stallion.c

来自「linux 内核源代码」· C语言 代码 · 共 2,551 行 · 第 1/5 页

	if (portp->tx.buf == NULL)
		return;

	head = portp->tx.head;
	tail = portp->tx.tail;

	len = (head >= tail) ? (STL_TXBUFSIZE - (head - tail)) : (tail - head);
	len--;

	if (len > 0) {
		*head++ = ch;
		if (head >= (portp->tx.buf + STL_TXBUFSIZE))
			head = portp->tx.buf;
	}	
	portp->tx.head = head;
}

/*****************************************************************************/

/*
 *	If there are any characters in the buffer then make sure that TX
 *	interrupts are on and get'em out. Normally used after the putchar
 *	routine has been called.
 */

static void stl_flushchars(struct tty_struct *tty)
{
	struct stlport	*portp;

	pr_debug("stl_flushchars(tty=%p)\n", tty);

	if (tty == NULL)
		return;
	portp = tty->driver_data;
	if (portp == NULL)
		return;
	if (portp->tx.buf == NULL)
		return;

	stl_startrxtx(portp, -1, 1);
}

/*****************************************************************************/

static int stl_writeroom(struct tty_struct *tty)
{
	struct stlport	*portp;
	char		*head, *tail;

	pr_debug("stl_writeroom(tty=%p)\n", tty);

	if (tty == NULL)
		return 0;
	portp = tty->driver_data;
	if (portp == NULL)
		return 0;
	if (portp->tx.buf == NULL)
		return 0;

	head = portp->tx.head;
	tail = portp->tx.tail;
	return (head >= tail) ? (STL_TXBUFSIZE - (head - tail) - 1) : (tail - head - 1);
}

/*****************************************************************************/

/*
 *	Return number of chars in the TX buffer. Normally we would just
 *	calculate the number of chars in the buffer and return that, but if
 *	the buffer is empty and TX interrupts are still on then we return
 *	that the buffer still has 1 char in it. This way whoever called us
 *	will not think that ALL chars have drained - since the UART still
 *	must have some chars in it (we are busy after all).
 */

static int stl_charsinbuffer(struct tty_struct *tty)
{
	struct stlport	*portp;
	unsigned int	size;
	char		*head, *tail;

	pr_debug("stl_charsinbuffer(tty=%p)\n", tty);

	if (tty == NULL)
		return 0;
	portp = tty->driver_data;
	if (portp == NULL)
		return 0;
	if (portp->tx.buf == NULL)
		return 0;

	head = portp->tx.head;
	tail = portp->tx.tail;
	size = (head >= tail) ? (head - tail) : (STL_TXBUFSIZE - (tail - head));
	if ((size == 0) && test_bit(ASYI_TXBUSY, &portp->istate))
		size = 1;
	return size;
}

/*****************************************************************************/

/*
 *	Generate the serial struct info.
 */

static int stl_getserial(struct stlport *portp, struct serial_struct __user *sp)
{
	struct serial_struct	sio;
	struct stlbrd		*brdp;

	pr_debug("stl_getserial(portp=%p,sp=%p)\n", portp, sp);

	memset(&sio, 0, sizeof(struct serial_struct));
	sio.line = portp->portnr;
	sio.port = portp->ioaddr;
	sio.flags = portp->flags;
	sio.baud_base = portp->baud_base;
	sio.close_delay = portp->close_delay;
	sio.closing_wait = portp->closing_wait;
	sio.custom_divisor = portp->custom_divisor;
	sio.hub6 = 0;
	if (portp->uartp == &stl_cd1400uart) {
		sio.type = PORT_CIRRUS;
		sio.xmit_fifo_size = CD1400_TXFIFOSIZE;
	} else {
		sio.type = PORT_UNKNOWN;
		sio.xmit_fifo_size = SC26198_TXFIFOSIZE;
	}

	brdp = stl_brds[portp->brdnr];
	if (brdp != NULL)
		sio.irq = brdp->irq;

	return copy_to_user(sp, &sio, sizeof(struct serial_struct)) ? -EFAULT : 0;
}

/*****************************************************************************/

/*
 *	Set port according to the serial struct info.
 *	At this point we do not do any auto-configure stuff, so we will
 *	just quietly ignore any requests to change irq, etc.
 */

static int stl_setserial(struct stlport *portp, struct serial_struct __user *sp)
{
	struct serial_struct	sio;

	pr_debug("stl_setserial(portp=%p,sp=%p)\n", portp, sp);

	if (copy_from_user(&sio, sp, sizeof(struct serial_struct)))
		return -EFAULT;
	if (!capable(CAP_SYS_ADMIN)) {
		if ((sio.baud_base != portp->baud_base) ||
		    (sio.close_delay != portp->close_delay) ||
		    ((sio.flags & ~ASYNC_USR_MASK) !=
		    (portp->flags & ~ASYNC_USR_MASK)))
			return -EPERM;
	} 

	portp->flags = (portp->flags & ~ASYNC_USR_MASK) |
		(sio.flags & ASYNC_USR_MASK);
	portp->baud_base = sio.baud_base;
	portp->close_delay = sio.close_delay;
	portp->closing_wait = sio.closing_wait;
	portp->custom_divisor = sio.custom_divisor;
	stl_setport(portp, portp->tty->termios);
	return 0;
}

