media: imx7: mipi csis: Create media links in bound notifier

Implement a notifier bound op to register media links from the remote
sub-device's source pad(s) to the mipi csi-2 receiver sink pad.
Signed-off-by: Steve Longerbeam <slongerbeam@gmail.com>
Acked-by: Rui Miguel Silva <rmfrfs@gmail.com>
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>

drivers/staging/media/imx/imx7-mipi-csis.c

@@ -26,6 +26,7 @@
 
 #include <media/v4l2-device.h>
 #include <media/v4l2-fwnode.h>
+#include <media/v4l2-mc.h>
 #include <media/v4l2-subdev.h>
 
 #define CSIS_DRIVER_NAME			"imx7-mipi-csis"
@@ -385,6 +386,12 @@ static int mipi_csis_dump_regs(struct csi_state *state)
 	return 0;
 }
 
+static struct csi_state *
+mipi_notifier_to_csis_state(struct v4l2_async_notifier *n)
+{
+	return container_of(n, struct csi_state, notifier);
+}
+
 static struct csi_state *mipi_sd_to_csis_state(struct v4l2_subdev *sdev)
 {
 	return container_of(sdev, struct csi_state, mipi_sd);
@@ -948,6 +955,20 @@ static int mipi_csis_parse_dt(struct platform_device *pdev,
 
 static int mipi_csis_pm_resume(struct device *dev, bool runtime);
 
+static int mipi_csis_notify_bound(struct v4l2_async_notifier *notifier,
+				  struct v4l2_subdev *sd,
+				  struct v4l2_async_subdev *asd)
+{
+	struct csi_state *state = mipi_notifier_to_csis_state(notifier);
+	struct media_pad *sink = &state->mipi_sd.entity.pads[CSIS_PAD_SINK];
+
+	return v4l2_create_fwnode_links_to_pad(sd, sink);
+}
+
+static const struct v4l2_async_notifier_operations mipi_csis_notify_ops = {
+	.bound = mipi_csis_notify_bound,
+};
+
 static int mipi_csis_subdev_init(struct v4l2_subdev *mipi_sd,
 				 struct platform_device *pdev,
 				 const struct v4l2_subdev_ops *ops)
@@ -1016,6 +1037,8 @@ static int mipi_csis_async_register(struct csi_state *state)
 
 	fwnode_handle_put(ep);
 
+	state->notifier.ops = &mipi_csis_notify_ops;
+
 	ret = v4l2_async_subdev_notifier_register(&state->mipi_sd,
 						  &state->notifier);
 	if (ret)