[PATCH V7 0/2] watchdog: mtk: support pre-timeout when the bark irq is available

[PATCH V7 0/2] watchdog: mtk: support pre-timeout when the bark irq is available

[Wang Qing]

Use the bark interrupt as the pretimeout notifier if available.
The pretimeout notification shall occur at timeout-sec/2.

Wang Qing (2):
  watchdog: mtk: support pre-timeout when the bark irq is available
  doc: mtk-wdt: support pre-timeout when the bark irq is available

 .../devicetree/bindings/watchdog/mtk-wdt.txt       |  5 ++
 drivers/watchdog/mtk_wdt.c                         | 76 ++++++++++++++++++++--
 2 files changed, 76 insertions(+), 5 deletions(-)

-- 
2.7.4

[PATCH V7 1/2] watchdog: mtk: support pre-timeout when the bark irq is available

[Wang Qing]

Use the bark interrupt as the pretimeout notifier if available.

When the watchdog timer expires in dual mode, an interrupt will be
triggered first, then the timing restarts. The reset signal will be
initiated when the timer expires again.

The pretimeout notification shall occur at timeout-sec/2.

V2:
- panic() by default if WATCHDOG_PRETIMEOUT_GOV is not enabled.

V3:
- Modify the pretimeout behavior, manually reset after the pretimeout
- is processed and wait until timeout.

V4:
- Remove pretimeout related processing. 
- Add dual mode control separately.

V5:
- Fix some formatting and printing problems.

V6:
- Realize pretimeout processing through dualmode.

V7:
- Add set_pretimeout().

Signed-off-by: Wang Qing <wangqing@vivo.com>
---
 drivers/watchdog/mtk_wdt.c | 76 +++++++++++++++++++++++++++++++++++++++++++---
 1 file changed, 71 insertions(+), 5 deletions(-)

diff --git a/drivers/watchdog/mtk_wdt.c b/drivers/watchdog/mtk_wdt.c
index 97ca993..ab3ac5d
--- a/drivers/watchdog/mtk_wdt.c
+++ b/drivers/watchdog/mtk_wdt.c
@@ -25,6 +25,7 @@
 #include <linux/reset-controller.h>
 #include <linux/types.h>
 #include <linux/watchdog.h>
+#include <linux/interrupt.h>
 
 #define WDT_MAX_TIMEOUT		31
 #define WDT_MIN_TIMEOUT		1
@@ -184,15 +185,23 @@ static int mtk_wdt_set_timeout(struct watchdog_device *wdt_dev,
 {
 	struct mtk_wdt_dev *mtk_wdt = watchdog_get_drvdata(wdt_dev);
 	void __iomem *wdt_base = mtk_wdt->wdt_base;
+	unsigned int timeout_interval = timeout;
 	u32 reg;
 
 	wdt_dev->timeout = timeout;
-
+	/*
+	 * In dual mode, irq will be triggered at timeout / 2
+	 * the real timeout occurs at timeout
+	 */
+	if (wdt_dev->pretimeout) {
+		wdt_dev->pretimeout = timeout / 2;
+		timeout_interval = wdt_dev->pretimeout;
+	}
 	/*
 	 * One bit is the value of 512 ticks
 	 * The clock has 32 KHz
 	 */
-	reg = WDT_LENGTH_TIMEOUT(timeout << 6) | WDT_LENGTH_KEY;
+	reg = WDT_LENGTH_TIMEOUT(timeout_interval << 6) | WDT_LENGTH_KEY;
 	iowrite32(reg, wdt_base + WDT_LENGTH);
 
 	mtk_wdt_ping(wdt_dev);
@@ -239,13 +248,46 @@ static int mtk_wdt_start(struct watchdog_device *wdt_dev)
 		return ret;
 
 	reg = ioread32(wdt_base + WDT_MODE);
-	reg &= ~(WDT_MODE_IRQ_EN | WDT_MODE_DUAL_EN);
+	if (wdt_dev->pretimeout)
+		reg |= (WDT_MODE_IRQ_EN | WDT_MODE_DUAL_EN);
+	else
+		reg &= ~(WDT_MODE_IRQ_EN | WDT_MODE_DUAL_EN);
 	reg |= (WDT_MODE_EN | WDT_MODE_KEY);
 	iowrite32(reg, wdt_base + WDT_MODE);
 
 	return 0;
 }
 
+static int mtk_wdt_set_pretimeout(struct watchdog_device *wdd,
+					unsigned int timeout)
+{
+	struct mtk_wdt_dev *mtk_wdt = watchdog_get_drvdata(wdd);
+	void __iomem *wdt_base = mtk_wdt->wdt_base;
+	u32 reg = ioread32(wdt_base + WDT_MODE);
+
+	if (timeout && !wdd->pretimeout) {
+		wdd->pretimeout = wdd->timeout / 2;
+		reg |= (WDT_MODE_IRQ_EN | WDT_MODE_DUAL_EN);
+	} else if (!timeout && wdd->pretimeout) {
+		wdd->pretimeout = 0;
+		reg &= ~(WDT_MODE_IRQ_EN | WDT_MODE_DUAL_EN);
+	} else
+		return 0;
+
+	iowrite32(reg, wdt_base + WDT_MODE);
+
+	return mtk_wdt_set_timeout(wdd, wdd->timeout);
+}
+
+static irqreturn_t mtk_wdt_isr(int irq, void *arg)
+{
+	struct watchdog_device *wdd = arg;
+
+	watchdog_notify_pretimeout(wdd);
+
+	return IRQ_HANDLED;
+}
+
 static const struct watchdog_info mtk_wdt_info = {
 	.identity	= DRV_NAME,
 	.options	= WDIOF_SETTIMEOUT |
@@ -253,12 +295,21 @@ static const struct watchdog_info mtk_wdt_info = {
 			  WDIOF_MAGICCLOSE,
 };
 
+static const struct watchdog_info mtk_wdt_pt_info = {
+	.identity	= DRV_NAME,
+	.options	= WDIOF_SETTIMEOUT |
+			  WDIOF_PRETIMEOUT |
+			  WDIOF_KEEPALIVEPING |
+			  WDIOF_MAGICCLOSE,
+};
+
 static const struct watchdog_ops mtk_wdt_ops = {
 	.owner		= THIS_MODULE,
 	.start		= mtk_wdt_start,
 	.stop		= mtk_wdt_stop,
 	.ping		= mtk_wdt_ping,
 	.set_timeout	= mtk_wdt_set_timeout,
+	.set_pretimeout	= mtk_wdt_set_pretimeout,
 	.restart	= mtk_wdt_restart,
 };
 
@@ -267,7 +318,7 @@ static int mtk_wdt_probe(struct platform_device *pdev)
 	struct device *dev = &pdev->dev;
 	struct mtk_wdt_dev *mtk_wdt;
 	const struct mtk_wdt_data *wdt_data;
-	int err;
+	int err, irq;
 
 	mtk_wdt = devm_kzalloc(dev, sizeof(*mtk_wdt), GFP_KERNEL);
 	if (!mtk_wdt)
@@ -279,7 +330,22 @@ static int mtk_wdt_probe(struct platform_device *pdev)
 	if (IS_ERR(mtk_wdt->wdt_base))
 		return PTR_ERR(mtk_wdt->wdt_base);
 
