From: Ben Dooks > On 10/04/14 11:49, Sergei Shtylyov wrote: > > On 10-04-2014 13:20, David Laight wrote: > > > >>> It doesn't do any pin muxing. It switches SoC internal USB > >>> signals between > >>> USB controllers. The pins remain the same. > > > >> Doesn't something like that already happen for the companion USB1 > >> controllers for USB2 ports? > > > > Did you mean USB 1.1 and USB 2.0 controllers by USB1 and USB2? Yes. Why do you care which USB controller is driving the pins? > >> That also doesn't sound like you are changing the PHY. > > > > I am changing one of the PHY registers that controls USB port > > (Renesas calls it channel) multiplexing. > > > >> I'd have thought that would happen if you had a single controller > >> that select between multiply PHY. > > > > No, it's not the case. I realised that wasn't what you were doing, but at first it did seem to be what you were doing. > There is an interesting case, the USB3 shares a PHY with a SATA > and the PCIE and SATA also share a PHY on the R8A7790. Some of those look like pcb design decisions - so there is no dynamic changing, just config time plumbing. OTOH we are carrying PCIe using two SATA cables (the second carries the clock) so I suspect some SoC system pcbs may be able to support SATA or PCIe on the same connector). David -- To unsubscribe from this list: send the line "unsubscribe linux-tegra" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
