drivers/net/hamradio/baycom_par.c

   1 /*****************************************************************************/
   2
   3 /*
   4  *      baycom_par.c  -- baycom par96 and picpar radio modem driver.
   5  *
   6  *      Copyright (C) 1996-2000  Thomas Sailer (sailer@ife.ee.ethz.ch)
   7  *
   8  *      This program is free software; you can redistribute it and/or modify
   9  *      it under the terms of the GNU General Public License as published by
  10  *      the Free Software Foundation; either version 2 of the License, or
  11  *      (at your option) any later version.
  12  *
  13  *      This program is distributed in the hope that it will be useful,
  14  *      but WITHOUT ANY WARRANTY; without even the implied warranty of
  15  *      MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16  *      GNU General Public License for more details.
  17  *
  18  *      You should have received a copy of the GNU General Public License
  19  *      along with this program; if not, write to the Free Software
  20  *      Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  21  *
  22  *  Please note that the GPL allows you to use the driver, NOT the radio.
  23  *  In order to use the radio, you need a license from the communications
  24  *  authority of your country.
  25  *
  26  *
  27  *  Supported modems
  28  *
  29  *  par96:  This is a modem for 9600 baud FSK compatible to the G3RUH standard.
  30  *          The modem does all the filtering and regenerates the receiver clock.
  31  *          Data is transferred from and to the PC via a shift register.
  32  *          The shift register is filled with 16 bits and an interrupt is
  33  *          signalled. The PC then empties the shift register in a burst. This
  34  *          modem connects to the parallel port, hence the name. The modem
  35  *          leaves the implementation of the HDLC protocol and the scrambler
  36  *          polynomial to the PC. This modem is no longer available (at least
  37  *          from Baycom) and has been replaced by the PICPAR modem (see below).
  38  *          You may however still build one from the schematics published in
  39  *          cq-DL :-).
  40  *
  41  *  picpar: This is a redesign of the par96 modem by Henning Rech, DF9IC. The
  42  *          modem is protocol compatible to par96, but uses only three low
  43  *          power ICs and can therefore be fed from the parallel port and
  44  *          does not require an additional power supply. It features
  45  *          built in DCD circuitry. The driver should therefore be configured
  46  *          for hardware DCD.
  47  *
  48  *
  49  *  Command line options (insmod command line)
  50  *
  51  *  mode     driver mode string. Valid choices are par96 and picpar.
  52  *  iobase   base address of the port; common values are 0x378, 0x278, 0x3bc
  53  *
  54  *
  55  *  History:
  56  *   0.1  26.06.1996  Adapted from baycom.c and made network driver interface
  57  *        18.10.1996  Changed to new user space access routines (copy_{to,from}_user)
  58  *   0.3  26.04.1997  init code/data tagged
  59  *   0.4  08.07.1997  alternative ser12 decoding algorithm (uses delta CTS ints)
  60  *   0.5  11.11.1997  split into separate files for ser12/par96
  61  *   0.6  03.08.1999  adapt to Linus' new __setup/__initcall
  62  *                    removed some pre-2.2 kernel compatibility cruft
  63  *   0.7  10.08.1999  Check if parport can do SPP and is safe to access during interrupt contexts
  64  *   0.8  12.02.2000  adapted to softnet driver interface
  65  *                    removed direct parport access, uses parport driver methods
  66  *   0.9  03.07.2000  fix interface name handling
  67  */
  68
  69 /*****************************************************************************/
