diff --git a/drivers/char/amiserial.c b/drivers/char/amiserial.c
new file mode 100644
index 0000000..1dc4259
--- /dev/null
+++ b/drivers/char/amiserial.c
@@ -0,0 +1,2179 @@
+/*
+ *  linux/drivers/char/amiserial.c
+ *
+ * Serial driver for the amiga builtin port.
+ *
+ * This code was created by taking serial.c version 4.30 from kernel
+ * release 2.3.22, replacing all hardware related stuff with the
+ * corresponding amiga hardware actions, and removing all irrelevant
+ * code. As a consequence, it uses many of the constants and names
+ * associated with the registers and bits of 16550 compatible UARTS -
+ * but only to keep track of status, etc in the state variables. It
+ * was done this was to make it easier to keep the code in line with
+ * (non hardware specific) changes to serial.c.
+ *
+ * The port is registered with the tty driver as minor device 64, and
+ * therefore other ports should should only use 65 upwards.
+ *
+ * Richard Lucock 28/12/99
+ *
+ *  Copyright (C) 1991, 1992  Linus Torvalds
+ *  Copyright (C) 1992, 1993, 1994, 1995, 1996, 1997, 
+ * 		1998, 1999  Theodore Ts'o
+ *
+ */
+
+/*
+ * Serial driver configuration section.  Here are the various options:
+ *
+ * SERIAL_PARANOIA_CHECK
+ * 		Check the magic number for the async_structure where
+ * 		ever possible.
+ */
+
+#include <linux/config.h>
+#include <linux/delay.h>
+
+#undef SERIAL_PARANOIA_CHECK
+#define SERIAL_DO_RESTART
+
+/* Set of debugging defines */
+
+#undef SERIAL_DEBUG_INTR
+#undef SERIAL_DEBUG_OPEN
+#undef SERIAL_DEBUG_FLOW
+#undef SERIAL_DEBUG_RS_WAIT_UNTIL_SENT
+
+/* Sanity checks */
+
+#define SERIAL_INLINE
+  
+#if defined(MODULE) && defined(SERIAL_DEBUG_MCOUNT)
+#define DBG_CNT(s) printk("(%s): [%x] refc=%d, serc=%d, ttyc=%d -> %s\n", \
+ tty->name, (info->flags), serial_driver->refcount,info->count,tty->count,s)
+#else
+#define DBG_CNT(s)
+#endif
+
+/*
+ * End of serial driver configuration section.
+ */
+
+#include <linux/module.h>
+
+#include <linux/types.h>
+#include <linux/serial.h>
+#include <linux/serialP.h>
+#include <linux/serial_reg.h>
+static char *serial_version = "4.30";
+
+#include <linux/errno.h>
+#include <linux/signal.h>
+#include <linux/sched.h>
+#include <linux/kernel.h>
+#include <linux/timer.h>
+#include <linux/interrupt.h>
+#include <linux/tty.h>
+#include <linux/tty_flip.h>
+#include <linux/console.h>
+#include <linux/major.h>
+#include <linux/string.h>
+#include <linux/fcntl.h>
+#include <linux/ptrace.h>
+#include <linux/ioport.h>
+#include <linux/mm.h>
+#include <linux/slab.h>
+#include <linux/init.h>
+#include <linux/bitops.h>
+
+#include <asm/setup.h>
+
+#include <asm/system.h>
+
+#include <asm/irq.h>
+
+#include <asm/amigahw.h>
+#include <asm/amigaints.h>
+
+#ifdef SERIAL_INLINE
+#define _INLINE_ inline
+#endif
+
+static char *serial_name = "Amiga-builtin serial driver";
+
+static struct tty_driver *serial_driver;
+
+/* number of characters left in xmit buffer before we ask for more */
+#define WAKEUP_CHARS 256
+
+static struct async_struct *IRQ_ports;
+
+static unsigned char current_ctl_bits;
+
+static void change_speed(struct async_struct *info, struct termios *old);
+static void rs_wait_until_sent(struct tty_struct *tty, int timeout);
+
+
+static struct serial_state rs_table[1];
+
+#define NR_PORTS	(sizeof(rs_table)/sizeof(struct serial_state))
+
+/*
+ * tmp_buf is used as a temporary buffer by serial_write.  We need to
+ * lock it in case the copy_from_user blocks while swapping in a page,
+ * and some other program tries to do a serial write at the same time.
+ * Since the lock will only come under contention when the system is
+ * swapping and available memory is low, it makes sense to share one
+ * buffer across all the serial ports, since it significantly saves
+ * memory if large numbers of serial ports are open.
+ */
+static unsigned char *tmp_buf;
+static DECLARE_MUTEX(tmp_buf_sem);
+
+#include <asm/uaccess.h>
+
+#define serial_isroot()	(capable(CAP_SYS_ADMIN))
+
+
+static inline int serial_paranoia_check(struct async_struct *info,
+					char *name, const char *routine)
+{
+#ifdef SERIAL_PARANOIA_CHECK
+	static const char *badmagic =
+		"Warning: bad magic number for serial struct (%s) in %s\n";
+	static const char *badinfo =
+		"Warning: null async_struct for (%s) in %s\n";
+
+	if (!info) {
+		printk(badinfo, name, routine);
+		return 1;
+	}
+	if (info->magic != SERIAL_MAGIC) {
+		printk(badmagic, name, routine);
+		return 1;
+	}
+#endif
+	return 0;
+}
+
+/* some serial hardware definitions */
+#define SDR_OVRUN   (1<<15)
+#define SDR_RBF     (1<<14)
+#define SDR_TBE     (1<<13)
+#define SDR_TSRE    (1<<12)
+
+#define SERPER_PARENB    (1<<15)
+
+#define AC_SETCLR   (1<<15)
+#define AC_UARTBRK  (1<<11)
+
+#define SER_DTR     (1<<7)
+#define SER_RTS     (1<<6)
+#define SER_DCD     (1<<5)
+#define SER_CTS     (1<<4)
+#define SER_DSR     (1<<3)
+
+static __inline__ void rtsdtr_ctrl(int bits)
+{
+    ciab.pra = ((bits & (SER_RTS | SER_DTR)) ^ (SER_RTS | SER_DTR)) | (ciab.pra & ~(SER_RTS | SER_DTR));
+}
+
+/*
+ * ------------------------------------------------------------
+ * rs_stop() and rs_start()
+ *
+ * This routines are called before setting or resetting tty->stopped.
+ * They enable or disable transmitter interrupts, as necessary.
+ * ------------------------------------------------------------
+ */
+static void rs_stop(struct tty_struct *tty)
+{
+	struct async_struct *info = (struct async_struct *)tty->driver_data;
+	unsigned long flags;
+
+	if (serial_paranoia_check(info, tty->name, "rs_stop"))
+		return;
+
+	local_irq_save(flags);
+	if (info->IER & UART_IER_THRI) {
+		info->IER &= ~UART_IER_THRI;
+		/* disable Tx interrupt and remove any pending interrupts */
+		custom.intena = IF_TBE;
+		mb();
+		custom.intreq = IF_TBE;
+		mb();
+	}
+	local_irq_restore(flags);
+}
+
+static void rs_start(struct tty_struct *tty)
+{
+	struct async_struct *info = (struct async_struct *)tty->driver_data;
+	unsigned long flags;
+
+	if (serial_paranoia_check(info, tty->name, "rs_start"))
+		return;
+
+	local_irq_save(flags);
+	if (info->xmit.head != info->xmit.tail
+	    && info->xmit.buf
+	    && !(info->IER & UART_IER_THRI)) {
+		info->IER |= UART_IER_THRI;
+		custom.intena = IF_SETCLR | IF_TBE;
+		mb();
+		/* set a pending Tx Interrupt, transmitter should restart now */
+		custom.intreq = IF_SETCLR | IF_TBE;
+		mb();
+	}
+	local_irq_restore(flags);
+}
+
+/*
+ * ----------------------------------------------------------------------
+ *
+ * Here starts the interrupt handling routines.  All of the following
+ * subroutines are declared as inline and are folded into
+ * rs_interrupt().  They were separated out for readability's sake.
+ *
+ * Note: rs_interrupt() is a "fast" interrupt, which means that it
+ * runs with interrupts turned off.  People who may want to modify
+ * rs_interrupt() should try to keep the interrupt handler as fast as
+ * possible.  After you are done making modifications, it is not a bad
+ * idea to do:
+ * 
+ * gcc -S -DKERNEL -Wall -Wstrict-prototypes -O6 -fomit-frame-pointer serial.c
+ *
+ * and look at the resulting assemble code in serial.s.
+ *
+ * 				- Ted Ts'o (tytso@mit.edu), 7-Mar-93
+ * -----------------------------------------------------------------------
+ */
+
+/*
+ * This routine is used by the interrupt handler to schedule
+ * processing in the software interrupt portion of the driver.
