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      1 /*
      2  * Copyright (C) 2015 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 //#define LOG_NDEBUG 0
     18 #define LOG_TAG "UsbCameraHAL"
     19 
     20 #include <cstdlib>
     21 
     22 #include <log/log.h>
     23 #include <utils/Mutex.h>
     24 
     25 #include <hardware/camera_common.h>
     26 #include <hardware/hardware.h>
     27 
     28 #include "CameraHAL.h"
     29 #include "UsbCamera.h"
     30 
     31 /*
     32  * This file serves as the entry point to the HAL.  It contains the module
     33  * structure and functions used by the framework to load and interface to this
     34  * HAL, as well as the handles to the individual camera devices.
     35  */
     36 
     37 namespace usb_camera_hal {
     38 
     39 static CameraHAL gCameraHAL;
     40 
     41 CameraHAL::CameraHAL()
     42   : mCallbacks(NULL) {
     43     // Should not allocate the camera devices for now, as it is unclear if the device is plugged.
     44 
     45     // Start hotplug thread
     46     mHotplugThread = new HotplugThread(this);
     47     mHotplugThread->run("usb-camera-hotplug");
     48 }
     49 
     50 CameraHAL::~CameraHAL() {
     51     // Stop hotplug thread
     52     {
     53         android::Mutex::Autolock al(mModuleLock);
     54         if (mHotplugThread != NULL) {
     55             mHotplugThread->requestExit();
     56         }
     57 
     58         // Delete camera device from mCameras
     59     }
     60 
     61     // Joining done without holding mLock, otherwise deadlocks may ensue
     62     // as the threads try to access parent states.
     63     if (mHotplugThread != NULL) {
     64         mHotplugThread->join();
     65     }
     66 
     67     delete mHotplugThread;
     68 }
     69 
     70 int CameraHAL::getNumberOfCameras() {
     71     android::Mutex::Autolock al(mModuleLock);
     72     ALOGV("%s: %zu", __func__, mCameras.size());
     73     return static_cast<int>(mCameras.size());
     74 }
     75 
     76 int CameraHAL::getCameraInfo(int id, struct camera_info* info) {
     77     android::Mutex::Autolock al(mModuleLock);
     78     ALOGV("%s: camera id %d: info=%p", __func__, id, info);
     79     if (id < 0 || id >= static_cast<int>(mCameras.size())) {
     80         ALOGE("%s: Invalid camera id %d", __func__, id);
     81         return -ENODEV;
     82     }
     83 
     84     return mCameras[id]->getInfo(info);
     85 }
     86 
     87 int CameraHAL::setCallbacks(const camera_module_callbacks_t *callbacks) {
     88     ALOGV("%s : callbacks=%p", __func__, callbacks);
     89     mCallbacks = callbacks;
     90     return 0;
     91 }
     92 
     93 int CameraHAL::open(const hw_module_t* mod, const char* name, hw_device_t** dev) {
     94     int id;
     95     char *nameEnd;
     96 
     97     android::Mutex::Autolock al(mModuleLock);
     98     ALOGV("%s: module=%p, name=%s, device=%p", __func__, mod, name, dev);
     99     if (*name == '\0') {
    100         ALOGE("%s: Invalid camera id name is NULL", __func__);
    101         return -EINVAL;
    102     }
    103     id = strtol(name, &nameEnd, 10);
    104     if (*nameEnd != '\0') {
    105         ALOGE("%s: Invalid camera id name %s", __func__, name);
    106         return -EINVAL;
    107     } else if (id < 0 || id >= static_cast<int>(mCameras.size())) {
    108         ALOGE("%s: Invalid camera id %d", __func__, id);
    109         return -ENODEV;
    110     }
    111     return mCameras[id]->open(mod, dev);
    112 }
    113 
    114 extern "C" {
    115 
    116 static int get_number_of_cameras() {
    117     return gCameraHAL.getNumberOfCameras();
    118 }
    119 
    120 static int get_camera_info(int id, struct camera_info* info) {
    121     return gCameraHAL.getCameraInfo(id, info);
    122 }
    123 
    124 static int set_callbacks(const camera_module_callbacks_t *callbacks) {
    125     return gCameraHAL.setCallbacks(callbacks);
    126 }
    127 
    128 static int open_dev(const hw_module_t* mod, const char* name, hw_device_t** dev) {
    129     return gCameraHAL.open(mod, name, dev);
    130 }
    131 
    132 static hw_module_methods_t gCameraModuleMethods = {
    133     .open = open_dev
    134 };
    135 
    136 camera_module_t HAL_MODULE_INFO_SYM __attribute__ ((visibility("default"))) = {
    137     .common = {
    138         .tag                = HARDWARE_MODULE_TAG,
    139         .module_api_version = CAMERA_MODULE_API_VERSION_2_4,
    140         .hal_api_version    = HARDWARE_HAL_API_VERSION,
    141         .id                 = CAMERA_HARDWARE_MODULE_ID,
    142         .name               = "Default USB Camera HAL",
    143         .author             = "The Android Open Source Project",
    144         .methods            = &gCameraModuleMethods,
    145         .dso                = NULL,
    146         .reserved           = {0},
    147     },
    148     .get_number_of_cameras = get_number_of_cameras,
    149     .get_camera_info       = get_camera_info,
    150     .set_callbacks         = set_callbacks,
    151     .get_vendor_tag_ops    = NULL,
    152     .open_legacy           = NULL,
    153     .set_torch_mode        = NULL,
    154     .init                  = NULL,
    155     .reserved              = {0},
    156 };
    157 } // extern "C"
    158 
    159 } // namespace usb_camera_hal
    160