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From: Pavel Machek <pavel@ucw.cz>
To: Jacek Anaszewski <jacek.anaszewski@gmail.com>
Cc: fenglinw@codeaurora.org, linux-arm-msm@vger.kernel.org,
	linux-kernel@vger.kernel.org, Richard Purdie <rpurdie@rpsys.net>,
	Rob Herring <robh+dt@kernel.org>,
	Mark Rutland <mark.rutland@arm.com>,
	linux-leds@vger.kernel.org, devicetree@vger.kernel.org,
	subbaram@quicinc.com, aghayal@qti.qualcomm.com,
	wruan@quicinc.com, kgunda@qti.qualcomm.com
Subject: Re: [PATCH V2 1/2] leds: leds-qti-rgb: Add LED driver for QTI TRI_LED module
Date: Mon, 5 Jun 2017 23:16:09 +0200	[thread overview]
Message-ID: <20170605211609.GA9035@amd> (raw)
In-Reply-To: <8058ed85-5a64-8dc3-99ea-1ad8128e043d@gmail.com>

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Hi!

> Generally I came to a conclusion that it will be best to register
> additional LED RGB class device in an addition to three LED class
> devices representing each color. In order to avoid hard to solve
> locking problems I propose to allow for simultaneous access to LED
> class devices and LED RGB class device gathering them.
> 
> All in all, currently we also don't give an exclusive access to
> a particular LED class device, which always can lead to overwriting
> current brightness by another process. These issues must be arbitrated
> by user space.
> 
> I propose that LED RGB class device exposed following files:
> 
> - red_brightness
> - green_brightness
> - blue_brightness
> - latch_color

Actually, I'd just do single file, "rgb_brightness" with 3
values. Overhead of writing 3 values is pretty much 0.
									Pavel

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

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  reply	other threads:[~2017-06-05 21:16 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2017-06-01  7:25 [PATCH V2 1/2] leds: leds-qti-rgb: Add LED driver for QTI TRI_LED module fenglinw
2017-06-04 18:33 ` Jacek Anaszewski
2017-06-05 21:16   ` Pavel Machek [this message]
2017-06-06 20:07     ` Jacek Anaszewski
2017-06-06 20:13       ` Pavel Machek
2017-06-07 22:08 ` Rob Herring

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