drivers/net/hamradio/baycom_ser_fdx.c - kernel/msm-4.19 - Gitiles

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

 /*
  *	baycom_ser_fdx.c  -- baycom ser12 fullduplex radio modem driver.
  *
  *	Copyright (C) 1996-2000  Thomas Sailer (sailer@ife.ee.ethz.ch)
  *
  *	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.
  *
  *	This program is distributed in the hope that it will be useful,
  *	but WITHOUT ANY WARRANTY; without even the implied warranty of
  *	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  *	GNU General Public License for more details.
  *
  *	You should have received a copy of the GNU General Public License
  *	along with this program; if not, write to the Free Software
  *	Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  *
  *  Please note that the GPL allows you to use the driver, NOT the radio.
  *  In order to use the radio, you need a license from the communications
  *  authority of your country.
  *
  *
  *  Supported modems
  *
  *  ser12:  This is a very simple 1200 baud AFSK modem. The modem consists only
  *          of a modulator/demodulator chip, usually a TI TCM3105. The computer
  *          is responsible for regenerating the receiver bit clock, as well as
  *          for handling the HDLC protocol. The modem connects to a serial port,
  *          hence the name. Since the serial port is not used as an async serial
  *          port, the kernel driver for serial ports cannot be used, and this
  *          driver only supports standard serial hardware (8250, 16450, 16550A)
  *
  *          This modem usually draws its supply current out of the otherwise unused
  *          TXD pin of the serial port. Thus a contiguous stream of 0x00-bytes
  *          is transmitted to achieve a positive supply voltage.
  *
  *  hsk:    This is a 4800 baud FSK modem, designed for TNC use. It works fine
  *          in 'baycom-mode' :-)  In contrast to the TCM3105 modem, power is
  *          externally supplied. So there's no need to provide the 0x00-byte-stream
  *          when receiving or idle, which drastically reduces interrupt load.
  *
  *  Command line options (insmod command line)
  *
  *  mode     ser#    hardware DCD
  *           ser#*   software DCD
  *           ser#+   hardware DCD, inverted signal at DCD pin
  *           '#' denotes the baud rate / 100, eg. ser12* is '1200 baud, soft DCD'
  *  iobase   base address of the port; common values are 0x3f8, 0x2f8, 0x3e8, 0x2e8
  *  baud     baud rate (between 300 and 4800)
  *  irq      interrupt line of the port; common values are 4,3
  *
  *
  *  History:
  *   0.1  26.06.1996  Adapted from baycom.c and made network driver interface
  *        18.10.1996  Changed to new user space access routines (copy_{to,from}_user)
  *   0.3  26.04.1997  init code/data tagged
  *   0.4  08.07.1997  alternative ser12 decoding algorithm (uses delta CTS ints)
  *   0.5  11.11.1997  ser12/par96 split into separate files
  *   0.6  24.01.1998  Thorsten Kranzkowski, dl8bcu and Thomas Sailer:
  *                    reduced interrupt load in transmit case
  *                    reworked receiver
  *   0.7  03.08.1999  adapt to Linus' new __setup/__initcall
  *   0.8  10.08.1999  use module_init/module_exit
  *   0.9  12.02.2000  adapted to softnet driver interface
  *   0.10 03.07.2000  fix interface name handling
  */

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

 #include <linux/capability.h>
 #include <linux/module.h>
 #include <linux/ioport.h>
 #include <linux/string.h>
 #include <linux/init.h>
 #include <linux/hdlcdrv.h>
 #include <linux/baycom.h>
 #include <linux/jiffies.h>

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

 /* --------------------------------------------------------------------- */

 #define BAYCOM_DEBUG

 /* --------------------------------------------------------------------- */

 static const char bc_drvname[] = "baycom_ser_fdx";
 static const char bc_drvinfo[] = KERN_INFO "baycom_ser_fdx: (C) 1996-2000 Thomas Sailer, HB9JNX/AE4WA\n"
 "baycom_ser_fdx: version 0.10\n";

 /* --------------------------------------------------------------------- */

 #define NR_PORTS 4

 static struct net_device *baycom_device[NR_PORTS];

 /* --------------------------------------------------------------------- */

 #define RBR(iobase) (iobase+0)
 #define THR(iobase) (iobase+0)
 #define IER(iobase) (iobase+1)
 #define IIR(iobase) (iobase+2)
 #define FCR(iobase) (iobase+2)
 #define LCR(iobase) (iobase+3)
 #define MCR(iobase) (iobase+4)
 #define LSR(iobase) (iobase+5)
 #define MSR(iobase) (iobase+6)
 #define SCR(iobase) (iobase+7)
 #define DLL(iobase) (iobase+0)
 #define DLM(iobase) (iobase+1)

 #define SER12_EXTENT 8

 /* ---------------------------------------------------------------------- */
 /*
  * Information that need to be kept for each board.
  */

 struct baycom_state {
 	struct hdlcdrv_state hdrv;

 	unsigned int baud, baud_us, baud_arbdiv, baud_uartdiv, baud_dcdtimeout;
 	int opt_dcd;

 	struct modem_state {
 		unsigned char flags;
 		unsigned char ptt;
 		unsigned int shreg;
 		struct modem_state_ser12 {
 			unsigned char tx_bit;
 			unsigned char last_rxbit;
 			int dcd_sum0, dcd_sum1, dcd_sum2;
 			int dcd_time;
 			unsigned int pll_time;
 			unsigned int txshreg;
 		} ser12;
 	} modem;

 #ifdef BAYCOM_DEBUG
 	struct debug_vals {
 		unsigned long last_jiffies;
 		unsigned cur_intcnt;
 		unsigned last_intcnt;
 		int cur_pllcorr;
 		int last_pllcorr;
 	} debug_vals;
 #endif /* BAYCOM_DEBUG */
 };

 /* --------------------------------------------------------------------- */

 static inline void baycom_int_freq(struct baycom_state *bc)
 {
 #ifdef BAYCOM_DEBUG
 	unsigned long cur_jiffies = jiffies;
 	/*
 	 * measure the interrupt frequency
 	 */
 	bc->debug_vals.cur_intcnt++;
 	if (time_after_eq(cur_jiffies, bc->debug_vals.last_jiffies + HZ)) {
 		bc->debug_vals.last_jiffies = cur_jiffies;
 		bc->debug_vals.last_intcnt = bc->debug_vals.cur_intcnt;
 		bc->debug_vals.cur_intcnt = 0;
 		bc->debug_vals.last_pllcorr = bc->debug_vals.cur_pllcorr;
 		bc->debug_vals.cur_pllcorr = 0;
 	}
 #endif /* BAYCOM_DEBUG */
 }

 /* --------------------------------------------------------------------- */
 /*
  * ===================== SER12 specific routines =========================
  */

