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37  *          from Baycom) and has been replaced by the PICPAR modem (see below).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/bug.h>
90 #include <asm/system.h>
91 #include <asm/uaccess.h>
92 
93 /* --------------------------------------------------------------------- */
94 
95 #define BAYCOM_DEBUG
96 
97 /*
98  * modem options; bit mask
99  */
100 #define BAYCOM_OPTIONS_SOFTDCD  1
101 
102 /* --------------------------------------------------------------------- */
103 
104 static const char bc_drvname[] = "baycom_par";
105 static const char bc_drvinfo[] = KERN_INFO "baycom_par: (C) 1996-2000 Thomas Sailer, HB9JNX/AE4WA\n"
106 KERN_INFO "baycom_par: version 0.9 compiled " __TIME__ " " __DATE__ "\n";
107 
108 /* --------------------------------------------------------------------- */
109 
110 #define NR_PORTS 4
111 
112 static struct net_device *baycom_device[NR_PORTS];
113 
114 /* --------------------------------------------------------------------- */
115 
116 #define PAR96_BURSTBITS 16
117 #define PAR96_BURST     4
118 #define PAR96_PTT       2
119 #define PAR96_TXBIT     1
120 #define PAR96_ACK       0x40
121 #define PAR96_RXBIT     0x20
122 #define PAR96_DCD       0x10
123 #define PAR97_POWER     0xf8
124 
125 /* ---------------------------------------------------------------------- */
126 /*
127  * Information that need to be kept for each board.
128  */
129 
130 struct baycom_state {
131 	struct hdlcdrv_state hdrv;
132 
133 	struct pardevice *pdev;
134 	unsigned int options;
135 
136 	struct modem_state {
137 		short arb_divider;
138 		unsigned char flags;
139 		unsigned int shreg;
140 		struct modem_state_par96 {
141 			int dcd_count;
142 			unsigned int dcd_shreg;
143 			unsigned long descram;
144 			unsigned long scram;
145 		} par96;
146 	} modem;
147 
148 #ifdef BAYCOM_DEBUG
149 	struct debug_vals {
150 		unsigned long last_jiffies;
151 		unsigned cur_intcnt;
152 		unsigned last_intcnt;
153 		int cur_pllcorr;
154 		int last_pllcorr;
155 	} debug_vals;
156 #endif /* BAYCOM_DEBUG */
157 };
158 
159 /* --------------------------------------------------------------------- */
160 
161 static void __inline__ baycom_int_freq(struct baycom_state *bc)
162 {
163 #ifdef BAYCOM_DEBUG
164 	unsigned long cur_jiffies = jiffies;
165 	/*
166 	 * measure the interrupt frequency
167 	 */
168 	bc->debug_vals.cur_intcnt++;
169 	if (time_after_eq(cur_jiffies, bc->debug_vals.last_jiffies + HZ)) {
170 		bc->debug_vals.last_jiffies = cur_jiffies;
171 		bc->debug_vals.last_intcnt = bc->debug_vals.cur_intcnt;
172 		bc->debug_vals.cur_intcnt = 0;
173 		bc->debug_vals.last_pllcorr = bc->debug_vals.cur_pllcorr;
174 		bc->debug_vals.cur_pllcorr = 0;
175 	}
176 #endif /* BAYCOM_DEBUG */
177 }
178 
179 /* --------------------------------------------------------------------- */
180 /*
181  * ===================== PAR96 specific routines =========================
182  */
183 
184 #define PAR96_DESCRAM_TAP1 0x20000
185 #define PAR96_DESCRAM_TAP2 0x01000
