git.oblomov.eu Git - linux-2.6/blob - drivers/net/hamradio/hdlcdrv.c

   1 /*****************************************************************************/
   2
   3 /*
   4  *      hdlcdrv.c  -- HDLC packet radio network 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  *  The driver was derived from Donald Beckers skeleton.c
  27  *      Written 1993-94 by Donald Becker.
  28  *
  29  *  History:
  30  *   0.1  21.09.1996  Started
  31  *        18.10.1996  Changed to new user space access routines
  32  *                    (copy_{to,from}_user)
  33  *   0.2  21.11.1996  various small changes
  34  *   0.3  03.03.1997  fixed (hopefully) IP not working with ax.25 as a module
  35  *   0.4  16.04.1997  init code/data tagged
  36  *   0.5  30.07.1997  made HDLC buffers bigger (solves a problem with the
  37  *                    soundmodem driver)
  38  *   0.6  05.04.1998  add spinlocks
  39  *   0.7  03.08.1999  removed some old compatibility cruft
  40  *   0.8  12.02.2000  adapted to softnet driver interface
  41  */
  42
  43 /*****************************************************************************/
  44
  45 #include <linux/module.h>
  46 #include <linux/types.h>
  47 #include <linux/net.h>
  48 #include <linux/in.h>
  49 #include <linux/if.h>
  50 #include <linux/slab.h>
  51 #include <linux/errno.h>
  52 #include <linux/init.h>
  53 #include <linux/bitops.h>
  54
  55 #include <linux/netdevice.h>
  56 #include <linux/if_arp.h>
  57 #include <linux/skbuff.h>
  58 #include <linux/hdlcdrv.h>
  59 #include <linux/random.h>
  60 #include <net/ax25.h>
  61 #include <asm/uaccess.h>
  62
  63 #include <linux/crc-ccitt.h>
  64
  65 /* --------------------------------------------------------------------- */
  66
  67 #define KISS_VERBOSE
  68
  69 /* --------------------------------------------------------------------- */
  70
  71 #define PARAM_TXDELAY   1
  72 #define PARAM_PERSIST   2
  73 #define PARAM_SLOTTIME  3
  74 #define PARAM_TXTAIL    4
  75 #define PARAM_FULLDUP   5
  76 #define PARAM_HARDWARE  6
  77 #define PARAM_RETURN    255
  78
  79 /* --------------------------------------------------------------------- */
  80 /*
  81  * the CRC routines are stolen from WAMPES
  82  * by Dieter Deyke
  83  */
  84
  85
  86 /*---------------------------------------------------------------------------*/
  87
  88 static inline void append_crc_ccitt(unsigned char *buffer, int len)
  89 {
  90         unsigned int crc = crc_ccitt(0xffff, buffer, len) ^ 0xffff;
  91         buffer += len;
  92         *buffer++ = crc;
  93         *buffer++ = crc >> 8;
  94 }
  95
  96 /*---------------------------------------------------------------------------*/
  97
  98 static inline int check_crc_ccitt(const unsigned char *buf, int cnt)
  99 {
 100         return (crc_ccitt(0xffff, buf, cnt) & 0xffff) == 0xf0b8;
 101 }
 102
 103 /*---------------------------------------------------------------------------*/
 104
 105 #if 0
 106 static int calc_crc_ccitt(const unsigned char *buf, int cnt)
 107 {
 108         unsigned int crc = 0xffff;
 109
 110         for (; cnt > 0; cnt--)
 111                 crc = (crc >> 8) ^ crc_ccitt_table[(crc ^ *buf++) & 0xff];
 112         crc ^= 0xffff;
 113         return (crc & 0xffff);
 114 }
 115 #endif
 116
 117 /* ---------------------------------------------------------------------- */
 118
 119 #define tenms_to_2flags(s,tenms) ((tenms * s->par.bitrate) / 100 / 16)
 120
 121 /* ---------------------------------------------------------------------- */
 122 /*
 123  * The HDLC routines
 124  */
 125
 126 static int hdlc_rx_add_bytes(struct hdlcdrv_state *s, unsigned int bits,
 127                              int num)
 128 {
 129         int added = 0;
 130