 /* --------------------------------------------------------------------- */

 static inline void ser12_set_divisor(struct net_device *dev,
                                      unsigned int divisor)
 {
         outb(0x81, LCR(dev->base_addr));        /* DLAB = 1 */
         outb(divisor, DLL(dev->base_addr));
         outb(divisor >> 8, DLM(dev->base_addr));
         outb(0x01, LCR(dev->base_addr));        /* word length = 6 */
         /*
          * make sure the next interrupt is generated;
          * 0 must be used to power the modem; the modem draws its
          * power from the TxD line
          */
         outb(0x00, THR(dev->base_addr));
         /*
          * it is important not to set the divider while transmitting;
          * this reportedly makes some UARTs generating interrupts
          * in the hundredthousands per second region
          * Reported by: Ignacio.Arenaza@studi.epfl.ch (Ignacio Arenaza Nuno)
          */
 }

 /* --------------------------------------------------------------------- */

 #if 0
 static inline unsigned int hweight16(unsigned int w)
         __attribute__ ((unused));
 static inline unsigned int hweight8(unsigned int w)
         __attribute__ ((unused));

 static inline unsigned int hweight16(unsigned int w)
 {
         unsigned short res = (w & 0x5555) + ((w >> 1) & 0x5555);
         res = (res & 0x3333) + ((res >> 2) & 0x3333);
         res = (res & 0x0F0F) + ((res >> 4) & 0x0F0F);
         return (res & 0x00FF) + ((res >> 8) & 0x00FF);
 }

 static inline unsigned int hweight8(unsigned int w)
 {
         unsigned short res = (w & 0x55) + ((w >> 1) & 0x55);
         res = (res & 0x33) + ((res >> 2) & 0x33);
         return (res & 0x0F) + ((res >> 4) & 0x0F);
 }
 #endif

 /* --------------------------------------------------------------------- */

 static __inline__ void ser12_rx(struct net_device *dev, struct baycom_state *bc, struct timeval *tv, unsigned char curs)
 {
 	int timediff;
 	int bdus8 = bc->baud_us >> 3;
 	int bdus4 = bc->baud_us >> 2;
 	int bdus2 = bc->baud_us >> 1;

 	timediff = 1000000 + tv->tv_usec - bc->modem.ser12.pll_time;
 	while (timediff >= 500000)
 		timediff -= 1000000;
 	while (timediff >= bdus2) {
 		timediff -= bc->baud_us;
 		bc->modem.ser12.pll_time += bc->baud_us;
 		bc->modem.ser12.dcd_time--;
 		/* first check if there is room to add a bit */
 		if (bc->modem.shreg & 1) {
 			hdlcdrv_putbits(&bc->hdrv, (bc->modem.shreg >> 1) ^ 0xffff);
 			bc->modem.shreg = 0x10000;
 		}
 		/* add a one bit */
 		bc->modem.shreg >>= 1;
 	}
 	if (bc->modem.ser12.dcd_time <= 0) {
 		if (!bc->opt_dcd)
 			hdlcdrv_setdcd(&bc->hdrv, (bc->modem.ser12.dcd_sum0 +
 						   bc->modem.ser12.dcd_sum1 +
 						   bc->modem.ser12.dcd_sum2) < 0);
 		bc->modem.ser12.dcd_sum2 = bc->modem.ser12.dcd_sum1;
 		bc->modem.ser12.dcd_sum1 = bc->modem.ser12.dcd_sum0;
 		bc->modem.ser12.dcd_sum0 = 2; /* slight bias */
 		bc->modem.ser12.dcd_time += 120;
 	}
 	if (bc->modem.ser12.last_rxbit != curs) {
 		bc->modem.ser12.last_rxbit = curs;
 		bc->modem.shreg |= 0x10000;
 		/* adjust the PLL */
 		if (timediff > 0)
 			bc->modem.ser12.pll_time += bdus8;
 		else
 			bc->modem.ser12.pll_time += 1000000 - bdus8;
 		/* update DCD */
 		if (abs(timediff) > bdus4)
 			bc->modem.ser12.dcd_sum0 += 4;
 		else
 			bc->modem.ser12.dcd_sum0--;
 #ifdef BAYCOM_DEBUG
 		bc->debug_vals.cur_pllcorr = timediff;
 #endif /* BAYCOM_DEBUG */
 	}
 	while (bc->modem.ser12.pll_time >= 1000000)
 		bc->modem.ser12.pll_time -= 1000000;
 }

 /* --------------------------------------------------------------------- */

 static irqreturn_t ser12_interrupt(int irq, void *dev_id)
 {
 	struct net_device *dev = (struct net_device *)dev_id;
 	struct baycom_state *bc = netdev_priv(dev);
 	struct timeval tv;
 	unsigned char iir, msr;
 	unsigned int txcount = 0;

 	if (!bc || bc->hdrv.magic != HDLCDRV_MAGIC)
 		return IRQ_NONE;
 	/* fast way out for shared irq */
 	if ((iir = inb(IIR(dev->base_addr))) & 1)
 		return IRQ_NONE;
 	/* get current time */
 	do_gettimeofday(&tv);
 	msr = inb(MSR(dev->base_addr));
 	/* delta DCD */
 	if ((msr & 8) && bc->opt_dcd)
 		hdlcdrv_setdcd(&bc->hdrv, !((msr ^ bc->opt_dcd) & 0x80));
 	do {
 		switch (iir & 6) {
 		case 6:
 			inb(LSR(dev->base_addr));
 			break;

 		case 4:
 			inb(RBR(dev->base_addr));
 			break;

 		case 2:
 			/*
 			 * make sure the next interrupt is generated;
 			 * 0 must be used to power the modem; the modem draws its
 			 * power from the TxD line
 			 */
 			outb(0x00, THR(dev->base_addr));
 			baycom_int_freq(bc);
 			txcount++;
 			/*
 			 * first output the last bit (!) then call HDLC transmitter,
 			 * since this may take quite long
 			 */
 			if (bc->modem.ptt)
 				outb(0x0e | (!!bc->modem.ser12.tx_bit), MCR(dev->base_addr));
 			else
 				outb(0x0d, MCR(dev->base_addr));       /* transmitter off */
 			break;

