CH341_BIT_RTS
priv->mcr |= CH341_BIT_RTS | CH341_BIT_DTR;
priv->mcr &= ~(CH341_BIT_RTS | CH341_BIT_DTR);
priv->mcr &= ~(CH341_BIT_DTR | CH341_BIT_RTS);
priv->mcr |= (CH341_BIT_DTR | CH341_BIT_RTS);
priv->mcr |= CH341_BIT_RTS;
priv->mcr &= ~CH341_BIT_RTS;
| ((mcr & CH341_BIT_RTS) ? TIOCM_RTS : 0)