Hi Olof, On Wed, Jan 18, 2012 at 9:35 PM, Olof Johansson <olof@xxxxxxxxx> wrote: > On Wed, Jan 18, 2012 at 03:48:30PM -0700, Stephen Warren wrote: >> On 01/11/2012 09:32 PM, Simon Glass wrote: >> > This adds a property to indicate a port which can switch between host and device >> > mode. >> > >> > Signed-off-by: Simon Glass <sjg@xxxxxxxxxxxx> >> > --- >> > >> > doc/device-tree-bindings/usb/tegra-usb.txt | 4 ++++ >> > 1 files changed, 4 insertions(+), 0 deletions(-) >> > >> > diff --git a/doc/device-tree-bindings/usb/tegra-usb.txt b/doc/device-tree-bindings/usb/tegra-usb.txt >> > index 035d63d..96fd022 100644 >> > --- a/doc/device-tree-bindings/usb/tegra-usb.txt >> > +++ b/doc/device-tree-bindings/usb/tegra-usb.txt >> > @@ -11,3 +11,7 @@ Required properties : >> > - phy_type : Should be one of "ulpi" or "utmi". >> > - nvidia,vbus-gpio : If present, specifies a gpio that needs to be >> > activated for the bus to be powered. >> > + >> > +Optional properties: >> > + - support-host-mode : If present then this peripheral can switch between >> > + host and device mode >> >> All of Tegra's USB ports support host mode, and it's the typical mode of >> operation. The TRM also indicates that all USB ports support device mode >> (possibly depending on the PHY type that's been selected for or attached >> to port). Port 2 explicitly doesn't support run-time switching, but by >> omission, ports 1 and 3 do. >> >> Hence, "support-host-mode" is not an accurate name, and doesn't match >> the description given either. >> >> I think that it'd be better to: >> * Add properties to explicitly specify whether the port is >> intended/allowed to operate (per board design) in each of host or device >> mode. >> * Default to static host mode if no properties are present. >> >> i.e.: >> >> +Optional properties: >> + - enable-host-mode : Indicate that the port is intended to operate in >> + host mode. >> + - enable-device-mode : Indicate that the port is intended to operate >> + in device mode. > > fsl-usb.txt uses "dr_mode" here, which might make sense to reuse given some of > the shared IP in question for device mode: > > - dr_mode : indicates the working mode for "fsl-usb2-dr" compatible > controllers. Can be "host", "peripheral", or "otg". Default to > "host" if not defined for backward compatibility. What does 'dr' mean? Regards, Simon > > > -Olof -- To unsubscribe from this list: send the line "unsubscribe linux-tegra" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
