linux/drivers/media/media-device.c

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/*
* Media device
*
* 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/types.h>
#include <linux/ioctl.h>
#include <linux/media.h>
#include <linux/export.h>
#include <media/media-device.h>
#include <media/media-devnode.h>
[media] media: Entities, pads and links As video hardware pipelines become increasingly complex and configurable, the current hardware description through v4l2 subdevices reaches its limits. In addition to enumerating and configuring subdevices, video camera drivers need a way to discover and modify at runtime how those subdevices are connected. This is done through new elements called entities, pads and links. An entity is a basic media hardware building block. It can correspond to a large variety of logical blocks such as physical hardware devices (CMOS sensor for instance), logical hardware devices (a building block in a System-on-Chip image processing pipeline), DMA channels or physical connectors. A pad is a connection endpoint through which an entity can interact with other entities. Data (not restricted to video) produced by an entity flows from the entity's output to one or more entity inputs. Pads should not be confused with physical pins at chip boundaries. A link is a point-to-point oriented connection between two pads, either on the same entity or on different entities. Data flows from a source pad to a sink pad. Links are stored in the source entity. To make backwards graph walk faster, a copy of all links is also stored in the sink entity. The copy is known as a backlink and is only used to help graph traversal. The entity API is made of three functions: - media_entity_init() initializes an entity. The caller must provide an array of pads as well as an estimated number of links. The links array is allocated dynamically and will be reallocated if it grows beyond the initial estimate. - media_entity_cleanup() frees resources allocated for an entity. It must be called during the cleanup phase after unregistering the entity and before freeing it. - media_entity_create_link() creates a link between two entities. An entry in the link array of each entity is allocated and stores pointers to source and sink pads. When a media device is unregistered, all its entities are unregistered automatically. The code is based on Hans Verkuil <hverkuil@xs4all.nl> initial work. Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> Signed-off-by: Sakari Ailus <sakari.ailus@iki.fi> Acked-by: Hans Verkuil <hverkuil@xs4all.nl> Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
2009-12-09 11:40:00 +00:00
#include <media/media-entity.h>
/* -----------------------------------------------------------------------------
* Userspace API
*/
static int media_device_open(struct file *filp)
{
return 0;
}
static int media_device_close(struct file *filp)
{
return 0;
}
static int media_device_get_info(struct media_device *dev,
struct media_device_info __user *__info)
{
struct media_device_info info;
memset(&info, 0, sizeof(info));
strlcpy(info.driver, dev->dev->driver->name, sizeof(info.driver));
strlcpy(info.model, dev->model, sizeof(info.model));
strlcpy(info.serial, dev->serial, sizeof(info.serial));
strlcpy(info.bus_info, dev->bus_info, sizeof(info.bus_info));
info.media_version = MEDIA_API_VERSION;
info.hw_revision = dev->hw_revision;
info.driver_version = dev->driver_version;
if (copy_to_user(__info, &info, sizeof(*__info)))
return -EFAULT;
return 0;
}
static struct media_entity *find_entity(struct media_device *mdev, u32 id)
{
struct media_entity *entity;
int next = id & MEDIA_ENT_ID_FLAG_NEXT;
id &= ~MEDIA_ENT_ID_FLAG_NEXT;
spin_lock(&mdev->lock);
media_device_for_each_entity(entity, mdev) {
if ((entity->id == id && !next) ||
(entity->id > id && next)) {
spin_unlock(&mdev->lock);
return entity;
}
}
spin_unlock(&mdev->lock);
return NULL;
}
static long media_device_enum_entities(struct media_device *mdev,
struct media_entity_desc __user *uent)
{
struct media_entity *ent;
struct media_entity_desc u_ent;
if (copy_from_user(&u_ent.id, &uent->id, sizeof(u_ent.id)))
return -EFAULT;
ent = find_entity(mdev, u_ent.id);
if (ent == NULL)
return -EINVAL;
u_ent.id = ent->id;
u_ent.name[0] = '\0';
if (ent->name)
strlcpy(u_ent.name, ent->name, sizeof(u_ent.name));
u_ent.type = ent->type;
u_ent.revision = ent->revision;
u_ent.flags = ent->flags;
u_ent.group_id = ent->group_id;
u_ent.pads = ent->num_pads;
u_ent.links = ent->num_links - ent->num_backlinks;
memcpy(&u_ent.raw, &ent->info, sizeof(ent->info));
if (copy_to_user(uent, &u_ent, sizeof(u_ent)))
return -EFAULT;
return 0;
}
static void media_device_kpad_to_upad(const struct media_pad *kpad,
struct media_pad_desc *upad)
{
