of_node_put needs to be called when the device node which is got
from of_parse_phandle has finished using it.

Besides, of_address_to_resource always returns -EINVAL for error, delete
the assignment for ret.

Signed-off-by: Peter Chen <peter.chen@nxp.com>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>

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>

scpi_get_sensor_value like other scpi operations needs to be static.
This patch marks it as static to be consistent with others.

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

dvfs_get packed structure is used to read the DVFS/OPP index from the
firmware. It just contains a single byte that needs no packing making
the whole structure defination unnecessary.

This patch replaces the unnecessary dvfs_get packed structure with an
unsigned byte.

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

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>

Currently we have Tx timeout of 50ms while Rx timeout of 20 ms. Tx state
machine is maintained by the mailbox framework and Rx by SCPI driver.

It is possible that before msg_submit call tx_prepare(because of other
message in the queue and the channel being active), wait for completion
in scpi_send_message times out and the buffers are freed. In that case
when Tx state machine timer goes off later, poll_txdone calls
scpi_tx_prepare on that message, which adds it to the rx_pending list,
corrupting link pointers.

This patch reduces the Tx timeout to 20ms and increases Rx timeout to
30ms to avoid the above mentioned issue.

Reported-by: Jon Medhurst (Tixy) <tixy@linaro.org>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>

scpi_process_cmd converts the status word from little endian to cpu
endianness. However scpi_send_message again does the conversion which is
wrong and shows up as a bug only when running in big-endian kernel.

Similarly scpi_sensor_get_value passes the sensor index in the cpu
endianness to SCP which results in SCPI_ERR_RANGE in big-endian mode.

This patch fixes the above mentioned issue for big-endian kernel.

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

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>

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>