isicom.c

/*
 *	This program is free software; you can redistribute it and/or
 *	modify it under the terms of the GNU General Public License
 *	as published by the Free Software Foundation; either version
 *	2 of the License, or (at your option) any later version.
 *
 *	Original driver code supplied by Multi-Tech
 *
 *	Changes
 *	1/9/98	alan@redhat.com		Merge to 2.0.x kernel tree
 *					Obtain and use official major/minors
 *					Loader switched to a misc device
 *					(fixed range check bug as a side effect)
 *					Printk clean up
 *	9/12/98	alan@redhat.com		Rough port to 2.1.x
 *
 *	10/6/99 sameer			Merged the ISA and PCI drivers to
 *					a new unified driver.
 *
 *	3/9/99	sameer			Added support for ISI4616 cards.
 *
 *	16/9/99	sameer			We do not force RTS low anymore.
 *					This is to prevent the firmware
 *					from getting confused.
 *
 *	26/10/99 sameer			Cosmetic changes:The driver now
 *					dumps the Port Count information
 *					along with I/O address and IRQ.
 *
 *	13/12/99 sameer			Fixed the problem with IRQ sharing.
 *
 *	10/5/00  sameer			Fixed isicom_shutdown_board()
 *					to not lower DTR on all the ports
 *					when the last port on the card is
 *					closed.
 *
 *	10/5/00  sameer			Signal mask setup command added
 *					to  isicom_setup_port and
 *					isicom_shutdown_port.
 *
 *	24/5/00  sameer			The driver is now SMP aware.
 *
 *
 *	27/11/00 Vinayak P Risbud	Fixed the Driver Crash Problem
 *
 *
 *	03/01/01  anil .s		Added support for resetting the
 *					internal modems on ISI cards.
 *
 *	08/02/01  anil .s		Upgraded the driver for kernel
 *					2.4.x
 *
 *	11/04/01  Kevin			Fixed firmware load problem with
 *					ISIHP-4X card
 *
 *	30/04/01  anil .s		Fixed the remote login through
 *					ISI port problem. Now the link
 *					does not go down before password
 *					prompt.
 *
 *	03/05/01  anil .s		Fixed the problem with IRQ sharing
 *					among ISI-PCI cards.
 *
 *	03/05/01  anil .s		Added support to display the version
 *					info during insmod as well as module
 *					listing by lsmod.
 *
 *	10/05/01  anil .s		Done the modifications to the source
 *					file and Install script so that the
 *					same installation can be used for
 *					2.2.x and 2.4.x kernel.
 *
 *	06/06/01  anil .s		Now we drop both dtr and rts during
 *					shutdown_port as well as raise them
 *					during isicom_config_port.
 *
 *	09/06/01 acme@conectiva.com.br	use capable, not suser, do
 *					restore_flags on failure in
 *					isicom_send_break, verify put_user
 *					result
 *
 *	11/02/03  ranjeeth		Added support for 230 Kbps and 460 Kbps
 *					Baud index extended to 21
 *
 *	20/03/03  ranjeeth		Made to work for Linux Advanced server.
 *					Taken care of license warning.
 *
 *	10/12/03  Ravindra		Made to work for Fedora Core 1 of
 *					Red Hat Distribution
 *
 *	06/01/05  Alan Cox 		Merged the ISI and base kernel strands
 *					into a single 2.6 driver
 *
 *	***********************************************************
 *
 *	To use this driver you also need the support package. You
 *	can find this in RPM format on
 *		ftp://ftp.linux.org.uk/pub/linux/alan
 *
 *	You can find the original tools for this direct from Multitech
 *		ftp://ftp.multitech.com/ISI-Cards/
 *
 *	Having installed the cards the module options (/etc/modprobe.conf)
 *
 *	options isicom   io=card1,card2,card3,card4 irq=card1,card2,card3,card4
 *
 *	Omit those entries for boards you don't have installed.
 *
 *	TODO
 *		Merge testing
 *		64-bit verification
 */

#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/tty.h>
#include <linux/tty_flip.h>
#include <linux/termios.h>
#include <linux/fs.h>
#include <linux/sched.h>
#include <linux/serial.h>
#include <linux/mm.h>
#include <linux/miscdevice.h>
#include <linux/interrupt.h>
#include <linux/timer.h>
#include <linux/delay.h>
#include <linux/ioport.h>

#include <asm/uaccess.h>
#include <asm/io.h>
#include <asm/system.h>

#include <linux/pci.h>

#include <linux/isicom.h>

#define InterruptTheCard(base) outw(0, (base) + 0xc)
#define ClearInterrupt(base) inw((base) + 0x0a)

#ifdef DEBUG
#define pr_dbg(str...) printk(KERN_DEBUG "ISICOM: " str)
#define isicom_paranoia_check(a, b, c) __isicom_paranoia_check((a), (b), (c))
#else
#define pr_dbg(str...) do { } while (0)
#define isicom_paranoia_check(a, b, c) 0
#endif

static int isicom_probe(struct pci_dev *, const struct pci_device_id *);
static void __devexit isicom_remove(struct pci_dev *);

static struct pci_device_id isicom_pci_tbl[] = {
	{ PCI_DEVICE(VENDOR_ID, 0x2028) },
	{ PCI_DEVICE(VENDOR_ID, 0x2051) },
	{ PCI_DEVICE(VENDOR_ID, 0x2052) },
	{ PCI_DEVICE(VENDOR_ID, 0x2053) },
	{ PCI_DEVICE(VENDOR_ID, 0x2054) },
	{ PCI_DEVICE(VENDOR_ID, 0x2055) },
	{ PCI_DEVICE(VENDOR_ID, 0x2056) },
	{ PCI_DEVICE(VENDOR_ID, 0x2057) },
	{ PCI_DEVICE(VENDOR_ID, 0x2058) },
	{ 0 }
};
MODULE_DEVICE_TABLE(pci, isicom_pci_tbl);

static struct pci_driver isicom_driver = {
	.name		= "isicom",
	.id_table	= isicom_pci_tbl,
	.probe		= isicom_probe,
	.remove		= __devexit_p(isicom_remove)
};

static int prev_card = 3;	/*	start servicing isi_card[0]	*/
static struct tty_driver *isicom_normal;

static struct timer_list tx;
static char re_schedule = 1;

static int ISILoad_ioctl(struct inode *inode, struct file *filp, unsigned  int cmd, unsigned long arg);

static void isicom_tx(unsigned long _data);
static void isicom_start(struct tty_struct *tty);

/*   baud index mappings from linux defns to isi */

static signed char linuxb_to_isib[] = {
	-1, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 11, 13, 15, 16, 17, 18, 19
};

struct	isi_board {
	unsigned long		base;
	unsigned char		irq;
	unsigned char		port_count;
	unsigned short		status;
	unsigned short		port_status; /* each bit represents a single port */
	unsigned short		shift_count;
	struct isi_port		* ports;
	signed char		count;
	unsigned char		isa;
	spinlock_t		card_lock; /* Card wide lock 11/5/00 -sameer */
	unsigned long		flags;
};

struct	isi_port {
	unsigned short		magic;
	unsigned int		flags;
	int			count;
	int			blocked_open;
	int			close_delay;
	u16			channel;
	u16			status;
	u16			closing_wait;
	struct isi_board	* card;
	struct tty_struct 	* tty;
	wait_queue_head_t	close_wait;
	wait_queue_head_t	open_wait;
	struct work_struct	hangup_tq;
	struct work_struct	bh_tqueue;
	unsigned char		* xmit_buf;
	int			xmit_head;
	int			xmit_tail;
	int			xmit_cnt;
};

static struct isi_board isi_card[BOARD_COUNT];
static struct isi_port  isi_ports[PORT_COUNT];

