tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
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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 - nvidia,phy : phandle of the PHY instance, the controller is connected to.
15
16Required properties for phy_type == ulpi:
17 - nvidia,phy-reset-gpio : The GPIO used to reset the PHY.
18
19Optional properties:
20 - dr_mode : dual role mode. Indicates the working mode for
21 nvidia,tegra20-ehci compatible controllers. Can be "host", "peripheral",
22 or "otg". Default to "host" if not defined for backward compatibility.
23 host means this is a host controller
24 peripheral means it is device controller
25 otg means it can operate as either ("on the go")
26 - nvidia,has-legacy-mode : boolean indicates whether this controller can
27 operate in legacy mode (as APX 2500 / 2600). In legacy mode some
28 registers are accessed through the APB_MISC base address instead of
29 the USB controller. Since this is a legacy issue it probably does not
30 warrant a compatible string of its own.
31 - nvidia,needs-double-reset : boolean is to be set for some of the Tegra2
32 USB ports, which need reset twice due to hardware issues.