linux/drivers/net/hamradio/hdlcdrv.c
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   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/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
  88static 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
  98static 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
 106static 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
 126static 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
 144static 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
 168void 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
 224static 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
 265void 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
 365static 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
 377void 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 ((prandom_u32() % 256) > s->ch_params.ppersist)
 393                return;
 394        start_tx(dev, s);
 395}
 396
 397/* --------------------------------------------------------------------- */
 398/*
 399 * ===================== network driver interface =========================
 400 */
 401
 402static netdev_tx_t hdlcdrv_send_packet(struct sk_buff *skb,
 403                                       struct net_device *dev)
 404{
 405        struct hdlcdrv_state *sm = netdev_priv(dev);
 406
 407        if (skb->data[0] != 0) {
 408                do_kiss_params(sm, skb->data, skb->len);
 409                dev_kfree_skb(skb);
 410                return NETDEV_TX_OK;
 411        }
 412        if (sm->skb)
 413                return NETDEV_TX_LOCKED;
 414        netif_stop_queue(dev);
 415        sm->skb = skb;
 416        return NETDEV_TX_OK;
 417}
 418
 419/* --------------------------------------------------------------------- */
 420
 421static int hdlcdrv_set_mac_address(struct net_device *dev, void *addr)
 422{
 423        struct sockaddr *sa = (struct sockaddr *)addr;
 424
 425        /* addr is an AX.25 shifted ASCII mac address */
 426        memcpy(dev->dev_addr, sa->sa_data, dev->addr_len); 
 427        return 0;                                         
 428}
 429
 430/* --------------------------------------------------------------------- */
 431/*
 432 * Open/initialize the board. This is called (in the current kernel)
 433 * sometime after booting when the 'ifconfig' program is run.
 434 *
 435 * This routine should set everything up anew at each open, even
 436 * registers that "should" only need to be set once at boot, so that
 437 * there is non-reboot way to recover if something goes wrong.
 438 */
 439
 440static int hdlcdrv_open(struct net_device *dev)
 441{
 442        struct hdlcdrv_state *s = netdev_priv(dev);
 443        int i;
 444
 445        if (!s->ops || !s->ops->open)
 446                return -ENODEV;
 447
 448        /*
 449         * initialise some variables
 450         */
 451        s->opened = 1;
 452        s->hdlcrx.hbuf.rd = s->hdlcrx.hbuf.wr = 0;
 453        s->hdlcrx.in_hdlc_rx = 0;
 454        s->hdlcrx.rx_state = 0;
 455        
 456        s->hdlctx.hbuf.rd = s->hdlctx.hbuf.wr = 0;
 457        s->hdlctx.in_hdlc_tx = 0;
 458        s->hdlctx.tx_state = 1;
 459        s->hdlctx.numflags = 0;
 460        s->hdlctx.bitstream = s->hdlctx.bitbuf = s->hdlctx.numbits = 0;
 461        s->hdlctx.ptt = 0;
 462        s->hdlctx.slotcnt = s->ch_params.slottime;
 463        s->hdlctx.calibrate = 0;
 464
 465        i = s->ops->open(dev);
 466        if (i)
 467                return i;
 468        netif_start_queue(dev);
 469        return 0;
 470}
 471
 472/* --------------------------------------------------------------------- */
 473/* 
 474 * The inverse routine to hdlcdrv_open(). 
