[PATCH 0/6] usb: typec: add Qualcomm PMI8998 USB Type-C role-switch support

[taygoth <taygoth@gmail.com>]

This series adds USB Type-C role-switch support for the PMI8998 PMIC
used on SDM845 phones (OnePlus 6/6T, Xiaomi Poco F1, SHIFT 6mq), which
have been locked to USB peripheral mode under mainline kernels until
now.

The PMI8998 SMB2 charger block integrates a Type-C detection unit at
SPMI offset 0x1300 that performs CC sensing, debounce and Rp/Rd
resolution entirely in hardware. The state is exposed through the
TYPE_C_STATUS_4 register and reported via a single consolidated
"type-c-change" interrupt. The new driver reads that status on every
interrupt and pushes the negotiated role to a usb_role_switch consumer
(dwc3), enabling automatic peripheral/host switching on cable change.
Because the hardware handles the Type-C state machine natively, no
software TCPM port manager is required.

The Type-C block shares the SMB2 USBIN region with the already
mainlined qcom_pmi8998-charger driver. The two coexist on the shared
SPMI regmap without write conflict: the typec driver only reads
TYPE_C_STATUS_* and touches the IRQ enable bits at offsets
0x130b-0x130f and 0x1367-0x1368.

The PMI8998 USB OTG VBUS boost converter at offset 0x1100 has the
same CMD_OTG / OTG_CFG / OTG_CURRENT_LIMIT register layout as PM8150B,
so the existing drivers/regulator/qcom_usb_vbus-regulator can drive it
through a compatible cascade -- only the DT binding needs the new
compatible string added.

Power Delivery is not implemented. The PMI8998 PDPHY block at offset
0x1700 is register-identical to PM8150B and could be wired through
the existing drivers/usb/typec/tcpm/qcom code in a follow-up if PD
negotiation becomes a requirement.

Tested-on: OnePlus 6T (sdm845-oneplus-fajita) running Mobian
6.12-sdm845. A USB flash drive, USB ethernet adapter, USB WiFi
adapter (TP-Link Archer T2) and a self-powered USB-C dock with
downstream ethernet all enumerate through xHCI after the role
transitions from peripheral to host. Repeat plug/unplug cycles drive
the role through device -> none -> host -> none -> device cleanly
with no IRQ stalls or stale role-switch state.

Series mirror:
  https://github.com/taygoth/linux/tree/pmi8998-typec

taygoth (6):
  dt-bindings: regulator: qcom,usb-vbus-regulator: add PMI8998
  dt-bindings: usb: add Qualcomm PMI8998 Type-C controller
  usb: typec: add Qualcomm PMI8998 role-switch driver
  arm64: dts: qcom: pmi8998: add USB Type-C and VBUS regulator nodes
  arm64: dts: qcom: sdm845-oneplus-common: enable USB Type-C role
    switching
  MAINTAINERS: add entry for Qualcomm PMI8998 USB Type-C driver

 .../regulator/qcom,usb-vbus-regulator.yaml    |   1 +
 .../bindings/usb/qcom,pmi8998-typec.yaml      |  97 ++++++++
 MAINTAINERS                                   |   8 +
 arch/arm64/boot/dts/qcom/pmi8998.dtsi         |  19 ++
 .../boot/dts/qcom/sdm845-oneplus-common.dtsi  |  43 +++-
 drivers/usb/typec/Kconfig                     |  17 ++
 drivers/usb/typec/Makefile                    |   1 +
 drivers/usb/typec/qcom_pmi8998_typec.c        | 213 ++++++++++++++++++
 8 files changed, 392 insertions(+), 7 deletions(-)
 create mode 100644 Documentation/devicetree/bindings/usb/qcom,pmi8998-typec.yaml
 create mode 100644 drivers/usb/typec/qcom_pmi8998_typec.c


base-commit: 5200f5f493f79f14bbdc349e402a40dfb32f23c8
-- 
2.47.3