diff mbox series

watchdog: max63xx_wdt: Add support for specifying WDI logic via GPIO

Message ID 20220428091603.6838-1-pali@kernel.org
State Changes Requested, archived
Headers show
Series watchdog: max63xx_wdt: Add support for specifying WDI logic via GPIO | expand

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robh/patch-applied success
robh/dtbs-check warning build log
robh/dt-meta-schema success

Commit Message

Pali Rohár April 28, 2022, 9:16 a.m. UTC
On some boards is WDI logic of max6370 chip connected via GPIO. So extend
max63xx_wdt driver and DTS schema to allow specifying WDI logic via GPIO.

Signed-off-by: Pali Rohár <pali@kernel.org>
---
 .../bindings/watchdog/maxim,max63xx.yaml      |  4 +++
 drivers/watchdog/max63xx_wdt.c                | 28 +++++++++++++++++++
 2 files changed, 32 insertions(+)

Comments

Guenter Roeck April 28, 2022, 1:10 p.m. UTC | #1
On 4/28/22 02:16, Pali Rohár wrote:
> On some boards is WDI logic of max6370 chip connected via GPIO. So extend
> max63xx_wdt driver and DTS schema to allow specifying WDI logic via GPIO.
> 
> Signed-off-by: Pali Rohár <pali@kernel.org>

How is that different to just using the gpio watchdog driver ?

Guenter

> ---
>   .../bindings/watchdog/maxim,max63xx.yaml      |  4 +++
>   drivers/watchdog/max63xx_wdt.c                | 28 +++++++++++++++++++
>   2 files changed, 32 insertions(+)
> 
> diff --git a/Documentation/devicetree/bindings/watchdog/maxim,max63xx.yaml b/Documentation/devicetree/bindings/watchdog/maxim,max63xx.yaml
> index ab9641e845db..a97aa0135ef9 100644
> --- a/Documentation/devicetree/bindings/watchdog/maxim,max63xx.yaml
> +++ b/Documentation/devicetree/bindings/watchdog/maxim,max63xx.yaml
> @@ -27,6 +27,10 @@ properties:
>       description: This is a 1-byte memory-mapped address
>       maxItems: 1
>   
> +  gpios:
> +    description: Optional GPIO used for controlling WDI when WDI bit is not mapped to memory
> +    maxItems: 1
> +
>   required:
>     - compatible
>     - reg
> diff --git a/drivers/watchdog/max63xx_wdt.c b/drivers/watchdog/max63xx_wdt.c
> index 9e1541cfae0d..eaf00c3f06a5 100644
> --- a/drivers/watchdog/max63xx_wdt.c
> +++ b/drivers/watchdog/max63xx_wdt.c
> @@ -27,6 +27,7 @@
>   #include <linux/io.h>
>   #include <linux/slab.h>
>   #include <linux/property.h>
> +#include <linux/gpio/consumer.h>
>   
>   #define DEFAULT_HEARTBEAT 60
>   #define MAX_HEARTBEAT     60
> @@ -53,6 +54,9 @@ struct max63xx_wdt {
>   	void __iomem *base;
>   	spinlock_t lock;
>   
> +	/* GPIOs */
> +	struct gpio_desc *gpio_wdi;
> +
>   	/* WDI and WSET bits write access routines */
>   	void (*ping)(struct max63xx_wdt *wdt);
>   	void (*set)(struct max63xx_wdt *wdt, u8 set);
> @@ -158,6 +162,17 @@ static const struct watchdog_info max63xx_wdt_info = {
>   	.identity = "max63xx Watchdog",
>   };
>   
> +static void max63xx_gpio_ping(struct max63xx_wdt *wdt)
> +{
> +	spin_lock(&wdt->lock);
> +
> +	gpiod_set_value_cansleep(wdt->gpio_wdi, 1);
> +	udelay(1);
> +	gpiod_set_value_cansleep(wdt->gpio_wdi, 0);
> +
> +	spin_unlock(&wdt->lock);
> +}
> +
>   static void max63xx_mmap_ping(struct max63xx_wdt *wdt)
>   {
>   	u8 val;
> @@ -225,6 +240,19 @@ static int max63xx_wdt_probe(struct platform_device *pdev)
>   		return -EINVAL;
>   	}
>   
> +	wdt->gpio_wdi = devm_gpiod_get(dev, NULL, GPIOD_FLAGS_BIT_DIR_OUT);
> +	if (IS_ERR(wdt->gpio_wdi) && PTR_ERR(wdt->gpio_wdi) != -ENOENT) {
> +		if (PTR_ERR(wdt->gpio_wdi) != -EPROBE_DEFER)
> +			dev_err(dev, "unable to request gpio: %ld\n",
> +				PTR_ERR(wdt->gpio_wdi));
> +		return PTR_ERR(wdt->gpio_wdi);
> +	}
> +
> +	if (!IS_ERR(wdt->gpio_wdi))
> +		wdt->ping = max63xx_gpio_ping;
> +	else
> +		wdt->gpio_wdi = NULL;
> +
>   	err = max63xx_mmap_init(pdev, wdt);
>   	if (err)
>   		return err;
Pali Rohár April 28, 2022, 2:32 p.m. UTC | #2
On Thursday 28 April 2022 06:10:56 Guenter Roeck wrote:
> On 4/28/22 02:16, Pali Rohár wrote:
> > On some boards is WDI logic of max6370 chip connected via GPIO. So extend
> > max63xx_wdt driver and DTS schema to allow specifying WDI logic via GPIO.
> > 
> > Signed-off-by: Pali Rohár <pali@kernel.org>
> 
> How is that different to just using the gpio watchdog driver ?

