linux/Documentation/leds/leds-lp5562.txt
<<
>>
Prefs
   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.
 121
lxr.linux.no kindly hosted by Redpill Linpro AS, provider of Linux consulting and operations services since 1995.