+ */
+static _INLINE_ void rs_sched_event(struct async_struct *info,
+				  int event)
+{
+	info->event |= 1 << event;
+	tasklet_schedule(&info->tlet);
+}
+
+static _INLINE_ void receive_chars(struct async_struct *info)
+{
+        int status;
+	int serdatr;
+	struct tty_struct *tty = info->tty;
+	unsigned char ch;
+	struct	async_icount *icount;
+
+	icount = &info->state->icount;
+
+	status = UART_LSR_DR; /* We obviously have a character! */
+	serdatr = custom.serdatr;
+	mb();
+	custom.intreq = IF_RBF;
+	mb();
+
+	if((serdatr & 0x1ff) == 0)
+	    status |= UART_LSR_BI;
+	if(serdatr & SDR_OVRUN)
+	    status |= UART_LSR_OE;
+
+	ch = serdatr & 0xff;
+	if (tty->flip.count >= TTY_FLIPBUF_SIZE)
+	  goto ignore_char;
+	*tty->flip.char_buf_ptr = ch;
+	icount->rx++;
+
+#ifdef SERIAL_DEBUG_INTR
+	printk("DR%02x:%02x...", ch, status);
+#endif
+	*tty->flip.flag_buf_ptr = 0;
+
+	/*
+	 * We don't handle parity or frame errors - but I have left
+	 * the code in, since I'm not sure that the errors can't be
+	 * detected.
+	 */
+
+	if (status & (UART_LSR_BI | UART_LSR_PE |
+		      UART_LSR_FE | UART_LSR_OE)) {
+	  /*
+	   * For statistics only
+	   */
+	  if (status & UART_LSR_BI) {
+	    status &= ~(UART_LSR_FE | UART_LSR_PE);
+	    icount->brk++;
+	  } else if (status & UART_LSR_PE)
+	    icount->parity++;
+	  else if (status & UART_LSR_FE)
+	    icount->frame++;
+	  if (status & UART_LSR_OE)
+	    icount->overrun++;
+
+	  /*
+	   * Now check to see if character should be
+	   * ignored, and mask off conditions which
+	   * should be ignored.
+	   */
+	  if (status & info->ignore_status_mask)
+	    goto ignore_char;
+
+	  status &= info->read_status_mask;
+
+	  if (status & (UART_LSR_BI)) {
+#ifdef SERIAL_DEBUG_INTR
+	    printk("handling break....");
+#endif
+	    *tty->flip.flag_buf_ptr = TTY_BREAK;
+	    if (info->flags & ASYNC_SAK)
+	      do_SAK(tty);
+	  } else if (status & UART_LSR_PE)
+	    *tty->flip.flag_buf_ptr = TTY_PARITY;
+	  else if (status & UART_LSR_FE)
+	    *tty->flip.flag_buf_ptr = TTY_FRAME;
+	  if (status & UART_LSR_OE) {
+	    /*
+	     * Overrun is special, since it's
+	     * reported immediately, and doesn't
+	     * affect the current character
+	     */
+	    if (tty->flip.count < TTY_FLIPBUF_SIZE) {
+	      tty->flip.count++;
+	      tty->flip.flag_buf_ptr++;
+	      tty->flip.char_buf_ptr++;
+	      *tty->flip.flag_buf_ptr = TTY_OVERRUN;
+	    }
+	  }
+	}
+	tty->flip.flag_buf_ptr++;
+	tty->flip.char_buf_ptr++;
+	tty->flip.count++;
+ ignore_char:
+
+	tty_flip_buffer_push(tty);
+}
+
+static _INLINE_ void transmit_chars(struct async_struct *info)
+{
+	custom.intreq = IF_TBE;
+	mb();
+	if (info->x_char) {
+	        custom.serdat = info->x_char | 0x100;
+		mb();
+		info->state->icount.tx++;
+		info->x_char = 0;
+		return;
+	}
+	if (info->xmit.head == info->xmit.tail
+	    || info->tty->stopped
+	    || info->tty->hw_stopped) {
+		info->IER &= ~UART_IER_THRI;
+	        custom.intena = IF_TBE;
+		mb();
+		return;
+	}
+
+	custom.serdat = info->xmit.buf[info->xmit.tail++] | 0x100;
+	mb();
+	info->xmit.tail = info->xmit.tail & (SERIAL_XMIT_SIZE-1);
+	info->state->icount.tx++;
+
+	if (CIRC_CNT(info->xmit.head,
+		     info->xmit.tail,
+		     SERIAL_XMIT_SIZE) < WAKEUP_CHARS)
+		rs_sched_event(info, RS_EVENT_WRITE_WAKEUP);
+
+#ifdef SERIAL_DEBUG_INTR
+	printk("THRE...");
+#endif
+	if (info->xmit.head == info->xmit.tail) {
+	        custom.intena = IF_TBE;
+		mb();
+		info->IER &= ~UART_IER_THRI;
+	}
+}
+
+static _INLINE_ void check_modem_status(struct async_struct *info)
+{
+	unsigned char status = ciab.pra & (SER_DCD | SER_CTS | SER_DSR);
+	unsigned char dstatus;
+	struct	async_icount *icount;
+
+	/* Determine bits that have changed */
+	dstatus = status ^ current_ctl_bits;
+	current_ctl_bits = status;
+
+	if (dstatus) {
+		icount = &info->state->icount;
+		/* update input line counters */
+		if (dstatus & SER_DSR)
+			icount->dsr++;
+		if (dstatus & SER_DCD) {
+			icount->dcd++;
+#ifdef CONFIG_HARD_PPS
+			if ((info->flags & ASYNC_HARDPPS_CD) &&
+			    !(status & SER_DCD))
+				hardpps();
+#endif
+		}
+		if (dstatus & SER_CTS)
+			icount->cts++;
+		wake_up_interruptible(&info->delta_msr_wait);
+	}
+
+	if ((info->flags & ASYNC_CHECK_CD) && (dstatus & SER_DCD)) {
+#if (defined(SERIAL_DEBUG_OPEN) || defined(SERIAL_DEBUG_INTR))
+		printk("ttyS%d CD now %s...", info->line,
+		       (!(status & SER_DCD)) ? "on" : "off");
+#endif
+		if (!(status & SER_DCD))
+			wake_up_interruptible(&info->open_wait);
+		else {
+#ifdef SERIAL_DEBUG_OPEN
+			printk("doing serial hangup...");
+#endif
+			if (info->tty)
+				tty_hangup(info->tty);
+		}
+	}
+	if (info->flags & ASYNC_CTS_FLOW) {
+		if (info->tty->hw_stopped) {
+			if (!(status & SER_CTS)) {
+#if (defined(SERIAL_DEBUG_INTR) || defined(SERIAL_DEBUG_FLOW))
+				printk("CTS tx start...");
+#endif
+				info->tty->hw_stopped = 0;
+				info->IER |= UART_IER_THRI;
+				custom.intena = IF_SETCLR | IF_TBE;
+				mb();
+				/* set a pending Tx Interrupt, transmitter should restart now */
+				custom.intreq = IF_SETCLR | IF_TBE;
+				mb();
+				rs_sched_event(info, RS_EVENT_WRITE_WAKEUP);
+				return;
+			}
+		} else {
+			if ((status & SER_CTS)) {
+#if (defined(SERIAL_DEBUG_INTR) || defined(SERIAL_DEBUG_FLOW))
+				printk("CTS tx stop...");
+#endif
+				info->tty->hw_stopped = 1;
+				info->IER &= ~UART_IER_THRI;
+				/* disable Tx interrupt and remove any pending interrupts */
+				custom.intena = IF_TBE;
+				mb();
+				custom.intreq = IF_TBE;
+				mb();
+			}
+		}
+	}
+}
+
+static irqreturn_t ser_vbl_int( int irq, void *data, struct pt_regs *regs)
+{
+        /* vbl is just a periodic interrupt we tie into to update modem status */
+	struct async_struct * info = IRQ_ports;
+	/*
+	 * TBD - is it better to unregister from this interrupt or to
+	 * ignore it if MSI is clear ?
+	 */
+	if(info->IER & UART_IER_MSI)
+	  check_modem_status(info);
+	return IRQ_HANDLED;
+}
+
+static irqreturn_t ser_rx_int(int irq, void *dev_id, struct pt_regs * regs)
+{
+	struct async_struct * info;
+
+#ifdef SERIAL_DEBUG_INTR
+	printk("ser_rx_int...");
+#endif
+
+	info = IRQ_ports;
+	if (!info || !info->tty)
+		return IRQ_NONE;
+
+	receive_chars(info);
+	info->last_active = jiffies;
+#ifdef SERIAL_DEBUG_INTR
+	printk("end.\n");
+#endif
+	return IRQ_HANDLED;
+}
+
+static irqreturn_t ser_tx_int(int irq, void *dev_id, struct pt_regs * regs)
+{
+	struct async_struct * info;
+
+	if (custom.serdatr & SDR_TBE) {
+#ifdef SERIAL_DEBUG_INTR
+	  printk("ser_tx_int...");
+#endif
+
+	  info = IRQ_ports;
+	  if (!info || !info->tty)
+		return IRQ_NONE;
+
+	  transmit_chars(info);
+	  info->last_active = jiffies;
+#ifdef SERIAL_DEBUG_INTR
+	  printk("end.\n");
+#endif
+	}
+	return IRQ_HANDLED;
+}
+
+/*
+ * -------------------------------------------------------------------
+ * Here ends the serial interrupt routines.
+ * -------------------------------------------------------------------
+ */
+
+/*
+ * This routine is used to handle the "bottom half" processing for the
+ * serial driver, known also the "software interrupt" processing.
+ * This processing is done at the kernel interrupt level, after the
+ * rs_interrupt() has returned, BUT WITH INTERRUPTS TURNED ON.  This
+ * is where time-consuming activities which can not be done in the
+ * interrupt driver proper are done; the interrupt driver schedules
+ * them using rs_sched_event(), and they get done here.
