drivers/net/hamradio/baycom_par.c - LeafOS-Devices/android_kernel_samsung_gta4xl - Gitiles

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

 /*
  *	baycom_par.c  -- baycom par96 and picpar 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
  *
  *  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  *          from Baycom) and has been replaced by the PICPAR modem (see below).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  26.06.1996  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  split into separate files for ser12/par96
  *   0.6  03.08.1999  adapt to Linus' new __setup/__initcall
  *                    removed some pre-2.2 kernel compatibility cruft
  *   0.7  10.08.1999  Check if parport can do SPP and is safe to access during interrupt contexts
  *   0.8  12.02.2000  adapted to softnet driver interface
  *                    removed direct parport access, uses parport driver methods
  *   0.9  03.07.2000  fix interface name handling
  */

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

 #include <linux/module.h>
 #include <linux/kernel.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 <linux/init.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>
 #include <linux/bitops.h>
 #include <linux/jiffies.h>

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

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

 #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) 1996-2000 Thomas Sailer, HB9JNX/AE4WA\n"
 "baycom_par: version 0.9\n";

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

 #define NR_PORTS 4

 static struct net_device *baycom_device[NR_PORTS];

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

 #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 */
 };

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

 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 (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 */
 }

 /* --------------------------------------------------------------------- */
 /*
  * ===================== 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 net_device *dev, struct baycom_state *bc)
 {
 	int i;
 	unsigned int data = hdlcdrv_getbits(&bc->hdrv);
 	struct parport *pp = bc->pdev->port;

 	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;
 		pp->ops->write_data(pp, val);
 		pp->ops->write_data(pp, val | PAR96_BURST);
 	}
 }

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

 static __inline__ void par96_rx(struct net_device *dev, struct baycom_state *bc)
 {
 	int i;
 	unsigned int data, mask, mask2, descx;
 	struct parport *pp = bc->pdev->port;

 	/*
 	 * 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 (pp->ops->read_status(pp) & 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 */
 		pp->ops->write_data(pp, PAR97_POWER | PAR96_PTT);
 		descx ^= ((descx >> PAR96_DESCRAM_TAPSH1) ^
 			  (descx >> PAR96_DESCRAM_TAPSH2));
 		data >>= 1;
 		if (!(descx & 1))
 			data |= 0x8000;
 		pp->ops->write_data(pp, PAR97_POWER | PAR96_PTT | PAR96_BURST);
 	}
 	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, !!(pp->ops->read_status(pp) & PAR96_DCD));
 	}
 }

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

 static void par96_interrupt(void *dev_id)
 {
 	struct net_device *dev = dev_id;
 	struct baycom_state *bc = netdev_priv(dev);

 	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;
 			local_irq_enable();
 			hdlcdrv_arbitrate(dev, &bc->hdrv);
 		}
 	}
 	local_irq_enable();
 	hdlcdrv_transmitter(dev, &bc->hdrv);
 	hdlcdrv_receiver(dev, &bc->hdrv);
         local_irq_disable();
 }

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

 static void par96_wakeup(void *handle)
 {
         struct net_device *dev = (struct net_device *)handle;
 	struct baycom_state *bc = netdev_priv(dev);

 	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 net_device *dev)
 {
 	struct baycom_state *bc = netdev_priv(dev);
 	struct parport *pp;

 	if (!dev || !bc)
 		return -ENXIO;
 	pp = parport_find_base(dev->base_addr);
 	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%lx has no irq\n", pp->base);
 		parport_put_port(pp);
 		return -ENXIO;
 	}
 	if ((~pp->modes) & (PARPORT_MODE_PCSPP | PARPORT_MODE_SAFEININT)) {
 		printk(KERN_ERR "baycom_par: parport at 0x%lx cannot be used\n", pp->base);
 		parport_put_port(pp);
 		return -ENXIO;
 	}
 	memset(&bc->modem, 0, sizeof(bc->modem));
 	bc->hdrv.par.bitrate = 9600;
 	bc->pdev = parport_register_device(pp, dev->name, NULL, par96_wakeup,
 				 par96_interrupt, PARPORT_DEV_EXCL, dev);
 	parport_put_port(pp);
 	if (!bc->pdev) {
 		printk(KERN_ERR "baycom_par: cannot register parport at 0x%lx\n", dev->base_addr);
 		return -ENXIO;
 	}
 	if (parport_claim(bc->pdev)) {
 		printk(KERN_ERR "baycom_par: parport at 0x%lx busy\n", pp->base);
 		parport_unregister_device(bc->pdev);
 		return -EBUSY;
 	}
 	pp = bc->pdev->port;
 	dev->irq = pp->irq;
 	pp->ops->data_forward(pp);
         bc->hdrv.par.bitrate = 9600;
 	pp->ops->write_data(pp, PAR96_PTT | PAR97_POWER); /* switch off PTT */
 	pp->ops->enable_irq(pp);
 	printk(KERN_INFO "%s: par96 at iobase 0x%lx irq %u options 0x%x\n",
 	       bc_drvname, dev->base_addr, dev->irq, bc->options);
 	return 0;
 }

