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Date:   Thu, 6 Apr 2023 08:52:31 +0200
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Subject: Re: [PATCH v8 4/6] leds: class: store the color index in struct
 led_classdev
To:     Andy Shevchenko <andy.shevchenko@gmail.com>
CC:     <lee.jones@linaro.org>, <pavel@ucw.cz>, <robh+dt@kernel.org>,
        <sven.schwermer@disruptive-technologies.com>,
        <krzysztof.kozlowski+dt@linaro.org>, <johan+linaro@kernel.org>,
        <marijn.suijten@somainline.org>, <jacek.anaszewski@gmail.com>,
        <linux-leds@vger.kernel.org>, <devicetree@vger.kernel.org>,
        <linux-kernel@vger.kernel.org>
References: <20230328161541.599463-1-jjhiblot@traphandler.com>
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From:   Jean-Jacques Hiblot <jjhiblot@traphandler.com>
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On 28/03/2023 19:15, Andy Shevchenko wrote:
> On Tue, Mar 28, 2023 at 7:15 PM Jean-Jacques Hiblot
> <jjhiblot@traphandler.com> wrote:
>>
>> This information might be useful for more than only deriving the led's
>> name. And since we have this information, we can expose it in the sysfs.
> 
> ...
> 
>> +Date:          March 2023
>> +KernelVersion: 6.3
> 
> Outdated version.
> 
> ...
> 
>> +               Color of the led.
>> +
>> +               This is a read-only file. Reading this file returns the color
>> +               of the led as a string (ex: "red", "green").
> 
> There are no strict rules about colour and I don't think it's a good
> idea. Why in such a case is it different to label? My proposal here at
> least documenting that the colour must follow one of the existing
> naming standards (like RGB in hex, HTML, or name in accordance with
> chosen standard).
Actually the colors are defined in an array: led_colors (led-core.c: 88)
So the color is one of the following: white, red, reen, blue, amber, 
violet, yellow, ir, multicolor, rgb

There is mention in the TODO file of changing the way RGB leds are 
handled and the RGB leds would probably show the hex RGB values here.

> 
> Yet, it won't technically prevent abusing that, but at least will show
> the intention and allow pointing out to the bugs or develop user space
> tooling based on existing parsers (if any).
>