Cameras in Embedded Systems - Device Tree and ACPI Implementation

Explore the intricacies of camera integration in embedded systems through a comprehensive examination of Device Tree and ACPI implementations. Delve into the evolution from platform data to Device Tree solutions, focusing on the V4L2 framework and its asynchronous capabilities. Gain insights into driver implementation, Device Tree source utilization, and the current state of ACPI support. Learn about the components of embedded camera systems, including sensors, lenses, flashes, and Image Signal Processors (ISPs). Discover how to navigate media graphs, handle probing and device setup, and implement V4L2 async for both ISPs and sensors. Examine Device Tree standards, bindings, and graph structures, along with ACPI Device Specific Data and firmware node APIs. Understand camera module power sequences and firmware logistics to enhance your embedded systems development skills.

Intro
A typical embedded system with a camera
Image signal processors
Video4 Linux and Media controller
Example of a media graph
Probing
Media device setup
V4L2 async example (ISP)
V4L2 async (sensor)
Device Tree standard and bindings
Device tree graphs phandle properties can be used to refer to other nodes in the tree
Sensor node
ISP node board specific part
OF graph API
ACPI Device Specific Data
fwnode property API
Fwnode graph API
Flash
Camera module power on and power off sequences
Firmware logistics