GPIO watchdog driver does not support max6370 memory mapped
configuration.

With this change, max6370 can use memory mapped space for watchdog
configuration and GPIO WDI for pinging.

> Guenter
> 
> > ---
> >   .../bindings/watchdog/maxim,max63xx.yaml      |  4 +++
> >   drivers/watchdog/max63xx_wdt.c                | 28 +++++++++++++++++++
> >   2 files changed, 32 insertions(+)
> > 
> > diff --git a/Documentation/devicetree/bindings/watchdog/maxim,max63xx.yaml b/Documentation/devicetree/bindings/watchdog/maxim,max63xx.yaml
> > index ab9641e845db..a97aa0135ef9 100644
> > --- a/Documentation/devicetree/bindings/watchdog/maxim,max63xx.yaml
> > +++ b/Documentation/devicetree/bindings/watchdog/maxim,max63xx.yaml
> > @@ -27,6 +27,10 @@ properties:
> >       description: This is a 1-byte memory-mapped address
> >       maxItems: 1
> > +  gpios:
> > +    description: Optional GPIO used for controlling WDI when WDI bit is not mapped to memory
> > +    maxItems: 1
> > +
> >   required:
> >     - compatible
> >     - reg
> > diff --git a/drivers/watchdog/max63xx_wdt.c b/drivers/watchdog/max63xx_wdt.c
> > index 9e1541cfae0d..eaf00c3f06a5 100644
> > --- a/drivers/watchdog/max63xx_wdt.c
> > +++ b/drivers/watchdog/max63xx_wdt.c
> > @@ -27,6 +27,7 @@
> >   #include <linux/io.h>
> >   #include <linux/slab.h>
> >   #include <linux/property.h>
> > +#include <linux/gpio/consumer.h>
> >   #define DEFAULT_HEARTBEAT 60
> >   #define MAX_HEARTBEAT     60
> > @@ -53,6 +54,9 @@ struct max63xx_wdt {
> >   	void __iomem *base;
> >   	spinlock_t lock;
> > +	/* GPIOs */
> > +	struct gpio_desc *gpio_wdi;
> > +
> >   	/* WDI and WSET bits write access routines */
> >   	void (*ping)(struct max63xx_wdt *wdt);
> >   	void (*set)(struct max63xx_wdt *wdt, u8 set);
> > @@ -158,6 +162,17 @@ static const struct watchdog_info max63xx_wdt_info = {
> >   	.identity = "max63xx Watchdog",
> >   };
> > +static void max63xx_gpio_ping(struct max63xx_wdt *wdt)
> > +{
> > +	spin_lock(&wdt->lock);
> > +
> > +	gpiod_set_value_cansleep(wdt->gpio_wdi, 1);
> > +	udelay(1);
> > +	gpiod_set_value_cansleep(wdt->gpio_wdi, 0);
> > +
> > +	spin_unlock(&wdt->lock);
> > +}
> > +
> >   static void max63xx_mmap_ping(struct max63xx_wdt *wdt)
> >   {
> >   	u8 val;
