[libcamera-devel] [PATCH 3/3] ipa: raspberrypi: Update sensor's V4L2_CID_NOTIFY_GAINS control when present

[David Plowman]

If the sensor exposes the V4L2_CID_NOTIFY_GAINS controls, assume it
wants to be told the colour gains.

We want these to be applied as soon as possible so we add a new
setSensorControls signal to the IPA which passes these back to the
pipeline handler without using the DelayedControls mechanism.

Signed-off-by: David Plowman <david.plowman at raspberrypi.com>
---
 include/libcamera/ipa/raspberrypi.mojom       |  1 +
 src/ipa/raspberrypi/raspberrypi.cpp           | 22 +++++++++++++++++++
 .../pipeline/raspberrypi/raspberrypi.cpp      | 10 +++++++++
 3 files changed, 33 insertions(+)

diff --git a/include/libcamera/ipa/raspberrypi.mojom b/include/libcamera/ipa/raspberrypi.mojom
index acd3cafe..e7647724 100644
--- a/include/libcamera/ipa/raspberrypi.mojom
+++ b/include/libcamera/ipa/raspberrypi.mojom
@@ -123,6 +123,7 @@ interface IPARPiEventInterface {
 	statsMetadataComplete(uint32 bufferId, libcamera.ControlList controls);
 	runIsp(uint32 bufferId);
 	embeddedComplete(uint32 bufferId);
+	setSensorControls(libcamera.ControlList controls);
 	setIspControls(libcamera.ControlList controls);
 	setDelayedControls(libcamera.ControlList controls);
 };
diff --git a/src/ipa/raspberrypi/raspberrypi.cpp b/src/ipa/raspberrypi/raspberrypi.cpp
index 0ed41385..8c20c066 100644
--- a/src/ipa/raspberrypi/raspberrypi.cpp
+++ b/src/ipa/raspberrypi/raspberrypi.cpp
@@ -1061,6 +1061,28 @@ void IPARPi::processStats(unsigned int bufferId)
 
 		setDelayedControls.emit(ctrls);
 	}
+
+	auto itCtrl = sensorCtrls_.find(V4L2_CID_NOTIFY_GAINS);
+	if (itCtrl != sensorCtrls_.end()) {
+		struct AwbStatus awbStatus;
+		if (rpiMetadata_.Get("awb.status", awbStatus) == 0) {
+			/*
+			 * This control is a linear gain value where the default is
+			 * defined to correspond to a gain of 1. The order of the gains
+			 * is always B, Gb, Gr, R.
+			 */
+			int unity = itCtrl->second.def().get<int32_t>();
+			ControlList ctrls(sensorCtrls_);
+			int32_t gains[4] = { static_cast<int32_t>(awbStatus.gain_b * unity),
+					     unity, unity,
+					     static_cast<int32_t>(awbStatus.gain_r * unity) };
+			ControlValue c(Span<const uint8_t>{ reinterpret_cast<uint8_t *>(gains),
+							    sizeof(gains) });
+			ctrls.set(V4L2_CID_NOTIFY_GAINS, c);
+
+			setSensorControls.emit(ctrls);
+		}
+	}
 }
 
 void IPARPi::applyAWB(const struct AwbStatus *awbStatus, ControlList &ctrls)
diff --git a/src/libcamera/pipeline/raspberrypi/raspberrypi.cpp b/src/libcamera/pipeline/raspberrypi/raspberrypi.cpp
index b5c687da..59d3bbd8 100644
--- a/src/libcamera/pipeline/raspberrypi/raspberrypi.cpp
+++ b/src/libcamera/pipeline/raspberrypi/raspberrypi.cpp
@@ -196,6 +196,7 @@ public:
 	void statsMetadataComplete(uint32_t bufferId, const ControlList &controls);
 	void runIsp(uint32_t bufferId);
 	void embeddedComplete(uint32_t bufferId);
+	void setSensorControls(const ControlList &controls);
 	void setIspControls(const ControlList &controls);
 	void setDelayedControls(const ControlList &controls);
 	void setSensorControls(ControlList &controls);
@@ -1405,6 +1406,7 @@ int RPiCameraData::loadIPA(ipa::RPi::SensorConfig *sensorConfig)
 	ipa_->statsMetadataComplete.connect(this, &RPiCameraData::statsMetadataComplete);
 	ipa_->runIsp.connect(this, &RPiCameraData::runIsp);
 	ipa_->embeddedComplete.connect(this, &RPiCameraData::embeddedComplete);
+	ipa_->setSensorControls.connect(this, &RPiCameraData::setSensorControls);
 	ipa_->setIspControls.connect(this, &RPiCameraData::setIspControls);
 	ipa_->setDelayedControls.connect(this, &RPiCameraData::setDelayedControls);
 
@@ -1524,6 +1526,14 @@ void RPiCameraData::embeddedComplete(uint32_t bufferId)
 	handleState();
 }
 
+void RPiCameraData::setSensorControls(const ControlList &controls)
+{
+	ControlList ctrls = controls;
+
+	sensor_->setControls(&ctrls);
+	handleState();
+}
+
 void RPiCameraData::setIspControls(const ControlList &controls)
 {
 	ControlList ctrls = controls;
-- 
2.30.2