[v5,0/3] Add USB role switch support to DWC2

Message

Amelie Delaunay July 28, 2020, 7:45 a.m. UTC

When using usb-c connector (but it can also be the case with a micro-b
connector), iddig, avalid, bvalid, vbusvalid input signals may not be
connected to the DWC2 OTG controller.
DWC2 OTG controller features an overriding control of the PHY voltage valid
and ID input signals.
So, missing signals can be forced using usb role from usb role switch and
this override feature.

This series adds support for usb role switch to dwc2, by using overriding
control of the PHY voltage valid and ID input signals.

It has been tested on stm32mp157c-dk2 [1], which has a Type-C connector
managed by a Type-C port controller, and connected to USB OTG controller.

[1] https://www.st.com/en/evaluation-tools/stm32mp157c-dk2.html

Amelie Delaunay (3):
  dt-bindings: usb: dwc2: add optional usb-role-switch property
  usb: dwc2: override PHY input signals with usb role switch support
  usb: dwc2: don't use ID/Vbus detection if usb-role-switch on STM32MP15
    SoCs
---
Changes in v5:
- Use device_property_read_bool instead of of_read_property_bool in params.c
Changes in v4:
- Simplify call to dwc2_force_mode in drd.c
- Add error_drd label in probe error path in platform.c
Changes in v3:
- Fix build issue reported by kernel test robot in drd.c
Changes in v2:
- Previous DT patch already in stm32-next branch so removed from v2 patchset
  "ARM: dts: stm32: enable usb-role-switch on USB OTG on stm32mp15xx-dkx"
- DWC2 DT bindings update added
- Build issue reported by kernel test robot fixed
- Martin's comments taken into account
---
 .../devicetree/bindings/usb/dwc2.yaml         |   4 +
 drivers/usb/dwc2/Kconfig                      |   1 +
 drivers/usb/dwc2/Makefile                     |   2 +-
 drivers/usb/dwc2/core.h                       |   9 +
 drivers/usb/dwc2/drd.c                        | 180 ++++++++++++++++++
 drivers/usb/dwc2/gadget.c                     |   2 +-
 drivers/usb/dwc2/params.c                     |   2 +-
 drivers/usb/dwc2/platform.c                   |  20 +-
 8 files changed, 215 insertions(+), 5 deletions(-)
 create mode 100644 drivers/usb/dwc2/drd.c