7.1. AMD Image Signal Processor (amdisp4)

7.1.1. Introduction

This file documents the driver for the AMD ISP4 that is part of AMD Ryzen AI Max 300 Series.

The driver is located under drivers/media/platform/amd/isp4 and uses the Media-Controller API.

The driver exposes one video capture device to userspace and provide web camera like interface. Internally the video device is connected to the isp4 sub-device responsible for communication with the CCPU FW.

7.1.2. Topology

Diagram of the media pipeline topology

The driver has 1 sub-device: Representing isp4 image signal processor. The driver has 1 video device: Capture device for retrieving images.

  • 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. The sub-device is connected to one video node (isp4_capture) with immutable active link. The sub-device represents ISP with connected sensor similar to smart cameras (sensors with integrated ISP). sub-device has only one link to the video device for capturing the frames. The sub-device communicates with CCPU FW for streaming configuration and buffer management.

  • isp4_capture - Frames Capture Video Node

Isp4_capture is a capture device to capture frames to memory. The entity is connected to isp4 sub-device. The video device provides web camera like interface to userspace. It supports mmap and dma buf types of memory.

7.1.3. Capturing Video Frames Example

v4l2-ctl "-d" "/dev/video0" "--set-fmt-video=width=1920,height=1080,pixelformat=NV12" "--stream-mmap" "--stream-count=10"