MAX310X_IRQEN_REG
max310x_port_write(port, MAX310X_IRQEN_REG, val | MAX310X_IRQ_CTS_BIT);
max310x_port_write(port, MAX310X_IRQEN_REG, 0);
max310x_port_write(&s->p[i].port, MAX310X_IRQEN_REG, 0);