 475 */
 476
 477static int hdlcdrv_close(struct net_device *dev)
 478{
 479        struct hdlcdrv_state *s = netdev_priv(dev);
 480        int i = 0;
 481
 482        netif_stop_queue(dev);
 483
 484        if (s->ops && s->ops->close)
 485                i = s->ops->close(dev);
 486        if (s->skb)
 487                dev_kfree_skb(s->skb);
 488        s->skb = NULL;
 489        s->opened = 0;
 490        return i;
 491}
 492
 493/* --------------------------------------------------------------------- */
 494
 495static int hdlcdrv_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
 496{
 497        struct hdlcdrv_state *s = netdev_priv(dev);
 498        struct hdlcdrv_ioctl bi;
 499
 500        if (cmd != SIOCDEVPRIVATE) {
 501                if (s->ops && s->ops->ioctl)
 502                        return s->ops->ioctl(dev, ifr, &bi, cmd);
 503                return -ENOIOCTLCMD;
 504        }
 505        if (copy_from_user(&bi, ifr->ifr_data, sizeof(bi)))
 506                return -EFAULT;
 507
 508        switch (bi.cmd) {
 509        default:
 510                if (s->ops && s->ops->ioctl)
 511                        return s->ops->ioctl(dev, ifr, &bi, cmd);
 512                return -ENOIOCTLCMD;
 513
 514        case HDLCDRVCTL_GETCHANNELPAR:
 515                bi.data.cp.tx_delay = s->ch_params.tx_delay;
 516                bi.data.cp.tx_tail = s->ch_params.tx_tail;
 517                bi.data.cp.slottime = s->ch_params.slottime;
 518                bi.data.cp.ppersist = s->ch_params.ppersist;
 519                bi.data.cp.fulldup = s->ch_params.fulldup;
 520                break;
 521
 522        case HDLCDRVCTL_SETCHANNELPAR:
 523                if (!capable(CAP_NET_ADMIN))
 524                        return -EACCES;
 525                s->ch_params.tx_delay = bi.data.cp.tx_delay;
 526                s->ch_params.tx_tail = bi.data.cp.tx_tail;
 527                s->ch_params.slottime = bi.data.cp.slottime;
 528                s->ch_params.ppersist = bi.data.cp.ppersist;
 529                s->ch_params.fulldup = bi.data.cp.fulldup;
 530                s->hdlctx.slotcnt = 1;
 531                return 0;
 532                
 533        case HDLCDRVCTL_GETMODEMPAR:
 534                bi.data.mp.iobase = dev->base_addr;
 535                bi.data.mp.irq = dev->irq;
 536                bi.data.mp.dma = dev->dma;
 537                bi.data.mp.dma2 = s->ptt_out.dma2;
 538                bi.data.mp.seriobase = s->ptt_out.seriobase;
 539                bi.data.mp.pariobase = s->ptt_out.pariobase;
 540                bi.data.mp.midiiobase = s->ptt_out.midiiobase;
 541                break;
 542
 543        case HDLCDRVCTL_SETMODEMPAR:
 544                if ((!capable(CAP_SYS_RAWIO)) || netif_running(dev))
 545                        return -EACCES;
 546                dev->base_addr = bi.data.mp.iobase;
 547                dev->irq = bi.data.mp.irq;
 548                dev->dma = bi.data.mp.dma;
 549                s->ptt_out.dma2 = bi.data.mp.dma2;
 550                s->ptt_out.seriobase = bi.data.mp.seriobase;
 551                s->ptt_out.pariobase = bi.data.mp.pariobase;
 552                s->ptt_out.midiiobase = bi.data.mp.midiiobase;
 553                return 0;       
 554        
 555        case HDLCDRVCTL_GETSTAT:
 556                bi.data.cs.ptt = hdlcdrv_ptt(s);
 557                bi.data.cs.dcd = s->hdlcrx.dcd;
 558                bi.data.cs.ptt_keyed = s->ptt_keyed;
 559                bi.data.cs.tx_packets = dev->stats.tx_packets;
 560                bi.data.cs.tx_errors = dev->stats.tx_errors;
 561                bi.data.cs.rx_packets = dev->stats.rx_packets;
 562                bi.data.cs.rx_errors = dev->stats.rx_errors;
 563                break;          
 564
 565        case HDLCDRVCTL_OLDGETSTAT:
 566                bi.data.ocs.ptt = hdlcdrv_ptt(s);
 567                bi.data.ocs.dcd = s->hdlcrx.dcd;
 568                bi.data.ocs.ptt_keyed = s->ptt_keyed;
 569                break;          
 570
 571        case HDLCDRVCTL_CALIBRATE:
 572                if(!capable(CAP_SYS_RAWIO))
 573                        return -EPERM;
 574                s->hdlctx.calibrate = bi.data.calibrate * s->par.bitrate / 16;
 575                return 0;
 576
 577        case HDLCDRVCTL_GETSAMPLES:
 578#ifndef HDLCDRV_DEBUG
 579                return -EPERM;
 580#else /* HDLCDRV_DEBUG */
 581                if (s->bitbuf_channel.rd == s->bitbuf_channel.wr) 
 582                        return -EAGAIN;
 583                bi.data.bits = 
 584                        s->bitbuf_channel.buffer[s->bitbuf_channel.rd];
 585                s->bitbuf_channel.rd = (s->bitbuf_channel.rd+1) %
 586                        sizeof(s->bitbuf_channel.buffer);
 587                break;
 588#endif /* HDLCDRV_DEBUG */
 589                                
 590        case HDLCDRVCTL_GETBITS:
 591#ifndef HDLCDRV_DEBUG
 592                return -EPERM;
 593#else /* HDLCDRV_DEBUG */
 594                if (s->bitbuf_hdlc.rd == s->bitbuf_hdlc.wr) 
 595                        return -EAGAIN;
 596                bi.data.bits = 
 597                        s->bitbuf_hdlc.buffer[s->bitbuf_hdlc.rd];
 598                s->bitbuf_hdlc.rd = (s->bitbuf_hdlc.rd+1) %
 599                        sizeof(s->bitbuf_hdlc.buffer);
 600                break;          
 601#endif /* HDLCDRV_DEBUG */
 602
 603        case HDLCDRVCTL_DRIVERNAME:
 604                if (s->ops && s->ops->drvname) {
 605                        strncpy(bi.data.drivername, s->ops->drvname, 
 606                                sizeof(bi.data.drivername));
 607                        break;
 608                }
 609                bi.data.drivername[0] = '\0';
 610                break;
 611                
 612        }
 613        if (copy_to_user(ifr->ifr_data, &bi, sizeof(bi)))
 614                return -EFAULT;
 615        return 0;
 616
 617}
 618
 619/* --------------------------------------------------------------------- */
 620
 621static const struct net_device_ops hdlcdrv_netdev = {
 622        .ndo_open       = hdlcdrv_open,
 623        .ndo_stop       = hdlcdrv_close,
 624        .ndo_start_xmit = hdlcdrv_send_packet,
 625        .ndo_do_ioctl   = hdlcdrv_ioctl,
 626        .ndo_set_mac_address = hdlcdrv_set_mac_address,
 627};
 628
 629/*
 630 * Initialize fields in hdlcdrv
 631 */
 632static void hdlcdrv_setup(struct net_device *dev)
 633{
 634        static const struct hdlcdrv_channel_params dflt_ch_params = { 
 635                20, 2, 10, 40, 0 
 636        };
 637        struct hdlcdrv_state *s = netdev_priv(dev);
 638
 639        /*
 640         * initialize the hdlcdrv_state struct
 641         */
 642        s->ch_params = dflt_ch_params;
 643        s->ptt_keyed = 0;
 644
 645        spin_lock_init(&s->hdlcrx.hbuf.lock);
 646        s->hdlcrx.hbuf.rd = s->hdlcrx.hbuf.wr = 0;
 647        s->hdlcrx.in_hdlc_rx = 0;
 648        s->hdlcrx.rx_state = 0;
 649        
 650        spin_lock_init(&s->hdlctx.hbuf.lock);
 651        s->hdlctx.hbuf.rd = s->hdlctx.hbuf.wr = 0;
 652        s->hdlctx.in_hdlc_tx = 0;
 653        s->hdlctx.tx_state = 1;
 654        s->hdlctx.numflags = 0;
 655        s->hdlctx.bitstream = s->hdlctx.bitbuf = s->hdlctx.numbits = 0;
 656        s->hdlctx.ptt = 0;
 657        s->hdlctx.slotcnt = s->ch_params.slottime;
 658        s->hdlctx.calibrate = 0;
 659
 660#ifdef HDLCDRV_DEBUG
 661        s->bitbuf_channel.rd = s->bitbuf_channel.wr = 0;
 662        s->bitbuf_channel.shreg = 0x80;
 663
 664        s->bitbuf_hdlc.rd = s->bitbuf_hdlc.wr = 0;
 665        s->bitbuf_hdlc.shreg = 0x80;