 		default:
 			msr = inb(MSR(dev->base_addr));
 			/* delta DCD */
 			if ((msr & 8) && bc->opt_dcd)
 				hdlcdrv_setdcd(&bc->hdrv, !((msr ^ bc->opt_dcd) & 0x80));
 			break;
 		}
 		iir = inb(IIR(dev->base_addr));
 	} while (!(iir & 1));
 	ser12_rx(dev, bc, &tv, msr & 0x10); /* CTS */
 	if (bc->modem.ptt && txcount) {
 		if (bc->modem.ser12.txshreg <= 1) {
 			bc->modem.ser12.txshreg = 0x10000 | hdlcdrv_getbits(&bc->hdrv);
 			if (!hdlcdrv_ptt(&bc->hdrv)) {
 				ser12_set_divisor(dev, 115200/100/8);
 				bc->modem.ptt = 0;
 				goto end_transmit;
 			}
 		}
 		bc->modem.ser12.tx_bit = !(bc->modem.ser12.tx_bit ^ (bc->modem.ser12.txshreg & 1));
 		bc->modem.ser12.txshreg >>= 1;
 	}
  end_transmit:
 	local_irq_enable();
 	if (!bc->modem.ptt && txcount) {
 		hdlcdrv_arbitrate(dev, &bc->hdrv);
 		if (hdlcdrv_ptt(&bc->hdrv)) {
 			ser12_set_divisor(dev, bc->baud_uartdiv);
 			bc->modem.ser12.txshreg = 1;
 			bc->modem.ptt = 1;
 		}
 	}
 	hdlcdrv_transmitter(dev, &bc->hdrv);
 	hdlcdrv_receiver(dev, &bc->hdrv);
 	local_irq_disable();
 	return IRQ_HANDLED;
 }

 /* --------------------------------------------------------------------- */

 enum uart { c_uart_unknown, c_uart_8250,
 	    c_uart_16450, c_uart_16550, c_uart_16550A};
 static const char *uart_str[] = {
 	"unknown", "8250", "16450", "16550", "16550A"
 };

 static enum uart ser12_check_uart(unsigned int iobase)
 {
 	unsigned char b1,b2,b3;
 	enum uart u;
 	enum uart uart_tab[] =
 		{ c_uart_16450, c_uart_unknown, c_uart_16550, c_uart_16550A };

 	b1 = inb(MCR(iobase));
 	outb(b1 | 0x10, MCR(iobase));	/* loopback mode */
 	b2 = inb(MSR(iobase));
 	outb(0x1a, MCR(iobase));
 	b3 = inb(MSR(iobase)) & 0xf0;
 	outb(b1, MCR(iobase));			/* restore old values */
 	outb(b2, MSR(iobase));
 	if (b3 != 0x90)
 		return c_uart_unknown;
 	inb(RBR(iobase));
 	inb(RBR(iobase));
 	outb(0x01, FCR(iobase));		/* enable FIFOs */
 	u = uart_tab[(inb(IIR(iobase)) >> 6) & 3];
 	if (u == c_uart_16450) {
 		outb(0x5a, SCR(iobase));
 		b1 = inb(SCR(iobase));
 		outb(0xa5, SCR(iobase));
 		b2 = inb(SCR(iobase));
 		if ((b1 != 0x5a) || (b2 != 0xa5))
 			u = c_uart_8250;
 	}
 	return u;
 }

 /* --------------------------------------------------------------------- */

 static int ser12_open(struct net_device *dev)
 {
 	struct baycom_state *bc = netdev_priv(dev);
 	enum uart u;

 	if (!dev || !bc)
 		return -ENXIO;
 	if (!dev->base_addr || dev->base_addr > 0xffff-SER12_EXTENT ||
 	    dev->irq < 2 || dev->irq > nr_irqs) {
 		printk(KERN_INFO "baycom_ser_fdx: invalid portnumber (max %u) "
 				"or irq (2 <= irq <= %d)\n",
 				0xffff-SER12_EXTENT, nr_irqs);
 		return -ENXIO;
 	}
 	if (bc->baud < 300 || bc->baud > 4800) {
 		printk(KERN_INFO "baycom_ser_fdx: invalid baudrate "
 				"(300...4800)\n");
 		return -EINVAL;
 	}
 	if (!request_region(dev->base_addr, SER12_EXTENT, "baycom_ser_fdx")) {
 		printk(KERN_WARNING "BAYCOM_SER_FSX: I/O port 0x%04lx busy\n",
 		       dev->base_addr);
 		return -EACCES;
 	}
 	memset(&bc->modem, 0, sizeof(bc->modem));
 	bc->hdrv.par.bitrate = bc->baud;
 	bc->baud_us = 1000000/bc->baud;
 	bc->baud_uartdiv = (115200/8)/bc->baud;
 	if ((u = ser12_check_uart(dev->base_addr)) == c_uart_unknown){
 		release_region(dev->base_addr, SER12_EXTENT);
 		return -EIO;
 	}
 	outb(0, FCR(dev->base_addr));  /* disable FIFOs */
 	outb(0x0d, MCR(dev->base_addr));
 	outb(0, IER(dev->base_addr));
 	if (request_irq(dev->irq, ser12_interrupt, IRQF_DISABLED | IRQF_SHARED,
 			"baycom_ser_fdx", dev)) {
 		release_region(dev->base_addr, SER12_EXTENT);
 		return -EBUSY;
 	}
 	/*
 	 * set the SIO to 6 Bits/character; during receive,
 	 * the baud rate is set to produce 100 ints/sec
 	 * to feed the channel arbitration process,
 	 * during transmit to baud ints/sec to run
 	 * the transmitter
 	 */
 	ser12_set_divisor(dev, 115200/100/8);
 	/*
 	 * enable transmitter empty interrupt and modem status interrupt
 	 */
 	outb(0x0a, IER(dev->base_addr));
 	/*
 	 * make sure the next interrupt is generated;
 	 * 0 must be used to power the modem; the modem draws its
 	 * power from the TxD line
 	 */
 	outb(0x00, THR(dev->base_addr));
 	hdlcdrv_setdcd(&bc->hdrv, 0);
 	printk(KERN_INFO "%s: ser_fdx at iobase 0x%lx irq %u baud %u uart %s\n",
 	       bc_drvname, dev->base_addr, dev->irq, bc->baud, uart_str[u]);
 	return 0;
 }

 /* --------------------------------------------------------------------- */

 static int ser12_close(struct net_device *dev)
 {
 	struct baycom_state *bc = netdev_priv(dev);

 	if (!dev || !bc)
 		return -EINVAL;
 	/*
 	 * disable interrupts
 	 */
 	outb(0, IER(dev->base_addr));
 	outb(1, MCR(dev->base_addr));
 	free_irq(dev->irq, dev);
 	release_region(dev->base_addr, SER12_EXTENT);
 	printk(KERN_INFO "%s: close ser_fdx at iobase 0x%lx irq %u\n",
 	       bc_drvname, dev->base_addr, dev->irq);
 	return 0;
 }

 /* --------------------------------------------------------------------- */
 /*
  * ===================== hdlcdrv driver interface =========================
  */