+ */
+
+static void do_softint(unsigned long private_)
+{
+	struct async_struct	*info = (struct async_struct *) private_;
+	struct tty_struct	*tty;
+
+	tty = info->tty;
+	if (!tty)
+		return;
+
+	if (test_and_clear_bit(RS_EVENT_WRITE_WAKEUP, &info->event)) {
+		tty_wakeup(tty);
+		wake_up_interruptible(&tty->write_wait);
+	}
+}
+
+/*
+ * ---------------------------------------------------------------
+ * Low level utility subroutines for the serial driver:  routines to
+ * figure out the appropriate timeout for an interrupt chain, routines
+ * to initialize and startup a serial port, and routines to shutdown a
+ * serial port.  Useful stuff like that.
+ * ---------------------------------------------------------------
+ */
+
+static int startup(struct async_struct * info)
+{
+	unsigned long flags;
+	int	retval=0;
+	unsigned long page;
+
+	page = get_zeroed_page(GFP_KERNEL);
+	if (!page)
+		return -ENOMEM;
+
+	local_irq_save(flags);
+
+	if (info->flags & ASYNC_INITIALIZED) {
+		free_page(page);
+		goto errout;
+	}
+
+	if (info->xmit.buf)
+		free_page(page);
+	else
+		info->xmit.buf = (unsigned char *) page;
+
+#ifdef SERIAL_DEBUG_OPEN
+	printk("starting up ttys%d ...", info->line);
+#endif
+
+	/* Clear anything in the input buffer */
+
+	custom.intreq = IF_RBF;
+	mb();
+
+	retval = request_irq(IRQ_AMIGA_VERTB, ser_vbl_int, 0, "serial status", info);
+	if (retval) {
+	  if (serial_isroot()) {
+	    if (info->tty)
+	      set_bit(TTY_IO_ERROR,
+		      &info->tty->flags);
+	    retval = 0;
+	  }
+	  goto errout;
+	}
+
+	/* enable both Rx and Tx interrupts */
+	custom.intena = IF_SETCLR | IF_RBF | IF_TBE;
+	mb();
+	info->IER = UART_IER_MSI;
+
+	/* remember current state of the DCD and CTS bits */
+	current_ctl_bits = ciab.pra & (SER_DCD | SER_CTS | SER_DSR);
+
+	IRQ_ports = info;
+
+	info->MCR = 0;
+	if (info->tty->termios->c_cflag & CBAUD)
+	  info->MCR = SER_DTR | SER_RTS;
+	rtsdtr_ctrl(info->MCR);
+
+	if (info->tty)
+		clear_bit(TTY_IO_ERROR, &info->tty->flags);
+	info->xmit.head = info->xmit.tail = 0;
+
+	/*
+	 * Set up the tty->alt_speed kludge
+	 */
+	if (info->tty) {
+		if ((info->flags & ASYNC_SPD_MASK) == ASYNC_SPD_HI)
+			info->tty->alt_speed = 57600;
+		if ((info->flags & ASYNC_SPD_MASK) == ASYNC_SPD_VHI)
+			info->tty->alt_speed = 115200;
+		if ((info->flags & ASYNC_SPD_MASK) == ASYNC_SPD_SHI)
+			info->tty->alt_speed = 230400;
+		if ((info->flags & ASYNC_SPD_MASK) == ASYNC_SPD_WARP)
+			info->tty->alt_speed = 460800;
+	}
+
+	/*
+	 * and set the speed of the serial port
+	 */
+	change_speed(info, NULL);
+
+	info->flags |= ASYNC_INITIALIZED;
+	local_irq_restore(flags);
+	return 0;
+
+errout:
+	local_irq_restore(flags);
+	return retval;
+}
+
+/*
+ * This routine will shutdown a serial port; interrupts are disabled, and
+ * DTR is dropped if the hangup on close termio flag is on.
+ */
+static void shutdown(struct async_struct * info)
+{
+	unsigned long	flags;
+	struct serial_state *state;
+
+	if (!(info->flags & ASYNC_INITIALIZED))
+		return;
+
+	state = info->state;
+
+#ifdef SERIAL_DEBUG_OPEN
+	printk("Shutting down serial port %d ....\n", info->line);
+#endif
+
+	local_irq_save(flags); /* Disable interrupts */
+
+	/*
+	 * clear delta_msr_wait queue to avoid mem leaks: we may free the irq
+	 * here so the queue might never be waken up
+	 */
+	wake_up_interruptible(&info->delta_msr_wait);
+
+	IRQ_ports = NULL;
+
+	/*
+	 * Free the IRQ, if necessary
+	 */
+	free_irq(IRQ_AMIGA_VERTB, info);
+
+	if (info->xmit.buf) {
+		free_page((unsigned long) info->xmit.buf);
+		info->xmit.buf = NULL;
+	}
+
+	info->IER = 0;
+	custom.intena = IF_RBF | IF_TBE;
+	mb();
+
+	/* disable break condition */
+	custom.adkcon = AC_UARTBRK;
+	mb();
+
+	if (!info->tty || (info->tty->termios->c_cflag & HUPCL))
+		info->MCR &= ~(SER_DTR|SER_RTS);
+	rtsdtr_ctrl(info->MCR);
+
+	if (info->tty)
+		set_bit(TTY_IO_ERROR, &info->tty->flags);
+
+	info->flags &= ~ASYNC_INITIALIZED;
+	local_irq_restore(flags);
+}
+
+
+/*
+ * This routine is called to set the UART divisor registers to match
+ * the specified baud rate for a serial port.
+ */
+static void change_speed(struct async_struct *info,
+			 struct termios *old_termios)
+{
+	int	quot = 0, baud_base, baud;
+	unsigned cflag, cval = 0;
+	int	bits;
+	unsigned long	flags;
+
+	if (!info->tty || !info->tty->termios)
+		return;
+	cflag = info->tty->termios->c_cflag;
+
+	/* Byte size is always 8 bits plus parity bit if requested */
+
+	cval = 3; bits = 10;
+	if (cflag & CSTOPB) {
+		cval |= 0x04;
+		bits++;
+	}
+	if (cflag & PARENB) {
+		cval |= UART_LCR_PARITY;
+		bits++;
+	}
+	if (!(cflag & PARODD))
+		cval |= UART_LCR_EPAR;
+#ifdef CMSPAR
+	if (cflag & CMSPAR)
+		cval |= UART_LCR_SPAR;
+#endif
+
+	/* Determine divisor based on baud rate */
+	baud = tty_get_baud_rate(info->tty);
+	if (!baud)
+		baud = 9600;	/* B0 transition handled in rs_set_termios */
+	baud_base = info->state->baud_base;
+	if (baud == 38400 &&
+	    ((info->flags & ASYNC_SPD_MASK) == ASYNC_SPD_CUST))
+		quot = info->state->custom_divisor;
+	else {
+		if (baud == 134)
+			/* Special case since 134 is really 134.5 */
+			quot = (2*baud_base / 269);
+		else if (baud)
+			quot = baud_base / baud;
+	}
+	/* If the quotient is zero refuse the change */
+	if (!quot && old_termios) {
+		info->tty->termios->c_cflag &= ~CBAUD;
+		info->tty->termios->c_cflag |= (old_termios->c_cflag & CBAUD);
+		baud = tty_get_baud_rate(info->tty);
+		if (!baud)
+			baud = 9600;
+		if (baud == 38400 &&
+		    ((info->flags & ASYNC_SPD_MASK) == ASYNC_SPD_CUST))
+			quot = info->state->custom_divisor;
+		else {
+			if (baud == 134)
+				/* Special case since 134 is really 134.5 */
+				quot = (2*baud_base / 269);
+			else if (baud)
+				quot = baud_base / baud;
+		}
+	}
+	/* As a last resort, if the quotient is zero, default to 9600 bps */
+	if (!quot)
+		quot = baud_base / 9600;
+	info->quot = quot;
+	info->timeout = ((info->xmit_fifo_size*HZ*bits*quot) / baud_base);
+	info->timeout += HZ/50;		/* Add .02 seconds of slop */
+
+	/* CTS flow control flag and modem status interrupts */
+	info->IER &= ~UART_IER_MSI;
+	if (info->flags & ASYNC_HARDPPS_CD)
+		info->IER |= UART_IER_MSI;
+	if (cflag & CRTSCTS) {
+		info->flags |= ASYNC_CTS_FLOW;
+		info->IER |= UART_IER_MSI;
+	} else
+		info->flags &= ~ASYNC_CTS_FLOW;
+	if (cflag & CLOCAL)
+		info->flags &= ~ASYNC_CHECK_CD;
+	else {
+		info->flags |= ASYNC_CHECK_CD;
+		info->IER |= UART_IER_MSI;
+	}
+	/* TBD:
+	 * Does clearing IER_MSI imply that we should disbale the VBL interrupt ?
+	 */
+
+	/*
+	 * Set up parity check flag
+	 */
+#define RELEVANT_IFLAG(iflag) (iflag & (IGNBRK|BRKINT|IGNPAR|PARMRK|INPCK))
+
+	info->read_status_mask = UART_LSR_OE | UART_LSR_DR;
+	if (I_INPCK(info->tty))
+		info->read_status_mask |= UART_LSR_FE | UART_LSR_PE;
+	if (I_BRKINT(info->tty) || I_PARMRK(info->tty))
+		info->read_status_mask |= UART_LSR_BI;
+
+	/*
+	 * Characters to ignore
+	 */
+	info->ignore_status_mask = 0;
+	if (I_IGNPAR(info->tty))
+		info->ignore_status_mask |= UART_LSR_PE | UART_LSR_FE;
+	if (I_IGNBRK(info->tty)) {
+		info->ignore_status_mask |= UART_LSR_BI;
+		/*
+		 * If we're ignore parity and break indicators, ignore 
+		 * overruns too.  (For real raw support).