186 #define PAR96_DESCRAM_TAP3 0x00001
187 
188 #define PAR96_DESCRAM_TAPSH1 17
189 #define PAR96_DESCRAM_TAPSH2 12
190 #define PAR96_DESCRAM_TAPSH3 0
191 
192 #define PAR96_SCRAM_TAP1 0x20000 /* X^17 */
193 #define PAR96_SCRAM_TAPN 0x00021 /* X^0+X^5 */
194 
195 /* --------------------------------------------------------------------- */
196 
197 static __inline__ void par96_tx(struct net_device *dev, struct baycom_state *bc)
198 {
199 	int i;
200 	unsigned int data = hdlcdrv_getbits(&bc->hdrv);
201 	struct parport *pp = bc->pdev->port;
202 
203 	for(i = 0; i < PAR96_BURSTBITS; i++, data >>= 1) {
204 		unsigned char val = PAR97_POWER;
205 		bc->modem.par96.scram = ((bc->modem.par96.scram << 1) |
206 					 (bc->modem.par96.scram & 1));
207 		if (!(data & 1))
208 			bc->modem.par96.scram ^= 1;
209 		if (bc->modem.par96.scram & (PAR96_SCRAM_TAP1 << 1))
210 			bc->modem.par96.scram ^=
211 				(PAR96_SCRAM_TAPN << 1);
212 		if (bc->modem.par96.scram & (PAR96_SCRAM_TAP1 << 2))
213 			val |= PAR96_TXBIT;
214 		pp->ops->write_data(pp, val);
215 		pp->ops->write_data(pp, val | PAR96_BURST);
216 	}
217 }
218 
219 /* --------------------------------------------------------------------- */
220 
221 static __inline__ void par96_rx(struct net_device *dev, struct baycom_state *bc)
222 {
223 	int i;
224 	unsigned int data, mask, mask2, descx;
225 	struct parport *pp = bc->pdev->port;
226 
227 	/*
228 	 * do receiver; differential decode and descramble on the fly
229 	 */
230 	for(data = i = 0; i < PAR96_BURSTBITS; i++) {
231 		bc->modem.par96.descram = (bc->modem.par96.descram << 1);
232 		if (pp->ops->read_status(pp) & PAR96_RXBIT)
233 			bc->modem.par96.descram |= 1;
234 		descx = bc->modem.par96.descram ^
235 			(bc->modem.par96.descram >> 1);
236 		/* now the diff decoded data is inverted in descram */
237 		pp->ops->write_data(pp, PAR97_POWER | PAR96_PTT);
238 		descx ^= ((descx >> PAR96_DESCRAM_TAPSH1) ^
239 			  (descx >> PAR96_DESCRAM_TAPSH2));
240 		data >>= 1;
241 		if (!(descx & 1))
242 			data |= 0x8000;
243 		pp->ops->write_data(pp, PAR97_POWER | PAR96_PTT | PAR96_BURST);
244 	}
245 	hdlcdrv_putbits(&bc->hdrv, data);
246 	/*
247 	 * do DCD algorithm
248 	 */
249 	if (bc->options & BAYCOM_OPTIONS_SOFTDCD) {
250 		bc->modem.par96.dcd_shreg = (bc->modem.par96.dcd_shreg >> 16)
251 			| (data << 16);
252 		/* search for flags and set the dcd counter appropriately */
253 		for(mask = 0x1fe00, mask2 = 0xfc00, i = 0;
254 		    i < PAR96_BURSTBITS; i++, mask <<= 1, mask2 <<= 1)
255 			if ((bc->modem.par96.dcd_shreg & mask) == mask2)
256 				bc->modem.par96.dcd_count = HDLCDRV_MAXFLEN+4;
257 		/* check for abort/noise sequences */
258 		for(mask = 0x1fe00, mask2 = 0x1fe00, i = 0;
259 		    i < PAR96_BURSTBITS; i++, mask <<= 1, mask2 <<= 1)
260 			if (((bc->modem.par96.dcd_shreg & mask) == mask2) &&
261 			    (bc->modem.par96.dcd_count >= 0))
262 				bc->modem.par96.dcd_count -= HDLCDRV_MAXFLEN-10;
263 		/* decrement and set the dcd variable */
264 		if (bc->modem.par96.dcd_count >= 0)
265 			bc->modem.par96.dcd_count -= 2;
