summaryrefslogtreecommitdiff
path: root/driver_zodiac.c
blob: 11a53ed83adfeffca8d20f22ed69866d550e1da8 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
/*
 * Handle the Rockwell binary packet format supported by the old Zodiac chipset
 *
 * Week counters are not limited to 10 bits. It's unknown what
 * the firmware is doing to disambiguate them, if anything; it might just
 * be adding a fixed offset based on a hidden epoch value, in which case
 * unhappy things will occur on the next rollover.
 *
 * This file is Copyright (c) 2010 by the GPSD project
 * BSD terms apply: see the file COPYING in the distribution root for details.
 */

#ifdef __linux__
/* FreeBSD chokes on this */
/* if we insist on C99, then we need this to get M_LN2 from math.h */
/* if we insisnt on C99, then we need this to get M_LN2 from math.h */
/* 500 means X/Open 1995 */
#define _XOPEN_SOURCE 500
/* round() needs  _POSIX_C_SOURCE >= 200112L */
#define  _POSIX_C_SOURCE 200112L
#endif /* __linux__ */


#include <stdio.h>
#include <stdbool.h>
#include <string.h>
#include <math.h>
#include <unistd.h>

#include "gpsd.h"
#include "bits.h"
#include "strfuncs.h"

/* Zodiac protocol description uses 1-origin indexing by little-endian word */
#define get16z(buf, n)	( (buf[2*(n)-2])	\
		| (buf[2*(n)-1] << 8))
#define get32z(buf, n)	( (buf[2*(n)-2])	\
		| (buf[2*(n)-1] << 8) \
		| (buf[2*(n)+0] << 16) \
		| (buf[2*(n)+1] << 24))
#define getstringz(to, from, s, e)			\
    (void)memcpy(to, from+2*(s)-2, 2*((e)-(s)+1))

#ifdef ZODIAC_ENABLE
struct header
{
    unsigned short sync;
    unsigned short id;
    unsigned short ndata;
    unsigned short flags;
    unsigned short csum;
};

static unsigned short zodiac_checksum(unsigned short *w, int n)
{
    unsigned short csum = 0;

    while (n-- > 0)
	csum += *(w++);
    return -csum;
}

static ssize_t end_write(int fd, void *d, size_t len)
/* write an array of shorts in little-endian format */
{
    unsigned char buf[BUFSIZ];
    short *data = (short *)d;

    size_t n;
    for (n = 0; n < (size_t)(len/2); n++)
	putle16(buf, n*2, data[n]);
    return write(fd, (char*)buf, len);
}

/* zodiac_spew - Takes a message type, an array of data words, and a length
 * for the array, and prepends a 5 word header (including checksum).
 * The data words are expected to be checksummed.
 */
static ssize_t zodiac_spew(struct gps_device_t *session, unsigned short type,
			   unsigned short *dat, int dlen)
{
    struct header h;
    int i;
    char buf[BUFSIZ];

    h.sync = 0x81ff;
    h.id = (unsigned short)type;
    h.ndata = (unsigned short)(dlen - 1);
    h.flags = 0;
    h.csum = zodiac_checksum((unsigned short *)&h, 4);

    if (!BAD_SOCKET(session->gpsdata.gps_fd)) {
	size_t hlen, datlen;
	hlen = sizeof(h);
	datlen = sizeof(unsigned short) * dlen;
	if (end_write(session->gpsdata.gps_fd, &h, hlen) != (ssize_t) hlen ||
	    end_write(session->gpsdata.gps_fd, dat,
		      datlen) != (ssize_t) datlen) {
	    gpsd_log(&session->context->errout, LOG_RAW,
		     "Reconfigure write failed\n");
	    return -1;
	}
    }

