xref: /linux/include/media/media-device.h (revision cc04a46f11ea046ed53e2c832ae29e4790f7e35f)
1 /*
2  * Media device
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_DEVICE_H
24 #define _MEDIA_DEVICE_H
25 
26 #include <linux/list.h>
27 #include <linux/mutex.h>
28 #include <linux/spinlock.h>
29 
30 #include <media/media-devnode.h>
31 #include <media/media-entity.h>
32 
33 struct device;
34 
35 /**
36  * struct media_device - Media device
37  * @dev:	Parent device
38  * @devnode:	Media device node
39  * @model:	Device model name
40  * @serial:	Device serial number (optional)
41  * @bus_info:	Unique and stable device location identifier
42  * @hw_revision: Hardware device revision
43  * @driver_version: Device driver version
44  * @entity_id:	ID of the next entity to be registered
45  * @entities:	List of registered entities
46  * @lock:	Entities list lock
47  * @graph_mutex: Entities graph operation lock
48  * @link_notify: Link state change notification callback
49  *
50  * This structure represents an abstract high-level media device. It allows easy
51  * access to entities and provides basic media device-level support. The
52  * structure can be allocated directly or embedded in a larger structure.
53  *
54  * The parent @dev is a physical device. It must be set before registering the
55  * media device.
56  *
57  * @model is a descriptive model name exported through sysfs. It doesn't have to
58  * be unique.
59  */
60 struct media_device {
61 	/* dev->driver_data points to this struct. */
62 	struct device *dev;
63 	struct media_devnode devnode;
64 
65 	char model[32];
66 	char serial[40];
67 	char bus_info[32];
68 	u32 hw_revision;
69 	u32 driver_version;
70 
71 	u32 entity_id;
72 	struct list_head entities;
73 
74 	/* Protects the entities list */
75 	spinlock_t lock;
76 	/* Serializes graph operations. */
77 	struct mutex graph_mutex;
78 
79 	int (*link_notify)(struct media_link *link, u32 flags,
80 			   unsigned int notification);
81 };
82 
83 /* Supported link_notify @notification values. */
84 #define MEDIA_DEV_NOTIFY_PRE_LINK_CH	0
85 #define MEDIA_DEV_NOTIFY_POST_LINK_CH	1
86 
87 /* media_devnode to media_device */
88 #define to_media_device(node) container_of(node, struct media_device, devnode)
89 
90 int __must_check __media_device_register(struct media_device *mdev,
91 					 struct module *owner);
92 #define media_device_register(mdev) __media_device_register(mdev, THIS_MODULE)
93 void media_device_unregister(struct media_device *mdev);
94 
95 int __must_check media_device_register_entity(struct media_device *mdev,
96 					      struct media_entity *entity);
97 void media_device_unregister_entity(struct media_entity *entity);
98 
99 /* Iterate over all entities. */
100 #define media_device_for_each_entity(entity, mdev)			\
101 	list_for_each_entry(entity, &(mdev)->entities, list)
102 
103 #endif
104