Messages in this thread | | | Subject | Re: [PATCH 2/2] leds: lp5024: Add the LP5024/18 RGB LED driver | From | Jacek Anaszewski <> | Date | Mon, 7 Jan 2019 22:13:59 +0100 |
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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
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