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/compat.h>
  34#include <linux/module.h>
  35#include <linux/types.h>
  36#include <linux/net.h>
  37#include <linux/in.h>
  38#include <linux/if.h>
  39#include <linux/errno.h>
  40#include <linux/init.h>
  41#include <linux/bitops.h>
  42
  43#include <linux/netdevice.h>
  44#include <linux/if_arp.h>
  45#include <linux/skbuff.h>
  46#include <linux/hdlcdrv.h>
  47#include <linux/random.h>
  48#include <net/ax25.h> 
  49#include <linux/uaccess.h>
  50
  51#include <linux/crc-ccitt.h>
  52
  53/* --------------------------------------------------------------------- */
  54
  55#define KISS_VERBOSE
  56
  57/* --------------------------------------------------------------------- */
  58
  59#define PARAM_TXDELAY   1
  60#define PARAM_PERSIST   2
  61#define PARAM_SLOTTIME  3
  62#define PARAM_TXTAIL    4
  63#define PARAM_FULLDUP   5
  64#define PARAM_HARDWARE  6
  65#define PARAM_RETURN    255
  66
  67/* --------------------------------------------------------------------- */
  68/*
  69 * the CRC routines are stolen from WAMPES
  70 * by Dieter Deyke
  71 */
  72
  73
  74/*---------------------------------------------------------------------------*/
  75
  76static inline void append_crc_ccitt(unsigned char *buffer, int len)
  77{
  78        unsigned int crc = crc_ccitt(0xffff, buffer, len) ^ 0xffff;
  79        buffer += len;
  80        *buffer++ = crc;
  81        *buffer++ = crc >> 8;
  82}
  83
  84/*---------------------------------------------------------------------------*/
  85
  86static inline int check_crc_ccitt(const unsigned char *buf, int cnt)
  87{
  88        return (crc_ccitt(0xffff, buf, cnt) & 0xffff) == 0xf0b8;
  89}
  90
  91/*---------------------------------------------------------------------------*/
  92
  93#if 0
  94static int calc_crc_ccitt(const unsigned char *buf, int cnt)
  95{
  96        unsigned int crc = 0xffff;
  97
  98        for (; cnt > 0; cnt--)
  99                crc = (crc >> 8) ^ crc_ccitt_table[(crc ^ *buf++) & 0xff];
 100        crc ^= 0xffff;
 101        return crc & 0xffff;
 102}
 103#endif
 104
 105/* ---------------------------------------------------------------------- */
 106
 107#define tenms_to_2flags(s,tenms) ((tenms * s->par.bitrate) / 100 / 16)
 108
 109/* ---------------------------------------------------------------------- */
 110/*
 111 * The HDLC routines
 112 */
 113
 114static int hdlc_rx_add_bytes(struct hdlcdrv_state *s, unsigned int bits, 
 115                             int num)
 116{
 117        int added = 0;
 118        
 119        while (s->hdlcrx.rx_state && num >= 8) {
 120                if (s->hdlcrx.len >= sizeof(s->hdlcrx.buffer)) {
 121                        s->hdlcrx.rx_state = 0;
 122                        return 0;
 123                }
 124                *s->hdlcrx.bp++ = bits >> (32-num);
 125                s->hdlcrx.len++;
 126                num -= 8;
 127                added += 8;
 128        }
 129        return added;
 130}
 131
 132static void hdlc_rx_flag(struct net_device *dev, struct hdlcdrv_state *s)
 133{
 134        struct sk_buff *skb;
 135        int pkt_len;
 136        unsigned char *cp;
 137
 138        if (s->hdlcrx.len < 4) 
 139                return;
 140        if (!check_crc_ccitt(s->hdlcrx.buffer, s->hdlcrx.len)) 
 141                return;
 142        pkt_len = s->hdlcrx.len - 2 + 1; /* KISS kludge */
 143        if (!(skb = dev_alloc_skb(pkt_len))) {
 144                printk("%s: memory squeeze, dropping packet\n", dev->name);
 145                dev->stats.rx_dropped++;
 146                return;
 147        }
 148        cp = skb_put(skb, pkt_len);
 149        *cp++ = 0; /* KISS kludge */
 150        memcpy(cp, s->hdlcrx.buffer, pkt_len - 1);
 151        skb->protocol = ax25_type_trans(skb, dev);
 152        netif_rx(skb);
 153        dev->stats.rx_packets++;
 154}
 155
 156void hdlcdrv_receiver(struct net_device *dev, struct hdlcdrv_state *s)
 157{
 158        int i;
