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1 /*
2  * Copyright (C) 2010 The Android Open Source Project
3  *
4  * Licensed under the Apache License, Version 2.0 (the "License");
5  * you may not use this file except in compliance with the License.
6  * You may obtain a copy of the License at
7  *
8  *      http://www.apache.org/licenses/LICENSE-2.0
9  *
10  * Unless required by applicable law or agreed to in writing, software
11  * distributed under the License is distributed on an "AS IS" BASIS,
12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13  * See the License for the specific language governing permissions and
14  * limitations under the License.
15  */
16 
17 /* this implements a GPS hardware library for the Android emulator.
18  * the following code should be built as a shared library that will be
19  * placed into /system/lib/hw/gps.goldfish.so
20  *
21  * it will be loaded by the code in hardware/libhardware/hardware.c
22  * which is itself called from android_location_GpsLocationProvider.cpp
23  */
24 
25 
26 #include <errno.h>
27 #include <pthread.h>
28 #include <fcntl.h>
29 #include <sys/epoll.h>
30 #include <math.h>
31 #include <time.h>
32 
33 #define  LOG_TAG  "gps_qemu"
34 #include <cutils/log.h>
35 #include <cutils/sockets.h>
36 #include <hardware/gps.h>
37 #include <hardware/qemud.h>
38 
39 /* the name of the qemud-controlled socket */
40 #define  QEMU_CHANNEL_NAME  "gps"
41 
42 #define  GPS_DEBUG  0
43 
44 #if GPS_DEBUG
45 #  define  D(...)   LOGD(__VA_ARGS__)
46 #else
47 #  define  D(...)   ((void)0)
48 #endif
49 
50 /*****************************************************************/
51 /*****************************************************************/
52 /*****                                                       *****/
53 /*****       N M E A   T O K E N I Z E R                     *****/
54 /*****                                                       *****/
55 /*****************************************************************/
56 /*****************************************************************/
57 
58 typedef struct {
59     const char*  p;
60     const char*  end;
61 } Token;
62 
63 #define  MAX_NMEA_TOKENS  16
64 
65 typedef struct {
66     int     count;
67     Token   tokens[ MAX_NMEA_TOKENS ];
68 } NmeaTokenizer;
69 
70 static int
nmea_tokenizer_init(NmeaTokenizer * t,const char * p,const char * end)71 nmea_tokenizer_init( NmeaTokenizer*  t, const char*  p, const char*  end )
72 {
73     int    count = 0;
74     char*  q;
75 
76     // the initial '$' is optional
77     if (p < end && p[0] == '$')
78         p += 1;
79 
80     // remove trailing newline
81     if (end > p && end[-1] == '\n') {
82         end -= 1;
83         if (end > p && end[-1] == '\r')
84             end -= 1;
85     }
86 
87     // get rid of checksum at the end of the sentecne
88     if (end >= p+3 && end[-3] == '*') {
89         end -= 3;
90     }
91 
92     while (p < end) {
93         const char*  q = p;
94 
95         q = memchr(p, ',', end-p);
96         if (q == NULL)
97             q = end;
98 
99         if (q > p) {
100             if (count < MAX_NMEA_TOKENS) {
101                 t->tokens[count].p   = p;
102                 t->tokens[count].end = q;
103                 count += 1;
104             }
105         }
106         if (q < end)
107             q += 1;
108 
109         p = q;
110     }
111 
112     t->count = count;
113     return count;
114 }
115 
116 static Token
