[media] staging: v4l: omap4iss: Use V4L2 graph PM operations

Power on devices represented by entities in the graph through the pipeline
state using V4L2 graph PM operations instead of what was in the omap3isp
driver.

Signed-off-by: Sakari Ailus <[e-mail]>
Cc: Laurent Pinchart <[e-mail]>
Signed-off-by: Mauro Carvalho Chehab <[e-mail]>

drivers/staging/media/omap4iss/iss.c

···
 }
 
 /* -----------------------------------------------------------------------------
- * Pipeline power management
- *
- * Entities must be powered up when part of a pipeline that contains at least
- * one open video device node.
- *
- * To achieve this use the entity use_count field to track the number of users.
- * For entities corresponding to video device nodes the use_count field stores
- * the users count of the node. For entities corresponding to subdevs the
- * use_count field stores the total number of users of all video device nodes
- * in the pipeline.
- *
- * The omap4iss_pipeline_pm_use() function must be called in the open() and
- * close() handlers of video device nodes. It increments or decrements the use
- * count of all subdev entities in the pipeline.
- *
- * To react to link management on powered pipelines, the link setup notification
- * callback updates the use count of all entities in the source and sink sides
- * of the link.
- */
-
-/*
- * iss_pipeline_pm_use_count - Count the number of users of a pipeline
- * @entity: The entity
- *
- * Return the total number of users of all video device nodes in the pipeline.
- */
-static int iss_pipeline_pm_use_count(struct media_entity *entity,
-				     struct media_entity_graph *graph)
-{
-	int use = 0;
-
-	media_entity_graph_walk_start(graph, entity);
-
-	while ((entity = media_entity_graph_walk_next(graph))) {
-		if (is_media_entity_v4l2_io(entity))
-			use += entity->use_count;
-	}
-
-	return use;
-}
-
-/*
- * iss_pipeline_pm_power_one - Apply power change to an entity
- * @entity: The entity
- * @change: Use count change
- *
- * Change the entity use count by @change. If the entity is a subdev update its
- * power state by calling the core::s_power operation when the use count goes
- * from 0 to != 0 or from != 0 to 0.
- *
- * Return 0 on success or a negative error code on failure.
- */
-static int iss_pipeline_pm_power_one(struct media_entity *entity, int change)
-{
-	struct v4l2_subdev *subdev;
-
-	subdev = is_media_entity_v4l2_subdev(entity)
-	       ? media_entity_to_v4l2_subdev(entity) : NULL;
-
-	if (entity->use_count == 0 && change > 0 && subdev) {
-		int ret;
-
-		ret = v4l2_subdev_call(subdev, core, s_power, 1);
-		if (ret < 0 && ret != -ENOIOCTLCMD)
-			return ret;
-	}
-
-	entity->use_count += change;
-	WARN_ON(entity->use_count < 0);
-
-	if (entity->use_count == 0 && change < 0 && subdev)
-		v4l2_subdev_call(subdev, core, s_power, 0);
-
-	return 0;
-}
-
-/*
- * iss_pipeline_pm_power - Apply power change to all entities in a pipeline
- * @entity: The entity
- * @change: Use count change
- *
- * Walk the pipeline to update the use count and the power state of all non-node
- * entities.
- *
- * Return 0 on success or a negative error code on failure.
- */
-static int iss_pipeline_pm_power(struct media_entity *entity, int change,
-				 struct media_entity_graph *graph)
-{
-	struct media_entity *first = entity;
-	int ret = 0;
-
-	if (!change)
-		return 0;
-
-	media_entity_graph_walk_start(graph, entity);
-
-	while (!ret && (entity = media_entity_graph_walk_next(graph)))
-		if (is_media_entity_v4l2_subdev(entity))
-			ret = iss_pipeline_pm_power_one(entity, change);
-
-	if (!ret)
-		return 0;
-
-	media_entity_graph_walk_start(graph, first);
-
-	while ((first = media_entity_graph_walk_next(graph)) &&
-	       first != entity)
-		if (is_media_entity_v4l2_subdev(first))
-			iss_pipeline_pm_power_one(first, -change);
-
-	return ret;
-}
-
-/*
- * omap4iss_pipeline_pm_use - Update the use count of an entity
- * @entity: The entity
- * @use: Use (1) or stop using (0) the entity
- *
- * Update the use count of all entities in the pipeline and power entities on or
- * off accordingly.
- *
- * Return 0 on success or a negative error code on failure. Powering entities
- * off is assumed to never fail. No failure can occur when the use parameter is
- * set to 0.
- */
-int omap4iss_pipeline_pm_use(struct media_entity *entity, int use,
-			     struct media_entity_graph *graph)
-{
-	int change = use ? 1 : -1;
-	int ret;
-
-	mutex_lock(&entity->graph_obj.mdev->graph_mutex);
-
-	/* Apply use count to node. */
-	entity->use_count += change;
-	WARN_ON(entity->use_count < 0);
-
-	/* Apply power change to connected non-nodes. */
-	ret = iss_pipeline_pm_power(entity, change, graph);
-	if (ret < 0)
-		entity->use_count -= change;
-
-	mutex_unlock(&entity->graph_obj.mdev->graph_mutex);
-
-	return ret;
-}
-
-/*
- * iss_pipeline_link_notify - Link management notification callback
- * @link: The link
- * @flags: New link flags that will be applied
- *
- * React to link management on powered pipelines by updating the use count of
- * all entities in the source and sink sides of the link. Entities are powered
- * on or off accordingly.
- *
- * Return 0 on success or a negative error code on failure. Powering entities
- * off is assumed to never fail. This function will not fail for disconnection
- * events.
- */
-static int iss_pipeline_link_notify(struct media_link *link, u32 flags,
-				    unsigned int notification)
-{
-	struct media_entity_graph *graph =
-		&container_of(link->graph_obj.mdev, struct iss_device,
-			      media_dev)->pm_count_graph;
-	struct media_entity *source = link->source->entity;
-	struct media_entity *sink = link->sink->entity;
-	int source_use;
-	int sink_use;
-	int ret;
-
-	if (notification == MEDIA_DEV_NOTIFY_PRE_LINK_CH) {
-		ret = media_entity_graph_walk_init(graph,
-						   link->graph_obj.mdev);
-		if (ret)
-			return ret;
-	}
-
-	source_use = iss_pipeline_pm_use_count(source, graph);
-	sink_use = iss_pipeline_pm_use_count(sink, graph);
-
-	if (notification == MEDIA_DEV_NOTIFY_POST_LINK_CH &&
-	    !(flags & MEDIA_LNK_FL_ENABLED)) {
-		/* Powering off entities is assumed to never fail. */
-		iss_pipeline_pm_power(source, -sink_use, graph);
-		iss_pipeline_pm_power(sink, -source_use, graph);
-		return 0;
-	}
-
-	if (notification == MEDIA_DEV_NOTIFY_PRE_LINK_CH &&
-	    (flags & MEDIA_LNK_FL_ENABLED)) {
-		ret = iss_pipeline_pm_power(source, sink_use, graph);
-		if (ret < 0)
-			return ret;
-
-		ret = iss_pipeline_pm_power(sink, source_use, graph);
-		if (ret < 0)
-			iss_pipeline_pm_power(source, -sink_use, graph);
-	}
-
-	if (notification == MEDIA_DEV_NOTIFY_POST_LINK_CH)
-		media_entity_graph_walk_cleanup(graph);
-
-	return ret;
-}
-
-/* -----------------------------------------------------------------------------
  * Pipeline stream management
  */
 
