media: v4l: async: Obtain async connection based on sub-device

Add v4l2_async_connection_unique() function for obtaining a struct
v4l2_async_connection, typically allocated by drivers together with their
own information on an external sub-device.

The relation between connections and sub-devices still remains 1:1 but
this code becomes more complex when the relation soon changes.
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Tested-by: Philipp Zabel <p.zabel@pengutronix.de> # imx6qp
Tested-by: Niklas Söderlund <niklas.soderlund@ragnatech.se> # rcar + adv746x
Tested-by: Aishwarya Kothari <aishwarya.kothari@toradex.com> # Apalis i.MX6Q with TC358743
Tested-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com> # Renesas RZ/G2L SMARC
Signed-off-by: Mauro Carvalho Chehab <mchehab@kernel.org>

drivers/media/platform/rockchip/rkisp1/rkisp1-csi.c

@@ -381,6 +381,7 @@ static int rkisp1_csi_s_stream(struct v4l2_subdev *sd, int enable)
 	struct rkisp1_csi *csi = to_rkisp1_csi(sd);
 	struct rkisp1_device *rkisp1 = csi->rkisp1;
 	struct rkisp1_sensor_async *source_asd;
+	struct v4l2_async_connection *asc;
 	struct media_pad *source_pad;
 	struct v4l2_subdev *source;
 	int ret;
@@ -406,7 +407,11 @@ static int rkisp1_csi_s_stream(struct v4l2_subdev *sd, int enable)
 		return -EPIPE;
 	}
 
-	source_asd = container_of(source->asd, struct rkisp1_sensor_async, asd);
+	asc = v4l2_async_connection_unique(source);
+	if (!asc)
+		return -EPIPE;
+
+	source_asd = container_of(asc, struct rkisp1_sensor_async, asd);
 	if (source_asd->mbus_type != V4L2_MBUS_CSI2_DPHY)
 		return -EINVAL;
 

drivers/media/platform/rockchip/rkisp1/rkisp1-isp.c

@@ -868,9 +868,13 @@ static int rkisp1_isp_s_stream(struct v4l2_subdev *sd, int enable)
 		mbus_flags = 0;
 	} else {
 		const struct rkisp1_sensor_async *asd;
+		struct v4l2_async_connection *asc;
 
-		asd = container_of(rkisp1->source->asd,
-				   struct rkisp1_sensor_async, asd);
+		asc = v4l2_async_connection_unique(rkisp1->source);
+		if (!asc)
+			return -EPIPE;
+
+		asd = container_of(asc, struct rkisp1_sensor_async, asd);
 
 		mbus_type = asd->mbus_type;
 		mbus_flags = asd->mbus_flags;

drivers/media/platform/ti/omap3isp/isp.h

@@ -224,8 +224,17 @@ struct isp_async_subdev {
 	struct isp_bus_cfg bus;
 };
 
-#define v4l2_subdev_to_bus_cfg(sd) \
-	(&container_of((sd)->asd, struct isp_async_subdev, asd)->bus)
+static inline struct isp_bus_cfg *
+v4l2_subdev_to_bus_cfg(struct v4l2_subdev *sd)
+{
+	struct v4l2_async_connection *asc;
+
+	asc = v4l2_async_connection_unique(sd);
+	if (!asc)
+		return NULL;
+
+	return &container_of(asc, struct isp_async_subdev, asd)->bus;
+}
 
 #define v4l2_dev_to_isp_device(dev) \
 	container_of(dev, struct isp_device, v4l2_dev)

drivers/media/platform/ti/omap3isp/ispccdc.c

@@ -1140,8 +1140,13 @@ static void ccdc_configure(struct isp_ccdc_device *ccdc)
 	if (ccdc->input == CCDC_INPUT_PARALLEL) {
 		struct v4l2_subdev *sd =
 			to_isp_pipeline(&ccdc->subdev.entity)->external;
+		struct isp_bus_cfg *bus_cfg;
 
-		parcfg = &v4l2_subdev_to_bus_cfg(sd)->bus.parallel;
+		bus_cfg = v4l2_subdev_to_bus_cfg(sd);
+		if (WARN_ON(!bus_cfg))
+			return;
+
+		parcfg = &bus_cfg->bus.parallel;
 		ccdc->bt656 = parcfg->bt656;
 	}
 
