From patchwork Sun Feb 23 10:40:34 2014 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sakari Ailus X-Patchwork-Id: 3703401 Return-Path: X-Original-To: patchwork-linux-media@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork2.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.19.201]) by patchwork2.web.kernel.org (Postfix) with ESMTP id 258A5BF13A for ; Sun, 23 Feb 2014 10:39:01 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id DAC37201C0 for ; Sun, 23 Feb 2014 10:38:59 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 111DE20136 for ; Sun, 23 Feb 2014 10:38:58 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1750838AbaBWKid (ORCPT ); Sun, 23 Feb 2014 05:38:33 -0500 Received: from nblzone-211-213.nblnetworks.fi ([83.145.211.213]:46372 "EHLO hillosipuli.retiisi.org.uk" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1750754AbaBWKib (ORCPT ); Sun, 23 Feb 2014 05:38:31 -0500 Received: from lanttu.localdomain (salottisipuli.retiisi.org.uk [IPv6:2001:1bc8:102:7fc9::83:2]) by hillosipuli.retiisi.org.uk (Postfix) with ESMTP id CD16F6008E; Sun, 23 Feb 2014 12:38:27 +0200 (EET) From: Sakari Ailus To: linux-media@vger.kernel.org, hverkuil@xs4all.nl Cc: laurent.pinchart@ideasonboard.com, k.debski@samsung.com Subject: [PATCH v5.2 3/7] v4l: Add timestamp source flags, mask and document them Date: Sun, 23 Feb 2014 12:40:34 +0200 Message-Id: <1393152034-21336-1-git-send-email-sakari.ailus@iki.fi> X-Mailer: git-send-email 1.7.10.4 In-Reply-To: <53071CFA.5060503@iki.fi> References: <53071CFA.5060503@iki.fi> Sender: linux-media-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-media@vger.kernel.org X-Spam-Status: No, score=-7.4 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_HI, RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=ham 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 Some devices do not produce timestamps that correspond to the end of the frame. The user space should be informed on the matter. This patch achieves that by adding buffer flags (and a mask) for timestamp sources since more possible timestamping points are expected than just two. A three-bit mask is defined (V4L2_BUF_FLAG_TSTAMP_SRC_MASK) and two of the eight possible values is are defined V4L2_BUF_FLAG_TSTAMP_SRC_EOF for end of frame (value zero) V4L2_BUF_FLAG_TSTAMP_SRC_SOE for start of exposure (next value). Signed-off-by: Sakari Ailus Acked-by: Hans Verkuil --- since v5.1: - Remove the note on timestamp inaccuracy from SOE timestamps. - Add ..."or transmitted" for EOF timestamps. - Correct language related to valid buffer types and SOE timestamps. Documentation/DocBook/media/v4l/io.xml | 36 +++++++++++++++++++++++++----- drivers/media/v4l2-core/videobuf2-core.c | 4 +++- include/media/videobuf2-core.h | 2 ++ include/uapi/linux/videodev2.h | 4 ++++ 4 files changed, 39 insertions(+), 7 deletions(-) diff --git a/Documentation/DocBook/media/v4l/io.xml b/Documentation/DocBook/media/v4l/io.xml index 46d24b3..d44401c 100644 --- a/Documentation/DocBook/media/v4l/io.xml +++ b/Documentation/DocBook/media/v4l/io.xml @@ -653,12 +653,6 @@ plane, are stored in struct v4l2_plane instead. In that case, struct v4l2_buffer contains an array of plane structures. - For timestamp types that are sampled from the system clock -(V4L2_BUF_FLAG_TIMESTAMP_MONOTONIC) it is guaranteed that