linux/drivers/net/hamradio/hdlcdrv.c
<<
>>
Prefs
   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
  89static 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
  99static 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
 107static 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
 127static 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
 145static 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
 169void 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
 225static 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
 266void 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
 366static 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
 378void 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
 403static 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
 422static 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
 441static 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
 478static 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
 496static 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
 622static 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 */
 633static 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/* --------------------------------------------------------------------- */
 687struct 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
 727void 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
 742EXPORT_SYMBOL(hdlcdrv_receiver);
 743EXPORT_SYMBOL(hdlcdrv_transmitter);
 744EXPORT_SYMBOL(hdlcdrv_arbitrate);
 745EXPORT_SYMBOL(hdlcdrv_register);
 746EXPORT_SYMBOL(hdlcdrv_unregister);
 747
 748/* --------------------------------------------------------------------- */
 749
 750static 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
 759static void __exit hdlcdrv_cleanup_driver(void)
 760{
 761        printk(KERN_INFO "hdlcdrv: cleanup\n");
 762}
 763
 764/* --------------------------------------------------------------------- */
 765
 766MODULE_AUTHOR("Thomas M. Sailer, sailer@ife.ee.ethz.ch, hb9jnx@hb9w.che.eu");
 767MODULE_DESCRIPTION("Packet Radio network interface HDLC encoder/decoder");
 768MODULE_LICENSE("GPL");
 769module_init(hdlcdrv_init_driver);
 770module_exit(hdlcdrv_cleanup_driver);
 771
 772/* --------------------------------------------------------------------- */
 773