> > @@ -225,6 +240,19 @@ static int max63xx_wdt_probe(struct platform_device *pdev)
> >   		return -EINVAL;
> >   	}
> > +	wdt->gpio_wdi = devm_gpiod_get(dev, NULL, GPIOD_FLAGS_BIT_DIR_OUT);
> > +	if (IS_ERR(wdt->gpio_wdi) && PTR_ERR(wdt->gpio_wdi) != -ENOENT) {
> > +		if (PTR_ERR(wdt->gpio_wdi) != -EPROBE_DEFER)
> > +			dev_err(dev, "unable to request gpio: %ld\n",
> > +				PTR_ERR(wdt->gpio_wdi));
> > +		return PTR_ERR(wdt->gpio_wdi);
> > +	}
> > +
> > +	if (!IS_ERR(wdt->gpio_wdi))
> > +		wdt->ping = max63xx_gpio_ping;
> > +	else
> > +		wdt->gpio_wdi = NULL;
> > +
> >   	err = max63xx_mmap_init(pdev, wdt);
> >   	if (err)
> >   		return err;
>
Guenter Roeck April 28, 2022, 3:29 p.m. UTC | #3
On 4/28/22 07:32, Pali Rohár wrote:
> On Thursday 28 April 2022 06:10:56 Guenter Roeck wrote:
>> On 4/28/22 02:16, Pali Rohár wrote:
>>> On some boards is WDI logic of max6370 chip connected via GPIO. So extend
>>> max63xx_wdt driver and DTS schema to allow specifying WDI logic via GPIO.
>>>
>>> Signed-off-by: Pali Rohár <pali@kernel.org>
>>
>> How is that different to just using the gpio watchdog driver ?
> 
> GPIO watchdog driver does not support max6370 memory mapped
> configuration.
> 
> With this change, max6370 can use memory mapped space for watchdog
> configuration and GPIO WDI for pinging.
> 

Ok, that makes sense. Comments below.

Thanks,
Guenter

>> Guenter
>>
>>> ---
>>>    .../bindings/watchdog/maxim,max63xx.yaml      |  4 +++
>>>    drivers/watchdog/max63xx_wdt.c                | 28 +++++++++++++++++++
>>>    2 files changed, 32 insertions(+)
>>>
>>> diff --git a/Documentation/devicetree/bindings/watchdog/maxim,max63xx.yaml b/Documentation/devicetree/bindings/watchdog/maxim,max63xx.yaml
>>> index ab9641e845db..a97aa0135ef9 100644
>>> --- a/Documentation/devicetree/bindings/watchdog/maxim,max63xx.yaml
>>> +++ b/Documentation/devicetree/bindings/watchdog/maxim,max63xx.yaml
>>> @@ -27,6 +27,10 @@ properties:
>>>        description: This is a 1-byte memory-mapped address
>>>        maxItems: 1
>>> +  gpios:
>>> +    description: Optional GPIO used for controlling WDI when WDI bit is not mapped to memory
>>> +    maxItems: 1
>>> +
>>>    required:
>>>      - compatible
>>>      - reg

Devicetree patches needs to be separate.

