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/capability.h>
  46 #include <linux/module.h>
  47 #include <linux/types.h>
  48 #include <linux/net.h>
  49 #include <linux/in.h>
  50 #include <linux/if.h>
  51 #include <linux/slab.h>
  52 #include <linux/errno.h>
  53 #include <linux/init.h>
  54 #include <linux/bitops.h>
  55
  56 #include <linux/netdevice.h>
  57 #include <linux/if_arp.h>
  58 #include <linux/skbuff.h>
  59 #include <linux/hdlcdrv.h>
  60 #include <linux/random.h>
  61 #include <net/ax25.h>
  62 #include <asm/uaccess.h>
  63
  64 #include <linux/crc-ccitt.h>
  65
  66 /* --------------------------------------------------------------------- */
  67
  68 #define KISS_VERBOSE
  69
  70 /* --------------------------------------------------------------------- */
  71
  72 #define PARAM_TXDELAY   1
  73 #define PARAM_PERSIST   2
  74 #define PARAM_SLOTTIME  3
  75 #define PARAM_TXTAIL    4
  76 #define PARAM_FULLDUP   5
  77 #define PARAM_HARDWARE  6
  78 #define PARAM_RETURN    255
  79
  80 /* --------------------------------------------------------------------- */
  81 /*
  82  * the CRC routines are stolen from WAMPES
  83  * by Dieter Deyke
  84  */
  85
  86
  87 /*---------------------------------------------------------------------------*/
  88
  89 static inline void append_crc_ccitt(unsigned char *buffer, int len)
  90 {
  91         unsigned int crc = crc_ccitt(0xffff, buffer, len) ^ 0xffff;
  92         buffer += len;
  93         *buffer++ = crc;
  94         *buffer++ = crc >> 8;
  95 }
  96
  97 /*---------------------------------------------------------------------------*/
  98
  99 static inline int check_crc_ccitt(const unsigned char *buf, int cnt)
 100 {
 101         return (crc_ccitt(0xffff, buf, cnt) & 0xffff) == 0xf0b8;
 102 }
 103
 104 /*---------------------------------------------------------------------------*/
 105
 106 #if 0
 107 static int calc_crc_ccitt(const unsigned char *buf, int cnt)
 108 {
 109         unsigned int crc = 0xffff;
 110
 111         for (; cnt > 0; cnt--)
 112                 crc = (crc >> 8) ^ crc_ccitt_table[(crc ^ *buf++) & 0xff];
 113         crc ^= 0xffff;
 114         return (crc & 0xffff);
 115 }
 116 #endif
 117
 118 /* ---------------------------------------------------------------------- */
 119
 120 #define tenms_to_2flags(s,tenms) ((tenms * s->par.bitrate) / 100 / 16)
 121
 122 /* ---------------------------------------------------------------------- */
 123 /*
 124  * The HDLC routines
 125  */
 126
 127 static int hdlc_rx_add_bytes(struct hdlcdrv_state *s, unsigned int bits,
 128                              int num)
 129 {
 130         int added = 0;
 131
 132         while (s->hdlcrx.rx_state && num >= 8) {
 133                 if (s->hdlcrx.len >= sizeof(s->hdlcrx.buffer)) {
 134                         s->hdlcrx.rx_state = 0;
 135                         return 0;
 136                 }
 137                 *s->hdlcrx.bp++ = bits >> (32-num);
 138                 s->hdlcrx.len++;
 139                 num -= 8;
 140                 added += 8;
 141         }
 142         return added;
 143 }
 144
 145 static void hdlc_rx_flag(struct net_device *dev, struct hdlcdrv_state *s)
 146 {
 147         struct sk_buff *skb;
 148         int pkt_len;
 149         unsigned char *cp;
 150
 151         if (s->hdlcrx.len < 4)
 152                 return;
 153         if (!check_crc_ccitt(s->hdlcrx.buffer, s->hdlcrx.len))
 154                 return;
 155         pkt_len = s->hdlcrx.len - 2 + 1; /* KISS kludge */
 156         if (!(skb = dev_alloc_skb(pkt_len))) {
 157                 printk("%s: memory squeeze, dropping packet\n", dev->name);
 158                 dev->stats.rx_dropped++;
 159                 return;
 160         }
 161         cp = skb_put(skb, pkt_len);
 162         *cp++ = 0; /* KISS kludge */
 163         memcpy(cp, s->hdlcrx.buffer, pkt_len - 1);
 164         skb->protocol = ax25_type_trans(skb, dev);
 165         netif_rx(skb);
 166         dev->stats.rx_packets++;
 167 }
 168
