[PATCH v3 1/2] watchdog: dw_wdt: add stop watchdog operation

[PATCH v3 1/2] watchdog: dw_wdt: add stop watchdog operation

[Oleksij Rempel]

From: Steffen Trumtrar <s.trumtrar@pengutronix.de>

The only way of stopping the watchdog is by resetting it.
Add the watchdog op for stopping the device and reset if
a reset line is provided.

Signed-off-by: Steffen Trumtrar <s.trumtrar@pengutronix.de>
Signed-off-by: Oleksij Rempel <o.rempel@pengutronix.de>
Cc: Wim Van Sebroeck <wim@iguana.be>
Cc: Guenter Roeck <linux@roeck-us.net>
Cc: linux-watchdog at vger.kernel.org
---

changes v3:
 - don't return error if rst is not present and set WDOG_HW_RUNNING bit
   to notify watchdog core.

changes v2:
 - test if dw_wdt->rst is NULL instead of IS_ERR

 drivers/watchdog/dw_wdt.c | 16 ++++++++++++++++
 1 file changed, 16 insertions(+)

diff --git a/drivers/watchdog/dw_wdt.c b/drivers/watchdog/dw_wdt.c
index 36be987ff9ef..6cc56b18ee52 100644
--- a/drivers/watchdog/dw_wdt.c
+++ b/drivers/watchdog/dw_wdt.c
@@ -135,6 +135,21 @@ static int dw_wdt_start(struct watchdog_device *wdd)
 	return 0;
 }
 
+static int dw_wdt_stop(struct watchdog_device *wdd)
+{
+	struct dw_wdt *dw_wdt = to_dw_wdt(wdd);
+
+	if (!dw_wdt->rst) {
+		set_bit(WDOG_HW_RUNNING, &wdd->status);
+		return 0;
+	}
+
+	reset_control_assert(dw_wdt->rst);
+	reset_control_deassert(dw_wdt->rst);
+
+	return 0;
+}
+
 static int dw_wdt_restart(struct watchdog_device *wdd,
 			  unsigned long action, void *data)
 {
@@ -173,6 +188,7 @@ static const struct watchdog_info dw_wdt_ident = {
 static const struct watchdog_ops dw_wdt_ops = {
 	.owner		= THIS_MODULE,
 	.start		= dw_wdt_start,
+	.stop		= dw_wdt_stop,
 	.ping		= dw_wdt_ping,
 	.set_timeout	= dw_wdt_set_timeout,
 	.get_timeleft	= dw_wdt_get_timeleft,
-- 
2.11.0

[PATCH v3 2/2] ARM: socfpga: dtsi: add dw-wdt reset lines

[Oleksij Rempel]

From: Steffen Trumtrar <s.trumtrar@pengutronix.de>

Signed-off-by: Steffen Trumtrar <s.trumtrar@pengutronix.de>
Signed-off-by: Oleksij Rempel <o.rempel@pengutronix.de>
Cc: Dinh Nguyen <dinguyen@opensource.altera.com>
Cc: linux-arm-kernel at lists.infradead.org
---

no changes since version v1

 arch/arm/boot/dts/socfpga.dtsi | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/arch/arm/boot/dts/socfpga.dtsi b/arch/arm/boot/dts/socfpga.dtsi
index 7e24dc8e82d4..6e49cee084b8 100644
--- a/arch/arm/boot/dts/socfpga.dtsi
+++ b/arch/arm/boot/dts/socfpga.dtsi
@@ -924,6 +924,7 @@
 			reg = <0xffd02000 0x1000>;
 			interrupts = <0 171 4>;
 			clocks = <&osc1>;
+			resets = <&rst L4WD0_RESET>;
 			status = "disabled";
 		};
 
@@ -932,6 +933,7 @@
 			reg = <0xffd03000 0x1000>;
 			interrupts = <0 172 4>;
 			clocks = <&osc1>;
+			resets = <&rst L4WD1_RESET>;
 			status = "disabled";
 		};
 	};
-- 
2.11.0