upad->entity = kpad->entity->id;
upad->index = kpad->index;
upad->flags = kpad->flags;
}
static long media_device_enum_links(struct media_device *mdev,
struct media_links_enum __user *ulinks)
{
struct media_entity *entity;
struct media_links_enum links;
if (copy_from_user(&links, ulinks, sizeof(links)))
return -EFAULT;
entity = find_entity(mdev, links.entity);
if (entity == NULL)
return -EINVAL;
if (links.pads) {
unsigned int p;
for (p = 0; p < entity->num_pads; p++) {
struct media_pad_desc pad;
media_device_kpad_to_upad(&entity->pads[p], &pad);
if (copy_to_user(&links.pads[p], &pad, sizeof(pad)))
return -EFAULT;
}
}
if (links.links) {
struct media_link_desc __user *ulink;
unsigned int l;
for (l = 0, ulink = links.links; l < entity->num_links; l++) {
struct media_link_desc link;
/* Ignore backlinks. */
if (entity->links[l].source->entity != entity)
continue;
media_device_kpad_to_upad(entity->links[l].source,
&link.source);
media_device_kpad_to_upad(entity->links[l].sink,
&link.sink);
link.flags = entity->links[l].flags;
if (copy_to_user(ulink, &link, sizeof(*ulink)))
return -EFAULT;
ulink++;
}
}
if (copy_to_user(ulinks, &links, sizeof(*ulinks)))
return -EFAULT;
return 0;
}
static long media_device_setup_link(struct media_device *mdev,
struct media_link_desc __user *_ulink)
{
struct media_link *link = NULL;
struct media_link_desc ulink;
struct media_entity *source;
struct media_entity *sink;
int ret;
if (copy_from_user(&ulink, _ulink, sizeof(ulink)))
return -EFAULT;
/* Find the source and sink entities and link.
*/
source = find_entity(mdev, ulink.source.entity);
sink = find_entity(mdev, ulink.sink.entity);
if (source == NULL || sink == NULL)
return -EINVAL;
if (ulink.source.index >= source->num_pads ||
ulink.sink.index >= sink->num_pads)
return -EINVAL;
link = media_entity_find_link(&source->pads[ulink.source.index],
&sink->pads[ulink.sink.index]);
if (link == NULL)
return -EINVAL;
/* Setup the link on both entities. */
ret = __media_entity_setup_link(link, ulink.flags);
if (copy_to_user(_ulink, &ulink, sizeof(ulink)))
return -EFAULT;
return ret;
}
static long media_device_ioctl(struct file *filp, unsigned int cmd,
unsigned long arg)
{
struct media_devnode *devnode = media_devnode_data(filp);
struct media_device *dev = to_media_device(devnode);
long ret;
switch (cmd) {
case MEDIA_IOC_DEVICE_INFO:
ret = media_device_get_info(dev,
(struct media_device_info __user *)arg);
break;
case MEDIA_IOC_ENUM_ENTITIES:
ret = media_device_enum_entities(dev,
(struct media_entity_desc __user *)arg);
break;
case MEDIA_IOC_ENUM_LINKS:
mutex_lock(&dev->graph_mutex);
ret = media_device_enum_links(dev,
(struct media_links_enum __user *)arg);
mutex_unlock(&dev->graph_mutex);
break;
case MEDIA_IOC_SETUP_LINK:
mutex_lock(&dev->graph_mutex);
ret = media_device_setup_link(dev,
(struct media_link_desc __user *)arg);
mutex_unlock(&dev->graph_mutex);
break;
default:
ret = -ENOIOCTLCMD;
}
return ret;
}
static const struct media_file_operations media_device_fops = {
.owner = THIS_MODULE,
.open = media_device_open,
.ioctl = media_device_ioctl,
.release = media_device_close,
};
/* -----------------------------------------------------------------------------
* sysfs
*/
static ssize_t show_model(struct device *cd,
struct device_attribute *attr, char *buf)
{
struct media_device *mdev = to_media_device(to_media_devnode(cd));
return sprintf(buf, "%.*s\n", (int)sizeof(mdev->model), mdev->model);
}
static DEVICE_ATTR(model, S_IRUGO, show_model, NULL);
/* -----------------------------------------------------------------------------
* Registration/unregistration
*/
static void media_device_release(struct media_devnode *mdev)
{
}
/**
* media_device_register - register a media device
* @mdev: The media device
*
* The caller is responsible for initializing the media device before
* registration. The following fields must be set:
*
* - dev must point to the parent device
* - model must be filled with the device model name
*/
int __must_check media_device_register(struct media_device *mdev)
{
int ret;
if (WARN_ON(mdev->dev == NULL || mdev->model[0] == 0))
return -EINVAL;
