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Diffstat (limited to 'src/v4l2/v4l2_compat_manager.cpp')
-rw-r--r--src/v4l2/v4l2_compat_manager.cpp250
1 files changed, 250 insertions, 0 deletions
diff --git a/src/v4l2/v4l2_compat_manager.cpp b/src/v4l2/v4l2_compat_manager.cpp
new file mode 100644
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+++ b/src/v4l2/v4l2_compat_manager.cpp
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+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ * Copyright (C) 2019, Google Inc.
+ *
+ * v4l2_compat_manager.cpp - V4L2 compatibility manager
+ */
+
+#include "v4l2_compat_manager.h"
+
+#include <dlfcn.h>
+#include <fcntl.h>
+#include <map>
+#include <stdarg.h>
+#include <string.h>
+#include <sys/eventfd.h>
+#include <sys/mman.h>
+#include <sys/stat.h>
+#include <sys/sysmacros.h>
+#include <sys/types.h>
+#include <unistd.h>
+
+#include <libcamera/camera.h>
+#include <libcamera/camera_manager.h>
+
+#include "log.h"
+
+using namespace libcamera;
+
+LOG_DEFINE_CATEGORY(V4L2Compat)
+
+V4L2CompatManager::V4L2CompatManager()
+ : cm_(nullptr), initialized_(false)
+{
+ openat_func_ = (openat_func_t)dlsym(RTLD_NEXT, "openat");
+ dup_func_ = (dup_func_t )dlsym(RTLD_NEXT, "dup");
+ close_func_ = (close_func_t )dlsym(RTLD_NEXT, "close");
+ ioctl_func_ = (ioctl_func_t )dlsym(RTLD_NEXT, "ioctl");
+ mmap_func_ = (mmap_func_t )dlsym(RTLD_NEXT, "mmap");
+ munmap_func_ = (munmap_func_t)dlsym(RTLD_NEXT, "munmap");
+}
+
+V4L2CompatManager::~V4L2CompatManager()
+{
+ devices_.clear();
+ mmaps_.clear();
+
+ if (isRunning()) {
+ exit(0);
+ /* \todo Wait with a timeout, just in case. */
+ wait();
+ }
+}
+
+int V4L2CompatManager::init()
+{
+ start();
+
+ MutexLocker locker(mutex_);
+ cv_.wait(locker, [&] { return initialized_; });
+
+ return 0;
+}
+
+void V4L2CompatManager::run()
+{
+ cm_ = new CameraManager();
+
+ int ret = cm_->start();
+ if (ret) {
+ LOG(V4L2Compat, Error) << "Failed to start camera manager: "
+ << strerror(-ret);
+ return;
+ }
+
+ LOG(V4L2Compat, Debug) << "Started camera manager";
+
+ /*
+ * For each Camera registered in the system, a V4L2CameraProxy gets
+ * created here to wrap a camera device.
+ */
+ unsigned int index = 0;
+ for (auto &camera : cm_->cameras()) {
+ V4L2CameraProxy *proxy = new V4L2CameraProxy(index, camera);
+ proxies_.emplace_back(proxy);
+ ++index;
+ }
+
+ /*
+ * libcamera has been initialized. Unlock the init() caller as we're
+ * now ready to handle calls from the framework.
+ */
+ mutex_.lock();
+ initialized_ = true;
+ mutex_.unlock();
+ cv_.notify_one();
+
+ /* Now start processing events and messages. */
+ exec();
+
+ proxies_.clear();
+ cm_->stop();
+ delete cm_;
+ cm_ = nullptr;
+}
+
+V4L2CompatManager *V4L2CompatManager::instance()
+{
+ static V4L2CompatManager instance;
+ return &instance;
+}
+
+V4L2CameraProxy *V4L2CompatManager::getProxy(int fd)
+{
+ auto device = devices_.find(fd);
+ if (device == devices_.end())
+ return nullptr;
+
+ return device->second;
+}
+
+int V4L2CompatManager::getCameraIndex(int fd)
+{
+ struct stat statbuf;
+ int ret = fstat(fd, &statbuf);
+ if (ret < 0)
+ return -1;
+
+ std::shared_ptr<Camera> target = cm_->get(statbuf.st_rdev);
+ if (!target)
+ return -1;
+
+ unsigned int index = 0;
+ for (auto &camera : cm_->cameras()) {
+ if (camera == target)
+ return index;
+ ++index;
+ }
+
+ return -1;
+}
+
+int V4L2CompatManager::openat(int dirfd, const char *path, int oflag, mode_t mode)
+{
+ int fd = openat_func_(dirfd, path, oflag, mode);
+ if (fd < 0)
+ return fd;
+
+ struct stat statbuf;
+ int ret = fstat(fd, &statbuf);
+ if (ret < 0 || (statbuf.st_mode & S_IFMT) != S_IFCHR ||
+ major(statbuf.st_rdev) != 81)
+ return fd;
+
+ if (!isRunning())
+ init();
+
+ ret = getCameraIndex(fd);
+ if (ret < 0) {
+ LOG(V4L2Compat, Info) << "No camera found for " << path;
+ return fd;
+ }
+
+ close_func_(fd);
+
+ unsigned int camera_index = static_cast<unsigned int>(ret);
+
+ V4L2CameraProxy *proxy = proxies_[camera_index].get();
+ ret = proxy->open(oflag & O_NONBLOCK);
+ if (ret < 0)
+ return ret;
+
+ int efd = eventfd(0, oflag & (O_CLOEXEC | O_NONBLOCK));
+ if (efd < 0) {
+ proxy->close();
+ return efd;
+ }
+
+ devices_.emplace(efd, proxy);
+
+ return efd;
+}
+
+int V4L2CompatManager::dup(int oldfd)
+{
+ int newfd = dup_func_(oldfd);
+ if (newfd < 0)
+ return newfd;
+
+ auto device = devices_.find(oldfd);
+ if (device != devices_.end()) {
+ V4L2CameraProxy *proxy = device->second;
+ devices_[newfd] = proxy;
+ proxy->dup();
+ }
+
+ return newfd;
+}
+
+int V4L2CompatManager::close(int fd)
+{
+ V4L2CameraProxy *proxy = getProxy(fd);
+ if (proxy) {
+ proxy->close();
+ devices_.erase(fd);
+ return 0;
+ }
+
+ return close_func_(fd);
+}
+
+void *V4L2CompatManager::mmap(void *addr, size_t length, int prot, int flags,
+ int fd, off_t offset)
+{
+ V4L2CameraProxy *proxy = getProxy(fd);
+ if (!proxy)
+ return mmap_func_(addr, length, prot, flags, fd, offset);
+
+ void *map = proxy->mmap(length, prot, flags, offset);
+ if (map == MAP_FAILED)
+ return map;
+
+ mmaps_[map] = proxy;
+ return map;
+}
+
+int V4L2CompatManager::munmap(void *addr, size_t length)
+{
+ auto device = mmaps_.find(addr);
+ if (device == mmaps_.end())
+ return munmap_func_(addr, length);
+
+ V4L2CameraProxy *proxy = device->second;
+
+ int ret = proxy->munmap(addr, length);
+ if (ret < 0)
+ return ret;
+
+ mmaps_.erase(device);
+
+ return 0;
+}
+
+int V4L2CompatManager::ioctl(int fd, unsigned long request, void *arg)
+{
+ V4L2CameraProxy *proxy = getProxy(fd);
+ if (!proxy)
+ return ioctl_func_(fd, request, arg);
+
+ return proxy->ioctl(request, arg);
+}