B_LOW_ACTIVE_POLARITY
irqEntry.polarity = B_LOW_ACTIVE_POLARITY;
? B_HIGH_ACTIVE_POLARITY : B_LOW_ACTIVE_POLARITY;
? B_HIGH_ACTIVE_POLARITY : B_LOW_ACTIVE_POLARITY;
if (triggerPolarity & B_LOW_ACTIVE_POLARITY)
config = B_LOW_ACTIVE_POLARITY;