Can't get power button to work

[AidenH]

hi, yeah, the power|suspend button and the reset button attach directly to the PMIC (power management integrated circuit).  See the schematic diagram here (although its a bit out-of-date).

... I have not tried to see the event from evtest !?!  ... also I have tested in both debian and ubuntu, holding the power on button for two seconds will cause the PMIC to signal the GPU ( OS ) to pull up the power off dialogue.

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edit:  ok... the trick to see the event ( power on ) in evtest, is to select the axp81x option (1).

... the event comes up nicely, code 116 ( key_power ).

( this I tested with evtest on ubuntu mate )

So, if you want to build your own monitor, you need to first tell the OS not to respond to 116, key_power,  then map that key for your own purposes.

As Mark indicated, it does work... the trick is to to select the right device. 

You can see in the code box below the output from running evtest on a ubuntu box, and selecting axp81x-supplyer, which was device event number 1 in that case. Credit goes to xalius for posting it in that thread I linked earlier about the power button. The button was pressed twice, so you can see a 1 when it was pressed, and a 0 when it is released. 

Code:

ubuntu@pine64:~$ sudo evtest

No device specified, trying to scan all of /dev/input/event*
Available devices:
/dev/input/event0:      sunxi-keyboard
/dev/input/event1:      axp81x-supplyer
/dev/input/event2:      sunxi-ths
/dev/input/event3:      audiocodec sunxi Audio Jack
/dev/input/event4:      sunxi_ir_recv
/dev/input/event5:      MCE IR Keyboard/Mouse (sunxi-rc-recv)

Select the device event number [0-5]: 1

Input driver version is 1.0.1
Input device ID: bus 0x19 vendor 0x1 product 0x1 version 0x100
Input device name: "axp81x-supplyer"
Supported events:
 Event type 0 (EV_SYN)
 Event type 1 (EV_KEY)
   Event code 116 (KEY_POWER)
 Event type 2 (EV_REL)
Properties:
Testing ... (interrupt to exit)
Event: time 1466799328.888825, type 1 (EV_KEY), code 116 (KEY_POWER), value 1
Event: time 1466799328.888825, -------------- SYN_REPORT ------------
Event: time 1466799328.999256, type 1 (EV_KEY), code 116 (KEY_POWER), value 0
Event: time 1466799328.999256, -------------- SYN_REPORT ------------
Event: time 1466799329.630542, type 1 (EV_KEY), code 116 (KEY_POWER), value 1
Event: time 1466799329.630542, -------------- SYN_REPORT ------------
Event: time 1466799329.798206, type 1 (EV_KEY), code 116 (KEY_POWER), value 0
Event: time 1466799329.798206, -------------- SYN_REPORT ------------

I am definitely using the apx81x-supplyer device to test and still not getting any output.  I followed the example from the xalius link that pfeerick posted. Not sure what's wrong.