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		if (bi.data.calibrate > INT_MAX / s->par.bitrate)
575			return -EINVAL;
576		s->hdlctx.calibrate = bi.data.calibrate * s->par.bitrate / 16;
577		return 0;
578
579	case HDLCDRVCTL_GETSAMPLES:
580#ifndef HDLCDRV_DEBUG
581		return -EPERM;
582#else /* HDLCDRV_DEBUG */
583		if (s->bitbuf_channel.rd == s->bitbuf_channel.wr)
584			return -EAGAIN;
585		bi.data.bits =
586			s->bitbuf_channel.buffer[s->bitbuf_channel.rd];
587		s->bitbuf_channel.rd = (s->bitbuf_channel.rd+1) %
588			sizeof(s->bitbuf_channel.buffer);
589		break;
590#endif /* HDLCDRV_DEBUG */
591
592	case HDLCDRVCTL_GETBITS:
593#ifndef HDLCDRV_DEBUG
594		return -EPERM;
595#else /* HDLCDRV_DEBUG */
596		if (s->bitbuf_hdlc.rd == s->bitbuf_hdlc.wr)
597			return -EAGAIN;
598		bi.data.bits =
599			s->bitbuf_hdlc.buffer[s->bitbuf_hdlc.rd];
600		s->bitbuf_hdlc.rd = (s->bitbuf_hdlc.rd+1) %
601			sizeof(s->bitbuf_hdlc.buffer);
602		break;
603#endif /* HDLCDRV_DEBUG */
604
605	case HDLCDRVCTL_DRIVERNAME:
606		if (s->ops && s->ops->drvname) {
607			strncpy(bi.data.drivername, s->ops->drvname,
608				sizeof(bi.data.drivername));
609			break;
610		}
611		bi.data.drivername[0] = '\0';
612		break;
613
614	}
615	if (copy_to_user(ifr->ifr_data, &bi, sizeof(bi)))
616		return -EFAULT;
617	return 0;
618
619}
620
621/* --------------------------------------------------------------------- */
622
623static const struct net_device_ops hdlcdrv_netdev = {
624	.ndo_open	= hdlcdrv_open,
625	.ndo_stop	= hdlcdrv_close,
626	.ndo_start_xmit = hdlcdrv_send_packet,
627	.ndo_do_ioctl	= hdlcdrv_ioctl,
628	.ndo_set_mac_address = hdlcdrv_set_mac_address,
629};
630
631/*
632 * Initialize fields in hdlcdrv
633 */
634static void hdlcdrv_setup(struct net_device *dev)
635{
636	static const struct hdlcdrv_channel_params dflt_ch_params = {
637		20, 2, 10, 40, 0
638	};
639	struct hdlcdrv_state *s = netdev_priv(dev);
640
641	/*
642	 * initialize the hdlcdrv_state struct
643	 */
644	s->ch_params = dflt_ch_params;
645	s->ptt_keyed = 0;
646
647	spin_lock_init(&s->hdlcrx.hbuf.lock);
648	s->hdlcrx.hbuf.rd = s->hdlcrx.hbuf.wr = 0;
649	s->hdlcrx.in_hdlc_rx = 0;
650	s->hdlcrx.rx_state = 0;
651
652	spin_lock_init(&s->hdlctx.hbuf.lock);
653	s->hdlctx.hbuf.rd = s->hdlctx.hbuf.wr = 0;
654	s->hdlctx.in_hdlc_tx = 0;
655	s->hdlctx.tx_state = 1;
656	s->hdlctx.numflags = 0;
657	s->hdlctx.bitstream = s->hdlctx.bitbuf = s->hdlctx.numbits = 0;
658	s->hdlctx.ptt = 0;
659	s->hdlctx.slotcnt = s->ch_params.slottime;
660	s->hdlctx.calibrate = 0;
661
662#ifdef HDLCDRV_DEBUG
663	s->bitbuf_channel.rd = s->bitbuf_channel.wr = 0;
664	s->bitbuf_channel.shreg = 0x80;
665
666	s->bitbuf_hdlc.rd = s->bitbuf_hdlc.wr = 0;
667	s->bitbuf_hdlc.shreg = 0x80;
668#endif /* HDLCDRV_DEBUG */
669
670
671	/* Fill in the fields of the device structure */
672
673	s->skb = NULL;
674
675	dev->netdev_ops = &hdlcdrv_netdev;
676	dev->header_ops = &ax25_header_ops;
677
678	dev->type = ARPHRD_AX25;           /* AF_AX25 device */
