[PATCHv3] watchdog: xilinx: Add clock support

[PATCHv3] watchdog: xilinx: Add clock support

[Shubhrajyoti Datta]

Add support for the clock. Currently we enable
at probe and relinquish at remove.

Reviewed-by: Guenter Roeck <linux-0h96xk9xTtrk1uMJSBkQmQ@public.gmane.org>
Acked-by: Sören Brinkmann <soren.brinkmann-gjFFaj9aHVfQT0dZR+AlfA@public.gmane.org>
Signed-off-by: Shubhrajyoti Datta <shubhrajyoti.datta-gjFFaj9aHVfQT0dZR+AlfA@public.gmane.org>
---
v2:
fix spaces and error path.
v3:
do not fail existing dts

 .../devicetree/bindings/watchdog/of-xilinx-wdt.txt |  3 +++
 drivers/watchdog/of_xilinx_wdt.c                   | 29 ++++++++++++++++++++--
 2 files changed, 30 insertions(+), 2 deletions(-)

diff --git a/Documentation/devicetree/bindings/watchdog/of-xilinx-wdt.txt b/Documentation/devicetree/bindings/watchdog/of-xilinx-wdt.txt
index 6d63782..c6ae9c9 100644
--- a/Documentation/devicetree/bindings/watchdog/of-xilinx-wdt.txt
+++ b/Documentation/devicetree/bindings/watchdog/of-xilinx-wdt.txt
@@ -7,6 +7,8 @@ Required properties:
 - reg			: Physical base address and size
 
 Optional properties:
+- clocks		: Input clock specifier. Refer to common clock
+			  bindings.
 - clock-frequency	: Frequency of clock in Hz
 - xlnx,wdt-enable-once	: 0 - Watchdog can be restarted
 			  1 - Watchdog can be enabled just once
@@ -17,6 +19,7 @@ Example:
 axi-timebase-wdt@40100000 {
 	clock-frequency = <50000000>;
 	compatible = "xlnx,xps-timebase-wdt-1.00.a";
+	clocks = <&clkc 15>;
 	reg = <0x40100000 0x10000>;
 	xlnx,wdt-enable-once = <0x0>;
 	xlnx,wdt-interval = <0x1b>;
diff --git a/drivers/watchdog/of_xilinx_wdt.c b/drivers/watchdog/of_xilinx_wdt.c
index b2e1b4c..120840a 100644
--- a/drivers/watchdog/of_xilinx_wdt.c
+++ b/drivers/watchdog/of_xilinx_wdt.c
@@ -10,6 +10,7 @@
  * 2 of the License, or (at your option) any later version.
  */
 
+#include <linux/clk.h>
 #include <linux/err.h>
 #include <linux/module.h>
 #include <linux/types.h>
@@ -45,6 +46,7 @@ struct xwdt_device {
 	u32 wdt_interval;
 	spinlock_t spinlock;
 	struct watchdog_device xilinx_wdt_wdd;
+	struct clk		*clk;
 };
 
 static int xilinx_wdt_start(struct watchdog_device *wdd)
@@ -195,16 +197,34 @@ static int xwdt_probe(struct platform_device *pdev)
 	spin_lock_init(&xdev->spinlock);
 	watchdog_set_drvdata(xilinx_wdt_wdd, xdev);
 
+	xdev->clk = devm_clk_get(&pdev->dev, NULL);
+	if (IS_ERR(xdev->clk)) {
+		if (PTR_ERR(xdev->clk) == -ENOENT) {
+			dev_err(&pdev->dev, "input clock not found\n");
+			xdev->clk = NULL;
+		} else {
+			rc = PTR_ERR(xdev->clk);
+			dev_err(&pdev->dev, "axi clock error %d\n", rc);
+			return rc;
+		}
+	}
+
+	rc = clk_prepare_enable(xdev->clk);
+	if (rc) {
+		dev_err(&pdev->dev, "unable to enable clock\n");
+		return rc;
+	}
+
 	rc = xwdt_selftest(xdev);
 	if (rc == XWT_TIMER_FAILED) {
 		dev_err(&pdev->dev, "SelfTest routine error\n");
-		return rc;
+		goto err_clk_disable;
 	}
 