-	mtk_wdt->wdt_dev.info = &mtk_wdt_info;
+	irq = platform_get_irq(pdev, 0);
+	if (irq > 0) {
+		err = devm_request_irq(&pdev->dev, irq, mtk_wdt_isr, 0, "wdt_bark",
+					&mtk_wdt->wdt_dev);
+		if (err)
+			return err;
+
+		mtk_wdt->wdt_dev.info = &mtk_wdt_pt_info;
+		mtk_wdt->wdt_dev.pretimeout = WDT_MAX_TIMEOUT / 2;
+	} else {
+		if (irq == -EPROBE_DEFER)
+			return -EPROBE_DEFER;
+
+		mtk_wdt->wdt_dev.info = &mtk_wdt_info;
+	}
+
 	mtk_wdt->wdt_dev.ops = &mtk_wdt_ops;
 	mtk_wdt->wdt_dev.timeout = WDT_MAX_TIMEOUT;
 	mtk_wdt->wdt_dev.max_hw_heartbeat_ms = WDT_MAX_TIMEOUT * 1000;
-- 
2.7.4

Re: [PATCH V7 1/2] watchdog: mtk: support pre-timeout when the bark irq is available

[Guenter Roeck]

On 4/22/21 7:53 PM, Wang Qing wrote:
> Use the bark interrupt as the pretimeout notifier if available.
> 
> When the watchdog timer expires in dual mode, an interrupt will be
> triggered first, then the timing restarts. The reset signal will be
> initiated when the timer expires again.
> 
> The pretimeout notification shall occur at timeout-sec/2.
> 
> V2:
> - panic() by default if WATCHDOG_PRETIMEOUT_GOV is not enabled.
> 
> V3:
> - Modify the pretimeout behavior, manually reset after the pretimeout
> - is processed and wait until timeout.
> 
> V4:
> - Remove pretimeout related processing. 
> - Add dual mode control separately.
> 
> V5:
> - Fix some formatting and printing problems.
> 
> V6:
> - Realize pretimeout processing through dualmode.
> 
> V7:
> - Add set_pretimeout().
> 
> Signed-off-by: Wang Qing <wangqing@vivo.com>
> ---
>  drivers/watchdog/mtk_wdt.c | 76 +++++++++++++++++++++++++++++++++++++++++++---
>  1 file changed, 71 insertions(+), 5 deletions(-)
> 
> diff --git a/drivers/watchdog/mtk_wdt.c b/drivers/watchdog/mtk_wdt.c
> index 97ca993..ab3ac5d
> --- a/drivers/watchdog/mtk_wdt.c
> +++ b/drivers/watchdog/mtk_wdt.c
> @@ -25,6 +25,7 @@
>  #include <linux/reset-controller.h>
>  #include <linux/types.h>
>  #include <linux/watchdog.h>
> +#include <linux/interrupt.h>
>  
>  #define WDT_MAX_TIMEOUT		31
>  #define WDT_MIN_TIMEOUT		1
> @@ -184,15 +185,23 @@ static int mtk_wdt_set_timeout(struct watchdog_device *wdt_dev,
>  {
>  	struct mtk_wdt_dev *mtk_wdt = watchdog_get_drvdata(wdt_dev);
>  	void __iomem *wdt_base = mtk_wdt->wdt_base;
> +	unsigned int timeout_interval = timeout;
>  	u32 reg;
>  
>  	wdt_dev->timeout = timeout;
> -
> +	/*
> +	 * In dual mode, irq will be triggered at timeout / 2
> +	 * the real timeout occurs at timeout
> +	 */
> +	if (wdt_dev->pretimeout) {
> +		wdt_dev->pretimeout = timeout / 2;

min_timeout is set to 1. I don't this works well if timeout == 1.
You'll either need to set min_timeout to 2, or handle that case.

> +		timeout_interval = wdt_dev->pretimeout;

timeout_interval is unnecessary. Just update timeout accordingly.
It needs to take the situation of timeout == 1 into account, though.

> +	}
>  	/*
>  	 * One bit is the value of 512 ticks
>  	 * The clock has 32 KHz
>  	 */
> -	reg = WDT_LENGTH_TIMEOUT(timeout << 6) | WDT_LENGTH_KEY;
> +	reg = WDT_LENGTH_TIMEOUT(timeout_interval << 6) | WDT_LENGTH_KEY;
>  	iowrite32(reg, wdt_base + WDT_LENGTH);
>  
>  	mtk_wdt_ping(wdt_dev);
> @@ -239,13 +248,46 @@ static int mtk_wdt_start(struct watchdog_device *wdt_dev)
>  		return ret;
>  
>  	reg = ioread32(wdt_base + WDT_MODE);
> -	reg &= ~(WDT_MODE_IRQ_EN | WDT_MODE_DUAL_EN);
> +	if (wdt_dev->pretimeout)
> +		reg |= (WDT_MODE_IRQ_EN | WDT_MODE_DUAL_EN);
> +	else
> +		reg &= ~(WDT_MODE_IRQ_EN | WDT_MODE_DUAL_EN);
>  	reg |= (WDT_MODE_EN | WDT_MODE_KEY);
>  	iowrite32(reg, wdt_base + WDT_MODE);
>  
>  	return 0;
>  }
>  
> +static int mtk_wdt_set_pretimeout(struct watchdog_device *wdd,
> +					unsigned int timeout)
> +{
> +	struct mtk_wdt_dev *mtk_wdt = watchdog_get_drvdata(wdd);
> +	void __iomem *wdt_base = mtk_wdt->wdt_base;
> +	u32 reg = ioread32(wdt_base + WDT_MODE);
> +
> +	if (timeout && !wdd->pretimeout) {
> +		wdd->pretimeout = wdd->timeout / 2;
> +		reg |= (WDT_MODE_IRQ_EN | WDT_MODE_DUAL_EN);
> +	} else if (!timeout && wdd->pretimeout) {
> +		wdd->pretimeout = 0;
> +		reg &= ~(WDT_MODE_IRQ_EN | WDT_MODE_DUAL_EN);
> +	} else
> +		return 0;
> +
> +	iowrite32(reg, wdt_base + WDT_MODE);

What is the point of setting the mode here ? It will
be set again in mtk_wdt_set_timeout(). Seems to me all
you need to do here is to set wdd->pretimeout,
then call mtk_wdt_set_timeout().

Guenter

> +
> +	return mtk_wdt_set_timeout(wdd, wdd->timeout);
> +}
> +
> +static irqreturn_t mtk_wdt_isr(int irq, void *arg)
> +{
> +	struct watchdog_device *wdd = arg;
> +
> +	watchdog_notify_pretimeout(wdd);
> +
> +	return IRQ_HANDLED;
> +}
> +
>  static const struct watchdog_info mtk_wdt_info = {
>  	.identity	= DRV_NAME,
>  	.options	= WDIOF_SETTIMEOUT |
> @@ -253,12 +295,21 @@ static const struct watchdog_info mtk_wdt_info = {
>  			  WDIOF_MAGICCLOSE,
>  };
>  
> +static const struct watchdog_info mtk_wdt_pt_info = {
> +	.identity	= DRV_NAME,
> +	.options	= WDIOF_SETTIMEOUT |
> +			  WDIOF_PRETIMEOUT |
> +			  WDIOF_KEEPALIVEPING |
> +			  WDIOF_MAGICCLOSE,
> +};
> +
>  static const struct watchdog_ops mtk_wdt_ops = {
>  	.owner		= THIS_MODULE,
>  	.start		= mtk_wdt_start,
>  	.stop		= mtk_wdt_stop,
>  	.ping		= mtk_wdt_ping,
>  	.set_timeout	= mtk_wdt_set_timeout,
> +	.set_pretimeout	= mtk_wdt_set_pretimeout,
>  	.restart	= mtk_wdt_restart,
>  };
>  
> @@ -267,7 +318,7 @@ static int mtk_wdt_probe(struct platform_device *pdev)
>  	struct device *dev = &pdev->dev;
>  	struct mtk_wdt_dev *mtk_wdt;
>  	const struct mtk_wdt_data *wdt_data;
> -	int err;
> +	int err, irq;
>  
>  	mtk_wdt = devm_kzalloc(dev, sizeof(*mtk_wdt), GFP_KERNEL);
>  	if (!mtk_wdt)
> @@ -279,7 +330,22 @@ static int mtk_wdt_probe(struct platform_device *pdev)
>  	if (IS_ERR(mtk_wdt->wdt_base))
>  		return PTR_ERR(mtk_wdt->wdt_base);
>  
> -	mtk_wdt->wdt_dev.info = &mtk_wdt_info;
> +	irq = platform_get_irq(pdev, 0);
> +	if (irq > 0) {
> +		err = devm_request_irq(&pdev->dev, irq, mtk_wdt_isr, 0, "wdt_bark",
> +					&mtk_wdt->wdt_dev);
> +		if (err)
> +			return err;
> +
> +		mtk_wdt->wdt_dev.info = &mtk_wdt_pt_info;
> +		mtk_wdt->wdt_dev.pretimeout = WDT_MAX_TIMEOUT / 2;
> +	} else {
> +		if (irq == -EPROBE_DEFER)
> +			return -EPROBE_DEFER;
> +
> +		mtk_wdt->wdt_dev.info = &mtk_wdt_info;
> +	}
> +
>  	mtk_wdt->wdt_dev.ops = &mtk_wdt_ops;
>  	mtk_wdt->wdt_dev.timeout = WDT_MAX_TIMEOUT;
>  	mtk_wdt->wdt_dev.max_hw_heartbeat_ms = WDT_MAX_TIMEOUT * 1000;
> 

