Files
android_development/tools/emulator/system/gps/gps_qemu.c
Laurent Tu 91d9d51f5d Return accuracy in GPS emulation
Accuracy is now a required field for location. To comply, set an
accuracy in returned fix. The accuracy is constant for now since
computing it from the NMEA sentence seems to be very complicated.

Bug: 6864500

Change-Id: Iff4c36b440b095539c717d35a812ee2ed7c1725f
2012-10-11 20:43:53 -07:00

956 lines
24 KiB
C

/*
* Copyright (C) 2010 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
/* this implements a GPS hardware library for the Android emulator.
* the following code should be built as a shared library that will be
* placed into /system/lib/hw/gps.goldfish.so
*
* it will be loaded by the code in hardware/libhardware/hardware.c
* which is itself called from android_location_GpsLocationProvider.cpp
*/
#include <errno.h>
#include <pthread.h>
#include <fcntl.h>
#include <sys/epoll.h>
#include <math.h>
#include <time.h>
#define LOG_TAG "gps_qemu"
#include <cutils/log.h>
#include <cutils/sockets.h>
#include <hardware/gps.h>
#include <hardware/qemud.h>
/* the name of the qemud-controlled socket */
#define QEMU_CHANNEL_NAME "gps"
#define GPS_DEBUG 0
#if GPS_DEBUG
# define D(...) ALOGD(__VA_ARGS__)
#else
# define D(...) ((void)0)
#endif
/*****************************************************************/
/*****************************************************************/
/***** *****/
/***** N M E A T O K E N I Z E R *****/
/***** *****/
/*****************************************************************/
/*****************************************************************/
typedef struct {
const char* p;
const char* end;
} Token;
#define MAX_NMEA_TOKENS 16
typedef struct {
int count;
Token tokens[ MAX_NMEA_TOKENS ];
} NmeaTokenizer;
static int
nmea_tokenizer_init( NmeaTokenizer* t, const char* p, const char* end )
{
int count = 0;
char* q;
// the initial '$' is optional
if (p < end && p[0] == '$')
p += 1;
// remove trailing newline
if (end > p && end[-1] == '\n') {
end -= 1;
if (end > p && end[-1] == '\r')
end -= 1;
}
// get rid of checksum at the end of the sentecne
if (end >= p+3 && end[-3] == '*') {
end -= 3;
}
while (p < end) {
const char* q = p;
q = memchr(p, ',', end-p);
if (q == NULL)
q = end;
if (q > p) {
if (count < MAX_NMEA_TOKENS) {
t->tokens[count].p = p;
t->tokens[count].end = q;
count += 1;
}
}
if (q < end)
q += 1;
p = q;
}
t->count = count;
return count;
}
static Token
nmea_tokenizer_get( NmeaTokenizer* t, int index )
{
Token tok;
static const char* dummy = "";
if (index < 0 || index >= t->count) {
tok.p = tok.end = dummy;
} else
tok = t->tokens[index];
return tok;
}
static int
str2int( const char* p, const char* end )
{
int result = 0;
int len = end - p;
for ( ; len > 0; len--, p++ )
{
int c;
if (p >= end)
goto Fail;
c = *p - '0';
if ((unsigned)c >= 10)
goto Fail;
result = result*10 + c;
}
return result;
Fail:
return -1;
}
static double
str2float( const char* p, const char* end )
{
int result = 0;
int len = end - p;
char temp[16];