679	dev->hard_header_len = AX25_MAX_HEADER_LEN + AX25_BPQ_HEADER_LEN;
680	dev->mtu = AX25_DEF_PACLEN;        /* eth_mtu is the default */
681	dev->addr_len = AX25_ADDR_LEN;     /* sizeof an ax.25 address */
682	memcpy(dev->broadcast, &ax25_bcast, AX25_ADDR_LEN);
683	memcpy(dev->dev_addr, &ax25_defaddr, AX25_ADDR_LEN);
684	dev->tx_queue_len = 16;
685}
686
687/* --------------------------------------------------------------------- */
688struct net_device *hdlcdrv_register(const struct hdlcdrv_ops *ops,
689				    unsigned int privsize, const char *ifname,
690				    unsigned int baseaddr, unsigned int irq,
691				    unsigned int dma)
692{
693	struct net_device *dev;
694	struct hdlcdrv_state *s;
695	int err;
696
697	BUG_ON(ops == NULL);
698
699	if (privsize < sizeof(struct hdlcdrv_state))
700		privsize = sizeof(struct hdlcdrv_state);
701
702	dev = alloc_netdev(privsize, ifname, NET_NAME_UNKNOWN, hdlcdrv_setup);
703	if (!dev)
704		return ERR_PTR(-ENOMEM);
705
706	/*
707	 * initialize part of the hdlcdrv_state struct
708	 */
709	s = netdev_priv(dev);
710	s->magic = HDLCDRV_MAGIC;
711	s->ops = ops;
712	dev->base_addr = baseaddr;
713	dev->irq = irq;
714	dev->dma = dma;
715
716	err = register_netdev(dev);
717	if (err < 0) {
718		printk(KERN_WARNING "hdlcdrv: cannot register net "
719		       "device %s\n", dev->name);
720		free_netdev(dev);
721		dev = ERR_PTR(err);
722	}
723	return dev;
724}
725
726/* --------------------------------------------------------------------- */
727
728void hdlcdrv_unregister(struct net_device *dev)
729{
730	struct hdlcdrv_state *s = netdev_priv(dev);
731
732	BUG_ON(s->magic != HDLCDRV_MAGIC);
733
734	if (s->opened && s->ops->close)
735		s->ops->close(dev);
736	unregister_netdev(dev);
737
738	free_netdev(dev);
739}
740
741/* --------------------------------------------------------------------- */
742
743EXPORT_SYMBOL(hdlcdrv_receiver);
744EXPORT_SYMBOL(hdlcdrv_transmitter);
745EXPORT_SYMBOL(hdlcdrv_arbitrate);
746EXPORT_SYMBOL(hdlcdrv_register);
747EXPORT_SYMBOL(hdlcdrv_unregister);
748
749/* --------------------------------------------------------------------- */
750
751static int __init hdlcdrv_init_driver(void)
752{
753	printk(KERN_INFO "hdlcdrv: (C) 1996-2000 Thomas Sailer HB9JNX/AE4WA\n");
754	printk(KERN_INFO "hdlcdrv: version 0.8\n");
755	return 0;
756}
757
758/* --------------------------------------------------------------------- */
759
760static void __exit hdlcdrv_cleanup_driver(void)
761{
762	printk(KERN_INFO "hdlcdrv: cleanup\n");
763}
764
765/* --------------------------------------------------------------------- */
766
767MODULE_AUTHOR("Thomas M. Sailer, sailer@ife.ee.ethz.ch, hb9jnx@hb9w.che.eu");
768MODULE_DESCRIPTION("Packet Radio network interface HDLC encoder/decoder");
769MODULE_LICENSE("GPL");
770module_init(hdlcdrv_init_driver);
771module_exit(hdlcdrv_cleanup_driver);
772
773/* --------------------------------------------------------------------- */
774