+		 */
+		if (I_IGNPAR(info->tty))
+			info->ignore_status_mask |= UART_LSR_OE;
+	}
+	/*
+	 * !!! ignore all characters if CREAD is not set
+	 */
+	if ((cflag & CREAD) == 0)
+		info->ignore_status_mask |= UART_LSR_DR;
+	local_irq_save(flags);
+
+	{
+	  short serper;
+
+	/* Set up the baud rate */
+	  serper = quot - 1;
+
+	/* Enable or disable parity bit */
+
+	if(cval & UART_LCR_PARITY)
+	  serper |= (SERPER_PARENB);
+
+	custom.serper = serper;
+	mb();
+	}
+
+	info->LCR = cval;				/* Save LCR */
+	local_irq_restore(flags);
+}
+
+static void rs_put_char(struct tty_struct *tty, unsigned char ch)
+{
+	struct async_struct *info = (struct async_struct *)tty->driver_data;
+	unsigned long flags;
+
+	if (serial_paranoia_check(info, tty->name, "rs_put_char"))
+		return;
+
+	if (!tty || !info->xmit.buf)
+		return;
+
+	local_irq_save(flags);
+	if (CIRC_SPACE(info->xmit.head,
+		       info->xmit.tail,
+		       SERIAL_XMIT_SIZE) == 0) {
+		local_irq_restore(flags);
+		return;
+	}
+
+	info->xmit.buf[info->xmit.head++] = ch;
+	info->xmit.head &= SERIAL_XMIT_SIZE-1;
+	local_irq_restore(flags);
+}
+
+static void rs_flush_chars(struct tty_struct *tty)
+{
+	struct async_struct *info = (struct async_struct *)tty->driver_data;
+	unsigned long flags;
+
+	if (serial_paranoia_check(info, tty->name, "rs_flush_chars"))
+		return;
+
+	if (info->xmit.head == info->xmit.tail
+	    || tty->stopped
+	    || tty->hw_stopped
+	    || !info->xmit.buf)
+		return;
+
+	local_irq_save(flags);
+	info->IER |= UART_IER_THRI;
+	custom.intena = IF_SETCLR | IF_TBE;
+	mb();
+	/* set a pending Tx Interrupt, transmitter should restart now */
+	custom.intreq = IF_SETCLR | IF_TBE;
+	mb();
+	local_irq_restore(flags);
+}
+
+static int rs_write(struct tty_struct * tty, const unsigned char *buf, int count)
+{
+	int	c, ret = 0;
+	struct async_struct *info = (struct async_struct *)tty->driver_data;
+	unsigned long flags;
+
+	if (serial_paranoia_check(info, tty->name, "rs_write"))
+		return 0;
+
+	if (!tty || !info->xmit.buf || !tmp_buf)
+		return 0;
+
+	local_save_flags(flags);
+	local_irq_disable();
+	while (1) {
+		c = CIRC_SPACE_TO_END(info->xmit.head,
+				      info->xmit.tail,
+				      SERIAL_XMIT_SIZE);
+		if (count < c)
+			c = count;
+		if (c <= 0) {
+			break;
+		}
+		memcpy(info->xmit.buf + info->xmit.head, buf, c);
+		info->xmit.head = ((info->xmit.head + c) &
+				   (SERIAL_XMIT_SIZE-1));
+		buf += c;
+		count -= c;
+		ret += c;
+	}
+	local_irq_restore(flags);
+
+	if (info->xmit.head != info->xmit.tail
+	    && !tty->stopped
+	    && !tty->hw_stopped
+	    && !(info->IER & UART_IER_THRI)) {
+		info->IER |= UART_IER_THRI;
+		local_irq_disable();
+		custom.intena = IF_SETCLR | IF_TBE;
+		mb();
+		/* set a pending Tx Interrupt, transmitter should restart now */
+		custom.intreq = IF_SETCLR | IF_TBE;
+		mb();
+		local_irq_restore(flags);
+	}
+	return ret;
+}
+
+static int rs_write_room(struct tty_struct *tty)
+{
+	struct async_struct *info = (struct async_struct *)tty->driver_data;
+
+	if (serial_paranoia_check(info, tty->name, "rs_write_room"))
+		return 0;
+	return CIRC_SPACE(info->xmit.head, info->xmit.tail, SERIAL_XMIT_SIZE);
+}
+
+static int rs_chars_in_buffer(struct tty_struct *tty)
+{
+	struct async_struct *info = (struct async_struct *)tty->driver_data;
+
+	if (serial_paranoia_check(info, tty->name, "rs_chars_in_buffer"))
+		return 0;
+	return CIRC_CNT(info->xmit.head, info->xmit.tail, SERIAL_XMIT_SIZE);
+}
+
+static void rs_flush_buffer(struct tty_struct *tty)
+{
+	struct async_struct *info = (struct async_struct *)tty->driver_data;
+	unsigned long flags;
+
+	if (serial_paranoia_check(info, tty->name, "rs_flush_buffer"))
+		return;
+	local_irq_save(flags);
+	info->xmit.head = info->xmit.tail = 0;
+	local_irq_restore(flags);
+	wake_up_interruptible(&tty->write_wait);
+	tty_wakeup(tty);
+}
+
+/*
+ * This function is used to send a high-priority XON/XOFF character to
+ * the device
+ */
+static void rs_send_xchar(struct tty_struct *tty, char ch)
+{
+	struct async_struct *info = (struct async_struct *)tty->driver_data;
+        unsigned long flags;
+
+	if (serial_paranoia_check(info, tty->name, "rs_send_char"))
+		return;
+
+	info->x_char = ch;
+	if (ch) {
+		/* Make sure transmit interrupts are on */
+
+	        /* Check this ! */
+	        local_irq_save(flags);
+		if(!(custom.intenar & IF_TBE)) {
+		    custom.intena = IF_SETCLR | IF_TBE;
+		    mb();
+		    /* set a pending Tx Interrupt, transmitter should restart now */
+		    custom.intreq = IF_SETCLR | IF_TBE;
+		    mb();
+		}
+		local_irq_restore(flags);
+
+		info->IER |= UART_IER_THRI;
+	}
+}
+
+/*
+ * ------------------------------------------------------------
+ * rs_throttle()
+ * 
+ * This routine is called by the upper-layer tty layer to signal that
+ * incoming characters should be throttled.
+ * ------------------------------------------------------------
+ */
+static void rs_throttle(struct tty_struct * tty)
+{
+	struct async_struct *info = (struct async_struct *)tty->driver_data;
+	unsigned long flags;
+#ifdef SERIAL_DEBUG_THROTTLE
+	char	buf[64];
+
+	printk("throttle %s: %d....\n", tty_name(tty, buf),
+	       tty->ldisc.chars_in_buffer(tty));
+#endif
+
+	if (serial_paranoia_check(info, tty->name, "rs_throttle"))
+		return;
+
+	if (I_IXOFF(tty))
+		rs_send_xchar(tty, STOP_CHAR(tty));
+
+	if (tty->termios->c_cflag & CRTSCTS)
+		info->MCR &= ~SER_RTS;
+
+	local_irq_save(flags);
+	rtsdtr_ctrl(info->MCR);
+	local_irq_restore(flags);
+}
+
+static void rs_unthrottle(struct tty_struct * tty)
+{
+	struct async_struct *info = (struct async_struct *)tty->driver_data;
+	unsigned long flags;
+#ifdef SERIAL_DEBUG_THROTTLE
+	char	buf[64];
+
+	printk("unthrottle %s: %d....\n", tty_name(tty, buf),
+	       tty->ldisc.chars_in_buffer(tty));
+#endif
+
+	if (serial_paranoia_check(info, tty->name, "rs_unthrottle"))
+		return;
+
+	if (I_IXOFF(tty)) {
+		if (info->x_char)
+			info->x_char = 0;
+		else
+			rs_send_xchar(tty, START_CHAR(tty));
+	}
+	if (tty->termios->c_cflag & CRTSCTS)
+		info->MCR |= SER_RTS;
+	local_irq_save(flags);
+	rtsdtr_ctrl(info->MCR);
+	local_irq_restore(flags);
+}
+
+/*
+ * ------------------------------------------------------------
+ * rs_ioctl() and friends
+ * ------------------------------------------------------------
+ */
+
+static int get_serial_info(struct async_struct * info,
+			   struct serial_struct * retinfo)
+{
+	struct serial_struct tmp;
+	struct serial_state *state = info->state;
+   
+	if (!retinfo)
+		return -EFAULT;
+	memset(&tmp, 0, sizeof(tmp));
+	tmp.type = state->type;
+	tmp.line = state->line;
+	tmp.port = state->port;
+	tmp.irq = state->irq;
+	tmp.flags = state->flags;
+	tmp.xmit_fifo_size = state->xmit_fifo_size;
+	tmp.baud_base = state->baud_base;
+	tmp.close_delay = state->close_delay;
+	tmp.closing_wait = state->closing_wait;
+	tmp.custom_divisor = state->custom_divisor;
+	if (copy_to_user(retinfo,&tmp,sizeof(*retinfo)))
+		return -EFAULT;
+	return 0;
+}
+
+static int set_serial_info(struct async_struct * info,
+			   struct serial_struct * new_info)
+{
+	struct serial_struct new_serial;
+ 	struct serial_state old_state, *state;
+	unsigned int		change_irq,change_port;
+	int 			retval = 0;
+
+	if (copy_from_user(&new_serial,new_info,sizeof(new_serial)))
+		return -EFAULT;
+	state = info->state;
+	old_state = *state;
+  
+	change_irq = new_serial.irq != state->irq;
+	change_port = (new_serial.port != state->port);
+	if(change_irq || change_port || (new_serial.xmit_fifo_size != state->xmit_fifo_size))
+	  return -EINVAL;
+  
+	if (!serial_isroot()) {
+		if ((new_serial.baud_base != state->baud_base) ||
+		    (new_serial.close_delay != state->close_delay) ||
+		    (new_serial.xmit_fifo_size != state->xmit_fifo_size) ||
+		    ((new_serial.flags & ~ASYNC_USR_MASK) !=
+		     (state->flags & ~ASYNC_USR_MASK)))
+			return -EPERM;
+		state->flags = ((state->flags & ~ASYNC_USR_MASK) |
+			       (new_serial.flags & ASYNC_USR_MASK));
+		info->flags = ((info->flags & ~ASYNC_USR_MASK) |
+			       (new_serial.flags & ASYNC_USR_MASK));
+		state->custom_divisor = new_serial.custom_divisor;
+		goto check_and_exit;
+	}
+
+	if (new_serial.baud_base < 9600)
+		return -EINVAL;
+
+	/*
+	 * OK, past this point, all the error checking has been done.