 169 void hdlcdrv_receiver(struct net_device *dev, struct hdlcdrv_state *s)
 170 {
 171         int i;
 172         unsigned int mask1, mask2, mask3, mask4, mask5, mask6, word;
 173
 174         if (!s || s->magic != HDLCDRV_MAGIC)
 175                 return;
 176         if (test_and_set_bit(0, &s->hdlcrx.in_hdlc_rx))
 177                 return;
 178
 179         while (!hdlcdrv_hbuf_empty(&s->hdlcrx.hbuf)) {
 180                 word = hdlcdrv_hbuf_get(&s->hdlcrx.hbuf);
 181
 182 #ifdef HDLCDRV_DEBUG
 183                 hdlcdrv_add_bitbuffer_word(&s->bitbuf_hdlc, word);
 184 #endif /* HDLCDRV_DEBUG */
 185                 s->hdlcrx.bitstream >>= 16;
 186                 s->hdlcrx.bitstream |= word << 16;
 187                 s->hdlcrx.bitbuf >>= 16;
 188                 s->hdlcrx.bitbuf |= word << 16;
 189                 s->hdlcrx.numbits += 16;
 190                 for(i = 15, mask1 = 0x1fc00, mask2 = 0x1fe00, mask3 = 0x0fc00,
 191                     mask4 = 0x1f800, mask5 = 0xf800, mask6 = 0xffff;
 192                     i >= 0;
 193                     i--, mask1 <<= 1, mask2 <<= 1, mask3 <<= 1, mask4 <<= 1,
 194                     mask5 <<= 1, mask6 = (mask6 << 1) | 1) {
 195                         if ((s->hdlcrx.bitstream & mask1) == mask1)
 196                                 s->hdlcrx.rx_state = 0; /* abort received */
 197                         else if ((s->hdlcrx.bitstream & mask2) == mask3) {
 198                                 /* flag received */
 199                                 if (s->hdlcrx.rx_state) {
 200                                         hdlc_rx_add_bytes(s, s->hdlcrx.bitbuf
 201                                                           << (8+i),
 202                                                           s->hdlcrx.numbits
 203                                                           -8-i);
 204                                         hdlc_rx_flag(dev, s);
 205                                 }
 206                                 s->hdlcrx.len = 0;
 207                                 s->hdlcrx.bp = s->hdlcrx.buffer;
 208                                 s->hdlcrx.rx_state = 1;
 209                                 s->hdlcrx.numbits = i;
 210                         } else if ((s->hdlcrx.bitstream & mask4) == mask5) {
 211                                 /* stuffed bit */
 212                                 s->hdlcrx.numbits--;
 213                                 s->hdlcrx.bitbuf = (s->hdlcrx.bitbuf & (~mask6)) |
 214                                         ((s->hdlcrx.bitbuf & mask6) << 1);
 215                         }
 216                 }
 217                 s->hdlcrx.numbits -= hdlc_rx_add_bytes(s, s->hdlcrx.bitbuf,
 218                                                        s->hdlcrx.numbits);
 219         }
 220         clear_bit(0, &s->hdlcrx.in_hdlc_rx);
 221 }
 222
 223 /* ---------------------------------------------------------------------- */
 224
 225 static inline void do_kiss_params(struct hdlcdrv_state *s,
 226                                   unsigned char *data, unsigned long len)
 227 {
 228
 229 #ifdef KISS_VERBOSE
 230 #define PKP(a,b) printk(KERN_INFO "hdlcdrv.c: channel params: " a "\n", b)
 231 #else /* KISS_VERBOSE */
 232 #define PKP(a,b)
 233 #endif /* KISS_VERBOSE */
 234
 235         if (len < 2)
 236                 return;
 237         switch(data[0]) {
 238         case PARAM_TXDELAY:
 239                 s->ch_params.tx_delay = data[1];
 240                 PKP("TX delay = %ums", 10 * s->ch_params.tx_delay);
 241                 break;
 242         case PARAM_PERSIST:
 243                 s->ch_params.ppersist = data[1];
 244                 PKP("p persistence = %u", s->ch_params.ppersist);
 245                 break;
 246         case PARAM_SLOTTIME:
 247                 s->ch_params.slottime = data[1];
 248                 PKP("slot time = %ums", s->ch_params.slottime);
 249                 break;
 250         case PARAM_TXTAIL:
 251                 s->ch_params.tx_tail = data[1];
 252                 PKP("TX tail = %ums", s->ch_params.tx_tail);
