Re: LED backlight on Droid 4 and others

From: Pavel Machek <pavel@ucw.cz>
To: Tony Lindgren <tony@atomide.com>
Cc: Lee Jones <lee.jones@linaro.org>,
	kernel list <linux-kernel@vger.kernel.org>,
	linux-arm-kernel <linux-arm-kernel@lists.infradead.org>,
	linux-omap@vger.kernel.org, sre@kernel.org, nekit1000@gmail.com,
	mpartap@gmx.net, merlijn@wizzup.org, martin_rysavy@centrum.cz,
	agx@sigxcpu.org, daniel.thompson@linaro.org,
	jingoohan1@gmail.com, dri-devel@lists.freedesktop.org,
	tomi.valkeinen@ti.com, jjhiblot@ti.com, tony@atomide.com
Subject: Re: LED backlight on Droid 4 and others
Date: Wed, 12 Feb 2020 21:16:38 +0100	[thread overview]
Message-ID: <20200212201638.GB20085@amd> (raw)
In-Reply-To: <20200211172900.GH64767@atomide.com>

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Hi!

> > > It would be good to get LED backlight to work in clean way for 5.6
> > > kernel.
> ...
> > > [If you have an idea what else is needed, it would be welcome; it
> > > works for me in development tree but not in tree I'd like to
> > > upstream.]
> > > 
> > > Lee, would you be willing to take "backlight: add led-backlight
> > > driver"? Would it help if I got "leds: Add managed API to get a LED
> > > from a device driver" and "leds: Add of_led_get() and led_put()" into
> > > for_next tree of the LED subsystem?
> > 
> > It looks like you have an open question from Tony on v10.
> > 
> > Is that patch orthogonal, or are there depend{ants,encies}?
> 
> Uhh looks like we messed up a bit with integration. Now droid4
> LCD backlight can no longer be enabled at all manually in v5.6-rc1
> without the "add led-backlight driver" patch.. Should we just
> merge it to fix it rather than start scrambling with other
> temporary hacks?

We should just merge the "add led-backlight driver". Everything should
be ready for it. I'm sorry if I broke something working, I was not
aware it worked at all.

Unfortunately, this is backlight code, not LED, so I can't just merge it.

> I don't care if we use "default-brightness", or if we use
> "default-brightness-level". The binding merged says now
> "default-brightness", so let's go with that one. That's what
> other LED drivers are using too.

No opinion on that.

Best regards,
									Pavel
-- 
(english) http://www.livejournal.com/~pavelmachek
(cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html

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