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  37  *          from Baycom) and has been replaced by the PICPAR modem (see below).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
  88 #include <asm/bug.h>
  89 #include <asm/system.h>
  90 #include <asm/uaccess.h>
  91
  92 /* --------------------------------------------------------------------- */
  93
  94 #define BAYCOM_DEBUG
  95
  96 /*
  97  * modem options; bit mask
  98  */
  99 #define BAYCOM_OPTIONS_SOFTDCD  1
 100
 101 /* --------------------------------------------------------------------- */
 102
 103 static const char bc_drvname[] = "baycom_par";
 104 static const char bc_drvinfo[] = KERN_INFO "baycom_par: (C) 1996-2000 Thomas Sailer, HB9JNX/AE4WA\n"
 105 KERN_INFO "baycom_par: version 0.9 compiled " __TIME__ " " __DATE__ "\n";
 106
 107 /* --------------------------------------------------------------------- */
 108
 109 #define NR_PORTS 4
 110
 111 static struct net_device *baycom_device[NR_PORTS];
 112
 113 /* --------------------------------------------------------------------- */
 114
 115 #define PAR96_BURSTBITS 16
 116 #define PAR96_BURST     4
 117 #define PAR96_PTT       2
 118 #define PAR96_TXBIT     1
 119 #define PAR96_ACK       0x40
 120 #define PAR96_RXBIT     0x20
 121 #define PAR96_DCD       0x10
 122 #define PAR97_POWER     0xf8
 123
 124 /* ---------------------------------------------------------------------- */
 125 /*
 126  * Information that need to be kept for each board.
 127  */
 128
 129 struct baycom_state {
 130         struct hdlcdrv_state hdrv;
 131
 132         struct pardevice *pdev;
 133         unsigned int options;
 134
 135         struct modem_state {
 136                 short arb_divider;
 137                 unsigned char flags;
 138                 unsigned int shreg;
 139                 struct modem_state_par96 {
 140                         int dcd_count;
 141                         unsigned int dcd_shreg;
 142                         unsigned long descram;
 143                         unsigned long scram;
 144                 } par96;
 145         } modem;
 146
 147 #ifdef BAYCOM_DEBUG
 148         struct debug_vals {
 149                 unsigned long last_jiffies;
 150                 unsigned cur_intcnt;
 151                 unsigned last_intcnt;
 152                 int cur_pllcorr;
 153                 int last_pllcorr;
 154         } debug_vals;
 155 #endif /* BAYCOM_DEBUG */
 156 };
 157
 158 /* --------------------------------------------------------------------- */
 159
 160 static void __inline__ baycom_int_freq(struct baycom_state *bc)
 161 {
 162 #ifdef BAYCOM_DEBUG
 163         unsigned long cur_jiffies = jiffies;
 164         /*
 165          * measure the interrupt frequency
 166          */
 167         bc->debug_vals.cur_intcnt++;
 168         if ((cur_jiffies - bc->debug_vals.last_jiffies) >= HZ) {
 169                 bc->debug_vals.last_jiffies = cur_jiffies;
 170                 bc->debug_vals.last_intcnt = bc->debug_vals.cur_intcnt;
 171                 bc->debug_vals.cur_intcnt = 0;
 172                 bc->debug_vals.last_pllcorr = bc->debug_vals.cur_pllcorr;
 173                 bc->debug_vals.cur_pllcorr = 0;
 174         }
 175 #endif /* BAYCOM_DEBUG */
 176 }
 177
 178 /* --------------------------------------------------------------------- */
 179 /*
 180  * ===================== PAR96 specific routines =========================
 181  */
 182
 183 #define PAR96_DESCRAM_TAP1 0x20000
 184 #define PAR96_DESCRAM_TAP2 0x01000
 185 #define PAR96_DESCRAM_TAP3 0x00001
 186
 187 #define PAR96_DESCRAM_TAPSH1 17
 188 #define PAR96_DESCRAM_TAPSH2 12
 189 #define PAR96_DESCRAM_TAPSH3 0
 190
 191 #define PAR96_SCRAM_TAP1 0x20000 /* X^17 */