 131         while (s->hdlcrx.rx_state && num >= 8) {
 132                 if (s->hdlcrx.len >= sizeof(s->hdlcrx.buffer)) {
 133                         s->hdlcrx.rx_state = 0;
 134                         return 0;
 135                 }
 136                 *s->hdlcrx.bp++ = bits >> (32-num);
 137                 s->hdlcrx.len++;
 138                 num -= 8;
 139                 added += 8;
 140         }
 141         return added;
 142 }
 143
 144 static void hdlc_rx_flag(struct net_device *dev, struct hdlcdrv_state *s)
 145 {
 146         struct sk_buff *skb;
 147         int pkt_len;
 148         unsigned char *cp;
 149
 150         if (s->hdlcrx.len < 4)
 151                 return;
 152         if (!check_crc_ccitt(s->hdlcrx.buffer, s->hdlcrx.len))
 153                 return;
 154         pkt_len = s->hdlcrx.len - 2 + 1; /* KISS kludge */
 155         if (!(skb = dev_alloc_skb(pkt_len))) {
 156                 printk("%s: memory squeeze, dropping packet\n", dev->name);
 157                 dev->stats.rx_dropped++;
 158                 return;
 159         }
 160         cp = skb_put(skb, pkt_len);
 161         *cp++ = 0; /* KISS kludge */
 162         memcpy(cp, s->hdlcrx.buffer, pkt_len - 1);
 163         skb->protocol = ax25_type_trans(skb, dev);
 164         netif_rx(skb);
 165         dev->stats.rx_packets++;
 166 }
 167
 168 void hdlcdrv_receiver(struct net_device *dev, struct hdlcdrv_state *s)
 169 {
 170         int i;
 171         unsigned int mask1, mask2, mask3, mask4, mask5, mask6, word;
 172
 173         if (!s || s->magic != HDLCDRV_MAGIC)
 174                 return;
 175         if (test_and_set_bit(0, &s->hdlcrx.in_hdlc_rx))
 176                 return;
 177
 178         while (!hdlcdrv_hbuf_empty(&s->hdlcrx.hbuf)) {
 179                 word = hdlcdrv_hbuf_get(&s->hdlcrx.hbuf);
 180
 181 #ifdef HDLCDRV_DEBUG
 182                 hdlcdrv_add_bitbuffer_word(&s->bitbuf_hdlc, word);
 183 #endif /* HDLCDRV_DEBUG */
 184                 s->hdlcrx.bitstream >>= 16;
 185                 s->hdlcrx.bitstream |= word << 16;
 186                 s->hdlcrx.bitbuf >>= 16;
 187                 s->hdlcrx.bitbuf |= word << 16;
 188                 s->hdlcrx.numbits += 16;
 189                 for(i = 15, mask1 = 0x1fc00, mask2 = 0x1fe00, mask3 = 0x0fc00,
 190                     mask4 = 0x1f800, mask5 = 0xf800, mask6 = 0xffff;
 191                     i >= 0;
 192                     i--, mask1 <<= 1, mask2 <<= 1, mask3 <<= 1, mask4 <<= 1,
 193                     mask5 <<= 1, mask6 = (mask6 << 1) | 1) {
 194                         if ((s->hdlcrx.bitstream & mask1) == mask1)
 195                                 s->hdlcrx.rx_state = 0; /* abort received */
 196                         else if ((s->hdlcrx.bitstream & mask2) == mask3) {
 197                                 /* flag received */
 198                                 if (s->hdlcrx.rx_state) {
 199                                         hdlc_rx_add_bytes(s, s->hdlcrx.bitbuf
 200                                                           << (8+i),
 201                                                           s->hdlcrx.numbits
 202                                                           -8-i);
 203                                         hdlc_rx_flag(dev, s);
 204                                 }
 205                                 s->hdlcrx.len = 0;
 206                                 s->hdlcrx.bp = s->hdlcrx.buffer;
 207                                 s->hdlcrx.rx_state = 1;
 208                                 s->hdlcrx.numbits = i;
 209                         } else if ((s->hdlcrx.bitstream & mask4) == mask5) {
 210                                 /* stuffed bit */
 211                                 s->hdlcrx.numbits--;
