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