@@ -2436,7 +2441,11 @@ static int ccdc_link_validate(struct v4l2_subdev *sd,
 	if (ccdc->input == CCDC_INPUT_PARALLEL) {
 		struct v4l2_subdev *sd =
 			media_entity_to_v4l2_subdev(link->source->entity);
-		struct isp_bus_cfg *bus_cfg = v4l2_subdev_to_bus_cfg(sd);
+		struct isp_bus_cfg *bus_cfg;
+
+		bus_cfg = v4l2_subdev_to_bus_cfg(sd);
+		if (WARN_ON(!bus_cfg))
+			return -EPIPE;
 
 		parallel_shift = bus_cfg->bus.parallel.data_lane_shift;
 	} else {

drivers/media/platform/ti/omap3isp/ispccp2.c

@@ -360,6 +360,8 @@ static int ccp2_if_configure(struct isp_ccp2_device *ccp2)
 	pad = media_pad_remote_pad_first(&ccp2->pads[CCP2_PAD_SINK]);
 	sensor = media_entity_to_v4l2_subdev(pad->entity);
 	buscfg = v4l2_subdev_to_bus_cfg(pipe->external);
+	if (WARN_ON(!buscfg))
+		return -EPIPE;
 
 	ret = ccp2_phyif_config(ccp2, &buscfg->bus.ccp2);
 	if (ret < 0)

drivers/media/platform/ti/omap3isp/ispcsi2.c

@@ -564,6 +564,8 @@ static int csi2_configure(struct isp_csi2_device *csi2)
 	pad = media_pad_remote_pad_first(&csi2->pads[CSI2_PAD_SINK]);
 	sensor = media_entity_to_v4l2_subdev(pad->entity);
 	buscfg = v4l2_subdev_to_bus_cfg(pipe->external);
+	if (WARN_ON(!buscfg))
+		return -EPIPE;
 
 	csi2->frame_skip = 0;
 	v4l2_subdev_call(sensor, sensor, g_skip_frames, &csi2->frame_skip);

drivers/media/platform/ti/omap3isp/ispcsiphy.c

@@ -163,13 +163,17 @@ static int csiphy_set_power(struct isp_csiphy *phy, u32 power)
 static int omap3isp_csiphy_config(struct isp_csiphy *phy)
 {
 	struct isp_pipeline *pipe = to_isp_pipeline(phy->entity);
-	struct isp_bus_cfg *buscfg = v4l2_subdev_to_bus_cfg(pipe->external);
+	struct isp_bus_cfg *buscfg;
 	struct isp_csiphy_lanes_cfg *lanes;
 	int csi2_ddrclk_khz;
 	unsigned int num_data_lanes, used_lanes = 0;
 	unsigned int i;
 	u32 reg;
 
+	buscfg = v4l2_subdev_to_bus_cfg(pipe->external);
+	if (WARN_ON(!buscfg))
+		return -EPIPE;
+
 	if (buscfg->interface == ISP_INTERFACE_CCP2B_PHY1
 	    || buscfg->interface == ISP_INTERFACE_CCP2B_PHY2) {
 		lanes = &buscfg->bus.ccp2.lanecfg;
@@ -306,8 +310,13 @@ void omap3isp_csiphy_release(struct isp_csiphy *phy)
 	mutex_lock(&phy->mutex);
 	if (phy->entity) {
 		struct isp_pipeline *pipe = to_isp_pipeline(phy->entity);
-		struct isp_bus_cfg *buscfg =
-			v4l2_subdev_to_bus_cfg(pipe->external);
+		struct isp_bus_cfg *buscfg;
+
+		buscfg = v4l2_subdev_to_bus_cfg(pipe->external);
+		if (WARN_ON(!buscfg)) {
+			mutex_unlock(&phy->mutex);
+			return;
+		}
 
 		csiphy_routing_cfg(phy, buscfg->interface, false,
 				   buscfg->bus.ccp2.phy_layer);

drivers/media/v4l2-core/v4l2-async.c

@@ -751,6 +751,13 @@ __v4l2_async_nf_add_i2c(struct v4l2_async_notifier *notifier, int adapter_id,
 }
 EXPORT_SYMBOL_GPL(__v4l2_async_nf_add_i2c);
 
+struct v4l2_async_connection *
+v4l2_async_connection_unique(struct v4l2_subdev *sd)
+{
+	return sd->asd;
+}
+EXPORT_SYMBOL_GPL(v4l2_async_connection_unique);
+
 int v4l2_async_register_subdev(struct v4l2_subdev *sd)
 {
 	struct v4l2_async_notifier *subdev_notifier;

include/media/v4l2-async.h

@@ -210,6 +210,17 @@ __v4l2_async_nf_add_i2c(struct v4l2_async_notifier *notifier,
 	((type *)__v4l2_async_nf_add_i2c(notifier, adapter, address, \
 					 sizeof(type)))
 
+/**
+ * v4l2_async_connection_unique - return a unique &struct v4l2_async_connection
+ *				  for a sub-device
+ * @sd: the sub-device
+ *
+ * Return an async connection for a sub-device, when there is a single
+ * one only.
+ */
+struct v4l2_async_connection *
+v4l2_async_connection_unique(struct v4l2_subdev *sd);
+
 /**
  * v4l2_async_nf_register - registers a subdevice asynchronous notifier
  *