hwmon: Versatile Express hwmon driver

hwmon framework driver for Versatile Express sensors, providing
information about board level voltage (only when regulator driver
is not configured), currents, temperature and power/energy usage.
Labels for the values can be defined as DT properties.

Signed-off-by: Pawel Moll <pawel.moll@arm.com>
Acked-by: Guenter Roeck <linux@roeck-us.net>

1 files changed, 34 insertions, 0 deletions

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+Kernel driver vexpress
+======================
+
+Supported systems:
+  * ARM Ltd. Versatile Express platform
+    Prefix: 'vexpress'
+    Datasheets:
+      * "Hardware Description" sections of the Technical Reference Manuals
+        for the Versatile Express boards:
+        http://infocenter.arm.com/help/topic/com.arm.doc.subset.boards.express/index.html
+      * Section "4.4.14. System Configuration registers" of the V2M-P1 TRM:
+        http://infocenter.arm.com/help/index.jsp?topic=/com.arm.doc.dui0447-/index.html
+
+Author: Pawel Moll
+
+Description
+-----------
+
+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. Theses 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.