--- zzzz-none-000/linux-3.10.107/Documentation/leds/leds-lp5521.txt	2017-06-27 09:49:32.000000000 +0000
+++ scorpion-7490-727/linux-3.10.107/Documentation/leds/leds-lp5521.txt	2021-02-04 17:41:59.000000000 +0000
@@ -18,7 +18,25 @@
 More details of the instructions can be found from the public data sheet.
 
 LP5521 has the internal program memory for running various LED patterns.
-For the details, please refer to 'firmware' section in leds-lp55xx.txt
+There are two ways to run LED patterns.
+
+1) Legacy interface - enginex_mode and enginex_load
+  Control interface for the engines:
+  x is 1 .. 3
+  enginex_mode : disabled, load, run
+  enginex_load : store program (visible only in engine load mode)
+
+  Example (start to blink the channel 2 led):
+  cd   /sys/class/leds/lp5521:channel2/device
+  echo "load" > engine3_mode
+  echo "037f4d0003ff6000" > engine3_load
+  echo "run" > engine3_mode
+
+  To stop the engine:
+  echo "disabled" > engine3_mode
+
+2) Firmware interface - LP55xx common interface
+  For the details, please refer to 'firmware' section in leds-lp55xx.txt
 
 sysfs contains a selftest entry.
 The test communicates with the chip and checks that