Hi Dmitry, On Wednesday 25 May 2016 02:14 PM, Vignesh R wrote: > 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. > It would be great if you could comment on how would you like to see support for absolute rotary-encoder(the one I described above)? As a new driver or handle it by adding new compatible to existing rotary-encoder driver? -- Regards Vignesh -- To unsubscribe from this list: send the line "unsubscribe linux-input" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
