From mboxrd@z Thu Jan 1 00:00:00 1970 From: Pavel Machek Subject: Re: "advanced" LED controllers Date: Mon, 2 Mar 2015 10:21:11 +0100 Message-ID: <20150302092111.GA19233@amd> References: <20150219211424.GN13603@saruman.tx.rr.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: Sender: linux-kernel-owner@vger.kernel.org To: Alexandre Courbot Cc: Geert Uytterhoeven , Felipe Balbi , Bryan Wu , Richard Purdie , "linux-leds@vger.kernel.org" , Linux Kernel Mailing List , Linux OMAP Mailing List , "linux-gpio@vger.kernel.org" List-Id: linux-gpio@vger.kernel.org On Wed 2015-02-25 18:06:07, Alexandre Courbot wrote: > On Wed, Feb 25, 2015 at 5:25 PM, Geert Uytterhoeven > wrote: > > CC linux-gpio, as this looks like the LED equivalent of bulk gpio? > > Indeed. The LED core could implement something similar to > gpiod_set_array() to allow several LEDs to be set in one call. If the > controller supports it, it would then set all the LEDs at once, > otherwise the core would apply the values serially. > > In leds-gpio.c, this multiple LED setting could be implemented by a > single call to gpiod_set_array() and the right thing would happen. Actually, there are two issues: some controlles can set all LEDs at once, and some can program pwm level smoothly using given program (and handle multiple leds in the process). -- (english) http://www.livejournal.com/~pavelmachek (cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html