if (len >= (int)sizeof(temp))
return 0.;
memcpy( temp, p, len );
temp[len] = 0;
return strtod( temp, NULL );
}
/*****************************************************************/
/*****************************************************************/
/***** *****/
/***** N M E A P A R S E R *****/
/***** *****/
/*****************************************************************/
/*****************************************************************/
#define NMEA_MAX_SIZE 83
typedef struct {
int pos;
int overflow;
int utc_year;
int utc_mon;
int utc_day;
int utc_diff;
GpsLocation fix;
gps_location_callback callback;
char in[ NMEA_MAX_SIZE+1 ];
} NmeaReader;
static void
nmea_reader_update_utc_diff( NmeaReader* r )
{
time_t now = time(NULL);
struct tm tm_local;
struct tm tm_utc;
long time_local, time_utc;
gmtime_r( &now, &tm_utc );
localtime_r( &now, &tm_local );
time_local = tm_local.tm_sec +
60*(tm_local.tm_min +
60*(tm_local.tm_hour +
24*(tm_local.tm_yday +
365*tm_local.tm_year)));
time_utc = tm_utc.tm_sec +
60*(tm_utc.tm_min +
60*(tm_utc.tm_hour +
24*(tm_utc.tm_yday +
365*tm_utc.tm_year)));
r->utc_diff = time_utc - time_local;
}
static void
nmea_reader_init( NmeaReader* r )
{
memset( r, 0, sizeof(*r) );
r->pos = 0;
r->overflow = 0;
r->utc_year = -1;
r->utc_mon = -1;
r->utc_day = -1;
r->callback = NULL;
r->fix.size = sizeof(r->fix);
nmea_reader_update_utc_diff( r );
}
static void
nmea_reader_set_callback( NmeaReader* r, gps_location_callback cb )
{
r->callback = cb;
if (cb != NULL && r->fix.flags != 0) {
D("%s: sending latest fix to new callback", __FUNCTION__);
r->callback( &r->fix );
r->fix.flags = 0;
}
}
static int
nmea_reader_update_time( NmeaReader* r, Token tok )
{
int hour, minute;
double seconds;
struct tm tm;
time_t fix_time;
if (tok.p + 6 > tok.end)
return -1;
if (r->utc_year < 0) {
// no date yet, get current one
time_t now = time(NULL);
gmtime_r( &now, &tm );
r->utc_year = tm.tm_year + 1900;
r->utc_mon = tm.tm_mon + 1;
r->utc_day = tm.tm_mday;
}
hour = str2int(tok.p, tok.p+2);
minute = str2int(tok.p+2, tok.p+4);
seconds = str2float(tok.p+4, tok.end);
tm.tm_hour = hour;
tm.tm_min = minute;
tm.tm_sec = (int) seconds;
tm.tm_year = r->utc_year - 1900;
tm.tm_mon = r->utc_mon - 1;
tm.tm_mday = r->utc_day;
tm.tm_isdst = -1;
fix_time = mktime( &tm ) + r->utc_diff;
r->fix.timestamp = (long long)fix_time * 1000;
return 0;
}
static int
nmea_reader_update_date( NmeaReader* r, Token date, Token time )
{
Token tok = date;
int day, mon, year;
if (tok.p + 6 != tok.end) {
D("date not properly formatted: '%.*s'", tok.end-tok.p, tok.p);
return -1;
}
day = str2int(tok.p, tok.p+2);
mon = str2int(tok.p+2, tok.p+4);
year = str2int(tok.p+4, tok.p+6) + 2000;
if ((day|mon|year) < 0) {
D("date not properly formatted: '%.*s'", tok.end-tok.p, tok.p);
return -1;
}
r->utc_year = year;
r->utc_mon = mon;
r->utc_day = day;
return nmea_reader_update_time( r, time );
}
static double
convert_from_hhmm( Token tok )
{
double val = str2float(tok.p, tok.end);
int degrees = (int)(floor(val) / 100);
