stallion.c

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 *	CD1400 UART specific data initialization.
 */
static uart_t stl_cd1400uart = {
	stl_cd1400panelinit,
	stl_cd1400portinit,
	stl_cd1400setport,
	stl_cd1400getsignals,
	stl_cd1400setsignals,
	stl_cd1400enablerxtx,
	stl_cd1400startrxtx,
	stl_cd1400disableintrs,
	stl_cd1400sendbreak,
	stl_cd1400flowctrl,
	stl_cd1400sendflow,
	stl_cd1400flush,
	stl_cd1400datastate,
	stl_cd1400eiointr
};

/*
 *	Define the offsets within the register bank of a cd1400 based panel.
 *	These io address offsets are common to the EasyIO board as well.
 */
#define	EREG_ADDR	0
#define	EREG_DATA	4
#define	EREG_RXACK	5
#define	EREG_TXACK	6
#define	EREG_MDACK	7

#define	EREG_BANKSIZE	8

#define	CD1400_CLK	25000000
#define	CD1400_CLK8M	20000000

/*
 *	Define the cd1400 baud rate clocks. These are used when calculating
 *	what clock and divisor to use for the required baud rate. Also
 *	define the maximum baud rate allowed, and the default base baud.
 */
static int	stl_cd1400clkdivs[] = {
	CD1400_CLK0, CD1400_CLK1, CD1400_CLK2, CD1400_CLK3, CD1400_CLK4
};

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

/*
 *	SC26198 UART specific data initization.
 */
static uart_t stl_sc26198uart = {
	stl_sc26198panelinit,
	stl_sc26198portinit,
	stl_sc26198setport,
	stl_sc26198getsignals,
	stl_sc26198setsignals,
	stl_sc26198enablerxtx,
	stl_sc26198startrxtx,
	stl_sc26198disableintrs,
	stl_sc26198sendbreak,
	stl_sc26198flowctrl,
	stl_sc26198sendflow,
	stl_sc26198flush,
	stl_sc26198datastate,
	stl_sc26198intr
};

/*
 *	Define the offsets within the register bank of a sc26198 based panel.
 */
#define	XP_DATA		0
#define	XP_ADDR		1
#define	XP_MODID	2
#define	XP_STATUS	2
#define	XP_IACK		3

#define	XP_BANKSIZE	4

/*
 *	Define the sc26198 baud rate table. Offsets within the table
 *	represent the actual baud rate selector of sc26198 registers.
 */
static unsigned int	sc26198_baudtable[] = {
	50, 75, 150, 200, 300, 450, 600, 900, 1200, 1800, 2400, 3600,
	4800, 7200, 9600, 14400, 19200, 28800, 38400, 57600, 115200,
	230400, 460800, 921600
};

#define	SC26198_NRBAUDS		ARRAY_SIZE(sc26198_baudtable)

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

/*
 *	Define the driver info for a user level control device. Used mainly
 *	to get at port stats - only not using the port device itself.
 */
static const struct file_operations	stl_fsiomem = {
	.owner		= THIS_MODULE,
	.ioctl		= stl_memioctl,
};

static struct class *stallion_class;

/*
 *	Check for any arguments passed in on the module load command line.
 */

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

/*
 *	Parse the supplied argument string, into the board conf struct.
 */

static int __init stl_parsebrd(struct stlconf *confp, char **argp)
{
	char	*sp;
	unsigned int i;

	pr_debug("stl_parsebrd(confp=%p,argp=%p)\n", confp, argp);

	if ((argp[0] == NULL) || (*argp[0] == 0))
		return 0;

	for (sp = argp[0], i = 0; (*sp != 0) && (i < 25); sp++, i++)
		*sp = tolower(*sp);

	for (i = 0; i < ARRAY_SIZE(stl_brdstr); i++)
		if (strcmp(stl_brdstr[i].name, argp[0]) == 0)
			break;

	if (i == ARRAY_SIZE(stl_brdstr)) {
		printk("STALLION: unknown board name, %s?\n", argp[0]);
		return 0;
	}

	confp->brdtype = stl_brdstr[i].type;

	i = 1;
	if ((argp[i] != NULL) && (*argp[i] != 0))
		confp->ioaddr1 = simple_strtoul(argp[i], NULL, 0);
	i++;
	if (confp->brdtype == BRD_ECH) {
		if ((argp[i] != NULL) && (*argp[i] != 0))
			confp->ioaddr2 = simple_strtoul(argp[i], NULL, 0);
		i++;
	}
	if ((argp[i] != NULL) && (*argp[i] != 0))
		confp->irq = simple_strtoul(argp[i], NULL, 0);
	return 1;
}

