Re: [PATCH v7 2/5] dt-bindings: leds: Add LED_COLOR_ID_MOONLIGHT definitions

From: Gene Chen <gene.chen.richtek@gmail.com>
To: Jacek Anaszewski <jacek.anaszewski@gmail.com>
Cc: Pavel Machek <pavel@ucw.cz>, Rob Herring <robh+dt@kernel.org>,
	Matthias Brugger <matthias.bgg@gmail.com>,
	Dan Murphy <dmurphy@ti.com>,
	Linux LED Subsystem <linux-leds@vger.kernel.org>,
	devicetree <devicetree@vger.kernel.org>,
	linux-arm Mailing List <linux-arm-kernel@lists.infradead.org>,
	"moderated list:ARM/Mediatek SoC support" 
	<linux-mediatek@lists.infradead.org>,
	Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
	Gene Chen <gene_chen@richtek.com>,
	Wilma.Wu@mediatek.com, shufan_lee@richtek.com,
	cy_huang@richtek.com, benjamin.chao@mediatek.com
Subject: Re: [PATCH v7 2/5] dt-bindings: leds: Add LED_COLOR_ID_MOONLIGHT definitions
Date: Tue, 24 Nov 2020 16:32:40 +0800	[thread overview]
Message-ID: <CAE+NS34-oU3FnfBsHD3W+z-4QNr3LgnEjXhDbNrVf+KJg_bDEw@mail.gmail.com> (raw)
In-Reply-To: <CAE+NS34vDejgf8Ydfer_rY25qaG-DQQ5H-9-Er+Shz0=UF-EzA@mail.gmail.com>

Fix Typo.

Gene Chen <gene.chen.richtek@gmail.com> 於 2020年11月24日 週二 下午3:33寫道：
>
> Jacek Anaszewski <jacek.anaszewski@gmail.com> 於 2020年11月24日 週二 上午4:52寫道：
> >
> > On 11/23/20 4:00 AM, Gene Chen wrote:
> > > Jacek Anaszewski <jacek.anaszewski@gmail.com> 於 2020年11月20日 週五 上午6:26寫道：
> > >>
> > >> On 11/19/20 10:57 PM, Pavel Machek wrote:
> > >>> On Thu 2020-11-19 22:03:14, Jacek Anaszewski wrote:
> > >>>> Hi Pavel, Gene,
> > >>>>
> > >>>> On 11/18/20 10:37 PM, Pavel Machek wrote:
> > >>>>> Hi!
> > >>>>>
> > >>>>>> From: Gene Chen <gene_chen@richtek.com>
> > >>>>>>
> > >>>>>> Add LED_COLOR_ID_MOONLIGHT definitions
> > >>>>>
> > >>>>> Why is moonlight a color? Camera flashes are usually white, no?
> > >>>>>
> > >>>>> At least it needs a comment...
> > >>>>
> > >>>> That's my fault, In fact I should have asked about adding
> > >>>> LED_FUNCTION_MOONLIGHT, it was evidently too late for me that evening...
> > >>>
> > >>> Aha, that makes more sense.
> > >>>
> > >>> But please let's call it "torch" if we do that, as that is already
> > >>> used in kernel sources... and probably in the interface, too:
> > >>
> > >> I'd say that torch is something different that moonlight,
> > >> but we would need more input from Gene to learn more about
> > >> the nature of light emitted by ML LED on his device.
> > >>
> > >> Please note that torch is usually meant as the other mode of
> > >> flash LED (sometimes it is called "movie mode"), which is already
> > >> handled by brightness file of LED class flash device (i.e. its LED class
> > >> subset), and which also maps to v4l2-flash TORCH mode.
> > >>
> > >
> > > It's used to front camera fill light.
> > > More brightness than screen backlight, and more soft light than flash.
> > > I think LED_ID_COLOR_WHITE is okay.
> >
> > So why in v6 you assigned LED_COLOR_ID_AMBER to it?
> >

we suppose Moonlight can be white or amber.

> > Regardless of that, now we're talking about LED function - you chose
> > LED_FUNCTION_INDICATOR for it, but inferring from your above description
> > - it certainly doesn't fit here.
> >
> > Also register names, containing part "ML" indicate that this LED's
> > intended function is moonlinght, which your description somehow
> > corroborates.
> >
> > Moonlight LEDs become ubiquitous nowadays so sooner or later we will
> > need to add this function anyway [0].
> >
> > [0]
> > https://landscapelightingoakville.com/what-is-moon-lighting-and-why-does-it-remain-so-popular/
> >
>
> According to reference,
> "When you are trying to imitate moonlight you need to use low voltage,
> softer lighting. You don’t want something that’s too bright"
> which is focus on brightness instead of color.
>
> So we suppose Moonlight can be white or amber.
>
> Should I add LED_FUNCTION_MOONLIGHT and set LED_COLOR_ID_WHITE?
>
> > --
> > Best regards,
> > Jacek Anaszewski