 159        unsigned int mask1, mask2, mask3, mask4, mask5, mask6, word;
 160        
 161        if (!s || s->magic != HDLCDRV_MAGIC) 
 162                return;
 163        if (test_and_set_bit(0, &s->hdlcrx.in_hdlc_rx))
 164                return;
 165
 166        while (!hdlcdrv_hbuf_empty(&s->hdlcrx.hbuf)) {
 167                word = hdlcdrv_hbuf_get(&s->hdlcrx.hbuf);       
 168
 169#ifdef HDLCDRV_DEBUG
 170                hdlcdrv_add_bitbuffer_word(&s->bitbuf_hdlc, word);
 171#endif /* HDLCDRV_DEBUG */
 172                s->hdlcrx.bitstream >>= 16;
 173                s->hdlcrx.bitstream |= word << 16;
 174                s->hdlcrx.bitbuf >>= 16;
 175                s->hdlcrx.bitbuf |= word << 16;
 176                s->hdlcrx.numbits += 16;
 177                for(i = 15, mask1 = 0x1fc00, mask2 = 0x1fe00, mask3 = 0x0fc00,
 178                    mask4 = 0x1f800, mask5 = 0xf800, mask6 = 0xffff; 
 179                    i >= 0; 
 180                    i--, mask1 <<= 1, mask2 <<= 1, mask3 <<= 1, mask4 <<= 1, 
 181                    mask5 <<= 1, mask6 = (mask6 << 1) | 1) {
 182                        if ((s->hdlcrx.bitstream & mask1) == mask1)
 183                                s->hdlcrx.rx_state = 0; /* abort received */
 184                        else if ((s->hdlcrx.bitstream & mask2) == mask3) {
 185                                /* flag received */
 186                                if (s->hdlcrx.rx_state) {
 187                                        hdlc_rx_add_bytes(s, s->hdlcrx.bitbuf 
 188                                                          << (8+i),
 189                                                          s->hdlcrx.numbits
 190                                                          -8-i);
 191                                        hdlc_rx_flag(dev, s);
 192                                }
 193                                s->hdlcrx.len = 0;
 194                                s->hdlcrx.bp = s->hdlcrx.buffer;
 195                                s->hdlcrx.rx_state = 1;
 196                                s->hdlcrx.numbits = i;
 197                        } else if ((s->hdlcrx.bitstream & mask4) == mask5) {
 198                                /* stuffed bit */
 199                                s->hdlcrx.numbits--;
 200                                s->hdlcrx.bitbuf = (s->hdlcrx.bitbuf & (~mask6)) |
 201                                        ((s->hdlcrx.bitbuf & mask6) << 1);
 202                        }
 203                }
 204                s->hdlcrx.numbits -= hdlc_rx_add_bytes(s, s->hdlcrx.bitbuf,
 205                                                       s->hdlcrx.numbits);
 206        }
 207        clear_bit(0, &s->hdlcrx.in_hdlc_rx);
 208}
 209
 210/* ---------------------------------------------------------------------- */
 211
 212static inline void do_kiss_params(struct hdlcdrv_state *s,
 213                                  unsigned char *data, unsigned long len)
 214{
 215
 216#ifdef KISS_VERBOSE
 217#define PKP(a,b) printk(KERN_INFO "hdlcdrv.c: channel params: " a "\n", b)
 218#else /* KISS_VERBOSE */              
 219#define PKP(a,b) 
 220#endif /* KISS_VERBOSE */             
 221
 222        if (len < 2)
 223                return;
 224        switch(data[0]) {
 225        case PARAM_TXDELAY:
 226                s->ch_params.tx_delay = data[1];
 227                PKP("TX delay = %ums", 10 * s->ch_params.tx_delay);
 228                break;
 229        case PARAM_PERSIST:   
 230                s->ch_params.ppersist = data[1];
 231                PKP("p persistence = %u", s->ch_params.ppersist);
 232                break;
 233        case PARAM_SLOTTIME:  
 234                s->ch_params.slottime = data[1];
 235                PKP("slot time = %ums", s->ch_params.slottime);
 236                break;
 237        case PARAM_TXTAIL:    
 238                s->ch_params.tx_tail = data[1];
 239                PKP("TX tail = %ums", s->ch_params.tx_tail);
 240                break;
 241        case PARAM_FULLDUP:   
