mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-08-21 08:19:28 +00:00
![Kim, Milo](/assets/img/avatar_default.png)
The lp5521 has autonomous operation mode without external control. Using lp5521_platform_data, various led patterns can be configurable. For supporting this feature, new functions and device attribute are added. Structure of lp5521_led_pattern: 3 channels are supported - red, green and blue. Pattern(s) of each channel and numbers of pattern(s) are defined in the pla= tform data. Pattern data are hexa codes which include pattern commands such like set pwm, wait, ramp up/down, branch and so on. Pattern mode functions: * lp5521_clear_program_memory Before running new led pattern, program memory should be cleared. * lp5521_write_program_memory Pattern data updated in the program memory via the i2c. * lp5521_get_pattern Get pattern from predefined in the platform data. * lp5521_run_led_pattern Stop current pattern or run new pattern. Transition time is required between different operation mode. Device attribute - 'led_pattern': To load specific led pattern, new device attribute is added. When the lp5521 driver is unloaded, stop current led pattern mode. Documentation updated : description about how to define the led patterns and example. [akpm@linux-foundation.org: checkpatch fixes] Signed-off-by: Milo(Woogyom) Kim <milo.kim@ti.com> Acked-by: Linus Walleij <linus.walleij@linaro.org> Cc: Arun MURTHY <arun.murthy@stericsson.com> Cc: Srinidhi Kasagar <srinidhi.kasagar@stericsson.com> Cc: Richard Purdie <rpurdie@rpsys.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
151 lines
4.3 KiB
Text
151 lines
4.3 KiB
Text
Kernel driver for lp5521
|
|
========================
|
|
|
|
* National Semiconductor LP5521 led driver chip
|
|
* Datasheet: http://www.national.com/pf/LP/LP5521.html
|
|
|
|
Authors: Mathias Nyman, Yuri Zaporozhets, Samu Onkalo
|
|
Contact: Samu Onkalo (samu.p.onkalo-at-nokia.com)
|
|
|
|
Description
|
|
-----------
|
|
|
|
LP5521 can drive up to 3 channels. Leds can be controlled directly via
|
|
the led class control interface. Channels have generic names:
|
|
lp5521:channelx, where x is 0 .. 2
|
|
|
|
All three channels can be also controlled using the engine micro programs.
|
|
More details of the instructions can be found from the public data sheet.
|
|
|
|
Control interface for the engines:
|
|
x is 1 .. 3
|
|
enginex_mode : disabled, load, run
|
|
enginex_load : store program (visible only in engine load mode)
|
|
|
|
Example (start to blink the channel 2 led):
|
|
cd /sys/class/leds/lp5521:channel2/device
|
|
echo "load" > engine3_mode
|
|
echo "037f4d0003ff6000" > engine3_load
|
|
echo "run" > engine3_mode
|
|
|
|
stop the engine:
|
|
echo "disabled" > engine3_mode
|
|
|
|
sysfs contains a selftest entry.
|
|
The test communicates with the chip and checks that
|
|
the clock mode is automatically set to the requested one.
|
|
|
|
Each channel has its own led current settings.
|
|
/sys/class/leds/lp5521:channel0/led_current - RW
|
|
/sys/class/leds/lp5521:channel0/max_current - RO
|
|
Format: 10x mA i.e 10 means 1.0 mA
|
|
|
|
example platform data:
|
|
|
|
Note: chan_nr can have values between 0 and 2.
|
|
The name of each channel can be configurable.