266 		hdlcdrv_setdcd(&bc->hdrv, bc->modem.par96.dcd_count > 0);
267 	} else {
268 		hdlcdrv_setdcd(&bc->hdrv, !!(pp->ops->read_status(pp) & PAR96_DCD));
269 	}
270 }
271 
272 /* --------------------------------------------------------------------- */
273 
274 static void par96_interrupt(int irq, void *dev_id, struct pt_regs *regs)
275 {
276 	struct net_device *dev = (struct net_device *)dev_id;
277 	struct baycom_state *bc = netdev_priv(dev);
278 
279 	baycom_int_freq(bc);
280 	/*
281 	 * check if transmitter active
282 	 */
283 	if (hdlcdrv_ptt(&bc->hdrv))
284 		par96_tx(dev, bc);
285 	else {
286 		par96_rx(dev, bc);
287 		if (--bc->modem.arb_divider <= 0) {
288 			bc->modem.arb_divider = 6;
289 			local_irq_enable();
290 			hdlcdrv_arbitrate(dev, &bc->hdrv);
291 		}
292 	}
293 	local_irq_enable();
294 	hdlcdrv_transmitter(dev, &bc->hdrv);
295 	hdlcdrv_receiver(dev, &bc->hdrv);
296         local_irq_disable();
297 }
298 
299 /* --------------------------------------------------------------------- */
300 
301 static void par96_wakeup(void *handle)
302 {
303         struct net_device *dev = (struct net_device *)handle;
304 	struct baycom_state *bc = netdev_priv(dev);
305 
306 	printk(KERN_DEBUG "baycom_par: %s: why am I being woken up?\n", dev->name);
307 	if (!parport_claim(bc->pdev))
308 		printk(KERN_DEBUG "baycom_par: %s: I'm broken.\n", dev->name);
309 }
310 
311 /* --------------------------------------------------------------------- */
312 
313 static int par96_open(struct net_device *dev)
314 {
315 	struct baycom_state *bc = netdev_priv(dev);
316 	struct parport *pp;
317 
318 	if (!dev || !bc)
319 		return -ENXIO;
320 	pp = parport_find_base(dev->base_addr);
321 	if (!pp) {
322 		printk(KERN_ERR "baycom_par: parport at 0x%lx unknown\n", dev->base_addr);
323 		return -ENXIO;
324 	}
325 	if (pp->irq < 0) {
326 		printk(KERN_ERR "baycom_par: parport at 0x%lx has no irq\n", pp->base);
327 		parport_put_port(pp);
328 		return -ENXIO;
329 	}
330 	if ((~pp->modes) & (PARPORT_MODE_PCSPP | PARPORT_MODE_SAFEININT)) {
331 		printk(KERN_ERR "baycom_par: parport at 0x%lx cannot be used\n", pp->base);
332 		parport_put_port(pp);
333 		return -ENXIO;
334 	}
335 	memset(&bc->modem, 0, sizeof(bc->modem));
336 	bc->hdrv.par.bitrate = 9600;
337 	bc->pdev = parport_register_device(pp, dev->name, NULL, par96_wakeup,
338 				 par96_interrupt, PARPORT_DEV_EXCL, dev);
339 	parport_put_port(pp);
340 	if (!bc->pdev) {
341 		printk(KERN_ERR "baycom_par: cannot register parport at 0x%lx\n", dev->base_addr);
342 		return -ENXIO;
343 	}
344 	if (parport_claim(bc->pdev)) {
345 		printk(KERN_ERR "baycom_par: parport at 0x%lx busy\n", pp->base);
346 		parport_unregister_device(bc->pdev);
347 		return -EBUSY;
348 	}
349 	pp = bc->pdev->port;
350 	dev->irq = pp->irq;
351 	pp->ops->data_forward(pp);
352         bc->hdrv.par.bitrate = 9600;
353 	pp->ops->write_data(pp, PAR96_PTT | PAR97_POWER); /* switch off PTT */
354 	pp->ops->enable_irq(pp);
355 	printk(KERN_INFO "%s: par96 at iobase 0x%lx irq %u options 0x%x\n",