nmea_tokenizer_get(NmeaTokenizer * t,int index)117 nmea_tokenizer_get( NmeaTokenizer*  t, int  index )
118 {
119     Token  tok;
120     static const char*  dummy = "";
121 
122     if (index < 0 || index >= t->count) {
123         tok.p = tok.end = dummy;
124     } else
125         tok = t->tokens[index];
126 
127     return tok;
128 }
129 
130 
131 static int
str2int(const char * p,const char * end)132 str2int( const char*  p, const char*  end )
133 {
134     int   result = 0;
135     int   len    = end - p;
136 
137     for ( ; len > 0; len--, p++ )
138     {
139         int  c;
140 
141         if (p >= end)
142             goto Fail;
143 
144         c = *p - '0';
145         if ((unsigned)c >= 10)
146             goto Fail;
147 
148         result = result*10 + c;
149     }
150     return  result;
151 
152 Fail:
153     return -1;
154 }
155 
156 static double
str2float(const char * p,const char * end)157 str2float( const char*  p, const char*  end )
158 {
159     int   result = 0;
160     int   len    = end - p;
161     char  temp[16];
162 
163     if (len >= (int)sizeof(temp))
164         return 0.;
165 
166     memcpy( temp, p, len );
167     temp[len] = 0;
168     return strtod( temp, NULL );
169 }
170 
171 /*****************************************************************/
172 /*****************************************************************/
173 /*****                                                       *****/
174 /*****       N M E A   P A R S E R                           *****/
175 /*****                                                       *****/
176 /*****************************************************************/
177 /*****************************************************************/
178 
179 #define  NMEA_MAX_SIZE  83
180 
181 typedef struct {
182     int     pos;
183     int     overflow;
184     int     utc_year;
185     int     utc_mon;
186     int     utc_day;
187     int     utc_diff;
188     GpsLocation  fix;
189     gps_location_callback  callback;
190     char    in[ NMEA_MAX_SIZE+1 ];
191 } NmeaReader;
192 
193 
194 static void
nmea_reader_update_utc_diff(NmeaReader * r)195 nmea_reader_update_utc_diff( NmeaReader*  r )
196 {
197     time_t         now = time(NULL);
198     struct tm      tm_local;
199     struct tm      tm_utc;
200     long           time_local, time_utc;
201 
202     gmtime_r( &now, &tm_utc );
203     localtime_r( &now, &tm_local );
204 
205     time_local = tm_local.tm_sec +
206                  60*(tm_local.tm_min +
207                  60*(tm_local.tm_hour +
208                  24*(tm_local.tm_yday +
209                  365*tm_local.tm_year)));
210 
211     time_utc = tm_utc.tm_sec +
212                60*(tm_utc.tm_min +
213                60*(tm_utc.tm_hour +
214                24*(tm_utc.tm_yday +
215                365*tm_utc.tm_year)));
216 
217     r->utc_diff = time_utc - time_local;
218 }
219 
220 
221 static void
nmea_reader_init(NmeaReader * r)222 nmea_reader_init( NmeaReader*  r )
223 {
224     memset( r, 0, sizeof(*r) );
225 
226     r->pos      = 0;
227     r->overflow = 0;
228     r->utc_year = -1;
229     r->utc_mon  = -1;
230     r->utc_day  = -1;
231     r->callback = NULL;
232     r->fix.size = sizeof(r->fix);
233 
234     nmea_reader_update_utc_diff( r );
235 }
236 
237 
238 static void
nmea_reader_set_callback(NmeaReader * r,gps_location_callback cb)239 nmea_reader_set_callback( NmeaReader*  r, gps_location_callback  cb )
240 {
241     r->callback = cb;
