TYPE3
[iec.git] / src / type3_AndroidCloud / anbox-master / android / sensors / sensors_qemu.c
diff --git a/src/type3_AndroidCloud/anbox-master/android/sensors/sensors_qemu.c b/src/type3_AndroidCloud/anbox-master/android/sensors/sensors_qemu.c
new file mode 100644 (file)
index 0000000..b0e858c
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+/*
+ * Copyright (C) 2009 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 sensors hardware library for the Android emulator.
+ * the following code should be built as a shared library that will be
+ * placed into /system/lib/hw/sensors.goldfish.so
+ *
+ * it will be loaded by the code in hardware/libhardware/hardware.c
+ * which is itself called from com_android_server_SensorService.cpp
+ */
+
+
+/* we connect with the emulator through the "sensors" qemud service
+ */
+#define  SENSORS_SERVICE_NAME "sensors"
+
+#define LOG_TAG "QemuSensors"
+
+#include <unistd.h>
+#include <fcntl.h>
+#include <errno.h>
+#include <string.h>
+#include <cutils/log.h>
+#include <cutils/sockets.h>
+#include <hardware/sensors.h>
+
+#if 0
+#define  D(...)  ALOGD(__VA_ARGS__)
+#else
+#define  D(...)  ((void)0)
+#endif
+
+#define  E(...)  ALOGE(__VA_ARGS__)
+
+#include <hardware/qemud.h>
+
+/** SENSOR IDS AND NAMES
+ **/
+
+#define MAX_NUM_SENSORS 8
+
+#define SUPPORTED_SENSORS  ((1<<MAX_NUM_SENSORS)-1)
+
+#define  ID_BASE           SENSORS_HANDLE_BASE
+#define  ID_ACCELERATION   (ID_BASE+0)
+#define  ID_MAGNETIC_FIELD (ID_BASE+1)
+#define  ID_ORIENTATION    (ID_BASE+2)
+#define  ID_TEMPERATURE    (ID_BASE+3)
+#define  ID_PROXIMITY      (ID_BASE+4)
+#define  ID_LIGHT          (ID_BASE+5)
+#define  ID_PRESSURE       (ID_BASE+6)
+#define  ID_HUMIDITY       (ID_BASE+7)
+
+#define  SENSORS_ACCELERATION    (1 << ID_ACCELERATION)
+#define  SENSORS_MAGNETIC_FIELD  (1 << ID_MAGNETIC_FIELD)
+#define  SENSORS_ORIENTATION     (1 << ID_ORIENTATION)
+#define  SENSORS_TEMPERATURE     (1 << ID_TEMPERATURE)
+#define  SENSORS_PROXIMITY       (1 << ID_PROXIMITY)
+#define  SENSORS_LIGHT           (1 << ID_LIGHT)
+#define  SENSORS_PRESSURE        (1 << ID_PRESSURE)
+#define  SENSORS_HUMIDITY        (1 << ID_HUMIDITY)
+
+#define  ID_CHECK(x)  ((unsigned)((x) - ID_BASE) < MAX_NUM_SENSORS)
+
+#define  SENSORS_LIST  \
+    SENSOR_(ACCELERATION,"acceleration") \
+    SENSOR_(MAGNETIC_FIELD,"magnetic-field") \
+    SENSOR_(ORIENTATION,"orientation") \
+    SENSOR_(TEMPERATURE,"temperature") \
+    SENSOR_(PROXIMITY,"proximity") \
+    SENSOR_(LIGHT, "light") \
+    SENSOR_(PRESSURE, "pressure") \
+    SENSOR_(HUMIDITY, "humidity")
+
+static const struct {
+    const char*  name;
+    int          id; } _sensorIds[MAX_NUM_SENSORS] =
+{
+#define SENSOR_(x,y)  { y, ID_##x },
+    SENSORS_LIST
+#undef  SENSOR_
+};
+
+static const char*
+_sensorIdToName( int  id )
+{
+    int  nn;
+    for (nn = 0; nn < MAX_NUM_SENSORS; nn++)
+        if (id == _sensorIds[nn].id)
+            return _sensorIds[nn].name;
+    return "<UNKNOWN>";
+}
+
+static int
+_sensorIdFromName( const char*  name )
+{
+    int  nn;
+
+    if (name == NULL)
+        return -1;
+
+    for (nn = 0; nn < MAX_NUM_SENSORS; nn++)
+        if (!strcmp(name, _sensorIds[nn].name))
+            return _sensorIds[nn].id;
+
+    return -1;
+}
+
+/* return the current time in nanoseconds */
+static int64_t now_ns(void) {
+    struct timespec  ts;
+    clock_gettime(CLOCK_MONOTONIC, &ts);
+    return (int64_t)ts.tv_sec * 1000000000 + ts.tv_nsec;
+}
+
+/** SENSORS POLL DEVICE
+ **
+ ** This one is used to read sensor data from the hardware.
