/*

   * dz.c: Serial port driver for DECstations equipped

   *       with the DZ chipset.
   *

   * Copyright (C) 1998 Olivier A. D. Lebaillif
   *

   * Email: olivier.lebaillif@ifrsys.com
   *

   * Copyright (C) 2004, 2006  Maciej W. Rozycki
   *

   * [31-AUG-98] triemer
   * Changed IRQ to use Harald's dec internals interrupts.h
   * removed base_addr code - moving address assignment to setup.c
   * Changed name of dz_init to rs_init to be consistent with tc code
   * [13-NOV-98] triemer fixed code to receive characters

   *    after patches by harald to irq code.

   * [09-JAN-99] triemer minor fix for schedule - due to removal of timeout
   *            field from "current" - somewhere between 2.1.121 and 2.1.131
   Qua Jun 27 15:02:26 BRT 2001
   * [27-JUN-2001] Arnaldo Carvalho de Melo <acme@conectiva.com.br> - cleanups

   *
   * Parts (C) 1999 David Airlie, airlied@linux.ie
   * [07-SEP-99] Bugfixes

   *
   * [06-Jan-2002] Russell King <rmk@arm.linux.org.uk>
   * Converted to new serial core
   */
  
  #undef DEBUG_DZ

  #if defined(CONFIG_SERIAL_DZ_CONSOLE) && defined(CONFIG_MAGIC_SYSRQ)
  #define SUPPORT_SYSRQ
  #endif
  
  #include <linux/delay.h>

  #include <linux/module.h>
  #include <linux/interrupt.h>
  #include <linux/init.h>
  #include <linux/console.h>

  #include <linux/sysrq.h>

  #include <linux/tty.h>
  #include <linux/tty_flip.h>
  #include <linux/serial_core.h>
  #include <linux/serial.h>
  
  #include <asm/bootinfo.h>
  #include <asm/dec/interrupts.h>
  #include <asm/dec/kn01.h>
  #include <asm/dec/kn02.h>
  #include <asm/dec/machtype.h>
  #include <asm/dec/prom.h>
  #include <asm/irq.h>
  #include <asm/system.h>
  #include <asm/uaccess.h>

  #include "dz.h"

  static char *dz_name = "DECstation DZ serial driver version ";

  static char *dz_version = "1.03";

  
  struct dz_port {
  	struct uart_port	port;
  	unsigned int		cflag;
  };
  
  static struct dz_port dz_ports[DZ_NB_PORT];

  /*
   * ------------------------------------------------------------
   * dz_in () and dz_out ()
   *

   * These routines are used to access the registers of the DZ

   * chip, hiding relocation differences between implementation.
   * ------------------------------------------------------------
   */
  
  static inline unsigned short dz_in(struct dz_port *dport, unsigned offset)
  {
  	volatile unsigned short *addr =
  		(volatile unsigned short *) (dport->port.membase + offset);

  	return *addr;
  }
  
  static inline void dz_out(struct dz_port *dport, unsigned offset,
                            unsigned short value)
  {
  	volatile unsigned short *addr =
  		(volatile unsigned short *) (dport->port.membase + offset);

  	*addr = value;
  }
  
  /*
   * ------------------------------------------------------------
   * rs_stop () and rs_start ()
   *

   * These routines are called before setting or resetting
   * tty->stopped. They enable or disable transmitter interrupts,

   * as necessary.
   * ------------------------------------------------------------
   */

  static void dz_stop_tx(struct uart_port *uport)

  {
  	struct dz_port *dport = (struct dz_port *)uport;
  	unsigned short tmp, mask = 1 << dport->port.line;
  	unsigned long flags;
  
  	spin_lock_irqsave(&dport->port.lock, flags);
  	tmp = dz_in(dport, DZ_TCR);	/* read the TX flag */
  	tmp &= ~mask;			/* clear the TX flag */
  	dz_out(dport, DZ_TCR, tmp);
  	spin_unlock_irqrestore(&dport->port.lock, flags);
  }

  static void dz_start_tx(struct uart_port *uport)