242     if (cb != NULL && r->fix.flags != 0) {
243         D("%s: sending latest fix to new callback", __FUNCTION__);
244         r->callback( &r->fix );
245         r->fix.flags = 0;
246     }
247 }
248 
249 
250 static int
nmea_reader_update_time(NmeaReader * r,Token tok)251 nmea_reader_update_time( NmeaReader*  r, Token  tok )
252 {
253     int        hour, minute;
254     double     seconds;
255     struct tm  tm;
256     time_t     fix_time;
257 
258     if (tok.p + 6 > tok.end)
259         return -1;
260 
261     if (r->utc_year < 0) {
262         // no date yet, get current one
263         time_t  now = time(NULL);
264         gmtime_r( &now, &tm );
265         r->utc_year = tm.tm_year + 1900;
266         r->utc_mon  = tm.tm_mon + 1;
267         r->utc_day  = tm.tm_mday;
268     }
269 
270     hour    = str2int(tok.p,   tok.p+2);
271     minute  = str2int(tok.p+2, tok.p+4);
272     seconds = str2float(tok.p+4, tok.end);
273 
274     tm.tm_hour  = hour;
275     tm.tm_min   = minute;
276     tm.tm_sec   = (int) seconds;
277     tm.tm_year  = r->utc_year - 1900;
278     tm.tm_mon   = r->utc_mon - 1;
279     tm.tm_mday  = r->utc_day;
280     tm.tm_isdst = -1;
281 
282     fix_time = mktime( &tm ) + r->utc_diff;
283     r->fix.timestamp = (long long)fix_time * 1000;
284     return 0;
285 }
286 
287 static int
nmea_reader_update_date(NmeaReader * r,Token date,Token time)288 nmea_reader_update_date( NmeaReader*  r, Token  date, Token  time )
289 {
290     Token  tok = date;
291     int    day, mon, year;
292 
293     if (tok.p + 6 != tok.end) {
294         D("date not properly formatted: '%.*s'", tok.end-tok.p, tok.p);
295         return -1;
296     }
297     day  = str2int(tok.p, tok.p+2);
298     mon  = str2int(tok.p+2, tok.p+4);
299     year = str2int(tok.p+4, tok.p+6) + 2000;
300 
301     if ((day|mon|year) < 0) {
302         D("date not properly formatted: '%.*s'", tok.end-tok.p, tok.p);
303         return -1;
304     }
305 
306     r->utc_year  = year;
307     r->utc_mon   = mon;
308     r->utc_day   = day;
309 
310     return nmea_reader_update_time( r, time );
311 }
312 
313 
314 static double
convert_from_hhmm(Token tok)315 convert_from_hhmm( Token  tok )
316 {
317     double  val     = str2float(tok.p, tok.end);
318     int     degrees = (int)(floor(val) / 100);
319     double  minutes = val - degrees*100.;
320     double  dcoord  = degrees + minutes / 60.0;
321     return dcoord;
322 }
323 
324 
325 static int
nmea_reader_update_latlong(NmeaReader * r,Token latitude,char latitudeHemi,Token longitude,char longitudeHemi)326 nmea_reader_update_latlong( NmeaReader*  r,
327                             Token        latitude,
328                             char         latitudeHemi,
329                             Token        longitude,
330                             char         longitudeHemi )
331 {
332     double   lat, lon;
333     Token    tok;
334 
335     tok = latitude;
336     if (tok.p + 6 > tok.end) {
337         D("latitude is too short: '%.*s'", tok.end-tok.p, tok.p);
338         return -1;
339     }
340     lat = convert_from_hhmm(tok);
341     if (latitudeHemi == 'S')
342         lat = -lat;
343 
344     tok = longitude;
345     if (tok.p + 6 > tok.end) {
346         D("longitude is too short: '%.*s'", tok.end-tok.p, tok.p);
347         return -1;
348     }
349     lon = convert_from_hhmm(tok);
350     if (longitudeHemi == 'W')
351         lon = -lon;
352 
353     r->fix.flags    |= GPS_LOCATION_HAS_LAT_LONG;
