1 /*****************************************************************************/
2 
3 /*
4  *	baycom_par.c  -- baycom par96 and picpar radio modem 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  *
27  *  Supported modems
28  *
29  *  par96:  This is a modem for 9600 baud FSK compatible to the G3RUH standard.
30  *          The modem does all the filtering and regenerates the receiver clock.
31  *          Data is transferred from and to the PC via a shift register.
32  *          The shift register is filled with 16 bits and an interrupt is
33  *          signalled. The PC then empties the shift register in a burst. This
34  *          modem connects to the parallel port, hence the name. The modem
35  *          leaves the implementation of the HDLC protocol and the scrambler
36  *          polynomial to the PC. This modem is no longer available (at least
37  *          from Baycom) and has been replaced by the PICPAR modem (see below).
38  *          You may however still build one from the schematics published in
39  *          cq-DL :-).
40  *
41  *  picpar: This is a redesign of the par96 modem by Henning Rech, DF9IC. The
42  *          modem is protocol compatible to par96, but uses only three low
43  *          power ICs and can therefore be fed from the parallel port and
44  *          does not require an additional power supply. It features
45  *          built in DCD circuitry. The driver should therefore be configured
46  *          for hardware DCD.
47  *
48  *
49  *  Command line options (insmod command line)
50  *
51  *  mode     driver mode string. Valid choices are par96 and picpar.
52  *  iobase   base address of the port; common values are 0x378, 0x278, 0x3bc
53  *
54  *
55  *  History:
56  *   0.1  26.06.1996  Adapted from baycom.c and made network driver interface
57  *        18.10.1996  Changed to new user space access routines (copy_{to,from}_user)
58  *   0.3  26.04.1997  init code/data tagged
59  *   0.4  08.07.1997  alternative ser12 decoding algorithm (uses delta CTS ints)
60  *   0.5  11.11.1997  split into separate files for ser12/par96
61  *   0.6  03.08.1999  adapt to Linus' new __setup/__initcall
62  *                    removed some pre-2.2 kernel compatibility cruft
63  *   0.7  10.08.1999  Check if parport can do SPP and is safe to access during interrupt contexts
64  *   0.8  12.02.2000  adapted to softnet driver interface
65  *                    removed direct parport access, uses parport driver methods
66  *   0.9  03.07.2000  fix interface name handling
67  */
68 
69 /*****************************************************************************/
70 
71 #include <linux/module.h>
72 #include <linux/kernel.h>
73 #include <linux/types.h>
74 #include <linux/fcntl.h>
75 #include <linux/interrupt.h>
76 #include <linux/ioport.h>
77 #include <linux/in.h>
78 #include <linux/string.h>
79 #include <linux/init.h>
80 #include <linux/delay.h>
81 #include <linux/errno.h>
82 #include <linux/netdevice.h>
83 #include <linux/hdlcdrv.h>
84 #include <linux/baycom.h>
85 #include <linux/parport.h>
86 #include <linux/bitops.h>
87 #include <linux/jiffies.h>
88 
89 #include <asm/system.h>
90 #include <asm/uaccess.h>
91 
92 /* --------------------------------------------------------------------- */
93 
94 #define BAYCOM_DEBUG
95 
96 /*
97  * modem options; bit mask
98  */
99 #define BAYCOM_OPTIONS_SOFTDCD  1
100 
101 /* --------------------------------------------------------------------- */
102 
103 static const char bc_drvname[] = "baycom_par";
104 static const char bc_drvinfo[] = KERN_INFO "baycom_par: (C) 1996-2000 Thomas Sailer, HB9JNX/AE4WA\n"
105 KERN_INFO "baycom_par: version 0.9 compiled " __TIME__ " " __DATE__ "\n";
106 
107 /* --------------------------------------------------------------------- */
108 
109 #define NR_PORTS 4
110 
111 static struct net_device *baycom_device[NR_PORTS];
112 
113 /* --------------------------------------------------------------------- */
114 
115 #define PAR96_BURSTBITS 16
116 #define PAR96_BURST     4
117 #define PAR96_PTT       2
118 #define PAR96_TXBIT     1
119 #define PAR96_ACK       0x40
120 #define PAR96_RXBIT     0x20
121 #define PAR96_DCD       0x10
122 #define PAR97_POWER     0xf8
123 
124 /* ---------------------------------------------------------------------- */
125 /*
126  * Information that need to be kept for each board.
