uvc: Handle UVC events internally in uvc.c

The event notifier for the UVC device is registered in
uvc_stream_set_event_handler(), which requires exposing the
uvc_events_process() event handler to the uvc_stream class.

Make the event handler internal by registering it in uvc_events_init().
This requires passing the uvc_stream pointer to the uvc_open() function
and storing it internally in the uvc_device object.

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>

5 files changed, 29 insertions, 31 deletions

diff --git a/main.c b/main.c
index 1bff6ef..a99659b 100644
--- a/main.c
+++ b/main.c
@@ -115,8 +115,8 @@ int main(int argc, char *argv[])
 		goto done;
 	}
 
-	uvc_stream_init_uvc(stream, fc);
 	uvc_stream_set_event_handler(stream, &events);
+	uvc_stream_init_uvc(stream, fc);
 
 	/* Main capture loop */
 	events_loop(&events);
diff --git a/stream.c b/stream.c
index b6e0efe..2b95ee8 100644
--- a/stream.c
+++ b/stream.c
@@ -178,11 +178,6 @@ int uvc_stream_set_format(struct uvc_stream *stream)
 	return v4l2_set_format(cap, &fmt);
 }
 
-static int uvc_video_init(struct uvc_device *dev __attribute__((__unused__)))
-{
-	return 0;
-}
-
 /* ---------------------------------------------------------------------------
  * Stream handling
  */
@@ -202,7 +197,7 @@ struct uvc_stream *uvc_stream_new(const char *uvc_device,
 	if (stream->cap == NULL)
 		goto error;
 
-	stream->uvc = uvc_open(uvc_device);
+	stream->uvc = uvc_open(uvc_device, stream);
 	if (stream->uvc == NULL)
 		goto error;
 
@@ -236,15 +231,11 @@ void uvc_stream_init_uvc(struct uvc_stream *stream,
 	stream->uvc->maxsize = 0;
 	stream->uvc->fc = fc;
 
-	uvc_events_init(stream->uvc);
-	uvc_video_init(stream->uvc);
+	uvc_events_init(stream->uvc, stream->events);
 }
 
 void uvc_stream_set_event_handler(struct uvc_stream *stream,
 				  struct events *events)
 {
 	stream->events = events;
-
-	events_watch_fd(stream->events, stream->uvc->vdev->fd, EVENT_EXCEPTION,
-			uvc_events_process, stream);
 }
diff --git a/stream.h b/stream.h
index ba3d8af..4dbe344 100644
--- a/stream.h
+++ b/stream.h
@@ -65,6 +65,12 @@ struct uvc_stream *uvc_stream_new(const char *uvc_device,
  * contains all the parameters of the UVC function that will be handled by the
  * UVC stream. It can be parsed from the UVC function ConfigFS directory using
  * configfs_parse_uvc_function().
+ *
+ * uvc_stream_init_uvc() also registers UVC event notifiers for the stream. The
+ * caller must have called the uvc_stream_set_event_handler() function first,
+ * and ensure that the event handler is immediately usable. If the event loop is
+ * already running, all initialization steps required to handle events must be
+ * fully performed before calling this function.
  */
 void uvc_stream_init_uvc(struct uvc_stream *stream,
 			 struct uvc_function_config *fc);
@@ -75,11 +81,7 @@ void uvc_stream_init_uvc(struct uvc_stream *stream,
  * @events: the event handler
  *
  * This function sets the event handler that the stream can use to be notified
- * of file descriptor events. Event notifiers can be registered by this
- * function, the caller must ensure that the event handler is immediately
- * usable. If the event loop is already running, all initialization steps
- * required to handle events must be fully performed before calling this
- * function.
+ * of file descriptor events.
  */
 void uvc_stream_set_event_handler(struct uvc_stream *stream,
 				  struct events *events);
diff --git a/uvc.c b/uvc.c
index dc8c98e..7131a50 100644
--- a/uvc.c
+++ b/uvc.c
@@ -27,12 +27,13 @@
 #include <sys/ioctl.h>
 
 #include "configfs.h"
+#include "events.h"
 #include "stream.h"
 #include "tools.h"
 #include "uvc.h"
 #include "v4l2.h"
 
