libcamera: ipu3: imgu: Add parameters video device

Add the parameters video device to the data structure of the ImgUDevice.
Even if the video device is configured, prepared to import buffers and
started no buffers are ever queued to it so it does not yet effect the
capture. Nor is does this change hinder the current capture mode to
function.

This is done in preparation to attach an IPA to the IPU3 pipeline.

Signed-off-by: Niklas Söderlund <niklas.soderlund@ragnatech.se>
Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com>
Reviewed-by: Jacopo Mondi <jacopo@jmondi.org>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>

2 files changed, 41 insertions, 3 deletions

diff --git a/src/libcamera/pipeline/ipu3/imgu.cpp b/src/libcamera/pipeline/ipu3/imgu.cpp
index 08f0fce9..c8610220 100644
--- a/src/libcamera/pipeline/ipu3/imgu.cpp
+++ b/src/libcamera/pipeline/ipu3/imgu.cpp
@@ -363,6 +363,11 @@ int ImgUDevice::init(MediaDevice *media, unsigned int index)
 	if (ret)
 		return ret;
 
+	param_ = V4L2VideoDevice::fromEntityName(media, name_ + " parameters");
+	ret = param_->open();
+	if (ret)
+		return ret;
+
 	stat_ = V4L2VideoDevice::fromEntityName(media, name_ + " 3a stat");
 	ret = stat_->open();
 	if (ret)
@@ -475,6 +480,13 @@ int ImgUDevice::configure(const PipeConfig &pipeConfig, V4L2DeviceFormat *inputF
 
 	LOG(IPU3, Debug) << "ImgU GDC format = " << gdcFormat.toString();
 
+	StreamConfiguration paramCfg = {};
+	paramCfg.size = inputFormat->size;
+	V4L2DeviceFormat paramFormat;
+	ret = configureVideoDevice(param_.get(), PAD_PARAM, paramCfg, &paramFormat);
+	if (ret)
+		return ret;
+
 	StreamConfiguration statCfg = {};
 	statCfg.size = inputFormat->size;
 	V4L2DeviceFormat statFormat;
@@ -505,8 +517,11 @@ int ImgUDevice::configureVideoDevice(V4L2VideoDevice *dev, unsigned int pad,
 	if (ret)
 		return ret;
 
-	/* No need to apply format to the stat node. */
-	if (dev == stat_.get())
+	/*
+	 * No need to apply format to the param or stat video devices as the
+	 * driver ignores the operation.
+	 */
+	if (dev == param_.get() || dev == stat_.get())
 		return 0;
 
 	*outputFormat = {};
@@ -537,6 +552,12 @@ int ImgUDevice::allocateBuffers(unsigned int bufferCount)
 		return ret;
 	}
 
+	ret = param_->importBuffers(bufferCount);
+	if (ret < 0) {
+		LOG(IPU3, Error) << "Failed to allocate ImgU param buffers";
+		goto error;
+	}
+
 	/*
 	 * The kernel fails to start if buffers are not either imported or
 	 * allocated for the statistics video device. As statistics buffers are
@@ -586,6 +607,10 @@ void ImgUDevice::freeBuffers()
 	if (ret)
 		LOG(IPU3, Error) << "Failed to release ImgU output buffers";
 
+	ret = param_->releaseBuffers();
+	if (ret)
+		LOG(IPU3, Error) << "Failed to release ImgU param buffers";
+
 	ret = stat_->releaseBuffers();
 	if (ret)
 		LOG(IPU3, Error) << "Failed to release ImgU stat buffers";
@@ -616,6 +641,12 @@ int ImgUDevice::start()
 		return ret;
 	}
 
+	ret = param_->streamOn();
+	if (ret) {
+		LOG(IPU3, Error) << "Failed to start ImgU param";
+		return ret;
+	}
+
 	ret = stat_->streamOn();
 	if (ret) {
 		LOG(IPU3, Error) << "Failed to start ImgU stat";
@@ -637,6 +668,7 @@ int ImgUDevice::stop()
 
 	ret = output_->streamOff();
 	ret |= viewfinder_->streamOff();
+	ret |= param_->streamOff();
 	ret |= stat_->streamOff();
 	ret |= input_->streamOff();
 
@@ -678,6 +710,7 @@ int ImgUDevice::linkSetup(const std::string &source, unsigned int sourcePad,
 int ImgUDevice::enableLinks(bool enable)
 {
 	std::string viewfinderName = name_ + " viewfinder";
+	std::string paramName = name_ + " parameters";
 	std::string outputName = name_ + " output";
 	std::string statName = name_ + " 3a stat";
 	std::string inputName = name_ + " input";
@@ -695,6 +728,10 @@ int ImgUDevice::enableLinks(bool enable)
 	if (ret)
 		return ret;
 
+	ret = linkSetup(paramName, 0, name_, PAD_PARAM, enable);
+	if (ret)
+		return ret;
+
 	return linkSetup(name_, PAD_STAT, statName, 0, enable);
 }
 
diff --git a/src/libcamera/pipeline/ipu3/imgu.h b/src/libcamera/pipeline/ipu3/imgu.h
index 37f5ae77..4a1896e2 100644
--- a/src/libcamera/pipeline/ipu3/imgu.h
+++ b/src/libcamera/pipeline/ipu3/imgu.h
@@ -71,13 +71,14 @@ public:
 
 	std::unique_ptr<V4L2Subdevice> imgu_;
 	std::unique_ptr<V4L2VideoDevice> input_;
+	std::unique_ptr<V4L2VideoDevice> param_;
 	std::unique_ptr<V4L2VideoDevice> output_;
 	std::unique_ptr<V4L2VideoDevice> viewfinder_;
 	std::unique_ptr<V4L2VideoDevice> stat_;
-	/* \todo Add param video device for 3A tuning */
 
 private:
 	static constexpr unsigned int PAD_INPUT = 0;
+	static constexpr unsigned int PAD_PARAM = 1;
 	static constexpr unsigned int PAD_OUTPUT = 2;
 	static constexpr unsigned int PAD_VF = 3;
 	static constexpr unsigned int PAD_STAT = 4;