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

 static int par96_close(struct net_device *dev)
 {
 	struct baycom_state *bc = netdev_priv(dev);
 	struct parport *pp;

 	if (!dev || !bc)
 		return -EINVAL;
 	pp = bc->pdev->port;
 	/* disable interrupt */
 	pp->ops->disable_irq(pp);
 	/* switch off PTT */
 	pp->ops->write_data(pp, PAR96_PTT | PAR97_POWER);
 	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);
 	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 par96_ops = {
 	.drvname = bc_drvname,
 	.drvinfo = bc_drvinfo,
 	.open    = par96_open,
 	.close   = par96_close,
 	.ioctl   = 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 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:
 		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 (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, "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;

 }

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

 /*
  * command line settable parameters
  */
 static char *mode[NR_PORTS] = { "picpar", };
 static int iobase[NR_PORTS] = { 0x378, };

 module_param_array(mode, charp, NULL, 0);
 MODULE_PARM_DESC(mode, "baycom operating mode; eg. par96 or picpar");
 module_param_array(iobase, int, NULL, 0);
 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");
 MODULE_LICENSE("GPL");

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

 static int __init init_baycompar(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, "bcp%d", i);

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

 		dev = hdlcdrv_register(&par96_ops,
 				       sizeof(struct baycom_state),
 				       ifname, iobase[i], 0, 0);
 		if (IS_ERR(dev))
 			break;

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

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

 static void __exit cleanup_baycompar(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_baycompar);
 module_exit(cleanup_baycompar);

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

 #ifndef MODULE

 /*
  * format: baycom_par=io,mode
  * mode: par96,picpar
  */

 static int __init baycom_par_setup(char *str)
 {
         static unsigned nr_dev;
 	int ints[2];

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

 __setup("baycom_par=", baycom_par_setup);

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

	/*
	* baycom_par.c -- baycom par96 and picpar 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
	*
	* 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 26.06.1996 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 split into separate files for ser12/par96
	* 0.6 03.08.1999 adapt to Linus' new __setup/__initcall
	* removed some pre-2.2 kernel compatibility cruft
	* 0.7 10.08.1999 Check if parport can do SPP and is safe to access during interrupt contexts
	* 0.8 12.02.2000 adapted to softnet driver interface
	* removed direct parport access, uses parport driver methods
	* 0.9 03.07.2000 fix interface name handling
	*/

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

	#include <linux/module.h>
	#include <linux/kernel.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 <linux/init.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>
	#include <linux/bitops.h>
	#include <linux/jiffies.h>

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

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

	#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) 1996-2000 Thomas Sailer, HB9JNX/AE4WA\n"
	"baycom_par: version 0.9\n";

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

	#define NR_PORTS 4

	static struct net_device *baycom_device[NR_PORTS];

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

	#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 */
	};

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

	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 (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 */
	}

	/* --------------------------------------------------------------------- */
	/*
	* ===================== 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 net_device dev, struct baycom_state bc)
	{
	int i;
	unsigned int data = hdlcdrv_getbits(&bc->hdrv);
	struct parport *pp = bc->pdev->port;

	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;
	pp->ops->write_data(pp, val);
	pp->ops->write_data(pp, val \| PAR96_BURST);
	}
	}

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

	static __inline__ void par96_rx(struct net_device dev, struct baycom_state bc)
	{
	int i;
	unsigned int data, mask, mask2, descx;
	struct parport *pp = bc->pdev->port;

	/*
	* 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 (pp->ops->read_status(pp) & 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 */
	pp->ops->write_data(pp, PAR97_POWER \| PAR96_PTT);
	descx ^= ((descx >> PAR96_DESCRAM_TAPSH1) ^
	(descx >> PAR96_DESCRAM_TAPSH2));
	data >>= 1;
	if (!(descx & 1))
	data \|= 0x8000;
	pp->ops->write_data(pp, PAR97_POWER \| PAR96_PTT \| PAR96_BURST);
	}
	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, !!(pp->ops->read_status(pp) & PAR96_DCD));
	}
	}

