BIT_TO_SHIFT
cur = (val >> BIT_TO_SHIFT(bit)) & fsel_mask;
val &= ~(fsel_mask << BIT_TO_SHIFT(bit));
val |= fsel << BIT_TO_SHIFT(bit);
return (val >> BIT_TO_SHIFT(bit)) & BRCMSTB_PULL_MASK;
val &= ~(BRCMSTB_PULL_MASK << BIT_TO_SHIFT(bit));
val |= (arg << BIT_TO_SHIFT(bit));
fsel = (val >> BIT_TO_SHIFT(bit)) & pc->pin_funcs[pin].func_mask;