patch-2.1.71 linux/drivers/net/hamradio/baycom_par.c

• Lines: 662
• Date: Sun Nov 30 10:30:19 1997
• Orig file: v2.1.70/linux/drivers/net/hamradio/baycom_par.c
• Orig date: Wed Dec 31 16:00:00 1969

diff -u --recursive --new-file v2.1.70/linux/drivers/net/hamradio/baycom_par.c linux/drivers/net/hamradio/baycom_par.c
@@ -0,0 +1,661 @@
+/*****************************************************************************/
+
+/*
+ *	baycom_par.c  -- baycom par96 and picpar radio modem driver.
+ *
+ *	Copyright (C) 1997  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
+ *
+ *  par96:  This is a modem for 9600 baud FSK compatible to the G3RUH standard.
+ *          The modem does all the filtering and regenerates the receiver clock.
+ *          Data is transferred from and to the PC via a shift register.
+ *          The shift register is filled with 16 bits and an interrupt is
+ *          signalled. The PC then empties the shift register in a burst. This
+ *          modem connects to the parallel port, hence the name. The modem
+ *          leaves the implementation of the HDLC protocol and the scrambler
+ *          polynomial to the PC. This modem is no longer available (at least
+ *          from Baycom) and has been replaced by the PICPAR modem (see below).
+ *          You may however still build one from the schematics published in
+ *          cq-DL :-).
+ *
+ *  picpar: This is a redesign of the par96 modem by Henning Rech, DF9IC. The
+ *          modem is protocol compatible to par96, but uses only three low
+ *          power ICs and can therefore be fed from the parallel port and
+ *          does not require an additional power supply. It features
+ *          built in DCD circuitry. The driver should therefore be configured
+ *          for hardware DCD.
+ *
+ *
+ *  Command line options (insmod command line)
+ *
+ *  mode     driver mode string. Valid choices are par96 and picpar.
+ *  iobase   base address of the port; common values are 0x378, 0x278, 0x3bc
+ *
+ *
+ *  History:
+ *   0.1  26.06.96  Adapted from baycom.c and made network driver interface
+ *        18.10.96  Changed to new user space access routines (copy_{to,from}_user)
+ *   0.3  26.04.97  init code/data tagged
+ *   0.4  08.07.97  alternative ser12 decoding algorithm (uses delta CTS ints)
+ *   0.5  11.11.97  split into separate files for ser12/par96
+ */
+
+/*****************************************************************************/
+
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/sched.h>
+#include <linux/types.h>
+#include <linux/fcntl.h>
+#include <linux/interrupt.h>
+#include <linux/ioport.h>
+#include <linux/in.h>
+#include <linux/string.h>
+#include <asm/system.h>
+#include <asm/bitops.h>
+#include <asm/io.h>
+#include <linux/delay.h>
+#include <linux/errno.h>
+#include <linux/netdevice.h>
+#include <linux/hdlcdrv.h>
+#include <linux/baycom.h>
+#include <linux/parport.h>
+
+/* --------------------------------------------------------------------- */
+
+/*
+ * currently this module is supposed to support both module styles, i.e.
+ * the old one present up to about 2.1.9, and the new one functioning
+ * starting with 2.1.21. The reason is I have a kit allowing to compile
+ * this module also under 2.0.x which was requested by several people.