    (void)snprintf(buf, sizeof(buf),
		   "%04x %04x %04x %04x %04x",
		   h.sync, h.id, h.ndata, h.flags, h.csum);
    for (i = 0; i < dlen; i++)
	str_appendf(buf, sizeof(buf), " %04x", dat[i]);

    gpsd_log(&session->context->errout, LOG_RAW,
	     "Sent Zodiac packet: %s\n", buf);

    return 0;
}

static void send_rtcm(struct gps_device_t *session,
		      const char *rtcmbuf, size_t rtcmbytes)
{
    unsigned short data[34];
    int n = 1 + (int)(rtcmbytes / 2 + rtcmbytes % 2);

    if (session->driver.zodiac.sn++ > 32767)
	session->driver.zodiac.sn = 0;

    memset(data, 0, sizeof(data));
    data[0] = session->driver.zodiac.sn;	/* sequence number */
    memcpy(&data[1], rtcmbuf, rtcmbytes);
    data[n] = zodiac_checksum(data, n);

    (void)zodiac_spew(session, 1351, data, n + 1);
}

static ssize_t zodiac_send_rtcm(struct gps_device_t *session,
				const char *rtcmbuf, size_t rtcmbytes)
{
    while (rtcmbytes > 0) {
	size_t len = (size_t) (rtcmbytes > 64 ? 64 : rtcmbytes);
	send_rtcm(session, rtcmbuf, len);
	rtcmbytes -= len;
	rtcmbuf += len;
    }
    return 1;
}

#define getzword(n)	get16z(session->lexer.outbuffer, n)
#define getzlong(n)	get32z(session->lexer.outbuffer, n)

static gps_mask_t handle1000(struct gps_device_t *session)
/* time-position-velocity report */
{
    gps_mask_t mask;
    double subseconds;
    struct tm unpacked_date;
    /* ticks                      = getzlong(6); */
    /* sequence                   = getzword(8); */
    /* measurement_sequence       = getzword(9); */
    session->gpsdata.status = (getzword(10) & 0x1c) ? 0 : 1;
    if (session->gpsdata.status != 0)
	session->newdata.mode = (getzword(10) & 1) ? MODE_2D : MODE_3D;
    else
	session->newdata.mode = MODE_NO_FIX;

    /* solution_type                 = getzword(11); */
    session->gpsdata.satellites_used = (int)getzword(12);
    /* polar_navigation              = getzword(13); */
    session->context->gps_week = (unsigned short)getzword(14);
    /* gps_seconds                   = getzlong(15); */
    /* gps_nanoseconds               = getzlong(17); */
    unpacked_date.tm_mday = (int)getzword(19);
    unpacked_date.tm_mon = (int)getzword(20) - 1;
    unpacked_date.tm_year = (int)getzword(21) - 1900;
    unpacked_date.tm_hour = (int)getzword(22);
    unpacked_date.tm_min = (int)getzword(23);
    unpacked_date.tm_sec = (int)getzword(24);
    unpacked_date.tm_isdst = 0;
    subseconds = (int)getzlong(25) / 1e9;
    session->newdata.time = (timestamp_t)mkgmtime(&unpacked_date) + subseconds;
    session->newdata.latitude = ((long)getzlong(27)) * RAD_2_DEG * 1e-8;
    session->newdata.longitude = ((long)getzlong(29)) * RAD_2_DEG * 1e-8;
    /*
     * The Rockwell Jupiter TU30-D140 reports altitude as uncorrected height
     * above WGS84 geoid.  The Zodiac binary protocol manual does not
     * specify whether word 31 is geodetic or WGS 84.
     */
    session->newdata.altitude = ((long)getzlong(31)) * 1e-2;
    session->gpsdata.separation = ((short)getzword(33)) * 1e-2;
    session->newdata.altitude -= session->gpsdata.separation;
    session->newdata.speed = (int)getzlong(34) * 1e-2;
    session->newdata.track = (int)getzword(36) * RAD_2_DEG * 1e-3;
    session->mag_var = ((short)getzword(37)) * RAD_2_DEG * 1e-4;
    session->newdata.climb = ((short)getzword(38)) * 1e-2;
    /* map_datum                   = getzword(39); */
    /*
     * The manual says these are 1-sigma.  Device reports only eph, circular
     * error; no harm in assigning it to both x and y components.
     */
    session->newdata.epx = session->newdata.epy =
	(int)getzlong(40) * 1e-2 * (1 / sqrt(2)) * GPSD_CONFIDENCE;
    session->newdata.epv = (int)getzlong(42) * 1e-2 * GPSD_CONFIDENCE;
    session->newdata.ept = (int)getzlong(44) * 1e-2 * GPSD_CONFIDENCE;
    session->newdata.eps = (int)getzword(46) * 1e-2 * GPSD_CONFIDENCE;
    /* clock_bias                  = (int)getzlong(47) * 1e-2; */
    /* clock_bias_sd               = (int)getzlong(49) * 1e-2; */
    /* clock_drift                 = (int)getzlong(51) * 1e-2; */
    /* clock_drift_sd              = (int)getzlong(53) * 1e-2; */

