Subject: [PATCH 1/5] gpiolib: devres: Introduce the function devm_request_gpio_array

From: [email-masked] (Rob Jones)
Date: Wed, 09 Jul 2014 12:18:33 +0100

Please note that I submitted a patch on 02/07/14 to create this
function which was acked by Linus Walleij on 05/07/14.

Great minds think alike, and all that.

However, I think that the version I submitted better replicates the
original (non devm) functionality, see below.

I didn't, however, add it to the documentation. +1 on that.

On 06/07/14 18:47, Himangi Saraogi wrote:
> This patch introduces the function devm_request_gpio_array that
> allocates multiple GPIOs in a single call in a managed manner. The
> function is also included in the documentation and a declaration is
> added in include/linux/gpio.h.
>
> Signed-off-by: Himangi Saraogi <[email-masked]>
> ---
>   Documentation/driver-model/devres.txt |  1 +
>   drivers/gpio/devres.c                 | 21 +++++++++++++++++++++
>   include/linux/gpio.h                  |  2 ++
>   3 files changed, 24 insertions(+)
>
> diff --git a/Documentation/driver-model/devres.txt b/Documentation/driver-model/devres.txt
> index 9e2098e..756f6cf 100644
> --- a/Documentation/driver-model/devres.txt
> +++ b/Documentation/driver-model/devres.txt
> @@ -337,6 +337,7 @@ GPIO
>     devm_gpiod_put()
>     devm_gpio_request()
>     devm_gpio_request_one()
> +  devm_gpio_request_array()
>     devm_gpio_free()
>
>   SND
> diff --git a/drivers/gpio/devres.c b/drivers/gpio/devres.c
> index 65978cf..adae7fa 100644
> --- a/drivers/gpio/devres.c
> +++ b/drivers/gpio/devres.c
> @@ -229,6 +229,27 @@ int devm_gpio_request_one(struct device *dev, unsigned gpio,
>   EXPORT_SYMBOL(devm_gpio_request_one);
>
>   /**
> + *	devm_gpio_request_array - request multiple GPIOs in a single call
> + *	@dev:   device to request for
> + *	@array:	array of the 'struct gpio'
> + *	@num:	how many GPIOs in the array
> + */
> +int devm_gpio_request_array(struct device *dev, const struct gpio *array,
> +			    size_t num)
> +{
> +	int i, err;
> +
> +	for (i = 0; i < num; i++, array++) {
> +		err = devm_gpio_request_one(dev, array->gpio, array->flags,
> +					    array->label);
> +		if (err)
> +			return err;

The failure path in the version I submitted frees up any already
allocated gpios on the first failure.

> +	}
> +	return 0;
> +}
> +EXPORT_SYMBOL_GPL(devm_gpio_request_array);
> +
> +/**
>    *      devm_gpio_free - free a GPIO
>    *      @dev: device to free GPIO for
>    *      @gpio: GPIO to free
> diff --git a/include/linux/gpio.h b/include/linux/gpio.h
> index 85aa5d0..c85f243 100644
> --- a/include/linux/gpio.h
> +++ b/include/linux/gpio.h
> @@ -84,6 +84,8 @@ struct device;
>   int devm_gpio_request(struct device *dev, unsigned gpio, const char *label);
>   int devm_gpio_request_one(struct device *dev, unsigned gpio,
>   			  unsigned long flags, const char *label);
> +int devm_gpio_request_array(struct device *dev, const struct gpio *array,
> +			    size_t num);
>   void devm_gpio_free(struct device *dev, unsigned int gpio);
>
>   #else /* ! CONFIG_GPIOLIB */
>

-- 
Rob Jones
Codethink Ltd
mailto:rob.jones at codethink.co.uk
tel:+44 161 236 5575