Reference

1. ESP32+P/S2 Synatics touchpad——https://gwliang.com/posts/esp32-touchpad/
2. Source code from Linux kernel——https://github.com/torvalds/linux/blob/master/drivers/hid/hid-elan.c
3. An old reference material——https://www.spinics.net/lists/kernel/msg1336681.html
4. Windows I2C Over I2C HID——https://learn.microsoft.com/en-us/windows-hardware/drivers/hid/hid-over-i2c-guide
5. TouchPad Implementation Guide——https://learn.microsoft.com/en-us/windows-hardware/design/component-guidelines/touchpad-implementation-guide
6. TouchPad Protocol Implementation——https://learn.microsoft.com/en-us/windows-hardware/design/component-guidelines/touchpad-protocol-implementation
7. TouchPad Device Bus Connectivity——https://learn.microsoft.com/en-us/windows-hardware/design/component-guidelines/touchpad-device-bus-connectivity
8. TouchPad Tuning Guidelines——https://learn.microsoft.com/en-us/windows-hardware/design/component-guidelines/touchpad-tuning-guidelines