127  */
128 
129 struct baycom_state {
130 	struct hdlcdrv_state hdrv;
131 
132 	struct pardevice *pdev;
133 	unsigned int options;
134 
135 	struct modem_state {
136 		short arb_divider;
137 		unsigned char flags;
138 		unsigned int shreg;
139 		struct modem_state_par96 {
140 			int dcd_count;
141 			unsigned int dcd_shreg;
142 			unsigned long descram;
143 			unsigned long scram;
144 		} par96;
145 	} modem;
146 
147 #ifdef BAYCOM_DEBUG
148 	struct debug_vals {
149 		unsigned long last_jiffies;
150 		unsigned cur_intcnt;
151 		unsigned last_intcnt;
152 		int cur_pllcorr;
153 		int last_pllcorr;
154 	} debug_vals;
155 #endif /* BAYCOM_DEBUG */
156 };
157 
158 /* --------------------------------------------------------------------- */
159 
160 static void __inline__ baycom_int_freq(struct baycom_state *bc)
161 {
162 #ifdef BAYCOM_DEBUG
163 	unsigned long cur_jiffies = jiffies;
164 	/*
165 	 * measure the interrupt frequency
166 	 */
167 	bc->debug_vals.cur_intcnt++;
168 	if (time_after_eq(cur_jiffies, bc->debug_vals.last_jiffies + HZ)) {
169 		bc->debug_vals.last_jiffies = cur_jiffies;
170 		bc->debug_vals.last_intcnt = bc->debug_vals.cur_intcnt;
171 		bc->debug_vals.cur_intcnt = 0;
172 		bc->debug_vals.last_pllcorr = bc->debug_vals.cur_pllcorr;
173 		bc->debug_vals.cur_pllcorr = 0;
174 	}
175 #endif /* BAYCOM_DEBUG */
176 }
177 
178 /* --------------------------------------------------------------------- */
179 /*
180  * ===================== PAR96 specific routines =========================
181  */
182 
183 #define PAR96_DESCRAM_TAP1 0x20000
184 #define PAR96_DESCRAM_TAP2 0x01000
185 #define PAR96_DESCRAM_TAP3 0x00001
186 
187 #define PAR96_DESCRAM_TAPSH1 17
188 #define PAR96_DESCRAM_TAPSH2 12
189 #define PAR96_DESCRAM_TAPSH3 0
190 
191 #define PAR96_SCRAM_TAP1 0x20000 /* X^17 */
192 #define PAR96_SCRAM_TAPN 0x00021 /* X^0+X^5 */
193 
194 /* --------------------------------------------------------------------- */
195 
196 static __inline__ void par96_tx(struct net_device *dev, struct baycom_state *bc)
197 {
198 	int i;
199 	unsigned int data = hdlcdrv_getbits(&bc->hdrv);
200 	struct parport *pp = bc->pdev->port;
201 
202 	for(i = 0; i < PAR96_BURSTBITS; i++, data >>= 1) {
203 		unsigned char val = PAR97_POWER;
204 		bc->modem.par96.scram = ((bc->modem.par96.scram << 1) |
205 					 (bc->modem.par96.scram & 1));
206 		if (!(data & 1))
207 			bc->modem.par96.scram ^= 1;
208 		if (bc->modem.par96.scram & (PAR96_SCRAM_TAP1 << 1))
209 			bc->modem.par96.scram ^=
210 				(PAR96_SCRAM_TAPN << 1);
211 		if (bc->modem.par96.scram & (PAR96_SCRAM_TAP1 << 2))
212 			val |= PAR96_TXBIT;
213 		pp->ops->write_data(pp, val);
214 		pp->ops->write_data(pp, val | PAR96_BURST);
215 	}
216 }
217 
218 /* --------------------------------------------------------------------- */
219 
220 static __inline__ void par96_rx(struct net_device *dev, struct baycom_state *bc)
221 {
222 	int i;
223 	unsigned int data, mask, mask2, descx;
224 	struct parport *pp = bc->pdev->port;
225 
226 	/*
227 	 * do receiver; differential decode and descramble on the fly
228 	 */
229 	for(data = i = 0; i < PAR96_BURSTBITS; i++) {
230 		bc->modem.par96.descram = (bc->modem.par96.descram << 1);
231 		if (pp->ops->read_status(pp) & PAR96_RXBIT)
232 			bc->modem.par96.descram |= 1;
233 		descx = bc->modem.par96.descram ^
234 			(bc->modem.par96.descram >> 1);
235 		/* now the diff decoded data is inverted in descram */
