59a18c24ba
I was debugging some gpio issues and I thought that the output of gpio debugfs was telling me the high or low level of the gpios with a '1' or a '0'. We saw a line like this though: gpio93 : in 4 2mA pull down and I started to think that there may be a gas leak in the building because '4' doesn't mean high or low, and other pins said '0' or '1'. It turns out, '4' is the function selection for the pinmux of the gpio and not the value on the pin. Reading code helps decipher what debugfs is actually saying. Add support to read the input or output pin depending on how the pin is configured so we can easily see the high or low value of the pin in debugfs. Now the output looks like gpio93 : in low func4 2mA pull down which clearly shows that the pin is an input, low, with function 4 and a 2mA drive strength plus a pull down. Cc: Bjorn Andersson <bjorn.andersson@linaro.org> Cc: Alexandru M Stan <amstan@chromium.org> Signed-off-by: Stephen Boyd <swboyd@chromium.org> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
See Documentation/00-INDEX for a list of what is contained in each file.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.