  {
  	struct dz_port *dport = (struct dz_port *)uport;
  	unsigned short tmp, mask = 1 << dport->port.line;
  	unsigned long flags;
  
  	spin_lock_irqsave(&dport->port.lock, flags);
  	tmp = dz_in(dport, DZ_TCR);	/* read the TX flag */
  	tmp |= mask;			/* set the TX flag */
  	dz_out(dport, DZ_TCR, tmp);
  	spin_unlock_irqrestore(&dport->port.lock, flags);
  }
  
  static void dz_stop_rx(struct uart_port *uport)
  {
  	struct dz_port *dport = (struct dz_port *)uport;
  	unsigned long flags;
  
  	spin_lock_irqsave(&dport->port.lock, flags);
  	dport->cflag &= ~DZ_CREAD;

  	dz_out(dport, DZ_LPR, dport->cflag | dport->port.line);

  	spin_unlock_irqrestore(&dport->port.lock, flags);
  }
  
  static void dz_enable_ms(struct uart_port *port)
  {
  	/* nothing to do */
  }
  
  /*
   * ------------------------------------------------------------

   *

   * Here start the interrupt handling routines.  All of the following
   * subroutines are declared as inline and are folded into
   * dz_interrupt.  They were separated out for readability's sake.
   *
   * Note: dz_interrupt() is a "fast" interrupt, which means that it

   * runs with interrupts turned off.  People who may want to modify

   * dz_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:

   *

   *	make drivers/serial/dz.s
   *
   * and look at the resulting assemble code in dz.s.
   *
   * ------------------------------------------------------------
   */
  
  /*
   * ------------------------------------------------------------
   * receive_char ()
   *
   * This routine deals with inputs from any lines.
   * ------------------------------------------------------------
   */

  static inline void dz_receive_chars(struct dz_port *dport_in)

  {

  	struct dz_port *dport;

  	struct tty_struct *tty = NULL;
  	struct uart_icount *icount;

  	int lines_rx[DZ_NB_PORT] = { [0 ... DZ_NB_PORT - 1] = 0 };
  	unsigned short status;

  	unsigned char ch, flag;

  	int i;

  	while ((status = dz_in(dport_in, DZ_RBUF)) & DZ_DVAL) {
  		dport = &dz_ports[LINE(status)];
  		tty = dport->port.info->tty;	/* point to the proper dev */

  		ch = UCHAR(status);		/* grab the char */

  		icount = &dport->port.icount;

  		icount->rx++;

  		flag = TTY_NORMAL;
  		if (status & DZ_FERR) {		/* frame error */
  			/*
  			 * There is no separate BREAK status bit, so
  			 * treat framing errors as BREAKs for Magic SysRq
  			 * and SAK; normally, otherwise.

  			 */

  			if (uart_handle_break(&dport->port))
  				continue;
  			if (dport->port.flags & UPF_SAK)
  				flag = TTY_BREAK;
  			else

  				flag = TTY_FRAME;

  		} else if (status & DZ_OERR)	/* overrun error */
  			flag = TTY_OVERRUN;
  		else if (status & DZ_PERR)	/* parity error */
  			flag = TTY_PARITY;
  
  		/* keep track of the statistics */
  		switch (flag) {
  		case TTY_FRAME:
  			icount->frame++;
  			break;
  		case TTY_PARITY:
  			icount->parity++;
  			break;
  		case TTY_OVERRUN:
  			icount->overrun++;
  			break;
  		case TTY_BREAK:
  			icount->brk++;
  			break;
  		default:
  			break;

  		}

  		if (uart_handle_sysrq_char(&dport->port, ch))

  			continue;
  
  		if ((status & dport->port.ignore_status_mask) == 0) {
  			uart_insert_char(&dport->port,
  					 status, DZ_OERR, ch, flag);
  			lines_rx[LINE(status)] = 1;
  		}
  	}
  	for (i = 0; i < DZ_NB_PORT; i++)
  		if (lines_rx[i])
  			tty_flip_buffer_push(dz_ports[i].port.info->tty);

  }
  
  /*
   * ------------------------------------------------------------
   * transmit_char ()
   *
   * This routine deals with outputs to any lines.
   * ------------------------------------------------------------
   */

  static inline void dz_transmit_chars(struct dz_port *dport_in)

  {

  	struct dz_port *dport;
  	struct circ_buf *xmit;
  	unsigned short status;

  	unsigned char tmp;

  	status = dz_in(dport_in, DZ_CSR);
  	dport = &dz_ports[LINE(status)];
  	xmit = &dport->port.info->xmit;
  
  	if (dport->port.x_char) {		/* XON/XOFF chars */

  		dz_out(dport, DZ_TDR, dport->port.x_char);
  		dport->port.icount.tx++;
  		dport->port.x_char = 0;
  		return;
  	}