236 		pp->ops->write_data(pp, PAR97_POWER | PAR96_PTT);
237 		descx ^= ((descx >> PAR96_DESCRAM_TAPSH1) ^
238 			  (descx >> PAR96_DESCRAM_TAPSH2));
239 		data >>= 1;
240 		if (!(descx & 1))
241 			data |= 0x8000;
242 		pp->ops->write_data(pp, PAR97_POWER | PAR96_PTT | PAR96_BURST);
243 	}
244 	hdlcdrv_putbits(&bc->hdrv, data);
245 	/*
246 	 * do DCD algorithm
247 	 */
248 	if (bc->options & BAYCOM_OPTIONS_SOFTDCD) {
249 		bc->modem.par96.dcd_shreg = (bc->modem.par96.dcd_shreg >> 16)
250 			| (data << 16);
251 		/* search for flags and set the dcd counter appropriately */
252 		for(mask = 0x1fe00, mask2 = 0xfc00, i = 0;
253 		    i < PAR96_BURSTBITS; i++, mask <<= 1, mask2 <<= 1)
254 			if ((bc->modem.par96.dcd_shreg & mask) == mask2)
255 				bc->modem.par96.dcd_count = HDLCDRV_MAXFLEN+4;
256 		/* check for abort/noise sequences */
257 		for(mask = 0x1fe00, mask2 = 0x1fe00, i = 0;
258 		    i < PAR96_BURSTBITS; i++, mask <<= 1, mask2 <<= 1)
259 			if (((bc->modem.par96.dcd_shreg & mask) == mask2) &&
260 			    (bc->modem.par96.dcd_count >= 0))
261 				bc->modem.par96.dcd_count -= HDLCDRV_MAXFLEN-10;
262 		/* decrement and set the dcd variable */
263 		if (bc->modem.par96.dcd_count >= 0)
264 			bc->modem.par96.dcd_count -= 2;
265 		hdlcdrv_setdcd(&bc->hdrv, bc->modem.par96.dcd_count > 0);
266 	} else {
267 		hdlcdrv_setdcd(&bc->hdrv, !!(pp->ops->read_status(pp) & PAR96_DCD));
268 	}
269 }
270 
271 /* --------------------------------------------------------------------- */
272 
273 static void par96_interrupt(void *dev_id)
274 {
275 	struct net_device *dev = dev_id;
276 	struct baycom_state *bc = netdev_priv(dev);
277 
278 	baycom_int_freq(bc);
279 	/*
280 	 * check if transmitter active
281 	 */
282 	if (hdlcdrv_ptt(&bc->hdrv))
283 		par96_tx(dev, bc);
284 	else {
285 		par96_rx(dev, bc);
286 		if (--bc->modem.arb_divider <= 0) {
287 			bc->modem.arb_divider = 6;
288 			local_irq_enable();
289 			hdlcdrv_arbitrate(dev, &bc->hdrv);
290 		}
291 	}
292 	local_irq_enable();
293 	hdlcdrv_transmitter(dev, &bc->hdrv);
294 	hdlcdrv_receiver(dev, &bc->hdrv);
295         local_irq_disable();
296 }
297 
298 /* --------------------------------------------------------------------- */
299 
300 static void par96_wakeup(void *handle)
301 {
302         struct net_device *dev = (struct net_device *)handle;
303 	struct baycom_state *bc = netdev_priv(dev);
304 
305 	printk(KERN_DEBUG "baycom_par: %s: why am I being woken up?\n", dev->name);
306 	if (!parport_claim(bc->pdev))
307 		printk(KERN_DEBUG "baycom_par: %s: I'm broken.\n", dev->name);
308 }
309 
310 /* --------------------------------------------------------------------- */
311 
312 static int par96_open(struct net_device *dev)
313 {
314 	struct baycom_state *bc = netdev_priv(dev);
315 	struct parport *pp;
316 
317 	if (!dev || !bc)
318 		return -ENXIO;
319 	pp = parport_find_base(dev->base_addr);
320 	if (!pp) {
321 		printk(KERN_ERR "baycom_par: parport at 0x%lx unknown\n", dev->base_addr);
322 		return -ENXIO;
323 	}
324 	if (pp->irq < 0) {
325 		printk(KERN_ERR "baycom_par: parport at 0x%lx has no irq\n", pp->base);
326 		parport_put_port(pp);
327 		return -ENXIO;
328 	}
329 	if ((~pp->modes) & (PARPORT_MODE_PCSPP | PARPORT_MODE_SAFEININT)) {
330 		printk(KERN_ERR "baycom_par: parport at 0x%lx cannot be used\n", pp->base);
331 		parport_put_port(pp);
332 		return -ENXIO;
333 	}
334 	memset(&bc->modem, 0, sizeof(bc->modem));
