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37 *          from Baycom) and has been replaced by the PICPAR modem (see below).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