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07c61d4da4
We currently only notify user-space about line config changes that are made from user-space. Any kernel config changes are not signalled. Let's improve the situation by emitting the events closer to the source. To that end let's call the relevant notifier chain from the functions setting direction, gpiod_set_config(), gpiod_set_consumer_name() and gpiod_toggle_active_low(). This covers all the options that we can inform the user-space about. We ignore events which don't have corresponding flags exported to user-space on purpose - otherwise the user would see a config-changed event but the associated line-info would remain unchanged. gpiod_direction_output/input() can be called from any context. Fortunately, we now emit line state events using an atomic notifier chain, so it's no longer an issue. Let's also add non-notifying wrappers around the direction setters in order to not emit superfluous reconfigure events when requesting the lines as the initial config should be part of the request notification. Use gpio_do_set_config() instead of gpiod_set_debounce() for configuring debouncing via hardware from the character device code to avoid multiple reconfigure events. Reviewed-by: Kent Gibson <warthog618@gmail.com> Link: https://lore.kernel.org/r/20241018-gpio-notify-in-kernel-events-v5-8-c79135e58a1c@linaro.org Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@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.