+ * This will go in 2.2
+ */
+#include <linux/version.h>
+
+#if LINUX_VERSION_CODE >= 0x20100
+#include <asm/uaccess.h>
+#else
+#include <asm/segment.h>
+#include <linux/mm.h>
+
+#undef put_user
+#undef get_user
+
+#define put_user(x,ptr) ({ __put_user((unsigned long)(x),(ptr),sizeof(*(ptr))); 0; })
+#define get_user(x,ptr) ({ x = ((__typeof__(*(ptr)))__get_user((ptr),sizeof(*(ptr)))); 0; })
+
+extern __inline__ int copy_from_user(void *to, const void *from, unsigned long n)
+{
+        int i = verify_area(VERIFY_READ, from, n);
+        if (i)
+                return i;
+        memcpy_fromfs(to, from, n);
+        return 0;
+}
+
+extern __inline__ int copy_to_user(void *to, const void *from, unsigned long n)
+{
+        int i = verify_area(VERIFY_WRITE, to, n);
+        if (i)
+                return i;
+        memcpy_tofs(to, from, n);
+        return 0;
+}
+#endif
+
+#if LINUX_VERSION_CODE >= 0x20123
+#include <linux/init.h>
+#else
+#define __init
+#define __initdata
+#define __initfunc(x) x
+#endif
+
+/* --------------------------------------------------------------------- */
+
+#define BAYCOM_DEBUG
+
+/*
+ * modem options; bit mask
+ */
+#define BAYCOM_OPTIONS_SOFTDCD  1
+
+/* --------------------------------------------------------------------- */
+
+static const char bc_drvname[] = "baycom_par";
+static const char bc_drvinfo[] = KERN_INFO "baycom_par: (C) 1997 Thomas Sailer, HB9JNX/AE4WA\n"
+KERN_INFO "baycom_par: version 0.5 compiled " __TIME__ " " __DATE__ "\n";
+
+/* --------------------------------------------------------------------- */
+
+#define NR_PORTS 4
+
+static struct device baycom_device[NR_PORTS];
+
+static struct {
+	const char *mode;
+	int iobase;
+} baycom_ports[NR_PORTS] = { { NULL, 0 }, };
+
+/* --------------------------------------------------------------------- */
+
+#define SER12_EXTENT 8
+
+#define LPT_DATA(dev)    ((dev)->base_addr+0)
+#define LPT_STATUS(dev)  ((dev)->base_addr+1)
+#define LPT_CONTROL(dev) ((dev)->base_addr+2)
+#define LPT_IRQ_ENABLE      0x10
+
+#define PAR96_BURSTBITS 16
+#define PAR96_BURST     4
+#define PAR96_PTT       2
+#define PAR96_TXBIT     1
+#define PAR96_ACK       0x40
+#define PAR96_RXBIT     0x20
+#define PAR96_DCD       0x10
+#define PAR97_POWER     0xf8
+
+/* ---------------------------------------------------------------------- */
+/*
+ * Information that need to be kept for each board.
+ */
+
+struct baycom_state {
+	struct hdlcdrv_state hdrv;
+
+	struct pardevice *pdev;
+	unsigned int options;
+
+	struct modem_state {
+		short arb_divider;
+		unsigned char flags;
+		unsigned int shreg;
+		struct modem_state_par96 {
+			int dcd_count;
+			unsigned int dcd_shreg;
+			unsigned long descram;
+			unsigned long scram;
+		} par96;
+	} 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 */
+};
+
+/* --------------------------------------------------------------------- */
+
+#define min(a, b) (((a) < (b)) ? (a) : (b))
+#define max(a, b) (((a) > (b)) ? (a) : (b))
+
+/* --------------------------------------------------------------------- */
+
+static void __inline__ 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 ((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 */
+}
+
+/* --------------------------------------------------------------------- */
+/*
+ * ===================== PAR96 specific routines =========================
+ */
+
+#define PAR96_DESCRAM_TAP1 0x20000
+#define PAR96_DESCRAM_TAP2 0x01000
+#define PAR96_DESCRAM_TAP3 0x00001
+
+#define PAR96_DESCRAM_TAPSH1 17
+#define PAR96_DESCRAM_TAPSH2 12
+#define PAR96_DESCRAM_TAPSH3 0
+
+#define PAR96_SCRAM_TAP1 0x20000 /* X^17 */
+#define PAR96_SCRAM_TAPN 0x00021 /* X^0+X^5 */
+
+/* --------------------------------------------------------------------- */
