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From:   Geert Uytterhoeven <geert@linux-m68k.org>
Date:   Fri, 19 Feb 2021 10:20:18 +0100
Message-ID: <CAMuHMdXrD4-bcTR0ioY20qZOMaDparyFDqCzQr71te1_Uqw4eQ@mail.gmail.com>
Subject: Re: [PATCH v7 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>,
        Andy Shevchenko <andy.shevchenko@gmail.com>,
        Alexandre Belloni <alexandre.belloni@bootlin.com>,
        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>,
        "open list:DOCUMENTATION" <linux-doc@vger.kernel.org>
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Hi Drew,

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

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@linux-m68k.org

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