Device Calibration - Kmdf Hid Minidriver For Touch I2c

// Forward return HidTransportReadReport(DeviceObject, Packet); Some I2C touch controllers accept calibration commands via HID Feature reports. Your minidriver can intercept USAGE_CALIBRATION writes, re-map them to the I2C device's register set, or override them entirely. 5. Registry-Based vs. ACPI-Based Calibration KMDF drivers cannot easily read large configuration from the registry during a boot-start scenario. The standard approaches:

NTSTATUS EvtHidDeviceReadReport(DEVICE_OBJECT *DeviceObject, PHID_XFER_PACKET Packet) Kmdf Hid Minidriver For Touch I2c Device Calibration

// Clamp to HID Logical range (e.g., 0..32767) calibratedX = max(0, min(32767, calibratedX)); calibratedY = max(0, min(32767, calibratedY)); Registry-Based vs

| Method | Storage Location | Read Access in Driver | Use Case | |--------|----------------|----------------------|-----------| | | \_SB.I2C0.TS1.CALX , CALY | IoGetDeviceProperty + ACPI parser | Firmware-defined, immutable | | Registry | HKLM\SYSTEM\CurrentControlSet\...\Parameters | RtlQueryRegistryValues | User-modifiable, dynamic | | Private IOCTL | Passed from service | EvtIoDeviceControl | Live calibration from UI app | 0..32767) calibratedX = max(0

// Forward return HidTransportReadReport(DeviceObject, Packet); Some I2C touch controllers accept calibration commands via HID Feature reports. Your minidriver can intercept USAGE_CALIBRATION writes, re-map them to the I2C device's register set, or override them entirely. 5. Registry-Based vs. ACPI-Based Calibration KMDF drivers cannot easily read large configuration from the registry during a boot-start scenario. The standard approaches:

NTSTATUS EvtHidDeviceReadReport(DEVICE_OBJECT *DeviceObject, PHID_XFER_PACKET Packet)

// Clamp to HID Logical range (e.g., 0..32767) calibratedX = max(0, min(32767, calibratedX)); calibratedY = max(0, min(32767, calibratedY));

| Method | Storage Location | Read Access in Driver | Use Case | |--------|----------------|----------------------|-----------| | | \_SB.I2C0.TS1.CALX , CALY | IoGetDeviceProperty + ACPI parser | Firmware-defined, immutable | | Registry | HKLM\SYSTEM\CurrentControlSet\...\Parameters | RtlQueryRegistryValues | User-modifiable, dynamic | | Private IOCTL | Passed from service | EvtIoDeviceControl | Live calibration from UI app |