1 /* SPDX-License-Identifier: GPL-2.0-only */ 2 /* 3 * V4L2 asynchronous subdevice registration API 4 * 5 * Copyright (C) 2012-2013, Guennadi Liakhovetski <g.liakhovetski@gmx.de> 6 */ 7 8 #ifndef V4L2_ASYNC_H 9 #define V4L2_ASYNC_H 10 11 #include <linux/list.h> 12 #include <linux/mutex.h> 13 14 struct dentry; 15 struct device; 16 struct device_node; 17 struct v4l2_device; 18 struct v4l2_subdev; 19 struct v4l2_async_notifier; 20 21 /** 22 * enum v4l2_async_match_type - type of asynchronous subdevice logic to be used 23 * in order to identify a match 24 * 25 * @V4L2_ASYNC_MATCH_TYPE_I2C: Match will check for I2C adapter ID and address 26 * @V4L2_ASYNC_MATCH_TYPE_FWNODE: Match will use firmware node 27 * 28 * This enum is used by the asynchronous connection logic to define the 29 * algorithm that will be used to match an asynchronous device. 30 */ 31 enum v4l2_async_match_type { 32 V4L2_ASYNC_MATCH_TYPE_I2C, 33 V4L2_ASYNC_MATCH_TYPE_FWNODE, 34 }; 35 36 /** 37 * struct v4l2_async_match_desc - async connection match information 38 * 39 * @type: type of match that will be used 40 * @fwnode: pointer to &struct fwnode_handle to be matched. 41 * Used if @match_type is %V4L2_ASYNC_MATCH_TYPE_FWNODE. 42 * @i2c: embedded struct with I2C parameters to be matched. 43 * Both @match.i2c.adapter_id and @match.i2c.address 44 * should be matched. 45 * Used if @match_type is %V4L2_ASYNC_MATCH_TYPE_I2C. 46 * @i2c.adapter_id: 47 * I2C adapter ID to be matched. 48 * Used if @match_type is %V4L2_ASYNC_MATCH_TYPE_I2C. 49 * @i2c.address: 50 * I2C address to be matched. 51 * Used if @match_type is %V4L2_ASYNC_MATCH_TYPE_I2C. 52 */ 53 struct v4l2_async_match_desc { 54 enum v4l2_async_match_type type; 55 union { 56 struct fwnode_handle *fwnode; 57 struct { 58 int adapter_id; 59 unsigned short address; 60 } i2c; 61 }; 62 }; 63 64 /** 65 * struct v4l2_async_connection - sub-device connection descriptor, as known to 66 * a bridge 67 * 68 * @match: struct of match type and per-bus type matching data sets 69 * @notifier: the async notifier the connection is related to 70 * @asc_entry: used to add struct v4l2_async_connection objects to the 71 * notifier @waiting_list or @done_list 72 * @asc_subdev_entry: entry in struct v4l2_async_subdev.asc_list list 73 * @sd: the related sub-device 74 * 75 * When this struct is used as a member in a driver specific struct, the driver 76 * specific struct shall contain the &struct v4l2_async_connection as its first 77 * member. 78 */ 79 struct v4l2_async_connection { 80 struct v4l2_async_match_desc match; 81 struct v4l2_async_notifier *notifier; 82 struct list_head asc_entry; 83 struct list_head asc_subdev_entry; 84 struct v4l2_subdev *sd; 85 }; 86 87 /** 88 * struct v4l2_async_notifier_operations - Asynchronous V4L2 notifier operations 89 * @bound: a sub-device has been bound by the given connection 90 * @complete: All connections have been bound successfully. The complete 91 * callback is only executed for the root notifier. 92 * @unbind: a subdevice is leaving 93 * @destroy: the asc is about to be freed 94 */ 95 struct v4l2_async_notifier_operations { 96 int (*bound)(struct v4l2_async_notifier *notifier, 97 struct v4l2_subdev *subdev, 98 struct v4l2_async_connection *asc); 99 int (*complete)(struct v4l2_async_notifier *notifier); 100 void (*unbind)(struct v4l2_async_notifier *notifier, 101 struct v4l2_subdev *subdev, 102 struct v4l2_async_connection *asc); 103 void (*destroy)(struct v4l2_async_connection *asc); 104 }; 105 106 /** 107 * struct v4l2_async_notifier - v4l2_device notifier data 108 * 109 * @ops: notifier operations 110 * @v4l2_dev: v4l2_device of the root notifier, NULL otherwise 111 * @sd: sub-device that registered the notifier, NULL otherwise 112 * @parent: parent notifier 113 * @waiting_list: list of struct v4l2_async_connection, waiting for their 114 * drivers 115 * @done_list: list of struct v4l2_subdev, already probed 116 * @notifier_entry: member in a global list of notifiers 117 */ 118 struct v4l2_async_notifier { 119 const struct v4l2_async_notifier_operations *ops; 120 struct v4l2_device *v4l2_dev; 121 struct v4l2_subdev *sd; 122 struct v4l2_async_notifier *parent; 123 struct list_head waiting_list; 124 struct list_head done_list; 125 struct list_head notifier_entry; 126 }; 127 128 /** 129 * struct v4l2_async_subdev_endpoint - Entry in sub-device's fwnode list 130 * 131 * @async_subdev_endpoint_entry: An entry in async_subdev_endpoint_list of 132 * &struct v4l2_subdev 133 * @endpoint: Endpoint fwnode agains which to match the sub-device 134 */ 135 struct v4l2_async_subdev_endpoint { 136 struct list_head async_subdev_endpoint_entry; 137 struct fwnode_handle *endpoint; 138 }; 139 140 /** 141 * v4l2_async_debug_init - Initialize debugging tools. 