Re: [PATCH v2 2/2] leds: lp50xx: Add the LP50XX family of the RGB LED driver

From: Dan Murphy
Date: Thu Jan 17 2019 - 08:27:27 EST


Hello

On 1/17/19 4:06 AM, Pavel Machek wrote:
> Hi!
>
>>>>> You know what? First, submit driver with similar functionality to
>>>>> existing RGB drivers, using same interface existing drivers are
>>>>> using. When that is accepted, we can talk about extending
>>>>> kernel<->user interfaces.
>>>>>
>>>>
>>>> I could do that but then there is no way for users to have any other color but "white" with this driver.
>>>> That defeats the purpose of the device itself.
>>>
>>> No, that is not what I meant.
>>>
>>> We do have RGB drivers in tree, they just present three separate LEDs
>>> -- red, green and blue. I ask you to do the same for initial
>>> submission.
>>>
>>
>> For clarification you are asking me to register a LED class per
>> output pin?
>
> Yes.
>

OK I can do that but I would like to get Jacek to align with this as he
suggested creating the code as I submitted based on the review of the
devices data sheet.

LED class registration per LED module or for the single Banked output.

>> As explained before the Master brightness register has absolute control over the output current
>> to the LED outputs regardless of the color control setting.
>>
>
> Yes, just set master brightness to 255 and you can ignore it.

OK Sounds fine. Will just need to do an init that sets the color
register to 0 and brightness to 0 so we don't have a flash.

>
>>> You'll still be able to set brightness independently on the
>>> red/green/blue LEDs...
>>>
>>
>> But which one would control the overall brightness of the cluster?
>
> You would not have that control in initial version of the patch.
>

See above on alignment

Dan

> Pavel
>


--
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Dan Murphy