media: platform: Switch to v4l2_async_notifier_add_subdev

Switch all media platform drivers to call v4l2_async_notifier_add_subdev()
to add asd's to a notifier, in place of referencing the notifier->subdevs[]
array. These drivers also must now call v4l2_async_notifier_init() before
adding asd's to their notifiers.

There may still be cases where a platform driver maintains a list of
asd's that is a duplicate of the notifier asd_list, in which case its
possible the platform driver list can be removed, and can reference the
notifier asd_list instead. One example of where a duplicate list has
been removed in this patch is xilinx-vipp.c. If there are such cases
remaining, those drivers should be optimized to remove the duplicate
platform driver asd lists.

None of the changes to the platform drivers in this patch have been
tested. Verify that the async subdevices needed by the platform are
bound at load time, and that the driver unloads and reloads correctly
with no memory leaking of asd objects.

Suggested-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Steve Longerbeam <slongerbeam@gmail.com>
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>

21 files changed, 416 insertions, 332 deletions

diff --git a/drivers/media/pci/intel/ipu3/ipu3-cio2.c b/drivers/media/pci/intel/ipu3/ipu3-cio2.c
index d7926c31388f..06b422233215 100644
--- a/drivers/media/pci/intel/ipu3/ipu3-cio2.c
+++ b/drivers/media/pci/intel/ipu3/ipu3-cio2.c
@@ -1506,7 +1506,7 @@ static int cio2_notifier_init(struct cio2_device *cio2)
 	if (ret < 0)
 		return ret;
 
-	if (!cio2->notifier.num_subdevs)
+	if (list_empty(&cio2->notifier.asd_list))
 		return -ENODEV;	/* no endpoint */
 
 	cio2->notifier.ops = &cio2_async_ops;
diff --git a/drivers/media/platform/am437x/am437x-vpfe.c b/drivers/media/platform/am437x/am437x-vpfe.c
index cac6aec0ffa7..0b1a03b64b19 100644
--- a/drivers/media/platform/am437x/am437x-vpfe.c
+++ b/drivers/media/platform/am437x/am437x-vpfe.c
@@ -2423,30 +2423,32 @@ static const struct v4l2_async_notifier_operations vpfe_async_ops = {
 };
 
 static struct vpfe_config *
-vpfe_get_pdata(struct platform_device *pdev)
+vpfe_get_pdata(struct vpfe_device *vpfe)
 {
 	struct device_node *endpoint = NULL;
 	struct v4l2_fwnode_endpoint bus_cfg;
+	struct device *dev = vpfe->pdev;
 	struct vpfe_subdev_info *sdinfo;
 	struct vpfe_config *pdata;
 	unsigned int flags;
 	unsigned int i;
 	int err;
 
-	dev_dbg(&pdev->dev, "vpfe_get_pdata\n");
+	dev_dbg(dev, "vpfe_get_pdata\n");
 
-	if (!IS_ENABLED(CONFIG_OF) || !pdev->dev.of_node)
-		return pdev->dev.platform_data;
+	v4l2_async_notifier_init(&vpfe->notifier);
 
-	pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL);
+	if (!IS_ENABLED(CONFIG_OF) || !dev->of_node)
+		return dev->platform_data;
+
+	pdata = devm_kzalloc(dev, sizeof(*pdata), GFP_KERNEL);
 	if (!pdata)
 		return NULL;
 
 	for (i = 0; ; i++) {
 		struct device_node *rem;
 
-		endpoint = of_graph_get_next_endpoint(pdev->dev.of_node,
-						      endpoint);
+		endpoint = of_graph_get_next_endpoint(dev->of_node, endpoint);
 		if (!endpoint)
 			break;
 
@@ -2474,16 +2476,16 @@ vpfe_get_pdata(struct platform_device *pdev)
 		err = v4l2_fwnode_endpoint_parse(of_fwnode_handle(endpoint),
 						 &bus_cfg);
 		if (err) {
-			dev_err(&pdev->dev, "Could not parse the endpoint\n");
-			goto done;
+			dev_err(dev, "Could not parse the endpoint\n");
+			goto cleanup;
 		}
 
 		sdinfo->vpfe_param.bus_width = bus_cfg.bus.parallel.bus_width;
 
 		if (sdinfo->vpfe_param.bus_width < 8 ||
 			sdinfo->vpfe_param.bus_width > 16) {
-			dev_err(&pdev->dev, "Invalid bus width.\n");
-			goto done;
+			dev_err(dev, "Invalid bus width.\n");
+			goto cleanup;
 		}
 
 		flags = bus_cfg.bus.parallel.flags;
@@ -2496,29 +2498,25 @@ vpfe_get_pdata(struct platform_device *pdev)
 
 		rem = of_graph_get_remote_port_parent(endpoint);
 		if (!rem) {
-			dev_err(&pdev->dev, "Remote device at %pOF not found\n",
+			dev_err(dev, "Remote device at %pOF not found\n",
 				endpoint);
-			goto done;
+			goto cleanup;
 		}
 