/*
 *	Locking functions for card level locking. We need to own both
 *	the kernel lock for the card and have the card in a position that
 *	it wants to talk.
 */

static int lock_card(struct isi_board *card)
{
	char		retries;
	unsigned long base = card->base;

	for (retries = 0; retries < 100; retries++) {
		spin_lock_irqsave(&card->card_lock, card->flags);
		if (inw(base + 0xe) & 0x1) {
			return 1;
		} else {
			spin_unlock_irqrestore(&card->card_lock, card->flags);
			udelay(1000);   /* 1ms */
		}
	}
	printk(KERN_WARNING "ISICOM: Failed to lock Card (0x%lx)\n", card->base);
	return 0;	/* Failed to aquire the card! */
}

static int lock_card_at_interrupt(struct isi_board *card)
{
	unsigned char		retries;
	unsigned long base = card->base;

	for (retries = 0; retries < 200; retries++) {
		spin_lock_irqsave(&card->card_lock, card->flags);

		if (inw(base + 0xe) & 0x1)
			return 1;
		else
			spin_unlock_irqrestore(&card->card_lock, card->flags);
	}
	/* Failing in interrupt is an acceptable event */
	return 0;	/* Failed to aquire the card! */
}

static void unlock_card(struct isi_board *card)
{
	spin_unlock_irqrestore(&card->card_lock, card->flags);
}

/*
 *  ISI Card specific ops ...
 */

static void raise_dtr(struct isi_port *port)
{
	struct isi_board *card = port->card;
	unsigned long base = card->base;
	u16 channel = port->channel;

	if (!lock_card(card))
		return;

	outw(0x8000 | (channel << card->shift_count) | 0x02, base);
	outw(0x0504, base);
	InterruptTheCard(base);
	port->status |= ISI_DTR;
	unlock_card(card);
}

static inline void drop_dtr(struct isi_port *port)
{
	struct isi_board *card = port->card;
	unsigned long base = card->base;
	u16 channel = port->channel;

	if (!lock_card(card))
		return;

	outw(0x8000 | (channel << card->shift_count) | 0x02, base);
	outw(0x0404, base);
	InterruptTheCard(base);
	port->status &= ~ISI_DTR;
	unlock_card(card);
}

static inline void raise_rts(struct isi_port *port)
{
	struct isi_board *card = port->card;
	unsigned long base = card->base;
	u16 channel = port->channel;

	if (!lock_card(card))
		return;

	outw(0x8000 | (channel << card->shift_count) | 0x02, base);
	outw(0x0a04, base);
	InterruptTheCard(base);
	port->status |= ISI_RTS;
	unlock_card(card);
}
static inline void drop_rts(struct isi_port *port)
{
	struct isi_board *card = port->card;
	unsigned long base = card->base;
	u16 channel = port->channel;

	if (!lock_card(card))
		return;

	outw(0x8000 | (channel << card->shift_count) | 0x02, base);
	outw(0x0804, base);
	InterruptTheCard(base);
	port->status &= ~ISI_RTS;
	unlock_card(card);
}

static inline void raise_dtr_rts(struct isi_port *port)
{
	struct isi_board *card = port->card;
	unsigned long base = card->base;
	u16 channel = port->channel;

	if (!lock_card(card))
		return;

	outw(0x8000 | (channel << card->shift_count) | 0x02, base);
	outw(0x0f04, base);
	InterruptTheCard(base);
	port->status |= (ISI_DTR | ISI_RTS);
	unlock_card(card);
}

static void drop_dtr_rts(struct isi_port *port)
{
	struct isi_board *card = port->card;
	unsigned long base = card->base;
	u16 channel = port->channel;

	if (!lock_card(card))
		return;

	outw(0x8000 | (channel << card->shift_count) | 0x02, base);
	outw(0x0c04, base);
	InterruptTheCard(base);
	port->status &= ~(ISI_RTS | ISI_DTR);
	unlock_card(card);
}

static inline void kill_queue(struct isi_port *port, short queue)
{
	struct isi_board *card = port->card;
	unsigned long base = card->base;
	u16 channel = port->channel;

	if (!lock_card(card))
		return;

	outw(0x8000 | (channel << card->shift_count) | 0x02, base);
	outw((queue << 8) | 0x06, base);
	InterruptTheCard(base);
	unlock_card(card);
}


/*
 *  Firmware loader driver specific routines. This needs to mostly die
 *  and be replaced with request_firmware.
 */

static struct file_operations ISILoad_fops = {
	.owner		= THIS_MODULE,
	.ioctl		= ISILoad_ioctl,
};

static struct miscdevice isiloader_device = {
	ISILOAD_MISC_MINOR, "isictl", &ISILoad_fops
};


static inline int WaitTillCardIsFree(unsigned long base)
{
	unsigned long count=0;
	while( (!(inw(base+0xe) & 0x1)) && (count++ < 6000000));
	if (inw(base+0xe)&0x1)
		return 0;
	else
		return 1;
}

static int ISILoad_ioctl(struct inode *inode, struct file *filp,
	unsigned int cmd, unsigned long arg)
{
	unsigned int card, i, j, signature, status, portcount = 0;
	unsigned long t, base;
	u16 word_count;
	bin_frame frame;
	void __user *argp = (void __user *)arg;
	/* exec_record exec_rec; */

	if (get_user(card, (int __user *)argp))
		return -EFAULT;

	if (card < 0 || card >= BOARD_COUNT)
		return -ENXIO;

	base=isi_card[card].base;

	if (base==0)
		return -ENXIO;	/* disabled or not used */

	switch(cmd) {
	case MIOCTL_RESET_CARD:
		if (!capable(CAP_SYS_ADMIN))
			return -EPERM;
		printk(KERN_DEBUG "ISILoad:Resetting Card%d at 0x%lx ",card+1,base);

		inw(base+0x8);

		for (t=jiffies+HZ/100;time_before(jiffies, t););

		outw(0,base+0x8); /* Reset */

		for (j=1;j<=3;j++) {
			for (t=jiffies+HZ;time_before(jiffies, t););
			printk(".");
		}
		signature=(inw(base+0x4)) & 0xff;
		if (isi_card[card].isa) {

			if (!(inw(base+0xe) & 0x1) || (inw(base+0x2))) {
#ifdef ISICOM_DEBUG
				printk("\nbase+0x2=0x%x , base+0xe=0x%x",inw(base+0x2),inw(base+0xe));
#endif
				printk("\nISILoad:ISA Card%d reset failure (Possible bad I/O Port Address 0x%lx).\n",card+1,base);
				return -EIO;
			}
		}
		else {
			portcount = inw(base+0x2);
			if (!(inw(base+0xe) & 0x1) || ((portcount!=0) && (portcount!=4) && (portcount!=8))) {
#ifdef ISICOM_DEBUG
				printk("\nbase+0x2=0x%x , base+0xe=0x%x",inw(base+0x2),inw(base+0xe));
#endif
				printk("\nISILoad:PCI Card%d reset failure (Possible bad I/O Port Address 0x%lx).\n",card+1,base);
				return -EIO;
			}
		}
		switch(signature) {
		case	0xa5:
		case	0xbb:
		case	0xdd:
				if (isi_card[card].isa)
					isi_card[card].port_count = 8;
				else {
					if (portcount == 4)
						isi_card[card].port_count = 4;
					else
						isi_card[card].port_count = 8;
				}
				isi_card[card].shift_count = 12;
				break;

		case	0xcc:	isi_card[card].port_count = 16;
				isi_card[card].shift_count = 11;
				break;

		default: printk("ISILoad:Card%d reset failure (Possible bad I/O Port Address 0x%lx).\n",card+1,base);
#ifdef ISICOM_DEBUG
			printk("Sig=0x%x\n",signature);
#endif
			return -EIO;
		}
		printk("-Done\n");
		return put_user(signature,(unsigned __user *)argp);

	case	MIOCTL_LOAD_FIRMWARE:
			if (!capable(CAP_SYS_ADMIN))
				return -EPERM;

			if (copy_from_user(&frame, argp, sizeof(bin_frame)))
				return -EFAULT;

			if (WaitTillCardIsFree(base))
				return -EIO;

			outw(0xf0,base); /* start upload sequence */
			outw(0x00,base);
			outw((frame.addr), base); /* lsb of adderess */

			word_count=(frame.count >> 1) + frame.count % 2;
			outw(word_count, base);
			InterruptTheCard(base);

			for (i=0;i<=0x2f;i++);	/* a wee bit of delay */

			if (WaitTillCardIsFree(base))
				return -EIO;

			if ((status=inw(base+0x4))!=0) {
				printk(KERN_WARNING "ISILoad:Card%d rejected load header:\nAddress:0x%x \nCount:0x%x \nStatus:0x%x \n",
				card+1, frame.addr, frame.count, status);
				return -EIO;
			}
			outsw(base, (void *) frame.bin_data, word_count);