Re:Re: [PATCH V7 1/2] watchdog: mtk: support pre-timeout when the bark irq is available

[王擎]

>On 4/22/21 7:53 PM, Wang Qing wrote:
>> Use the bark interrupt as the pretimeout notifier if available.
>> 
>> When the watchdog timer expires in dual mode, an interrupt will be
>> triggered first, then the timing restarts. The reset signal will be
>> initiated when the timer expires again.
>> 
>> The pretimeout notification shall occur at timeout-sec/2.
>> 
>> V2:
>> - panic() by default if WATCHDOG_PRETIMEOUT_GOV is not enabled.
>> 
>> V3:
>> - Modify the pretimeout behavior, manually reset after the pretimeout
>> - is processed and wait until timeout.
>> 
>> V4:
>> - Remove pretimeout related processing. 
>> - Add dual mode control separately.
>> 
>> V5:
>> - Fix some formatting and printing problems.
>> 
>> V6:
>> - Realize pretimeout processing through dualmode.
>> 
>> V7:
>> - Add set_pretimeout().
>> 
>> Signed-off-by: Wang Qing <wangqing@vivo.com>
>> ---
>>  drivers/watchdog/mtk_wdt.c | 76 +++++++++++++++++++++++++++++++++++++++++++---
>>  1 file changed, 71 insertions(+), 5 deletions(-)
>> 
>> diff --git a/drivers/watchdog/mtk_wdt.c b/drivers/watchdog/mtk_wdt.c
>> index 97ca993..ab3ac5d
>> --- a/drivers/watchdog/mtk_wdt.c
>> +++ b/drivers/watchdog/mtk_wdt.c
>> @@ -25,6 +25,7 @@
>>  #include <linux/reset-controller.h>
>>  #include <linux/types.h>
>>  #include <linux/watchdog.h>
>> +#include <linux/interrupt.h>
>>  
>>  #define WDT_MAX_TIMEOUT		31
>>  #define WDT_MIN_TIMEOUT		1
>> @@ -184,15 +185,23 @@ static int mtk_wdt_set_timeout(struct watchdog_device *wdt_dev,
>>  {
>>  	struct mtk_wdt_dev *mtk_wdt = watchdog_get_drvdata(wdt_dev);
>>  	void __iomem *wdt_base = mtk_wdt->wdt_base;
>> +	unsigned int timeout_interval = timeout;
>>  	u32 reg;
>>  
>>  	wdt_dev->timeout = timeout;
>> -
>> +	/*
>> +	 * In dual mode, irq will be triggered at timeout / 2
>> +	 * the real timeout occurs at timeout
>> +	 */
>> +	if (wdt_dev->pretimeout) {
>> +		wdt_dev->pretimeout = timeout / 2;
>
>min_timeout is set to 1. I don't this works well if timeout == 1.
>You'll either need to set min_timeout to 2, or handle that case.

It is appropriate to change min_timeout  to 2.

>
>> +		timeout_interval = wdt_dev->pretimeout;
>
>timeout_interval is unnecessary. Just update timeout accordingly.
>It needs to take the situation of timeout == 1 into account, though.

timeout represents the reset time. When the user calls timeout_show, 
He hopes to get the configured timeout, not the value changed
by pre-timeout.
I modify it like this more in line with the original intention.

>
>> +	}
>>  	/*
>>  	 * One bit is the value of 512 ticks
>>  	 * The clock has 32 KHz
>>  	 */
>> -	reg = WDT_LENGTH_TIMEOUT(timeout << 6) | WDT_LENGTH_KEY;
>> +	reg = WDT_LENGTH_TIMEOUT(timeout_interval << 6) | WDT_LENGTH_KEY;
>>  	iowrite32(reg, wdt_base + WDT_LENGTH);
>>  
>>  	mtk_wdt_ping(wdt_dev);
>> @@ -239,13 +248,46 @@ static int mtk_wdt_start(struct watchdog_device *wdt_dev)
>>  		return ret;
>>  
>>  	reg = ioread32(wdt_base + WDT_MODE);
>> -	reg &= ~(WDT_MODE_IRQ_EN | WDT_MODE_DUAL_EN);
>> +	if (wdt_dev->pretimeout)
>> +		reg |= (WDT_MODE_IRQ_EN | WDT_MODE_DUAL_EN);
>> +	else
>> +		reg &= ~(WDT_MODE_IRQ_EN | WDT_MODE_DUAL_EN);
>>  	reg |= (WDT_MODE_EN | WDT_MODE_KEY);
>>  	iowrite32(reg, wdt_base + WDT_MODE);
>>  
>>  	return 0;
>>  }
>>  
>> +static int mtk_wdt_set_pretimeout(struct watchdog_device *wdd,
>> +					unsigned int timeout)
>> +{
>> +	struct mtk_wdt_dev *mtk_wdt = watchdog_get_drvdata(wdd);
>> +	void __iomem *wdt_base = mtk_wdt->wdt_base;
>> +	u32 reg = ioread32(wdt_base + WDT_MODE);
>> +
>> +	if (timeout && !wdd->pretimeout) {
>> +		wdd->pretimeout = wdd->timeout / 2;
>> +		reg |= (WDT_MODE_IRQ_EN | WDT_MODE_DUAL_EN);
>> +	} else if (!timeout && wdd->pretimeout) {
>> +		wdd->pretimeout = 0;
>> +		reg &= ~(WDT_MODE_IRQ_EN | WDT_MODE_DUAL_EN);
>> +	} else
>> +		return 0;
>> +
>> +	iowrite32(reg, wdt_base + WDT_MODE);
>
>What is the point of setting the mode here ? It will
>be set again in mtk_wdt_set_timeout(). Seems to me all
>you need to do here is to set wdd->pretimeout,
>then call mtk_wdt_set_timeout().

mtk_wdt_set_timeout() only set timeout and ping().
Here also need to config to the dualmode or not.

