From patchwork Fri Jan 9 15:23:06 2015 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jacek Anaszewski X-Patchwork-Id: 27862 Received: from mail.tu-berlin.de ([130.149.7.33]) by www.linuxtv.org with esmtp (Exim 4.72) (envelope-from ) id 1Y9bWa-0003Hq-Mm; Fri, 09 Jan 2015 16:30:56 +0100 X-tubIT-Incoming-IP: 209.132.180.67 Received: from vger.kernel.org ([209.132.180.67]) by mail.tu-berlin.de (exim-4.72/mailfrontend-6) with esmtp id 1Y9bWX-0000pA-5s; Fri, 09 Jan 2015 16:30:55 +0100 Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757836AbbAIPY7 (ORCPT + 1 other); Fri, 9 Jan 2015 10:24:59 -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 Received: from epcpsbgm2.samsung.com (epcpsbgm2 [203.254.230.27]) by mailout1.samsung.com (Oracle Communications Messaging Server 7u4-24.01(7.0.4.24.0) 64bit (built Nov 17 2011)) with ESMTP id <0NHX001W21HH7A00@mailout1.samsung.com>; Sat, 10 Jan 2015 00:24:53 +0900 (KST) X-AuditID: cbfee61b-f79d76d0000024d6-86-54aff2c52ef3 Received: from epmmp2 ( [203.254.227.17]) by epcpsbgm2.samsung.com (EPCPMTA) with SMTP id CA.C6.09430.5C2FFA45; Sat, 10 Jan 2015 00:24:53 +0900 (KST) Received: from AMDC2362.DIGITAL.local ([106.120.53.23]) by mmp2.samsung.com (Oracle Communications Messaging Server 7u4-24.01 (7.0.4.24.0) 64bit (built Nov 17 2011)) with ESMTPA id <0NHX003F51EOLH20@mmp2.samsung.com>; Sat, 10 Jan 2015 00:24:53 +0900 (KST) 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-media-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-media@vger.kernel.org X-PMX-Version: 6.0.0.2142326, Antispam-Engine: 2.7.2.2107409, Antispam-Data: 2015.1.9.152425 X-PMX-Spam: Gauge=IIIIIIII, Probability=8%, Report=' MULTIPLE_RCPTS 0.1, HTML_00_01 0.05, HTML_00_10 0.05, BODYTEXTP_SIZE_3000_LESS 0, BODY_SIZE_1800_1899 0, BODY_SIZE_2000_LESS 0, BODY_SIZE_5000_LESS 0, BODY_SIZE_7000_LESS 0, REFERENCES 0, URI_ENDS_IN_HTML 0, __ANY_URI 0, __CP_URI_IN_BODY 0, __FRAUD_BODY_WEBMAIL 0, __FRAUD_WEBMAIL 0, __HAS_FROM 0, __HAS_MSGID 0, __HAS_X_MAILER 0, __HAS_X_MAILING_LIST 0, __IN_REP_TO 0, __MIME_TEXT_ONLY 0, __MULTIPLE_RCPTS_CC_X2 0, __REFERENCES 0, __SANE_MSGID 0, __SUBJ_ALPHA_END 0, __TO_MALFORMED_2 0, __TO_NO_NAME 0, __URI_NO_WWW 0, __URI_NS ' 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 Acked-by: Pavel Machek --- 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.