 212                                 s->hdlcrx.bitbuf = (s->hdlcrx.bitbuf & (~mask6)) |
 213                                         ((s->hdlcrx.bitbuf & mask6) << 1);
 214                         }
 215                 }
 216                 s->hdlcrx.numbits -= hdlc_rx_add_bytes(s, s->hdlcrx.bitbuf,
 217                                                        s->hdlcrx.numbits);
 218         }
 219         clear_bit(0, &s->hdlcrx.in_hdlc_rx);
 220 }
 221
 222 /* ---------------------------------------------------------------------- */
 223
 224 static inline void do_kiss_params(struct hdlcdrv_state *s,
 225                                   unsigned char *data, unsigned long len)
 226 {
 227
 228 #ifdef KISS_VERBOSE
 229 #define PKP(a,b) printk(KERN_INFO "hdlcdrv.c: channel params: " a "\n", b)
 230 #else /* KISS_VERBOSE */
 231 #define PKP(a,b)
 232 #endif /* KISS_VERBOSE */
 233
 234         if (len < 2)
 235                 return;
 236         switch(data[0]) {
 237         case PARAM_TXDELAY:
 238                 s->ch_params.tx_delay = data[1];
 239                 PKP("TX delay = %ums", 10 * s->ch_params.tx_delay);
 240                 break;
 241         case PARAM_PERSIST:
 242                 s->ch_params.ppersist = data[1];
 243                 PKP("p persistence = %u", s->ch_params.ppersist);
 244                 break;
 245         case PARAM_SLOTTIME:
 246                 s->ch_params.slottime = data[1];
 247                 PKP("slot time = %ums", s->ch_params.slottime);
 248                 break;
 249         case PARAM_TXTAIL:
 250                 s->ch_params.tx_tail = data[1];
 251                 PKP("TX tail = %ums", s->ch_params.tx_tail);
 252                 break;
 253         case PARAM_FULLDUP:
 254                 s->ch_params.fulldup = !!data[1];
 255                 PKP("%s duplex", s->ch_params.fulldup ? "full" : "half");
 256                 break;
 257         default:
 258                 break;
 259         }
 260 #undef PKP
 261 }
 262
 263 /* ---------------------------------------------------------------------- */
 264
 265 void hdlcdrv_transmitter(struct net_device *dev, struct hdlcdrv_state *s)
 266 {
 267         unsigned int mask1, mask2, mask3;
 268         int i;
 269         struct sk_buff *skb;
 270         int pkt_len;
 271
 272         if (!s || s->magic != HDLCDRV_MAGIC)
 273                 return;
 274         if (test_and_set_bit(0, &s->hdlctx.in_hdlc_tx))
 275                 return;
 276         for (;;) {
 277                 if (s->hdlctx.numbits >= 16) {
 278                         if (hdlcdrv_hbuf_full(&s->hdlctx.hbuf)) {
 279                                 clear_bit(0, &s->hdlctx.in_hdlc_tx);
 280                                 return;
 281                         }
 282                         hdlcdrv_hbuf_put(&s->hdlctx.hbuf, s->hdlctx.bitbuf);
 283                         s->hdlctx.bitbuf >>= 16;
 284                         s->hdlctx.numbits -= 16;
 285                 }
 286                 switch (s->hdlctx.tx_state) {
 287                 default:
 288                         clear_bit(0, &s->hdlctx.in_hdlc_tx);
 289                         return;
 290                 case 0:
 291                 case 1:
 292                         if (s->hdlctx.numflags) {
 293                                 s->hdlctx.numflags--;
 294                                 s->hdlctx.bitbuf |=
 295                                         0x7e7e << s->hdlctx.numbits;
 296                                 s->hdlctx.numbits += 16;
 297                                 break;
 298                         }
 299                         if (s->hdlctx.tx_state == 1) {
 300                                 clear_bit(0, &s->hdlctx.in_hdlc_tx);
 301                                 return;
