linux/drivers/net/hamradio/hdlcdrv.c
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   1// SPDX-License-Identifier: GPL-2.0-or-later
   2/*****************************************************************************/
   3
   4/*
   5 *      hdlcdrv.c  -- HDLC packet radio network driver.
   6 *
   7 *      Copyright (C) 1996-2000  Thomas Sailer (sailer@ife.ee.ethz.ch)
   8 *
   9 *  Please note that the GPL allows you to use the driver, NOT the radio.
  10 *  In order to use the radio, you need a license from the communications
  11 *  authority of your country.
  12 *
  13 *  The driver was derived from Donald Beckers skeleton.c
  14 *      Written 1993-94 by Donald Becker.
  15 *
  16 *  History:
  17 *   0.1  21.09.1996  Started
  18 *        18.10.1996  Changed to new user space access routines 
  19 *                    (copy_{to,from}_user)
  20 *   0.2  21.11.1996  various small changes
  21 *   0.3  03.03.1997  fixed (hopefully) IP not working with ax.25 as a module
  22 *   0.4  16.04.1997  init code/data tagged
  23 *   0.5  30.07.1997  made HDLC buffers bigger (solves a problem with the
  24 *                    soundmodem driver)
  25 *   0.6  05.04.1998  add spinlocks
  26 *   0.7  03.08.1999  removed some old compatibility cruft
  27 *   0.8  12.02.2000  adapted to softnet driver interface
  28 */
  29
  30/*****************************************************************************/
  31
  32#include <linux/capability.h>
  33#include <linux/module.h>
  34#include <linux/types.h>
  35#include <linux/net.h>
  36#include <linux/in.h>
  37#include <linux/if.h>
  38#include <linux/errno.h>
  39#include <linux/init.h>
  40#include <linux/bitops.h>
  41
  42#include <linux/netdevice.h>
  43#include <linux/if_arp.h>
  44#include <linux/skbuff.h>
  45#include <linux/hdlcdrv.h>
  46#include <linux/random.h>
  47#include <net/ax25.h> 
  48#include <linux/uaccess.h>
  49
  50#include <linux/crc-ccitt.h>
  51
  52/* --------------------------------------------------------------------- */
  53
  54#define KISS_VERBOSE
  55
  56/* --------------------------------------------------------------------- */
  57
  58#define PARAM_TXDELAY   1
  59#define PARAM_PERSIST   2
  60#define PARAM_SLOTTIME  3
  61#define PARAM_TXTAIL    4
  62#define PARAM_FULLDUP   5
  63#define PARAM_HARDWARE  6
  64#define PARAM_RETURN    255
  65
  66/* --------------------------------------------------------------------- */
  67/*
  68 * the CRC routines are stolen from WAMPES
  69 * by Dieter Deyke
  70 */
  71
  72
  73/*---------------------------------------------------------------------------*/
  74
  75static inline void append_crc_ccitt(unsigned char *buffer, int len)
  76{
  77        unsigned int crc = crc_ccitt(0xffff, buffer, len) ^ 0xffff;
  78        buffer += len;
  79        *buffer++ = crc;
  80        *buffer++ = crc >> 8;
  81}
  82
  83/*---------------------------------------------------------------------------*/
  84
  85static inline int check_crc_ccitt(const unsigned char *buf, int cnt)
  86{
  87        return (crc_ccitt(0xffff, buf, cnt) & 0xffff) == 0xf0b8;
  88}
  89
  90/*---------------------------------------------------------------------------*/
  91
  92#if 0
  93static int calc_crc_ccitt(const unsigned char *buf, int cnt)
  94{
  95        unsigned int crc = 0xffff;
  96
  97        for (; cnt > 0; cnt--)
  98                crc = (crc >> 8) ^ crc_ccitt_table[(crc ^ *buf++) & 0xff];
  99        crc ^= 0xffff;
 100        return crc & 0xffff;
 101}
 102#endif
 103
 104/* ---------------------------------------------------------------------- */
 105
 106#define tenms_to_2flags(s,tenms) ((tenms * s->par.bitrate) / 100 / 16)
 107
 108/* ---------------------------------------------------------------------- */
