1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*****************************************************************************/
3
4 /*
5 * baycom_par.c -- baycom par96 and picpar radio modem driver.
6 *
7 * Copyright (C) 1996-2000 Thomas Sailer (sailer@ife.ee.ethz.ch)
8 *
9 * Please note that the GPL allows you to use the driver, NOT the radio.
10 * In order to use the radio, you need a license from the communications
11 * authority of your country.
12 *
13 * Supported modems
14 *
15 * par96: This is a modem for 9600 baud FSK compatible to the G3RUH standard.
16 * The modem does all the filtering and regenerates the receiver clock.
17 * Data is transferred from and to the PC via a shift register.
18 * The shift register is filled with 16 bits and an interrupt is
19 * signalled. The PC then empties the shift register in a burst. This
20 * modem connects to the parallel port, hence the name. The modem
21 * leaves the implementation of the HDLC protocol and the scrambler
22 * polynomial to the PC. This modem is no longer available (at least
23 * from Baycom) and has been replaced by the PICPAR modem (see below).
24 * You may however still build one from the schematics published in
25 * cq-DL :-).
26 *
27 * picpar: This is a redesign of the par96 modem by Henning Rech, DF9IC. The
28 * modem is protocol compatible to par96, but uses only three low
29 * power ICs and can therefore be fed from the parallel port and
30 * does not require an additional power supply. It features
31 * built in DCD circuitry. The driver should therefore be configured
32 * for hardware DCD.
33 *
34 * Command line options (insmod command line)
35 *
36 * mode driver mode string. Valid choices are par96 and picpar.
37 * iobase base address of the port; common values are 0x378, 0x278, 0x3bc
38 *
39 * History:
40 * 0.1 26.06.1996 Adapted from baycom.c and made network driver interface
41 * 18.10.1996 Changed to new user space access routines (copy_{to,from}_user)
42 * 0.3 26.04.1997 init code/data tagged
43 * 0.4 08.07.1997 alternative ser12 decoding algorithm (uses delta CTS ints)
44 * 0.5 11.11.1997 split into separate files for ser12/par96
45 * 0.6 03.08.1999 adapt to Linus' new __setup/__initcall
46 * removed some pre-2.2 kernel compatibility cruft
47 * 0.7 10.08.1999 Check if parport can do SPP and is safe to access during interrupt contexts
48 * 0.8 12.02.2000 adapted to softnet driver interface
49 * removed direct parport access, uses parport driver methods
50 * 0.9 03.07.2000 fix interface name handling
51 */
52
53 /*****************************************************************************/
54
55 #include <linux/module.h>
56 #include <linux/kernel.h>
57 #include <linux/types.h>
58 #include <linux/fcntl.h>
59 #include <linux/interrupt.h>
60 #include <linux/ioport.h>
61 #include <linux/in.h>
62 #include <linux/string.h>
63 #include <linux/init.h>
64 #include <linux/delay.h>
65 #include <linux/errno.h>
66 #include <linux/netdevice.h>
67 #include <linux/hdlcdrv.h>
68 #include <linux/baycom.h>
69 #include <linux/parport.h>
70 #include <linux/bitops.h>
71 #include <linux/jiffies.h>
72
73 #include <linux/uaccess.h>
74
75 /* --------------------------------------------------------------------- */
76
77 #define BAYCOM_DEBUG
78
79 /*
80 * modem options; bit mask
81 */
82 #define BAYCOM_OPTIONS_SOFTDCD 1
83
84 /* --------------------------------------------------------------------- */
85
86 static const char bc_drvname[] = "baycom_par";
87 static const char bc_drvinfo[] = KERN_INFO "baycom_par: (C) 1996-2000 Thomas Sailer, HB9JNX/AE4WA\n"
88 "baycom_par: version 0.9\n";
89
90 /* --------------------------------------------------------------------- */
91
92 #define NR_PORTS 4
93
94 static struct net_device *baycom_device[NR_PORTS];
95
96 /* --------------------------------------------------------------------- */
97
98 #define PAR96_BURSTBITS 16
99 #define PAR96_BURST 4
100 #define PAR96_PTT 2
101 #define PAR96_TXBIT 1
102 #define PAR96_ACK 0x40
103 #define PAR96_RXBIT 0x20
104 #define PAR96_DCD 0x10
105 #define PAR97_POWER 0xf8
106
107 /* ---------------------------------------------------------------------- */
108 /*
109 * Information that need to be kept for each board.
