RE: sysbus usb xhci

[Sai Pavan Boddu]

Thanks Philippe & Gred. I would start with the below pointers.

Regards,
Sai Pavan

> -----Original Message-----
> From: Philippe Mathieu-Daudé <address@hidden>
> Sent: Thursday, January 2, 2020 4:56 PM
> To: address@hidden; Sai Pavan Boddu <address@hidden>
> Cc: address@hidden; address@hidden
> Subject: Re: sysbus usb xhci
> 
> On 1/2/20 10:45 AM, address@hidden wrote:
> > On Thu, Jan 02, 2020 at 07:13:25AM +0000, Sai Pavan Boddu wrote:
> >> Hi Gred,
> >>
> >> We are seeing of options to reuse the hcd-xhci model and use it over
> >> system bus interface rather than pci. (for Xilinx ZynqMP SOC, usb
> emulation) Are there any plans of implementing a sysbus device ? if none it
> would be good if provided few pointers to start.
> >
> > There have been some discussions about this for a (IIRC) sbsa machine,
> > but I'm not sure whenever that where just ideas or some code exists.
> >
> >> Im looking at hcd-ehci/ochi as a reference, let me know if there are any
> know limitations for this usecase.
> >
> > Yep, the path for xhci would be quite simliar:  Create a new
> > XHCIPciState struct, move over all pci-specific bits from XHCIState,
> > leaving the generic stuff in XHCIState for sharing with sysbus.
> > Possibly move all pci-specific code bits into a new source file (for
> > cleanup, will also allow to build qemu with CONFIG_PCI=n and still
> > have XHCI enabled).
> >
> > Once this separation is done you should be able to create a sysbus
> > device, reusing the generic xhci code and adding sysbus plumbing
> > (mmio, irq, ...)
> 
> The SDHCI commits b635d98cf32..8b7455c75e seem similar to what you
> want to achieve (see also commit ce8646034).