return error status on more routines; minor simplification of freq setting
return error status on more routines; minor simplification of freq setting

adafruit/micropython,adafruit/micropython,adafruit/circuitpython,adafruit/circuitpython,adafruit/circuitpython,adafruit/circuitpython,adafruit/micropython,adafruit/micropython,adafruit/circuitpython,adafruit/micropython,adafruit/circuitpython