 /* --------------------------------------------------------------------- */

 static int baycom_ioctl(struct net_device *dev, struct ifreq *ifr,
 			struct hdlcdrv_ioctl *hi, int cmd);

 /* --------------------------------------------------------------------- */

 static struct hdlcdrv_ops ser12_ops = {
 	.drvname = bc_drvname,
 	.drvinfo = bc_drvinfo,
 	.open    = ser12_open,
 	.close   = ser12_close,
 	.ioctl   = baycom_ioctl,
 };

 /* --------------------------------------------------------------------- */

 static int baycom_setmode(struct baycom_state *bc, const char *modestr)
 {
 	unsigned int baud;

 	if (!strncmp(modestr, "ser", 3)) {
 		baud = simple_strtoul(modestr+3, NULL, 10);
 		if (baud >= 3 && baud <= 48)
 			bc->baud = baud*100;
 	}
 	if (strchr(modestr, '*'))
 		bc->opt_dcd = 0;
 	else if (strchr(modestr, '+'))
 		bc->opt_dcd = -1;
 	else
 		bc->opt_dcd = 1;
 	return 0;
 }

 /* --------------------------------------------------------------------- */

 static int baycom_ioctl(struct net_device *dev, struct ifreq *ifr,
 			struct hdlcdrv_ioctl *hi, int cmd)
 {
 	struct baycom_state *bc;
 	struct baycom_ioctl bi;

 	if (!dev)
 		return -EINVAL;

 	bc = netdev_priv(dev);
 	BUG_ON(bc->hdrv.magic != HDLCDRV_MAGIC);

 	if (cmd != SIOCDEVPRIVATE)
 		return -ENOIOCTLCMD;
 	switch (hi->cmd) {
 	default:
 		break;

 	case HDLCDRVCTL_GETMODE:
 		sprintf(hi->data.modename, "ser%u", bc->baud / 100);
 		if (bc->opt_dcd <= 0)
 			strcat(hi->data.modename, (!bc->opt_dcd) ? "*" : "+");
 		if (copy_to_user(ifr->ifr_data, hi, sizeof(struct hdlcdrv_ioctl)))
 			return -EFAULT;
 		return 0;

 	case HDLCDRVCTL_SETMODE:
 		if (netif_running(dev) || !capable(CAP_NET_ADMIN))
 			return -EACCES;
 		hi->data.modename[sizeof(hi->data.modename)-1] = '\0';
 		return baycom_setmode(bc, hi->data.modename);

 	case HDLCDRVCTL_MODELIST:
 		strcpy(hi->data.modename, "ser12,ser3,ser24");
 		if (copy_to_user(ifr->ifr_data, hi, sizeof(struct hdlcdrv_ioctl)))
 			return -EFAULT;
 		return 0;

 	case HDLCDRVCTL_MODEMPARMASK:
 		return HDLCDRV_PARMASK_IOBASE | HDLCDRV_PARMASK_IRQ;

 	}

 	if (copy_from_user(&bi, ifr->ifr_data, sizeof(bi)))
 		return -EFAULT;
 	switch (bi.cmd) {
 	default:
 		return -ENOIOCTLCMD;

 #ifdef BAYCOM_DEBUG
 	case BAYCOMCTL_GETDEBUG:
 		bi.data.dbg.debug1 = bc->hdrv.ptt_keyed;
 		bi.data.dbg.debug2 = bc->debug_vals.last_intcnt;
 		bi.data.dbg.debug3 = bc->debug_vals.last_pllcorr;
 		break;
 #endif /* BAYCOM_DEBUG */

 	}
 	if (copy_to_user(ifr->ifr_data, &bi, sizeof(bi)))
 		return -EFAULT;
 	return 0;

 }

 /* --------------------------------------------------------------------- */

 /*
  * command line settable parameters
  */
 static char *mode[NR_PORTS] = { "ser12*", };
 static int iobase[NR_PORTS] = { 0x3f8, };
 static int irq[NR_PORTS] = { 4, };
 static int baud[NR_PORTS] = { [0 ... NR_PORTS-1] = 1200 };

 module_param_array(mode, charp, NULL, 0);
 MODULE_PARM_DESC(mode, "baycom operating mode; * for software DCD");
 module_param_array(iobase, int, NULL, 0);
 MODULE_PARM_DESC(iobase, "baycom io base address");
 module_param_array(irq, int, NULL, 0);
 MODULE_PARM_DESC(irq, "baycom irq number");
 module_param_array(baud, int, NULL, 0);
 MODULE_PARM_DESC(baud, "baycom baud rate (300 to 4800)");

 MODULE_AUTHOR("Thomas M. Sailer, sailer@ife.ee.ethz.ch, hb9jnx@hb9w.che.eu");
 MODULE_DESCRIPTION("Baycom ser12 full duplex amateur radio modem driver");
 MODULE_LICENSE("GPL");

 /* --------------------------------------------------------------------- */

 static int __init init_baycomserfdx(void)
 {
 	int i, found = 0;
 	char set_hw = 1;

 	printk(bc_drvinfo);
 	/*
 	 * register net devices
 	 */
 	for (i = 0; i < NR_PORTS; i++) {
 		struct net_device *dev;
 		struct baycom_state *bc;
 		char ifname[IFNAMSIZ];

 		sprintf(ifname, "bcsf%d", i);

 		if (!mode[i])
 			set_hw = 0;
 		if (!set_hw)
 			iobase[i] = irq[i] = 0;

 		dev = hdlcdrv_register(&ser12_ops,
 				       sizeof(struct baycom_state),
 				       ifname, iobase[i], irq[i], 0);
 		if (IS_ERR(dev))
 			break;

 		bc = netdev_priv(dev);
 		if (set_hw && baycom_setmode(bc, mode[i]))
 			set_hw = 0;
 		bc->baud = baud[i];
 		found++;
 		baycom_device[i] = dev;
 	}

 	if (!found)
 		return -ENXIO;
 	return 0;
 }

 static void __exit cleanup_baycomserfdx(void)
 {
 	int i;

 	for(i = 0; i < NR_PORTS; i++) {
 		struct net_device *dev = baycom_device[i];
 		if (dev)
 			hdlcdrv_unregister(dev);
 	}
 }

 module_init(init_baycomserfdx);
 module_exit(cleanup_baycomserfdx);

 /* --------------------------------------------------------------------- */

 #ifndef MODULE

 /*
  * format: baycom_ser_fdx=io,irq,mode
  * mode: ser#    hardware DCD
  *       ser#*   software DCD
  *       ser#+   hardware DCD, inverted signal at DCD pin
  * '#' denotes the baud rate / 100, eg. ser12* is '1200 baud, soft DCD'
  */

 static int __init baycom_ser_fdx_setup(char *str)
 {
         static unsigned nr_dev;
         int ints[4];

         if (nr_dev >= NR_PORTS)
                 return 0;
         str = get_options(str, 4, ints);
         if (ints[0] < 2)
                 return 0;
         mode[nr_dev] = str;
         iobase[nr_dev] = ints[1];
         irq[nr_dev] = ints[2];
 	if (ints[0] >= 3)
 		baud[nr_dev] = ints[3];
 	nr_dev++;
 	return 1;
 }

