Re: [PATCH v7 3/3] docs/pinctrl: document debugfs files

From: Geert Uytterhoeven
Date: Fri Feb 19 2021 - 04:21:19 EST


Hi Drew,

On Wed, Feb 17, 2021 at 11:15 PM Drew Fustini <drew@xxxxxxxxxxxxxxx> wrote:
> Document debugfs directories and files created for pinctrl subsystem.
>
> Suggested-by: Andy Shevchenko <andy.shevchenko@xxxxxxxxx>
> Reviewed-by: Andy Shevchenko <andy.shevchenko@xxxxxxxxx>
> Reviewed-by: Tony Lindgren <tony@xxxxxxxxxxx>
> Signed-off-by: Drew Fustini <drew@xxxxxxxxxxxxxxx>

Thanks for your patch!

> --- a/Documentation/driver-api/pinctl.rst
> +++ b/Documentation/driver-api/pinctl.rst
> @@ -1428,3 +1428,40 @@ on the pins defined by group B::
> The above has to be done from process context. The reservation of the pins
> will be done when the state is activated, so in effect one specific pin
> can be used by different functions at different times on a running system.
> +
> +
> +Debugfs files
> +=============
> +These files are created in ``/sys/kernel/debug/pinctrl``:
> +
> +- ``pinctrl-devices``: prints each pin controller device along with columns to
> + indicate support for pinmux and pinconf
> +
> +- ``pinctrl-handles``: iterate through the list of pin controller handles and
> + print the corresponding pinmux maps

Do you need the iterate part?

"prints each configured pin controller handle and the corresponding
pinmux maps"?

> +
> +- ``pinctrl-maps``: print all pinctrl maps
> +
> +A sub-directory is created inside of ``/sys/kernel/debug/pinctrl`` for each pin
> +controller device containing these files:

Sort the below alphabetically?

> +
> +- ``pins``: prints a line for each pin registered on the pin controller. The
> + pinctrl driver may add additional information such as register contents.
> +
> +- ``gpio-ranges``: print ranges that map gpio lines to pins on the controller
> +
> +- ``pingroups``: print all pin groups registered on the pin controller
> +
> +- ``pinconf-pins``: print pin config settings for each pin
> +
> +- ``pinconf-groups``: print pin config settings per pin group
> +
> +- ``pinmux-functions``: print each pin function along with the pin groups that
> + map to the pin function
> +
> +- ``pinmux-pins``: iterate through all pins and print mux owner, gpio owner
> + and if the pin is a hog
> +
> +- ``pinmux-select``: write to this file to activate a pin function and group::

a pin function for a group?

> +
> + echo "<function-name group-name>" > pinmux-select

Gr{oetje,eeting}s,

Geert

--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@xxxxxxxxxxxxxx

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
-- Linus Torvalds