-		pdata->asd[i] = devm_kzalloc(&pdev->dev,
-					     sizeof(struct v4l2_async_subdev),
-					     GFP_KERNEL);
-		if (!pdata->asd[i]) {
+		pdata->asd[i] = v4l2_async_notifier_add_fwnode_subdev(
+			&vpfe->notifier, of_fwnode_handle(rem),
+			sizeof(struct v4l2_async_subdev));
+		if (IS_ERR(pdata->asd[i])) {
 			of_node_put(rem);
-			pdata = NULL;
-			goto done;
+			goto cleanup;
 		}
-
-		pdata->asd[i]->match_type = V4L2_ASYNC_MATCH_FWNODE;
-		pdata->asd[i]->match.fwnode = of_fwnode_handle(rem);
-		of_node_put(rem);
 	}
 
 	of_node_put(endpoint);
 	return pdata;
 
-done:
+cleanup:
+	v4l2_async_notifier_cleanup(&vpfe->notifier);
 	of_node_put(endpoint);
 	return NULL;
 }
@@ -2530,34 +2528,39 @@ done:
  */
 static int vpfe_probe(struct platform_device *pdev)
 {
-	struct vpfe_config *vpfe_cfg = vpfe_get_pdata(pdev);
+	struct vpfe_config *vpfe_cfg;
 	struct vpfe_device *vpfe;
 	struct vpfe_ccdc *ccdc;
 	struct resource	*res;
 	int ret;
 
-	if (!vpfe_cfg) {
-		dev_err(&pdev->dev, "No platform data\n");
-		return -EINVAL;
-	}
-
 	vpfe = devm_kzalloc(&pdev->dev, sizeof(*vpfe), GFP_KERNEL);
 	if (!vpfe)
 		return -ENOMEM;
 
 	vpfe->pdev = &pdev->dev;
+
+	vpfe_cfg = vpfe_get_pdata(vpfe);
+	if (!vpfe_cfg) {
+		dev_err(&pdev->dev, "No platform data\n");
+		return -EINVAL;
+	}
+
 	vpfe->cfg = vpfe_cfg;
 	ccdc = &vpfe->ccdc;
 
 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 	ccdc->ccdc_cfg.base_addr = devm_ioremap_resource(&pdev->dev, res);
-	if (IS_ERR(ccdc->ccdc_cfg.base_addr))
-		return PTR_ERR(ccdc->ccdc_cfg.base_addr);
+	if (IS_ERR(ccdc->ccdc_cfg.base_addr)) {
+		ret = PTR_ERR(ccdc->ccdc_cfg.base_addr);
+		goto probe_out_cleanup;
+	}
 
 	ret = platform_get_irq(pdev, 0);
 	if (ret <= 0) {
 		dev_err(&pdev->dev, "No IRQ resource\n");
-		return -ENODEV;
+		ret = -ENODEV;
+		goto probe_out_cleanup;
 	}
 	vpfe->irq = ret;
 
@@ -2565,14 +2568,15 @@ static int vpfe_probe(struct platform_device *pdev)
 			       "vpfe_capture0", vpfe);
 	if (ret) {
 		dev_err(&pdev->dev, "Unable to request interrupt\n");
-		return -EINVAL;
+		ret = -EINVAL;
+		goto probe_out_cleanup;
 	}
 
 	ret = v4l2_device_register(&pdev->dev, &vpfe->v4l2_dev);
 	if (ret) {
 		vpfe_err(vpfe,
 			"Unable to register v4l2 device.\n");
-		return ret;
+		goto probe_out_cleanup;
 	}
 
 	/* set the driver data in platform device */
@@ -2596,11 +2600,8 @@ static int vpfe_probe(struct platform_device *pdev)
 		goto probe_out_v4l2_unregister;
 	}
 
-	vpfe->notifier.subdevs = vpfe->cfg->asd;
-	vpfe->notifier.num_subdevs = ARRAY_SIZE(vpfe->cfg->asd);
 	vpfe->notifier.ops = &vpfe_async_ops;
-	ret = v4l2_async_notifier_register(&vpfe->v4l2_dev,
-						&vpfe->notifier);
+	ret = v4l2_async_notifier_register(&vpfe->v4l2_dev, &vpfe->notifier);
 	if (ret) {
 		vpfe_err(vpfe, "Error registering async notifier\n");
 		ret = -EINVAL;
@@ -2611,6 +2612,8 @@ static int vpfe_probe(struct platform_device *pdev)
 
 probe_out_v4l2_unregister:
 	v4l2_device_unregister(&vpfe->v4l2_dev);
+probe_out_cleanup:
+	v4l2_async_notifier_cleanup(&vpfe->notifier);
 	return ret;
 }
 
