Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932287AbVKCNcD (ORCPT ); Thu, 3 Nov 2005 08:32:03 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S932472AbVKCNcB (ORCPT ); Thu, 3 Nov 2005 08:32:01 -0500 Received: from atrey.karlin.mff.cuni.cz ([195.113.31.123]:34456 "EHLO atrey.karlin.mff.cuni.cz") by vger.kernel.org with ESMTP id S932287AbVKCNcA (ORCPT ); Thu, 3 Nov 2005 08:32:00 -0500 Date: Thu, 3 Nov 2005 10:59:38 +0100 From: Pavel Machek To: Geert Uytterhoeven Cc: Pavel Machek , Robert Schwebel , Vojtech Pavlik , rpurdie@rpsys.net, lenz@cs.wisc.edu, kernel list , Russell King Subject: Re: best way to handle LEDs Message-ID: <20051103095938.GB703@openzaurus.ucw.cz> References: <20051101234459.GA443@elf.ucw.cz> <20051102202622.GN23316@pengutronix.de> <20051102211334.GH23943@elf.ucw.cz> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.3.27i Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1303 Lines: 34 Hi! > > > > yellow off: not charging > > > > yellow on: charging > > > > yellow fast blink: charge error > > > > > > > > I think even slow blinking was used somewhere. I have some code from > > > > John Lenz (attached); it uses sysfs interface, exports led collor, and > > > > allows setting different frequencies. > > > > > > > > Is that acceptable, or should some other interface be used? > > > > > > IMHO reducing digital outputs to LEDs goes not far enough. All System- > > > on-Chip CPUs have General Purpose I/O pins today, which can act as > > > inputs or outputs and may be used for LEDs, matrix keyboard lines, > > > > We have some leds that are *not* on GPIO pins (like driven by > > ACPI). We'd like to support those, too. > > I though ACPI was software? These LEDs have to be driven by some hardware, > right? Right, but you don't know by *which* hardware. Only ACPI AML code knows. So from linux POW, they are handled by ACPI. It may even trap to SMM BIOS. -- 64 bytes from 195.113.31.123: icmp_seq=28 ttl=51 time=448769.1 ms - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/