double minutes = val - degrees*100.;
double dcoord = degrees + minutes / 60.0;
return dcoord;
}
static int
nmea_reader_update_latlong( NmeaReader* r,
Token latitude,
char latitudeHemi,
Token longitude,
char longitudeHemi )
{
double lat, lon;
Token tok;
tok = latitude;
if (tok.p + 6 > tok.end) {
D("latitude is too short: '%.*s'", tok.end-tok.p, tok.p);
return -1;
}
lat = convert_from_hhmm(tok);
if (latitudeHemi == 'S')
lat = -lat;
tok = longitude;
if (tok.p + 6 > tok.end) {
D("longitude is too short: '%.*s'", tok.end-tok.p, tok.p);
return -1;
}
lon = convert_from_hhmm(tok);
if (longitudeHemi == 'W')
lon = -lon;
r->fix.flags |= GPS_LOCATION_HAS_LAT_LONG;
r->fix.latitude = lat;
r->fix.longitude = lon;
return 0;
}
static int
nmea_reader_update_altitude( NmeaReader* r,
Token altitude,
Token units )
{
double alt;
Token tok = altitude;
if (tok.p >= tok.end)
return -1;
r->fix.flags |= GPS_LOCATION_HAS_ALTITUDE;
r->fix.altitude = str2float(tok.p, tok.end);
return 0;
}
static int
nmea_reader_update_bearing( NmeaReader* r,
Token bearing )
{
double alt;
Token tok = bearing;
if (tok.p >= tok.end)
return -1;
r->fix.flags |= GPS_LOCATION_HAS_BEARING;
r->fix.bearing = str2float(tok.p, tok.end);
return 0;
}
static int
nmea_reader_update_speed( NmeaReader* r,
Token speed )
{
double alt;
Token tok = speed;
if (tok.p >= tok.end)
return -1;
r->fix.flags |= GPS_LOCATION_HAS_SPEED;
r->fix.speed = str2float(tok.p, tok.end);
return 0;
}
static int
nmea_reader_update_accuracy( NmeaReader* r )
{
// Always return 20m accuracy.
// Possibly parse it from the NMEA sentence in the future.
r->fix.flags |= GPS_LOCATION_HAS_ACCURACY;
r->fix.accuracy = 20;
return 0;
}
static void
nmea_reader_parse( NmeaReader* r )
{
/* we received a complete sentence, now parse it to generate
* a new GPS fix...
*/
NmeaTokenizer tzer[1];
Token tok;
D("Received: '%.*s'", r->pos, r->in);
if (r->pos < 9) {
D("Too short. discarded.");
return;
}
nmea_tokenizer_init(tzer, r->in, r->in + r->pos);
#if GPS_DEBUG
{
int n;
D("Found %d tokens", tzer->count);
for (n = 0; n < tzer->count; n++) {
Token tok = nmea_tokenizer_get(tzer,n);
D("%2d: '%.*s'", n, tok.end-tok.p, tok.p);
}
}
#endif
tok = nmea_tokenizer_get(tzer, 0);
if (tok.p + 5 > tok.end) {
D("sentence id '%.*s' too short, ignored.", tok.end-tok.p, tok.p);
return;
}
// ignore first two characters.
tok.p += 2;
if ( !memcmp(tok.p, "GGA", 3) ) {
// GPS fix
Token tok_time = nmea_tokenizer_get(tzer,1);
Token tok_latitude = nmea_tokenizer_get(tzer,2);
Token tok_latitudeHemi = nmea_tokenizer_get(tzer,3);
Token tok_longitude = nmea_tokenizer_get(tzer,4);
Token tok_longitudeHemi = nmea_tokenizer_get(tzer,5);
Token tok_altitude = nmea_tokenizer_get(tzer,9);
Token tok_altitudeUnits = nmea_tokenizer_get(tzer,10);
nmea_reader_update_time(r, tok_time);
nmea_reader_update_latlong(r, tok_latitude,
tok_latitudeHemi.p[0],
tok_longitude,
tok_longitudeHemi.p[0]);
nmea_reader_update_altitude(r, tok_altitude, tok_altitudeUnits);
} else if ( !memcmp(tok.p, "GSA", 3) ) {
// do something ?
