specialix.c

来自「linux 内核源代码」· C语言 代码 · 共 2,562 行 · 第 1/5 页

	func_exit();
}


/*
 * Setting up port characteristics.
 * Must be called with disabled interrupts
 */
static void sx_change_speed(struct specialix_board *bp, struct specialix_port *port)
{
	struct tty_struct *tty;
	unsigned long baud;
	long tmp;
	unsigned char cor1 = 0, cor3 = 0;
	unsigned char mcor1 = 0, mcor2 = 0;
	static unsigned long again;
	unsigned long flags;

	func_enter();

	if (!(tty = port->tty) || !tty->termios) {
		func_exit();
		return;
	}

	port->IER  = 0;
	port->COR2 = 0;
	/* Select port on the board */
	spin_lock_irqsave(&bp->lock, flags);
	sx_out(bp, CD186x_CAR, port_No(port));

	/* The Specialix board doens't implement the RTS lines.
	   They are used to set the IRQ level. Don't touch them. */
	if (SX_CRTSCTS(tty))
		port->MSVR = MSVR_DTR | (sx_in(bp, CD186x_MSVR) & MSVR_RTS);
	else
		port->MSVR =  (sx_in(bp, CD186x_MSVR) & MSVR_RTS);
	spin_unlock_irqrestore(&bp->lock, flags);
	dprintk (SX_DEBUG_TERMIOS, "sx: got MSVR=%02x.\n", port->MSVR);
	baud = tty_get_baud_rate(tty);

	if (baud == 38400) {
		if ((port->flags & ASYNC_SPD_MASK) == ASYNC_SPD_HI)
			baud = 57600;
		if ((port->flags & ASYNC_SPD_MASK) == ASYNC_SPD_VHI)
			baud = 115200;
	}

	if (!baud) {
		/* Drop DTR & exit */
		dprintk (SX_DEBUG_TERMIOS, "Dropping DTR...  Hmm....\n");
		if (!SX_CRTSCTS (tty)) {
			port -> MSVR &= ~ MSVR_DTR;
			spin_lock_irqsave(&bp->lock, flags);
			sx_out(bp, CD186x_MSVR, port->MSVR );
			spin_unlock_irqrestore(&bp->lock, flags);
		}
		else
			dprintk (SX_DEBUG_TERMIOS, "Can't drop DTR: no DTR.\n");
		return;
	} else {
		/* Set DTR on */
		if (!SX_CRTSCTS (tty)) {
			port ->MSVR |= MSVR_DTR;
		}
	}

	/*
	 * Now we must calculate some speed depended things
	 */

	/* Set baud rate for port */
	tmp = port->custom_divisor ;
	if ( tmp )
		printk (KERN_INFO "sx%d: Using custom baud rate divisor %ld. \n"
		                  "This is an untested option, please be carefull.\n",
		                  port_No (port), tmp);
	else
		tmp = (((SX_OSCFREQ + baud/2) / baud +
		         CD186x_TPC/2) / CD186x_TPC);

	if ((tmp < 0x10) && time_before(again, jiffies)) {
		again = jiffies + HZ * 60;
		/* Page 48 of version 2.0 of the CL-CD1865 databook */
		if (tmp >= 12) {
			printk (KERN_INFO "sx%d: Baud rate divisor is %ld. \n"
			        "Performance degradation is possible.\n"
			        "Read specialix.txt for more info.\n",
			        port_No (port), tmp);
		} else {
			printk (KERN_INFO "sx%d: Baud rate divisor is %ld. \n"
			        "Warning: overstressing Cirrus chip. "
			        "This might not work.\n"
			        "Read specialix.txt for more info.\n",
			        port_No (port), tmp);
		}
	}
	spin_lock_irqsave(&bp->lock, flags);
	sx_out(bp, CD186x_RBPRH, (tmp >> 8) & 0xff);
	sx_out(bp, CD186x_TBPRH, (tmp >> 8) & 0xff);
	sx_out(bp, CD186x_RBPRL, tmp & 0xff);
	sx_out(bp, CD186x_TBPRL, tmp & 0xff);
	spin_unlock_irqrestore(&bp->lock, flags);
	if (port->custom_divisor)
		baud = (SX_OSCFREQ + port->custom_divisor/2) / port->custom_divisor;
	baud = (baud + 5) / 10;		/* Estimated CPS */

	/* Two timer ticks seems enough to wakeup something like SLIP driver */
	tmp = ((baud + HZ/2) / HZ) * 2 - CD186x_NFIFO;
	port->wakeup_chars = (tmp < 0) ? 0 : ((tmp >= SERIAL_XMIT_SIZE) ?
					      SERIAL_XMIT_SIZE - 1 : tmp);

