[libcamera-devel] [PATCH v7 2/3] libcamera: camera_sensor: Enable to set a test pattern mode

[Laurent Pinchart]

Hi Hiro,

Thank you for the patch.

On Wed, Nov 24, 2021 at 04:08:11AM +0900, Hirokazu Honda wrote:
> This adds a function to set a camera sensor driver a test pattern
> mode.
> 
> Signed-off-by: Hirokazu Honda <hiroh at chromium.org>
> Reviewed-by: Kieran Bingham <kieran.bingham at ideasonboard.com>
> Reviewed-by: Laurent Pinchart <laurent.pinchart at ideasonboard.com>

The patch I've reviewed differs significantly from this one. Please drop
my tag in v8.

> ---
>  include/libcamera/internal/camera_sensor.h |  7 +++
>  src/libcamera/camera_sensor.cpp            | 60 +++++++++++++++++++---
>  src/libcamera/control_ids.yaml             |  5 ++
>  3 files changed, 65 insertions(+), 7 deletions(-)
> 
> diff --git a/include/libcamera/internal/camera_sensor.h b/include/libcamera/internal/camera_sensor.h
> index edef2220..f355f323 100644
> --- a/include/libcamera/internal/camera_sensor.h
> +++ b/include/libcamera/internal/camera_sensor.h
> @@ -27,6 +27,9 @@ namespace libcamera {
>  
>  class BayerFormat;
>  class MediaEntity;
> +class Request;

Not needed anymore.

> +
> +struct CameraSensorProperties;
>  
>  class CameraSensor : protected Loggable
>  {
> @@ -47,6 +50,7 @@ public:
>  	{
>  		return testPatternModes_;
>  	}
> +	int setTestPatternMode(controls::draft::TestPatternModeEnum testPatternMode);
>  
>  	V4L2SubdeviceFormat getFormat(const std::vector<unsigned int> &mbusCodes,
>  				      const Size &size) const;
> @@ -82,6 +86,8 @@ private:
>  	std::unique_ptr<V4L2Subdevice> subdev_;
>  	unsigned int pad_;
>  
> +	const CameraSensorProperties *staticProps_;
> +
>  	std::string model_;
>  	std::string id_;
>  
> @@ -89,6 +95,7 @@ private:
>  	std::vector<unsigned int> mbusCodes_;
>  	std::vector<Size> sizes_;
>  	std::vector<controls::draft::TestPatternModeEnum> testPatternModes_;
> +	controls::draft::TestPatternModeEnum testPatternMode_;
>  
>  	Size pixelArraySize_;
>  	Rectangle activeArea_;
> diff --git a/src/libcamera/camera_sensor.cpp b/src/libcamera/camera_sensor.cpp
> index f0aa9f24..e1293980 100644
> --- a/src/libcamera/camera_sensor.cpp
> +++ b/src/libcamera/camera_sensor.cpp
> @@ -17,6 +17,7 @@
>  #include <string.h>
>  
>  #include <libcamera/property_ids.h>
> +#include <libcamera/request.h>

Not needed anymore either.

