From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933532AbbCDQRK (ORCPT ); Wed, 4 Mar 2015 11:17:10 -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 X-AuditID: cbfee61b-f79d76d0000024d6-8f-54f730014a74 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-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 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. -- 1.7.9.5