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-rw-r--r--drivers/media/Makefile2
-rw-r--r--drivers/media/media-device.c56
-rw-r--r--drivers/media/media-entity.c147
3 files changed, 204 insertions, 1 deletions
diff --git a/drivers/media/Makefile b/drivers/media/Makefile
index 36731aae57ea..64755c99ded2 100644
--- a/drivers/media/Makefile
+++ b/drivers/media/Makefile
@@ -2,7 +2,7 @@
# Makefile for the kernel multimedia device drivers.
#
-media-objs := media-device.o media-devnode.o
+media-objs := media-device.o media-devnode.o media-entity.o
ifeq ($(CONFIG_MEDIA_CONTROLLER),y)
obj-$(CONFIG_MEDIA_SUPPORT) += media.o
diff --git a/drivers/media/media-device.c b/drivers/media/media-device.c
index bcd3985d415a..a36509a1df09 100644
--- a/drivers/media/media-device.c
+++ b/drivers/media/media-device.c
@@ -25,6 +25,7 @@
#include <media/media-device.h>
#include <media/media-devnode.h>
+#include <media/media-entity.h>
static const struct media_file_operations media_device_fops = {
.owner = THIS_MODULE,
@@ -69,6 +70,10 @@ int __must_check media_device_register(struct media_device *mdev)
if (WARN_ON(mdev->dev == NULL || mdev->model[0] == 0))
return -EINVAL;
+ mdev->entity_id = 1;
+ INIT_LIST_HEAD(&mdev->entities);
+ spin_lock_init(&mdev->lock);
+
/* Register the device node. */
mdev->devnode.fops = &media_device_fops;
mdev->devnode.parent = mdev->dev;
@@ -94,7 +99,58 @@ EXPORT_SYMBOL_GPL(media_device_register);
*/
void media_device_unregister(struct media_device *mdev)
{
+ struct media_entity *entity;
+ struct media_entity *next;
+
+ list_for_each_entry_safe(entity, next, &mdev->entities, list)
+ media_device_unregister_entity(entity);
+
device_remove_file(&mdev->devnode.dev, &dev_attr_model);
media_devnode_unregister(&mdev->devnode);
}
EXPORT_SYMBOL_GPL(media_device_unregister);
+
+/**
+ * media_device_register_entity - Register an entity with a media device
+ * @mdev: The media device
+ * @entity: The entity
+ */
+int __must_check media_device_register_entity(struct media_device *mdev,
+ struct media_entity *entity)
+{
+ /* Warn if we apparently re-register an entity */
+ WARN_ON(entity->parent != NULL);
+ entity->parent = mdev;
+
+ spin_lock(&mdev->lock);
+ if (entity->id == 0)
+ entity->id = mdev->entity_id++;
+ else
+ mdev->entity_id = max(entity->id + 1, mdev->entity_id);
+ list_add_tail(&entity->list, &mdev->entities);
+ spin_unlock(&mdev->lock);
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(media_device_register_entity);
+
+/**
+ * media_device_unregister_entity - Unregister an entity
+ * @entity: The entity
+ *
+ * If the entity has never been registered this function will return
+ * immediately.
+ */
+void media_device_unregister_entity(struct media_entity *entity)
+{
+ struct media_device *mdev = entity->parent;
+
+ if (mdev == NULL)
+ return;
+
+ spin_lock(&mdev->lock);
+ list_del(&entity->list);
+ spin_unlock(&mdev->lock);
+ entity->parent = NULL;
+}
+EXPORT_SYMBOL_GPL(media_device_unregister_entity);
diff --git a/drivers/media/media-entity.c b/drivers/media/media-entity.c
new file mode 100644
index 000000000000..5c31df9ed765
--- /dev/null
+++ b/drivers/media/media-entity.c
@@ -0,0 +1,147 @@
+/*
+ * Media entity
+ *
+ * Copyright (C) 2010 Nokia Corporation
+ *
+ * Contacts: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
+ * Sakari Ailus <sakari.ailus@iki.fi>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ */
+
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <media/media-entity.h>
+
+/**
+ * media_entity_init - Initialize a media entity
+ *
+ * @num_pads: Total number of sink and source pads.
