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docs/pinctrl: document debugfs files 

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>
Link: https://lore.kernel.org/r/20210302053059.1049035-5-drew@beagleboard.org
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
This commit is contained in:
Drew Fustini 2021-03-01 21:30:59 -08:00 committed by Linus Walleij
parent 5513b411ea
commit 1ae6478b0e
1 changed files with 37 additions and 0 deletions
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37
Documentation/driver-api/pin-control.rst
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@ -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``: 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:
- ``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 for a group::
echo "<group-name function-name>" > pinmux-select