Re: [Linux-stm32] [PATCH v7 10/12] ARM: dts: stm32: Fix schema warnings for pwm-leds

From: Alexander Dahl <post@lespocky.de>
To: Ahmad Fatoum <a.fatoum@pengutronix.de>
Cc: linux-arm-kernel@lists.infradead.org, devicetree@vger.kernel.org,
	Alexander Dahl <ada@thorsis.com>,
	linux-kernel@vger.kernel.org,
	linux-stm32@st-md-mailman.stormreply.com
Subject: Re: [Linux-stm32] [PATCH v7 10/12] ARM: dts: stm32: Fix schema warnings for pwm-leds
Date: Sat, 31 Oct 2020 14:54:09 +0100	[thread overview]
Message-ID: <20201031135408.lgpiy5goa7l4cg2k@falbala.internal.home.lespocky.de> (raw)
In-Reply-To: <f6ed201d-51b6-f278-7a95-3e3e49dc19ee@pengutronix.de>

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Hei hei,

On Tue, Oct 27, 2020 at 11:58:10AM +0100, Ahmad Fatoum wrote:
> Hello,
> 
> On 10/27/20 11:05 AM, Alexander Dahl wrote:
> > Hello Ahmad,
> > 
> > thanks for your feedback, comments below.
> > 
> 
> >>> -	led-rgb {
> >>> +	led-controller-2 {
> >>
> >> Is a single RGB LED really a controller?
> > 
> > I just followed the recommendations by Rob here.
> 
> Do you happen to know if the new multicolor LED support could be used here?
> 
> I find it unfortunate that the device tree loses information relevant to humans
> to adhere to a fixed nomenclature. Apparently led-controller isn't even codified
> in the YAML binding (It's just in the examples). If you respin, please add a
> comment that this is a single RGB led. I'd prefer to keep the information
> in the DTB as well though.

Slightly off-topic, but while I was working on the patch based on your
feedback I tried to find some information on that Linux Automation
MC-1 board.  However I could not find any? Is there some website, some
datasheet or maybe a schematic online?  The vendor prefix says "Linux
Automation GmbH", but I find only that USB-SD-Mux on their page?

Greets
Alex

> 
> 
> 
> > 
> >>>  		compatible = "pwm-leds";
> >>>  
> >>> -		led-red {
> >>> +		led-2 {
> >>
> >> Shouldn't this have been led-1 as well or is the numbering "global" ?
> > 
> > Also good question. This numbering is for dts only, it usually does
> > not correspond with LEDs on the board, so it could be numbered per
> > led-controller as well?
> 
> I'd prefer that it starts by 1. That way it's aligned with PWM channel
> ID.
> 
> Thanks for fixing the dtschema warnings by the way!
> 
> Cheers,
> Ahmad
> 
> > 
> > Greets
> > Alex
> > 
> >>
> >>>  			label = "mc1:red:rgb";
> >>>  			pwms = <&leds_pwm 1 1000000 0>;
> >>>  			max-brightness = <255>;
> >>>  			active-low;
> >>>  		};
> >>>  
> >>> -		led-green {
> >>> +		led-3 {
> >>>  			label = "mc1:green:rgb";
> >>>  			pwms = <&leds_pwm 2 1000000 0>;
> >>>  			max-brightness = <255>;
> >>>  			active-low;
> >>>  		};
> >>>  
> >>> -		led-blue {
> >>> +		led-4 {
> >>>  			label = "mc1:blue:rgb";
> >>>  			pwms = <&leds_pwm 3 1000000 0>;
> >>>  			max-brightness = <255>;
> >>>
> >>
> >> -- 
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> > 
> 
> -- 
> Pengutronix e.K.                           |                             |
> Steuerwalder Str. 21                       | http://www.pengutronix.de/  |
> 31137 Hildesheim, Germany                  | Phone: +49-5121-206917-0    |
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