			InterruptTheCard(base);

			for (i=0;i<=0x0f;i++);	/* another wee bit of delay */

			if (WaitTillCardIsFree(base))
				return -EIO;

			if ((status=inw(base+0x4))!=0) {
				printk(KERN_ERR "ISILoad:Card%d got out of sync.Card Status:0x%x\n",card+1, status);
				return -EIO;
			}
			return 0;

	case	MIOCTL_READ_FIRMWARE:
			if (!capable(CAP_SYS_ADMIN))
				return -EPERM;

			if (copy_from_user(&frame, argp, sizeof(bin_header)))
				return -EFAULT;

			if (WaitTillCardIsFree(base))
				return -EIO;

			outw(0xf1,base); /* start download sequence */
			outw(0x00,base);
			outw((frame.addr), base); /* lsb of adderess */

			word_count=(frame.count >> 1) + frame.count % 2;
			outw(word_count+1, base);
			InterruptTheCard(base);

			for (i=0;i<=0xf;i++);	/* a wee bit of delay */

			if (WaitTillCardIsFree(base))
				return -EIO;

			if ((status=inw(base+0x4))!=0) {
				printk(KERN_WARNING "ISILoad:Card%d rejected verify header:\nAddress:0x%x \nCount:0x%x \nStatus:0x%x \n",
				card+1, frame.addr, frame.count, status);
				return -EIO;
			}

			inw(base);
			insw(base, frame.bin_data, word_count);
			InterruptTheCard(base);

			for (i=0;i<=0x0f;i++);	/* another wee bit of delay */

			if (WaitTillCardIsFree(base))
				return -EIO;

			if ((status=inw(base+0x4))!=0) {
				printk(KERN_ERR "ISILoad:Card%d verify got out of sync.Card Status:0x%x\n",card+1, status);
				return -EIO;
			}

			if (copy_to_user(argp, &frame, sizeof(bin_frame)))
				return -EFAULT;
			return 0;

	case	MIOCTL_XFER_CTRL:
			if (!capable(CAP_SYS_ADMIN))
				return -EPERM;
			if (WaitTillCardIsFree(base))
				return -EIO;

			outw(0xf2, base);
			outw(0x800, base);
			outw(0x0, base);
			outw(0x0, base);
			InterruptTheCard(base);
			outw(0x0, base+0x4); /* for ISI4608 cards */

			isi_card[card].status |= FIRMWARE_LOADED;
			return 0;

	default:
#ifdef ISICOM_DEBUG
		printk(KERN_DEBUG "ISILoad: Received Ioctl cmd 0x%x.\n", cmd);
#endif
		return -ENOIOCTLCMD;
	}
}


/*
 *	ISICOM Driver specific routines ...
 *
 */

static inline int __isicom_paranoia_check(struct isi_port const *port,
	char *name, const char *routine)
{
	if (!port) {
		printk(KERN_WARNING "ISICOM: Warning: bad isicom magic for "
			"dev %s in %s.\n", name, routine);
		return 1;
	}
	if (port->magic != ISICOM_MAGIC) {
		printk(KERN_WARNING "ISICOM: Warning: NULL isicom port for "
			"dev %s in %s.\n", name, routine);
		return 1;
	}

	return 0;
}

/*
 *	Transmitter.
 *
 *	We shovel data into the card buffers on a regular basis. The card
 *	will do the rest of the work for us.
 */

static void isicom_tx(unsigned long _data)
{
	short count = (BOARD_COUNT-1), card, base;
	short txcount, wrd, residue, word_count, cnt;
	struct isi_port *port;
	struct tty_struct *tty;

	/*	find next active board	*/
	card = (prev_card + 1) & 0x0003;
	while(count-- > 0) {
		if (isi_card[card].status & BOARD_ACTIVE)
			break;
		card = (card + 1) & 0x0003;
	}
	if (!(isi_card[card].status & BOARD_ACTIVE))
		goto sched_again;

	prev_card = card;

	count = isi_card[card].port_count;
	port = isi_card[card].ports;
	base = isi_card[card].base;
	for (;count > 0;count--, port++) {
		if (!lock_card_at_interrupt(&isi_card[card]))
			continue;
		/* port not active or tx disabled to force flow control */
		if (!(port->flags & ASYNC_INITIALIZED) ||
				!(port->status & ISI_TXOK))
			unlock_card(&isi_card[card]);
			continue;

		tty = port->tty;


		if (tty == NULL) {
			unlock_card(&isi_card[card]);
			continue;
		}

		txcount = min_t(short, TX_SIZE, port->xmit_cnt);
		if (txcount <= 0 || tty->stopped || tty->hw_stopped) {
			unlock_card(&isi_card[card]);
			continue;
		}
		if (!(inw(base + 0x02) & (1 << port->channel))) {
			unlock_card(&isi_card[card]);
			continue;
		}
		pr_dbg("txing %d bytes, port%d.\n", txcount,
			port->channel + 1);
		outw((port->channel << isi_card[card].shift_count) | txcount,
			base);
		residue = NO;
		wrd = 0;
		while (1) {
			cnt = min_t(int, txcount, (SERIAL_XMIT_SIZE - port->xmit_tail));
			if (residue == YES) {
				residue = NO;
				if (cnt > 0) {
					wrd |= (port->xmit_buf[port->xmit_tail] << 8);
					port->xmit_tail = (port->xmit_tail + 1) & (SERIAL_XMIT_SIZE - 1);
					port->xmit_cnt--;
					txcount--;
					cnt--;
					outw(wrd, base);
				}
				else {
					outw(wrd, base);
					break;
				}
			}
			if (cnt <= 0) break;
			word_count = cnt >> 1;
			outsw(base, port->xmit_buf+port->xmit_tail, word_count);
			port->xmit_tail = (port->xmit_tail + (word_count << 1)) &
						(SERIAL_XMIT_SIZE - 1);
			txcount -= (word_count << 1);
			port->xmit_cnt -= (word_count << 1);
			if (cnt & 0x0001) {
				residue = YES;
				wrd = port->xmit_buf[port->xmit_tail];
				port->xmit_tail = (port->xmit_tail + 1) & (SERIAL_XMIT_SIZE - 1);
				port->xmit_cnt--;
				txcount--;
			}
		}

		InterruptTheCard(base);
		if (port->xmit_cnt <= 0)
			port->status &= ~ISI_TXOK;
		if (port->xmit_cnt <= WAKEUP_CHARS)
			schedule_work(&port->bh_tqueue);
		unlock_card(&isi_card[card]);
	}