+	 * At this point, we start making changes.....
+	 */
+
+	state->baud_base = new_serial.baud_base;
+	state->flags = ((state->flags & ~ASYNC_FLAGS) |
+			(new_serial.flags & ASYNC_FLAGS));
+	info->flags = ((state->flags & ~ASYNC_INTERNAL_FLAGS) |
+		       (info->flags & ASYNC_INTERNAL_FLAGS));
+	state->custom_divisor = new_serial.custom_divisor;
+	state->close_delay = new_serial.close_delay * HZ/100;
+	state->closing_wait = new_serial.closing_wait * HZ/100;
+	info->tty->low_latency = (info->flags & ASYNC_LOW_LATENCY) ? 1 : 0;
+
+check_and_exit:
+	if (info->flags & ASYNC_INITIALIZED) {
+		if (((old_state.flags & ASYNC_SPD_MASK) !=
+		     (state->flags & ASYNC_SPD_MASK)) ||
+		    (old_state.custom_divisor != state->custom_divisor)) {
+			if ((state->flags & ASYNC_SPD_MASK) == ASYNC_SPD_HI)
+				info->tty->alt_speed = 57600;
+			if ((state->flags & ASYNC_SPD_MASK) == ASYNC_SPD_VHI)
+				info->tty->alt_speed = 115200;
+			if ((state->flags & ASYNC_SPD_MASK) == ASYNC_SPD_SHI)
+				info->tty->alt_speed = 230400;
+			if ((state->flags & ASYNC_SPD_MASK) == ASYNC_SPD_WARP)
+				info->tty->alt_speed = 460800;
+			change_speed(info, NULL);
+		}
+	} else
+		retval = startup(info);
+	return retval;
+}
+
+
+/*
+ * get_lsr_info - get line status register info
+ *
+ * Purpose: Let user call ioctl() to get info when the UART physically
+ * 	    is emptied.  On bus types like RS485, the transmitter must
+ * 	    release the bus after transmitting. This must be done when
+ * 	    the transmit shift register is empty, not be done when the
+ * 	    transmit holding register is empty.  This functionality
+ * 	    allows an RS485 driver to be written in user space. 
+ */
+static int get_lsr_info(struct async_struct * info, unsigned int *value)
+{
+	unsigned char status;
+	unsigned int result;
+	unsigned long flags;
+
+	local_irq_save(flags);
+	status = custom.serdatr;
+	mb();
+	local_irq_restore(flags);
+	result = ((status & SDR_TSRE) ? TIOCSER_TEMT : 0);
+	if (copy_to_user(value, &result, sizeof(int)))
+		return -EFAULT;
+	return 0;
+}
+
+
+static int rs_tiocmget(struct tty_struct *tty, struct file *file)
+{
+	struct async_struct * info = (struct async_struct *)tty->driver_data;
+	unsigned char control, status;
+	unsigned long flags;
+
+	if (serial_paranoia_check(info, tty->name, "rs_ioctl"))
+		return -ENODEV;
+	if (tty->flags & (1 << TTY_IO_ERROR))
+		return -EIO;
+
+	control = info->MCR;
+	local_irq_save(flags);
+	status = ciab.pra;
+	local_irq_restore(flags);
+	return    ((control & SER_RTS) ? TIOCM_RTS : 0)
+		| ((control & SER_DTR) ? TIOCM_DTR : 0)
+		| (!(status  & SER_DCD) ? TIOCM_CAR : 0)
+		| (!(status  & SER_DSR) ? TIOCM_DSR : 0)
+		| (!(status  & SER_CTS) ? TIOCM_CTS : 0);
+}
+
+static int rs_tiocmset(struct tty_struct *tty, struct file *file,
+		       unsigned int set, unsigned int clear)
+{
+	struct async_struct * info = (struct async_struct *)tty->driver_data;
+	unsigned long flags;
+
+	if (serial_paranoia_check(info, tty->name, "rs_ioctl"))
+		return -ENODEV;
+	if (tty->flags & (1 << TTY_IO_ERROR))
+		return -EIO;
+
+	local_irq_save(flags);
+	if (set & TIOCM_RTS)
+		info->MCR |= SER_RTS;
+	if (set & TIOCM_DTR)
+		info->MCR |= SER_DTR;
+	if (clear & TIOCM_RTS)
+		info->MCR &= ~SER_RTS;
+	if (clear & TIOCM_DTR)
+		info->MCR &= ~SER_DTR;
+	rtsdtr_ctrl(info->MCR);
+	local_irq_restore(flags);
+	return 0;
+}
+
+/*
+ * rs_break() --- routine which turns the break handling on or off
+ */
+static void rs_break(struct tty_struct *tty, int break_state)
+{
+	struct async_struct * info = (struct async_struct *)tty->driver_data;
+	unsigned long flags;
+
+	if (serial_paranoia_check(info, tty->name, "rs_break"))
+		return;
+
+	local_irq_save(flags);
+	if (break_state == -1)
+	  custom.adkcon = AC_SETCLR | AC_UARTBRK;
+	else
+	  custom.adkcon = AC_UARTBRK;
+	mb();
+	local_irq_restore(flags);
+}
+
+
+static int rs_ioctl(struct tty_struct *tty, struct file * file,
+		    unsigned int cmd, unsigned long arg)
+{
+	struct async_struct * info = (struct async_struct *)tty->driver_data;
+	struct async_icount cprev, cnow;	/* kernel counter temps */
+	struct serial_icounter_struct icount;
+	unsigned long flags;
+
+	if (serial_paranoia_check(info, tty->name, "rs_ioctl"))
+		return -ENODEV;
+
+	if ((cmd != TIOCGSERIAL) && (cmd != TIOCSSERIAL) &&
+	    (cmd != TIOCSERCONFIG) && (cmd != TIOCSERGSTRUCT) &&
+	    (cmd != TIOCMIWAIT) && (cmd != TIOCGICOUNT)) {
+		if (tty->flags & (1 << TTY_IO_ERROR))
+		    return -EIO;
+	}
+
+	switch (cmd) {
+		case TIOCGSERIAL:
+			return get_serial_info(info,
+					       (struct serial_struct *) arg);
+		case TIOCSSERIAL:
+			return set_serial_info(info,
+					       (struct serial_struct *) arg);
+		case TIOCSERCONFIG:
+			return 0;
+
+		case TIOCSERGETLSR: /* Get line status register */
+			return get_lsr_info(info, (unsigned int *) arg);
+
+		case TIOCSERGSTRUCT:
+			if (copy_to_user((struct async_struct *) arg,
+					 info, sizeof(struct async_struct)))
+				return -EFAULT;
+			return 0;
+
+		/*
+		 * Wait for any of the 4 modem inputs (DCD,RI,DSR,CTS) to change
+		 * - mask passed in arg for lines of interest
+ 		 *   (use |'ed TIOCM_RNG/DSR/CD/CTS for masking)
+		 * Caller should use TIOCGICOUNT to see which one it was
+		 */
+		case TIOCMIWAIT:
+			local_irq_save(flags);
+			/* note the counters on entry */
+			cprev = info->state->icount;
+			local_irq_restore(flags);
+			while (1) {
+				interruptible_sleep_on(&info->delta_msr_wait);
+				/* see if a signal did it */
+				if (signal_pending(current))
+					return -ERESTARTSYS;
+				local_irq_save(flags);
+				cnow = info->state->icount; /* atomic copy */
+				local_irq_restore(flags);
+				if (cnow.rng == cprev.rng && cnow.dsr == cprev.dsr && 
+				    cnow.dcd == cprev.dcd && cnow.cts == cprev.cts)
+					return -EIO; /* no change => error */
+				if ( ((arg & TIOCM_RNG) && (cnow.rng != cprev.rng)) ||
+				     ((arg & TIOCM_DSR) && (cnow.dsr != cprev.dsr)) ||
+				     ((arg & TIOCM_CD)  && (cnow.dcd != cprev.dcd)) ||
+				     ((arg & TIOCM_CTS) && (cnow.cts != cprev.cts)) ) {
+					return 0;
+				}
+				cprev = cnow;
+			}
+			/* NOTREACHED */
+
+		/* 
+		 * Get counter of input serial line interrupts (DCD,RI,DSR,CTS)
+		 * Return: write counters to the user passed counter struct
+		 * NB: both 1->0 and 0->1 transitions are counted except for
+		 *     RI where only 0->1 is counted.
