Am Freitag, den 11.12.2015, 19:28 +0100 schrieb Hans de Goede: [...] > >> diff --git a/Documentation/devicetree/bindings/usb/usb-ehci.txt b/Documentation/devicetree/bindings/usb/usb-ehci.txt > >> index a12d601..0701812 100644 > >> --- a/Documentation/devicetree/bindings/usb/usb-ehci.txt > >> +++ b/Documentation/devicetree/bindings/usb/usb-ehci.txt > >> @@ -18,7 +18,7 @@ Optional properties: > >> - clocks : a list of phandle + clock specifier pairs > >> - phys : phandle + phy specifier pair > >> - phy-names : "usb" > >> - - resets : phandle + reset specifier pair > >> + - resets : a list of phandle + reset specifier pairs > > > > Are there documented names for these resets? > > This binding is a generic ehci controller binding, so even if > the names are documented for the allwinner SoC we should > not use names, just like the binding is deliberately not > using names for the clocks either to keep it generic, so > that we can reuse the binding + driver with many different SoCs. I know, I'm just interested in understanding why this is necessary ... > > Is the companion you > > mention the Port Control? > > Sort of, with USB-2, USB-1 compatibility is handled via a mux on the > datalines (controlled by the EHCI controller Port Control) which muxes > the lines to an USB-1 controller (typically either UHCI or OHCI) when the > device does not connect after USB-2 highspeed handshaking. > > This USB-1 controller (or controller_S_ in some case since the > USB-1 companions may have less root-ports per controller then the EHCI > has root-ports) is called the companion controller. > > The 2 controllers are supposed to be 100% independent but on the H3 > Allwinner has done something (not documented) which requires one to > deassert reset on both before you can talk to either one. ... so thank you for the explanation. Acked-by: Philipp Zabel <p.zabel@xxxxxxxxxxxxxx> regards Philipp -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