} else if ( !memcmp(tok.p, "RMC", 3) ) {
Token tok_time = nmea_tokenizer_get(tzer,1);
Token tok_fixStatus = nmea_tokenizer_get(tzer,2);
Token tok_latitude = nmea_tokenizer_get(tzer,3);
Token tok_latitudeHemi = nmea_tokenizer_get(tzer,4);
Token tok_longitude = nmea_tokenizer_get(tzer,5);
Token tok_longitudeHemi = nmea_tokenizer_get(tzer,6);
Token tok_speed = nmea_tokenizer_get(tzer,7);
Token tok_bearing = nmea_tokenizer_get(tzer,8);
Token tok_date = nmea_tokenizer_get(tzer,9);
D("in RMC, fixStatus=%c", tok_fixStatus.p[0]);
if (tok_fixStatus.p[0] == 'A')
{
nmea_reader_update_date( r, tok_date, tok_time );
nmea_reader_update_latlong( r, tok_latitude,
tok_latitudeHemi.p[0],
tok_longitude,
tok_longitudeHemi.p[0] );
nmea_reader_update_bearing( r, tok_bearing );
nmea_reader_update_speed ( r, tok_speed );
}
} else {
tok.p -= 2;
D("unknown sentence '%.*s", tok.end-tok.p, tok.p);
}
// Always update accuracy
nmea_reader_update_accuracy( r );
if (r->fix.flags != 0) {
#if GPS_DEBUG
char temp[256];
char* p = temp;
char* end = p + sizeof(temp);
struct tm utc;
p += snprintf( p, end-p, "sending fix" );
if (r->fix.flags & GPS_LOCATION_HAS_LAT_LONG) {
p += snprintf(p, end-p, " lat=%g lon=%g", r->fix.latitude, r->fix.longitude);
}
if (r->fix.flags & GPS_LOCATION_HAS_ALTITUDE) {
p += snprintf(p, end-p, " altitude=%g", r->fix.altitude);
}
if (r->fix.flags & GPS_LOCATION_HAS_SPEED) {
p += snprintf(p, end-p, " speed=%g", r->fix.speed);
}
if (r->fix.flags & GPS_LOCATION_HAS_BEARING) {
p += snprintf(p, end-p, " bearing=%g", r->fix.bearing);
}
if (r->fix.flags & GPS_LOCATION_HAS_ACCURACY) {
p += snprintf(p,end-p, " accuracy=%g", r->fix.accuracy);
}
gmtime_r( (time_t*) &r->fix.timestamp, &utc );
p += snprintf(p, end-p, " time=%s", asctime( &utc ) );
D(temp);
#endif
if (r->callback) {
r->callback( &r->fix );
r->fix.flags = 0;
}
else {
D("no callback, keeping data until needed !");
}
}
}
static void
nmea_reader_addc( NmeaReader* r, int c )
{
if (r->overflow) {
r->overflow = (c != '\n');
return;
}
if (r->pos >= (int) sizeof(r->in)-1 ) {
r->overflow = 1;
r->pos = 0;
return;
}
r->in[r->pos] = (char)c;
r->pos += 1;
if (c == '\n') {
nmea_reader_parse( r );
r->pos = 0;
}
}
/*****************************************************************/
/*****************************************************************/
/***** *****/
/***** C O N N E C T I O N S T A T E *****/
/***** *****/
/*****************************************************************/
/*****************************************************************/
/* commands sent to the gps thread */
enum {
CMD_QUIT = 0,
CMD_START = 1,
CMD_STOP = 2
};
/* this is the state of our connection to the qemu_gpsd daemon */
typedef struct {
int init;
int fd;
GpsCallbacks callbacks;
pthread_t thread;
int control[2];
} GpsState;
static GpsState _gps_state[1];
static void
gps_state_done( GpsState* s )
{
// tell the thread to quit, and wait for it
char cmd = CMD_QUIT;
void* dummy;
write( s->control[0], &cmd, 1 );
pthread_join(s->thread, &dummy);
// close the control socket pair
close( s->control[0] ); s->control[0] = -1;
close( s->control[1] ); s->control[1] = -1;
// close connection to the QEMU GPS daemon
close( s->fd ); s->fd = -1;
s->init = 0;
}
static void
gps_state_start( GpsState* s )
{
char cmd = CMD_START;
int ret;