 253                 break;
 254         case PARAM_FULLDUP:
 255                 s->ch_params.fulldup = !!data[1];
 256                 PKP("%s duplex", s->ch_params.fulldup ? "full" : "half");
 257                 break;
 258         default:
 259                 break;
 260         }
 261 #undef PKP
 262 }
 263
 264 /* ---------------------------------------------------------------------- */
 265
 266 void hdlcdrv_transmitter(struct net_device *dev, struct hdlcdrv_state *s)
 267 {
 268         unsigned int mask1, mask2, mask3;
 269         int i;
 270         struct sk_buff *skb;
 271         int pkt_len;
 272
 273         if (!s || s->magic != HDLCDRV_MAGIC)
 274                 return;
 275         if (test_and_set_bit(0, &s->hdlctx.in_hdlc_tx))
 276                 return;
 277         for (;;) {
 278                 if (s->hdlctx.numbits >= 16) {
 279                         if (hdlcdrv_hbuf_full(&s->hdlctx.hbuf)) {
 280                                 clear_bit(0, &s->hdlctx.in_hdlc_tx);
 281                                 return;
 282                         }
 283                         hdlcdrv_hbuf_put(&s->hdlctx.hbuf, s->hdlctx.bitbuf);
 284                         s->hdlctx.bitbuf >>= 16;
 285                         s->hdlctx.numbits -= 16;
 286                 }
 287                 switch (s->hdlctx.tx_state) {
 288                 default:
 289                         clear_bit(0, &s->hdlctx.in_hdlc_tx);
 290                         return;
 291                 case 0:
 292                 case 1:
 293                         if (s->hdlctx.numflags) {
 294                                 s->hdlctx.numflags--;
 295                                 s->hdlctx.bitbuf |=
 296                                         0x7e7e << s->hdlctx.numbits;
 297                                 s->hdlctx.numbits += 16;
 298                                 break;
 299                         }
 300                         if (s->hdlctx.tx_state == 1) {
 301                                 clear_bit(0, &s->hdlctx.in_hdlc_tx);
 302                                 return;
 303                         }
 304                         if (!(skb = s->skb)) {
 305                                 int flgs = tenms_to_2flags(s, s->ch_params.tx_tail);
 306                                 if (flgs < 2)
 307                                         flgs = 2;
 308                                 s->hdlctx.tx_state = 1;
 309                                 s->hdlctx.numflags = flgs;
 310                                 break;
 311                         }
 312                         s->skb = NULL;
 313                         netif_wake_queue(dev);
 314                         pkt_len = skb->len-1; /* strip KISS byte */
 315                         if (pkt_len >= HDLCDRV_MAXFLEN || pkt_len < 2) {
 316                                 s->hdlctx.tx_state = 0;
 317                                 s->hdlctx.numflags = 1;
 318                                 dev_kfree_skb_irq(skb);
 319                                 break;
 320                         }
 321                         skb_copy_from_linear_data_offset(skb, 1,
 322                                                          s->hdlctx.buffer,
 323                                                          pkt_len);
 324                         dev_kfree_skb_irq(skb);
 325                         s->hdlctx.bp = s->hdlctx.buffer;
 326                         append_crc_ccitt(s->hdlctx.buffer, pkt_len);
 327                         s->hdlctx.len = pkt_len+2; /* the appended CRC */
 328                         s->hdlctx.tx_state = 2;
 329                         s->hdlctx.bitstream = 0;
 330                         dev->stats.tx_packets++;
 331                         break;
 332                 case 2:
 333                         if (!s->hdlctx.len) {
 334                                 s->hdlctx.tx_state = 0;
 335                                 s->hdlctx.numflags = 1;
 336                                 break;
 337                         }
