libcamera: camera: Add helper to check for exclusive access

Some operations on the camera requires the application to have exclusive
access to the camera. To help check for this in these operations add a
helper.

Signed-off-by: Niklas Söderlund <niklas.soderlund@ragnatech.se>
Signed-off-by: Jacopo Mondi <jacopo@jmondi.org>
Signed-off-by: Kieran Bingham <kieran.bingham@ideasonboard.com>
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>

1 files changed, 18 insertions, 4 deletions

diff --git a/src/libcamera/camera.cpp b/src/libcamera/camera.cpp
index e8dab6f0..62291d2c 100644
--- a/src/libcamera/camera.cpp
+++ b/src/libcamera/camera.cpp
@@ -241,16 +241,30 @@ Camera::streamConfiguration(std::vector<Stream *> &streams)
  */
 int Camera::configureStreams(std::map<Stream *, StreamConfiguration> &config)
 {
+	int ret;
+
+	ret = exclusiveAccess();
+	if (ret)
+		return ret;
+
+	if (!config.size()) {
+		LOG(Camera, Error)
+			<< "Can't configure streams without a configuration";
+		return -EINVAL;
+	}
+
+	return pipe_->configureStreams(this, config);
+}
+
+int Camera::exclusiveAccess()
+{
 	if (disconnected_)
 		return -ENODEV;
 
 	if (!acquired_)
 		return -EACCES;
 
-	if (!config.size())
-		return -EINVAL;
-
-	return pipe_->configureStreams(this, config);
+	return 0;
 }
 
 } /* namespace libcamera */