[libcamera-devel] [PATCH 2/2] ipa: raspberrypi: Update sensor's RED/BLUE balance controls when present

[David Plowman]

If the sensor exposes V4L2_CID_RED_BALANCE and V4L2_CID_BLUE_BALANCE
controls, assume it wants to be told the colour gains. We will need to
add these to the list of delayed controls we can apply.

Signed-off-by: David Plowman <david.plowman at raspberrypi.com>
---
 src/ipa/raspberrypi/raspberrypi.cpp             | 17 ++++++++++++++---
 .../pipeline/raspberrypi/raspberrypi.cpp        |  9 +++++++++
 2 files changed, 23 insertions(+), 3 deletions(-)

diff --git a/src/ipa/raspberrypi/raspberrypi.cpp b/src/ipa/raspberrypi/raspberrypi.cpp
index 1c928b72..7437a77e 100644
--- a/src/ipa/raspberrypi/raspberrypi.cpp
+++ b/src/ipa/raspberrypi/raspberrypi.cpp
@@ -1030,13 +1030,24 @@ void IPARPi::processStats(unsigned int bufferId)
 	RPiController::StatisticsPtr statistics = std::make_shared<bcm2835_isp_stats>(*stats);
 	controller_.Process(statistics, &rpiMetadata_);
 
+	ControlList ctrls(sensorCtrls_);
+
 	struct AgcStatus agcStatus;
-	if (rpiMetadata_.Get("agc.status", agcStatus) == 0) {
-		ControlList ctrls(sensorCtrls_);
+	if (rpiMetadata_.Get("agc.status", agcStatus) == 0)
 		applyAGC(&agcStatus, ctrls);
 
-		setDelayedControls.emit(ctrls);
+	struct AwbStatus awbStatus;
+	if (rpiMetadata_.Get("awb.status", awbStatus) == 0 &&
+	    sensorCtrls_.find(V4L2_CID_RED_BALANCE) != sensorCtrls_.end() &&
+	    sensorCtrls_.find(V4L2_CID_BLUE_BALANCE) != sensorCtrls_.end()) {
+		ctrls.set(V4L2_CID_RED_BALANCE,
+			  static_cast<int32_t>(awbStatus.gain_r * 256));
+		ctrls.set(V4L2_CID_BLUE_BALANCE,
+			  static_cast<int32_t>(awbStatus.gain_b * 256));
 	}
+
+	if (!ctrls.empty())
+		setDelayedControls.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 2cac802c..7bac1503 100644
--- a/src/libcamera/pipeline/raspberrypi/raspberrypi.cpp
+++ b/src/libcamera/pipeline/raspberrypi/raspberrypi.cpp
@@ -1027,6 +1027,15 @@ bool PipelineHandlerRPi::match(DeviceEnumerator *enumerator)
 		{ V4L2_CID_EXPOSURE, { sensorConfig.exposureDelay, false } },
 		{ V4L2_CID_VBLANK, { sensorConfig.vblankDelay, true } }
 	};
+
+	/* If the sensor exposes red/blue balance controls, we will update them. */
+	const ControlInfoMap &sensorControls = data->unicam_[Unicam::Image].dev()->controls();
+	if (sensorControls.find(V4L2_CID_RED_BALANCE) != sensorControls.end() &&
+	    sensorControls.find(V4L2_CID_BLUE_BALANCE) != sensorControls.end()) {
+		params[V4L2_CID_RED_BALANCE] = { sensorConfig.vblankDelay, false };
+		params[V4L2_CID_BLUE_BALANCE] = { sensorConfig.vblankDelay, false };
+	}
+
 	data->delayedCtrls_ = std::make_unique<DelayedControls>(data->unicam_[Unicam::Image].dev(), params);
 	data->sensorMetadata_ = sensorConfig.sensorMetadata;
 
-- 
2.20.1