 192 #define PAR96_SCRAM_TAPN 0x00021 /* X^0+X^5 */
 193
 194 /* --------------------------------------------------------------------- */
 195
 196 static __inline__ void par96_tx(struct net_device *dev, struct baycom_state *bc)
 197 {
 198         int i;
 199         unsigned int data = hdlcdrv_getbits(&bc->hdrv);
 200         struct parport *pp = bc->pdev->port;
 201
 202         for(i = 0; i < PAR96_BURSTBITS; i++, data >>= 1) {
 203                 unsigned char val = PAR97_POWER;
 204                 bc->modem.par96.scram = ((bc->modem.par96.scram << 1) |
 205                                          (bc->modem.par96.scram & 1));
 206                 if (!(data & 1))
 207                         bc->modem.par96.scram ^= 1;
 208                 if (bc->modem.par96.scram & (PAR96_SCRAM_TAP1 << 1))
 209                         bc->modem.par96.scram ^=
 210                                 (PAR96_SCRAM_TAPN << 1);
 211                 if (bc->modem.par96.scram & (PAR96_SCRAM_TAP1 << 2))
 212                         val |= PAR96_TXBIT;
 213                 pp->ops->write_data(pp, val);
 214                 pp->ops->write_data(pp, val | PAR96_BURST);
 215         }
 216 }
 217
 218 /* --------------------------------------------------------------------- */
 219
 220 static __inline__ void par96_rx(struct net_device *dev, struct baycom_state *bc)
 221 {
 222         int i;
 223         unsigned int data, mask, mask2, descx;
 224         struct parport *pp = bc->pdev->port;
 225
 226         /*
 227          * do receiver; differential decode and descramble on the fly
 228          */
 229         for(data = i = 0; i < PAR96_BURSTBITS; i++) {
 230                 bc->modem.par96.descram = (bc->modem.par96.descram << 1);
 231                 if (pp->ops->read_status(pp) & PAR96_RXBIT)
 232                         bc->modem.par96.descram |= 1;
 233                 descx = bc->modem.par96.descram ^
 234                         (bc->modem.par96.descram >> 1);
 235                 /* now the diff decoded data is inverted in descram */
 236                 pp->ops->write_data(pp, PAR97_POWER | PAR96_PTT);
 237                 descx ^= ((descx >> PAR96_DESCRAM_TAPSH1) ^
 238                           (descx >> PAR96_DESCRAM_TAPSH2));
 239                 data >>= 1;
 240                 if (!(descx & 1))
 241                         data |= 0x8000;
 242                 pp->ops->write_data(pp, PAR97_POWER | PAR96_PTT | PAR96_BURST);
 243         }
 244         hdlcdrv_putbits(&bc->hdrv, data);
 245         /*
 246          * do DCD algorithm
 247          */
 248         if (bc->options & BAYCOM_OPTIONS_SOFTDCD) {
 249                 bc->modem.par96.dcd_shreg = (bc->modem.par96.dcd_shreg >> 16)
 250                         | (data << 16);
 251                 /* search for flags and set the dcd counter appropriately */
 252                 for(mask = 0x1fe00, mask2 = 0xfc00, i = 0;
 253                     i < PAR96_BURSTBITS; i++, mask <<= 1, mask2 <<= 1)
 254                         if ((bc->modem.par96.dcd_shreg & mask) == mask2)
 255                                 bc->modem.par96.dcd_count = HDLCDRV_MAXFLEN+4;
 256                 /* check for abort/noise sequences */
 257                 for(mask = 0x1fe00, mask2 = 0x1fe00, i = 0;
 258                     i < PAR96_BURSTBITS; i++, mask <<= 1, mask2 <<= 1)
 259                         if (((bc->modem.par96.dcd_shreg & mask) == mask2) &&
 260                             (bc->modem.par96.dcd_count >= 0))
 261                                 bc->modem.par96.dcd_count -= HDLCDRV_MAXFLEN-10;
 262                 /* decrement and set the dcd variable */
 263                 if (bc->modem.par96.dcd_count >= 0)
 264                         bc->modem.par96.dcd_count -= 2;
