Add vehicle hal.

- vehicle hal is used for supporting car specific features.
- Each property can be written (=set), read (=get), or subscribed.
- Each property has configuration informaiton to tell what that property
  is and how it can be accessed.
- also adding dummy hal implementation.

bug: 25183740

Change-Id: Ib1cc1c11540f156db73552f2a18a8efb361002af
diff --git a/modules/Android.mk b/modules/Android.mk
index 9f7e5f0..4f30d3c 100644
--- a/modules/Android.mk
+++ b/modules/Android.mk
@@ -1,4 +1,4 @@
 hardware_modules := gralloc hwcomposer audio nfc nfc-nci local_time \
 	power usbaudio audio_remote_submix camera usbcamera consumerir sensors vibrator \
-	tv_input fingerprint input
+	tv_input fingerprint input vehicle
 include $(call all-named-subdir-makefiles,$(hardware_modules))
diff --git a/modules/vehicle/Android.mk b/modules/vehicle/Android.mk
new file mode 100644
index 0000000..a666bc6
--- /dev/null
+++ b/modules/vehicle/Android.mk
@@ -0,0 +1,28 @@
+# Copyright (C) 2012 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.
+
+LOCAL_PATH := $(call my-dir)
+
+include $(CLEAR_VARS)
+
+LOCAL_MODULE := vehicle.default
+
+LOCAL_MODULE_RELATIVE_PATH := hw
+LOCAL_C_INCLUDES := hardware/libhardware
+LOCAL_SRC_FILES := vehicle.c timeUtil.cpp
+LOCAL_SHARED_LIBRARIES := liblog libcutils libutils
+LOCAL_MODULE_TAGS := optional
+
+include $(BUILD_SHARED_LIBRARY)
+
diff --git a/modules/vehicle/timeUtil.cpp b/modules/vehicle/timeUtil.cpp
new file mode 100644
index 0000000..fb27dad
--- /dev/null
+++ b/modules/vehicle/timeUtil.cpp
@@ -0,0 +1,24 @@
+/*
+ * Copyright (C) 2015 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.
+ */
+
+#include <stdint.h>
+#include <utils/SystemClock.h>
+
+extern "C" {
+    int64_t elapsedRealtimeNano() {
+        return android::elapsedRealtimeNano();
+    }
+}
diff --git a/modules/vehicle/vehicle.c b/modules/vehicle/vehicle.c
new file mode 100644
index 0000000..b5ea444
--- /dev/null
+++ b/modules/vehicle/vehicle.c
@@ -0,0 +1,564 @@
+/*
+ * Copyright (C) 2015 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.
+ */
+
+#define LOG_TAG "vehicle_hw_default"
+#define LOG_NDEBUG 1
+#define RADIO_PRESET_NUM 6
+
+#include <errno.h>
+#include <malloc.h>
+#include <pthread.h>
+#include <stdint.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/prctl.h>
+#include <sys/time.h>
+#include <time.h>
+
+#include <cutils/log.h>
+#include <system/radio.h>
+#include <hardware/hardware.h>
+#include <hardware/vehicle.h>
+
+extern int64_t elapsedRealtimeNano();
+
+static char VEHICLE_MAKE[] = "android_car";
+
+typedef struct vehicle_device_impl {
+    vehicle_hw_device_t vehicle_device;
+    uint32_t initialized_;
+    vehicle_event_callback_fn event_fn_;
+    vehicle_error_callback_fn error_fn_;
+} vehicle_device_impl_t ;
+
+static pthread_mutex_t lock_;
+
+typedef struct subscription {
+    // Each subscription has it's own thread.
+    pthread_t thread_id;
+    int32_t prop;
+    float sample_rate;
+    pthread_mutex_t lock;
+    // This field should be protected by the above mutex.
+    // TODO change this to something better as flag alone takes long time to finish.
