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/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 /** 48 * struct uclass_driver - Driver for the uclass 49 * 50 * A uclass_driver provides a consistent interface to a set of related 51 * drivers. 52 * 53 * @name: Name of uclass driver 54 * @id: ID number of this uclass 55 * @post_bind: Called after a new device is bound to this uclass 56 * @pre_unbind: Called before a device is unbound from this uclass 57 * @pre_probe: Called before a new device is probed 58 * @post_probe: Called after a new device is probed 59 * @pre_remove: Called before a device is removed 60 * @child_post_bind: Called after a child is bound to a device in this uclass 61 * @init: Called to set up the uclass 62 * @destroy: Called to destroy the uclass 63 * @priv_auto_alloc_size: If non-zero this is the size of the private data 64 * to be allocated in the uclass's ->priv pointer. If zero, then the uclass 65 * driver is responsible for allocating any data required. 66 * @per_device_auto_alloc_size: Each device can hold private data owned 67 * by the uclass. If required this will be automatically allocated if this 68 * value is non-zero. 69 * @per_device_platdata_auto_alloc_size: Each device can hold platform data 70 * owned by the uclass as 'dev->uclass_platdata'. If the value is non-zero, 71 * then this will be automatically allocated. 72 * @per_child_auto_alloc_size: Each child device (of a parent in this 73 * uclass) can hold parent data for the device/uclass. This value is only 74 * used as a falback if this member is 0 in the driver. 75 * @per_child_platdata_auto_alloc_size: A bus likes to store information about 76 * its children. If non-zero this is the size of this data, to be allocated 77 * in the child device's parent_platdata pointer. This value is only used as 78 * a falback if this member is 0 in the driver. 79 * @ops: Uclass operations, providing the consistent interface to devices 80 * within the uclass. 81 * @flags: Flags for this uclass (DM_UC_...) 82 */ 83 struct uclass_driver { 84 const char *name; 85 enum uclass_id id; 86 int (*post_bind)(struct udevice *dev); 87 int (*pre_unbind)(struct udevice *dev); 88 int (*pre_probe)(struct udevice *dev); 89 int (*post_probe)(struct udevice *dev); 90 int (*pre_remove)(struct udevice *dev); 91 int (*child_post_bind)(struct udevice *dev); 92 int (*child_pre_probe)(struct udevice *dev); 93 int (*init)(struct uclass *class); 94 int (*destroy)(struct uclass *class); 95 int priv_auto_alloc_size; 96 int per_device_auto_alloc_size; 97 int per_device_platdata_auto_alloc_size; 98 int per_child_auto_alloc_size; 99 int per_child_platdata_auto_alloc_size; 100 const void *ops; 101 uint32_t flags; 102 }; 103 104 /* Declare a new uclass_driver */ 105 #define UCLASS_DRIVER(__name) \ 106 ll_entry_declare(struct uclass_driver, __name, uclass) 107 108 /** 109 * uclass_get() - Get a uclass based on an ID, creating it if needed 110 * 111 * Every uclass is identified by an ID, a number from 0 to n-1 where n is 112 * the number of uclasses. This function allows looking up a uclass by its 113 * ID. 114 * 115 * @key: ID to look up 116 * @ucp: Returns pointer to uclass (there is only one per ID) 117 * @return 0 if OK, -ve on error 118 */ 119 int uclass_get(enum uclass_id key, struct uclass **ucp); 120 121 /** 122 * uclass_get_device() - Get a uclass device based on an ID and index 123 * 124 * The device is probed to activate it ready for use. 125 * 126 * @id: ID to look up 127 * @index: Device number within that uclass (0=first) 128 * @devp: Returns pointer to device (there is only one per for each ID) 129 * @return 0 if OK, -ve on error 130 */ 131 int uclass_get_device(enum uclass_id id, int index, struct udevice **devp); 132 133 /** 134 * uclass_get_device_by_name() - Get a uclass device by its name 135 * 136 * This searches the devices in the uclass for one with the exactly given name. 137 * 138 * The device is probed to activate it ready for use. 139 * 140 * @id: ID to look up 141 * @name: name of a device to get 142 * @devp: Returns pointer to device (the first one with the name) 143 * @return 0 if OK, -ve on error 144 */ 145 int uclass_get_device_by_name(enum uclass_id id, const char *name, 146 struct udevice **devp); 147 148 /** 149 * uclass_get_device_by_seq() - Get a uclass device based on an ID and sequence 150 * 151 * If an active device has this sequence it will be returned. If there is no 152 * such device then this will check for a device that is requesting this 153 * sequence. 