Re: [PATCH] gpiolib: fix chip->base handling in of_gpio_simple_xlate()

[Daniel Mack]

(Cc: Arnd)

On 22.07.2012 19:10, Daniel Mack wrote:
> of_gpio_simple_xlate() is called for each chip when a GPIO is looked up.
> When registering several chips off the same DT node (with different pin
> offsets) however, the lookup fails as the GPIO number passed in to
> of_gpio_simple_xlate() is likely higher than the chip's ->ngpio value.
> 
> Fix that by taking into account the chip's ->base value, and return the
> relative offset of the pin inside the chip.
> 
> Signed-off-by: Daniel Mack <zonque@xxxxxxxxx>
> Cc: Grant Likely <grant.likely@xxxxxxxxxxxx>
> Cc: Linus Walleij <linus.walleij@xxxxxxxxxxxxxx>
> ---
> 
> I'm currently porting the PXA pieces over to DT, and stumbled over what
> looks like an obvious bug to me. Correct me if I'm mistaken, but I see
> no reason why one shouldn't be able to instanciate several GPIO chips
> from a single DT node.
> 
> Thanks,
> Daniel
> 
>  drivers/gpio/gpiolib-of.c |    4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/gpio/gpiolib-of.c b/drivers/gpio/gpiolib-of.c
> index d18068a..51bc232 100644
> --- a/drivers/gpio/gpiolib-of.c
> +++ b/drivers/gpio/gpiolib-of.c
> @@ -147,13 +147,13 @@ int of_gpio_simple_xlate(struct gpio_chip *gc,
>  	if (WARN_ON(gpiospec->args_count < gc->of_gpio_n_cells))
>  		return -EINVAL;
>  
> -	if (gpiospec->args[0] >= gc->ngpio)
> +	if (gpiospec->args[0] >= gc->ngpio + gc->base)
>  		return -EINVAL;
>  
>  	if (flags)
>  		*flags = gpiospec->args[1];
>  
> -	return gpiospec->args[0];
> +	return gpiospec->args[0] - gc->base;
>  }
>  EXPORT_SYMBOL(of_gpio_simple_xlate);
>  
> 


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