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8dab91970a
Rename the leds documentation files to ReST, add an index for them and adjust in order to produce a nice html output via the Sphinx build system. At its new index.rst, let's add a :orphan: while this is not linked to the main index.rst file, in order to avoid build warnings. Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org> Acked-by: Pavel Machek <pavel@ucw.cz> Signed-off-by: Jacek Anaszewski <jacek.anaszewski@gmail.com>
138 lines
3.6 KiB
ReStructuredText
138 lines
3.6 KiB
ReStructuredText
========================
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Kernel driver for lp5562
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========================
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* TI LP5562 LED Driver
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Author: Milo(Woogyom) Kim <milo.kim@ti.com>
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Description
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===========
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LP5562 can drive up to 4 channels. R/G/B and White.
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LEDs can be controlled directly via the led class control interface.
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All four channels can be also controlled using the engine micro programs.
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LP5562 has the internal program memory for running various LED patterns.
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For the details, please refer to 'firmware' section in leds-lp55xx.txt
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Device attribute
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================
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engine_mux
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3 Engines are allocated in LP5562, but the number of channel is 4.
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Therefore each channel should be mapped to the engine number.
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Value: RGB or W
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This attribute is used for programming LED data with the firmware interface.
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Unlike the LP5521/LP5523/55231, LP5562 has unique feature for the engine mux,
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so additional sysfs is required
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LED Map
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===== === ===============================
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Red ... Engine 1 (fixed)
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Green ... Engine 2 (fixed)
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Blue ... Engine 3 (fixed)
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White ... Engine 1 or 2 or 3 (selective)
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===== === ===============================
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How to load the program data using engine_mux
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=============================================
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Before loading the LP5562 program data, engine_mux should be written between
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the engine selection and loading the firmware.
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Engine mux has two different mode, RGB and W.
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RGB is used for loading RGB program data, W is used for W program data.
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For example, run blinking green channel pattern::
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echo 2 > /sys/bus/i2c/devices/xxxx/select_engine # 2 is for green channel
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echo "RGB" > /sys/bus/i2c/devices/xxxx/engine_mux # engine mux for RGB
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echo 1 > /sys/class/firmware/lp5562/loading
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echo "4000600040FF6000" > /sys/class/firmware/lp5562/data
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echo 0 > /sys/class/firmware/lp5562/loading
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echo 1 > /sys/bus/i2c/devices/xxxx/run_engine
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To run a blinking white pattern::
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echo 1 or 2 or 3 > /sys/bus/i2c/devices/xxxx/select_engine
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echo "W" > /sys/bus/i2c/devices/xxxx/engine_mux
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echo 1 > /sys/class/firmware/lp5562/loading
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echo "4000600040FF6000" > /sys/class/firmware/lp5562/data
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echo 0 > /sys/class/firmware/lp5562/loading
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echo 1 > /sys/bus/i2c/devices/xxxx/run_engine
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How to load the predefined patterns
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===================================
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Please refer to 'leds-lp55xx.txt"
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Setting Current of Each Channel
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===============================
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Like LP5521 and LP5523/55231, LP5562 provides LED current settings.
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The 'led_current' and 'max_current' are used.
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Example of Platform data
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========================
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::
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static struct lp55xx_led_config lp5562_led_config[] = {
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{
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.name = "R",
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.chan_nr = 0,
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.led_current = 20,
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.max_current = 40,
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},
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{
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.name = "G",
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.chan_nr = 1,
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.led_current = 20,
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.max_current = 40,
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},
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{
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.name = "B",
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.chan_nr = 2,
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.led_current = 20,
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.max_current = 40,
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},
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{
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.name = "W",
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.chan_nr = 3,
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.led_current = 20,
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.max_current = 40,
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},
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};
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static int lp5562_setup(void)
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{
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/* setup HW resources */
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}
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static void lp5562_release(void)
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{
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/* Release HW resources */
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}
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static void lp5562_enable(bool state)
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{
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/* Control of chip enable signal */
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}
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static struct lp55xx_platform_data lp5562_platform_data = {
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.led_config = lp5562_led_config,
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.num_channels = ARRAY_SIZE(lp5562_led_config),
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.setup_resources = lp5562_setup,
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.release_resources = lp5562_release,
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.enable = lp5562_enable,
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};
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To configure the platform specific data, lp55xx_platform_data structure is used
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If the current is set to 0 in the platform data, that channel is
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disabled and it is not visible in the sysfs.
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