 265                 hdlcdrv_setdcd(&bc->hdrv, bc->modem.par96.dcd_count > 0);
 266         } else {
 267                 hdlcdrv_setdcd(&bc->hdrv, !!(pp->ops->read_status(pp) & PAR96_DCD));
 268         }
 269 }
 270
 271 /* --------------------------------------------------------------------- */
 272
 273 static void par96_interrupt(int irq, void *dev_id, struct pt_regs *regs)
 274 {
 275         struct net_device *dev = (struct net_device *)dev_id;
 276         struct baycom_state *bc = netdev_priv(dev);
 277
 278         baycom_int_freq(bc);
 279         /*
 280          * check if transmitter active
 281          */
 282         if (hdlcdrv_ptt(&bc->hdrv))
 283                 par96_tx(dev, bc);
 284         else {
 285                 par96_rx(dev, bc);
 286                 if (--bc->modem.arb_divider <= 0) {
 287                         bc->modem.arb_divider = 6;
 288                         local_irq_enable();
 289                         hdlcdrv_arbitrate(dev, &bc->hdrv);
 290                 }
 291         }
 292         local_irq_enable();
 293         hdlcdrv_transmitter(dev, &bc->hdrv);
 294         hdlcdrv_receiver(dev, &bc->hdrv);
 295         local_irq_disable();
 296 }
 297
 298 /* --------------------------------------------------------------------- */
 299
 300 static void par96_wakeup(void *handle)
 301 {
 302         struct net_device *dev = (struct net_device *)handle;
 303         struct baycom_state *bc = netdev_priv(dev);
 304
 305         printk(KERN_DEBUG "baycom_par: %s: why am I being woken up?\n", dev->name);
 306         if (!parport_claim(bc->pdev))
 307                 printk(KERN_DEBUG "baycom_par: %s: I'm broken.\n", dev->name);
 308 }
 309
 310 /* --------------------------------------------------------------------- */
 311
 312 static int par96_open(struct net_device *dev)
 313 {
 314         struct baycom_state *bc = netdev_priv(dev);
 315         struct parport *pp;
 316
 317         if (!dev || !bc)
 318                 return -ENXIO;
 319         pp = parport_find_base(dev->base_addr);
 320         if (!pp) {
 321                 printk(KERN_ERR "baycom_par: parport at 0x%lx unknown\n", dev->base_addr);
 322                 return -ENXIO;
 323         }
 324         if (pp->irq < 0) {
 325                 printk(KERN_ERR "baycom_par: parport at 0x%lx has no irq\n", pp->base);
 326                 parport_put_port(pp);
 327                 return -ENXIO;
 328         }
 329         if ((~pp->modes) & (PARPORT_MODE_PCSPP | PARPORT_MODE_SAFEININT)) {
 330                 printk(KERN_ERR "baycom_par: parport at 0x%lx cannot be used\n", pp->base);
 331                 parport_put_port(pp);
 332                 return -ENXIO;
 333         }
 334         memset(&bc->modem, 0, sizeof(bc->modem));
 335         bc->hdrv.par.bitrate = 9600;
 336         bc->pdev = parport_register_device(pp, dev->name, NULL, par96_wakeup,
 337                                  par96_interrupt, PARPORT_DEV_EXCL, dev);
 338         parport_put_port(pp);
 339         if (!bc->pdev) {
 340                 printk(KERN_ERR "baycom_par: cannot register parport at 0x%lx\n", dev->base_addr);
 341                 return -ENXIO;
 342         }
 343         if (parport_claim(bc->pdev)) {
 344                 printk(KERN_ERR "baycom_par: parport at 0x%lx busy\n", pp->base);
 345                 parport_unregister_device(bc->pdev);
 346                 return -EBUSY;
 347         }
 348         pp = bc->pdev->port;
 349         dev->irq = pp->irq;
 350         pp->ops->data_forward(pp);
 351         bc->hdrv.par.bitrate = 9600;
 352         pp->ops->write_data(pp, PAR96_PTT | PAR97_POWER); /* switch off PTT */
 353         pp->ops->enable_irq(pp);
 354         printk(KERN_INFO "%s: par96 at iobase 0x%lx irq %u options 0x%x\n",