    mask =
	TIME_SET | NTPTIME_IS | LATLON_SET | ALTITUDE_SET | CLIMB_SET | SPEED_SET |
	TRACK_SET | STATUS_SET | MODE_SET;
    gpsd_log(&session->context->errout, LOG_DATA,
	     "1000: time=%.2f lat=%.2f lon=%.2f alt=%.2f track=%.2f speed=%.2f climb=%.2f mode=%d status=%d\n",
	     session->newdata.time, session->newdata.latitude,
	     session->newdata.longitude, session->newdata.altitude,
	     session->newdata.track, session->newdata.speed,
	     session->newdata.climb, session->newdata.mode,
	     session->gpsdata.status);
    return mask;
}

static gps_mask_t handle1002(struct gps_device_t *session)
/* satellite signal quality report */
{
    int i;

    /* ticks                      = getzlong(6); */
    /* sequence                   = getzword(8); */
    /* measurement_sequence       = getzword(9); */
    int gps_week = getzword(10);
    int gps_seconds = getzlong(11);
    /* gps_nanoseconds            = getzlong(13); */
    /* Note: this week counter is not limited to 10 bits. */
    session->context->gps_week = (unsigned short)gps_week;
    session->gpsdata.satellites_used = 0;
    for (i = 0; i < ZODIAC_CHANNELS; i++) {
	int status, prn;
	session->driver.zodiac.Zv[i] = status = (int)getzword(15 + (3 * i));
	session->driver.zodiac.Zs[i] = prn = (int)getzword(16 + (3 * i));

	if (status & 1)
	    session->gpsdata.satellites_used++;

	session->gpsdata.skyview[i].PRN = (short)prn;
	session->gpsdata.skyview[i].ss = (float)getzword(17 + (3 * i));
	session->gpsdata.skyview[i].used = (bool)(status & 1);
    }
    session->gpsdata.skyview_time = gpsd_gpstime_resolve(session,
						      (unsigned short)gps_week,
						      (double)gps_seconds);
    gpsd_log(&session->context->errout, LOG_DATA,
	     "1002: visible=%d used=%d mask={SATELLITE|USED}\n",
	     session->gpsdata.satellites_visible,
	     session->gpsdata.satellites_used);
    return SATELLITE_SET | USED_IS;
}

static gps_mask_t handle1003(struct gps_device_t *session)
/* skyview report */
{
    int i, n;

    /* The Polaris (and probably the DAGR) emit some strange variant of
     * this message which causes gpsd to crash filtering on impossible
     * number of satellites avoids this */
    n = (int)getzword(14);
    if ((n < 0) || (n > 12))
	return 0;

    gpsd_zero_satellites(&session->gpsdata);

    /* ticks              = getzlong(6); */
    /* sequence           = getzword(8); */
    session->gpsdata.dop.gdop = (unsigned int)getzword(9) * 1e-2;
    session->gpsdata.dop.pdop = (unsigned int)getzword(10) * 1e-2;
    session->gpsdata.dop.hdop = (unsigned int)getzword(11) * 1e-2;
    session->gpsdata.dop.vdop = (unsigned int)getzword(12) * 1e-2;
    session->gpsdata.dop.tdop = (unsigned int)getzword(13) * 1e-2;
    session->gpsdata.satellites_visible = n;

