summaryrefslogtreecommitdiff
path: root/drivers/net/hamradio/baycom_par.c
blob: 1f7ceafd61ffa4c1ac9d93c9720d5e6863250817 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
/*****************************************************************************/

/*
 *	baycom_par.c  -- baycom par96 and picpar radio modem driver.
 *
 *	Copyright (C) 1996-2000  Thomas Sailer (sailer@ife.ee.ethz.ch)
 *
 *	This program is free software; you can redistribute it and/or modify
 *	it under the terms of the GNU General Public License as published by
 *	the Free Software Foundation; either version 2 of the License, or
 *	(at your option) any later version.
 *
 *	This program is distributed in the hope that it will be useful,
 *	but WITHOUT ANY WARRANTY; without even the implied warranty of
 *	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *	GNU General Public License for more details.
 *
 *	You should have received a copy of the GNU General Public License
 *	along with this program; if not, write to the Free Software
 *	Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 *
 *  Please note that the GPL allows you to use the driver, NOT the radio.
 *  In order to use the radio, you need a license from the communications
 *  authority of your country.
 *
 *
 *  Supported modems
 *
 *  par96:  This is a modem for 9600 baud FSK compatible to the G3RUH standard.
 *          The modem does all the filtering and regenerates the receiver clock.
 *          Data is transferred from and to the PC via a shift register.
 *          The shift register is filled with 16 bits and an interrupt is
 *          signalled. The PC then empties the shift register in a burst. This
 *          modem connects to the parallel port, hence the name. The modem
 *          leaves the implementation of the HDLC protocol and the scrambler
 *          polynomial to the PC. This modem is no longer available (at least
 *          from Baycom) and has been replaced by the PICPAR modem (see below).
 *          You may however still build one from the schematics published in
 *          cq-DL :-).
 *
 *  picpar: This is a redesign of the par96 modem by Henning Rech, DF9IC. The
 *          modem is protocol compatible to par96, but uses only three low
 *          power ICs and can therefore be fed from the parallel port and
 *          does not require an additional power supply. It features
 *          built in DCD circuitry. The driver should therefore be configured
 *          for hardware DCD.
 *
 *
 *  Command line options (insmod command line)
 *
 *  mode     driver mode string. Valid choices are par96 and picpar.
 *  iobase   base address of the port; common values are 0x378, 0x278, 0x3bc
 *
 *
 *  History:
 *   0.1  26.06.1996  Adapted from baycom.c and made network driver interface
 *        18.10.1996  Changed to new user space access routines (copy_{to,from}_user)
 *   0.3  26.04.1997  init code/data tagged
 *   0.4  08.07.1997  alternative ser12 decoding algorithm (uses delta CTS ints)
 *   0.5  11.11.1997  split into separate files for ser12/par96
 *   0.6  03.08.1999  adapt to Linus' new __setup/__initcall
 *                    removed some pre-2.2 kernel compatibility cruft
 *   0.7  10.08.1999  Check if parport can do SPP and is safe to access during interrupt contexts
 *   0.8  12.02.2000  adapted to softnet driver interface
 *                    removed direct parport access, uses parport driver methods
 *   0.9  03.07.2000  fix interface name handling
 */

/*****************************************************************************/

#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/types.h>
#include <linux/fcntl.h>
#include <linux/interrupt.h>
#include <linux/ioport.h>
#include <linux/in.h>
#include <linux/string.h>
#include <linux/init.h>
#include <linux/delay.h>
#include <linux/errno.h>
#include <linux/netdevice.h>
#include <linux/hdlcdrv.h>
#include <linux/baycom.h>
#include <linux/parport.h>
#include <linux/bitops.h>
#include <linux/jiffies.h>

#include <linux/uaccess.h>

/* --------------------------------------------------------------------- */

#define BAYCOM_DEBUG

/*
 * modem options; bit mask
 */
#define BAYCOM_OPTIONS_SOFTDCD  1

/* --------------------------------------------------------------------- */

static const char bc_drvname[] = "baycom_par";
static const char bc_drvinfo[] = KERN_INFO "baycom_par: (C) 1996-2000 Thomas Sailer, HB9JNX/AE4WA\n"
"baycom_par: version 0.9\n";

/* --------------------------------------------------------------------- */

#define NR_PORTS 4

static struct net_device *baycom_device[NR_PORTS];

