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 v4l2_device;
  19 struct v4l2_subdev;
  20 struct v4l2_async_notifier;
  21
  22 /* A random max subdevice number, used to allocate an array on stack */
  23 #define V4L2_MAX_SUBDEVS 128U
  24
  25 enum v4l2_async_bus_type {
  26         V4L2_ASYNC_BUS_CUSTOM,
  27         V4L2_ASYNC_BUS_PLATFORM,
  28         V4L2_ASYNC_BUS_I2C,
  29 };
  30
  31 /**
  32  * struct v4l2_async_subdev - sub-device descriptor, as known to a bridge
  33  * @bus_type:   subdevice bus type to select the appropriate matching method
  34  * @match:      union of per-bus type matching data sets
  35  * @list:       used to link struct v4l2_async_subdev objects, waiting to be
  36  *              probed, to a notifier->waiting list
  37  */
  38 struct v4l2_async_subdev {
  39         enum v4l2_async_bus_type bus_type;
  40         union {
  41                 struct {
  42                         const char *name;
  43                 } platform;
  44                 struct {
  45                         int adapter_id;
  46                         unsigned short address;
  47                 } i2c;
  48                 struct {
  49                         bool (*match)(struct device *,
  50                                       struct v4l2_async_subdev *);
  51                         void *priv;
  52                 } custom;
  53         } match;
  54
  55         /* v4l2-async core private: not to be used by drivers */
  56         struct list_head list;
  57 };
  58
  59 /**
  60  * v4l2_async_subdev_list - provided by subdevices
  61  * @list:       links struct v4l2_async_subdev_list objects to a global list
  62  *              before probing, and onto notifier->done after probing
  63  * @asd:        pointer to respective struct v4l2_async_subdev
  64  * @notifier:   pointer to managing notifier
  65  */
  66 struct v4l2_async_subdev_list {
  67         struct list_head list;
  68         struct v4l2_async_subdev *asd;
  69         struct v4l2_async_notifier *notifier;
  70 };
  71
  72 /**
  73  * v4l2_async_notifier - v4l2_device notifier data
  74  * @num_subdevs:number of subdevices
  75  * @subdev:     array of pointers to subdevice descriptors
  76  * @v4l2_dev:   pointer to struct v4l2_device
  77  * @waiting:    list of struct v4l2_async_subdev, waiting for their drivers
  78  * @done:       list of struct v4l2_async_subdev_list, already probed
  79  * @list:       member in a global list of notifiers
  80  * @bound:      a subdevice driver has successfully probed one of subdevices
  81  * @complete:   all subdevices have been probed successfully
  82  * @unbind:     a subdevice is leaving
  83  */
  84 struct v4l2_async_notifier {
  85         unsigned int num_subdevs;
  86         struct v4l2_async_subdev **subdev;
  87         struct v4l2_device *v4l2_dev;
  88         struct list_head waiting;
  89         struct list_head done;
  90         struct list_head list;
  91         int (*bound)(struct v4l2_async_notifier *notifier,
  92                      struct v4l2_subdev *subdev,
  93                      struct v4l2_async_subdev *asd);
  94         int (*complete)(struct v4l2_async_notifier *notifier);
  95         void (*unbind)(struct v4l2_async_notifier *notifier,
  96                        struct v4l2_subdev *subdev,
  97                        struct v4l2_async_subdev *asd);
  98 };
  99
 100 int v4l2_async_notifier_register(struct v4l2_device *v4l2_dev,
 101                                  struct v4l2_async_notifier *notifier);
 102 void v4l2_async_notifier_unregister(struct v4l2_async_notifier *notifier);
 103 int v4l2_async_register_subdev(struct v4l2_subdev *sd);
 104 void v4l2_async_unregister_subdev(struct v4l2_subdev *sd);
 105 #endif