clk: introduce TC9564 clock support

This series adds support for the clock controller present within the Toshiba TC9564 SoC.

This SoC attaches to a host system via PCIe. It includes a PCIe switch with three downstream ports. To one of these ports an embedded PCIe endpoint is attached, and it implements two PCI functions. BAR 4 for both PCI functions provides access to the registers that enable or disable a set of clocks.

Both TC9564 PCI functions can provide PCI endpoint buses via devicetree. Each PCI endpoint bus provides access to one of the function's BARs. Subordinate devices (like the clock controller) can then be defined as nodes accessible on the endpoint bus.

Only one of the two PCI functions is permitted to define the clock device node.

-Alex

NOTE:
This series is built upon linux-next, with this patch applied:
https://lore.kernel.org/lkml/[email protected]/
The series (with that patch) is available in this git branch:
https://github.com/alexelder/linux/tree/outgoing/clock-v3

Between version 2 and version 3:
- What was formerly described as a "clock" node is now "clock-controller"
- The clock-controller DTS node, which dropped its reg property in v2, is now a sub-device of the config syscon
- The config syscon is now (also) compatible with "simple-mfd"
- The clock-controller DTS node no longer defines a toshiba,config-syscon property, and the config syscon no longer requires a label
- The clock-controller now requires a (parent) clock property
- The header file is no longer included in the binding example
- The binding example now includes the definition of fixed 25 MHz clock

- The clock driver now gets its regmap by calling syscon_node_to_regmap() on its device parent's devicetree node
- The clock driver now must its parent clock from devicetree
- Added Brian's Reviewed-by tag to the second patch

- A new 25 MHz fixed clock is defined in a new patch, and is later used by the clock controller

Version 2 is available here:
https://lore.kernel.org/lkml/[email protected]/

Between version 1 and version 2:
- Previously, this driver also included reset functionality. That is now in a separate reset (only) driver, which will be sent for review separately
- Dropped the "config syscon" devicetree binding
- Reworded the clock binding description to focus on hardware only
- Clock IDs are now consecutive (no more commented-out values)
- Get the definition of of_device_id from <linux/device_id/of.h> rather than <linux/platform_device.h>
- Dropped a comma that followed a ternminating empty array entry
- Config option COMMON_CLK_TC9564 now selects MFD_SYSCON
- Clarified in config help text that the reset and stmmac drivers are the "others" that use the config syscon
- Moved the clock devicetree node to be a peer (rather than a child) of the syscon node.

Version 1 is available here:
https://lore.kernel.org/lkml/[email protected]/

Alex Elder (4):
dt-bindings: clock: introduce toshiba,tc9564-clock.yaml
clk: toshiba: introduce a TC9564 SoC clock driver
arm64: dts: qcom: define a fixed 25 MHz clock
arm64: dts: qcom: qcs6490-rb3gen2: add the clock controller

 .../bindings/clock/toshiba,tc9564-clock.yaml  |  65 +++++
 MAINTAINERS                                   |   8 +
 arch/arm64/boot/dts/qcom/qcs6490-rb3gen2.dts  |  22 +-
 drivers/clk/Kconfig                           |  12 +
 drivers/clk/Makefile                          |   1 +
 drivers/clk/clk-tc9564.c                      | 268 ++++++++++++++++++
 include/dt-bindings/clock/toshiba,tc9564.h    |  34 +++
 7 files changed, 409 insertions(+), 1 deletion(-)
 create mode 100644 Documentation/devicetree/bindings/clock/toshiba,tc9564-clock.yaml
 create mode 100644 drivers/clk/clk-tc9564.c
 create mode 100644 include/dt-bindings/clock/toshiba,tc9564.h

base-commit: dc44eb73f8da11f478815bc29b6509a6a4c5c35f

2.53.0