 242                s->ch_params.fulldup = !!data[1];
 243                PKP("%s duplex", s->ch_params.fulldup ? "full" : "half");
 244                break;
 245        default:
 246                break;
 247        }
 248#undef PKP
 249}
 250
 251/* ---------------------------------------------------------------------- */
 252
 253void hdlcdrv_transmitter(struct net_device *dev, struct hdlcdrv_state *s)
 254{
 255        unsigned int mask1, mask2, mask3;
 256        int i;
 257        struct sk_buff *skb;
 258        int pkt_len;
 259
 260        if (!s || s->magic != HDLCDRV_MAGIC) 
 261                return;
 262        if (test_and_set_bit(0, &s->hdlctx.in_hdlc_tx))
 263                return;
 264        for (;;) {
 265                if (s->hdlctx.numbits >= 16) {
 266                        if (hdlcdrv_hbuf_full(&s->hdlctx.hbuf)) {
 267                                clear_bit(0, &s->hdlctx.in_hdlc_tx);
 268                                return;
 269                        }
 270                        hdlcdrv_hbuf_put(&s->hdlctx.hbuf, s->hdlctx.bitbuf);
 271                        s->hdlctx.bitbuf >>= 16;
 272                        s->hdlctx.numbits -= 16;
 273                }
 274                switch (s->hdlctx.tx_state) {
 275                default:
 276                        clear_bit(0, &s->hdlctx.in_hdlc_tx);
 277                        return;
 278                case 0:
 279                case 1:
 280                        if (s->hdlctx.numflags) {
 281                                s->hdlctx.numflags--;
 282                                s->hdlctx.bitbuf |= 
 283                                        0x7e7e << s->hdlctx.numbits;
 284                                s->hdlctx.numbits += 16;
 285                                break;
 286                        }
 287                        if (s->hdlctx.tx_state == 1) {
 288                                clear_bit(0, &s->hdlctx.in_hdlc_tx);
 289                                return;
 290                        }
 291                        if (!(skb = s->skb)) {
 292                                int flgs = tenms_to_2flags(s, s->ch_params.tx_tail);
 293                                if (flgs < 2)
 294                                        flgs = 2;
 295                                s->hdlctx.tx_state = 1;
 296                                s->hdlctx.numflags = flgs;
 297                                break;
 298                        }
 299                        s->skb = NULL;
 300                        netif_wake_queue(dev);
 301                        pkt_len = skb->len-1; /* strip KISS byte */
 302                        if (pkt_len >= HDLCDRV_MAXFLEN || pkt_len < 2) {
 303                                s->hdlctx.tx_state = 0;
 304                                s->hdlctx.numflags = 1;
 305                                dev_kfree_skb_irq(skb);
 306                                break;
 307                        }
 308                        skb_copy_from_linear_data_offset(skb, 1,
 309                                                         s->hdlctx.buffer,
 310                                                         pkt_len);
 311                        dev_kfree_skb_irq(skb);
 312                        s->hdlctx.bp = s->hdlctx.buffer;
 313                        append_crc_ccitt(s->hdlctx.buffer, pkt_len);
 314                        s->hdlctx.len = pkt_len+2; /* the appended CRC */
 315                        s->hdlctx.tx_state = 2;
 316                        s->hdlctx.bitstream = 0;
 317                        dev->stats.tx_packets++;
 318                        break;
 319                case 2:
 320                        if (!s->hdlctx.len) {
 321                                s->hdlctx.tx_state = 0;
 322                                s->hdlctx.numflags = 1;
 323                                break;
 324                        }
 325                        s->hdlctx.len--;
 326                        s->hdlctx.bitbuf |= *s->hdlctx.bp <<
