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References: <20210216224455.1504008-1-drew@beagleboard.org> <20210216224455.1504008-4-drew@beagleboard.org>
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From:   Andy Shevchenko <andy.shevchenko@gmail.com>
Date:   Wed, 17 Feb 2021 12:16:54 +0200
Message-ID: <CAHp75Vdp58uCVS2Gw3pQ7wVatHHcFrHB53-ynybxcAcJ2bUKpg@mail.gmail.com>
Subject: Re: [PATCH v6 3/3] docs/pinctrl: document debugfs files
To:     Drew Fustini <drew@beagleboard.org>
Cc:     Linus Walleij <linus.walleij@linaro.org>,
        "open list:GPIO SUBSYSTEM" <linux-gpio@vger.kernel.org>,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
        Tony Lindgren <tony@atomide.com>,
        Alexandre Belloni <alexandre.belloni@bootlin.com>,
        Geert Uytterhoeven <geert@linux-m68k.org>,
        Pantelis Antoniou <pantelis.antoniou@konsulko.com>,
        Jason Kridner <jkridner@beagleboard.org>,
        Robert Nelson <robertcnelson@beagleboard.org>,
        Joe Perches <joe@perches.com>,
        Dan Carpenter <dan.carpenter@oracle.com>,
        Jonathan Corbet <corbet@lwn.net>,
        Linux Documentation List <linux-doc@vger.kernel.org>
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On Wed, Feb 17, 2021 at 12:45 AM Drew Fustini <drew@beagleboard.org> wrote:
>
> Document debugfs directories and files created for pinctrl subsystem.

Thanks for doing this!
I won't bikeshed now because it's about debugfs anyway, so
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>

> Suggested-by: Andy Shevchenko <andy.shevchenko@gmail.com>
> Signed-off-by: Drew Fustini <drew@beagleboard.org>
> ---
>  Documentation/driver-api/pinctl.rst | 37 +++++++++++++++++++++++++++++
>  1 file changed, 37 insertions(+)
>
> diff --git a/Documentation/driver-api/pinctl.rst b/Documentation/driver-api/pinctl.rst
> index 3d2deaf48841..37bc3bd64cd8 100644
> --- 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
> +
> +- ``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:
> +
> +- ``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::
> +
> +        echo "<function-name group-name>" > pinmux-select
> --
> 2.25.1
>


--
With Best Regards,
Andy Shevchenko