mxser_new.c

来自「linux 内核源代码」· C语言 代码 · 共 2,540 行 · 第 1/5 页

	if (i == BAUD_TABLE_NO) {
		quot = info->baud_base % info->speed;
		quot *= 8;
		if ((quot % info->speed) > (info->speed / 2)) {
			quot /= info->speed;
			quot++;
		} else {
			quot /= info->speed;
		}
		SET_MOXA_MUST_ENUM_VALUE(info->ioaddr, quot);
	} else
		SET_MOXA_MUST_ENUM_VALUE(info->ioaddr, 0);

	return ret;
}

/*
 * This routine is called to set the UART divisor registers to match
 * the specified baud rate for a serial port.
 */
static int mxser_change_speed(struct mxser_port *info,
		struct ktermios *old_termios)
{
	unsigned cflag, cval, fcr;
	int ret = 0;
	unsigned char status;
	long baud;

	if (!info->tty || !info->tty->termios)
		return ret;
	cflag = info->tty->termios->c_cflag;
	if (!(info->ioaddr))
		return ret;

	if (mxser_set_baud_method[info->tty->index] == 0) {
		if ((cflag & CBAUD) == B_SPEC)
			baud = info->speed;
		else
			baud = tty_get_baud_rate(info->tty);
		mxser_set_baud(info, baud);
	}

	/* byte size and parity */
	switch (cflag & CSIZE) {
	case CS5:
		cval = 0x00;
		break;
	case CS6:
		cval = 0x01;
		break;
	case CS7:
		cval = 0x02;
		break;
	case CS8:
		cval = 0x03;
		break;
	default:
		cval = 0x00;
		break;		/* too keep GCC shut... */
	}
	if (cflag & CSTOPB)
		cval |= 0x04;
	if (cflag & PARENB)
		cval |= UART_LCR_PARITY;
	if (!(cflag & PARODD))
		cval |= UART_LCR_EPAR;
	if (cflag & CMSPAR)
		cval |= UART_LCR_SPAR;

	if ((info->type == PORT_8250) || (info->type == PORT_16450)) {
		if (info->board->chip_flag) {
			fcr = UART_FCR_ENABLE_FIFO;
			fcr |= MOXA_MUST_FCR_GDA_MODE_ENABLE;
			SET_MOXA_MUST_FIFO_VALUE(info);
		} else
			fcr = 0;
	} else {
		fcr = UART_FCR_ENABLE_FIFO;
		if (info->board->chip_flag) {
			fcr |= MOXA_MUST_FCR_GDA_MODE_ENABLE;
			SET_MOXA_MUST_FIFO_VALUE(info);
		} else {
			switch (info->rx_trigger) {
			case 1:
				fcr |= UART_FCR_TRIGGER_1;
				break;
			case 4:
				fcr |= UART_FCR_TRIGGER_4;
				break;
			case 8:
				fcr |= UART_FCR_TRIGGER_8;
				break;
			default:
				fcr |= UART_FCR_TRIGGER_14;
				break;
			}
		}
	}

	/* CTS flow control flag and modem status interrupts */
	info->IER &= ~UART_IER_MSI;
	info->MCR &= ~UART_MCR_AFE;
	if (cflag & CRTSCTS) {
		info->flags |= ASYNC_CTS_FLOW;
		info->IER |= UART_IER_MSI;
		if ((info->type == PORT_16550A) || (info->board->chip_flag)) {
			info->MCR |= UART_MCR_AFE;
		} else {
			status = inb(info->ioaddr + UART_MSR);
			if (info->tty->hw_stopped) {
				if (status & UART_MSR_CTS) {
					info->tty->hw_stopped = 0;
					if (info->type != PORT_16550A &&
							!info->board->chip_flag) {
						outb(info->IER & ~UART_IER_THRI,
							info->ioaddr +
							UART_IER);
						info->IER |= UART_IER_THRI;
						outb(info->IER, info->ioaddr +
								UART_IER);
					}
					tty_wakeup(info->tty);
				}
			} else {
				if (!(status & UART_MSR_CTS)) {
					info->tty->hw_stopped = 1;
					if ((info->type != PORT_16550A) &&
							(!info->board->chip_flag)) {
						info->IER &= ~UART_IER_THRI;
						outb(info->IER, info->ioaddr +
								UART_IER);
					}
				}
			}
		}
	} else {
		info->flags &= ~ASYNC_CTS_FLOW;
	}
	outb(info->MCR, info->ioaddr + UART_MCR);
	if (cflag & CLOCAL) {
		info->flags &= ~ASYNC_CHECK_CD;
	} else {
		info->flags |= ASYNC_CHECK_CD;
		info->IER |= UART_IER_MSI;
	}
	outb(info->IER, info->ioaddr + UART_IER);