the timestamp is -taken after the complete frame has been received (or transmitted in -case of video output devices). For other kinds of -timestamps this may vary depending on the driver. - struct <structname>v4l2_buffer</structname> @@ -1119,6 +1113,36 @@ in which case caches have not been used. The CAPTURE buffer timestamp has been taken from the corresponding OUTPUT buffer. This flag applies only to mem2mem devices. + + V4L2_BUF_FLAG_TSTAMP_SRC_MASK + 0x00070000 + Mask for timestamp sources below. The timestamp source + defines the point of time the timestamp is taken in relation to + the frame. Logical and operation between the + flags field and + V4L2_BUF_FLAG_TSTAMP_SRC_MASK produces the + value of the timestamp source. + + + V4L2_BUF_FLAG_TSTAMP_SRC_EOF + 0x00000000 + End Of Frame. The buffer timestamp has been taken + when the last pixel of the frame has been received or the + last pixel of the frame has been transmitted. In practice, + software generated timestamps will typically be read from + the clock a small amount of time after the last pixel has + been received or transmitten, depending on the system and + other activity in it. + + + V4L2_BUF_FLAG_TSTAMP_SRC_SOE + 0x00010000 + Start Of Exposure. The buffer timestamp has been + taken when the exposure of the frame has begun. This is + only valid for the + V4L2_BUF_TYPE_VIDEO_CAPTURE buffer + type. +
diff --git a/drivers/media/v4l2-core/videobuf2-core.c b/drivers/media/v4l2-core/videobuf2-core.c index 5a5fb7f..6e314b0 100644 --- a/drivers/media/v4l2-core/videobuf2-core.c +++ b/drivers/media/v4l2-core/videobuf2-core.c @@ -2195,7 +2195,9 @@ int vb2_queue_init(struct vb2_queue *q) WARN_ON(!q->io_modes) || WARN_ON(!q->ops->queue_setup) || WARN_ON(!q->ops->buf_queue) || - WARN_ON(q->timestamp_type & ~V4L2_BUF_FLAG_TIMESTAMP_MASK)) + WARN_ON(q->timestamp_type & + ~(V4L2_BUF_FLAG_TIMESTAMP_MASK | + V4L2_BUF_FLAG_TSTAMP_SRC_MASK))) return -EINVAL; /* Warn that the driver should choose an appropriate timestamp type */ diff --git a/include/media/videobuf2-core.h b/include/media/videobuf2-core.h index bef53ce..b6b992d 100644 --- a/include/media/videobuf2-core.h +++ b/include/media/videobuf2-core.h @@ -312,6 +312,8 @@ struct v4l2_fh; * @buf_struct_size: size of the driver-specific buffer structure; * "0" indicates the driver doesn't want to use a custom buffer * structure type, so sizeof(struct vb2_buffer) will is used + * @timestamp_type: Timestamp flags; V4L2_BUF_FLAGS_TIMESTAMP_* and + * V4L2_BUF_FLAGS_TSTAMP_SRC_* * @gfp_flags: additional gfp flags used when allocating the buffers. * Typically this is 0, but it may be e.g. GFP_DMA or __GFP_DMA32 * to force the buffer allocation to a specific memory zone. diff --git a/include/uapi/linux/videodev2.h b/include/uapi/linux/videodev2.h index e9ee444..82e8661 100644 --- a/include/uapi/linux/videodev2.h +++ b/include/uapi/linux/videodev2.h @@ -695,6 +695,10 @@ struct v4l2_buffer { #define V4L2_BUF_FLAG_TIMESTAMP_UNKNOWN 0x00000000 #define V4L2_BUF_FLAG_TIMESTAMP_MONOTONIC 0x00002000 #define V4L2_BUF_FLAG_TIMESTAMP_COPY 0x00004000 +/* Timestamp sources. */ +#define V4L2_BUF_FLAG_TSTAMP_SRC_MASK 0x00070000 +#define V4L2_BUF_FLAG_TSTAMP_SRC_EOF 0x00000000 +#define V4L2_BUF_FLAG_TSTAMP_SRC_SOE 0x00010000 /** * struct v4l2_exportbuffer - export of video buffer as DMABUF file descriptor