You dont have to set the pinmode for analogread.
To read pin 12 (pa1) you have to use analogRead(1);
PA1 = 1
PA7 = 7
PA0 pin 13 is the aref, don't use this pin, it doesn't have internal pull-up enabled, and can destroy stuff. And i know, i have killed 4-5 leds on this pin when i was making the core, trail and error ;D