142 * 143 * @debugfs_dir: pointer to the parent debugfs &struct dentry 144 */ 145 void v4l2_async_debug_init(struct dentry *debugfs_dir); 146 147 /** 148 * v4l2_async_nf_init - Initialize a notifier. 149 * 150 * @notifier: pointer to &struct v4l2_async_notifier 151 * @v4l2_dev: pointer to &struct v4l2_device 152 * 153 * This function initializes the notifier @asc_entry. It must be called 154 * before adding a subdevice to a notifier, using one of: 155 * v4l2_async_nf_add_fwnode_remote(), 156 * v4l2_async_nf_add_fwnode() or 157 * v4l2_async_nf_add_i2c(). 158 */ 159 void v4l2_async_nf_init(struct v4l2_async_notifier *notifier, 160 struct v4l2_device *v4l2_dev); 161 162 /** 163 * v4l2_async_subdev_nf_init - Initialize a sub-device notifier. 164 * 165 * @notifier: pointer to &struct v4l2_async_notifier 166 * @sd: pointer to &struct v4l2_subdev 167 * 168 * This function initializes the notifier @asc_list. It must be called 169 * before adding a subdevice to a notifier, using one of: 170 * v4l2_async_nf_add_fwnode_remote(), v4l2_async_nf_add_fwnode() or 171 * v4l2_async_nf_add_i2c(). 172 */ 173 void v4l2_async_subdev_nf_init(struct v4l2_async_notifier *notifier, 174 struct v4l2_subdev *sd); 175 176 struct v4l2_async_connection * 177 __v4l2_async_nf_add_fwnode(struct v4l2_async_notifier *notifier, 178 struct fwnode_handle *fwnode, 179 unsigned int asc_struct_size); 180 /** 181 * v4l2_async_nf_add_fwnode - Allocate and add a fwnode async 182 * subdev to the notifier's master asc_list. 183 * 184 * @notifier: pointer to &struct v4l2_async_notifier 185 * @fwnode: fwnode handle of the sub-device to be matched, pointer to 186 * &struct fwnode_handle 187 * @type: Type of the driver's async sub-device or connection struct. The 188 * &struct v4l2_async_connection shall be the first member of the 189 * driver's async struct, i.e. both begin at the same memory address. 190 * 191 * Allocate a fwnode-matched asc of size asc_struct_size, and add it to the 192 * notifiers @asc_list. The function also gets a reference of the fwnode which 193 * is released later at notifier cleanup time. 194 */ 195 #define v4l2_async_nf_add_fwnode(notifier, fwnode, type) \ 196 ((type *)__v4l2_async_nf_add_fwnode(notifier, fwnode, sizeof(type))) 197 198 struct v4l2_async_connection * 199 __v4l2_async_nf_add_fwnode_remote(struct v4l2_async_notifier *notif, 200 struct fwnode_handle *endpoint, 201 unsigned int asc_struct_size); 202 /** 203 * v4l2_async_nf_add_fwnode_remote - Allocate and add a fwnode 204 * remote async subdev to the 205 * notifier's master asc_list. 206 * 207 * @notifier: pointer to &struct v4l2_async_notifier 208 * @ep: local endpoint pointing to the remote connection to be matched, 209 * pointer to &struct fwnode_handle 210 * @type: Type of the driver's async connection struct. The &struct 211 * v4l2_async_connection shall be the first member of the driver's async 212 * connection struct, i.e. both begin at the same memory address. 213 * 214 * Gets the remote endpoint of a given local endpoint, set it up for fwnode 215 * matching and adds the async connection to the notifier's @asc_list. The 216 * function also gets a reference of the fwnode which is released later at 217 * notifier cleanup time. 218 * 219 * This is just like v4l2_async_nf_add_fwnode(), but with the 220 * exception that the fwnode refers to a local endpoint, not the remote one. 221 */ 222 #define v4l2_async_nf_add_fwnode_remote(notifier, ep, type) \ 223 ((type *)__v4l2_async_nf_add_fwnode_remote(notifier, ep, sizeof(type))) 224 225 struct v4l2_async_connection * 226 __v4l2_async_nf_add_i2c(struct v4l2_async_notifier *notifier, 227 int adapter_id, unsigned short address, 228 unsigned int asc_struct_size); 229 /** 230 * v4l2_async_nf_add_i2c - Allocate and add an i2c async 231 * subdev to the notifier's master asc_list. 232 * 233 * @notifier: pointer to &struct v4l2_async_notifier 234 * @adapter: I2C adapter ID to be matched 235 * @address: I2C address of connection to be matched 236 * @type: Type of the driver's async connection struct. The &struct 237 * v4l2_async_connection shall be the first member of the driver's async 238 * connection struct, i.e. both begin at the same memory address. 