1Tegra SOC USB controllers 2 3The device node for a USB controller that is part of a Tegra 4SOC is as described in the document "Open Firmware Recommended 5Practice : Universal Serial Bus" with the following modifications 6and additions : 7 8Required properties : 9 - compatible : Should be "nvidia,tegra20-ehci" for USB controllers 10 used in host mode. 11 - phy_type : Should be one of "ulpi" or "utmi". 12 - nvidia,vbus-gpio : If present, specifies a gpio that needs to be 13 activated for the bus to be powered. 14 15Optional properties: 16 - dr_mode : dual role mode. Indicates the working mode for 17 nvidia,tegra20-ehci compatible controllers. Can be "host", "peripheral", 18 or "otg". Default to "host" if not defined for backward compatibility. 19 host means this is a host controller 20 peripheral means it is device controller 21 otg means it can operate as either ("on the go") 22 - nvidia,has-legacy-mode : boolean indicates whether this controller can 23 operate in legacy mode (as APX 2500 / 2600). In legacy mode some 24 registers are accessed through the APB_MISC base address instead of 25 the USB controller. 26