|
|
If the name field is not defined, the default name will be set to 'xxxx:channelN'
|
|
(XXXX : pdata->label or i2c client name, N : channel number)
|
|
|
|
static struct lp5521_led_config lp5521_led_config[] = {
|
|
{
|
|
.name = "red",
|
|
.chan_nr = 0,
|
|
.led_current = 50,
|
|
.max_current = 130,
|
|
}, {
|
|
.name = "green",
|
|
.chan_nr = 1,
|
|
.led_current = 0,
|
|
.max_current = 130,
|
|
}, {
|
|
.name = "blue",
|
|
.chan_nr = 2,
|
|
.led_current = 0,
|
|
.max_current = 130,
|
|
}
|
|
};
|
|
|
|
static int lp5521_setup(void)
|
|
{
|
|
/* setup HW resources */
|
|
}
|
|
|
|
static void lp5521_release(void)
|
|
{
|
|
/* Release HW resources */
|
|
}
|
|
|
|
static void lp5521_enable(bool state)
|
|
{
|
|
/* Control of chip enable signal */
|
|
}
|
|
|
|
static struct lp5521_platform_data lp5521_platform_data = {
|
|
.led_config = lp5521_led_config,
|
|
.num_channels = ARRAY_SIZE(lp5521_led_config),
|
|
.clock_mode = LP5521_CLOCK_EXT,
|
|
.setup_resources = lp5521_setup,
|
|
.release_resources = lp5521_release,
|
|
.enable = lp5521_enable,
|
|
};
|
|
|
|
If the current is set to 0 in the platform data, that channel is
|
|
disabled and it is not visible in the sysfs.
|
|
|
|
The 'update_config' : CONFIG register (ADDR 08h)
|
|
This value is platform-specific data.
|
|
If update_config is not defined, the CONFIG register is set with
|
|
'LP5521_PWRSAVE_EN | LP5521_CP_MODE_AUTO | LP5521_R_TO_BATT'.
|
|
(Enable auto-powersave, set charge pump to auto, red to battery)
|
|
|
|
example of update_config :
|
|
|
|
#define LP5521_CONFIGS (LP5521_PWM_HF | LP5521_PWRSAVE_EN | \
|
|
LP5521_CP_MODE_AUTO | LP5521_R_TO_BATT | \
|
|
LP5521_CLK_INT)
|
|
|
|
static struct lp5521_platform_data lp5521_pdata = {
|
|
.led_config = lp5521_led_config,
|
|
.num_channels = ARRAY_SIZE(lp5521_led_config),
|
|
.clock_mode = LP5521_CLOCK_INT,
|
|
.update_config = LP5521_CONFIGS,
|
|
};
|
|
|
|
LED patterns : LP5521 has autonomous operation without external control.
|
|
Pattern data can be defined in the platform data.
|
|
|
|
example of led pattern data :
|
|
|
|
/* RGB(50,5,0) 500ms on, 500ms off, infinite loop */
|
|
static u8 pattern_red[] = {
|
|
0x40, 0x32, 0x60, 0x00, 0x40, 0x00, 0x60, 0x00,
|
|
};
|
|
|
|
static u8 pattern_green[] = {
|
|
0x40, 0x05, 0x60, 0x00, 0x40, 0x00, 0x60, 0x00,
|
|
};
|
|
|
|
static struct lp5521_led_pattern board_led_patterns[] = {
|
|
{
|
|
.r = pattern_red,
|
|
.g = pattern_green,
|
|
.size_r = ARRAY_SIZE(pattern_red),
|
|
.size_g = ARRAY_SIZE(pattern_green),
|
|
},
|
|
};
|
|
|
|
static struct lp5521_platform_data lp5521_platform_data = {
|
|
.led_config = lp5521_led_config,
|
|
.num_channels = ARRAY_SIZE(lp5521_led_config),
|
|
.clock_mode = LP5521_CLOCK_EXT,
|
|
.patterns = board_led_patterns,
|
|
.num_patterns = ARRAY_SIZE(board_led_patterns),
|
|
};
|
|
|
|
Then predefined led pattern(s) can be executed via the sysfs.
|
|
To start the pattern #1,
|
|
# echo 1 > /sys/bus/i2c/devices/xxxx/led_pattern
|
|
(xxxx : i2c bus & slave address)
|
|
To end the pattern,
|
|
# echo 0 > /sys/bus/i2c/devices/xxxx/led_pattern
|