The atkbd device on the Lenovo Yoga 300-11IBR 2-in-1 sends unknown
keycodes when the touchpad is toggled on/off:
[ 1918.995562] atkbd serio0: Unknown key pressed (translated set 2, code 0x63 on isa0060/serio0).
[ 1918.995610] atkbd serio0: Use 'setkeycodes 63 <keycode>' to make it known.
[ 1919.032121] atkbd serio0: Unknown key released (translated set 2, code 0x63 on isa0060/serio0).
[ 1919.032135] atkbd serio0: Use 'setkeycodes 63 <keycode>' to make it known.
[ 1926.098414] atkbd serio0: Unknown key pressed (translated set 2, code 0x62 on isa0060/serio0).
[ 1926.098461] atkbd serio0: Use 'setkeycodes 62 <keycode>' to make it known.
[ 1926.146537] atkbd serio0: Unknown key released (translated set 2, code 0x62 on isa0060/serio0).
[ 1926.146583] atkbd serio0: Use 'setkeycodes 62 <keycode>' to make it known.
The "Ideapad extra buttons" driver alreadys sends f22 / f23 key-events
when the touchpad is toggles off, so map the keycodes for the duplicate
atkbd events to unknown to silence these kernel warnings.
KEYBOARD_KEY_ae=!volumedown
KEYBOARD_KEY_b0=!volumeup
+evdev:atkbd:dmi:*:svnLENOVO:*:pvrLenovoYoga300-11IBR:*
+ KEYBOARD_KEY_62=unknown # Touchpad on, also emitted by "Ideapad extra buttons", ignore
+ KEYBOARD_KEY_63=unknown # Touchpad off, also emitted by "Ideapad extra buttons", ignore
+
# Fix for volume keys on Lenovo Yoga S940
# For 10th gen it should be pn81Q8 instead of pn81Q7 but
# I don't have a device to test