If you have to click OK after entering your passcode, this command will unlock your phone:

adb shell input text XXXX && adb shell input keyevent 66

Where

• XXXX is your passcode.
• 66 is the keycode of the OK button.
• adb shell input text XXXX will enter your passcode.
• adb shell input keyevent 66 will simulate clicking the OK button.