@@ -2626,6 +2629,7 @@ static int vpfe_remove(struct platform_device *pdev)
 	pm_runtime_disable(&pdev->dev);
 
 	v4l2_async_notifier_unregister(&vpfe->notifier);
+	v4l2_async_notifier_cleanup(&vpfe->notifier);
 	v4l2_device_unregister(&vpfe->v4l2_dev);
 	video_unregister_device(&vpfe->video_dev);
 
diff --git a/drivers/media/platform/atmel/atmel-isc.c b/drivers/media/platform/atmel/atmel-isc.c
index dc637bffe63c..334de0f2e36a 100644
--- a/drivers/media/platform/atmel/atmel-isc.c
+++ b/drivers/media/platform/atmel/atmel-isc.c
@@ -1983,8 +1983,10 @@ static void isc_subdev_cleanup(struct isc_device *isc)
 {
 	struct isc_subdev_entity *subdev_entity;
 
-	list_for_each_entry(subdev_entity, &isc->subdev_entities, list)
+	list_for_each_entry(subdev_entity, &isc->subdev_entities, list) {
 		v4l2_async_notifier_unregister(&subdev_entity->notifier);
+		v4l2_async_notifier_cleanup(&subdev_entity->notifier);
+	}
 
 	INIT_LIST_HEAD(&isc->subdev_entities);
 }
@@ -2201,8 +2203,15 @@ static int atmel_isc_probe(struct platform_device *pdev)
 	}
 
 	list_for_each_entry(subdev_entity, &isc->subdev_entities, list) {
-		subdev_entity->notifier.subdevs = &subdev_entity->asd;
-		subdev_entity->notifier.num_subdevs = 1;
+		v4l2_async_notifier_init(&subdev_entity->notifier);
+
+		ret = v4l2_async_notifier_add_subdev(&subdev_entity->notifier,
+						     subdev_entity->asd);
+		if (ret) {
+			fwnode_handle_put(subdev_entity->asd->match.fwnode);
+			goto cleanup_subdev;
+		}
+
 		subdev_entity->notifier.ops = &isc_async_ops;
 
 		ret = v4l2_async_notifier_register(&isc->v4l2_dev,
diff --git a/drivers/media/platform/atmel/atmel-isi.c b/drivers/media/platform/atmel/atmel-isi.c
index 26874575d381..c4d5f05786e8 100644
--- a/drivers/media/platform/atmel/atmel-isi.c
+++ b/drivers/media/platform/atmel/atmel-isi.c
@@ -1124,7 +1124,6 @@ static int isi_graph_parse(struct atmel_isi *isi, struct device_node *node)
 
 static int isi_graph_init(struct atmel_isi *isi)
 {
-	struct v4l2_async_subdev **subdevs = NULL;
 	int ret;
 
 	/* Parse the graph to extract a list of subdevice DT nodes. */
@@ -1134,23 +1133,20 @@ static int isi_graph_init(struct atmel_isi *isi)
 		return ret;
 	}
 
-	/* Register the subdevices notifier. */
-	subdevs = devm_kzalloc(isi->dev, sizeof(*subdevs), GFP_KERNEL);
-	if (!subdevs) {
+	v4l2_async_notifier_init(&isi->notifier);
+
+	ret = v4l2_async_notifier_add_subdev(&isi->notifier, &isi->entity.asd);
+	if (ret) {
 		of_node_put(isi->entity.node);
-		return -ENOMEM;
+		return ret;
 	}
 
-	subdevs[0] = &isi->entity.asd;
-
-	isi->notifier.subdevs = subdevs;
-	isi->notifier.num_subdevs = 1;
 	isi->notifier.ops = &isi_graph_notify_ops;
 
 	ret = v4l2_async_notifier_register(&isi->v4l2_dev, &isi->notifier);
 	if (ret < 0) {
 		dev_err(isi->dev, "Notifier registration failed\n");
-		of_node_put(isi->entity.node);
+		v4l2_async_notifier_cleanup(&isi->notifier);
 		return ret;
 	}
 
@@ -1303,6 +1299,7 @@ static int atmel_isi_remove(struct platform_device *pdev)
 			isi->fb_descriptors_phys);
 	pm_runtime_disable(&pdev->dev);
 	v4l2_async_notifier_unregister(&isi->notifier);
+	v4l2_async_notifier_cleanup(&isi->notifier);
 	v4l2_device_unregister(&isi->v4l2_dev);
 
 	return 0;
diff --git a/drivers/media/platform/cadence/cdns-csi2rx.c b/drivers/media/platform/cadence/cdns-csi2rx.c
index 43e43c7b3e98..da3eb349716f 100644
--- a/drivers/media/platform/cadence/cdns-csi2rx.c
+++ b/drivers/media/platform/cadence/cdns-csi2rx.c
@@ -399,18 +399,22 @@ static int csi2rx_parse_dt(struct csi2rx_priv *csi2rx)
 	csi2rx->asd.match_type = V4L2_ASYNC_MATCH_FWNODE;
 	of_node_put(ep);
 