 __setup("baycom_ser_fdx=", baycom_ser_fdx_setup);

 #endif /* MODULE */
 /* --------------------------------------------------------------------- */
	/*****************************************************************************/

	/*
	* baycom_ser_fdx.c -- baycom ser12 fullduplex radio modem driver.
	*
	* Copyright (C) 1996-2000 Thomas Sailer (sailer@ife.ee.ethz.ch)
	*
	* 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.
	*
	* This program is distributed in the hope that it will be useful,
	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	* GNU General Public License for more details.
	*
	* You should have received a copy of the GNU General Public License
	* along with this program; if not, write to the Free Software
	* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
	*
	* Please note that the GPL allows you to use the driver, NOT the radio.
	* In order to use the radio, you need a license from the communications
	* authority of your country.
	*
	*
	* Supported modems
	*
	* ser12: This is a very simple 1200 baud AFSK modem. The modem consists only
	* of a modulator/demodulator chip, usually a TI TCM3105. The computer
	* is responsible for regenerating the receiver bit clock, as well as
	* for handling the HDLC protocol. The modem connects to a serial port,
	* hence the name. Since the serial port is not used as an async serial
	* port, the kernel driver for serial ports cannot be used, and this
	* driver only supports standard serial hardware (8250, 16450, 16550A)
	*
	* This modem usually draws its supply current out of the otherwise unused
	* TXD pin of the serial port. Thus a contiguous stream of 0x00-bytes
	* is transmitted to achieve a positive supply voltage.
	*
	* hsk: This is a 4800 baud FSK modem, designed for TNC use. It works fine
	* in 'baycom-mode' :-) In contrast to the TCM3105 modem, power is
	* externally supplied. So there's no need to provide the 0x00-byte-stream
	* when receiving or idle, which drastically reduces interrupt load.
	*
	* Command line options (insmod command line)
	*
	* mode ser# hardware DCD
	* ser#* software DCD
	* ser#+ hardware DCD, inverted signal at DCD pin
	* '#' denotes the baud rate / 100, eg. ser12* is '1200 baud, soft DCD'
	* iobase base address of the port; common values are 0x3f8, 0x2f8, 0x3e8, 0x2e8
	* baud baud rate (between 300 and 4800)
	* irq interrupt line of the port; common values are 4,3
	*
	*
	* History:
	* 0.1 26.06.1996 Adapted from baycom.c and made network driver interface
	* 18.10.1996 Changed to new user space access routines (copy_{to,from}_user)
	* 0.3 26.04.1997 init code/data tagged
	* 0.4 08.07.1997 alternative ser12 decoding algorithm (uses delta CTS ints)
	* 0.5 11.11.1997 ser12/par96 split into separate files
	* 0.6 24.01.1998 Thorsten Kranzkowski, dl8bcu and Thomas Sailer:
	* reduced interrupt load in transmit case
	* reworked receiver
	* 0.7 03.08.1999 adapt to Linus' new __setup/__initcall
	* 0.8 10.08.1999 use module_init/module_exit
	* 0.9 12.02.2000 adapted to softnet driver interface
	* 0.10 03.07.2000 fix interface name handling
	*/

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

	#include <linux/capability.h>
	#include <linux/module.h>
	#include <linux/ioport.h>
	#include <linux/string.h>
	#include <linux/init.h>
	#include <linux/hdlcdrv.h>
	#include <linux/baycom.h>
	#include <linux/jiffies.h>

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

	/* --------------------------------------------------------------------- */

	#define BAYCOM_DEBUG

	/* --------------------------------------------------------------------- */

	static const char bc_drvname[] = "baycom_ser_fdx";
	static const char bc_drvinfo[] = KERN_INFO "baycom_ser_fdx: (C) 1996-2000 Thomas Sailer, HB9JNX/AE4WA\n"
	"baycom_ser_fdx: version 0.10\n";

	/* --------------------------------------------------------------------- */

	#define NR_PORTS 4

	static struct net_device *baycom_device[NR_PORTS];

	/* --------------------------------------------------------------------- */

	#define RBR(iobase) (iobase+0)
	#define THR(iobase) (iobase+0)
	#define IER(iobase) (iobase+1)
	#define IIR(iobase) (iobase+2)
	#define FCR(iobase) (iobase+2)
	#define LCR(iobase) (iobase+3)
	#define MCR(iobase) (iobase+4)
	#define LSR(iobase) (iobase+5)
	#define MSR(iobase) (iobase+6)
	#define SCR(iobase) (iobase+7)
	#define DLL(iobase) (iobase+0)
	#define DLM(iobase) (iobase+1)

	#define SER12_EXTENT 8

	/* ---------------------------------------------------------------------- */
	/*
	* Information that need to be kept for each board.
	*/

	struct baycom_state {
	struct hdlcdrv_state hdrv;

	unsigned int baud, baud_us, baud_arbdiv, baud_uartdiv, baud_dcdtimeout;
	int opt_dcd;

	struct modem_state {
	unsigned char flags;
	unsigned char ptt;
	unsigned int shreg;
	struct modem_state_ser12 {
	unsigned char tx_bit;
	unsigned char last_rxbit;
	int dcd_sum0, dcd_sum1, dcd_sum2;
	int dcd_time;
	unsigned int pll_time;
	unsigned int txshreg;
	} ser12;
	} modem;

	#ifdef BAYCOM_DEBUG
	struct debug_vals {
	unsigned long last_jiffies;
	unsigned cur_intcnt;
	unsigned last_intcnt;
	int cur_pllcorr;
	int last_pllcorr;
	} debug_vals;
	#endif /* BAYCOM_DEBUG */
	};

	/* --------------------------------------------------------------------- */

	static inline void baycom_int_freq(struct baycom_state *bc)
	{
	#ifdef BAYCOM_DEBUG
	unsigned long cur_jiffies = jiffies;
	/*
	* measure the interrupt frequency
	*/
	bc->debug_vals.cur_intcnt++;
	if (time_after_eq(cur_jiffies, bc->debug_vals.last_jiffies + HZ)) {
	bc->debug_vals.last_jiffies = cur_jiffies;
	bc->debug_vals.last_intcnt = bc->debug_vals.cur_intcnt;
	bc->debug_vals.cur_intcnt = 0;
	bc->debug_vals.last_pllcorr = bc->debug_vals.cur_pllcorr;
	bc->debug_vals.cur_pllcorr = 0;
	}
	#endif /* BAYCOM_DEBUG */
	}

