This patch introduces an additional layer of abstraction between
CSS power management hooks and the SCPI driver. A new set of APIs
are introduced in order to abstract out power management operations
from underlying communication mechanism with the SCP.
The SCPI and the associated MHU drivers are moved into a `drivers`
folder in CSS. The new SCP communication abstraction layer is added
in the `drivers/scp` folder. The existing CSS power management
uses the new APIs to reflect this abstraction.
Change-Id: I7d775129fc0558e9703c2724523fb8f0a916838c
Signed-off-by: Soby Mathew <soby.mathew@arm.com>
This patch implements CSS platform hook to support NODE_HW_STATE PSCI
API. The platform hook queries SCP to obtain CSS power state. Power
states returned by SCP are then converted to expected PSCI return codes.
Juno's PSCI operation structure is modified to use the CSS
implementation.
Change-Id: I4a5edac0e5895dd77b51398cbd78f934831dafc0
This patch adds the capability to power down at system power domain level
on Juno via the PSCI SYSTEM SUSPEND API. The CSS power management helpers
are modified to add support for power management operations at system
power domain level. A new helper for populating `get_sys_suspend_power_state`
handler in plat_psci_ops is defined. On entering the system suspend state,
the SCP powers down the SYSTOP power domain on the SoC and puts the memory
into retention mode. On wakeup from the power down, the system components
on the CSS will be reinitialized by the platform layer and the PSCI client
is responsible for restoring the context of these system components.
According to PSCI Specification, interrupts targeted to cores in PSCI CPU
SUSPEND should be able to resume it. On Juno, when the system power domain
is suspended, the GIC is also powered down. The SCP resumes the final core
to be suspend when an external wake-up event is received. But the other
cores cannot be woken up by a targeted interrupt, because GIC doesn't
forward these interrupts to the SCP. Due to this hardware limitation,
we down-grade PSCI CPU SUSPEND requests targeted to the system power domain
level to cluster power domain level in `juno_validate_power_state()`
and the CSS default `plat_arm_psci_ops` is overridden in juno_pm.c.
A system power domain resume helper `arm_system_pwr_domain_resume()` is
defined for ARM standard platforms which resumes/re-initializes the
system components on wakeup from system suspend. The security setup also
needs to be done on resume from system suspend, which means
`plat_arm_security_setup()` must now be included in the BL3-1 image in
addition to previous BL images if system suspend need to be supported.
Change-Id: Ie293f75f09bad24223af47ab6c6e1268f77bcc47
This patch does the following reorganization to psci power management (PM)
handler setup for ARM standard platform ports :
1. The mailbox programming required during `plat_setup_psci_ops()` is identical
for all ARM platforms. Hence the implementation of this API is now moved
to the common `arm_pm.c` file. Each ARM platform now must define the
PLAT_ARM_TRUSTED_MAILBOX_BASE macro, which in current platforms is the same
as ARM_SHARED_RAM_BASE.
2. The PSCI PM handler callback structure, `plat_psci_ops`, must now be
exported via `plat_arm_psci_pm_ops`. This allows the common implementation
of `plat_setup_psci_ops()` to return a platform specific `plat_psci_ops`.
In the case of CSS platforms, a default weak implementation of the same is
provided in `css_pm.c` which can be overridden by each CSS platform.
3. For CSS platforms, the PSCI PM handlers defined in `css_pm.c` are now
made library functions and a new header file `css_pm.h` is added to export
these generic PM handlers. This allows the platform to reuse the
adequate CSS PM handlers and redefine others which need to be customized
when overriding the default `plat_arm_psci_pm_ops` in `css_pm.c`.
Change-Id: I277910f609e023ee5d5ff0129a80ecfce4356ede
Soby Mathew
Jeenu Viswambharan