[PATCH v5 00/12] Ambarella CV75 SoC minimal bring-up

This series adds minimal Ambarella CV75 support for early bring-up with
a serial console: DT bindings, RCT/CCU clocks, pinctrl, PL061 GPIO
variant, 8250-based UART, ARCH_AMBARELLA, CV75 EVK DT, and MAINTAINERS.

This is again a single unified series (as in v2). It supersedes the v3
A/B/C split and the later v4 B resend.

  v3-A: bindings + RCT/CCU + SoC/EVK DT + MAINTAINERS
  v3-B / v4-B: pinctrl + PL061 GPIO
  v3-C: 8250_dw UART quirks

Please apply via the SoC tree; subsystem maintainers are Cc'd for their
pieces.

Verified with checkpatch --strict, dt_binding_check (ambarella),
CHECK_DTBS for cv75-evk, and CV75 boot / UART / clk_summary.

Signed-off-by: Long Zhao <[email protected]>
---
Changes in v5:
- Reunify into one series toward soc@ (v2-style topics); supersede
  v3 A/B/C and v4 B (Krzysztof)
- UART: drop 8250_dw quirks; add standalone 8250_ambarella + binding
  (Linus, Andy)
- Fold review/self-fix commits into the corresponding topic patches
- pinctrl binding: drop redundant groups $ref (Krzysztof)
- Sashiko: address applicable findings
  - clk: guard parent_rate == 0; include fsdiv/fsout in PLL approx;
    clamp VCO range; clear divider disable bit on non-zero set_rate;
    integer determine_rate uses achievable params; 32-bit
    COMPILE_TEST uses DIV64_U64_ROUND_CLOSEST
  - PINCTRL_AMB depends on HAS_IOMEM and defaults when ARCH_AMBARELLA
    (ARCH no longer selects PINCTRL_AMB)
  - IOMUX: one commit per group; use BIT() for altfunc (offset 31)
  - PL061: per-pin AFSEL claim instead of wiping the bank at probe
  - GIC: omit unused #size-cells, keep only #address-cells = <0>
  - RCT remains clock-only (no #reset-cells / reset provider)
- No change: ARM_PSCI / HAVE_ARM_ARCH_TIMER (same as ARCH_AIROHA);
  syscon.yaml has no select block; GPIO pinconf-only DT nodes (GPIO
  mux is via gpiochip request, IOMUX alt 0)

Link to v2:
https://lore.kernel.org/r/20260806-longzhao-upstream-cv75-v2-v2-0-6b09707c5fe9@ambarella.com
Link to v3-A:
https://lore.kernel.org/r/[email protected]
Link to v3-B:
https://lore.kernel.org/r/[email protected]
Link to v3-C:
https://lore.kernel.org/r/[email protected]
Link to v4-B:
https://lore.kernel.org/r/[email protected]

---
Long Zhao (12):
      dt-bindings: arm: add Ambarella CV75 platforms
      dt-bindings: mfd: syscon: add Ambarella CV75 secure scratchpad
      dt-bindings: clock: add Ambarella CV75 RCT
      dt-bindings: pinctrl: add Ambarella CV75 pinctrl
      dt-bindings: gpio: pl061: add Ambarella CV75 variant
      dt-bindings: serial: add Ambarella CV75 UART
      clk: ambarella: add CV75 CCU driver
      gpio: pl061: add Ambarella CV75 register layout variant
      pinctrl: ambarella: add CV75 pin controller
      serial: 8250: add Ambarella UART driver
      arm64: ambarella: add ARCH_AMBARELLA and CV75 EVK DT
      MAINTAINERS: add ARM/AMBARELLA SoC support

 .../devicetree/bindings/arm/ambarella.yaml         |  24 +
 .../bindings/clock/ambarella,cv75-rct.yaml         |  58 ++
 .../devicetree/bindings/gpio/pl061-gpio.yaml       |  35 +-
 Documentation/devicetree/bindings/mfd/syscon.yaml  |   1 +
 .../bindings/pinctrl/ambarella,cv75-pinctrl.yaml   | 239 ++++++
 .../bindings/serial/ambarella,cv75-uart.yaml       |  56 ++
 .../devicetree/bindings/vendor-prefixes.yaml       |   2 +
 MAINTAINERS                                        |  16 +
 arch/arm64/Kconfig.platforms                       |   8 +
 arch/arm64/boot/dts/Makefile                       |   1 +
 arch/arm64/boot/dts/ambarella/Makefile             |   3 +
 arch/arm64/boot/dts/ambarella/cv75-evk.dts         |  30 +
 arch/arm64/boot/dts/ambarella/cv75.dtsi            | 176 +++++
 arch/arm64/configs/defconfig                       |   2 +
 drivers/clk/Kconfig                                |   1 +
 drivers/clk/Makefile                               |   1 +
 drivers/clk/ambarella/Kconfig                      |  13 +
 drivers/clk/ambarella/Makefile                     |   6 +
 drivers/clk/ambarella/ccu-cv75.c                   | 296 +++++++
 drivers/clk/ambarella/ccu_common.c                 |  60 ++
 drivers/clk/ambarella/ccu_common.h                 |  25 +
 drivers/clk/ambarella/ccu_mux_div.c                | 234 ++++++
 drivers/clk/ambarella/ccu_mux_div.h                |  35 +
 drivers/clk/ambarella/ccu_pll.c                    | 421 ++++++++++
 drivers/clk/ambarella/ccu_pll.h                    |  70 ++
 drivers/gpio/gpio-pl061.c                          | 314 ++++++--
 drivers/pinctrl/Kconfig                            |  15 +
 drivers/pinctrl/Makefile                           |   2 +
 drivers/pinctrl/pinctrl-ambarella-cv75.c           | 561 ++++++++++++++
 drivers/pinctrl/pinctrl-ambarella.c                | 863 +++++++++++++++++++++
 drivers/pinctrl/pinctrl-ambarella.h                |  50 ++
 drivers/tty/serial/8250/8250_ambarella.c           | 312 ++++++++
 drivers/tty/serial/8250/Kconfig                    |   9 +
 drivers/tty/serial/8250/Makefile                   |   1 +
 include/dt-bindings/clock/ambarella,cv75-rct.h     |  15 +
 35 files changed, 3883 insertions(+), 72 deletions(-)
---
base-commit: 34cf6dafc47441dfb6b356a095b89c3585a93714
change-id: 20260818-cv75-v5-9e2039b349bc

Best regards,
--  
Long Zhao <[email protected]>