test/log

/* SPDX-License-Identifier: LGPL-2.1-or-later */
/*
 * Copyright (C) 2019, Google Inc.
 *
 * v4l2_device.cpp - Common base for V4L2 video devices and subdevices
 */

#include "libcamera/internal/v4l2_device.h"

#include <fcntl.h>
#include <iomanip>
#include <limits.h>
#include <stdlib.h>
#include <string.h>
#include <sys/ioctl.h>
#include <sys/syscall.h>
#include <unistd.h>

#include "libcamera/internal/event_notifier.h"
#include "libcamera/internal/log.h"
#include "libcamera/internal/sysfs.h"
#include "libcamera/internal/utils.h"

/**
 * \file v4l2_device.h
 * \brief Common base for V4L2 devices and subdevices
 */

namespace libcamera {

LOG_DEFINE_CATEGORY(V4L2)

namespace {

ControlType v4l2CtrlType(uint32_t ctrlType)
{
	switch (ctrlType) {
	case V4L2_CTRL_TYPE_U8:
		return ControlTypeByte;

	case V4L2_CTRL_TYPE_BOOLEAN:
		return ControlTypeBool;

	case V4L2_CTRL_TYPE_INTEGER:
		return ControlTypeInteger32;

	case V4L2_CTRL_TYPE_INTEGER64:
		return ControlTypeInteger64;

	case V4L2_CTRL_TYPE_MENU:
	case V4L2_CTRL_TYPE_BUTTON:
	case V4L2_CTRL_TYPE_BITMASK:
	case V4L2_CTRL_TYPE_INTEGER_MENU:
		/*
		 * More precise types may be needed, for now use a 32-bit
		 * integer type.
		 */
		return ControlTypeInteger32;

	default:
		return ControlTypeNone;
	}
}

std::unique_ptr<ControlId> v4l2ControlId(const v4l2_query_ext_ctrl &ctrl)
{
	const size_t len = strnlen(ctrl.name, sizeof(ctrl.name));
	const std::string name(static_cast<const char *>(ctrl.name), len);
	const ControlType type = v4l2CtrlType(ctrl.type);

	return std::make_unique<ControlId>(ctrl.id, name, type);
}

ControlInfo v4l2ControlInfo(const v4l2_query_ext_ctrl &ctrl)
{
	switch (ctrl.type) {
	case V4L2_CTRL_TYPE_U8:
		return ControlInfo(static_cast<uint8_t>(ctrl.minimum),
				   static_cast<uint8_t>(ctrl.maximum),
				   static_cast<uint8_t>(ctrl.default_value));

	case V4L2_CTRL_TYPE_BOOLEAN:
		return ControlInfo(static_cast<bool>(ctrl.minimum),
				   static_cast<bool>(ctrl.maximum),
				   static_cast<bool>(ctrl.default_value));

	case V4L2_CTRL_TYPE_INTEGER64:
		return ControlInfo(static_cast<int64_t>(ctrl.minimum),
				   static_cast<int64_t>(ctrl.maximum),
				   static_cast<int64_t>(ctrl.default_value));

	default:
		return ControlInfo(static_cast<int32_t>(ctrl.minimum),
				   static_cast<int32_t>(ctrl.maximum),
				   static_cast<int32_t>(ctrl.default_value));
	}
}
} /* namespace */

/**
 * \class V4L2Device
 * \brief Base class for V4L2VideoDevice and V4L2Subdevice
 *
 * The V4L2Device class groups together the methods and fields common to
 * both the V4L2VideoDevice and V4L2Subdevice classes, and provides a base
 * class with methods to open and close the device node associated with the
 * device and to perform IOCTL system calls on it.
 *
 * The V4L2Device class cannot be instantiated directly, as its constructor
 * is protected. Users should instead create instances of one the derived
 * classes to model either a V4L2 video device or a V4L2 subdevice.
 */

/**
 * \brief Construct a V4L2Device
 * \param[in] deviceNode The device node filesystem path
 *
 * Initialize the file descriptor to -1 and store the \a deviceNode to be used
 * at open() time, and the \a logTag to prefix log messages with.
 */
V4L2Device::V4L2Device(const std::string &deviceNode)
	: deviceNode_(deviceNode), fd_(-1), fdEventNotifier_(nullptr),
	  frameStartEnabled_(false)
{
}

/**
 * \brief Destroy a V4L2Device
 */
V4L2Device::~V4L2Device()
{
}

/**
 * \brief Open a V4L2 device node
 * \param[in] flags Access mode flags
 *
 * Open the device node path with the provided access mode \a flags and
 * initialize the file descriptor, which was initially set to -1.
 *
 * \return 0 on success or a negative error code otherwise
 */
int V4L2Device::open(unsigned int flags)
{
	if (isOpen()) {
		LOG(V4L2, Error) << "Device already open";
		return -EBUSY;
	}

	int ret = syscall(SYS_openat, AT_FDCWD, deviceNode_.c_str(), flags);
	if (ret < 0) {
		ret = -errno;
		LOG(V4L2, Error) << "Failed to open V4L2 device: "
				 << strerror(-ret);
		return ret;
	}

	setFd(ret);

	listControls();

	return 0;
}

/**
 * \brief Set the file descriptor of a V4L2 device
 * \param[in] fd The file descriptor handle
 *
 * This method allows a device to provide an already opened file descriptor
 * referring to the V4L2 device node, instead of opening it with open(). This
 * can be used for V4L2 M2M devices where a single video device node is used for
 * both the output and capture devices, or when receiving an open file
 * descriptor in a context that doesn't have permission to open the device node
 * itself.
 *
 * This method and the open() method are mutually exclusive, only one of the two
 * shall be used for a V4L2Device instance.
 *
 * \return 0 on success or a negative error code otherwise
 */
int V4L2Device::setFd(int fd)
{
	if (isOpen())
		return -EBUSY;

	fd_ = fd;

	fdEventNotifier_ = new EventNotifier(fd_, EventNotifier::Exception);
	fdEventNotifier_->activated.connect(this, &V4L2Device::eventAvailable);
Mode	Name	Size
-rw-r--r--	log_api.cpp	2846	log plain
-rw-r--r--	log_process.cpp	3177	log plain
-rw-r--r--	meson.build	400	log plain