[PATCH v8 0/4] phy: nuvoton: extend MA35D1 USB2 PHY driver for dual-port OTG support

[Joey Lu <a0987203069@gmail.com>]

The MA35D1 SoC has two USB PHY ports managed by a shared hardware block:

  - PHY0 (USB0): OTG port shared between the DWC2 gadget controller and
    the EHCI0/OHCI0 host controllers.  A hardware mux automatically routes
    USB0 signals to the correct controller based on the USB ID pin state.

  - PHY1 (USB1): dedicated host-only port for EHCI1/OHCI1.

This series extends the existing phy-ma35d1-usb2.c driver and its binding
to cover both ports and add OTG role-switch support, while keeping full
backward compatibility with existing device trees.

Changes since v7:

  - phy: add "depends on USB_ROLE_SWITCH || !USB_ROLE_SWITCH" to
    PHY_MA35_USB, so a built-in PHY driver cannot be combined with a
    modular role switch core (link failure on usb_role_switch_register()).

  - phy: restore the PHY reset fallback.  If the PHY is already in
    operation mode but its clocks do not become stable, reset it and poll
    again instead of failing immediately.  The reset is still skipped when
    the already-running PHY reports stable clocks.

  - phy: gate the HUSBH0_GATE clock dynamically again.  The clock is no
    longer enabled for the whole lifetime of the driver (devm_clk_get()
    instead of devm_clk_get_enabled()); .power_on/.power_off enable and
    disable it, and .init enables it around its register accesses.  The
    gate can therefore close when neither port is powered.

  - phy: nuvoton,oc-active-high: keep writing the polarity bit
    unconditionally, so that an absent property means active-low as
    documented in the binding, regardless of what the bootloader left in
    MISCFCR0.  The bit only affects the EHCI/OHCI host ports' VBUS
    switch and is irrelevant to the gadget use of PHY0.  This is a new
    property in this series, and no mainline DT depends on a
    bootloader-programmed polarity.

  - Patches 1-3 are unchanged.

Changes since v6:

  - phy: update the copyright notice in the rewritten driver header to
    "2024-2026" instead of "2026", preserving the original 2024 date
    rather than dropping it.

  - phy: split the unused linux/io.h removal out of patch 4 into its
    own patch (3/4), since it's unrelated cleanup that predates this
    series (the driver has never done direct MMIO access; all register
    access goes through regmap via syscon_regmap_lookup_by_phandle()).
    Placed immediately before patch 4 since that is the first patch in
    the series to touch this file.


Joey Lu (4):
  dt-bindings: phy: nuvoton,ma35d1-usb2-phy: extend for dual-port and
    OTG
  arm64: dts: nuvoton: ma35d1: add USB controllers and dual-port PHY
    node
  phy: nuvoton: phy-ma35d1-usb2: remove unused linux/io.h include
  phy: nuvoton: phy-ma35d1-usb2: extend to dual-port with OTG support

 .../bindings/phy/nuvoton,ma35d1-usb2-phy.yaml |  44 ++-
 .../boot/dts/nuvoton/ma35d1-iot-512m.dts      |  36 ++
 .../boot/dts/nuvoton/ma35d1-som-256m.dts      |  36 ++
 arch/arm64/boot/dts/nuvoton/ma35d1.dtsi       |  65 ++++
 drivers/phy/nuvoton/Kconfig                   |   1 +
 drivers/phy/nuvoton/phy-ma35d1-usb2.c         | 313 +++++++++++++-----
 6 files changed, 419 insertions(+), 76 deletions(-)


base-commit: cee9395acd8043be0644b25c34bfa86623f2b935
-- 
2.43.0