summaryrefslogtreecommitdiff
path: root/src/libcamera/camera_lens.cpp
blob: b3d48199ec3b6740167658e23c59d2889841b7f4 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
/* SPDX-License-Identifier: LGPL-2.1-or-later */
/*
 * Copyright (C) 2021, Google Inc.
 *
 * camera_lens.cpp - A camera lens
 */

#include "libcamera/internal/camera_lens.h"

#include <libcamera/base/utils.h>

#include "libcamera/internal/v4l2_subdevice.h"

/**
 * \file camera_lens.h
 * \brief A camera lens controller
 */

namespace libcamera {

LOG_DEFINE_CATEGORY(CameraLens)

/**
 * \class CameraLens
 * \brief A camera lens based on V4L2 subdevices
 *
 * The CameraLens class eases handling of lens for pipeline handlers by
 * hiding the details of the V4L2 subdevice kernel API and caching lens
 * information.
 */

/**
 * \brief Construct a CameraLens
 * \param[in] entity The media entity backing the camera lens controller
 *
 * Once constructed the instance must be initialized with init().
 */
CameraLens::CameraLens(const MediaEntity *entity)
	: entity_(entity)
{
}

/**
 * \brief Destroy a CameraLens
 */
CameraLens::~CameraLens() = default;

/**
 * \brief Initialize the camera lens instance
 *
 * This function performs the initialisation steps of the CameraLens that may
 * fail. It shall be called once and only once after constructing the instance.
 *
 * \return 0 on success or a negative error code otherwise
 */
int CameraLens::init()
{
	if (entity_->function() != MEDIA_ENT_F_LENS) {
		LOG(CameraLens, Error)
			<< "Invalid lens function "
			<< utils::hex(entity_->function());
		return -EINVAL;
	}

	/* Create and open the subdev. */
	subdev_ = std::make_unique<V4L2Subdevice>(entity_);
	int ret = subdev_->open();
	if (ret < 0)
		return ret;

	ret = validateLensDriver();
	if (ret)
		return ret;

	model_ = subdev_->model();
	return 0;
}

/**
 * \brief This function sets the focal point of the lens to a specific position.
 * \param[in] position The focal point of the lens
 *
 * This function sets the value of focal point of the lens as in \a position.
 *
 * \return 0 on success or -EINVAL otherwise
 */
int CameraLens::setFocusPosition(int32_t position)
{
	ControlList lensCtrls(subdev_->controls());
	lensCtrls.set(V4L2_CID_FOCUS_ABSOLUTE, static_cast<int32_t>(position));

	if (subdev_->setControls(&lensCtrls))
		return -EINVAL;

	return 0;
}

int CameraLens::validateLensDriver()
{
	int ret = 0;
	static constexpr uint32_t mandatoryControls[] = {
		V4L2_CID_FOCUS_ABSOLUTE,
	};

	const ControlInfoMap &controls = subdev_->controls();
	for (uint32_t ctrl : mandatoryControls) {
		if (!controls.count(ctrl)) {
			LOG(CameraLens, Error)
				<< "Mandatory V4L2 control " << utils::hex(ctrl)
				<< " not available";
			ret = -EINVAL;
		}
	}

	if (ret) {
		LOG(CameraLens, Error)
			<< "The lens kernel driver needs to be fixed";
		LOG(CameraLens, Error)
			<< "See Documentation/lens_driver_requirements.rst in"
			<< " the libcamera sources for more information";
		return ret;
	}

	return ret;
}

/**
 * \fn CameraLens::model()
 * \brief Retrieve the lens model name
 *
 * The lens model name is a free-formed string that uniquely identifies the
 * lens model.
 *
 * \return The lens model name
 */

std::string CameraLens::logPrefix() const
{
	return "'" + entity_->name() + "'";
}

/**
 * \fn CameraLens::controls()
 * \brief Retrieve the V4L2 controls of the lens' subdev
 *
 * \return A map of the V4L2 controls supported by the lens' driver
 */
const ControlInfoMap &CameraLens::controls() const
{
	return subdev_->controls();
}

} /* namespace libcamera */