drivers/net/hamradio/baycom_par.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*****************************************************************************/
   3
   4 /*
   5  *      baycom_par.c  -- baycom par96 and picpar radio modem driver.
   6  *
   7  *      Copyright (C) 1996-2000  Thomas Sailer (sailer@ife.ee.ethz.ch)
   8  *
   9  *  Please note that the GPL allows you to use the driver, NOT the radio.
  10  *  In order to use the radio, you need a license from the communications
  11  *  authority of your country.
  12  *
  13  *  Supported modems
  14  *
  15  *  par96:  This is a modem for 9600 baud FSK compatible to the G3RUH standard.
  16  *          The modem does all the filtering and regenerates the receiver clock.
  17  *          Data is transferred from and to the PC via a shift register.
  18  *          The shift register is filled with 16 bits and an interrupt is
  19  *          signalled. The PC then empties the shift register in a burst. This
  20  *          modem connects to the parallel port, hence the name. The modem
  21  *          leaves the implementation of the HDLC protocol and the scrambler
  22  *          polynomial to the PC. This modem is no longer available (at least
  23  *          from Baycom) and has been replaced by the PICPAR modem (see below).
  24  *          You may however still build one from the schematics published in
  25  *          cq-DL :-).
  26  *
  27  *  picpar: This is a redesign of the par96 modem by Henning Rech, DF9IC. The
  28  *          modem is protocol compatible to par96, but uses only three low
  29  *          power ICs and can therefore be fed from the parallel port and
  30  *          does not require an additional power supply. It features
  31  *          built in DCD circuitry. The driver should therefore be configured
  32  *          for hardware DCD.
  33  *
  34  *  Command line options (insmod command line)
  35  *
  36  *  mode     driver mode string. Valid choices are par96 and picpar.
  37  *  iobase   base address of the port; common values are 0x378, 0x278, 0x3bc
  38  *
  39  *  History:
  40  *   0.1  26.06.1996  Adapted from baycom.c and made network driver interface
  41  *        18.10.1996  Changed to new user space access routines (copy_{to,from}_user)
  42  *   0.3  26.04.1997  init code/data tagged
  43  *   0.4  08.07.1997  alternative ser12 decoding algorithm (uses delta CTS ints)
  44  *   0.5  11.11.1997  split into separate files for ser12/par96
  45  *   0.6  03.08.1999  adapt to Linus' new __setup/__initcall
  46  *                    removed some pre-2.2 kernel compatibility cruft
  47  *   0.7  10.08.1999  Check if parport can do SPP and is safe to access during interrupt contexts
  48  *   0.8  12.02.2000  adapted to softnet driver interface
  49  *                    removed direct parport access, uses parport driver methods
  50  *   0.9  03.07.2000  fix interface name handling
  51  */
  52
  53 /*****************************************************************************/
  54
  55 #include <linux/module.h>
  56 #include <linux/kernel.h>
  57 #include <linux/types.h>
  58 #include <linux/fcntl.h>
  59 #include <linux/interrupt.h>
  60 #include <linux/ioport.h>
  61 #include <linux/in.h>
  62 #include <linux/string.h>
  63 #include <linux/init.h>
  64 #include <linux/delay.h>
  65 #include <linux/errno.h>
  66 #include <linux/netdevice.h>
  67 #include <linux/hdlcdrv.h>
  68 #include <linux/baycom.h>
  69 #include <linux/parport.h>
  70 #include <linux/bitops.h>
  71 #include <linux/jiffies.h>
  72
  73 #include <linux/uaccess.h>
  74
  75 /* --------------------------------------------------------------------- */
  76
  77 #define BAYCOM_DEBUG
  78
  79 /*
  80  * modem options; bit mask
  81  */
  82 #define BAYCOM_OPTIONS_SOFTDCD  1
  83
  84 /* --------------------------------------------------------------------- */
  85
  86 static const char bc_drvname[] = "baycom_par";
  87 static const char bc_drvinfo[] = KERN_INFO "baycom_par: (C) 1996-2000 Thomas Sailer, HB9JNX/AE4WA\n"
  88 "baycom_par: version 0.9\n";
  89
  90 /* --------------------------------------------------------------------- */
  91
  92 #define NR_PORTS 4
  93
  94 static struct net_device *baycom_device[NR_PORTS];
  95
  96 /* --------------------------------------------------------------------- */
  97
  98 #define PAR96_BURSTBITS 16
  99 #define PAR96_BURST     4
 100 #define PAR96_PTT       2
 101 #define PAR96_TXBIT     1
 102 #define PAR96_ACK       0x40
 103 #define PAR96_RXBIT     0x20
 104 #define PAR96_DCD       0x10
 105 #define PAR97_POWER     0xf8
 106
 107 /* ---------------------------------------------------------------------- */
 108 /*
 109  * Information that need to be kept for each board.