+		 */
+		case TIOCGICOUNT:
+			local_irq_save(flags);
+			cnow = info->state->icount;
+			local_irq_restore(flags);
+			icount.cts = cnow.cts;
+			icount.dsr = cnow.dsr;
+			icount.rng = cnow.rng;
+			icount.dcd = cnow.dcd;
+			icount.rx = cnow.rx;
+			icount.tx = cnow.tx;
+			icount.frame = cnow.frame;
+			icount.overrun = cnow.overrun;
+			icount.parity = cnow.parity;
+			icount.brk = cnow.brk;
+			icount.buf_overrun = cnow.buf_overrun;
+
+			if (copy_to_user((void *)arg, &icount, sizeof(icount)))
+				return -EFAULT;
+			return 0;
+		case TIOCSERGWILD:
+		case TIOCSERSWILD:
+			/* "setserial -W" is called in Debian boot */
+			printk ("TIOCSER?WILD ioctl obsolete, ignored.\n");
+			return 0;
+
+		default:
+			return -ENOIOCTLCMD;
+		}
+	return 0;
+}
+
+static void rs_set_termios(struct tty_struct *tty, struct termios *old_termios)
+{
+	struct async_struct *info = (struct async_struct *)tty->driver_data;
+	unsigned long flags;
+	unsigned int cflag = tty->termios->c_cflag;
+
+	if (   (cflag == old_termios->c_cflag)
+	    && (   RELEVANT_IFLAG(tty->termios->c_iflag) 
+		== RELEVANT_IFLAG(old_termios->c_iflag)))
+	  return;
+
+	change_speed(info, old_termios);
+
+	/* Handle transition to B0 status */
+	if ((old_termios->c_cflag & CBAUD) &&
+	    !(cflag & CBAUD)) {
+		info->MCR &= ~(SER_DTR|SER_RTS);
+		local_irq_save(flags);
+		rtsdtr_ctrl(info->MCR);
+		local_irq_restore(flags);
+	}
+
+	/* Handle transition away from B0 status */
+	if (!(old_termios->c_cflag & CBAUD) &&
+	    (cflag & CBAUD)) {
+		info->MCR |= SER_DTR;
+		if (!(tty->termios->c_cflag & CRTSCTS) || 
+		    !test_bit(TTY_THROTTLED, &tty->flags)) {
+			info->MCR |= SER_RTS;
+		}
+		local_irq_save(flags);
+		rtsdtr_ctrl(info->MCR);
+		local_irq_restore(flags);
+	}
+
+	/* Handle turning off CRTSCTS */
+	if ((old_termios->c_cflag & CRTSCTS) &&
+	    !(tty->termios->c_cflag & CRTSCTS)) {
+		tty->hw_stopped = 0;
+		rs_start(tty);
+	}
+
+#if 0
+	/*
+	 * No need to wake up processes in open wait, since they
+	 * sample the CLOCAL flag once, and don't recheck it.
+	 * XXX  It's not clear whether the current behavior is correct
+	 * or not.  Hence, this may change.....
+	 */
+	if (!(old_termios->c_cflag & CLOCAL) &&
+	    (tty->termios->c_cflag & CLOCAL))
+		wake_up_interruptible(&info->open_wait);
+#endif
+}
+
+/*
+ * ------------------------------------------------------------
+ * rs_close()
+ * 
+ * This routine is called when the serial port gets closed.  First, we
+ * wait for the last remaining data to be sent.  Then, we unlink its
+ * async structure from the interrupt chain if necessary, and we free
+ * that IRQ if nothing is left in the chain.
+ * ------------------------------------------------------------
+ */
+static void rs_close(struct tty_struct *tty, struct file * filp)
+{
+	struct async_struct * info = (struct async_struct *)tty->driver_data;
+	struct serial_state *state;
+	unsigned long flags;
+
+	if (!info || serial_paranoia_check(info, tty->name, "rs_close"))
+		return;
+
+	state = info->state;
+
+	local_irq_save(flags);
+
+	if (tty_hung_up_p(filp)) {
+		DBG_CNT("before DEC-hung");
+		local_irq_restore(flags);
+		return;
+	}
+
+#ifdef SERIAL_DEBUG_OPEN
+	printk("rs_close ttys%d, count = %d\n", info->line, state->count);
+#endif
+	if ((tty->count == 1) && (state->count != 1)) {
+		/*
+		 * Uh, oh.  tty->count is 1, which means that the tty
+		 * structure will be freed.  state->count should always
+		 * be one in these conditions.  If it's greater than
+		 * one, we've got real problems, since it means the
+		 * serial port won't be shutdown.
+		 */
+		printk("rs_close: bad serial port count; tty->count is 1, "
+		       "state->count is %d\n", state->count);
+		state->count = 1;
+	}
+	if (--state->count < 0) {
+		printk("rs_close: bad serial port count for ttys%d: %d\n",
+		       info->line, state->count);
+		state->count = 0;
+	}
+	if (state->count) {
+		DBG_CNT("before DEC-2");
+		local_irq_restore(flags);
+		return;
+	}
+	info->flags |= ASYNC_CLOSING;
+	/*
+	 * Now we wait for the transmit buffer to clear; and we notify 
+	 * the line discipline to only process XON/XOFF characters.
+	 */
+	tty->closing = 1;
+	if (info->closing_wait != ASYNC_CLOSING_WAIT_NONE)
+		tty_wait_until_sent(tty, info->closing_wait);
+	/*
+	 * At this point we stop accepting input.  To do this, we
+	 * disable the receive line status interrupts, and tell the
+	 * interrupt driver to stop checking the data ready bit in the
+	 * line status register.
+	 */
+	info->read_status_mask &= ~UART_LSR_DR;
+	if (info->flags & ASYNC_INITIALIZED) {
+	        /* disable receive interrupts */
+	        custom.intena = IF_RBF;
+		mb();
+		/* clear any pending receive interrupt */
+		custom.intreq = IF_RBF;
+		mb();
+
+		/*
+		 * Before we drop DTR, make sure the UART transmitter
+		 * has completely drained; this is especially
+		 * important if there is a transmit FIFO!
+		 */
+		rs_wait_until_sent(tty, info->timeout);
+	}
+	shutdown(info);
+	if (tty->driver->flush_buffer)
+		tty->driver->flush_buffer(tty);
+		
+	tty_ldisc_flush(tty);
+	tty->closing = 0;
+	info->event = 0;
+	info->tty = NULL;
+	if (info->blocked_open) {
+		if (info->close_delay) {
+			msleep_interruptible(jiffies_to_msecs(info->close_delay));
+		}
+		wake_up_interruptible(&info->open_wait);
+	}
+	info->flags &= ~(ASYNC_NORMAL_ACTIVE|ASYNC_CLOSING);
+	wake_up_interruptible(&info->close_wait);
+	local_irq_restore(flags);
+}
+
+/*
+ * rs_wait_until_sent() --- wait until the transmitter is empty
+ */
+static void rs_wait_until_sent(struct tty_struct *tty, int timeout)
+{
+	struct async_struct * info = (struct async_struct *)tty->driver_data;
+	unsigned long orig_jiffies, char_time;
+	int lsr;
+
+	if (serial_paranoia_check(info, tty->name, "rs_wait_until_sent"))
+		return;
+
+	if (info->xmit_fifo_size == 0)
+		return; /* Just in case.... */
+
+	orig_jiffies = jiffies;
+	/*
+	 * Set the check interval to be 1/5 of the estimated time to
+	 * send a single character, and make it at least 1.  The check
+	 * interval should also be less than the timeout.
+	 * 
+	 * Note: we have to use pretty tight timings here to satisfy
+	 * the NIST-PCTS.
+	 */
+	char_time = (info->timeout - HZ/50) / info->xmit_fifo_size;
+	char_time = char_time / 5;
+	if (char_time == 0)
+		char_time = 1;
+	if (timeout)
+	  char_time = min_t(unsigned long, char_time, timeout);
+	/*
+	 * If the transmitter hasn't cleared in twice the approximate
+	 * amount of time to send the entire FIFO, it probably won't
+	 * ever clear.  This assumes the UART isn't doing flow
+	 * control, which is currently the case.  Hence, if it ever
+	 * takes longer than info->timeout, this is probably due to a
+	 * UART bug of some kind.  So, we clamp the timeout parameter at
+	 * 2*info->timeout.
+	 */
+	if (!timeout || timeout > 2*info->timeout)
+		timeout = 2*info->timeout;
+#ifdef SERIAL_DEBUG_RS_WAIT_UNTIL_SENT
+	printk("In rs_wait_until_sent(%d) check=%lu...", timeout, char_time);
+	printk("jiff=%lu...", jiffies);
+#endif
+	while(!((lsr = custom.serdatr) & SDR_TSRE)) {
+#ifdef SERIAL_DEBUG_RS_WAIT_UNTIL_SENT
+		printk("serdatr = %d (jiff=%lu)...", lsr, jiffies);
+#endif
+		msleep_interruptible(jiffies_to_msecs(char_time));
+		if (signal_pending(current))
+			break;
+		if (timeout && time_after(jiffies, orig_jiffies + timeout))
+			break;
+	}
+	current->state = TASK_RUNNING;
+#ifdef SERIAL_DEBUG_RS_WAIT_UNTIL_SENT
+	printk("lsr = %d (jiff=%lu)...done\n", lsr, jiffies);
+#endif
+}
+
+/*
+ * rs_hangup() --- called by tty_hangup() when a hangup is signaled.