Thanks,
Qing
>
>Guenter
>
>> +
>> +	return mtk_wdt_set_timeout(wdd, wdd->timeout);
>> +}
>> +
>> +static irqreturn_t mtk_wdt_isr(int irq, void *arg)
>> +{
>> +	struct watchdog_device *wdd = arg;
>> +
>> +	watchdog_notify_pretimeout(wdd);
>> +
>> +	return IRQ_HANDLED;
>> +}
>> +
>>  static const struct watchdog_info mtk_wdt_info = {
>>  	.identity	= DRV_NAME,
>>  	.options	= WDIOF_SETTIMEOUT |
>> @@ -253,12 +295,21 @@ static const struct watchdog_info mtk_wdt_info = {
>>  			  WDIOF_MAGICCLOSE,
>>  };
>>  
>> +static const struct watchdog_info mtk_wdt_pt_info = {
>> +	.identity	= DRV_NAME,
>> +	.options	= WDIOF_SETTIMEOUT |
>> +			  WDIOF_PRETIMEOUT |
>> +			  WDIOF_KEEPALIVEPING |
>> +			  WDIOF_MAGICCLOSE,
>> +};
>> +
>>  static const struct watchdog_ops mtk_wdt_ops = {
>>  	.owner		= THIS_MODULE,
>>  	.start		= mtk_wdt_start,
>>  	.stop		= mtk_wdt_stop,
>>  	.ping		= mtk_wdt_ping,
>>  	.set_timeout	= mtk_wdt_set_timeout,
>> +	.set_pretimeout	= mtk_wdt_set_pretimeout,
>>  	.restart	= mtk_wdt_restart,
>>  };
>>  
>> @@ -267,7 +318,7 @@ static int mtk_wdt_probe(struct platform_device *pdev)
>>  	struct device *dev = &pdev->dev;
>>  	struct mtk_wdt_dev *mtk_wdt;
>>  	const struct mtk_wdt_data *wdt_data;
>> -	int err;
>> +	int err, irq;
>>  
>>  	mtk_wdt = devm_kzalloc(dev, sizeof(*mtk_wdt), GFP_KERNEL);
>>  	if (!mtk_wdt)
>> @@ -279,7 +330,22 @@ static int mtk_wdt_probe(struct platform_device *pdev)
>>  	if (IS_ERR(mtk_wdt->wdt_base))
>>  		return PTR_ERR(mtk_wdt->wdt_base);
>>  
>> -	mtk_wdt->wdt_dev.info = &mtk_wdt_info;
>> +	irq = platform_get_irq(pdev, 0);
>> +	if (irq > 0) {
>> +		err = devm_request_irq(&pdev->dev, irq, mtk_wdt_isr, 0, "wdt_bark",
>> +					&mtk_wdt->wdt_dev);
>> +		if (err)
>> +			return err;
>> +
>> +		mtk_wdt->wdt_dev.info = &mtk_wdt_pt_info;
>> +		mtk_wdt->wdt_dev.pretimeout = WDT_MAX_TIMEOUT / 2;
>> +	} else {
>> +		if (irq == -EPROBE_DEFER)
>> +			return -EPROBE_DEFER;
>> +
>> +		mtk_wdt->wdt_dev.info = &mtk_wdt_info;
>> +	}
>> +
>>  	mtk_wdt->wdt_dev.ops = &mtk_wdt_ops;
>>  	mtk_wdt->wdt_dev.timeout = WDT_MAX_TIMEOUT;
>>  	mtk_wdt->wdt_dev.max_hw_heartbeat_ms = WDT_MAX_TIMEOUT * 1000;
>> 
>

Re: [PATCH V7 1/2] watchdog: mtk: support pre-timeout when the bark irq is available

[Guenter Roeck]

On 4/22/21 8:48 PM, 王擎 wrote:
> 
>> On 4/22/21 7:53 PM, Wang Qing wrote:
>>> Use the bark interrupt as the pretimeout notifier if available.
>>>
>>> When the watchdog timer expires in dual mode, an interrupt will be
>>> triggered first, then the timing restarts. The reset signal will be
>>> initiated when the timer expires again.
>>>
>>> The pretimeout notification shall occur at timeout-sec/2.
>>>
>>> V2:
>>> - panic() by default if WATCHDOG_PRETIMEOUT_GOV is not enabled.
>>>
>>> V3:
>>> - Modify the pretimeout behavior, manually reset after the pretimeout
>>> - is processed and wait until timeout.
>>>
>>> V4:
>>> - Remove pretimeout related processing. 
>>> - Add dual mode control separately.
>>>
>>> V5:
>>> - Fix some formatting and printing problems.
>>>
>>> V6:
>>> - Realize pretimeout processing through dualmode.
>>>
>>> V7:
>>> - Add set_pretimeout().
>>>
>>> Signed-off-by: Wang Qing <wangqing@vivo.com>
>>> ---
>>>  drivers/watchdog/mtk_wdt.c | 76 +++++++++++++++++++++++++++++++++++++++++++---
>>>  1 file changed, 71 insertions(+), 5 deletions(-)
>>>
>>> diff --git a/drivers/watchdog/mtk_wdt.c b/drivers/watchdog/mtk_wdt.c
>>> index 97ca993..ab3ac5d
>>> --- a/drivers/watchdog/mtk_wdt.c
>>> +++ b/drivers/watchdog/mtk_wdt.c
>>> @@ -25,6 +25,7 @@
>>>  #include <linux/reset-controller.h>
>>>  #include <linux/types.h>
>>>  #include <linux/watchdog.h>
>>> +#include <linux/interrupt.h>
>>>  
>>>  #define WDT_MAX_TIMEOUT		31
>>>  #define WDT_MIN_TIMEOUT		1
>>> @@ -184,15 +185,23 @@ static int mtk_wdt_set_timeout(struct watchdog_device *wdt_dev,
>>>  {
>>>  	struct mtk_wdt_dev *mtk_wdt = watchdog_get_drvdata(wdt_dev);
>>>  	void __iomem *wdt_base = mtk_wdt->wdt_base;
>>> +	unsigned int timeout_interval = timeout;
>>>  	u32 reg;
>>>  
>>>  	wdt_dev->timeout = timeout;
>>> -
>>> +	/*
>>> +	 * In dual mode, irq will be triggered at timeout / 2
>>> +	 * the real timeout occurs at timeout
>>> +	 */
>>> +	if (wdt_dev->pretimeout) {
>>> +		wdt_dev->pretimeout = timeout / 2;
>>
>> min_timeout is set to 1. I don't this works well if timeout == 1.
>> You'll either need to set min_timeout to 2, or handle that case.
> 
> It is appropriate to change min_timeout  to 2.
> 
>>
>>> +		timeout_interval = wdt_dev->pretimeout;
>>
>> timeout_interval is unnecessary. Just update timeout accordingly.
>> It needs to take the situation of timeout == 1 into account, though.
> 
> timeout represents the reset time. When the user calls timeout_show, 
> He hopes to get the configured timeout, not the value changed
> by pre-timeout.
> I modify it like this more in line with the original intention.
> 
>>
>>> +	}
>>>  	/*
>>>  	 * One bit is the value of 512 ticks
>>>  	 * The clock has 32 KHz
>>>  	 */
>>> -	reg = WDT_LENGTH_TIMEOUT(timeout << 6) | WDT_LENGTH_KEY;
>>> +	reg = WDT_LENGTH_TIMEOUT(timeout_interval << 6) | WDT_LENGTH_KEY;
>>>  	iowrite32(reg, wdt_base + WDT_LENGTH);
>>>  
>>>  	mtk_wdt_ping(wdt_dev);
>>> @@ -239,13 +248,46 @@ static int mtk_wdt_start(struct watchdog_device *wdt_dev)
>>>  		return ret;
>>>  
>>>  	reg = ioread32(wdt_base + WDT_MODE);
>>> -	reg &= ~(WDT_MODE_IRQ_EN | WDT_MODE_DUAL_EN);
>>> +	if (wdt_dev->pretimeout)
>>> +		reg |= (WDT_MODE_IRQ_EN | WDT_MODE_DUAL_EN);
>>> +	else
>>> +		reg &= ~(WDT_MODE_IRQ_EN | WDT_MODE_DUAL_EN);
>>>  	reg |= (WDT_MODE_EN | WDT_MODE_KEY);
>>>  	iowrite32(reg, wdt_base + WDT_MODE);
>>>  
>>>  	return 0;
>>>  }
>>>  
>>> +static int mtk_wdt_set_pretimeout(struct watchdog_device *wdd,
>>> +					unsigned int timeout)
>>> +{
>>> +	struct mtk_wdt_dev *mtk_wdt = watchdog_get_drvdata(wdd);
>>> +	void __iomem *wdt_base = mtk_wdt->wdt_base;
>>> +	u32 reg = ioread32(wdt_base + WDT_MODE);
>>> +
>>> +	if (timeout && !wdd->pretimeout) {
>>> +		wdd->pretimeout = wdd->timeout / 2;
>>> +		reg |= (WDT_MODE_IRQ_EN | WDT_MODE_DUAL_EN);
>>> +	} else if (!timeout && wdd->pretimeout) {
>>> +		wdd->pretimeout = 0;
>>> +		reg &= ~(WDT_MODE_IRQ_EN | WDT_MODE_DUAL_EN);
>>> +	} else
>>> +		return 0;
>>> +
>>> +	iowrite32(reg, wdt_base + WDT_MODE);
>>
>> What is the point of setting the mode here ? It will
>> be set again in mtk_wdt_set_timeout(). Seems to me all
>> you need to do here is to set wdd->pretimeout,
>> then call mtk_wdt_set_timeout().
> 
> mtk_wdt_set_timeout() only set timeout and ping().
> Here also need to config to the dualmode or not.
> 
Ah, you are correct. Sorry, I confused this with the start function.
That makes me wonder if it would be better to extract a separate
function, mtk_wdt_set_mode(), for that purpose. Thoughts ?

