Merge tag 'arm-scpi-for-v4.4' of git://git.kernel.org/pub/scm/linux/kernel/git/sudeep.holla/linux into next/drivers

Merge "ARM System Control and Power Interface(SCPI) support" from Sudeep Holla

It adds support for the following features provided by SCP firmware
using different subsystems in Linux:
  1. SCPI mailbox protocol driver which using mailbox framework
  2. Clocks provided by SCP using clock framework
  3. CPU DVFS(cpufreq) using existing arm-big-little driver
  4. SCPI based sensors including temperature sensors

* tag 'arm-scpi-for-v4.4' of git://git.kernel.org/pub/scm/linux/kernel/git/sudeep.holla/linux:
  hwmon: Support thermal zones registration for SCP temperature sensors
  hwmon: Support sensors exported via ARM SCP interface
  firmware: arm_scpi: Extend to support sensors
  Documentation: add DT bindings for ARM SCPI sensors
  cpufreq: arm_big_little: add SCPI interface driver
  clk: scpi: add support for cpufreq virtual device
  clk: add support for clocks provided by SCP(System Control Processor)
  firmware: add support for ARM System Control and Power Interface(SCPI) protocol
  Documentation: add DT binding for ARM System Control and Power Interface(SCPI) protocol

drivers/firmware/Kconfig

@@ -8,6 +8,25 @@ menu "Firmware Drivers"
 config ARM_PSCI_FW
 	bool
 
+config ARM_SCPI_PROTOCOL
+	tristate "ARM System Control and Power Interface (SCPI) Message Protocol"
+	depends on ARM_MHU
+	help
+	  System Control and Power Interface (SCPI) Message Protocol is
+	  defined for the purpose of communication between the Application
+	  Cores(AP) and the System Control Processor(SCP). The MHU peripheral
+	  provides a mechanism for inter-processor communication between SCP
+	  and AP.
+
+	  SCP controls most of the power managament on the Application
+	  Processors. It offers control and management of: the core/cluster
+	  power states, various power domain DVFS including the core/cluster,
+	  certain system clocks configuration, thermal sensors and many
+	  others.
+
+	  This protocol library provides interface for all the client drivers
+	  making use of the features offered by the SCP.
+
 config EDD
 	tristate "BIOS Enhanced Disk Drive calls determine boot disk"
 	depends on X86