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Diffstat (limited to 'Documentation/leds/leds-lp5562.rst')
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diff --git a/Documentation/leds/leds-lp5562.rst b/Documentation/leds/leds-lp5562.rst new file mode 100644 index 0000000000..79bbb2487f --- /dev/null +++ b/Documentation/leds/leds-lp5562.rst @@ -0,0 +1,137 @@ +======================== +Kernel driver for lp5562 +======================== + +* TI LP5562 LED Driver + +Author: Milo(Woogyom) Kim <milo.kim@ti.com> + +Description +=========== + + LP5562 can drive up to 4 channels. R/G/B and White. + LEDs can be controlled directly via the led class control interface. + + All four channels can be also controlled using the engine micro programs. + LP5562 has the internal program memory for running various LED patterns. + For the details, please refer to 'firmware' section in leds-lp55xx.txt + +Device attribute +================ + +engine_mux + 3 Engines are allocated in LP5562, but the number of channel is 4. + Therefore each channel should be mapped to the engine number. + + Value: RGB or W + + This attribute is used for programming LED data with the firmware interface. + Unlike the LP5521/LP5523/55231, LP5562 has unique feature for the engine mux, + so additional sysfs is required + + LED Map + + ===== === =============================== + Red ... Engine 1 (fixed) + Green ... Engine 2 (fixed) + Blue ... Engine 3 (fixed) + White ... Engine 1 or 2 or 3 (selective) + ===== === =============================== + +How to load the program data using engine_mux +============================================= + + Before loading the LP5562 program data, engine_mux should be written between + the engine selection and loading the firmware. + Engine mux has two different mode, RGB and W. + RGB is used for loading RGB program data, W is used for W program data. + + For example, run blinking green channel pattern:: + + echo 2 > /sys/bus/i2c/devices/xxxx/select_engine # 2 is for green channel + echo "RGB" > /sys/bus/i2c/devices/xxxx/engine_mux # engine mux for RGB + echo 1 > /sys/class/firmware/lp5562/loading + echo "4000600040FF6000" > /sys/class/firmware/lp5562/data + echo 0 > /sys/class/firmware/lp5562/loading + echo 1 > /sys/bus/i2c/devices/xxxx/run_engine + + To run a blinking white pattern:: + + echo 1 or 2 or 3 > /sys/bus/i2c/devices/xxxx/select_engine + echo "W" > /sys/bus/i2c/devices/xxxx/engine_mux + echo 1 > /sys/class/firmware/lp5562/loading + echo "4000600040FF6000" > /sys/class/firmware/lp5562/data + echo 0 > /sys/class/firmware/lp5562/loading + echo 1 > /sys/bus/i2c/devices/xxxx/run_engine + +How to load the predefined patterns +=================================== + + Please refer to 'leds-lp55xx.txt" + +Setting Current of Each Channel +=============================== + + Like LP5521 and LP5523/55231, LP5562 provides LED current settings. + The 'led_current' and 'max_current' are used. + +Example of Platform data +======================== + +:: + + static struct lp55xx_led_config lp5562_led_config[] = { + { + .name = "R", + .chan_nr = 0, + .led_current = 20, + .max_current = 40, + }, + { + .name = "G", + .chan_nr = 1, + .led_current = 20, + .max_current = 40, + }, + { + .name = "B", + .chan_nr = 2, + .led_current = 20, + .max_current = 40, + }, + { + .name = "W", + .chan_nr = 3, + .led_current = 20, + .max_current = 40, + }, + }; + + static int lp5562_setup(void) + { + /* setup HW resources */ + } + + static void lp5562_release(void) + { + /* Release HW resources */ + } + + static void lp5562_enable(bool state) + { + /* Control of chip enable signal */ + } + + static struct lp55xx_platform_data lp5562_platform_data = { + .led_config = lp5562_led_config, + .num_channels = ARRAY_SIZE(lp5562_led_config), + .setup_resources = lp5562_setup, + .release_resources = lp5562_release, + .enable = lp5562_enable, + }; + +To configure the platform specific data, lp55xx_platform_data structure is used + + +If the current is set to 0 in the platform data, that channel is +disabled and it is not visible in the sysfs. |