239 * 240 * Same as v4l2_async_nf_add_fwnode() but for I2C matched 241 * connections. 242 */ 243 #define v4l2_async_nf_add_i2c(notifier, adapter, address, type) \ 244 ((type *)__v4l2_async_nf_add_i2c(notifier, adapter, address, \ 245 sizeof(type))) 246 247 /** 248 * v4l2_async_subdev_endpoint_add - Add an endpoint fwnode to async sub-device 249 * matching list 250 * 251 * @sd: the sub-device 252 * @fwnode: the endpoint fwnode to match 253 * 254 * Add a fwnode to the async sub-device's matching list. This allows registering 255 * multiple async sub-devices from a single device. 256 * 257 * Note that calling v4l2_subdev_cleanup() as part of the sub-device's cleanup 258 * if endpoints have been added to the sub-device's fwnode matching list. 259 * 260 * Returns an error on failure, 0 on success. 261 */ 262 int v4l2_async_subdev_endpoint_add(struct v4l2_subdev *sd, 263 struct fwnode_handle *fwnode); 264 265 /** 266 * v4l2_async_connection_unique - return a unique &struct v4l2_async_connection 267 * for a sub-device 268 * @sd: the sub-device 269 * 270 * Return an async connection for a sub-device, when there is a single 271 * one only. 272 */ 273 struct v4l2_async_connection * 274 v4l2_async_connection_unique(struct v4l2_subdev *sd); 275 276 /** 277 * v4l2_async_nf_register - registers a subdevice asynchronous notifier 278 * 279 * @notifier: pointer to &struct v4l2_async_notifier 280 */ 281 int v4l2_async_nf_register(struct v4l2_async_notifier *notifier); 282 283 /** 284 * v4l2_async_nf_unregister - unregisters a subdevice 285 * asynchronous notifier 286 * 287 * @notifier: pointer to &struct v4l2_async_notifier 288 */ 289 void v4l2_async_nf_unregister(struct v4l2_async_notifier *notifier); 290 291 /** 292 * v4l2_async_nf_cleanup - clean up notifier resources 293 * @notifier: the notifier the resources of which are to be cleaned up 294 * 295 * Release memory resources related to a notifier, including the async 296 * connections allocated for the purposes of the notifier but not the notifier 297 * itself. The user is responsible for calling this function to clean up the 298 * notifier after calling v4l2_async_nf_add_fwnode_remote(), 299 * v4l2_async_nf_add_fwnode() or v4l2_async_nf_add_i2c(). 300 * 301 * There is no harm from calling v4l2_async_nf_cleanup() in other 302 * cases as long as its memory has been zeroed after it has been 303 * allocated. 304 */ 305 void v4l2_async_nf_cleanup(struct v4l2_async_notifier *notifier); 306 307 /** 308 * v4l2_async_register_subdev - registers a sub-device to the asynchronous 309 * subdevice framework 310 * 311 * @sd: pointer to &struct v4l2_subdev 312 */ 313 int v4l2_async_register_subdev(struct v4l2_subdev *sd); 314 315 /** 316 * v4l2_async_register_subdev_sensor - registers a sensor sub-device to the 317 * asynchronous sub-device framework and 318 * parse set up common sensor related 319 * devices 320 * 321 * @sd: pointer to struct &v4l2_subdev 322 * 323 * This function is just like v4l2_async_register_subdev() with the exception 324 * that calling it will also parse firmware interfaces for remote references 325 * using v4l2_async_nf_parse_fwnode_sensor() and registers the 326 * async sub-devices. The sub-device is similarly unregistered by calling 327 * v4l2_async_unregister_subdev(). 328 * 329 * While registered, the subdev module is marked as in-use. 330 * 331 * An error is returned if the module is no longer loaded on any attempts 332 * to register it. 333 */ 334 int __must_check 335 v4l2_async_register_subdev_sensor(struct v4l2_subdev *sd); 336 337 /** 338 * v4l2_async_unregister_subdev - unregisters a sub-device to the asynchronous 339 * subdevice framework 340 * 341 * @sd: pointer to &struct v4l2_subdev 342 */ 343 void v4l2_async_unregister_subdev(struct v4l2_subdev *sd); 344 #endif 345