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81f2a5b4a0
Now LP55xx provides automatic clock detection API, lp55xx_is_extclk_used(). The clock configuration can be done by the driver itself. (a) Concept The default value is set by each driver with clock selection. The internal clock selection bit is updated in case that the external clock is not detected or clock rate is not 32KHz. (b) Change on LP55xx platform data The clock configuration is done automatically, so no need to define 'update_config' in the platform side. Correlated information are removed in the documentations and header. (c) Definitions moved from header to driver files CONFIG register values are moved each driver, LP5521 and LP5562. Not necessary definitions are removed also. Signed-off-by: Milo(Woogyom) Kim <milo.kim@ti.com> Signed-off-by: Bryan Wu <cooloney@gmail.com>
120 lines
3.3 KiB
Text
120 lines
3.3 KiB
Text
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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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: 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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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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How to load the program data using engine_mux
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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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Please refer to 'leds-lp55xx.txt"
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Setting Current of Each Channel
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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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To configure the platform specific data, lp55xx_platform_data structure is used.
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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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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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