356 	       bc_drvname, dev->base_addr, dev->irq, bc->options);
357 	return 0;
358 }
359 
360 /* --------------------------------------------------------------------- */
361 
362 static int par96_close(struct net_device *dev)
363 {
364 	struct baycom_state *bc = netdev_priv(dev);
365 	struct parport *pp;
366 
367 	if (!dev || !bc)
368 		return -EINVAL;
369 	pp = bc->pdev->port;
370 	/* disable interrupt */
371 	pp->ops->disable_irq(pp);
372 	/* switch off PTT */
373 	pp->ops->write_data(pp, PAR96_PTT | PAR97_POWER);
374 	parport_release(bc->pdev);
375 	parport_unregister_device(bc->pdev);
376 	printk(KERN_INFO "%s: close par96 at iobase 0x%lx irq %u\n",
377 	       bc_drvname, dev->base_addr, dev->irq);
378 	return 0;
379 }
380 
381 /* --------------------------------------------------------------------- */
382 /*
383  * ===================== hdlcdrv driver interface =========================
384  */
385 
386 static int baycom_ioctl(struct net_device *dev, struct ifreq *ifr,
387 			struct hdlcdrv_ioctl *hi, int cmd);
388 
389 /* --------------------------------------------------------------------- */
390 
391 static struct hdlcdrv_ops par96_ops = {
392 	.drvname = bc_drvname,
393 	.drvinfo = bc_drvinfo,
394 	.open    = par96_open,
395 	.close   = par96_close,
396 	.ioctl   = baycom_ioctl
397 };
398 
399 /* --------------------------------------------------------------------- */
400 
401 static int baycom_setmode(struct baycom_state *bc, const char *modestr)
402 {
403 	if (!strncmp(modestr, "picpar", 6))
404 		bc->options = 0;
405 	else if (!strncmp(modestr, "par96", 5))
406 		bc->options = BAYCOM_OPTIONS_SOFTDCD;
407 	else
408 		bc->options = !!strchr(modestr, '*');
409 	return 0;
410 }
411 
412 /* --------------------------------------------------------------------- */
413 
414 static int baycom_ioctl(struct net_device *dev, struct ifreq *ifr,
415 			struct hdlcdrv_ioctl *hi, int cmd)
416 {
417 	struct baycom_state *bc;
418 	struct baycom_ioctl bi;
419 
420 	if (!dev)
421 		return -EINVAL;
422 
423 	bc = netdev_priv(dev);
424 	BUG_ON(bc->hdrv.magic != HDLCDRV_MAGIC);
425 
426 	if (cmd != SIOCDEVPRIVATE)
427 		return -ENOIOCTLCMD;
428 	switch (hi->cmd) {
429 	default:
430 		break;
431 
432 	case HDLCDRVCTL_GETMODE:
433 		strcpy(hi->data.modename, bc->options ? "par96" : "picpar");
434 		if (copy_to_user(ifr->ifr_data, hi, sizeof(struct hdlcdrv_ioctl)))
435 			return -EFAULT;
436 		return 0;
437 
438 	case HDLCDRVCTL_SETMODE:
439 		if (netif_running(dev) || !capable(CAP_NET_ADMIN))
440 			return -EACCES;
441 		hi->data.modename[sizeof(hi->data.modename)-1] = '\0';
442 		return baycom_setmode(bc, hi->data.modename);
443 
444 	case HDLCDRVCTL_MODELIST:
445 		strcpy(hi->data.modename, "par96,picpar");
446 		if (copy_to_user(ifr->ifr_data, hi, sizeof(struct hdlcdrv_ioctl)))
447 			return -EFAULT;
448 		return 0;
449 
450 	case HDLCDRVCTL_MODEMPARMASK:
451 		return HDLCDRV_PARMASK_IOBASE;
452 
453 	}
454 
455 	if (copy_from_user(&bi, ifr->ifr_data, sizeof(bi)))
456 		return -EFAULT;
