controls: Split FrameDurations into FrameDuration and FrameDurationLimits

We need a separate control to report the nominal frame duration, but
it's also useful to report the min/max frame duration values that will
be used. Split the FrameDurations control into FrameDuration and
FrameDurationLimits respectively to support both of these.

Signed-off-by: Paul Elder <paul.elder@ideasonboard.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Hirokazu Honda <hiroh@chromium.org>
Reviewed-by: Jacopo Mondi <jacopo@jmondi.org>

include/libcamera/ipa/raspberrypi.h

@@ -44,7 +44,7 @@ static const ControlInfoMap Controls = {
 	{ &controls::Sharpness, ControlInfo(0.0f, 16.0f, 1.0f) },
 	{ &controls::ColourCorrectionMatrix, ControlInfo(-16.0f, 16.0f) },
 	{ &controls::ScalerCrop, ControlInfo(Rectangle{}, Rectangle(65535, 65535, 65535, 65535), Rectangle{}) },
-	{ &controls::FrameDurations, ControlInfo(INT64_C(1000), INT64_C(1000000000)) },
+	{ &controls::FrameDurationLimits, ControlInfo(INT64_C(1000), INT64_C(1000000000)) },
 	{ &controls::draft::NoiseReductionMode, ControlInfo(controls::draft::NoiseReductionModeValues) },
 };
 

src/android/camera_device.cpp

@@ -864,7 +864,7 @@ const camera_metadata_t *CameraDevice::getStaticMetadata()
 
 	int64_t minFrameDurationNsec = -1;
 	int64_t maxFrameDurationNsec = -1;
-	const auto frameDurationsInfo = controlsInfo.find(&controls::FrameDurations);
+	const auto frameDurationsInfo = controlsInfo.find(&controls::FrameDurationLimits);
 	if (frameDurationsInfo != controlsInfo.end()) {
 		minFrameDurationNsec = frameDurationsInfo->second.min().get<int64_t>() * 1000;
 		maxFrameDurationNsec = frameDurationsInfo->second.max().get<int64_t>() * 1000;

src/ipa/raspberrypi/raspberrypi.cpp

@@ -859,7 +859,7 @@ void IPARPi::queueRequest(const ControlList &controls)
 			break;
 		}
 
-		case controls::FRAME_DURATIONS: {
+		case controls::FRAME_DURATION_LIMITS: {
 			auto frameDurations = ctrl.second.get<Span<const int64_t>>();
 			applyFrameDurations(frameDurations[0], frameDurations[1]);
 			break;
@@ -1074,7 +1074,7 @@ void IPARPi::applyFrameDurations(double minFrameDuration, double maxFrameDuratio
 	maxFrameDuration_ = std::max(maxFrameDuration_, minFrameDuration_);
 
 	/* Return the validated limits via metadata. */
-	libcameraMetadata_.set(controls::FrameDurations,
+	libcameraMetadata_.set(controls::FrameDurationLimits,
 			       { static_cast<int64_t>(minFrameDuration_),
 				 static_cast<int64_t>(maxFrameDuration_) });
 

src/libcamera/control_ids.yaml

@@ -323,7 +323,14 @@ controls:
         step to respect the received gain factor and shall report
         their total value in the request metadata.
 
-  - FrameDurations:
+  - FrameDuration:
+      type: int64_t
+      description: |
+        The instantaneous frame duration from start of frame exposure to start
+        of next exposure, expressed in microseconds. This control is meant to
+        be returned in metadata.
+
+  - FrameDurationLimits:
       type: int64_t
       description: |
         The minimum and maximum (in that order) frame duration,

src/libcamera/pipeline/ipu3/ipu3.cpp

@@ -983,7 +983,8 @@ int PipelineHandlerIPU3::initControls(IPU3CameraData *data)
 		frameDurations[i] = frameSize / (sensorInfo.pixelRate / 1000000U);
 	}
 
-	controls[&controls::FrameDurations] = ControlInfo(frameDurations[0],
+	controls[&controls::FrameDurationLimits] =
+		ControlInfo(frameDurations[0],
 			    frameDurations[1],
 			    frameDurations[2]);