 109/*
 110 * The HDLC routines
 111 */
 112
 113static int hdlc_rx_add_bytes(struct hdlcdrv_state *s, unsigned int bits, 
 114                             int num)
 115{
 116        int added = 0;
 117        
 118        while (s->hdlcrx.rx_state && num >= 8) {
 119                if (s->hdlcrx.len >= sizeof(s->hdlcrx.buffer)) {
 120                        s->hdlcrx.rx_state = 0;
 121                        return 0;
 122                }
 123                *s->hdlcrx.bp++ = bits >> (32-num);
 124                s->hdlcrx.len++;
 125                num -= 8;
 126                added += 8;
 127        }
 128        return added;
 129}
 130
 131static void hdlc_rx_flag(struct net_device *dev, struct hdlcdrv_state *s)
 132{
 133        struct sk_buff *skb;
 134        int pkt_len;
 135        unsigned char *cp;
 136
 137        if (s->hdlcrx.len < 4) 
 138                return;
 139        if (!check_crc_ccitt(s->hdlcrx.buffer, s->hdlcrx.len)) 
 140                return;
 141        pkt_len = s->hdlcrx.len - 2 + 1; /* KISS kludge */
 142        if (!(skb = dev_alloc_skb(pkt_len))) {
 143                printk("%s: memory squeeze, dropping packet\n", dev->name);
 144                dev->stats.rx_dropped++;
 145                return;
 146        }
 147        cp = skb_put(skb, pkt_len);
 148        *cp++ = 0; /* KISS kludge */
 149        memcpy(cp, s->hdlcrx.buffer, pkt_len - 1);
 150        skb->protocol = ax25_type_trans(skb, dev);
 151        netif_rx(skb);
 152        dev->stats.rx_packets++;
 153}
 154
 155void hdlcdrv_receiver(struct net_device *dev, struct hdlcdrv_state *s)
 156{
 157        int i;
 158        unsigned int mask1, mask2, mask3, mask4, mask5, mask6, word;
 159        
 160        if (!s || s->magic != HDLCDRV_MAGIC) 
 161                return;
 162        if (test_and_set_bit(0, &s->hdlcrx.in_hdlc_rx))
 163                return;
 164
 165        while (!hdlcdrv_hbuf_empty(&s->hdlcrx.hbuf)) {
 166                word = hdlcdrv_hbuf_get(&s->hdlcrx.hbuf);       
 167
 168#ifdef HDLCDRV_DEBUG
 169                hdlcdrv_add_bitbuffer_word(&s->bitbuf_hdlc, word);
 170#endif /* HDLCDRV_DEBUG */
 171                s->hdlcrx.bitstream >>= 16;
 172                s->hdlcrx.bitstream |= word << 16;
 173                s->hdlcrx.bitbuf >>= 16;
 174                s->hdlcrx.bitbuf |= word << 16;
 175                s->hdlcrx.numbits += 16;
 176                for(i = 15, mask1 = 0x1fc00, mask2 = 0x1fe00, mask3 = 0x0fc00,
 177                    mask4 = 0x1f800, mask5 = 0xf800, mask6 = 0xffff; 
 178                    i >= 0; 
 179                    i--, mask1 <<= 1, mask2 <<= 1, mask3 <<= 1, mask4 <<= 1, 
 180                    mask5 <<= 1, mask6 = (mask6 << 1) | 1) {
 181                        if ((s->hdlcrx.bitstream & mask1) == mask1)
 182                                s->hdlcrx.rx_state = 0; /* abort received */
 183                        else if ((s->hdlcrx.bitstream & mask2) == mask3) {
 184                                /* flag received */
 185                                if (s->hdlcrx.rx_state) {
 186                                        hdlc_rx_add_bytes(s, s->hdlcrx.bitbuf 
 187                                                          << (8+i),
 188                                                          s->hdlcrx.numbits
 189                                                          -8-i);
 190                                        hdlc_rx_flag(dev, s);
 191                                }
 192                                s->hdlcrx.len = 0;
 193                                s->hdlcrx.bp = s->hdlcrx.buffer;
 194                                s->hdlcrx.rx_state = 1;
 195                                s->hdlcrx.numbits = i;
