projects / linux.git / blame
| Commit | Line | Data |
|---|---|---|
| ff45262a KM |
1 | Kernel driver for LP5562 |
| 2 | ======================== | |
| 3 | ||
| 4 | * TI LP5562 LED Driver | |
| 5 | ||
| 6 | Author: Milo(Woogyom) Kim <[email protected]> | |
| 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. |