+    uint32_t stop_thread;
+    vehicle_device_impl_t* impl;
+    pthread_t thread;
+    pthread_cond_t cond;
+    char name[100];
+} subscription_t;
+
+static vehicle_prop_config_t CONFIGS[] = {
+    {
+        .prop = VEHICLE_PROPERTY_INFO_MAKE,
+        .access = VEHICLE_PROP_ACCESS_READ,
+        .change_mode = VEHICLE_PROP_CHANGE_MODE_STATIC,
+        .value_type = VEHICLE_VALUE_TYPE_STRING,
+        .min_sample_rate = 0,
+        .max_sample_rate = 0,
+        .hal_data = NULL,
+    },
+    {
+        .prop = VEHICLE_PROPERTY_GEAR_SELECTION,
+        .access = VEHICLE_PROP_ACCESS_READ,
+        .change_mode = VEHICLE_PROP_CHANGE_MODE_ON_CHANGE,
+        .value_type = VEHICLE_VALUE_TYPE_INT32,
+        .min_sample_rate = 0,
+        .max_sample_rate = 0,
+        .hal_data = NULL,
+    },
+    {
+        .prop = VEHICLE_PROPERTY_DRIVING_STATUS,
+        .access = VEHICLE_PROP_ACCESS_READ,
+        .change_mode = VEHICLE_PROP_CHANGE_MODE_ON_CHANGE,
+        .value_type = VEHICLE_VALUE_TYPE_INT32,
+        .min_sample_rate = 0,
+        .max_sample_rate = 0,
+        .hal_data = NULL,
+    },
+    {
+        .prop = VEHICLE_PROPERTY_PARKING_BRAKE_ON,
+        .access = VEHICLE_PROP_ACCESS_READ,
+        .change_mode = VEHICLE_PROP_CHANGE_MODE_ON_CHANGE,
+        .value_type = VEHICLE_VALUE_TYPE_BOOLEAN,
+        .min_sample_rate = 0,
+        .max_sample_rate = 0,
+        .hal_data = NULL,
+    },
+    {
+        .prop = VEHICLE_PROPERTY_PERF_VEHICLE_SPEED,
+        .access = VEHICLE_PROP_ACCESS_READ,
+        .change_mode = VEHICLE_PROP_CHANGE_MODE_CONTINUOUS,
+        .value_type = VEHICLE_VALUE_TYPE_FLOAT,
+        .min_sample_rate = 0.1,
+        .max_sample_rate = 10.0,
+        .hal_data = NULL,
+    },
+    {
+        .prop = VEHICLE_PROPERTY_RADIO_PRESET,
+        .access = VEHICLE_PROP_ACCESS_READ_WRITE,
+        .change_mode = VEHICLE_PROP_CHANGE_MODE_ON_CHANGE,
+        .value_type = VEHICLE_VALUE_TYPE_INT32_VEC4,
+        .vehicle_radio_num_presets = RADIO_PRESET_NUM,
+        .min_sample_rate = 0,
+        .max_sample_rate = 0,
+        .hal_data = NULL,
+    },
+};
+
+vehicle_prop_config_t* find_config(int prop) {
+    int i;
+    for (i = 0; i < sizeof(CONFIGS) / sizeof(vehicle_prop_config_t); i++) {
+        if (CONFIGS[i].prop == prop) {
+            return &CONFIGS[i];
+        }
+    }
+    return NULL;
+}
+
+static int alloc_vehicle_str_from_cstr(const char* string, vehicle_str_t* vehicle_str) {
+    int len = strlen(string);
+    vehicle_str->data = (uint8_t*) malloc(len);
+    if (vehicle_str->data == NULL) {
+        return -ENOMEM;
+    }
+    memcpy(vehicle_str->data, string, len);
+    vehicle_str->len = len;
+    return 0;
+}
+
+static vehicle_prop_config_t const * vdev_list_properties(vehicle_hw_device_t* device,
+        int* num_properties) {
+    ALOGD("vdev_list_properties.");
+
+    *num_properties = sizeof(CONFIGS) / sizeof(vehicle_prop_config_t);
+    return CONFIGS;
+}
+
+static int vdev_init(vehicle_hw_device_t* device,
+                     vehicle_event_callback_fn event_callback_fn,
+                     vehicle_error_callback_fn error_callback_fn) {
+    ALOGD("vdev_init.");
+    vehicle_device_impl_t* impl = (vehicle_device_impl_t*)device;
+    pthread_mutex_lock(&lock_);
+    if (impl->initialized_) {
+        ALOGE("vdev_init: Callback and Error functions are already existing.");
+        pthread_mutex_unlock(&lock_);
+        return -EEXIST;
+    }
+
+    impl->initialized_ = 1;
+    impl->event_fn_ = event_callback_fn;
+    impl->error_fn_ = error_callback_fn;
+    pthread_mutex_unlock(&lock_);
+    return 0;
+}
+
+static int vdev_release(vehicle_hw_device_t* device) {
+    vehicle_device_impl_t* impl = (vehicle_device_impl_t*)device;
+    pthread_mutex_lock(&lock_);
+    if (!impl->initialized_) {
+        ALOGD("vdev_release: Already released before, returning early.");
+    } else {
+        // unsubscribe_all()
+        impl->initialized_ = 0;
+    }
+    pthread_mutex_unlock(&lock_);
+    return 0;
+}
+
