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Kernel driver for lp5523
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* 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
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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
enginex_leds:
led mux control
::
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
LP5523 has three master faders. If a channel is mapped to one of
the master faders, its output is dimmed based on the value of the master
fader.
For example::
echo "123000123" > master_fader_leds
creates the following channel-fader mappings::
channel 0,6 to master_fader1
channel 1,7 to master_fader2
channel 2,8 to master_fader3
Then, to have 25% of the original output on channel 0,6::
echo 64 > master_fader1
To have 0% of the original output (i.e. no output) channel 1,7::
echo 0 > master_fader2
To have 100% of the original output (i.e. no dimming) on channel 2,8::
echo 255 > master_fader3
To clear all master fader controls::
echo "000000000" > master_fader_leds
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::
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,
};
Note
chan_nr can have values between 0 and 8.
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