	/*	schedule another tx for hopefully in about 10ms	*/
sched_again:
	if (!re_schedule) {
		re_schedule = 2;
 		return;
	}

	init_timer(&tx);
	tx.expires = jiffies + HZ/100;
	tx.data = 0;
	tx.function = isicom_tx;
	add_timer(&tx);

	return;
}

/* 	Interrupt handlers 	*/


static void isicom_bottomhalf(void *data)
{
	struct isi_port *port = (struct isi_port *) data;
	struct tty_struct *tty = port->tty;

	if (!tty)
		return;

	tty_wakeup(tty);
	wake_up_interruptible(&tty->write_wait);
}

/*
 *	Main interrupt handler routine
 */

static irqreturn_t isicom_interrupt(int irq, void *dev_id, struct pt_regs *regs)
{
	struct isi_board *card = dev_id;
	struct isi_port *port;
	struct tty_struct *tty;
	unsigned long base;
	u16 header, word_count, count, channel;
	short byte_count;
	unsigned char *rp;

	if (!card || !(card->status & FIRMWARE_LOADED))
		return IRQ_NONE;

	base = card->base;
	spin_lock(&card->card_lock);

	if (card->isa == NO) {
		/*
		 * disable any interrupts from the PCI card and lower the
		 * interrupt line
		 */
		outw(0x8000, base+0x04);
		ClearInterrupt(base);
	}

	inw(base);		/* get the dummy word out */
	header = inw(base);
	channel = (header & 0x7800) >> card->shift_count;
	byte_count = header & 0xff;

	if (channel + 1 > card->port_count) {
		printk(KERN_WARNING "ISICOM: isicom_interrupt(0x%lx): %d(channel) > port_count.\n",
				base, channel+1);
		if (card->isa)
			ClearInterrupt(base);
		else
			outw(0x0000, base+0x04); /* enable interrupts */
		spin_unlock(&card->card_lock);
		return IRQ_HANDLED;
	}
	port = card->ports + channel;
	if (!(port->flags & ASYNC_INITIALIZED)) {
		if (card->isa)
			ClearInterrupt(base);
		else
			outw(0x0000, base+0x04); /* enable interrupts */
		return IRQ_HANDLED;
	}

	tty = port->tty;
	if (tty == NULL) {
		word_count = byte_count >> 1;
		while(byte_count > 1) {
			inw(base);
			byte_count -= 2;
		}
		if (byte_count & 0x01)
			inw(base);
		if (card->isa == YES)
			ClearInterrupt(base);
		else
			outw(0x0000, base+0x04); /* enable interrupts */
		spin_unlock(&card->card_lock);
		return IRQ_HANDLED;
	}

	if (header & 0x8000) {		/* Status Packet */
		header = inw(base);
		switch(header & 0xff) {
		case 0:	/* Change in EIA signals */

			if (port->flags & ASYNC_CHECK_CD) {
				if (port->status & ISI_DCD) {
					if (!(header & ISI_DCD)) {
					/* Carrier has been lost  */
						pr_dbg("interrupt: DCD->low.\n");
						port->status &= ~ISI_DCD;
						schedule_work(&port->hangup_tq);
					}
				}
				else {
					if (header & ISI_DCD) {
					/* Carrier has been detected */
						pr_dbg("interrupt: DCD->high.\n");
						port->status |= ISI_DCD;
						wake_up_interruptible(&port->open_wait);
					}
				}
			}
			else {
				if (header & ISI_DCD)
					port->status |= ISI_DCD;
				else
					port->status &= ~ISI_DCD;
			}

			if (port->flags & ASYNC_CTS_FLOW) {
				if (port->tty->hw_stopped) {
					if (header & ISI_CTS) {
						port->tty->hw_stopped = 0;
						/* start tx ing */
						port->status |= (ISI_TXOK | ISI_CTS);
						schedule_work(&port->bh_tqueue);
					}
				}
				else {
					if (!(header & ISI_CTS)) {
						port->tty->hw_stopped = 1;
						/* stop tx ing */
						port->status &= ~(ISI_TXOK | ISI_CTS);
					}
				}
			}
			else {
				if (header & ISI_CTS)
					port->status |= ISI_CTS;
				else
					port->status &= ~ISI_CTS;
			}

			if (header & ISI_DSR)
				port->status |= ISI_DSR;
			else
				port->status &= ~ISI_DSR;

			if (header & ISI_RI)
				port->status |= ISI_RI;
			else
				port->status &= ~ISI_RI;

			break;

		case 1:	/* Received Break !!!	 */
			tty_insert_flip_char(tty, 0, TTY_BREAK);
			if (port->flags & ASYNC_SAK)
				do_SAK(tty);
			tty_flip_buffer_push(tty);
			break;

		case 2:	/* Statistics		 */
			pr_dbg("isicom_interrupt: stats!!!.\n");
			break;

		default:
			pr_dbg("Intr: Unknown code in status packet.\n");
			break;
		}
	}
	else {				/* Data   Packet */

		count = tty_prepare_flip_string(tty, &rp, byte_count & ~1);
		pr_dbg("Intr: Can rx %d of %d bytes.\n", count, byte_count);
		word_count = count >> 1;
		insw(base, rp, word_count);
		byte_count -= (word_count << 1);
		if (count & 0x0001) {
			tty_insert_flip_char(tty,  inw(base) & 0xff, TTY_NORMAL);
			byte_count -= 2;
		}
		if (byte_count > 0) {
			pr_dbg("Intr(0x%lx:%d): Flip buffer overflow! dropping "
				"bytes...\n", base, channel + 1);
			while(byte_count > 0) { /* drain out unread xtra data */
				inw(base);
				byte_count -= 2;
			}
		}
		tty_flip_buffer_push(tty);
	}
	if (card->isa == YES)
		ClearInterrupt(base);
	else
		outw(0x0000, base+0x04); /* enable interrupts */
	return IRQ_HANDLED;
}

static void isicom_config_port(struct isi_port *port)
{
	struct isi_board *card = port->card;
	struct tty_struct *tty;
	unsigned long baud;
	unsigned long base = card->base;
	u16 channel_setup, channel = port->channel,
		shift_count = card->shift_count;
	unsigned char flow_ctrl;

	if (!(tty = port->tty) || !tty->termios)
		return;
	baud = C_BAUD(tty);
	if (baud & CBAUDEX) {
		baud &= ~CBAUDEX;

		/*  if CBAUDEX bit is on and the baud is set to either 50 or 75
		 *  then the card is programmed for 57.6Kbps or 115Kbps
		 *  respectively.
		 */

		if (baud < 1 || baud > 2)
			port->tty->termios->c_cflag &= ~CBAUDEX;
		else
			baud += 15;
	}
	if (baud == 15) {

		/*  the ASYNC_SPD_HI and ASYNC_SPD_VHI options are set
		 *  by the set_serial_info ioctl ... this is done by
		 *  the 'setserial' utility.
		 */

		if ((port->flags & ASYNC_SPD_MASK) == ASYNC_SPD_HI)
			baud++; /*  57.6 Kbps */
		if ((port->flags & ASYNC_SPD_MASK) == ASYNC_SPD_VHI)
			baud +=2; /*  115  Kbps */
	}
	if (linuxb_to_isib[baud] == -1) {
		/* hang up */
		drop_dtr(port);
		return;
	}
	else
		raise_dtr(port);

	if (lock_card(card)) {
		outw(0x8000 | (channel << shift_count) |0x03, base);
		outw(linuxb_to_isib[baud] << 8 | 0x03, base);
		channel_setup = 0;
		switch(C_CSIZE(tty)) {
		case CS5:
			channel_setup |= ISICOM_CS5;
			break;
		case CS6:
			channel_setup |= ISICOM_CS6;
			break;
		case CS7:
			channel_setup |= ISICOM_CS7;
			break;
		case CS8:
			channel_setup |= ISICOM_CS8;
			break;
		}

		if (C_CSTOPB(tty))
			channel_setup |= ISICOM_2SB;
		if (C_PARENB(tty)) {
			channel_setup |= ISICOM_EVPAR;
			if (C_PARODD(tty))
				channel_setup |= ISICOM_ODPAR;
		}
		outw(channel_setup, base);
		InterruptTheCard(base);
		unlock_card(card);
	}
	if (C_CLOCAL(tty))
		port->flags &= ~ASYNC_CHECK_CD;
	else
		port->flags |= ASYNC_CHECK_CD;

	/* flow control settings ...*/
	flow_ctrl = 0;
	port->flags &= ~ASYNC_CTS_FLOW;
	if (C_CRTSCTS(tty)) {
		port->flags |= ASYNC_CTS_FLOW;
		flow_ctrl |= ISICOM_CTSRTS;
	}
	if (I_IXON(tty))
		flow_ctrl |= ISICOM_RESPOND_XONXOFF;
	if (I_IXOFF(tty))
		flow_ctrl |= ISICOM_INITIATE_XONXOFF;

	if (lock_card(card)) {
		outw(0x8000 | (channel << shift_count) |0x04, base);
		outw(flow_ctrl << 8 | 0x05, base);
		outw((STOP_CHAR(tty)) << 8 | (START_CHAR(tty)), base);
		InterruptTheCard(base);
		unlock_card(card);
	}