354     r->fix.latitude  = lat;
355     r->fix.longitude = lon;
356     return 0;
357 }
358 
359 
360 static int
nmea_reader_update_altitude(NmeaReader * r,Token altitude,Token units)361 nmea_reader_update_altitude( NmeaReader*  r,
362                              Token        altitude,
363                              Token        units )
364 {
365     double  alt;
366     Token   tok = altitude;
367 
368     if (tok.p >= tok.end)
369         return -1;
370 
371     r->fix.flags   |= GPS_LOCATION_HAS_ALTITUDE;
372     r->fix.altitude = str2float(tok.p, tok.end);
373     return 0;
374 }
375 
376 
377 static int
nmea_reader_update_bearing(NmeaReader * r,Token bearing)378 nmea_reader_update_bearing( NmeaReader*  r,
379                             Token        bearing )
380 {
381     double  alt;
382     Token   tok = bearing;
383 
384     if (tok.p >= tok.end)
385         return -1;
386 
387     r->fix.flags   |= GPS_LOCATION_HAS_BEARING;
388     r->fix.bearing  = str2float(tok.p, tok.end);
389     return 0;
390 }
391 
392 
393 static int
nmea_reader_update_speed(NmeaReader * r,Token speed)394 nmea_reader_update_speed( NmeaReader*  r,
395                           Token        speed )
396 {
397     double  alt;
398     Token   tok = speed;
399 
400     if (tok.p >= tok.end)
401         return -1;
402 
403     r->fix.flags   |= GPS_LOCATION_HAS_SPEED;
404     r->fix.speed    = str2float(tok.p, tok.end);
405     return 0;
406 }
407 
408 
409 static void
nmea_reader_parse(NmeaReader * r)410 nmea_reader_parse( NmeaReader*  r )
411 {
412    /* we received a complete sentence, now parse it to generate
413     * a new GPS fix...
414     */
415     NmeaTokenizer  tzer[1];
416     Token          tok;
417 
418     D("Received: '%.*s'", r->pos, r->in);
419     if (r->pos < 9) {
420         D("Too short. discarded.");
421         return;
422     }
423 
424     nmea_tokenizer_init(tzer, r->in, r->in + r->pos);
425 #if GPS_DEBUG
426     {
427         int  n;
428         D("Found %d tokens", tzer->count);
429         for (n = 0; n < tzer->count; n++) {
430             Token  tok = nmea_tokenizer_get(tzer,n);
431             D("%2d: '%.*s'", n, tok.end-tok.p, tok.p);
432         }
433     }
434 #endif
435 
436     tok = nmea_tokenizer_get(tzer, 0);
437     if (tok.p + 5 > tok.end) {
438         D("sentence id '%.*s' too short, ignored.", tok.end-tok.p, tok.p);
439         return;
440     }
441 
442     // ignore first two characters.
443     tok.p += 2;
444     if ( !memcmp(tok.p, "GGA", 3) ) {
445         // GPS fix
446         Token  tok_time          = nmea_tokenizer_get(tzer,1);
447         Token  tok_latitude      = nmea_tokenizer_get(tzer,2);
448         Token  tok_latitudeHemi  = nmea_tokenizer_get(tzer,3);
449         Token  tok_longitude     = nmea_tokenizer_get(tzer,4);
450         Token  tok_longitudeHemi = nmea_tokenizer_get(tzer,5);
451         Token  tok_altitude      = nmea_tokenizer_get(tzer,9);
452         Token  tok_altitudeUnits = nmea_tokenizer_get(tzer,10);
453 
454         nmea_reader_update_time(r, tok_time);
455         nmea_reader_update_latlong(r, tok_latitude,
456                                       tok_latitudeHemi.p[0],
457                                       tok_longitude,
458                                       tok_longitudeHemi.p[0]);
459         nmea_reader_update_altitude(r, tok_altitude, tok_altitudeUnits);
460 
461     } else if ( !memcmp(tok.p, "GSA", 3) ) {
462         // do something ?
