Hi, On Wednesday 24 August 2016 02:05 PM, Daniel Mack wrote: > Hi, > > On 08/24/2016 09:58 AM, Vignesh R wrote: >> This series adds support for rotary-switch on AM335x-ICE that is >> connected to TI PCA9536 I2C GPIO expander. >> First patch adds new generic driver to read status of group of GPIO >> lines and report the value as an input event. The second patch adds DT >> entries for the same. >> >> v2: https://lkml.org/lkml/2016/8/23/111 >> v1: https://lkml.org/lkml/2016/8/12/7 > > Is there a reason why the rotary-encoder driver cannot handle this? > Commit 7dde4e74744 ("Input: rotary-encoder - support more than 2 gpios > as input") added support for that mode AFAIU. > Rotary encoder driver handles incremental encoders only and does not support absolute encoders. The rotary switch on am335x-ice is different from the incremental encoders in the sense that GPIO line status directly reflect the position(number) pointed by the dial of the encoder. So, there is no need to count steps or know the direction of rotation as it does not matter. I did try to enhance rotary-encoder driver to support absolute encoder[1] but the comment there was to write new driver that simply translates gpio-encoded value into ABS* event. Indeed, the new driver looks more simple and can handle more such hardwares. [1] https://lkml.org/lkml/2016/5/19/98 -- Regards Vignesh -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