 	rc = watchdog_register_device(xilinx_wdt_wdd);
 	if (rc) {
 		dev_err(&pdev->dev, "Cannot register watchdog (err=%d)\n", rc);
-		return rc;
+		goto err_clk_disable;
 	}
 
 	dev_info(&pdev->dev, "Xilinx Watchdog Timer at %p with timeout %ds\n",
@@ -213,6 +233,10 @@ static int xwdt_probe(struct platform_device *pdev)
 	platform_set_drvdata(pdev, xdev);
 
 	return 0;
+err_clk_disable:
+	clk_disable_unprepare(xdev->clk);
+
+	return rc;
 }
 
 static int xwdt_remove(struct platform_device *pdev)
@@ -220,6 +244,7 @@ static int xwdt_remove(struct platform_device *pdev)
 	struct xwdt_device *xdev = platform_get_drvdata(pdev);
 
 	watchdog_unregister_device(&xdev->xilinx_wdt_wdd);
+	clk_disable_unprepare(xdev->clk);
 
 	return 0;
 }
-- 
2.1.1

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Re: [PATCHv3] watchdog: xilinx: Add clock support

[Guenter Roeck]

On 08/11/2016 06:20 AM, Shubhrajyoti Datta wrote:
> Add support for the clock. Currently we enable
> at probe and relinquish at remove.
>
> Reviewed-by: Guenter Roeck <linux-0h96xk9xTtrk1uMJSBkQmQ@public.gmane.org>
> Acked-by: Sören Brinkmann <soren.brinkmann-gjFFaj9aHVfQT0dZR+AlfA@public.gmane.org>
> Signed-off-by: Shubhrajyoti Datta <shubhrajyoti.datta-gjFFaj9aHVfQT0dZR+AlfA@public.gmane.org>
> ---
> v2:
> fix spaces and error path.
> v3:
> do not fail existing dts
>
>  .../devicetree/bindings/watchdog/of-xilinx-wdt.txt |  3 +++
>  drivers/watchdog/of_xilinx_wdt.c                   | 29 ++++++++++++++++++++--
>  2 files changed, 30 insertions(+), 2 deletions(-)
>
> diff --git a/Documentation/devicetree/bindings/watchdog/of-xilinx-wdt.txt b/Documentation/devicetree/bindings/watchdog/of-xilinx-wdt.txt
> index 6d63782..c6ae9c9 100644
> --- a/Documentation/devicetree/bindings/watchdog/of-xilinx-wdt.txt
> +++ b/Documentation/devicetree/bindings/watchdog/of-xilinx-wdt.txt
> @@ -7,6 +7,8 @@ Required properties:
>  - reg			: Physical base address and size
>
>  Optional properties:
> +- clocks		: Input clock specifier. Refer to common clock
> +			  bindings.
>  - clock-frequency	: Frequency of clock in Hz
>  - xlnx,wdt-enable-once	: 0 - Watchdog can be restarted
>  			  1 - Watchdog can be enabled just once
> @@ -17,6 +19,7 @@ Example:
>  axi-timebase-wdt@40100000 {
>  	clock-frequency = <50000000>;
>  	compatible = "xlnx,xps-timebase-wdt-1.00.a";
> +	clocks = <&clkc 15>;
>  	reg = <0x40100000 0x10000>;
>  	xlnx,wdt-enable-once = <0x0>;
>  	xlnx,wdt-interval = <0x1b>;
> diff --git a/drivers/watchdog/of_xilinx_wdt.c b/drivers/watchdog/of_xilinx_wdt.c
> index b2e1b4c..120840a 100644
> --- a/drivers/watchdog/of_xilinx_wdt.c
> +++ b/drivers/watchdog/of_xilinx_wdt.c
> @@ -10,6 +10,7 @@
>   * 2 of the License, or (at your option) any later version.
>   */
>
> +#include <linux/clk.h>
>  #include <linux/err.h>
>  #include <linux/module.h>
>  #include <linux/types.h>
> @@ -45,6 +46,7 @@ struct xwdt_device {
>  	u32 wdt_interval;
>  	spinlock_t spinlock;
>  	struct watchdog_device xilinx_wdt_wdd;
> +	struct clk		*clk;
>  };
>
>  static int xilinx_wdt_start(struct watchdog_device *wdd)
> @@ -195,16 +197,34 @@ static int xwdt_probe(struct platform_device *pdev)
>  	spin_lock_init(&xdev->spinlock);
>  	watchdog_set_drvdata(xilinx_wdt_wdd, xdev);
>
> +	xdev->clk = devm_clk_get(&pdev->dev, NULL);
> +	if (IS_ERR(xdev->clk)) {
> +		if (PTR_ERR(xdev->clk) == -ENOENT) {
> +			dev_err(&pdev->dev, "input clock not found\n");

No, this is not an error. The clock is optional.