	/*	rx enabled -> enable port for rx on the card	*/
	if (C_CREAD(tty)) {
		card->port_status |= (1 << channel);
		outw(card->port_status, base + 0x02);
	}
}

/* open et all */

static inline void isicom_setup_board(struct isi_board *bp)
{
	int channel;
	struct isi_port *port;
	unsigned long flags;

	spin_lock_irqsave(&bp->card_lock, flags);
	if (bp->status & BOARD_ACTIVE) {
		spin_unlock_irqrestore(&bp->card_lock, flags);
		return;
	}
	port = bp->ports;
	bp->status |= BOARD_ACTIVE;
	spin_unlock_irqrestore(&bp->card_lock, flags);
	for (channel = 0; channel < bp->port_count; channel++, port++)
		drop_dtr_rts(port);
	return;
}

static int isicom_setup_port(struct isi_port *port)
{
	struct isi_board *card = port->card;
	unsigned long flags;

	if (port->flags & ASYNC_INITIALIZED) {
		return 0;
	}
	if (!port->xmit_buf) {
		unsigned long page;

		if (!(page = get_zeroed_page(GFP_KERNEL)))
			return -ENOMEM;

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

	spin_lock_irqsave(&card->card_lock, flags);
	if (port->tty)
		clear_bit(TTY_IO_ERROR, &port->tty->flags);
	if (port->count == 1)
		card->count++;

	port->xmit_cnt = port->xmit_head = port->xmit_tail = 0;

	/*	discard any residual data	*/
	kill_queue(port, ISICOM_KILLTX | ISICOM_KILLRX);

	isicom_config_port(port);
	port->flags |= ASYNC_INITIALIZED;
	spin_unlock_irqrestore(&card->card_lock, flags);

	return 0;
}

static int block_til_ready(struct tty_struct *tty, struct file *filp, struct isi_port *port)
{
	struct isi_board *card = port->card;
	int do_clocal = 0, retval;
	unsigned long flags;
	DECLARE_WAITQUEUE(wait, current);

	/* block if port is in the process of being closed */

	if (tty_hung_up_p(filp) || port->flags & ASYNC_CLOSING) {
		pr_dbg("block_til_ready: close in progress.\n");
		interruptible_sleep_on(&port->close_wait);
		if (port->flags & ASYNC_HUP_NOTIFY)
			return -EAGAIN;
		else
			return -ERESTARTSYS;
	}

	/* if non-blocking mode is set ... */

	if ((filp->f_flags & O_NONBLOCK) || (tty->flags & (1 << TTY_IO_ERROR))) {
		pr_dbg("block_til_ready: non-block mode.\n");
		port->flags |= ASYNC_NORMAL_ACTIVE;
		return 0;
	}

	if (C_CLOCAL(tty))
		do_clocal = 1;

	/* block waiting for DCD to be asserted, and while
						callout dev is busy */
	retval = 0;
	add_wait_queue(&port->open_wait, &wait);

	spin_lock_irqsave(&card->card_lock, flags);
	if (!tty_hung_up_p(filp))
		port->count--;
	port->blocked_open++;
	spin_unlock_irqrestore(&card->card_lock, flags);

	while (1) {
		raise_dtr_rts(port);

		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 || (port->status & ISI_DCD))) {
			break;
		}
		if (signal_pending(current)) {
			retval = -ERESTARTSYS;
			break;
		}
		schedule();
	}
	set_current_state(TASK_RUNNING);
	remove_wait_queue(&port->open_wait, &wait);
	spin_lock_irqsave(&card->card_lock, flags);
	if (!tty_hung_up_p(filp))
		port->count++;
	port->blocked_open--;
	spin_unlock_irqrestore(&card->card_lock, flags);
	if (retval)
		return retval;
	port->flags |= ASYNC_NORMAL_ACTIVE;
	return 0;
}

static int isicom_open(struct tty_struct *tty, struct file *filp)
{
	struct isi_port *port;
	struct isi_board *card;
	unsigned int line, board;
	int error;

	line = tty->index;
	if (line < 0 || line > PORT_COUNT-1)
		return -ENODEV;
	board = BOARD(line);
	card = &isi_card[board];

	if (!(card->status & FIRMWARE_LOADED))
		return -ENODEV;

	/*  open on a port greater than the port count for the card !!! */
	if (line > ((board * 16) + card->port_count - 1))
		return -ENODEV;

	port = &isi_ports[line];
	if (isicom_paranoia_check(port, tty->name, "isicom_open"))
		return -ENODEV;

	isicom_setup_board(card);

	port->count++;
	tty->driver_data = port;
	port->tty = tty;
	if ((error = isicom_setup_port(port))!=0)
		return error;
	if ((error = block_til_ready(tty, filp, port))!=0)
		return error;

	return 0;
}

/* close et all */

static inline void isicom_shutdown_board(struct isi_board *bp)
{
	unsigned long flags;

	spin_lock_irqsave(&bp->card_lock, flags);
	if (bp->status & BOARD_ACTIVE) {
		bp->status &= ~BOARD_ACTIVE;
	}
	spin_unlock_irqrestore(&bp->card_lock, flags);
}

static void isicom_shutdown_port(struct isi_port *port)
{
	struct isi_board *card = port->card;
	struct tty_struct *tty;
	unsigned long flags;

	tty = port->tty;

	spin_lock_irqsave(&card->card_lock, flags);
	if (!(port->flags & ASYNC_INITIALIZED)) {
		spin_unlock_irqrestore(&card->card_lock, flags);
		return;
	}
	if (port->xmit_buf) {
		free_page((unsigned long) port->xmit_buf);
		port->xmit_buf = NULL;
	}
	port->flags &= ~ASYNC_INITIALIZED;
	/* 3rd October 2000 : Vinayak P Risbud */
	port->tty = NULL;
	spin_unlock_irqrestore(&card->card_lock, flags);

	/*Fix done by Anil .S on 30-04-2001
	remote login through isi port has dtr toggle problem
	due to which the carrier drops before the password prompt
	appears on the remote end. Now we drop the dtr only if the
	HUPCL(Hangup on close) flag is set for the tty*/

	if (C_HUPCL(tty))
		/* drop dtr on this port */
		drop_dtr(port);

	/* any other port uninits  */
	if (tty)
		set_bit(TTY_IO_ERROR, &tty->flags);

	if (--card->count < 0) {
		pr_dbg("isicom_shutdown_port: bad board(0x%lx) count %d.\n",
			card->base, card->count);
		card->count = 0;
	}