	/* Receiver timeout will be transmission time for 1.5 chars */
	tmp = (SPECIALIX_TPS + SPECIALIX_TPS/2 + baud/2) / baud;
	tmp = (tmp > 0xff) ? 0xff : tmp;
	spin_lock_irqsave(&bp->lock, flags);
	sx_out(bp, CD186x_RTPR, tmp);
	spin_unlock_irqrestore(&bp->lock, flags);
	switch (C_CSIZE(tty)) {
	 case CS5:
		cor1 |= COR1_5BITS;
		break;
	 case CS6:
		cor1 |= COR1_6BITS;
		break;
	 case CS7:
		cor1 |= COR1_7BITS;
		break;
	 case CS8:
		cor1 |= COR1_8BITS;
		break;
	}

	if (C_CSTOPB(tty))
		cor1 |= COR1_2SB;

	cor1 |= COR1_IGNORE;
	if (C_PARENB(tty)) {
		cor1 |= COR1_NORMPAR;
		if (C_PARODD(tty))
			cor1 |= COR1_ODDP;
		if (I_INPCK(tty))
			cor1 &= ~COR1_IGNORE;
	}
	/* Set marking of some errors */
	port->mark_mask = RCSR_OE | RCSR_TOUT;
	if (I_INPCK(tty))
		port->mark_mask |= RCSR_FE | RCSR_PE;
	if (I_BRKINT(tty) || I_PARMRK(tty))
		port->mark_mask |= RCSR_BREAK;
	if (I_IGNPAR(tty))
		port->mark_mask &= ~(RCSR_FE | RCSR_PE);
	if (I_IGNBRK(tty)) {
		port->mark_mask &= ~RCSR_BREAK;
		if (I_IGNPAR(tty))
			/* Real raw mode. Ignore all */
			port->mark_mask &= ~RCSR_OE;
	}
	/* Enable Hardware Flow Control */
	if (C_CRTSCTS(tty)) {
#ifdef SPECIALIX_BRAIN_DAMAGED_CTS
		port->IER |= IER_DSR | IER_CTS;
		mcor1 |= MCOR1_DSRZD | MCOR1_CTSZD;
		mcor2 |= MCOR2_DSROD | MCOR2_CTSOD;
		spin_lock_irqsave(&bp->lock, flags);
		tty->hw_stopped = !(sx_in(bp, CD186x_MSVR) & (MSVR_CTS|MSVR_DSR));
		spin_unlock_irqrestore(&bp->lock, flags);
#else
		port->COR2 |= COR2_CTSAE;
#endif
	}
	/* Enable Software Flow Control. FIXME: I'm not sure about this */
	/* Some people reported that it works, but I still doubt it */
	if (I_IXON(tty)) {
		port->COR2 |= COR2_TXIBE;
		cor3 |= (COR3_FCT | COR3_SCDE);
		if (I_IXANY(tty))
			port->COR2 |= COR2_IXM;
		spin_lock_irqsave(&bp->lock, flags);
		sx_out(bp, CD186x_SCHR1, START_CHAR(tty));
		sx_out(bp, CD186x_SCHR2, STOP_CHAR(tty));
		sx_out(bp, CD186x_SCHR3, START_CHAR(tty));
		sx_out(bp, CD186x_SCHR4, STOP_CHAR(tty));
		spin_unlock_irqrestore(&bp->lock, flags);
	}
	if (!C_CLOCAL(tty)) {
		/* Enable CD check */
		port->IER |= IER_CD;
		mcor1 |= MCOR1_CDZD;
		mcor2 |= MCOR2_CDOD;
	}

	if (C_CREAD(tty))
		/* Enable receiver */
		port->IER |= IER_RXD;

	/* Set input FIFO size (1-8 bytes) */
	cor3 |= sx_rxfifo;
	/* Setting up CD186x channel registers */
	spin_lock_irqsave(&bp->lock, flags);
	sx_out(bp, CD186x_COR1, cor1);
	sx_out(bp, CD186x_COR2, port->COR2);
	sx_out(bp, CD186x_COR3, cor3);
	spin_unlock_irqrestore(&bp->lock, flags);
	/* Make CD186x know about registers change */
	sx_wait_CCR(bp);
	spin_lock_irqsave(&bp->lock, flags);
	sx_out(bp, CD186x_CCR, CCR_CORCHG1 | CCR_CORCHG2 | CCR_CORCHG3);
	/* Setting up modem option registers */
	dprintk (SX_DEBUG_TERMIOS, "Mcor1 = %02x, mcor2 = %02x.\n", mcor1, mcor2);
	sx_out(bp, CD186x_MCOR1, mcor1);
	sx_out(bp, CD186x_MCOR2, mcor2);
	spin_unlock_irqrestore(&bp->lock, flags);
	/* Enable CD186x transmitter & receiver */
	sx_wait_CCR(bp);
	spin_lock_irqsave(&bp->lock, flags);
	sx_out(bp, CD186x_CCR, CCR_TXEN | CCR_RXEN);
	/* Enable interrupts */
	sx_out(bp, CD186x_IER, port->IER);
	/* And finally set the modem lines... */
	sx_out(bp, CD186x_MSVR, port->MSVR);
	spin_unlock_irqrestore(&bp->lock, flags);

