linux/include/media/media-entity.h
Laurent Pinchart 503c3d829e [media] media: Entity use count
Due to the wide differences between drivers regarding power management
needs, the media controller does not implement power management.
However, the media_entity structure includes a use_count field that
media drivers can use to track the number of users of every entity for
power management needs.

The use_count field is owned by media drivers and must not be touched by
entity drivers. Access to the field must be protected by the media
device graph_mutex lock.

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Acked-by: Hans Verkuil <hverkuil@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
2011-03-22 04:53:12 -03:00

147 lines
4.4 KiB
C

/*
* 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
*/
#ifndef _MEDIA_ENTITY_H
#define _MEDIA_ENTITY_H
#include <linux/list.h>
#define MEDIA_ENT_TYPE_SHIFT 16
#define MEDIA_ENT_TYPE_MASK 0x00ff0000
#define MEDIA_ENT_SUBTYPE_MASK 0x0000ffff
#define MEDIA_ENT_T_DEVNODE (1 << MEDIA_ENT_TYPE_SHIFT)
#define MEDIA_ENT_T_DEVNODE_V4L (MEDIA_ENT_T_DEVNODE + 1)
#define MEDIA_ENT_T_DEVNODE_FB (MEDIA_ENT_T_DEVNODE + 2)
#define MEDIA_ENT_T_DEVNODE_ALSA (MEDIA_ENT_T_DEVNODE + 3)
#define MEDIA_ENT_T_DEVNODE_DVB (MEDIA_ENT_T_DEVNODE + 4)
#define MEDIA_ENT_T_V4L2_SUBDEV (2 << MEDIA_ENT_TYPE_SHIFT)
#define MEDIA_ENT_T_V4L2_SUBDEV_SENSOR (MEDIA_ENT_T_V4L2_SUBDEV + 1)
#define MEDIA_ENT_T_V4L2_SUBDEV_FLASH (MEDIA_ENT_T_V4L2_SUBDEV + 2)
#define MEDIA_ENT_T_V4L2_SUBDEV_LENS (MEDIA_ENT_T_V4L2_SUBDEV + 3)
#define MEDIA_ENT_FL_DEFAULT (1 << 0)
#define MEDIA_LNK_FL_ENABLED (1 << 0)
#define MEDIA_LNK_FL_IMMUTABLE (1 << 1)
#define MEDIA_PAD_FL_SINK (1 << 0)
#define MEDIA_PAD_FL_SOURCE (1 << 1)
struct media_link {
struct media_pad *source; /* Source pad */
struct media_pad *sink; /* Sink pad */
struct media_link *reverse; /* Link in the reverse direction */
unsigned long flags; /* Link flags (MEDIA_LNK_FL_*) */
};
struct media_pad {
struct media_entity *entity; /* Entity this pad belongs to */
u16 index; /* Pad index in the entity pads array */
unsigned long flags; /* Pad flags (MEDIA_PAD_FL_*) */
};
struct media_entity {
struct list_head list;
struct media_device *parent; /* Media device this entity belongs to*/
u32 id; /* Entity ID, unique in the parent media
* device context */
const char *name; /* Entity name */
u32 type; /* Entity type (MEDIA_ENT_T_*) */
u32 revision; /* Entity revision, driver specific */
unsigned long flags; /* Entity flags (MEDIA_ENT_FL_*) */
u32 group_id; /* Entity group ID */
u16 num_pads; /* Number of sink and source pads */
u16 num_links; /* Number of existing links, both
* enabled and disabled */
u16 num_backlinks; /* Number of backlinks */
u16 max_links; /* Maximum number of links */
struct media_pad *pads; /* Pads array (num_pads elements) */
struct media_link *links; /* Links array (max_links elements)*/
/* Reference counts must never be negative, but are signed integers on
* purpose: a simple WARN_ON(<0) check can be used to detect reference
* count bugs that would make them negative.
*/
int use_count; /* Use count for the entity. */
union {
/* Node specifications */
struct {
u32 major;
u32 minor;
} v4l;
struct {
u32 major;
u32 minor;
} fb;
struct {
u32 card;
u32 device;
u32 subdevice;
} alsa;
int dvb;
/* Sub-device specifications */
/* Nothing needed yet */
};
};
static inline u32 media_entity_type(struct media_entity *entity)
{
return entity->type & MEDIA_ENT_TYPE_MASK;
}
static inline u32 media_entity_subtype(struct media_entity *entity)
{
return entity->type & MEDIA_ENT_SUBTYPE_MASK;
}
#define MEDIA_ENTITY_ENUM_MAX_DEPTH 16
struct media_entity_graph {
struct {
struct media_entity *entity;
int link;
} stack[MEDIA_ENTITY_ENUM_MAX_DEPTH];
int top;
};
int media_entity_init(struct media_entity *entity, u16 num_pads,
struct media_pad *pads, u16 extra_links);
void media_entity_cleanup(struct media_entity *entity);
int media_entity_create_link(struct media_entity *source, u16 source_pad,
struct media_entity *sink, u16 sink_pad, u32 flags);
struct media_entity *media_entity_get(struct media_entity *entity);
void media_entity_put(struct media_entity *entity);
void media_entity_graph_walk_start(struct media_entity_graph *graph,
struct media_entity *entity);
struct media_entity *
media_entity_graph_walk_next(struct media_entity_graph *graph);
#endif