 302                         }
 303                         if (!(skb = s->skb)) {
 304                                 int flgs = tenms_to_2flags(s, s->ch_params.tx_tail);
 305                                 if (flgs < 2)
 306                                         flgs = 2;
 307                                 s->hdlctx.tx_state = 1;
 308                                 s->hdlctx.numflags = flgs;
 309                                 break;
 310                         }
 311                         s->skb = NULL;
 312                         netif_wake_queue(dev);
 313                         pkt_len = skb->len-1; /* strip KISS byte */
 314                         if (pkt_len >= HDLCDRV_MAXFLEN || pkt_len < 2) {
 315                                 s->hdlctx.tx_state = 0;
 316                                 s->hdlctx.numflags = 1;
 317                                 dev_kfree_skb_irq(skb);
 318                                 break;
 319                         }
 320                         skb_copy_from_linear_data_offset(skb, 1,
 321                                                          s->hdlctx.buffer,
 322                                                          pkt_len);
 323                         dev_kfree_skb_irq(skb);
 324                         s->hdlctx.bp = s->hdlctx.buffer;
 325                         append_crc_ccitt(s->hdlctx.buffer, pkt_len);
 326                         s->hdlctx.len = pkt_len+2; /* the appended CRC */
 327                         s->hdlctx.tx_state = 2;
 328                         s->hdlctx.bitstream = 0;
 329                         dev->stats.tx_packets++;
 330                         break;
 331                 case 2:
 332                         if (!s->hdlctx.len) {
 333                                 s->hdlctx.tx_state = 0;
 334                                 s->hdlctx.numflags = 1;
 335                                 break;
 336                         }
 337                         s->hdlctx.len--;
 338                         s->hdlctx.bitbuf |= *s->hdlctx.bp <<
 339                                 s->hdlctx.numbits;
 340                         s->hdlctx.bitstream >>= 8;
 341                         s->hdlctx.bitstream |= (*s->hdlctx.bp++) << 16;
 342                         mask1 = 0x1f000;
 343                         mask2 = 0x10000;
 344                         mask3 = 0xffffffff >> (31-s->hdlctx.numbits);
 345                         s->hdlctx.numbits += 8;
 346                         for(i = 0; i < 8; i++, mask1 <<= 1, mask2 <<= 1,
 347                             mask3 = (mask3 << 1) | 1) {
 348                                 if ((s->hdlctx.bitstream & mask1) != mask1)
 349                                         continue;
 350                                 s->hdlctx.bitstream &= ~mask2;
 351                                 s->hdlctx.bitbuf =
 352                                         (s->hdlctx.bitbuf & mask3) |
 353                                                 ((s->hdlctx.bitbuf &
 354                                                  (~mask3)) << 1);
 355                                 s->hdlctx.numbits++;
 356                                 mask3 = (mask3 << 1) | 1;
 357                         }
 358                         break;
 359                 }
 360         }
 361 }
 362
 363 /* ---------------------------------------------------------------------- */
 364
 365 static void start_tx(struct net_device *dev, struct hdlcdrv_state *s)
 366 {
 367         s->hdlctx.tx_state = 0;
 368         s->hdlctx.numflags = tenms_to_2flags(s, s->ch_params.tx_delay);
 369         s->hdlctx.bitbuf = s->hdlctx.bitstream = s->hdlctx.numbits = 0;
 370         hdlcdrv_transmitter(dev, s);
 371         s->hdlctx.ptt = 1;
