Hi Geert, Yoshihiro, I'm a bit stuck with the usb3 drivers for RZ/V2M. The RZ/V2M USB3 is very similar to R-Car Gen3, the main difference being where the DRD registers are located and additional clocks, interrupts and resets exposed. The DRD registers are still part of the USBP address space, though they have been moved above the other USBP regs. There is however, one big difference. On RZ/V2M, you can only access the corresponding registers for whatever DRD mode has been set in the DRD_CON register, PERI_CON bit. That is to say, when PERI_CON=1 (periph mode), reading from a USBH register will cause an abort, and when PERI_CON=0 (host mode), reading from a USBP register will cause an abort. This makes role switching rather difficult in Linux as the usb host hub code does some work in a delayed work queue, after role switch. I am therefore advocating that users can only enable host or peripheral in DT, and role switching is not allowed. Is that reasonable? How can I ensure only one driver is enabled? This unfortunately opens up another problem... So that the USBH driver can set the DRD mode, it needs access to the USBP address space. Could that be just be additional reg entry in DT for this? I'm not sure how to go about this, any advice appreciated! Thanks Phil