[PATCH v3 1/2] watchdog: dw_wdt: add stop watchdog operation

[Guenter Roeck]

On Mon, Sep 25, 2017 at 07:25:30AM +0200, Oleksij Rempel wrote:
> From: Steffen Trumtrar <s.trumtrar@pengutronix.de>
> 
> The only way of stopping the watchdog is by resetting it.
> Add the watchdog op for stopping the device and reset if
> a reset line is provided.
> 
> Signed-off-by: Steffen Trumtrar <s.trumtrar@pengutronix.de>
> Signed-off-by: Oleksij Rempel <o.rempel@pengutronix.de>
> Cc: Wim Van Sebroeck <wim@iguana.be>
> Cc: Guenter Roeck <linux@roeck-us.net>
> Cc: linux-watchdog at vger.kernel.org
> ---
> 
> changes v3:
>  - don't return error if rst is not present and set WDOG_HW_RUNNING bit
>    to notify watchdog core.
> 
> changes v2:
>  - test if dw_wdt->rst is NULL instead of IS_ERR
> 
>  drivers/watchdog/dw_wdt.c | 16 ++++++++++++++++
>  1 file changed, 16 insertions(+)
> 
> diff --git a/drivers/watchdog/dw_wdt.c b/drivers/watchdog/dw_wdt.c
> index 36be987ff9ef..6cc56b18ee52 100644
> --- a/drivers/watchdog/dw_wdt.c
> +++ b/drivers/watchdog/dw_wdt.c
> @@ -135,6 +135,21 @@ static int dw_wdt_start(struct watchdog_device *wdd)
>  	return 0;
>  }
>  
> +static int dw_wdt_stop(struct watchdog_device *wdd)
> +{
> +	struct dw_wdt *dw_wdt = to_dw_wdt(wdd);
> +
> +	if (!dw_wdt->rst) {
> +		set_bit(WDOG_HW_RUNNING, &wdd->status);

Setting WDOG_HW_RUNNING should be dropped from dw_wdt_start().

Guenter

> +		return 0;
> +	}
> +
> +	reset_control_assert(dw_wdt->rst);
> +	reset_control_deassert(dw_wdt->rst);
> +
> +	return 0;
> +}
> +
>  static int dw_wdt_restart(struct watchdog_device *wdd,
>  			  unsigned long action, void *data)
>  {
> @@ -173,6 +188,7 @@ static const struct watchdog_info dw_wdt_ident = {
>  static const struct watchdog_ops dw_wdt_ops = {
>  	.owner		= THIS_MODULE,
>  	.start		= dw_wdt_start,
> +	.stop		= dw_wdt_stop,
>  	.ping		= dw_wdt_ping,
>  	.set_timeout	= dw_wdt_set_timeout,
>  	.get_timeleft	= dw_wdt_get_timeleft,
> -- 
> 2.11.0
> 

[PATCH v3 1/2] watchdog: dw_wdt: add stop watchdog operation

[Oleksij Rempel]