  70
  71 #include <linux/module.h>
  72 #include <linux/kernel.h>
  73 #include <linux/types.h>
  74 #include <linux/fcntl.h>
  75 #include <linux/interrupt.h>
  76 #include <linux/ioport.h>
  77 #include <linux/in.h>
  78 #include <linux/string.h>
  79 #include <linux/init.h>
  80 #include <linux/delay.h>
  81 #include <linux/errno.h>
  82 #include <linux/netdevice.h>
  83 #include <linux/hdlcdrv.h>
  84 #include <linux/baycom.h>
  85 #include <linux/parport.h>
  86 #include <linux/bitops.h>
  87 #include <linux/jiffies.h>
  88
  89 #include <linux/uaccess.h>
  90
  91 /* --------------------------------------------------------------------- */
  92
  93 #define BAYCOM_DEBUG
  94
  95 /*
  96  * modem options; bit mask
  97  */
  98 #define BAYCOM_OPTIONS_SOFTDCD  1
  99
 100 /* --------------------------------------------------------------------- */
 101
 102 static const char bc_drvname[] = "baycom_par";
 103 static const char bc_drvinfo[] = KERN_INFO "baycom_par: (C) 1996-2000 Thomas Sailer, HB9JNX/AE4WA\n"
 104 "baycom_par: version 0.9\n";
 105
 106 /* --------------------------------------------------------------------- */
 107
 108 #define NR_PORTS 4
 109
 110 static struct net_device *baycom_device[NR_PORTS];
 111
 112 /* --------------------------------------------------------------------- */
 113
 114 #define PAR96_BURSTBITS 16
 115 #define PAR96_BURST     4
 116 #define PAR96_PTT       2
 117 #define PAR96_TXBIT     1
 118 #define PAR96_ACK       0x40
 119 #define PAR96_RXBIT     0x20
 120 #define PAR96_DCD       0x10
 121 #define PAR97_POWER     0xf8
 122
 123 /* ---------------------------------------------------------------------- */
 124 /*
 125  * Information that need to be kept for each board.
 126  */
 127
 128 struct baycom_state {
 129         struct hdlcdrv_state hdrv;
 130
 131         struct pardevice *pdev;
 132         unsigned int options;
 133
 134         struct modem_state {
 135                 short arb_divider;
 136                 unsigned char flags;
 137                 unsigned int shreg;
 138                 struct modem_state_par96 {
 139                         int dcd_count;
 140                         unsigned int dcd_shreg;
 141                         unsigned long descram;
 142                         unsigned long scram;
 143                 } par96;
 144         } modem;
 145
 146 #ifdef BAYCOM_DEBUG
 147         struct debug_vals {
 148                 unsigned long last_jiffies;
 149                 unsigned cur_intcnt;
 150                 unsigned last_intcnt;
 151                 int cur_pllcorr;
 152                 int last_pllcorr;
 153         } debug_vals;
 154 #endif /* BAYCOM_DEBUG */
 155 };
 156
 157 /* --------------------------------------------------------------------- */
 158
 159 static inline void baycom_int_freq(struct baycom_state *bc)
 160 {
 161 #ifdef BAYCOM_DEBUG
 162         unsigned long cur_jiffies = jiffies;
 163         /*
 164          * measure the interrupt frequency
 165          */
 166         bc->debug_vals.cur_intcnt++;
 167         if (time_after_eq(cur_jiffies, bc->debug_vals.last_jiffies + HZ)) {
 168                 bc->debug_vals.last_jiffies = cur_jiffies;
 169                 bc->debug_vals.last_intcnt = bc->debug_vals.cur_intcnt;
 170                 bc->debug_vals.cur_intcnt = 0;
 171                 bc->debug_vals.last_pllcorr = bc->debug_vals.cur_pllcorr;
 172                 bc->debug_vals.cur_pllcorr = 0;
 173         }
 174 #endif /* BAYCOM_DEBUG */
 175 }
 176
 177 /* --------------------------------------------------------------------- */
 178 /*
 179  * ===================== PAR96 specific routines =========================
 180  */
 181
 182 #define PAR96_DESCRAM_TAP1 0x20000
 183 #define PAR96_DESCRAM_TAP2 0x01000