463     } else if ( !memcmp(tok.p, "RMC", 3) ) {
464         Token  tok_time          = nmea_tokenizer_get(tzer,1);
465         Token  tok_fixStatus     = nmea_tokenizer_get(tzer,2);
466         Token  tok_latitude      = nmea_tokenizer_get(tzer,3);
467         Token  tok_latitudeHemi  = nmea_tokenizer_get(tzer,4);
468         Token  tok_longitude     = nmea_tokenizer_get(tzer,5);
469         Token  tok_longitudeHemi = nmea_tokenizer_get(tzer,6);
470         Token  tok_speed         = nmea_tokenizer_get(tzer,7);
471         Token  tok_bearing       = nmea_tokenizer_get(tzer,8);
472         Token  tok_date          = nmea_tokenizer_get(tzer,9);
473 
474         D("in RMC, fixStatus=%c", tok_fixStatus.p[0]);
475         if (tok_fixStatus.p[0] == 'A')
476         {
477             nmea_reader_update_date( r, tok_date, tok_time );
478 
479             nmea_reader_update_latlong( r, tok_latitude,
480                                            tok_latitudeHemi.p[0],
481                                            tok_longitude,
482                                            tok_longitudeHemi.p[0] );
483 
484             nmea_reader_update_bearing( r, tok_bearing );
485             nmea_reader_update_speed  ( r, tok_speed );
486         }
487     } else {
488         tok.p -= 2;
489         D("unknown sentence '%.*s", tok.end-tok.p, tok.p);
490     }
491     if (r->fix.flags != 0) {
492 #if GPS_DEBUG
493         char   temp[256];
494         char*  p   = temp;
495         char*  end = p + sizeof(temp);
496         struct tm   utc;
497 
498         p += snprintf( p, end-p, "sending fix" );
499         if (r->fix.flags & GPS_LOCATION_HAS_LAT_LONG) {
500             p += snprintf(p, end-p, " lat=%g lon=%g", r->fix.latitude, r->fix.longitude);
501         }
502         if (r->fix.flags & GPS_LOCATION_HAS_ALTITUDE) {
503             p += snprintf(p, end-p, " altitude=%g", r->fix.altitude);
504         }
505         if (r->fix.flags & GPS_LOCATION_HAS_SPEED) {
506             p += snprintf(p, end-p, " speed=%g", r->fix.speed);
507         }
508         if (r->fix.flags & GPS_LOCATION_HAS_BEARING) {
509             p += snprintf(p, end-p, " bearing=%g", r->fix.bearing);
510         }
511         if (r->fix.flags & GPS_LOCATION_HAS_ACCURACY) {
512             p += snprintf(p,end-p, " accuracy=%g", r->fix.accuracy);
513         }
514         gmtime_r( (time_t*) &r->fix.timestamp, &utc );
515         p += snprintf(p, end-p, " time=%s", asctime( &utc ) );
516         D(temp);
517 #endif
518         if (r->callback) {
519             r->callback( &r->fix );
520             r->fix.flags = 0;
521         }
522         else {
523             D("no callback, keeping data until needed !");
524         }
525     }
526 }
527 
528 
529 static void
nmea_reader_addc(NmeaReader * r,int c)530 nmea_reader_addc( NmeaReader*  r, int  c )
531 {
532     if (r->overflow) {
533         r->overflow = (c != '\n');
534         return;
535     }
536 
537     if (r->pos >= (int) sizeof(r->in)-1 ) {
538         r->overflow = 1;
539         r->pos      = 0;
540         return;
541     }
542 
543     r->in[r->pos] = (char)c;
544     r->pos       += 1;
545 
546     if (c == '\n') {
547         nmea_reader_parse( r );
548         r->pos = 0;
549     }
550 }
551 
552 
553 /*****************************************************************/
554 /*****************************************************************/
555 /*****                                                       *****/
556 /*****       C O N N E C T I O N   S T A T E                 *****/
557 /*****                                                       *****/
558 /*****************************************************************/
559 /*****************************************************************/
560 
561 /* commands sent to the gps thread */
562 enum {
563     CMD_QUIT  = 0,
564     CMD_START = 1,
565     CMD_STOP  = 2
566 };
567 
568 
569 /* this is the state of our connection to the qemu_gpsd daemon */