[media] media: Entities, pads and links As video hardware pipelines become increasingly complex and configurable, the current hardware description through v4l2 subdevices reaches its limits. In addition to enumerating and configuring subdevices, video camera drivers need a way to discover and modify at runtime how those subdevices are connected. This is done through new elements called entities, pads and links. An entity is a basic media hardware building block. It can correspond to a large variety of logical blocks such as physical hardware devices (CMOS sensor for instance), logical hardware devices (a building block in a System-on-Chip image processing pipeline), DMA channels or physical connectors. A pad is a connection endpoint through which an entity can interact with other entities. Data (not restricted to video) produced by an entity flows from the entity's output to one or more entity inputs. Pads should not be confused with physical pins at chip boundaries. A link is a point-to-point oriented connection between two pads, either on the same entity or on different entities. Data flows from a source pad to a sink pad. Links are stored in the source entity. To make backwards graph walk faster, a copy of all links is also stored in the sink entity. The copy is known as a backlink and is only used to help graph traversal. The entity API is made of three functions: - media_entity_init() initializes an entity. The caller must provide an array of pads as well as an estimated number of links. The links array is allocated dynamically and will be reallocated if it grows beyond the initial estimate. - media_entity_cleanup() frees resources allocated for an entity. It must be called during the cleanup phase after unregistering the entity and before freeing it. - media_entity_create_link() creates a link between two entities. An entry in the link array of each entity is allocated and stores pointers to source and sink pads. When a media device is unregistered, all its entities are unregistered automatically. The code is based on Hans Verkuil <hverkuil@xs4all.nl> initial work. Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> Signed-off-by: Sakari Ailus <sakari.ailus@iki.fi> Acked-by: Hans Verkuil <hverkuil@xs4all.nl> Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
2009-12-09 11:40:00 +00:00
mdev->entity_id = 1;
INIT_LIST_HEAD(&mdev->entities);
spin_lock_init(&mdev->lock);
mutex_init(&mdev->graph_mutex);
[media] media: Entities, pads and links As video hardware pipelines become increasingly complex and configurable, the current hardware description through v4l2 subdevices reaches its limits. In addition to enumerating and configuring subdevices, video camera drivers need a way to discover and modify at runtime how those subdevices are connected. This is done through new elements called entities, pads and links. An entity is a basic media hardware building block. It can correspond to a large variety of logical blocks such as physical hardware devices (CMOS sensor for instance), logical hardware devices (a building block in a System-on-Chip image processing pipeline), DMA channels or physical connectors. A pad is a connection endpoint through which an entity can interact with other entities. Data (not restricted to video) produced by an entity flows from the entity's output to one or more entity inputs. Pads should not be confused with physical pins at chip boundaries. A link is a point-to-point oriented connection between two pads, either on the same entity or on different entities. Data flows from a source pad to a sink pad. Links are stored in the source entity. To make backwards graph walk faster, a copy of all links is also stored in the sink entity. The copy is known as a backlink and is only used to help graph traversal. The entity API is made of three functions: - media_entity_init() initializes an entity. The caller must provide an array of pads as well as an estimated number of links. The links array is allocated dynamically and will be reallocated if it grows beyond the initial estimate. - media_entity_cleanup() frees resources allocated for an entity. It must be called during the cleanup phase after unregistering the entity and before freeing it. - media_entity_create_link() creates a link between two entities. An entry in the link array of each entity is allocated and stores pointers to source and sink pads. When a media device is unregistered, all its entities are unregistered automatically. The code is based on Hans Verkuil <hverkuil@xs4all.nl> initial work. Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> Signed-off-by: Sakari Ailus <sakari.ailus@iki.fi> Acked-by: Hans Verkuil <hverkuil@xs4all.nl> Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
2009-12-09 11:40:00 +00:00
/* Register the device node. */
mdev->devnode.fops = &media_device_fops;
mdev->devnode.parent = mdev->dev;
mdev->devnode.release = media_device_release;
ret = media_devnode_register(&mdev->devnode);
if (ret < 0)
return ret;
ret = device_create_file(&mdev->devnode.dev, &dev_attr_model);
if (ret < 0) {
media_devnode_unregister(&mdev->devnode);
return ret;
}
return 0;
}
EXPORT_SYMBOL_GPL(media_device_register);
/**
* media_device_unregister - unregister a media device
* @mdev: The media device
*
*/
void media_device_unregister(struct media_device *mdev)
{