+
+static __inline__ void par96_tx(struct device *dev, struct baycom_state *bc)
+{
+	int i;
+	unsigned int data = hdlcdrv_getbits(&bc->hdrv);
+
+	for(i = 0; i < PAR96_BURSTBITS; i++, data >>= 1) {
+		unsigned char val = PAR97_POWER;
+		bc->modem.par96.scram = ((bc->modem.par96.scram << 1) |
+					 (bc->modem.par96.scram & 1));
+		if (!(data & 1))
+			bc->modem.par96.scram ^= 1;
+		if (bc->modem.par96.scram & (PAR96_SCRAM_TAP1 << 1))
+			bc->modem.par96.scram ^=
+				(PAR96_SCRAM_TAPN << 1);
+		if (bc->modem.par96.scram & (PAR96_SCRAM_TAP1 << 2))
+			val |= PAR96_TXBIT;
+		outb(val, LPT_DATA(dev));
+		outb(val | PAR96_BURST, LPT_DATA(dev));
+	}
+}
+
+/* --------------------------------------------------------------------- */
+
+static __inline__ void par96_rx(struct device *dev, struct baycom_state *bc)
+{
+	int i;
+	unsigned int data, mask, mask2, descx;
+
+	/*
+	 * do receiver; differential decode and descramble on the fly
+	 */
+	for(data = i = 0; i < PAR96_BURSTBITS; i++) {
+		bc->modem.par96.descram = (bc->modem.par96.descram << 1);
+		if (inb(LPT_STATUS(dev)) & PAR96_RXBIT)
+			bc->modem.par96.descram |= 1;
+		descx = bc->modem.par96.descram ^
+			(bc->modem.par96.descram >> 1);
+		/* now the diff decoded data is inverted in descram */
+		outb(PAR97_POWER | PAR96_PTT, LPT_DATA(dev));
+		descx ^= ((descx >> PAR96_DESCRAM_TAPSH1) ^
+			  (descx >> PAR96_DESCRAM_TAPSH2));
+		data >>= 1;
+		if (!(descx & 1))
+			data |= 0x8000;
+		outb(PAR97_POWER | PAR96_PTT | PAR96_BURST, LPT_DATA(dev));
+	}
+	hdlcdrv_putbits(&bc->hdrv, data);
+	/*
+	 * do DCD algorithm
+	 */
+	if (bc->options & BAYCOM_OPTIONS_SOFTDCD) {
+		bc->modem.par96.dcd_shreg = (bc->modem.par96.dcd_shreg >> 16)
+			| (data << 16);
+		/* search for flags and set the dcd counter appropriately */
+		for(mask = 0x1fe00, mask2 = 0xfc00, i = 0;
+		    i < PAR96_BURSTBITS; i++, mask <<= 1, mask2 <<= 1)
+			if ((bc->modem.par96.dcd_shreg & mask) == mask2)
+				bc->modem.par96.dcd_count = HDLCDRV_MAXFLEN+4;
+		/* check for abort/noise sequences */
+		for(mask = 0x1fe00, mask2 = 0x1fe00, i = 0;
+		    i < PAR96_BURSTBITS; i++, mask <<= 1, mask2 <<= 1)
+			if (((bc->modem.par96.dcd_shreg & mask) == mask2) &&
+			    (bc->modem.par96.dcd_count >= 0))
+				bc->modem.par96.dcd_count -= HDLCDRV_MAXFLEN-10;
+		/* decrement and set the dcd variable */
+		if (bc->modem.par96.dcd_count >= 0)
+			bc->modem.par96.dcd_count -= 2;
+		hdlcdrv_setdcd(&bc->hdrv, bc->modem.par96.dcd_count > 0);
+	} else {
+		hdlcdrv_setdcd(&bc->hdrv, !!(inb(LPT_STATUS(dev)) & PAR96_DCD));
+	}
+}
+
+/* --------------------------------------------------------------------- */
+
+static void par96_interrupt(int irq, void *dev_id, struct pt_regs *regs)
+{
+	struct parport *pp = (struct parport *)dev_id;
+	struct pardevice *pd = pp->cad;
+	struct device *dev = (struct device *)pd->private;
+	struct baycom_state *bc = (struct baycom_state *)dev->priv;
+
+	if (!dev || !bc || bc->hdrv.magic != HDLCDRV_MAGIC)
+		return;
+
+	baycom_int_freq(bc);
+	/*
+	 * check if transmitter active
+	 */
+	if (hdlcdrv_ptt(&bc->hdrv))
+		par96_tx(dev, bc);
+	else {
+		par96_rx(dev, bc);
+		if (--bc->modem.arb_divider <= 0) {
+			bc->modem.arb_divider = 6;
+			sti();
+			hdlcdrv_arbitrate(dev, &bc->hdrv);
+		}
+	}
+	sti();
+	hdlcdrv_transmitter(dev, &bc->hdrv);
+	hdlcdrv_receiver(dev, &bc->hdrv);
+}
+
+/* --------------------------------------------------------------------- */
+
+static int par96_preempt(void *handle)
+{
+	/* we cannot relinquish the port in the middle of an operation */
+	return 1;
+}
+
+/* --------------------------------------------------------------------- */
+
+static void par96_wakeup(void *handle)
+{
+        struct device *dev = (struct device *)handle;