	/* last port was closed , shutdown that boad too */
	if (C_HUPCL(tty)) {
		if (!card->count)
			isicom_shutdown_board(card);
	}
}

static void isicom_close(struct tty_struct *tty, struct file *filp)
{
	struct isi_port *port = tty->driver_data;
	struct isi_board *card = port->card;
	unsigned long flags;

	if (!port)
		return;
	if (isicom_paranoia_check(port, tty->name, "isicom_close"))
		return;

	pr_dbg("Close start!!!.\n");

	spin_lock_irqsave(&card->card_lock, flags);
	if (tty_hung_up_p(filp)) {
		spin_unlock_irqrestore(&card->card_lock, flags);
		return;
	}

	if (tty->count == 1 && port->count != 1) {
		printk(KERN_WARNING "ISICOM:(0x%lx) isicom_close: bad port count"
			"tty->count = 1	port count = %d.\n",
			card->base, port->count);
		port->count = 1;
	}
	if (--port->count < 0) {
		printk(KERN_WARNING "ISICOM:(0x%lx) isicom_close: bad port count for"
			"channel%d = %d", card->base, port->channel,
			port->count);
		port->count = 0;
	}

	if (port->count) {
		spin_unlock_irqrestore(&card->card_lock, flags);
		return;
	}
	port->flags |= ASYNC_CLOSING;
	tty->closing = 1;
	spin_unlock_irqrestore(&card->card_lock, flags);

	if (port->closing_wait != ASYNC_CLOSING_WAIT_NONE)
		tty_wait_until_sent(tty, port->closing_wait);
	/* indicate to the card that no more data can be received
	   on this port */
	spin_lock_irqsave(&card->card_lock, flags);
	if (port->flags & ASYNC_INITIALIZED) {
		card->port_status &= ~(1 << port->channel);
		outw(card->port_status, card->base + 0x02);
	}
	isicom_shutdown_port(port);
	spin_unlock_irqrestore(&card->card_lock, flags);

	if (tty->driver->flush_buffer)
		tty->driver->flush_buffer(tty);
	tty_ldisc_flush(tty);

	spin_lock_irqsave(&card->card_lock, flags);
	tty->closing = 0;

	if (port->blocked_open) {
		spin_unlock_irqrestore(&card->card_lock, flags);
		if (port->close_delay) {
			pr_dbg("scheduling until time out.\n");
			msleep_interruptible(jiffies_to_msecs(port->close_delay));
		}
		spin_lock_irqsave(&card->card_lock, flags);
		wake_up_interruptible(&port->open_wait);
	}
	port->flags &= ~(ASYNC_NORMAL_ACTIVE | ASYNC_CLOSING);
	wake_up_interruptible(&port->close_wait);
	spin_unlock_irqrestore(&card->card_lock, flags);
}

/* write et all */
static int isicom_write(struct tty_struct *tty,	const unsigned char *buf,
	int count)
{
	struct isi_port *port = tty->driver_data;
	struct isi_board *card = port->card;
	unsigned long flags;
	int cnt, total = 0;

	if (isicom_paranoia_check(port, tty->name, "isicom_write"))
		return 0;

	if (!tty || !port->xmit_buf)
		return 0;

	spin_lock_irqsave(&card->card_lock, flags);

	while(1) {
		cnt = min_t(int, count, min(SERIAL_XMIT_SIZE - port->xmit_cnt - 1,
					SERIAL_XMIT_SIZE - port->xmit_head));
		if (cnt <= 0)
			break;

		memcpy(port->xmit_buf + port->xmit_head, buf, cnt);
		port->xmit_head = (port->xmit_head + cnt) & (SERIAL_XMIT_SIZE - 1);
		port->xmit_cnt += cnt;
		buf += cnt;
		count -= cnt;
		total += cnt;
	}
	if (port->xmit_cnt && !tty->stopped && !tty->hw_stopped)
		port->status |= ISI_TXOK;
	spin_unlock_irqrestore(&card->card_lock, flags);
	return total;
}

/* put_char et all */
static void isicom_put_char(struct tty_struct *tty, unsigned char ch)
{
	struct isi_port *port = tty->driver_data;
	struct isi_board *card = port->card;
	unsigned long flags;

	if (isicom_paranoia_check(port, tty->name, "isicom_put_char"))
		return;

	if (!tty || !port->xmit_buf)
		return;

	spin_lock_irqsave(&card->card_lock, flags);
	if (port->xmit_cnt >= SERIAL_XMIT_SIZE - 1) {
		spin_unlock_irqrestore(&card->card_lock, flags);
		return;
	}

	port->xmit_buf[port->xmit_head++] = ch;
	port->xmit_head &= (SERIAL_XMIT_SIZE - 1);
	port->xmit_cnt++;
	spin_unlock_irqrestore(&card->card_lock, flags);
}

/* flush_chars et all */
static void isicom_flush_chars(struct tty_struct *tty)
{
	struct isi_port *port = tty->driver_data;

	if (isicom_paranoia_check(port, tty->name, "isicom_flush_chars"))
		return;

	if (port->xmit_cnt <= 0 || tty->stopped || tty->hw_stopped || !port->xmit_buf)
		return;

	/* this tells the transmitter to consider this port for
	   data output to the card ... that's the best we can do. */
	port->status |= ISI_TXOK;
}

/* write_room et all */
static int isicom_write_room(struct tty_struct *tty)
{
	struct isi_port *port = tty->driver_data;
	int free;

	if (isicom_paranoia_check(port, tty->name, "isicom_write_room"))
		return 0;

	free = SERIAL_XMIT_SIZE - port->xmit_cnt - 1;
	if (free < 0)
		free = 0;
	return free;
}

/* chars_in_buffer et all */
static int isicom_chars_in_buffer(struct tty_struct *tty)
{
	struct isi_port *port = tty->driver_data;
	if (isicom_paranoia_check(port, tty->name, "isicom_chars_in_buffer"))
		return 0;
	return port->xmit_cnt;
}

/* ioctl et all */
static inline void isicom_send_break(struct isi_port *port, unsigned long length)
{
	struct isi_board *card = port->card;
	unsigned long base = card->base;

	if (!lock_card(card))
		return;

	outw(0x8000 | ((port->channel) << (card->shift_count)) | 0x3, base);
	outw((length & 0xff) << 8 | 0x00, base);
	outw((length & 0xff00), base);
	InterruptTheCard(base);

	unlock_card(card);
}

static int isicom_tiocmget(struct tty_struct *tty, struct file *file)
{
	struct isi_port *port = tty->driver_data;
	/* just send the port status */
	u16 status = port->status;

	if (isicom_paranoia_check(port, tty->name, "isicom_ioctl"))
		return -ENODEV;

	return  ((status & ISI_RTS) ? TIOCM_RTS : 0) |
		((status & ISI_DTR) ? TIOCM_DTR : 0) |
		((status & ISI_DCD) ? TIOCM_CAR : 0) |
		((status & ISI_DSR) ? TIOCM_DSR : 0) |
		((status & ISI_CTS) ? TIOCM_CTS : 0) |
		((status & ISI_RI ) ? TIOCM_RI  : 0);
}

static int isicom_tiocmset(struct tty_struct *tty, struct file *file,
	unsigned int set, unsigned int clear)
{
	struct isi_port *port = tty->driver_data;

	if (isicom_paranoia_check(port, tty->name, "isicom_ioctl"))
		return -ENODEV;

	if (set & TIOCM_RTS)
		raise_rts(port);
	if (set & TIOCM_DTR)
		raise_dtr(port);

	if (clear & TIOCM_RTS)
		drop_rts(port);
	if (clear & TIOCM_DTR)
		drop_dtr(port);

	return 0;
}

static int isicom_set_serial_info(struct isi_port *port,
	struct serial_struct __user *info)
{
	struct serial_struct newinfo;
	int reconfig_port;

	if (copy_from_user(&newinfo, info, sizeof(newinfo)))
		return -EFAULT;

	reconfig_port = ((port->flags & ASYNC_SPD_MASK) !=
		(newinfo.flags & ASYNC_SPD_MASK));

	if (!capable(CAP_SYS_ADMIN)) {
		if ((newinfo.close_delay != port->close_delay) ||
				(newinfo.closing_wait != port->closing_wait) ||
				((newinfo.flags & ~ASYNC_USR_MASK) !=
				(port->flags & ~ASYNC_USR_MASK)))
			return -EPERM;
		port->flags = ((port->flags & ~ ASYNC_USR_MASK) |
				(newinfo.flags & ASYNC_USR_MASK));
	}
	else {
		port->close_delay = newinfo.close_delay;
		port->closing_wait = newinfo.closing_wait;
		port->flags = ((port->flags & ~ASYNC_FLAGS) |
				(newinfo.flags & ASYNC_FLAGS));
	}
	if (reconfig_port) {
		isicom_config_port(port);
	}
	return 0;
}

static int isicom_get_serial_info(struct isi_port *port,
	struct serial_struct __user *info)
{
	struct serial_struct out_info;