 196                        } else if ((s->hdlcrx.bitstream & mask4) == mask5) {
 197                                /* stuffed bit */
 198                                s->hdlcrx.numbits--;
 199                                s->hdlcrx.bitbuf = (s->hdlcrx.bitbuf & (~mask6)) |
 200                                        ((s->hdlcrx.bitbuf & mask6) << 1);
 201                        }
 202                }
 203                s->hdlcrx.numbits -= hdlc_rx_add_bytes(s, s->hdlcrx.bitbuf,
 204                                                       s->hdlcrx.numbits);
 205        }
 206        clear_bit(0, &s->hdlcrx.in_hdlc_rx);
 207}
 208
 209/* ---------------------------------------------------------------------- */
 210
 211static inline void do_kiss_params(struct hdlcdrv_state *s,
 212                                  unsigned char *data, unsigned long len)
 213{
 214
 215#ifdef KISS_VERBOSE
 216#define PKP(a,b) printk(KERN_INFO "hdlcdrv.c: channel params: " a "\n", b)
 217#else /* KISS_VERBOSE */              
 218#define PKP(a,b) 
 219#endif /* KISS_VERBOSE */             
 220
 221        if (len < 2)
 222                return;
 223        switch(data[0]) {
 224        case PARAM_TXDELAY:
 225                s->ch_params.tx_delay = data[1];
 226                PKP("TX delay = %ums", 10 * s->ch_params.tx_delay);
 227                break;
 228        case PARAM_PERSIST:   
 229                s->ch_params.ppersist = data[1];
 230                PKP("p persistence = %u", s->ch_params.ppersist);
 231                break;
 232        case PARAM_SLOTTIME:  
 233                s->ch_params.slottime = data[1];
 234                PKP("slot time = %ums", s->ch_params.slottime);
 235                break;
 236        case PARAM_TXTAIL:    
 237                s->ch_params.tx_tail = data[1];
 238                PKP("TX tail = %ums", s->ch_params.tx_tail);
 239                break;
 240        case PARAM_FULLDUP:   
 241                s->ch_params.fulldup = !!data[1];
 242                PKP("%s duplex", s->ch_params.fulldup ? "full" : "half");
 243                break;
 244        default:
 245                break;
 246        }
 247#undef PKP
 248}
 249
 250/* ---------------------------------------------------------------------- */
 251
 252void hdlcdrv_transmitter(struct net_device *dev, struct hdlcdrv_state *s)
 253{
 254        unsigned int mask1, mask2, mask3;
 255        int i;
 256        struct sk_buff *skb;
 257        int pkt_len;
 258
 259        if (!s || s->magic != HDLCDRV_MAGIC) 
 260                return;
 261        if (test_and_set_bit(0, &s->hdlctx.in_hdlc_tx))
 262                return;
 263        for (;;) {
 264                if (s->hdlctx.numbits >= 16) {
 265                        if (hdlcdrv_hbuf_full(&s->hdlctx.hbuf)) {
 266                                clear_bit(0, &s->hdlctx.in_hdlc_tx);
 267                                return;
 268                        }
 269                        hdlcdrv_hbuf_put(&s->hdlctx.hbuf, s->hdlctx.bitbuf);
 270                        s->hdlctx.bitbuf >>= 16;
 271                        s->hdlctx.numbits -= 16;
 272                }
 273                switch (s->hdlctx.tx_state) {
 274                default:
 275                        clear_bit(0, &s->hdlctx.in_hdlc_tx);
 276                        return;
 277                case 0:
 278                case 1:
 279                        if (s->hdlctx.numflags) {
 280                                s->hdlctx.numflags--;
 281                                s->hdlctx.bitbuf |= 
 282                                        0x7e7e << s->hdlctx.numbits;
 283                                s->hdlctx.numbits += 16;
 284                                break;
 285                        }
 286                        if (s->hdlctx.tx_state == 1) {
