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
  31 struct media_pipeline {
  32 };
  33
  34 struct 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
  41 struct 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  */
  56 struct 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
  63 struct 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
 106 static inline u32 media_entity_type(struct media_entity *entity)
 107 {
 108         return entity->type & MEDIA_ENT_TYPE_MASK;
 109 }
 110
 111 static 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
 119 /*
 120  * The number of pads can't be bigger than the number of entities,
 121  * as the worse-case scenario is to have one entity linked up to
 122  * MEDIA_ENTITY_ENUM_MAX_ID - 1 entities.
 123  */
 124 #define MEDIA_ENTITY_MAX_PADS           (MEDIA_ENTITY_ENUM_MAX_ID - 1)
 125
 126 struct media_entity_graph {
 127         struct {
 128                 struct media_entity *entity;
 129                 int link;
 130         } stack[MEDIA_ENTITY_ENUM_MAX_DEPTH];
 131
 132         DECLARE_BITMAP(entities, MEDIA_ENTITY_ENUM_MAX_ID);
 133         int top;
 134 };
 135
 136 int media_entity_init(struct media_entity *entity, u16 num_pads,
 137                 struct media_pad *pads, u16 extra_links);
 138 void media_entity_cleanup(struct media_entity *entity);
 139
 140 int media_entity_create_link(struct media_entity *source, u16 source_pad,
 141                 struct media_entity *sink, u16 sink_pad, u32 flags);
 142 void __media_entity_remove_links(struct media_entity *entity);
 143 void media_entity_remove_links(struct media_entity *entity);
 144
 145 int __media_entity_setup_link(struct media_link *link, u32 flags);
 146 int media_entity_setup_link(struct media_link *link, u32 flags);
 147 struct media_link *media_entity_find_link(struct media_pad *source,
 148                 struct media_pad *sink);
 149 struct media_pad *media_entity_remote_pad(struct media_pad *pad);
 150
 151 struct media_entity *media_entity_get(struct media_entity *entity);
 152 void media_entity_put(struct media_entity *entity);
 153
 154 void media_entity_graph_walk_start(struct media_entity_graph *graph,
 155                 struct media_entity *entity);
 156 struct media_entity *
 157 media_entity_graph_walk_next(struct media_entity_graph *graph);
 158 __must_check int media_entity_pipeline_start(struct media_entity *entity,
 159                                              struct media_pipeline *pipe);
 160 void media_entity_pipeline_stop(struct media_entity *entity);
 161
 162 #define media_entity_call(entity, operation, args...)                   \
 163         (((entity)->ops && (entity)->ops->operation) ?                  \
 164          (entity)->ops->operation((entity) , ##args) : -ENOIOCTLCMD)
 165
 166 #endif