+ ** We implement this by simply reading the data from the
+ ** emulator through the QEMUD channel.
+ **/
+
+typedef struct SensorDevice {
+    struct sensors_poll_device_1  device;
+    sensors_event_t               sensors[MAX_NUM_SENSORS];
+    uint32_t                      pendingSensors;
+    int64_t                       timeStart;
+    int64_t                       timeOffset;
+    uint32_t                      active_sensors;
+    int                           fd;
+    pthread_mutex_t               lock;
+} SensorDevice;
+
+/* Grab the file descriptor to the emulator's sensors service pipe.
+ * This function returns a file descriptor on success, or -errno on
+ * failure, and assumes the SensorDevice instance's lock is held.
+ *
+ * This is needed because set_delay(), poll() and activate() can be called
+ * from different threads, and poll() is blocking.
+ *
+ * Note that the emulator's sensors service creates a new client for each
+ * connection through qemud_channel_open(), where each client has its own
+ * delay and set of activated sensors. This precludes calling
+ * qemud_channel_open() on each request, because a typical emulated system
+ * will do something like:
+ *
+ * 1) On a first thread, de-activate() all sensors first, then call poll(),
+ *    which results in the thread blocking.
+ *
+ * 2) On a second thread, slightly later, call set_delay() then activate()
+ *    to enable the acceleration sensor.
+ *
+ * The system expects this to unblock the first thread which will receive
+ * new sensor events after the activate() call in 2).
+ *
+ * This cannot work if both threads don't use the same connection.
+ *
+ * TODO(digit): This protocol is brittle, implement another control channel
+ *              for set_delay()/activate()/batch() when supporting HAL 1.3
+ */
+static int sensor_device_get_fd_locked(SensorDevice* dev) {
+    /* Create connection to service on first call */
+    if (dev->fd < 0) {
+        dev->fd = qemud_channel_open(SENSORS_SERVICE_NAME);
+        if (dev->fd < 0) {
+            int ret = -errno;
+            E("%s: Could not open connection to service: %s", __FUNCTION__,
+                strerror(-ret));
+            return ret;
+        }
+    }
+    return dev->fd;
+}
+
+/* Send a command to the sensors virtual device. |dev| is a device instance and
+ * |cmd| is a zero-terminated command string. Return 0 on success, or -errno
+ * on failure. */
+static int sensor_device_send_command_locked(SensorDevice* dev,
+                                             const char* cmd) {
+    int fd = sensor_device_get_fd_locked(dev);
+    if (fd < 0) {
+        return fd;
+    }
+
+    int ret = 0;
+    if (qemud_channel_send(fd, cmd, strlen(cmd)) < 0) {
+        ret = -errno;
+        E("%s(fd=%d): ERROR: %s", __FUNCTION__, fd, strerror(errno));
+    }
+    return ret;
+}
+
+/* Pick up one pending sensor event. On success, this returns the sensor
+ * id, and sets |*event| accordingly. On failure, i.e. if there are no
+ * pending events, return -EINVAL.
+ *
+ * Note: The device's lock must be acquired.