 287                                clear_bit(0, &s->hdlctx.in_hdlc_tx);
 288                                return;
 289                        }
 290                        if (!(skb = s->skb)) {
 291                                int flgs = tenms_to_2flags(s, s->ch_params.tx_tail);
 292                                if (flgs < 2)
 293                                        flgs = 2;
 294                                s->hdlctx.tx_state = 1;
 295                                s->hdlctx.numflags = flgs;
 296                                break;
 297                        }
 298                        s->skb = NULL;
 299                        netif_wake_queue(dev);
 300                        pkt_len = skb->len-1; /* strip KISS byte */
 301                        if (pkt_len >= HDLCDRV_MAXFLEN || pkt_len < 2) {
 302                                s->hdlctx.tx_state = 0;
 303                                s->hdlctx.numflags = 1;
 304                                dev_kfree_skb_irq(skb);
 305                                break;
 306                        }
 307                        skb_copy_from_linear_data_offset(skb, 1,
 308                                                         s->hdlctx.buffer,
 309                                                         pkt_len);
 310                        dev_kfree_skb_irq(skb);
 311                        s->hdlctx.bp = s->hdlctx.buffer;
 312                        append_crc_ccitt(s->hdlctx.buffer, pkt_len);
 313                        s->hdlctx.len = pkt_len+2; /* the appended CRC */
 314                        s->hdlctx.tx_state = 2;
 315                        s->hdlctx.bitstream = 0;
 316                        dev->stats.tx_packets++;
 317                        break;
 318                case 2:
 319                        if (!s->hdlctx.len) {
 320                                s->hdlctx.tx_state = 0;
 321                                s->hdlctx.numflags = 1;
 322                                break;
 323                        }
 324                        s->hdlctx.len--;
 325                        s->hdlctx.bitbuf |= *s->hdlctx.bp <<
 326                                s->hdlctx.numbits;
 327                        s->hdlctx.bitstream >>= 8;
 328                        s->hdlctx.bitstream |= (*s->hdlctx.bp++) << 16;
 329                        mask1 = 0x1f000;
 330                        mask2 = 0x10000;
 331                        mask3 = 0xffffffff >> (31-s->hdlctx.numbits);
 332                        s->hdlctx.numbits += 8;
 333                        for(i = 0; i < 8; i++, mask1 <<= 1, mask2 <<= 1, 
 334                            mask3 = (mask3 << 1) | 1) {
 335                                if ((s->hdlctx.bitstream & mask1) != mask1) 
 336                                        continue;
 337                                s->hdlctx.bitstream &= ~mask2;
 338                                s->hdlctx.bitbuf = 
 339                                        (s->hdlctx.bitbuf & mask3) |
 340                                                ((s->hdlctx.bitbuf & 
 341                                                 (~mask3)) << 1);
 342                                s->hdlctx.numbits++;
 343                                mask3 = (mask3 << 1) | 1;
 344                        }
 345                        break;
 346                }
 347        }
 348}
 349
 350/* ---------------------------------------------------------------------- */
 351
 352static void start_tx(struct net_device *dev, struct hdlcdrv_state *s)
 353{
 354        s->hdlctx.tx_state = 0;
 355        s->hdlctx.numflags = tenms_to_2flags(s, s->ch_params.tx_delay);
 356        s->hdlctx.bitbuf = s->hdlctx.bitstream = s->hdlctx.numbits = 0;
 357        hdlcdrv_transmitter(dev, s);