+	struct baycom_state *bc = (struct baycom_state *)dev->priv;
+
+	printk(KERN_DEBUG "baycom_par: %s: why am I being woken up?\n", dev->name);
+	if (!parport_claim(bc->pdev))
+		printk(KERN_DEBUG "baycom_par: %s: I'm broken.\n", dev->name);
+}
+
+/* --------------------------------------------------------------------- */
+
+static int par96_open(struct device *dev)
+{
+	struct baycom_state *bc = (struct baycom_state *)dev->priv;
+	struct parport *pp = parport_enumerate();
+
+	if (!dev || !bc)
+		return -ENXIO;
+	while (pp && pp->base != dev->base_addr) 
+		pp = pp->next;
+	if (!pp) {
+		printk(KERN_ERR "baycom_par: parport at 0x%lx unknown\n", dev->base_addr);
+		return -ENXIO;
+	}
+	if (pp->irq < 0) {
+		printk(KERN_ERR "baycom_par: parport at 0x%x has no irq\n", pp->base);
+		return -ENXIO;
+	}
+	memset(&bc->modem, 0, sizeof(bc->modem));
+	bc->hdrv.par.bitrate = 9600;
+	if (!(bc->pdev = parport_register_device(pp, dev->name, par96_preempt, par96_wakeup, 
+						 par96_interrupt, PARPORT_DEV_LURK, dev))) {
+		printk(KERN_ERR "baycom_par: cannot register parport at 0x%x\n", pp->base);
+		return -ENXIO;
+	}
+	if (parport_claim(bc->pdev)) {
+		printk(KERN_ERR "baycom_par: parport at 0x%x busy\n", pp->base);
+		parport_unregister_device(bc->pdev);
+		return -EBUSY;
+	}
+	dev->irq = pp->irq;
+	/* bc->pdev->port->ops->change_mode(bc->pdev->port, PARPORT_MODE_PCSPP);  not yet implemented */
+	/* switch off PTT */
+	outb(PAR96_PTT | PAR97_POWER, LPT_DATA(dev));
+	/*bc->pdev->port->ops->enable_irq(bc->pdev->port);  not yet implemented */
+        outb(LPT_IRQ_ENABLE, LPT_CONTROL(dev));	
+	printk(KERN_INFO "%s: par96 at iobase 0x%lx irq %u options 0x%x\n",
+	       bc_drvname, dev->base_addr, dev->irq, bc->options);
+	MOD_INC_USE_COUNT;
+	return 0;
+}
+
+/* --------------------------------------------------------------------- */
+
+static int par96_close(struct device *dev)
+{
+	struct baycom_state *bc = (struct baycom_state *)dev->priv;
+
+	if (!dev || !bc)
+		return -EINVAL;
+	/* disable interrupt */
+        outb(0, LPT_CONTROL(dev));
+	/*bc->pdev->port->ops->disable_irq(bc->pdev->port);  not yet implemented */
+	/* switch off PTT */
+	outb(PAR96_PTT | PAR97_POWER, LPT_DATA(dev));
+	parport_release(bc->pdev);
+	parport_unregister_device(bc->pdev);
+	printk(KERN_INFO "%s: close par96 at iobase 0x%lx irq %u\n",
+	       bc_drvname, dev->base_addr, dev->irq);
+	MOD_DEC_USE_COUNT;
+	return 0;
+}
+
+/* --------------------------------------------------------------------- */
+/*
+ * ===================== hdlcdrv driver interface =========================
+ */
+
+static int baycom_ioctl(struct device *dev, struct ifreq *ifr,
+			struct hdlcdrv_ioctl *hi, int cmd);
+
+/* --------------------------------------------------------------------- */
+
+static struct hdlcdrv_ops par96_ops = {
+	bc_drvname,
+	bc_drvinfo,
+	par96_open,
+	par96_close,
+	baycom_ioctl
+};
+
+/* --------------------------------------------------------------------- */
+
+static int baycom_setmode(struct baycom_state *bc, const char *modestr)
+{
+	if (!strncmp(modestr, "picpar", 6))
+		bc->options = 0;
+	else if (!strncmp(modestr, "par96", 5))
+		bc->options = BAYCOM_OPTIONS_SOFTDCD;
+	else
+		bc->options = !!strchr(modestr, '*');
+	return 0;
+}
+
+/* --------------------------------------------------------------------- */
+
+static int baycom_ioctl(struct device *dev, struct ifreq *ifr,
+			struct hdlcdrv_ioctl *hi, int cmd)
+{
+	struct baycom_state *bc;
+	struct baycom_ioctl bi;
+	int cmd2;
+
+	if (!dev || !dev->priv ||
+	    ((struct baycom_state *)dev->priv)->hdrv.magic != HDLCDRV_MAGIC) {
+		printk(KERN_ERR "bc_ioctl: invalid device struct\n");
+		return -EINVAL;
+	}
+	bc = (struct baycom_state *)dev->priv;
+
