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diff --git a/Documentation/leds/leds-lp5523.rst b/Documentation/leds/leds-lp5523.rst new file mode 100644 index 000000000..7d7362a1d --- /dev/null +++ b/Documentation/leds/leds-lp5523.rst @@ -0,0 +1,147 @@ +======================== +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 + enginex_leds: + led mux control + + :: + + 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:: + + 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, + }; + +Note + chan_nr can have values between 0 and 8. |