1 files changed, 147 insertions, 0 deletions
diff --git a/Documentation/leds/leds-lp5523.rst b/Documentation/leds/leds-lp5523.rst
new file mode 100644
index 000000000000..7d7362a1dd57
--- /dev/null
+++ b/Documentation/leds/leds-lp5523.rst
@@ -0,0 +1,147 @@
+========================
+Kernel driver for lp5523
+========================
+
+* National Semiconductor LP5523 led driver chip
+* Datasheet: http://www.national.com/pf/LP/LP5523.html
+
+Authors: Mathias Nyman, Yuri Zaporozhets, Samu Onkalo
+Contact: Samu Onkalo (samu.p.onkalo-at-nokia.com)
+
+Description
+-----------
+LP5523 can drive up to 9 channels. Leds can be controlled directly via
+the led class control interface.
+The name of each channel is configurable in the platform data - name and label.
+There are three options to make the channel name.
+
+a) Define the 'name' in the platform data
+
+To make specific channel name, then use 'name' platform data.
+
+- /sys/class/leds/R1               (name: 'R1')
+- /sys/class/leds/B1               (name: 'B1')
+
+b) Use the 'label' with no 'name' field
+
+For one device name with channel number, then use 'label'.
+- /sys/class/leds/RGB:channelN     (label: 'RGB', N: 0 ~ 8)
+
+c) Default
+
+If both fields are NULL, 'lp5523' is used by default.
+- /sys/class/leds/lp5523:channelN  (N: 0 ~ 8)
+
+LP5523 has the internal program memory for running various LED patterns.
+There are two ways to run LED patterns.
+
+1) Legacy interface - enginex_mode, enginex_load and enginex_leds
+
+  Control interface for the engines:
+
+  x is 1 .. 3
+
+  enginex_mode:
+	disabled, load, run
+  enginex_load:
+	microcode load
+  enginex_leds:
+	led mux control
+
+  ::
+
+	cd /sys/class/leds/lp5523:channel2/device
+	echo "load" > engine3_mode
+	echo "9d80400004ff05ff437f0000" > engine3_load
+	echo "111111111" > engine3_leds
+	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
+
+LP5523 has three master faders. If a channel is mapped to one of
+the master faders, its output is dimmed based on the value of the master
+fader.
+
+For example::
+
+  echo "123000123" > master_fader_leds
+
+creates the following channel-fader mappings::
+
+  channel 0,6 to master_fader1
+  channel 1,7 to master_fader2
+  channel 2,8 to master_fader3
+
+Then, to have 25% of the original output on channel 0,6::
+
+  echo 64 > master_fader1
+
+To have 0% of the original output (i.e. no output) channel 1,7::
+
+  echo 0 > master_fader2
+
+To have 100% of the original output (i.e. no dimming) on channel 2,8::
+
+  echo 255 > master_fader3
+
+To clear all master fader controls::
+
+  echo "000000000" > master_fader_leds
+
+Selftest uses always the current from the platform data.
+
+Each channel contains led current settings.
+- /sys/class/leds/lp5523:channel2/led_current - RW
+- /sys/class/leds/lp5523:channel2/max_current - RO
+
+Format: 10x mA i.e 10 means 1.0 mA
+
+Example platform data::
+
+	static struct lp55xx_led_config lp5523_led_config[] = {
+		{
+			.name		= "D1",
+			.chan_nr        = 0,
+			.led_current    = 50,
+			.max_current    = 130,
+		},
+	...
+		{
+			.chan_nr        = 8,
+			.led_current    = 50,
+			.max_current    = 130,
+		}
+	};
+
+	static int lp5523_setup(void)
+	{
+		/* Setup HW resources */
+	}
+
+	static void lp5523_release(void)
+	{
+		/* Release HW resources */
+	}
+
+	static void lp5523_enable(bool state)
+	{
+		/* Control chip enable signal */
+	}
+
+	static struct lp55xx_platform_data lp5523_platform_data = {
+		.led_config     = lp5523_led_config,
+		.num_channels   = ARRAY_SIZE(lp5523_led_config),
+		.clock_mode     = LP55XX_CLOCK_EXT,
+		.setup_resources   = lp5523_setup,
+		.release_resources = lp5523_release,
+		.enable            = lp5523_enable,
+	};
+
+Note
+  chan_nr can have values between 0 and 8.