    for (i = 0; i < ZODIAC_CHANNELS; i++) {
	if (i < session->gpsdata.satellites_visible) {
	    session->gpsdata.skyview[i].PRN = (short)getzword(15 + (3 * i));
	    session->gpsdata.skyview[i].azimuth =
		(short)(((short)getzword(16 + (3 * i))) * RAD_2_DEG * 1e-4);
	    if (session->gpsdata.skyview[i].azimuth < 0)
		session->gpsdata.skyview[i].azimuth += 360;
	    session->gpsdata.skyview[i].elevation =
		(short)(((short)getzword(17 + (3 * i))) * RAD_2_DEG * 1e-4);
	} else {
	    session->gpsdata.skyview[i].PRN = 0;
	    session->gpsdata.skyview[i].azimuth = 0;
	    session->gpsdata.skyview[i].elevation = 0;
	}
    }
    session->gpsdata.skyview_time = NAN;
    gpsd_log(&session->context->errout, LOG_DATA,
	     "NAVDOP: visible=%d gdop=%.2f pdop=%.2f "
	     "hdop=%.2f vdop=%.2f tdop=%.2f mask={SATELLITE|DOP}\n",
	     session->gpsdata.satellites_visible,
	     session->gpsdata.dop.gdop,
	     session->gpsdata.dop.hdop,
	     session->gpsdata.dop.vdop,
	     session->gpsdata.dop.pdop, session->gpsdata.dop.tdop);
    return SATELLITE_SET | DOP_SET;
}

static void handle1005(struct gps_device_t *session UNUSED)
/* fix quality report */
{
    /* ticks              = getzlong(6); */
    /* sequence           = getzword(8); */
    int numcorrections = (int)getzword(12);

    if (session->newdata.mode == MODE_NO_FIX)
	session->gpsdata.status = STATUS_NO_FIX;
    else if (numcorrections == 0)
	session->gpsdata.status = STATUS_FIX;
    else
	session->gpsdata.status = STATUS_DGPS_FIX;
}

static gps_mask_t handle1011(struct gps_device_t *session)
/* version report */
{
    /*
     * This is UNTESTED -- but harmless if buggy.  Added to support
     * client querying of the ID with firmware version in 2006.
     * The Zodiac is supposed to send one of these messages on startup.
     */
    getstringz(session->subtype, session->lexer.outbuffer, 19, 28);	/* software version field */
    gpsd_log(&session->context->errout, LOG_DATA,
	     "1011: subtype=%s mask={DEVICEID}\n",
	     session->subtype);
    return DEVICEID_SET;
}


static void handle1108(struct gps_device_t *session)
/* leap-second correction report */
{
    /* ticks              = getzlong(6); */
    /* sequence           = getzword(8); */
    /* utc_week_seconds   = getzlong(14); */
    /* leap_nanoseconds   = getzlong(17); */
    if ((int)(getzword(19) & 3) == 3) {
	session->context->valid |= LEAP_SECOND_VALID;
	session->context->leap_seconds = (int)getzword(16);
    }
}

static gps_mask_t zodiac_analyze(struct gps_device_t *session)
{
    unsigned int id =
	(unsigned int)((session->lexer.outbuffer[3] << 8) |
		       session->lexer.outbuffer[2]);
    /*
     * The guard looks superfluous, but it keeps the rather expensive
     * gpsd_packetdump() function from being called even when the debug
     * level does not actually require it.
     */
    if (session->context->errout.debug >= LOG_RAW)
	gpsd_log(&session->context->errout, LOG_RAW,
		 "Raw Zodiac packet type %d length %zd: %s\n",
		 id, session->lexer.outbuflen, gpsd_prettydump(session));

    if (session->lexer.outbuflen < 10)
	return 0;

    /*
     * Normal cycle for these devices is 1001 1002.
     * We count 1001 as end of cycle because 1002 doesn't
     * carry fix information.
     */
    session->cycle_end_reliable = true;

    switch (id) {
    case 1000:
	return handle1000(session) | (CLEAR_IS | REPORT_IS);
    case 1002:
	return handle1002(session);
    case 1003:
	return handle1003(session);
    case 1005:
	handle1005(session);
	return 0;
    case 1011:
	return handle1011(session);
    case 1108:
	handle1108(session);
	return 0;
    default:
	return 0;
    }
}