335 	bc->hdrv.par.bitrate = 9600;
336 	bc->pdev = parport_register_device(pp, dev->name, NULL, par96_wakeup,
337 				 par96_interrupt, PARPORT_DEV_EXCL, dev);
338 	parport_put_port(pp);
339 	if (!bc->pdev) {
340 		printk(KERN_ERR "baycom_par: cannot register parport at 0x%lx\n", dev->base_addr);
341 		return -ENXIO;
342 	}
343 	if (parport_claim(bc->pdev)) {
344 		printk(KERN_ERR "baycom_par: parport at 0x%lx busy\n", pp->base);
345 		parport_unregister_device(bc->pdev);
346 		return -EBUSY;
347 	}
348 	pp = bc->pdev->port;
349 	dev->irq = pp->irq;
350 	pp->ops->data_forward(pp);
351         bc->hdrv.par.bitrate = 9600;
352 	pp->ops->write_data(pp, PAR96_PTT | PAR97_POWER); /* switch off PTT */
353 	pp->ops->enable_irq(pp);
354 	printk(KERN_INFO "%s: par96 at iobase 0x%lx irq %u options 0x%x\n",
355 	       bc_drvname, dev->base_addr, dev->irq, bc->options);
356 	return 0;
357 }
358 
359 /* --------------------------------------------------------------------- */
360 
361 static int par96_close(struct net_device *dev)
362 {
363 	struct baycom_state *bc = netdev_priv(dev);
364 	struct parport *pp;
365 
366 	if (!dev || !bc)
367 		return -EINVAL;
368 	pp = bc->pdev->port;
369 	/* disable interrupt */
370 	pp->ops->disable_irq(pp);
371 	/* switch off PTT */
372 	pp->ops->write_data(pp, PAR96_PTT | PAR97_POWER);
373 	parport_release(bc->pdev);
374 	parport_unregister_device(bc->pdev);
375 	printk(KERN_INFO "%s: close par96 at iobase 0x%lx irq %u\n",
376 	       bc_drvname, dev->base_addr, dev->irq);
377 	return 0;
378 }
379 
380 /* --------------------------------------------------------------------- */
381 /*
382  * ===================== hdlcdrv driver interface =========================
383  */
384 
385 static int baycom_ioctl(struct net_device *dev, struct ifreq *ifr,
386 			struct hdlcdrv_ioctl *hi, int cmd);
387 
388 /* --------------------------------------------------------------------- */
389 
390 static struct hdlcdrv_ops par96_ops = {
391 	.drvname = bc_drvname,
392 	.drvinfo = bc_drvinfo,
393 	.open    = par96_open,
394 	.close   = par96_close,
395 	.ioctl   = baycom_ioctl
396 };
397 
398 /* --------------------------------------------------------------------- */
399 
400 static int baycom_setmode(struct baycom_state *bc, const char *modestr)
401 {
402 	if (!strncmp(modestr, "picpar", 6))
403 		bc->options = 0;
404 	else if (!strncmp(modestr, "par96", 5))
405 		bc->options = BAYCOM_OPTIONS_SOFTDCD;
406 	else
407 		bc->options = !!strchr(modestr, '*');
408 	return 0;
409 }
410 
411 /* --------------------------------------------------------------------- */
412 
413 static int baycom_ioctl(struct net_device *dev, struct ifreq *ifr,
414 			struct hdlcdrv_ioctl *hi, int cmd)
415 {
416 	struct baycom_state *bc;
417 	struct baycom_ioctl bi;
418 
419 	if (!dev)
420 		return -EINVAL;
421 
422 	bc = netdev_priv(dev);
423 	BUG_ON(bc->hdrv.magic != HDLCDRV_MAGIC);
424 
425 	if (cmd != SIOCDEVPRIVATE)
426 		return -ENOIOCTLCMD;
427 	switch (hi->cmd) {
428 	default:
429 		break;
430 
431 	case HDLCDRVCTL_GETMODE:
432 		strcpy(hi->data.modename, bc->options ? "par96" : "picpar");
433 		if (copy_to_user(ifr->ifr_data, hi, sizeof(struct hdlcdrv_ioctl)))
434 			return -EFAULT;
435 		return 0;
436 
437 	case HDLCDRVCTL_SETMODE:
438 		if (netif_running(dev) || !capable(CAP_NET_ADMIN))
439 			return -EACCES;
440 		hi->data.modename[sizeof(hi->data.modename)-1] = '\0';
441 		return baycom_setmode(bc, hi->data.modename);
