tca8418_write_byte
error = tca8418_write_byte(keypad_data, REG_INT_STAT, reg);
error |= tca8418_write_byte(keypad_data, REG_KP_GPIO1, reg);
error |= tca8418_write_byte(keypad_data, REG_KP_GPIO2, reg >> 8);
error |= tca8418_write_byte(keypad_data, REG_KP_GPIO3, reg >> 16);
error |= tca8418_write_byte(keypad_data, REG_DEBOUNCE_DIS1, reg);
error |= tca8418_write_byte(keypad_data, REG_DEBOUNCE_DIS2, reg >> 8);
error |= tca8418_write_byte(keypad_data, REG_DEBOUNCE_DIS3, reg >> 16);
error = tca8418_write_byte(keypad_data, REG_CFG,