 327                                s->hdlctx.numbits;
 328                        s->hdlctx.bitstream >>= 8;
 329                        s->hdlctx.bitstream |= (*s->hdlctx.bp++) << 16;
 330                        mask1 = 0x1f000;
 331                        mask2 = 0x10000;
 332                        mask3 = 0xffffffff >> (31-s->hdlctx.numbits);
 333                        s->hdlctx.numbits += 8;
 334                        for(i = 0; i < 8; i++, mask1 <<= 1, mask2 <<= 1, 
 335                            mask3 = (mask3 << 1) | 1) {
 336                                if ((s->hdlctx.bitstream & mask1) != mask1) 
 337                                        continue;
 338                                s->hdlctx.bitstream &= ~mask2;
 339                                s->hdlctx.bitbuf = 
 340                                        (s->hdlctx.bitbuf & mask3) |
 341                                                ((s->hdlctx.bitbuf & 
 342                                                 (~mask3)) << 1);
 343                                s->hdlctx.numbits++;
 344                                mask3 = (mask3 << 1) | 1;
 345                        }
 346                        break;
 347                }
 348        }
 349}
 350
 351/* ---------------------------------------------------------------------- */
 352
 353static void start_tx(struct net_device *dev, struct hdlcdrv_state *s)
 354{
 355        s->hdlctx.tx_state = 0;
 356        s->hdlctx.numflags = tenms_to_2flags(s, s->ch_params.tx_delay);
 357        s->hdlctx.bitbuf = s->hdlctx.bitstream = s->hdlctx.numbits = 0;
 358        hdlcdrv_transmitter(dev, s);
 359        s->hdlctx.ptt = 1;
 360        s->ptt_keyed++;
 361}
 362
 363/* ---------------------------------------------------------------------- */
 364
 365void hdlcdrv_arbitrate(struct net_device *dev, struct hdlcdrv_state *s)
 366{
 367        if (!s || s->magic != HDLCDRV_MAGIC || s->hdlctx.ptt || !s->skb) 
 368                return;
 369        if (s->ch_params.fulldup) {
 370                start_tx(dev, s);
 371                return;
 372        }
 373        if (s->hdlcrx.dcd) {
 374                s->hdlctx.slotcnt = s->ch_params.slottime;
 375                return;
 376        }
 377        if ((--s->hdlctx.slotcnt) > 0)
 378                return;
 379        s->hdlctx.slotcnt = s->ch_params.slottime;
 380        if ((prandom_u32() % 256) > s->ch_params.ppersist)
 381                return;
 382        start_tx(dev, s);
 383}
 384
 385/* --------------------------------------------------------------------- */
 386/*
 387 * ===================== network driver interface =========================
 388 */
 389
 390static netdev_tx_t hdlcdrv_send_packet(struct sk_buff *skb,
 391                                       struct net_device *dev)
 392{
 393        struct hdlcdrv_state *sm = netdev_priv(dev);
 394
 395        if (skb->protocol == htons(ETH_P_IP))
 396                return ax25_ip_xmit(skb);
 397
 398        if (skb->data[0] != 0) {
 399                do_kiss_params(sm, skb->data, skb->len);
 400                dev_kfree_skb(skb);
 401                return NETDEV_TX_OK;
 402        }
 403        if (sm->skb) {
 404                dev_kfree_skb(skb);
 405                return NETDEV_TX_OK;
 406        }
 407        netif_stop_queue(dev);
 408        sm->skb = skb;
 409        return NETDEV_TX_OK;
 410}
 411
 412/* --------------------------------------------------------------------- */
 413
 414static int hdlcdrv_set_mac_address(struct net_device *dev, void *addr)
 415{
 416        struct sockaddr *sa = (struct sockaddr *)addr;
 417
 418        /* addr is an AX.25 shifted ASCII mac address */
 419        dev_addr_set(dev, sa->sa_data);
 420        return 0;                                         
 421}
 422
 423/* --------------------------------------------------------------------- */
 424/*
 425 * Open/initialize the board. This is called (in the current kernel)
 426 * sometime after booting when the 'ifconfig' program is run.