+static int vdev_get(vehicle_hw_device_t* device, vehicle_prop_value_t* data) {
+    ALOGD("vdev_get.");
+    //TODO all data supporting read should support get
+    if (!data) {
+        ALOGE("vdev_get: Data cannot be null.");
+        return -EINVAL;
+    }
+    vehicle_prop_config_t* config = find_config(data->prop);
+    if (config == NULL) {
+        ALOGE("vdev_get: cannot find config 0x%x", data->prop);
+        return -EINVAL;
+    }
+    data->value_type = config->value_type;
+    // for STATIC type, time can be just 0 instead
+    data->timestamp = elapsedRealtimeNano();
+    int r;
+    switch (data->prop) {
+        case VEHICLE_PROPERTY_INFO_MAKE:
+            r = alloc_vehicle_str_from_cstr(VEHICLE_MAKE, &(data->value.str_value));
+            if (r != 0) {
+                ALOGE("vdev_get: alloc failed");
+                return r;
+            }
+            break;
+
+        case VEHICLE_PROPERTY_RADIO_PRESET: {
+              int radio_preset = data->value.int32_array[0];
+              if (radio_preset < VEHICLE_RADIO_PRESET_MIN_VALUE ||
+                  radio_preset >= RADIO_PRESET_NUM) {
+                  ALOGE("%s Invalid radio preset: %d\n", __func__, radio_preset);
+                  return -1;
+              }
+              ALOGD("%s Radio Preset number: %d", __func__, radio_preset);
+              int32_t selector = radio_preset % 2 == 0;
+              // Populate the channel and subchannel to be some variation of the
+              // preset number for mocking.
+
+              // Restore the preset number.
+              data->value.int32_array[0] = radio_preset;
+              // Channel type values taken from
+              // system/core/include/system/radio.h
+              data->value.int32_array[1] = selector ? RADIO_BAND_FM : RADIO_BAND_AM;
+              // For FM set a value in Mhz and for AM set a value in Khz range
+              // (channel).
+              data->value.int32_array[2] = selector ? 99000000 : 100000;
+              // For FM we have a sub-channel and we care about it, for AM pass
+              // a dummy value.
+              data->value.int32_array[3] = selector ? radio_preset : -1;
+              break;
+        }
+
+        default:
+            // actual implementation will be much complex than this. It should track proper last
+            // state. Here just fill with zero.
+            memset(&(data->value), 0, sizeof(data->value));
+            break;
+    }
+    ALOGI("vdev_get, type 0x%x, time %ld, value_type %d", data->prop, data->timestamp,
+            data->value_type);
+    return 0;
+}
+
+static int vdev_set(vehicle_hw_device_t* device, const vehicle_prop_value_t* data) {
+    ALOGD("vdev_set.");
+    // Just print what data will be setting here.
+    ALOGD("Setting property %d with value type %d\n", data->prop, data->value_type);
+    vehicle_prop_config_t* config = find_config(data->prop);
+    if (config == NULL) {
+        ALOGE("vdev_set: cannot find config 0x%x", data->prop);
+        return -EINVAL;
+    }
+    if (config->value_type != data->value_type) {
+        ALOGE("vdev_set: type mismatch, passed 0x%x expecting 0x%x", data->value_type,
+                config->value_type);
+        return -EINVAL;
+    }
+    switch (data->value_type) {
+        case VEHICLE_VALUE_TYPE_FLOAT:
+            ALOGD("Value type: FLOAT\nValue: %f\n", data->value.float_value);
+            break;
+        case VEHICLE_VALUE_TYPE_INT32:
+            ALOGD("Value type: INT32\nValue: %d\n", data->value.int32_value);
+            break;
+        case VEHICLE_VALUE_TYPE_INT64:
+            ALOGD("Value type: INT64\nValue: %lld\n", data->value.int64_value);
+            break;
+        case VEHICLE_VALUE_TYPE_BOOLEAN:
+            ALOGD("Value type: BOOLEAN\nValue: %d\n", data->value.boolean_value);
+            break;
+        case VEHICLE_VALUE_TYPE_STRING:
+            ALOGD("Value type: STRING\n Size: %d\n", data->value.str_value.len);
+            // NOTE: We only handle ASCII strings here.