 358        s->hdlctx.ptt = 1;
 359        s->ptt_keyed++;
 360}
 361
 362/* ---------------------------------------------------------------------- */
 363
 364void hdlcdrv_arbitrate(struct net_device *dev, struct hdlcdrv_state *s)
 365{
 366        if (!s || s->magic != HDLCDRV_MAGIC || s->hdlctx.ptt || !s->skb) 
 367                return;
 368        if (s->ch_params.fulldup) {
 369                start_tx(dev, s);
 370                return;
 371        }
 372        if (s->hdlcrx.dcd) {
 373                s->hdlctx.slotcnt = s->ch_params.slottime;
 374                return;
 375        }
 376        if ((--s->hdlctx.slotcnt) > 0)
 377                return;
 378        s->hdlctx.slotcnt = s->ch_params.slottime;
 379        if ((prandom_u32() % 256) > s->ch_params.ppersist)
 380                return;
 381        start_tx(dev, s);
 382}
 383
 384/* --------------------------------------------------------------------- */
 385/*
 386 * ===================== network driver interface =========================
 387 */
 388
 389static netdev_tx_t hdlcdrv_send_packet(struct sk_buff *skb,
 390                                       struct net_device *dev)
 391{
 392        struct hdlcdrv_state *sm = netdev_priv(dev);
 393
 394        if (skb->protocol == htons(ETH_P_IP))
 395                return ax25_ip_xmit(skb);
 396
 397        if (skb->data[0] != 0) {
 398                do_kiss_params(sm, skb->data, skb->len);
 399                dev_kfree_skb(skb);
 400                return NETDEV_TX_OK;
 401        }
 402        if (sm->skb) {
 403                dev_kfree_skb(skb);
 404                return NETDEV_TX_OK;
 405        }
 406        netif_stop_queue(dev);
 407        sm->skb = skb;
 408        return NETDEV_TX_OK;
 409}
 410
 411/* --------------------------------------------------------------------- */
 412
 413static int hdlcdrv_set_mac_address(struct net_device *dev, void *addr)
 414{
 415        struct sockaddr *sa = (struct sockaddr *)addr;
 416
 417        /* addr is an AX.25 shifted ASCII mac address */
 418        memcpy(dev->dev_addr, sa->sa_data, dev->addr_len); 
 419        return 0;                                         
 420}
 421
 422/* --------------------------------------------------------------------- */
 423/*
 424 * Open/initialize the board. This is called (in the current kernel)
 425 * sometime after booting when the 'ifconfig' program is run.
 426 *
 427 * This routine should set everything up anew at each open, even
 428 * registers that "should" only need to be set once at boot, so that
 429 * there is non-reboot way to recover if something goes wrong.
 430 */
 431
 432static int hdlcdrv_open(struct net_device *dev)
 433{
 434        struct hdlcdrv_state *s = netdev_priv(dev);
 435        int i;
 436
 437        if (!s->ops || !s->ops->open)
 438                return -ENODEV;
 439
 440        /*
 441         * initialise some variables
 442         */
 443        s->opened = 1;
 444        s->hdlcrx.hbuf.rd = s->hdlcrx.hbuf.wr = 0;
 445        s->hdlcrx.in_hdlc_rx = 0;
 446        s->hdlcrx.rx_state = 0;
 447        
 448        s->hdlctx.hbuf.rd = s->hdlctx.hbuf.wr = 0;
 449        s->hdlctx.in_hdlc_tx = 0;
 450        s->hdlctx.tx_state = 1;
 451        s->hdlctx.numflags = 0;
 452        s->hdlctx.bitstream = s->hdlctx.bitbuf = s->hdlctx.numbits = 0;
 453        s->hdlctx.ptt = 0;
 454        s->hdlctx.slotcnt = s->ch_params.slottime;
 455        s->hdlctx.calibrate = 0;
 456
 457        i = s->ops->open(dev);
 458        if (i)
 459                return i;
 460        netif_start_queue(dev);
 461        return 0;
 462}
 463
 464/* --------------------------------------------------------------------- */
 465/* 
 466 * The inverse routine to hdlcdrv_open(). 
