Input: tm2-touchkey - add touchkey driver support for TM2
This patch adds support for the TM2 touch key and led functionality.
The driver interfaces with userspace through an input device and reports
KEY_PHONE and KEY_BACK event types. LED brightness can be controlled by
"/sys/class/leds/tm2-touchkey/brightness".
Signed-off-by: Beomho Seo <beomho.seo@samsung.com> Signed-off-by: Jaechul Lee <jcsing.lee@samsung.com> Reviewed-by: Javier Martinez Canillas <javier@osg.samsung.com> Reviewed-by: Andi Shyti <andi.shyti@samsung.com> Reviewed-by: Chanwoo Choi <cw00.choi@samsung.com> Tested-by: Chanwoo Choi <cw00.choi@samsung.com> Acked-by: Krzysztof Kozlowski <krzk@kernel.org> Acked-by: Rob Herring <robh@kernel.org> Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>