 184 #define PAR96_DESCRAM_TAP3 0x00001
 185
 186 #define PAR96_DESCRAM_TAPSH1 17
 187 #define PAR96_DESCRAM_TAPSH2 12
 188 #define PAR96_DESCRAM_TAPSH3 0
 189
 190 #define PAR96_SCRAM_TAP1 0x20000 /* X^17 */
 191 #define PAR96_SCRAM_TAPN 0x00021 /* X^0+X^5 */
 192
 193 /* --------------------------------------------------------------------- */
 194
 195 static inline void par96_tx(struct net_device *dev, struct baycom_state *bc)
 196 {
 197         int i;
 198         unsigned int data = hdlcdrv_getbits(&bc->hdrv);
 199         struct parport *pp = bc->pdev->port;
 200
 201         for(i = 0; i < PAR96_BURSTBITS; i++, data >>= 1) {
 202                 unsigned char val = PAR97_POWER;
 203                 bc->modem.par96.scram = ((bc->modem.par96.scram << 1) |
 204                                          (bc->modem.par96.scram & 1));
 205                 if (!(data & 1))
 206                         bc->modem.par96.scram ^= 1;
 207                 if (bc->modem.par96.scram & (PAR96_SCRAM_TAP1 << 1))
 208                         bc->modem.par96.scram ^=
 209                                 (PAR96_SCRAM_TAPN << 1);
 210                 if (bc->modem.par96.scram & (PAR96_SCRAM_TAP1 << 2))
 211                         val |= PAR96_TXBIT;
 212                 pp->ops->write_data(pp, val);
 213                 pp->ops->write_data(pp, val | PAR96_BURST);
 214         }
 215 }
 216
 217 /* --------------------------------------------------------------------- */
 218
 219 static inline void par96_rx(struct net_device *dev, struct baycom_state *bc)
 220 {
 221         int i;
 222         unsigned int data, mask, mask2, descx;
 223         struct parport *pp = bc->pdev->port;
 224
 225         /*
 226          * do receiver; differential decode and descramble on the fly
 227          */
 228         for(data = i = 0; i < PAR96_BURSTBITS; i++) {
 229                 bc->modem.par96.descram = (bc->modem.par96.descram << 1);
 230                 if (pp->ops->read_status(pp) & PAR96_RXBIT)
 231                         bc->modem.par96.descram |= 1;
 232                 descx = bc->modem.par96.descram ^
 233                         (bc->modem.par96.descram >> 1);
 234                 /* now the diff decoded data is inverted in descram */
 235                 pp->ops->write_data(pp, PAR97_POWER | PAR96_PTT);
 236                 descx ^= ((descx >> PAR96_DESCRAM_TAPSH1) ^
 237                           (descx >> PAR96_DESCRAM_TAPSH2));
 238                 data >>= 1;
 239                 if (!(descx & 1))
 240                         data |= 0x8000;
 241                 pp->ops->write_data(pp, PAR97_POWER | PAR96_PTT | PAR96_BURST);
 242         }
 243         hdlcdrv_putbits(&bc->hdrv, data);
 244         /*
 245          * do DCD algorithm
 246          */
 247         if (bc->options & BAYCOM_OPTIONS_SOFTDCD) {
 248                 bc->modem.par96.dcd_shreg = (bc->modem.par96.dcd_shreg >> 16)
 249                         | (data << 16);
 250                 /* search for flags and set the dcd counter appropriately */
 251                 for(mask = 0x1fe00, mask2 = 0xfc00, i = 0;
 252                     i < PAR96_BURSTBITS; i++, mask <<= 1, mask2 <<= 1)
 253                         if ((bc->modem.par96.dcd_shreg & mask) == mask2)
 254                                 bc->modem.par96.dcd_count = HDLCDRV_MAXFLEN+4;
 255                 /* check for abort/noise sequences */
 256                 for(mask = 0x1fe00, mask2 = 0x1fe00, i = 0;
 257                     i < PAR96_BURSTBITS; i++, mask <<= 1, mask2 <<= 1)
 258                         if (((bc->modem.par96.dcd_shreg & mask) == mask2) &&
 259                             (bc->modem.par96.dcd_count >= 0))
 260                                 bc->modem.par96.dcd_count -= HDLCDRV_MAXFLEN-10;
