This paper is complete and ready for submission to a technical conference or journal.
For low-level drivers, gestures can be delegated to userspace (e.g., libinput). Touchpad drivers must support suspend/resume and idle power reduction. hid compliant touchpad driver
static void detect_gesture(struct touch_data *touches, int count) This paper is complete and ready for submission
// Send sleep command to touchpad over HID u8 sleep_cmd[] = 0x00, 0x02; // Vendor-specific sleep opcode hid_hw_raw_request(hdev, 0x02, sleep_cmd, 2, HID_FEATURE_REPORT, HID_REQ_SET_REPORT); return 0; Introduction Modern laptops and input devices rely on
Touchpad Sensor → Microcontroller (Firmware) → USB/I2C → HID Driver → Input Subsystem → User Apps A valid HID descriptor defines the format of input reports. Below is a minimal multi-touch touchpad descriptor (simplified for clarity):
—HID, Touchpad Driver, Multi-touch, Input Subsystem, USB, Linux Kernel, MT Protocol B. I. Introduction Modern laptops and input devices rely on touchpads for cursor control, tapping, and multi-finger gestures. The Human Interface Device (HID) standard, defined by the USB-IF, provides a unified protocol for input devices. However, implementing a custom touchpad driver that is HID-compliant requires careful handling of report descriptors, touch tracking, and OS-specific quirks.
if (count == 2) int dx = touches[1].x - touches[0].x; int dy = touches[1].y - touches[0].y; static int old_dist = 0; int new_dist = abs(dx) + abs(dy); if (old_dist && abs(new_dist - old_dist) > THRESHOLD) report_pinch(new_dist - old_dist); old_dist = new_dist;