Re: [rfc] [patch] clean up to ehci-omap (Was: Re: [patch] omap: usb: ehci: fix use of hcd->regs)

[David Brownell <david-b@pacbell.net>]

On Friday 12 September 2008, Gadiyar, Anand wrote:
> 1. TLL vs PHY mode needs to be set somewhere. Me thinks this information ought
> to come from board-specific data and the driver would need to set things up
> accordingly. What would be a good way to do this?

Define an ehci_omap_platform_data struct and use it for
the stuff that shouldn't be in mach-omap2 ... I seem to
not understand why there would be a question here.


> 2. The OHCI driver (not yet in linux-omap and not in a shape to go ought at the
> moment either) would need to touch a lot of common registers during init/exit/re-init.
> Any ideas where to put this code such that we can have the EHCI driver, or the
> OHCI driver, or both loaded and unloaded at will and still working without interfering
> with each other.

Sounds like code that can live in mach-omap2 and be called
when the drivers start or stop.


> 3. For OHCI, the transceiver used on the expansion board happens to be an ISP1301
> for which there currently exists a driver (drivers/i2c/chips/isp1301_omap.c). Since this is
> meant to be an OTG transceiver, the driver does otg_set_transceiver.

And does OMAP2 have the OMAP1 OTG controller?  If not, then
you can't use that driver.


> But MUSB is the OTG controller and has it's own transceiver... and we can't have two of 
> those, right? :) Ideas welcome.

You'll need a new driver; since it's host only, it would only
need to be a little stub.  The interface shouldn't matter much;
just make it general enough that other hardware could use it.
(Nothing OMAP-specific, etc.)

- Dave