[libcamera-devel] [PATCH 2/2] android: camera_hal_manager: Support camera hotplug

[Umang Jain]

Extend the support for camera hotplug from libcamera's CameraManager
to CameraHalManager. Use camera module callbacks to let the framework
know about the hotplug events and change the status of cameras being
being hotplugged or unplugged via camera_device_status_change().

Signed-off-by: Umang Jain <email at uajain.com>
---
 src/android/camera_device.h        |  1 +
 src/android/camera_hal_manager.cpp | 40 ++++++++++++++++++++++++++++--
 src/android/camera_hal_manager.h   |  3 +++
 3 files changed, 42 insertions(+), 2 deletions(-)

diff --git a/src/android/camera_device.h b/src/android/camera_device.h
index 4e5fb98..fa9706c 100644
--- a/src/android/camera_device.h
+++ b/src/android/camera_device.h
@@ -47,6 +47,7 @@ public:
 
 	unsigned int id() const { return id_; }
 	camera3_device_t *camera3Device() { return &camera3Device_; }
+	const libcamera::Camera *getCamera() { return camera_.get(); };
 
 	int facing() const { return facing_; }
 	int orientation() const { return orientation_; }
diff --git a/src/android/camera_hal_manager.cpp b/src/android/camera_hal_manager.cpp
index 3ddcab5..b498278 100644
--- a/src/android/camera_hal_manager.cpp
+++ b/src/android/camera_hal_manager.cpp
@@ -59,8 +59,6 @@ int CameraHalManager::init()
 	/*
 	 * For each Camera registered in the system, a CameraDevice
 	 * gets created here to wraps a libcamera Camera instance.
-	 *
-	 * \todo Support camera hotplug.
 	 */
 	unsigned int index = 0;
 	for (auto &cam : cameraManager_->cameras()) {
@@ -73,6 +71,10 @@ int CameraHalManager::init()
 		++index;
 	}
 
+	/* Support camera hotplug */
+	cameraManager_->cameraAdded.connect(this, &CameraHalManager::cameraAdded);
+	cameraManager_->cameraRemoved.connect(this, &CameraHalManager::cameraRemoved);
+
 	return 0;
 }
 
@@ -93,6 +95,40 @@ CameraDevice *CameraHalManager::open(unsigned int id,
 	return camera;
 }
 
+void CameraHalManager::cameraAdded(std::shared_ptr<Camera> cam)
+{
+	unsigned int id = cameras_.size();
+	CameraDevice *camera = new CameraDevice(id, cam);
+	int ret = camera->initialize();
+	if (ret) {
+		LOG(HAL, Error) << "Failed to initialize camera: " << cam->name();
+		return;
+	}
+
+	cameras_.emplace_back(camera);
+	callbacks_->camera_device_status_change(callbacks_, id,
+						CAMERA_DEVICE_STATUS_PRESENT);
+	LOG(HAL, Debug) << "Camera " << cam->name() << " ID:" << id
+			<< " added and initialized successfully.";
+}
+
+void CameraHalManager::cameraRemoved(std::shared_ptr<Camera> cam)
+{
+	auto iter = std::find_if(cameras_.begin(), cameras_.end(),
+				[cam](std::unique_ptr<CameraDevice> &camera) {
+					return cam.get() == camera->getCamera();
+				});
+	if (iter == cameras_.end())
+		return;
+
+	unsigned int id = (*iter)->id();
+	callbacks_->camera_device_status_change(callbacks_, id,
+						CAMERA_DEVICE_STATUS_NOT_PRESENT);
+	cameras_.erase(iter);
+	LOG(HAL, Debug) << "Camera " << cam->name() << " ID:" << id
+			<< " removed successfully.";
+}
+
 unsigned int CameraHalManager::numCameras() const
 {
 	return cameraManager_->cameras().size();
diff --git a/src/android/camera_hal_manager.h b/src/android/camera_hal_manager.h
index 4345b1e..52ab9e2 100644
--- a/src/android/camera_hal_manager.h
+++ b/src/android/camera_hal_manager.h
@@ -33,6 +33,9 @@ public:
 	int setCallbacks(const camera_module_callbacks_t *callbacks);
 
 private:
+	void cameraAdded(std::shared_ptr<libcamera::Camera> cam);
+	void cameraRemoved(std::shared_ptr<libcamera::Camera> cam);
+
 	libcamera::CameraManager *cameraManager_;
 
 	const camera_module_callbacks_t *callbacks_;
-- 
2.26.2