442 
443 	case HDLCDRVCTL_MODELIST:
444 		strcpy(hi->data.modename, "par96,picpar");
445 		if (copy_to_user(ifr->ifr_data, hi, sizeof(struct hdlcdrv_ioctl)))
446 			return -EFAULT;
447 		return 0;
448 
449 	case HDLCDRVCTL_MODEMPARMASK:
450 		return HDLCDRV_PARMASK_IOBASE;
451 
452 	}
453 
454 	if (copy_from_user(&bi, ifr->ifr_data, sizeof(bi)))
455 		return -EFAULT;
456 	switch (bi.cmd) {
457 	default:
458 		return -ENOIOCTLCMD;
459 
460 #ifdef BAYCOM_DEBUG
461 	case BAYCOMCTL_GETDEBUG:
462 		bi.data.dbg.debug1 = bc->hdrv.ptt_keyed;
463 		bi.data.dbg.debug2 = bc->debug_vals.last_intcnt;
464 		bi.data.dbg.debug3 = bc->debug_vals.last_pllcorr;
465 		break;
466 #endif /* BAYCOM_DEBUG */
467 
468 	}
469 	if (copy_to_user(ifr->ifr_data, &bi, sizeof(bi)))
470 		return -EFAULT;
471 	return 0;
472 
473 }
474 
475 /* --------------------------------------------------------------------- */
476 
477 /*
478  * command line settable parameters
479  */
480 static const char *mode[NR_PORTS] = { "picpar", };
481 static int iobase[NR_PORTS] = { 0x378, };
482 
483 module_param_array(mode, charp, NULL, 0);
484 MODULE_PARM_DESC(mode, "baycom operating mode; eg. par96 or picpar");
485 module_param_array(iobase, int, NULL, 0);
486 MODULE_PARM_DESC(iobase, "baycom io base address");
487 
488 MODULE_AUTHOR("Thomas M. Sailer, sailer@ife.ee.ethz.ch, hb9jnx@hb9w.che.eu");
489 MODULE_DESCRIPTION("Baycom par96 and picpar amateur radio modem driver");
490 MODULE_LICENSE("GPL");
491 
492 /* --------------------------------------------------------------------- */
493 
494 static int __init init_baycompar(void)
495 {
496 	int i, found = 0;
497 	char set_hw = 1;
498 
499 	printk(bc_drvinfo);
500 	/*
501 	 * register net devices
502 	 */
503 	for (i = 0; i < NR_PORTS; i++) {
504 		struct net_device *dev;
505 		struct baycom_state *bc;
506 		char ifname[IFNAMSIZ];
507 
508 		sprintf(ifname, "bcp%d", i);
509 
510 		if (!mode[i])
511 			set_hw = 0;
512 		if (!set_hw)
513 			iobase[i] = 0;
514 
515 		dev = hdlcdrv_register(&par96_ops,
516 				       sizeof(struct baycom_state),
517 				       ifname, iobase[i], 0, 0);
518 		if (IS_ERR(dev))
519 			break;
520 
521 		bc = netdev_priv(dev);
522 		if (set_hw && baycom_setmode(bc, mode[i]))
523 			set_hw = 0;
524 		found++;
525 		baycom_device[i] = dev;
526 	}
527 
528 	if (!found)
529 		return -ENXIO;
530 	return 0;
531 }
532 
533 static void __exit cleanup_baycompar(void)
534 {
535 	int i;
536 
537 	for(i = 0; i < NR_PORTS; i++) {
538 		struct net_device *dev = baycom_device[i];
539 
540 		if (dev)
541 			hdlcdrv_unregister(dev);
542 	}
543 }
544 
545 module_init(init_baycompar);
546 module_exit(cleanup_baycompar);
547 
548 /* --------------------------------------------------------------------- */
549 
550 #ifndef MODULE
551 
552 /*
553  * format: baycom_par=io,mode
554  * mode: par96,picpar
555  */
556 
557 static int __init baycom_par_setup(char *str)
558 {
559         static unsigned nr_dev;
560 	int ints[2];
561 
562         if (nr_dev >= NR_PORTS)
563                 return 0;
564         str = get_options(str, 2, ints);
565         if (ints[0] < 1)
566                 return 0;
567         mode[nr_dev] = str;
568         iobase[nr_dev] = ints[1];
569 	nr_dev++;
570 	return 1;
571 }
572 
573 __setup("baycom_par=", baycom_par_setup);
574 
575 #endif /* MODULE */
576 /* --------------------------------------------------------------------- */
577