Re: [PATCH] gpio: msic: Fix calculating register address in msic_gpio_to_oreg()

[Mathias Nyman <mathias.nyman@linux.intel.com>]

On 07/24/2012 01:35 PM, Axel Lin wrote:
> In the case offset is 20 ... 23, the equation to get the register should be:
>          INTEL_MSIC_GPIO1HV0CTLO - offset + 20
>
> With above equation, we can get below mapping between offset and the register:
>          offset is 20: INTEL_MSIC_GPIO1HV0CTLO
>          offset is 21: INTEL_MSIC_GPIO1HV1CTLO
>          offset is 22: INTEL_MSIC_GPIO1HV2CTLO
>          offset is 23: INTEL_MSIC_GPIO1HV3CTLO
>
> Signed-off-by: Axel Lin<axel.lin@gmail.com>
> ---
>   drivers/gpio/gpio-msic.c |    2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/gpio/gpio-msic.c b/drivers/gpio/gpio-msic.c
> index 71a838f..b389862 100644
> --- a/drivers/gpio/gpio-msic.c
> +++ b/drivers/gpio/gpio-msic.c
> @@ -99,7 +99,7 @@ static int msic_gpio_to_oreg(unsigned offset)
>   	if (offset<  20)
>   		return INTEL_MSIC_GPIO0HV0CTLO - offset + 16;
>
> -	return INTEL_MSIC_GPIO1HV0CTLO + offset + 20;
> +	return INTEL_MSIC_GPIO1HV0CTLO - offset + 20;
>   }
>
>   static int msic_gpio_direction_input(struct gpio_chip *chip, unsigned offset)

Nice, good catch.

The last 4 of the 24 gpios will work properly as outputs with this fix.

Acked-by: Mathias Nyman <mathias.nyman@linux.intel.com>