From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758005AbbAIPZB (ORCPT ); Fri, 9 Jan 2015 10:25:01 -0500 Received: from mailout1.samsung.com ([203.254.224.24]:24608 "EHLO mailout1.samsung.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757855AbbAIPYz (ORCPT ); Fri, 9 Jan 2015 10:24:55 -0500 X-AuditID: cbfee61b-f79d76d0000024d6-86-54aff2c52ef3 From: Jacek Anaszewski To: linux-leds@vger.kernel.org, linux-media@vger.kernel.org, linux-kernel@vger.kernel.org Cc: devicetree@vger.kernel.org, kyungmin.park@samsung.com, b.zolnierkie@samsung.com, pavel@ucw.cz, cooloney@gmail.com, rpurdie@rpsys.net, sakari.ailus@iki.fi, s.nawrocki@samsung.com, Jacek Anaszewski Subject: [PATCH/RFC v10 16/19] Documentation: leds: Add description of v4l2-flash sub-device Date: Fri, 09 Jan 2015 16:23:06 +0100 Message-id: <1420816989-1808-17-git-send-email-j.anaszewski@samsung.com> X-Mailer: git-send-email 1.7.9.5 In-reply-to: <1420816989-1808-1-git-send-email-j.anaszewski@samsung.com> References: <1420816989-1808-1-git-send-email-j.anaszewski@samsung.com> X-Brightmail-Tracker: H4sIAAAAAAAAA+NgFlrPLMWRmVeSWpSXmKPExsVy+t9jQd2jn9aHGCxcYmqxccZ6VoujOycy Wcw/co7Vovfqc0aLs01v2C0u75rDZrH1zTpGi54NW1kt7p46ymaxe9dTVovDb9pZLc7sX8nm wOOxc9Zddo/DXxeyeOyZ/4PVo2/LKkaPFau/s3t83iQXwBbFZZOSmpNZllqkb5fAldH98BRb wUueilmH/rE3ML7j6mLk5JAQMJFY/XwSM4QtJnHh3nq2LkYuDiGB6YwSGzqOMEM47UwS297d YwGpYhMwlPj54jVTFyMHh4hAtMSlY/UgNcwCLxgl7k1+wAZSIywQJ3GicREjiM0ioCrRe7UR bAOvgIfEwt13WEF6JQQUJOZMsgExOYHCLb+dQEwhAXeJN1cNJzDyLmBkWMUomlqQXFCclJ5r pFecmFtcmpeul5yfu4kRHIzPpHcwrmqwOMQowMGoxMO7QW59iBBrYllxZe4hRgkOZiUR3obN QCHelMTKqtSi/Pii0pzU4kOM0hwsSuK8SvZtIUIC6YklqdmpqQWpRTBZJg5OqQZG3Z1R6rZ3 ZjLGFLBfjLObOPmgaNF228kGR52fz62YO3NCdgqP77VDKw72SbhopvxYz+rt2GyqcuvQjINR 5QnO8xjLSzrsXLYXuthkVN/dbTNZ8aCH9aL9rJM7XglbNQtc19We48kgm/P/4Izzm3adNrpv vlU6Mjgudd29VU3pO9PvaZ95+CZciaU4I9FQi7moOBEA8N+qKEICAAA= Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org This patch extends LED Flash class documention by the description of interactions with v4l2-flash sub-device. Signed-off-by: Jacek Anaszewski Acked-by: Kyungmin Park Acked-by: Sakari Ailus Cc: Bryan Wu Cc: Richard Purdie --- Documentation/leds/leds-class-flash.txt | 13 +++++++++++++ 1 file changed, 13 insertions(+) diff --git a/Documentation/leds/leds-class-flash.txt b/Documentation/leds/leds-class-flash.txt index d80096b..2f38627 100644 --- a/Documentation/leds/leds-class-flash.txt +++ b/Documentation/leds/leds-class-flash.txt @@ -55,3 +55,16 @@ Following sysfs attributes are exposed for controlling flash led devices: upper limit Flash faults are cleared, if possible, by reading the attribute. + +A LED subsystem driver can be controlled also from the level of VideoForLinux2 +subsystem. In order to enable this CONFIG_V4L2_FLASH_LED_CLASS symbol has to +be defined in the kernel config. The driver must call the v4l2_flash_init +function to get registered in the V4L2 subsystem. On remove the +v4l2_flash_release function has to be called (see ). + +After proper initialization a V4L2 Flash sub-device is created. The sub-device +exposes a number of V4L2 controls, which allow for controlling a LED Flash class +device with use of its internal kernel API. +Opening the V4L2 Flash sub-device makes the LED subsystem sysfs interface +unavailable. The interface is re-enabled after the V4L2 Flash sub-device +is closed. -- 1.7.9.5