From patchwork Sun Mar 8 20:57:32 2015 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Pavel Machek X-Patchwork-Id: 5962971 Return-Path: X-Original-To: patchwork-linux-omap@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork1.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.136]) by patchwork1.web.kernel.org (Postfix) with ESMTP id 0959D9F373 for ; Sun, 8 Mar 2015 20:57:53 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 3B8A32024F for ; Sun, 8 Mar 2015 20:57:52 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 5F48C2024C for ; Sun, 8 Mar 2015 20:57:51 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752994AbbCHU5h (ORCPT ); Sun, 8 Mar 2015 16:57:37 -0400 Received: from atrey.karlin.mff.cuni.cz ([195.113.26.193]:50862 "EHLO atrey.karlin.mff.cuni.cz" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752649AbbCHU5g (ORCPT ); Sun, 8 Mar 2015 16:57:36 -0400 Received: by atrey.karlin.mff.cuni.cz (Postfix, from userid 512) id 5FE4A81F1E; Sun, 8 Mar 2015 21:57:33 +0100 (CET) Date: Sun, 8 Mar 2015 21:57:32 +0100 From: Pavel Machek 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" Subject: RGB LED control (was Re: "advanced" LED controllers) Message-ID: <20150308205732.GA385@amd> References: <20150219211424.GN13603@saruman.tx.rr.com> <20150302092111.GA19233@amd> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-omap-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-omap@vger.kernel.org X-Spam-Status: No, score=-6.9 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_HI, T_RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP Ok, so I played with RGB LED a bit, and we have quite a gap in documentation: what 50% brightness means is non-trivial and very important in case we want to do smooth blinking and color transitions. Signed-off-by: Pavel Machek diff --git a/Documentation/ABI/testing/sysfs-class-led b/Documentation/ABI/testing/sysfs-class-led index 3646ec8..649d7a6 100644 --- a/Documentation/ABI/testing/sysfs-class-led +++ b/Documentation/ABI/testing/sysfs-class-led @@ -8,6 +8,11 @@ Description: non-zero brightness settings. The value is between 0 and /sys/class/leds//max_brightness. + If LED supports continuous brightness settings, 50% brightness + should correspond to 50% brightness perceived by human, in a similar + manner pixel brightness on monitor does (not 50% PWM). + + What: /sys/class/leds//max_brightness Date: March 2006 KernelVersion: 2.6.17