Hi Dmitry, On 05/23/2016 02:48 PM, R, Vignesh wrote: > > > On 5/20/2016 10:04 PM, Dmitry Torokhov wrote: >> On Thu, May 19, 2016 at 02:34:00PM +0530, Vignesh R wrote: >>> There are rotary-encoders where GPIO lines reflect the actual position >>> of the rotary encoder dial. For example, if dial points to 9, then four >>> GPIO lines connected to the rotary encoder will read HLLH(1001b = 9). >>> Add support for such rotary-encoder. >>> The driver relies on rotary-encoder,absolute-encoder DT property to >>> detect such encoders. >>> Since, GPIO IRQs are not necessary to work with >>> such encoders, optional polling mode support is added using >>> input_poll_dev skeleton. This is can be used by enabling >>> CONFIG_INPUT_GPIO_ROTARY_ENCODER_POLL_MODE_SUPPORT. >> >> Does this really belong to a rotary encoder and not a new driver that >> simply translates gpio-encoded value into ABS* event? >> > > Currently rotary encoder driver only supports incremental/step counting > rotary devices. However, the device that is there on am335x-ice is an > absolute encoder but, IMO, nevertheless a kind of rotary encoder. The > only difference is that there is no need to count steps and the absolute > position value is always available as binary encoded state of connected > GPIOs. > The hardware on am335x-ice is a mechanical rotary encoder switch > connected over 4 GPIOs. It is same as binary encoder described at [1] > (except there are 4 GPIO lines), so this lead me to add support in > rotary-encoder. > > [1]https://en.wikipedia.org/wiki/Rotary_encoder#Standard_binary_encoding > Could you please comment on how would you like to support above described encoder: As a new driver or with existing driver with new compatible/mode setting via DT or as suggest by Uwe in another reply? IMHO, supporting using existing driver with new mode/compatible string looks a better option as the hardware is a kind of rotary-encoder. -- Regards Vignesh -- To unsubscribe from this list: send the line "unsubscribe linux-doc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