457 	switch (bi.cmd) {
458 	default:
459 		return -ENOIOCTLCMD;
460 
461 #ifdef BAYCOM_DEBUG
462 	case BAYCOMCTL_GETDEBUG:
463 		bi.data.dbg.debug1 = bc->hdrv.ptt_keyed;
464 		bi.data.dbg.debug2 = bc->debug_vals.last_intcnt;
465 		bi.data.dbg.debug3 = bc->debug_vals.last_pllcorr;
466 		break;
467 #endif /* BAYCOM_DEBUG */
468 
469 	}
470 	if (copy_to_user(ifr->ifr_data, &bi, sizeof(bi)))
471 		return -EFAULT;
472 	return 0;
473 
474 }
475 
476 /* --------------------------------------------------------------------- */
477 
478 /*
479  * command line settable parameters
480  */
481 static const char *mode[NR_PORTS] = { "picpar", };
482 static int iobase[NR_PORTS] = { 0x378, };
483 
484 module_param_array(mode, charp, NULL, 0);
485 MODULE_PARM_DESC(mode, "baycom operating mode; eg. par96 or picpar");
486 module_param_array(iobase, int, NULL, 0);
487 MODULE_PARM_DESC(iobase, "baycom io base address");
488 
489 MODULE_AUTHOR("Thomas M. Sailer, sailer@ife.ee.ethz.ch, hb9jnx@hb9w.che.eu");
490 MODULE_DESCRIPTION("Baycom par96 and picpar amateur radio modem driver");
491 MODULE_LICENSE("GPL");
492 
493 /* --------------------------------------------------------------------- */
494 
495 static int __init init_baycompar(void)
496 {
497 	int i, found = 0;
498 	char set_hw = 1;
499 
500 	printk(bc_drvinfo);
501 	/*
502 	 * register net devices
503 	 */
504 	for (i = 0; i < NR_PORTS; i++) {
505 		struct net_device *dev;
506 		struct baycom_state *bc;
507 		char ifname[IFNAMSIZ];
508 
509 		sprintf(ifname, "bcp%d", i);
510 
511 		if (!mode[i])
512 			set_hw = 0;
513 		if (!set_hw)
514 			iobase[i] = 0;
515 
516 		dev = hdlcdrv_register(&par96_ops,
517 				       sizeof(struct baycom_state),
518 				       ifname, iobase[i], 0, 0);
519 		if (IS_ERR(dev))
520 			break;
521 
522 		bc = netdev_priv(dev);
523 		if (set_hw && baycom_setmode(bc, mode[i]))
524 			set_hw = 0;
525 		found++;
526 		baycom_device[i] = dev;
527 	}
528 
529 	if (!found)
530 		return -ENXIO;
531 	return 0;
532 }
533 
534 static void __exit cleanup_baycompar(void)
535 {
536 	int i;
537 
538 	for(i = 0; i < NR_PORTS; i++) {
539 		struct net_device *dev = baycom_device[i];
540 
541 		if (dev)
542 			hdlcdrv_unregister(dev);
543 	}
544 }
545 
546 module_init(init_baycompar);
547 module_exit(cleanup_baycompar);
548 
549 /* --------------------------------------------------------------------- */
550 
551 #ifndef MODULE
552 
553 /*
554  * format: baycom_par=io,mode
555  * mode: par96,picpar
556  */
557 
558 static int __init baycom_par_setup(char *str)
559 {
560         static unsigned nr_dev;
561 	int ints[2];
562 
563         if (nr_dev >= NR_PORTS)
564                 return 0;
565         str = get_options(str, 2, ints);
566         if (ints[0] < 1)
567                 return 0;
568         mode[nr_dev] = str;
569         iobase[nr_dev] = ints[1];
570 	nr_dev++;
571 	return 1;
572 }
573 
574 __setup("baycom_par=", baycom_par_setup);
575 
576 #endif /* MODULE */
577 /* --------------------------------------------------------------------- */
578