On Mon, 10 Dec 2001, Greg KH wrote: >On Mon, Dec 10, 2001 at 12:00:31PM -0500, Dan Streetman wrote: >> >> On Fri, 7 Dec 2001, Greg KH wrote: >> >> >I don't know of anyone using the usbdevfs interface on devices that have >> >a kernel driver associated with it. Does anyone else? >> >> Yes, me. I have to talk via usbdevfs to HID devices. > >Why? Does the current HID driver not give you enough control over your >device?
well, initial work was done well before the hiddev driver was created. Now that it exists, it probably would be possible (with a bit of adding to the hiddev driver) to use it. But, since all the initial work was on straight USB thru usbdevfs, it would only be more work to move to using HID. and, the devices aren't "really" HID. they only use the HID protocol to 'wrap' the commands (i.e., there are a lot of SET_REPORTS where the actual associated data is the command). and, using straight HID simply isn't enough. The protocol by design gives no location (topology) info and no connect/disconnect info, etc. So it winds up being a mix-n-match of HID and USB, then there's the problem of matching the hiddev device to the usbdevfs device (to get topology info, etc) and, if DCP locking is ever implemented, it'll be hard/impossible to talk to it non-HID (if e.g. a serial number was needed). Easier to do straight USB...unless you're working on Windoze, in which case HID saves you from writing a kernel driver (or really a kernel driver for each release + sometimes each 'service pack'...) but anyway, why limit usbdevfs to only devices which don't have kernel drivers? the end user should be able to decide what should drive a certain device, right? -- Dan Streetman [EMAIL PROTECTED] -------------------------------------------------- 186,282 miles per second: It isn't just a good idea, it's the law! _______________________________________________ [EMAIL PROTECTED] To unsubscribe, use the last form field at: https://lists.sourceforge.net/lists/listinfo/linux-usb-devel
