leds-lp55xx: support firmware interface
This patch provides additional device attributes which enable
loading the firmware. ('select_engine' and 'run_engine')
To run a LED pattern, two parts of driver should be enabled.
Common features : lp55xx-common
===============================
Firmware interface for loading LED patterns
Chip specific features : leds-lp5521, leds-lp5523
=================================================
Register addresses for loading firmware data
Register addresses for running selected engine
Pattern programming sequence
============================
LP55xx chips have three program engines.
To load and run a LED pattern, the programming sequence is as follows.
(1) Select an engine number (1/2/3)
(2) Set engine mode to load
(3) Write pattern data into selected area
(4) Set engine mode to run
This sequence is almost same as the firmware interface.
(1) Select an engine number : 'select_engine' dev attribute
(2) Mode change to load : 'loading' of firmware class
(3) Write pattern data into selected area : 'data' of firmware class
(4) Mode change to run : 'run_engine' dev attribute
(1) and (4) are device specific features which provide callback functions
(2) and (3) are common features.
For example,
echo 1 or 2 or 3 > /sys/bus/i2c/devices/xxxx/select_engine
echo 1 > /sys/class/firmware/lp5521/loading
echo "4000600040FF6000" > /sys/class/firmware/lp5521/data
echo 0 > /sys/class/firmware/lp5521/loading
echo 1 > /sys/bus/i2c/devices/xxxx/run_engine
As soon as 'loading' is set to 0, registered callback is called.
Inside the callback, the selected engine is loaded and memory is updated.
To run programmed pattern, 'run_engine' attribute should be enabled.
Device specific data structure
==============================
o Firmware callback
load selected engine and update program memory
o Run engine
change the engine mode
o 'engine_idx' and firmware data, 'fw'
Those are used in the driver internally with callback functions
Signed-off-by: Milo(Woogyom) Kim <milo.kim@ti.com>
Signed-off-by: Bryan Wu <cooloney@gmail.com>
diff --git a/drivers/leds/Kconfig b/drivers/leds/Kconfig
index 3d7822b..fc680a9 100644
--- a/drivers/leds/Kconfig
+++ b/drivers/leds/Kconfig
@@ -196,6 +196,7 @@
config LEDS_LP55XX_COMMON
tristate "Common Driver for TI/National LP5521 and LP5523/55231"
depends on LEDS_LP5521 || LEDS_LP5523
+ select FW_LOADER
help
This option supports common operations for LP5521 and LP5523/55231
devices.