	func_exit();
}


/* Must be called with interrupts enabled */
static int sx_setup_port(struct specialix_board *bp, struct specialix_port *port)
{
	unsigned long flags;

	func_enter();

	if (port->flags & ASYNC_INITIALIZED) {
		func_exit();
		return 0;
	}

	if (!port->xmit_buf) {
		/* We may sleep in get_zeroed_page() */
		unsigned long tmp;

		if (!(tmp = get_zeroed_page(GFP_KERNEL))) {
			func_exit();
			return -ENOMEM;
		}

		if (port->xmit_buf) {
			free_page(tmp);
			func_exit();
			return -ERESTARTSYS;
		}
		port->xmit_buf = (unsigned char *) tmp;
	}

	spin_lock_irqsave(&port->lock, flags);

	if (port->tty)
		clear_bit(TTY_IO_ERROR, &port->tty->flags);

	port->xmit_cnt = port->xmit_head = port->xmit_tail = 0;
	sx_change_speed(bp, port);
	port->flags |= ASYNC_INITIALIZED;

	spin_unlock_irqrestore(&port->lock, flags);


	func_exit();
	return 0;
}


/* Must be called with interrupts disabled */
static void sx_shutdown_port(struct specialix_board *bp, struct specialix_port *port)
{
	struct tty_struct *tty;
	int i;
	unsigned long flags;

	func_enter();

	if (!(port->flags & ASYNC_INITIALIZED)) {
		func_exit();
		return;
	}

	if (sx_debug & SX_DEBUG_FIFO) {
		dprintk(SX_DEBUG_FIFO, "sx%d: port %d: %ld overruns, FIFO hits [ ",
			board_No(bp), port_No(port), port->overrun);
		for (i = 0; i < 10; i++) {
			dprintk(SX_DEBUG_FIFO, "%ld ", port->hits[i]);
		}
		dprintk(SX_DEBUG_FIFO, "].\n");
	}

	if (port->xmit_buf) {
		free_page((unsigned long) port->xmit_buf);
		port->xmit_buf = NULL;
	}

	/* Select port */
	spin_lock_irqsave(&bp->lock, flags);
	sx_out(bp, CD186x_CAR, port_No(port));

	if (!(tty = port->tty) || C_HUPCL(tty)) {
		/* Drop DTR */
		sx_out(bp, CD186x_MSVDTR, 0);
	}
	spin_unlock_irqrestore(&bp->lock, flags);
	/* Reset port */
	sx_wait_CCR(bp);
	spin_lock_irqsave(&bp->lock, flags);
	sx_out(bp, CD186x_CCR, CCR_SOFTRESET);
	/* Disable all interrupts from this port */
	port->IER = 0;
	sx_out(bp, CD186x_IER, port->IER);
	spin_unlock_irqrestore(&bp->lock, flags);
	if (tty)
		set_bit(TTY_IO_ERROR, &tty->flags);
	port->flags &= ~ASYNC_INITIALIZED;

	if (!bp->count)
		sx_shutdown_board(bp);
	func_exit();
}


static int block_til_ready(struct tty_struct *tty, struct file * filp,
                           struct specialix_port *port)
{
	DECLARE_WAITQUEUE(wait,  current);
	struct specialix_board *bp = port_Board(port);
	int    retval;
	int    do_clocal = 0;
	int    CD;
	unsigned long flags;

	func_enter();

	/*
	 * If the device is in the middle of being closed, then block
	 * until it's done, and then try again.
	 */
	if (tty_hung_up_p(filp) || port->flags & ASYNC_CLOSING) {
		interruptible_sleep_on(&port->close_wait);
		if (port->flags & ASYNC_HUP_NOTIFY) {
			func_exit();
			return -EAGAIN;
		} else {
			func_exit();
			return -ERESTARTSYS;
		}
	}

