xref: /linux/include/media/v4l2-async.h (revision b85d45947951d23cb22d90caecf4c1eb81342c96)
1 /*
2  * V4L2 asynchronous subdevice registration API
3  *
4  * Copyright (C) 2012-2013, Guennadi Liakhovetski <g.liakhovetski@gmx.de>
5  *
6  * This program is free software; you can redistribute it and/or modify
7  * it under the terms of the GNU General Public License version 2 as
8  * published by the Free Software Foundation.
9  */
10 
11 #ifndef V4L2_ASYNC_H
12 #define V4L2_ASYNC_H
13 
14 #include <linux/list.h>
15 #include <linux/mutex.h>
16 
17 struct device;
18 struct device_node;
19 struct v4l2_device;
20 struct v4l2_subdev;
21 struct v4l2_async_notifier;
22 
23 /* A random max subdevice number, used to allocate an array on stack */
24 #define V4L2_MAX_SUBDEVS 128U
25 
26 enum v4l2_async_match_type {
27 	V4L2_ASYNC_MATCH_CUSTOM,
28 	V4L2_ASYNC_MATCH_DEVNAME,
29 	V4L2_ASYNC_MATCH_I2C,
30 	V4L2_ASYNC_MATCH_OF,
31 };
32 
33 /**
34  * struct v4l2_async_subdev - sub-device descriptor, as known to a bridge
35  *
36  * @match_type:	type of match that will be used
37  * @match:	union of per-bus type matching data sets
38  * @list:	used to link struct v4l2_async_subdev objects, waiting to be
39  *		probed, to a notifier->waiting list
40  */
41 struct v4l2_async_subdev {
42 	enum v4l2_async_match_type match_type;
43 	union {
44 		struct {
45 			const struct device_node *node;
46 		} of;
47 		struct {
48 			const char *name;
49 		} device_name;
50 		struct {
51 			int adapter_id;
52 			unsigned short address;
53 		} i2c;
54 		struct {
55 			bool (*match)(struct device *,
56 				      struct v4l2_async_subdev *);
57 			void *priv;
58 		} custom;
59 	} match;
60 
61 	/* v4l2-async core private: not to be used by drivers */
62 	struct list_head list;
63 };
64 
65 /**
66  * struct v4l2_async_notifier - v4l2_device notifier data
67  *
68  * @num_subdevs: number of subdevices
69  * @subdevs:	array of pointers to subdevice descriptors
70  * @v4l2_dev:	pointer to struct v4l2_device
71  * @waiting:	list of struct v4l2_async_subdev, waiting for their drivers
72  * @done:	list of struct v4l2_subdev, already probed
73  * @list:	member in a global list of notifiers
74  * @bound:	a subdevice driver has successfully probed one of subdevices
75  * @complete:	all subdevices have been probed successfully
76  * @unbind:	a subdevice is leaving
77  */
78 struct v4l2_async_notifier {
79 	unsigned int num_subdevs;
80 	struct v4l2_async_subdev **subdevs;
81 	struct v4l2_device *v4l2_dev;
82 	struct list_head waiting;
83 	struct list_head done;
84 	struct list_head list;
85 	int (*bound)(struct v4l2_async_notifier *notifier,
86 		     struct v4l2_subdev *subdev,
87 		     struct v4l2_async_subdev *asd);
88 	int (*complete)(struct v4l2_async_notifier *notifier);
89 	void (*unbind)(struct v4l2_async_notifier *notifier,
90 		       struct v4l2_subdev *subdev,
91 		       struct v4l2_async_subdev *asd);
92 };
93 
94 int v4l2_async_notifier_register(struct v4l2_device *v4l2_dev,
95 				 struct v4l2_async_notifier *notifier);
96 void v4l2_async_notifier_unregister(struct v4l2_async_notifier *notifier);
97 int v4l2_async_register_subdev(struct v4l2_subdev *sd);
98 void v4l2_async_unregister_subdev(struct v4l2_subdev *sd);
99 #endif
100