On Wednesday 09 December 2015 16:12:24 Peter Chen wrote: > On Tue, Dec 08, 2015 at 09:24:03PM -0600, Rob Herring wrote: > > On Tue, Dec 08, 2015 at 10:58:48AM +0100, Arnd Bergmann wrote: > > > On Tuesday 08 December 2015 10:50:49 Philipp Zabel wrote: > > > > This something we don't have to define ad-hoc. The hub hangs off an USB > > > > controller, right? The "Open Firmware recommended practice: USB" > > > > document already describes how to represent USB devices in a generic > > > > manner: > > > > http://www.firmware.org/1275/bindings/usb/usb-1_0.ps > > > > > > > > Is there a reason not to reuse this? > > > > > > > > The usb hub node would be a child of the usb controller node, and it > > > > could use > > > > compatible = "usb,class9"; /* bDeviceClass 9 (Hub) */ > > > > > > Good point, I had not thought of that when I looked at the patches. > > > > > > Yes, let's do this way. I don't know if we ever implemented the simple > > > patch to associate a USB device with a device_node, but if not, then > > > let's do it now for this driver. A lot of people have asked for it in > > > the past. > > > > Agreed. Also, some hubs have I2C buses as well, but I still think under > > the USB bus is the right place. > > > > However, one complication here is often (probably this case) these > > addtional signals need to be controlled before the device enumerates. > > > > Yes, I did not find a way to let the USB bus code handle it, so I had to > write a platform driver to do it Looping in Ulf, he solved the same problem for SDIO devices recently, and probably remembers the details best. Arnd -- 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
