istallion.c

linux 内核源代码

	if (tty != cooktty)
		tty = cooktty;
	if (cooksize == 0)
		return;

	portp = tty->driver_data;
	if (portp == NULL)
		return;
	if (portp->brdnr >= stli_nrbrds)
		return;
	brdp = stli_brds[portp->brdnr];
	if (brdp == NULL)
		return;

	spin_lock_irqsave(&brd_lock, flags);
	EBRDENABLE(brdp);

	ap = (cdkasy_t __iomem *) EBRDGETMEMPTR(brdp, portp->addr);
	head = (unsigned int) readw(&ap->txq.head);
	tail = (unsigned int) readw(&ap->txq.tail);
	if (tail != ((unsigned int) readw(&ap->txq.tail)))
		tail = (unsigned int) readw(&ap->txq.tail);
	size = portp->txsize;
	if (head >= tail) {
		len = size - (head - tail) - 1;
		stlen = size - head;
	} else {
		len = tail - head - 1;
		stlen = len;
	}

	len = min(len, cooksize);
	count = 0;
	shbuf = EBRDGETMEMPTR(brdp, portp->txoffset);
	buf = stli_txcookbuf;

	while (len > 0) {
		stlen = min(len, stlen);
		memcpy_toio(shbuf + head, buf, stlen);
		buf += stlen;
		len -= stlen;
		count += stlen;
		head += stlen;
		if (head >= size) {
			head = 0;
			stlen = tail;
		}
	}

	ap = (cdkasy_t __iomem *) EBRDGETMEMPTR(brdp, portp->addr);
	writew(head, &ap->txq.head);

	if (test_bit(ST_TXBUSY, &portp->state)) {
		if (readl(&ap->changed.data) & DT_TXEMPTY)
			writel(readl(&ap->changed.data) & ~DT_TXEMPTY, &ap->changed.data);
	}
	hdrp = (cdkhdr_t __iomem *) EBRDGETMEMPTR(brdp, CDK_CDKADDR);
	bits = ((unsigned char __iomem *) hdrp) + brdp->slaveoffset +
		portp->portidx;
	writeb(readb(bits) | portp->portbit, bits);
	set_bit(ST_TXBUSY, &portp->state);

	EBRDDISABLE(brdp);
	spin_unlock_irqrestore(&brd_lock, flags);
}

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

static int stli_writeroom(struct tty_struct *tty)
{
	cdkasyrq_t __iomem *rp;
	struct stliport *portp;
	struct stlibrd *brdp;
	unsigned int head, tail, len;
	unsigned long flags;

	if (tty == stli_txcooktty) {
		if (stli_txcookrealsize != 0) {
			len = stli_txcookrealsize - stli_txcooksize;
			return len;
		}
	}

	portp = tty->driver_data;
	if (portp == NULL)
		return 0;
	if (portp->brdnr >= stli_nrbrds)
		return 0;
	brdp = stli_brds[portp->brdnr];
	if (brdp == NULL)
		return 0;

	spin_lock_irqsave(&brd_lock, flags);
	EBRDENABLE(brdp);
	rp = &((cdkasy_t __iomem *) EBRDGETMEMPTR(brdp, portp->addr))->txq;
	head = (unsigned int) readw(&rp->head);
	tail = (unsigned int) readw(&rp->tail);
	if (tail != ((unsigned int) readw(&rp->tail)))
		tail = (unsigned int) readw(&rp->tail);
	len = (head >= tail) ? (portp->txsize - (head - tail)) : (tail - head);
	len--;
	EBRDDISABLE(brdp);
	spin_unlock_irqrestore(&brd_lock, flags);

	if (tty == stli_txcooktty) {
		stli_txcookrealsize = len;
		len -= stli_txcooksize;
	}
	return len;
}