110 */
111
112 struct baycom_state {
113 struct hdlcdrv_state hdrv;
114
115 struct pardevice *pdev;
116 unsigned int options;
117
118 struct modem_state {
119 short arb_divider;
120 unsigned char flags;
121 unsigned int shreg;
122 struct modem_state_par96 {
123 int dcd_count;
124 unsigned int dcd_shreg;
125 unsigned long descram;
126 unsigned long scram;
127 } par96;
128 } modem;
129
130 #ifdef BAYCOM_DEBUG
131 struct debug_vals {
132 unsigned long last_jiffies;
133 unsigned cur_intcnt;
134 unsigned last_intcnt;
135 int cur_pllcorr;
136 int last_pllcorr;
137 } debug_vals;
138 #endif /* BAYCOM_DEBUG */
139 };
140
141 /* --------------------------------------------------------------------- */
142
baycom_int_freq(struct baycom_state * bc)143 static inline void baycom_int_freq(struct baycom_state *bc)
144 {
145 #ifdef BAYCOM_DEBUG
146 unsigned long cur_jiffies = jiffies;
147 /*
148 * measure the interrupt frequency
149 */
150 bc->debug_vals.cur_intcnt++;
151 if (time_after_eq(cur_jiffies, bc->debug_vals.last_jiffies + HZ)) {
152 bc->debug_vals.last_jiffies = cur_jiffies;
153 bc->debug_vals.last_intcnt = bc->debug_vals.cur_intcnt;
154 bc->debug_vals.cur_intcnt = 0;
155 bc->debug_vals.last_pllcorr = bc->debug_vals.cur_pllcorr;
156 bc->debug_vals.cur_pllcorr = 0;
157 }
158 #endif /* BAYCOM_DEBUG */
159 }
160
161 /* --------------------------------------------------------------------- */
162 /*
163 * ===================== PAR96 specific routines =========================
164 */
165
166 #define PAR96_DESCRAM_TAP1 0x20000
167 #define PAR96_DESCRAM_TAP2 0x01000
168 #define PAR96_DESCRAM_TAP3 0x00001
169
170 #define PAR96_DESCRAM_TAPSH1 17
171 #define PAR96_DESCRAM_TAPSH2 12
172 #define PAR96_DESCRAM_TAPSH3 0
173
174 #define PAR96_SCRAM_TAP1 0x20000 /* X^17 */
175 #define PAR96_SCRAM_TAPN 0x00021 /* X^0+X^5 */
176
177 /* --------------------------------------------------------------------- */
178
par96_tx(struct net_device * dev,struct baycom_state * bc)179 static inline void par96_tx(struct net_device *dev, struct baycom_state *bc)
180 {
181 int i;
182 unsigned int data = hdlcdrv_getbits(&bc->hdrv);
183 struct parport *pp = bc->pdev->port;
184
185 for(i = 0; i < PAR96_BURSTBITS; i++, data >>= 1) {
186 unsigned char val = PAR97_POWER;
187 bc->modem.par96.scram = ((bc->modem.par96.scram << 1) |
188 (bc->modem.par96.scram & 1));
189 if (!(data & 1))
190 bc->modem.par96.scram ^= 1;
191 if (bc->modem.par96.scram & (PAR96_SCRAM_TAP1 << 1))
192 bc->modem.par96.scram ^=
193 (PAR96_SCRAM_TAPN << 1);
194 if (bc->modem.par96.scram & (PAR96_SCRAM_TAP1 << 2))
195 val |= PAR96_TXBIT;
196 pp->ops->write_data(pp, val);
197 pp->ops->write_data(pp, val | PAR96_BURST);
198 }
199 }
200
201 /* --------------------------------------------------------------------- */
202
par96_rx(struct net_device * dev,struct baycom_state * bc)203 static inline void par96_rx(struct net_device *dev, struct baycom_state *bc)
