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 /* Enums used internally at the media controller to represent graphs */
  32
  33 /**
  34  * enum media_gobj_type - type of a graph object
  35  *
  36  * @MEDIA_GRAPH_ENTITY:         Identify a media entity
  37  * @MEDIA_GRAPH_PAD:            Identify a media pad
  38  * @MEDIA_GRAPH_LINK:           Identify a media link
  39  */
  40 enum media_gobj_type {
  41         MEDIA_GRAPH_ENTITY,
  42         MEDIA_GRAPH_PAD,
  43         MEDIA_GRAPH_LINK,
  44 };
  45
  46 #define MEDIA_BITS_PER_TYPE             8
  47 #define MEDIA_BITS_PER_LOCAL_ID         (32 - MEDIA_BITS_PER_TYPE)
  48 #define MEDIA_LOCAL_ID_MASK              GENMASK(MEDIA_BITS_PER_LOCAL_ID - 1, 0)
  49
  50 /* Structs to represent the objects that belong to a media graph */
  51
  52 /**
  53  * struct media_gobj - Define a graph object.
  54  *
  55  * @id:         Non-zero object ID identifier. The ID should be unique
  56  *              inside a media_device, as it is composed by
  57  *              MEDIA_BITS_PER_TYPE to store the type plus
  58  *              MEDIA_BITS_PER_LOCAL_ID to store a per-type ID
  59  *              (called as "local ID").
  60  *
  61  * All objects on the media graph should have this struct embedded
  62  */
  63 struct media_gobj {
  64         u32                     id;
  65 };
  66
  67
  68 struct media_pipeline {
  69 };
  70
  71 struct media_link {
  72         struct media_gobj graph_obj;
  73         struct media_pad *source;       /* Source pad */
  74         struct media_pad *sink;         /* Sink pad  */
  75         struct media_link *reverse;     /* Link in the reverse direction */
  76         unsigned long flags;            /* Link flags (MEDIA_LNK_FL_*) */
  77 };
  78
  79 struct media_pad {
  80         struct media_gobj graph_obj;
  81         struct media_entity *entity;    /* Entity this pad belongs to */
  82         u16 index;                      /* Pad index in the entity pads array */
  83         unsigned long flags;            /* Pad flags (MEDIA_PAD_FL_*) */
  84 };
  85
  86 /**
  87  * struct media_entity_operations - Media entity operations
  88  * @link_setup:         Notify the entity of link changes. The operation can
  89  *                      return an error, in which case link setup will be
  90  *                      cancelled. Optional.
  91  * @link_validate:      Return whether a link is valid from the entity point of
  92  *                      view. The media_entity_pipeline_start() function
  93  *                      validates all links by calling this operation. Optional.
  94  */
  95 struct media_entity_operations {
  96         int (*link_setup)(struct media_entity *entity,
  97                           const struct media_pad *local,
  98                           const struct media_pad *remote, u32 flags);
  99         int (*link_validate)(struct media_link *link);
 100 };
 101
 102 struct media_entity {
 103         struct media_gobj graph_obj;
 104         struct list_head list;
 105         struct media_device *parent;    /* Media device this entity belongs to*/
 106         const char *name;               /* Entity name */
 107         u32 type;                       /* Entity type (MEDIA_ENT_T_*) */
 108         u32 revision;                   /* Entity revision, driver specific */
 109         unsigned long flags;            /* Entity flags (MEDIA_ENT_FL_*) */
 110         u32 group_id;                   /* Entity group ID */
 111
 112         u16 num_pads;                   /* Number of sink and source pads */
 113         u16 num_links;                  /* Number of existing links, both
 114                                          * enabled and disabled */
 115         u16 num_backlinks;              /* Number of backlinks */
 116         u16 max_links;                  /* Maximum number of links */
 117
 118         struct media_pad *pads;         /* Pads array (num_pads elements) */
 119         struct media_link *links;       /* Links array (max_links elements)*/
 120
 121         const struct media_entity_operations *ops;      /* Entity operations */
 122
 123         /* Reference counts must never be negative, but are signed integers on
 124          * purpose: a simple WARN_ON(<0) check can be used to detect reference
 125          * count bugs that would make them negative.