 427 *
 428 * This routine should set everything up anew at each open, even
 429 * registers that "should" only need to be set once at boot, so that
 430 * there is non-reboot way to recover if something goes wrong.
 431 */
 432
 433static int hdlcdrv_open(struct net_device *dev)
 434{
 435        struct hdlcdrv_state *s = netdev_priv(dev);
 436        int i;
 437
 438        if (!s->ops || !s->ops->open)
 439                return -ENODEV;
 440
 441        /*
 442         * initialise some variables
 443         */
 444        s->opened = 1;
 445        s->hdlcrx.hbuf.rd = s->hdlcrx.hbuf.wr = 0;
 446        s->hdlcrx.in_hdlc_rx = 0;
 447        s->hdlcrx.rx_state = 0;
 448        
 449        s->hdlctx.hbuf.rd = s->hdlctx.hbuf.wr = 0;
 450        s->hdlctx.in_hdlc_tx = 0;
 451        s->hdlctx.tx_state = 1;
 452        s->hdlctx.numflags = 0;
 453        s->hdlctx.bitstream = s->hdlctx.bitbuf = s->hdlctx.numbits = 0;
 454        s->hdlctx.ptt = 0;
 455        s->hdlctx.slotcnt = s->ch_params.slottime;
 456        s->hdlctx.calibrate = 0;
 457
 458        i = s->ops->open(dev);
 459        if (i)
 460                return i;
 461        netif_start_queue(dev);
 462        return 0;
 463}
 464
 465/* --------------------------------------------------------------------- */
 466/* 
 467 * The inverse routine to hdlcdrv_open(). 
 468 */
 469
 470static int hdlcdrv_close(struct net_device *dev)
 471{
 472        struct hdlcdrv_state *s = netdev_priv(dev);
 473        int i = 0;
 474
 475        netif_stop_queue(dev);
 476
 477        if (s->ops && s->ops->close)
 478                i = s->ops->close(dev);
 479        dev_kfree_skb(s->skb);
 480        s->skb = NULL;
 481        s->opened = 0;
 482        return i;
 483}
 484
 485/* --------------------------------------------------------------------- */
 486
 487static int hdlcdrv_siocdevprivate(struct net_device *dev, struct ifreq *ifr,
 488                                  void __user *data, int cmd)
 489{
 490        struct hdlcdrv_state *s = netdev_priv(dev);
 491        struct hdlcdrv_ioctl bi;
 492
 493        if (cmd != SIOCDEVPRIVATE)
 494                return -ENOIOCTLCMD;
 495
 496        if (in_compat_syscall()) /* to be implemented */
 497                return -ENOIOCTLCMD;
 498
 499        if (copy_from_user(&bi, data, sizeof(bi)))
 500                return -EFAULT;
 501
 502        switch (bi.cmd) {
 503        default:
 504                if (s->ops && s->ops->ioctl)
 505                        return s->ops->ioctl(dev, data, &bi, cmd);
 506                return -ENOIOCTLCMD;
 507
 508        case HDLCDRVCTL_GETCHANNELPAR:
 509                bi.data.cp.tx_delay = s->ch_params.tx_delay;
 510                bi.data.cp.tx_tail = s->ch_params.tx_tail;
 511                bi.data.cp.slottime = s->ch_params.slottime;
 512                bi.data.cp.ppersist = s->ch_params.ppersist;
 513                bi.data.cp.fulldup = s->ch_params.fulldup;
 514                break;
 515
 516        case HDLCDRVCTL_SETCHANNELPAR:
 517                if (!capable(CAP_NET_ADMIN))
 518                        return -EACCES;
 519                s->ch_params.tx_delay = bi.data.cp.tx_delay;
 520                s->ch_params.tx_tail = bi.data.cp.tx_tail;