+ */
+static int sensor_device_pick_pending_event_locked(SensorDevice* d,
+                                                   sensors_event_t*  event)
+{
+    uint32_t mask = SUPPORTED_SENSORS & d->pendingSensors;
+    if (mask) {
+        uint32_t i = 31 - __builtin_clz(mask);
+        d->pendingSensors &= ~(1U << i);
+        *event = d->sensors[i];
+        event->sensor = i;
+        event->version = sizeof(*event);
+
+        D("%s: %d [%f, %f, %f]", __FUNCTION__,
+                i,
+                event->data[0],
+                event->data[1],
+                event->data[2]);
+        return i;
+    }
+    E("No sensor to return!!! pendingSensors=0x%08x", d->pendingSensors);
+    // we may end-up in a busy loop, slow things down, just in case.
+    usleep(100000);
+    return -EINVAL;
+}
+
+/* Block until new sensor events are reported by the emulator, or if a
+ * 'wake' command is received through the service. On succes, return 0
+ * and updates the |pendingEvents| and |sensors| fields of |dev|.
+ * On failure, return -errno.
+ *
+ * Note: The device lock must be acquired when calling this function, and
+ *       will still be held on return. However, the function releases the
+ *       lock temporarily during the blocking wait.
+ */
+static int sensor_device_poll_event_locked(SensorDevice* dev)
+{
+    D("%s: dev=%p", __FUNCTION__, dev);
+
+    int fd = sensor_device_get_fd_locked(dev);
+    if (fd < 0) {
+        E("%s: Could not get pipe channel: %s", __FUNCTION__, strerror(-fd));
+        return fd;
+    }
+
+    // Accumulate pending events into |events| and |new_sensors| mask
+    // until a 'sync' or 'wake' command is received. This also simplifies the
+    // code a bit.
+    uint32_t new_sensors = 0U;
+    sensors_event_t* events = dev->sensors;
+
+    int64_t event_time = -1;
+    int ret = 0;
+
+    for (;;) {
+        /* Release the lock since we're going to block on recv() */
+        pthread_mutex_unlock(&dev->lock);
+
+        /* read the next event */
+        char buff[256];
+        int len = qemud_channel_recv(fd, buff, sizeof(buff) - 1U);
+        /* re-acquire the lock to modify the device state. */
+        pthread_mutex_lock(&dev->lock);
+
+        if (len < 0) {
+            ret = -errno;
+            E("%s(fd=%d): Could not receive event data len=%d, errno=%d: %s",
+              __FUNCTION__, fd, len, errno, strerror(errno));
+            break;
+        }
+        buff[len] = 0;
+        D("%s(fd=%d): received [%s]", __FUNCTION__, fd, buff);
+
+
+        /* "wake" is sent from the emulator to exit this loop. */
+        /* TODO(digit): Is it still needed? */
+        if (!strcmp((const char*)buff, "wake")) {
+            ret = 0x7FFFFFFF;
+            break;
+        }
+
+        float params[3];
+
+        /* "acceleration:<x>:<y>:<z>" corresponds to an acceleration event */
+        if (sscanf(buff, "acceleration:%g:%g:%g", params+0, params+1, params+2)
+                == 3) {
+            new_sensors |= SENSORS_ACCELERATION;
+            events[ID_ACCELERATION].acceleration.x = params[0];
+            events[ID_ACCELERATION].acceleration.y = params[1];
+            events[ID_ACCELERATION].acceleration.z = params[2];
+            events[ID_ACCELERATION].type = SENSOR_TYPE_ACCELEROMETER;
+            continue;
+        }
+
+        /* "orientation:<azimuth>:<pitch>:<roll>" is sent when orientation
+         * changes */
+        if (sscanf(buff, "orientation:%g:%g:%g", params+0, params+1, params+2)
+                == 3) {
+            new_sensors |= SENSORS_ORIENTATION;
+            events[ID_ORIENTATION].orientation.azimuth = params[0];
+            events[ID_ORIENTATION].orientation.pitch   = params[1];
+            events[ID_ORIENTATION].orientation.roll    = params[2];
+            events[ID_ORIENTATION].orientation.status  =
+                    SENSOR_STATUS_ACCURACY_HIGH;
+            events[ID_ORIENTATION].type = SENSOR_TYPE_ORIENTATION;
+            continue;
