blob: 810fcffa4c496671450cb08e9d4c67f572b7d0cb [file] [log] [blame]
/* 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() + "'";
}
} /* namespace libcamera */