195 lines
6.7 KiB
Plaintext
195 lines
6.7 KiB
Plaintext
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
|