 467 */
 468
 469static int hdlcdrv_close(struct net_device *dev)
 470{
 471        struct hdlcdrv_state *s = netdev_priv(dev);
 472        int i = 0;
 473
 474        netif_stop_queue(dev);
 475
 476        if (s->ops && s->ops->close)
 477                i = s->ops->close(dev);
 478        dev_kfree_skb(s->skb);
 479        s->skb = NULL;
 480        s->opened = 0;
 481        return i;
 482}
 483
 484/* --------------------------------------------------------------------- */
 485
 486static int hdlcdrv_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
 487{
 488        struct hdlcdrv_state *s = netdev_priv(dev);
 489        struct hdlcdrv_ioctl bi;
 490
 491        if (cmd != SIOCDEVPRIVATE) {
 492                if (s->ops && s->ops->ioctl)
 493                        return s->ops->ioctl(dev, ifr, &bi, cmd);
 494                return -ENOIOCTLCMD;
 495        }
 496        if (copy_from_user(&bi, ifr->ifr_data, sizeof(bi)))
 497                return -EFAULT;
 498
 499        switch (bi.cmd) {
 500        default:
 501                if (s->ops && s->ops->ioctl)
 502                        return s->ops->ioctl(dev, ifr, &bi, cmd);
 503                return -ENOIOCTLCMD;
 504
 505        case HDLCDRVCTL_GETCHANNELPAR:
 506                bi.data.cp.tx_delay = s->ch_params.tx_delay;
 507                bi.data.cp.tx_tail = s->ch_params.tx_tail;
 508                bi.data.cp.slottime = s->ch_params.slottime;
 509                bi.data.cp.ppersist = s->ch_params.ppersist;
 510                bi.data.cp.fulldup = s->ch_params.fulldup;
 511                break;
 512
 513        case HDLCDRVCTL_SETCHANNELPAR:
 514                if (!capable(CAP_NET_ADMIN))
 515                        return -EACCES;
 516                s->ch_params.tx_delay = bi.data.cp.tx_delay;
 517                s->ch_params.tx_tail = bi.data.cp.tx_tail;
 518                s->ch_params.slottime = bi.data.cp.slottime;
 519                s->ch_params.ppersist = bi.data.cp.ppersist;
 520                s->ch_params.fulldup = bi.data.cp.fulldup;
 521                s->hdlctx.slotcnt = 1;
 522                return 0;
 523                
 524        case HDLCDRVCTL_GETMODEMPAR:
 525                bi.data.mp.iobase = dev->base_addr;
 526                bi.data.mp.irq = dev->irq;
 527                bi.data.mp.dma = dev->dma;
 528                bi.data.mp.dma2 = s->ptt_out.dma2;
 529                bi.data.mp.seriobase = s->ptt_out.seriobase;
 530                bi.data.mp.pariobase = s->ptt_out.pariobase;
 531                bi.data.mp.midiiobase = s->ptt_out.midiiobase;
 532                break;
 533
 534        case HDLCDRVCTL_SETMODEMPAR:
 535                if ((!capable(CAP_SYS_RAWIO)) || netif_running(dev))
 536                        return -EACCES;
 537                dev->base_addr = bi.data.mp.iobase;
 538                dev->irq = bi.data.mp.irq;
 539                dev->dma = bi.data.mp.dma;
 540                s->ptt_out.dma2 = bi.data.mp.dma2;
 541                s->ptt_out.seriobase = bi.data.mp.seriobase;
 542                s->ptt_out.pariobase = bi.data.mp.pariobase;
 543                s->ptt_out.midiiobase = bi.data.mp.midiiobase;
 544                return 0;       
 545        
 546        case HDLCDRVCTL_GETSTAT:
 547                bi.data.cs.ptt = hdlcdrv_ptt(s);
 548                bi.data.cs.dcd = s->hdlcrx.dcd;
 549                bi.data.cs.ptt_keyed = s->ptt_keyed;
 550                bi.data.cs.tx_packets = dev->stats.tx_packets;
 551                bi.data.cs.tx_errors = dev->stats.tx_errors;
 552                bi.data.cs.rx_packets = dev->stats.rx_packets;
 553                bi.data.cs.rx_errors = dev->stats.rx_errors;
 554                break;          
 555
 556        case HDLCDRVCTL_OLDGETSTAT:
 557                bi.data.ocs.ptt = hdlcdrv_ptt(s);
