From patchwork Wed Mar 4 16:14:37 2015 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jacek Anaszewski X-Patchwork-Id: 28505 Received: from mail.tu-berlin.de ([130.149.7.33]) by www.linuxtv.org with esmtp (Exim 4.72) (envelope-from ) id 1YTC0I-0000IB-T9; Wed, 04 Mar 2015 17:18:34 +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 1YTC0G-0002de-5r; Wed, 04 Mar 2015 17:18:34 +0100 Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933514AbbCDQRJ (ORCPT + 1 other); Wed, 4 Mar 2015 11:17:09 -0500 Received: from mailout2.samsung.com ([203.254.224.25]:13749 "EHLO mailout2.samsung.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933436AbbCDQRH (ORCPT ); Wed, 4 Mar 2015 11:17:07 -0500 Received: from epcpsbgm2.samsung.com (epcpsbgm2 [203.254.230.27]) by mailout2.samsung.com (Oracle Communications Messaging Server 7u4-24.01(7.0.4.24.0) 64bit (built Nov 17 2011)) with ESMTP id <0NKP003UP3WH5YA0@mailout2.samsung.com>; Thu, 05 Mar 2015 01:17:05 +0900 (KST) X-AuditID: cbfee61b-f79d76d0000024d6-8f-54f730014a74 Received: from epmmp1.local.host ( [203.254.227.16]) by epcpsbgm2.samsung.com (EPCPMTA) with SMTP id C0.87.09430.10037F45; Thu, 05 Mar 2015 01:17:05 +0900 (KST) Received: from AMDC2362.DIGITAL.local ([106.120.53.23]) by mmp1.samsung.com (Oracle Communications Messaging Server 7u4-24.01 (7.0.4.24.0) 64bit (built Nov 17 2011)) with ESMTPA id <0NKP0082A3SJHN70@mmp1.samsung.com>; Thu, 05 Mar 2015 01:17:05 +0900 (KST) From: Jacek Anaszewski To: linux-leds@vger.kernel.org, linux-media@vger.kernel.org Cc: linux-kernel@vger.kernel.org, devicetree@vger.kernel.org, kyungmin.park@samsung.com, pavel@ucw.cz, cooloney@gmail.com, rpurdie@rpsys.net, sakari.ailus@iki.fi, s.nawrocki@samsung.com, Jacek Anaszewski Subject: [PATCH/RFC v12 16/19] Documentation: leds: Add description of v4l2-flash sub-device Date: Wed, 04 Mar 2015 17:14:37 +0100 Message-id: <1425485680-8417-17-git-send-email-j.anaszewski@samsung.com> X-Mailer: git-send-email 1.7.9.5 In-reply-to: <1425485680-8417-1-git-send-email-j.anaszewski@samsung.com> References: <1425485680-8417-1-git-send-email-j.anaszewski@samsung.com> X-Brightmail-Tracker: H4sIAAAAAAAAA+NgFlrNLMWRmVeSWpSXmKPExsVy+t9jAV1Gg+8hBrO2C1gc3TmRyWL+kXOs Fr1XnzNanG16w25xedccNoutb9YxWvRs2MpqcffUUTaL3bueslocftPOanFm/0o2B26PnbPu snsc/rqQxWPP/B+sHn1bVjF6rFj9nd3j8ya5ALYoLpuU1JzMstQifbsErox9X9vZC07wVExr vc/cwHiDq4uRk0NCwETi2ddmJghbTOLCvfVsXYxcHEICixgldr1fyw6SEBJoZ5L4czkNxGYT MJT4+eI1WIOIgLXErEPTWUAamAXeMErM2nAOKMHBISwQJ/GpIQOkhkVAVeLAlY2sIDavgIdE 7+VtYCUSAgoScybZgIQ5gcJnb65ngljlLnH44X6WCYy8CxgZVjGKphYkFxQnpeca6RUn5haX 5qXrJefnbmIEB+Ez6R2MqxosDjEKcDAq8fAeiP0WIsSaWFZcmXuIUYKDWUmE9znb9xAh3pTE yqrUovz4otKc1OJDjNIcLErivEr2bSFCAumJJanZqakFqUUwWSYOTqkGxnW1czf8/fnmzie/ qG3dLPv/nFpYcfAFc8K7myKhD5qTZJedeKimriGT0PSnQeTCpL82i9SOlUddT+lz61+0bvY2 d4+oc+WblnfMivtc98tMNX/T5aJDl9MS/y2+k6/4pJJnosemllf8V00bE6PjDMT2XH59a98d wcsec3Z+n1y2X2GinFXwnktKLMUZiYZazEXFiQCogemdPgIAAA== 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: 2015.3.4.161220 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_1700_1799 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 --- 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 19bb673..8623413 100644 --- a/Documentation/leds/leds-class-flash.txt +++ b/Documentation/leds/leds-class-flash.txt @@ -20,3 +20,16 @@ Following sysfs attributes are exposed for controlling flash LED devices: - max_flash_timeout - flash_strobe - flash_fault + +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.