Re: [PATCH v1 1/2] of: property: Add fw_devlink support for "gpio" and "gpios" binding

Saravana Kannan
2021-01-21T18:34:11Z

On Thu, Jan 21, 2021 at 5:11 AM Linus Walleij <linus.walleij@linaro.org> wrote:
>
> On Wed, Jan 20, 2021 at 9:05 AM Saravana Kannan <saravanak@google.com> wrote:
>
> > To provide backward compatibility for boards that use deprecated DT
> > bindings, we need to add fw_devlink support for "gpio" and "gpios".
>
> You do some more stuff in the patch so describe that too.
> Especially the check for hogs and #gpio-cells.
> Describe why you do that. Maybe even with a comment in
> the code because I don't think everyone will understand.

Ack

>
> > + if (strcmp(prop_name, "gpio") && strcmp(prop_name, "gpios"))
> > + return NULL;
>
> This part is easy to understand.
>
> > + if (of_find_property(np, "gpio-hog", NULL))
> > + return NULL;
> > +
> > + if (of_parse_phandle_with_args(np, prop_name, "#gpio-cells", index,
> > + &sup_args))
> > + return NULL;
>
> This part is hard to understand. Insert comments and tell the reader
> of the code what is going on and why.

I assume the "hard to understand" part is the gpio-hog part? Because
the last line is pretty straightforward -- it's returning the index-th
phandle. Also, it's a copy-paste from the DEFINE_SIMPLE_PROP macro.

-Saravana