	/*
	 * Set up parity check flag
	 */
	info->read_status_mask = UART_LSR_OE | UART_LSR_THRE | UART_LSR_DR;
	if (I_INPCK(info->tty))
		info->read_status_mask |= UART_LSR_FE | UART_LSR_PE;
	if (I_BRKINT(info->tty) || I_PARMRK(info->tty))
		info->read_status_mask |= UART_LSR_BI;

	info->ignore_status_mask = 0;

	if (I_IGNBRK(info->tty)) {
		info->ignore_status_mask |= UART_LSR_BI;
		info->read_status_mask |= UART_LSR_BI;
		/*
		 * If we're ignore parity and break indicators, ignore
		 * overruns too.  (For real raw support).
		 */
		if (I_IGNPAR(info->tty)) {
			info->ignore_status_mask |=
						UART_LSR_OE |
						UART_LSR_PE |
						UART_LSR_FE;
			info->read_status_mask |=
						UART_LSR_OE |
						UART_LSR_PE |
						UART_LSR_FE;
		}
	}
	if (info->board->chip_flag) {
		SET_MOXA_MUST_XON1_VALUE(info->ioaddr, START_CHAR(info->tty));
		SET_MOXA_MUST_XOFF1_VALUE(info->ioaddr, STOP_CHAR(info->tty));
		if (I_IXON(info->tty)) {
			ENABLE_MOXA_MUST_RX_SOFTWARE_FLOW_CONTROL(info->ioaddr);
		} else {
			DISABLE_MOXA_MUST_RX_SOFTWARE_FLOW_CONTROL(info->ioaddr);
		}
		if (I_IXOFF(info->tty)) {
			ENABLE_MOXA_MUST_TX_SOFTWARE_FLOW_CONTROL(info->ioaddr);
		} else {
			DISABLE_MOXA_MUST_TX_SOFTWARE_FLOW_CONTROL(info->ioaddr);
		}
	}


	outb(fcr, info->ioaddr + UART_FCR);	/* set fcr */
	outb(cval, info->ioaddr + UART_LCR);

	return ret;
}

static void mxser_check_modem_status(struct mxser_port *port, int status)
{
	/* update input line counters */
	if (status & UART_MSR_TERI)
		port->icount.rng++;
	if (status & UART_MSR_DDSR)
		port->icount.dsr++;
	if (status & UART_MSR_DDCD)
		port->icount.dcd++;
	if (status & UART_MSR_DCTS)
		port->icount.cts++;
	port->mon_data.modem_status = status;
	wake_up_interruptible(&port->delta_msr_wait);

	if ((port->flags & ASYNC_CHECK_CD) && (status & UART_MSR_DDCD)) {
		if (status & UART_MSR_DCD)
			wake_up_interruptible(&port->open_wait);
	}

	if (port->flags & ASYNC_CTS_FLOW) {
		if (port->tty->hw_stopped) {
			if (status & UART_MSR_CTS) {
				port->tty->hw_stopped = 0;

				if ((port->type != PORT_16550A) &&
						(!port->board->chip_flag)) {
					outb(port->IER & ~UART_IER_THRI,
						port->ioaddr + UART_IER);
					port->IER |= UART_IER_THRI;
					outb(port->IER, port->ioaddr +
							UART_IER);
				}
				tty_wakeup(port->tty);
			}
		} else {
			if (!(status & UART_MSR_CTS)) {
				port->tty->hw_stopped = 1;
				if (port->type != PORT_16550A &&
						!port->board->chip_flag) {
					port->IER &= ~UART_IER_THRI;
					outb(port->IER, port->ioaddr +
							UART_IER);
				}
			}
		}
	}
}

static int mxser_startup(struct mxser_port *info)
{
	unsigned long page;
	unsigned long flags;

	page = __get_free_page(GFP_KERNEL);
	if (!page)
		return -ENOMEM;

	spin_lock_irqsave(&info->slock, flags);

	if (info->flags & ASYNC_INITIALIZED) {
		free_page(page);
		spin_unlock_irqrestore(&info->slock, flags);
		return 0;
	}

	if (!info->ioaddr || !info->type) {
		if (info->tty)
			set_bit(TTY_IO_ERROR, &info->tty->flags);
		free_page(page);
		spin_unlock_irqrestore(&info->slock, flags);
		return 0;
	}
	if (info->xmit_buf)
		free_page(page);
	else
		info->xmit_buf = (unsigned char *) page;