-struct uvc_device *uvc_open(const char *devname)
+struct uvc_device *uvc_open(const char *devname, struct uvc_stream *stream)
 {
 	struct uvc_device *dev;
 
@@ -41,6 +42,7 @@ struct uvc_device *uvc_open(const char *devname)
 		return NULL;
 
 	memset(dev, 0, sizeof *dev);
+	dev->stream = stream;
 
 	dev->vdev = v4l2_open(devname);
 	if (dev->vdev == NULL) {
@@ -229,10 +231,9 @@ uvc_events_process_setup(struct uvc_device *dev,
 }
 
 static void
-uvc_events_process_data(struct uvc_stream *stream,
+uvc_events_process_data(struct uvc_device *dev,
 			const struct uvc_request_data *data)
 {
-	struct uvc_device *dev = stream->uvc;
 	const struct uvc_streaming_control *ctrl =
 		(const struct uvc_streaming_control *)&data->data;
 	struct uvc_streaming_control *target;
@@ -267,14 +268,13 @@ uvc_events_process_data(struct uvc_stream *stream,
 		dev->width = frame->width;
 		dev->height = frame->height;
 
-		uvc_stream_set_format(stream);
+		uvc_stream_set_format(dev->stream);
 	}
 }
 
-void uvc_events_process(void *d)
+static void uvc_events_process(void *d)
 {
-	struct uvc_stream *stream = d;
-	struct uvc_device *dev = stream->uvc;
+	struct uvc_device *dev = d;
 	struct v4l2_event v4l2_event;
 	const struct uvc_event *uvc_event = (void *)&v4l2_event.u.data;
 	struct uvc_request_data resp;
@@ -300,15 +300,15 @@ void uvc_events_process(void *d)
 		break;
 
 	case UVC_EVENT_DATA:
-		uvc_events_process_data(stream, &uvc_event->data);
+		uvc_events_process_data(dev, &uvc_event->data);
 		return;
 
 	case UVC_EVENT_STREAMON:
-		uvc_stream_enable(stream, 1);
+		uvc_stream_enable(dev->stream, 1);
 		return;
 
 	case UVC_EVENT_STREAMOFF:
-		uvc_stream_enable(stream, 0);
+		uvc_stream_enable(dev->stream, 0);
 		return;
 	}
 
@@ -320,7 +320,7 @@ void uvc_events_process(void *d)
 	}
 }
 
-void uvc_events_init(struct uvc_device *dev)
+void uvc_events_init(struct uvc_device *dev, struct events *events)
 {
 	struct v4l2_event_subscription sub;
 
@@ -337,4 +337,7 @@ void uvc_events_init(struct uvc_device *dev)
 	ioctl(dev->vdev->fd, VIDIOC_SUBSCRIBE_EVENT, &sub);
 	sub.type = UVC_EVENT_STREAMOFF;
 	ioctl(dev->vdev->fd, VIDIOC_SUBSCRIBE_EVENT, &sub);
+
+	events_watch_fd(events, dev->vdev->fd, EVENT_EXCEPTION,
+			uvc_events_process, dev);
 }
diff --git a/uvc.h b/uvc.h
index bfbf2fe..febc662 100644
--- a/uvc.h
+++ b/uvc.h
@@ -22,13 +22,16 @@
 
 #include <linux/usb/video.h>
 
+struct events;
 struct v4l2_device;
 struct uvc_function_config;
+struct uvc_stream;
 
 struct uvc_device
 {
 	struct v4l2_device *vdev;
 
+	struct uvc_stream *stream;
 	struct uvc_function_config *fc;
 
 	struct uvc_streaming_control probe;
@@ -42,9 +45,8 @@ struct uvc_device
 	unsigned int maxsize;
 };
 
-void uvc_events_process(void *d);
-struct uvc_device *uvc_open(const char *devname);
+struct uvc_device *uvc_open(const char *devname, struct uvc_stream *stream);
 void uvc_close(struct uvc_device *dev);
-void uvc_events_init(struct uvc_device *dev);
+void uvc_events_init(struct uvc_device *dev, struct events *events);
 
 #endif /* __UVC_H__ */