Based on your request, the most valuable feature to implement for a KMDF HID Minidriver for a Touch I2C device is a .
Windows stores calibration data for touch devices in a specific registry location. If your driver needs to apply a static offset or scale factor at boot, it should query this path or its own device parameters.
Microsoft standardized (Common.Class Extension) to simplify this. However, the generic in-box driver ( HIDI2C.sys ) lacks device-specific features—most notably, custom calibration routines .
Device (TCH0) Name (_HID, "YOUR0001") Name (_CID, "PNP0C50") // HID over I2C standard Method (_DSM, 4, Serialized) // UUID for Touch Calibration Data If (LEqual (Arg0, ToUUID ("XXXXXXXX-XXXX-XXXX-XXXX-XXXXXXXXXXXX"))) If (LEqual (Arg1, Zero)) // Revision 0 If (LEqual (Arg2, One)) // Function 1: Get Calibration Coefficients Return (Package() 0x00010000, // Coefficient A (Fixed-point or integer scaled) 0x00000000, // Coefficient B 0x00000020, // Coefficient C (Offset X) 0x00000000, // Coefficient D 0x00010000, // Coefficient E 0x00000040 // Coefficient F (Offset Y) ) Return (Buffer (One) 0x00 ) Use code with caution. KMDF Implementation: Evaluating _DSM kmdf hid minidriver for touch i2c device calibration
Multiply the raw value by a calibration factor if the active touch area is smaller than the sensor grid.
// Define the calibration data structure typedef struct _CALIBRATION_DATA ULONG ulXScale; ULONG ulYScale; ULONG ulXOffset; ULONG ulYOffset; CALIBRATION_DATA, *PCALIBRATION_DATA;
In your KMDF driver, implement a EvtIoDeviceControl callback: Based on your request, the most valuable feature
Step 3: Coordinate Transformation (In-Driver Software Calibration)
Set up a fixed-point multiplication matrix helper function within the data parsing loop.
Apply these values immediately during hardware re-initialisation. 5. Debugging and Testing Best Practices Microsoft standardized (Common
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The KMDF HID minidriver is a type of kernel-mode driver that uses the Kernel-Mode Driver Framework (KMDF) to interact with the operating system. The minidriver is designed to work with HID devices, which include touchscreens, touchpads, and other human interface devices.