+ * @extra_links: Initial estimate of the number of extra links.
+ * @pads: Array of 'num_pads' pads.
+ *
+ * The total number of pads is an intrinsic property of entities known by the
+ * entity driver, while the total number of links depends on hardware design
+ * and is an extrinsic property unknown to the entity driver. However, in most
+ * use cases the entity driver can guess the number of links which can safely
+ * be assumed to be equal to or larger than the number of pads.
+ *
+ * For those reasons the links array can be preallocated based on the entity
+ * driver guess and will be reallocated later if extra links need to be
+ * created.
+ *
+ * This function allocates a links array with enough space to hold at least
+ * 'num_pads' + 'extra_links' elements. The media_entity::max_links field will
+ * be set to the number of allocated elements.
+ *
+ * The pads array is managed by the entity driver and passed to
+ * media_entity_init() where its pointer will be stored in the entity structure.
+ */
+int
+media_entity_init(struct media_entity *entity, u16 num_pads,
+ struct media_pad *pads, u16 extra_links)
+{
+ struct media_link *links;
+ unsigned int max_links = num_pads + extra_links;
+ unsigned int i;
+
+ links = kzalloc(max_links * sizeof(links[0]), GFP_KERNEL);
+ if (links == NULL)
+ return -ENOMEM;
+
+ entity->group_id = 0;
+ entity->max_links = max_links;
+ entity->num_links = 0;
+ entity->num_backlinks = 0;
+ entity->num_pads = num_pads;
+ entity->pads = pads;
+ entity->links = links;
+
+ for (i = 0; i < num_pads; i++) {
+ pads[i].entity = entity;
+ pads[i].index = i;
+ }
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(media_entity_init);
+
+void
+media_entity_cleanup(struct media_entity *entity)
+{
+ kfree(entity->links);
+}
+EXPORT_SYMBOL_GPL(media_entity_cleanup);
+
+static struct media_link *media_entity_add_link(struct media_entity *entity)
+{
+ if (entity->num_links >= entity->max_links) {
+ struct media_link *links = entity->links;
+ unsigned int max_links = entity->max_links + 2;
+ unsigned int i;
+
+ links = krealloc(links, max_links * sizeof(*links), GFP_KERNEL);
+ if (links == NULL)
+ return NULL;
+
+ for (i = 0; i < entity->num_links; i++)
+ links[i].reverse->reverse = &links[i];
+
+ entity->max_links = max_links;
+ entity->links = links;
+ }
+
+ return &entity->links[entity->num_links++];
+}
+
+int
+media_entity_create_link(struct media_entity *source, u16 source_pad,
+ struct media_entity *sink, u16 sink_pad, u32 flags)
+{
+ struct media_link *link;
+ struct media_link *backlink;
+
+ BUG_ON(source == NULL || sink == NULL);
+ BUG_ON(source_pad >= source->num_pads);
+ BUG_ON(sink_pad >= sink->num_pads);
+
+ link = media_entity_add_link(source);
+ if (link == NULL)
+ return -ENOMEM;
+
+ link->source = &source->pads[source_pad];
+ link->sink = &sink->pads[sink_pad];
+ link->flags = flags;
+
+ /* Create the backlink. Backlinks are used to help graph traversal and
+ * are not reported to userspace.
+ */
+ backlink = media_entity_add_link(sink);
+ if (backlink == NULL) {
+ source->num_links--;
+ return -ENOMEM;
+ }
+
+ backlink->source = &source->pads[source_pad];
+ backlink->sink = &sink->pads[sink_pad];
+ backlink->flags = flags;
+
+ link->reverse = backlink;
+ backlink->reverse = link;
+
+ sink->num_backlinks++;
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(media_entity_create_link);

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