On Tue, Jan 05, 2016 at 08:36:31AM -0600, Rob Herring wrote: > > 2. There are MFD USB devices, which includes several interfaces under > > USB device, > > like i2c, gpios, etc. Due to lack of device tree support, USB > > class/device driver doesn't know > > which kinds of interfaces are needed for this board. > > Are you talking about a device hard wired on the same board or > something like GPIOs on FTDI chip which could be hot-plugged in any > host (including non-DT based)? I talked about the case that the device hard wired on the board. Hot-plug device's bus topology is unknown, we can't describe it statically at dts. > > For the hotplug case, we will need a way to associate a DT overlay > with the USB device and there may not even be a base DT to map the > overlay into. In this case, the USB device's driver will need to load > the overlay and trigger enumerating the child devices. Anyway, this is > a separate issue from your problem. > Since both you and Alan agree with my problem should be fixed at bootloader, I give the kernel solution up. The another thing I open to discuss is how to let USB devices know its device node, the user reported issue that they can't handle interfaces below in USB device since that. -- Best Regards, Peter Chen -- 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
