drivers/scmi-msg: smt entry points for incoming messages ...

This change implements SCMI channels for reading a SCMI message from a
shared memory and call the SCMI message drivers to route the message
to the target platform services.

SMT refers to the shared memory management protocol which is used
to get/put message/response in shared memory. SMT is a 28byte header
stating shared memory state and exchanged protocol data.

The processing entry for a SCMI message can be a secure interrupt
or fastcall SMCCC invocation.

SMT description in this implementation is based on the OP-TEE
project [1] itself based in the SCP-firmware implementation [2].

Link: [1] https://github.com/OP-TEE/optee_os/commit/a58c4d706d2333d2b21a3eba7e2ec0cb257bca1d
Link: [2] https://github.com/ARM-software/SCP-firmware.git

Change-Id: I416c7dab5c67954c6fe80bae8d8cdfdcda66873e
Signed-off-by: Etienne Carriere <etienne.carriere@linaro.org>

drivers/scmi-msg: support for reset domain protocol ...

Adds SCMI reset domain protocol support in the SCMI message drivers
as defined in SCMI specification v2.0 [1]. Not all the messages
defined in the specification are supported.

scmi_msg_get_rd_handler() sanitizes the message_id value
against any speculative use of reset domain ID as a index since by
SCMI specification, IDs are indices.

This implementation is based on the OP-TEE project implementation [2]
itself based on the SCP-firmware implementation [3] of the SCMI
protocol server side.

Link: [1] http://infocenter.arm.com/help/topic/com.arm.doc.den0056a/DEN0056A_System_Control_and_Management_Interface.pdf
Link: [2] https://github.com/OP-TEE/optee_os/commit/56a1f10ed99d683ee3a8af29b6147a59a99ef3e0
Link: [3] https://github.com/ARM-software/SCP-firmware.git

Change-Id: If7cf13de40a815dedb40dcd5af8b6bb6725d9078
Signed-off-by: Etienne Carriere <etienne.carriere@linaro.org>

drivers/scmi-msg: support for clock protocol ...

Adds SCMI clock protocol support in the SCMI message drivers as
defined in SCMI specification v2.0 [1] for clock protocol messages.

Platform can provide one of the plat_scmi_clock_*() handler for the
supported operations set/get state/rate and others.

scmi_msg_get_clock_handler() sanitizes the message_id value
against any speculative use of clock ID as a index since by
SCMI specification, IDs are indices.

This implementation is based on the OP-TEE project implementation [2]
itself based on the SCP-firmware implementation [3] of the SCMI
protocol server side.

Link: [1] http://infocenter.arm.com/help/topic/com.arm.doc.den0056a/DEN0056A_System_Control_and_Management_Interface.pdf
Link: [2] https://github.com/OP-TEE/optee_os/commit/a7a9e3ba71dd908aafdc4c5ed9b29b15faa9692d
Link: [3] https://github.com/ARM-software/SCP-firmware.git

Change-Id: Ib56e096512042d4f7b9563d1e4181554eb8ed02c
Signed-off-by: Etienne Carriere <etienne.carriere@linaro.org>

drivers/scmi-msg: driver for processing scmi messages ...

This change introduces drivers to allow a platform to create a basic
SCMI service and register handlers for client request (SCMI agent) on
system resources. This is the first piece of the drivers: an entry
function, the SCMI base protocol support and helpers for create
the response message.

With this change, scmi_process_message() is the entry function to
process an incoming SCMI message. The function expect the message
is already copied from shared memory into secure memory. The message
structure stores message reference and output buffer reference where
response message shall be stored.

scmi_process_message() calls the SCMI protocol driver according to
the protocol ID in the message. The SCMI protocol driver will call
defined platform handlers according to the message content.

This change introduces only the SCMI base protocol as defined in
SCMI specification v2.0 [1]. Not all the messages defined
in the specification are supported.

The SCMI message implementation is derived from the OP-TEE project [2]
itself based on the SCP-firmware implementation [3] of the SCMI protocol
server side.

Link: [1] http://infocenter.arm.com/help/topic/com.arm.doc.den0056a/DEN0056A_System_Control_and_Management_Interface.pdf
Link: [2] https://github.com/OP-TEE/optee_os/commit/ae8c8068098d291e6e55744dbc237ec39fd9840a
Link: [3] https://github.com/ARM-software/SCP-firmware/tree/v2.6.0

Change-Id: I639c4154a39fca60606264baf8d32452641f45e9
Signed-off-by: Etienne Carriere <etienne.carriere@linaro.org>