On Mon, Jan 15, 2024 at 2:49 AM Kent Gibson <warthog618@xxxxxxxxx> wrote: > > Add documentation for the GPIO character device userspace API. > > Added to the userspace-api book, but also provide a link from the > admin-guide book, as historically the GPIO documentation has been > there. ... > +.. note:: > + Do NOT abuse userspace APIs to control hardware that has proper kernel > + drivers. There may already be a driver for your use case, and an existing > + kernel driver is sure to provide a superior solution to bitbashing > + from userspace. > + > + Read Documentation/driver-api/gpio/drivers-on-gpio.rst to avoid reinventing > + kernel wheels in userspace. > + > + Similarly, for multi-function lines there may be other subsystems, such as > + Documentation/spi/index.rst, Documentation/i2c/index.rst, > + Documentation/driver-api/pwm.rst, Documentation/w1/index.rst etc, that > + provide suitable drivers and APIs for your hardware. Very good note and would be nice to convince users to follow it: https://stackoverflow.com/q/77683532/2511795 (OOH you might be proud it's Rust, OTOH as described above) -- With Best Regards, Andy Shevchenko