> +			xdev->clk = NULL;
> +		} else {
> +			rc = PTR_ERR(xdev->clk);
> +			dev_err(&pdev->dev, "axi clock error %d\n", rc);

This could be -EPROBE_DEFER, which would not warrant an error message.

> +			return rc;
> +		}
> +	}
> +
> +	rc = clk_prepare_enable(xdev->clk);
> +	if (rc) {
> +		dev_err(&pdev->dev, "unable to enable clock\n");
> +		return rc;
> +	}
> +
>  	rc = xwdt_selftest(xdev);
>  	if (rc == XWT_TIMER_FAILED) {
>  		dev_err(&pdev->dev, "SelfTest routine error\n");
> -		return rc;
> +		goto err_clk_disable;
>  	}
>
>  	rc = watchdog_register_device(xilinx_wdt_wdd);
>  	if (rc) {
>  		dev_err(&pdev->dev, "Cannot register watchdog (err=%d)\n", rc);
> -		return rc;
> +		goto err_clk_disable;
>  	}
>
>  	dev_info(&pdev->dev, "Xilinx Watchdog Timer at %p with timeout %ds\n",
> @@ -213,6 +233,10 @@ static int xwdt_probe(struct platform_device *pdev)
>  	platform_set_drvdata(pdev, xdev);
>
>  	return 0;
> +err_clk_disable:
> +	clk_disable_unprepare(xdev->clk);
> +
> +	return rc;
>  }
>
>  static int xwdt_remove(struct platform_device *pdev)
> @@ -220,6 +244,7 @@ static int xwdt_remove(struct platform_device *pdev)
>  	struct xwdt_device *xdev = platform_get_drvdata(pdev);
>
>  	watchdog_unregister_device(&xdev->xilinx_wdt_wdd);
> +	clk_disable_unprepare(xdev->clk);
>
>  	return 0;
>  }
>

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Re: [PATCHv3] watchdog: xilinx: Add clock support

[Shubhrajyoti Datta]

Hi ,
Thanks for the review.