+ */
+static void rs_hangup(struct tty_struct *tty)
+{
+	struct async_struct * info = (struct async_struct *)tty->driver_data;
+	struct serial_state *state = info->state;
+
+	if (serial_paranoia_check(info, tty->name, "rs_hangup"))
+		return;
+
+	state = info->state;
+
+	rs_flush_buffer(tty);
+	shutdown(info);
+	info->event = 0;
+	state->count = 0;
+	info->flags &= ~ASYNC_NORMAL_ACTIVE;
+	info->tty = NULL;
+	wake_up_interruptible(&info->open_wait);
+}
+
+/*
+ * ------------------------------------------------------------
+ * rs_open() and friends
+ * ------------------------------------------------------------
+ */
+static int block_til_ready(struct tty_struct *tty, struct file * filp,
+			   struct async_struct *info)
+{
+#ifdef DECLARE_WAITQUEUE
+	DECLARE_WAITQUEUE(wait, current);
+#else
+	struct wait_queue wait = { current, NULL };
+#endif
+	struct serial_state *state = info->state;
+	int		retval;
+	int		do_clocal = 0, extra_count = 0;
+	unsigned long	flags;
+
+	/*
+	 * If the device is in the middle of being closed, then block
+	 * until it's done, and then try again.
+	 */
+	if (tty_hung_up_p(filp) ||
+	    (info->flags & ASYNC_CLOSING)) {
+		if (info->flags & ASYNC_CLOSING)
+			interruptible_sleep_on(&info->close_wait);
+#ifdef SERIAL_DO_RESTART
+		return ((info->flags & ASYNC_HUP_NOTIFY) ?
+			-EAGAIN : -ERESTARTSYS);
+#else
+		return -EAGAIN;
+#endif
+	}
+
+	/*
+	 * If non-blocking mode is set, or the port is not enabled,
+	 * then make the check up front and then exit.
+	 */
+	if ((filp->f_flags & O_NONBLOCK) ||
+	    (tty->flags & (1 << TTY_IO_ERROR))) {
+		info->flags |= ASYNC_NORMAL_ACTIVE;
+		return 0;
+	}
+
+	if (tty->termios->c_cflag & CLOCAL)
+		do_clocal = 1;
+
+	/*
+	 * Block waiting for the carrier detect and the line to become
+	 * free (i.e., not in use by the callout).  While we are in
+	 * this loop, state->count is dropped by one, so that
+	 * rs_close() knows when to free things.  We restore it upon
+	 * exit, either normal or abnormal.
+	 */
+	retval = 0;
+	add_wait_queue(&info->open_wait, &wait);
+#ifdef SERIAL_DEBUG_OPEN
+	printk("block_til_ready before block: ttys%d, count = %d\n",
+	       state->line, state->count);
+#endif
+	local_irq_save(flags);
+	if (!tty_hung_up_p(filp)) {
+		extra_count = 1;
+		state->count--;
+	}
+	local_irq_restore(flags);
+	info->blocked_open++;
+	while (1) {
+		local_irq_save(flags);
+		if (tty->termios->c_cflag & CBAUD)
+		        rtsdtr_ctrl(SER_DTR|SER_RTS);
+		local_irq_restore(flags);
+		set_current_state(TASK_INTERRUPTIBLE);
+		if (tty_hung_up_p(filp) ||
+		    !(info->flags & ASYNC_INITIALIZED)) {
+#ifdef SERIAL_DO_RESTART
+			if (info->flags & ASYNC_HUP_NOTIFY)
+				retval = -EAGAIN;
+			else
+				retval = -ERESTARTSYS;
+#else
+			retval = -EAGAIN;
+#endif
+			break;
+		}
+		if (!(info->flags & ASYNC_CLOSING) &&
+		    (do_clocal || (!(ciab.pra & SER_DCD)) ))
+			break;
+		if (signal_pending(current)) {
+			retval = -ERESTARTSYS;
+			break;
+		}
+#ifdef SERIAL_DEBUG_OPEN
+		printk("block_til_ready blocking: ttys%d, count = %d\n",
+		       info->line, state->count);
+#endif
+		schedule();
+	}
+	current->state = TASK_RUNNING;
+	remove_wait_queue(&info->open_wait, &wait);
+	if (extra_count)
+		state->count++;
+	info->blocked_open--;
+#ifdef SERIAL_DEBUG_OPEN
+	printk("block_til_ready after blocking: ttys%d, count = %d\n",
+	       info->line, state->count);
+#endif
+	if (retval)
+		return retval;
+	info->flags |= ASYNC_NORMAL_ACTIVE;
+	return 0;
+}
+
+static int get_async_struct(int line, struct async_struct **ret_info)
+{
+	struct async_struct *info;
+	struct serial_state *sstate;
+
+	sstate = rs_table + line;
+	sstate->count++;
+	if (sstate->info) {
+		*ret_info = sstate->info;
+		return 0;
+	}
+	info = kmalloc(sizeof(struct async_struct), GFP_KERNEL);
+	if (!info) {
+		sstate->count--;
+		return -ENOMEM;
+	}
+	memset(info, 0, sizeof(struct async_struct));
+#ifdef DECLARE_WAITQUEUE
+	init_waitqueue_head(&info->open_wait);
+	init_waitqueue_head(&info->close_wait);
+	init_waitqueue_head(&info->delta_msr_wait);
+#endif
+	info->magic = SERIAL_MAGIC;
+	info->port = sstate->port;
+	info->flags = sstate->flags;
+	info->xmit_fifo_size = sstate->xmit_fifo_size;
+	info->line = line;
+	tasklet_init(&info->tlet, do_softint, (unsigned long)info);
+	info->state = sstate;
+	if (sstate->info) {
+		kfree(info);
+		*ret_info = sstate->info;
+		return 0;
+	}
+	*ret_info = sstate->info = info;
+	return 0;
+}
+
+/*
+ * This routine is called whenever a serial port is opened.  It
+ * enables interrupts for a serial port, linking in its async structure into
+ * the IRQ chain.   It also performs the serial-specific
+ * initialization for the tty structure.
+ */
+static int rs_open(struct tty_struct *tty, struct file * filp)
+{
+	struct async_struct	*info;
+	int 			retval, line;
+	unsigned long		page;
+
+	line = tty->index;
+	if ((line < 0) || (line >= NR_PORTS)) {
+		return -ENODEV;
+	}
+	retval = get_async_struct(line, &info);
+	if (retval) {
+		return retval;
+	}
+	tty->driver_data = info;
+	info->tty = tty;
+	if (serial_paranoia_check(info, tty->name, "rs_open"))
+		return -ENODEV;
+
+#ifdef SERIAL_DEBUG_OPEN
+	printk("rs_open %s, count = %d\n", tty->name, info->state->count);
+#endif
+	info->tty->low_latency = (info->flags & ASYNC_LOW_LATENCY) ? 1 : 0;
+
+	if (!tmp_buf) {
+		page = get_zeroed_page(GFP_KERNEL);
+		if (!page) {
+			return -ENOMEM;
+		}
+		if (tmp_buf)
+			free_page(page);
+		else
+			tmp_buf = (unsigned char *) page;
+	}
+
+	/*
+	 * If the port is the middle of closing, bail out now
+	 */
+	if (tty_hung_up_p(filp) ||
+	    (info->flags & ASYNC_CLOSING)) {
+		if (info->flags & ASYNC_CLOSING)
+			interruptible_sleep_on(&info->close_wait);
+#ifdef SERIAL_DO_RESTART
+		return ((info->flags & ASYNC_HUP_NOTIFY) ?
+			-EAGAIN : -ERESTARTSYS);
+#else
+		return -EAGAIN;
+#endif
+	}
+
+	/*
+	 * Start up serial port
+	 */
+	retval = startup(info);
+	if (retval) {
+		return retval;
+	}
+
+	retval = block_til_ready(tty, filp, info);
+	if (retval) {
+#ifdef SERIAL_DEBUG_OPEN
+		printk("rs_open returning after block_til_ready with %d\n",
+		       retval);
+#endif
+		return retval;
+	}
+
+#ifdef SERIAL_DEBUG_OPEN
+	printk("rs_open %s successful...", tty->name);
+#endif
+	return 0;
+}
+
+/*
+ * /proc fs routines....
