+++ /dev/null
-LP5521/LP5523/LP55231/LP5562/LP8501 Common Driver
-=================================================
-
-Authors: Milo(Woogyom) Kim <milo.kim@ti.com>
-
-Description
------------
-LP5521, LP5523/55231, LP5562 and LP8501 have common features as below.
-
- Register access via the I2C
- Device initialization/deinitialization
- Create LED class devices for multiple output channels
- Device attributes for user-space interface
- Program memory for running LED patterns
-
-The LP55xx common driver provides these features using exported functions.
- lp55xx_init_device() / lp55xx_deinit_device()
- lp55xx_register_leds() / lp55xx_unregister_leds()
- lp55xx_regsister_sysfs() / lp55xx_unregister_sysfs()
-
-( Driver Structure Data )
-
-In lp55xx common driver, two different data structure is used.
-
-o lp55xx_led
- control multi output LED channels such as led current, channel index.
-o lp55xx_chip
- general chip control such like the I2C and platform data.
-
-For example, LP5521 has maximum 3 LED channels.
-LP5523/55231 has 9 output channels.
-
-lp55xx_chip for LP5521 ... lp55xx_led #1
- lp55xx_led #2
- lp55xx_led #3
-
-lp55xx_chip for LP5523 ... lp55xx_led #1
- lp55xx_led #2
- .
- .
- lp55xx_led #9
-
-( Chip Dependent Code )
-
-To support device specific configurations, special structure
-'lpxx_device_config' is used.
-
- Maximum number of channels
- Reset command, chip enable command
- Chip specific initialization
- Brightness control register access
- Setting LED output current
- Program memory address access for running patterns
- Additional device specific attributes
-
-( Firmware Interface )
-
-LP55xx family devices have the internal program memory for running
-various LED patterns.
-This pattern data is saved as a file in the user-land or
-hex byte string is written into the memory through the I2C.
-LP55xx common driver supports the firmware interface.
-
-LP55xx chips have three program engines.
-To load and run the pattern, the programming sequence is following.
- (1) Select an engine number (1/2/3)
- (2) Mode change to load
- (3) Write pattern data into selected area
- (4) Mode change to run
-
-The LP55xx common driver provides simple interfaces as below.
-select_engine : Select which engine is used for running program
-run_engine : Start program which is loaded via the firmware interface
-firmware : Load program data
-
-In case of LP5523, one more command is required, 'enginex_leds'.
-It is used for selecting LED output(s) at each engine number.
-In more details, please refer to 'leds-lp5523.txt'.
-
-For example, run blinking pattern in engine #1 of LP5521
-echo 1 > /sys/bus/i2c/devices/xxxx/select_engine
-echo 1 > /sys/class/firmware/lp5521/loading
-echo "4000600040FF6000" > /sys/class/firmware/lp5521/data
-echo 0 > /sys/class/firmware/lp5521/loading
-echo 1 > /sys/bus/i2c/devices/xxxx/run_engine
-
-For example, run blinking pattern in engine #3 of LP55231
-Two LEDs are configured as pattern output channels.
-echo 3 > /sys/bus/i2c/devices/xxxx/select_engine
-echo 1 > /sys/class/firmware/lp55231/loading
-echo "9d0740ff7e0040007e00a0010000" > /sys/class/firmware/lp55231/data
-echo 0 > /sys/class/firmware/lp55231/loading
-echo "000001100" > /sys/bus/i2c/devices/xxxx/engine3_leds
-echo 1 > /sys/bus/i2c/devices/xxxx/run_engine
-
-To start blinking patterns in engine #2 and #3 simultaneously,
-for idx in 2 3
-do
- echo $idx > /sys/class/leds/red/device/select_engine
- sleep 0.1
- echo 1 > /sys/class/firmware/lp5521/loading
- echo "4000600040FF6000" > /sys/class/firmware/lp5521/data
- echo 0 > /sys/class/firmware/lp5521/loading
-done
-echo 1 > /sys/class/leds/red/device/run_engine
-
-Here is another example for LP5523.
