R-Car/How-to-describe-device-tree-for-R-Car-Gen3-USB2-DRD-channel
< R-Car
Overview
When we would like to use a USB2.0 DRD channel of R-Car Gen3 SoCs, the following device nodes require "dr_mode" properties in your device tree. Otherwise, since phy-rcar-gen3-usb2.c driver doesn't initialize specific registers, the USB2.0 channel doesn't work correctly.
- ehci0
- ohci0
- hsusb
- ehci3 (if r8a77951)
- ohci3 (if r8a77951)
- hsusb3 (if r8a77951)
A "dr_mode" property can have "otg", "host" or "peripheral".
Optional property "renesas,no-otg-pins"
We can set "renesas,no-otg-pins" to the following device nodes to avoid checking of ID pins for "host" or "peripheral" mode.
- usb2_phy0
- usb3_phy3 (if r8a77951)
Summary
| dr_mode | Initial mode | Reference |
| "otg" | Act as host or peripheral (depends on ID signal) | salvator-common.dtsi, r8a77951-salvator-xs.dts |
| "host" | Act as host | r8a77995-draak.dts |
| "peripheral" | Act as peripheral | n/a |