/* --------------------------------------------------------------------- */

#define PAR96_BURSTBITS 16
#define PAR96_BURST     4
#define PAR96_PTT       2
#define PAR96_TXBIT     1
#define PAR96_ACK       0x40
#define PAR96_RXBIT     0x20
#define PAR96_DCD       0x10
#define PAR97_POWER     0xf8

/* ---------------------------------------------------------------------- */
/*
 * Information that need to be kept for each board.
 */

struct baycom_state {
	struct hdlcdrv_state hdrv;

	struct pardevice *pdev;
	unsigned int options;

	struct modem_state {
		short arb_divider;
		unsigned char flags;
		unsigned int shreg;
		struct modem_state_par96 {
			int dcd_count;
			unsigned int dcd_shreg;
			unsigned long descram;
			unsigned long scram;
		} par96;
	} modem;

#ifdef BAYCOM_DEBUG
	struct debug_vals {
		unsigned long last_jiffies;
		unsigned cur_intcnt;
		unsigned last_intcnt;
		int cur_pllcorr;
		int last_pllcorr;
	} debug_vals;
#endif /* BAYCOM_DEBUG */
};

/* --------------------------------------------------------------------- */

static inline void baycom_int_freq(struct baycom_state *bc)
{
#ifdef BAYCOM_DEBUG
	unsigned long cur_jiffies = jiffies;
	/*
	 * measure the interrupt frequency
	 */
	bc->debug_vals.cur_intcnt++;
	if (time_after_eq(cur_jiffies, bc->debug_vals.last_jiffies + HZ)) {
		bc->debug_vals.last_jiffies = cur_jiffies;
		bc->debug_vals.last_intcnt = bc->debug_vals.cur_intcnt;
		bc->debug_vals.cur_intcnt = 0;
		bc->debug_vals.last_pllcorr = bc->debug_vals.cur_pllcorr;
		bc->debug_vals.cur_pllcorr = 0;
	}
#endif /* BAYCOM_DEBUG */
}

/* --------------------------------------------------------------------- */
/*
 * ===================== PAR96 specific routines =========================
 */

#define PAR96_DESCRAM_TAP1 0x20000
#define PAR96_DESCRAM_TAP2 0x01000
#define PAR96_DESCRAM_TAP3 0x00001

#define PAR96_DESCRAM_TAPSH1 17
#define PAR96_DESCRAM_TAPSH2 12
#define PAR96_DESCRAM_TAPSH3 0

#define PAR96_SCRAM_TAP1 0x20000 /* X^17 */
#define PAR96_SCRAM_TAPN 0x00021 /* X^0+X^5 */

/* --------------------------------------------------------------------- */

static inline void par96_tx(struct net_device *dev, struct baycom_state *bc)
{
	int i;
	unsigned int data = hdlcdrv_getbits(&bc->hdrv);
	struct parport *pp = bc->pdev->port;

	for(i = 0; i < PAR96_BURSTBITS; i++, data >>= 1) {
		unsigned char val = PAR97_POWER;
		bc->modem.par96.scram = ((bc->modem.par96.scram << 1) |
					 (bc->modem.par96.scram & 1));
		if (!(data & 1))
			bc->modem.par96.scram ^= 1;
		if (bc->modem.par96.scram & (PAR96_SCRAM_TAP1 << 1))
			bc->modem.par96.scram ^=
				(PAR96_SCRAM_TAPN << 1);
		if (bc->modem.par96.scram & (PAR96_SCRAM_TAP1 << 2))
			val |= PAR96_TXBIT;
		pp->ops->write_data(pp, val);
		pp->ops->write_data(pp, val | PAR96_BURST);
	}
}

/* --------------------------------------------------------------------- */

static inline void par96_rx(struct net_device *dev, struct baycom_state *bc)
{
	int i;
	unsigned int data, mask, mask2, descx;
	struct parport *pp = bc->pdev->port;