 521                s->ch_params.slottime = bi.data.cp.slottime;
 522                s->ch_params.ppersist = bi.data.cp.ppersist;
 523                s->ch_params.fulldup = bi.data.cp.fulldup;
 524                s->hdlctx.slotcnt = 1;
 525                return 0;
 526                
 527        case HDLCDRVCTL_GETMODEMPAR:
 528                bi.data.mp.iobase = dev->base_addr;
 529                bi.data.mp.irq = dev->irq;
 530                bi.data.mp.dma = dev->dma;
 531                bi.data.mp.dma2 = s->ptt_out.dma2;
 532                bi.data.mp.seriobase = s->ptt_out.seriobase;
 533                bi.data.mp.pariobase = s->ptt_out.pariobase;
 534                bi.data.mp.midiiobase = s->ptt_out.midiiobase;
 535                break;
 536
 537        case HDLCDRVCTL_SETMODEMPAR:
 538                if ((!capable(CAP_SYS_RAWIO)) || netif_running(dev))
 539                        return -EACCES;
 540                dev->base_addr = bi.data.mp.iobase;
 541                dev->irq = bi.data.mp.irq;
 542                dev->dma = bi.data.mp.dma;
 543                s->ptt_out.dma2 = bi.data.mp.dma2;
 544                s->ptt_out.seriobase = bi.data.mp.seriobase;
 545                s->ptt_out.pariobase = bi.data.mp.pariobase;
 546                s->ptt_out.midiiobase = bi.data.mp.midiiobase;
 547                return 0;       
 548        
 549        case HDLCDRVCTL_GETSTAT:
 550                bi.data.cs.ptt = hdlcdrv_ptt(s);
 551                bi.data.cs.dcd = s->hdlcrx.dcd;
 552                bi.data.cs.ptt_keyed = s->ptt_keyed;
 553                bi.data.cs.tx_packets = dev->stats.tx_packets;
 554                bi.data.cs.tx_errors = dev->stats.tx_errors;
 555                bi.data.cs.rx_packets = dev->stats.rx_packets;
 556                bi.data.cs.rx_errors = dev->stats.rx_errors;
 557                break;          
 558
 559        case HDLCDRVCTL_OLDGETSTAT:
 560                bi.data.ocs.ptt = hdlcdrv_ptt(s);
 561                bi.data.ocs.dcd = s->hdlcrx.dcd;
 562                bi.data.ocs.ptt_keyed = s->ptt_keyed;
 563                break;          
 564
 565        case HDLCDRVCTL_CALIBRATE:
 566                if(!capable(CAP_SYS_RAWIO))
 567                        return -EPERM;
 568                if (s->par.bitrate <= 0)
 569                        return -EINVAL;
 570                if (bi.data.calibrate > INT_MAX / s->par.bitrate)
 571                        return -EINVAL;
 572                s->hdlctx.calibrate = bi.data.calibrate * s->par.bitrate / 16;
 573                return 0;
 574
 575        case HDLCDRVCTL_GETSAMPLES:
 576#ifndef HDLCDRV_DEBUG
 577                return -EPERM;
 578#else /* HDLCDRV_DEBUG */
 579                if (s->bitbuf_channel.rd == s->bitbuf_channel.wr) 
 580                        return -EAGAIN;
 581                bi.data.bits = 
 582                        s->bitbuf_channel.buffer[s->bitbuf_channel.rd];
 583                s->bitbuf_channel.rd = (s->bitbuf_channel.rd+1) %
 584                        sizeof(s->bitbuf_channel.buffer);
 585                break;
 586#endif /* HDLCDRV_DEBUG */
 587                                
 588        case HDLCDRVCTL_GETBITS:
 589#ifndef HDLCDRV_DEBUG