 110  */
 111
 112 struct baycom_state {
 113         struct hdlcdrv_state hdrv;
 114
 115         struct pardevice *pdev;
 116         unsigned int options;
 117
 118         struct modem_state {
 119                 short arb_divider;
 120                 unsigned char flags;
 121                 unsigned int shreg;
 122                 struct modem_state_par96 {
 123                         int dcd_count;
 124                         unsigned int dcd_shreg;
 125                         unsigned long descram;
 126                         unsigned long scram;
 127                 } par96;
 128         } modem;
 129
 130 #ifdef BAYCOM_DEBUG
 131         struct debug_vals {
 132                 unsigned long last_jiffies;
 133                 unsigned cur_intcnt;
 134                 unsigned last_intcnt;
 135                 int cur_pllcorr;
 136                 int last_pllcorr;
 137         } debug_vals;
 138 #endif /* BAYCOM_DEBUG */
 139 };
 140
 141 /* --------------------------------------------------------------------- */
 142
 143 static inline void baycom_int_freq(struct baycom_state *bc)
 144 {
 145 #ifdef BAYCOM_DEBUG
 146         unsigned long cur_jiffies = jiffies;
 147         /*
 148          * measure the interrupt frequency
 149          */
 150         bc->debug_vals.cur_intcnt++;
 151         if (time_after_eq(cur_jiffies, bc->debug_vals.last_jiffies + HZ)) {
 152                 bc->debug_vals.last_jiffies = cur_jiffies;
 153                 bc->debug_vals.last_intcnt = bc->debug_vals.cur_intcnt;
 154                 bc->debug_vals.cur_intcnt = 0;
 155                 bc->debug_vals.last_pllcorr = bc->debug_vals.cur_pllcorr;
 156                 bc->debug_vals.cur_pllcorr = 0;
 157         }
 158 #endif /* BAYCOM_DEBUG */
 159 }
 160
 161 /* --------------------------------------------------------------------- */
 162 /*
 163  * ===================== PAR96 specific routines =========================
 164  */
 165
 166 #define PAR96_DESCRAM_TAP1 0x20000
 167 #define PAR96_DESCRAM_TAP2 0x01000
 168 #define PAR96_DESCRAM_TAP3 0x00001
 169
 170 #define PAR96_DESCRAM_TAPSH1 17
 171 #define PAR96_DESCRAM_TAPSH2 12
 172 #define PAR96_DESCRAM_TAPSH3 0
 173
 174 #define PAR96_SCRAM_TAP1 0x20000 /* X^17 */
 175 #define PAR96_SCRAM_TAPN 0x00021 /* X^0+X^5 */
 176
 177 /* --------------------------------------------------------------------- */
 178
 179 static inline void par96_tx(struct net_device *dev, struct baycom_state *bc)
 180 {
 181         int i;
 182         unsigned int data = hdlcdrv_getbits(&bc->hdrv);
 183         struct parport *pp = bc->pdev->port;
 184
 185         for(i = 0; i < PAR96_BURSTBITS; i++, data >>= 1) {
 186                 unsigned char val = PAR97_POWER;
 187                 bc->modem.par96.scram = ((bc->modem.par96.scram << 1) |
 188                                          (bc->modem.par96.scram & 1));
 189                 if (!(data & 1))
 190                         bc->modem.par96.scram ^= 1;
 191                 if (bc->modem.par96.scram & (PAR96_SCRAM_TAP1 << 1))
 192                         bc->modem.par96.scram ^=
 193                                 (PAR96_SCRAM_TAPN << 1);
 194                 if (bc->modem.par96.scram & (PAR96_SCRAM_TAP1 << 2))
 195                         val |= PAR96_TXBIT;
 196                 pp->ops->write_data(pp, val);
 197                 pp->ops->write_data(pp, val | PAR96_BURST);
 198         }
 199 }
 200
 201 /* --------------------------------------------------------------------- */
 202
 203 static inline void par96_rx(struct net_device *dev, struct baycom_state *bc)
 204 {
 205         int i;
 206         unsigned int data, mask, mask2, descx;