570 typedef struct {
571     int                     init;
572     int                     fd;
573     GpsCallbacks            callbacks;
574     pthread_t               thread;
575     int                     control[2];
576 } GpsState;
577 
578 static GpsState  _gps_state[1];
579 
580 
581 static void
gps_state_done(GpsState * s)582 gps_state_done( GpsState*  s )
583 {
584     // tell the thread to quit, and wait for it
585     char   cmd = CMD_QUIT;
586     void*  dummy;
587     write( s->control[0], &cmd, 1 );
588     pthread_join(s->thread, &dummy);
589 
590     // close the control socket pair
591     close( s->control[0] ); s->control[0] = -1;
592     close( s->control[1] ); s->control[1] = -1;
593 
594     // close connection to the QEMU GPS daemon
595     close( s->fd ); s->fd = -1;
596     s->init = 0;
597 }
598 
599 
600 static void
gps_state_start(GpsState * s)601 gps_state_start( GpsState*  s )
602 {
603     char  cmd = CMD_START;
604     int   ret;
605 
606     do { ret=write( s->control[0], &cmd, 1 ); }
607     while (ret < 0 && errno == EINTR);
608 
609     if (ret != 1)
610         D("%s: could not send CMD_START command: ret=%d: %s",
611           __FUNCTION__, ret, strerror(errno));
612 }
613 
614 
615 static void
gps_state_stop(GpsState * s)616 gps_state_stop( GpsState*  s )
617 {
618     char  cmd = CMD_STOP;
619     int   ret;
620 
621     do { ret=write( s->control[0], &cmd, 1 ); }
622     while (ret < 0 && errno == EINTR);
623 
624     if (ret != 1)
625         D("%s: could not send CMD_STOP command: ret=%d: %s",
626           __FUNCTION__, ret, strerror(errno));
627 }
628 
629 
630 static int
epoll_register(int epoll_fd,int fd)631 epoll_register( int  epoll_fd, int  fd )
632 {
633     struct epoll_event  ev;
634     int                 ret, flags;
635 
636     /* important: make the fd non-blocking */
637     flags = fcntl(fd, F_GETFL);
638     fcntl(fd, F_SETFL, flags | O_NONBLOCK);
639 
640     ev.events  = EPOLLIN;
641     ev.data.fd = fd;
642     do {
643         ret = epoll_ctl( epoll_fd, EPOLL_CTL_ADD, fd, &ev );
644     } while (ret < 0 && errno == EINTR);
645     return ret;
646 }
647 
648 
649 static int
epoll_deregister(int epoll_fd,int fd)650 epoll_deregister( int  epoll_fd, int  fd )
651 {
652     int  ret;
653     do {
654         ret = epoll_ctl( epoll_fd, EPOLL_CTL_DEL, fd, NULL );
655     } while (ret < 0 && errno == EINTR);
656     return ret;
657 }
658 
659 /* this is the main thread, it waits for commands from gps_state_start/stop and,
660  * when started, messages from the QEMU GPS daemon. these are simple NMEA sentences
661  * that must be parsed to be converted into GPS fixes sent to the framework
662  */
663 static void
gps_state_thread(void * arg)664 gps_state_thread( void*  arg )
665 {
666     GpsState*   state = (GpsState*) arg;
667     NmeaReader  reader[1];
668     int         epoll_fd   = epoll_create(2);
669     int         started    = 0;
670     int         gps_fd     = state->fd;
671     int         control_fd = state->control[1];
672 
673     nmea_reader_init( reader );
674 
675     // register control file descriptors for polling
676     epoll_register( epoll_fd, control_fd );
677     epoll_register( epoll_fd, gps_fd );
678 
679     D("gps thread running");
680 
681     // now loop
682     for (;;) {
683         struct epoll_event   events[2];
684         int                  ne, nevents;
685 
686         nevents = epoll_wait( epoll_fd, events, 2, -1 );
687         if (nevents < 0) {
688             if (errno != EINTR)
689                 LOGE("epoll_wait() unexpected error: %s", strerror(errno));
690             continue;
691         }
692         D("gps thread received %d events", nevents);
693         for (ne = 0; ne < nevents; ne++) {
694             if ((events[ne].events & (EPOLLERR|EPOLLHUP)) != 0) {
695                 LOGE("EPOLLERR or EPOLLHUP after epoll_wait() !?");
696                 return;
