1Kernel driver for LP5562
  2========================
  3
  4* TI LP5562 LED Driver
  5
  6Author: Milo(Woogyom) Kim <milo.kim@ti.com>
  7
  8Description
  9
 10  LP5562 can drive up to 4 channels. R/G/B and White.
 11  LEDs can be controlled directly via the led class control interface.
 12
 13  All four channels can be also controlled using the engine micro programs.
 14  LP5562 has the internal program memory for running various LED patterns.
 15  For the details, please refer to 'firmware' section in leds-lp55xx.txt
 16
 17Device attribute: engine_mux
 18
 19  3 Engines are allocated in LP5562, but the number of channel is 4.
 20  Therefore each channel should be mapped to the engine number.
 21  Value : RGB or W
 22
 23  This attribute is used for programming LED data with the firmware interface.
 24  Unlike the LP5521/LP5523/55231, LP5562 has unique feature for the engine mux,
 25  so additional sysfs is required.
 26
 27  LED Map
 28  Red   ... Engine 1 (fixed)
 29  Green ... Engine 2 (fixed)
 30  Blue  ... Engine 3 (fixed)
 31  White ... Engine 1 or 2 or 3 (selective)
 32
 33How to load the program data using engine_mux
 34
 35  Before loading the LP5562 program data, engine_mux should be written between
 36  the engine selection and loading the firmware.
 37  Engine mux has two different mode, RGB and W.
 38  RGB is used for loading RGB program data, W is used for W program data.
 39
 40  For example, run blinking green channel pattern,
 41  echo 2 > /sys/bus/i2c/devices/xxxx/select_engine     # 2 is for green channel
 42  echo "RGB" > /sys/bus/i2c/devices/xxxx/engine_mux    # engine mux for RGB
 43  echo 1 > /sys/class/firmware/lp5562/loading
 44  echo "4000600040FF6000" > /sys/class/firmware/lp5562/data
 45  echo 0 > /sys/class/firmware/lp5562/loading
 46  echo 1 > /sys/bus/i2c/devices/xxxx/run_engine
 47
 48  To run a blinking white pattern,
 49  echo 1 or 2 or 3 > /sys/bus/i2c/devices/xxxx/select_engine
 50  echo "W" > /sys/bus/i2c/devices/xxxx/engine_mux
 51  echo 1 > /sys/class/firmware/lp5562/loading
 52  echo "4000600040FF6000" > /sys/class/firmware/lp5562/data
 53  echo 0 > /sys/class/firmware/lp5562/loading
 54  echo 1 > /sys/bus/i2c/devices/xxxx/run_engine
 55
 56How to load the predefined patterns
 57
 58  Please refer to 'leds-lp55xx.txt"
 59
 60Setting Current of Each Channel
 61
 62  Like LP5521 and LP5523/55231, LP5562 provides LED current settings.
 63  The 'led_current' and 'max_current' are used.
 64
 65(Example of Platform data)
 66
 67To configure the platform specific data, lp55xx_platform_data structure is used.
 68
 69static struct lp55xx_led_config lp5562_led_config[] = {
 70	{
 71		.name 		= "R",
 72		.chan_nr	= 0,
 73		.led_current	= 20,
 74		.max_current	= 40,
 75	},
 76	{
 77		.name 		= "G",
 78		.chan_nr	= 1,
 79		.led_current	= 20,
 80		.max_current	= 40,
 81	},
 82	{
 83		.name 		= "B",
 84		.chan_nr	= 2,
 85		.led_current	= 20,
 86		.max_current	= 40,
 87	},
 88	{
 89		.name 		= "W",
 90		.chan_nr	= 3,
 91		.led_current	= 20,
 92		.max_current	= 40,
 93	},
 94};
 95
 96static int lp5562_setup(void)
 97{
 98	/* setup HW resources */
 99}
100
101static void lp5562_release(void)
102{
103	/* Release HW resources */
104}
105
106static void lp5562_enable(bool state)
107{
108	/* Control of chip enable signal */
109}
110
111static struct lp55xx_platform_data lp5562_platform_data = {
112        .led_config     = lp5562_led_config,
113        .num_channels   = ARRAY_SIZE(lp5562_led_config),
114        .setup_resources   = lp5562_setup,
115        .release_resources = lp5562_release,
116        .enable            = lp5562_enable,
117};
118
119If the current is set to 0 in the platform data, that channel is
120disabled and it is not visible in the sysfs.