Thanks,
Guenter

> Thanks,
> Qing
>>
>> Guenter
>>
>>> +
>>> +	return mtk_wdt_set_timeout(wdd, wdd->timeout);
>>> +}
>>> +
>>> +static irqreturn_t mtk_wdt_isr(int irq, void *arg)
>>> +{
>>> +	struct watchdog_device *wdd = arg;
>>> +
>>> +	watchdog_notify_pretimeout(wdd);
>>> +
>>> +	return IRQ_HANDLED;
>>> +}
>>> +
>>>  static const struct watchdog_info mtk_wdt_info = {
>>>  	.identity	= DRV_NAME,
>>>  	.options	= WDIOF_SETTIMEOUT |
>>> @@ -253,12 +295,21 @@ static const struct watchdog_info mtk_wdt_info = {
>>>  			  WDIOF_MAGICCLOSE,
>>>  };
>>>  
>>> +static const struct watchdog_info mtk_wdt_pt_info = {
>>> +	.identity	= DRV_NAME,
>>> +	.options	= WDIOF_SETTIMEOUT |
>>> +			  WDIOF_PRETIMEOUT |
>>> +			  WDIOF_KEEPALIVEPING |
>>> +			  WDIOF_MAGICCLOSE,
>>> +};
>>> +
>>>  static const struct watchdog_ops mtk_wdt_ops = {
>>>  	.owner		= THIS_MODULE,
>>>  	.start		= mtk_wdt_start,
>>>  	.stop		= mtk_wdt_stop,
>>>  	.ping		= mtk_wdt_ping,
>>>  	.set_timeout	= mtk_wdt_set_timeout,
>>> +	.set_pretimeout	= mtk_wdt_set_pretimeout,
>>>  	.restart	= mtk_wdt_restart,
>>>  };
>>>  
>>> @@ -267,7 +318,7 @@ static int mtk_wdt_probe(struct platform_device *pdev)
>>>  	struct device *dev = &pdev->dev;
>>>  	struct mtk_wdt_dev *mtk_wdt;
>>>  	const struct mtk_wdt_data *wdt_data;
>>> -	int err;
>>> +	int err, irq;
>>>  
>>>  	mtk_wdt = devm_kzalloc(dev, sizeof(*mtk_wdt), GFP_KERNEL);
>>>  	if (!mtk_wdt)
>>> @@ -279,7 +330,22 @@ static int mtk_wdt_probe(struct platform_device *pdev)
>>>  	if (IS_ERR(mtk_wdt->wdt_base))
>>>  		return PTR_ERR(mtk_wdt->wdt_base);
>>>  
>>> -	mtk_wdt->wdt_dev.info = &mtk_wdt_info;
>>> +	irq = platform_get_irq(pdev, 0);
>>> +	if (irq > 0) {
>>> +		err = devm_request_irq(&pdev->dev, irq, mtk_wdt_isr, 0, "wdt_bark",
>>> +					&mtk_wdt->wdt_dev);
>>> +		if (err)
>>> +			return err;
>>> +
>>> +		mtk_wdt->wdt_dev.info = &mtk_wdt_pt_info;
>>> +		mtk_wdt->wdt_dev.pretimeout = WDT_MAX_TIMEOUT / 2;
>>> +	} else {
>>> +		if (irq == -EPROBE_DEFER)
>>> +			return -EPROBE_DEFER;
>>> +
>>> +		mtk_wdt->wdt_dev.info = &mtk_wdt_info;
>>> +	}
>>> +
>>>  	mtk_wdt->wdt_dev.ops = &mtk_wdt_ops;
>>>  	mtk_wdt->wdt_dev.timeout = WDT_MAX_TIMEOUT;
>>>  	mtk_wdt->wdt_dev.max_hw_heartbeat_ms = WDT_MAX_TIMEOUT * 1000;
>>>
>>
> 
> 

Re:Re: [PATCH V7 1/2] watchdog: mtk: support pre-timeout when the bark irq is available

[王擎]