204 {
205 int i;
206 unsigned int data, mask, mask2, descx;
207 struct parport *pp = bc->pdev->port;
208
209 /*
210 * do receiver; differential decode and descramble on the fly
211 */
212 for(data = i = 0; i < PAR96_BURSTBITS; i++) {
213 bc->modem.par96.descram = (bc->modem.par96.descram << 1);
214 if (pp->ops->read_status(pp) & PAR96_RXBIT)
215 bc->modem.par96.descram |= 1;
216 descx = bc->modem.par96.descram ^
217 (bc->modem.par96.descram >> 1);
218 /* now the diff decoded data is inverted in descram */
219 pp->ops->write_data(pp, PAR97_POWER | PAR96_PTT);
220 descx ^= ((descx >> PAR96_DESCRAM_TAPSH1) ^
221 (descx >> PAR96_DESCRAM_TAPSH2));
222 data >>= 1;
223 if (!(descx & 1))
224 data |= 0x8000;
225 pp->ops->write_data(pp, PAR97_POWER | PAR96_PTT | PAR96_BURST);
226 }
227 hdlcdrv_putbits(&bc->hdrv, data);
228 /*
229 * do DCD algorithm
230 */
231 if (bc->options & BAYCOM_OPTIONS_SOFTDCD) {
232 bc->modem.par96.dcd_shreg = (bc->modem.par96.dcd_shreg >> 16)
233 | (data << 16);
234 /* search for flags and set the dcd counter appropriately */
235 for(mask = 0x1fe00, mask2 = 0xfc00, i = 0;
236 i < PAR96_BURSTBITS; i++, mask <<= 1, mask2 <<= 1)
237 if ((bc->modem.par96.dcd_shreg & mask) == mask2)
238 bc->modem.par96.dcd_count = HDLCDRV_MAXFLEN+4;
239 /* check for abort/noise sequences */
240 for(mask = 0x1fe00, mask2 = 0x1fe00, i = 0;
241 i < PAR96_BURSTBITS; i++, mask <<= 1, mask2 <<= 1)
242 if (((bc->modem.par96.dcd_shreg & mask) == mask2) &&
243 (bc->modem.par96.dcd_count >= 0))
244 bc->modem.par96.dcd_count -= HDLCDRV_MAXFLEN-10;
245 /* decrement and set the dcd variable */
246 if (bc->modem.par96.dcd_count >= 0)
247 bc->modem.par96.dcd_count -= 2;
248 hdlcdrv_setdcd(&bc->hdrv, bc->modem.par96.dcd_count > 0);
249 } else {
250 hdlcdrv_setdcd(&bc->hdrv, !!(pp->ops->read_status(pp) & PAR96_DCD));
251 }
252 }
253
254 /* --------------------------------------------------------------------- */
255
par96_interrupt(void * dev_id)256 static void par96_interrupt(void *dev_id)
257 {
258 struct net_device *dev = dev_id;
259 struct baycom_state *bc = netdev_priv(dev);
260
261 baycom_int_freq(bc);
262 /*
263 * check if transmitter active
264 */
265 if (hdlcdrv_ptt(&bc->hdrv))
266 par96_tx(dev, bc);
267 else {
268 par96_rx(dev, bc);
269 if (--bc->modem.arb_divider <= 0) {
270 bc->modem.arb_divider = 6;
271 local_irq_enable();
272 hdlcdrv_arbitrate(dev, &bc->hdrv);
273 }
274 }
275 local_irq_enable();
276 hdlcdrv_transmitter(dev, &bc->hdrv);
277 hdlcdrv_receiver(dev, &bc->hdrv);
278 local_irq_disable();
279 }
280
281 /* --------------------------------------------------------------------- */
282
par96_wakeup(void * handle)283 static void par96_wakeup(void *handle)
284 {
285 struct net_device *dev = (struct net_device *)handle;
286 struct baycom_state *bc = netdev_priv(dev);
287
288 printk(KERN_DEBUG "baycom_par: %s: why am I being woken up?\n", dev->name);
