[U-Boot] [PATCH V2 1/6] dm: gpio: add a default gpio xlate routine

[Stephen Warren]

On 04/11/2016 11:00 AM, Eric Nelson wrote:
> Many drivers use a common form of offset + flags for device
> tree nodes. e.g.:
> 	<&gpio1 2 GPIO_ACTIVE_LOW>
>
> This patch adds a common implementation of this type of parsing
> and calls it when a gpio driver doesn't supply its' own xlate
> routine.
>
> This will allow removal of the driver-specific versions in a
> handful of drivers and simplify the addition of new drivers.

The series,
Acked-by: Stephen Warren <swarren at nvidia.com>

Although one nit below.

> diff --git a/drivers/gpio/gpio-uclass.c b/drivers/gpio/gpio-uclass.c

> +int gpio_xlate_offs_flags(struct udevice *dev,
> +					 struct gpio_desc *desc,
> +					 struct fdtdec_phandle_args *args)
> +{
> +	int ret = -EINVAL;
> +	if (args->args_count > 1) {
> +		desc->offset = args->args[0];
> +		if (args->args[1] & GPIO_ACTIVE_LOW)
> +			desc->flags = GPIOD_ACTIVE_LOW;
> +		ret = 0;
> +	}
> +	return ret;
> +}

Why not return the error first, and avoid the need for an extra 
indentation level for the rest of the function, and make it quite a bit 
more readable in my opinion. The default could also be made to cover 
more situations (e.g. bindings that define a single cell for the GPIO 
but not cell at all for any flags):

if (args->args_count < 1)
     return -EINVAL;

desc->offset = args->args[0];

if (args->args_count < 2)
     return 0;

if (args->args[1] & GPIO_ACTIVE_LOW)
     desc->flags = GPIOD_ACTIVE_LOW;

return 0;