[media] media: Entities, pads and links As video hardware pipelines become increasingly complex and configurable, the current hardware description through v4l2 subdevices reaches its limits. In addition to enumerating and configuring subdevices, video camera drivers need a way to discover and modify at runtime how those subdevices are connected. This is done through new elements called entities, pads and links. An entity is a basic media hardware building block. It can correspond to a large variety of logical blocks such as physical hardware devices (CMOS sensor for instance), logical hardware devices (a building block in a System-on-Chip image processing pipeline), DMA channels or physical connectors. A pad is a connection endpoint through which an entity can interact with other entities. Data (not restricted to video) produced by an entity flows from the entity's output to one or more entity inputs. Pads should not be confused with physical pins at chip boundaries. A link is a point-to-point oriented connection between two pads, either on the same entity or on different entities. Data flows from a source pad to a sink pad. Links are stored in the source entity. To make backwards graph walk faster, a copy of all links is also stored in the sink entity. The copy is known as a backlink and is only used to help graph traversal. The entity API is made of three functions: - media_entity_init() initializes an entity. The caller must provide an array of pads as well as an estimated number of links. The links array is allocated dynamically and will be reallocated if it grows beyond the initial estimate. - media_entity_cleanup() frees resources allocated for an entity. It must be called during the cleanup phase after unregistering the entity and before freeing it. - media_entity_create_link() creates a link between two entities. An entry in the link array of each entity is allocated and stores pointers to source and sink pads. When a media device is unregistered, all its entities are unregistered automatically. The code is based on Hans Verkuil <hverkuil@xs4all.nl> initial work. Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> Signed-off-by: Sakari Ailus <sakari.ailus@iki.fi> Acked-by: Hans Verkuil <hverkuil@xs4all.nl> Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
2009-12-09 11:40:00 +00:00
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] media: Entities, pads and links As video hardware pipelines become increasingly complex and configurable, the current hardware description through v4l2 subdevices reaches its limits. In addition to enumerating and configuring subdevices, video camera drivers need a way to discover and modify at runtime how those subdevices are connected. This is done through new elements called entities, pads and links. An entity is a basic media hardware building block. It can correspond to a large variety of logical blocks such as physical hardware devices (CMOS sensor for instance), logical hardware devices (a building block in a System-on-Chip image processing pipeline), DMA channels or physical connectors. A pad is a connection endpoint through which an entity can interact with other entities. Data (not restricted to video) produced by an entity flows from the entity's output to one or more entity inputs. Pads should not be confused with physical pins at chip boundaries. A link is a point-to-point oriented connection between two pads, either on the same entity or on different entities. Data flows from a source pad to a sink pad. Links are stored in the source entity. To make backwards graph walk faster, a copy of all links is also stored in the sink entity. The copy is known as a backlink and is only used to help graph traversal. The entity API is made of three functions: - media_entity_init() initializes an entity. The caller must provide an array of pads as well as an estimated number of links. The links array is allocated dynamically and will be reallocated if it grows beyond the initial estimate. - media_entity_cleanup() frees resources allocated for an entity. It must be called during the cleanup phase after unregistering the entity and before freeing it. - media_entity_create_link() creates a link between two entities. An entry in the link array of each entity is allocated and stores pointers to source and sink pads. When a media device is unregistered, all its entities are unregistered automatically. The code is based on Hans Verkuil <hverkuil@xs4all.nl> initial work. Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> Signed-off-by: Sakari Ailus <sakari.ailus@iki.fi> Acked-by: Hans Verkuil <hverkuil@xs4all.nl> Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
2009-12-09 11:40:00 +00:00
/**
* 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);