controls: rpi: Add a vendor rpi::ScalerCrops control

Add a vendor control rpi::ScalerCrops that is analogous to the current
core::ScalerCrop, but can apply a different crop to each configured
stream.

This control takes a span of Rectangle structures - the order of
rectangles must match the order of streams configured by the application.

Signed-off-by: Naushir Patuck <naush@raspberrypi.com>
Reviewed-by: Jacopo Mondi <jacopo.mondi@ideasonboard.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>

src/ipa/rpi/common/ipa_base.cpp

@@ -96,6 +96,13 @@ const ControlInfoMap::Map ipaAfControls{
 	{ &controls::LensPosition, ControlInfo(0.0f, 32.0f, 1.0f) }
 };
 
+/* Platform specific controls */
+const std::map<const std::string, ControlInfoMap::Map> platformControls {
+	{ "pisp", {
+		{ &controls::rpi::ScalerCrops, ControlInfo(Rectangle{}, Rectangle(65535, 65535, 65535, 65535), Rectangle{}) }
+	} },
+};
+
 } /* namespace */
 
 LOG_DEFINE_CATEGORY(IPARPI)
@@ -159,6 +166,10 @@ int32_t IpaBase::init(const IPASettings &settings, const InitParams &params, Ini
 	if (lensPresent_)
 		ctrlMap.merge(ControlInfoMap::Map(ipaAfControls));
 
+	auto platformCtrlsIt = platformControls.find(controller_.getTarget());
+	if (platformCtrlsIt != platformControls.end())
+		ctrlMap.merge(ControlInfoMap::Map(platformCtrlsIt->second));
+
 	monoSensor_ = params.sensorInfo.cfaPattern == properties::draft::ColorFilterArrangementEnum::MONO;
 	if (!monoSensor_)
 		ctrlMap.merge(ControlInfoMap::Map(ipaColourControls));
@@ -1070,6 +1081,7 @@ void IpaBase::applyControls(const ControlList &controls)
 			break;
 		}
 
+		case controls::rpi::SCALER_CROPS:
 		case controls::SCALER_CROP: {
 			/* We do nothing with this, but should avoid the warning below. */
 			break;

src/libcamera/control_ids_rpi.yaml

@@ -30,4 +30,29 @@ controls:
 
         \sa StatsOutputEnable
 
+  - ScalerCrops:
+      type: Rectangle
+      size: [n]
+      description: |
+        An array of rectangles, where each singular value has identical
+        functionality to the ScalerCrop control. This control allows the
+        Raspberry Pi pipeline handler to control individual scaler crops per
+        output stream.
+
+        The order of rectangles passed into the control must match the order of
+        streams configured by the application. The pipeline handler will only
+        configure crop retangles up-to the number of output streams configured.
+        All subsequent rectangles passed into this control are ignored by the
+        pipeline handler.
+
+        If both rpi::ScalerCrops and ScalerCrop controls are present in a
+        ControlList, the latter is discarded, and crops are obtained from this
+        control.
+
+        Note that using different crop rectangles for each output stream with
+        this control is only applicable on the Pi5/PiSP platform. This control
+        should also be considered temporary/draft and will be replaced with
+        official libcamera API support for per-stream controls in the future.
+
+        \sa ScalerCrop
 ...