-	csi2rx->notifier.subdevs = devm_kzalloc(csi2rx->dev,
-						sizeof(*csi2rx->notifier.subdevs),
-						GFP_KERNEL);
-	if (!csi2rx->notifier.subdevs)
-		return -ENOMEM;
+	v4l2_async_notifier_init(&csi2rx->notifier);
+
+	ret = v4l2_async_notifier_add_subdev(&csi2rx->notifier, &csi2rx->asd);
+	if (ret) {
+		fwnode_handle_put(csi2rx->asd.match.fwnode);
+		return ret;
+	}
 
-	csi2rx->notifier.subdevs[0] = &csi2rx->asd;
-	csi2rx->notifier.num_subdevs = 1;
 	csi2rx->notifier.ops = &csi2rx_notifier_ops;
 
-	return v4l2_async_subdev_notifier_register(&csi2rx->subdev,
-						   &csi2rx->notifier);
+	ret = v4l2_async_subdev_notifier_register(&csi2rx->subdev,
+						  &csi2rx->notifier);
+	if (ret)
+		v4l2_async_notifier_cleanup(&csi2rx->notifier);
+
+	return ret;
 }
 
 static int csi2rx_probe(struct platform_device *pdev)
@@ -450,11 +454,11 @@ static int csi2rx_probe(struct platform_device *pdev)
 	ret = media_entity_pads_init(&csi2rx->subdev.entity, CSI2RX_PAD_MAX,
 				     csi2rx->pads);
 	if (ret)
-		goto err_free_priv;
+		goto err_cleanup;
 
 	ret = v4l2_async_register_subdev(&csi2rx->subdev);
 	if (ret < 0)
-		goto err_free_priv;
+		goto err_cleanup;
 
 	dev_info(&pdev->dev,
 		 "Probed CSI2RX with %u/%u lanes, %u streams, %s D-PHY\n",
@@ -463,6 +467,8 @@ static int csi2rx_probe(struct platform_device *pdev)
 
 	return 0;
 
+err_cleanup:
+	v4l2_async_notifier_cleanup(&csi2rx->notifier);
 err_free_priv:
 	kfree(csi2rx);
 	return ret;
diff --git a/drivers/media/platform/davinci/vpif_capture.c b/drivers/media/platform/davinci/vpif_capture.c
index 03873b641427..187f965e341e 100644
--- a/drivers/media/platform/davinci/vpif_capture.c
+++ b/drivers/media/platform/davinci/vpif_capture.c
@@ -1517,6 +1517,8 @@ vpif_capture_get_pdata(struct platform_device *pdev)
 	struct vpif_capture_chan_config *chan;
 	unsigned int i;
 
+	v4l2_async_notifier_init(&vpif_obj.notifier);
+
 	/*
 	 * DT boot: OF node from parent device contains
 	 * video ports & endpoints data.
@@ -1548,14 +1550,25 @@ vpif_capture_get_pdata(struct platform_device *pdev)
 		if (!endpoint)
 			break;
 
+		rem = of_graph_get_remote_port_parent(endpoint);
+		if (!rem) {
+			dev_dbg(&pdev->dev, "Remote device at %pOF not found\n",
+				endpoint);
+			of_node_put(endpoint);
+			goto done;
+		}
+
 		sdinfo = &pdata->subdev_info[i];
 		chan = &pdata->chan_config[i];
 		chan->inputs = devm_kcalloc(&pdev->dev,
 					    VPIF_CAPTURE_NUM_CHANNELS,
 					    sizeof(*chan->inputs),
 					    GFP_KERNEL);
-		if (!chan->inputs)
-			return NULL;
+		if (!chan->inputs) {
+			of_node_put(rem);
+			of_node_put(endpoint);
+			goto err_cleanup;
+		}
 
 		chan->input_count++;
 		chan->inputs[i].input.type = V4L2_INPUT_TYPE_CAMERA;
@@ -1564,12 +1577,16 @@ vpif_capture_get_pdata(struct platform_device *pdev)
 
 		err = v4l2_fwnode_endpoint_parse(of_fwnode_handle(endpoint),
 						 &bus_cfg);
+		of_node_put(endpoint);
 		if (err) {
 			dev_err(&pdev->dev, "Could not parse the endpoint\n");
+			of_node_put(rem);
 			goto done;
 		}
+
 		dev_dbg(&pdev->dev, "Endpoint %pOF, bus_width = %d\n",
 			endpoint, bus_cfg.bus.parallel.bus_width);
+
 		flags = bus_cfg.bus.parallel.flags;
 
 		if (flags & V4L2_MBUS_HSYNC_ACTIVE_HIGH)
@@ -1578,38 +1595,29 @@ vpif_capture_get_pdata(struct platform_device *pdev)
 		if (flags & V4L2_MBUS_VSYNC_ACTIVE_HIGH)
 			chan->vpif_if.vd_pol = 1;
 