 372         s->ptt_keyed++;
 373 }
 374
 375 /* ---------------------------------------------------------------------- */
 376
 377 void hdlcdrv_arbitrate(struct net_device *dev, struct hdlcdrv_state *s)
 378 {
 379         if (!s || s->magic != HDLCDRV_MAGIC || s->hdlctx.ptt || !s->skb)
 380                 return;
 381         if (s->ch_params.fulldup) {
 382                 start_tx(dev, s);
 383                 return;
 384         }
 385         if (s->hdlcrx.dcd) {
 386                 s->hdlctx.slotcnt = s->ch_params.slottime;
 387                 return;
 388         }
 389         if ((--s->hdlctx.slotcnt) > 0)
 390                 return;
 391         s->hdlctx.slotcnt = s->ch_params.slottime;
 392         if ((random32() % 256) > s->ch_params.ppersist)
 393                 return;
 394         start_tx(dev, s);
 395 }
 396
 397 /* --------------------------------------------------------------------- */
 398 /*
 399  * ===================== network driver interface =========================
 400  */
 401
 402 static int hdlcdrv_send_packet(struct sk_buff *skb, struct net_device *dev)
 403 {
 404         struct hdlcdrv_state *sm = netdev_priv(dev);
 405
 406         if (skb->data[0] != 0) {
 407                 do_kiss_params(sm, skb->data, skb->len);
 408                 dev_kfree_skb(skb);
 409                 return 0;
 410         }
 411         if (sm->skb)
 412                 return NETDEV_TX_LOCKED;
 413         netif_stop_queue(dev);
 414         sm->skb = skb;
 415         return 0;
 416 }
 417
 418 /* --------------------------------------------------------------------- */
 419
 420 static int hdlcdrv_set_mac_address(struct net_device *dev, void *addr)
 421 {
 422         struct sockaddr *sa = (struct sockaddr *)addr;
 423
 424         /* addr is an AX.25 shifted ASCII mac address */
 425         memcpy(dev->dev_addr, sa->sa_data, dev->addr_len);
 426         return 0;
 427 }
 428
 429 /* --------------------------------------------------------------------- */
 430 /*
 431  * Open/initialize the board. This is called (in the current kernel)
 432  * sometime after booting when the 'ifconfig' program is run.
 433  *
 434  * This routine should set everything up anew at each open, even
 435  * registers that "should" only need to be set once at boot, so that
 436  * there is non-reboot way to recover if something goes wrong.
 437  */
 438
 439 static int hdlcdrv_open(struct net_device *dev)
 440 {
 441         struct hdlcdrv_state *s = netdev_priv(dev);
 442         int i;
 443
 444         if (!s->ops || !s->ops->open)
 445                 return -ENODEV;
 446
 447         /*
 448          * initialise some variables
 449          */
 450         s->opened = 1;
 451         s->hdlcrx.hbuf.rd = s->hdlcrx.hbuf.wr = 0;
 452         s->hdlcrx.in_hdlc_rx = 0;
 453         s->hdlcrx.rx_state = 0;
 454
 455         s->hdlctx.hbuf.rd = s->hdlctx.hbuf.wr = 0;
 456         s->hdlctx.in_hdlc_tx = 0;
 457         s->hdlctx.tx_state = 1;
 458         s->hdlctx.numflags = 0;
 459         s->hdlctx.bitstream = s->hdlctx.bitbuf = s->hdlctx.numbits = 0;
 460         s->hdlctx.ptt = 0;
 461         s->hdlctx.slotcnt = s->ch_params.slottime;
 462         s->hdlctx.calibrate = 0;
 463
 464         i = s->ops->open(dev);
 465         if (i)
 466                 return i;
 467         netif_start_queue(dev);
 468         return 0;
 469 }
 470
 471 /* --------------------------------------------------------------------- */
 472 /*
 473  * The inverse routine to hdlcdrv_open().
 474  */
 475
 476 static int hdlcdrv_close(struct net_device *dev)
 477 {
 478         struct hdlcdrv_state *s = netdev_priv(dev);
 479         int i = 0;
 480
 481         netif_stop_queue(dev);
 482
 483         if (s->ops && s->ops->close)
