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 * @match.fwnode: 52 * pointer to &struct fwnode_handle to be matched. 53 * Used if @match_type is %V4L2_ASYNC_MATCH_FWNODE. 54 * @match.device_name: 55 * string containing the device name to be matched. 56 * Used if @match_type is %V4L2_ASYNC_MATCH_DEVNAME. 57 * @match.i2c: embedded struct with I2C parameters to be matched. 58 * Both @match.i2c.adapter_id and @match.i2c.address 59 * should be matched. 60 * Used if @match_type is %V4L2_ASYNC_MATCH_I2C. 61 * @match.i2c.adapter_id: 62 * I2C adapter ID to be matched. 63 * Used if @match_type is %V4L2_ASYNC_MATCH_I2C. 64 * @match.i2c.address: 65 * I2C address to be matched. 66 * Used if @match_type is %V4L2_ASYNC_MATCH_I2C. 67 * @match.custom: 68 * Driver-specific match criteria. 69 * Used if @match_type is %V4L2_ASYNC_MATCH_CUSTOM. 70 * @match.custom.match: 71 * Driver-specific match function to be used if 72 * %V4L2_ASYNC_MATCH_CUSTOM. 73 * @match.custom.priv: 74 * Driver-specific private struct with match parameters 75 * to be used if %V4L2_ASYNC_MATCH_CUSTOM. 76 * @list: used to link struct v4l2_async_subdev objects, waiting to be 77 * probed, to a notifier->waiting list 78 * 79 * When this struct is used as a member in a driver specific struct, 80 * the driver specific struct shall contain the &struct 81 * v4l2_async_subdev as its first member. 82 */ 83 struct v4l2_async_subdev { 84 enum v4l2_async_match_type match_type; 85 union { 86 struct fwnode_handle *fwnode; 87 const char *device_name; 88 struct { 89 int adapter_id; 90 unsigned short address; 91 } i2c; 92 struct { 93 bool (*match)(struct device *, 94 struct v4l2_async_subdev *); 95 void *priv; 96 } custom; 97 } match; 98 99 /* v4l2-async core private: not to be used by drivers */ 100 struct list_head list; 101 }; 102 103 /** 104 * struct v4l2_async_notifier_operations - Asynchronous V4L2 notifier operations 105 * @bound: a subdevice driver has successfully probed one of the subdevices 106 * @complete: All subdevices have been probed successfully. The complete 107 * callback is only executed for the root notifier. 108 * @unbind: a subdevice is leaving 109 */ 110 struct v4l2_async_notifier_operations { 111 int (*bound)(struct v4l2_async_notifier *notifier, 112 struct v4l2_subdev *subdev, 113 struct v4l2_async_subdev *asd); 114 int (*complete)(struct v4l2_async_notifier *notifier); 115 void (*unbind)(struct v4l2_async_notifier *notifier, 116 struct v4l2_subdev *subdev, 117 struct v4l2_async_subdev *asd); 118 }; 119 120 /** 121 * struct v4l2_async_notifier - v4l2_device notifier data 122 * 123 * @ops: notifier operations 124 * @num_subdevs: number of subdevices used in the subdevs array 125 * @max_subdevs: number of subdevices allocated in the subdevs array 126 * @subdevs: array of pointers to subdevice descriptors 127 * @v4l2_dev: v4l2_device of the root notifier, NULL otherwise 128 * @sd: sub-device that registered the notifier, NULL otherwise 129 * @parent: parent notifier 130 * @waiting: list of struct v4l2_async_subdev, waiting for their drivers 131 * @done: list of struct v4l2_subdev, already probed 132 * @list: member in a global list of notifiers 133 */ 134 struct v4l2_async_notifier { 135 const struct v4l2_async_notifier_operations *ops; 136 unsigned int num_subdevs; 137 unsigned int max_subdevs; 138 struct v4l2_async_subdev **subdevs; 139 struct v4l2_device *v4l2_dev; 140 struct v4l2_subdev *sd; 141 struct v4l2_async_notifier *parent; 142 struct list_head waiting; 143 struct list_head done; 144 struct list_head list; 145 }; 146 147 /** 148 * v4l2_async_notifier_register - registers a subdevice asynchronous notifier 149 * 150 * @v4l2_dev: pointer to &struct v4l2_device 151 * @notifier: pointer to &struct v4l2_async_notifier 152 */ 153 int v4l2_async_notifier_register(struct v4l2_device *v4l2_dev, 154 struct v4l2_async_notifier *notifier); 155 156 /** 157 * v4l2_async_subdev_notifier_register - registers a subdevice asynchronous 158 * notifier for a sub-device 159 * 160 * @sd: pointer to &struct v4l2_subdev 161 * @notifier: pointer to &struct v4l2_async_notifier 162 */ 163 int v4l2_async_subdev_notifier_register(struct v4l2_subdev *sd, 164 struct v4l2_async_notifier *notifier); 165 166 /** 167 * v4l2_async_notifier_unregister - unregisters a subdevice asynchronous notifier 168 * 169 * @notifier: pointer to &struct v4l2_async_notifier 170 */ 171 void v4l2_async_notifier_unregister(struct v4l2_async_notifier *notifier); 172 173 /** 174 * v4l2_async_notifier_cleanup - clean up notifier resources 175 * @notifier: the notifier the resources of which are to be cleaned up 176 * 177 * Release memory resources related to a notifier, including the async 178 * sub-devices allocated for the purposes of the notifier but not the notifier 179 * itself. The user is responsible for calling this function to clean up the 180 * notifier after calling @v4l2_async_notifier_parse_fwnode_endpoints or 181 * @v4l2_fwnode_reference_parse_sensor_common. 182 * 183 * There is no harm from calling v4l2_async_notifier_cleanup in other 184 * cases as long as its memory has been zeroed after it has been 185 * allocated. 186 */ 187 void v4l2_async_notifier_cleanup(struct v4l2_async_notifier *notifier); 188 189 /** 190 * v4l2_async_register_subdev - registers a sub-device to the asynchronous 191 * subdevice framework 192 * 193 * @sd: pointer to &struct v4l2_subdev 194 */ 195 int v4l2_async_register_subdev(struct v4l2_subdev *sd); 196 197 /** 198 * v4l2_async_register_subdev_sensor_common - registers a sensor sub-device to 199 * the asynchronous sub-device 200 * framework and parse set up common 201 * sensor related devices 202 * 203 * @sd: pointer to struct &v4l2_subdev 204 * 205 * This function is just like v4l2_async_register_subdev() with the exception 206 * that calling it will also parse firmware interfaces for remote references 207 * using v4l2_async_notifier_parse_fwnode_sensor_common() and registers the 208 * async sub-devices. The sub-device is similarly unregistered by calling 209 * v4l2_async_unregister_subdev(). 210 * 211 * While registered, the subdev module is marked as in-use. 212 * 213 * An error is returned if the module is no longer loaded on any attempts 214 * to register it. 215 */ 216 int __must_check v4l2_async_register_subdev_sensor_common( 217 struct v4l2_subdev *sd); 218 219 /** 220 * v4l2_async_unregister_subdev - unregisters a sub-device to the asynchronous 221 * subdevice framework 222 * 223 * @sd: pointer to &struct v4l2_subdev 224 */ 225 void v4l2_async_unregister_subdev(struct v4l2_subdev *sd); 226 #endif 227