firmware: arm_scpi: Fix kernel doc warnings

Kernel doc validation script is unhappy and complains with the below set
of warnings.

| Function parameter or member 'device_domain_id' not described in 'scpi_ops'
| Function parameter or member 'get_transition_latency' not described in 'scpi_ops'
| Function parameter or member 'add_opps_to_device' not described in 'scpi_ops'
| Function parameter or member 'sensor_get_capability' not described in 'scpi_ops'
| Function parameter or member 'sensor_get_info' not described in 'scpi_ops'
| Function parameter or member 'sensor_get_value' not described in 'scpi_ops'
| Function parameter or member 'device_get_power_state' not described in 'scpi_ops'
| Function parameter or member 'device_set_power_state' not described in 'scpi_ops'

Fix them adding appropriate documents or missing keywords.

Link: https://lore.kernel.org/r/20210712130801.2436492-1-sudeep.holla@arm.com
Reviewed-by: Cristian Marussi <cristian.marussi@arm.com>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>

firmware: arm_scpi: Add include guard to linux/scpi_protocol.h

If this header is include twice, it will generate loads of compile
time error with the following below error pattern. It was reported by
0day kbuild robot on a branch pushed with double inclusion by accident.
This is based on the similar change in linux/scmi_protocol.h

error: conflicting types for ‘...’
note: previous declaration of ‘...’ was here
error: redefinition of ‘...’

Add a header include guard just in case.

Link: https://lore.kernel.org/r/20200403171018.1230-2-sudeep.holla@arm.com
Reported-by: kbuild test robot <lkp@intel.com>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 201

Based on 1 normalized pattern(s):

this program is free software you can redistribute it and or modify
it under the terms and conditions of the gnu general public license
version 2 as published by the free software foundation this program
is distributed in the hope it will be useful but without any
warranty without even the implied warranty of merchantability or
fitness for a particular purpose see the gnu general public license
for more details you should have received a copy of the gnu general
public license along with this program if not see http www gnu org
licenses

extracted by the scancode license scanner the SPDX license identifier

GPL-2.0-only

has been chosen to replace the boilerplate/reference in 228 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Reviewed-by: Steve Winslow <swinslow@gmail.com>
Reviewed-by: Richard Fontana <rfontana@redhat.com>
Reviewed-by: Alexios Zavras <alexios.zavras@intel.com>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190528171438.107155473@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

firmware: arm_scpi: add support to populate OPPs and get transition latency

Currently only CPU devices use the transition latency and the OPPs
populated in the SCPI driver. scpi-cpufreq has logic to handle these.
However, even GPU and other users of SCPI DVFS will need the same logic.

In order to avoid duplication, this patch adds support to get DVFS
transition latency and add all the OPPs to the device using OPP library
helper functions. The helper functions added here can be used for any
device whose DVFS are managed by SCPI.

Also, we also have incorrect dependency on the cluster identifier for
the CPUs. It's fundamentally wrong as the domain id need not match the
cluster id. This patch gets rid of that dependency by making use of the
clock bindings which are already in place.

Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>

firmware: arm_scpi: add support for device power state management

SCPI protocol supports device power state management. This deals with
power states of various peripheral devices in the system other than the
core compute subsystem.

This patch adds support for the power state management of those
peripheral devices.

Tested-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Tested-by: Jon Medhurst <tixy@linaro.org>
Reviewed-by: Jon Medhurst <tixy@linaro.org>
Reviewed-by: Kevin Hilman <khilman@baylibre.com>
Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>

hwmon: (scpi) add energy meter support

SCPI specification v1.1 adds support for energy sensors. This patch
adds support for the same.

Acked-by: Guenter Roeck <linux@roeck-us.net>
Reviewed-by: Punit Agrawal <punit.agrawal@arm.com>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>

firmware: arm_scpi: add support for 64-bit sensor values

SCPI specification version 1.1 extended the sensor from 32-bit to 64-bit
values in order to accommodate new sensor class with 64-bit requirements

Since the SCPI driver sets the higher 32-bit for older protocol version
to zeros, there's no need to explicitly check the SCPI protocol version
and the backward compatibility is maintainted.

Acked-by: Guenter Roeck <linux@roeck-us.net>
Reviewed-by: Punit Agrawal <punit.agrawal@arm.com>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>

scpi: hide get_scpi_ops in module from built-in code

The scpi_clock driver can be built-in when CONFIG_COMPILE_TEST
is set even when ARM_SCPI_PROTOCOL is a loadable module, and
that results in a link error:

drivers/built-in.o: In function `scpi_clocks_probe':
(.text+0x14453c): undefined reference to `get_scpi_ops'

Using #if IS_REACHABLE() around the get_scpi_ops() declaration
makes it build successfully in this case for compile-testing,
but the effect is the same as when ARM_SCPI_PROTOCOL is
disabled, as the code will not be used.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Punit Agrawal <punit.agrawal@arm.com>

firmware: arm_scpi: Extend to support sensors

ARM System Control Processor (SCP) provides an API to query and use
the sensors available in the system. Extend the SCPI driver to support
sensor messages.

Signed-off-by: Punit Agrawal <punit.agrawal@arm.com>
Acked-by: Sudeep Holla <sudeep.holla@arm.com>

firmware: add support for ARM System Control and Power Interface(SCPI) protocol

This patch adds support for System Control and Power Interface (SCPI)
Message Protocol used between the Application Cores(AP) and the System
Control Processor(SCP). The MHU peripheral provides a mechanism for
inter-processor communication between SCP's M3 processor and AP.

SCP 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 driver provides interface for all the client drivers using
SCPI to make use of the features offered by the SCP.

Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
Reviewed-by: Jon Medhurst (Tixy) <tixy@linaro.org>
Cc: Jassi Brar <jassisinghbrar@gmail.com>
Cc: Liviu Dudau <Liviu.Dudau@arm.com>
Cc: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>