[v9,0/3] Adding the Sparx5 Switch Reset Driver

Message

Steen Hegelund April 16, 2021, 8:40 a.m. UTC

This series provides the Microchip Sparx5 Switch Reset Driver

The Sparx5 Switch SoC has a number of components that can be reset
individually, but at least the Switch Core needs to be in a well defined
state at power on, when any of the Sparx5 drivers starts to access the
Switch Core, this reset driver is available.

The reset driver is loaded early via the postcore_initcall interface, and
will then be available for the other Sparx5 drivers (SGPIO, SwitchDev etc)
that are loaded next, and the first of them to be loaded can perform the
one-time Switch Core reset that is needed.

The driver has protection so that the system busses, DDR controller, PCI-E
and ARM A53 CPU and a few other subsystems are not touched by the reset.

Sparx5 will no longer use the existing Ocelot chip reset driver, but use
this new switch reset driver as it has the reset controller interface that
allows the first client to perform the reset on behalf of all the Sparx5
component drivers.

The Sparx5 Chip Register Model can be browsed at this location:
https://github.com/microchip-ung/sparx-5_reginfo
and the datasheet is available here:
https://ww1.microchip.com/downloads/en/DeviceDoc/SparX-5_Family_L2L3_Enterprise_10G_Ethernet_Switches_Datasheet_00003822B.pdf

History:

v8 -> v9 Added reviewed-by tag.

v7 -> v8 Updated the commit descriptions to explain the change from using
         the existing Ocelot chip reset driver to use a new switch reset
         driver.

v6 -> v7 Use devm_platform_get_and_ioremap_resource to get the IO range.
         Rebase on v5.12-rc1

v5 -> v6 Using the existing CPU syscon for reset protection and add a small
         IO range for the GCB Reset Register.

v4 -> v5 Changed the two syscons into IO ranges and updated the bindings to
         reflect this change.

v3 -> v4 Added commit message descriptions

v2 -> v3 Removed unused headers
         Renamed the reset controller dev member.
         Use regmap_read_poll_timeout instead of polling a function.
         Used two separate syscon entries in the binding
         Simplified the syscon error handling.
         Simplified the devm_reset_controller_register error handling.
         Moved the contents of the mchp_sparx5_reset_config function into
         the probe function.

v1 -> v2 Removed debug prints
         Changed the error handling to save the error code before jumping.

Steen Hegelund (3):
  dt-bindings: reset: microchip sparx5 reset driver bindings
  reset: mchp: sparx5: add switch reset driver
  arm64: dts: reset: add microchip sparx5 switch reset driver

 .../bindings/reset/microchip,rst.yaml         |  58 +++++++
 arch/arm64/boot/dts/microchip/sparx5.dtsi     |   7 +-
 drivers/reset/Kconfig                         |   8 +
 drivers/reset/Makefile                        |   1 +
 drivers/reset/reset-microchip-sparx5.c        | 146 ++++++++++++++++++
 5 files changed, 218 insertions(+), 2 deletions(-)
 create mode 100644 Documentation/devicetree/bindings/reset/microchip,rst.yaml
 create mode 100644 drivers/reset/reset-microchip-sparx5.c