  	/* If nothing to do or stopped or hardware stopped. */

  	if (uart_circ_empty(xmit) || uart_tx_stopped(&dport->port)) {

  		dz_stop_tx(&dport->port);

  		return;
  	}
  
  	/*

  	 * If something to do... (remember the dz has no output fifo,
  	 * so we go one char at a time) :-<

  	 */
  	tmp = xmit->buf[xmit->tail];
  	xmit->tail = (xmit->tail + 1) & (DZ_XMIT_SIZE - 1);
  	dz_out(dport, DZ_TDR, tmp);
  	dport->port.icount.tx++;
  
  	if (uart_circ_chars_pending(xmit) < DZ_WAKEUP_CHARS)
  		uart_write_wakeup(&dport->port);

  	/* Are we are done. */

  	if (uart_circ_empty(xmit))

  		dz_stop_tx(&dport->port);

  }
  
  /*
   * ------------------------------------------------------------

   * check_modem_status()

   *

   * DS 3100 & 5100: Only valid for the MODEM line, duh!
   * DS 5000/200: Valid for the MODEM and PRINTER line.

   * ------------------------------------------------------------
   */
  static inline void check_modem_status(struct dz_port *dport)
  {

  	/*
  	 * FIXME:
  	 * 1. No status change interrupt; use a timer.
  	 * 2. Handle the 3100/5000 as appropriate. --macro
  	 */

  	unsigned short status;

  	/* If not the modem line just return.  */

  	if (dport->port.line != DZ_MODEM)
  		return;
  
  	status = dz_in(dport, DZ_MSR);
  
  	/* it's easy, since DSR2 is the only bit in the register */
  	if (status)
  		dport->port.icount.dsr++;
  }
  
  /*
   * ------------------------------------------------------------
   * dz_interrupt ()
   *
   * this is the main interrupt routine for the DZ chip.
   * It deals with the multiple ports.
   * ------------------------------------------------------------
   */

  static irqreturn_t dz_interrupt(int irq, void *dev)

  {

  	struct dz_port *dport = (struct dz_port *)dev;

  	unsigned short status;
  
  	/* get the reason why we just got an irq */

  	status = dz_in(dport, DZ_CSR);

  	if ((status & (DZ_RDONE | DZ_RIE)) == (DZ_RDONE | DZ_RIE))

  		dz_receive_chars(dport);

  	if ((status & (DZ_TRDY | DZ_TIE)) == (DZ_TRDY | DZ_TIE))

  		dz_transmit_chars(dport);

  	return IRQ_HANDLED;
  }
  
  /*
   * -------------------------------------------------------------------
   * Here ends the DZ interrupt routines.
   * -------------------------------------------------------------------
   */
  
  static unsigned int dz_get_mctrl(struct uart_port *uport)
  {

  	/*
  	 * FIXME: Handle the 3100/5000 as appropriate. --macro
  	 */

  	struct dz_port *dport = (struct dz_port *)uport;
  	unsigned int mctrl = TIOCM_CAR | TIOCM_DSR | TIOCM_CTS;
  
  	if (dport->port.line == DZ_MODEM) {

  		if (dz_in(dport, DZ_MSR) & DZ_MODEM_DSR)
  			mctrl &= ~TIOCM_DSR;
  	}
  
  	return mctrl;
  }
  
  static void dz_set_mctrl(struct uart_port *uport, unsigned int mctrl)
  {

  	/*
  	 * FIXME: Handle the 3100/5000 as appropriate. --macro
  	 */

  	struct dz_port *dport = (struct dz_port *)uport;
  	unsigned short tmp;
  
  	if (dport->port.line == DZ_MODEM) {
  		tmp = dz_in(dport, DZ_TCR);
  		if (mctrl & TIOCM_DTR)
  			tmp &= ~DZ_MODEM_DTR;
  		else
  			tmp |= DZ_MODEM_DTR;
  		dz_out(dport, DZ_TCR, tmp);
  	}
  }
  
  /*
   * -------------------------------------------------------------------
   * startup ()
   *
   * various initialization tasks

   * -------------------------------------------------------------------

   */
  static int dz_startup(struct uart_port *uport)
  {
  	struct dz_port *dport = (struct dz_port *)uport;
  	unsigned long flags;
  	unsigned short tmp;

  	spin_lock_irqsave(&dport->port.lock, flags);
  
