Just submitted the Apple Silicon Type-C PD controller changes separate from the PHY and DWC3 work for USB3: https://lore.kernel.org/asahi/20250914-apple-usb3-tipd-v1-0-4e99c8649024@kernel.org/
The PD controller on these machines negotiates the correct mode (usb, displayport, thunderbolt) with the other end and then is responsible for propagating this to other subsystems. On Apple Silicon the entire type-c stack is a bit cursed and requires tearing down dwc3 for each mode change. We thus added debouncing here and made sure to call the usb-role-switch and typec-mux functions in just the right order.
Like last time this does NOT enable DisplayPort or Thunderbolt, it's just the very first step towards that.