On Wed, Apr 15, 2020 at 08:59:09AM -0500, Robert Nelson wrote: > On Wed, Apr 15, 2020 at 8:47 AM Grygorii Strashko > <grygorii.strashko@xxxxxx> wrote: > > On 15/04/2020 16:20, Robert Nelson wrote: > > > Hi Grygorii, > > > > > > On Wed, Apr 15, 2020 at 8:15 AM Grygorii Strashko > > > <grygorii.strashko@xxxxxx> wrote: > > >> > > >> For this platforms the dynamic GPIO muxing/configuration is not supported, and GPIO block by itself > > >> does not provide such functions as pullup/pulldown. > > > > > > Correct, that's the state today, while Drew is investing time into > > > trying to figure out how to properly extend this feature into our > > > platform. > > > > Sry, but it's not clear what's the final target (at least from public part of this thread). > > We are mainly targeting am335x based devices. Today (well last few > years) we've utilized a "hack-ish" kernel module (bone-pinmux-helper) > to allow users to overide/change the pinmux-ing directly from > user-space... (This evil module allows us to specify a list of > options for each pin, thus users can easily configure specifies of the > pin, aka gpio_pd/gpio_pu/etc from user-space...). Since that time, > mainline has now grown a generic gpio pull-up/pull-down functionality, > with the ability to re-control these values directly from a generic > gpio library (libgpiod). Hello Grygorii - As Robert described, I wanted to make us of the new support for bias flags in the gpiolib uapi which allows userspace libraries like libgpiod set pull-up or pull-down on lines [0]. Is there no way for gpio-omap to call into the pinctrl-single backend to set the bias bits (PULLUDEN and PULLTYPESEL) in pad control registers? Thank you, Drew [0] https://lore.kernel.org/linux-gpio/20191105020429.18942-1-warthog618@xxxxxxxxx/
