From mboxrd@z Thu Jan  1 00:00:00 1970
From: nicolas.ferre@atmel.com (Nicolas Ferre)
Date: Tue, 7 Aug 2012 14:47:01 +0200
Subject: [PATCH 2/4] ARM: at91: gpio: implement gpio_free
In-Reply-To: <1342359637-15325-2-git-send-email-plagnioj@jcrosoft.com>
References: <20120715131618.GF4450@game.jcrosoft.org>
 <1342359637-15325-1-git-send-email-plagnioj@jcrosoft.com>
 <1342359637-15325-2-git-send-email-plagnioj@jcrosoft.com>
Message-ID: <50210E45.9060605@atmel.com>
To: linux-arm-kernel@lists.infradead.org
List-Id: linux-arm-kernel.lists.infradead.org

On 07/15/2012 03:40 PM, Jean-Christophe PLAGNIOL-VILLARD :
> configure a gpio as input when freeing it to reduce power consumption
> 
> Cc: Nicolas Ferre <nicolas.ferre@atmel.com>
> Signed-off-by: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>
> ---
>  arch/arm/mach-at91/gpio.c |    7 ++++++-
>  1 file changed, 6 insertions(+), 1 deletion(-)
> 
> diff --git a/arch/arm/mach-at91/gpio.c b/arch/arm/mach-at91/gpio.c
> index 994ed02..3833f82 100644
> --- a/arch/arm/mach-at91/gpio.c
> +++ b/arch/arm/mach-at91/gpio.c
> @@ -45,6 +45,7 @@ struct at91_gpio_chip {
>  #define to_at91_gpio_chip(c) container_of(c, struct at91_gpio_chip, chip)
>  
>  static int at91_gpiolib_request(struct gpio_chip *chip, unsigned offset);
> +static void at91_gpiolib_free(struct gpio_chip *chip, unsigned offset);
>  static void at91_gpiolib_dbg_show(struct seq_file *s, struct gpio_chip *chip);
>  static void at91_gpiolib_set(struct gpio_chip *chip, unsigned offset, int val);
>  static int at91_gpiolib_get(struct gpio_chip *chip, unsigned offset);
> @@ -59,6 +60,7 @@ static int at91_gpiolib_to_irq(struct gpio_chip *chip, unsigned offset);
>  		.chip = {						\
>  			.label		  = name,			\
>  			.request	  = at91_gpiolib_request,	\
> +			.free		  = at91_gpiolib_free,		\
>  			.direction_input  = at91_gpiolib_direction_input, \
>  			.direction_output = at91_gpiolib_direction_output, \
>  			.get		  = at91_gpiolib_get,		\
> @@ -863,7 +865,10 @@ void __init at91_gpio_irq_setup(void)
>  }
>  
>  /* gpiolib support */
> -
> +static void at91_gpiolib_free(struct gpio_chip *chip, unsigned offset)
> +{
> +	at91_gpiolib_direction_input(chip, offset);

I know we talked about it, but now I am not sure.
Maybe a safer solution would be to not touching the gpio configuration
when freeing it...

> +}
>  
>  static int at91_gpiolib_request(struct gpio_chip *chip, unsigned offset)
>  {
> 


-- 
Nicolas Ferre