mirror of
https://github.com/openwrt/openwrt.git
synced 2024-12-27 17:18:59 +00:00
0171157d45
The patches were generated from the RPi repo with the following command: git format-patch v6.6.44..rpi-6.6.y Signed-off-by: Álvaro Fernández Rojas <noltari@gmail.com>
163 lines
7.1 KiB
Diff
163 lines
7.1 KiB
Diff
From d68e76260316002869aea1b0edf4be399bb592b8 Mon Sep 17 00:00:00 2001
|
|
From: Jacopo Mondi <jacopo.mondi@ideasonboard.com>
|
|
Date: Mon, 29 Jan 2024 17:23:55 +0100
|
|
Subject: [PATCH 1153/1215] media: admin-guide: Document the Raspberry Pi PiSP
|
|
BE
|
|
|
|
Add documentation for the PiSP Back End memory-to-memory ISP.
|
|
|
|
Signed-off-by: Jacopo Mondi <jacopo.mondi@ideasonboard.com>
|
|
---
|
|
.../admin-guide/media/raspberrypi-pisp-be.dot | 20 ++++
|
|
.../admin-guide/media/raspberrypi-pisp-be.rst | 109 ++++++++++++++++++
|
|
.../admin-guide/media/v4l-drivers.rst | 1 +
|
|
3 files changed, 130 insertions(+)
|
|
create mode 100644 Documentation/admin-guide/media/raspberrypi-pisp-be.dot
|
|
create mode 100644 Documentation/admin-guide/media/raspberrypi-pisp-be.rst
|
|
|
|
--- /dev/null
|
|
+++ b/Documentation/admin-guide/media/raspberrypi-pisp-be.dot
|
|
@@ -0,0 +1,20 @@
|
|
+digraph board {
|
|
+ rankdir=TB
|
|
+ n00000001 [label="{{<port0> 0 | <port1> 1 | <port2> 2 | <port7> 7} | pispbe\n | {<port3> 3 | <port4> 4 | <port5> 5 | <port6> 6}}", shape=Mrecord, style=filled, fillcolor=green]
|
|
+ n00000001:port3 -> n0000001c [style=bold]
|
|
+ n00000001:port4 -> n00000022 [style=bold]
|
|
+ n00000001:port5 -> n00000028 [style=bold]
|
|
+ n00000001:port6 -> n0000002e [style=bold]
|
|
+ n0000000a [label="pispbe-input\n/dev/video0", shape=box, style=filled, fillcolor=yellow]
|
|
+ n0000000a -> n00000001:port0 [style=bold]
|
|
+ n00000010 [label="pispbe-tdn_input\n/dev/video1", shape=box, style=filled, fillcolor=yellow]
|
|
+ n00000010 -> n00000001:port1 [style=bold]
|
|
+ n00000016 [label="pispbe-stitch_input\n/dev/video2", shape=box, style=filled, fillcolor=yellow]
|
|
+ n00000016 -> n00000001:port2 [style=bold]
|
|
+ n0000001c [label="pispbe-output0\n/dev/video3", shape=box, style=filled, fillcolor=yellow]
|
|
+ n00000022 [label="pispbe-output1\n/dev/video4", shape=box, style=filled, fillcolor=yellow]
|
|
+ n00000028 [label="pispbe-tdn_output\n/dev/video5", shape=box, style=filled, fillcolor=yellow]
|
|
+ n0000002e [label="pispbe-stitch_output\n/dev/video6", shape=box, style=filled, fillcolor=yellow]
|
|
+ n00000034 [label="pispbe-config\n/dev/video7", shape=box, style=filled, fillcolor=yellow]
|
|
+ n00000034 -> n00000001:port7 [style=bold]
|
|
+}
|
|
--- /dev/null
|
|
+++ b/Documentation/admin-guide/media/raspberrypi-pisp-be.rst
|
|
@@ -0,0 +1,109 @@
|
|
+.. SPDX-License-Identifier: GPL-2.0
|
|
+
|
|
+=========================================================
|
|
+Raspberry Pi PiSP Back End Memory-to-Memory ISP (pisp-be)
|
|
+=========================================================
|
|
+
|
|
+The PiSP Back End
|
|
+=================
|
|
+
|
|
+The PiSP Back End is a memory-to-memory Image Signal Processor (ISP) which reads
|
|
+image data from DRAM memory and performs image processing as specified by the
|
|
+application through the parameters in a configuration buffer, before writing
|
|
+pixel data back to memory through two distinct output channels.
|
|
+
|
|
+The ISP registers and programming model are documented in the `Raspberry Pi
|
|
+Image Signal Processor (PiSP) Specification document`_
|
|
+
|
|
+The PiSP Back End ISP processes images in tiles. The handling of image
|
|
+tessellation and the computation of low-level configuration parameters is
|
|
+realized by a free software library called `libpisp
|
|
+<https://github.com/raspberrypi/libpisp>`_.