+ */
+
+static inline int line_info(char *buf, struct serial_state *state)
+{
+	struct async_struct *info = state->info, scr_info;
+	char	stat_buf[30], control, status;
+	int	ret;
+	unsigned long flags;
+
+	ret = sprintf(buf, "%d: uart:amiga_builtin",state->line);
+
+	/*
+	 * Figure out the current RS-232 lines
+	 */
+	if (!info) {
+		info = &scr_info;	/* This is just for serial_{in,out} */
+
+		info->magic = SERIAL_MAGIC;
+		info->flags = state->flags;
+		info->quot = 0;
+		info->tty = NULL;
+	}
+	local_irq_save(flags);
+	status = ciab.pra;
+	control = info ? info->MCR : status;
+	local_irq_restore(flags);
+
+	stat_buf[0] = 0;
+	stat_buf[1] = 0;
+	if(!(control & SER_RTS))
+		strcat(stat_buf, "|RTS");
+	if(!(status & SER_CTS))
+		strcat(stat_buf, "|CTS");
+	if(!(control & SER_DTR))
+		strcat(stat_buf, "|DTR");
+	if(!(status & SER_DSR))
+		strcat(stat_buf, "|DSR");
+	if(!(status & SER_DCD))
+		strcat(stat_buf, "|CD");
+
+	if (info->quot) {
+		ret += sprintf(buf+ret, " baud:%d",
+			       state->baud_base / info->quot);
+	}
+
+	ret += sprintf(buf+ret, " tx:%d rx:%d",
+		      state->icount.tx, state->icount.rx);
+
+	if (state->icount.frame)
+		ret += sprintf(buf+ret, " fe:%d", state->icount.frame);
+
+	if (state->icount.parity)
+		ret += sprintf(buf+ret, " pe:%d", state->icount.parity);
+
+	if (state->icount.brk)
+		ret += sprintf(buf+ret, " brk:%d", state->icount.brk);
+
+	if (state->icount.overrun)
+		ret += sprintf(buf+ret, " oe:%d", state->icount.overrun);
+
+	/*
+	 * Last thing is the RS-232 status lines
+	 */
+	ret += sprintf(buf+ret, " %s\n", stat_buf+1);
+	return ret;
+}
+
+static int rs_read_proc(char *page, char **start, off_t off, int count,
+			int *eof, void *data)
+{
+	int len = 0, l;
+	off_t	begin = 0;
+
+	len += sprintf(page, "serinfo:1.0 driver:%s\n", serial_version);
+	l = line_info(page + len, &rs_table[0]);
+	len += l;
+	if (len+begin > off+count)
+	  goto done;
+	if (len+begin < off) {
+	  begin += len;
+	  len = 0;
+	}
+	*eof = 1;
+done:
+	if (off >= len+begin)
+		return 0;
+	*start = page + (off-begin);
+	return ((count < begin+len-off) ? count : begin+len-off);
+}
+
+/*
+ * ---------------------------------------------------------------------
+ * rs_init() and friends
+ *
+ * rs_init() is called at boot-time to initialize the serial driver.
+ * ---------------------------------------------------------------------
+ */
+
+/*
+ * This routine prints out the appropriate serial driver version
+ * number, and identifies which options were configured into this
+ * driver.
+ */
+static _INLINE_ void show_serial_version(void)
+{
+ 	printk(KERN_INFO "%s version %s\n", serial_name, serial_version);
+}
+
+
+int register_serial(struct serial_struct *req);
+void unregister_serial(int line);
+
+
+static struct tty_operations serial_ops = {
+	.open = rs_open,
+	.close = rs_close,
+	.write = rs_write,
+	.put_char = rs_put_char,
+	.flush_chars = rs_flush_chars,
+	.write_room = rs_write_room,
+	.chars_in_buffer = rs_chars_in_buffer,
+	.flush_buffer = rs_flush_buffer,
+	.ioctl = rs_ioctl,
+	.throttle = rs_throttle,
+	.unthrottle = rs_unthrottle,
+	.set_termios = rs_set_termios,
+	.stop = rs_stop,
+	.start = rs_start,
+	.hangup = rs_hangup,
+	.break_ctl = rs_break,
+	.send_xchar = rs_send_xchar,
+	.wait_until_sent = rs_wait_until_sent,
+	.read_proc = rs_read_proc,
+	.tiocmget = rs_tiocmget,
+	.tiocmset = rs_tiocmset,
+};
+
+/*
+ * The serial driver boot-time initialization code!
+ */
+static int __init rs_init(void)
+{
+	unsigned long flags;
+	struct serial_state * state;
+
+	if (!MACH_IS_AMIGA || !AMIGAHW_PRESENT(AMI_SERIAL))
+		return -ENODEV;
+
+	serial_driver = alloc_tty_driver(1);
+	if (!serial_driver)
+		return -ENOMEM;
+
+	/*
+	 *  We request SERDAT and SERPER only, because the serial registers are
+	 *  too spreaded over the custom register space
+	 */
+	if (!request_mem_region(CUSTOM_PHYSADDR+0x30, 4, "amiserial [Paula]"))
+		return -EBUSY;
+
+	IRQ_ports = NULL;
+
+	show_serial_version();
+
+	/* Initialize the tty_driver structure */
+
+	serial_driver->owner = THIS_MODULE;
+	serial_driver->driver_name = "amiserial";
+	serial_driver->name = "ttyS";
+	serial_driver->major = TTY_MAJOR;
+	serial_driver->minor_start = 64;
+	serial_driver->type = TTY_DRIVER_TYPE_SERIAL;
+	serial_driver->subtype = SERIAL_TYPE_NORMAL;
+	serial_driver->init_termios = tty_std_termios;
+	serial_driver->init_termios.c_cflag =
+		B9600 | CS8 | CREAD | HUPCL | CLOCAL;
+	serial_driver->flags = TTY_DRIVER_REAL_RAW;
+	tty_set_operations(serial_driver, &serial_ops);
+
+	if (tty_register_driver(serial_driver))
+		panic("Couldn't register serial driver\n");
+
+	state = rs_table;
+	state->magic = SSTATE_MAGIC;
+	state->port = (int)&custom.serdatr; /* Just to give it a value */
+	state->line = 0;
+	state->custom_divisor = 0;
+	state->close_delay = 5*HZ/10;
+	state->closing_wait = 30*HZ;
+	state->icount.cts = state->icount.dsr = 
+	  state->icount.rng = state->icount.dcd = 0;
+	state->icount.rx = state->icount.tx = 0;
+	state->icount.frame = state->icount.parity = 0;
+	state->icount.overrun = state->icount.brk = 0;
+	/*
+	if(state->port && check_region(state->port,REGION_LENGTH(state)))
+	  continue;
+	*/
+
+	printk(KERN_INFO "ttyS%d is the amiga builtin serial port\n",
+		       state->line);
+
+	/* Hardware set up */
+
+	state->baud_base = amiga_colorclock;
+	state->xmit_fifo_size = 1;
+
+	local_irq_save(flags);
+
+	/* set ISRs, and then disable the rx interrupts */
+	request_irq(IRQ_AMIGA_TBE, ser_tx_int, 0, "serial TX", state);
+	request_irq(IRQ_AMIGA_RBF, ser_rx_int, SA_INTERRUPT, "serial RX", state);
+
+	/* turn off Rx and Tx interrupts */
+	custom.intena = IF_RBF | IF_TBE;
+	mb();
+
+	/* clear any pending interrupt */
+	custom.intreq = IF_RBF | IF_TBE;
+	mb();
+
+	local_irq_restore(flags);
+
+	/*
+	 * set the appropriate directions for the modem control flags,
+	 * and clear RTS and DTR
+	 */
+	ciab.ddra |= (SER_DTR | SER_RTS);   /* outputs */
+	ciab.ddra &= ~(SER_DCD | SER_CTS | SER_DSR);  /* inputs */
+
+	return 0;
+}
+
+static __exit void rs_exit(void) 
+{
+	int error;
+	struct async_struct *info = rs_table[0].info;
+
+	/* printk("Unloading %s: version %s\n", serial_name, serial_version); */
+	tasklet_kill(&info->tlet);
+	if ((error = tty_unregister_driver(serial_driver)))
+		printk("SERIAL: failed to unregister serial driver (%d)\n",
+		       error);
+	put_tty_driver(serial_driver);
+
+	if (info) {
+	  rs_table[0].info = NULL;
+	  kfree(info);
+	}
+
+	if (tmp_buf) {
+		free_page((unsigned long) tmp_buf);
+		tmp_buf = NULL;
+	}
+
+	release_mem_region(CUSTOM_PHYSADDR+0x30, 4);
+}
+
+module_init(rs_init)
+module_exit(rs_exit)
+
+
+/*
+ * ------------------------------------------------------------
+ * Serial console driver
+ * ------------------------------------------------------------
+ */
+#ifdef CONFIG_SERIAL_CONSOLE
+
+static void amiga_serial_putc(char c)
+{
+	custom.serdat = (unsigned char)c | 0x100;
+	while (!(custom.serdatr & 0x2000))
+		barrier();
+}
+
+/*
+ *	Print a string to the serial port trying not to disturb
+ *	any possible real use of the port...
+ *
+ *	The console must be locked when we get here.
+ */
+static void serial_console_write(struct console *co, const char *s,
+				unsigned count)
+{
+	unsigned short intena = custom.intenar;
+
+	custom.intena = IF_TBE;
+
+	while (count--) {
+		if (*s == '\n')
+			amiga_serial_putc('\r');
+		amiga_serial_putc(*s++);
+	}
+
+	custom.intena = IF_SETCLR | (intena & IF_TBE);
+}
+
+static struct tty_driver *serial_console_device(struct console *c, int *index)
+{
+	*index = 0;
+	return serial_driver;
+}
+
+static struct console sercons = {
+	.name =		"ttyS",
+	.write =	serial_console_write,
+	.device =	serial_console_device,
+	.flags =	CON_PRINTBUFFER,
+	.index =	-1,
+};
+
+/*
+ *	Register console.
+ */
+static int __init amiserial_console_init(void)
+{
+	register_console(&sercons);
+	return 0;
+}
+console_initcall(amiserial_console_init);
+#endif
+
+MODULE_LICENSE("GPL");