From patchwork Tue Apr 16 19:32:43 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sakari Ailus X-Patchwork-Id: 13632460 Received: from mgamail.intel.com (mgamail.intel.com [198.175.65.13]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id C20BD139D01 for ; Tue, 16 Apr 2024 19:33:41 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=198.175.65.13 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1713296023; cv=none; b=lMyciVx1mQR5z3JztzA5PPFLG+W7wo16PldRKhkmx9jKnQvCRdkcINbr2CPduR/Ydua6gBDZspv+2Ym2iJ+/JYU7uBXVD/6mGSQJrUxcwkZ6doNCLiv2cX5jT12+DiDaJxeAjePNF9skD1Hguf6VZ2QLGNfGT2+bQ7voqu7AUis= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1713296023; c=relaxed/simple; bh=2hHBHb9a2LHDXxsOGs2nNxxqI4BCTfEtOUY1FDAPwVc=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=Wv1LfS5bj3gcVA1RgoxaYL+teCvmbOzRvg3sYGVJMA8kMx7n6kAamGXx/NNpBcLJUvtE2fP2zSkEmdCQF19g24/y+cqzMcRxaNQeEphXmHGpVzEta3akHTo4zo46WA9qmIHrmgDsR8iethw9bIANXcjXTmMwxjyfo+3wFkYpgvs= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.intel.com; spf=none smtp.mailfrom=linux.intel.com; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b=eqxy+QHR; arc=none smtp.client-ip=198.175.65.13 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.intel.com Authentication-Results: smtp.subspace.kernel.org; spf=none smtp.mailfrom=linux.intel.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b="eqxy+QHR" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1713296022; x=1744832022; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=2hHBHb9a2LHDXxsOGs2nNxxqI4BCTfEtOUY1FDAPwVc=; b=eqxy+QHRNSi0NHUu4WhLcTYLMiOfC28/QkVl5LsK3G/TftVAI+5+dPzx Vkri41NhI3qs5Lb+2YilLTHVMhNJ6mBagoTlE5WVi/fgKFClu3A60lkVX HiSt9KodzIJKg1D5NNC5399cvOPo0Hs41K7o4hyc2gmjDYIwOES1rp46n s8sGWIeOMqn+oJJB58QlIm/ikm0OE6yVJ7vmhCO9rIx75obhVmZW3KQJV N0jb1TmkbzjZQSO1SAe23R/TVsil1DisoC0wGLvL/6aU93KQ0DyNlpoyn tCwoF2jryHGKbYbNgtZ8i6Z2OoFIpjzTmzI7Y8H1Jc4+TD00uC6HyXlcD Q==; X-CSE-ConnectionGUID: EEi7DHMYRciiZcVyjit/6w== X-CSE-MsgGUID: AKlfXrCMR3eUQidqfkYfQw== X-IronPort-AV: E=McAfee;i="6600,9927,11046"; a="19906062" X-IronPort-AV: E=Sophos;i="6.07,206,1708416000"; d="scan'208";a="19906062" Received: from orviesa005.jf.intel.com ([10.64.159.145]) by orvoesa105.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 16 Apr 2024 12:33:42 -0700 X-CSE-ConnectionGUID: XXibV3UET+yYjnzfCVe7bQ== X-CSE-MsgGUID: 9zIc7MUhQlanw9dSz85O6w== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.07,206,1708416000"; d="scan'208";a="27155285" Received: from turnipsi.fi.intel.com (HELO kekkonen.fi.intel.com) ([10.237.72.44]) by orviesa005-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 16 Apr 2024 12:33:39 -0700 Received: from svinhufvud.ger.corp.intel.com (localhost [IPv6:::1]) by kekkonen.fi.intel.com (Postfix) with ESMTP id 320E312056F; Tue, 16 Apr 2024 22:33:35 +0300 (EEST) From: Sakari Ailus To: linux-media@vger.kernel.org Cc: Laurent Pinchart , tomi.valkeinen@ideasonboard.com, bingbu.cao@intel.com, hongju.wang@intel.com, hverkuil@xs4all.nl, Andrey Konovalov , Jacopo Mondi , Dmitry Perchanov , "Ng, Khai Wen" , Alain Volmat Subject: [PATCH v9 10/46] media: Documentation: v4l: Document internal sink pads Date: Tue, 16 Apr 2024 22:32:43 +0300 Message-Id: <20240416193319.778192-11-sakari.ailus@linux.intel.com> X-Mailer: git-send-email 2.39.2 In-Reply-To: <20240416193319.778192-1-sakari.ailus@linux.intel.com> References: <20240416193319.778192-1-sakari.ailus@linux.intel.com> Precedence: bulk X-Mailing-List: linux-media@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Document internal sink pads, pads that have both SINK and INTERNAL flags set. Use the IMX219 camera sensor as an example. Signed-off-by: Sakari Ailus Reviewed-by Julien Massot --- .../userspace-api/media/v4l/dev-subdev.rst | 145 ++++++++++++++++++ 1 file changed, 145 insertions(+) diff --git a/Documentation/userspace-api/media/v4l/dev-subdev.rst b/Documentation/userspace-api/media/v4l/dev-subdev.rst index b76e02e54512..d30dcb9e2537 100644 --- a/Documentation/userspace-api/media/v4l/dev-subdev.rst +++ b/Documentation/userspace-api/media/v4l/dev-subdev.rst @@ -553,6 +553,27 @@ A stream at a specific point in the media pipeline is identified by the sub-device and a (pad, stream) pair. For sub-devices that do not support multiplexed streams the 'stream' field is always 0. +.. _v4l2-subdev-internal-source-pads: + +Internal sink pads and routing +^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ + +Cases where a single sub-device source pad is traversed by multiple streams, one +or more of which originate from within the sub-device itself, are special as +there is