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

/*
 *	Return the number of characters in the transmit buffer. Normally we
 *	will return the number of chars in the shared memory ring queue.
 *	We need to kludge around the case where the shared memory buffer is
 *	empty but not all characters have drained yet, for this case just
 *	return that there is 1 character in the buffer!
 */

static int stli_charsinbuffer(struct tty_struct *tty)
{
	cdkasyrq_t __iomem *rp;
	struct stliport *portp;
	struct stlibrd *brdp;
	unsigned int head, tail, len;
	unsigned long flags;

	if (tty == stli_txcooktty)
		stli_flushchars(tty);
	portp = tty->driver_data;
	if (portp == NULL)
		return 0;
	if (portp->brdnr >= stli_nrbrds)
		return 0;
	brdp = stli_brds[portp->brdnr];
	if (brdp == NULL)
		return 0;

	spin_lock_irqsave(&brd_lock, flags);
	EBRDENABLE(brdp);
	rp = &((cdkasy_t __iomem *) EBRDGETMEMPTR(brdp, portp->addr))->txq;
	head = (unsigned int) readw(&rp->head);
	tail = (unsigned int) readw(&rp->tail);
	if (tail != ((unsigned int) readw(&rp->tail)))
		tail = (unsigned int) readw(&rp->tail);
	len = (head >= tail) ? (head - tail) : (portp->txsize - (tail - head));
	if ((len == 0) && test_bit(ST_TXBUSY, &portp->state))
		len = 1;
	EBRDDISABLE(brdp);
	spin_unlock_irqrestore(&brd_lock, flags);

	return len;
}

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

/*
 *	Generate the serial struct info.
 */

static int stli_getserial(struct stliport *portp, struct serial_struct __user *sp)
{
	struct serial_struct sio;
	struct stlibrd *brdp;

	memset(&sio, 0, sizeof(struct serial_struct));
	sio.type = PORT_UNKNOWN;
	sio.line = portp->portnr;
	sio.irq = 0;
	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.xmit_fifo_size = 0;
	sio.hub6 = 0;

	brdp = stli_brds[portp->brdnr];
	if (brdp != NULL)
		sio.port = brdp->iobase;
		
	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 stli_setserial(struct stliport *portp, struct serial_struct __user *sp)
{
	struct serial_struct sio;
	int rc;

	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;

	if ((rc = stli_setport(portp)) < 0)
		return rc;
	return 0;
}

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

static int stli_tiocmget(struct tty_struct *tty, struct file *file)
{
	struct stliport *portp = tty->driver_data;
	struct stlibrd *brdp;
	int rc;

	if (portp == NULL)
		return -ENODEV;
	if (portp->brdnr >= stli_nrbrds)
		return 0;
	brdp = stli_brds[portp->brdnr];
	if (brdp == NULL)
		return 0;
	if (tty->flags & (1 << TTY_IO_ERROR))
		return -EIO;

	if ((rc = stli_cmdwait(brdp, portp, A_GETSIGNALS,
			       &portp->asig, sizeof(asysigs_t), 1)) < 0)
		return rc;

	return stli_mktiocm(portp->asig.sigvalue);
}

static int stli_tiocmset(struct tty_struct *tty, struct file *file,
			 unsigned int set, unsigned int clear)
{
	struct stliport *portp = tty->driver_data;
	struct stlibrd *brdp;
	int rts = -1, dtr = -1;

	if (portp == NULL)
		return -ENODEV;
	if (portp->brdnr >= stli_nrbrds)
		return 0;
	brdp = stli_brds[portp->brdnr];
	if (brdp == NULL)
		return 0;
	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;

	stli_mkasysigs(&portp->asig, dtr, rts);

	return stli_cmdwait(brdp, portp, A_SETSIGNALS, &portp->asig,
			    sizeof(asysigs_t), 0);
}

static int stli_ioctl(struct tty_struct *tty, struct file *file, unsigned int cmd, unsigned long arg)
{
	struct stliport *portp;
	struct stlibrd *brdp;
	unsigned int ival;
	int rc;
	void __user *argp = (void __user *)arg;

	portp = tty->driver_data;
	if (portp == NULL)
		return -ENODEV;
	if (portp->brdnr >= stli_nrbrds)
		return 0;
	brdp = stli_brds[portp->brdnr];
	if (brdp == NULL)
		return 0;