  	/* enable the interrupt and the scanning */
  	tmp = dz_in(dport, DZ_CSR);
  	tmp |= DZ_RIE | DZ_TIE | DZ_MSE;
  	dz_out(dport, DZ_CSR, tmp);
  
  	spin_unlock_irqrestore(&dport->port.lock, flags);
  
  	return 0;
  }

  /*

   * -------------------------------------------------------------------
   * shutdown ()
   *
   * 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 dz_shutdown(struct uart_port *uport)
  {

  	dz_stop_tx(uport);

  }
  
  /*

   * -------------------------------------------------------------------
   * dz_tx_empty() -- get the transmitter empty status

   *
   * 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 unsigned int dz_tx_empty(struct uart_port *uport)
  {
  	struct dz_port *dport = (struct dz_port *)uport;

  	unsigned short tmp, mask = 1 << dport->port.line;

  	tmp = dz_in(dport, DZ_TCR);
  	tmp &= mask;
  
  	return tmp ? 0 : TIOCSER_TEMT;

  }
  
  static void dz_break_ctl(struct uart_port *uport, int break_state)
  {

  	/*
  	 * FIXME: Can't access BREAK bits in TDR easily;
  	 * reuse the code for polled TX. --macro
  	 */

  	struct dz_port *dport = (struct dz_port *)uport;
  	unsigned long flags;

  	unsigned short tmp, mask = 1 << dport->port.line;

  
  	spin_lock_irqsave(&uport->lock, flags);
  	tmp = dz_in(dport, DZ_TCR);
  	if (break_state)
  		tmp |= mask;
  	else
  		tmp &= ~mask;
  	dz_out(dport, DZ_TCR, tmp);
  	spin_unlock_irqrestore(&uport->lock, flags);
  }

  static void dz_set_termios(struct uart_port *uport, struct ktermios *termios,
  			   struct ktermios *old_termios)

  {
  	struct dz_port *dport = (struct dz_port *)uport;
  	unsigned long flags;
  	unsigned int cflag, baud;
  
  	cflag = dport->port.line;
  
  	switch (termios->c_cflag & CSIZE) {
  	case CS5:
  		cflag |= DZ_CS5;
  		break;
  	case CS6:
  		cflag |= DZ_CS6;
  		break;
  	case CS7:
  		cflag |= DZ_CS7;
  		break;
  	case CS8:
  	default:
  		cflag |= DZ_CS8;
  	}
  
  	if (termios->c_cflag & CSTOPB)
  		cflag |= DZ_CSTOPB;
  	if (termios->c_cflag & PARENB)
  		cflag |= DZ_PARENB;
  	if (termios->c_cflag & PARODD)
  		cflag |= DZ_PARODD;
  
  	baud = uart_get_baud_rate(uport, termios, old_termios, 50, 9600);
  	switch (baud) {
  	case 50:
  		cflag |= DZ_B50;
  		break;
  	case 75:
  		cflag |= DZ_B75;
  		break;
  	case 110:
  		cflag |= DZ_B110;
  		break;
  	case 134:
  		cflag |= DZ_B134;
  		break;
  	case 150:
  		cflag |= DZ_B150;
  		break;
  	case 300:
  		cflag |= DZ_B300;
  		break;
  	case 600:
  		cflag |= DZ_B600;
  		break;
  	case 1200:
  		cflag |= DZ_B1200;
  		break;
  	case 1800:
  		cflag |= DZ_B1800;
  		break;
  	case 2000:
  		cflag |= DZ_B2000;
  		break;
  	case 2400:
  		cflag |= DZ_B2400;
  		break;
  	case 3600:
  		cflag |= DZ_B3600;
  		break;
  	case 4800:
  		cflag |= DZ_B4800;
  		break;
  	case 7200:
  		cflag |= DZ_B7200;
  		break;
  	case 9600:
  	default:
  		cflag |= DZ_B9600;
  	}
  
  	if (termios->c_cflag & CREAD)
  		cflag |= DZ_RXENAB;
  
  	spin_lock_irqsave(&dport->port.lock, flags);

  	dz_out(dport, DZ_LPR, cflag | dport->port.line);

  	dport->cflag = cflag;
  