 261                 /* decrement and set the dcd variable */
 262                 if (bc->modem.par96.dcd_count >= 0)
 263                         bc->modem.par96.dcd_count -= 2;
 264                 hdlcdrv_setdcd(&bc->hdrv, bc->modem.par96.dcd_count > 0);
 265         } else {
 266                 hdlcdrv_setdcd(&bc->hdrv, !!(pp->ops->read_status(pp) & PAR96_DCD));
 267         }
 268 }
 269
 270 /* --------------------------------------------------------------------- */
 271
 272 static void par96_interrupt(void *dev_id)
 273 {
 274         struct net_device *dev = dev_id;
 275         struct baycom_state *bc = netdev_priv(dev);
 276
 277         baycom_int_freq(bc);
 278         /*
 279          * check if transmitter active
 280          */
 281         if (hdlcdrv_ptt(&bc->hdrv))
 282                 par96_tx(dev, bc);
 283         else {
 284                 par96_rx(dev, bc);
 285                 if (--bc->modem.arb_divider <= 0) {
 286                         bc->modem.arb_divider = 6;
 287                         local_irq_enable();
 288                         hdlcdrv_arbitrate(dev, &bc->hdrv);
 289                 }
 290         }
 291         local_irq_enable();
 292         hdlcdrv_transmitter(dev, &bc->hdrv);
 293         hdlcdrv_receiver(dev, &bc->hdrv);
 294         local_irq_disable();
 295 }
 296
 297 /* --------------------------------------------------------------------- */
 298
 299 static void par96_wakeup(void *handle)
 300 {
 301         struct net_device *dev = (struct net_device *)handle;
 302         struct baycom_state *bc = netdev_priv(dev);
 303
 304         printk(KERN_DEBUG "baycom_par: %s: why am I being woken up?\n", dev->name);
 305         if (!parport_claim(bc->pdev))
 306                 printk(KERN_DEBUG "baycom_par: %s: I'm broken.\n", dev->name);
 307 }
 308
 309 /* --------------------------------------------------------------------- */
 310
 311 static int par96_open(struct net_device *dev)
 312 {
 313         struct baycom_state *bc = netdev_priv(dev);
 314         struct parport *pp;
 315
 316         if (!dev || !bc)
 317                 return -ENXIO;
 318         pp = parport_find_base(dev->base_addr);
 319         if (!pp) {
 320                 printk(KERN_ERR "baycom_par: parport at 0x%lx unknown\n", dev->base_addr);
 321                 return -ENXIO;
 322         }
 323         if (pp->irq < 0) {
 324                 printk(KERN_ERR "baycom_par: parport at 0x%lx has no irq\n", pp->base);
 325                 parport_put_port(pp);
 326                 return -ENXIO;
 327         }
 328         if ((~pp->modes) & (PARPORT_MODE_PCSPP | PARPORT_MODE_SAFEININT)) {
 329                 printk(KERN_ERR "baycom_par: parport at 0x%lx cannot be used\n", pp->base);
 330                 parport_put_port(pp);
 331                 return -ENXIO;
 332         }
 333         memset(&bc->modem, 0, sizeof(bc->modem));
 334         bc->hdrv.par.bitrate = 9600;
 335         bc->pdev = parport_register_device(pp, dev->name, NULL, par96_wakeup,
 336                                  par96_interrupt, PARPORT_DEV_EXCL, dev);
 337         parport_put_port(pp);
 338         if (!bc->pdev) {
 339                 printk(KERN_ERR "baycom_par: cannot register parport at 0x%lx\n", dev->base_addr);
 340                 return -ENXIO;
 341         }
 342         if (parport_claim(bc->pdev)) {
 343                 printk(KERN_ERR "baycom_par: parport at 0x%lx busy\n", pp->base);
 344                 parport_unregister_device(bc->pdev);
 345                 return -EBUSY;
 346         }
 347         pp = bc->pdev->port;
 348         dev->irq = pp->irq;
 349         pp->ops->data_forward(pp);
 350         bc->hdrv.par.bitrate = 9600;
 351         pp->ops->write_data(pp, PAR96_PTT | PAR97_POWER); /* switch off PTT */
