libcamera: camera_sensor: Enable to set a test pattern mode

This adds a function to set a camera sensor driver a test pattern
mode. CameraSensor initializes the test pattern mode by Off.

Signed-off-by: Hirokazu Honda <hiroh@chromium.org>
Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Jacopo Mondi <jacopo@jmondi.org>

include/libcamera/internal/camera_sensor.h

@@ -29,6 +29,8 @@ class BayerFormat;
 class CameraLens;
 class MediaEntity;
 
+struct CameraSensorProperties;
+
 class CameraSensor : protected Loggable
 {
 public:
@@ -47,6 +49,7 @@ public:
 	{
 		return testPatternModes_;
 	}
+	int setTestPatternMode(controls::draft::TestPatternModeEnum mode);
 
 	V4L2SubdeviceFormat getFormat(const std::vector<unsigned int> &mbusCodes,
 				      const Size &size) const;
@@ -75,15 +78,16 @@ private:
 	int validateSensorDriver();
 	void initVimcDefaultProperties();
 	void initStaticProperties();
-	void initTestPatternModes(
-		const std::map<controls::draft::TestPatternModeEnum, int32_t>
-			&testPatternModeMap);
+	void initTestPatternModes();
 	int initProperties();
+	int applyTestPatternMode(controls::draft::TestPatternModeEnum mode);
 
 	const MediaEntity *entity_;
 	std::unique_ptr<V4L2Subdevice> subdev_;
 	unsigned int pad_;
 
+	const CameraSensorProperties *staticProps_;
+
 	std::string model_;
 	std::string id_;
 
@@ -91,6 +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_;

src/libcamera/camera_sensor.cpp

@@ -54,8 +54,8 @@ 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),
+	  bayerFormat_(nullptr), properties_(properties::properties)
 {
 }
 
@@ -161,7 +161,7 @@ int CameraSensor::init()
 	if (ret)
 		return ret;
 
-	return 0;
+	return applyTestPatternMode(controls::draft::TestPatternModeEnum::TestPatternModeOff);
 }
 
 int CameraSensor::validateSensorDriver()
@@ -300,21 +300,30 @@ 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();
 }
 
-void CameraSensor::initTestPatternModes(
-	const std::map<controls::draft::TestPatternModeEnum, int32_t> &testPatternModes)
+void CameraSensor::initTestPatternModes()
 {
 	const auto &v4l2TestPattern = controls().find(V4L2_CID_TEST_PATTERN);
 	if (v4l2TestPattern == controls().end()) {
+		LOG(CameraSensor, Debug) << "V4L2_CID_TEST_PATTERN is not supported";
+		return;
+	}
+
+	const auto &testPatternModes = staticProps_->testPatternModes;
+	if (testPatternModes.empty()) {
+		/*
+		 * The camera sensor supports test patterns but we don't know
+		 * how to map them so this should be fixed.
+		 */
 		LOG(CameraSensor, Debug) << "No static test pattern map for \'"
 					 << model() << "\'";
 		return;
@@ -504,6 +513,53 @@ Size CameraSensor::resolution() const
  * \return The list of test pattern modes
  */
 
+/**
+ * \brief Set the test pattern mode for the camera sensor
+ * \param[in] mode The test pattern mode
+ *
+ * The new \a mode is applied to the sensor if it differs from the active test
+ * pattern mode. Otherwise, this function is a no-op. Setting the same test
+ * pattern mode for every frame thus incurs no performance penalty.
+ */
+int CameraSensor::setTestPatternMode(controls::draft::TestPatternModeEnum mode)
+{
+	if (testPatternMode_ == mode)
+		return 0;
+
+	return applyTestPatternMode(mode);
+}
+
+int CameraSensor::applyTestPatternMode(controls::draft::TestPatternModeEnum mode)
+{
+	if (testPatternModes_.empty()) {
+		LOG(CameraSensor, Error)
+			<< "Camera sensor does not support test pattern modes.";
+		return 0;
+	}
+
+	auto it = std::find(testPatternModes_.begin(), testPatternModes_.end(),
+			    mode);
+	if (it == testPatternModes_.end()) {
+		LOG(CameraSensor, Error) << "Unsupported test pattern mode "
+					 << mode;
+		return -EINVAL;
+	}
+
+	LOG(CameraSensor, Debug) << "Apply test pattern mode " << mode;
+
+	int32_t index = staticProps_->testPatternModes.at(mode);
+	ControlList ctrls{ controls() };
+	ctrls.set(V4L2_CID_TEST_PATTERN, index);
+
+	int ret = setControls(&ctrls);
+	if (ret)
+		return ret;
+
+	testPatternMode_ = mode;
+
+	return 0;
+}
+
 /**
  * \brief Retrieve the best sensor format for a desired output
  * \param[in] mbusCodes The list of acceptable media bus codes