On Thu, Aug 11, 2016 at 7:57 PM, Guenter Roeck <linux-0h96xk9xTtrk1uMJSBkQmQ@public.gmane.org> wrote:
> On 08/11/2016 06:20 AM, Shubhrajyoti Datta wrote:
>>
>> Add support for the clock. Currently we enable
>> at probe and relinquish at remove.
>>
>> Reviewed-by: Guenter Roeck <linux-0h96xk9xTtrk1uMJSBkQmQ@public.gmane.org>
>> Acked-by: Sören Brinkmann <soren.brinkmann-gjFFaj9aHVfQT0dZR+AlfA@public.gmane.org>
>> Signed-off-by: Shubhrajyoti Datta <shubhrajyoti.datta-gjFFaj9aHVfQT0dZR+AlfA@public.gmane.org>
>> ---
>> v2:
>> fix spaces and error path.
>> v3:
>> do not fail existing dts
>>
>>  .../devicetree/bindings/watchdog/of-xilinx-wdt.txt |  3 +++
>>  drivers/watchdog/of_xilinx_wdt.c                   | 29
>> ++++++++++++++++++++--
>>  2 files changed, 30 insertions(+), 2 deletions(-)
>>
>> diff --git a/Documentation/devicetree/bindings/watchdog/of-xilinx-wdt.txt
>> b/Documentation/devicetree/bindings/watchdog/of-xilinx-wdt.txt
>> index 6d63782..c6ae9c9 100644
>> --- a/Documentation/devicetree/bindings/watchdog/of-xilinx-wdt.txt
>> +++ b/Documentation/devicetree/bindings/watchdog/of-xilinx-wdt.txt
>> @@ -7,6 +7,8 @@ Required properties:
>>  - reg                  : Physical base address and size
>>
>>  Optional properties:
>> +- clocks               : Input clock specifier. Refer to common clock
>> +                         bindings.
>>  - clock-frequency      : Frequency of clock in Hz
>>  - xlnx,wdt-enable-once : 0 - Watchdog can be restarted
>>                           1 - Watchdog can be enabled just once
>> @@ -17,6 +19,7 @@ Example:
>>  axi-timebase-wdt@40100000 {
>>         clock-frequency = <50000000>;
>>         compatible = "xlnx,xps-timebase-wdt-1.00.a";
>> +       clocks = <&clkc 15>;
>>         reg = <0x40100000 0x10000>;
>>         xlnx,wdt-enable-once = <0x0>;
>>         xlnx,wdt-interval = <0x1b>;
>> diff --git a/drivers/watchdog/of_xilinx_wdt.c
>> b/drivers/watchdog/of_xilinx_wdt.c
>> index b2e1b4c..120840a 100644
>> --- a/drivers/watchdog/of_xilinx_wdt.c
>> +++ b/drivers/watchdog/of_xilinx_wdt.c
>> @@ -10,6 +10,7 @@
>>   * 2 of the License, or (at your option) any later version.
>>   */
>>
>> +#include <linux/clk.h>
>>  #include <linux/err.h>
>>  #include <linux/module.h>
>>  #include <linux/types.h>
>> @@ -45,6 +46,7 @@ struct xwdt_device {
>>         u32 wdt_interval;
>>         spinlock_t spinlock;
>>         struct watchdog_device xilinx_wdt_wdd;
>> +       struct clk              *clk;
>>  };
>>
>>  static int xilinx_wdt_start(struct watchdog_device *wdd)
>> @@ -195,16 +197,34 @@ static int xwdt_probe(struct platform_device *pdev)
>>         spin_lock_init(&xdev->spinlock);
>>         watchdog_set_drvdata(xilinx_wdt_wdd, xdev);
>>
>> +       xdev->clk = devm_clk_get(&pdev->dev, NULL);
>> +       if (IS_ERR(xdev->clk)) {
>> +               if (PTR_ERR(xdev->clk) == -ENOENT) {
>> +                       dev_err(&pdev->dev, "input clock not found\n");
>
>
> No, this is not an error. The clock is optional.
yes will make it info instead.

>
>> +                       xdev->clk = NULL;
>> +               } else {
>> +                       rc = PTR_ERR(xdev->clk);
>> +                       dev_err(&pdev->dev, "axi clock error %d\n", rc);
>
>
> This could be -EPROBE_DEFER, which would not warrant an error message.
sure also since the error code will be given to the core I am removing
the print from the driver.

>
>
>> +                       return rc;
>> +               }
>> +       }
>> +
>> +       rc = clk_prepare_enable(xdev->clk);
>> +       if (rc) {
>> +               dev_err(&pdev->dev, "unable to enable clock\n");
>> +               return rc;
>> +       }
>> +
>>         rc = xwdt_selftest(xdev);
>>         if (rc == XWT_TIMER_FAILED) {
>>                 dev_err(&pdev->dev, "SelfTest routine error\n");
>> -               return rc;
>> +               goto err_clk_disable;
>>         }
>>
>>         rc = watchdog_register_device(xilinx_wdt_wdd);
>>         if (rc) {
>>                 dev_err(&pdev->dev, "Cannot register watchdog (err=%d)\n",
>> rc);
>> -               return rc;
>> +               goto err_clk_disable;
>>         }
>>
>>         dev_info(&pdev->dev, "Xilinx Watchdog Timer at %p with timeout
>> %ds\n",
>> @@ -213,6 +233,10 @@ static int xwdt_probe(struct platform_device *pdev)
>>         platform_set_drvdata(pdev, xdev);
>>
>>         return 0;
>> +err_clk_disable:
>> +       clk_disable_unprepare(xdev->clk);
>> +
>> +       return rc;
>>  }
>>
>>  static int xwdt_remove(struct platform_device *pdev)
>> @@ -220,6 +244,7 @@ static int xwdt_remove(struct platform_device *pdev)
>>         struct xwdt_device *xdev = platform_get_drvdata(pdev);
>>
>>         watchdog_unregister_device(&xdev->xilinx_wdt_wdd);
>> +       clk_disable_unprepare(xdev->clk);
>>
>>         return 0;
>>  }
>>
>
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