Re: Double tap to wake optionality

Hi David,

On Mon, Sep 07, 2026 at 12:02:12AM +0200, David Heidelberg wrote:

Hello!

Most of touchscreens has ability to jump into low power mode and get woken
up by gesture (such as double tap).

I wonder about suggestion what property should drivers use to implement this
policy where driver doesn't have to jump into low-power mode but completely
power-off (and save battery). My thinking was something such as

/sys/class/input/inputX/gesture_to_wake
(while gesture sounds a bit weird, it seems that TS are capable to recognize
different patterns, not only double-tap).


                    userspace
                       │
                       │ gesture_to_wake = 1
                       ▼
              touchscreen driver
                       │
          ┌────────────┴────────────┐
          │                         │
       gesture ON               gesture OFF
          │                         │
          ▼                         ▼
   low-power TS mode          complete power-off
          │
          ▼
     IRQ configured
     as wake source

How is it different from the power/wakeup device attribute? Device's
suspend  routines check device_may_wakeup() and then either completely
power off controllers or configure them for wake up.

How exactly wakeup is handled - any touch, or double-tap, or something
else - is up to the controller and its firmware.

Thanks.

-- 
Dmitry