	/* --------------------------------------------------------------------- */
	/*
	* ===================== SER12 specific routines =========================
	*/

	/* --------------------------------------------------------------------- */

	static inline void ser12_set_divisor(struct net_device *dev,
	unsigned int divisor)
	{
	outb(0x81, LCR(dev->base_addr)); /* DLAB = 1 */
	outb(divisor, DLL(dev->base_addr));
	outb(divisor >> 8, DLM(dev->base_addr));
	outb(0x01, LCR(dev->base_addr)); /* word length = 6 */
	/*
	* make sure the next interrupt is generated;
	* 0 must be used to power the modem; the modem draws its
	* power from the TxD line
	*/
	outb(0x00, THR(dev->base_addr));
	/*
	* it is important not to set the divider while transmitting;
	* this reportedly makes some UARTs generating interrupts
	* in the hundredthousands per second region
	* Reported by: Ignacio.Arenaza@studi.epfl.ch (Ignacio Arenaza Nuno)
	*/
	}

	/* --------------------------------------------------------------------- */

	#if 0
	static inline unsigned int hweight16(unsigned int w)
	__attribute__ ((unused));
	static inline unsigned int hweight8(unsigned int w)
	__attribute__ ((unused));

	static inline unsigned int hweight16(unsigned int w)
	{
	unsigned short res = (w & 0x5555) + ((w >> 1) & 0x5555);
	res = (res & 0x3333) + ((res >> 2) & 0x3333);
	res = (res & 0x0F0F) + ((res >> 4) & 0x0F0F);
	return (res & 0x00FF) + ((res >> 8) & 0x00FF);
	}

	static inline unsigned int hweight8(unsigned int w)
	{
	unsigned short res = (w & 0x55) + ((w >> 1) & 0x55);
	res = (res & 0x33) + ((res >> 2) & 0x33);
	return (res & 0x0F) + ((res >> 4) & 0x0F);
	}
	#endif

	/* --------------------------------------------------------------------- */

	static __inline__ void ser12_rx(struct net_device dev, struct baycom_state bc, struct timeval *tv, unsigned char curs)
	{
	int timediff;
	int bdus8 = bc->baud_us >> 3;
	int bdus4 = bc->baud_us >> 2;
	int bdus2 = bc->baud_us >> 1;

	timediff = 1000000 + tv->tv_usec - bc->modem.ser12.pll_time;
	while (timediff >= 500000)
	timediff -= 1000000;
	while (timediff >= bdus2) {
	timediff -= bc->baud_us;
	bc->modem.ser12.pll_time += bc->baud_us;
	bc->modem.ser12.dcd_time--;
	/* first check if there is room to add a bit */
	if (bc->modem.shreg & 1) {
	hdlcdrv_putbits(&bc->hdrv, (bc->modem.shreg >> 1) ^ 0xffff);
	bc->modem.shreg = 0x10000;
	}
	/* add a one bit */
	bc->modem.shreg >>= 1;
	}
	if (bc->modem.ser12.dcd_time <= 0) {
	if (!bc->opt_dcd)
	hdlcdrv_setdcd(&bc->hdrv, (bc->modem.ser12.dcd_sum0 +
	bc->modem.ser12.dcd_sum1 +
	bc->modem.ser12.dcd_sum2) < 0);
	bc->modem.ser12.dcd_sum2 = bc->modem.ser12.dcd_sum1;
	bc->modem.ser12.dcd_sum1 = bc->modem.ser12.dcd_sum0;
	bc->modem.ser12.dcd_sum0 = 2; /* slight bias */
	bc->modem.ser12.dcd_time += 120;
	}
	if (bc->modem.ser12.last_rxbit != curs) {
	bc->modem.ser12.last_rxbit = curs;
	bc->modem.shreg \|= 0x10000;
	/* adjust the PLL */
	if (timediff > 0)
	bc->modem.ser12.pll_time += bdus8;
	else
	bc->modem.ser12.pll_time += 1000000 - bdus8;
	/* update DCD */
	if (abs(timediff) > bdus4)
	bc->modem.ser12.dcd_sum0 += 4;
	else
	bc->modem.ser12.dcd_sum0--;
	#ifdef BAYCOM_DEBUG
	bc->debug_vals.cur_pllcorr = timediff;
	#endif /* BAYCOM_DEBUG */
	}
	while (bc->modem.ser12.pll_time >= 1000000)
	bc->modem.ser12.pll_time -= 1000000;
	}

	/* --------------------------------------------------------------------- */

	static irqreturn_t ser12_interrupt(int irq, void *dev_id)
	{
	struct net_device dev = (struct net_device )dev_id;
	struct baycom_state *bc = netdev_priv(dev);
	struct timeval tv;
	unsigned char iir, msr;
	unsigned int txcount = 0;

	if (!bc \|\| bc->hdrv.magic != HDLCDRV_MAGIC)
	return IRQ_NONE;
	/* fast way out for shared irq */
	if ((iir = inb(IIR(dev->base_addr))) & 1)
	return IRQ_NONE;
	/* get current time */
	do_gettimeofday(&tv);
	msr = inb(MSR(dev->base_addr));
	/* delta DCD */
	if ((msr & 8) && bc->opt_dcd)
	hdlcdrv_setdcd(&bc->hdrv, !((msr ^ bc->opt_dcd) & 0x80));
	do {
	switch (iir & 6) {
	case 6:
	inb(LSR(dev->base_addr));
	break;

	case 4:
	inb(RBR(dev->base_addr));
	break;

	case 2:
	/*
	* make sure the next interrupt is generated;
	* 0 must be used to power the modem; the modem draws its
	* power from the TxD line
	*/
	outb(0x00, THR(dev->base_addr));
	baycom_int_freq(bc);
	txcount++;
	/*
	* first output the last bit (!) then call HDLC transmitter,
	* since this may take quite long
	*/
	if (bc->modem.ptt)
	outb(0x0e \| (!!bc->modem.ser12.tx_bit), MCR(dev->base_addr));
	else
	outb(0x0d, MCR(dev->base_addr)); /* transmitter off */
	break;

