From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from perceval.ideasonboard.com (perceval.ideasonboard.com [213.167.242.64]) (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 28CB5EEC0; Tue, 5 Aug 2025 11:37:34 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=213.167.242.64 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1754393857; cv=none; b=RZy6IOMKS2Ta59d4T1hT4GBYWkYKsxN0bZ+/ZpxRn0yT1zCVZ2m2p+ZjHZQWFwyth6laB6Z95TRop66sKd9LGlFFSS6/qyvMZu3YM6IFCLv4LP0PJlqPb6OuynxyekQ20o6HhjUtbImd6igCkUabMzmxDnGFsLXO/vdjr3BdBs0= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1754393857; c=relaxed/simple; bh=pzknJzdLsQ0UdjwXfakRUzrYvY8rSGUHH5bJks8yJCE=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=nXjOciraCxtDju/sPrLYa9wUGQvxcL91czTSlI4gA+gEwq9QtAGXl+L3suzcdVmzHFrSjTYPTA9TidoUbo5G4wp4pA8rfAXsnV26r4akviV/1zdB/Sinnz+pcEBSu9VYn6eh2ZGa2TJXaC+T1N7vtTa5B3Vb6wMggPDQ1aeFpd8= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=ideasonboard.com; spf=pass smtp.mailfrom=ideasonboard.com; dkim=pass (1024-bit key) header.d=ideasonboard.com header.i=@ideasonboard.com header.b=wQDNy6KL; arc=none smtp.client-ip=213.167.242.64 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=ideasonboard.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=ideasonboard.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=ideasonboard.com header.i=@ideasonboard.com header.b="wQDNy6KL" Received: from pendragon.ideasonboard.com (81-175-209-231.bb.dnainternet.fi [81.175.209.231]) by perceval.ideasonboard.com (Postfix) with UTF8SMTPSA id CF00F664; Tue, 5 Aug 2025 13:36:45 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=ideasonboard.com; s=mail; t=1754393806; bh=pzknJzdLsQ0UdjwXfakRUzrYvY8rSGUHH5bJks8yJCE=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=wQDNy6KLUkiR3+cp4aRj4/Ic0aLZJOCX1CWxfDlIBj0EKQtkgjhdzeRxrQ16OTgI/ hrnh0HATxPbHq48EkYymZt0RWFd6dnhMDBBKYI5+xLeUeDyRWtxcsnMVw22p4OElh/ DD/gqN+kbtebQsvPsnOVOuj0WtM8ajiy1lWrhAmc= Date: Tue, 5 Aug 2025 14:37:19 +0300 From: Laurent Pinchart To: Bin Du Cc: mchehab@kernel.org, hverkuil@xs4all.nl, bryan.odonoghue@linaro.org, sakari.ailus@linux.intel.com, prabhakar.mahadev-lad.rj@bp.renesas.com, linux-media@vger.kernel.org, linux-kernel@vger.kernel.org, pratap.nirujogi@amd.com, benjamin.chan@amd.com, king.li@amd.com, gjorgji.rosikopulos@amd.com, Phil.Jawich@amd.com, Dominic.Antony@amd.com, Svetoslav.Stoilov@amd.com Subject: Re: [PATCH v2 8/8] Documentation: add documentation of AMD isp 4 driver Message-ID: <20250805113719.GF24627@pendragon.ideasonboard.com> References: <20250618091959.68293-1-Bin.Du@amd.com> <20250618091959.68293-9-Bin.Du@amd.com> Precedence: bulk X-Mailing-List: linux-media@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20250618091959.68293-9-Bin.Du@amd.com> On Wed, Jun 18, 2025 at 05:19:59PM +0800, Bin Du wrote: > Add documentation for AMD isp 4 and describe the main components > > Signed-off-by: Bin Du > Signed-off-by: Svetoslav Stoilov > --- > Documentation/admin-guide/media/amdisp4-1.rst | 64 +++++++++++++++++++ > Documentation/admin-guide/media/amdisp4.dot | 8 +++ > MAINTAINERS | 2 + > 3 files changed, 74 insertions(+) > create mode 100644 Documentation/admin-guide/media/amdisp4-1.rst > create mode 100644 Documentation/admin-guide/media/amdisp4.dot > > diff --git a/Documentation/admin-guide/media/amdisp4-1.rst b/Documentation/admin-guide/media/amdisp4-1.rst > new file mode 100644 > index 000000000000..417b15af689a > --- /dev/null > +++ b/Documentation/admin-guide/media/amdisp4-1.rst > @@ -0,0 +1,64 @@ > +.. SPDX-License-Identifier: GPL-2.0 > + > +.. include:: > + > +==================================== > +AMD Image Signal Processor (amdisp4) > +==================================== > + > +Introduction > +============ > + > +This file documents the driver for the AMD ISP4 that is part of > +AMD Ryzen AI Max 385 SoC. > + > +The driver is located under drivers/media/platform/amd/isp4 and uses > +the Media-Controller API. > + > +Topology > +======== > + > +.. _amdisp4_topology_graph: > + > +.. kernel-figure:: amdisp4.dot > + :alt: Diagram of the media pipeline topology > + :align: center > + > + > + > +The driver has 1 sub-device: > + > +- isp: used to resize and process bayer raw frames in to yuv. > + > +The driver has 1 video device: > + > +- + > + > + - ISP4 Image Signal Processing Subdevice Node > +----------------------------------------------- > + > +The isp4 is represented as a single V4L2 subdev, the sub-device does not > +provide interface to the user space. Doesn't it ? The driver sets the V4L2_SUBDEV_FL_HAS_DEVNODE flag for the subdev, and calls v4l2_device_register_subdev_nodes(). As far as I understand, the camera is exposed by the firmware with a webcam-like interface. We need to better understand your plans with this driver. If everything is handled by the firmware, why are the sensor and subdev exposed to userspace ? Why can't you expose a single video capture device, with a media device, and handle everything behind the scene ? I assume there may be more features coming later. Please document the plan, we can't provide feedback on the architecture otherwise. > The sub-device is connected to one video node > +(isp4_capture) with immutable active link. The isp entity is connected > +to sensor pad 0 and receives the frames using CSI-2 protocol. The sub-device is > +also responsible to configure CSI2-2 receiver. > +The sub-device processes bayer raw data from the connected sensor and output > +them to different YUV formats. The isp also has scaling capabilities. > + > + - isp4_capture - Frames Capture Video Node > +-------------------------------------------- > + > +Isp4_capture is a capture device to capture frames to memory. > +This entity is the DMA engine that write the frames to memory. > +The entity is connected to isp4 sub-device. > + > +Capturing Video Frames Example > +============================== > + > +.. code-block:: bash > + > + # set the links This seems very under-documented. > + > + # start streaming: > + v4l2-ctl "-d" "/dev/video0" "--set-fmt-video=width=1920,height=1080,pixelformat=NV12" "--stream-mmap" "--stream-count=10" > diff --git a/Documentation/admin-guide/media/amdisp4.dot b/Documentation/admin-guide/media/amdisp4.dot > new file mode 100644 > index 000000000000..a4c2f0cceb30 > --- /dev/null > +++ b/Documentation/admin-guide/media/amdisp4.dot > @@ -0,0 +1,8 @@ > +digraph board { > + rankdir=TB > + n00000001 [label="{{ 0} | amd isp4\n | { 1}}", shape=Mrecord, style=filled, fillcolor=green] > + n00000001:port1 -> n00000004 [style=bold] > + n00000004 [label="Preview\n/dev/video0", shape=box, style=filled, fillcolor=yellow] > + n0000000a [label="{{} | ov05c10 22-0010\n/dev/v4l-subdev0 | { 0}}", shape=Mrecord, style=filled, fillcolor=green] > + n0000000a:port0 -> n00000001:port0 [style=bold] > +} > diff --git a/MAINTAINERS b/MAINTAINERS > index 15070afb14b5..e4455bde376f 100644 > --- a/MAINTAINERS > +++ b/MAINTAINERS > @@ -1113,6 +1113,8 @@ M: Nirujogi Pratap > L: linux-media@vger.kernel.org > S: Maintained > T: git git://linuxtv.org/media.git > +F: Documentation/admin-guide/media/amdisp4-1.rst > +F: Documentation/admin-guide/media/amdisp4.dot > F: drivers/media/platform/amd/Kconfig > F: drivers/media/platform/amd/Makefile > F: drivers/media/platform/amd/isp4/* -- Regards, Laurent Pinchart