	/*
	 * If non-blocking mode is set, or the port is not enabled,
	 * then make the check up front and then exit.
	 */
	if ((filp->f_flags & O_NONBLOCK) ||
	    (tty->flags & (1 << TTY_IO_ERROR))) {
		port->flags |= ASYNC_NORMAL_ACTIVE;
		func_exit();
		return 0;
	}

	if (C_CLOCAL(tty))
		do_clocal = 1;

	/*
	 * Block waiting for the carrier detect and the line to become
	 * free (i.e., not in use by the callout).  While we are in
	 * this loop, info->count is dropped by one, so that
	 * rs_close() knows when to free things.  We restore it upon
	 * exit, either normal or abnormal.
	 */
	retval = 0;
	add_wait_queue(&port->open_wait, &wait);
	spin_lock_irqsave(&port->lock, flags);
	if (!tty_hung_up_p(filp)) {
		port->count--;
	}
	spin_unlock_irqrestore(&port->lock, flags);
	port->blocked_open++;
	while (1) {
		spin_lock_irqsave(&bp->lock, flags);
		sx_out(bp, CD186x_CAR, port_No(port));
		CD = sx_in(bp, CD186x_MSVR) & MSVR_CD;
		if (SX_CRTSCTS (tty)) {
			/* Activate RTS */
			port->MSVR |= MSVR_DTR;		/* WTF? */
			sx_out (bp, CD186x_MSVR, port->MSVR);
		} else {
			/* Activate DTR */
			port->MSVR |= MSVR_DTR;
			sx_out (bp, CD186x_MSVR, port->MSVR);
		}
		spin_unlock_irqrestore(&bp->lock, flags);
		set_current_state(TASK_INTERRUPTIBLE);
		if (tty_hung_up_p(filp) ||
		    !(port->flags & ASYNC_INITIALIZED)) {
			if (port->flags & ASYNC_HUP_NOTIFY)
				retval = -EAGAIN;
			else
				retval = -ERESTARTSYS;
			break;
		}
		if (!(port->flags & ASYNC_CLOSING) &&
		    (do_clocal || CD))
			break;
		if (signal_pending(current)) {
			retval = -ERESTARTSYS;
			break;
		}
		schedule();
	}

	set_current_state(TASK_RUNNING);
	remove_wait_queue(&port->open_wait, &wait);
	spin_lock_irqsave(&port->lock, flags);
	if (!tty_hung_up_p(filp)) {
		port->count++;
	}
	port->blocked_open--;
	spin_unlock_irqrestore(&port->lock, flags);
	if (retval) {
		func_exit();
		return retval;
	}

	port->flags |= ASYNC_NORMAL_ACTIVE;
	func_exit();
	return 0;
}


static int sx_open(struct tty_struct * tty, struct file * filp)
{
	int board;
	int error;
	struct specialix_port * port;
	struct specialix_board * bp;
	int i;
	unsigned long flags;

	func_enter();

	board = SX_BOARD(tty->index);

	if (board >= SX_NBOARD || !(sx_board[board].flags & SX_BOARD_PRESENT)) {
		func_exit();
		return -ENODEV;
	}

	bp = &sx_board[board];
	port = sx_port + board * SX_NPORT + SX_PORT(tty->index);
	port->overrun = 0;
	for (i = 0; i < 10; i++)
		port->hits[i]=0;

	dprintk (SX_DEBUG_OPEN, "Board = %d, bp = %p, port = %p, portno = %d.\n",
	        board, bp, port, SX_PORT(tty->index));

	if (sx_paranoia_check(port, tty->name, "sx_open")) {
		func_enter();
		return -ENODEV;
	}

	if ((error = sx_setup_board(bp))) {
		func_exit();
		return error;
	}

	spin_lock_irqsave(&bp->lock, flags);
	port->count++;
	bp->count++;
	tty->driver_data = port;
	port->tty = tty;
	spin_unlock_irqrestore(&bp->lock, flags);

	if ((error = sx_setup_port(bp, port))) {
		func_enter();
		return error;
	}

	if ((error = block_til_ready(tty, filp, port))) {
		func_enter();
		return error;
	}

	func_exit();
	return 0;
}


static void sx_close(struct tty_struct * tty, struct file * filp)
{
	struct specialix_port *port = (struct specialix_port *) tty->driver_data;
	struct specialix_board *bp;
	unsigned long flags;
	unsigned long timeout;

	func_enter();
	if (!port || sx_paranoia_check(port, tty->name, "close")) {
		func_exit();
		return;
	}
	spin_lock_irqsave(&port->lock, flags);

	if (tty_hung_up_p(filp)) {
		spin_unlock_irqrestore(&port->lock, flags);