0001 ========================
0002 Kernel driver for lp5562
0003 ========================
0004
0005 * TI LP5562 LED Driver
0006
0007 Author: Milo(Woogyom) Kim <milo.kim@ti.com>
0008
0009 Description
0010 ===========
0011
0012 LP5562 can drive up to 4 channels. R/G/B and White.
0013 LEDs can be controlled directly via the led class control interface.
0014
0015 All four channels can be also controlled using the engine micro programs.
0016 LP5562 has the internal program memory for running various LED patterns.
0017 For the details, please refer to 'firmware' section in leds-lp55xx.txt
0018
0019 Device attribute
0020 ================
0021
0022 engine_mux
0023 3 Engines are allocated in LP5562, but the number of channel is 4.
0024 Therefore each channel should be mapped to the engine number.
0025
0026 Value: RGB or W
0027
0028 This attribute is used for programming LED data with the firmware interface.
0029 Unlike the LP5521/LP5523/55231, LP5562 has unique feature for the engine mux,
0030 so additional sysfs is required
0031
0032 LED Map
0033
0034 ===== === ===============================
0035 Red ... Engine 1 (fixed)
0036 Green ... Engine 2 (fixed)
0037 Blue ... Engine 3 (fixed)
0038 White ... Engine 1 or 2 or 3 (selective)
0039 ===== === ===============================
0040
0041 How to load the program data using engine_mux
0042 =============================================
0043
0044 Before loading the LP5562 program data, engine_mux should be written between
0045 the engine selection and loading the firmware.
0046 Engine mux has two different mode, RGB and W.
0047 RGB is used for loading RGB program data, W is used for W program data.
0048
0049 For example, run blinking green channel pattern::
0050
0051 echo 2 > /sys/bus/i2c/devices/xxxx/select_engine # 2 is for green channel
0052 echo "RGB" > /sys/bus/i2c/devices/xxxx/engine_mux # engine mux for RGB
0053 echo 1 > /sys/class/firmware/lp5562/loading
0054 echo "4000600040FF6000" > /sys/class/firmware/lp5562/data
0055 echo 0 > /sys/class/firmware/lp5562/loading
0056 echo 1 > /sys/bus/i2c/devices/xxxx/run_engine
0057
0058 To run a blinking white pattern::
0059
0060 echo 1 or 2 or 3 > /sys/bus/i2c/devices/xxxx/select_engine
0061 echo "W" > /sys/bus/i2c/devices/xxxx/engine_mux
0062 echo 1 > /sys/class/firmware/lp5562/loading
0063 echo "4000600040FF6000" > /sys/class/firmware/lp5562/data
0064 echo 0 > /sys/class/firmware/lp5562/loading
0065 echo 1 > /sys/bus/i2c/devices/xxxx/run_engine
0066
0067 How to load the predefined patterns
0068 ===================================
0069
0070 Please refer to 'leds-lp55xx.txt"
0071
0072 Setting Current of Each Channel
0073 ===============================
0074
0075 Like LP5521 and LP5523/55231, LP5562 provides LED current settings.
0076 The 'led_current' and 'max_current' are used.
0077
0078 Example of Platform data
0079 ========================
0080
0081 ::
0082
0083 static struct lp55xx_led_config lp5562_led_config[] = {
0084 {
0085 .name = "R",
0086 .chan_nr = 0,
0087 .led_current = 20,
0088 .max_current = 40,
0089 },
0090 {
0091 .name = "G",
0092 .chan_nr = 1,
0093 .led_current = 20,
0094 .max_current = 40,
0095 },
0096 {
0097 .name = "B",
0098 .chan_nr = 2,
0099 .led_current = 20,
0100 .max_current = 40,
0101 },
0102 {
0103 .name = "W",
0104 .chan_nr = 3,
0105 .led_current = 20,
0106 .max_current = 40,
0107 },
0108 };
0109
0110 static int lp5562_setup(void)
0111 {
0112 /* setup HW resources */
0113 }
0114
0115 static void lp5562_release(void)
0116 {
0117 /* Release HW resources */
0118 }
0119
0120 static void lp5562_enable(bool state)
0121 {
0122 /* Control of chip enable signal */
0123 }
0124
0125 static struct lp55xx_platform_data lp5562_platform_data = {
0126 .led_config = lp5562_led_config,
0127 .num_channels = ARRAY_SIZE(lp5562_led_config),
0128 .setup_resources = lp5562_setup,
0129 .release_resources = lp5562_release,
0130 .enable = lp5562_enable,
0131 };
0132
0133 To configure the platform specific data, lp55xx_platform_data structure is used
0134
0135
0136 If the current is set to 0 in the platform data, that channel is
0137 disabled and it is not visible in the sysfs.
