[media] media: Move media_device link_notify operation to an ops structure

This will allow adding new operations without increasing the
media_device structure size for drivers that don't implement any media
device operation.
Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Acked-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>

drivers/media/media-entity.c

@@ -808,8 +808,8 @@ int __media_entity_setup_link(struct media_link *link, u32 flags)
 
 	mdev = source->graph_obj.mdev;
 
-	if (mdev->link_notify) {
-		ret = mdev->link_notify(link, flags,
+	if (mdev->ops && mdev->ops->link_notify) {
+		ret = mdev->ops->link_notify(link, flags,
 					     MEDIA_DEV_NOTIFY_PRE_LINK_CH);
 		if (ret < 0)
 			return ret;
@@ -817,8 +817,9 @@ int __media_entity_setup_link(struct media_link *link, u32 flags)
 
 	ret = __media_entity_setup_link_notify(link, flags);
 
-	if (mdev->link_notify)
-		mdev->link_notify(link, flags, MEDIA_DEV_NOTIFY_POST_LINK_CH);
+	if (mdev->ops && mdev->ops->link_notify)
+		mdev->ops->link_notify(link, flags,
+				       MEDIA_DEV_NOTIFY_POST_LINK_CH);
 
 	return ret;
 }

drivers/media/platform/exynos4-is/media-dev.c

@@ -1190,6 +1190,10 @@ static int fimc_md_link_notify(struct media_link *link, unsigned int flags,
 	return ret ? -EPIPE : 0;
 }
 
+static const struct media_device_ops fimc_md_ops = {
+	.link_notify = fimc_md_link_notify,
+};
+
 static ssize_t fimc_md_sysfs_show(struct device *dev,
 				  struct device_attribute *attr, char *buf)
 {
@@ -1416,7 +1420,7 @@ static int fimc_md_probe(struct platform_device *pdev)
 
 	strlcpy(fmd->media_dev.model, "SAMSUNG S5P FIMC",
 		sizeof(fmd->media_dev.model));
-	fmd->media_dev.link_notify = fimc_md_link_notify;
+	fmd->media_dev.ops = &fimc_md_ops;
 	fmd->media_dev.dev = dev;
 
 	v4l2_dev = &fmd->v4l2_dev;

drivers/media/platform/omap3isp/isp.c

@@ -657,6 +657,10 @@ static irqreturn_t isp_isr(int irq, void *_isp)
 	return IRQ_HANDLED;
 }
 
+static const struct media_device_ops isp_media_ops = {
+	.link_notify = v4l2_pipeline_link_notify,
+};
+
 /* -----------------------------------------------------------------------------
  * Pipeline stream management
  */
@@ -1680,7 +1684,7 @@ static int isp_register_entities(struct isp_device *isp)
 	strlcpy(isp->media_dev.model, "TI OMAP3 ISP",
 		sizeof(isp->media_dev.model));
 	isp->media_dev.hw_revision = isp->revision;
-	isp->media_dev.link_notify = v4l2_pipeline_link_notify;
+	isp->media_dev.ops = &isp_media_ops;
 	media_device_init(&isp->media_dev);
 
 	isp->v4l2_dev.mdev = &isp->media_dev;

drivers/staging/media/omap4iss/iss.c

@@ -362,6 +362,10 @@ static irqreturn_t iss_isr(int irq, void *_iss)
 	return IRQ_HANDLED;
 }
 
+static const struct media_device_ops iss_media_ops = {
+	.link_notify = v4l2_pipeline_link_notify,
+};
+
 /* -----------------------------------------------------------------------------
  * Pipeline stream management
  */
@@ -988,7 +992,7 @@ static int iss_register_entities(struct iss_device *iss)
 	strlcpy(iss->media_dev.model, "TI OMAP4 ISS",
 		sizeof(iss->media_dev.model));
 	iss->media_dev.hw_revision = iss->revision;
-	iss->media_dev.link_notify = v4l2_pipeline_link_notify;
+	iss->media_dev.ops = &iss_media_ops;
 	ret = media_device_register(&iss->media_dev);
 	if (ret < 0) {
 		dev_err(iss->dev, "Media device registration failed (%d)\n",

include/media/media-device.h

@@ -48,6 +48,16 @@ struct media_entity_notify {
 	void (*notify)(struct media_entity *entity, void *notify_data);
 };
 
+/**
+ * struct media_device_ops - Media device operations
+ * @link_notify: Link state change notification callback. This callback is
+ *		 called with the graph_mutex held.
+ */
+struct media_device_ops {
+	int (*link_notify)(struct media_link *link, u32 flags,
+			   unsigned int notification);
+};
+
 /**
  * struct media_device - Media device
  * @dev:	Parent device
@@ -80,8 +90,7 @@ struct media_entity_notify {
  * @enable_source: Enable Source Handler function pointer
  * @disable_source: Disable Source Handler function pointer
  *
- * @link_notify: Link state change notification callback. This callback is
- *		 called with the graph_mutex held.
+ * @ops:	Operation handler callbacks
  *
  * This structure represents an abstract high-level media device. It allows easy
  * access to entities and provides basic media device-level support. The
@@ -150,8 +159,7 @@ struct media_device {
 			     struct media_pipeline *pipe);
 	void (*disable_source)(struct media_entity *entity);
 
-	int (*link_notify)(struct media_link *link, u32 flags,
-			   unsigned int notification);
+	const struct media_device_ops *ops;
 };
 
 /* We don't need to include pci.h or usb.h here */