	/*
	 * do receiver; differential decode and descramble on the fly
	 */
	for(data = i = 0; i < PAR96_BURSTBITS; i++) {
		bc->modem.par96.descram = (bc->modem.par96.descram << 1);
		if (pp->ops->read_status(pp) & PAR96_RXBIT)
			bc->modem.par96.descram |= 1;
		descx = bc->modem.par96.descram ^
			(bc->modem.par96.descram >> 1);
		/* now the diff decoded data is inverted in descram */
		pp->ops->write_data(pp, PAR97_POWER | PAR96_PTT);
		descx ^= ((descx >> PAR96_DESCRAM_TAPSH1) ^
			  (descx >> PAR96_DESCRAM_TAPSH2));
		data >>= 1;
		if (!(descx & 1))
			data |= 0x8000;
		pp->ops->write_data(pp, PAR97_POWER | PAR96_PTT | PAR96_BURST);
	}
	hdlcdrv_putbits(&bc->hdrv, data);
	/*
	 * do DCD algorithm
	 */
	if (bc->options & BAYCOM_OPTIONS_SOFTDCD) {
		bc->modem.par96.dcd_shreg = (bc->modem.par96.dcd_shreg >> 16)
			| (data << 16);
		/* search for flags and set the dcd counter appropriately */
		for(mask = 0x1fe00, mask2 = 0xfc00, i = 0;
		    i < PAR96_BURSTBITS; i++, mask <<= 1, mask2 <<= 1)
			if ((bc->modem.par96.dcd_shreg & mask) == mask2)
				bc->modem.par96.dcd_count = HDLCDRV_MAXFLEN+4;
		/* check for abort/noise sequences */
		for(mask = 0x1fe00, mask2 = 0x1fe00, i = 0;
		    i < PAR96_BURSTBITS; i++, mask <<= 1, mask2 <<= 1)
			if (((bc->modem.par96.dcd_shreg & mask) == mask2) &&
			    (bc->modem.par96.dcd_count >= 0))
				bc->modem.par96.dcd_count -= HDLCDRV_MAXFLEN-10;
		/* decrement and set the dcd variable */
		if (bc->modem.par96.dcd_count >= 0)
			bc->modem.par96.dcd_count -= 2;
		hdlcdrv_setdcd(&bc->hdrv, bc->modem.par96.dcd_count > 0);
	} else {
		hdlcdrv_setdcd(&bc->hdrv, !!(pp->ops->read_status(pp) & PAR96_DCD));
	}
}

/* --------------------------------------------------------------------- */

static void par96_interrupt(void *dev_id)
{
	struct net_device *dev = dev_id;
	struct baycom_state *bc = netdev_priv(dev);

	baycom_int_freq(bc);
	/*
	 * check if transmitter active
	 */
	if (hdlcdrv_ptt(&bc->hdrv))
		par96_tx(dev, bc);
	else {
		par96_rx(dev, bc);
		if (--bc->modem.arb_divider <= 0) {
			bc->modem.arb_divider = 6;
			local_irq_enable();
			hdlcdrv_arbitrate(dev, &bc->hdrv);
		}
	}
	local_irq_enable();
	hdlcdrv_transmitter(dev, &bc->hdrv);
	hdlcdrv_receiver(dev, &bc->hdrv);
        local_irq_disable();
}

/* --------------------------------------------------------------------- */

static void par96_wakeup(void *handle)
{
        struct net_device *dev = (struct net_device *)handle;
	struct baycom_state *bc = netdev_priv(dev);

	printk(KERN_DEBUG "baycom_par: %s: why am I being woken up?\n", dev->name);
	if (!parport_claim(bc->pdev))
		printk(KERN_DEBUG "baycom_par: %s: I'm broken.\n", dev->name);
}

/* --------------------------------------------------------------------- */

static int par96_open(struct net_device *dev)
{
	struct baycom_state *bc = netdev_priv(dev);
	struct pardev_cb par_cb;
	struct parport *pp;
	int i;

	if (!dev || !bc)
		return -ENXIO;
	pp = parport_find_base(dev->base_addr);
	if (!pp) {
		printk(KERN_ERR "baycom_par: parport at 0x%lx unknown\n", dev->base_addr);
		return -ENXIO;
	}
	if (pp->irq < 0) {
		printk(KERN_ERR "baycom_par: parport at 0x%lx has no irq\n", pp->base);
		parport_put_port(pp);
		return -ENXIO;
	}
	if ((~pp->modes) & (PARPORT_MODE_PCSPP | PARPORT_MODE_SAFEININT)) {
		printk(KERN_ERR "baycom_par: parport at 0x%lx cannot be used\n", pp->base);
		parport_put_port(pp);
		return -ENXIO;
	}
	memset(&bc->modem, 0, sizeof(bc->modem));
	bc->hdrv.par.bitrate = 9600;
	memset(&par_cb, 0, sizeof(par_cb));
	par_cb.wakeup = par96_wakeup;
	par_cb.irq_func = par96_interrupt;
	par_cb.private = (void *)dev;
	par_cb.flags = PARPORT_DEV_EXCL;
	for (i = 0; i < NR_PORTS; i++)
		if (baycom_device[i] == dev)
			break;