-		rem = of_graph_get_remote_port_parent(endpoint);
-		if (!rem) {
-			dev_dbg(&pdev->dev, "Remote device at %pOF not found\n",
-				endpoint);
-			goto done;
-		}
-
 		dev_dbg(&pdev->dev, "Remote device %pOF found\n", rem);
 		sdinfo->name = rem->full_name;
 
-		pdata->asd[i] = devm_kzalloc(&pdev->dev,
-					     sizeof(struct v4l2_async_subdev),
-					     GFP_KERNEL);
-		if (!pdata->asd[i]) {
+		pdata->asd[i] = v4l2_async_notifier_add_fwnode_subdev(
+			&vpif_obj.notifier, of_fwnode_handle(rem),
+			sizeof(struct v4l2_async_subdev));
+		if (IS_ERR(pdata->asd[i])) {
 			of_node_put(rem);
-			pdata = NULL;
-			goto done;
+			goto err_cleanup;
 		}
-
-		pdata->asd[i]->match_type = V4L2_ASYNC_MATCH_FWNODE;
-		pdata->asd[i]->match.fwnode = of_fwnode_handle(rem);
-		of_node_put(rem);
 	}
 
 done:
-	if (pdata) {
-		pdata->asd_sizes[0] = i;
-		pdata->subdev_count = i;
-		pdata->card_name = "DA850/OMAP-L138 Video Capture";
-	}
+	pdata->asd_sizes[0] = i;
+	pdata->subdev_count = i;
+	pdata->card_name = "DA850/OMAP-L138 Video Capture";
 
 	return pdata;
+
+err_cleanup:
+	v4l2_async_notifier_cleanup(&vpif_obj.notifier);
+
+	return NULL;
 }
 
 /**
@@ -1634,23 +1642,18 @@ static __init int vpif_probe(struct platform_device *pdev)
 		return -EINVAL;
 	}
 
-	if (!pdev->dev.platform_data) {
-		dev_warn(&pdev->dev, "Missing platform data.  Giving up.\n");
-		return -EINVAL;
-	}
-
 	vpif_dev = &pdev->dev;
 
 	err = initialize_vpif();
 	if (err) {
 		v4l2_err(vpif_dev->driver, "Error initializing vpif\n");
-		return err;
+		goto cleanup;
 	}
 
 	err = v4l2_device_register(vpif_dev, &vpif_obj.v4l2_dev);
 	if (err) {
 		v4l2_err(vpif_dev->driver, "Error registering v4l2 device\n");
-		return err;
+		goto cleanup;
 	}
 
 	while ((res = platform_get_resource(pdev, IORESOURCE_IRQ, res_idx))) {
@@ -1699,8 +1702,6 @@ static __init int vpif_probe(struct platform_device *pdev)
 		}
 		vpif_probe_complete();
 	} else {
-		vpif_obj.notifier.subdevs = vpif_obj.config->asd;
-		vpif_obj.notifier.num_subdevs = vpif_obj.config->asd_sizes[0];
 		vpif_obj.notifier.ops = &vpif_async_ops;
 		err = v4l2_async_notifier_register(&vpif_obj.v4l2_dev,
 						   &vpif_obj.notifier);
@@ -1718,6 +1719,8 @@ probe_subdev_out:
 	kfree(vpif_obj.sd);
 vpif_unregister:
 	v4l2_device_unregister(&vpif_obj.v4l2_dev);
+cleanup:
+	v4l2_async_notifier_cleanup(&vpif_obj.notifier);
 
 	return err;
 }
@@ -1733,6 +1736,8 @@ static int vpif_remove(struct platform_device *device)
 	struct channel_obj *ch;
 	int i;
 
+	v4l2_async_notifier_unregister(&vpif_obj.notifier);
+	v4l2_async_notifier_cleanup(&vpif_obj.notifier);
 	v4l2_device_unregister(&vpif_obj.v4l2_dev);
 
 	kfree(vpif_obj.sd);
diff --git a/drivers/media/platform/davinci/vpif_display.c b/drivers/media/platform/davinci/vpif_display.c
index 78eba66f4b2b..3517487d9760 100644
--- a/drivers/media/platform/davinci/vpif_display.c
+++ b/drivers/media/platform/davinci/vpif_display.c
@@ -1300,6 +1300,8 @@ static __init int vpif_probe(struct platform_device *pdev)
 		goto vpif_unregister;
 	}
 
