xref: /openbmc/linux/include/media/v4l2-async.h (revision 94cdda6b)
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  * @bus_type:	subdevice bus type to select the appropriate matching method
36  * @match:	union of per-bus type matching data sets
37  * @list:	used to link struct v4l2_async_subdev objects, waiting to be
38  *		probed, to a notifier->waiting list
39  */
40 struct v4l2_async_subdev {
41 	enum v4l2_async_match_type match_type;
42 	union {
43 		struct {
44 			const struct device_node *node;
45 		} of;
46 		struct {
47 			const char *name;
48 		} device_name;
49 		struct {
50 			int adapter_id;
51 			unsigned short address;
52 		} i2c;
53 		struct {
54 			bool (*match)(struct device *,
55 				      struct v4l2_async_subdev *);
56 			void *priv;
57 		} custom;
58 	} match;
59 
60 	/* v4l2-async core private: not to be used by drivers */
61 	struct list_head list;
62 };
63 
64 /**
65  * v4l2_async_notifier - v4l2_device notifier data
66  * @num_subdevs:number of subdevices
67  * @subdevs:	array of pointers to subdevice descriptors
68  * @v4l2_dev:	pointer to struct v4l2_device
69  * @waiting:	list of struct v4l2_async_subdev, waiting for their drivers
70  * @done:	list of struct v4l2_subdev, already probed
71  * @list:	member in a global list of notifiers
72  * @bound:	a subdevice driver has successfully probed one of subdevices
73  * @complete:	all subdevices have been probed successfully
74  * @unbind:	a subdevice is leaving
75  */
76 struct v4l2_async_notifier {
77 	unsigned int num_subdevs;
78 	struct v4l2_async_subdev **subdevs;
79 	struct v4l2_device *v4l2_dev;
80 	struct list_head waiting;
81 	struct list_head done;
82 	struct list_head list;
83 	int (*bound)(struct v4l2_async_notifier *notifier,
84 		     struct v4l2_subdev *subdev,
85 		     struct v4l2_async_subdev *asd);
86 	int (*complete)(struct v4l2_async_notifier *notifier);
87 	void (*unbind)(struct v4l2_async_notifier *notifier,
88 		       struct v4l2_subdev *subdev,
89 		       struct v4l2_async_subdev *asd);
90 };
91 
92 int v4l2_async_notifier_register(struct v4l2_device *v4l2_dev,
93 				 struct v4l2_async_notifier *notifier);
94 void v4l2_async_notifier_unregister(struct v4l2_async_notifier *notifier);
95 int v4l2_async_register_subdev(struct v4l2_subdev *sd);
96 void v4l2_async_unregister_subdev(struct v4l2_subdev *sd);
97 #endif
98