  	/* setup accept flag */
  	dport->port.read_status_mask = DZ_OERR;
  	if (termios->c_iflag & INPCK)
  		dport->port.read_status_mask |= DZ_FERR | DZ_PERR;
  
  	/* characters to ignore */
  	uport->ignore_status_mask = 0;
  	if (termios->c_iflag & IGNPAR)
  		dport->port.ignore_status_mask |= DZ_FERR | DZ_PERR;
  
  	spin_unlock_irqrestore(&dport->port.lock, flags);
  }
  
  static const char *dz_type(struct uart_port *port)
  {
  	return "DZ";
  }
  
  static void dz_release_port(struct uart_port *port)
  {
  	/* nothing to do */
  }
  
  static int dz_request_port(struct uart_port *port)
  {
  	return 0;
  }
  
  static void dz_config_port(struct uart_port *port, int flags)
  {
  	if (flags & UART_CONFIG_TYPE)
  		port->type = PORT_DZ;
  }
  
  /*
   * verify the new serial_struct (for TIOCSSERIAL).
   */
  static int dz_verify_port(struct uart_port *port, struct serial_struct *ser)
  {
  	int ret = 0;
  	if (ser->type != PORT_UNKNOWN && ser->type != PORT_DZ)
  		ret = -EINVAL;
  	if (ser->irq != port->irq)
  		ret = -EINVAL;
  	return ret;
  }
  
  static struct uart_ops dz_ops = {
  	.tx_empty	= dz_tx_empty,
  	.get_mctrl	= dz_get_mctrl,
  	.set_mctrl	= dz_set_mctrl,
  	.stop_tx	= dz_stop_tx,
  	.start_tx	= dz_start_tx,
  	.stop_rx	= dz_stop_rx,
  	.enable_ms	= dz_enable_ms,
  	.break_ctl	= dz_break_ctl,
  	.startup	= dz_startup,
  	.shutdown	= dz_shutdown,
  	.set_termios	= dz_set_termios,
  	.type		= dz_type,
  	.release_port	= dz_release_port,
  	.request_port	= dz_request_port,
  	.config_port	= dz_config_port,
  	.verify_port	= dz_verify_port,
  };
  
  static void __init dz_init_ports(void)
  {
  	static int first = 1;
  	struct dz_port *dport;
  	unsigned long base;
  	int i;
  
  	if (!first)
  		return;
  	first = 0;
  
  	if (mips_machtype == MACH_DS23100 ||
  	    mips_machtype == MACH_DS5100)

  		base = CKSEG1ADDR(KN01_SLOT_BASE + KN01_DZ11);

  	else

  		base = CKSEG1ADDR(KN02_SLOT_BASE + KN02_DZ11);

  
  	for (i = 0, dport = dz_ports; i < DZ_NB_PORT; i++, dport++) {
  		spin_lock_init(&dport->port.lock);
  		dport->port.membase	= (char *) base;

  		dport->port.iotype	= UPIO_MEM;

  		dport->port.irq		= dec_interrupt[DEC_IRQ_DZ11];
  		dport->port.line	= i;
  		dport->port.fifosize	= 1;
  		dport->port.ops		= &dz_ops;
  		dport->port.flags	= UPF_BOOT_AUTOCONF;
  	}
  }
  
  static void dz_reset(struct dz_port *dport)
  {
  	dz_out(dport, DZ_CSR, DZ_CLR);

  	while (dz_in(dport, DZ_CSR) & DZ_CLR);

  	iob();
  
  	/* enable scanning */
  	dz_out(dport, DZ_CSR, DZ_MSE);
  }
  
  #ifdef CONFIG_SERIAL_DZ_CONSOLE

  /*
   * -------------------------------------------------------------------
   * dz_console_putchar() -- transmit a character
   *
   * Polled transmission.  This is tricky.  We need to mask transmit
   * interrupts so that they do not interfere, enable the transmitter
   * for the line requested and then wait till the transmit scanner
   * requests data for this line.  But it may request data for another
   * line first, in which case we have to disable its transmitter and
   * repeat waiting till our line pops up.  Only then the character may
   * be transmitted.  Finally, the state of the transmitter mask is
   * restored.  Welcome to the world of PDP-11!
   * -------------------------------------------------------------------
   */

  static void dz_console_putchar(struct uart_port *uport, int ch)

