[PATCH v4 0/3] SCMI System Power Support

[Cristian Marussi]

Hi all,

this series wants to add the core SCMI System Power support and related
events' handling logic: the protocol support itself is trivial and boils
down to some bare initializations and supporting one SCMI System Power
notification event meant to carry platform-originated System transition
requests. This is patch [1/3].

On top of this a new SCMI driver has been developed which registers for
such System Power notification and acts accordingly to satisfy such
plaform system-state transition requests that can be of forceful or
graceful kind.

In order to comply with such graceful requests, and co-operate with
userspace entities to drive a clean shutdown/reboot, the logic of the
driver relies on the same orderly_* API methods used by ACPI when handling
ACPI Shutdown bus events.
As an alternative method to tunnel graceful requests to userspace it is
possible to configure, via available module parameters, a specific signal
to be sent to CAD pid. This is patch [2/3].

Patch [3/3] is a mere JUNO example of the minimal DT bindings needed to
enable the protocol at the DT level and is NOT meant to be upstream as of
now.

Based on scmi-next/for-next/scmi on top of:

commit 08fc3399646a ("firmware: arm_scmi: Add base notifications support")

Thanks

Cristian

----
v3 --> v4
- rebased on top of scmi-next/for-next/scmi 5.8-rc3 
- fixed some strict checkpatch issues

V2 --> V3
- changed Kconfig to fix naming and defaulting System Power Control
  driver to n
- fixes related to changes in SCMI Notifications core support V10

V1 --> V2
- use common event enums
- introduced optional alternative signal based comms 2 userspace


[1] git://git.kernel.org/pub/scm/linux/kernel/git/sudeep.holla/linux.git

Cristian Marussi (3):
  firmware: arm_scmi: Add System Power Protocol support
  firmware: arm_scmi: Add SCMI System Power Control driver
  arm64: dts: juno: add SCMI SystemPower Protocol support

 arch/arm64/boot/dts/arm/juno-base.dtsi        |   4 +
 drivers/firmware/Kconfig                      |  12 +
 drivers/firmware/arm_scmi/Makefile            |   3 +-
 drivers/firmware/arm_scmi/driver.c            |   1 +
 .../firmware/arm_scmi/scmi_power_control.c    | 389 ++++++++++++++++++
 drivers/firmware/arm_scmi/system.c            | 136 ++++++
 include/linux/scmi_protocol.h                 |  18 +
 7 files changed, 562 insertions(+), 1 deletion(-)
 create mode 100644 drivers/firmware/arm_scmi/scmi_power_control.c
 create mode 100644 drivers/firmware/arm_scmi/system.c

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2.17.1