+	v4l2_async_notifier_init(&vpif_obj.notifier);
+
 	if (!vpif_obj.config->asd_sizes) {
 		i2c_adap = i2c_get_adapter(vpif_obj.config->i2c_adapter_id);
 		for (i = 0; i < subdev_count; i++) {
@@ -1323,20 +1325,27 @@ static __init int vpif_probe(struct platform_device *pdev)
 			goto probe_subdev_out;
 		}
 	} else {
-		vpif_obj.notifier.subdevs = vpif_obj.config->asd;
-		vpif_obj.notifier.num_subdevs = vpif_obj.config->asd_sizes[0];
+		for (i = 0; i < vpif_obj.config->asd_sizes[0]; i++) {
+			err = v4l2_async_notifier_add_subdev(
+				&vpif_obj.notifier, vpif_obj.config->asd[i]);
+			if (err)
+				goto probe_cleanup;
+		}
+
 		vpif_obj.notifier.ops = &vpif_async_ops;
 		err = v4l2_async_notifier_register(&vpif_obj.v4l2_dev,
 						   &vpif_obj.notifier);
 		if (err) {
 			vpif_err("Error registering async notifier\n");
 			err = -EINVAL;
-			goto probe_subdev_out;
+			goto probe_cleanup;
 		}
 	}
 
 	return 0;
 
+probe_cleanup:
+	v4l2_async_notifier_cleanup(&vpif_obj.notifier);
 probe_subdev_out:
 	kfree(vpif_obj.sd);
 vpif_unregister:
@@ -1355,6 +1364,11 @@ static int vpif_remove(struct platform_device *device)
 	struct channel_obj *ch;
 	int i;
 
+	if (vpif_obj.config->asd_sizes) {
+		v4l2_async_notifier_unregister(&vpif_obj.notifier);
+		v4l2_async_notifier_cleanup(&vpif_obj.notifier);
+	}
+
 	v4l2_device_unregister(&vpif_obj.v4l2_dev);
 
 	kfree(vpif_obj.sd);
diff --git a/drivers/media/platform/exynos4-is/media-dev.c b/drivers/media/platform/exynos4-is/media-dev.c
index 18a393f51a26..fbad0635c6b5 100644
--- a/drivers/media/platform/exynos4-is/media-dev.c
+++ b/drivers/media/platform/exynos4-is/media-dev.c
@@ -457,11 +457,16 @@ static int fimc_md_parse_port_node(struct fimc_md *fmd,
 
 	fmd->sensor[index].asd.match_type = V4L2_ASYNC_MATCH_FWNODE;
 	fmd->sensor[index].asd.match.fwnode = of_fwnode_handle(rem);
-	fmd->async_subdevs[index] = &fmd->sensor[index].asd;
+
+	ret = v4l2_async_notifier_add_subdev(&fmd->subdev_notifier,
+					     &fmd->sensor[index].asd);
+	if (ret) {
+		of_node_put(rem);
+		return ret;
+	}
 
 	fmd->num_sensors++;
 
-	of_node_put(rem);
 	return 0;
 }
 
@@ -500,7 +505,7 @@ static int fimc_md_register_sensor_entities(struct fimc_md *fmd)
 		ret = fimc_md_parse_port_node(fmd, port, index);
 		if (ret < 0) {
 			of_node_put(node);
-			goto rpm_put;
+			goto cleanup;
 		}
 		index++;
 	}
@@ -514,12 +519,18 @@ static int fimc_md_register_sensor_entities(struct fimc_md *fmd)
 		ret = fimc_md_parse_port_node(fmd, node, index);
 		if (ret < 0) {
 			of_node_put(node);
-			break;
+			goto cleanup;
 		}
 		index++;
 	}
+
 rpm_put:
 	pm_runtime_put(fmd->pmf);
+	return 0;
+
+cleanup:
+	v4l2_async_notifier_cleanup(&fmd->subdev_notifier);
+	pm_runtime_put(fmd->pmf);
 	return ret;
 }
 
@@ -1460,6 +1471,8 @@ static int fimc_md_probe(struct platform_device *pdev)
 
 	platform_set_drvdata(pdev, fmd);
 
+	v4l2_async_notifier_init(&fmd->subdev_notifier);
+
 	ret = fimc_md_register_platform_entities(fmd, dev->of_node);
 	if (ret)
 		goto err_clk;
@@ -1470,7 +1483,7 @@ static int fimc_md_probe(struct platform_device *pdev)
 
 	ret = device_create_file(&pdev->dev, &dev_attr_subdev_conf_mode);
 	if (ret)
-		goto err_m_ent;
+		goto err_cleanup;
 	/*
 	 * FIMC platform devices need to be registered before the sclk_cam
 	 * clocks provider, as one of these devices needs to be activated
@@ -1483,8 +1496,6 @@ static int fimc_md_probe(struct platform_device *pdev)
 	}
 
 	if (fmd->num_sensors > 0) {
-		fmd->subdev_notifier.subdevs = fmd->async_subdevs;
-		fmd->subdev_notifier.num_subdevs = fmd->num_sensors;
 		fmd->subdev_notifier.ops = &subdev_notifier_ops;
 		fmd->num_sensors = 0;
 
