From: Christian Lamparter <chunkeey@gmail.com>
Date: Wed, 20 Oct 2021 22:35:29 +0000 (+0200)
Subject: base-files: leds: do reverse lookup in get_dt_led()
X-Git-Url: http://git.lede-project.org./?a=commitdiff_plain;h=0a7a4a0f77a26009eb6429674b83e544761d74c9;p=openwrt%2Fstaging%2Fchunkeey.git

base-files: leds: do reverse lookup in get_dt_led()

In order to match the "label"-less DT properties we have to get
creative. In theory the dt-node should have everything (i.e.:
color, function and function-enumerator) to make the device-name
in /sys/class/leds. But thanks to color being a binary value
and not a "string", we would have to maintain a lookup table that
keeps in sync with the dt-binding.

It's much easier to use the "uevent" property of every led-class
device and do reverse lookup with it by comparing the OF_FULLNAME
with the alias pathname.

(This works with gpio-leds ... let's see where it breaks)

Signed-off-by: Christian Lamparter <chunkeey@gmail.com>
---

diff --git a/package/base-files/files/lib/functions/leds.sh b/package/base-files/files/lib/functions/leds.sh
index a7532faa2f..936b165e1c 100644
--- a/package/base-files/files/lib/functions/leds.sh
+++ b/package/base-files/files/lib/functions/leds.sh
@@ -13,13 +13,26 @@ get_dt_led_path() {
 
 get_dt_led() {
 	local label
+	local of_path
 	local ledpath=$(get_dt_led_path $1)
 
-	[ -n "$ledpath" ] && \
+	[ -n "$ledpath" ] && {
 		label=$(cat "$ledpath/label" 2>/dev/null) || \
 		label=$(cat "$ledpath/chan-name" 2>/dev/null) || \
 		label=$(basename "$ledpath")
 
+		[ -d "/sys/class/leds/$label" ] || {
+			label=""
+			for node in /sys/class/leds/*; do
+				of_path=$(grep OF_FULLNAME "$node/uevent" | cut -f2 -d'=')
+				[ "/proc/device-tree$of_path" = "$ledpath" ] && {
+					label=$(basename "$node")
+					break
+				}
+			done
+		}
+	}
+
 	echo "$label"
 }