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

/*
 *	Allocate a new board structure. Fill out the basic info in it.
 */

static struct stlbrd *stl_allocbrd(void)
{
	struct stlbrd	*brdp;

	brdp = kzalloc(sizeof(struct stlbrd), GFP_KERNEL);
	if (!brdp) {
		printk("STALLION: failed to allocate memory (size=%Zd)\n",
			sizeof(struct stlbrd));
		return NULL;
	}

	brdp->magic = STL_BOARDMAGIC;
	return brdp;
}

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

static int stl_open(struct tty_struct *tty, struct file *filp)
{
	struct stlport	*portp;
	struct stlbrd	*brdp;
	unsigned int	minordev, brdnr, panelnr;
	int		portnr, rc;

	pr_debug("stl_open(tty=%p,filp=%p): device=%s\n", tty, filp, tty->name);

	minordev = tty->index;
	brdnr = MINOR2BRD(minordev);
	if (brdnr >= stl_nrbrds)
		return -ENODEV;
	brdp = stl_brds[brdnr];
	if (brdp == NULL)
		return -ENODEV;
	minordev = MINOR2PORT(minordev);
	for (portnr = -1, panelnr = 0; panelnr < STL_MAXPANELS; panelnr++) {
		if (brdp->panels[panelnr] == NULL)
			break;
		if (minordev < brdp->panels[panelnr]->nrports) {
			portnr = minordev;
			break;
		}
		minordev -= brdp->panels[panelnr]->nrports;
	}
	if (portnr < 0)
		return -ENODEV;

	portp = brdp->panels[panelnr]->ports[portnr];
	if (portp == NULL)
		return -ENODEV;

/*
 *	On the first open of the device setup the port hardware, and
 *	initialize the per port data structure.
 */
	portp->tty = tty;
	tty->driver_data = portp;
	portp->refcount++;

	if ((portp->flags & ASYNC_INITIALIZED) == 0) {
		if (!portp->tx.buf) {
			portp->tx.buf = kmalloc(STL_TXBUFSIZE, GFP_KERNEL);
			if (!portp->tx.buf)
				return -ENOMEM;
			portp->tx.head = portp->tx.buf;
			portp->tx.tail = portp->tx.buf;
		}
		stl_setport(portp, tty->termios);
		portp->sigs = stl_getsignals(portp);
		stl_setsignals(portp, 1, 1);
		stl_enablerxtx(portp, 1, 1);
		stl_startrxtx(portp, 1, 0);
		clear_bit(TTY_IO_ERROR, &tty->flags);
		portp->flags |= ASYNC_INITIALIZED;
	}

/*
 *	Check if this port is in the middle of closing. If so then wait
 *	until it is closed then return error status, based on flag settings.
 *	The sleep here does not need interrupt protection since the wakeup
 *	for it is done with the same context.
 */
	if (portp->flags & ASYNC_CLOSING) {
		interruptible_sleep_on(&portp->close_wait);
		if (portp->flags & ASYNC_HUP_NOTIFY)
			return -EAGAIN;
		return -ERESTARTSYS;
	}

/*
 *	Based on type of open being done check if it can overlap with any
 *	previous opens still in effect. If we are a normal serial device
 *	then also we might have to wait for carrier.
 */
	if (!(filp->f_flags & O_NONBLOCK))
		if ((rc = stl_waitcarrier(portp, filp)) != 0)
			return rc;

	portp->flags |= ASYNC_NORMAL_ACTIVE;

	return 0;
}

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

/*
 *	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 stl_waitcarrier(struct stlport *portp, struct file *filp)
{
	unsigned long	flags;
	int		rc, doclocal;

	pr_debug("stl_waitcarrier(portp=%p,filp=%p)\n", portp, filp);

	rc = 0;
	doclocal = 0;

	spin_lock_irqsave(&stallion_lock, flags);

	if (portp->tty->termios->c_cflag & CLOCAL)
		doclocal++;

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

	for (;;) {
		/* Takes brd_lock internally */
		stl_setsignals(portp, 1, 1);
		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_CLOSING) == 0) &&
		    (doclocal || (portp->sigs & TIOCM_CD)))
			break;
		if (signal_pending(current)) {
			rc = -ERESTARTSYS;
			break;
		}
		/* FIXME */
		interruptible_sleep_on(&portp->open_wait);
	}

	if (! tty_hung_up_p(filp))
		portp->refcount++;
	portp->openwaitcnt--;
	spin_unlock_irqrestore(&stallion_lock, flags);

	return rc;
}

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

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

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

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

	stl_flush(portp);
	tty_wakeup(tty);
}

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

static void stl_waituntilsent(struct tty_struct *tty, int timeout)
{
	struct stlport	*portp;
	unsigned long	tend;

	pr_debug("stl_waituntilsent(tty=%p,timeout=%d)\n", tty, timeout);