>On 4/22/21 8:48 PM, 王擎 wrote:
>> 
>>> On 4/22/21 7:53 PM, Wang Qing wrote:
>>>> Use the bark interrupt as the pretimeout notifier if available.
>>>>
>>>> When the watchdog timer expires in dual mode, an interrupt will be
>>>> triggered first, then the timing restarts. The reset signal will be
>>>> initiated when the timer expires again.
>>>>
>>>> The pretimeout notification shall occur at timeout-sec/2.
>>>>
>>>> V2:
>>>> - panic() by default if WATCHDOG_PRETIMEOUT_GOV is not enabled.
>>>>
>>>> V3:
>>>> - Modify the pretimeout behavior, manually reset after the pretimeout
>>>> - is processed and wait until timeout.
>>>>
>>>> V4:
>>>> - Remove pretimeout related processing. 
>>>> - Add dual mode control separately.
>>>>
>>>> V5:
>>>> - Fix some formatting and printing problems.
>>>>
>>>> V6:
>>>> - Realize pretimeout processing through dualmode.
>>>>
>>>> V7:
>>>> - Add set_pretimeout().
>>>>
>>>> Signed-off-by: Wang Qing <wangqing@vivo.com>
>>>> ---
>>>>  drivers/watchdog/mtk_wdt.c | 76 +++++++++++++++++++++++++++++++++++++++++++---
>>>>  1 file changed, 71 insertions(+), 5 deletions(-)
>>>>
>>>> diff --git a/drivers/watchdog/mtk_wdt.c b/drivers/watchdog/mtk_wdt.c
>>>> index 97ca993..ab3ac5d
>>>> --- a/drivers/watchdog/mtk_wdt.c
>>>> +++ b/drivers/watchdog/mtk_wdt.c
>>>> @@ -25,6 +25,7 @@
>>>>  #include <linux/reset-controller.h>
>>>>  #include <linux/types.h>
>>>>  #include <linux/watchdog.h>
>>>> +#include <linux/interrupt.h>
>>>>  
>>>>  #define WDT_MAX_TIMEOUT		31
>>>>  #define WDT_MIN_TIMEOUT		1
>>>> @@ -184,15 +185,23 @@ static int mtk_wdt_set_timeout(struct watchdog_device *wdt_dev,
>>>>  {
>>>>  	struct mtk_wdt_dev *mtk_wdt = watchdog_get_drvdata(wdt_dev);
>>>>  	void __iomem *wdt_base = mtk_wdt->wdt_base;
>>>> +	unsigned int timeout_interval = timeout;
>>>>  	u32 reg;
>>>>  
>>>>  	wdt_dev->timeout = timeout;
>>>> -
>>>> +	/*
>>>> +	 * In dual mode, irq will be triggered at timeout / 2
>>>> +	 * the real timeout occurs at timeout
>>>> +	 */
>>>> +	if (wdt_dev->pretimeout) {
>>>> +		wdt_dev->pretimeout = timeout / 2;
>>>
>>> min_timeout is set to 1. I don't this works well if timeout == 1.
>>> You'll either need to set min_timeout to 2, or handle that case.
>> 
>> It is appropriate to change min_timeout  to 2.
>> 
>>>
>>>> +		timeout_interval = wdt_dev->pretimeout;
>>>
>>> timeout_interval is unnecessary. Just update timeout accordingly.
>>> It needs to take the situation of timeout == 1 into account, though.

I plan to remove timeout_interval and directly use (timeout-pretimeout)
update timeout.

>> 
>> timeout represents the reset time. When the user calls timeout_show, 
>> He hopes to get the configured timeout, not the value changed
>> by pre-timeout.
>> I modify it like this more in line with the original intention.
>> 
>>>
>>>> +	}
>>>>  	/*
>>>>  	 * One bit is the value of 512 ticks
>>>>  	 * The clock has 32 KHz
>>>>  	 */
>>>> -	reg = WDT_LENGTH_TIMEOUT(timeout << 6) | WDT_LENGTH_KEY;
>>>> +	reg = WDT_LENGTH_TIMEOUT(timeout_interval << 6) | WDT_LENGTH_KEY;
>>>>  	iowrite32(reg, wdt_base + WDT_LENGTH);
>>>>  
>>>>  	mtk_wdt_ping(wdt_dev);
>>>> @@ -239,13 +248,46 @@ static int mtk_wdt_start(struct watchdog_device *wdt_dev)
>>>>  		return ret;
>>>>  
>>>>  	reg = ioread32(wdt_base + WDT_MODE);
>>>> -	reg &= ~(WDT_MODE_IRQ_EN | WDT_MODE_DUAL_EN);
>>>> +	if (wdt_dev->pretimeout)
>>>> +		reg |= (WDT_MODE_IRQ_EN | WDT_MODE_DUAL_EN);
>>>> +	else
>>>> +		reg &= ~(WDT_MODE_IRQ_EN | WDT_MODE_DUAL_EN);
>>>>  	reg |= (WDT_MODE_EN | WDT_MODE_KEY);
>>>>  	iowrite32(reg, wdt_base + WDT_MODE);
>>>>  
>>>>  	return 0;
>>>>  }
>>>>  
>>>> +static int mtk_wdt_set_pretimeout(struct watchdog_device *wdd,
>>>> +					unsigned int timeout)
>>>> +{
>>>> +	struct mtk_wdt_dev *mtk_wdt = watchdog_get_drvdata(wdd);
>>>> +	void __iomem *wdt_base = mtk_wdt->wdt_base;
>>>> +	u32 reg = ioread32(wdt_base + WDT_MODE);
>>>> +
>>>> +	if (timeout && !wdd->pretimeout) {
>>>> +		wdd->pretimeout = wdd->timeout / 2;
>>>> +		reg |= (WDT_MODE_IRQ_EN | WDT_MODE_DUAL_EN);
>>>> +	} else if (!timeout && wdd->pretimeout) {
>>>> +		wdd->pretimeout = 0;
>>>> +		reg &= ~(WDT_MODE_IRQ_EN | WDT_MODE_DUAL_EN);
>>>> +	} else
>>>> +		return 0;
>>>> +
>>>> +	iowrite32(reg, wdt_base + WDT_MODE);
>>>
>>> What is the point of setting the mode here ? It will
>>> be set again in mtk_wdt_set_timeout(). Seems to me all
>>> you need to do here is to set wdd->pretimeout,
>>> then call mtk_wdt_set_timeout().
>> 
>> mtk_wdt_set_timeout() only set timeout and ping().
>> Here also need to config to the dualmode or not.
>> 
>Ah, you are correct. Sorry, I confused this with the start function.
>That makes me wonder if it would be better to extract a separate
>function, mtk_wdt_set_mode(), for that purpose. Thoughts ?

I have done this, but I found there is no good abstract method, 
because wdt mode is used in combination, for example：
WDT_MODE_EN is included in start(), and here is not.
And the judgment of pretimeout here is also different.

Thanks,
Qing

>
>Thanks,
>Guenter
>
>> Thanks,
>> Qing
>>>
>>> Guenter
>>>
>>>> +
>>>> +	return mtk_wdt_set_timeout(wdd, wdd->timeout);
>>>> +}
>>>> +
>>>> +static irqreturn_t mtk_wdt_isr(int irq, void *arg)
>>>> +{
>>>> +	struct watchdog_device *wdd = arg;
>>>> +
>>>> +	watchdog_notify_pretimeout(wdd);
>>>> +
>>>> +	return IRQ_HANDLED;
>>>> +}
>>>> +
>>>>  static const struct watchdog_info mtk_wdt_info = {
>>>>  	.identity	= DRV_NAME,
>>>>  	.options	= WDIOF_SETTIMEOUT |
>>>> @@ -253,12 +295,21 @@ static const struct watchdog_info mtk_wdt_info = {
>>>>  			  WDIOF_MAGICCLOSE,
>>>>  };
>>>>  
>>>> +static const struct watchdog_info mtk_wdt_pt_info = {
>>>> +	.identity	= DRV_NAME,
>>>> +	.options	= WDIOF_SETTIMEOUT |
>>>> +			  WDIOF_PRETIMEOUT |
>>>> +			  WDIOF_KEEPALIVEPING |
>>>> +			  WDIOF_MAGICCLOSE,
>>>> +};
>>>> +
>>>>  static const struct watchdog_ops mtk_wdt_ops = {
>>>>  	.owner		= THIS_MODULE,
>>>>  	.start		= mtk_wdt_start,
>>>>  	.stop		= mtk_wdt_stop,
>>>>  	.ping		= mtk_wdt_ping,
>>>>  	.set_timeout	= mtk_wdt_set_timeout,
>>>> +	.set_pretimeout	= mtk_wdt_set_pretimeout,
>>>>  	.restart	= mtk_wdt_restart,
>>>>  };
>>>>  
>>>> @@ -267,7 +318,7 @@ static int mtk_wdt_probe(struct platform_device *pdev)
>>>>  	struct device *dev = &pdev->dev;
>>>>  	struct mtk_wdt_dev *mtk_wdt;
>>>>  	const struct mtk_wdt_data *wdt_data;
>>>> -	int err;
>>>> +	int err, irq;
>>>>  
>>>>  	mtk_wdt = devm_kzalloc(dev, sizeof(*mtk_wdt), GFP_KERNEL);
>>>>  	if (!mtk_wdt)
>>>> @@ -279,7 +330,22 @@ static int mtk_wdt_probe(struct platform_device *pdev)
>>>>  	if (IS_ERR(mtk_wdt->wdt_base))
>>>>  		return PTR_ERR(mtk_wdt->wdt_base);
>>>>  
>>>> -	mtk_wdt->wdt_dev.info = &mtk_wdt_info;
>>>> +	irq = platform_get_irq(pdev, 0);
>>>> +	if (irq > 0) {
>>>> +		err = devm_request_irq(&pdev->dev, irq, mtk_wdt_isr, 0, "wdt_bark",
>>>> +					&mtk_wdt->wdt_dev);
>>>> +		if (err)
>>>> +			return err;
>>>> +
>>>> +		mtk_wdt->wdt_dev.info = &mtk_wdt_pt_info;
>>>> +		mtk_wdt->wdt_dev.pretimeout = WDT_MAX_TIMEOUT / 2;
>>>> +	} else {
>>>> +		if (irq == -EPROBE_DEFER)
>>>> +			return -EPROBE_DEFER;
>>>> +
>>>> +		mtk_wdt->wdt_dev.info = &mtk_wdt_info;
>>>> +	}
>>>> +
>>>>  	mtk_wdt->wdt_dev.ops = &mtk_wdt_ops;
>>>>  	mtk_wdt->wdt_dev.timeout = WDT_MAX_TIMEOUT;
>>>>  	mtk_wdt->wdt_dev.max_hw_heartbeat_ms = WDT_MAX_TIMEOUT * 1000;
>>>>
>>>
>> 
>> 
>