 338                         s->hdlctx.len--;
 339                         s->hdlctx.bitbuf |= *s->hdlctx.bp <<
 340                                 s->hdlctx.numbits;
 341                         s->hdlctx.bitstream >>= 8;
 342                         s->hdlctx.bitstream |= (*s->hdlctx.bp++) << 16;
 343                         mask1 = 0x1f000;
 344                         mask2 = 0x10000;
 345                         mask3 = 0xffffffff >> (31-s->hdlctx.numbits);
 346                         s->hdlctx.numbits += 8;
 347                         for(i = 0; i < 8; i++, mask1 <<= 1, mask2 <<= 1,
 348                             mask3 = (mask3 << 1) | 1) {
 349                                 if ((s->hdlctx.bitstream & mask1) != mask1)
 350                                         continue;
 351                                 s->hdlctx.bitstream &= ~mask2;
 352                                 s->hdlctx.bitbuf =
 353                                         (s->hdlctx.bitbuf & mask3) |
 354                                                 ((s->hdlctx.bitbuf &
 355                                                  (~mask3)) << 1);
 356                                 s->hdlctx.numbits++;
 357                                 mask3 = (mask3 << 1) | 1;
 358                         }
 359                         break;
 360                 }
 361         }
 362 }
 363
 364 /* ---------------------------------------------------------------------- */
 365
 366 static void start_tx(struct net_device *dev, struct hdlcdrv_state *s)
 367 {
 368         s->hdlctx.tx_state = 0;
 369         s->hdlctx.numflags = tenms_to_2flags(s, s->ch_params.tx_delay);
 370         s->hdlctx.bitbuf = s->hdlctx.bitstream = s->hdlctx.numbits = 0;
 371         hdlcdrv_transmitter(dev, s);
 372         s->hdlctx.ptt = 1;
 373         s->ptt_keyed++;
 374 }
 375
 376 /* ---------------------------------------------------------------------- */
 377
 378 void hdlcdrv_arbitrate(struct net_device *dev, struct hdlcdrv_state *s)
 379 {
 380         if (!s || s->magic != HDLCDRV_MAGIC || s->hdlctx.ptt || !s->skb)
 381                 return;
 382         if (s->ch_params.fulldup) {
 383                 start_tx(dev, s);
 384                 return;
 385         }
 386         if (s->hdlcrx.dcd) {
 387                 s->hdlctx.slotcnt = s->ch_params.slottime;
 388                 return;
 389         }
 390         if ((--s->hdlctx.slotcnt) > 0)
 391                 return;
 392         s->hdlctx.slotcnt = s->ch_params.slottime;
 393         if ((random32() % 256) > s->ch_params.ppersist)
 394                 return;
 395         start_tx(dev, s);
 396 }
 397
 398 /* --------------------------------------------------------------------- */
 399 /*
 400  * ===================== network driver interface =========================
 401  */
 402
 403 static netdev_tx_t hdlcdrv_send_packet(struct sk_buff *skb,
 404                                        struct net_device *dev)
 405 {
 406         struct hdlcdrv_state *sm = netdev_priv(dev);
 407
 408         if (skb->data[0] != 0) {
 409                 do_kiss_params(sm, skb->data, skb->len);
 410                 dev_kfree_skb(skb);
 411                 return NETDEV_TX_OK;
 412         }
 413         if (sm->skb)
 414                 return NETDEV_TX_LOCKED;
 415         netif_stop_queue(dev);
 416         sm->skb = skb;
 417         return NETDEV_TX_OK;
 418 }
 419
 420 /* --------------------------------------------------------------------- */
 421
 422 static int hdlcdrv_set_mac_address(struct net_device *dev, void *addr)
 423 {
 424         struct sockaddr *sa = (struct sockaddr *)addr;
 425
 426         /* addr is an AX.25 shifted ASCII mac address */
 427         memcpy(dev->dev_addr, sa->sa_data, dev->addr_len);
 428         return 0;
 429 }
 430
 431 /* --------------------------------------------------------------------- */
 432 /*
 433  * Open/initialize the board. This is called (in the current kernel)
 434  * sometime after booting when the 'ifconfig' program is run.
