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