On Fri, 21 Jan 2011, Alan Ott wrote: > Well, what I really want is the Usage Page and Usage of the device. For some > background, I maintain a library called hidapi[1] for accessing HID devices in > a cross platform way. There are currently four backends, Linux-hidraw, > Linux-libusb, Mac OS, and Windows. > > I've recently received requests for supporting composite HID devices. Since a > composite device will show up as multiple devices with the same VID/PID, one > needs a way to differentiate between its different interfaces. On Windows and > Mac, the platform HID libraries support getting the Usage Page and Usage of > each interface. On Linux/libusb I can request the HID report descriptor and > parse it myself, but I have to claim the interface to do it, and to do that, I > have to detach the kernel driver. Needless to say, detaching the kernel driver > is not good, especially when the library is supposed to be just scanning for > devices. > > For these reasons, it would be really convenient to get the report descriptor > from sysfs. In this case, you can still get the report descriptor from hidraw (which is parallel to any other HID-bus based kernel driver). Woudl that suit your needs? -- Jiri Kosina SUSE Labs, Novell Inc. -- To unsubscribe from this list: send the line "unsubscribe linux-input" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
