base-files: maintain LED config state

Record the state of any hardware LED configured through UCI and use that
information to revert the state when applying updated settings while
maintaining default behaviour of system LEDs.

Signed-off-by: Jo-Philipp Wich <jo@mein.io>

1 files changed, 17 insertions, 5 deletions

diff --git a/package/base-files/files/etc/init.d/led b/package/base-files/files/etc/init.d/led
index a6be788a5e..1d10f723d0 100755
--- a/package/base-files/files/etc/init.d/led
+++ b/package/base-files/files/etc/init.d/led
@@ -37,6 +37,12 @@ load_led() {
 	[ -e /sys/class/leds/${sysfs}/brightness ] && {
 		echo "setting up led ${name}"
 
+		printf "%s %s %d\n" \
+			"$sysfs" \
+			"$(sed -ne 's/^.*\[\(.*\)\].*$/\1/p' /sys/class/leds/${sysfs}/trigger)" \
+			"$(cat /sys/class/leds/${sysfs}/brightness)" \
+				>> /var/run/led.state
+
 		[ "$default" = 0 ] &&
 			echo 0 >/sys/class/leds/${sysfs}/brightness
 
@@ -103,11 +109,17 @@ load_led() {
 
 start() {
 	[ -e /sys/class/leds/ ] && {
-		local led
-		for led in /sys/class/leds/*; do
-			[ -e "$led/trigger" ] && echo "none" > "$led/trigger"
-			[ -e "$led/brightness" ] && echo "0" > "$led/brightness"
-		done
+		[ -s /var/run/led.state ] && {
+			local led trigger brightness
+			while read led trigger brightness; do
+				[ -e "/sys/class/leds/$led/trigger" ] && \
+					echo "$trigger" > "/sys/class/leds/$led/trigger"
+
+				[ -e "/sys/class/leds/$led/brightness" ] && \
+					echo "$brightness" > "/sys/class/leds/$led/brightness"
+			done < /var/run/led.state
+			rm /var/run/led.state
+		}
 
 		config_load system
 		config_foreach load_led led