	if (i == NR_PORTS) {
		pr_err("%s: no device found\n", bc_drvname);
		parport_put_port(pp);
		return -ENODEV;
	}
	bc->pdev = parport_register_dev_model(pp, dev->name, &par_cb, i);
	parport_put_port(pp);
	if (!bc->pdev) {
		printk(KERN_ERR "baycom_par: cannot register parport at 0x%lx\n", dev->base_addr);
		return -ENXIO;
	}
	if (parport_claim(bc->pdev)) {
		printk(KERN_ERR "baycom_par: parport at 0x%lx busy\n", pp->base);
		parport_unregister_device(bc->pdev);
		return -EBUSY;
	}
	pp = bc->pdev->port;
	dev->irq = pp->irq;
	pp->ops->data_forward(pp);
        bc->hdrv.par.bitrate = 9600;
	pp->ops->write_data(pp, PAR96_PTT | PAR97_POWER); /* switch off PTT */
	pp->ops->enable_irq(pp);
	printk(KERN_INFO "%s: par96 at iobase 0x%lx irq %u options 0x%x\n",
	       bc_drvname, dev->base_addr, dev->irq, bc->options);
	return 0;
}

/* --------------------------------------------------------------------- */

static int par96_close(struct net_device *dev)
{
	struct baycom_state *bc = netdev_priv(dev);
	struct parport *pp;

	if (!dev || !bc)
		return -EINVAL;
	pp = bc->pdev->port;
	/* disable interrupt */
	pp->ops->disable_irq(pp);
	/* switch off PTT */
	pp->ops->write_data(pp, PAR96_PTT | PAR97_POWER);
	parport_release(bc->pdev);
	parport_unregister_device(bc->pdev);
	printk(KERN_INFO "%s: close par96 at iobase 0x%lx irq %u\n",
	       bc_drvname, dev->base_addr, dev->irq);
	return 0;
}

/* --------------------------------------------------------------------- */
/*
 * ===================== hdlcdrv driver interface =========================
 */

static int baycom_ioctl(struct net_device *dev, struct ifreq *ifr,
			struct hdlcdrv_ioctl *hi, int cmd);

/* --------------------------------------------------------------------- */

static const struct hdlcdrv_ops par96_ops = {
	.drvname = bc_drvname,
	.drvinfo = bc_drvinfo,
	.open    = par96_open,
	.close   = par96_close,
	.ioctl   = baycom_ioctl
};

/* --------------------------------------------------------------------- */

static int baycom_setmode(struct baycom_state *bc, const char *modestr)
{
	if (!strncmp(modestr, "picpar", 6))
		bc->options = 0;
	else if (!strncmp(modestr, "par96", 5))
		bc->options = BAYCOM_OPTIONS_SOFTDCD;
	else
		bc->options = !!strchr(modestr, '*');
	return 0;
}

/* --------------------------------------------------------------------- */

static int baycom_ioctl(struct net_device *dev, struct ifreq *ifr,
			struct hdlcdrv_ioctl *hi, int cmd)
{
	struct baycom_state *bc;
	struct baycom_ioctl bi;

	if (!dev)
		return -EINVAL;

	bc = netdev_priv(dev);
	BUG_ON(bc->hdrv.magic != HDLCDRV_MAGIC);

	if (cmd != SIOCDEVPRIVATE)
		return -ENOIOCTLCMD;
	switch (hi->cmd) {
	default:
		break;

	case HDLCDRVCTL_GETMODE:
		strcpy(hi->data.modename, bc->options ? "par96" : "picpar");
		if (copy_to_user(ifr->ifr_data, hi, sizeof(struct hdlcdrv_ioctl)))
			return -EFAULT;
		return 0;

	case HDLCDRVCTL_SETMODE:
		if (netif_running(dev) || !capable(CAP_NET_ADMIN))
			return -EACCES;
		hi->data.modename[sizeof(hi->data.modename)-1] = '\0';
		return baycom_setmode(bc, hi->data.modename);

	case HDLCDRVCTL_MODELIST:
		strcpy(hi->data.modename, "par96,picpar");
		if (copy_to_user(ifr->ifr_data, hi, sizeof(struct hdlcdrv_ioctl)))
			return -EFAULT;
		return 0;

	case HDLCDRVCTL_MODEMPARMASK:
		return HDLCDRV_PARMASK_IOBASE;

