On 11/24/07, David Brownell <[EMAIL PROTECTED]> wrote: > On Saturday 24 November 2007, Grant Likely wrote: > > On 11/24/07, David Brownell <[EMAIL PROTECTED]> wrote: > > > On Friday 23 November 2007, Grant Likely wrote: > > > > +config USB_C67X00_DRV > > > > +tristate "Cypress C67x00 support" > > > > +# only allowed to be =y if both USB!=m and USB_GADGET!=m > > > > > > This is wrong. Remember that since this is a dual-role driver, > > > there are exactly three possible driver modes ... and the driver > > > must support only one of them at a time: > > > > Actually, this part has 2 serial in interface engines; either of which > > can be in host, peripheral or OTG mode. So; it is entirely relevant > > for the driver to be doing both host and peripheral at the same time > > with a single device. > > While conforming with USB specs? Has that changed recently?
Let me rephrase; the silicon implements 2 USB engines with separate pinouts. They can be configured as 2 host controllers; 2 peripheral controllers or 1 of each. They share registers and the IRQ line from the software interface, but they are distinctly separate USB busses. This driver actually implements 2 sub devices. Each sub device is either bound to the host part of the driver or the gadget part. > > In the not-too-distant past I know there was explicit language > saying that such configurations are not allowed. (At least, > in terms of external connectors. A board using USB for internal > peripheral connections would be OK.) > > Those issues can be deferred until peripheral support exists. > At that point you'll need to get better solutions to those config > issues... ok > > > > > Hmmm ... your patches don't include peripheral mode support yet. > > > > No, nobody has written it yet. > > Then what's it doing in that GIT tree you pointed me at? :) Sitting there being useless. :-) That driver doesn't actually work; it's just a proof of concept placeholder (which is why I didn't include it in my series) > > > > > Either all these gadget hooks should vanish, or you should try > > > to get the controller mode stuff right from the beginning. > > > > > > I've appended the relevant Kconfig bits from the musb_hdrc > > > driver, which (despite some glitches) are pretty much correct. > > > > I'll drop the gadget hooks for now. Most likely gadget and OTG > > support will require more changes to this driver regardless, so it's > > not a big deal. > > OK. Then the first incaration of this will be as a host-only > driver, in its own directory, and adding peripheral support will > cause minor lunacy. :) :-) g. -- Grant Likely, B.Sc., P.Eng. Secret Lab Technologies Ltd. [EMAIL PROTECTED] (403) 399-0195 _______________________________________________ Linuxppc-dev mailing list Linuxppc-dev@ozlabs.org https://ozlabs.org/mailman/listinfo/linuxppc-dev
