śr., 29 kwi 2020 o 14:38 Linus Walleij <linus.wall...@linaro.org> napisał(a): > > On Wed, Apr 29, 2020 at 2:06 PM Bartosz Golaszewski <b...@bgdev.pl> wrote: > > > I understand the need to set debounce time to make line events > > reliable. As I see it: there'll be a couple steps to add this. > > I think there is a serious user-facing problem here though, because > not all GPIO controllers supports debounce, so the call may return > "nope" (error code). > > I think that is unavoidable with things like pull-up/down or drive > strength, but for debounce I think we could do better.
For bias we don't return an error if the operation is not supported by the driver. > drivers/input/keyboard/gpio_keys.c contains generic > debounce code using kernel timers if the GPIO driver > cannot provide debouncing, and I have thought for a long > time that it would be nice if we could do this generic, so that > we always provide debouncing if requested, even for in-kernel > consumers but most certainly for userspace consumers, > else userspace will just start to reinvent this too. > Thanks for bringing this to my attention. This definitely looks like something we could pull into gpiolib for others to use. Bart