Re: Re: [PATCH V7 1/2] watchdog: mtk: support pre-timeout when the bark irq is available

[Guenter Roeck]

On Fri, Apr 23, 2021 at 03:12:24PM +0800, 王擎 wrote:
> 
> >On 4/22/21 8:48 PM, 王擎 wrote:
> >> 
> >>> On 4/22/21 7:53 PM, Wang Qing wrote:
> >>>> Use the bark interrupt as the pretimeout notifier if available.
> >>>>
> >>>> When the watchdog timer expires in dual mode, an interrupt will be
> >>>> triggered first, then the timing restarts. The reset signal will be
> >>>> initiated when the timer expires again.
> >>>>
> >>>> The pretimeout notification shall occur at timeout-sec/2.
> >>>>
> >>>> V2:
> >>>> - panic() by default if WATCHDOG_PRETIMEOUT_GOV is not enabled.
> >>>>
> >>>> V3:
> >>>> - Modify the pretimeout behavior, manually reset after the pretimeout
> >>>> - is processed and wait until timeout.
> >>>>
> >>>> V4:
> >>>> - Remove pretimeout related processing. 
> >>>> - Add dual mode control separately.
> >>>>
> >>>> V5:
> >>>> - Fix some formatting and printing problems.
> >>>>
> >>>> V6:
> >>>> - Realize pretimeout processing through dualmode.
> >>>>
> >>>> V7:
> >>>> - Add set_pretimeout().
> >>>>
> >>>> Signed-off-by: Wang Qing <wangqing@vivo.com>
> >>>> ---
> >>>>  drivers/watchdog/mtk_wdt.c | 76 +++++++++++++++++++++++++++++++++++++++++++---
> >>>>  1 file changed, 71 insertions(+), 5 deletions(-)
> >>>>
> >>>> diff --git a/drivers/watchdog/mtk_wdt.c b/drivers/watchdog/mtk_wdt.c
> >>>> index 97ca993..ab3ac5d
> >>>> --- a/drivers/watchdog/mtk_wdt.c
> >>>> +++ b/drivers/watchdog/mtk_wdt.c
> >>>> @@ -25,6 +25,7 @@
> >>>>  #include <linux/reset-controller.h>
> >>>>  #include <linux/types.h>
> >>>>  #include <linux/watchdog.h>
> >>>> +#include <linux/interrupt.h>
> >>>>  
> >>>>  #define WDT_MAX_TIMEOUT		31
> >>>>  #define WDT_MIN_TIMEOUT		1
> >>>> @@ -184,15 +185,23 @@ static int mtk_wdt_set_timeout(struct watchdog_device *wdt_dev,
> >>>>  {
> >>>>  	struct mtk_wdt_dev *mtk_wdt = watchdog_get_drvdata(wdt_dev);
> >>>>  	void __iomem *wdt_base = mtk_wdt->wdt_base;
> >>>> +	unsigned int timeout_interval = timeout;
> >>>>  	u32 reg;
> >>>>  
> >>>>  	wdt_dev->timeout = timeout;
> >>>> -
> >>>> +	/*
> >>>> +	 * In dual mode, irq will be triggered at timeout / 2
> >>>> +	 * the real timeout occurs at timeout
> >>>> +	 */
> >>>> +	if (wdt_dev->pretimeout) {
> >>>> +		wdt_dev->pretimeout = timeout / 2;
> >>>
> >>> min_timeout is set to 1. I don't this works well if timeout == 1.
> >>> You'll either need to set min_timeout to 2, or handle that case.
> >> 
> >> It is appropriate to change min_timeout  to 2.
> >> 
> >>>
> >>>> +		timeout_interval = wdt_dev->pretimeout;
> >>>
> >>> timeout_interval is unnecessary. Just update timeout accordingly.
> >>> It needs to take the situation of timeout == 1 into account, though.
> 
> I plan to remove timeout_interval and directly use (timeout-pretimeout)
> update timeout.
> 
> >> 
> >> timeout represents the reset time. When the user calls timeout_show, 
> >> He hopes to get the configured timeout, not the value changed
> >> by pre-timeout.
> >> I modify it like this more in line with the original intention.
> >> 
> >>>
> >>>> +	}
> >>>>  	/*
> >>>>  	 * One bit is the value of 512 ticks
> >>>>  	 * The clock has 32 KHz
> >>>>  	 */
> >>>> -	reg = WDT_LENGTH_TIMEOUT(timeout << 6) | WDT_LENGTH_KEY;
> >>>> +	reg = WDT_LENGTH_TIMEOUT(timeout_interval << 6) | WDT_LENGTH_KEY;
> >>>>  	iowrite32(reg, wdt_base + WDT_LENGTH);
> >>>>  
> >>>>  	mtk_wdt_ping(wdt_dev);
> >>>> @@ -239,13 +248,46 @@ static int mtk_wdt_start(struct watchdog_device *wdt_dev)
> >>>>  		return ret;
> >>>>  
> >>>>  	reg = ioread32(wdt_base + WDT_MODE);
> >>>> -	reg &= ~(WDT_MODE_IRQ_EN | WDT_MODE_DUAL_EN);
> >>>> +	if (wdt_dev->pretimeout)
> >>>> +		reg |= (WDT_MODE_IRQ_EN | WDT_MODE_DUAL_EN);
> >>>> +	else
> >>>> +		reg &= ~(WDT_MODE_IRQ_EN | WDT_MODE_DUAL_EN);
> >>>>  	reg |= (WDT_MODE_EN | WDT_MODE_KEY);
> >>>>  	iowrite32(reg, wdt_base + WDT_MODE);
> >>>>  
> >>>>  	return 0;
> >>>>  }
> >>>>  
> >>>> +static int mtk_wdt_set_pretimeout(struct watchdog_device *wdd,
> >>>> +					unsigned int timeout)
> >>>> +{
> >>>> +	struct mtk_wdt_dev *mtk_wdt = watchdog_get_drvdata(wdd);
> >>>> +	void __iomem *wdt_base = mtk_wdt->wdt_base;
> >>>> +	u32 reg = ioread32(wdt_base + WDT_MODE);
> >>>> +
> >>>> +	if (timeout && !wdd->pretimeout) {
> >>>> +		wdd->pretimeout = wdd->timeout / 2;
> >>>> +		reg |= (WDT_MODE_IRQ_EN | WDT_MODE_DUAL_EN);
> >>>> +	} else if (!timeout && wdd->pretimeout) {
> >>>> +		wdd->pretimeout = 0;
> >>>> +		reg &= ~(WDT_MODE_IRQ_EN | WDT_MODE_DUAL_EN);
> >>>> +	} else
> >>>> +		return 0;

Please run your patch through checkpatch; the above results
in a note about a missing { }.