154 * 155 * The device is probed to activate it ready for use. 156 * 157 * @id: ID to look up 158 * @seq: Sequence number to find (0=first) 159 * @devp: Returns pointer to device (there is only one for each seq) 160 * @return 0 if OK, -ve on error 161 */ 162 int uclass_get_device_by_seq(enum uclass_id id, int seq, struct udevice **devp); 163 164 /** 165 * uclass_get_device_by_of_offset() - Get a uclass device by device tree node 166 * 167 * This searches the devices in the uclass for one attached to the given 168 * device tree node. 169 * 170 * The device is probed to activate it ready for use. 171 * 172 * @id: ID to look up 173 * @node: Device tree offset to search for (if -ve then -ENODEV is returned) 174 * @devp: Returns pointer to device (there is only one for each node) 175 * @return 0 if OK, -ve on error 176 */ 177 int uclass_get_device_by_of_offset(enum uclass_id id, int node, 178 struct udevice **devp); 179 180 /** 181 * uclass_get_device_by_phandle() - Get a uclass device by phandle 182 * 183 * This searches the devices in the uclass for one with the given phandle. 184 * 185 * The device is probed to activate it ready for use. 186 * 187 * @id: uclass ID to look up 188 * @parent: Parent device containing the phandle pointer 189 * @name: Name of property in the parent device node 190 * @devp: Returns pointer to device (there is only one for each node) 191 * @return 0 if OK, -ENOENT if there is no @name present in the node, other 192 * -ve on error 193 */ 194 int uclass_get_device_by_phandle(enum uclass_id id, struct udevice *parent, 195 const char *name, struct udevice **devp); 196 197 /** 198 * uclass_get_device_by_driver() - Get a uclass device for a driver 199 * 200 * This searches the devices in the uclass for one that uses the given 201 * driver. Use DM_GET_DRIVER(name) for the @drv argument, where 'name' is 202 * the driver name - as used in U_BOOT_DRIVER(name). 203 * 204 * The device is probed to activate it ready for use. 205 * 206 * @id: ID to look up 207 * @drv: Driver to look for 208 * @devp: Returns pointer to the first device with that driver 209 * @return 0 if OK, -ve on error 210 */ 211 int uclass_get_device_by_driver(enum uclass_id id, const struct driver *drv, 212 struct udevice **devp); 213 214 /** 215 * uclass_first_device() - Get the first device in a uclass 216 * 217 * The device returned is probed if necessary, and ready for use 218 * 219 * @id: Uclass ID to look up 220 * @devp: Returns pointer to the first device in that uclass, or NULL if none 221 * @return 0 if OK (found or not found), other -ve on error 222 */ 223 int uclass_first_device(enum uclass_id id, struct udevice **devp); 224 225 /** 226 * uclass_first_device_err() - Get the first device in a uclass 227 * 228 * The device returned is probed if necessary, and ready for use 229 * 230 * @id: Uclass ID to look up 231 * @devp: Returns pointer to the first device in that uclass, or NULL if none 232 * @return 0 if found, -ENODEV if not found, other -ve on error 233 */ 234 int uclass_first_device_err(enum uclass_id id, struct udevice **devp); 235 236 /** 237 * uclass_next_device() - Get the next device in a uclass 238 * 239 * The device returned is probed if necessary, and ready for use 240 * 241 * @devp: On entry, pointer to device to lookup. On exit, returns pointer 242 * to the next device in the same uclass, or NULL if none 243 * @return 0 if OK (found or not found), other -ve on error 244 */ 245 int uclass_next_device(struct udevice **devp); 246 247 /** 248 * uclass_resolve_seq() - Resolve a device's sequence number 249 * 250 * On entry dev->seq is -1, and dev->req_seq may be -1 (to allocate a 251 * sequence number automatically, or >= 0 to select a particular number. 252 * If the requested sequence number is in use, then this device will 253 * be allocated another one. 254 * 255 * Note that the device's seq value is not changed by this function. 256 * 257 * @dev: Device for which to allocate sequence number 258 * @return sequence number allocated, or -ve on error 259 */ 260 int uclass_resolve_seq(struct udevice *dev); 261 262 /** 263 * uclass_foreach_dev() - Helper function to iteration through devices 264 * 265 * This creates a for() loop which works through the available devices in 266 * a uclass in order from start to end. 267 * 268 * @pos: struct udevice * to hold the current device. Set to NULL when there 269 * are no more devices. 270 * @uc: uclass to scan 271 */ 272 #define uclass_foreach_dev(pos, uc) \ 273 list_for_each_entry(pos, &uc->dev_head, uclass_node) 274 275 /** 276 * uclass_foreach_dev_safe() - Helper function to safely iteration through devs 277 * 278 * This creates a for() loop which works through the available devices in 279 * a uclass in order from start to end. Inside the loop, it is safe to remove 280 * @pos if required. 281 * 282 * @pos: struct udevice * to hold the current device. Set to NULL when there 283 * are no more devices. 284 * @next: struct udevice * to hold the next next 285 * @uc: uclass to scan 286 */ 287 #define uclass_foreach_dev_safe(pos, next, uc) \ 288 list_for_each_entry_safe(pos, next, &uc->dev_head, uclass_node) 289 290 #endif 291