	}

	if (copy_from_user(&bi, ifr->ifr_data, sizeof(bi)))
		return -EFAULT;
	switch (bi.cmd) {
	default:
		return -ENOIOCTLCMD;

#ifdef BAYCOM_DEBUG
	case BAYCOMCTL_GETDEBUG:
		bi.data.dbg.debug1 = bc->hdrv.ptt_keyed;
		bi.data.dbg.debug2 = bc->debug_vals.last_intcnt;
		bi.data.dbg.debug3 = bc->debug_vals.last_pllcorr;
		break;
#endif /* BAYCOM_DEBUG */

	}
	if (copy_to_user(ifr->ifr_data, &bi, sizeof(bi)))
		return -EFAULT;
	return 0;

}

/* --------------------------------------------------------------------- */

/*
 * command line settable parameters
 */
static char *mode[NR_PORTS] = { "picpar", };
static int iobase[NR_PORTS] = { 0x378, };

module_param_array(mode, charp, NULL, 0);
MODULE_PARM_DESC(mode, "baycom operating mode; eg. par96 or picpar");
module_param_hw_array(iobase, int, ioport, NULL, 0);
MODULE_PARM_DESC(iobase, "baycom io base address");

MODULE_AUTHOR("Thomas M. Sailer, sailer@ife.ee.ethz.ch, hb9jnx@hb9w.che.eu");
MODULE_DESCRIPTION("Baycom par96 and picpar amateur radio modem driver");
MODULE_LICENSE("GPL");

/* --------------------------------------------------------------------- */

static int baycom_par_probe(struct pardevice *par_dev)
{
	struct device_driver *drv = par_dev->dev.driver;
	int len = strlen(drv->name);

	if (strncmp(par_dev->name, drv->name, len))
		return -ENODEV;

	return 0;
}

static struct parport_driver baycom_par_driver = {
	.name = "bcp",
	.probe = baycom_par_probe,
	.devmodel = true,
};

static int __init init_baycompar(void)
{
	int i, found = 0, ret;
	char set_hw = 1;

	printk(bc_drvinfo);

	ret = parport_register_driver(&baycom_par_driver);
	if (ret)
		return ret;

	/*
	 * register net devices
	 */
	for (i = 0; i < NR_PORTS; i++) {
		struct net_device *dev;
		struct baycom_state *bc;
		char ifname[IFNAMSIZ];

		sprintf(ifname, "bcp%d", i);

		if (!mode[i])
			set_hw = 0;
		if (!set_hw)
			iobase[i] = 0;

		dev = hdlcdrv_register(&par96_ops,
				       sizeof(struct baycom_state),
				       ifname, iobase[i], 0, 0);
		if (IS_ERR(dev)) 
			break;

		bc = netdev_priv(dev);
		if (set_hw && baycom_setmode(bc, mode[i]))
			set_hw = 0;
		found++;
		baycom_device[i] = dev;
	}

	if (!found) {
		parport_unregister_driver(&baycom_par_driver);
		return -ENXIO;
	}
	return 0;
}

static void __exit cleanup_baycompar(void)
{
	int i;

	for(i = 0; i < NR_PORTS; i++) {
		struct net_device *dev = baycom_device[i];

		if (dev)
			hdlcdrv_unregister(dev);
	}
	parport_unregister_driver(&baycom_par_driver);
}

module_init(init_baycompar);
module_exit(cleanup_baycompar);

/* --------------------------------------------------------------------- */

#ifndef MODULE

/*
 * format: baycom_par=io,mode
 * mode: par96,picpar
 */

static int __init baycom_par_setup(char *str)
{
        static unsigned nr_dev;
	int ints[2];

        if (nr_dev >= NR_PORTS)
                return 0;
        str = get_options(str, 2, ints);
        if (ints[0] < 1)
                return 0;
        mode[nr_dev] = str;
        iobase[nr_dev] = ints[1];
	nr_dev++;
	return 1;
}

__setup("baycom_par=", baycom_par_setup);

#endif /* MODULE */
/* --------------------------------------------------------------------- */