> >>>> +
> >>>> +	iowrite32(reg, wdt_base + WDT_MODE);
> >>>
> >>> What is the point of setting the mode here ? It will
> >>> be set again in mtk_wdt_set_timeout(). Seems to me all
> >>> you need to do here is to set wdd->pretimeout,
> >>> then call mtk_wdt_set_timeout().
> >> 
> >> mtk_wdt_set_timeout() only set timeout and ping().
> >> Here also need to config to the dualmode or not.
> >> 
> >Ah, you are correct. Sorry, I confused this with the start function.
> >That makes me wonder if it would be better to extract a separate
> >function, mtk_wdt_set_mode(), for that purpose. Thoughts ?
> 
> I have done this, but I found there is no good abstract method, 
> because wdt mode is used in combination, for example：
> WDT_MODE_EN is included in start(), and here is not.
> And the judgment of pretimeout here is also different.
> 
Ok, makes sense. Another minor comment above, though.

Thanks,
Guenter

> Thanks,
> Qing
> 
> >
> >Thanks,
> >Guenter
> >
> >> Thanks,
> >> Qing
> >>>
> >>> Guenter
> >>>
> >>>> +
> >>>> +	return mtk_wdt_set_timeout(wdd, wdd->timeout);
> >>>> +}
> >>>> +
> >>>> +static irqreturn_t mtk_wdt_isr(int irq, void *arg)
> >>>> +{
> >>>> +	struct watchdog_device *wdd = arg;
> >>>> +
> >>>> +	watchdog_notify_pretimeout(wdd);
> >>>> +
> >>>> +	return IRQ_HANDLED;
> >>>> +}
> >>>> +
> >>>>  static const struct watchdog_info mtk_wdt_info = {
> >>>>  	.identity	= DRV_NAME,
> >>>>  	.options	= WDIOF_SETTIMEOUT |
> >>>> @@ -253,12 +295,21 @@ static const struct watchdog_info mtk_wdt_info = {
> >>>>  			  WDIOF_MAGICCLOSE,
> >>>>  };
> >>>>  
> >>>> +static const struct watchdog_info mtk_wdt_pt_info = {
> >>>> +	.identity	= DRV_NAME,
> >>>> +	.options	= WDIOF_SETTIMEOUT |
> >>>> +			  WDIOF_PRETIMEOUT |
> >>>> +			  WDIOF_KEEPALIVEPING |
> >>>> +			  WDIOF_MAGICCLOSE,
> >>>> +};
> >>>> +
> >>>>  static const struct watchdog_ops mtk_wdt_ops = {
> >>>>  	.owner		= THIS_MODULE,
> >>>>  	.start		= mtk_wdt_start,
> >>>>  	.stop		= mtk_wdt_stop,
> >>>>  	.ping		= mtk_wdt_ping,
> >>>>  	.set_timeout	= mtk_wdt_set_timeout,
> >>>> +	.set_pretimeout	= mtk_wdt_set_pretimeout,
> >>>>  	.restart	= mtk_wdt_restart,
> >>>>  };
> >>>>  
> >>>> @@ -267,7 +318,7 @@ static int mtk_wdt_probe(struct platform_device *pdev)
> >>>>  	struct device *dev = &pdev->dev;
> >>>>  	struct mtk_wdt_dev *mtk_wdt;
> >>>>  	const struct mtk_wdt_data *wdt_data;
> >>>> -	int err;
> >>>> +	int err, irq;
> >>>>  
> >>>>  	mtk_wdt = devm_kzalloc(dev, sizeof(*mtk_wdt), GFP_KERNEL);
> >>>>  	if (!mtk_wdt)
> >>>> @@ -279,7 +330,22 @@ static int mtk_wdt_probe(struct platform_device *pdev)
> >>>>  	if (IS_ERR(mtk_wdt->wdt_base))
> >>>>  		return PTR_ERR(mtk_wdt->wdt_base);
> >>>>  
> >>>> -	mtk_wdt->wdt_dev.info = &mtk_wdt_info;
> >>>> +	irq = platform_get_irq(pdev, 0);
> >>>> +	if (irq > 0) {
> >>>> +		err = devm_request_irq(&pdev->dev, irq, mtk_wdt_isr, 0, "wdt_bark",
> >>>> +					&mtk_wdt->wdt_dev);
> >>>> +		if (err)
> >>>> +			return err;
> >>>> +
> >>>> +		mtk_wdt->wdt_dev.info = &mtk_wdt_pt_info;
> >>>> +		mtk_wdt->wdt_dev.pretimeout = WDT_MAX_TIMEOUT / 2;
> >>>> +	} else {
> >>>> +		if (irq == -EPROBE_DEFER)
> >>>> +			return -EPROBE_DEFER;
> >>>> +
> >>>> +		mtk_wdt->wdt_dev.info = &mtk_wdt_info;
> >>>> +	}
> >>>> +
> >>>>  	mtk_wdt->wdt_dev.ops = &mtk_wdt_ops;
> >>>>  	mtk_wdt->wdt_dev.timeout = WDT_MAX_TIMEOUT;
> >>>>  	mtk_wdt->wdt_dev.max_hw_heartbeat_ms = WDT_MAX_TIMEOUT * 1000;
> >>>>
> >>>
> >> 
> >> 
> >
> 
> 

[PATCH V7 2/2] doc: mtk-wdt: support pre-timeout when the bark irq is available

[Wang Qing]

Add description of pre-timeout in mtk-wdt.

Signed-off-by: Wang Qing <wangqing@vivo.com>
---
 Documentation/devicetree/bindings/watchdog/mtk-wdt.txt | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/Documentation/devicetree/bindings/watchdog/mtk-wdt.txt b/Documentation/devicetree/bindings/watchdog/mtk-wdt.txt
index e36ba60..8e27777
--- a/Documentation/devicetree/bindings/watchdog/mtk-wdt.txt
+++ b/Documentation/devicetree/bindings/watchdog/mtk-wdt.txt
@@ -1,5 +1,8 @@
 Mediatek SoCs Watchdog timer
 
+The watchdog supports a pre-timeout interrupt that fires timeout-sec/2
+before the expiry.
+
 Required properties:
 
 - compatible should contain:
@@ -17,6 +20,7 @@ Required properties:
 - reg : Specifies base physical address and size of the registers.
 
 Optional properties:
+- interrupts: Watchdog pre-timeout (bark) interrupt.
 - timeout-sec: contains the watchdog timeout in seconds.
 - #reset-cells: Should be 1.
 
@@ -26,6 +30,7 @@ watchdog: watchdog@10007000 {
 	compatible = "mediatek,mt8183-wdt",
 		     "mediatek,mt6589-wdt";
 	reg = <0 0x10007000 0 0x100>;
+	interrupts = <GIC_SPI 139 IRQ_TYPE_NONE>;
 	timeout-sec = <10>;
 	#reset-cells = <1>;
 };
-- 
2.7.4