>  
>  #include <libcamera/base/utils.h>
>  
> @@ -54,8 +55,9 @@ LOG_DEFINE_CATEGORY(CameraSensor)
>   * Once constructed the instance must be initialized with init().
>   */
>  CameraSensor::CameraSensor(const MediaEntity *entity)
> -	: entity_(entity), pad_(UINT_MAX), bayerFormat_(nullptr),
> -	  properties_(properties::properties)
> +	: entity_(entity), pad_(UINT_MAX), staticProps_(nullptr),
> +	  testPatternMode_(controls::draft::TestPatternModeUnset),
> +	  bayerFormat_(nullptr), properties_(properties::properties)
>  {
>  }
>  
> @@ -300,14 +302,14 @@ void CameraSensor::initVimcDefaultProperties()
>  
>  void CameraSensor::initStaticProperties()
>  {
> -	const CameraSensorProperties *props = CameraSensorProperties::get(model_);
> -	if (!props)
> +	staticProps_ = CameraSensorProperties::get(model_);
> +	if (!staticProps_)
>  		return;
>  
>  	/* Register the properties retrieved from the sensor database. */
> -	properties_.set(properties::UnitCellSize, props->unitCellSize);
> +	properties_.set(properties::UnitCellSize, staticProps_->unitCellSize);
>  
> -	initTestPatternModes(props->testPatternModes);
> +	initTestPatternModes(staticProps_->testPatternModes);
>  }
>  
>  void CameraSensor::initTestPatternModes(
> @@ -315,7 +317,15 @@ void CameraSensor::initTestPatternModes(
>  {
>  	const auto &v4l2TestPattern = controls().find(V4L2_CID_TEST_PATTERN);
>  	if (v4l2TestPattern == controls().end()) {
> -		LOG(CameraSensor, Debug) << "No static test pattern map for \'"
> +		LOG(CameraSensor, Debug)
> +			<< "V4L2_CID_TEST_PATTERN is not supported";
> +		return;
> +	}
> +
> +	if (testPatternModes.empty()) {
> +		// The camera sensor supports test patterns but we don't know
> +		// how to map them so this should be fixed.

We use C-style comments.

> +		LOG(CameraSensor, Error) << "No static test pattern map for \'"

No need to escape the single quote.

>  					 << model() << "\'";
>  		return;
>  	}
> @@ -531,6 +541,42 @@ Size CameraSensor::resolution() const
>   * \return The list of test pattern modes
>   */
>  
> +/**
> + * \brief Set the test pattern mode for the camera sensor
> + * \param[in] testPatternMode Test pattern mode control value to set the camera
> + * sensor
> + *
> + * \return 0 on success or a negative error code otherwise
> + */
> +int CameraSensor::setTestPatternMode(controls::draft::TestPatternModeEnum testPatternMode)
> +{
> +	if (testPatternMode_ == testPatternMode)
> +		return 0;
> +
> +	if (!staticProps_ || testPatternModes_.empty())
> +		return 0;

Shouldn't this return an error ?

> +
> +	auto it = std::find(testPatternModes_.begin(), testPatternModes_.end(),
> +			    testPatternMode);
> +	if (it == testPatternModes_.end()) {
> +		LOG(CameraSensor, Error) << "Unsupported test pattern mode "
> +					 << testPatternMode;
> +		return -EINVAL;
> +	}
> +
> +	int32_t index = staticProps_->testPatternModes.at(testPatternMode);
> +	ControlList ctrls{ controls() };
> +	ctrls.set(V4L2_CID_TEST_PATTERN, index);
> +
> +	int ret = setControls(&ctrls);
> +	if (ret)
> +		return ret;
> +
> +	testPatternMode_ = testPatternMode;

This brings the question of where control values should be cached, to
avoid applying controls that haven't changed. I don't think this need is
limited to the CameraSensor class, so a more generic solution at the
pipeline handler level may be better. This doesn't have to be addressed
now though.

> +
> +	return 0;
> +}
> +
>  /**
>   * \brief Retrieve the best sensor format for a desired output
>   * \param[in] mbusCodes The list of acceptable media bus codes
> diff --git a/src/libcamera/control_ids.yaml b/src/libcamera/control_ids.yaml
> index 9d4638ae..083bac7b 100644
> --- a/src/libcamera/control_ids.yaml
> +++ b/src/libcamera/control_ids.yaml
> @@ -639,6 +639,11 @@ controls:
>          Control to select the test pattern mode. Currently identical to
>          ANDROID_SENSOR_TEST_PATTERN_MODE.
>        enum:
> +        - name: TestPatternModeUnset
> +          value: -1
> +          description: |
> +            No test pattern is set. Returned frames by the camera device are
> +            undefined.

Why do we need this ? It's not documented in the commit message. If we
need this new value, its addition should be split to a separate commit,
with a proper explanation.

>          - name: TestPatternModeOff
>            value: 0
>            description: |

-- 
Regards,

Laurent Pinchart