KEYP_CLOCK_FREQ
udelay((2 * DIV_ROUND_UP(USEC_PER_SEC, KEYP_CLOCK_FREQ)) + 1);
udelay((4 * DIV_ROUND_UP(USEC_PER_SEC, KEYP_CLOCK_FREQ)) + 1);
cycles = (row_hold_ns * KEYP_CLOCK_FREQ) / NSEC_PER_SEC;