 207         struct parport *pp = bc->pdev->port;
 208
 209         /*
 210          * do receiver; differential decode and descramble on the fly
 211          */
 212         for(data = i = 0; i < PAR96_BURSTBITS; i++) {
 213                 bc->modem.par96.descram = (bc->modem.par96.descram << 1);
 214                 if (pp->ops->read_status(pp) & PAR96_RXBIT)
 215                         bc->modem.par96.descram |= 1;
 216                 descx = bc->modem.par96.descram ^
 217                         (bc->modem.par96.descram >> 1);
 218                 /* now the diff decoded data is inverted in descram */
 219                 pp->ops->write_data(pp, PAR97_POWER | PAR96_PTT);
 220                 descx ^= ((descx >> PAR96_DESCRAM_TAPSH1) ^
 221                           (descx >> PAR96_DESCRAM_TAPSH2));
 222                 data >>= 1;
 223                 if (!(descx & 1))
 224                         data |= 0x8000;
 225                 pp->ops->write_data(pp, PAR97_POWER | PAR96_PTT | PAR96_BURST);
 226         }
 227         hdlcdrv_putbits(&bc->hdrv, data);
 228         /*
 229          * do DCD algorithm
 230          */
 231         if (bc->options & BAYCOM_OPTIONS_SOFTDCD) {
 232                 bc->modem.par96.dcd_shreg = (bc->modem.par96.dcd_shreg >> 16)
 233                         | (data << 16);
 234                 /* search for flags and set the dcd counter appropriately */
 235                 for(mask = 0x1fe00, mask2 = 0xfc00, i = 0;
 236                     i < PAR96_BURSTBITS; i++, mask <<= 1, mask2 <<= 1)
 237                         if ((bc->modem.par96.dcd_shreg & mask) == mask2)
 238                                 bc->modem.par96.dcd_count = HDLCDRV_MAXFLEN+4;
 239                 /* check for abort/noise sequences */
 240                 for(mask = 0x1fe00, mask2 = 0x1fe00, i = 0;
 241                     i < PAR96_BURSTBITS; i++, mask <<= 1, mask2 <<= 1)
 242                         if (((bc->modem.par96.dcd_shreg & mask) == mask2) &&
 243                             (bc->modem.par96.dcd_count >= 0))
 244                                 bc->modem.par96.dcd_count -= HDLCDRV_MAXFLEN-10;
 245                 /* decrement and set the dcd variable */
 246                 if (bc->modem.par96.dcd_count >= 0)
 247                         bc->modem.par96.dcd_count -= 2;
 248                 hdlcdrv_setdcd(&bc->hdrv, bc->modem.par96.dcd_count > 0);
 249         } else {
 250                 hdlcdrv_setdcd(&bc->hdrv, !!(pp->ops->read_status(pp) & PAR96_DCD));
 251         }
 252 }
 253
 254 /* --------------------------------------------------------------------- */
 255
 256 static void par96_interrupt(void *dev_id)
 257 {
 258         struct net_device *dev = dev_id;
 259         struct baycom_state *bc = netdev_priv(dev);
 260
 261         baycom_int_freq(bc);
 262         /*
 263          * check if transmitter active
 264          */
 265         if (hdlcdrv_ptt(&bc->hdrv))
 266                 par96_tx(dev, bc);
 267         else {
 268                 par96_rx(dev, bc);
 269                 if (--bc->modem.arb_divider <= 0) {
 270                         bc->modem.arb_divider = 6;
 271                         local_irq_enable();
 272                         hdlcdrv_arbitrate(dev, &bc->hdrv);
 273                 }
 274         }
 275         local_irq_enable();
 276         hdlcdrv_transmitter(dev, &bc->hdrv);
 277         hdlcdrv_receiver(dev, &bc->hdrv);
 278         local_irq_disable();
 279 }
 280
 281 /* --------------------------------------------------------------------- */
 282
 283 static void par96_wakeup(void *handle)
 284 {
 285         struct net_device *dev = (struct net_device *)handle;
