[PATCHv2 1/2] gpio: xilinx: dt-binding: Add clock node

[PATCHv2 1/2] gpio: xilinx: dt-binding: Add clock node

[Shubhrajyoti Datta]

Add the clock node to the dt binding.

Signed-off-by: Shubhrajyoti Datta <shubhrajyoti.datta@xilinx.com>
---
v2: 
Make clocks optional
Add clock name

 .../devicetree/bindings/gpio/gpio-xilinx.txt       |    4 ++++
 1 files changed, 4 insertions(+), 0 deletions(-)

diff --git a/Documentation/devicetree/bindings/gpio/gpio-xilinx.txt b/Documentation/devicetree/bindings/gpio/gpio-xilinx.txt
index 63bf4be..1372007 100644
--- a/Documentation/devicetree/bindings/gpio/gpio-xilinx.txt
+++ b/Documentation/devicetree/bindings/gpio/gpio-xilinx.txt
@@ -25,12 +25,16 @@ Optional properties:
 - xlnx,dout-default-2 : as above but the second channel
 - xlnx,gpio2-width : as above but for the second channel
 - xlnx,tri-default-2 : as above but for the second channel
+- clocks: Input clock specifier. Refer to common clock bindings.
+- clock-names: Input clock name, should be s_axi_aclk.
 
 
 Example:
 gpio: gpio@40000000 {
 	#gpio-cells = <2>;
 	compatible = "xlnx,xps-gpio-1.00.a";
+	clocks = <&clkc 15>;
+	clock-names = "s_axi_aclk";
 	gpio-controller ;
 	interrupt-parent = <&microblaze_0_intc>;
 	interrupts = < 6 2 >;
-- 
1.7.1

[PATCHv2 2/2] gpio: xilinx: Add clock support

[Shubhrajyoti Datta]

Add basic clock support for xilinx gpio.

Signed-off-by: Shubhrajyoti Datta <shubhrajyoti.datta@xilinx.com>
---
v2 :
no change

 drivers/gpio/gpio-xilinx.c |   22 ++++++++++++++++++++++
 1 files changed, 22 insertions(+), 0 deletions(-)

diff --git a/drivers/gpio/gpio-xilinx.c b/drivers/gpio/gpio-xilinx.c
index 14b2a62..923cab8 100644
--- a/drivers/gpio/gpio-xilinx.c
+++ b/drivers/gpio/gpio-xilinx.c
@@ -13,6 +13,7 @@
  */
 
 #include <linux/bitops.h>
+#include <linux/clk.h>
 #include <linux/init.h>
 #include <linux/errno.h>
 #include <linux/module.h>
@@ -45,6 +46,7 @@
  * @gpio_state: GPIO state shadow register
  * @gpio_dir: GPIO direction shadow register
  * @gpio_lock: Lock used for synchronization
+ * @clk: Clock resource for this controller
  */
 struct xgpio_instance {
 	struct of_mm_gpio_chip mmchip;
@@ -52,6 +54,7 @@ struct xgpio_instance {
 	u32 gpio_state[2];
 	u32 gpio_dir[2];
 	spinlock_t gpio_lock[2];
+	struct clk *clk;
 };
 
 static inline int xgpio_index(struct xgpio_instance *chip, int gpio)
@@ -282,6 +285,7 @@ static int xgpio_remove(struct platform_device *pdev)
 	struct xgpio_instance *chip = platform_get_drvdata(pdev);
 
 	of_mm_gpiochip_remove(&chip->mmchip);
+	clk_disable_unprepare(chip->clk);
 
 	return 0;
 }
@@ -307,6 +311,23 @@ static int xgpio_probe(struct platform_device *pdev)
 
 	platform_set_drvdata(pdev, chip);
 
+	/* Retrieve GPIO clock */
+	chip->clk = devm_clk_get(&pdev->dev, NULL);
+	if (IS_ERR(chip->clk)) {
+		if (PTR_ERR(chip->clk) == -ENOENT) {
+			dev_info(&pdev->dev, "No clocks found for clk\n");
+			chip->clk = NULL;
+		} else {
+			dev_err(&pdev->dev, "axi clock error\n");
+			return PTR_ERR(chip->clk);
+		}
+	}
+	status = clk_prepare_enable(chip->clk);
+	if (status) {
+		dev_err(&pdev->dev, "Unable to enable clock.\n");
+		return status;
+	}
+
 	/* Update GPIO state shadow register with default value */
 	of_property_read_u32(np, "xlnx,dout-default", &chip->gpio_state[0]);
 
@@ -362,6 +383,7 @@ static int xgpio_probe(struct platform_device *pdev)
 	if (status) {
 		pr_err("%s: error in probe function with status %d\n",
 		       np->full_name, status);
+		clk_disable_unprepare(chip->clk);
 		return status;
 	}
 
-- 
1.7.1

Re: [PATCHv2 2/2] gpio: xilinx: Add clock support

[Sören Brinkmann]