/*****************************************************************************/

static int stl_tiocmget(struct tty_struct *tty, struct file *file)
{
	struct stlport	*portp;

	if (tty == NULL)
		return -ENODEV;
	portp = tty->driver_data;
	if (portp == NULL)
		return -ENODEV;
	if (tty->flags & (1 << TTY_IO_ERROR))
		return -EIO;

	return stl_getsignals(portp);
}

static int stl_tiocmset(struct tty_struct *tty, struct file *file,
			unsigned int set, unsigned int clear)
{
	struct stlport	*portp;
	int rts = -1, dtr = -1;

	if (tty == NULL)
		return -ENODEV;
	portp = tty->driver_data;
	if (portp == NULL)
		return -ENODEV;
	if (tty->flags & (1 << TTY_IO_ERROR))
		return -EIO;

	if (set & TIOCM_RTS)
		rts = 1;
	if (set & TIOCM_DTR)
		dtr = 1;
	if (clear & TIOCM_RTS)
		rts = 0;
	if (clear & TIOCM_DTR)
		dtr = 0;

	stl_setsignals(portp, dtr, rts);
	return 0;
}

static int stl_ioctl(struct tty_struct *tty, struct file *file, unsigned int cmd, unsigned long arg)
{
	struct stlport	*portp;
	unsigned int	ival;
	int		rc;
	void __user *argp = (void __user *)arg;

	pr_debug("stl_ioctl(tty=%p,file=%p,cmd=%x,arg=%lx)\n", tty, file, cmd,
			arg);

	if (tty == NULL)
		return -ENODEV;
	portp = tty->driver_data;
	if (portp == NULL)
		return -ENODEV;

	if ((cmd != TIOCGSERIAL) && (cmd != TIOCSSERIAL) &&
 	    (cmd != COM_GETPORTSTATS) && (cmd != COM_CLRPORTSTATS))
		if (tty->flags & (1 << TTY_IO_ERROR))
			return -EIO;

	rc = 0;

	switch (cmd) {
	case TIOCGSOFTCAR:
		rc = put_user(((tty->termios->c_cflag & CLOCAL) ? 1 : 0),
			(unsigned __user *) argp);
		break;
	case TIOCSSOFTCAR:
		if (get_user(ival, (unsigned int __user *) arg))
			return -EFAULT;
		tty->termios->c_cflag =
				(tty->termios->c_cflag & ~CLOCAL) |
				(ival ? CLOCAL : 0);
		break;
	case TIOCGSERIAL:
		rc = stl_getserial(portp, argp);
		break;
	case TIOCSSERIAL:
		rc = stl_setserial(portp, argp);
		break;
	case COM_GETPORTSTATS:
		rc = stl_getportstats(portp, argp);
		break;
	case COM_CLRPORTSTATS:
		rc = stl_clrportstats(portp, argp);
		break;
	case TIOCSERCONFIG:
	case TIOCSERGWILD:
	case TIOCSERSWILD:
	case TIOCSERGETLSR:
	case TIOCSERGSTRUCT:
	case TIOCSERGETMULTI:
	case TIOCSERSETMULTI:
	default:
		rc = -ENOIOCTLCMD;
		break;
	}

	return rc;
}

/*****************************************************************************/

/*
 *	Start the transmitter again. Just turn TX interrupts back on.
 */

static void stl_start(struct tty_struct *tty)
{
	struct stlport	*portp;

	pr_debug("stl_start(tty=%p)\n", tty);

	if (tty == NULL)
		return;
	portp = tty->driver_data;
	if (portp == NULL)
		return;
	stl_startrxtx(portp, -1, 1);
}

/*****************************************************************************/

static void stl_settermios(struct tty_struct *tty, struct ktermios *old)
{
	struct stlport	*portp;
	struct ktermios	*tiosp;

	pr_debug("stl_settermios(tty=%p,old=%p)\n", tty, old);

	if (tty == NULL)
		return;
	portp = tty->driver_data;
	if (portp == NULL)
		return;

	tiosp = tty->termios;
	if ((tiosp->c_cflag == old->c_cflag) &&
	    (tiosp->c_iflag == old->c_iflag))
		return;

	stl_setport(portp, tiosp);
	stl_setsignals(portp, ((tiosp->c_cflag & (CBAUD & ~CBAUDEX)) ? 1 : 0),
		-1);
	if ((old->c_cflag & CRTSCTS) && ((tiosp->c_cflag & CRTSCTS) == 0)) {
		tty->hw_stopped = 0;
		stl_start(tty);
	}
	if (((old->c_cflag & CLOCAL) == 0) && (tiosp->c_cflag & CLOCAL))
		wake_up_interruptible(&portp->open_wait);
}

/*****************************************************************************/

/*
 *	Attempt to flow control who ever is sending us data. Based on termios
 *	settings use software or/and hardware flow control.
 */

static void stl_throttle(struct tty_struct *tty)
{
	struct stlport	*portp;

	pr_debug("stl_throttle(tty=%p)\n", tty);

	if (tty == NULL)
		return;
	portp = tty->driver_data;
	if (portp == NULL)
		return;
	stl_flowctrl(portp, 0);
}

