On Mon, Dec 7, 2015 at 7:42 PM, Martin Pieuchot <m...@openbsd.org> wrote: > I'd really prefer a solution that doesn't need any button. In other > words to always be able to use your device from userland if the kernel > is not using it. > > One way would be to always attach a ugen(4) driver to every USB device, > I think that's what FreeBSD does. The other way would be to use the > usb(4) bus interface to talk to your device. In both cases some work > is needed to guarantee that an endpoint is only driven by one driver at > a time. Right now this is done by attaching only one driver.
It will be good if this limitation is removed (I know the FreeBSD approach but FreeBSD libusb is not under libusb project due to license concerns) and then libusb will be more useful. Or a method like Linux where the kernel driver can be dynamically detached (so that usbfs generic driver is attached and libusb uses usbfs under Linux). > To which driver your device currently attaches? What kind of transfers > to you want to submit from userland? The libusb already allow your to > submit(some) control transfers. It would be nice if you could improve > this rather than adding a hack like this one. > As mentioned in another email reply, PICKit 2 is a generic USB device and it uses control transfer and interrupt transfer. It is a bit unique that PICkit 2 has two USB configurations, one for HID and one for custom USB ( a legacy from the PICKit 1 days). -- Xiaofan