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

	static void par96_interrupt(void *dev_id)
	{
	struct net_device *dev = dev_id;
	struct baycom_state *bc = netdev_priv(dev);

	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;
	local_irq_enable();
	hdlcdrv_arbitrate(dev, &bc->hdrv);
	}
	}
	local_irq_enable();
	hdlcdrv_transmitter(dev, &bc->hdrv);
	hdlcdrv_receiver(dev, &bc->hdrv);
	local_irq_disable();
	}

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

	static void par96_wakeup(void *handle)
	{
	struct net_device dev = (struct net_device )handle;
	struct baycom_state *bc = netdev_priv(dev);

	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 net_device *dev)
	{
	struct baycom_state *bc = netdev_priv(dev);
	struct parport *pp;

	if (!dev \|\| !bc)
	return -ENXIO;
	pp = parport_find_base(dev->base_addr);
	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%lx has no irq\n", pp->base);
	parport_put_port(pp);
	return -ENXIO;
	}
	if ((~pp->modes) & (PARPORT_MODE_PCSPP \| PARPORT_MODE_SAFEININT)) {
	printk(KERN_ERR "baycom_par: parport at 0x%lx cannot be used\n", pp->base);
	parport_put_port(pp);
	return -ENXIO;
	}
	memset(&bc->modem, 0, sizeof(bc->modem));
	bc->hdrv.par.bitrate = 9600;
	bc->pdev = parport_register_device(pp, dev->name, NULL, par96_wakeup,
	par96_interrupt, PARPORT_DEV_EXCL, dev);
	parport_put_port(pp);
	if (!bc->pdev) {
	printk(KERN_ERR "baycom_par: cannot register parport at 0x%lx\n", dev->base_addr);
	return -ENXIO;
	}
	if (parport_claim(bc->pdev)) {
	printk(KERN_ERR "baycom_par: parport at 0x%lx busy\n", pp->base);
	parport_unregister_device(bc->pdev);
	return -EBUSY;
	}
	pp = bc->pdev->port;
	dev->irq = pp->irq;
	pp->ops->data_forward(pp);
	bc->hdrv.par.bitrate = 9600;
	pp->ops->write_data(pp, PAR96_PTT \| PAR97_POWER); /* switch off PTT */
	pp->ops->enable_irq(pp);
	printk(KERN_INFO "%s: par96 at iobase 0x%lx irq %u options 0x%x\n",
	bc_drvname, dev->base_addr, dev->irq, bc->options);
	return 0;
	}

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

	static int par96_close(struct net_device *dev)
	{
	struct baycom_state *bc = netdev_priv(dev);
	struct parport *pp;

	if (!dev \|\| !bc)
	return -EINVAL;
	pp = bc->pdev->port;
	/* disable interrupt */
	pp->ops->disable_irq(pp);
	/* switch off PTT */
	pp->ops->write_data(pp, PAR96_PTT \| PAR97_POWER);
	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);
	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 par96_ops = {
	.drvname = bc_drvname,
	.drvinfo = bc_drvinfo,
	.open = par96_open,
	.close = par96_close,
	.ioctl = 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 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:
	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 (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, "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;

	}

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

	/*
	* command line settable parameters
	*/
	static char *mode[NR_PORTS] = { "picpar", };
	static int iobase[NR_PORTS] = { 0x378, };

	module_param_array(mode, charp, NULL, 0);
	MODULE_PARM_DESC(mode, "baycom operating mode; eg. par96 or picpar");
	module_param_array(iobase, int, NULL, 0);
	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");
	MODULE_LICENSE("GPL");

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

	static int __init init_baycompar(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, "bcp%d", i);

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

	dev = hdlcdrv_register(&par96_ops,
	sizeof(struct baycom_state),
	ifname, iobase[i], 0, 0);
	if (IS_ERR(dev))
	break;

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

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

	static void __exit cleanup_baycompar(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_baycompar);
	module_exit(cleanup_baycompar);

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

	#ifndef MODULE

	/*
	* format: baycom_par=io,mode
	* mode: par96,picpar
	*/

	static int __init baycom_par_setup(char *str)
	{
	static unsigned nr_dev;
	int ints[2];

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

	__setup("baycom_par=", baycom_par_setup);

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