From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from smtp1.linuxfoundation.org (smtp1.linux-foundation.org [172.17.192.35]) by mail.linuxfoundation.org (Postfix) with ESMTPS id 70BE387A for ; Thu, 23 Jul 2015 21:29:59 +0000 (UTC) Received: from atrey.karlin.mff.cuni.cz (atrey.karlin.mff.cuni.cz [195.113.26.193]) by smtp1.linuxfoundation.org (Postfix) with ESMTP id C03711A1 for ; Thu, 23 Jul 2015 21:29:58 +0000 (UTC) Date: Thu, 23 Jul 2015 23:29:56 +0200 From: Pavel Machek To: josh@joshtriplett.org Message-ID: <20150723212956.GB25053@amd> References: <20150723105726.GC30929@amd> <20150723121441.GB29747@amd> <20150723084251.54da2be0@gandalf.local.home> <20150723202901.GA30318@amd> <20150723210018.GA2077@cloud> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20150723210018.GA2077@cloud> Cc: "ksummit-discuss@lists.linuxfoundation.org" , riverful.kim@samsung.com, kyungmin.park@samsung.com, John Stultz , Bjorn Andersson Subject: Re: [Ksummit-discuss] [CORE TOPIC] Mainline kernel on a cellphone List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On Thu 2015-07-23 14:00:18, josh@joshtriplett.org wrote: > On Thu, Jul 23, 2015 at 10:29:02PM +0200, Pavel Machek wrote: > > Questions I had in mind: > > > > 1) RGB leds. They are not same as 3 leds. Plus there' hw acceleration > > on them. How to support them? > > Seems like internally we should treat them as 3 LEDs, but the interface > to userspace or to the LED trigger mechanism should group the three > brightness values together rather than handling them separately. Yes. It should me "make it show magenta" not "set red to x, blue to y, green to z"... > Is the hardware acceleration something more than PWM? Yes. It can do quite complex patterns autonomously. "Blink red three times, then slowly go to full brightness and back". It can do as complex stuff as blink n times, then delay, for n is prime number. Pavel -- (english) http://www.livejournal.com/~pavelmachek (cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html