 355                bc_drvname, dev->base_addr, dev->irq, bc->options);
 356         return 0;
 357 }
 358
 359 /* --------------------------------------------------------------------- */
 360
 361 static int par96_close(struct net_device *dev)
 362 {
 363         struct baycom_state *bc = netdev_priv(dev);
 364         struct parport *pp;
 365
 366         if (!dev || !bc)
 367                 return -EINVAL;
 368         pp = bc->pdev->port;
 369         /* disable interrupt */
 370         pp->ops->disable_irq(pp);
 371         /* switch off PTT */
 372         pp->ops->write_data(pp, PAR96_PTT | PAR97_POWER);
 373         parport_release(bc->pdev);
 374         parport_unregister_device(bc->pdev);
 375         printk(KERN_INFO "%s: close par96 at iobase 0x%lx irq %u\n",
 376                bc_drvname, dev->base_addr, dev->irq);
 377         return 0;
 378 }
 379
 380 /* --------------------------------------------------------------------- */
 381 /*
 382  * ===================== hdlcdrv driver interface =========================
 383  */
 384
 385 static int baycom_ioctl(struct net_device *dev, struct ifreq *ifr,
 386                         struct hdlcdrv_ioctl *hi, int cmd);
 387
 388 /* --------------------------------------------------------------------- */
 389
 390 static struct hdlcdrv_ops par96_ops = {
 391         .drvname = bc_drvname,
 392         .drvinfo = bc_drvinfo,
 393         .open    = par96_open,
 394         .close   = par96_close,
 395         .ioctl   = baycom_ioctl
 396 };
 397
 398 /* --------------------------------------------------------------------- */
 399
 400 static int baycom_setmode(struct baycom_state *bc, const char *modestr)
 401 {
 402         if (!strncmp(modestr, "picpar", 6))
 403                 bc->options = 0;
 404         else if (!strncmp(modestr, "par96", 5))
 405                 bc->options = BAYCOM_OPTIONS_SOFTDCD;
 406         else
 407                 bc->options = !!strchr(modestr, '*');
 408         return 0;
 409 }
 410
 411 /* --------------------------------------------------------------------- */
 412
 413 static int baycom_ioctl(struct net_device *dev, struct ifreq *ifr,
 414                         struct hdlcdrv_ioctl *hi, int cmd)
 415 {
 416         struct baycom_state *bc;
 417         struct baycom_ioctl bi;
 418
 419         if (!dev)
 420                 return -EINVAL;
 421
 422         bc = netdev_priv(dev);
 423         BUG_ON(bc->hdrv.magic != HDLCDRV_MAGIC);
 424
 425         if (cmd != SIOCDEVPRIVATE)
 426                 return -ENOIOCTLCMD;
 427         switch (hi->cmd) {
 428         default:
 429                 break;
 430
 431         case HDLCDRVCTL_GETMODE:
 432                 strcpy(hi->data.modename, bc->options ? "par96" : "picpar");
 433                 if (copy_to_user(ifr->ifr_data, hi, sizeof(struct hdlcdrv_ioctl)))
 434                         return -EFAULT;
 435                 return 0;
 436
 437         case HDLCDRVCTL_SETMODE:
 438                 if (netif_running(dev) || !capable(CAP_NET_ADMIN))
 439                         return -EACCES;
 440                 hi->data.modename[sizeof(hi->data.modename)-1] = '\0';
 441                 return baycom_setmode(bc, hi->data.modename);
 442
 443         case HDLCDRVCTL_MODELIST:
 444                 strcpy(hi->data.modename, "par96,picpar");
 445                 if (copy_to_user(ifr->ifr_data, hi, sizeof(struct hdlcdrv_ioctl)))
 446                         return -EFAULT;
 447                 return 0;
 448
 449         case HDLCDRVCTL_MODEMPARMASK:
 450                 return HDLCDRV_PARMASK_IOBASE;
 451
 452         }
 453
 454         if (copy_from_user(&bi, ifr->ifr_data, sizeof(bi)))
 455                 return -EFAULT;