@@ -1500,10 +1511,12 @@ err_clk_p:
 	fimc_md_unregister_clk_provider(fmd);
 err_attr:
 	device_remove_file(&pdev->dev, &dev_attr_subdev_conf_mode);
-err_clk:
-	fimc_md_put_clocks(fmd);
+err_cleanup:
+	v4l2_async_notifier_cleanup(&fmd->subdev_notifier);
 err_m_ent:
 	fimc_md_unregister_entities(fmd);
+err_clk:
+	fimc_md_put_clocks(fmd);
 err_md:
 	media_device_cleanup(&fmd->media_dev);
 	v4l2_device_unregister(&fmd->v4l2_dev);
@@ -1519,6 +1532,7 @@ static int fimc_md_remove(struct platform_device *pdev)
 
 	fimc_md_unregister_clk_provider(fmd);
 	v4l2_async_notifier_unregister(&fmd->subdev_notifier);
+	v4l2_async_notifier_cleanup(&fmd->subdev_notifier);
 
 	v4l2_device_unregister(&fmd->v4l2_dev);
 	device_remove_file(&pdev->dev, &dev_attr_subdev_conf_mode);
diff --git a/drivers/media/platform/exynos4-is/media-dev.h b/drivers/media/platform/exynos4-is/media-dev.h
index 957787a2f480..9f527670395a 100644
--- a/drivers/media/platform/exynos4-is/media-dev.h
+++ b/drivers/media/platform/exynos4-is/media-dev.h
@@ -149,7 +149,6 @@ struct fimc_md {
 	} clk_provider;
 
 	struct v4l2_async_notifier subdev_notifier;
-	struct v4l2_async_subdev *async_subdevs[FIMC_MAX_SENSORS];
 
 	bool user_subdev_api;
 	spinlock_t slock;
diff --git a/drivers/media/platform/pxa_camera.c b/drivers/media/platform/pxa_camera.c
index 6717834e8041..2f083acdd269 100644
--- a/drivers/media/platform/pxa_camera.c
+++ b/drivers/media/platform/pxa_camera.c
@@ -697,7 +697,6 @@ struct pxa_camera_dev {
 	struct v4l2_pix_format	current_pix;
 
 	struct v4l2_async_subdev asd;
-	struct v4l2_async_subdev *asds[1];
 
 	/*
 	 * PXA27x is only supposed to handle one camera on its Quick Capture
@@ -2352,12 +2351,10 @@ static int pxa_camera_pdata_from_dt(struct device *dev,
 
 	asd->match_type = V4L2_ASYNC_MATCH_FWNODE;
 	remote = of_graph_get_remote_port(np);
-	if (remote) {
+	if (remote)
 		asd->match.fwnode = of_fwnode_handle(remote);
-		of_node_put(remote);
-	} else {
+	else
 		dev_notice(dev, "no remote for %pOF\n", np);
-	}
 
 out:
 	of_node_put(np);
@@ -2495,9 +2492,14 @@ static int pxa_camera_probe(struct platform_device *pdev)
 	if (err)
 		goto exit_deactivate;
 
-	pcdev->asds[0] = &pcdev->asd;
-	pcdev->notifier.subdevs = pcdev->asds;
-	pcdev->notifier.num_subdevs = 1;
+	v4l2_async_notifier_init(&pcdev->notifier);
+
+	err = v4l2_async_notifier_add_subdev(&pcdev->notifier, &pcdev->asd);
+	if (err) {
+		fwnode_handle_put(pcdev->asd.match.fwnode);
+		goto exit_free_v4l2dev;
+	}
+
 	pcdev->notifier.ops = &pxa_camera_sensor_ops;
 
 	if (!of_have_populated_dt())
@@ -2505,7 +2507,7 @@ static int pxa_camera_probe(struct platform_device *pdev)
 
 	err = pxa_camera_init_videobuf2(pcdev);
 	if (err)
-		goto exit_free_v4l2dev;
+		goto exit_notifier_cleanup;
 
 	if (pcdev->mclk) {
 		v4l2_clk_name_i2c(clk_name, sizeof(clk_name),
@@ -2516,7 +2518,7 @@ static int pxa_camera_probe(struct platform_device *pdev)
 						    clk_name, NULL);
 		if (IS_ERR(pcdev->mclk_clk)) {
 			err = PTR_ERR(pcdev->mclk_clk);
-			goto exit_free_v4l2dev;
+			goto exit_notifier_cleanup;
 		}
 	}
 