/*****************************************************************************/

/*
 *	Unflow control the device sending us data...
 */

static void stl_unthrottle(struct tty_struct *tty)
{
	struct stlport	*portp;

	pr_debug("stl_unthrottle(tty=%p)\n", tty);

	if (tty == NULL)
		return;
	portp = tty->driver_data;
	if (portp == NULL)
		return;
	stl_flowctrl(portp, 1);
}

/*****************************************************************************/

/*
 *	Stop the transmitter. Basically to do this we will just turn TX
 *	interrupts off.
 */

static void stl_stop(struct tty_struct *tty)
{
	struct stlport	*portp;

	pr_debug("stl_stop(tty=%p)\n", tty);

	if (tty == NULL)
		return;
	portp = tty->driver_data;
	if (portp == NULL)
		return;
	stl_startrxtx(portp, -1, 0);
}

/*****************************************************************************/

/*
 *	Hangup this port. This is pretty much like closing the port, only
 *	a little more brutal. No waiting for data to drain. Shutdown the
 *	port and maybe drop signals.
 */

static void stl_hangup(struct tty_struct *tty)
{
	struct stlport	*portp;

	pr_debug("stl_hangup(tty=%p)\n", tty);

	if (tty == NULL)
		return;
	portp = tty->driver_data;
	if (portp == NULL)
		return;

	portp->flags &= ~ASYNC_INITIALIZED;
	stl_disableintrs(portp);
	if (tty->termios->c_cflag & HUPCL)
		stl_setsignals(portp, 0, 0);
	stl_enablerxtx(portp, 0, 0);
	stl_flushbuffer(tty);
	portp->istate = 0;
	set_bit(TTY_IO_ERROR, &tty->flags);
	if (portp->tx.buf != NULL) {
		kfree(portp->tx.buf);
		portp->tx.buf = NULL;
		portp->tx.head = NULL;
		portp->tx.tail = NULL;
	}
	portp->tty = NULL;
	portp->flags &= ~ASYNC_NORMAL_ACTIVE;
	portp->refcount = 0;
	wake_up_interruptible(&portp->open_wait);
}

/*****************************************************************************/

static void stl_breakctl(struct tty_struct *tty, int state)
{
	struct stlport	*portp;

	pr_debug("stl_breakctl(tty=%p,state=%d)\n", tty, state);

	if (tty == NULL)
		return;
	portp = tty->driver_data;
	if (portp == NULL)
		return;

	stl_sendbreak(portp, ((state == -1) ? 1 : 2));
}

/*****************************************************************************/

static void stl_sendxchar(struct tty_struct *tty, char ch)
{
	struct stlport	*portp;

	pr_debug("stl_sendxchar(tty=%p,ch=%x)\n", tty, ch);

	if (tty == NULL)
		return;
	portp = tty->driver_data;
	if (portp == NULL)
		return;

	if (ch == STOP_CHAR(tty))
		stl_sendflow(portp, 0);
	else if (ch == START_CHAR(tty))
		stl_sendflow(portp, 1);
	else
		stl_putchar(tty, ch);
}

/*****************************************************************************/

#define	MAXLINE		80

/*
 *	Format info for a specified port. The line is deliberately limited
 *	to 80 characters. (If it is too long it will be truncated, if too
 *	short then padded with spaces).
 */

static int stl_portinfo(struct stlport *portp, int portnr, char *pos)
{
	char	*sp;
	int	sigs, cnt;

	sp = pos;
	sp += sprintf(sp, "%d: uart:%s tx:%d rx:%d",
		portnr, (portp->hwid == 1) ? "SC26198" : "CD1400",
		(int) portp->stats.txtotal, (int) portp->stats.rxtotal);

	if (portp->stats.rxframing)
		sp += sprintf(sp, " fe:%d", (int) portp->stats.rxframing);
	if (portp->stats.rxparity)
		sp += sprintf(sp, " pe:%d", (int) portp->stats.rxparity);
	if (portp->stats.rxbreaks)
		sp += sprintf(sp, " brk:%d", (int) portp->stats.rxbreaks);
	if (portp->stats.rxoverrun)
		sp += sprintf(sp, " oe:%d", (int) portp->stats.rxoverrun);

	sigs = stl_getsignals(portp);
	cnt = sprintf(sp, "%s%s%s%s%s ",
		(sigs & TIOCM_RTS) ? "|RTS" : "",
		(sigs & TIOCM_CTS) ? "|CTS" : "",
		(sigs & TIOCM_DTR) ? "|DTR" : "",
		(sigs & TIOCM_CD) ? "|DCD" : "",
		(sigs & TIOCM_DSR) ? "|DSR" : "");
	*sp = ' ';
	sp += cnt;

	for (cnt = sp - pos; cnt < (MAXLINE - 1); cnt++)
		*sp++ = ' ';
	if (cnt >= MAXLINE)
		pos[(MAXLINE - 2)] = '+';