 558                bi.data.ocs.dcd = s->hdlcrx.dcd;
 559                bi.data.ocs.ptt_keyed = s->ptt_keyed;
 560                break;          
 561
 562        case HDLCDRVCTL_CALIBRATE:
 563                if(!capable(CAP_SYS_RAWIO))
 564                        return -EPERM;
 565                if (s->par.bitrate <= 0)
 566                        return -EINVAL;
 567                if (bi.data.calibrate > INT_MAX / s->par.bitrate)
 568                        return -EINVAL;
 569                s->hdlctx.calibrate = bi.data.calibrate * s->par.bitrate / 16;
 570                return 0;
 571
 572        case HDLCDRVCTL_GETSAMPLES:
 573#ifndef HDLCDRV_DEBUG
 574                return -EPERM;
 575#else /* HDLCDRV_DEBUG */
 576                if (s->bitbuf_channel.rd == s->bitbuf_channel.wr) 
 577                        return -EAGAIN;
 578                bi.data.bits = 
 579                        s->bitbuf_channel.buffer[s->bitbuf_channel.rd];
 580                s->bitbuf_channel.rd = (s->bitbuf_channel.rd+1) %
 581                        sizeof(s->bitbuf_channel.buffer);
 582                break;
 583#endif /* HDLCDRV_DEBUG */
 584                                
 585        case HDLCDRVCTL_GETBITS:
 586#ifndef HDLCDRV_DEBUG
 587                return -EPERM;
 588#else /* HDLCDRV_DEBUG */
 589                if (s->bitbuf_hdlc.rd == s->bitbuf_hdlc.wr) 
 590                        return -EAGAIN;
 591                bi.data.bits = 
 592                        s->bitbuf_hdlc.buffer[s->bitbuf_hdlc.rd];
 593                s->bitbuf_hdlc.rd = (s->bitbuf_hdlc.rd+1) %
 594                        sizeof(s->bitbuf_hdlc.buffer);
 595                break;          
 596#endif /* HDLCDRV_DEBUG */
 597
 598        case HDLCDRVCTL_DRIVERNAME:
 599                if (s->ops && s->ops->drvname) {
 600                        strncpy(bi.data.drivername, s->ops->drvname, 
 601                                sizeof(bi.data.drivername));
 602                        break;
 603                }
 604                bi.data.drivername[0] = '\0';
 605                break;
 606                
 607        }
 608        if (copy_to_user(ifr->ifr_data, &bi, sizeof(bi)))
 609                return -EFAULT;
 610        return 0;
 611
 612}
 613
 614/* --------------------------------------------------------------------- */
 615
 616static const struct net_device_ops hdlcdrv_netdev = {
 617        .ndo_open       = hdlcdrv_open,
 618        .ndo_stop       = hdlcdrv_close,
 619        .ndo_start_xmit = hdlcdrv_send_packet,
 620        .ndo_do_ioctl   = hdlcdrv_ioctl,
 621        .ndo_set_mac_address = hdlcdrv_set_mac_address,
 622};
 623
 624/*
 625 * Initialize fields in hdlcdrv
 626 */
 627static void hdlcdrv_setup(struct net_device *dev)
 628{
 629        static const struct hdlcdrv_channel_params dflt_ch_params = { 
 630                20, 2, 10, 40, 0 
 631        };
 632        struct hdlcdrv_state *s = netdev_priv(dev);
 633
 634        /*
 635         * initialize the hdlcdrv_state struct
 636         */
 637        s->ch_params = dflt_ch_params;
 638        s->ptt_keyed = 0;
 639
 640        spin_lock_init(&s->hdlcrx.hbuf.lock);
 641        s->hdlcrx.hbuf.rd = s->hdlcrx.hbuf.wr = 0;
 642        s->hdlcrx.in_hdlc_rx = 0;
 643        s->hdlcrx.rx_state = 0;
 644        
 645        spin_lock_init(&s->hdlctx.hbuf.lock);
 646        s->hdlctx.hbuf.rd = s->hdlctx.hbuf.wr = 0;
 647        s->hdlctx.in_hdlc_tx = 0;
 648        s->hdlctx.tx_state = 1;
 649        s->hdlctx.numflags = 0;
 650        s->hdlctx.bitstream = s->hdlctx.bitbuf = s->hdlctx.numbits = 0;
 651        s->hdlctx.ptt = 0;
 652        s->hdlctx.slotcnt = s->ch_params.slottime;
 653        s->hdlctx.calibrate = 0;
 654
 655#ifdef HDLCDRV_DEBUG
 656        s->bitbuf_channel.rd = s->bitbuf_channel.wr = 0;
 657        s->bitbuf_channel.shreg = 0x80;
 658