 484                 i = s->ops->close(dev);
 485         if (s->skb)
 486                 dev_kfree_skb(s->skb);
 487         s->skb = NULL;
 488         s->opened = 0;
 489         return i;
 490 }
 491
 492 /* --------------------------------------------------------------------- */
 493
 494 static int hdlcdrv_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
 495 {
 496         struct hdlcdrv_state *s = netdev_priv(dev);
 497         struct hdlcdrv_ioctl bi;
 498
 499         if (cmd != SIOCDEVPRIVATE) {
 500                 if (s->ops && s->ops->ioctl)
 501                         return s->ops->ioctl(dev, ifr, &bi, cmd);
 502                 return -ENOIOCTLCMD;
 503         }
 504         if (copy_from_user(&bi, ifr->ifr_data, sizeof(bi)))
 505                 return -EFAULT;
 506
 507         switch (bi.cmd) {
 508         default:
 509                 if (s->ops && s->ops->ioctl)
 510                         return s->ops->ioctl(dev, ifr, &bi, cmd);
 511                 return -ENOIOCTLCMD;
 512
 513         case HDLCDRVCTL_GETCHANNELPAR:
 514                 bi.data.cp.tx_delay = s->ch_params.tx_delay;
 515                 bi.data.cp.tx_tail = s->ch_params.tx_tail;
 516                 bi.data.cp.slottime = s->ch_params.slottime;
 517                 bi.data.cp.ppersist = s->ch_params.ppersist;
 518                 bi.data.cp.fulldup = s->ch_params.fulldup;
 519                 break;
 520
 521         case HDLCDRVCTL_SETCHANNELPAR:
 522                 if (!capable(CAP_NET_ADMIN))
 523                         return -EACCES;
 524                 s->ch_params.tx_delay = bi.data.cp.tx_delay;
 525                 s->ch_params.tx_tail = bi.data.cp.tx_tail;
 526                 s->ch_params.slottime = bi.data.cp.slottime;
 527                 s->ch_params.ppersist = bi.data.cp.ppersist;
 528                 s->ch_params.fulldup = bi.data.cp.fulldup;
 529                 s->hdlctx.slotcnt = 1;
 530                 return 0;
 531
 532         case HDLCDRVCTL_GETMODEMPAR:
 533                 bi.data.mp.iobase = dev->base_addr;
 534                 bi.data.mp.irq = dev->irq;
 535                 bi.data.mp.dma = dev->dma;
 536                 bi.data.mp.dma2 = s->ptt_out.dma2;
 537                 bi.data.mp.seriobase = s->ptt_out.seriobase;
 538                 bi.data.mp.pariobase = s->ptt_out.pariobase;
 539                 bi.data.mp.midiiobase = s->ptt_out.midiiobase;
 540                 break;
 541
 542         case HDLCDRVCTL_SETMODEMPAR:
 543                 if ((!capable(CAP_SYS_RAWIO)) || netif_running(dev))
 544                         return -EACCES;
 545                 dev->base_addr = bi.data.mp.iobase;
 546                 dev->irq = bi.data.mp.irq;
 547                 dev->dma = bi.data.mp.dma;
 548                 s->ptt_out.dma2 = bi.data.mp.dma2;
 549                 s->ptt_out.seriobase = bi.data.mp.seriobase;
 550                 s->ptt_out.pariobase = bi.data.mp.pariobase;
 551                 s->ptt_out.midiiobase = bi.data.mp.midiiobase;
 552                 return 0;
 553
 554         case HDLCDRVCTL_GETSTAT:
 555                 bi.data.cs.ptt = hdlcdrv_ptt(s);
 556                 bi.data.cs.dcd = s->hdlcrx.dcd;
 557                 bi.data.cs.ptt_keyed = s->ptt_keyed;
 558                 bi.data.cs.tx_packets = dev->stats.tx_packets;
 559                 bi.data.cs.tx_errors = dev->stats.tx_errors;
 560                 bi.data.cs.rx_packets = dev->stats.rx_packets;
 561                 bi.data.cs.rx_errors = dev->stats.rx_errors;
 562                 break;
 563
 564         case HDLCDRVCTL_OLDGETSTAT:
 565                 bi.data.ocs.ptt = hdlcdrv_ptt(s);
 566                 bi.data.ocs.dcd = s->hdlcrx.dcd;
 567                 bi.data.ocs.ptt_keyed = s->ptt_keyed;