+            // Print the UTF-8 string.
+            char *ascii_out = (char *) malloc ((data->value.str_value.len + 1) * sizeof (char));
+            memcpy(ascii_out, data->value.str_value.data, data->value.str_value.len);
+            ascii_out[data->value.str_value.len] = '\0';
+            ALOGD("Value: %s\n", ascii_out);
+            break;
+        case VEHICLE_VALUE_TYPE_INT32_VEC4:
+            ALOGD("Value type: INT32_VEC4\nValue[0]: %d Value[1] %d Value[2] %d Value[3] %d",
+                  data->value.int32_array[0], data->value.int32_array[1],
+                  data->value.int32_array[2], data->value.int32_array[3]);
+            break;
+        default:
+            ALOGD("Value type not yet handled: %d.\n", data->value_type);
+    }
+    return 0;
+}
+
+void print_subscribe_info(vehicle_device_impl_t* impl) {
+    char buf[100];
+    int i;
+    for (i = 0; i < sizeof(CONFIGS) / sizeof(vehicle_prop_config_t); i++) {
+        subscription_t* sub = (subscription_t*)CONFIGS[i].hal_data;
+        if (sub != NULL) {
+            sprintf(buf, "prop: %d rate: %f", sub->prop, sub->sample_rate);
+            ALOGD(buf);
+        }
+    }
+}
+
+// This should be run in a separate thread always.
+void fake_event_thread(struct subscription *sub) {
+    if (!sub) {
+        ALOGE("oops! subscription object cannot be NULL.");
+        exit(-1);
+    }
+    prctl(PR_SET_NAME, (unsigned long)sub->name, 0, 0, 0);
+    // Emit values in a loop, every 2 seconds.
+    while (1) {
+        // Create a random value depending on the property type.
+        vehicle_prop_value_t event;
+        event.prop = sub->prop;
+        event.timestamp = elapsedRealtimeNano();
+        switch (sub->prop) {
+            case VEHICLE_PROPERTY_DRIVING_STATUS:
+                event.value_type = VEHICLE_VALUE_TYPE_INT32;
+                switch ((event.timestamp & 0x30000000)>>28) {
+                    case 0:
+                        event.value.driving_status = VEHICLE_DRIVING_STATUS_UNRESTRICTED;
+                        break;
+                    case 1:
+                        event.value.driving_status = VEHICLE_DRIVING_STATUS_NO_VIDEO;
+                        break;
+                    case 2:
+                        event.value.driving_status = VEHICLE_DRIVING_STATUS_NO_KEYBOARD_INPUT;
+                        break;
+                    default:
+                        event.value.driving_status = VEHICLE_DRIVING_STATUS_NO_CONFIG;
+                }
+                break;
+            case VEHICLE_PROPERTY_GEAR_SELECTION:
+                event.value_type = VEHICLE_VALUE_TYPE_INT32;
+                switch ((event.timestamp & 0x30000000)>>28) {
+                    case 0:
+                        event.value.gear_selection = VEHICLE_GEAR_PARKING;
+                        break;
+                    case 1:
+                        event.value.gear_selection = VEHICLE_GEAR_NEUTRAL;
+                        break;
+                    case 2:
+                        event.value.gear_selection = VEHICLE_GEAR_DRIVE;
+                        break;
+                    case 3:
+                        event.value.gear_selection = VEHICLE_GEAR_REVERSE;
+                        break;
+                }
+                break;
+            case VEHICLE_PROPERTY_PARKING_BRAKE_ON:
+                event.value_type = VEHICLE_VALUE_TYPE_BOOLEAN;
+                if (event.timestamp & 0x20000000) {
+                    event.value.parking_brake = VEHICLE_FALSE;
+                } else {
+                    event.value.parking_brake = VEHICLE_TRUE;
+                }
+                break;
+            case VEHICLE_PROPERTY_PERF_VEHICLE_SPEED:
+                event.value_type = VEHICLE_VALUE_TYPE_FLOAT;
+                event.value.vehicle_speed = (float) ((event.timestamp & 0xff000000)>>24);
+                break;
+            case VEHICLE_PROPERTY_RADIO_PRESET:
+                event.value_type = VEHICLE_VALUE_TYPE_INT32_VEC4;
+                int presetInfo1[4] = {1  /* preset number */, 0  /* AM Band */, 1000, 0};
+                int presetInfo2[4] = {2  /* preset number */, 1  /* FM Band */, 1000, 0};
+                if (event.timestamp & 0x20000000) {
+                    memcpy(event.value.int32_array, presetInfo1, sizeof(presetInfo1));
+                } else {
+                    memcpy(event.value.int32_array, presetInfo2, sizeof(presetInfo2));
+                }
+                break;
+            default: // unsupported
+                if (sub->impl->error_fn_ != NULL) {
+                    sub->impl->error_fn_(VEHICLE_ERROR_UNKNOWN, VEHICLE_PROPERTY_INVALID,
+                            VEHICLE_OPERATION_GENERIC);
+                } else {
+                    ALOGE("Error function is null");
+                }
+                ALOGE("Unsupported prop 0x%x, quit", sub->prop);
+                return;
+        }
+        if (sub->impl->event_fn_ != NULL) {
+            sub->impl->event_fn_(&event);
+        } else {
+            ALOGE("Event function is null");
+            return;
+        }
+        pthread_mutex_lock(&sub->lock);
+        if (sub->stop_thread) {
+            ALOGD("exiting subscription request here.");
+            // Do any cleanup here.