On Wed, 2016-11-09 at 10:39:51 +0530, Shubhrajyoti Datta wrote:
> Add basic clock support for xilinx gpio.
> 
> Signed-off-by: Shubhrajyoti Datta <shubhrajyoti.datta-gjFFaj9aHVfQT0dZR+AlfA@public.gmane.org>
> ---
> v2 :
> no change
> 
>  drivers/gpio/gpio-xilinx.c |   22 ++++++++++++++++++++++
>  1 files changed, 22 insertions(+), 0 deletions(-)
> 
> diff --git a/drivers/gpio/gpio-xilinx.c b/drivers/gpio/gpio-xilinx.c
> index 14b2a62..923cab8 100644
> --- a/drivers/gpio/gpio-xilinx.c
> +++ b/drivers/gpio/gpio-xilinx.c
> @@ -13,6 +13,7 @@
>   */
>  
>  #include <linux/bitops.h>
> +#include <linux/clk.h>
>  #include <linux/init.h>
>  #include <linux/errno.h>
>  #include <linux/module.h>
> @@ -45,6 +46,7 @@
>   * @gpio_state: GPIO state shadow register
>   * @gpio_dir: GPIO direction shadow register
>   * @gpio_lock: Lock used for synchronization
> + * @clk: Clock resource for this controller
>   */
>  struct xgpio_instance {
>  	struct of_mm_gpio_chip mmchip;
> @@ -52,6 +54,7 @@ struct xgpio_instance {
>  	u32 gpio_state[2];
>  	u32 gpio_dir[2];
>  	spinlock_t gpio_lock[2];
> +	struct clk *clk;
>  };
>  
>  static inline int xgpio_index(struct xgpio_instance *chip, int gpio)
> @@ -282,6 +285,7 @@ static int xgpio_remove(struct platform_device *pdev)
>  	struct xgpio_instance *chip = platform_get_drvdata(pdev);
>  
>  	of_mm_gpiochip_remove(&chip->mmchip);
> +	clk_disable_unprepare(chip->clk);
>  
>  	return 0;
>  }
> @@ -307,6 +311,23 @@ static int xgpio_probe(struct platform_device *pdev)
>  
>  	platform_set_drvdata(pdev, chip);
>  
> +	/* Retrieve GPIO clock */
> +	chip->clk = devm_clk_get(&pdev->dev, NULL);

The driver should use the clock-name documented in the binding to do the
clock lookup.

> +	if (IS_ERR(chip->clk)) {
> +		if (PTR_ERR(chip->clk) == -ENOENT) {
> +			dev_info(&pdev->dev, "No clocks found for clk\n");

This is pretty much just noise. The clocks property is optional. No need
to be too verbose about that. It would be quite a lot of printing if
every driver would report absent optional DT properties.

	Sören
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Re: [PATCHv2 2/2] gpio: xilinx: Add clock support

[Shubhrajyoti Datta]

On Wed, Nov 9, 2016 at 11:57 AM, Sören Brinkmann
<soren.brinkmann@xilinx.com> wrote:
> On Wed, 2016-11-09 at 10:39:51 +0530, Shubhrajyoti Datta wrote:
>> Add basic clock support for xilinx gpio.
>>
>> Signed-off-by: Shubhrajyoti Datta <shubhrajyoti.datta@xilinx.com>
>> ---
>> v2 :
>> no change
>>
>>  drivers/gpio/gpio-xilinx.c |   22 ++++++++++++++++++++++
>>  1 files changed, 22 insertions(+), 0 deletions(-)
>>
>> diff --git a/drivers/gpio/gpio-xilinx.c b/drivers/gpio/gpio-xilinx.c
>> index 14b2a62..923cab8 100644
>> --- a/drivers/gpio/gpio-xilinx.c
>> +++ b/drivers/gpio/gpio-xilinx.c
>> @@ -13,6 +13,7 @@
>>   */
>>
>>  #include <linux/bitops.h>
>> +#include <linux/clk.h>
>>  #include <linux/init.h>
>>  #include <linux/errno.h>
>>  #include <linux/module.h>
>> @@ -45,6 +46,7 @@
>>   * @gpio_state: GPIO state shadow register
>>   * @gpio_dir: GPIO direction shadow register
>>   * @gpio_lock: Lock used for synchronization
>> + * @clk: Clock resource for this controller
>>   */
>>  struct xgpio_instance {
>>       struct of_mm_gpio_chip mmchip;
>> @@ -52,6 +54,7 @@ struct xgpio_instance {
>>       u32 gpio_state[2];
>>       u32 gpio_dir[2];
>>       spinlock_t gpio_lock[2];
>> +     struct clk *clk;
>>  };
>>
>>  static inline int xgpio_index(struct xgpio_instance *chip, int gpio)
>> @@ -282,6 +285,7 @@ static int xgpio_remove(struct platform_device *pdev)
>>       struct xgpio_instance *chip = platform_get_drvdata(pdev);
>>
>>       of_mm_gpiochip_remove(&chip->mmchip);
>> +     clk_disable_unprepare(chip->clk);
>>
>>       return 0;
>>  }
>> @@ -307,6 +311,23 @@ static int xgpio_probe(struct platform_device *pdev)
>>
>>       platform_set_drvdata(pdev, chip);
>>
>> +     /* Retrieve GPIO clock */
>> +     chip->clk = devm_clk_get(&pdev->dev, NULL);
>
> The driver should use the clock-name documented in the binding to do the
> clock lookup.

