[PATCH v2] pca953x: Add optional reset gpio control

[PATCH v2] pca953x: Add optional reset gpio control

[Steve Longerbeam]

In version 2:

- Specify that reset signal to PCA953x chip is active low, in
  binding doc.
- reorder includes in gpio-pca953x.c.
- remove dev_err() on devm_gpiod_get_optional() error return.


Steve Longerbeam (1):
  gpio: pca953x: Add optional reset gpio control

 Documentation/devicetree/bindings/gpio/gpio-pca953x.txt | 4 ++++
 drivers/gpio/gpio-pca953x.c                             | 9 +++++++++
 2 files changed, 13 insertions(+)

-- 
2.7.4

[PATCH v2] gpio: pca953x: Add optional reset gpio control

[Steve Longerbeam]

Add optional reset-gpios pin control. If present, de-assert the
specified reset gpio pin to bring the chip out of reset.

Signed-off-by: Steve Longerbeam <steve_longerbeam@mentor.com>
Cc: Linus Walleij <linus.walleij@linaro.org>
Cc: Alexandre Courbot <gnurou@gmail.com>
Cc: linux-gpio@vger.kernel.org
Cc: linux-kernel@vger.kernel.org

--

v2:
- Specify that reset signal to PCA953x chip is active low, in
  binding doc.
- reorder includes in gpio-pca953x.c.
- remove dev_err() on devm_gpiod_get_optional() error return.
---
 Documentation/devicetree/bindings/gpio/gpio-pca953x.txt | 4 ++++
 drivers/gpio/gpio-pca953x.c                             | 9 +++++++++
 2 files changed, 13 insertions(+)

diff --git a/Documentation/devicetree/bindings/gpio/gpio-pca953x.txt b/Documentation/devicetree/bindings/gpio/gpio-pca953x.txt
index 08dd15f..e639357 100644
--- a/Documentation/devicetree/bindings/gpio/gpio-pca953x.txt
+++ b/Documentation/devicetree/bindings/gpio/gpio-pca953x.txt
@@ -29,6 +29,10 @@ Required properties:
 	onsemi,pca9654
 	exar,xra1202
 
+Optional properties:
+ - reset-gpios: GPIO specification for the RESET input. This is an
+		active low signal to the PCA953x.
+
 Example:
 
 
diff --git a/drivers/gpio/gpio-pca953x.c b/drivers/gpio/gpio-pca953x.c
index d5d72d8..d44232a 100644
--- a/drivers/gpio/gpio-pca953x.c
+++ b/drivers/gpio/gpio-pca953x.c
@@ -14,6 +14,7 @@
 #include <linux/module.h>
 #include <linux/init.h>
 #include <linux/gpio.h>
+#include <linux/gpio/consumer.h>
 #include <linux/interrupt.h>
 #include <linux/i2c.h>
 #include <linux/platform_data/pca953x.h>
@@ -754,8 +755,16 @@ static int pca953x_probe(struct i2c_client *client,
 		invert = pdata->invert;
 		chip->names = pdata->names;
 	} else {
+		struct gpio_desc *reset_gpio;
+
 		chip->gpio_start = -1;
 		irq_base = 0;
+
+		/* See if we need to de-assert a reset pin */
+		reset_gpio = devm_gpiod_get_optional(&client->dev, "reset",
+						     GPIOD_OUT_LOW);
+		if (IS_ERR(reset_gpio))
+			return PTR_ERR(reset_gpio);
 	}
 
 	chip->client = client;
-- 
2.7.4

Re: [PATCH v2] gpio: pca953x: Add optional reset gpio control

[Andy Shevchenko]

On Tue, Jan 10, 2017 at 9:29 PM, Steve Longerbeam <slongerbeam@gmail.com> wrote:
> Add optional reset-gpios pin control. If present, de-assert the
> specified reset gpio pin to bring the chip out of reset.
>
> Signed-off-by: Steve Longerbeam <steve_longerbeam@mentor.com>
> Cc: Linus Walleij <linus.walleij@linaro.org>
> Cc: Alexandre Courbot <gnurou@gmail.com>
> Cc: linux-gpio@vger.kernel.org
> Cc: linux-kernel@vger.kernel.org


> --
>
> v2:
> - Specify that reset signal to PCA953x chip is active low, in
>   binding doc.
> - reorder includes in gpio-pca953x.c.
> - remove dev_err() on devm_gpiod_get_optional() error return.

This should go after delimiter.

FWIW:
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>

> ---
>  Documentation/devicetree/bindings/gpio/gpio-pca953x.txt | 4 ++++
>  drivers/gpio/gpio-pca953x.c                             | 9 +++++++++
>  2 files changed, 13 insertions(+)
>
> diff --git a/Documentation/devicetree/bindings/gpio/gpio-pca953x.txt b/Documentation/devicetree/bindings/gpio/gpio-pca953x.txt
> index 08dd15f..e639357 100644
> --- a/Documentation/devicetree/bindings/gpio/gpio-pca953x.txt
> +++ b/Documentation/devicetree/bindings/gpio/gpio-pca953x.txt
> @@ -29,6 +29,10 @@ Required properties:
>         onsemi,pca9654
>         exar,xra1202
>
> +Optional properties:
> + - reset-gpios: GPIO specification for the RESET input. This is an
> +               active low signal to the PCA953x.
> +
>  Example:
>
>
> diff --git a/drivers/gpio/gpio-pca953x.c b/drivers/gpio/gpio-pca953x.c
> index d5d72d8..d44232a 100644
> --- a/drivers/gpio/gpio-pca953x.c
> +++ b/drivers/gpio/gpio-pca953x.c
> @@ -14,6 +14,7 @@
>  #include <linux/module.h>
>  #include <linux/init.h>
>  #include <linux/gpio.h>
> +#include <linux/gpio/consumer.h>
>  #include <linux/interrupt.h>
>  #include <linux/i2c.h>
>  #include <linux/platform_data/pca953x.h>
> @@ -754,8 +755,16 @@ static int pca953x_probe(struct i2c_client *client,
>                 invert = pdata->invert;
>                 chip->names = pdata->names;
>         } else {
> +               struct gpio_desc *reset_gpio;
> +
>                 chip->gpio_start = -1;
>                 irq_base = 0;
> +
> +               /* See if we need to de-assert a reset pin */
> +               reset_gpio = devm_gpiod_get_optional(&client->dev, "reset",
> +                                                    GPIOD_OUT_LOW);
> +               if (IS_ERR(reset_gpio))
> +                       return PTR_ERR(reset_gpio);
>         }
>
>         chip->client = client;
> --
> 2.7.4
>



-- 
With Best Regards,
Andy Shevchenko

Re: [PATCH v2] gpio: pca953x: Add optional reset gpio control

[Linus Walleij]

On Tue, Jan 10, 2017 at 8:29 PM, Steve Longerbeam <slongerbeam@gmail.com> wrote:

> Add optional reset-gpios pin control. If present, de-assert the
> specified reset gpio pin to bring the chip out of reset.
>
> Signed-off-by: Steve Longerbeam <steve_longerbeam@mentor.com>
> Cc: Linus Walleij <linus.walleij@linaro.org>
> Cc: Alexandre Courbot <gnurou@gmail.com>
> Cc: linux-gpio@vger.kernel.org
> Cc: linux-kernel@vger.kernel.org

v2 patch applied adding a few review tags.

Yours,
Linus Walleij