289 if (!parport_claim(bc->pdev))
290 printk(KERN_DEBUG "baycom_par: %s: I'm broken.\n", dev->name);
291 }
292
293 /* --------------------------------------------------------------------- */
294
par96_open(struct net_device * dev)295 static int par96_open(struct net_device *dev)
296 {
297 struct baycom_state *bc = netdev_priv(dev);
298 struct pardev_cb par_cb;
299 struct parport *pp;
300 int i;
301
302 if (!dev || !bc)
303 return -ENXIO;
304 pp = parport_find_base(dev->base_addr);
305 if (!pp) {
306 printk(KERN_ERR "baycom_par: parport at 0x%lx unknown\n", dev->base_addr);
307 return -ENXIO;
308 }
309 if (pp->irq < 0) {
310 printk(KERN_ERR "baycom_par: parport at 0x%lx has no irq\n", pp->base);
311 parport_put_port(pp);
312 return -ENXIO;
313 }
314 if ((~pp->modes) & (PARPORT_MODE_PCSPP | PARPORT_MODE_SAFEININT)) {
315 printk(KERN_ERR "baycom_par: parport at 0x%lx cannot be used\n", pp->base);
316 parport_put_port(pp);
317 return -ENXIO;
318 }
319 memset(&bc->modem, 0, sizeof(bc->modem));
320 bc->hdrv.par.bitrate = 9600;
321 memset(&par_cb, 0, sizeof(par_cb));
322 par_cb.wakeup = par96_wakeup;
323 par_cb.irq_func = par96_interrupt;
324 par_cb.private = (void *)dev;
325 par_cb.flags = PARPORT_DEV_EXCL;
326 for (i = 0; i < NR_PORTS; i++)
327 if (baycom_device[i] == dev)
328 break;
329
330 if (i == NR_PORTS) {
331 pr_err("%s: no device found\n", bc_drvname);
332 parport_put_port(pp);
333 return -ENODEV;
334 }
335 bc->pdev = parport_register_dev_model(pp, dev->name, &par_cb, i);
336 parport_put_port(pp);
337 if (!bc->pdev) {
338 printk(KERN_ERR "baycom_par: cannot register parport at 0x%lx\n", dev->base_addr);
339 return -ENXIO;
340 }
341 if (parport_claim(bc->pdev)) {
342 printk(KERN_ERR "baycom_par: parport at 0x%lx busy\n", pp->base);
343 parport_unregister_device(bc->pdev);
344 return -EBUSY;
345 }
346 pp = bc->pdev->port;
347 dev->irq = pp->irq;
348 pp->ops->data_forward(pp);
349 bc->hdrv.par.bitrate = 9600;
350 pp->ops->write_data(pp, PAR96_PTT | PAR97_POWER); /* switch off PTT */
351 pp->ops->enable_irq(pp);
352 printk(KERN_INFO "%s: par96 at iobase 0x%lx irq %u options 0x%x\n",
353 bc_drvname, dev->base_addr, dev->irq, bc->options);
354 return 0;
355 }
356
357 /* --------------------------------------------------------------------- */
358
par96_close(struct net_device * dev)359 static int par96_close(struct net_device *dev)
360 {
361 struct baycom_state *bc = netdev_priv(dev);
362 struct parport *pp;
363
364 if (!dev || !bc)
365 return -EINVAL;
366 pp = bc->pdev->port;
367 /* disable interrupt */
368 pp->ops->disable_irq(pp);
369 /* switch off PTT */
370 pp->ops->write_data(pp, PAR96_PTT | PAR97_POWER);
371 parport_release(bc->pdev);
372 parport_unregister_device(bc->pdev);
373 printk(KERN_INFO "%s: close par96 at iobase 0x%lx irq %u\n",
374 bc_drvname, dev->base_addr, dev->irq);
375 return 0;
376 }
377
378 /* --------------------------------------------------------------------- */