no external sink pad for such routes. In those cases, the sources of +the internally generated streams are represented by internal sink pads, which +are sink pads that have the :ref:`MEDIA_PAD_FL_INTERNAL ` +pad flag set. + +Internal pads have all the properties of an external pad, including formats and +selections. The format in this case is the source format of the stream. An +internal pad always has a single stream only (0). + +Routes from an internal sink pad to an external source pad are typically not +modifiable but they can be activated and deactivated using the +:ref:`V4L2_SUBDEV_ROUTE_FL_ACTIVE ` flag, depending +on driver capabilities. + Interaction between routes, streams, formats and selections ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ @@ -668,3 +689,127 @@ To configure this pipeline, the userspace must take the following steps: the configurations along the stream towards the receiver, using :ref:`VIDIOC_SUBDEV_S_FMT ` ioctls to configure each stream endpoint in each sub-device. + +Internal pads setup example +^^^^^^^^^^^^^^^^^^^^^^^^^^^ + +A simple example of a multiplexed stream setup might be as follows: + +- An IMX219 camera sensor source sub-device, with one source pad (0), one + internal sink pad (1) as the source of the image data and an internal sink + pad (2) as the source of the embedded data. There are two routes, one from the + internal sink pad 1 to the source 0 (image data) and another from the internal + sink pad 2 to the source pad 0 (embedded data). Both streams are always + active, i.e. there is no need to separately enable the embedded data + stream. The sensor uses the CSI-2 interface. + +- A CSI-2 receiver in the SoC. The receiver has a single sink pad (pad 0), + connected to the sensor, and two source pads (pads 1 and 2), to the DMA + engine. The receiver demultiplexes the incoming streams to the source pads. + +- DMA engines in the SoC, one for each stream. Each DMA engine is connected to a + single source pad of the receiver. + +The sensor and the receiver are modelled as V4L2 sub-devices, exposed to +userspace via /dev/v4l-subdevX device nodes. The DMA engines are modelled as +V4L2 devices, exposed to userspace via /dev/videoX nodes. + +To configure this pipeline, the userspace must take the following steps: + +1) Set up media links between entities: enable the links from the sensor to the + receiver and from the receiver to the DMA engines. This step does not differ + from normal non-multiplexed media controller setup. + +2) Configure routing + +.. flat-table:: Camera sensor. There are no configurable routes. + :header-rows: 1 + + * - Sink Pad/Stream + - Source Pad/Stream + - Routing Flags + - Comments + * - 1/0 + - 0/0 + - V4L2_SUBDEV_ROUTE_FL_ACTIVE + - Pixel data stream from the sink pad + * - 2/0 + - 0/1 + - V4L2_SUBDEV_ROUTE_FL_ACTIVE + - Metadata stream from the internal sink pad + +.. flat-table:: Receiver routing table. Typically both routes need to be + explicitly set. + :header-rows: 1 + + * - Sink Pad/Stream + - Source Pad/Stream + - Routing Flags + - Comments + * - 0/0 + - 1/0 + - V4L2_SUBDEV_ROUTE_FL_ACTIVE + - Pixel data stream from camera sensor + * - 0/1 + - 2/0 + - V4L2_SUBDEV_ROUTE_FL_ACTIVE + - Metadata stream from camera sensor + +The options available in sensor's routing configuration are dictated by hardware +capabilities: typically camera sensors always produce an image data stream while +it may be possible to enable and disable the embedded data stream. + +3) Configure formats and selections + + This example assumes that the formats are propagated from sink pad to the + source pad as-is. The tables contain fields of both struct v4l2_subdev_format + and struct v4l2_mbus_framefmt. + +.. flat-table:: Formats set on the sub-devices. Bold values are set, others are + static or propagated. The order is aligned with configured + routes. + :header-rows: 1 + :fill-cells: + + * - Sub-device + - Pad/Stream + - Width + - Height + - Code + * - :rspan:`3` IMX219 + - 1/0 + - 3296 + - 2480 + - MEDIA_BUS_FMT_SRGGB10 + * - 0/0 + - **3296** + - **2480** + - **MEDIA_BUS_FMT_SRGGB10** + * - 2/0 + - 3296 + - 2 + - MEDIA_BUS_FMT_IMX219_EMBEDDED + * - 1/1 + - 3296 + - 2 + - MEDIA_BUS_FMT_META_10 + * - :rspan:`3` CSI-2 receiver + - 0/0 + - **3296** + - **2480** + - **MEDIA_BUS_FMT_SRGGB10** + * - 1/0 + - 3296 + - 2480 + - MEDIA_BUS_FMT_SRGGB10 + * - 0/1 + - **3296** + - **2** + - **MEDIA_BUS_FMT_META_10** + * - 2/0 + - 3296 + - 2 + - MEDIA_BUS_FMT_META_10 + +The embedded data format does not need to be configured as the format is +dictated by the pixel data format in this case.