[PATCH v5 0/4] Add USB2.0 PHY and USB3.0 PHY support for SpacemiT K1

[Ze Huang]

This patch series introduces support for the USB2.0 PHY and PCIe/USB3.0
Combo PHY on the SpacemiT K1 SoC. The implementation has been tested on the
Milk-V Jupiter and BananaPi-f3.

K1 includes three USB ports as follows[1]:
- A USB2.0 OTG Port
- A USB2.0 Host Only Port
- A USB3.0 Port with a USB2.0 DRD interface

USB3.0 PHY for USB3.0 Port is shared with PCIe port A, meaning that only one of
these interfaces (PCIe or USB3.0) can be active at a given time.

Link: https://developer.spacemit.com/documentation?token=AjHDwrW78igAAEkiHracBI9HnTb#part5 [1]

Signed-off-by: Ze Huang <huangze at whut.edu.cn>
---
Changes in v5:
- phy driver for usb2:
  - convert readl/writel to regmap
  - fix typo: sentinal -> sentinel
- Link to v4: https://lore.kernel.org/r/20250526-b4-k1-usb3-phy-v2-v4-0-eca668fc16a2@whut.edu.cn

Changes in v4:
- combphy driver:
  - add in-code comments to indicate that PCIe mode is not yet supported.
  - replace custom spacemit_reg_update() with standard regmap API.
  - drop spacemit_combphy_wait_ready helper function as only used once.
  - Fix PHY init timeout handling: ensure proper error reporting when PLL
    lock fails during USB3 PHY initialization
- Link to v3: https://lore.kernel.org/r/20250517-b4-k1-usb3-phy-v2-v3-0-e0655613a163@whut.edu.cn

Changes in v3:
- improve commit message, provide more info about phy hardware
- drop superfluous local variable in `spacemit_combphy_wait_ready`
- replace devm_reset_control_get with devm_reset_control_get_exclusive
- Link to v2: https://lore.kernel.org/r/20250418-b4-k1-usb3-phy-v2-v2-0-b69e02da84eb@whut.edu.cn

Changes in v2:
- combphy dt-bindings:
  - fix reg-names
  - describe reg
  - describe #phy-cells argument
- drop stale ".owner" in driver struct
- add support for usb lfps_thres in combphy
- fix Kconfig depends on
- Link to v1: https://lore.kernel.org/all/20250407-b4-k1-usb3-v3-2-v1-0-bf0bcc41c9ba@whut.edu.cn

---
Ze Huang (4):
      dt-bindings: phy: spacemit: add K1 USB2 PHY
      dt-bindings: phy: spacemit: add K1 PCIe/USB3 combo PHY
      phy: spacemit: support K1 USB2.0 PHY controller
      phy: spacemit: add USB3 support for K1 PCIe/USB3 combo PHY

 .../bindings/phy/spacemit,k1-combphy.yaml          |  72 ++++++
 .../devicetree/bindings/phy/spacemit,usb2-phy.yaml |  40 ++++
 drivers/phy/Kconfig                                |   1 +
 drivers/phy/Makefile                               |   1 +
 drivers/phy/spacemit/Kconfig                       |  21 ++
 drivers/phy/spacemit/Makefile                      |   3 +
 drivers/phy/spacemit/phy-k1-combphy.c              | 266 +++++++++++++++++++++
 drivers/phy/spacemit/phy-k1-usb2.c                 | 144 +++++++++++
 8 files changed, 548 insertions(+)
---
base-commit: 64e9fdfc89a76fed38d8ddeed72d42ec71957ed9
change-id: 20250417-b4-k1-usb3-phy-v2-fb1e41849049

Best regards,
-- 
Ze Huang <huangze at whut.edu.cn>