>>> diff --git a/drivers/watchdog/max63xx_wdt.c b/drivers/watchdog/max63xx_wdt.c
>>> index 9e1541cfae0d..eaf00c3f06a5 100644
>>> --- a/drivers/watchdog/max63xx_wdt.c
>>> +++ b/drivers/watchdog/max63xx_wdt.c
>>> @@ -27,6 +27,7 @@
>>>    #include <linux/io.h>
>>>    #include <linux/slab.h>
>>>    #include <linux/property.h>
>>> +#include <linux/gpio/consumer.h>
>>>    #define DEFAULT_HEARTBEAT 60
>>>    #define MAX_HEARTBEAT     60
>>> @@ -53,6 +54,9 @@ struct max63xx_wdt {
>>>    	void __iomem *base;
>>>    	spinlock_t lock;
>>> +	/* GPIOs */
>>> +	struct gpio_desc *gpio_wdi;
>>> +
>>>    	/* WDI and WSET bits write access routines */
>>>    	void (*ping)(struct max63xx_wdt *wdt);
>>>    	void (*set)(struct max63xx_wdt *wdt, u8 set);
>>> @@ -158,6 +162,17 @@ static const struct watchdog_info max63xx_wdt_info = {
>>>    	.identity = "max63xx Watchdog",
>>>    };
>>> +static void max63xx_gpio_ping(struct max63xx_wdt *wdt)
>>> +{
>>> +	spin_lock(&wdt->lock);
>>> +
>>> +	gpiod_set_value_cansleep(wdt->gpio_wdi, 1);
>>> +	udelay(1);
>>> +	gpiod_set_value_cansleep(wdt->gpio_wdi, 0);
>>> +
>>> +	spin_unlock(&wdt->lock);
>>> +}
>>> +
>>>    static void max63xx_mmap_ping(struct max63xx_wdt *wdt)
>>>    {
>>>    	u8 val;
>>> @@ -225,6 +240,19 @@ static int max63xx_wdt_probe(struct platform_device *pdev)
>>>    		return -EINVAL;
>>>    	}
>>> +	wdt->gpio_wdi = devm_gpiod_get(dev, NULL, GPIOD_FLAGS_BIT_DIR_OUT);
>>> +	if (IS_ERR(wdt->gpio_wdi) && PTR_ERR(wdt->gpio_wdi) != -ENOENT) {
>>> +		if (PTR_ERR(wdt->gpio_wdi) != -EPROBE_DEFER)
>>> +			dev_err(dev, "unable to request gpio: %ld\n",
>>> +				PTR_ERR(wdt->gpio_wdi));

Please use dev_err_probe().

>>> +		return PTR_ERR(wdt->gpio_wdi);
>>> +	}
>>> +
>>> +	if (!IS_ERR(wdt->gpio_wdi))
>>> +		wdt->ping = max63xx_gpio_ping;
>>> +	else
>>> +		wdt->gpio_wdi = NULL;

Why set gpio_wdi to NULL? It isn't used if the ping function is not set.

>>> +
>>>    	err = max63xx_mmap_init(pdev, wdt);

Doesn't this override the gpio ping function set above ?

>>>    	if (err)
>>>    		return err;
>>
Pali Rohár April 28, 2022, 6:25 p.m. UTC | #4
On Thursday 28 April 2022 08:29:52 Guenter Roeck wrote:
> On 4/28/22 07:32, Pali Rohár wrote:
> > On Thursday 28 April 2022 06:10:56 Guenter Roeck wrote:
> > > On 4/28/22 02:16, Pali Rohár wrote:
> > > > On some boards is WDI logic of max6370 chip connected via GPIO. So extend
> > > > max63xx_wdt driver and DTS schema to allow specifying WDI logic via GPIO.
> > > > 
> > > > Signed-off-by: Pali Rohár <pali@kernel.org>
> > > 
> > > How is that different to just using the gpio watchdog driver ?
> > 
> > GPIO watchdog driver does not support max6370 memory mapped
> > configuration.
> > 
> > With this change, max6370 can use memory mapped space for watchdog
> > configuration and GPIO WDI for pinging.
> > 
> 
> Ok, that makes sense. Comments below.
> 
> Thanks,
> Guenter
> 
> > > Guenter
> > > 
> > > > ---
> > > >    .../bindings/watchdog/maxim,max63xx.yaml      |  4 +++
> > > >    drivers/watchdog/max63xx_wdt.c                | 28 +++++++++++++++++++
> > > >    2 files changed, 32 insertions(+)
> > > > 
> > > > diff --git a/Documentation/devicetree/bindings/watchdog/maxim,max63xx.yaml b/Documentation/devicetree/bindings/watchdog/maxim,max63xx.yaml
> > > > index ab9641e845db..a97aa0135ef9 100644
> > > > --- a/Documentation/devicetree/bindings/watchdog/maxim,max63xx.yaml
> > > > +++ b/Documentation/devicetree/bindings/watchdog/maxim,max63xx.yaml
> > > > @@ -27,6 +27,10 @@ properties:
> > > >        description: This is a 1-byte memory-mapped address
> > > >        maxItems: 1
> > > > +  gpios:
> > > > +    description: Optional GPIO used for controlling WDI when WDI bit is not mapped to memory
> > > > +    maxItems: 1
> > > > +
> > > >    required:
> > > >      - compatible
> > > >      - reg
> 
> Devicetree patches needs to be separate.