379 /*
380 * ===================== hdlcdrv driver interface =========================
381 */
382
383 static int baycom_ioctl(struct net_device *dev, void __user *data,
384 struct hdlcdrv_ioctl *hi, int cmd);
385
386 /* --------------------------------------------------------------------- */
387
388 static const struct hdlcdrv_ops par96_ops = {
389 .drvname = bc_drvname,
390 .drvinfo = bc_drvinfo,
391 .open = par96_open,
392 .close = par96_close,
393 .ioctl = baycom_ioctl
394 };
395
396 /* --------------------------------------------------------------------- */
397
baycom_setmode(struct baycom_state * bc,const char * modestr)398 static int baycom_setmode(struct baycom_state *bc, const char *modestr)
399 {
400 if (!strncmp(modestr, "picpar", 6))
401 bc->options = 0;
402 else if (!strncmp(modestr, "par96", 5))
403 bc->options = BAYCOM_OPTIONS_SOFTDCD;
404 else
405 bc->options = !!strchr(modestr, '*');
406 return 0;
407 }
408
409 /* --------------------------------------------------------------------- */
410
baycom_ioctl(struct net_device * dev,void __user * data,struct hdlcdrv_ioctl * hi,int cmd)411 static int baycom_ioctl(struct net_device *dev, void __user *data,
412 struct hdlcdrv_ioctl *hi, int cmd)
413 {
414 struct baycom_state *bc;
415 struct baycom_ioctl bi;
416
417 if (!dev)
418 return -EINVAL;
419
420 bc = netdev_priv(dev);
421 BUG_ON(bc->hdrv.magic != HDLCDRV_MAGIC);
422
423 if (cmd != SIOCDEVPRIVATE)
424 return -ENOIOCTLCMD;
425 switch (hi->cmd) {
426 default:
427 break;
428
429 case HDLCDRVCTL_GETMODE:
430 strcpy(hi->data.modename, bc->options ? "par96" : "picpar");
431 if (copy_to_user(data, hi, sizeof(struct hdlcdrv_ioctl)))
432 return -EFAULT;
433 return 0;
434
435 case HDLCDRVCTL_SETMODE:
436 if (netif_running(dev) || !capable(CAP_NET_ADMIN))
437 return -EACCES;
438 hi->data.modename[sizeof(hi->data.modename)-1] = '\0';
439 return baycom_setmode(bc, hi->data.modename);
440
441 case HDLCDRVCTL_MODELIST:
442 strcpy(hi->data.modename, "par96,picpar");
443 if (copy_to_user(data, hi, sizeof(struct hdlcdrv_ioctl)))
444 return -EFAULT;
445 return 0;
446
447 case HDLCDRVCTL_MODEMPARMASK:
448 return HDLCDRV_PARMASK_IOBASE;
449
450 }
451
452 if (copy_from_user(&bi, data, sizeof(bi)))
453 return -EFAULT;
454 switch (bi.cmd) {
455 default:
456 return -ENOIOCTLCMD;
457
458 #ifdef BAYCOM_DEBUG
459 case BAYCOMCTL_GETDEBUG:
460 bi.data.dbg.debug1 = bc->hdrv.ptt_keyed;
461 bi.data.dbg.debug2 = bc->debug_vals.last_intcnt;
462 bi.data.dbg.debug3 = bc->debug_vals.last_pllcorr;
463 break;
464 #endif /* BAYCOM_DEBUG */
465
466 }
467 if (copy_to_user(data, &bi, sizeof(bi)))
468 return -EFAULT;
469 return 0;
470
471 }
472
473 /* --------------------------------------------------------------------- */
474
475 /*
476 * command line settable parameters
477 */
478 static char *mode[NR_PORTS] = { "picpar", };
479 static int iobase[NR_PORTS] = { 0x378, };
