istallion.c

powerpc内核mpc8241linux系统下char驱动程序

			interruptible_sleep_on(&portp->raw_wait);
		}
	}

/*
 *	Write the close command into shared memory.
 */
	EBRDENABLE(brdp);
	cp = &((volatile cdkasy_t *) EBRDGETMEMPTR(brdp, portp->addr))->ctrl;
	cp->closearg = arg;
	cp->close = 1;
	hdrp = (volatile cdkhdr_t *) EBRDGETMEMPTR(brdp, CDK_CDKADDR);
	bits = ((volatile unsigned char *) hdrp) + brdp->slaveoffset +
		portp->portidx;
	*bits |= portp->portbit;
	EBRDDISABLE(brdp);

	set_bit(ST_CLOSING, &portp->state);
	if (wait == 0) {
		restore_flags(flags);
		return(0);
	}

/*
 *	Slave is in action, so now we must wait for the open acknowledgment
 *	to come back.
 */
	rc = 0;
	while (test_bit(ST_CLOSING, &portp->state)) {
		if (signal_pending(current)) {
			rc = -ERESTARTSYS;
			break;
		}
		interruptible_sleep_on(&portp->raw_wait);
	}
	restore_flags(flags);

	if ((rc == 0) && (portp->rc != 0))
		rc = -EIO;
	return(rc);
}

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

/*
 *	Send a command to the slave and wait for the response. This must
 *	have user context (it sleeps). This routine is generic in that it
 *	can send any type of command. Its purpose is to wait for that command
 *	to complete (as opposed to initiating the command then returning).
 */

static int stli_cmdwait(stlibrd_t *brdp, stliport_t *portp, unsigned long cmd, void *arg, int size, int copyback)
{
	unsigned long	flags;

#if DEBUG
	printk("stli_cmdwait(brdp=%x,portp=%x,cmd=%x,arg=%x,size=%d,"
		"copyback=%d)\n", (int) brdp, (int) portp, (int) cmd,
		(int) arg, size, copyback);
#endif

	save_flags(flags);
	cli();
	while (test_bit(ST_CMDING, &portp->state)) {
		if (signal_pending(current)) {
			restore_flags(flags);
			return(-ERESTARTSYS);
		}
		interruptible_sleep_on(&portp->raw_wait);
	}

	stli_sendcmd(brdp, portp, cmd, arg, size, copyback);

	while (test_bit(ST_CMDING, &portp->state)) {
		if (signal_pending(current)) {
			restore_flags(flags);
			return(-ERESTARTSYS);
		}
		interruptible_sleep_on(&portp->raw_wait);
	}
	restore_flags(flags);

	if (portp->rc != 0)
		return(-EIO);
	return(0);
}

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

/*
 *	Send the termios settings for this port to the slave. This sleeps
 *	waiting for the command to complete - so must have user context.
 */

static int stli_setport(stliport_t *portp)
{
	stlibrd_t	*brdp;
	asyport_t	aport;

#if DEBUG
	printk("stli_setport(portp=%x)\n", (int) portp);
#endif

	if (portp == (stliport_t *) NULL)
		return(-ENODEV);
	if (portp->tty == (struct tty_struct *) NULL)
		return(-ENODEV);
	if ((portp->brdnr < 0) && (portp->brdnr >= stli_nrbrds))
		return(-ENODEV);
	brdp = stli_brds[portp->brdnr];
	if (brdp == (stlibrd_t *) NULL)
		return(-ENODEV);

	stli_mkasyport(portp, &aport, portp->tty->termios);
	return(stli_cmdwait(brdp, portp, A_SETPORT, &aport, sizeof(asyport_t), 0));
}

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

/*
 *	Wait for a specified delay period, this is not a busy-loop. It will
 *	give up the processor while waiting. Unfortunately this has some
 *	rather intimate knowledge of the process management stuff.
 */

static void stli_delay(int len)
{
#if DEBUG
	printk("stli_delay(len=%d)\n", len);
#endif
	if (len > 0) {
		current->state = TASK_INTERRUPTIBLE;
		schedule_timeout(len);
		current->state = TASK_RUNNING;
	}
}

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

/*
 *	Possibly need to wait for carrier (DCD signal) to come high. Say
 *	maybe because if we are clocal then we don't need to wait...
 */

static int stli_waitcarrier(stlibrd_t *brdp, stliport_t *portp, struct file *filp)
{
	unsigned long	flags;
	int		rc, doclocal;