 456         switch (bi.cmd) {
 457         default:
 458                 return -ENOIOCTLCMD;
 459
 460 #ifdef BAYCOM_DEBUG
 461         case BAYCOMCTL_GETDEBUG:
 462                 bi.data.dbg.debug1 = bc->hdrv.ptt_keyed;
 463                 bi.data.dbg.debug2 = bc->debug_vals.last_intcnt;
 464                 bi.data.dbg.debug3 = bc->debug_vals.last_pllcorr;
 465                 break;
 466 #endif /* BAYCOM_DEBUG */
 467
 468         }
 469         if (copy_to_user(ifr->ifr_data, &bi, sizeof(bi)))
 470                 return -EFAULT;
 471         return 0;
 472
 473 }
 474
 475 /* --------------------------------------------------------------------- */
 476
 477 /*
 478  * command line settable parameters
 479  */
 480 static const char *mode[NR_PORTS] = { "picpar", };
 481 static int iobase[NR_PORTS] = { 0x378, };
 482
 483 module_param_array(mode, charp, NULL, 0);
 484 MODULE_PARM_DESC(mode, "baycom operating mode; eg. par96 or picpar");
 485 module_param_array(iobase, int, NULL, 0);
 486 MODULE_PARM_DESC(iobase, "baycom io base address");
 487
 488 MODULE_AUTHOR("Thomas M. Sailer, sailer@ife.ee.ethz.ch, hb9jnx@hb9w.che.eu");
 489 MODULE_DESCRIPTION("Baycom par96 and picpar amateur radio modem driver");
 490 MODULE_LICENSE("GPL");
 491
 492 /* --------------------------------------------------------------------- */
 493
 494 static int __init init_baycompar(void)
 495 {
 496         int i, found = 0;
 497         char set_hw = 1;
 498
 499         printk(bc_drvinfo);
 500         /*
 501          * register net devices
 502          */
 503         for (i = 0; i < NR_PORTS; i++) {
 504                 struct net_device *dev;
 505                 struct baycom_state *bc;
 506                 char ifname[IFNAMSIZ];
 507
 508                 sprintf(ifname, "bcp%d", i);
 509
 510                 if (!mode[i])
 511                         set_hw = 0;
 512                 if (!set_hw)
 513                         iobase[i] = 0;
 514
 515                 dev = hdlcdrv_register(&par96_ops,
 516                                        sizeof(struct baycom_state),
 517                                        ifname, iobase[i], 0, 0);
 518                 if (IS_ERR(dev))
 519                         break;
 520
 521                 bc = netdev_priv(dev);
 522                 if (set_hw && baycom_setmode(bc, mode[i]))
 523                         set_hw = 0;
 524                 found++;
 525                 baycom_device[i] = dev;
 526         }
 527
 528         if (!found)
 529                 return -ENXIO;
 530         return 0;
 531 }
 532
 533 static void __exit cleanup_baycompar(void)
 534 {
 535         int i;
 536
 537         for(i = 0; i < NR_PORTS; i++) {
 538                 struct net_device *dev = baycom_device[i];
 539
 540                 if (dev)
 541                         hdlcdrv_unregister(dev);
 542         }
 543 }
 544
 545 module_init(init_baycompar);
 546 module_exit(cleanup_baycompar);
 547
 548 /* --------------------------------------------------------------------- */
 549
 550 #ifndef MODULE
 551
 552 /*
 553  * format: baycom_par=io,mode
 554  * mode: par96,picpar
 555  */
 556
 557 static int __init baycom_par_setup(char *str)
 558 {
 559         static unsigned nr_dev;
 560         int ints[2];
 561
 562         if (nr_dev >= NR_PORTS)
 563                 return 0;
 564         str = get_options(str, 2, ints);
 565         if (ints[0] < 1)
 566                 return 0;
 567         mode[nr_dev] = str;
 568         iobase[nr_dev] = ints[1];
 569         nr_dev++;
 570         return 1;
 571 }
 572
 573 __setup("baycom_par=", baycom_par_setup);
 574
 575 #endif /* MODULE */
 576 /* --------------------------------------------------------------------- */