	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 *) arg);
		break;
	case TIOCSSOFTCAR:
		if ((rc = get_user(ival, (unsigned __user *) arg)) == 0)
			tty->termios->c_cflag =
				(tty->termios->c_cflag & ~CLOCAL) |
				(ival ? CLOCAL : 0);
		break;
	case TIOCGSERIAL:
		rc = stli_getserial(portp, argp);
		break;
	case TIOCSSERIAL:
		rc = stli_setserial(portp, argp);
		break;
	case STL_GETPFLAG:
		rc = put_user(portp->pflag, (unsigned __user *)argp);
		break;
	case STL_SETPFLAG:
		if ((rc = get_user(portp->pflag, (unsigned __user *)argp)) == 0)
			stli_setport(portp);
		break;
	case COM_GETPORTSTATS:
		rc = stli_getportstats(portp, argp);
		break;
	case COM_CLRPORTSTATS:
		rc = stli_clrportstats(portp, argp);
		break;
	case TIOCSERCONFIG:
	case TIOCSERGWILD:
	case TIOCSERSWILD:
	case TIOCSERGETLSR:
	case TIOCSERGSTRUCT:
	case TIOCSERGETMULTI:
	case TIOCSERSETMULTI:
	default:
		rc = -ENOIOCTLCMD;
		break;
	}

	return rc;
}

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

/*
 *	This routine assumes that we have user context and can sleep.
 *	Looks like it is true for the current ttys implementation..!!
 */

static void stli_settermios(struct tty_struct *tty, struct ktermios *old)
{
	struct stliport *portp;
	struct stlibrd *brdp;
	struct ktermios *tiosp;
	asyport_t aport;

	if (tty == NULL)
		return;
	portp = tty->driver_data;
	if (portp == NULL)
		return;
	if (portp->brdnr >= stli_nrbrds)
		return;
	brdp = stli_brds[portp->brdnr];
	if (brdp == NULL)
		return;

	tiosp = tty->termios;

	stli_mkasyport(portp, &aport, tiosp);
	stli_cmdwait(brdp, portp, A_SETPORT, &aport, sizeof(asyport_t), 0);
	stli_mkasysigs(&portp->asig, ((tiosp->c_cflag & CBAUD) ? 1 : 0), -1);
	stli_cmdwait(brdp, portp, A_SETSIGNALS, &portp->asig,
		sizeof(asysigs_t), 0);
	if ((old->c_cflag & CRTSCTS) && ((tiosp->c_cflag & CRTSCTS) == 0))
		tty->hw_stopped = 0;
	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. We won't really
 *	do any flow control action here. We can't directly, and even if we
 *	wanted to we would have to send a command to the slave. The slave
 *	knows how to flow control, and will do so when its buffers reach its
 *	internal high water marks. So what we will do is set a local state
 *	bit that will stop us sending any RX data up from the poll routine
 *	(which is the place where RX data from the slave is handled).
 */

static void stli_throttle(struct tty_struct *tty)
{
	struct stliport	*portp = tty->driver_data;
	if (portp == NULL)
		return;
	set_bit(ST_RXSTOP, &portp->state);
}

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

/*
 *	Unflow control the device sending us data... That means that all
 *	we have to do is clear the RXSTOP state bit. The next poll call
 *	will then be able to pass the RX data back up.
 */

static void stli_unthrottle(struct tty_struct *tty)
{
	struct stliport	*portp = tty->driver_data;
	if (portp == NULL)
		return;
	clear_bit(ST_RXSTOP, &portp->state);
}

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

/*
 *	Stop the transmitter.
 */

static void stli_stop(struct tty_struct *tty)
{
}

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

/*
 *	Start the transmitter again.
 */

static void stli_start(struct tty_struct *tty)
{
}

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

/*
 *	Scheduler called hang up routine. This is called from the scheduler,
 *	not direct from the driver "poll" routine. We can't call it there
 *	since the real local hangup code will enable/disable the board and
 *	other things that we can't do while handling the poll. Much easier
 *	to deal with it some time later (don't really care when, hangups
 *	aren't that time critical).
 */

static void stli_dohangup(struct work_struct *ugly_api)
{
	struct stliport *portp = container_of(ugly_api, struct stliport, tqhangup);
	if (portp->tty != NULL) {
		tty_hangup(portp->tty);
	}