Hi Vesa,
On 1/5/19 1:39 AM, Vesa Jääskeläinen wrote:
Hi Jacek,
On 04/01/2019 23.37, Jacek Anaszewski wrote:
But, aside from that hypothetic issue, we need a solution for
LEDn_BRIGHTNESS feature of lp5024, i.e. setting color intensity
via a single register write. How would you propose to address that?
You could model it to something like this in device tree:
led-module @ <i2c-address> {
compatible = "lp5024";
// There is in hardware setup to use either linear or
// logarithmic scaling:
//enable-logarithmic-brightness;
led0 {
// this will create led instance for LED0 in lp5024
label = "lp-led0";
// This specifies LED number within lp5024
led-index = <0>; // set output-base as 0*3 == 0
element-red {
// refers to OUT0
output-offset = <0>;
};
element-green {
// refers to OUT1
output-offset = <1>;
};
element-blue {
// refers to OUT2
output-offset = <2>;
};
};
led1 {
// this will create led instance for LED1 in lp5024
label = "lp-led1";
// This specifies LED number within lp5024
led-index = <1>; // set output-base as 1*3 == 3
element-red {
// refers to OUT3
output-offset = <0>;
};
element-green {
// refers to OUT4
output-offset = <1>;
};
element-blue {
// refers to OUT5
output-offset = <2>;
};
};
bank-led {
// this will create led instance for bank leds in lp5024
label = "lp-bank-led";
// configured bank led configuration
led-index = <2 3 4 5 6 7>;
// As here is list of led-indices this entry is
// assumed to be bank configuration. Bank mode is enable
// for the indices.
// set output-base as BANK A
element-red {
// refers to BANK A
output-offset = <0>;
};
element-green {
// refers to BANK B
output-offset = <1>;
};
element-blue {
// refers to BANK C
output-offset = <2>;
};
};
};
This would then create three led instances and each led instance has
brightness setting and that goes straight to hardware.
If one would want to override hardware control for brightness then I
suppose you would define in led node something like:
brightness-model = "hsl"
This would then pick red, green and blue elements for hsl calculations
and others color elements for linear. LED specific hardware brightness
would then be either 0 or 0xFF depending if all of LED color elements
are zero or not.
Would that kind of model work?
I'd prefer to have single RGB LED device. And your DT design
is unnecessarily complex and a bit confusing.
Also, you provided scarce information about sysfs interface.
It would be nice to see the sequence of commands.
--
Best regards,
Jacek Anaszewski
