[PATCH v2 2/2] libcamera: pipeline: uvcvideo: Fix `ExposureTimeMode` control setting

[Barnabás Pőcze]

The mapping in `UVCCameraData::processControl()` is not entirely correct
because the control value is retrieved as a `bool` instead of `int32_t`.
Additionally, the available modes are not taken into account.

To fix this, retrieve the control with the proper type - `int32_t` -,
and use the available modes stored in `UVCCameraData` to determine
which value to use for the V4L2 control.

Fixes: bad8d591f8acfa ("libcamera: uvcvideo: Register ExposureTimeMode control")
Signed-off-by: Barnabás Pőcze <pobrn at protonmail.com>
---
 src/libcamera/pipeline/uvcvideo/uvcvideo.cpp | 38 +++++++++++++++-----
 1 file changed, 29 insertions(+), 9 deletions(-)

diff --git a/src/libcamera/pipeline/uvcvideo/uvcvideo.cpp b/src/libcamera/pipeline/uvcvideo/uvcvideo.cpp
index 1f604b91e..adab6aa18 100644
--- a/src/libcamera/pipeline/uvcvideo/uvcvideo.cpp
+++ b/src/libcamera/pipeline/uvcvideo/uvcvideo.cpp
@@ -103,8 +103,8 @@ public:
 	bool match(DeviceEnumerator *enumerator) override;
 
 private:
-	int processControl(ControlList *controls, unsigned int id,
-			   const ControlValue &value);
+	int processControl(UVCCameraData *data, ControlList *controls,
+			   unsigned int id, const ControlValue &value);
 	int processControls(UVCCameraData *data, Request *request);
 
 	bool acquireDevice(Camera *camera) override;
@@ -297,8 +297,8 @@ void PipelineHandlerUVC::stopDevice(Camera *camera)
 	data->video_->releaseBuffers();
 }
 
-int PipelineHandlerUVC::processControl(ControlList *controls, unsigned int id,
-				       const ControlValue &value)
+int PipelineHandlerUVC::processControl(UVCCameraData *data, ControlList *controls,
+				       unsigned int id, const ControlValue &value)
 {
 	uint32_t cid;
 
@@ -342,10 +342,30 @@ int PipelineHandlerUVC::processControl(ControlList *controls, unsigned int id,
 	}
 
 	case V4L2_CID_EXPOSURE_AUTO: {
-		int32_t ivalue = value.get<bool>()
-			       ? V4L2_EXPOSURE_APERTURE_PRIORITY
-			       : V4L2_EXPOSURE_MANUAL;
-		controls->set(V4L2_CID_EXPOSURE_AUTO, ivalue);
+		v4l2_exposure_auto_type exposureMode = {};
+
+		switch (value.get<int32_t>()) {
+		case controls::ExposureTimeModeAuto:
+			if (data->availableExposureModes_[V4L2_EXPOSURE_AUTO])
+				exposureMode = V4L2_EXPOSURE_AUTO;
+			else if (data->availableExposureModes_[V4L2_EXPOSURE_APERTURE_PRIORITY])
+				exposureMode = V4L2_EXPOSURE_APERTURE_PRIORITY;
+			else
+				ASSERT(false);
+			break;
+		case controls::ExposureTimeModeManual:
+			if (data->availableExposureModes_[V4L2_EXPOSURE_MANUAL])
+				exposureMode = V4L2_EXPOSURE_MANUAL;
+			else if (data->availableExposureModes_[V4L2_EXPOSURE_SHUTTER_PRIORITY])
+				exposureMode = V4L2_EXPOSURE_SHUTTER_PRIORITY;
+			else
+				ASSERT(false);
+			break;
+		default:
+			return -EINVAL;
+		}
+
+		controls->set(V4L2_CID_EXPOSURE_AUTO, exposureMode);
 		break;
 	}
 
@@ -383,7 +403,7 @@ int PipelineHandlerUVC::processControls(UVCCameraData *data, Request *request)
 	ControlList controls(data->video_->controls());
 
 	for (const auto &[id, value] : request->controls())
-		processControl(&controls, id, value);
+		processControl(data, &controls, id, value);
 
 	for (const auto &ctrl : controls)
 		LOG(UVC, Debug)
-- 
2.48.1