 435  *
 436  * This routine should set everything up anew at each open, even
 437  * registers that "should" only need to be set once at boot, so that
 438  * there is non-reboot way to recover if something goes wrong.
 439  */
 440
 441 static int hdlcdrv_open(struct net_device *dev)
 442 {
 443         struct hdlcdrv_state *s = netdev_priv(dev);
 444         int i;
 445
 446         if (!s->ops || !s->ops->open)
 447                 return -ENODEV;
 448
 449         /*
 450          * initialise some variables
 451          */
 452         s->opened = 1;
 453         s->hdlcrx.hbuf.rd = s->hdlcrx.hbuf.wr = 0;
 454         s->hdlcrx.in_hdlc_rx = 0;
 455         s->hdlcrx.rx_state = 0;
 456
 457         s->hdlctx.hbuf.rd = s->hdlctx.hbuf.wr = 0;
 458         s->hdlctx.in_hdlc_tx = 0;
 459         s->hdlctx.tx_state = 1;
 460         s->hdlctx.numflags = 0;
 461         s->hdlctx.bitstream = s->hdlctx.bitbuf = s->hdlctx.numbits = 0;
 462         s->hdlctx.ptt = 0;
 463         s->hdlctx.slotcnt = s->ch_params.slottime;
 464         s->hdlctx.calibrate = 0;
 465
 466         i = s->ops->open(dev);
 467         if (i)
 468                 return i;
 469         netif_start_queue(dev);
 470         return 0;
 471 }
 472
 473 /* --------------------------------------------------------------------- */
 474 /*
 475  * The inverse routine to hdlcdrv_open().
 476  */
 477
 478 static int hdlcdrv_close(struct net_device *dev)
 479 {
 480         struct hdlcdrv_state *s = netdev_priv(dev);
 481         int i = 0;
 482
 483         netif_stop_queue(dev);
 484
 485         if (s->ops && s->ops->close)
 486                 i = s->ops->close(dev);
 487         if (s->skb)
 488                 dev_kfree_skb(s->skb);
 489         s->skb = NULL;
 490         s->opened = 0;
 491         return i;
 492 }
 493
 494 /* --------------------------------------------------------------------- */
 495
 496 static int hdlcdrv_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
 497 {
 498         struct hdlcdrv_state *s = netdev_priv(dev);
 499         struct hdlcdrv_ioctl bi;
 500
 501         if (cmd != SIOCDEVPRIVATE) {
 502                 if (s->ops && s->ops->ioctl)
 503                         return s->ops->ioctl(dev, ifr, &bi, cmd);
 504                 return -ENOIOCTLCMD;
 505         }
 506         if (copy_from_user(&bi, ifr->ifr_data, sizeof(bi)))
 507                 return -EFAULT;
 508
 509         switch (bi.cmd) {
 510         default:
 511                 if (s->ops && s->ops->ioctl)
 512                         return s->ops->ioctl(dev, ifr, &bi, cmd);
 513                 return -ENOIOCTLCMD;
 514
 515         case HDLCDRVCTL_GETCHANNELPAR:
 516                 bi.data.cp.tx_delay = s->ch_params.tx_delay;
 517                 bi.data.cp.tx_tail = s->ch_params.tx_tail;
 518                 bi.data.cp.slottime = s->ch_params.slottime;
 519                 bi.data.cp.ppersist = s->ch_params.ppersist;
 520                 bi.data.cp.fulldup = s->ch_params.fulldup;
 521                 break;
 522
 523         case HDLCDRVCTL_SETCHANNELPAR:
 524                 if (!capable(CAP_NET_ADMIN))
 525                         return -EACCES;
 526                 s->ch_params.tx_delay = bi.data.cp.tx_delay;