 590                return -EPERM;
 591#else /* HDLCDRV_DEBUG */
 592                if (s->bitbuf_hdlc.rd == s->bitbuf_hdlc.wr) 
 593                        return -EAGAIN;
 594                bi.data.bits = 
 595                        s->bitbuf_hdlc.buffer[s->bitbuf_hdlc.rd];
 596                s->bitbuf_hdlc.rd = (s->bitbuf_hdlc.rd+1) %
 597                        sizeof(s->bitbuf_hdlc.buffer);
 598                break;          
 599#endif /* HDLCDRV_DEBUG */
 600
 601        case HDLCDRVCTL_DRIVERNAME:
 602                if (s->ops && s->ops->drvname) {
 603                        strlcpy(bi.data.drivername, s->ops->drvname,
 604                                sizeof(bi.data.drivername));
 605                        break;
 606                }
 607                bi.data.drivername[0] = '\0';
 608                break;
 609                
 610        }
 611        if (copy_to_user(data, &bi, sizeof(bi)))
 612                return -EFAULT;
 613        return 0;
 614
 615}
 616
 617/* --------------------------------------------------------------------- */
 618
 619static const struct net_device_ops hdlcdrv_netdev = {
 620        .ndo_open       = hdlcdrv_open,
 621        .ndo_stop       = hdlcdrv_close,
 622        .ndo_start_xmit = hdlcdrv_send_packet,
 623        .ndo_siocdevprivate  = hdlcdrv_siocdevprivate,
 624        .ndo_set_mac_address = hdlcdrv_set_mac_address,
 625};
 626
 627/*
 628 * Initialize fields in hdlcdrv
 629 */
 630static void hdlcdrv_setup(struct net_device *dev)
 631{
 632        static const struct hdlcdrv_channel_params dflt_ch_params = { 
 633                20, 2, 10, 40, 0 
 634        };
 635        struct hdlcdrv_state *s = netdev_priv(dev);
 636
 637        /*
 638         * initialize the hdlcdrv_state struct
 639         */
 640        s->ch_params = dflt_ch_params;
 641        s->ptt_keyed = 0;
 642
 643        spin_lock_init(&s->hdlcrx.hbuf.lock);
 644        s->hdlcrx.hbuf.rd = s->hdlcrx.hbuf.wr = 0;
 645        s->hdlcrx.in_hdlc_rx = 0;
 646        s->hdlcrx.rx_state = 0;
 647        
 648        spin_lock_init(&s->hdlctx.hbuf.lock);
 649        s->hdlctx.hbuf.rd = s->hdlctx.hbuf.wr = 0;
 650        s->hdlctx.in_hdlc_tx = 0;
 651        s->hdlctx.tx_state = 1;
 652        s->hdlctx.numflags = 0;
 653        s->hdlctx.bitstream = s->hdlctx.bitbuf = s->hdlctx.numbits = 0;
 654        s->hdlctx.ptt = 0;
 655        s->hdlctx.slotcnt = s->ch_params.slottime;
 656        s->hdlctx.calibrate = 0;
 657
 658#ifdef HDLCDRV_DEBUG
 659        s->bitbuf_channel.rd = s->bitbuf_channel.wr = 0;
 660        s->bitbuf_channel.shreg = 0x80;
 661
 662        s->bitbuf_hdlc.rd = s->bitbuf_hdlc.wr = 0;
 663        s->bitbuf_hdlc.shreg = 0x80;
 664#endif /* HDLCDRV_DEBUG */
 665
 666
 667        /* Fill in the fields of the device structure */
 668
 669        s->skb = NULL;
 670        
 671        dev->netdev_ops = &hdlcdrv_netdev;
 672        dev->header_ops = &ax25_header_ops;
 673        
 674        dev->type = ARPHRD_AX25;           /* AF_AX25 device */
 675        dev->hard_header_len = AX25_MAX_HEADER_LEN + AX25_BPQ_HEADER_LEN;
 676        dev->mtu = AX25_DEF_PACLEN;        /* eth_mtu is the default */
 677        dev->addr_len = AX25_ADDR_LEN;     /* sizeof an ax.25 address */