	/*
	 * Clear the FIFO buffers and disable them
	 * (they will be reenabled in mxser_change_speed())
	 */
	if (info->board->chip_flag)
		outb((UART_FCR_CLEAR_RCVR |
			UART_FCR_CLEAR_XMIT |
			MOXA_MUST_FCR_GDA_MODE_ENABLE), info->ioaddr + UART_FCR);
	else
		outb((UART_FCR_CLEAR_RCVR | UART_FCR_CLEAR_XMIT),
			info->ioaddr + UART_FCR);

	/*
	 * At this point there's no way the LSR could still be 0xFF;
	 * if it is, then bail out, because there's likely no UART
	 * here.
	 */
	if (inb(info->ioaddr + UART_LSR) == 0xff) {
		spin_unlock_irqrestore(&info->slock, flags);
		if (capable(CAP_SYS_ADMIN)) {
			if (info->tty)
				set_bit(TTY_IO_ERROR, &info->tty->flags);
			return 0;
		} else
			return -ENODEV;
	}

	/*
	 * Clear the interrupt registers.
	 */
	(void) inb(info->ioaddr + UART_LSR);
	(void) inb(info->ioaddr + UART_RX);
	(void) inb(info->ioaddr + UART_IIR);
	(void) inb(info->ioaddr + UART_MSR);

	/*
	 * Now, initialize the UART
	 */
	outb(UART_LCR_WLEN8, info->ioaddr + UART_LCR);	/* reset DLAB */
	info->MCR = UART_MCR_DTR | UART_MCR_RTS;
	outb(info->MCR, info->ioaddr + UART_MCR);

	/*
	 * Finally, enable interrupts
	 */
	info->IER = UART_IER_MSI | UART_IER_RLSI | UART_IER_RDI;

	if (info->board->chip_flag)
		info->IER |= MOXA_MUST_IER_EGDAI;
	outb(info->IER, info->ioaddr + UART_IER);	/* enable interrupts */

	/*
	 * And clear the interrupt registers again for luck.
	 */
	(void) inb(info->ioaddr + UART_LSR);
	(void) inb(info->ioaddr + UART_RX);
	(void) inb(info->ioaddr + UART_IIR);
	(void) inb(info->ioaddr + UART_MSR);

	if (info->tty)
		clear_bit(TTY_IO_ERROR, &info->tty->flags);
	info->xmit_cnt = info->xmit_head = info->xmit_tail = 0;

	/*
	 * and set the speed of the serial port
	 */
	mxser_change_speed(info, NULL);
	info->flags |= ASYNC_INITIALIZED;
	spin_unlock_irqrestore(&info->slock, flags);

	return 0;
}

/*
 * This routine will shutdown a serial port; interrupts maybe disabled, and
 * DTR is dropped if the hangup on close termio flag is on.
 */
static void mxser_shutdown(struct mxser_port *info)
{
	unsigned long flags;

	if (!(info->flags & ASYNC_INITIALIZED))
		return;

	spin_lock_irqsave(&info->slock, flags);

	/*
	 * clear delta_msr_wait queue to avoid mem leaks: we may free the irq
	 * here so the queue might never be waken up
	 */
	wake_up_interruptible(&info->delta_msr_wait);

	/*
	 * Free the IRQ, if necessary
	 */
	if (info->xmit_buf) {
		free_page((unsigned long) info->xmit_buf);
		info->xmit_buf = NULL;
	}

	info->IER = 0;
	outb(0x00, info->ioaddr + UART_IER);

	if (!info->tty || (info->tty->termios->c_cflag & HUPCL))
		info->MCR &= ~(UART_MCR_DTR | UART_MCR_RTS);
	outb(info->MCR, info->ioaddr + UART_MCR);