+            pthread_mutex_unlock(&sub->lock);
+            return 0;
+        }
+        struct timespec now;
+        clock_gettime(CLOCK_REALTIME, &now);
+        now.tv_sec += 1; // sleep for one sec
+        pthread_cond_timedwait(&sub->cond, &sub->lock, &now);
+        pthread_mutex_unlock(&sub->lock);
+    }
+}
+
+static int vdev_subscribe(vehicle_hw_device_t* device, int32_t prop, float sample_rate) {
+    ALOGD("vdev_subscribe 0x%x, %f", prop, sample_rate);
+    vehicle_device_impl_t* impl = (vehicle_device_impl_t*)device;
+    // Check that the device is initialized.
+    pthread_mutex_lock(&lock_);
+    if (!impl->initialized_) {
+        pthread_mutex_unlock(&lock_);
+        ALOGE("vdev_subscribe: have you called init()?");
+        return -EINVAL;
+    }
+    vehicle_prop_config_t* config = find_config(prop);
+    if (config == NULL) {
+        pthread_mutex_unlock(&lock_);
+        ALOGE("vdev_subscribe not supported property 0x%x", prop);
+        return -EINVAL;
+    }
+    if ((config->access != VEHICLE_PROP_ACCESS_READ) &&
+        (config->access != VEHICLE_PROP_ACCESS_READ_WRITE)) {
+        pthread_mutex_unlock(&lock_);
+        ALOGE("vdev_subscribe read not supported on the property 0x%x", prop);
+        return -EINVAL;
+    }
+    if (config->change_mode == VEHICLE_PROP_CHANGE_MODE_STATIC) {
+        pthread_mutex_unlock(&lock_);
+        ALOGE("vdev_subscribe cannot subscribe static property 0x%x", prop);
+        return -EINVAL;
+    }
+    if ((config->change_mode == VEHICLE_PROP_CHANGE_MODE_ON_CHANGE) && (sample_rate != 0)) {
+        pthread_mutex_unlock(&lock_);
+        ALOGE("vdev_subscribe on change type should have 0 sample rate, property 0x%x, sample rate %f",
+                prop, sample_rate);
+        return -EINVAL;
+    }
+    if ((config->max_sample_rate < sample_rate) || (config->min_sample_rate > sample_rate)) {
+
+        ALOGE("vdev_subscribe property 0x%x, invalid sample rate %f, min:%f, max:%f",
+                prop, sample_rate, config->min_sample_rate, config->max_sample_rate);
+        pthread_mutex_unlock(&lock_);
+        return -EINVAL;
+    }
+    subscription_t* sub = (subscription_t*)config->hal_data;
+    if (sub == NULL) {
+        sub = calloc(1, sizeof(subscription_t));
+        sub->prop = prop;
+        sub->sample_rate = sample_rate;
+        sub->stop_thread = 0;
+        sub->impl = impl;
+        pthread_mutex_init(&sub->lock, NULL);
+        pthread_cond_init(&sub->cond, NULL);
+        config->hal_data = sub;
+        sprintf(sub->name, "vhal0x%x", prop);
+    } else if (sub->sample_rate != sample_rate){ // sample rate changed
+        //TODO notify this to fake sensor thread
+        sub->sample_rate = sample_rate;
+        pthread_mutex_unlock(&lock_);
+        return 0;
+    }
+    int ret_code = pthread_create(
+        &sub->thread, NULL, fake_event_thread, sub);
+    print_subscribe_info(impl);
+    pthread_mutex_unlock(&lock_);
+    return 0;
+}
+
+static int vdev_unsubscribe(vehicle_hw_device_t* device, int32_t prop) {
+    ALOGD("vdev_unsubscribe 0x%x", prop);
+    vehicle_device_impl_t* impl = (vehicle_device_impl_t*)device;
+    pthread_mutex_lock(&lock_);
+    vehicle_prop_config_t* config = find_config(prop);