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

	if (timeout == 0)
		timeout = HZ;
	tend = jiffies + timeout;

	while (stl_datastate(portp)) {
		if (signal_pending(current))
			break;
		msleep_interruptible(20);
		if (time_after_eq(jiffies, tend))
			break;
	}
}

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

static void stl_close(struct tty_struct *tty, struct file *filp)
{
	struct stlport	*portp;
	unsigned long	flags;

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

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

	spin_lock_irqsave(&stallion_lock, flags);
	if (tty_hung_up_p(filp)) {
		spin_unlock_irqrestore(&stallion_lock, flags);
		return;
	}
	if ((tty->count == 1) && (portp->refcount != 1))
		portp->refcount = 1;
	if (portp->refcount-- > 1) {
		spin_unlock_irqrestore(&stallion_lock, flags);
		return;
	}

	portp->refcount = 0;
	portp->flags |= ASYNC_CLOSING;

/*
 *	May want to wait for any data to drain before closing. The BUSY
 *	flag keeps track of whether we are still sending or not - it is
 *	very accurate for the cd1400, not quite so for the sc26198.
 *	(The sc26198 has no "end-of-data" interrupt only empty FIFO)
 */
	tty->closing = 1;

	spin_unlock_irqrestore(&stallion_lock, flags);

	if (portp->closing_wait != ASYNC_CLOSING_WAIT_NONE)
		tty_wait_until_sent(tty, portp->closing_wait);
	stl_waituntilsent(tty, (HZ / 2));


	spin_lock_irqsave(&stallion_lock, flags);
	portp->flags &= ~ASYNC_INITIALIZED;
	spin_unlock_irqrestore(&stallion_lock, flags);

	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;
	if (portp->tx.buf != NULL) {
		kfree(portp->tx.buf);
		portp->tx.buf = NULL;
		portp->tx.head = NULL;
		portp->tx.tail = NULL;
	}
	set_bit(TTY_IO_ERROR, &tty->flags);
	tty_ldisc_flush(tty);

	tty->closing = 0;
	portp->tty = NULL;

	if (portp->openwaitcnt) {
		if (portp->close_delay)
			msleep_interruptible(jiffies_to_msecs(portp->close_delay));
		wake_up_interruptible(&portp->open_wait);
	}

	portp->flags &= ~(ASYNC_NORMAL_ACTIVE|ASYNC_CLOSING);
	wake_up_interruptible(&portp->close_wait);
}

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

/*
 *	Write routine. Take data and stuff it in to the TX ring queue.
 *	If transmit interrupts are not running then start them.
 */

static int stl_write(struct tty_struct *tty, const unsigned char *buf, int count)
{
	struct stlport	*portp;
	unsigned int	len, stlen;
	unsigned char	*chbuf;
	char		*head, *tail;

	pr_debug("stl_write(tty=%p,buf=%p,count=%d)\n", tty, buf, count);

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

/*
 *	If copying direct from user space we must cater for page faults,
 *	causing us to "sleep" here for a while. To handle this copy in all
 *	the data we need now, into a local buffer. Then when we got it all
 *	copy it into the TX buffer.
 */
	chbuf = (unsigned char *) buf;

	head = portp->tx.head;
	tail = portp->tx.tail;
	if (head >= tail) {
		len = STL_TXBUFSIZE - (head - tail) - 1;
		stlen = STL_TXBUFSIZE - (head - portp->tx.buf);
	} else {
		len = tail - head - 1;
		stlen = len;
	}

	len = min(len, (unsigned int)count);
	count = 0;
	while (len > 0) {
		stlen = min(len, stlen);
		memcpy(head, chbuf, stlen);
		len -= stlen;
		chbuf += stlen;
		count += stlen;
		head += stlen;
		if (head >= (portp->tx.buf + STL_TXBUFSIZE)) {
			head = portp->tx.buf;
			stlen = tail - head;
		}
	}
	portp->tx.head = head;

	clear_bit(ASYI_TXLOW, &portp->istate);
	stl_startrxtx(portp, -1, 1);

	return count;
}

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

static void stl_putchar(struct tty_struct *tty, unsigned char ch)
{
	struct stlport	*portp;
	unsigned int	len;
	char		*head, *tail;

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

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