	/* clear Rx/Tx FIFO's */
	if (info->board->chip_flag)
		outb(UART_FCR_CLEAR_RCVR | UART_FCR_CLEAR_XMIT |
				MOXA_MUST_FCR_GDA_MODE_ENABLE,
				info->ioaddr + UART_FCR);
	else
		outb(UART_FCR_CLEAR_RCVR | UART_FCR_CLEAR_XMIT,
			info->ioaddr + UART_FCR);

	/* read data port to reset things */
	(void) inb(info->ioaddr + UART_RX);

	if (info->tty)
		set_bit(TTY_IO_ERROR, &info->tty->flags);

	info->flags &= ~ASYNC_INITIALIZED;

	if (info->board->chip_flag)
		SET_MOXA_MUST_NO_SOFTWARE_FLOW_CONTROL(info->ioaddr);

	spin_unlock_irqrestore(&info->slock, flags);
}

/*
 * This routine is called whenever a serial port is opened.  It
 * enables interrupts for a serial port, linking in its async structure into
 * the IRQ chain.   It also performs the serial-specific
 * initialization for the tty structure.
 */
static int mxser_open(struct tty_struct *tty, struct file *filp)
{
	struct mxser_port *info;
	unsigned long flags;
	int retval, line;

	line = tty->index;
	if (line == MXSER_PORTS)
		return 0;
	if (line < 0 || line > MXSER_PORTS)
		return -ENODEV;
	info = &mxser_boards[line / MXSER_PORTS_PER_BOARD].ports[line % MXSER_PORTS_PER_BOARD];
	if (!info->ioaddr)
		return -ENODEV;

	tty->driver_data = info;
	info->tty = tty;
	/*
	 * Start up serial port
	 */
	spin_lock_irqsave(&info->slock, flags);
	info->count++;
	spin_unlock_irqrestore(&info->slock, flags);
	retval = mxser_startup(info);
	if (retval)
		return retval;

	retval = mxser_block_til_ready(tty, filp, info);
	if (retval)
		return retval;

	/* unmark here for very high baud rate (ex. 921600 bps) used */
	tty->low_latency = 1;
	return 0;
}

/*
 * This routine is called when the serial port gets closed.  First, we
 * wait for the last remaining data to be sent.  Then, we unlink its
 * async structure from the interrupt chain if necessary, and we free
 * that IRQ if nothing is left in the chain.
 */
static void mxser_close(struct tty_struct *tty, struct file *filp)
{
	struct mxser_port *info = tty->driver_data;

	unsigned long timeout;
	unsigned long flags;

	if (tty->index == MXSER_PORTS)
		return;
	if (!info)
		return;

	spin_lock_irqsave(&info->slock, flags);

	if (tty_hung_up_p(filp)) {
		spin_unlock_irqrestore(&info->slock, flags);
		return;
	}
	if ((tty->count == 1) && (info->count != 1)) {
		/*
		 * Uh, oh.  tty->count is 1, which means that the tty
		 * structure will be freed.  Info->count should always
		 * be one in these conditions.  If it's greater than
		 * one, we've got real problems, since it means the
		 * serial port won't be shutdown.
		 */
		printk(KERN_ERR "mxser_close: bad serial port count; "
			"tty->count is 1, info->count is %d\n", info->count);
		info->count = 1;
	}
	if (--info->count < 0) {
		printk(KERN_ERR "mxser_close: bad serial port count for "
			"ttys%d: %d\n", tty->index, info->count);
		info->count = 0;
	}
	if (info->count) {
		spin_unlock_irqrestore(&info->slock, flags);
		return;
	}
	info->flags |= ASYNC_CLOSING;
	spin_unlock_irqrestore(&info->slock, flags);
	/*
	 * Save the termios structure, since this port may have
	 * separate termios for callout and dialin.
	 */
	if (info->flags & ASYNC_NORMAL_ACTIVE)
		info->normal_termios = *tty->termios;
	/*
	 * Now we wait for the transmit buffer to clear; and we notify
	 * the line discipline to only process XON/XOFF characters.
	 */
	tty->closing = 1;
	if (info->closing_wait != ASYNC_CLOSING_WAIT_NONE)
		tty_wait_until_sent(tty, info->closing_wait);
	/*