+        }
+
+        /* "magnetic:<x>:<y>:<z>" is sent for the params of the magnetic
+         * field */
+        if (sscanf(buff, "magnetic:%g:%g:%g", params+0, params+1, params+2)
+                == 3) {
+            new_sensors |= SENSORS_MAGNETIC_FIELD;
+            events[ID_MAGNETIC_FIELD].magnetic.x = params[0];
+            events[ID_MAGNETIC_FIELD].magnetic.y = params[1];
+            events[ID_MAGNETIC_FIELD].magnetic.z = params[2];
+            events[ID_MAGNETIC_FIELD].magnetic.status =
+                    SENSOR_STATUS_ACCURACY_HIGH;
+            events[ID_MAGNETIC_FIELD].type = SENSOR_TYPE_MAGNETIC_FIELD;
+            continue;
+        }
+
+        /* "temperature:<celsius>" */
+        if (sscanf(buff, "temperature:%g", params+0) == 1) {
+            new_sensors |= SENSORS_TEMPERATURE;
+            events[ID_TEMPERATURE].temperature = params[0];
+            events[ID_TEMPERATURE].type = SENSOR_TYPE_TEMPERATURE;
+            continue;
+        }
+        /* "proximity:<value>" */
+        if (sscanf(buff, "proximity:%g", params+0) == 1) {
+            new_sensors |= SENSORS_PROXIMITY;
+            events[ID_PROXIMITY].distance = params[0];
+            events[ID_PROXIMITY].type = SENSOR_TYPE_PROXIMITY;
+            continue;
+        }
+        /* "light:<lux>" */
+        if (sscanf(buff, "light:%g", params+0) == 1) {
+            new_sensors |= SENSORS_LIGHT;
+            events[ID_LIGHT].light = params[0];
+            events[ID_LIGHT].type = SENSOR_TYPE_LIGHT;
+            continue;
+        }
+
+        /* "pressure:<hpa>" */
+        if (sscanf(buff, "pressure:%g", params+0) == 1) {
+            new_sensors |= SENSORS_PRESSURE;
+            events[ID_PRESSURE].pressure = params[0];
+            events[ID_PRESSURE].type = SENSOR_TYPE_PRESSURE;
+            continue;
+        }
+
+        /* "humidity:<percent>" */
+        if (sscanf(buff, "humidity:%g", params+0) == 1) {
+            new_sensors |= SENSORS_HUMIDITY;
+            events[ID_HUMIDITY].relative_humidity = params[0];
+            events[ID_HUMIDITY].type = SENSOR_TYPE_RELATIVE_HUMIDITY;
+            continue;
+        }
+
+        /* "sync:<time>" is sent after a series of sensor events.
+         * where 'time' is expressed in micro-seconds and corresponds
+         * to the VM time when the real poll occured.
+         */
+        if (sscanf(buff, "sync:%lld", &event_time) == 1) {
+            if (new_sensors) {
+                goto out;
+            }
+            D("huh ? sync without any sensor data ?");
+            continue;
+        }
+        D("huh ? unsupported command");
+    }
+out:
+    if (new_sensors) {
+        /* update the time of each new sensor event. */
+        dev->pendingSensors |= new_sensors;
+        int64_t t = (event_time < 0) ? 0 : event_time * 1000LL;
+
+        /* use the time at the first sync: as the base for later
+         * time values */
+        if (dev->timeStart == 0) {
+            dev->timeStart  = now_ns();
+            dev->timeOffset = dev->timeStart - t;
+        }
+        t += dev->timeOffset;
+
+        while (new_sensors) {
+            uint32_t i = 31 - __builtin_clz(new_sensors);
+            new_sensors &= ~(1U << i);
+            dev->sensors[i].timestamp = t;
+        }
+    }
+    return ret;
+}
+
+/** SENSORS POLL DEVICE FUNCTIONS **/
+
+static int sensor_device_close(struct hw_device_t* dev0)
+{
+    SensorDevice* dev = (void*)dev0;
+    // Assume that there are no other threads blocked on poll()
+    if (dev->fd >= 0) {
+        close(dev->fd);
+        dev->fd = -1;
+    }
+    pthread_mutex_destroy(&dev->lock);
+    free(dev);
+    return 0;
+}
+
+/* Return an array of sensor data. This function blocks until there is sensor
+ * related events to report. On success, it will write the events into the
+ * |data| array, which contains |count| items. The function returns the number
+ * of events written into the array, which shall never be greater than |count|.
