V4L/DVB: soc-camera: allow only one video queue per device

Multiple user-space application instances can open the same video device, but
it only makes sense for one of them to manage the videobuffer queue and set
video format of the device. Restrict soc-camera respectively.
Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

drivers/media/video/mx1_camera.c

@@ -638,7 +638,7 @@ static int mx1_camera_try_fmt(struct soc_camera_device *icd,
 	return 0;
 }
 
-static int mx1_camera_reqbufs(struct soc_camera_file *icf,
+static int mx1_camera_reqbufs(struct soc_camera_device *icd,
 			      struct v4l2_requestbuffers *p)
 {
 	int i;
@@ -650,7 +650,7 @@ static int mx1_camera_reqbufs(struct soc_camera_file *icf,
 	 * it hadn't triggered
 	 */
 	for (i = 0; i < p->count; i++) {
-		struct mx1_buffer *buf = container_of(icf->vb_vidq.bufs[i],
+		struct mx1_buffer *buf = container_of(icd->vb_vidq.bufs[i],
 						      struct mx1_buffer, vb);
 		buf->inwork = 0;
 		INIT_LIST_HEAD(&buf->vb.queue);
@@ -661,10 +661,10 @@ static int mx1_camera_reqbufs(struct soc_camera_file *icf,
 
 static unsigned int mx1_camera_poll(struct file *file, poll_table *pt)
 {
-	struct soc_camera_file *icf = file->private_data;
+	struct soc_camera_device *icd = file->private_data;
 	struct mx1_buffer *buf;
 
-	buf = list_entry(icf->vb_vidq.stream.next, struct mx1_buffer,
+	buf = list_entry(icd->vb_vidq.stream.next, struct mx1_buffer,
 			 vb.stream);
 
 	poll_wait(file, &buf->vb.done, pt);

drivers/media/video/mx3_camera.c

@@ -976,7 +976,7 @@ static int mx3_camera_try_fmt(struct soc_camera_device *icd,
 	return ret;
 }
 
-static int mx3_camera_reqbufs(struct soc_camera_file *icf,
+static int mx3_camera_reqbufs(struct soc_camera_device *icd,
 			      struct v4l2_requestbuffers *p)
 {
 	return 0;
@@ -984,9 +984,9 @@ static int mx3_camera_reqbufs(struct soc_camera_file *icf,
 
 static unsigned int mx3_camera_poll(struct file *file, poll_table *pt)
 {
-	struct soc_camera_file *icf = file->private_data;
+	struct soc_camera_device *icd = file->private_data;
 
-	return videobuf_poll_stream(file, &icf->vb_vidq, pt);
+	return videobuf_poll_stream(file, &icd->vb_vidq, pt);
 }
 
 static int mx3_camera_querycap(struct soc_camera_host *ici,

drivers/media/video/pxa_camera.c

@@ -1539,7 +1539,7 @@ static int pxa_camera_try_fmt(struct soc_camera_device *icd,
 	return ret;
 }
 
-static int pxa_camera_reqbufs(struct soc_camera_file *icf,
+static int pxa_camera_reqbufs(struct soc_camera_device *icd,
 			      struct v4l2_requestbuffers *p)
 {
 	int i;
@@ -1551,7 +1551,7 @@ static int pxa_camera_reqbufs(struct soc_camera_file *icf,
 	 * it hadn't triggered
 	 */
 	for (i = 0; i < p->count; i++) {
-		struct pxa_buffer *buf = container_of(icf->vb_vidq.bufs[i],
+		struct pxa_buffer *buf = container_of(icd->vb_vidq.bufs[i],
 						      struct pxa_buffer, vb);
 		buf->inwork = 0;
 		INIT_LIST_HEAD(&buf->vb.queue);
@@ -1562,10 +1562,10 @@ static int pxa_camera_reqbufs(struct soc_camera_file *icf,
 
 static unsigned int pxa_camera_poll(struct file *file, poll_table *pt)
 {
-	struct soc_camera_file *icf = file->private_data;
+	struct soc_camera_device *icd = file->private_data;
 	struct pxa_buffer *buf;
 
-	buf = list_entry(icf->vb_vidq.stream.next, struct pxa_buffer,
+	buf = list_entry(icd->vb_vidq.stream.next, struct pxa_buffer,
 			 vb.stream);
 
 	poll_wait(file, &buf->vb.done, pt);

drivers/media/video/sh_mobile_ceu_camera.c

@@ -1726,7 +1726,7 @@ static int sh_mobile_ceu_try_fmt(struct soc_camera_device *icd,
 	return ret;
 }
 
-static int sh_mobile_ceu_reqbufs(struct soc_camera_file *icf,
+static int sh_mobile_ceu_reqbufs(struct soc_camera_device *icd,
 				 struct v4l2_requestbuffers *p)
 {
 	int i;
@@ -1740,7 +1740,7 @@ static int sh_mobile_ceu_reqbufs(struct soc_camera_file *icf,
 	for (i = 0; i < p->count; i++) {
 		struct sh_mobile_ceu_buffer *buf;
 
-		buf = container_of(icf->vb_vidq.bufs[i],
+		buf = container_of(icd->vb_vidq.bufs[i],
 				   struct sh_mobile_ceu_buffer, vb);
 		INIT_LIST_HEAD(&buf->vb.queue);
 	}
@@ -1750,10 +1750,10 @@ static int sh_mobile_ceu_reqbufs(struct soc_camera_file *icf,
 
 static unsigned int sh_mobile_ceu_poll(struct file *file, poll_table *pt)
 {
-	struct soc_camera_file *icf = file->private_data;
+	struct soc_camera_device *icd = file->private_data;
 	struct sh_mobile_ceu_buffer *buf;
 
-	buf = list_entry(icf->vb_vidq.stream.next,
+	buf = list_entry(icd->vb_vidq.stream.next,
 			 struct sh_mobile_ceu_buffer, vb.stream);
 
 	poll_wait(file, &buf->vb.done, pt);

include/media/soc_camera.h

@@ -21,6 +21,8 @@
 
 extern struct bus_type soc_camera_bus_type;
 
+struct file;
+
 struct soc_camera_device {
 	struct list_head list;
 	struct device dev;
@@ -41,10 +43,7 @@ struct soc_camera_device {
 	/* soc_camera.c private count. Only accessed with .video_lock held */
 	int use_count;
 	struct mutex video_lock;	/* Protects device data */
-};
-
-struct soc_camera_file {
-	struct soc_camera_device *icd;
+	struct file *streamer;		/* stream owner */
 	struct videobuf_queue vb_vidq;
 };
 
@@ -79,7 +78,7 @@ struct soc_camera_host_ops {
 	int (*try_fmt)(struct soc_camera_device *, struct v4l2_format *);
 	void (*init_videobuf)(struct videobuf_queue *,
 			      struct soc_camera_device *);
-	int (*reqbufs)(struct soc_camera_file *, struct v4l2_requestbuffers *);
+	int (*reqbufs)(struct soc_camera_device *, struct v4l2_requestbuffers *);
 	int (*querycap)(struct soc_camera_host *, struct v4l2_capability *);
 	int (*set_bus_param)(struct soc_camera_device *, __u32);
 	int (*get_ctrl)(struct soc_camera_device *, struct v4l2_control *);