@@ -2527,6 +2529,8 @@ static int pxa_camera_probe(struct platform_device *pdev)
 	return 0;
 exit_free_clk:
 	v4l2_clk_unregister(pcdev->mclk_clk);
+exit_notifier_cleanup:
+	v4l2_async_notifier_cleanup(&pcdev->notifier);
 exit_free_v4l2dev:
 	v4l2_device_unregister(&pcdev->v4l2_dev);
 exit_deactivate:
@@ -2550,6 +2554,7 @@ static int pxa_camera_remove(struct platform_device *pdev)
 	dma_release_channel(pcdev->dma_chans[2]);
 
 	v4l2_async_notifier_unregister(&pcdev->notifier);
+	v4l2_async_notifier_cleanup(&pcdev->notifier);
 
 	if (pcdev->mclk_clk) {
 		v4l2_clk_unregister(pcdev->mclk_clk);
diff --git a/drivers/media/platform/qcom/camss/camss.c b/drivers/media/platform/qcom/camss/camss.c
index a838a7e560e3..45978db3b0be 100644
--- a/drivers/media/platform/qcom/camss/camss.c
+++ b/drivers/media/platform/qcom/camss/camss.c
@@ -462,61 +462,51 @@ static int camss_of_parse_endpoint_node(struct device *dev,
  *
  * Return number of "port" nodes found in "ports" node
  */
-static int camss_of_parse_ports(struct device *dev,
-				struct v4l2_async_notifier *notifier)
+static int camss_of_parse_ports(struct camss *camss)
 {
+	struct device *dev = camss->dev;
 	struct device_node *node = NULL;
 	struct device_node *remote = NULL;
-	unsigned int size, i;
-	int ret;
-
-	while ((node = of_graph_get_next_endpoint(dev->of_node, node)))
-		if (of_device_is_available(node))
-			notifier->num_subdevs++;
-
-	of_node_put(node);
-	size = sizeof(*notifier->subdevs) * notifier->num_subdevs;
-	notifier->subdevs = devm_kzalloc(dev, size, GFP_KERNEL);
-	if (!notifier->subdevs) {
-		dev_err(dev, "Failed to allocate memory\n");
-		return -ENOMEM;
-	}
+	int ret, num_subdevs = 0;
 
-	i = 0;
-	while ((node = of_graph_get_next_endpoint(dev->of_node, node))) {
+	for_each_endpoint_of_node(dev->of_node, node) {
 		struct camss_async_subdev *csd;
+		struct v4l2_async_subdev *asd;
 
 		if (!of_device_is_available(node))
 			continue;
 
-		csd = devm_kzalloc(dev, sizeof(*csd), GFP_KERNEL);
-		if (!csd) {
-			of_node_put(node);
-			dev_err(dev, "Failed to allocate memory\n");
-			return -ENOMEM;
-		}
-
-		notifier->subdevs[i++] = &csd->asd;
-
-		ret = camss_of_parse_endpoint_node(dev, node, csd);
-		if (ret < 0) {
-			of_node_put(node);
-			return ret;
-		}
-
 		remote = of_graph_get_remote_port_parent(node);
 		if (!remote) {
 			dev_err(dev, "Cannot get remote parent\n");
-			of_node_put(node);
-			return -EINVAL;
+			ret = -EINVAL;
+			goto err_cleanup;
 		}
 
-		csd->asd.match_type = V4L2_ASYNC_MATCH_FWNODE;
-		csd->asd.match.fwnode = of_fwnode_handle(remote);
+		asd = v4l2_async_notifier_add_fwnode_subdev(
+			&camss->notifier, of_fwnode_handle(remote),
+			sizeof(*csd));
+		if (IS_ERR(asd)) {
+			ret = PTR_ERR(asd);
+			of_node_put(remote);
+			goto err_cleanup;
+		}
+
+		csd = container_of(asd, struct camss_async_subdev, asd);
+
+		ret = camss_of_parse_endpoint_node(dev, node, csd);
+		if (ret < 0)
+			goto err_cleanup;
+
+		num_subdevs++;
 	}
-	of_node_put(node);
 
-	return notifier->num_subdevs;
+	return num_subdevs;
+
+err_cleanup:
+	v4l2_async_notifier_cleanup(&camss->notifier);
+	of_node_put(node);
+	return ret;
 }
 
 /*
@@ -823,7 +813,7 @@ static int camss_probe(struct platform_device *pdev)
 {
 	struct device *dev = &pdev->dev;
 	struct camss *camss;
-	int ret;
+	int num_subdevs, ret;
 
 	camss = kzalloc(sizeof(*camss), GFP_KERNEL);
 	if (!camss)
@@ -863,17 +853,19 @@ static int camss_probe(struct platform_device *pdev)
 	if (!camss->vfe)
 		return -ENOMEM;
 
-	ret = camss_of_parse_ports(dev, &camss->notifier);
-	if (ret < 0)
-		return ret;
+	v4l2_async_notifier_init(&camss->notifier);
+
+	num_subdevs = camss_of_parse_ports(camss);
+	if (num_subdevs < 0)
+		return num_subdevs;
 
 	ret = camss_init_subdevices(camss);
 	if (ret < 0)
-		return ret;
+		goto err_cleanup;
 
 	ret = dma_set_mask_and_coherent(dev, 0xffffffff);
 	if (ret)
-		return ret;
+		goto err_cleanup;
 
 	camss->media_dev.dev = camss->dev;
 	strscpy(camss->media_dev.model, "Qualcomm Camera Sub