#if DEBUG
	printk("stli_waitcarrier(brdp=%x,portp=%x,filp=%x)\n",
		(int) brdp, (int) portp, (int) filp);
#endif

	rc = 0;
	doclocal = 0;

	if (portp->flags & ASYNC_CALLOUT_ACTIVE) {
		if (portp->normaltermios.c_cflag & CLOCAL)
			doclocal++;
	} else {
		if (portp->tty->termios->c_cflag & CLOCAL)
			doclocal++;
	}

	save_flags(flags);
	cli();
	portp->openwaitcnt++;
	if (! tty_hung_up_p(filp))
		portp->refcount--;

	for (;;) {
		if ((portp->flags & ASYNC_CALLOUT_ACTIVE) == 0) {
			stli_mkasysigs(&portp->asig, 1, 1);
			if ((rc = stli_cmdwait(brdp, portp, A_SETSIGNALS,
			    &portp->asig, sizeof(asysigs_t), 0)) < 0)
				break;
		}
		if (tty_hung_up_p(filp) ||
		    ((portp->flags & ASYNC_INITIALIZED) == 0)) {
			if (portp->flags & ASYNC_HUP_NOTIFY)
				rc = -EBUSY;
			else
				rc = -ERESTARTSYS;
			break;
		}
		if (((portp->flags & ASYNC_CALLOUT_ACTIVE) == 0) &&
		    ((portp->flags & ASYNC_CLOSING) == 0) &&
		    (doclocal || (portp->sigs & TIOCM_CD))) {
			break;
		}
		if (signal_pending(current)) {
			rc = -ERESTARTSYS;
			break;
		}
		interruptible_sleep_on(&portp->open_wait);
	}

	if (! tty_hung_up_p(filp))
		portp->refcount++;
	portp->openwaitcnt--;
	restore_flags(flags);

	return(rc);
}

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

/*
 *	Write routine. Take the data and put it in the shared memory ring
 *	queue. If port is not already sending chars then need to mark the
 *	service bits for this port.
 */

static int stli_write(struct tty_struct *tty, int from_user, const unsigned char *buf, int count)
{
	volatile cdkasy_t	*ap;
	volatile cdkhdr_t	*hdrp;
	volatile unsigned char	*bits;
	unsigned char		*shbuf, *chbuf;
	stliport_t		*portp;
	stlibrd_t		*brdp;
	unsigned int		len, stlen, head, tail, size;
	unsigned long		flags;

#if DEBUG
	printk("stli_write(tty=%x,from_user=%d,buf=%x,count=%d)\n",
		(int) tty, from_user, (int) buf, count);
#endif

	if ((tty == (struct tty_struct *) NULL) ||
	    (stli_tmpwritebuf == (char *) NULL))
		return(0);
	if (tty == stli_txcooktty)
		stli_flushchars(tty);
	portp = tty->driver_data;
	if (portp == (stliport_t *) NULL)
		return(0);
	if ((portp->brdnr < 0) || (portp->brdnr >= stli_nrbrds))
		return(0);
	brdp = stli_brds[portp->brdnr];
	if (brdp == (stlibrd_t *) NULL)
		return(0);
	chbuf = (unsigned char *) buf;

/*
 *	If copying direct from user space we need to be able to handle page
 *	faults while we are copying. To do this copy as much as we can now
 *	into a kernel buffer. From there we copy it into shared memory. The
 *	big problem is that we do not want shared memory enabled when we are
 *	sleeping (other boards may be serviced while asleep). Something else
 *	to note here is the reading of the tail twice. Since the boards
 *	shared memory can be on an 8-bit bus then we need to be very careful
 *	reading 16 bit quantities - since both the board (slave) and host
 *	could be writing and reading at the same time.
 */
	if (from_user) {
		save_flags(flags);
		cli();
		EBRDENABLE(brdp);
		ap = (volatile cdkasy_t *) EBRDGETMEMPTR(brdp, portp->addr);
		head = (unsigned int) ap->txq.head;
		tail = (unsigned int) ap->txq.tail;
		if (tail != ((unsigned int) ap->txq.tail))
			tail = (unsigned int) ap->txq.tail;
		len = (head >= tail) ? (portp->txsize - (head - tail) - 1) :
			(tail - head - 1);
		count = MIN(len, count);
		EBRDDISABLE(brdp);
		restore_flags(flags);

		down(&stli_tmpwritesem);
		copy_from_user(stli_tmpwritebuf, chbuf, count);
		chbuf = &stli_tmpwritebuf[0];
	}

