_enabled(struct sunxi_wdt_dev *wdt)
+{
+	u32 reg;
+	void __iomem *wdt_base = wdt->wdt_base;
+	const struct sunxi_wdt_reg *regs = wdt->wdt_regs;
+
+	reg = readl(wdt_base + regs->wdt_mode);
+	return !!(reg & WDT_MODE_EN);
+}
+
 static const struct watchdog_info sunxi_wdt_info = {
 	.identity	= DRV_NAME,
 	.options	= WDIOF_SETTIMEOUT |
 			  WDIOF_KEEPALIVEPING |
-			  WDIOF_MAGICCLOSE,
+			  WDIOF_MAGICCLOSE |
+			  WDIOF_SETTIMEOUT,
 };
 
 static const struct watchdog_ops sunxi_wdt_ops = {
@@ -275,8 +313,12 @@ static int sunxi_wdt_probe(struct platform_device *pdev)
 
 	watchdog_set_drvdata(&sunxi_wdt->wdt_dev, sunxi_wdt);
 
-	sunxi_wdt_stop(&sunxi_wdt->wdt_dev);
-
+	if (sunxi_wdt_enabled(sunxi_wdt)) {
+		sunxi_wdt_read_timeout(&sunxi_wdt->wdt_dev);
+		set_bit(WDOG_HW_RUNNING, &sunxi_wdt->wdt_dev.status);
+	} else {
+		sunxi_wdt_stop(&sunxi_wdt->wdt_dev);
+	}
 	watchdog_stop_on_reboot(&sunxi_wdt->wdt_dev);
 	err = devm_watchdog_register_device(dev, &sunxi_wdt->wdt_dev);
 	if (unlikely(err))
-- 
2.25.1
Re: [PATCH v2] watchdog: sunxi_wdt: Allow watchdog to remain enabled after probe
Posted by Jernej Škrabec 2 weeks, 6 days ago 
Hi,

please send new versions as separate e-mail thread.

Dne petek, 14. februar 2025 ob 12:22:54 Srednjeevropski standardni čas je Regis Dargent napisal(a):
> If the watchdog is already running during probe, let it run on, read its
> configured timeout, and set its status so that it is correctly handled by the
> kernel.
> 
> Signed-off-by: Regis Dargent <regis.dargent@gmail.com>
> ---
>  drivers/watchdog/sunxi_wdt.c | 48 +++++++++++++++++++++++++++++++++---
>  1 file changed, 45 insertions(+), 3 deletions(-)

You should add changelog here.

> 
> diff --git a/drivers/watchdog/sunxi_wdt.c b/drivers/watchdog/sunxi_wdt.c
> index b85354a99582..0094bcd063c5 100644
> --- a/drivers/watchdog/sunxi_wdt.c
> +++ b/drivers/watchdog/sunxi_wdt.c
> @@ -140,6 +140,7 @@ static int sunxi_wdt_set_timeout(struct watchdog_device *wdt_dev,
>  		timeout++;
>  
>  	sunxi_wdt->wdt_dev.timeout = timeout;
> +	sunxi_wdt->wdt_dev.max_hw_heartbeat_ms = 0;
>  
>  	reg = readl(wdt_base + regs->wdt_mode);
>  	reg &= ~(WDT_TIMEOUT_MASK << regs->wdt_timeout_shift);
> @@ -152,6 +153,32 @@ static int sunxi_wdt_set_timeout(struct watchdog_device *wdt_dev,
>  	return 0;
>  }
>  
> +static int sunxi_wdt_read_timeout(struct watchdog_device *wdt_dev)
> +{
> +	struct sunxi_wdt_dev *sunxi_wdt = watchdog_get_drvdata(wdt_dev);
> +	void __iomem *wdt_base = sunxi_wdt->wdt_base;
> +	const struct sunxi_wdt_reg *regs = sunxi_wdt->wdt_regs;
> +	int i;
> +	u32 reg;
> +
> +	reg = readl(wdt_base + regs->wdt_mode);
> +	reg >>= regs->wdt_timeout_shift;
> +	reg &= WDT_TIMEOUT_MASK;
> +
> +	/* Start at 0 which actually means 0.5s */
> +	for (i = 0; ((i < WDT_MAX_TIMEOUT) && (wdt_timeout_map[i] != reg)); i++)

Drop parenthesis in condition.

> +		;
> +	if (i == 0) {
> +		wdt_dev->timeout = 1;
> +		wdt_dev->max_hw_heartbeat_ms = 500;
> +	} else {
> +		wdt_dev->timeout = i;
> +		wdt_dev->max_hw_heartbeat_ms = 0;
> +	}
> +
> +	return 0;
> +}
> +
>  static int sunxi_wdt_stop(struct watchdog_device *wdt_dev)
>  {
>  	struct sunxi_wdt_dev *sunxi_wdt = watchdog_get_drvdata(wdt_dev);
> @@ -192,11 +219,22 @@ static int sunxi_wdt_start(struct watchdog_device *wdt_dev)
>  	return 0;
>  }
>  
> +static bool sunxi_wdt_enabled(struct sunxi_wdt_dev *wdt)
> +{
> +	u32 reg;
> +	void __iomem *wdt_base = wdt->wdt_base;
> +	const struct sunxi_wdt_reg *regs = wdt->wdt_regs;

Inverse christmas tree.

> +
> +	reg = readl(wdt_base + regs->wdt_mode);
> +	return !!(reg & WDT_MODE_EN);
> +}
> +
>  static const struct watchdog_info sunxi_wdt_info = {
>  	.identity	= DRV_NAME,
>  	.options	= WDIOF_SETTIMEOUT |
>  			  WDIOF_KEEPALIVEPING |
> -			  WDIOF_MAGICCLOSE,
> +			  WDIOF_MAGICCLOSE |
> +			  WDIOF_SETTIMEOUT,

Drop this change. WDIOF_SETTIMEOUT is already defined.

>  };
>  
>  static const struct watchdog_ops sunxi_wdt_ops = {
> @@ -275,8 +313,12 @@ static int sunxi_wdt_probe(struct platform_device *pdev)
>  
>  	watchdog_set_drvdata(&sunxi_wdt->wdt_dev, sunxi_wdt);
>  
> -	sunxi_wdt_stop(&sunxi_wdt->wdt_dev);
> -
> +	if (sunxi_wdt_enabled(sunxi_wdt)) {

Also check for IS_ENABLED(CONFIG_WATCHDOG_HANDLE_BOOT_ENABLED). This will
allow user to select behaviour via Kconfig.

Best regards,
Jernej

> +		sunxi_wdt_read_timeout(&sunxi_wdt->wdt_dev);
> +		set_bit(WDOG_HW_RUNNING, &sunxi_wdt->wdt_dev.status);
> +	} else {
> +		sunxi_wdt_stop(&sunxi_wdt->wdt_dev);
> +	}
>  	watchdog_stop_on_reboot(&sunxi_wdt->wdt_dev);
>  	err = devm_watchdog_register_device(dev, &sunxi_wdt->wdt_dev);
>  	if (unlikely(err))
>

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