+ * On error, return -errno code.
+ *
+ * Note that according to the sensor HAL [1], it shall never return 0!
+ *
+ * [1] http://source.android.com/devices/sensors/hal-interface.html
+ */
+static int sensor_device_poll(struct sensors_poll_device_t *dev0,
+                              sensors_event_t* data, int count)
+{
+    SensorDevice* dev = (void*)dev0;
+    D("%s: dev=%p data=%p count=%d ", __FUNCTION__, dev, data, count);
+
+    if (count <= 0) {
+        return -EINVAL;
+    }
+
+    int result = 0;
+    pthread_mutex_lock(&dev->lock);
+    if (!dev->pendingSensors) {
+        /* Block until there are pending events. Note that this releases
+         * the lock during the blocking call, then re-acquires it before
+         * returning. */
+        int ret = sensor_device_poll_event_locked(dev);
+        if (ret < 0) {
+            result = ret;
+            goto out;
+        }
+        if (!dev->pendingSensors) {
+            /* 'wake' event received before any sensor data. */
+            result = -EIO;
+            goto out;
+        }
+    }
+    /* Now read as many pending events as needed. */
+    int i;
+    for (i = 0; i < count; i++)  {
+        if (!dev->pendingSensors) {
+            break;
+        }
+        int ret = sensor_device_pick_pending_event_locked(dev, data);
+        if (ret < 0) {
+            if (!result) {
+                result = ret;
+            }
+            break;
+        }
+        data++;
+        result++;
+    }
+out:
+    pthread_mutex_unlock(&dev->lock);
+    D("%s: result=%d", __FUNCTION__, result);
+    return result;
+}
+
+static int sensor_device_activate(struct sensors_poll_device_t *dev0,
+                                  int handle,
+                                  int enabled)
+{
+    SensorDevice* dev = (void*)dev0;
+
+    D("%s: handle=%s (%d) enabled=%d", __FUNCTION__,
+        _sensorIdToName(handle), handle, enabled);
+
+    /* Sanity check */
+    if (!ID_CHECK(handle)) {
+        E("%s: bad handle ID", __FUNCTION__);
+        return -EINVAL;
+    }
+
+    /* Exit early if sensor is already enabled/disabled. */
+    uint32_t mask = (1U << handle);
+    uint32_t sensors = enabled ? mask : 0;
+
+    pthread_mutex_lock(&dev->lock);
+
+    uint32_t active = dev->active_sensors;
+    uint32_t new_sensors = (active & ~mask) | (sensors & mask);
+    uint32_t changed = active ^ new_sensors;
+
+    int ret = 0;
+    if (changed) {
+        /* Send command to the emulator. */
+        char command[64];
+        snprintf(command,
+                 sizeof command,
+                 "set:%s:%d",
+                 _sensorIdToName(handle),
+                 enabled != 0);
+
+        ret = sensor_device_send_command_locked(dev, command);
+        if (ret < 0) {
+            E("%s: when sending command errno=%d: %s", __FUNCTION__, -ret,
+              strerror(-ret));
+        } else {
+            dev->active_sensors = new_sensors;
+        }
+    }
+    pthread_mutex_unlock(&dev->lock);
+    return ret;
+}
+
+static int sensor_device_set_delay(struct sensors_poll_device_t *dev0,
+                                   int handle __unused,
+                                   int64_t ns)
+{
+    SensorDevice* dev = (void*)dev0;
+
+    int ms = (int)(ns / 1000000);
+    D("%s: dev=%p delay-ms=%d", __FUNCTION__, dev, ms);
+
+    char command[64];
+    snprintf(command, sizeof command, "set-delay:%d", ms);
+
+    pthread_mutex_lock(&dev->lock);
+    int ret = sensor_device_send_command_locked(dev, command);
+    pthread_mutex_unlock(&dev->lock);
+    if (ret < 0) {
+        E("%s: Could not send command: %s", __FUNCTION__, strerror(-ret));
+    }
+    return ret;
+}
+
+/** MODULE REGISTRATION SUPPORT
+ **
+ ** This is required so that hardware/libhardware/hardware.c
+ ** will dlopen() this library appropriately.
