1 /* SPDX-License-Identifier: GPL-2.0+ */ 2 /* 3 * Copyright (c) 2013 Google, Inc 4 * 5 * (C) Copyright 2012 6 * Pavel Herrmann <morpheus.ibis@gmail.com> 7 */ 8 9 #ifndef _DM_UCLASS_H 10 #define _DM_UCLASS_H 11 12 #include <dm/ofnode.h> 13 #include <dm/uclass-id.h> 14 #include <linker_lists.h> 15 #include <linux/list.h> 16 17 /** 18 * struct uclass - a U-Boot drive class, collecting together similar drivers 19 * 20 * A uclass provides an interface to a particular function, which is 21 * implemented by one or more drivers. Every driver belongs to a uclass even 22 * if it is the only driver in that uclass. An example uclass is GPIO, which 23 * provides the ability to change read inputs, set and clear outputs, etc. 24 * There may be drivers for on-chip SoC GPIO banks, I2C GPIO expanders and 25 * PMIC IO lines, all made available in a unified way through the uclass. 26 * 27 * @priv: Private data for this uclass 28 * @uc_drv: The driver for the uclass itself, not to be confused with a 29 * 'struct driver' 30 * @dev_head: List of devices in this uclass (devices are attached to their 31 * uclass when their bind method is called) 32 * @sibling_node: Next uclass in the linked list of uclasses 33 */ 34 struct uclass { 35 void *priv; 36 struct uclass_driver *uc_drv; 37 struct list_head dev_head; 38 struct list_head sibling_node; 39 }; 40 41 struct driver; 42 struct udevice; 43 44 /* Members of this uclass sequence themselves with aliases */ 45 #define DM_UC_FLAG_SEQ_ALIAS (1 << 0) 46 47 /* Same as DM_FLAG_ALLOC_PRIV_DMA */ 48 #define DM_UC_FLAG_ALLOC_PRIV_DMA (1 << 5) 49 50 /** 51 * struct uclass_driver - Driver for the uclass 52 * 53 * A uclass_driver provides a consistent interface to a set of related 54 * drivers. 55 * 56 * @name: Name of uclass driver 57 * @id: ID number of this uclass 58 * @post_bind: Called after a new device is bound to this uclass 59 * @pre_unbind: Called before a device is unbound from this uclass 60 * @pre_probe: Called before a new device is probed 61 * @post_probe: Called after a new device is probed 62 * @pre_remove: Called before a device is removed 63 * @child_post_bind: Called after a child is bound to a device in this uclass 64 * @child_pre_probe: Called before a child in this uclass is probed 65 * @child_post_probe: Called after a child in this uclass is probed 66 * @init: Called to set up the uclass 67 * @destroy: Called to destroy the uclass 68 * @priv_auto_alloc_size: If non-zero this is the size of the private data 69 * to be allocated in the uclass's ->priv pointer. If zero, then the uclass 70 * driver is responsible for allocating any data required. 71 * @per_device_auto_alloc_size: Each device can hold private data owned 72 * by the uclass. If required this will be automatically allocated if this 73 * value is non-zero. 74 * @per_device_platdata_auto_alloc_size: Each device can hold platform data 75 * owned by the uclass as 'dev->uclass_platdata'. If the value is non-zero, 76 * then this will be automatically allocated. 77 * @per_child_auto_alloc_size: Each child device (of a parent in this 78 * uclass) can hold parent data for the device/uclass. This value is only 79 * used as a fallback if this member is 0 in the driver. 80 * @per_child_platdata_auto_alloc_size: A bus likes to store information about 81 * its children. If non-zero this is the size of this data, to be allocated 82 * in the child device's parent_platdata pointer. This value is only used as 83 * a fallback if this member is 0 in the driver. 84 * @ops: Uclass operations, providing the consistent interface to devices 85 * within the uclass. 86 * @flags: Flags for this uclass (DM_UC_...) 