Hi,

On 25.09.2017 18:16, Guenter Roeck wrote:
> On Mon, Sep 25, 2017 at 07:25:30AM +0200, Oleksij Rempel wrote:
>> From: Steffen Trumtrar <s.trumtrar@pengutronix.de>
>>
>> The only way of stopping the watchdog is by resetting it.
>> Add the watchdog op for stopping the device and reset if
>> a reset line is provided.
>>
>> Signed-off-by: Steffen Trumtrar <s.trumtrar@pengutronix.de>
>> Signed-off-by: Oleksij Rempel <o.rempel@pengutronix.de>
>> Cc: Wim Van Sebroeck <wim@iguana.be>
>> Cc: Guenter Roeck <linux@roeck-us.net>
>> Cc: linux-watchdog at vger.kernel.org
>> ---
>>
>> changes v3:
>>   - don't return error if rst is not present and set WDOG_HW_RUNNING bit
>>     to notify watchdog core.
>>
>> changes v2:
>>   - test if dw_wdt->rst is NULL instead of IS_ERR
>>
>>   drivers/watchdog/dw_wdt.c | 16 ++++++++++++++++
>>   1 file changed, 16 insertions(+)
>>
>> diff --git a/drivers/watchdog/dw_wdt.c b/drivers/watchdog/dw_wdt.c
>> index 36be987ff9ef..6cc56b18ee52 100644
>> --- a/drivers/watchdog/dw_wdt.c
>> +++ b/drivers/watchdog/dw_wdt.c
>> @@ -135,6 +135,21 @@ static int dw_wdt_start(struct watchdog_device *wdd)
>>   	return 0;
>>   }
>>   
>> +static int dw_wdt_stop(struct watchdog_device *wdd)
>> +{
>> +	struct dw_wdt *dw_wdt = to_dw_wdt(wdd);
>> +
>> +	if (!dw_wdt->rst) {
>> +		set_bit(WDOG_HW_RUNNING, &wdd->status);
> 
> Setting WDOG_HW_RUNNING should be dropped from dw_wdt_start().

you mean, this patch is OK, and i need to provide one more which is 
removing WDOG_HW_RUNNING from dw_wdt_start(). Correct?

Regards,
Oleksij

[PATCH v3 1/2] watchdog: dw_wdt: add stop watchdog operation

[Guenter Roeck]

On 09/25/2017 10:17 PM, Oleksij Rempel wrote:
> Hi,
> 
> On 25.09.2017 18:16, Guenter Roeck wrote:
>> On Mon, Sep 25, 2017 at 07:25:30AM +0200, Oleksij Rempel wrote:
>>> From: Steffen Trumtrar <s.trumtrar@pengutronix.de>
>>>
>>> The only way of stopping the watchdog is by resetting it.
>>> Add the watchdog op for stopping the device and reset if
>>> a reset line is provided.
>>>
>>> Signed-off-by: Steffen Trumtrar <s.trumtrar@pengutronix.de>
>>> Signed-off-by: Oleksij Rempel <o.rempel@pengutronix.de>
>>> Cc: Wim Van Sebroeck <wim@iguana.be>
>>> Cc: Guenter Roeck <linux@roeck-us.net>
>>> Cc: linux-watchdog at vger.kernel.org
>>> ---
>>>
>>> changes v3:
>>> ? - don't return error if rst is not present and set WDOG_HW_RUNNING bit
>>> ??? to notify watchdog core.
>>>
>>> changes v2:
>>> ? - test if dw_wdt->rst is NULL instead of IS_ERR
>>>
>>> ? drivers/watchdog/dw_wdt.c | 16 ++++++++++++++++
>>> ? 1 file changed, 16 insertions(+)
>>>
>>> diff --git a/drivers/watchdog/dw_wdt.c b/drivers/watchdog/dw_wdt.c
>>> index 36be987ff9ef..6cc56b18ee52 100644
>>> --- a/drivers/watchdog/dw_wdt.c
>>> +++ b/drivers/watchdog/dw_wdt.c
>>> @@ -135,6 +135,21 @@ static int dw_wdt_start(struct watchdog_device *wdd)
>>> ????? return 0;
>>> ? }
>>> +static int dw_wdt_stop(struct watchdog_device *wdd)
>>> +{
>>> +??? struct dw_wdt *dw_wdt = to_dw_wdt(wdd);
>>> +
>>> +??? if (!dw_wdt->rst) {
>>> +??????? set_bit(WDOG_HW_RUNNING, &wdd->status);
>>
>> Setting WDOG_HW_RUNNING should be dropped from dw_wdt_start().
> 
> you mean, this patch is OK, and i need to provide one more which is removing WDOG_HW_RUNNING from dw_wdt_start(). Correct?
> 

No. You are providing a stop function, thus the start function should not set the flag.

Guenter