Hi Prajosh, On Fri, May 23, 2014 at 6:55 AM, Prajosh Premdas <premdas.prajosh@xxxxxxxxx> wrote: > Hi > > I have some USB based touch controllers. These controllers are working > well using the hid_multitouch driver. > > I would also like to add some additional protocol support for > diagnostics and re calibration. I am using the touch interface for the > same, whereby the control endpoint is used to send the request and > digitizer end point is used to get the response. (it is a legacy > design so i cannot change it) > > My plan is to add the additional driver support to this file > drivers/input/touchscreen/usbtouchscreen.c and disable the default > support for the hid_multitouch by making an entry in the hid-blacklist > array in this file drivers/hid/usbhid/hid-quirks.c 2 things: - adding the device to hid-blacklist either in hid-quirks or hid-core.c will not help, the device will still be bound to the HID subsystem, and the usb driver will not be able to catch it. If you were to go to this road, you would have to add the VID/PID to hid-ignore in hid-core.c - I don't think it is a good idea to move from hid-multitouch to usbtouchscreen: as far as I know, this driver only support single touch devices, and it will be a burden to implement the multitouch part > > Is there a better idea than this? If you need to talk to the device through the control endpoint and get the responses through the interrupt endpoint, hidraw seems to be perfect for your case: you can either use the ioctl HIDIOCSFEATURE or directly write on the hidraw node to send reports, and reading back to the node will give you the interrupts. Bonus point, you are enterily in userspace, so no risk of crashing your kernel. Then, you just set up an udev rule if you need the commands to be launched at plug. You can find an example in samples/hidraw/hid-example.c in the kernel tree. Cheers, Benjamin -- 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