87 */ 88 struct uclass_driver { 89 const char *name; 90 enum uclass_id id; 91 int (*post_bind)(struct udevice *dev); 92 int (*pre_unbind)(struct udevice *dev); 93 int (*pre_probe)(struct udevice *dev); 94 int (*post_probe)(struct udevice *dev); 95 int (*pre_remove)(struct udevice *dev); 96 int (*child_post_bind)(struct udevice *dev); 97 int (*child_pre_probe)(struct udevice *dev); 98 int (*child_post_probe)(struct udevice *dev); 99 int (*init)(struct uclass *class); 100 int (*destroy)(struct uclass *class); 101 int priv_auto_alloc_size; 102 int per_device_auto_alloc_size; 103 int per_device_platdata_auto_alloc_size; 104 int per_child_auto_alloc_size; 105 int per_child_platdata_auto_alloc_size; 106 const void *ops; 107 uint32_t flags; 108 }; 109 110 /* Declare a new uclass_driver */ 111 #define UCLASS_DRIVER(__name) \ 112 ll_entry_declare(struct uclass_driver, __name, uclass) 113 114 /** 115 * uclass_get() - Get a uclass based on an ID, creating it if needed 116 * 117 * Every uclass is identified by an ID, a number from 0 to n-1 where n is 118 * the number of uclasses. This function allows looking up a uclass by its 119 * ID. 120 * 121 * @key: ID to look up 122 * @ucp: Returns pointer to uclass (there is only one per ID) 123 * @return 0 if OK, -ve on error 124 */ 125 int uclass_get(enum uclass_id key, struct uclass **ucp); 126 127 /** 128 * uclass_get_name() - Get the name of a uclass driver 129 * 130 * @id: ID to look up 131 * @returns the name of the uclass driver for that ID, or NULL if none 132 */ 133 const char *uclass_get_name(enum uclass_id id); 134 135 /** 136 * uclass_get_by_name() - Look up a uclass by its driver name 137 * 138 * @name: Name to look up 139 * @returns the associated uclass ID, or UCLASS_INVALID if not found 140 */ 141 enum uclass_id uclass_get_by_name(const char *name); 142 143 /** 144 * uclass_get_device() - Get a uclass device based on an ID and index 145 * 146 * The device is probed to activate it ready for use. 147 * 148 * @id: ID to look up 149 * @index: Device number within that uclass (0=first) 150 * @devp: Returns pointer to device (there is only one per for each ID) 151 * @return 0 if OK, -ve on error 152 */ 153 int uclass_get_device(enum uclass_id id, int index, struct udevice **devp); 154 155 /** 156 * uclass_get_device_by_name() - Get a uclass device by its name 157 * 158 * This searches the devices in the uclass for one with the exactly given name. 159 * 160 * The device is probed to activate it ready for use. 161 * 162 * @id: ID to look up 163 * @name: name of a device to get 164 * @devp: Returns pointer to device (the first one with the name) 165 * @return 0 if OK, -ve on error 166 */ 167 int uclass_get_device_by_name(enum uclass_id id, const char *name, 168 struct udevice **devp); 169 170 /** 171 * uclass_get_device_by_seq() - Get a uclass device based on an ID and sequence 172 * 173 * If an active device has this sequence it will be returned. If there is no 174 * such device then this will check for a device that is requesting this 175 * sequence. 176 * 177 * The device is probed to activate it ready for use. 178 * 179 * @id: ID to look up 180 * @seq: Sequence number to find (0=first) 181 * @devp: Returns pointer to device (there is only one for each seq) 182 * @return 0 if OK, -ve on error 183 */ 184 int uclass_get_device_by_seq(enum uclass_id id, int seq, struct udevice **devp); 185 186 /** 187 * uclass_get_device_by_of_offset() - Get a uclass device by device tree node 188 * 189 * This searches the devices in the uclass for one attached to the given 190 * device tree node. 191 * 192 * The device is probed to activate it ready for use. 193 * 194 * @id: ID to look up 195 * @node: Device tree offset to search for (if -ve then -ENODEV is returned) 196 * @devp: Returns pointer to device (there is only one for each node) 197 * @return 0 if OK, -ve on error 198 */ 199 int uclass_get_device_by_of_offset(enum uclass_id id, int node, 200 struct udevice **devp); 201 202 /** 203 * uclass_get_device_by_ofnode() - Get a uclass device by device tree node 204 * 205 * This searches the devices in the uclass for one attached to the given 206 * device tree node. 207 * 208 * The device is probed to activate it ready for use. 209 * 210 * @id: ID to look up 211 * @np: Device tree node to search for (if NULL then -ENODEV is returned) 212 * @devp: Returns pointer to device (there is only one for each node) 213 * @return 0 if OK, -ve on error 214 */ 215 int uclass_get_device_by_ofnode(enum uclass_id id, ofnode node, 216 struct udevice **devp); 217 218 /** 219 * uclass_get_device_by_phandle_id() - Get a uclass device by phandle id 220 * 221 * This searches the devices in the uclass for one with the given phandle id. 222 * 223 * The device is probed to activate it ready for use. 224 * 225 * @id: uclass ID to look up 226 * @phandle_id: the phandle id to look up 227 * @devp: Returns pointer to device (there is only one for each node) 228 * @return 0 if OK, -ENODEV if there is no device match the phandle, other 229 * -ve on error 230 */ 231 int uclass_get_device_by_phandle_id(enum uclass_id id, uint phandle_id, 232 struct udevice **devp); 233 234 /** 235 * uclass_get_device_by_phandle() - Get a uclass device by phandle 236 * 237 * This searches the devices in the uclass for one with the given phandle. 238 * 239 * The device is probed to activate it ready for use. 240 * 241 * @id: uclass ID to look up 242 * @parent: Parent device containing the phandle pointer 243 * @name: Name of property in the parent device node 244 * @devp: Returns pointer to device (there is only one for each node) 245 * @return 0 if OK, -ENOENT if there is no @name present in the node, other 246 * -ve on error 247 */ 248 int uclass_get_device_by_phandle(enum uclass_id id, struct udevice *parent, 249 const char *name, struct udevice **devp); 250 251 /** 252 * uclass_get_device_by_driver() - Get a uclass device for a driver 253 * 254 * This searches the devices in the uclass for one that uses the given 255 * driver. Use DM_GET_DRIVER(name) for the @drv argument, where 'name' is 256 * the driver name - as used in U_BOOT_DRIVER(name). 257 * 258 * The device is probed to activate it ready for use. 259 * 260 * @id: ID to look up 261 * @drv: Driver to look for 262 * @devp: Returns pointer to the first device with that driver 263 * @return 0 if OK, -ve on error 264 */ 265 int uclass_get_device_by_driver(enum uclass_id id, const struct driver *drv, 266 struct udevice **devp); 267 268 /** 269 * uclass_first_device() - Get the first device in a uclass 270 * 271 * The device returned is probed if necessary, and ready for use 272 * 273 * This function is useful to start iterating through a list of devices which 274 * are functioning correctly and can be probed. 275 * 276 * @id: Uclass ID to look up 277 * @devp: Returns pointer to the first device in that uclass if no error 278 * occurred, or NULL if there is no first device, or an error occurred with 279 * that device. 280 * @return 0 if OK (found or not found), other -ve on error 281 */ 282 int uclass_first_device(enum uclass_id id, struct udevice **devp); 283 284 /** 285 * uclass_first_device_err() - Get the first device in a uclass 286 * 287 * The device returned is probed if necessary, and ready for use 288 * 289 * @id: Uclass ID to look up 290 * @devp: Returns pointer to the first device in that uclass, or NULL if none 291 * @return 0 if found, -ENODEV if not found, other -ve on error 292 */ 293 int uclass_first_device_err(enum uclass_id id, struct udevice **devp); 294 295 /** 296 * uclass_next_device() - Get the next device in a uclass 297 * 298 * The device returned is probed if necessary, and ready for use 299 * 300 * This function is useful to iterate through a list of devices which 301 * are functioning correctly and can be probed. 302 * 303 * @devp: On entry, pointer to device to lookup. On exit, returns pointer 304 * to the next device in the uclass if no error occurred, or NULL if there is 305 * no next device, or an error occurred with that next device. 