 659        s->bitbuf_hdlc.rd = s->bitbuf_hdlc.wr = 0;
 660        s->bitbuf_hdlc.shreg = 0x80;
 661#endif /* HDLCDRV_DEBUG */
 662
 663
 664        /* Fill in the fields of the device structure */
 665
 666        s->skb = NULL;
 667        
 668        dev->netdev_ops = &hdlcdrv_netdev;
 669        dev->header_ops = &ax25_header_ops;
 670        
 671        dev->type = ARPHRD_AX25;           /* AF_AX25 device */
 672        dev->hard_header_len = AX25_MAX_HEADER_LEN + AX25_BPQ_HEADER_LEN;
 673        dev->mtu = AX25_DEF_PACLEN;        /* eth_mtu is the default */
 674        dev->addr_len = AX25_ADDR_LEN;     /* sizeof an ax.25 address */
 675        memcpy(dev->broadcast, &ax25_bcast, AX25_ADDR_LEN);
 676        memcpy(dev->dev_addr, &ax25_defaddr, AX25_ADDR_LEN);
 677        dev->tx_queue_len = 16;
 678}
 679
 680/* --------------------------------------------------------------------- */
 681struct net_device *hdlcdrv_register(const struct hdlcdrv_ops *ops,
 682                                    unsigned int privsize, const char *ifname,
 683                                    unsigned int baseaddr, unsigned int irq, 
 684                                    unsigned int dma) 
 685{
 686        struct net_device *dev;
 687        struct hdlcdrv_state *s;
 688        int err;
 689
 690        if (privsize < sizeof(struct hdlcdrv_state))
 691                privsize = sizeof(struct hdlcdrv_state);
 692
 693        dev = alloc_netdev(privsize, ifname, NET_NAME_UNKNOWN, hdlcdrv_setup);
 694        if (!dev)
 695                return ERR_PTR(-ENOMEM);
 696
 697        /*
 698         * initialize part of the hdlcdrv_state struct
 699         */
 700        s = netdev_priv(dev);
 701        s->magic = HDLCDRV_MAGIC;
 702        s->ops = ops;
 703        dev->base_addr = baseaddr;
 704        dev->irq = irq;
 705        dev->dma = dma;
 706
 707        err = register_netdev(dev);
 708        if (err < 0) {
 709                printk(KERN_WARNING "hdlcdrv: cannot register net "
 710                       "device %s\n", dev->name);
 711                free_netdev(dev);
 712                dev = ERR_PTR(err);
 713        }
 714        return dev;
 715}
 716
 717/* --------------------------------------------------------------------- */
 718
 719void hdlcdrv_unregister(struct net_device *dev) 
 720{
 721        struct hdlcdrv_state *s = netdev_priv(dev);
 722
 723        BUG_ON(s->magic != HDLCDRV_MAGIC);
 724
 725        if (s->opened && s->ops->close)
 726                s->ops->close(dev);
 727        unregister_netdev(dev);
 728        
 729        free_netdev(dev);
 730}
 731
 732/* --------------------------------------------------------------------- */
 733
 734EXPORT_SYMBOL(hdlcdrv_receiver);
 735EXPORT_SYMBOL(hdlcdrv_transmitter);
 736EXPORT_SYMBOL(hdlcdrv_arbitrate);
 737EXPORT_SYMBOL(hdlcdrv_register);
 738EXPORT_SYMBOL(hdlcdrv_unregister);
 739
 740/* --------------------------------------------------------------------- */
 741
 742static int __init hdlcdrv_init_driver(void)
 743{
 744        printk(KERN_INFO "hdlcdrv: (C) 1996-2000 Thomas Sailer HB9JNX/AE4WA\n");
 745        printk(KERN_INFO "hdlcdrv: version 0.8\n");
 746        return 0;
 747}
 748
 749/* --------------------------------------------------------------------- */
 750
 751static void __exit hdlcdrv_cleanup_driver(void)
 752{
 753        printk(KERN_INFO "hdlcdrv: cleanup\n");
 754}
 755
 756/* --------------------------------------------------------------------- */
 757
 758MODULE_AUTHOR("Thomas M. Sailer, sailer@ife.ee.ethz.ch, hb9jnx@hb9w.che.eu");
 759MODULE_DESCRIPTION("Packet Radio network interface HDLC encoder/decoder");
 760MODULE_LICENSE("GPL");
 761module_init(hdlcdrv_init_driver);
 762module_exit(hdlcdrv_cleanup_driver);
 763
 764/* --------------------------------------------------------------------- */
 765