Ok.

> > > > diff --git a/drivers/watchdog/max63xx_wdt.c b/drivers/watchdog/max63xx_wdt.c
> > > > index 9e1541cfae0d..eaf00c3f06a5 100644
> > > > --- a/drivers/watchdog/max63xx_wdt.c
> > > > +++ b/drivers/watchdog/max63xx_wdt.c
> > > > @@ -27,6 +27,7 @@
> > > >    #include <linux/io.h>
> > > >    #include <linux/slab.h>
> > > >    #include <linux/property.h>
> > > > +#include <linux/gpio/consumer.h>
> > > >    #define DEFAULT_HEARTBEAT 60
> > > >    #define MAX_HEARTBEAT     60
> > > > @@ -53,6 +54,9 @@ struct max63xx_wdt {
> > > >    	void __iomem *base;
> > > >    	spinlock_t lock;
> > > > +	/* GPIOs */
> > > > +	struct gpio_desc *gpio_wdi;
> > > > +
> > > >    	/* WDI and WSET bits write access routines */
> > > >    	void (*ping)(struct max63xx_wdt *wdt);
> > > >    	void (*set)(struct max63xx_wdt *wdt, u8 set);
> > > > @@ -158,6 +162,17 @@ static const struct watchdog_info max63xx_wdt_info = {
> > > >    	.identity = "max63xx Watchdog",
> > > >    };
> > > > +static void max63xx_gpio_ping(struct max63xx_wdt *wdt)
> > > > +{
> > > > +	spin_lock(&wdt->lock);
> > > > +
> > > > +	gpiod_set_value_cansleep(wdt->gpio_wdi, 1);
> > > > +	udelay(1);
> > > > +	gpiod_set_value_cansleep(wdt->gpio_wdi, 0);
> > > > +
> > > > +	spin_unlock(&wdt->lock);
> > > > +}
> > > > +
> > > >    static void max63xx_mmap_ping(struct max63xx_wdt *wdt)
> > > >    {
> > > >    	u8 val;
> > > > @@ -225,6 +240,19 @@ static int max63xx_wdt_probe(struct platform_device *pdev)
> > > >    		return -EINVAL;
> > > >    	}
> > > > +	wdt->gpio_wdi = devm_gpiod_get(dev, NULL, GPIOD_FLAGS_BIT_DIR_OUT);
> > > > +	if (IS_ERR(wdt->gpio_wdi) && PTR_ERR(wdt->gpio_wdi) != -ENOENT) {
> > > > +		if (PTR_ERR(wdt->gpio_wdi) != -EPROBE_DEFER)
> > > > +			dev_err(dev, "unable to request gpio: %ld\n",
> > > > +				PTR_ERR(wdt->gpio_wdi));
> 
> Please use dev_err_probe().

Ok.

> > > > +		return PTR_ERR(wdt->gpio_wdi);
> > > > +	}
> > > > +
> > > > +	if (!IS_ERR(wdt->gpio_wdi))
> > > > +		wdt->ping = max63xx_gpio_ping;
> > > > +	else
> > > > +		wdt->gpio_wdi = NULL;
> 
> Why set gpio_wdi to NULL? It isn't used if the ping function is not set.

