Kernel driver for lp5523 ======================== * National Semiconductor LP5523 led driver chip * Datasheet: http://www.national.com/pf/LP/LP5523.html Authors: Mathias Nyman, Yuri Zaporozhets, Samu Onkalo Contact: Samu Onkalo (samu.p.onkalo-at-nokia.com) Description ----------- LP5523 can drive up to 9 channels. Leds can be controlled directly via the led class control interface. The name of each channel is configurable in the platform data - name and label. There are three options to make the channel name. a) Define the 'name' in the platform data To make specific channel name, then use 'name' platform data. /sys/class/leds/R1 (name: 'R1') /sys/class/leds/B1 (name: 'B1') b) Use the 'label' with no 'name' field For one device name with channel number, then use 'label'. /sys/class/leds/RGB:channelN (label: 'RGB', N: 0 ~ 8) c) Default If both fields are NULL, 'lp5523' is used by default. /sys/class/leds/lp5523:channelN (N: 0 ~ 8) LP5523 has the internal program memory for running various LED patterns. There are two ways to run LED patterns. 1) Legacy interface - enginex_mode, enginex_load and enginex_leds Control interface for the engines: x is 1 .. 3 enginex_mode : disabled, load, run enginex_load : microcode load (visible only in load mode) enginex_leds : led mux control (visible only in load mode) cd /sys/class/leds/lp5523:channel2/device echo "load" > engine3_mode echo "9d80400004ff05ff437f0000" > engine3_load echo "111111111" > engine3_leds echo "run" > engine3_mode To stop the engine: echo "disabled" > engine3_mode 2) Firmware interface - LP55xx common interface For the details, please refer to 'firmware' section in leds-lp55xx.txt LP5523 has three master faders. If a channel is mapped to one of the master faders, its output is dimmed based on the value of the master fader. For example, echo "123000123" > master_fader_leds creates the following channel-fader mappings: channel 0,6 to master_fader1 channel 1,7 to master_fader2 channel 2,8 to master_fader3 Then, to have 25% of the original output on channel 0,6: echo 64 > master_fader1 To have 0% of the original output (i.e. no output) channel 1,7: echo 0 > master_fader2 To have 100% of the original output (i.e. no dimming) on channel 2,8: echo 255 > master_fader3 To clear all master fader controls: echo "000000000" > master_fader_leds Selftest uses always the current from the platform data. Each channel contains led current settings. /sys/class/leds/lp5523:channel2/led_current - RW /sys/class/leds/lp5523:channel2/max_current - RO Format: 10x mA i.e 10 means 1.0 mA Example platform data: Note - chan_nr can have values between 0 and 8. static struct lp55xx_led_config lp5523_led_config[] = { { .name = "D1", .chan_nr = 0, .led_current = 50, .max_current = 130, }, ... { .chan_nr = 8, .led_current = 50, .max_current = 130, } }; static int lp5523_setup(void) { /* Setup HW resources */ } static void lp5523_release(void) { /* Release HW resources */ } static void lp5523_enable(bool state) { /* Control chip enable signal */ } static struct lp55xx_platform_data lp5523_platform_data = { .led_config = lp5523_led_config, .num_channels = ARRAY_SIZE(lp5523_led_config), .clock_mode = LP55XX_CLOCK_EXT, .setup_resources = lp5523_setup, .release_resources = lp5523_release, .enable = lp5523_enable, };