Based on kernel version 4.16.1. Page generated on 2018-04-09 11:53 EST.
1 Kernel driver for LP5562 2 ======================== 3 4 * TI LP5562 LED Driver 5 6 Author: Milo(Woogyom) Kim <milo.kim@ti.com> 7 8 Description 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 17 Device 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 33 How 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 56 How to load the predefined patterns 57 58 Please refer to 'leds-lp55xx.txt" 59 60 Setting 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 67 To configure the platform specific data, lp55xx_platform_data structure is used. 68 69 static 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 96 static int lp5562_setup(void) 97 { 98 /* setup HW resources */ 99 } 100 101 static void lp5562_release(void) 102 { 103 /* Release HW resources */ 104 } 105 106 static void lp5562_enable(bool state) 107 { 108 /* Control of chip enable signal */ 109 } 110 111 static 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 }; 118 119 If the current is set to 0 in the platform data, that channel is 120 disabled and it is not visible in the sysfs.