···
 	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 = iss_pipeline_link_notify;
+	iss->media_dev.link_notify = v4l2_pipeline_link_notify;
 	ret = media_device_register(&iss->media_dev);
 	if (ret < 0) {
 		dev_err(iss->dev, "Media device registration failed (%d)\n",

drivers/staging/media/omap4iss/iss.h

···
 #define _OMAP4_ISS_H_
 
 #include <media/v4l2-device.h>
+#include <media/v4l2-mc.h>
+
 #include <linux/device.h>
 #include <linux/io.h>
 #include <linux/platform_device.h>
···
 struct iss_device {
 	struct v4l2_device v4l2_dev;
 	struct media_device media_dev;
-	struct media_entity_graph pm_count_graph;
 	struct device *dev;
 	u32 revision;
 
···
 				enum iss_isp_subclk_resource res);
 void omap4iss_isp_subclk_disable(struct iss_device *iss,
 				 enum iss_isp_subclk_resource res);
-
-int omap4iss_pipeline_pm_use(struct media_entity *entity, int use,
-			     struct media_entity_graph *graph);
 
 int omap4iss_register_entities(struct platform_device *pdev,
 			       struct v4l2_device *v4l2_dev);

drivers/staging/media/omap4iss/iss_video.c

···
 #include <linux/slab.h>
 #include <linux/vmalloc.h>
 #include <linux/module.h>
+
 #include <media/v4l2-dev.h>
 #include <media/v4l2-ioctl.h>
+#include <media/v4l2-mc.h>
 
 #include "iss_video.h"
 #include "iss.h"
···
 		goto done;
 	}
 
-	ret = media_entity_graph_walk_init(&handle->graph,
-					   &video->iss->media_dev);
-	if (ret)
-		goto done;
-
-	ret = omap4iss_pipeline_pm_use(&video->video.entity, 1,
-				       &handle->graph);
+	ret = v4l2_pipeline_pm_use(&video->video.entity, 1);
 	if (ret < 0) {
 		omap4iss_put(video->iss);
 		goto done;
···
 done:
 	if (ret < 0) {
 		v4l2_fh_del(&handle->vfh);
-		media_entity_graph_walk_cleanup(&handle->graph);
 		kfree(handle);
 	}
 
···
 	/* Disable streaming and free the buffers queue resources. */
 	iss_video_streamoff(file, vfh, video->type);
 
-	omap4iss_pipeline_pm_use(&video->video.entity, 0, &handle->graph);
+	v4l2_pipeline_pm_use(&video->video.entity, 0);
 
 	/* Release the videobuf2 queue */
 	vb2_queue_release(&handle->queue);
 
-	/* Release the file handle. */
-	media_entity_graph_walk_cleanup(&handle->graph);
 	v4l2_fh_del(vfh);
 	kfree(handle);
 	file->private_data = NULL;

drivers/staging/media/omap4iss/iss_video.h

···
 	struct vb2_queue queue;
 	struct v4l2_format format;
 	struct v4l2_fract timeperframe;
-	struct media_entity_graph graph;
 };
 
 #define to_iss_video_fh(fh)	container_of(fh, struct iss_video_fh, vfh)