Firmware implementing the PSCI functions described in ARM document
number ARM DEN 0022A ("Power State Coordination Interface System
Software on ARM processors") can be used by Zephyr to initiate various
CPU-centric power operations.
It is needed for virtualization, it is used to coordinate OSes and
hypervisors and it provides the functions used for SMP bring-up such as
CPU_ON and CPU_OFF.
A new PSCI driver is introduced to setup a proper subsystem used to
communicate with the PSCI firmware, implementing the basic operations:
get_version, cpu_on, cpu_off and affinity_info.
The current implementation only supports PSCI 0.2 and PSCI 1.0
The PSCI conduit (SMC or HVC) is setup reading the corresponding
property in the DTS node.
Signed-off-by: Carlo Caione <ccaione@baylibre.com>
57f7e31017