 286         struct baycom_state *bc = netdev_priv(dev);
 287
 288         printk(KERN_DEBUG "baycom_par: %s: why am I being woken up?\n", dev->name);
 289         if (!parport_claim(bc->pdev))
 290                 printk(KERN_DEBUG "baycom_par: %s: I'm broken.\n", dev->name);
 291 }
 292
 293 /* --------------------------------------------------------------------- */
 294
 295 static int par96_open(struct net_device *dev)
 296 {
 297         struct baycom_state *bc = netdev_priv(dev);
 298         struct pardev_cb par_cb;
 299         struct parport *pp;
 300         int i;
 301
 302         if (!dev || !bc)
 303                 return -ENXIO;
 304         pp = parport_find_base(dev->base_addr);
 305         if (!pp) {
 306                 printk(KERN_ERR "baycom_par: parport at 0x%lx unknown\n", dev->base_addr);
 307                 return -ENXIO;
 308         }
 309         if (pp->irq < 0) {
 310                 printk(KERN_ERR "baycom_par: parport at 0x%lx has no irq\n", pp->base);
 311                 parport_put_port(pp);
 312                 return -ENXIO;
 313         }
 314         if ((~pp->modes) & (PARPORT_MODE_PCSPP | PARPORT_MODE_SAFEININT)) {
 315                 printk(KERN_ERR "baycom_par: parport at 0x%lx cannot be used\n", pp->base);
 316                 parport_put_port(pp);
 317                 return -ENXIO;
 318         }
 319         memset(&bc->modem, 0, sizeof(bc->modem));
 320         bc->hdrv.par.bitrate = 9600;
 321         memset(&par_cb, 0, sizeof(par_cb));
 322         par_cb.wakeup = par96_wakeup;
 323         par_cb.irq_func = par96_interrupt;
 324         par_cb.private = (void *)dev;
 325         par_cb.flags = PARPORT_DEV_EXCL;
 326         for (i = 0; i < NR_PORTS; i++)
 327                 if (baycom_device[i] == dev)
 328                         break;
 329
 330         if (i == NR_PORTS) {
 331                 pr_err("%s: no device found\n", bc_drvname);
 332                 parport_put_port(pp);
 333                 return -ENODEV;
 334         }
 335         bc->pdev = parport_register_dev_model(pp, dev->name, &par_cb, i);
 336         parport_put_port(pp);
 337         if (!bc->pdev) {
 338                 printk(KERN_ERR "baycom_par: cannot register parport at 0x%lx\n", dev->base_addr);
 339                 return -ENXIO;
 340         }
 341         if (parport_claim(bc->pdev)) {
 342                 printk(KERN_ERR "baycom_par: parport at 0x%lx busy\n", pp->base);
 343                 parport_unregister_device(bc->pdev);
 344                 return -EBUSY;
 345         }
 346         pp = bc->pdev->port;
 347         dev->irq = pp->irq;
 348         pp->ops->data_forward(pp);
 349         bc->hdrv.par.bitrate = 9600;
 350         pp->ops->write_data(pp, PAR96_PTT | PAR97_POWER); /* switch off PTT */
 351         pp->ops->enable_irq(pp);
 352         printk(KERN_INFO "%s: par96 at iobase 0x%lx irq %u options 0x%x\n",
 353                bc_drvname, dev->base_addr, dev->irq, bc->options);
 354         return 0;
 355 }
 356
 357 /* --------------------------------------------------------------------- */
 358
 359 static int par96_close(struct net_device *dev)
 360 {
 361         struct baycom_state *bc = netdev_priv(dev);
 362         struct parport *pp;
 363
 364         if (!dev || !bc)
 365                 return -EINVAL;
 366         pp = bc->pdev->port;
 367         /* disable interrupt */
 368         pp->ops->disable_irq(pp);
 369         /* switch off PTT */
 370         pp->ops->write_data(pp, PAR96_PTT | PAR97_POWER);
 371         parport_release(bc->pdev);
 372         parport_unregister_device(bc->pdev);
 373         printk(KERN_INFO "%s: close par96 at iobase 0x%lx irq %u\n",