|
|
+
|
|
+The full image processing pipeline, which involves capturing RAW Bayer data from
|
|
+an image sensor through a MIPI CSI-2 compatible capture interface, storing them
|
|
+in DRAM memory and processing them in the PiSP Back End to obtain images usable
|
|
+by an application is implemented in `libcamera <https://libcamera.org>`_ as
|
|
+part of the Raspberry Pi platform support.
|
|
+
|
|
+The pisp-be driver
|
|
+==================
|
|
+
|
|
+The Raspberry Pi PiSP Back End (pisp-be) driver is located under
|
|
+drivers/media/platform/raspberrypi/pisp-be. It uses the `V4L2 API` to register
|
|
+a number of video capture and output devices, the `V4L2 subdev API` to register
|
|
+a subdevice for the ISP that connects the video devices in a single media graph
|
|
+realized using the `Media Controller (MC) API`.
|
|
+
|
|
+The media topology registered by the `pisp-be` driver is represented below:
|
|
+
|
|
+.. _pips-be-topology:
|
|
+
|
|
+.. kernel-figure:: raspberrypi-pisp-be.dot
|
|
+ :alt: Diagram of the default media pipeline topology
|
|
+ :align: center
|
|
+
|
|
+
|
|
+The media graph registers the following video device nodes:
|
|
+
|
|
+- pispbe-input: output device for images to be submitted to the ISP for
|
|
+ processing.
|
|
+- pispbe-tdn_input: output device for temporal denoise.
|
|
+- pispbe-stitch_input: output device for image stitching (HDR).
|
|
+- pispbe-output0: first capture device for processed images.
|
|
+- pispbe-output1: second capture device for processed images.
|
|
+- pispbe-tdn_output: capture device for temporal denoise.
|
|
+- pispbe-stitch_output: capture device for image stitching (HDR).
|
|
+- pispbe-config: output device for ISP configuration parameters.
|
|
+
|
|
+pispbe-input
|
|
+------------
|
|
+
|
|
+Images to be processed by the ISP are queued to the `pispbe-input` output device
|
|
+node. For a list of image formats supported as input to the ISP refer to the
|
|
+`Raspberry Pi Image Signal Processor (PiSP) Specification document`_.
|
|
+
|
|
+pispbe-tdn_input, pispbe-tdn_output
|
|
+-----------------------------------
|
|
+
|
|
+The `pispbe-tdn_input` output video device receives images to be processed by
|
|
+the temporal denoise block which are captured from the `pispbe-tdn_output`
|
|
+capture video device. Userspace is responsible for maintaining queues on both
|
|
+devices, and ensuring that buffers completed on the output are queued to the
|
|
+input.
|
|
+
|
|
+pispbe-stitch_input, pispbe-stitch_output
|
|
+-----------------------------------------
|
|
+
|
|
+To realize HDR (high dynamic range) image processing the image stitching and
|
|
+tonemapping blocks are used. The `pispbe-stitch_output` writes images to memory
|
|
+and the `pispbe-stitch_input` receives the previously written frame to process
|
|
+it along with the current input image. Userspace is responsible for maintaining
|
|
+queues on both devices, and ensuring that buffers completed on the output are
|
|
+queued to the input.
|
|
+
|
|
+pispbe-output0, pispbe-output1
|
|
+------------------------------
|
|
+
|
|
+The two capture devices write to memory the pixel data as processed by the ISP.
|
|
+
|
|
+pispbe-config
|
|
+-------------
|
|
+
|
|
+The `pispbe-config` output video devices receives a buffer of configuration
|
|
+parameters that define the desired image processing to be performed by the ISP.
|
|
+
|
|
+The format of the ISP configuration parameter is defined by
|
|
+:c:type:`pisp_be_tiles_config` C structure and the meaning of each parameter is
|
|
+described in the `Raspberry Pi Image Signal Processor (PiSP) Specification
|
|
+document`_.
|
|
+
|
|
+ISP configuration
|
|
+=================
|
|
+
|
|
+The ISP configuration is described solely by the content of the parameters
|
|
+buffer. The only parameter that userspace needs to configure using the V4L2 API
|
|
+is the image format on the output and capture video devices for validation of
|
|
+the content of the parameters buffer.
|
|
+
|
|
+.. _Raspberry Pi Image Signal Processor (PiSP) Specification document: https://datasheets.raspberrypi.com/camera/raspberry-pi-image-signal-processor-specification.pdf
|
|
--- a/Documentation/admin-guide/media/v4l-drivers.rst
|
|
+++ b/Documentation/admin-guide/media/v4l-drivers.rst
|
|
@@ -21,6 +21,7 @@ Video4Linux (V4L) driver-specific docume
|
|
omap4_camera
|
|
philips
|
|
qcom_camss
|
|
+ raspberrypi-pisp-be
|
|
rcar-fdp1
|
|
rkisp1
|
|
saa7134
|