8ff05989b4
Until now after a bcm2835 pin was freed its pinmux was set to GPIO_IN. So in case it was configured as GPIO_OUT before the configured output level also get lost. As long as GPIO sysfs was used this wasn't actually a problem because the pins and their possible output level were kept by sysfs. Since more and more Raspberry Pi users start using libgpiod they are confused about this behavior. So make the pin freeing behavior of GPIO_OUT configurable via module parameter. In case pinctrl-bcm2835.persist_gpio_outputs is set to 1, the output level is kept. This patch based on the downstream work of Phil Elwell. Link: https://github.com/raspberrypi/linux/pull/6117 Signed-off-by: Stefan Wahren <wahrenst@gmx.net> Message-ID: <20240503062745.11298-1-wahrenst@gmx.net> 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 reStructuredText markup notation.
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.