#ifdef CONTROLSEND_ENABLE
static ssize_t zodiac_control_send(struct gps_device_t *session,
				   char *msg, size_t len)
{
    unsigned short shortwords[256];

#define min(x,y)	((x) < (y) ? x : y)
    /*
     * We used to just cast msg to an unsigned short pointer.
     * This can fail on word-oriented achitectures like a SPARC.
     */
    memcpy((char *)shortwords, msg, min(sizeof(shortwords), len));

    /* and if len isn't even, it's your own fault */
    return zodiac_spew(session, shortwords[0], shortwords + 1,
		       (int)(len / 2 - 1));
}
#endif /* CONTROLSEND_ENABLE */

#ifdef RECONFIGURE_ENABLE
static bool zodiac_speed_switch(struct gps_device_t *session,
				speed_t speed, char parity, int stopbits)
{
    unsigned short data[15];

    if (session->driver.zodiac.sn++ > 32767)
	session->driver.zodiac.sn = 0;

    switch (parity) {
    case 'E':
    case 2:
	parity = (char)2;
	break;
    case 'O':
    case 1:
	parity = (char)1;
	break;
    case 'N':
    case 0:
    default:
	parity = (char)0;
	break;
    }

    memset(data, 0, sizeof(data));
    /* data is the part of the message starting at word 6 */
    data[0] = session->driver.zodiac.sn;	/* sequence number */
    data[1] = 1;		/* port 1 data valid */
    data[2] = (unsigned short)parity;	/* port 1 character width (8 bits) */
    data[3] = (unsigned short)(stopbits - 1);	/* port 1 stop bits (1 stopbit) */
    data[4] = 0;		/* port 1 parity (none) */
    data[5] = (unsigned short)(round(log((double)speed / 300) / M_LN2) + 1);	/* port 1 speed */
    data[14] = zodiac_checksum(data, 14);

    (void)zodiac_spew(session, 1330, data, 15);
    return true;		/* it would be nice to error-check this */
}
#endif /* RECONFIGURE_ENABLE */

#ifdef TIMEHINT_ENABLE
static double zodiac_time_offset(struct gps_device_t *session UNUSED)
{
    /* Removing/changing the magic number below is likely to disturb
     * the handling of the 1pps signal from the gps device. The regression
     * tests and simple gps applications do not detect this. A live test
     * with the 1pps signal active is required. */
    return 1.1;
}
#endif /* TIMEHINT_ENABLE */

/* this is everything we export */
/* *INDENT-OFF* */
const struct gps_type_t driver_zodiac =
{
    .type_name      = "Zodiac",		/* full name of type */
    .packet_type    = ZODIAC_PACKET,	/* associated lexer packet type */
    .flags	    = DRIVER_STICKY,	/* no flags set */
    .trigger	    = NULL,		/* no trigger */
    .channels       = 12,		/* consumer-grade GPS */
    .probe_detect   = NULL,		/* no probe */
    .get_packet     = generic_get,	/* use the generic packet getter */
    .parse_packet   = zodiac_analyze,	/* parse message packets */
    .rtcm_writer    = zodiac_send_rtcm,	/* send DGPS correction */
    .init_query     = NULL,		/* non-perturbing initial query */
    .event_hook     = NULL,		/* no configuration */
#ifdef RECONFIGURE_ENABLE
    .speed_switcher = zodiac_speed_switch,/* we can change baud rate */
    .mode_switcher  = NULL,		/* no mode switcher */
    .rate_switcher  = NULL,		/* no sample-rate switcher */
    .min_cycle      = 1,		/* not relevant, no rate switch */
#endif /* RECONFIGURE_ENABLE */
#ifdef CONTROLSEND_ENABLE
    .control_send   = zodiac_control_send,	/* for gpsctl and friends */
#endif /* CONTROLSEND_ENABLE */
#ifdef TIMEHINT_ENABLE
    .time_offset     = zodiac_time_offset,	/* compute NTO fudge factor */
#endif /* TIMEHINT_ENABLE */
};
/* *INDENT-ON* */

#endif /* ZODIAC_ENABLE */