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Diffstat (limited to 'kernel/Documentation/leds/leds-lp5523.txt')
-rw-r--r-- | kernel/Documentation/leds/leds-lp5523.txt | 100 |
1 files changed, 100 insertions, 0 deletions
diff --git a/kernel/Documentation/leds/leds-lp5523.txt b/kernel/Documentation/leds/leds-lp5523.txt new file mode 100644 index 000000000..5b3e91d4a --- /dev/null +++ b/kernel/Documentation/leds/leds-lp5523.txt @@ -0,0 +1,100 @@ +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 + +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, +}; |