	memset(&out_info, 0, sizeof(out_info));
/*	out_info.type = ? */
	out_info.line = port - isi_ports;
	out_info.port = port->card->base;
	out_info.irq = port->card->irq;
	out_info.flags = port->flags;
/*	out_info.baud_base = ? */
	out_info.close_delay = port->close_delay;
	out_info.closing_wait = port->closing_wait;
	if (copy_to_user(info, &out_info, sizeof(out_info)))
		return -EFAULT;
	return 0;
}

static int isicom_ioctl(struct tty_struct *tty, struct file *filp,
	unsigned int cmd, unsigned long arg)
{
	struct isi_port *port = tty->driver_data;
	void __user *argp = (void __user *)arg;
	int retval;

	if (isicom_paranoia_check(port, tty->name, "isicom_ioctl"))
		return -ENODEV;

	switch(cmd) {
	case TCSBRK:
		retval = tty_check_change(tty);
		if (retval)
			return retval;
		tty_wait_until_sent(tty, 0);
		if (!arg)
			isicom_send_break(port, HZ/4);
		return 0;

	case TCSBRKP:
		retval = tty_check_change(tty);
		if (retval)
			return retval;
		tty_wait_until_sent(tty, 0);
		isicom_send_break(port, arg ? arg * (HZ/10) : HZ/4);
		return 0;

	case TIOCGSOFTCAR:
		return put_user(C_CLOCAL(tty) ? 1 : 0, (unsigned long __user *)argp);

	case TIOCSSOFTCAR:
		if (get_user(arg, (unsigned long __user *) argp))
			return -EFAULT;
		tty->termios->c_cflag =
			((tty->termios->c_cflag & ~CLOCAL) |
			(arg ? CLOCAL : 0));
		return 0;

	case TIOCGSERIAL:
		return isicom_get_serial_info(port, argp);

	case TIOCSSERIAL:
		return isicom_set_serial_info(port, argp);

	default:
		return -ENOIOCTLCMD;
	}
	return 0;
}

/* set_termios et all */
static void isicom_set_termios(struct tty_struct *tty,
	struct termios *old_termios)
{
	struct isi_port *port = tty->driver_data;

	if (isicom_paranoia_check(port, tty->name, "isicom_set_termios"))
		return;

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

	isicom_config_port(port);

	if ((old_termios->c_cflag & CRTSCTS) &&
			!(tty->termios->c_cflag & CRTSCTS)) {
		tty->hw_stopped = 0;
		isicom_start(tty);
	}
}

/* throttle et all */
static void isicom_throttle(struct tty_struct *tty)
{
	struct isi_port *port = tty->driver_data;
	struct isi_board *card = port->card;

	if (isicom_paranoia_check(port, tty->name, "isicom_throttle"))
		return;

	/* tell the card that this port cannot handle any more data for now */
	card->port_status &= ~(1 << port->channel);
	outw(card->port_status, card->base + 0x02);
}

/* unthrottle et all */
static void isicom_unthrottle(struct tty_struct *tty)
{
	struct isi_port *port = tty->driver_data;
	struct isi_board *card = port->card;

	if (isicom_paranoia_check(port, tty->name, "isicom_unthrottle"))
		return;

	/* tell the card that this port is ready to accept more data */
	card->port_status |= (1 << port->channel);
	outw(card->port_status, card->base + 0x02);
}

/* stop et all */
static void isicom_stop(struct tty_struct *tty)
{
	struct isi_port *port = tty->driver_data;

	if (isicom_paranoia_check(port, tty->name, "isicom_stop"))
		return;

	/* this tells the transmitter not to consider this port for
	   data output to the card. */
	port->status &= ~ISI_TXOK;
}

/* start et all */
static void isicom_start(struct tty_struct *tty)
{
	struct isi_port *port = tty->driver_data;

	if (isicom_paranoia_check(port, tty->name, "isicom_start"))
		return;

	/* this tells the transmitter to consider this port for
	   data output to the card. */
	port->status |= ISI_TXOK;
}

/* hangup et all */
static void do_isicom_hangup(void *data)
{
	struct isi_port *port = data;
	struct tty_struct *tty;

	tty = port->tty;
	if (tty)
		tty_hangup(tty);
}

static void isicom_hangup(struct tty_struct *tty)
{
	struct isi_port *port = tty->driver_data;

	if (isicom_paranoia_check(port, tty->name, "isicom_hangup"))
		return;

	isicom_shutdown_port(port);
	port->count = 0;
	port->flags &= ~ASYNC_NORMAL_ACTIVE;
	port->tty = NULL;
	wake_up_interruptible(&port->open_wait);
}

/* flush_buffer et all */
static void isicom_flush_buffer(struct tty_struct *tty)
{
	struct isi_port *port = tty->driver_data;
	struct isi_board *card = port->card;
	unsigned long flags;

	if (isicom_paranoia_check(port, tty->name, "isicom_flush_buffer"))
		return;

	spin_lock_irqsave(&card->card_lock, flags);
	port->xmit_cnt = port->xmit_head = port->xmit_tail = 0;
	spin_unlock_irqrestore(&card->card_lock, flags);

	wake_up_interruptible(&tty->write_wait);
	tty_wakeup(tty);
}

/*
 * Driver init and deinit functions
 */

static int __devinit isicom_register_ioregion(struct pci_dev *pdev,
	const unsigned int index)
{
	struct isi_board *board = pci_get_drvdata(pdev);

	if (!board->base)
		return -EINVAL;

	if (!request_region(board->base, 16, ISICOM_NAME)) {
		dev_dbg(&pdev->dev, "I/O Region 0x%lx-0x%lx is busy. Card%d "
			"will be disabled.\n", board->base, board->base + 15,
			index + 1);
		return -EBUSY;
 	}

	return 0;
}

static void isicom_unregister_ioregion(struct pci_dev *pdev)
{
	struct isi_board *board = pci_get_drvdata(pdev);

	if (!board->base)
		return;

	release_region(board->base, 16);
	dev_dbg(&pdev->dev, "I/O Region 0x%lx-0x%lx released.\n",
		board->base, board->base + 15);
	board->base = 0;
}

static struct tty_operations isicom_ops = {
	.open			= isicom_open,
	.close			= isicom_close,
	.write			= isicom_write,
	.put_char		= isicom_put_char,
	.flush_chars		= isicom_flush_chars,
	.write_room		= isicom_write_room,
	.chars_in_buffer	= isicom_chars_in_buffer,
	.ioctl			= isicom_ioctl,
	.set_termios		= isicom_set_termios,
	.throttle		= isicom_throttle,
	.unthrottle		= isicom_unthrottle,
	.stop			= isicom_stop,
	.start			= isicom_start,
	.hangup			= isicom_hangup,
	.flush_buffer		= isicom_flush_buffer,
	.tiocmget		= isicom_tiocmget,
	.tiocmset		= isicom_tiocmset,
};

static int __devinit isicom_register_tty_driver(void)
{
	int error = -ENOMEM;

