Kernel driver vexpress¶
ARM Ltd. Versatile Express platform
"Hardware Description" sections of the Technical Reference Manuals for the Versatile Express boards:
Section "4.4.14. System Configuration registers" of the V2M-P1 TRM:
Author: Pawel Moll
Versatile Express platform (http://www.arm.com/versatileexpress/) is a reference & prototyping system for ARM Ltd. processors. It can be set up from a wide range of boards, each of them containing (apart of the main chip/FPGA) a number of microcontrollers responsible for platform configuration and control. These microcontrollers can also monitor the board and its environment by a number of internal and external sensors, providing information about power lines voltages and currents, board temperature and power usage. Some of them also calculate consumed energy and provide a cumulative use counter.
The configuration devices are _not_ memory mapped and must be accessed via a custom interface, abstracted by the "vexpress_config" API.
As these devices are non-discoverable, they must be described in a Device Tree passed to the kernel. Details of the DT binding for them can be found in Documentation/devicetree/bindings/hwmon/vexpress.txt.