 568                 break;
 569
 570         case HDLCDRVCTL_CALIBRATE:
 571                 if(!capable(CAP_SYS_RAWIO))
 572                         return -EPERM;
 573                 s->hdlctx.calibrate = bi.data.calibrate * s->par.bitrate / 16;
 574                 return 0;
 575
 576         case HDLCDRVCTL_GETSAMPLES:
 577 #ifndef HDLCDRV_DEBUG
 578                 return -EPERM;
 579 #else /* HDLCDRV_DEBUG */
 580                 if (s->bitbuf_channel.rd == s->bitbuf_channel.wr)
 581                         return -EAGAIN;
 582                 bi.data.bits =
 583                         s->bitbuf_channel.buffer[s->bitbuf_channel.rd];
 584                 s->bitbuf_channel.rd = (s->bitbuf_channel.rd+1) %
 585                         sizeof(s->bitbuf_channel.buffer);
 586                 break;
 587 #endif /* HDLCDRV_DEBUG */
 588
 589         case HDLCDRVCTL_GETBITS:
 590 #ifndef HDLCDRV_DEBUG
 591                 return -EPERM;
 592 #else /* HDLCDRV_DEBUG */
 593                 if (s->bitbuf_hdlc.rd == s->bitbuf_hdlc.wr)
 594                         return -EAGAIN;
 595                 bi.data.bits =
 596                         s->bitbuf_hdlc.buffer[s->bitbuf_hdlc.rd];
 597                 s->bitbuf_hdlc.rd = (s->bitbuf_hdlc.rd+1) %
 598                         sizeof(s->bitbuf_hdlc.buffer);
 599                 break;
 600 #endif /* HDLCDRV_DEBUG */
 601
 602         case HDLCDRVCTL_DRIVERNAME:
 603                 if (s->ops && s->ops->drvname) {
 604                         strncpy(bi.data.drivername, s->ops->drvname,
 605                                 sizeof(bi.data.drivername));
 606                         break;
 607                 }
 608                 bi.data.drivername[0] = '\0';
 609                 break;
 610
 611         }
 612         if (copy_to_user(ifr->ifr_data, &bi, sizeof(bi)))
 613                 return -EFAULT;
 614         return 0;
 615
 616 }
 617
 618 /* --------------------------------------------------------------------- */
 619
 620 static const struct net_device_ops hdlcdrv_netdev = {
 621         .ndo_open       = hdlcdrv_open,
 622         .ndo_stop       = hdlcdrv_close,
 623         .ndo_start_xmit = hdlcdrv_send_packet,
 624         .ndo_do_ioctl   = hdlcdrv_ioctl,
 625         .ndo_set_mac_address = hdlcdrv_set_mac_address,
 626 };
 627
 628 /*
 629  * Initialize fields in hdlcdrv
 630  */
 631 static void hdlcdrv_setup(struct net_device *dev)
 632 {
 633         static const struct hdlcdrv_channel_params dflt_ch_params = {
 634                 20, 2, 10, 40, 0
 635         };
 636         struct hdlcdrv_state *s = netdev_priv(dev);
 637
 638         /*
 639          * initialize the hdlcdrv_state struct
 640          */
 641         s->ch_params = dflt_ch_params;
 642         s->ptt_keyed = 0;
 643
 644         spin_lock_init(&s->hdlcrx.hbuf.lock);
 645         s->hdlcrx.hbuf.rd = s->hdlcrx.hbuf.wr = 0;
 646         s->hdlcrx.in_hdlc_rx = 0;
 647         s->hdlcrx.rx_state = 0;
 648
 649         spin_lock_init(&s->hdlctx.hbuf.lock);
 650         s->hdlctx.hbuf.rd = s->hdlctx.hbuf.wr = 0;
 651         s->hdlctx.in_hdlc_tx = 0;
 652         s->hdlctx.tx_state = 1;
 653         s->hdlctx.numflags = 0;
 654         s->hdlctx.bitstream = s->hdlctx.bitbuf = s->hdlctx.numbits = 0;
 655         s->hdlctx.ptt = 0;
 656         s->hdlctx.slotcnt = s->ch_params.slottime;
 657         s->hdlctx.calibrate = 0;
 658
 659 #ifdef HDLCDRV_DEBUG
 660         s->bitbuf_channel.rd = s->bitbuf_channel.wr = 0;
 661         s->bitbuf_channel.shreg = 0x80;
 662
 663         s->bitbuf_hdlc.rd = s->bitbuf_hdlc.wr = 0;
 664         s->bitbuf_hdlc.shreg = 0x80;
 665 #endif /* HDLCDRV_DEBUG */
 666
 667
 668         /* Fill in the fields of the device structure */
