DS4 on Arch Linux

[drkshadow]

Do you have CONFIG_INPUT_JOYDEV=m in your kernel config?

I believe I didn't need any other module for this, just plug it in and it magically works.

Ensure you can read device /dev/input/js*, either being in the group or maybe your systemd login session will set this up for you. In my case I didn't want to log out/in after adding myself to groups so I used newgrp and launched ppsspp from the new shell.

Anyway, first step, in dmesg you should see something like:
usb 1-5.1.2: Manufacturer: Sony Interactive Entertainment
input: Sony Interactive Entertainment Wireless Controller as

Second step, when you start ppsspp you should see something like:
030000004c050000cc09000011010000,Sony DualShock 4 V2,a:b1,b:b2,y:b3,x:b0,start:b9,guide:b12,back:b8,leftstick:b10,rightstick:b11,l​eftshoulder:b4,rightshoulder:b5,dpup:h0.1,dpleft:h0.8,dpdown:h0.4,dpright:h0.2,l​eftx:a0,lefty:a1,rightx:a2,righty:a5,lefttrigger:a3,righttrigger:a4,platform:Lin​ux,