do { ret=write( s->control[0], &cmd, 1 ); }
while (ret < 0 && errno == EINTR);
if (ret != 1)
D("%s: could not send CMD_START command: ret=%d: %s",
__FUNCTION__, ret, strerror(errno));
}
static void
gps_state_stop( GpsState* s )
{
char cmd = CMD_STOP;
int ret;
do { ret=write( s->control[0], &cmd, 1 ); }
while (ret < 0 && errno == EINTR);
if (ret != 1)
D("%s: could not send CMD_STOP command: ret=%d: %s",
__FUNCTION__, ret, strerror(errno));
}
static int
epoll_register( int epoll_fd, int fd )
{
struct epoll_event ev;
int ret, flags;
/* important: make the fd non-blocking */
flags = fcntl(fd, F_GETFL);
fcntl(fd, F_SETFL, flags | O_NONBLOCK);
ev.events = EPOLLIN;
ev.data.fd = fd;
do {
ret = epoll_ctl( epoll_fd, EPOLL_CTL_ADD, fd, &ev );
} while (ret < 0 && errno == EINTR);
return ret;
}
static int
epoll_deregister( int epoll_fd, int fd )
{
int ret;
do {
ret = epoll_ctl( epoll_fd, EPOLL_CTL_DEL, fd, NULL );
} while (ret < 0 && errno == EINTR);
return ret;
}
/* this is the main thread, it waits for commands from gps_state_start/stop and,
* when started, messages from the QEMU GPS daemon. these are simple NMEA sentences
* that must be parsed to be converted into GPS fixes sent to the framework
*/
static void
gps_state_thread( void* arg )
{
GpsState* state = (GpsState*) arg;
NmeaReader reader[1];
int epoll_fd = epoll_create(2);
int started = 0;
int gps_fd = state->fd;
int control_fd = state->control[1];
nmea_reader_init( reader );
// register control file descriptors for polling
epoll_register( epoll_fd, control_fd );
epoll_register( epoll_fd, gps_fd );
D("gps thread running");
// now loop
for (;;) {
struct epoll_event events[2];
int ne, nevents;
nevents = epoll_wait( epoll_fd, events, 2, -1 );
if (nevents < 0) {
if (errno != EINTR)
ALOGE("epoll_wait() unexpected error: %s", strerror(errno));
continue;
}
D("gps thread received %d events", nevents);
for (ne = 0; ne < nevents; ne++) {
if ((events[ne].events & (EPOLLERR|EPOLLHUP)) != 0) {
ALOGE("EPOLLERR or EPOLLHUP after epoll_wait() !?");
return;
}
if ((events[ne].events & EPOLLIN) != 0) {
int fd = events[ne].data.fd;
if (fd == control_fd)
{
char cmd = 255;
int ret;
D("gps control fd event");
do {
ret = read( fd, &cmd, 1 );
} while (ret < 0 && errno == EINTR);
if (cmd == CMD_QUIT) {
D("gps thread quitting on demand");
return;
}
else if (cmd == CMD_START) {
if (!started) {
D("gps thread starting location_cb=%p", state->callbacks.location_cb);
started = 1;
nmea_reader_set_callback( reader, state->callbacks.location_cb );
}
}
else if (cmd == CMD_STOP) {
if (started) {
D("gps thread stopping");
started = 0;
nmea_reader_set_callback( reader, NULL );
}
}
}
else if (fd == gps_fd)
{
char buff[32];
D("gps fd event");
for (;;) {
int nn, ret;
ret = read( fd, buff, sizeof(buff) );
if (ret < 0) {
if (errno == EINTR)
continue;
if (errno != EWOULDBLOCK)
ALOGE("error while reading from gps daemon socket: %s:", strerror(errno));
break;
}
D("received %d bytes: %.*s", ret, ret, buff);
for (nn = 0; nn < ret; nn++)
nmea_reader_addc( reader, buff[nn] );
}
D("gps fd event end");
}
else
{
ALOGE("epoll_wait() returned unkown fd %d ?", fd);
}
}
}
}
}
static void
gps_state_init( GpsState* state, GpsCallbacks* callbacks )
{
state->init = 1;
state->control[0] = -1;
state->control[1] = -1;
state->fd = -1;
