Dear Sascha Hauer, > Hi Marek, > > On Tue, Apr 17, 2012 at 12:15:43PM +0200, Marek Vasut wrote: > > This patchset introduces the USB Host driver for i.MX28 CPU, utilising > > the generic USB PHY infrastructure. > > Your patches won't work when more than one USB port is enabled because > of the singular usb transceiver present in the kernel. That of course is > not your fault. I think Heikki (Added to Cc) is working on this issue, > but I don't know the status here. All right, I'll let Heikki hack on that. I'm not sure if we have any mx28 based device with multiple USB ports in kernel. Do we ? > Another problem is that what you are doing does not integrate at all > with otg. Well, how should this be done to integrate with OTG then? > I don't ask you to implement otg support because you are > likely not interested in this, but since you are adding a new ehci > glue driver anyway I suggest another approach: > > Put a driver under drivers/usb/otg which: > > - matches a 'imx-usb' device > - gets/enables all clocks needed for USB > - finds the transceiver > - registers a ehci device So the PHY actually registers the EHCI driver (plat_bus->phy->ehci)? That's slightly weird, don't you think? > > Future additions would be: > > - Put a USB_MODE_HOST/DEVICE flag into platform_data, and register a > host or gadget driver depending on this flag > - Add a USB_MODE_OTG flag to platform_data and implement otg in this > driver (or use whatever infrastructure present in the kernel then) Ok, this sounds reasonable. > This is similar to what msm does. This way we have the clocks and phys > handled where they are needed. We may use this code on i.MX later. Ok, I'll check the MSM stuff. > We did this wrong on i.MX (and several other architectures) and getting > this right will be hard work. No need to introduce the same flaws again > with a new architecture. Ack, thanks for pointers. > Sascha Best regards, Marek Vasut -- 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
