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37 *          from Baycom) and has been replaced by the PICPAR modem (see below).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
103static const char bc_drvname[] = "baycom_par";
104static const char bc_drvinfo[] = KERN_INFO "baycom_par: (C) 1996-2000 Thomas Sailer, HB9JNX/AE4WA\n"
105KERN_INFO "baycom_par: version 0.9 compiled " __TIME__ " " __DATE__ "\n";
106
107/* --------------------------------------------------------------------- */
108
109#define NR_PORTS 4
110
111static 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
129struct 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
160static 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
196static __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
220static __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
273static void par96_interrupt(int irq, void *dev_id)
274{
275	struct net_device *dev = (struct net_device *)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
300static 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
312static 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
361static 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
385static int baycom_ioctl(struct net_device *dev, struct ifreq *ifr,
386			struct hdlcdrv_ioctl *hi, int cmd);
387
388/* --------------------------------------------------------------------- */
389
390static 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
400static 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
413static 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 */
480static const char *mode[NR_PORTS] = { "picpar", };
481static int iobase[NR_PORTS] = { 0x378, };
482
483module_param_array(mode, charp, NULL, 0);
484MODULE_PARM_DESC(mode, "baycom operating mode; eg. par96 or picpar");
485module_param_array(iobase, int, NULL, 0);
486MODULE_PARM_DESC(iobase, "baycom io base address");
487
488MODULE_AUTHOR("Thomas M. Sailer, sailer@ife.ee.ethz.ch, hb9jnx@hb9w.che.eu");
489MODULE_DESCRIPTION("Baycom par96 and picpar amateur radio modem driver");
490MODULE_LICENSE("GPL");
491
492/* --------------------------------------------------------------------- */
493
494static 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
533static 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
545module_init(init_baycompar);
546module_exit(cleanup_baycompar);
547
548/* --------------------------------------------------------------------- */
549
550#ifndef MODULE
551
552/*
553 * format: baycom_par=io,mode
554 * mode: par96,picpar
555 */
556
557static 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