[PATCH v2] libcamera: camera_sensor: Cache pixel rate

[Paul Elder]

Cache the pixel rate at set format time instead of fetching it from the
v4l2 subdev every time it's needed.

It needs to be cached at set format time as opposed to initialization
time as some sensor drives (eg. imx708) change the pixel rate depending
on the mode.

Signed-off-by: Paul Elder <paul.elder at ideasonboard.com>

---
Changes in v2:
- Cache the pixel rate at set format time instead of at initialization
  time
---
 include/libcamera/internal/camera_sensor.h | 2 ++
 src/libcamera/camera_sensor.cpp            | 8 +++++++-
 2 files changed, 9 insertions(+), 1 deletion(-)

diff --git a/include/libcamera/internal/camera_sensor.h b/include/libcamera/internal/camera_sensor.h
index 60a8b106d..da3bf12b3 100644
--- a/include/libcamera/internal/camera_sensor.h
+++ b/include/libcamera/internal/camera_sensor.h
@@ -105,6 +105,8 @@ private:
 	std::string model_;
 	std::string id_;
 
+	uint64_t pixelRate_;
+
 	V4L2Subdevice::Formats formats_;
 	std::vector<unsigned int> mbusCodes_;
 	std::vector<Size> sizes_;
diff --git a/src/libcamera/camera_sensor.cpp b/src/libcamera/camera_sensor.cpp
index 0ef78d9c8..127610321 100644
--- a/src/libcamera/camera_sensor.cpp
+++ b/src/libcamera/camera_sensor.cpp
@@ -515,6 +515,9 @@ int CameraSensor::initProperties()
 		properties_.set(properties::draft::ColorFilterArrangement, cfa);
 	}
 
+	ControlList ctrls = subdev_->getControls({ V4L2_CID_PIXEL_RATE });
+	pixelRate_ = ctrls.get(V4L2_CID_PIXEL_RATE).get<int64_t>();
+
 	return 0;
 }
 
@@ -814,6 +817,9 @@ int CameraSensor::setFormat(V4L2SubdeviceFormat *format, Transform transform)
 	if (ret)
 		return ret;
 
+	ControlList ctrls = subdev_->getControls({ V4L2_CID_PIXEL_RATE });
+	pixelRate_ = ctrls.get(V4L2_CID_PIXEL_RATE).get<int64_t>();
+
 	updateControlInfo();
 	return 0;
 }
@@ -1080,7 +1086,7 @@ int CameraSensor::sensorInfo(IPACameraSensorInfo *info) const
 		return -EINVAL;
 	}
 
-	info->pixelRate = ctrls.get(V4L2_CID_PIXEL_RATE).get<int64_t>();
+	info->pixelRate = pixelRate_;
 
 	const ControlInfo hblank = ctrls.infoMap()->at(V4L2_CID_HBLANK);
 	info->minLineLength = info->outputSize.width + hblank.min().get<int32_t>();
-- 
2.39.2