 527                 s->ch_params.tx_tail = bi.data.cp.tx_tail;
 528                 s->ch_params.slottime = bi.data.cp.slottime;
 529                 s->ch_params.ppersist = bi.data.cp.ppersist;
 530                 s->ch_params.fulldup = bi.data.cp.fulldup;
 531                 s->hdlctx.slotcnt = 1;
 532                 return 0;
 533
 534         case HDLCDRVCTL_GETMODEMPAR:
 535                 bi.data.mp.iobase = dev->base_addr;
 536                 bi.data.mp.irq = dev->irq;
 537                 bi.data.mp.dma = dev->dma;
 538                 bi.data.mp.dma2 = s->ptt_out.dma2;
 539                 bi.data.mp.seriobase = s->ptt_out.seriobase;
 540                 bi.data.mp.pariobase = s->ptt_out.pariobase;
 541                 bi.data.mp.midiiobase = s->ptt_out.midiiobase;
 542                 break;
 543
 544         case HDLCDRVCTL_SETMODEMPAR:
 545                 if ((!capable(CAP_SYS_RAWIO)) || netif_running(dev))
 546                         return -EACCES;
 547                 dev->base_addr = bi.data.mp.iobase;
 548                 dev->irq = bi.data.mp.irq;
 549                 dev->dma = bi.data.mp.dma;
 550                 s->ptt_out.dma2 = bi.data.mp.dma2;
 551                 s->ptt_out.seriobase = bi.data.mp.seriobase;
 552                 s->ptt_out.pariobase = bi.data.mp.pariobase;
 553                 s->ptt_out.midiiobase = bi.data.mp.midiiobase;
 554                 return 0;
 555
 556         case HDLCDRVCTL_GETSTAT:
 557                 bi.data.cs.ptt = hdlcdrv_ptt(s);
 558                 bi.data.cs.dcd = s->hdlcrx.dcd;
 559                 bi.data.cs.ptt_keyed = s->ptt_keyed;
 560                 bi.data.cs.tx_packets = dev->stats.tx_packets;
 561                 bi.data.cs.tx_errors = dev->stats.tx_errors;
 562                 bi.data.cs.rx_packets = dev->stats.rx_packets;
 563                 bi.data.cs.rx_errors = dev->stats.rx_errors;
 564                 break;
 565
 566         case HDLCDRVCTL_OLDGETSTAT:
 567                 bi.data.ocs.ptt = hdlcdrv_ptt(s);
 568                 bi.data.ocs.dcd = s->hdlcrx.dcd;
 569                 bi.data.ocs.ptt_keyed = s->ptt_keyed;
 570                 break;
 571
 572         case HDLCDRVCTL_CALIBRATE:
 573                 if(!capable(CAP_SYS_RAWIO))
 574                         return -EPERM;
 575                 s->hdlctx.calibrate = bi.data.calibrate * s->par.bitrate / 16;
 576                 return 0;
 577
 578         case HDLCDRVCTL_GETSAMPLES:
 579 #ifndef HDLCDRV_DEBUG
 580                 return -EPERM;
 581 #else /* HDLCDRV_DEBUG */
 582                 if (s->bitbuf_channel.rd == s->bitbuf_channel.wr)
 583                         return -EAGAIN;
 584                 bi.data.bits =
 585                         s->bitbuf_channel.buffer[s->bitbuf_channel.rd];
 586                 s->bitbuf_channel.rd = (s->bitbuf_channel.rd+1) %
 587                         sizeof(s->bitbuf_channel.buffer);
 588                 break;
 589 #endif /* HDLCDRV_DEBUG */
 590
 591         case HDLCDRVCTL_GETBITS:
 592 #ifndef HDLCDRV_DEBUG
 593                 return -EPERM;
 594 #else /* HDLCDRV_DEBUG */
 595                 if (s->bitbuf_hdlc.rd == s->bitbuf_hdlc.wr)