	/* tty driver structure initialization */
	isicom_normal = alloc_tty_driver(PORT_COUNT);
	if (!isicom_normal)
		goto end;

	isicom_normal->owner			= THIS_MODULE;
	isicom_normal->name 			= "ttyM";
	isicom_normal->devfs_name	 	= "isicom/";
	isicom_normal->major			= ISICOM_NMAJOR;
	isicom_normal->minor_start		= 0;
	isicom_normal->type			= TTY_DRIVER_TYPE_SERIAL;
	isicom_normal->subtype			= SERIAL_TYPE_NORMAL;
	isicom_normal->init_termios		= tty_std_termios;
	isicom_normal->init_termios.c_cflag	= B9600 | CS8 | CREAD | HUPCL |
		CLOCAL;
	isicom_normal->flags			= TTY_DRIVER_REAL_RAW;
	tty_set_operations(isicom_normal, &isicom_ops);

	if ((error = tty_register_driver(isicom_normal))) {
		pr_dbg("Couldn't register the dialin driver, error=%d\n",
			error);
		put_tty_driver(isicom_normal);
	}
end:
	return error;
}

static void isicom_unregister_tty_driver(void)
{
	int error;

	if ((error = tty_unregister_driver(isicom_normal)))
		pr_dbg("couldn't unregister normal driver, error=%d.\n", error);

	put_tty_driver(isicom_normal);
}

static int __devinit isicom_register_isr(struct pci_dev *pdev,
	const unsigned int index)
{
	struct isi_board *board = pci_get_drvdata(pdev);
	unsigned long irqflags = SA_INTERRUPT;
	int retval = -EINVAL;

	if (!board->base)
		goto end;

	if (board->isa == NO)
		irqflags |= SA_SHIRQ;

	retval = request_irq(board->irq, isicom_interrupt, irqflags,
		ISICOM_NAME, board);
	if (retval < 0)
		dev_warn(&pdev->dev, "Could not install handler at Irq %d. "
			"Card%d will be disabled.\n", board->irq, index + 1);
 	else
		retval = 0;
end:
	return retval;
}

static int __devinit reset_card(struct pci_dev *pdev,
	const unsigned int card, unsigned int *signature)
{
	struct isi_board *board = pci_get_drvdata(pdev);
	unsigned long base = board->base;
	unsigned int portcount = 0;
	int retval = 0;

	dev_dbg(&pdev->dev, "ISILoad:Resetting Card%d at 0x%lx\n", card + 1,
		base);

	inw(base + 0x8);

	mdelay(10);

	outw(0, base + 0x8); /* Reset */

	msleep(3000);

	*signature = inw(base + 0x4) & 0xff;

	if (board->isa == YES) {
		if (!(inw(base + 0xe) & 0x1) || (inw(base + 0x2))) {
			dev_dbg(&pdev->dev, "base+0x2=0x%lx, base+0xe=0x%lx\n",
				inw(base + 0x2), inw(base + 0xe));
			dev_err(&pdev->dev, "ISILoad:ISA Card%d reset failure "
				"(Possible bad I/O Port Address 0x%lx).\n",
				card + 1, base);
			retval = -EIO;
			goto end;
		}
	} else {
		portcount = inw(base + 0x2);
		if (!(inw(base + 0xe) & 0x1) || ((portcount != 0) &&
				(portcount != 4) && (portcount != 8))) {
			dev_dbg(&pdev->dev, "base+0x2=0x%lx, base+0xe=0x%lx\n",
				inw(base + 0x2), inw(base + 0xe));
			dev_err(&pdev->dev, "ISILoad:PCI Card%d reset failure "
				"(Possible bad I/O Port Address 0x%lx).\n",
				card + 1, base);
			retval = -EIO;
			goto end;
		}
	}

	switch (*signature) {
	case 0xa5:
	case 0xbb:
	case 0xdd:
		board->port_count = (board->isa == NO && portcount == 4) ? 4 :
			8;
		board->shift_count = 12;
		break;
	case 0xcc:
		board->port_count = 16;
		board->shift_count = 11;
		break;
	default:
		dev_warn(&pdev->dev, "ISILoad:Card%d reset failure (Possible "
			"bad I/O Port Address 0x%lx).\n", card + 1, base);
		dev_dbg(&pdev->dev, "Sig=0x%lx\n", signature);
		retval = -EIO;
	}
	dev_info(&pdev->dev, "-Done\n");

end:
	return retval;
}

/*
 *	Insmod can set static symbols so keep these static
 */
static int io[4];
static int irq[4];
static int card;

static int __devinit isicom_probe(struct pci_dev *pdev,
	const struct pci_device_id *ent)
{
	unsigned int ioaddr, signature, index;
	int retval = -EPERM;
	u8 pciirq;
	struct isi_board *board = NULL;

	if (card >= BOARD_COUNT)
		goto err;

	ioaddr = pci_resource_start(pdev, 3);
	/* i.e at offset 0x1c in the PCI configuration register space. */
	pciirq = pdev->irq;
	dev_info(&pdev->dev, "ISI PCI Card(Device ID 0x%x)\n", ent->device);

	/* allot the first empty slot in the array */
	for (index = 0; index < BOARD_COUNT; index++)
		if (isi_card[index].base == 0) {
			board = &isi_card[index];
			break;
		}

	board->base = ioaddr;
	board->irq = pciirq;
	board->isa = NO;
	card++;

	pci_set_drvdata(pdev, board);

	retval = isicom_register_ioregion(pdev, index);
	if (retval < 0)
		goto err;

	retval = isicom_register_isr(pdev, index);
	if (retval < 0)
		goto errunrr;

	retval = reset_card(pdev, index, &signature);
	if (retval < 0)
		goto errunri;

	return 0;

errunri:
	free_irq(board->irq, board);
errunrr:
	isicom_unregister_ioregion(pdev);
err:
	board->base = 0;
	return retval;
}

static void __devexit isicom_remove(struct pci_dev *pdev)
{
	struct isi_board *board = pci_get_drvdata(pdev);

	free_irq(board->irq, board);
	isicom_unregister_ioregion(pdev);
}

static int __devinit isicom_setup(void)
{
	int retval, idx, channel;
	struct isi_port *port;

	card = 0;
	memset(isi_ports, 0, sizeof(isi_ports));

	for(idx = 0; idx < BOARD_COUNT; idx++) {
		port = &isi_ports[idx * 16];
		isi_card[idx].ports = port;
		spin_lock_init(&isi_card[idx].card_lock);
		for (channel = 0; channel < 16; channel++, port++) {
			port->magic = ISICOM_MAGIC;
			port->card = &isi_card[idx];
			port->channel = channel;
			port->close_delay = 50 * HZ/100;
			port->closing_wait = 3000 * HZ/100;
			INIT_WORK(&port->hangup_tq, do_isicom_hangup, port);
			INIT_WORK(&port->bh_tqueue, isicom_bottomhalf, port);
			port->status = 0;
			init_waitqueue_head(&port->open_wait);
			init_waitqueue_head(&port->close_wait);
			/*  . . .  */
 		}
		isi_card[idx].base = 0;
		isi_card[idx].irq = 0;

		if (!io[idx])
			continue;

		if (irq[idx] == 2 || irq[idx] == 3 || irq[idx] == 4	||
				irq[idx] == 5	|| irq[idx] == 7	||
				irq[idx] == 10	|| irq[idx] == 11	||
				irq[idx] == 12	|| irq[idx] == 15) {
			printk(KERN_ERR "ISICOM: ISA not supported yet.\n");
			retval = -EINVAL;
			goto error;
		} else
			printk(KERN_ERR "ISICOM: Irq %d unsupported. "
				"Disabling Card%d...\n", irq[idx], idx + 1);
	}

	retval = isicom_register_tty_driver();
	if (retval < 0)
		goto error;

	retval = pci_register_driver(&isicom_driver);
	if (retval < 0) {
		printk(KERN_ERR "ISICOM: Unable to register pci driver.\n");
		goto errtty;
	}

	retval = misc_register(&isiloader_device);
	if (retval < 0)
		goto errpci;

	init_timer(&tx);
	tx.expires = jiffies + 1;
	tx.data = 0;
	tx.function = isicom_tx;
	re_schedule = 1;
	add_timer(&tx);

	return 0;
errpci:
	pci_unregister_driver(&isicom_driver);
errtty:
	isicom_unregister_tty_driver();
error:
	return retval;
}

static void __exit isicom_exit(void)
{
	unsigned int index = 0;

	re_schedule = 0;

	while (re_schedule != 2 && index++ < 100)
		msleep(10);

	pci_unregister_driver(&isicom_driver);
	isicom_unregister_tty_driver();
}

module_init(isicom_setup);
module_exit(isicom_exit);

MODULE_AUTHOR("MultiTech");
MODULE_DESCRIPTION("Driver for the ISI series of cards by MultiTech");
MODULE_LICENSE("GPL");
module_param_array(io, int, NULL, 0);
MODULE_PARM_DESC(io, "I/O ports for the cards");
module_param_array(irq, int, NULL, 0);
MODULE_PARM_DESC(irq, "Interrupts for the cards");