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Ubuntu Multitouch Kernel Driver Development - Details and testing



I'm developing a linux kernel driver for a multitouch device. I have used as start point the usbtouchscreen driver included in linux-3.0 kernel source.

Altough I can already make my mouse pointer move with touch there still a lot of questions that still arise:

- When properly configured will xinput list my device as mulitouch device ou touchscreen? The only thing I got so far was listed in Virtual Core Pointer category

- How should I properly configure and setup input device? This is how I am making:

    /* For single touch */
    input_set_abs_params(input_dev, ABS_X, 0, 6300, 0, 0);
    input_set_abs_params(input_dev, ABS_Y, 0, 6300, 0, 0);

    /* For multi-touch */
    input_mt_init_slots(input_dev, 6);
    input_set_abs_params(input_dev, ABS_MT_TOUCH_MAJOR, 0, 0xff, 0, 0);
    input_set_abs_params(input_dev, ABS_MT_POSITION_X, 0, 6300, 0, 0);
    input_set_abs_params(input_dev, ABS_MT_POSITION_Y, 0, 6300, 0, 0);

- How should I properly inject touches? In linux multitouch input protocol it says the following

The protocol is divided into two types, depending on the capabilities of the hardware. For devices handling anonymous contacts (type A), the protocol describes how to send the raw data for all contacts to the receiver. For devices capable of tracking identifiable contacts (type B), the protocoldescribes how to send updates for individual contacts via event slots.

What means anonymous contacts? My device sends raw data and my tracking is made on the kernel. By the time I'm about to inject touches in the kernel subsystem I have already touches identified and tracked. What is after all my device type?

Regardless, I have already tried the two types of reporting and non seem to give me multitouch input. This is how i'm doing right now:

       input_mt_slot(usbtouch->input, Touch->Id);
       input_mt_report_slot_state(usbtouch->input, MT_TOOL_FINGER, true);

       input_report_abs(usbtouch->input, ABS_MT_TOUCH_MAJOR, 128);
input_report_abs(usbtouch->input, ABS_MT_POSITION_X, Touch->ReportedPosition.X); input_report_abs(usbtouch->input, ABS_MT_POSITION_Y, Touch->ReportedPosition.Y);


    if (touch>0)
        input_report_key(usbtouch->input, BTN_TOUCH, true);

input_report_abs(usbtouch->input, ABS_X, Touch->ReportedPosition.X); input_report_abs(usbtouch->input, ABS_Y, Touch->ReportedPosition.Y);


- How can I test user side multitouch input? I'm trying to see if xinput lists my device as a multitouch device. No success. I'm also trying an example from qt4-demos, finger paint which always gives me nothing. Is there any "oficial" tool for ubuntu multitouch input testing?

I found this mailing list thru project utouch. I hope I'm doing this questions in the right place.

With my best regards,

Nuno Santos

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