+    if (config == NULL) {
+        pthread_mutex_unlock(&lock_);
+        return -EINVAL;
+    }
+    subscription_t* sub = (subscription_t*)config->hal_data;
+    if (sub == NULL) {
+        pthread_mutex_unlock(&lock_);
+        return -EINVAL;
+    }
+    config->hal_data = NULL;
+    pthread_mutex_unlock(&lock_);
+    pthread_mutex_lock(&sub->lock);
+    sub->stop_thread = 1;
+    pthread_cond_signal(&sub->cond);
+    pthread_mutex_unlock(&sub->lock);
+    pthread_join(sub->thread, NULL);
+    pthread_cond_destroy(&sub->cond);
+    pthread_mutex_destroy(&sub->lock);
+    free(sub);
+    pthread_mutex_lock(&lock_);
+    print_subscribe_info(impl);
+    pthread_mutex_unlock(&lock_);
+    return 0;
+}
+
+static int vdev_close(hw_device_t* device) {
+    vehicle_device_impl_t* impl = (vehicle_device_impl_t*)device;
+    if (impl) {
+        free(impl);
+        return 0;
+    } else {
+        return -1;
+    }
+}
+
+/*
+ * The open function is provided as an interface in harwdare.h which fills in
+ * all the information about specific implementations and version specific
+ * informations in hw_device_t structure. After calling open() the client should
+ * use the hw_device_t to execute any Vehicle HAL device specific functions.
+ */
+static int vdev_open(const hw_module_t* module, const char* __unused name,
+                     hw_device_t** device) {
+    ALOGD("vdev_open");
+
+    // Oops, out of memory!
+    vehicle_device_impl_t* vdev = calloc(1, sizeof(vehicle_device_impl_t));
+    if (vdev == NULL) {
+        return -ENOMEM;
+    }
+
+    // Common functions provided by harware.h to access module and device(s).
+    vdev->vehicle_device.common.tag = HARDWARE_DEVICE_TAG;
+    vdev->vehicle_device.common.version = VEHICLE_DEVICE_API_VERSION_1_0;
+    vdev->vehicle_device.common.module = (hw_module_t *) module;
+    vdev->vehicle_device.common.close = vdev_close;
+
+    // Define the Vehicle HAL device specific functions.
+    vdev->vehicle_device.list_properties = vdev_list_properties;
+    vdev->vehicle_device.init = vdev_init;
+    vdev->vehicle_device.release = vdev_release;
+    vdev->vehicle_device.get = vdev_get;
+    vdev->vehicle_device.set = vdev_set;
+    vdev->vehicle_device.subscribe = vdev_subscribe;
+    vdev->vehicle_device.unsubscribe = vdev_unsubscribe;
+
+    *device = (hw_device_t *) vdev;
+    return 0;
+}
+
+static struct hw_module_methods_t hal_module_methods = {
+    .open = vdev_open,
+};
+
+/*
+ * This structure is mandatory to be implemented by each HAL implementation. It
+ * exposes the open method (see hw_module_methods_t above) which opens a device.
+ * The vehicle HAL is supposed to be used as a single device HAL hence all the
+ * functions should be implemented inside of the vehicle_hw_device_t struct (see
+ * the vehicle.h in include/ folder.
+ */
+vehicle_module_t HAL_MODULE_INFO_SYM = {
+    .common = {
+        .tag = HARDWARE_MODULE_TAG,
+        .module_api_version = VEHICLE_MODULE_API_VERSION_1_0,
+        .hal_api_version = HARDWARE_HAL_API_VERSION,
+        .id = VEHICLE_HARDWARE_MODULE_ID,
+        .name = "Default vehicle HW HAL",
+        .author = "",
+        .methods = &hal_module_methods,
+    },
+};