697             }
698             if ((events[ne].events & EPOLLIN) != 0) {
699                 int  fd = events[ne].data.fd;
700 
701                 if (fd == control_fd)
702                 {
703                     char  cmd = 255;
704                     int   ret;
705                     D("gps control fd event");
706                     do {
707                         ret = read( fd, &cmd, 1 );
708                     } while (ret < 0 && errno == EINTR);
709 
710                     if (cmd == CMD_QUIT) {
711                         D("gps thread quitting on demand");
712                         return;
713                     }
714                     else if (cmd == CMD_START) {
715                         if (!started) {
716                             D("gps thread starting  location_cb=%p", state->callbacks.location_cb);
717                             started = 1;
718                             nmea_reader_set_callback( reader, state->callbacks.location_cb );
719                         }
720                     }
721                     else if (cmd == CMD_STOP) {
722                         if (started) {
723                             D("gps thread stopping");
724                             started = 0;
725                             nmea_reader_set_callback( reader, NULL );
726                         }
727                     }
728                 }
729                 else if (fd == gps_fd)
730                 {
731                     char  buff[32];
732                     D("gps fd event");
733                     for (;;) {
734                         int  nn, ret;
735 
736                         ret = read( fd, buff, sizeof(buff) );
737                         if (ret < 0) {
738                             if (errno == EINTR)
739                                 continue;
740                             if (errno != EWOULDBLOCK)
741                                 LOGE("error while reading from gps daemon socket: %s:", strerror(errno));
742                             break;
743                         }
744                         D("received %d bytes: %.*s", ret, ret, buff);
745                         for (nn = 0; nn < ret; nn++)
746                             nmea_reader_addc( reader, buff[nn] );
747                     }
748                     D("gps fd event end");
749                 }
750                 else
751                 {
752                     LOGE("epoll_wait() returned unkown fd %d ?", fd);
753                 }
754             }
755         }
756     }
757 }
758 
759 
760 static void
gps_state_init(GpsState * state,GpsCallbacks * callbacks)761 gps_state_init( GpsState*  state, GpsCallbacks* callbacks )
762 {
763     state->init       = 1;
764     state->control[0] = -1;
765     state->control[1] = -1;
766     state->fd         = -1;
767 
768     state->fd = qemud_channel_open(QEMU_CHANNEL_NAME);
769 
770     if (state->fd < 0) {
771         D("no gps emulation detected");
772         return;
773     }
774 
775     D("gps emulation will read from '%s' qemud channel", QEMU_CHANNEL_NAME );
776 
777     if ( socketpair( AF_LOCAL, SOCK_STREAM, 0, state->control ) < 0 ) {
778         LOGE("could not create thread control socket pair: %s", strerror(errno));
779         goto Fail;
780     }
781 
782     state->thread = callbacks->create_thread_cb( "gps_state_thread", gps_state_thread, state );
783 
784     if ( !state->thread ) {
785         LOGE("could not create gps thread: %s", strerror(errno));
786         goto Fail;
787     }
788 
789     state->callbacks = *callbacks;
790 
791     D("gps state initialized");
792     return;
793 
794 Fail:
795     gps_state_done( state );
796 }
797 
798 
799 /*****************************************************************/
800 /*****************************************************************/
801 /*****                                                       *****/
802 /*****       I N T E R F A C E                               *****/