 666#endif /* HDLCDRV_DEBUG */
 667
 668
 669        /* Fill in the fields of the device structure */
 670
 671        s->skb = NULL;
 672        
 673        dev->netdev_ops = &hdlcdrv_netdev;
 674        dev->header_ops = &ax25_header_ops;
 675        
 676        dev->type = ARPHRD_AX25;           /* AF_AX25 device */
 677        dev->hard_header_len = AX25_MAX_HEADER_LEN + AX25_BPQ_HEADER_LEN;
 678        dev->mtu = AX25_DEF_PACLEN;        /* eth_mtu is the default */
 679        dev->addr_len = AX25_ADDR_LEN;     /* sizeof an ax.25 address */
 680        memcpy(dev->broadcast, &ax25_bcast, AX25_ADDR_LEN);
 681        memcpy(dev->dev_addr, &ax25_defaddr, AX25_ADDR_LEN);
 682        dev->tx_queue_len = 16;
 683}
 684
 685/* --------------------------------------------------------------------- */
 686struct net_device *hdlcdrv_register(const struct hdlcdrv_ops *ops,
 687                                    unsigned int privsize, const char *ifname,
 688                                    unsigned int baseaddr, unsigned int irq, 
 689                                    unsigned int dma) 
 690{
 691        struct net_device *dev;
 692        struct hdlcdrv_state *s;
 693        int err;
 694
 695        BUG_ON(ops == NULL);
 696
 697        if (privsize < sizeof(struct hdlcdrv_state))
 698                privsize = sizeof(struct hdlcdrv_state);
 699
 700        dev = alloc_netdev(privsize, ifname, hdlcdrv_setup);
 701        if (!dev)
 702                return ERR_PTR(-ENOMEM);
 703
 704        /*
 705         * initialize part of the hdlcdrv_state struct
 706         */
 707        s = netdev_priv(dev);
 708        s->magic = HDLCDRV_MAGIC;
 709        s->ops = ops;
 710        dev->base_addr = baseaddr;
 711        dev->irq = irq;
 712        dev->dma = dma;
 713
 714        err = register_netdev(dev);
 715        if (err < 0) {
 716                printk(KERN_WARNING "hdlcdrv: cannot register net "
 717                       "device %s\n", dev->name);
 718                free_netdev(dev);
 719                dev = ERR_PTR(err);
 720        }
 721        return dev;
 722}
 723
 724/* --------------------------------------------------------------------- */
 725
 726void hdlcdrv_unregister(struct net_device *dev) 
 727{
 728        struct hdlcdrv_state *s = netdev_priv(dev);
 729
 730        BUG_ON(s->magic != HDLCDRV_MAGIC);
 731
 732        if (s->opened && s->ops->close)
 733                s->ops->close(dev);
 734        unregister_netdev(dev);
 735        
 736        free_netdev(dev);
 737}
 738
 739/* --------------------------------------------------------------------- */
 740
 741EXPORT_SYMBOL(hdlcdrv_receiver);
 742EXPORT_SYMBOL(hdlcdrv_transmitter);
 743EXPORT_SYMBOL(hdlcdrv_arbitrate);
 744EXPORT_SYMBOL(hdlcdrv_register);
 745EXPORT_SYMBOL(hdlcdrv_unregister);
 746
 747/* --------------------------------------------------------------------- */
 748
 749static int __init hdlcdrv_init_driver(void)
 750{
 751        printk(KERN_INFO "hdlcdrv: (C) 1996-2000 Thomas Sailer HB9JNX/AE4WA\n");
 752        printk(KERN_INFO "hdlcdrv: version 0.8\n");
 753        return 0;
 754}
 755
 756/* --------------------------------------------------------------------- */
 757
 758static void __exit hdlcdrv_cleanup_driver(void)
 759{
 760        printk(KERN_INFO "hdlcdrv: cleanup\n");
 761}
 762
 763/* --------------------------------------------------------------------- */
 764
 765MODULE_AUTHOR("Thomas M. Sailer, sailer@ife.ee.ethz.ch, hb9jnx@hb9w.che.eu");
 766MODULE_DESCRIPTION("Packet Radio network interface HDLC encoder/decoder");
 767MODULE_LICENSE("GPL");
 768module_init(hdlcdrv_init_driver);
 769module_exit(hdlcdrv_cleanup_driver);
 770
 771/* --------------------------------------------------------------------- */
 772