	default:
	msr = inb(MSR(dev->base_addr));
	/* delta DCD */
	if ((msr & 8) && bc->opt_dcd)
	hdlcdrv_setdcd(&bc->hdrv, !((msr ^ bc->opt_dcd) & 0x80));
	break;
	}
	iir = inb(IIR(dev->base_addr));
	} while (!(iir & 1));
	ser12_rx(dev, bc, &tv, msr & 0x10); /* CTS */
	if (bc->modem.ptt && txcount) {
	if (bc->modem.ser12.txshreg <= 1) {
	bc->modem.ser12.txshreg = 0x10000 \| hdlcdrv_getbits(&bc->hdrv);
	if (!hdlcdrv_ptt(&bc->hdrv)) {
	ser12_set_divisor(dev, 115200/100/8);
	bc->modem.ptt = 0;
	goto end_transmit;
	}
	}
	bc->modem.ser12.tx_bit = !(bc->modem.ser12.tx_bit ^ (bc->modem.ser12.txshreg & 1));
	bc->modem.ser12.txshreg >>= 1;
	}
	end_transmit:
	local_irq_enable();
	if (!bc->modem.ptt && txcount) {
	hdlcdrv_arbitrate(dev, &bc->hdrv);
	if (hdlcdrv_ptt(&bc->hdrv)) {
	ser12_set_divisor(dev, bc->baud_uartdiv);
	bc->modem.ser12.txshreg = 1;
	bc->modem.ptt = 1;
	}
	}
	hdlcdrv_transmitter(dev, &bc->hdrv);
	hdlcdrv_receiver(dev, &bc->hdrv);
	local_irq_disable();
	return IRQ_HANDLED;
	}

	/* --------------------------------------------------------------------- */

	enum uart { c_uart_unknown, c_uart_8250,
	c_uart_16450, c_uart_16550, c_uart_16550A};
	static const char *uart_str[] = {
	"unknown", "8250", "16450", "16550", "16550A"
	};

	static enum uart ser12_check_uart(unsigned int iobase)
	{
	unsigned char b1,b2,b3;
	enum uart u;
	enum uart uart_tab[] =
	{ c_uart_16450, c_uart_unknown, c_uart_16550, c_uart_16550A };

	b1 = inb(MCR(iobase));
	outb(b1 \| 0x10, MCR(iobase)); /* loopback mode */
	b2 = inb(MSR(iobase));
	outb(0x1a, MCR(iobase));
	b3 = inb(MSR(iobase)) & 0xf0;
	outb(b1, MCR(iobase)); /* restore old values */
	outb(b2, MSR(iobase));
	if (b3 != 0x90)
	return c_uart_unknown;
	inb(RBR(iobase));
	inb(RBR(iobase));
	outb(0x01, FCR(iobase)); /* enable FIFOs */
	u = uart_tab[(inb(IIR(iobase)) >> 6) & 3];
	if (u == c_uart_16450) {
	outb(0x5a, SCR(iobase));
	b1 = inb(SCR(iobase));
	outb(0xa5, SCR(iobase));
	b2 = inb(SCR(iobase));
	if ((b1 != 0x5a) \|\| (b2 != 0xa5))
	u = c_uart_8250;
	}
	return u;
	}

	/* --------------------------------------------------------------------- */

	static int ser12_open(struct net_device *dev)
	{
	struct baycom_state *bc = netdev_priv(dev);
	enum uart u;

	if (!dev \|\| !bc)
	return -ENXIO;
	if (!dev->base_addr \|\| dev->base_addr > 0xffff-SER12_EXTENT \|\|
	dev->irq < 2 \|\| dev->irq > nr_irqs) {
	printk(KERN_INFO "baycom_ser_fdx: invalid portnumber (max %u) "
	"or irq (2 <= irq <= %d)\n",
	0xffff-SER12_EXTENT, nr_irqs);
	return -ENXIO;
	}
	if (bc->baud < 300 \|\| bc->baud > 4800) {
	printk(KERN_INFO "baycom_ser_fdx: invalid baudrate "
	"(300...4800)\n");
	return -EINVAL;
	}
	if (!request_region(dev->base_addr, SER12_EXTENT, "baycom_ser_fdx")) {
	printk(KERN_WARNING "BAYCOM_SER_FSX: I/O port 0x%04lx busy\n",
	dev->base_addr);
	return -EACCES;
	}
	memset(&bc->modem, 0, sizeof(bc->modem));
	bc->hdrv.par.bitrate = bc->baud;
	bc->baud_us = 1000000/bc->baud;
	bc->baud_uartdiv = (115200/8)/bc->baud;
	if ((u = ser12_check_uart(dev->base_addr)) == c_uart_unknown){
	release_region(dev->base_addr, SER12_EXTENT);
	return -EIO;
	}
	outb(0, FCR(dev->base_addr)); /* disable FIFOs */
	outb(0x0d, MCR(dev->base_addr));
	outb(0, IER(dev->base_addr));
	if (request_irq(dev->irq, ser12_interrupt, IRQF_DISABLED \| IRQF_SHARED,
	"baycom_ser_fdx", dev)) {
	release_region(dev->base_addr, SER12_EXTENT);
	return -EBUSY;
	}
	/*
	* set the SIO to 6 Bits/character; during receive,
	* the baud rate is set to produce 100 ints/sec
	* to feed the channel arbitration process,
	* during transmit to baud ints/sec to run
	* the transmitter
	*/
	ser12_set_divisor(dev, 115200/100/8);
	/*
	* enable transmitter empty interrupt and modem status interrupt
	*/
	outb(0x0a, IER(dev->base_addr));
	/*
	* make sure the next interrupt is generated;
	* 0 must be used to power the modem; the modem draws its
	* power from the TxD line
	*/
	outb(0x00, THR(dev->base_addr));
	hdlcdrv_setdcd(&bc->hdrv, 0);
	printk(KERN_INFO "%s: ser_fdx at iobase 0x%lx irq %u baud %u uart %s\n",
	bc_drvname, dev->base_addr, dev->irq, bc->baud, uart_str[u]);
	return 0;
	}

	/* --------------------------------------------------------------------- */

	static int ser12_close(struct net_device *dev)
	{
	struct baycom_state *bc = netdev_priv(dev);

	if (!dev \|\| !bc)
	return -EINVAL;
	/*
	* disable interrupts
	*/
	outb(0, IER(dev->base_addr));
	outb(1, MCR(dev->base_addr));
	free_irq(dev->irq, dev);
	release_region(dev->base_addr, SER12_EXTENT);
	printk(KERN_INFO "%s: close ser_fdx at iobase 0x%lx irq %u\n",
	bc_drvname, dev->base_addr, dev->irq);
	return 0;
	}

	/* --------------------------------------------------------------------- */
	/*
	* ===================== hdlcdrv driver interface =========================
	*/

	/* --------------------------------------------------------------------- */

	static int baycom_ioctl(struct net_device dev, struct ifreq ifr,
	struct hdlcdrv_ioctl *hi, int cmd);

	/* --------------------------------------------------------------------- */

	static struct hdlcdrv_ops ser12_ops = {
	.drvname = bc_drvname,
	.drvinfo = bc_drvinfo,
	.open = ser12_open,
	.close = ser12_close,
	.ioctl = baycom_ioctl,
	};