480
481 module_param_array(mode, charp, NULL, 0);
482 MODULE_PARM_DESC(mode, "baycom operating mode; eg. par96 or picpar");
483 module_param_hw_array(iobase, int, ioport, NULL, 0);
484 MODULE_PARM_DESC(iobase, "baycom io base address");
485
486 MODULE_AUTHOR("Thomas M. Sailer, sailer@ife.ee.ethz.ch, hb9jnx@hb9w.che.eu");
487 MODULE_DESCRIPTION("Baycom par96 and picpar amateur radio modem driver");
488 MODULE_LICENSE("GPL");
489
490 /* --------------------------------------------------------------------- */
491
baycom_par_probe(struct pardevice * par_dev)492 static int baycom_par_probe(struct pardevice *par_dev)
493 {
494 struct device_driver *drv = par_dev->dev.driver;
495 int len = strlen(drv->name);
496
497 if (strncmp(par_dev->name, drv->name, len))
498 return -ENODEV;
499
500 return 0;
501 }
502
503 static struct parport_driver baycom_par_driver = {
504 .name = "bcp",
505 .probe = baycom_par_probe,
506 .devmodel = true,
507 };
508
init_baycompar(void)509 static int __init init_baycompar(void)
510 {
511 int i, found = 0, ret;
512 char set_hw = 1;
513
514 printk(bc_drvinfo);
515
516 ret = parport_register_driver(&baycom_par_driver);
517 if (ret)
518 return ret;
519
520 /*
521 * register net devices
522 */
523 for (i = 0; i < NR_PORTS; i++) {
524 struct net_device *dev;
525 struct baycom_state *bc;
526 char ifname[IFNAMSIZ];
527
528 sprintf(ifname, "bcp%d", i);
529
530 if (!mode[i])
531 set_hw = 0;
532 if (!set_hw)
533 iobase[i] = 0;
534
535 dev = hdlcdrv_register(&par96_ops,
536 sizeof(struct baycom_state),
537 ifname, iobase[i], 0, 0);
538 if (IS_ERR(dev))
539 break;
540
541 bc = netdev_priv(dev);
542 if (set_hw && baycom_setmode(bc, mode[i]))
543 set_hw = 0;
544 found++;
545 baycom_device[i] = dev;
546 }
547
548 if (!found) {
549 parport_unregister_driver(&baycom_par_driver);
550 return -ENXIO;
551 }
552 return 0;
553 }
554
cleanup_baycompar(void)555 static void __exit cleanup_baycompar(void)
556 {
557 int i;
558
559 for(i = 0; i < NR_PORTS; i++) {
560 struct net_device *dev = baycom_device[i];
561
562 if (dev)
563 hdlcdrv_unregister(dev);
564 }
565 parport_unregister_driver(&baycom_par_driver);
566 }
567
568 module_init(init_baycompar);
569 module_exit(cleanup_baycompar);
570
571 /* --------------------------------------------------------------------- */
572
573 #ifndef MODULE
574
575 /*
576 * format: baycom_par=io,mode
577 * mode: par96,picpar
578 */
579
baycom_par_setup(char * str)580 static int __init baycom_par_setup(char *str)
581 {
582 static unsigned nr_dev;
583 int ints[2];
584
585 if (nr_dev >= NR_PORTS)
586 return 0;
587 str = get_options(str, 2, ints);
588 if (ints[0] < 1)
589 return 0;
590 mode[nr_dev] = str;
591 iobase[nr_dev] = ints[1];
592 nr_dev++;
593 return 1;
594 }
595
596 __setup("baycom_par=", baycom_par_setup);
597
598 #endif /* MODULE */
599 /* --------------------------------------------------------------------- */
600