+	if (cmd != SIOCDEVPRIVATE)
+		return -ENOIOCTLCMD;
+	if (get_user(cmd2, (int *)ifr->ifr_data))
+		return -EFAULT;
+	switch (hi->cmd) {
+	default:
+		break;
+
+	case HDLCDRVCTL_GETMODE:
+		strcpy(hi->data.modename, bc->options ? "par96" : "picpar");
+		if (copy_to_user(ifr->ifr_data, hi, sizeof(struct hdlcdrv_ioctl)))
+			return -EFAULT;
+		return 0;
+
+	case HDLCDRVCTL_SETMODE:
+		if (!suser() || dev->start)
+			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, "par96,picpar");
+		if (copy_to_user(ifr->ifr_data, hi, sizeof(struct hdlcdrv_ioctl)))
+			return -EFAULT;
+		return 0;
+
+	case HDLCDRVCTL_MODEMPARMASK:
+		return HDLCDRV_PARMASK_IOBASE;
+
+	}
+
+	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;
+
+}
+
+/* --------------------------------------------------------------------- */
+
+__initfunc(int baycom_par_init(void))
+{
+	int i, j, found = 0;
+	char set_hw = 1;
+	struct baycom_state *bc;
+	char ifname[HDLCDRV_IFNAMELEN];
+
+
+	printk(bc_drvinfo);
+	/*
+	 * register net devices
+	 */
+	for (i = 0; i < NR_PORTS; i++) {
+		struct device *dev = baycom_device+i;
+		sprintf(ifname, "bcp%d", i);
+
+		if (!baycom_ports[i].mode)
+			set_hw = 0;
+		if (!set_hw)
+			baycom_ports[i].iobase = 0;
+		j = hdlcdrv_register_hdlcdrv(dev, &par96_ops,
+					     sizeof(struct baycom_state),
+					     ifname, baycom_ports[i].iobase, 0, 0);
+		if (!j) {
+			bc = (struct baycom_state *)dev->priv;
+			if (set_hw && baycom_setmode(bc, baycom_ports[i].mode))
+				set_hw = 0;
+			found++;
+		} else {
+			printk(KERN_WARNING "%s: cannot register net device\n",
+			       bc_drvname);
+		}
+	}
+	if (!found)
+		return -ENXIO;
+	return 0;
+}
+
+/* --------------------------------------------------------------------- */
+
+#ifdef MODULE
+
+/*
+ * command line settable parameters
+ */
+static const char *mode[NR_PORTS] = { "picpar", };
+static int iobase[NR_PORTS] = { 0x378, };
+
+#if LINUX_VERSION_CODE >= 0x20115
+
+MODULE_PARM(mode, "1-" __MODULE_STRING(NR_PORTS) "s");
+MODULE_PARM_DESC(mode, "baycom operating mode; eg. par96 or picpar");
+MODULE_PARM(iobase, "1-" __MODULE_STRING(NR_PORTS) "i");
+MODULE_PARM_DESC(iobase, "baycom io base address");
+
+MODULE_AUTHOR("Thomas M. Sailer, sailer@ife.ee.ethz.ch, hb9jnx@hb9w.che.eu");
+MODULE_DESCRIPTION("Baycom par96 and picpar amateur radio modem driver");
+
+#endif
+
+__initfunc(int init_module(void))
+{
+	int i;
+
+	for (i = 0; (i < NR_PORTS) && (mode[i]); i++) {
+		baycom_ports[i].mode = mode[i];
+		baycom_ports[i].iobase = iobase[i];
+	}
+	if (i < NR_PORTS-1)
+		baycom_ports[i+1].mode = NULL;
+	return baycom_par_init();
+}
+
+/* --------------------------------------------------------------------- */
+
+void cleanup_module(void)
+{
+	int i;
+
+	for(i = 0; i < NR_PORTS; i++) {
+		struct device *dev = baycom_device+i;
+		struct baycom_state *bc = (struct baycom_state *)dev->priv;
+
+		if (bc) {
+			if (bc->hdrv.magic != HDLCDRV_MAGIC)
+				printk(KERN_ERR "baycom: invalid magic in "
+				       "cleanup_module\n");
+			else
+				hdlcdrv_unregister_hdlcdrv(dev);
+		}
+	}
+}
+
+#else /* MODULE */
+/* --------------------------------------------------------------------- */
+/*
+ * format: baycom_par=io,mode
+ * mode: par96,picpar
+ */
+
+__initfunc(void baycom_par_setup(char *str, int *ints))
+{
+	int i;
+
+	for (i = 0; (i < NR_PORTS) && (baycom_ports[i].mode); i++);
+	if ((i >= NR_PORTS) || (ints[0] < 1)) {
+		printk(KERN_INFO "%s: too many or invalid interface "
+		       "specifications\n", bc_drvname);
+		return;
+	}
+	baycom_ports[i].mode = str;
+	baycom_ports[i].iobase = ints[1];
+	if (i < NR_PORTS-1)
+		baycom_ports[i+1].mode = NULL;
+}
+
+#endif /* MODULE */
+/* --------------------------------------------------------------------- */