[PATCH 0/4] omap legacy full speed usb cleanup for v3.6

Tony Lindgren tony at atomide.com
Fri May 25 03:22:46 EDT 2012

* Paul Walmsley <paul at pwsan.com> [120524 23:05]:
> On Mon, 21 May 2012, Tony Lindgren wrote:
> > This series removes the old legacy fulls speed support for
> > omap2 as it's pretty much only used for omap1 only.
> > 
> > For omap2, only n8x0 seems to have active development, and
> > that has the external high speed tusb chip instead.
> Just FYI, full speed host USB exists on OMAP4.  It's in section 23.13 of 
> the TRM and we have a hwmod for it.  No idea if anyone is actually using 
> it.

Interesting, so it's back on omap4 for some legacy compability reasons
i guess. It's not mentioned for omap3 at all, but maybe it's lurking
around there somewhere too.

Looking at the omap4 TRM, looks like there are two instances of OHCI:
The HS OHCI/EHCI controller, and the legacy FS OHCI only controller.
The legacy one is using separate transceiver pins (usbc1_*) from the
HS OHCI/EHCI controller pins (usbb[12]_*).

As the OHCI registers are standard, I'd assume it would be possible
to make the FS USB instance to work with the mach-omap2/usb-host.c
and drivers/usb/host/ohci-omap3.c driver. So it should still be OK
to remove the code in this series.

I doubt that anybody would want to use the legacy FS OHCI controller
instead of the HS OHCI/EHCI controller though.. If somebody
is actually using the legacy controller at usbc1_* pins, please



More information about the linux-arm-kernel mailing list