+ **/
+
+/*
+ * the following is the list of all supported sensors.
+ * this table is used to build sSensorList declared below
+ * according to which hardware sensors are reported as
+ * available from the emulator (see get_sensors_list below)
+ *
+ * note: numerical values for maxRange/resolution/power for
+ *       all sensors but light, pressure and humidity were
+ *       taken from the reference AK8976A implementation
+ */
+static const struct sensor_t sSensorListInit[] = {
+        { .name       = "Goldfish 3-axis Accelerometer",
+          .vendor     = "The Android Open Source Project",
+          .version    = 1,
+          .handle     = ID_ACCELERATION,
+          .type       = SENSOR_TYPE_ACCELEROMETER,
+          .maxRange   = 2.8f,
+          .resolution = 1.0f/4032.0f,
+          .power      = 3.0f,
+          .reserved   = {}
+        },
+
+        { .name       = "Goldfish 3-axis Magnetic field sensor",
+          .vendor     = "The Android Open Source Project",
+          .version    = 1,
+          .handle     = ID_MAGNETIC_FIELD,
+          .type       = SENSOR_TYPE_MAGNETIC_FIELD,
+          .maxRange   = 2000.0f,
+          .resolution = 1.0f,
+          .power      = 6.7f,
+          .reserved   = {}
+        },
+
+        { .name       = "Goldfish Orientation sensor",
+          .vendor     = "The Android Open Source Project",
+          .version    = 1,
+          .handle     = ID_ORIENTATION,
+          .type       = SENSOR_TYPE_ORIENTATION,
+          .maxRange   = 360.0f,
+          .resolution = 1.0f,
+          .power      = 9.7f,
+          .reserved   = {}
+        },
+
+        { .name       = "Goldfish Temperature sensor",
+          .vendor     = "The Android Open Source Project",
+          .version    = 1,
+          .handle     = ID_TEMPERATURE,
+          .type       = SENSOR_TYPE_TEMPERATURE,
+          .maxRange   = 80.0f,
+          .resolution = 1.0f,
+          .power      = 0.0f,
+          .reserved   = {}
+        },
+
+        { .name       = "Goldfish Proximity sensor",
+          .vendor     = "The Android Open Source Project",
+          .version    = 1,
+          .handle     = ID_PROXIMITY,
+          .type       = SENSOR_TYPE_PROXIMITY,
+          .maxRange   = 1.0f,
+          .resolution = 1.0f,
+          .power      = 20.0f,
+          .reserved   = {}
+        },
+
+        { .name       = "Goldfish Light sensor",
+          .vendor     = "The Android Open Source Project",
+          .version    = 1,
+          .handle     = ID_LIGHT,
+          .type       = SENSOR_TYPE_LIGHT,
+          .maxRange   = 40000.0f,
+          .resolution = 1.0f,
+          .power      = 20.0f,
+          .reserved   = {}
+        },
+
+        { .name       = "Goldfish Pressure sensor",
+          .vendor     = "The Android Open Source Project",
+          .version    = 1,
+          .handle     = ID_PRESSURE,
+          .type       = SENSOR_TYPE_PRESSURE,
+          .maxRange   = 800.0f,
+          .resolution = 1.0f,
+          .power      = 20.0f,
+          .reserved   = {}
+        },
+
+        { .name       = "Goldfish Humidity sensor",
