From patchwork Fri Apr 24 13:43:31 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Laurent Pinchart X-Patchwork-Id: 11507895 X-Patchwork-Delegate: kieran@bingham.xyz Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id F3D95912 for ; Fri, 24 Apr 2020 13:43:51 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id D4DFA20767 for ; Fri, 24 Apr 2020 13:43:51 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=ideasonboard.com header.i=@ideasonboard.com header.b="OiCyqtjw" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726920AbgDXNnv (ORCPT ); Fri, 24 Apr 2020 09:43:51 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:35276 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-FAIL-OK-FAIL) by vger.kernel.org with ESMTP id S1726717AbgDXNnv (ORCPT ); Fri, 24 Apr 2020 09:43:51 -0400 Received: from perceval.ideasonboard.com (perceval.ideasonboard.com [IPv6:2001:4b98:dc2:55:216:3eff:fef7:d647]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 02DC3C09B045; Fri, 24 Apr 2020 06:43:51 -0700 (PDT) Received: from pendragon.bb.dnainternet.fi (81-175-216-236.bb.dnainternet.fi [81.175.216.236]) by perceval.ideasonboard.com (Postfix) with ESMTPSA id 31C3D4F7; Fri, 24 Apr 2020 15:43:49 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=ideasonboard.com; s=mail; t=1587735829; bh=7p6WM4syAfD9Bhy1LHRcVn90YBrIr/1MSC7VUbYj7GE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=OiCyqtjwLjMOJ7ziJpqAyGsqFZSkz03OXx2tER7P3rXXa5PHwgnw6q3xD0I3GgoMT hfCYsJDCu/IFtSkp2oUtwfBw5C6mBH5vovs6Ik3X7Yvh/2DqlTIGRYtaH6oQbGecib Wtcbjwk9m6FrF6C2kxMh1LqFz2x+QAhm7A+bgqqs= From: Laurent Pinchart To: linux-media@vger.kernel.org Cc: =?utf-8?q?Niklas_S=C3=B6derlund?= , Helen Koike , Hans Verkuil , Sakari Ailus , linux-renesas-soc@vger.kernel.org Subject: [PATCH v8.1 3/6] media: v4l2: Extend VIDIOC_ENUM_FMT to support MC-centric devices Date: Fri, 24 Apr 2020 16:43:31 +0300 Message-Id: <20200424134331.22271-1-laurent.pinchart@ideasonboard.com> X-Mailer: git-send-email 2.25.3 In-Reply-To: <20200421135743.1381930-4-niklas.soderlund+renesas@ragnatech.se> References: <20200421135743.1381930-4-niklas.soderlund+renesas@ragnatech.se> MIME-Version: 1.0 Sender: linux-renesas-soc-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-renesas-soc@vger.kernel.org The VIDIOC_ENUM_FMT ioctl enumerates all formats supported by a video node. For MC-centric devices, its behaviour has always been ill-defined, with drivers implementing one of the following behaviours: - No support for VIDIOC_ENUM_FMT at all - Enumerating all formats supported by the video node, regardless of the configuration of the pipeline - Enumerating formats supported by the video node for the active configuration of the connected subdevice The first behaviour is obviously useless for applications. The second behaviour provides the most information, but doesn't offer a way to find what formats are compatible with a given pipeline configuration. The third behaviour fixes that, but with the drawback that applications can't enumerate all supported formats anymore, and have to modify the active configuration of the pipeline to enumerate formats. The situation is messy as none of the implemented behaviours are ideal, and userspace can't predict what will happen as the behaviour is driver-specific. To fix this, let's extend the VIDIOC_ENUM_FMT with a missing capability: enumerating pixel formats for a given media bus code. The media bus code is passed through the v4l2_fmtdesc structure in a new mbus_code field (repurposed from the reserved fields). With this capability in place, applications can enumerate pixel formats for a given media bus code without modifying the active configuration of the device. The current behaviour of the ioctl is preserved when the new mbus_code field is set to 0, ensuring compatibility with existing userspace. The API extension is documented as mandatory for MC-centric devices (as advertised through the V4L2_CAP_IO_MC capability), allowing applications and compliance tools to easily determine the availability of the VIDIOC_ENUM_FMT extension. Signed-off-by: Laurent Pinchart Reviewed-by: Niklas Söderlund Acked-by: Sakari Ailus Reviewed-by: Hans Verkuil Signed-off-by: Niklas Söderlund --- Changes since v8: - Zero the mbus_code field if V4L2_CAP_IO_MC isn't set - Document the new mbus_code field - Fix ref tags in documentation --- .../media/uapi/v4l/vidioc-enum-fmt.rst | 25 ++++++++++++++++--- drivers/media/v4l2-core/v4l2-ioctl.c | 13 ++++++++-- include/uapi/linux/videodev2.h | 3 ++- 3 files changed, 34 insertions(+), 7 deletions(-) diff --git a/Documentation/media/uapi/v4l/vidioc-enum-fmt.rst b/Documentation/media/uapi/v4l/vidioc-enum-fmt.rst index 8ca6ab701e4a..a987debc7654 100644 --- a/Documentation/media/uapi/v4l/vidioc-enum-fmt.rst +++ b/Documentation/media/uapi/v4l/vidioc-enum-fmt.rst @@ -48,10 +48,21 @@ one until ``EINVAL`` is returned. If applicable, drivers shall return formats in preference order, where preferred formats are returned before (that is, with lower ``index`` value) less-preferred formats. -.. note:: +If the driver doesn't advertise the ``V4L2_CAP_IO_MC`` :ref:`capability +`, applications shall initialize the ``mbus_code`` field +to zero and drivers shall ignore the value of the field. Drivers shall +enumerate all image formats. The enumerated formats may depend on the active +input or output of the device. - After switching input or output the list of enumerated image - formats may be different. +If the driver advertises the ``V4L2_CAP_IO_MC`` :ref:`capability +`, applications may initialize the ``mbus_code`` field to +a valid :ref:`media bus format code `. If the +``mbus_code`` field is not zero, drivers shall restrict enumeration to only the +image formats that can produce (for video output devices) or be produced from +(for video capture devices) that media bus code. Regardless of the value of +the ``mbus_code`` field, the enumerated image formats shall not depend on the +active configuration of the video device or device pipeline. Enumeration shall +otherwise operate as previously described. .. tabularcolumns:: |p{4.4cm}|p{4.4cm}|p{8.7cm}| @@ -106,7 +117,13 @@ formats in preference order, where preferred formats are returned before These codes are not the same as those used in the Windows world. * - __u32 - - ``reserved``\ [4] + - ``mbus_code`` + - Media bus code restricting the enumerated formats, set by the + application. Only applicable to drivers that advertise the + ``V4L2_CAP_IO_MC`` :ref:`capability `, shall be 0 + otherwise. + * - __u32 + - ``reserved``\ [3] - Reserved for future extensions. Drivers must set the array to zero. diff --git a/drivers/media/v4l2-core/v4l2-ioctl.c b/drivers/media/v4l2-core/v4l2-ioctl.c index 3545a8adf844..0550f20d7177 100644 --- a/drivers/media/v4l2-core/v4l2-ioctl.c +++ b/drivers/media/v4l2-core/v4l2-ioctl.c @@ -264,12 +264,13 @@ static void v4l_print_fmtdesc(const void *arg, bool write_only) { const struct v4l2_fmtdesc *p = arg; - pr_cont("index=%u, type=%s, flags=0x%x, pixelformat=%c%c%c%c, description='%.*s'\n", + pr_cont("index=%u, type=%s, flags=0x%x, pixelformat=%c%c%c%c, mbus_code=0x%04x, description='%.*s'\n", p->index, prt_names(p->type, v4l2_type_names), p->flags, (p->pixelformat & 0xff), (p->pixelformat >> 8) & 0xff, (p->pixelformat >> 16) & 0xff, (p->pixelformat >> 24) & 0xff, + p->mbus_code, (int)sizeof(p->description), p->description); } @@ -1467,12 +1468,20 @@ static int v4l_enum_fmt(const struct v4l2_ioctl_ops *ops, struct video_device *vdev = video_devdata(file); struct v4l2_fmtdesc *p = arg; int ret = check_fmt(file, p->type); + u32 mbus_code; u32 cap_mask; if (ret) return ret; ret = -EINVAL; + if (!(vdev->device_caps & V4L2_CAP_IO_MC)) + p->mbus_code = 0; + + mbus_code = p->mbus_code; + CLEAR_AFTER_FIELD(p, type); + p->mbus_code = mbus_code; + switch (p->type) { case V4L2_BUF_TYPE_VIDEO_CAPTURE: case V4L2_BUF_TYPE_VIDEO_CAPTURE_MPLANE: @@ -2752,7 +2761,7 @@ DEFINE_V4L_STUB_FUNC(dv_timings_cap) static const struct v4l2_ioctl_info v4l2_ioctls[] = { IOCTL_INFO(VIDIOC_QUERYCAP, v4l_querycap, v4l_print_querycap, 0), - IOCTL_INFO(VIDIOC_ENUM_FMT, v4l_enum_fmt, v4l_print_fmtdesc, INFO_FL_CLEAR(v4l2_fmtdesc, type)), + IOCTL_INFO(VIDIOC_ENUM_FMT, v4l_enum_fmt, v4l_print_fmtdesc, 0), IOCTL_INFO(VIDIOC_G_FMT, v4l_g_fmt, v4l_print_format, 0), IOCTL_INFO(VIDIOC_S_FMT, v4l_s_fmt, v4l_print_format, INFO_FL_PRIO), IOCTL_INFO(VIDIOC_REQBUFS, v4l_reqbufs, v4l_print_requestbuffers, INFO_FL_PRIO | INFO_FL_QUEUE), diff --git a/include/uapi/linux/videodev2.h b/include/uapi/linux/videodev2.h index c793263a3705..0ece960844a5 100644 --- a/include/uapi/linux/videodev2.h +++ b/include/uapi/linux/videodev2.h @@ -779,7 +779,8 @@ struct v4l2_fmtdesc { __u32 flags; __u8 description[32]; /* Description string */ __u32 pixelformat; /* Format fourcc */ - __u32 reserved[4]; + __u32 mbus_code; /* Media bus code */ + __u32 reserved[3]; }; #define V4L2_FMT_FLAG_COMPRESSED 0x0001