/*
* 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 (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,
};