803 /*****                                                       *****/
804 /*****************************************************************/
805 /*****************************************************************/
806 
807 
808 static int
qemu_gps_init(GpsCallbacks * callbacks)809 qemu_gps_init(GpsCallbacks* callbacks)
810 {
811     GpsState*  s = _gps_state;
812 
813     if (!s->init)
814         gps_state_init(s, callbacks);
815 
816     if (s->fd < 0)
817         return -1;
818 
819     return 0;
820 }
821 
822 static void
qemu_gps_cleanup(void)823 qemu_gps_cleanup(void)
824 {
825     GpsState*  s = _gps_state;
826 
827     if (s->init)
828         gps_state_done(s);
829 }
830 
831 
832 static int
qemu_gps_start()833 qemu_gps_start()
834 {
835     GpsState*  s = _gps_state;
836 
837     if (!s->init) {
838         D("%s: called with uninitialized state !!", __FUNCTION__);
839         return -1;
840     }
841 
842     D("%s: called", __FUNCTION__);
843     gps_state_start(s);
844     return 0;
845 }
846 
847 
848 static int
qemu_gps_stop()849 qemu_gps_stop()
850 {
851     GpsState*  s = _gps_state;
852 
853     if (!s->init) {
854         D("%s: called with uninitialized state !!", __FUNCTION__);
855         return -1;
856     }
857 
858     D("%s: called", __FUNCTION__);
859     gps_state_stop(s);
860     return 0;
861 }
862 
863 
864 static int
qemu_gps_inject_time(GpsUtcTime time,int64_t timeReference,int uncertainty)865 qemu_gps_inject_time(GpsUtcTime time, int64_t timeReference, int uncertainty)
866 {
867     return 0;
868 }
869 
870 static int
qemu_gps_inject_location(double latitude,double longitude,float accuracy)871 qemu_gps_inject_location(double latitude, double longitude, float accuracy)
872 {
873     return 0;
874 }
875 
876 static void
qemu_gps_delete_aiding_data(GpsAidingData flags)877 qemu_gps_delete_aiding_data(GpsAidingData flags)
878 {
879 }
880 
qemu_gps_set_position_mode(GpsPositionMode mode,int fix_frequency)881 static int qemu_gps_set_position_mode(GpsPositionMode mode, int fix_frequency)
882 {
883     // FIXME - support fix_frequency
884     return 0;
885 }
886 
887 static const void*
qemu_gps_get_extension(const char * name)888 qemu_gps_get_extension(const char* name)
889 {
890     // no extensions supported
891     return NULL;
892 }
893 
894 static const GpsInterface  qemuGpsInterface = {
895     sizeof(GpsInterface),
896     qemu_gps_init,
897     qemu_gps_start,
898     qemu_gps_stop,
899     qemu_gps_cleanup,
900     qemu_gps_inject_time,
901     qemu_gps_inject_location,
902     qemu_gps_delete_aiding_data,
903     qemu_gps_set_position_mode,
904     qemu_gps_get_extension,
905 };
906 
gps__get_gps_interface(struct gps_device_t * dev)907 const GpsInterface* gps__get_gps_interface(struct gps_device_t* dev)
908 {
909     return &qemuGpsInterface;
910 }
911 
open_gps(const struct hw_module_t * module,char const * name,struct hw_device_t ** device)912 static int open_gps(const struct hw_module_t* module, char const* name,
913         struct hw_device_t** device)
914 {
915     struct gps_device_t *dev = malloc(sizeof(struct gps_device_t));
916     memset(dev, 0, sizeof(*dev));
917 
918     dev->common.tag = HARDWARE_DEVICE_TAG;
919     dev->common.version = 0;
920     dev->common.module = (struct hw_module_t*)module;
921 //    dev->common.close = (int (*)(struct hw_device_t*))close_lights;
922     dev->get_gps_interface = gps__get_gps_interface;
923 
924     *device = (struct hw_device_t*)dev;
925     return 0;
926 }
927 
928 
929 static struct hw_module_methods_t gps_module_methods = {
930     .open = open_gps
931 };
932 
933 const struct hw_module_t HAL_MODULE_INFO_SYM = {
934     .tag = HARDWARE_MODULE_TAG,
935     .version_major = 1,
936     .version_minor = 0,
937     .id = GPS_HARDWARE_MODULE_ID,
938     .name = "Goldfish GPS Module",
939     .author = "The Android Open Source Project",
940     .methods = &gps_module_methods,
941 };
942