 374                bc_drvname, dev->base_addr, dev->irq);
 375         return 0;
 376 }
 377
 378 /* --------------------------------------------------------------------- */
 379 /*
 380  * ===================== hdlcdrv driver interface =========================
 381  */
 382
 383 static int baycom_ioctl(struct net_device *dev, void __user *data,
 384                         struct hdlcdrv_ioctl *hi, int cmd);
 385
 386 /* --------------------------------------------------------------------- */
 387
 388 static const struct hdlcdrv_ops par96_ops = {
 389         .drvname = bc_drvname,
 390         .drvinfo = bc_drvinfo,
 391         .open    = par96_open,
 392         .close   = par96_close,
 393         .ioctl   = baycom_ioctl
 394 };
 395
 396 /* --------------------------------------------------------------------- */
 397
 398 static int baycom_setmode(struct baycom_state *bc, const char *modestr)
 399 {
 400         if (!strncmp(modestr, "picpar", 6))
 401                 bc->options = 0;
 402         else if (!strncmp(modestr, "par96", 5))
 403                 bc->options = BAYCOM_OPTIONS_SOFTDCD;
 404         else
 405                 bc->options = !!strchr(modestr, '*');
 406         return 0;
 407 }
 408
 409 /* --------------------------------------------------------------------- */
 410
 411 static int baycom_ioctl(struct net_device *dev, void __user *data,
 412                         struct hdlcdrv_ioctl *hi, int cmd)
 413 {
 414         struct baycom_state *bc;
 415         struct baycom_ioctl bi;
 416
 417         if (!dev)
 418                 return -EINVAL;
 419
 420         bc = netdev_priv(dev);
 421         BUG_ON(bc->hdrv.magic != HDLCDRV_MAGIC);
 422
 423         if (cmd != SIOCDEVPRIVATE)
 424                 return -ENOIOCTLCMD;
 425         switch (hi->cmd) {
 426         default:
 427                 break;
 428
 429         case HDLCDRVCTL_GETMODE:
 430                 strcpy(hi->data.modename, bc->options ? "par96" : "picpar");
 431                 if (copy_to_user(data, hi, sizeof(struct hdlcdrv_ioctl)))
 432                         return -EFAULT;
 433                 return 0;
 434
 435         case HDLCDRVCTL_SETMODE:
 436                 if (netif_running(dev) || !capable(CAP_NET_ADMIN))
 437                         return -EACCES;
 438                 hi->data.modename[sizeof(hi->data.modename)-1] = '\0';
 439                 return baycom_setmode(bc, hi->data.modename);
 440
 441         case HDLCDRVCTL_MODELIST:
 442                 strcpy(hi->data.modename, "par96,picpar");
 443                 if (copy_to_user(data, hi, sizeof(struct hdlcdrv_ioctl)))
 444                         return -EFAULT;
 445                 return 0;
 446
 447         case HDLCDRVCTL_MODEMPARMASK:
 448                 return HDLCDRV_PARMASK_IOBASE;
 449
 450         }
 451
 452         if (copy_from_user(&bi, data, sizeof(bi)))
 453                 return -EFAULT;
 454         switch (bi.cmd) {
 455         default:
 456                 return -ENOIOCTLCMD;
 457
 458 #ifdef BAYCOM_DEBUG
 459         case BAYCOMCTL_GETDEBUG:
 460                 bi.data.dbg.debug1 = bc->hdrv.ptt_keyed;
 461                 bi.data.dbg.debug2 = bc->debug_vals.last_intcnt;
 462                 bi.data.dbg.debug3 = bc->debug_vals.last_pllcorr;
 463                 break;
 464 #endif /* BAYCOM_DEBUG */
 465
 466         }
 467         if (copy_to_user(data, &bi, sizeof(bi)))
 468                 return -EFAULT;
 469         return 0;
 470
 471 }
 472
 473 /* --------------------------------------------------------------------- */
 474
 475 /*
 476  * command line settable parameters
 477  */
 478 static char *mode[NR_PORTS] = { "picpar", };
