media_device.h

Go to the documentation of this file.

/* SPDX-License-Identifier: LGPL-2.1-or-later */
/*
 * Copyright (C) 2018, Google Inc.
 *
 * Media device handler
 */
 
#pragma once
 
#include <map>
#include <optional>
#include <string>
#include <vector>
 
#include <linux/media.h>
 
#include <libcamera/base/log.h>
#include <libcamera/base/signal.h>
#include <libcamera/base/unique_fd.h>
 
#include "libcamera/internal/media_object.h"
#include "libcamera/internal/v4l2_request.h"
 
namespace libcamera {
 
class MediaDevice : protected Loggable
{
public:
    MediaDevice(const std::string &deviceNode);
    ~MediaDevice();
 
    bool acquire();
    void release();
    bool busy() const { return acquired_; }
 
    bool lock();
    void unlock();
 
    int populate();
    bool isValid() const { return valid_; }
 
    const std::string &driver() const { return driver_; }
    const std::string &deviceNode() const { return deviceNode_; }
    const std::string &model() const { return model_; }
    unsigned int version() const { return version_; }
    unsigned int hwRevision() const { return hwRevision_; }
 
    const std::vector<MediaEntity *> &entities() const { return entities_; }
    MediaEntity *getEntityByName(const std::string &name) const;
 
    MediaLink *link(const std::string &sourceName, unsigned int sourceIdx,
            const std::string &sinkName, unsigned int sinkIdx);
    MediaLink *link(const MediaEntity *source, unsigned int sourceIdx,
            const MediaEntity *sink, unsigned int sinkIdx);
    MediaLink *link(const MediaPad *source, const MediaPad *sink);
    int disableLinks();
 
    Signal<> disconnected;
 
    std::vector<MediaEntity *> locateEntities(unsigned int function);
 
    int allocateRequests(unsigned int count,
                 std::vector<std::unique_ptr<V4L2Request>> *requests);
 
    bool supportsRequests();
 
protected:
    std::string logPrefix() const override;
 
private:
    int open();
    void close();
 
    MediaObject *object(unsigned int id);
    bool addObject(MediaObject *object);
    void clear();
 
    struct media_v2_interface *findInterface(const struct media_v2_topology &topology,
                         unsigned int entityId);
    bool populateEntities(const struct media_v2_topology &topology);
    bool populatePads(const struct media_v2_topology &topology);
    bool populateLinks(const struct media_v2_topology &topology);
    void fixupEntityFlags(struct media_v2_entity *entity);
 
    friend int MediaLink::setEnabled(bool enable);
    int setupLink(const MediaLink *link, unsigned int flags);
 
    std::string driver_;
    std::string deviceNode_;
    std::string model_;
    unsigned int version_;
    unsigned int hwRevision_;
 
    UniqueFD fd_;
    bool valid_;
    bool acquired_;
    std::optional<bool> supportsRequests_;
 
    std::map<unsigned int, MediaObject *> objects_;
    std::vector<MediaEntity *> entities_;
};
 
} /* namespace libcamera */