 678        memcpy(dev->broadcast, &ax25_bcast, AX25_ADDR_LEN);
 679        dev_addr_set(dev, (u8 *)&ax25_defaddr);
 680        dev->tx_queue_len = 16;
 681}
 682
 683/* --------------------------------------------------------------------- */
 684struct net_device *hdlcdrv_register(const struct hdlcdrv_ops *ops,
 685                                    unsigned int privsize, const char *ifname,
 686                                    unsigned int baseaddr, unsigned int irq, 
 687                                    unsigned int dma) 
 688{
 689        struct net_device *dev;
 690        struct hdlcdrv_state *s;
 691        int err;
 692
 693        if (privsize < sizeof(struct hdlcdrv_state))
 694                privsize = sizeof(struct hdlcdrv_state);
 695
 696        dev = alloc_netdev(privsize, ifname, NET_NAME_UNKNOWN, hdlcdrv_setup);
 697        if (!dev)
 698                return ERR_PTR(-ENOMEM);
 699
 700        /*
 701         * initialize part of the hdlcdrv_state struct
 702         */
 703        s = netdev_priv(dev);
 704        s->magic = HDLCDRV_MAGIC;
 705        s->ops = ops;
 706        dev->base_addr = baseaddr;
 707        dev->irq = irq;
 708        dev->dma = dma;
 709
 710        err = register_netdev(dev);
 711        if (err < 0) {
 712                printk(KERN_WARNING "hdlcdrv: cannot register net "
 713                       "device %s\n", dev->name);
 714                free_netdev(dev);
 715                dev = ERR_PTR(err);
 716        }
 717        return dev;
 718}
 719
 720/* --------------------------------------------------------------------- */
 721
 722void hdlcdrv_unregister(struct net_device *dev) 
 723{
 724        struct hdlcdrv_state *s = netdev_priv(dev);
 725
 726        BUG_ON(s->magic != HDLCDRV_MAGIC);
 727
 728        if (s->opened && s->ops->close)
 729                s->ops->close(dev);
 730        unregister_netdev(dev);
 731        
 732        free_netdev(dev);
 733}
 734
 735/* --------------------------------------------------------------------- */
 736
 737EXPORT_SYMBOL(hdlcdrv_receiver);
 738EXPORT_SYMBOL(hdlcdrv_transmitter);
 739EXPORT_SYMBOL(hdlcdrv_arbitrate);
 740EXPORT_SYMBOL(hdlcdrv_register);
 741EXPORT_SYMBOL(hdlcdrv_unregister);
 742
 743/* --------------------------------------------------------------------- */
 744
 745static int __init hdlcdrv_init_driver(void)
 746{
 747        printk(KERN_INFO "hdlcdrv: (C) 1996-2000 Thomas Sailer HB9JNX/AE4WA\n");
 748        printk(KERN_INFO "hdlcdrv: version 0.8\n");
 749        return 0;
 750}
 751
 752/* --------------------------------------------------------------------- */
 753
 754static void __exit hdlcdrv_cleanup_driver(void)
 755{
 756        printk(KERN_INFO "hdlcdrv: cleanup\n");
 757}
 758
 759/* --------------------------------------------------------------------- */
 760
 761MODULE_AUTHOR("Thomas M. Sailer, sailer@ife.ee.ethz.ch, hb9jnx@hb9w.che.eu");
 762MODULE_DESCRIPTION("Packet Radio network interface HDLC encoder/decoder");
 763MODULE_LICENSE("GPL");
 764module_init(hdlcdrv_init_driver);
 765module_exit(hdlcdrv_cleanup_driver);
 766
 767/* --------------------------------------------------------------------- */
 768