LXR linux/include/media/media-entity.h

   1/*
   2 * Media entity
   3 *
   4 * Copyright (C) 2010 Nokia Corporation
   5 *
   6 * Contacts: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
   7 *           Sakari Ailus <sakari.ailus@iki.fi>
   8 *
   9 * This program is free software; you can redistribute it and/or modify
  10 * it under the terms of the GNU General Public License version 2 as
  11 * published by the Free Software Foundation.
  12 *
  13 * This program is distributed in the hope that it will be useful,
  14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
  15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16 * GNU General Public License for more details.
  17 *
  18 * You should have received a copy of the GNU General Public License
  19 * along with this program; if not, write to the Free Software
  20 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  21 */
  22
  23#ifndef _MEDIA_ENTITY_H
  24#define _MEDIA_ENTITY_H
  25
  26#include <linux/bitops.h>
  27#include <linux/kernel.h>
  28#include <linux/list.h>
  29#include <linux/media.h>
  30
  31struct media_pipeline {
  32};
  33
  34struct media_link {
  35        struct media_pad *source;       /* Source pad */
  36        struct media_pad *sink;         /* Sink pad  */
  37        struct media_link *reverse;     /* Link in the reverse direction */
  38        unsigned long flags;            /* Link flags (MEDIA_LNK_FL_*) */
  39};
  40
  41struct media_pad {
  42        struct media_entity *entity;    /* Entity this pad belongs to */
  43        u16 index;                      /* Pad index in the entity pads array */
  44        unsigned long flags;            /* Pad flags (MEDIA_PAD_FL_*) */
  45};
  46
  47/**
  48 * struct media_entity_operations - Media entity operations
  49 * @link_setup:         Notify the entity of link changes. The operation can
  50 *                      return an error, in which case link setup will be
  51 *                      cancelled. Optional.
  52 * @link_validate:      Return whether a link is valid from the entity point of
  53 *                      view. The media_entity_pipeline_start() function
  54 *                      validates all links by calling this operation. Optional.
  55 */
  56struct media_entity_operations {
  57        int (*link_setup)(struct media_entity *entity,
  58                          const struct media_pad *local,
  59                          const struct media_pad *remote, u32 flags);
  60        int (*link_validate)(struct media_link *link);
  61};
  62
  63struct media_entity {
  64        struct list_head list;
  65        struct media_device *parent;    /* Media device this entity belongs to*/
  66        u32 id;                         /* Entity ID, unique in the parent media
  67                                         * device context */
  68        const char *name;               /* Entity name */
  69        u32 type;                       /* Entity type (MEDIA_ENT_T_*) */
  70        u32 revision;                   /* Entity revision, driver specific */
  71        unsigned long flags;            /* Entity flags (MEDIA_ENT_FL_*) */
  72        u32 group_id;                   /* Entity group ID */
  73
  74        u16 num_pads;                   /* Number of sink and source pads */
  75        u16 num_links;                  /* Number of existing links, both
  76                                         * enabled and disabled */
  77        u16 num_backlinks;              /* Number of backlinks */
  78        u16 max_links;                  /* Maximum number of links */
  79
  80        struct media_pad *pads;         /* Pads array (num_pads elements) */
  81        struct media_link *links;       /* Links array (max_links elements)*/
  82
  83        const struct media_entity_operations *ops;      /* Entity operations */
  84
  85        /* Reference counts must never be negative, but are signed integers on
  86         * purpose: a simple WARN_ON(<0) check can be used to detect reference
  87         * count bugs that would make them negative.
  88         */
  89        int stream_count;               /* Stream count for the entity. */
  90        int use_count;                  /* Use count for the entity. */
  91
  92        struct media_pipeline *pipe;    /* Pipeline this entity belongs to. */
  93
  94        union {
  95                /* Node specifications */
  96                struct {
  97                        u32 major;
  98                        u32 minor;
  99                } dev;
 100
 101                /* Sub-device specifications */
 102                /* Nothing needed yet */
 103        } info;
 104};
 105
 106static inline u32 media_entity_type(struct media_entity *entity)
 107{
 108        return entity->type & MEDIA_ENT_TYPE_MASK;
 109}
 110
 111static inline u32 media_entity_subtype(struct media_entity *entity)
 112{
 113        return entity->type & MEDIA_ENT_SUBTYPE_MASK;
 114}
 115
 116#define MEDIA_ENTITY_ENUM_MAX_DEPTH     16
 117#define MEDIA_ENTITY_ENUM_MAX_ID        64
 118
 119struct media_entity_graph {
 120        struct {
 121                struct media_entity *entity;
 122                int link;
 123        } stack[MEDIA_ENTITY_ENUM_MAX_DEPTH];
 124
 125        DECLARE_BITMAP(entities, MEDIA_ENTITY_ENUM_MAX_ID);
 126        int top;
 127};
 128
 129int media_entity_init(struct media_entity *entity, u16 num_pads,
 130                struct media_pad *pads, u16 extra_links);
 131void media_entity_cleanup(struct media_entity *entity);
 132
 133int media_entity_create_link(struct media_entity *source, u16 source_pad,
 134                struct media_entity *sink, u16 sink_pad, u32 flags);
 135void __media_entity_remove_links(struct media_entity *entity);
 136void media_entity_remove_links(struct media_entity *entity);
 137
 138int __media_entity_setup_link(struct media_link *link, u32 flags);
 139int media_entity_setup_link(struct media_link *link, u32 flags);
 140struct media_link *media_entity_find_link(struct media_pad *source,
 141                struct media_pad *sink);
 142struct media_pad *media_entity_remote_pad(struct media_pad *pad);
 143
 144struct media_entity *media_entity_get(struct media_entity *entity);
 145void media_entity_put(struct media_entity *entity);
 146
 147void media_entity_graph_walk_start(struct media_entity_graph *graph,
 148                struct media_entity *entity);
 149struct media_entity *
 150media_entity_graph_walk_next(struct media_entity_graph *graph);
 151__must_check int media_entity_pipeline_start(struct media_entity *entity,
 152                                             struct media_pipeline *pipe);
 153void media_entity_pipeline_stop(struct media_entity *entity);
 154
 155#define media_entity_call(entity, operation, args...)                   \
 156        (((entity)->ops && (entity)->ops->operation) ?                  \
 157         (entity)->ops->operation((entity) , ##args) : -ENOIOCTLCMD)
 158
 159#endif
 160