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 /** 27 * enum v4l2_async_match_type - type of asynchronous subdevice logic to be used 28 * in order to identify a match 29 * 30 * @V4L2_ASYNC_MATCH_CUSTOM: Match will use the logic provided by &struct 31 * v4l2_async_subdev.match ops 32 * @V4L2_ASYNC_MATCH_DEVNAME: Match will use the device name 33 * @V4L2_ASYNC_MATCH_I2C: Match will check for I2C adapter ID and address 34 * @V4L2_ASYNC_MATCH_FWNODE: Match will use firmware node 35 * 36 * This enum is used by the asyncrhronous sub-device logic to define the 37 * algorithm that will be used to match an asynchronous device. 38 */ 39 enum v4l2_async_match_type { 40 V4L2_ASYNC_MATCH_CUSTOM, 41 V4L2_ASYNC_MATCH_DEVNAME, 42 V4L2_ASYNC_MATCH_I2C, 43 V4L2_ASYNC_MATCH_FWNODE, 44 }; 45 46 /** 47 * struct v4l2_async_subdev - sub-device descriptor, as known to a bridge 48 * 49 * @match_type: type of match that will be used 50 * @match: union of per-bus type matching data sets 51 * @list: used to link struct v4l2_async_subdev objects, waiting to be 52 * probed, to a notifier->waiting list 53 */ 54 struct v4l2_async_subdev { 55 enum v4l2_async_match_type match_type; 56 union { 57 struct { 58 struct fwnode_handle *fwnode; 59 } fwnode; 60 struct { 61 const char *name; 62 } device_name; 63 struct { 64 int adapter_id; 65 unsigned short address; 66 } i2c; 67 struct { 68 bool (*match)(struct device *, 69 struct v4l2_async_subdev *); 70 void *priv; 71 } custom; 72 } match; 73 74 /* v4l2-async core private: not to be used by drivers */ 75 struct list_head list; 76 }; 77 78 /** 79 * struct v4l2_async_notifier - v4l2_device notifier data 80 * 81 * @num_subdevs: number of subdevices 82 * @subdevs: array of pointers to subdevice descriptors 83 * @v4l2_dev: pointer to struct v4l2_device 84 * @waiting: list of struct v4l2_async_subdev, waiting for their drivers 85 * @done: list of struct v4l2_subdev, already probed 86 * @list: member in a global list of notifiers 87 * @bound: a subdevice driver has successfully probed one of subdevices 88 * @complete: all subdevices have been probed successfully 89 * @unbind: a subdevice is leaving 90 */ 91 struct v4l2_async_notifier { 92 unsigned int num_subdevs; 93 struct v4l2_async_subdev **subdevs; 94 struct v4l2_device *v4l2_dev; 95 struct list_head waiting; 96 struct list_head done; 97 struct list_head list; 98 int (*bound)(struct v4l2_async_notifier *notifier, 99 struct v4l2_subdev *subdev, 100 struct v4l2_async_subdev *asd); 101 int (*complete)(struct v4l2_async_notifier *notifier); 102 void (*unbind)(struct v4l2_async_notifier *notifier, 103 struct v4l2_subdev *subdev, 104 struct v4l2_async_subdev *asd); 105 }; 106 107 /** 108 * v4l2_async_notifier_register - registers a subdevice asynchronous notifier 109 * 110 * @v4l2_dev: pointer to &struct v4l2_device 111 * @notifier: pointer to &struct v4l2_async_notifier 112 */ 113 int v4l2_async_notifier_register(struct v4l2_device *v4l2_dev, 114 struct v4l2_async_notifier *notifier); 115 116 /** 117 * v4l2_async_notifier_unregister - unregisters a subdevice asynchronous notifier 118 * 119 * @notifier: pointer to &struct v4l2_async_notifier 120 */ 121 void v4l2_async_notifier_unregister(struct v4l2_async_notifier *notifier); 122 123 /** 124 * v4l2_async_register_subdev - registers a sub-device to the asynchronous 125 * subdevice framework 126 * 127 * @sd: pointer to &struct v4l2_subdev 128 */ 129 int v4l2_async_register_subdev(struct v4l2_subdev *sd); 130 131 /** 132 * v4l2_async_unregister_subdev - unregisters a sub-device to the asynchronous 133 * subdevice framework 134 * 135 * @sd: pointer to &struct v4l2_subdev 136 */ 137 void v4l2_async_unregister_subdev(struct v4l2_subdev *sd); 138 #endif 139