include/media/v4l2-async.h

   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