-Full LED strings are selected by 'engine2_leds'.
-echo 2 > /sys/bus/i2c/devices/xxxx/select_engine
-echo 1 > /sys/class/firmware/lp5523/loading
-echo "9d80400004ff05ff437f0000" > /sys/class/firmware/lp5523/data
-echo 0 > /sys/class/firmware/lp5523/loading
-echo "111111111" > /sys/bus/i2c/devices/xxxx/engine2_leds
-echo 1 > /sys/bus/i2c/devices/xxxx/run_engine
-
-As soon as 'loading' is set to 0, registered callback is called.
-Inside the callback, the selected engine is loaded and memory is updated.
-To run programmed pattern, 'run_engine' attribute should be enabled.
-
-The pattern sequence of LP8501 is similar to LP5523.
-However pattern data is specific.
-Ex 1) Engine 1 is used
-echo 1 > /sys/bus/i2c/devices/xxxx/select_engine
-echo 1 > /sys/class/firmware/lp8501/loading
-echo "9d0140ff7e0040007e00a001c000" > /sys/class/firmware/lp8501/data
-echo 0 > /sys/class/firmware/lp8501/loading
-echo 1 > /sys/bus/i2c/devices/xxxx/run_engine
-
-Ex 2) Engine 2 and 3 are used at the same time
-echo 2 > /sys/bus/i2c/devices/xxxx/select_engine
-sleep 1
-echo 1 > /sys/class/firmware/lp8501/loading
-echo "9d0140ff7e0040007e00a001c000" > /sys/class/firmware/lp8501/data
-echo 0 > /sys/class/firmware/lp8501/loading
-sleep 1
-echo 3 > /sys/bus/i2c/devices/xxxx/select_engine
-sleep 1
-echo 1 > /sys/class/firmware/lp8501/loading
-echo "9d0340ff7e0040007e00a001c000" > /sys/class/firmware/lp8501/data
-echo 0 > /sys/class/firmware/lp8501/loading
-sleep 1
-echo 1 > /sys/class/leds/d1/device/run_engine
-
-( 'run_engine' and 'firmware_cb' )
-The sequence of running the program data is common.
-But each device has own specific register addresses for commands.
-To support this, 'run_engine' and 'firmware_cb' are configurable in each driver.
-run_engine : Control the selected engine
-firmware_cb : The callback function after loading the firmware is done.
- Chip specific commands for loading and updating program memory.
-
-( Predefined pattern data )
-
-Without the firmware interface, LP55xx driver provides another method for
-loading a LED pattern. That is 'predefined' pattern.
-A predefined pattern is defined in the platform data and load it(or them)
-via the sysfs if needed.
-To use the predefined pattern concept, 'patterns' and 'num_patterns' should be
-configured.
-
- Example of predefined pattern data:
-
- /* mode_1: blinking data */
- static const u8 mode_1[] = {
- 0x40, 0x00, 0x60, 0x00, 0x40, 0xFF, 0x60, 0x00,
- };
-
- /* mode_2: always on */
- static const u8 mode_2[] = { 0x40, 0xFF, };
-
- struct lp55xx_predef_pattern board_led_patterns[] = {
- {
- .r = mode_1,
- .size_r = ARRAY_SIZE(mode_1),
- },
- {
- .b = mode_2,
- .size_b = ARRAY_SIZE(mode_2),
- },
- }
-
- struct lp55xx_platform_data lp5562_pdata = {
- ...
- .patterns = board_led_patterns,
- .num_patterns = ARRAY_SIZE(board_led_patterns),
- };
-
-Then, mode_1 and mode_2 can be run via through the sysfs.
-
- echo 1 > /sys/bus/i2c/devices/xxxx/led_pattern # red blinking LED pattern
- echo 2 > /sys/bus/i2c/devices/xxxx/led_pattern # blue LED always on
-
-To stop running pattern,
- echo 0 > /sys/bus/i2c/devices/xxxx/led_pattern
git.samba.org / sfrench / cifs-2.6.git / blobdiff