linux-vybrid_public/Documentation/leds/leds-lp5523.txt

Kernel driver for lp5523
========================

* 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
-----------
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.
For the details, please refer to 'firmware' section in leds-lp55xx.txt

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:

Note - chan_nr can have values between 0 and 8.

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,
};