I thought that it would be more safer to have NULL value stored in
pointer variable as opposite of some non-NULL value used for the error
reporting. But I can remove this part of the code.

> > > > +
> > > >    	err = max63xx_mmap_init(pdev, wdt);
> 
> Doesn't this override the gpio ping function set above ?

Yes, it does. I forgot to amend local change to this patch. wdt->ping
has to be changed to gpio_ping _after_ max63xx_mmap_init call.

I will fix all those issues in v2.

> > > >    	if (err)
> > > >    		return err;
> > > 
>
diff mbox series

Patch

diff --git a/Documentation/devicetree/bindings/watchdog/maxim,max63xx.yaml b/Documentation/devicetree/bindings/watchdog/maxim,max63xx.yaml
index ab9641e845db..a97aa0135ef9 100644
--- a/Documentation/devicetree/bindings/watchdog/maxim,max63xx.yaml
+++ b/Documentation/devicetree/bindings/watchdog/maxim,max63xx.yaml
@@ -27,6 +27,10 @@  properties:
     description: This is a 1-byte memory-mapped address
     maxItems: 1
 
+  gpios:
+    description: Optional GPIO used for controlling WDI when WDI bit is not mapped to memory
+    maxItems: 1
+
 required:
   - compatible
   - reg
diff --git a/drivers/watchdog/max63xx_wdt.c b/drivers/watchdog/max63xx_wdt.c
index 9e1541cfae0d..eaf00c3f06a5 100644
--- a/drivers/watchdog/max63xx_wdt.c
+++ b/drivers/watchdog/max63xx_wdt.c
@@ -27,6 +27,7 @@ 
 #include <linux/io.h>
 #include <linux/slab.h>
 #include <linux/property.h>
+#include <linux/gpio/consumer.h>
 
 #define DEFAULT_HEARTBEAT 60
 #define MAX_HEARTBEAT     60
@@ -53,6 +54,9 @@  struct max63xx_wdt {
 	void __iomem *base;
 	spinlock_t lock;
 
+	/* GPIOs */
+	struct gpio_desc *gpio_wdi;
+
 	/* WDI and WSET bits write access routines */
 	void (*ping)(struct max63xx_wdt *wdt);
 	void (*set)(struct max63xx_wdt *wdt, u8 set);
@@ -158,6 +162,17 @@  static const struct watchdog_info max63xx_wdt_info = {
 	.identity = "max63xx Watchdog",
 };
 
+static void max63xx_gpio_ping(struct max63xx_wdt *wdt)
+{
+	spin_lock(&wdt->lock);
+
+	gpiod_set_value_cansleep(wdt->gpio_wdi, 1);
+	udelay(1);
+	gpiod_set_value_cansleep(wdt->gpio_wdi, 0);
+
+	spin_unlock(&wdt->lock);
+}
+
 static void max63xx_mmap_ping(struct max63xx_wdt *wdt)
 {
 	u8 val;
@@ -225,6 +240,19 @@  static int max63xx_wdt_probe(struct platform_device *pdev)
 		return -EINVAL;
 	}
 
+	wdt->gpio_wdi = devm_gpiod_get(dev, NULL, GPIOD_FLAGS_BIT_DIR_OUT);
+	if (IS_ERR(wdt->gpio_wdi) && PTR_ERR(wdt->gpio_wdi) != -ENOENT) {
+		if (PTR_ERR(wdt->gpio_wdi) != -EPROBE_DEFER)
+			dev_err(dev, "unable to request gpio: %ld\n",
+				PTR_ERR(wdt->gpio_wdi));
+		return PTR_ERR(wdt->gpio_wdi);
+	}
+
+	if (!IS_ERR(wdt->gpio_wdi))
+		wdt->ping = max63xx_gpio_ping;
+	else
+		wdt->gpio_wdi = NULL;
+
 	err = max63xx_mmap_init(pdev, wdt);
 	if (err)
 		return err;