Re: [Patch v5 2/2] gpio: Document GPIO hogging mechanism

[Arend van Spriel <arend@broadcom.com>]

On 01/12/15 11:20, Linus Walleij wrote:
> On Fri, Dec 19, 2014 at 9:07 PM, Benoit Parrot<bparrot@ti.com>  wrote:
>
>> Add GPIO hogging documentation to gpio.txt
>>
>> Signed-off-by: Benoit Parrot<bparrot@ti.com>
>> Reviewed-by: Alexandre Courbot<acourbot@nvidia.com>
>
> This is starting to look good ...
>
>> +               line_b {
>> +                       gpio-hog;
>> +                       gpios =<6 0>;
>> +                       state = "output-low";
>
> I don't like the state string.
>
> Instead have boolean properties for all states.
>
> line_b {
>      gpio-hog;
>      gpios =<6 0>;
>      output-low;
>      line-name = "foo-bar-gpio";
> }
>
> Then use of_property_read_bool() in the code to check which
> state is to be selected intially. You can check that no mutually
> exclusive state are selected, I don't like that an arbitrary string
> select the state like that, if we do it that way an enumerator would
> be better, I prefer bools.

To avoid the mutual exclusive state checking, would it not be more 
straightforward to use numeric enum values defined in boot/dts/include.

Regards,
Arend

> Yours,
> Linus Walleij
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