+          .vendor     = "The Android Open Source Project",
+          .version    = 1,
+          .handle     = ID_HUMIDITY,
+          .type       = SENSOR_TYPE_RELATIVE_HUMIDITY,
+          .maxRange   = 100.0f,
+          .resolution = 1.0f,
+          .power      = 20.0f,
+          .reserved   = {}
+        }
+};
+
+static struct sensor_t  sSensorList[MAX_NUM_SENSORS];
+
+static int sensors__get_sensors_list(struct sensors_module_t* module __unused,
+        struct sensor_t const** list)
+{
+    int  fd = qemud_channel_open(SENSORS_SERVICE_NAME);
+    char buffer[12];
+    int  mask, nn, count;
+    int  ret = 0;
+
+    if (fd < 0) {
+        E("%s: no qemud connection", __FUNCTION__);
+        goto out;
+    }
+    ret = qemud_channel_send(fd, "list-sensors", -1);
+    if (ret < 0) {
+        E("%s: could not query sensor list: %s", __FUNCTION__,
+          strerror(errno));
+        goto out;
+    }
+    ret = qemud_channel_recv(fd, buffer, sizeof buffer-1);
+    if (ret < 0) {
+        E("%s: could not receive sensor list: %s", __FUNCTION__,
+          strerror(errno));
+        goto out;
+    }
+    buffer[ret] = 0;
+
+    /* the result is a integer used as a mask for available sensors */
+    mask  = atoi(buffer);
+    count = 0;
+    for (nn = 0; nn < MAX_NUM_SENSORS; nn++) {
+        if (((1 << nn) & mask) == 0)
+            continue;
+
+        sSensorList[count++] = sSensorListInit[nn];
+    }
+    D("%s: returned %d sensors (mask=%d)", __FUNCTION__, count, mask);
+    *list = sSensorList;
+
+    ret = count;
+out:
+    if (fd >= 0) {
+        close(fd);
+    }
+    return ret;
+}
+
+
+static int
+open_sensors(const struct hw_module_t* module,
+             const char*               name,
+             struct hw_device_t*      *device)
+{
+    int  status = -EINVAL;
+
+    D("%s: name=%s", __FUNCTION__, name);
+
+    if (!strcmp(name, SENSORS_HARDWARE_POLL)) {
+        SensorDevice *dev = malloc(sizeof(*dev));
+
+        memset(dev, 0, sizeof(*dev));
+
+        dev->device.common.tag     = HARDWARE_DEVICE_TAG;
+        dev->device.common.version = SENSORS_DEVICE_API_VERSION_1_0;
+        dev->device.common.module  = (struct hw_module_t*) module;
+        dev->device.common.close   = sensor_device_close;
+        dev->device.poll           = sensor_device_poll;
+        dev->device.activate       = sensor_device_activate;
+        dev->device.setDelay       = sensor_device_set_delay;
+
+        dev->fd = -1;
+        pthread_mutex_init(&dev->lock, NULL);
+
+        *device = &dev->device.common;
+        status  = 0;
+    }
+    return status;
+}
+
+
+static struct hw_module_methods_t sensors_module_methods = {
+    .open = open_sensors
+};
+
+struct sensors_module_t HAL_MODULE_INFO_SYM = {
+    .common = {
+        .tag = HARDWARE_MODULE_TAG,
+        .version_major = 1,
+        .version_minor = 0,
+        .id = SENSORS_HARDWARE_MODULE_ID,
+        .name = "Goldfish SENSORS Module",
+        .author = "The Android Open Source Project",
+        .methods = &sensors_module_methods,
+    },
+    .get_sensors_list = sensors__get_sensors_list
+};