state->fd = qemud_channel_open(QEMU_CHANNEL_NAME);
if (state->fd < 0) {
D("no gps emulation detected");
return;
}
D("gps emulation will read from '%s' qemud channel", QEMU_CHANNEL_NAME );
if ( socketpair( AF_LOCAL, SOCK_STREAM, 0, state->control ) < 0 ) {
ALOGE("could not create thread control socket pair: %s", strerror(errno));
goto Fail;
}
state->thread = callbacks->create_thread_cb( "gps_state_thread", gps_state_thread, state );
if ( !state->thread ) {
ALOGE("could not create gps thread: %s", strerror(errno));
goto Fail;
}
state->callbacks = *callbacks;
D("gps state initialized");
return;
Fail:
gps_state_done( state );
}
/*****************************************************************/
/*****************************************************************/
/***** *****/
/***** I N T E R F A C E *****/
/***** *****/
/*****************************************************************/
/*****************************************************************/
static int
qemu_gps_init(GpsCallbacks* callbacks)
{
GpsState* s = _gps_state;
if (!s->init)
gps_state_init(s, callbacks);
if (s->fd < 0)
return -1;
return 0;
}
static void
qemu_gps_cleanup(void)
{
GpsState* s = _gps_state;
if (s->init)
gps_state_done(s);
}
static int
qemu_gps_start()
{
GpsState* s = _gps_state;
if (!s->init) {
D("%s: called with uninitialized state !!", __FUNCTION__);
return -1;
}
D("%s: called", __FUNCTION__);
gps_state_start(s);
return 0;
}
static int
qemu_gps_stop()
{
GpsState* s = _gps_state;
if (!s->init) {
D("%s: called with uninitialized state !!", __FUNCTION__);
return -1;
}
D("%s: called", __FUNCTION__);
gps_state_stop(s);
return 0;
}
static int
qemu_gps_inject_time(GpsUtcTime time, int64_t timeReference, int uncertainty)
{
return 0;
}
static int
qemu_gps_inject_location(double latitude, double longitude, float accuracy)
{
return 0;
}
static void
qemu_gps_delete_aiding_data(GpsAidingData flags)
{
}
static int qemu_gps_set_position_mode(GpsPositionMode mode, int fix_frequency)
{
// FIXME - support fix_frequency
return 0;
}
static const void*
qemu_gps_get_extension(const char* name)
{
// no extensions supported
return NULL;
}
static const GpsInterface qemuGpsInterface = {
sizeof(GpsInterface),
qemu_gps_init,
qemu_gps_start,
qemu_gps_stop,
qemu_gps_cleanup,
qemu_gps_inject_time,
qemu_gps_inject_location,
qemu_gps_delete_aiding_data,
qemu_gps_set_position_mode,
qemu_gps_get_extension,
};
const GpsInterface* gps__get_gps_interface(struct gps_device_t* dev)
{
return &qemuGpsInterface;
}
static int open_gps(const struct hw_module_t* module, char const* name,
struct hw_device_t** device)
{
struct gps_device_t *dev = malloc(sizeof(struct gps_device_t));
memset(dev, 0, sizeof(*dev));
dev->common.tag = HARDWARE_DEVICE_TAG;
dev->common.version = 0;
dev->common.module = (struct hw_module_t*)module;
// dev->common.close = (int (*)(struct hw_device_t*))close_lights;
dev->get_gps_interface = gps__get_gps_interface;
*device = (struct hw_device_t*)dev;
return 0;
}
static struct hw_module_methods_t gps_module_methods = {
.open = open_gps
};
struct hw_module_t HAL_MODULE_INFO_SYM = {
.tag = HARDWARE_MODULE_TAG,
.version_major = 1,
.version_minor = 0,
.id = GPS_HARDWARE_MODULE_ID,
.name = "Goldfish GPS Module",
.author = "The Android Open Source Project",
.methods = &gps_module_methods,
};