 596                         return -EAGAIN;
 597                 bi.data.bits =
 598                         s->bitbuf_hdlc.buffer[s->bitbuf_hdlc.rd];
 599                 s->bitbuf_hdlc.rd = (s->bitbuf_hdlc.rd+1) %
 600                         sizeof(s->bitbuf_hdlc.buffer);
 601                 break;
 602 #endif /* HDLCDRV_DEBUG */
 603
 604         case HDLCDRVCTL_DRIVERNAME:
 605                 if (s->ops && s->ops->drvname) {
 606                         strncpy(bi.data.drivername, s->ops->drvname,
 607                                 sizeof(bi.data.drivername));
 608                         break;
 609                 }
 610                 bi.data.drivername[0] = '\0';
 611                 break;
 612
 613         }
 614         if (copy_to_user(ifr->ifr_data, &bi, sizeof(bi)))
 615                 return -EFAULT;
 616         return 0;
 617
 618 }
 619
 620 /* --------------------------------------------------------------------- */
 621
 622 static const struct net_device_ops hdlcdrv_netdev = {
 623         .ndo_open       = hdlcdrv_open,
 624         .ndo_stop       = hdlcdrv_close,
 625         .ndo_start_xmit = hdlcdrv_send_packet,
 626         .ndo_do_ioctl   = hdlcdrv_ioctl,
 627         .ndo_set_mac_address = hdlcdrv_set_mac_address,
 628 };
 629
 630 /*
 631  * Initialize fields in hdlcdrv
 632  */
 633 static void hdlcdrv_setup(struct net_device *dev)
 634 {
 635         static const struct hdlcdrv_channel_params dflt_ch_params = {
 636                 20, 2, 10, 40, 0
 637         };
 638         struct hdlcdrv_state *s = netdev_priv(dev);
 639
 640         /*
 641          * initialize the hdlcdrv_state struct
 642          */
 643         s->ch_params = dflt_ch_params;
 644         s->ptt_keyed = 0;
 645
 646         spin_lock_init(&s->hdlcrx.hbuf.lock);
 647         s->hdlcrx.hbuf.rd = s->hdlcrx.hbuf.wr = 0;
 648         s->hdlcrx.in_hdlc_rx = 0;
 649         s->hdlcrx.rx_state = 0;
 650
 651         spin_lock_init(&s->hdlctx.hbuf.lock);
 652         s->hdlctx.hbuf.rd = s->hdlctx.hbuf.wr = 0;
 653         s->hdlctx.in_hdlc_tx = 0;
 654         s->hdlctx.tx_state = 1;
 655         s->hdlctx.numflags = 0;
 656         s->hdlctx.bitstream = s->hdlctx.bitbuf = s->hdlctx.numbits = 0;
 657         s->hdlctx.ptt = 0;
 658         s->hdlctx.slotcnt = s->ch_params.slottime;
 659         s->hdlctx.calibrate = 0;
 660
 661 #ifdef HDLCDRV_DEBUG
 662         s->bitbuf_channel.rd = s->bitbuf_channel.wr = 0;
 663         s->bitbuf_channel.shreg = 0x80;
 664
 665         s->bitbuf_hdlc.rd = s->bitbuf_hdlc.wr = 0;
 666         s->bitbuf_hdlc.shreg = 0x80;
 667 #endif /* HDLCDRV_DEBUG */
 668
 669
 670         /* Fill in the fields of the device structure */
 671
 672         s->skb = NULL;
 673
 674         dev->netdev_ops = &hdlcdrv_netdev;
 675         dev->header_ops = &ax25_header_ops;
 676
 677         dev->type = ARPHRD_AX25;           /* AF_AX25 device */
 678         dev->hard_header_len = AX25_MAX_HEADER_LEN + AX25_BPQ_HEADER_LEN;
 679         dev->mtu = AX25_DEF_PACLEN;        /* eth_mtu is the default */
 680         dev->addr_len = AX25_ADDR_LEN;     /* sizeof an ax.25 address */
 681         memcpy(dev->broadcast, &ax25_bcast, AX25_ADDR_LEN);