 126          */
 127         int stream_count;               /* Stream count for the entity. */
 128         int use_count;                  /* Use count for the entity. */
 129
 130         struct media_pipeline *pipe;    /* Pipeline this entity belongs to. */
 131
 132         union {
 133                 /* Node specifications */
 134                 struct {
 135                         u32 major;
 136                         u32 minor;
 137                 } dev;
 138
 139                 /* Sub-device specifications */
 140                 /* Nothing needed yet */
 141         } info;
 142 };
 143
 144 static inline u32 media_entity_type(struct media_entity *entity)
 145 {
 146         return entity->type & MEDIA_ENT_TYPE_MASK;
 147 }
 148
 149 static inline u32 media_entity_subtype(struct media_entity *entity)
 150 {
 151         return entity->type & MEDIA_ENT_SUBTYPE_MASK;
 152 }
 153
 154 static inline u32 media_entity_id(struct media_entity *entity)
 155 {
 156         return entity->graph_obj.id;
 157 }
 158
 159 static inline enum media_gobj_type media_type(struct media_gobj *gobj)
 160 {
 161         return gobj->id >> MEDIA_BITS_PER_LOCAL_ID;
 162 }
 163
 164 static inline u32 media_localid(struct media_gobj *gobj)
 165 {
 166         return gobj->id & MEDIA_LOCAL_ID_MASK;
 167 }
 168
 169 static inline u32 media_gobj_gen_id(enum media_gobj_type type, u32 local_id)
 170 {
 171         u32 id;
 172
 173         id = type << MEDIA_BITS_PER_LOCAL_ID;
 174         id |= local_id & MEDIA_LOCAL_ID_MASK;
 175
 176         return id;
 177 }
 178
 179 #define MEDIA_ENTITY_ENUM_MAX_DEPTH     16
 180 #define MEDIA_ENTITY_ENUM_MAX_ID        64
 181
 182 /*
 183  * The number of pads can't be bigger than the number of entities,
 184  * as the worse-case scenario is to have one entity linked up to
 185  * MEDIA_ENTITY_ENUM_MAX_ID - 1 entities.
 186  */
 187 #define MEDIA_ENTITY_MAX_PADS           (MEDIA_ENTITY_ENUM_MAX_ID - 1)
 188
 189 struct media_entity_graph {
 190         struct {
 191                 struct media_entity *entity;
 192                 int link;
 193         } stack[MEDIA_ENTITY_ENUM_MAX_DEPTH];
 194
 195         DECLARE_BITMAP(entities, MEDIA_ENTITY_ENUM_MAX_ID);
 196         int top;
 197 };
 198
 199 #define gobj_to_entity(gobj) \
 200                 container_of(gobj, struct media_entity, graph_obj)
 201
 202 void media_gobj_init(struct media_device *mdev,
 203                     enum media_gobj_type type,
 204                     struct media_gobj *gobj);
 205 void media_gobj_remove(struct media_gobj *gobj);
 206
 207 int media_entity_init(struct media_entity *entity, u16 num_pads,
 208                 struct media_pad *pads);
 209 void media_entity_cleanup(struct media_entity *entity);
 210
 211 int media_entity_create_link(struct media_entity *source, u16 source_pad,
 212                 struct media_entity *sink, u16 sink_pad, u32 flags);
 213 void __media_entity_remove_links(struct media_entity *entity);
 214 void media_entity_remove_links(struct media_entity *entity);
 215
 216 int __media_entity_setup_link(struct media_link *link, u32 flags);
 217 int media_entity_setup_link(struct media_link *link, u32 flags);
 218 struct media_link *media_entity_find_link(struct media_pad *source,
 219                 struct media_pad *sink);
 220 struct media_pad *media_entity_remote_pad(struct media_pad *pad);
 221
 222 struct media_entity *media_entity_get(struct media_entity *entity);
 223 void media_entity_put(struct media_entity *entity);
 224
 225 void media_entity_graph_walk_start(struct media_entity_graph *graph,
 226                 struct media_entity *entity);
 227 struct media_entity *
 228 media_entity_graph_walk_next(struct media_entity_graph *graph);
 229 __must_check int media_entity_pipeline_start(struct media_entity *entity,
 230                                              struct media_pipeline *pipe);
 231 void media_entity_pipeline_stop(struct media_entity *entity);
 232
 233 #define media_entity_call(entity, operation, args...)                   \
 234         (((entity)->ops && (entity)->ops->operation) ?                  \
 235          (entity)->ops->operation((entity) , ##args) : -ENOIOCTLCMD)
 236
 237 #endif