  {

  	struct dz_port *dport = (struct dz_port *)uport;

  	unsigned long flags;

  	unsigned short csr, tcr, trdy, mask;
  	int loops = 10000;

  
  	spin_lock_irqsave(&dport->port.lock, flags);

  	csr = dz_in(dport, DZ_CSR);
  	dz_out(dport, DZ_CSR, csr & ~DZ_TIE);
  	tcr = dz_in(dport, DZ_TCR);
  	tcr |= 1 << dport->port.line;
  	mask = tcr;
  	dz_out(dport, DZ_TCR, mask);
  	iob();
  	spin_unlock_irqrestore(&dport->port.lock, flags);

  	while (loops--) {
  		trdy = dz_in(dport, DZ_CSR);
  		if (!(trdy & DZ_TRDY))
  			continue;
  		trdy = (trdy & DZ_TLINE) >> 8;
  		if (trdy == dport->port.line)
  			break;
  		mask &= ~(1 << trdy);
  		dz_out(dport, DZ_TCR, mask);
  		iob();
  		udelay(2);
  	}

  	if (loops)				/* Cannot send otherwise. */
  		dz_out(dport, DZ_TDR, ch);

  	dz_out(dport, DZ_TCR, tcr);
  	dz_out(dport, DZ_CSR, csr);

  }

  /*

   * -------------------------------------------------------------------
   * dz_console_print ()
   *
   * dz_console_print is registered for printk.
   * The console must be locked when we get here.

   * -------------------------------------------------------------------

   */

  static void dz_console_print(struct console *co,

  			     const char *str,
  			     unsigned int count)
  {

  	struct dz_port *dport = &dz_ports[co->index];

  #ifdef DEBUG_DZ
  	prom_printf((char *) str);
  #endif

  	uart_console_write(&dport->port, str, count, dz_console_putchar);

  }
  
  static int __init dz_console_setup(struct console *co, char *options)
  {

  	struct dz_port *dport = &dz_ports[co->index];

  	int baud = 9600;
  	int bits = 8;
  	int parity = 'n';
  	int flow = 'n';

  
  	if (options)
  		uart_parse_options(options, &baud, &parity, &bits, &flow);
  
  	dz_reset(dport);

  	return uart_set_options(&dport->port, co, baud, parity, bits, flow);

  }

  static struct uart_driver dz_reg;
  static struct console dz_sercons = {

  	.name	= "ttyS",
  	.write	= dz_console_print,
  	.device	= uart_console_device,
  	.setup	= dz_console_setup,

  	.flags	= CON_PRINTBUFFER,
  	.index	= -1,
  	.data	= &dz_reg,

  };

  static int __init dz_serial_console_init(void)

  {

  	if (!IOASIC) {
  		dz_init_ports();
  		register_console(&dz_sercons);
  		return 0;
  	} else
  		return -ENXIO;

  }

  console_initcall(dz_serial_console_init);

  #define SERIAL_DZ_CONSOLE	&dz_sercons
  #else
  #define SERIAL_DZ_CONSOLE	NULL
  #endif /* CONFIG_SERIAL_DZ_CONSOLE */
  
  static struct uart_driver dz_reg = {
  	.owner			= THIS_MODULE,
  	.driver_name		= "serial",

  	.dev_name		= "ttyS",

  	.major			= TTY_MAJOR,
  	.minor			= 64,
  	.nr			= DZ_NB_PORT,
  	.cons			= SERIAL_DZ_CONSOLE,
  };

  static int __init dz_init(void)

  {

  	int ret, i;

  	if (IOASIC)
  		return -ENXIO;

  	printk("%s%s
  ", dz_name, dz_version);
  
  	dz_init_ports();

  #ifndef CONFIG_SERIAL_DZ_CONSOLE
  	/* reset the chip */
  	dz_reset(&dz_ports[0]);
  #endif

  	if (request_irq(dz_ports[0].port.irq, dz_interrupt,

  			IRQF_DISABLED, "DZ", &dz_ports[0]))

  		panic("Unable to register DZ interrupt");
  
  	ret = uart_register_driver(&dz_reg);
  	if (ret != 0)
  		return ret;
  
  	for (i = 0; i < DZ_NB_PORT; i++)
  		uart_add_one_port(&dz_reg, &dz_ports[i].port);
  
  	return ret;
  }

  module_init(dz_init);

  MODULE_DESCRIPTION("DECstation DZ serial driver");
  MODULE_LICENSE("GPL");