 682         memcpy(dev->dev_addr, &ax25_defaddr, AX25_ADDR_LEN);
 683         dev->tx_queue_len = 16;
 684 }
 685
 686 /* --------------------------------------------------------------------- */
 687 struct net_device *hdlcdrv_register(const struct hdlcdrv_ops *ops,
 688                                     unsigned int privsize, const char *ifname,
 689                                     unsigned int baseaddr, unsigned int irq,
 690                                     unsigned int dma)
 691 {
 692         struct net_device *dev;
 693         struct hdlcdrv_state *s;
 694         int err;
 695
 696         BUG_ON(ops == NULL);
 697
 698         if (privsize < sizeof(struct hdlcdrv_state))
 699                 privsize = sizeof(struct hdlcdrv_state);
 700
 701         dev = alloc_netdev(privsize, ifname, hdlcdrv_setup);
 702         if (!dev)
 703                 return ERR_PTR(-ENOMEM);
 704
 705         /*
 706          * initialize part of the hdlcdrv_state struct
 707          */
 708         s = netdev_priv(dev);
 709         s->magic = HDLCDRV_MAGIC;
 710         s->ops = ops;
 711         dev->base_addr = baseaddr;
 712         dev->irq = irq;
 713         dev->dma = dma;
 714
 715         err = register_netdev(dev);
 716         if (err < 0) {
 717                 printk(KERN_WARNING "hdlcdrv: cannot register net "
 718                        "device %s\n", dev->name);
 719                 free_netdev(dev);
 720                 dev = ERR_PTR(err);
 721         }
 722         return dev;
 723 }
 724
 725 /* --------------------------------------------------------------------- */
 726
 727 void hdlcdrv_unregister(struct net_device *dev)
 728 {
 729         struct hdlcdrv_state *s = netdev_priv(dev);
 730
 731         BUG_ON(s->magic != HDLCDRV_MAGIC);
 732
 733         if (s->opened && s->ops->close)
 734                 s->ops->close(dev);
 735         unregister_netdev(dev);
 736
 737         free_netdev(dev);
 738 }
 739
 740 /* --------------------------------------------------------------------- */
 741
 742 EXPORT_SYMBOL(hdlcdrv_receiver);
 743 EXPORT_SYMBOL(hdlcdrv_transmitter);
 744 EXPORT_SYMBOL(hdlcdrv_arbitrate);
 745 EXPORT_SYMBOL(hdlcdrv_register);
 746 EXPORT_SYMBOL(hdlcdrv_unregister);
 747
 748 /* --------------------------------------------------------------------- */
 749
 750 static int __init hdlcdrv_init_driver(void)
 751 {
 752         printk(KERN_INFO "hdlcdrv: (C) 1996-2000 Thomas Sailer HB9JNX/AE4WA\n");
 753         printk(KERN_INFO "hdlcdrv: version 0.8 compiled " __TIME__ " " __DATE__ "\n");
 754         return 0;
 755 }
 756
 757 /* --------------------------------------------------------------------- */
 758
 759 static void __exit hdlcdrv_cleanup_driver(void)
 760 {
 761         printk(KERN_INFO "hdlcdrv: cleanup\n");
 762 }
 763
 764 /* --------------------------------------------------------------------- */
 765
 766 MODULE_AUTHOR("Thomas M. Sailer, sailer@ife.ee.ethz.ch, hb9jnx@hb9w.che.eu");
 767 MODULE_DESCRIPTION("Packet Radio network interface HDLC encoder/decoder");
 768 MODULE_LICENSE("GPL");
 769 module_init(hdlcdrv_init_driver);
 770 module_exit(hdlcdrv_cleanup_driver);
 771
 772 /* --------------------------------------------------------------------- */