	/* --------------------------------------------------------------------- */

	static int baycom_setmode(struct baycom_state bc, const char modestr)
	{
	unsigned int baud;

	if (!strncmp(modestr, "ser", 3)) {
	baud = simple_strtoul(modestr+3, NULL, 10);
	if (baud >= 3 && baud <= 48)
	bc->baud = baud*100;
	}
	if (strchr(modestr, '*'))
	bc->opt_dcd = 0;
	else if (strchr(modestr, '+'))
	bc->opt_dcd = -1;
	else
	bc->opt_dcd = 1;
	return 0;
	}

	/* --------------------------------------------------------------------- */

	static int baycom_ioctl(struct net_device dev, struct ifreq ifr,
	struct hdlcdrv_ioctl *hi, int cmd)
	{
	struct baycom_state *bc;
	struct baycom_ioctl bi;

	if (!dev)
	return -EINVAL;

	bc = netdev_priv(dev);
	BUG_ON(bc->hdrv.magic != HDLCDRV_MAGIC);

	if (cmd != SIOCDEVPRIVATE)
	return -ENOIOCTLCMD;
	switch (hi->cmd) {
	default:
	break;

	case HDLCDRVCTL_GETMODE:
	sprintf(hi->data.modename, "ser%u", bc->baud / 100);
	if (bc->opt_dcd <= 0)
	strcat(hi->data.modename, (!bc->opt_dcd) ? "*" : "+");
	if (copy_to_user(ifr->ifr_data, hi, sizeof(struct hdlcdrv_ioctl)))
	return -EFAULT;
	return 0;

	case HDLCDRVCTL_SETMODE:
	if (netif_running(dev) \|\| !capable(CAP_NET_ADMIN))
	return -EACCES;
	hi->data.modename[sizeof(hi->data.modename)-1] = '\0';
	return baycom_setmode(bc, hi->data.modename);

	case HDLCDRVCTL_MODELIST:
	strcpy(hi->data.modename, "ser12,ser3,ser24");
	if (copy_to_user(ifr->ifr_data, hi, sizeof(struct hdlcdrv_ioctl)))
	return -EFAULT;
	return 0;

	case HDLCDRVCTL_MODEMPARMASK:
	return HDLCDRV_PARMASK_IOBASE \| HDLCDRV_PARMASK_IRQ;

	}

	if (copy_from_user(&bi, ifr->ifr_data, sizeof(bi)))
	return -EFAULT;
	switch (bi.cmd) {
	default:
	return -ENOIOCTLCMD;

	#ifdef BAYCOM_DEBUG
	case BAYCOMCTL_GETDEBUG:
	bi.data.dbg.debug1 = bc->hdrv.ptt_keyed;
	bi.data.dbg.debug2 = bc->debug_vals.last_intcnt;
	bi.data.dbg.debug3 = bc->debug_vals.last_pllcorr;
	break;
	#endif /* BAYCOM_DEBUG */

	}
	if (copy_to_user(ifr->ifr_data, &bi, sizeof(bi)))
	return -EFAULT;
	return 0;

	}

	/* --------------------------------------------------------------------- */

	/*
	* command line settable parameters
	*/
	static char mode[NR_PORTS] = { "ser12", };
	static int iobase[NR_PORTS] = { 0x3f8, };
	static int irq[NR_PORTS] = { 4, };
	static int baud[NR_PORTS] = { [0 ... NR_PORTS-1] = 1200 };

	module_param_array(mode, charp, NULL, 0);
	MODULE_PARM_DESC(mode, "baycom operating mode; * for software DCD");
	module_param_array(iobase, int, NULL, 0);
	MODULE_PARM_DESC(iobase, "baycom io base address");
	module_param_array(irq, int, NULL, 0);
	MODULE_PARM_DESC(irq, "baycom irq number");
	module_param_array(baud, int, NULL, 0);
	MODULE_PARM_DESC(baud, "baycom baud rate (300 to 4800)");

	MODULE_AUTHOR("Thomas M. Sailer, sailer@ife.ee.ethz.ch, hb9jnx@hb9w.che.eu");
	MODULE_DESCRIPTION("Baycom ser12 full duplex amateur radio modem driver");
	MODULE_LICENSE("GPL");

	/* --------------------------------------------------------------------- */

	static int __init init_baycomserfdx(void)
	{
	int i, found = 0;
	char set_hw = 1;

	printk(bc_drvinfo);
	/*
	* register net devices
	*/
	for (i = 0; i < NR_PORTS; i++) {
	struct net_device *dev;
	struct baycom_state *bc;
	char ifname[IFNAMSIZ];

	sprintf(ifname, "bcsf%d", i);

	if (!mode[i])
	set_hw = 0;
	if (!set_hw)
	iobase[i] = irq[i] = 0;

	dev = hdlcdrv_register(&ser12_ops,
	sizeof(struct baycom_state),
	ifname, iobase[i], irq[i], 0);
	if (IS_ERR(dev))
	break;

	bc = netdev_priv(dev);
	if (set_hw && baycom_setmode(bc, mode[i]))
	set_hw = 0;
	bc->baud = baud[i];
	found++;
	baycom_device[i] = dev;
	}

	if (!found)
	return -ENXIO;
	return 0;
	}

	static void __exit cleanup_baycomserfdx(void)
	{
	int i;

	for(i = 0; i < NR_PORTS; i++) {
	struct net_device *dev = baycom_device[i];
	if (dev)
	hdlcdrv_unregister(dev);
	}
	}

	module_init(init_baycomserfdx);
	module_exit(cleanup_baycomserfdx);

	/* --------------------------------------------------------------------- */

	#ifndef MODULE

	/*
	* format: baycom_ser_fdx=io,irq,mode
	* mode: ser# hardware DCD
	* ser#* software DCD
	* ser#+ hardware DCD, inverted signal at DCD pin
	* '#' denotes the baud rate / 100, eg. ser12* is '1200 baud, soft DCD'
	*/

	static int __init baycom_ser_fdx_setup(char *str)
	{
	static unsigned nr_dev;
	int ints[4];

	if (nr_dev >= NR_PORTS)
	return 0;
	str = get_options(str, 4, ints);
	if (ints[0] < 2)
	return 0;
	mode[nr_dev] = str;
	iobase[nr_dev] = ints[1];
	irq[nr_dev] = ints[2];
	if (ints[0] >= 3)
	baud[nr_dev] = ints[3];
	nr_dev++;
	return 1;
	}

	__setup("baycom_ser_fdx=", baycom_ser_fdx_setup);

	#endif /* MODULE */
	/* --------------------------------------------------------------------- */