/*
 *	All data is now local, shove as much as possible into shared memory.
 */
	save_flags(flags);
	cli();
	EBRDENABLE(brdp);
	ap = (volatile cdkasy_t *) EBRDGETMEMPTR(brdp, portp->addr);
	head = (unsigned int) ap->txq.head;
	tail = (unsigned int) ap->txq.tail;
	if (tail != ((unsigned int) ap->txq.tail))
		tail = (unsigned int) 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, count);
	count = 0;
	shbuf = (char *) EBRDGETMEMPTR(brdp, portp->txoffset);

	while (len > 0) {
		stlen = MIN(len, stlen);
		memcpy((shbuf + head), chbuf, stlen);
		chbuf += stlen;
		len -= stlen;
		count += stlen;
		head += stlen;
		if (head >= size) {
			head = 0;
			stlen = tail;
		}
	}

	ap = (volatile cdkasy_t *) EBRDGETMEMPTR(brdp, portp->addr);
	ap->txq.head = head;
	if (test_bit(ST_TXBUSY, &portp->state)) {
		if (ap->changed.data & DT_TXEMPTY)
			ap->changed.data &= ~DT_TXEMPTY;
	}
	hdrp = (volatile cdkhdr_t *) EBRDGETMEMPTR(brdp, CDK_CDKADDR);
	bits = ((volatile unsigned char *) hdrp) + brdp->slaveoffset +
		portp->portidx;
	*bits |= portp->portbit;
	set_bit(ST_TXBUSY, &portp->state);
	EBRDDISABLE(brdp);

	if (from_user)
		up(&stli_tmpwritesem);
	restore_flags(flags);

	return(count);
}

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

/*
 *	Output a single character. We put it into a temporary local buffer
 *	(for speed) then write out that buffer when the flushchars routine
 *	is called. There is a safety catch here so that if some other port
 *	writes chars before the current buffer has been, then we write them
 *	first them do the new ports.
 */

static void stli_putchar(struct tty_struct *tty, unsigned char ch)
{
#if DEBUG
	printk("stli_putchar(tty=%x,ch=%x)\n", (int) tty, (int) ch);
#endif

	if (tty == (struct tty_struct *) NULL)
		return;
	if (tty != stli_txcooktty) {
		if (stli_txcooktty != (struct tty_struct *) NULL)
			stli_flushchars(stli_txcooktty);
		stli_txcooktty = tty;
	}

	stli_txcookbuf[stli_txcooksize++] = ch;
}

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

/*
 *	Transfer characters from the local TX cooking buffer to the board.
 *	We sort of ignore the tty that gets passed in here. We rely on the
 *	info stored with the TX cook buffer to tell us which port to flush
 *	the data on. In any case we clean out the TX cook buffer, for re-use
 *	by someone else.
 */

static void stli_flushchars(struct tty_struct *tty)
{
	volatile cdkhdr_t	*hdrp;
	volatile unsigned char	*bits;
	volatile cdkasy_t	*ap;
	struct tty_struct	*cooktty;
	stliport_t		*portp;
	stlibrd_t		*brdp;
	unsigned int		len, stlen, head, tail, size, count, cooksize;
	unsigned char		*buf, *shbuf;
	unsigned long		flags;

#if DEBUG
	printk("stli_flushchars(tty=%x)\n", (int) tty);
#endif

	cooksize = stli_txcooksize;
	cooktty = stli_txcooktty;
	stli_txcooksize = 0;
	stli_txcookrealsize = 0;
	stli_txcooktty = (struct tty_struct *) NULL;

	if (tty == (struct tty_struct *) NULL)
		return;
	if (cooktty == (struct tty_struct *) NULL)
		return;
	if (tty != cooktty)
		tty = cooktty;
	if (cooksize == 0)
		return;

	portp = tty->driver_data;
	if (portp == (stliport_t *) NULL)
		return;
	if ((portp->brdnr < 0) || (portp->brdnr >= stli_nrbrds))
		return;
	brdp = stli_brds[portp->brdnr];
	if (brdp == (stlibrd_t *) NULL)
		return;

	save_flags(flags);
	cli();
	EBRDENABLE(brdp);

	ap = (volatile cdkasy_t *) EBRDGETMEMPTR(brdp, portp->addr);
	head = (unsigned int) ap->txq.head;
	tail = (unsigned int) ap->txq.tail;
	if (tail != ((unsigned int) ap->txq.tail))
		tail = (unsigned int) 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 = (char *) EBRDGETMEMPTR(brdp, portp->txoffset);
	buf = stli_txcookbuf;

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

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

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

	EBRDDISABLE(brdp);
	restore_flags(flags);
}

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

static int stli_writeroom(struct tty_struct *tty)
{
	volatile cdkasyrq_t	*rp;
	stliport_t		*portp;
	stlibrd_t		*brdp;