[PATCH v3 0/1] soc: add microchip polarfire soc system controller

[<conor.dooley@microchip.com>]

From: Conor Dooley <conor.dooley@microchip.com>

Since I submitted version 1 of this driver, I attempted to upstream
bindings for devices dependant on the system controller [0]. In that
process, Rob said that since they were devices with no resources,
other than a reference to the system controller, the devices should
not be in the device tree & instead they should be created by the
system controller (which it now does).

Since the sub devices using mpfs_sys_controller_get will now have the
system controller as their parent, this function now just checks if the
parent device is compatible. If the parent is compatible, the sub-
device then attempts to register as a consumer of the system controller

@Arnd Hopefully this clears up the issues you had with reference
counting & the lack of checks as to whether the device found by
mpfs_sys_controller_get was in fact a system controller.

Depends on [0] to change the compatible string in the dt-binding.
Thanks,
Conor.

Changes since v2:
- system controller is no longer an mfd, system controller now creates
  sub devices for itself.
- specify that a mpfs_mss_msg is used in mpfs_blocking_transaction
  rather than using a void pointer.
- as the subdevices are now all created by the system controller, the
  get() function now checks that the requesting device's parent is
  compatible.
- mpfs_sys_controller_get now passes a pointer to the device that is
  trying to register as a consumer rather than a device node.

Changes since v1:
- system controller is now an mfd
- parentage is now used to get the device node on the system controller
- mpfs_sys_controller_get() now updates the reference count
- "polarfire-soc" in compat string changed to "mpfs"

[0] https://lore.kernel.org/linux-riscv/20220214135840.168236-1-conor.dooley@microchip.com/

Conor Dooley (1):
  soc: add microchip polarfire soc system controller

 drivers/soc/Kconfig                         |   1 +
 drivers/soc/Makefile                        |   1 +
 drivers/soc/microchip/Kconfig               |  10 +
 drivers/soc/microchip/Makefile              |   1 +
 drivers/soc/microchip/mpfs-sys-controller.c | 194 ++++++++++++++++++++
 include/soc/microchip/mpfs.h                |   4 +-
 6 files changed, 209 insertions(+), 2 deletions(-)
 create mode 100644 drivers/soc/microchip/Kconfig
 create mode 100644 drivers/soc/microchip/Makefile
 create mode 100644 drivers/soc/microchip/mpfs-sys-controller.c

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2.35.1