My idea was to keep the clk name optional since there is only one clock.
Or do you think we should mandate the name if clk is provided.

>
>> +     if (IS_ERR(chip->clk)) {
>> +             if (PTR_ERR(chip->clk) == -ENOENT) {
>> +                     dev_info(&pdev->dev, "No clocks found for clk\n");
>
> This is pretty much just noise. The clocks property is optional. No need
> to be too verbose about that. It would be quite a lot of printing if
> every driver would report absent optional DT properties.
Ok will remove the print

>
>         Sören

Re: [PATCHv2 2/2] gpio: xilinx: Add clock support

[Sören Brinkmann]

On Wed, 2016-11-09 at 12:16:58 +0530, Shubhrajyoti Datta wrote:
> On Wed, Nov 9, 2016 at 11:57 AM, Sören Brinkmann
> <soren.brinkmann@xilinx.com> wrote:
> > On Wed, 2016-11-09 at 10:39:51 +0530, Shubhrajyoti Datta wrote:
> >> Add basic clock support for xilinx gpio.
> >>
> >> Signed-off-by: Shubhrajyoti Datta <shubhrajyoti.datta@xilinx.com>
> >> ---
> >> v2 :
> >> no change
> >>
> >>  drivers/gpio/gpio-xilinx.c |   22 ++++++++++++++++++++++
> >>  1 files changed, 22 insertions(+), 0 deletions(-)
> >>
> >> diff --git a/drivers/gpio/gpio-xilinx.c b/drivers/gpio/gpio-xilinx.c
> >> index 14b2a62..923cab8 100644
> >> --- a/drivers/gpio/gpio-xilinx.c
> >> +++ b/drivers/gpio/gpio-xilinx.c
> >> @@ -13,6 +13,7 @@
> >>   */
> >>
> >>  #include <linux/bitops.h>
> >> +#include <linux/clk.h>
> >>  #include <linux/init.h>
> >>  #include <linux/errno.h>
> >>  #include <linux/module.h>
> >> @@ -45,6 +46,7 @@
> >>   * @gpio_state: GPIO state shadow register
> >>   * @gpio_dir: GPIO direction shadow register
> >>   * @gpio_lock: Lock used for synchronization
> >> + * @clk: Clock resource for this controller
> >>   */
> >>  struct xgpio_instance {
> >>       struct of_mm_gpio_chip mmchip;
> >> @@ -52,6 +54,7 @@ struct xgpio_instance {
> >>       u32 gpio_state[2];
> >>       u32 gpio_dir[2];
> >>       spinlock_t gpio_lock[2];
> >> +     struct clk *clk;
> >>  };
> >>
> >>  static inline int xgpio_index(struct xgpio_instance *chip, int gpio)
> >> @@ -282,6 +285,7 @@ static int xgpio_remove(struct platform_device *pdev)
> >>       struct xgpio_instance *chip = platform_get_drvdata(pdev);
> >>
> >>       of_mm_gpiochip_remove(&chip->mmchip);
> >> +     clk_disable_unprepare(chip->clk);
> >>
> >>       return 0;
> >>  }
> >> @@ -307,6 +311,23 @@ static int xgpio_probe(struct platform_device *pdev)
> >>
> >>       platform_set_drvdata(pdev, chip);
> >>
> >> +     /* Retrieve GPIO clock */
> >> +     chip->clk = devm_clk_get(&pdev->dev, NULL);
> >
> > The driver should use the clock-name documented in the binding to do the
> > clock lookup.
> 
> My idea was to keep the clk name optional since there is only one clock.
> Or do you think we should mandate the name if clk is provided.

I'd make 'clock-names' mandatory if 'clocks' is present. That way there
won't be any trouble if this IP ever consumed additional clocks in the
future.

	Sören

Re: [PATCHv2 2/2] gpio: xilinx: Add clock support

[Shubhrajyoti Datta]

On Wed, Nov 9, 2016 at 10:48 PM, Sören Brinkmann
<soren.brinkmann-gjFFaj9aHVfQT0dZR+AlfA@public.gmane.org> wrote:
[...]
>>
>> My idea was to keep the clk name optional since there is only one clock.
>> Or do you think we should mandate the name if clk is provided.
>
> I'd make 'clock-names' mandatory if 'clocks' is present. That way there
> won't be any trouble if this IP ever consumed additional clocks in the
> future.
fixed that in v3.

Thanks
>
>         Sören
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