[openwrt/openwrt] base-files: add more name source to get_dt_led helper function

[LEDE Commits]

mkresin pushed a commit to openwrt/openwrt.git, branch master:
https://git.lede-project.org/4f4fc993db4cd074fb2b51586dadd10e882604ec

commit 4f4fc993db4cd074fb2b51586dadd10e882604ec
Author: Mathias Kresin <dev at kresin.me>
AuthorDate: Fri Jan 26 23:36:50 2018 +0100

    base-files: add more name source to get_dt_led helper function
    
    Not all LED driver are using the label devicetree property for the led
    name. Add support for the TI/National Semiconductor LP55xx Led Drivers,
    which are using the chan-name property for the led name, as fallback.
    
    Signed-off-by: Mathias Kresin <dev at kresin.me>
---
 package/base-files/files/lib/functions/leds.sh | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/package/base-files/files/lib/functions/leds.sh b/package/base-files/files/lib/functions/leds.sh
index 83e775f..e4423b4 100644
--- a/package/base-files/files/lib/functions/leds.sh
+++ b/package/base-files/files/lib/functions/leds.sh
@@ -8,7 +8,10 @@ get_dt_led() {
 	local nodepath="$basepath/aliases/led-$1"
 
 	[ -f "$nodepath" ] && ledpath=$(cat "$nodepath")
-	[ -n "$ledpath" ] && label=$(cat "$basepath$ledpath/label")
+	[ -n "$ledpath" ] && \
+		label=$(cat "$basepath$ledpath/label" 2>/dev/null) || \
+		label=$(cat "$basepath$ledpath/chan-name" 2>/dev/null) || \
+		echo "led label not found" 1>&2
 
 	echo "$label"
 }