recipes-bsp: Add support for gpio-shutdown

- Feature is enabled with ENABLE_GPIO_SHUTDOWN variable
- Include the gpio-shutdown overlay
- If using SysV init include the additional keymap and inittab entries
  to bind the KEY_POWER event
- Systemd init does not require any additional bindings

Signed-off-by: Otto Esko <otto.esko@gmail.com>

recipes-bsp/bootfiles/rpi-config_git.bb

@@ -34,6 +34,8 @@ ENABLE_UART ??= ""
 
 WM8960="${@bb.utils.contains("MACHINE_FEATURES", "wm8960", "1", "0", d)}"
 
+GPIO_SHUTDOWN_PIN ??= ""
+
 inherit deploy nopackages
 
 do_deploy() {
@@ -253,6 +255,22 @@ do_deploy() {
         echo "dtoverlay=mcp2515-can0,oscillator=${CAN_OSCILLATOR},interrupt=25" >>$CONFIG
     fi
 
+
+    if [ "${ENABLE_GPIO_SHUTDOWN}" = "1" ]; then
+        if ([ "${ENABLE_I2C}" = "1" ] || [ "${PITFT}" = "1" ]) && [ -z "${GPIO_SHUTDOWN_PIN}" ]; then
+            # By default GPIO shutdown uses the same pin as the (master) I2C SCL.
+            # If I2C is configured and an alternative pin is not configured for
+            # gpio-shutdown, there is a configuration conflict.
+            bbfatal "I2C and gpio-shutdown are both enabled and using the same pins!"
+        fi
+        echo "# Enable gpio-shutdown" >> $CONFIG
+        if [ -z "${GPIO_SHUTDOWN_PIN}" ]; then
+            echo "dtoverlay=gpio-shutdown" >> $CONFIG
+        else
+            echo "dtoverlay=gpio-shutdown,gpio_pin=${GPIO_SHUTDOWN_PIN}" >> $CONFIG
+        fi
+    fi
+
     # Append extra config if the user has provided any
     printf "${RPI_EXTRA_CONFIG}\n" >> $CONFIG
 

recipes-bsp/gpio-shutdown/files/bind_gpio_shutdown.tab

@@ -0,0 +1,2 @@
+# Action on special keypress (Key Power)
+kb::kbrequest:/sbin/shutdown -t1 -a -h -P now

recipes-bsp/gpio-shutdown/files/gpio-shutdown-keymap.sh

@@ -0,0 +1,13 @@
+#!/bin/sh
+##
+# Bind the gpio-shutdown keycode as Keyboard signal and load it to the
+# keymap during startup.
+##
+case "$1" in
+    start)
+    # Inject the gpio keycode to keymap
+    echo "keycode 116 = KeyboardSignal" | loadkeys
+    ;;
+    *)
+    ;;
+esac

recipes-bsp/gpio-shutdown/gpio-shutdown.bb

@@ -0,0 +1,31 @@
+SUMMARY = "GPIO shutdown bindings for SysV init"
+LICENSE = "GPLv2"
+LIC_FILES_CHKSUM = "file://${COMMON_LICENSE_DIR}/GPL-2.0-only;md5=801f80980d171dd6425610833a22dbe6"
+
+SRC_URI = "file://bind_gpio_shutdown.tab \
+    file://gpio-shutdown-keymap.sh \
+"
+
+inherit  update-rc.d
+
+INITSCRIPT_NAME = "gpio-shutdown-keymap.sh"
+# Run only once during startup
+INITSCRIPT_PARAMS = "start 99 S ."
+
+do_install() {
+    # The files are only needed if using SysV init.
+    if ${@bb.utils.contains('DISTRO_FEATURES', 'sysvinit', 'true', 'false', d)}; then
+        install -d ${D}${sysconfdir} \
+            ${D}${sysconfdir}/inittab.d \
+            ${D}${sysconfdir}/init.d
+
+        install -m 0755 ${WORKDIR}/gpio-shutdown-keymap.sh ${D}${sysconfdir}/init.d/
+        install -m 0755 ${WORKDIR}/bind_gpio_shutdown.tab ${D}${sysconfdir}/inittab.d/
+    elif ${@bb.utils.contains('DISTRO_FEATURES', 'systemd', 'true', 'false', d)}; then
+        # Systemd init does not require any configuration.
+        # Note: cannot have an empty branch, hence the redundant dir install.
+        install -d ${D}${sysconfdir}
+    else
+        bbwarn "Not using sysvinit or systemd. The gpio-shutdown may require additional configuration."
+    fi
+}