Name: gpio-shutdown Info: Initiates a shutdown when GPIO pin changes. The given GPIO pin is configured as an input key that generates KEY_POWER events.
This event is handled by systemd-logind by initiating a shutdown. Systemd versions older than 225 need an udev rule enable listening to the input device:
Alternatively this event can be handled also on systems without systemd, just by traditional SysV init daemon. KEY_POWER event (keycode 116) needs to be mapped to KeyboardSignal on console and then kb::kbrequest inittab action which is triggered by KeyboardSignal from console can be configured to issue system shutdown. Steps for this configuration are:
Add following lines to the /etc/console-setup/remap.inc file:
# Key Power as special keypress keycode 116 = KeyboardSignal
Then add following lines to /etc/inittab file:
# Action on special keypress (Key Power) kb::kbrequest:/sbin/shutdown -t1 -a -h -P now
And finally reload configuration by calling following commands:
# dpkg-reconfigure console-setup # service console-setup reload # init q
This overlay only handles shutdown. After shutdown, the system can be powered up again by driving GPIO3 low. The default configuration uses GPIO3 with a pullup, so if you connect a button between GPIO3 and GND (pin 5 and 6 on the 40-pin header), you get a shutdown and power-up button. Please note that Raspberry Pi 1 Model B rev 1 uses GPIO1 instead of GPIO3. Load: dtoverlay=gpio-shutdown,<param>=<val> Params: gpio_pin GPIO pin to trigger on (default 3) For Raspberry Pi 1 Model B rev 1 set this explicitly to value 1, e.g.:
dtoverlay=gpio-shutdown,gpio_pin=1
active_low When this is 1 (active low), a falling edge generates a key down event and a rising edge generates a key up event. When this is 0 (active high), this is reversed. The default is 1 (active low).
gpio_pull Desired pull-up/down state (off, down, up) Default is "up".
Note that the default pin (GPIO3) has an external pullup. Same applies for GPIO1 on Raspberry Pi 1 Model B rev 1.
debounce Specify the debounce interval in milliseconds (default 100)
Controls how logind shall handle the system power, reboot and sleep keys and the lid switch to trigger actions such as system power-off, reboot or suspend. Can be one of "ignore", "poweroff", "reboot", "halt", "kexec", "suspend", "hibernate", "hybrid-sleep", "suspend-then-hibernate", "lock", and "factory-reset". If "ignore", systemd-logind will never handle these keys. If "lock", all running sessions will be screen-locked; otherwise, the specified action will be taken in the respective event. Only input devices with the "power-switch" udev tag will be watched for key/lid switch events.