 352         pp->ops->enable_irq(pp);
 353         printk(KERN_INFO "%s: par96 at iobase 0x%lx irq %u options 0x%x\n",
 354                bc_drvname, dev->base_addr, dev->irq, bc->options);
 355         return 0;
 356 }
 357
 358 /* --------------------------------------------------------------------- */
 359
 360 static int par96_close(struct net_device *dev)
 361 {
 362         struct baycom_state *bc = netdev_priv(dev);
 363         struct parport *pp;
 364
 365         if (!dev || !bc)
 366                 return -EINVAL;
 367         pp = bc->pdev->port;
 368         /* disable interrupt */
 369         pp->ops->disable_irq(pp);
 370         /* switch off PTT */
 371         pp->ops->write_data(pp, PAR96_PTT | PAR97_POWER);
 372         parport_release(bc->pdev);
 373         parport_unregister_device(bc->pdev);
 374         printk(KERN_INFO "%s: close par96 at iobase 0x%lx irq %u\n",
 375                bc_drvname, dev->base_addr, dev->irq);
 376         return 0;
 377 }
 378
 379 /* --------------------------------------------------------------------- */
 380 /*
 381  * ===================== hdlcdrv driver interface =========================
 382  */
 383
 384 static int baycom_ioctl(struct net_device *dev, struct ifreq *ifr,
 385                         struct hdlcdrv_ioctl *hi, int cmd);
 386
 387 /* --------------------------------------------------------------------- */
 388
 389 static struct hdlcdrv_ops par96_ops = {
 390         .drvname = bc_drvname,
 391         .drvinfo = bc_drvinfo,
 392         .open    = par96_open,
 393         .close   = par96_close,
 394         .ioctl   = baycom_ioctl
 395 };
 396
 397 /* --------------------------------------------------------------------- */
 398
 399 static int baycom_setmode(struct baycom_state *bc, const char *modestr)
 400 {
 401         if (!strncmp(modestr, "picpar", 6))
 402                 bc->options = 0;
 403         else if (!strncmp(modestr, "par96", 5))
 404                 bc->options = BAYCOM_OPTIONS_SOFTDCD;
 405         else
 406                 bc->options = !!strchr(modestr, '*');
 407         return 0;
 408 }
 409
 410 /* --------------------------------------------------------------------- */
 411
 412 static int baycom_ioctl(struct net_device *dev, struct ifreq *ifr,
 413                         struct hdlcdrv_ioctl *hi, int cmd)
 414 {
 415         struct baycom_state *bc;
 416         struct baycom_ioctl bi;
 417
 418         if (!dev)
 419                 return -EINVAL;
 420
 421         bc = netdev_priv(dev);
 422         BUG_ON(bc->hdrv.magic != HDLCDRV_MAGIC);
 423
 424         if (cmd != SIOCDEVPRIVATE)
 425                 return -ENOIOCTLCMD;
 426         switch (hi->cmd) {
 427         default:
 428                 break;
 429
 430         case HDLCDRVCTL_GETMODE:
 431                 strcpy(hi->data.modename, bc->options ? "par96" : "picpar");
 432                 if (copy_to_user(ifr->ifr_data, hi, sizeof(struct hdlcdrv_ioctl)))
 433                         return -EFAULT;
 434                 return 0;
 435
 436         case HDLCDRVCTL_SETMODE:
 437                 if (netif_running(dev) || !capable(CAP_NET_ADMIN))
 438                         return -EACCES;
 439                 hi->data.modename[sizeof(hi->data.modename)-1] = '\0';
 440                 return baycom_setmode(bc, hi->data.modename);
 441
 442         case HDLCDRVCTL_MODELIST:
 443                 strcpy(hi->data.modename, "par96,picpar");
 444                 if (copy_to_user(ifr->ifr_data, hi, sizeof(struct hdlcdrv_ioctl)))
 445                         return -EFAULT;
 446                 return 0;
 447
 448         case HDLCDRVCTL_MODEMPARMASK:
 449                 return HDLCDRV_PARMASK_IOBASE;
 450
 451         }
 452
 453         if (copy_from_user(&bi, ifr->ifr_data, sizeof(bi)))