306 * @return 0 if OK (found or not found), other -ve on error 307 */ 308 int uclass_next_device(struct udevice **devp); 309 310 /** 311 * uclass_next_device_err() - Get the next device in a uclass 312 * 313 * The device returned is probed if necessary, and ready for use 314 * 315 * @devp: On entry, pointer to device to lookup. On exit, returns pointer 316 * to the next device in the uclass if no error occurred, or -ENODEV if 317 * there is no next device. 318 * @return 0 if found, -ENODEV if not found, other -ve on error 319 */ 320 int uclass_next_device_err(struct udevice **devp); 321 322 /** 323 * uclass_first_device_check() - Get the first device in a uclass 324 * 325 * The device returned is probed if necessary, and ready for use 326 * 327 * This function is useful to start iterating through a list of devices which 328 * are functioning correctly and can be probed. 329 * 330 * @id: Uclass ID to look up 331 * @devp: Returns pointer to the first device in that uclass, or NULL if there 332 * is no first device 333 * @return 0 if OK (found or not found), other -ve on error. If an error occurs 334 * it is still possible to move to the next device. 335 */ 336 int uclass_first_device_check(enum uclass_id id, struct udevice **devp); 337 338 /** 339 * uclass_next_device_check() - Get the next device in a uclass 340 * 341 * The device returned is probed if necessary, and ready for use 342 * 343 * This function is useful to start iterating through a list of devices which 344 * are functioning correctly and can be probed. 345 * 346 * @devp: On entry, pointer to device to lookup. On exit, returns pointer 347 * to the next device in the uclass if any 348 * @return 0 if OK (found or not found), other -ve on error. If an error occurs 349 * it is still possible to move to the next device. 350 */ 351 int uclass_next_device_check(struct udevice **devp); 352 353 /** 354 * uclass_resolve_seq() - Resolve a device's sequence number 355 * 356 * On entry dev->seq is -1, and dev->req_seq may be -1 (to allocate a 357 * sequence number automatically, or >= 0 to select a particular number. 358 * If the requested sequence number is in use, then this device will 359 * be allocated another one. 360 * 361 * Note that the device's seq value is not changed by this function. 362 * 363 * @dev: Device for which to allocate sequence number 364 * @return sequence number allocated, or -ve on error 365 */ 366 int uclass_resolve_seq(struct udevice *dev); 367 368 /** 369 * uclass_foreach_dev() - Helper function to iteration through devices 370 * 371 * This creates a for() loop which works through the available devices in 372 * a uclass in order from start to end. 373 * 374 * @pos: struct udevice * to hold the current device. Set to NULL when there 375 * are no more devices. 376 * @uc: uclass to scan 377 */ 378 #define uclass_foreach_dev(pos, uc) \ 379 list_for_each_entry(pos, &uc->dev_head, uclass_node) 380 381 /** 382 * uclass_foreach_dev_safe() - Helper function to safely iteration through devs 383 * 384 * This creates a for() loop which works through the available devices in 385 * a uclass in order from start to end. Inside the loop, it is safe to remove 386 * @pos if required. 387 * 388 * @pos: struct udevice * to hold the current device. Set to NULL when there 389 * are no more devices. 390 * @next: struct udevice * to hold the next next 391 * @uc: uclass to scan 392 */ 393 #define uclass_foreach_dev_safe(pos, next, uc) \ 394 list_for_each_entry_safe(pos, next, &uc->dev_head, uclass_node) 395 396 /** 397 * uclass_foreach_dev_probe() - Helper function to iteration through devices 398 * of given uclass 399 * 400 * This creates a for() loop which works through the available devices in 401 * a uclass in order from start to end. Devices are probed if necessary, 402 * and ready for use. 403 * 404 * @id: Uclass ID 405 * @dev: struct udevice * to hold the current device. Set to NULL when there 406 * are no more devices. 407 */ 408 #define uclass_foreach_dev_probe(id, dev) \ 409 for (int _ret = uclass_first_device_err(id, &dev); !_ret && dev; \ 410 _ret = uclass_next_device_err(&dev)) 411 412 #endif 413