That is great to know, thanks, Dave, I know that USBMOD register (used by tdi_reset) is not EHCI, and is not needed for integrated Transaction Translator (TT). It is specific to the TDI design when the core can be configured to be BE/LE, host/device, etc. I think it would be better if we can take that out of ehci.h. For integrated TT, it is documented in USB spec 2.0, in chapter 11.14. And root hub is in chapter 10.2.8. Xilinx's EHCI controller is designed per EHCI spec, and the integrated TT design is per USB 2.0. Thanks, Julie. > -----Original Message----- > From: David Brownell [mailto:david-b@xxxxxxxxxxx] > Sent: Wednesday, February 11, 2009 10:53 PM > To: Julie Zhu > Cc: linux-usb@xxxxxxxxxxxxxxx > Subject: Re: What is TDI in ehci_is_TDI() > > On Thursday 05 February 2009, Julie Zhu wrote: > > The part worries me is that in ehci_reset(): > > > > if (ehci_is_TDI(ehci)) > > tdi_reset (ehci); > > > > And in tdi_reset(), it accesses a USBMOD register, which is not EHCI > > defined. > > > > Can someone clarify the correct way to implement the driver for an EHCI > > compliant host controller with transaction translator? Since the USBMOD > > register is not EHCI specified, we are not going to have that. Have I > > missed something? > > You'd have to check docs for the TDI/ARC/ChipIdea/... core, > to see how it defines that extension. > > Note that as I implied earlier, I was told there's a patent > on some part of that "obvious" design. I'd sure hope that > if Xilinx is packaging an EHCI that doesn't need a companion > controller (or external highspeed hub) to talk to full/low > speed hardware, it's on top of such issues. > > Any patents would not apply to the interface, as far as I > understand things. Or copyrights. :) > > - Dave This email and any attachments are intended for the sole use of the named recipient(s) and contain(s) confidential information that may be proprietary, privileged or copyrighted under applicable law. If you are not the intended recipient, do not read, copy, or forward this email message or any attachments. Delete this email message and any attachments immediately. -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
