Add support for the PolarFire SoC system controller

From: Conor Dooley <[email protected]>

This patch series adds support for the system controller on the PolarFire SoC, using the mailbox framework. A Microchip directory in the SoC subsystem has been created to hold the mailbox client driver and will be used for future service drivers.

These drivers are gated by the kconfig option:
CONFIG_SOC_MICROCHIP_POLARFIRE, so this patch series depends on Atish Patra's PolarFire SoC support patches which introduce it (this series is in 5.13-rc7).

The following link, which is a direct download of a pdf, contains documentation for the system controller:
https://www.microsemi.com/document-portal/doc_download/1244853-ug0905-polarfire-soc-fpga-system-services-user-guide

Changes from v8:
* Change GENMASK to GENMASK_ULL to avoid shift count over warnings on other arm & microblaze
* Check return value of mutex lock acquistion

Changes from v7:
* Remove functions in header that are redundant without service drivers to avoid test failure

Changes from v6:
* Re-add the maintainers section that was removed from base pfsoc support patch series
* Removed Cyril Jean from maintainers entry.

Changes from v5:
* Removed excess functions, cleanup in mailbox-mpfs.c

Changes from v4:
* Changed dt binding from Rob Herring's feedback
* Shortened some verbose variable names
* Reordered binding patches
* Write directly into response array, rather than allocate in controller isr and memcpy in client

Changes from v3:
* Fixed mboxes reference in dt binding for mailbox client
* Bug fixes and cleanup from Jonathan Neuschäfer's feedback on mailbox-mpfs.c & mpfs-sys-controller.c
* Renamed dt binding files to match compatible strings
* Removed PFSoC gating condition on drivers/soc/microchip subdirectory
* Converted all size based operations to bytes for consistency
* Converted response array to a structure, enabling support for more complex services that return a status instead of/alongside a payload.

Changes from v2:
* Further reworked dt bindings to satisfy errors and feedback
(hopefully phandle array is the correct type for the mboxes)
* Full maintainers entry moved to Atish's PFSoC support series, this series now only adds mailbox driver
* Converted config options from MPFS to POLARFIRE_SOC so they are more recognisable
* Further simplified driver code from feedback

Changes from v1:
* Squashed header into first patch
* Fixed DT binding warnings & small fixes
* Cleaned up drivers from feedback

Conor Dooley (5):
dt-bindings: add bindings for polarfire soc mailbox
mbox: add polarfire soc system controller mailbox
dt-bindings: add bindings for polarfire soc system controller
soc: add polarfire soc system controller
MAINTAINERS: add entry for polarfire soc mailbox

 .../microchip,polarfire-soc-mailbox.yaml      |  47 ++++
 ...icrochip,polarfire-soc-sys-controller.yaml |  35 +++
 MAINTAINERS                                   |   8 +
 drivers/mailbox/Kconfig                       |  12 +
 drivers/mailbox/Makefile                      |   2 +
 drivers/mailbox/mailbox-mpfs.c                | 251 ++++++++++++++++++
 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   | 121 +++++++++
 include/soc/microchip/mpfs.h                  |  43 +++
 12 files changed, 532 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/mailbox/microchip,polarfire-soc-mailbox.yaml
 create mode 100644 Documentation/devicetree/bindings/soc/microchip/microchip,polarfire-soc-sys-controller.yaml
 create mode 100644 drivers/mailbox/mailbox-mpfs.c
 create mode 100644 drivers/soc/microchip/Kconfig
 create mode 100644 drivers/soc/microchip/Makefile
 create mode 100644 drivers/soc/microchip/mpfs-sys-controller.c
 create mode 100644 include/soc/microchip/mpfs.h

2.31.1