 669
 670         s->skb = NULL;
 671
 672         dev->netdev_ops = &hdlcdrv_netdev;
 673         dev->header_ops = &ax25_header_ops;
 674
 675         dev->type = ARPHRD_AX25;           /* AF_AX25 device */
 676         dev->hard_header_len = AX25_MAX_HEADER_LEN + AX25_BPQ_HEADER_LEN;
 677         dev->mtu = AX25_DEF_PACLEN;        /* eth_mtu is the default */
 678         dev->addr_len = AX25_ADDR_LEN;     /* sizeof an ax.25 address */
 679         memcpy(dev->broadcast, &ax25_bcast, AX25_ADDR_LEN);
 680         memcpy(dev->dev_addr, &ax25_defaddr, AX25_ADDR_LEN);
 681         dev->tx_queue_len = 16;
 682 }
 683
 684 /* --------------------------------------------------------------------- */
 685 struct net_device *hdlcdrv_register(const struct hdlcdrv_ops *ops,
 686                                     unsigned int privsize, const char *ifname,
 687                                     unsigned int baseaddr, unsigned int irq,
 688                                     unsigned int dma)
 689 {
 690         struct net_device *dev;
 691         struct hdlcdrv_state *s;
 692         int err;
 693
 694         BUG_ON(ops == NULL);
 695
 696         if (privsize < sizeof(struct hdlcdrv_state))
 697                 privsize = sizeof(struct hdlcdrv_state);
 698
 699         dev = alloc_netdev(privsize, ifname, hdlcdrv_setup);
 700         if (!dev)
 701                 return ERR_PTR(-ENOMEM);
 702
 703         /*
 704          * initialize part of the hdlcdrv_state struct
 705          */
 706         s = netdev_priv(dev);
 707         s->magic = HDLCDRV_MAGIC;
 708         s->ops = ops;
 709         dev->base_addr = baseaddr;
 710         dev->irq = irq;
 711         dev->dma = dma;
 712
 713         err = register_netdev(dev);
 714         if (err < 0) {
 715                 printk(KERN_WARNING "hdlcdrv: cannot register net "
 716                        "device %s\n", dev->name);
 717                 free_netdev(dev);
 718                 dev = ERR_PTR(err);
 719         }
 720         return dev;
 721 }
 722
 723 /* --------------------------------------------------------------------- */
 724
 725 void hdlcdrv_unregister(struct net_device *dev)
 726 {
 727         struct hdlcdrv_state *s = netdev_priv(dev);
 728
 729         BUG_ON(s->magic != HDLCDRV_MAGIC);
 730
 731         if (s->opened && s->ops->close)
 732                 s->ops->close(dev);
 733         unregister_netdev(dev);
 734
 735         free_netdev(dev);
 736 }
 737
 738 /* --------------------------------------------------------------------- */
 739
 740 EXPORT_SYMBOL(hdlcdrv_receiver);
 741 EXPORT_SYMBOL(hdlcdrv_transmitter);
 742 EXPORT_SYMBOL(hdlcdrv_arbitrate);
 743 EXPORT_SYMBOL(hdlcdrv_register);
 744 EXPORT_SYMBOL(hdlcdrv_unregister);
 745
 746 /* --------------------------------------------------------------------- */
 747
 748 static int __init hdlcdrv_init_driver(void)
 749 {
 750         printk(KERN_INFO "hdlcdrv: (C) 1996-2000 Thomas Sailer HB9JNX/AE4WA\n");
 751         printk(KERN_INFO "hdlcdrv: version 0.8 compiled " __TIME__ " " __DATE__ "\n");
 752         return 0;
 753 }
 754
 755 /* --------------------------------------------------------------------- */
 756
 757 static void __exit hdlcdrv_cleanup_driver(void)
 758 {
 759         printk(KERN_INFO "hdlcdrv: cleanup\n");
 760 }
 761
 762 /* --------------------------------------------------------------------- */
 763
 764 MODULE_AUTHOR("Thomas M. Sailer, sailer@ife.ee.ethz.ch, hb9jnx@hb9w.che.eu");
 765 MODULE_DESCRIPTION("Packet Radio network interface HDLC encoder/decoder");
 766 MODULE_LICENSE("GPL");
 767 module_init(hdlcdrv_init_driver);
 768 module_exit(hdlcdrv_cleanup_driver);
 769
 770 /* --------------------------------------------------------------------- */