 479 static int iobase[NR_PORTS] = { 0x378, };
 480
 481 module_param_array(mode, charp, NULL, 0);
 482 MODULE_PARM_DESC(mode, "baycom operating mode; eg. par96 or picpar");
 483 module_param_hw_array(iobase, int, ioport, NULL, 0);
 484 MODULE_PARM_DESC(iobase, "baycom io base address");
 485
 486 MODULE_AUTHOR("Thomas M. Sailer, sailer@ife.ee.ethz.ch, hb9jnx@hb9w.che.eu");
 487 MODULE_DESCRIPTION("Baycom par96 and picpar amateur radio modem driver");
 488 MODULE_LICENSE("GPL");
 489
 490 /* --------------------------------------------------------------------- */
 491
 492 static int baycom_par_probe(struct pardevice *par_dev)
 493 {
 494         struct device_driver *drv = par_dev->dev.driver;
 495         int len = strlen(drv->name);
 496
 497         if (strncmp(par_dev->name, drv->name, len))
 498                 return -ENODEV;
 499
 500         return 0;
 501 }
 502
 503 static struct parport_driver baycom_par_driver = {
 504         .name = "bcp",
 505         .probe = baycom_par_probe,
 506 };
 507
 508 static int __init init_baycompar(void)
 509 {
 510         int i, found = 0, ret;
 511         char set_hw = 1;
 512
 513         printk(bc_drvinfo);
 514
 515         ret = parport_register_driver(&baycom_par_driver);
 516         if (ret)
 517                 return ret;
 518
 519         /*
 520          * register net devices
 521          */
 522         for (i = 0; i < NR_PORTS; i++) {
 523                 struct net_device *dev;
 524                 struct baycom_state *bc;
 525                 char ifname[IFNAMSIZ];
 526
 527                 sprintf(ifname, "bcp%d", i);
 528
 529                 if (!mode[i])
 530                         set_hw = 0;
 531                 if (!set_hw)
 532                         iobase[i] = 0;
 533
 534                 dev = hdlcdrv_register(&par96_ops,
 535                                        sizeof(struct baycom_state),
 536                                        ifname, iobase[i], 0, 0);
 537                 if (IS_ERR(dev))
 538                         break;
 539
 540                 bc = netdev_priv(dev);
 541                 if (set_hw && baycom_setmode(bc, mode[i]))
 542                         set_hw = 0;
 543                 found++;
 544                 baycom_device[i] = dev;
 545         }
 546
 547         if (!found) {
 548                 parport_unregister_driver(&baycom_par_driver);
 549                 return -ENXIO;
 550         }
 551         return 0;
 552 }
 553
 554 static void __exit cleanup_baycompar(void)
 555 {
 556         int i;
 557
 558         for(i = 0; i < NR_PORTS; i++) {
 559                 struct net_device *dev = baycom_device[i];
 560
 561                 if (dev)
 562                         hdlcdrv_unregister(dev);
 563         }
 564         parport_unregister_driver(&baycom_par_driver);
 565 }
 566
 567 module_init(init_baycompar);
 568 module_exit(cleanup_baycompar);
 569
 570 /* --------------------------------------------------------------------- */
 571
 572 #ifndef MODULE
 573
 574 /*
 575  * format: baycom_par=io,mode
 576  * mode: par96,picpar
 577  */
 578
 579 static int __init baycom_par_setup(char *str)
 580 {
 581         static unsigned nr_dev;
 582         int ints[2];
 583
 584         if (nr_dev >= NR_PORTS)
 585                 return 0;
 586         str = get_options(str, 2, ints);
 587         if (ints[0] < 1)
 588                 return 0;
 589         mode[nr_dev] = str;
 590         iobase[nr_dev] = ints[1];
 591         nr_dev++;
 592         return 1;
 593 }
 594
 595 __setup("baycom_par=", baycom_par_setup);
 596
 597 #endif /* MODULE */
 598 /* --------------------------------------------------------------------- */