 454                 return -EFAULT;
 455         switch (bi.cmd) {
 456         default:
 457                 return -ENOIOCTLCMD;
 458
 459 #ifdef BAYCOM_DEBUG
 460         case BAYCOMCTL_GETDEBUG:
 461                 bi.data.dbg.debug1 = bc->hdrv.ptt_keyed;
 462                 bi.data.dbg.debug2 = bc->debug_vals.last_intcnt;
 463                 bi.data.dbg.debug3 = bc->debug_vals.last_pllcorr;
 464                 break;
 465 #endif /* BAYCOM_DEBUG */
 466
 467         }
 468         if (copy_to_user(ifr->ifr_data, &bi, sizeof(bi)))
 469                 return -EFAULT;
 470         return 0;
 471
 472 }
 473
 474 /* --------------------------------------------------------------------- */
 475
 476 /*
 477  * command line settable parameters
 478  */
 479 static char *mode[NR_PORTS] = { "picpar", };
 480 static int iobase[NR_PORTS] = { 0x378, };
 481
 482 module_param_array(mode, charp, NULL, 0);
 483 MODULE_PARM_DESC(mode, "baycom operating mode; eg. par96 or picpar");
 484 module_param_array(iobase, int, NULL, 0);
 485 MODULE_PARM_DESC(iobase, "baycom io base address");
 486
 487 MODULE_AUTHOR("Thomas M. Sailer, sailer@ife.ee.ethz.ch, hb9jnx@hb9w.che.eu");
 488 MODULE_DESCRIPTION("Baycom par96 and picpar amateur radio modem driver");
 489 MODULE_LICENSE("GPL");
 490
 491 /* --------------------------------------------------------------------- */
 492
 493 static int __init init_baycompar(void)
 494 {
 495         int i, found = 0;
 496         char set_hw = 1;
 497
 498         printk(bc_drvinfo);
 499         /*
 500          * register net devices
 501          */
 502         for (i = 0; i < NR_PORTS; i++) {
 503                 struct net_device *dev;
 504                 struct baycom_state *bc;
 505                 char ifname[IFNAMSIZ];
 506
 507                 sprintf(ifname, "bcp%d", i);
 508
 509                 if (!mode[i])
 510                         set_hw = 0;
 511                 if (!set_hw)
 512                         iobase[i] = 0;
 513
 514                 dev = hdlcdrv_register(&par96_ops,
 515                                        sizeof(struct baycom_state),
 516                                        ifname, iobase[i], 0, 0);
 517                 if (IS_ERR(dev))
 518                         break;
 519
 520                 bc = netdev_priv(dev);
 521                 if (set_hw && baycom_setmode(bc, mode[i]))
 522                         set_hw = 0;
 523                 found++;
 524                 baycom_device[i] = dev;
 525         }
 526
 527         if (!found)
 528                 return -ENXIO;
 529         return 0;
 530 }
 531
 532 static void __exit cleanup_baycompar(void)
 533 {
 534         int i;
 535
 536         for(i = 0; i < NR_PORTS; i++) {
 537                 struct net_device *dev = baycom_device[i];
 538
 539                 if (dev)
 540                         hdlcdrv_unregister(dev);
 541         }
 542 }
 543
 544 module_init(init_baycompar);
 545 module_exit(cleanup_baycompar);
 546
 547 /* --------------------------------------------------------------------- */
 548
 549 #ifndef MODULE
 550
 551 /*
 552  * format: baycom_par=io,mode
 553  * mode: par96,picpar
 554  */
 555
 556 static int __init baycom_par_setup(char *str)
 557 {
 558         static unsigned nr_dev;
 559         int ints[2];
 560
 561         if (nr_dev >= NR_PORTS)
 562                 return 0;
 563         str = get_options(str, 2, ints);
 564         if (ints[0] < 1)
 565                 return 0;
 566         mode[nr_dev] = str;
 567         iobase[nr_dev] = ints[1];
 568         nr_dev++;
 569         return 1;
 570 }
 571
 572 __setup("baycom_par=", baycom_par_setup);
 573
 574 #endif /* MODULE */
 575 /* --------------------------------------------------------------------- */