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 udevice; 42 43 /* Members of this uclass sequence themselves with aliases */ 44 #define DM_UC_FLAG_SEQ_ALIAS (1 << 0) 45 46 /** 47 * struct uclass_driver - Driver for the uclass 48 * 49 * A uclass_driver provides a consistent interface to a set of related 50 * drivers. 51 * 52 * @name: Name of uclass driver 53 * @id: ID number of this uclass 54 * @post_bind: Called after a new device is bound to this uclass 55 * @pre_unbind: Called before a device is unbound from this uclass 56 * @pre_probe: Called before a new device is probed 57 * @post_probe: Called after a new device is probed 58 * @pre_remove: Called before a device is removed 59 * @child_post_bind: Called after a child is bound to a device in this uclass 60 * @init: Called to set up the uclass 61 * @destroy: Called to destroy the uclass 62 * @priv_auto_alloc_size: If non-zero this is the size of the private data 63 * to be allocated in the uclass's ->priv pointer. If zero, then the uclass 64 * driver is responsible for allocating any data required. 65 * @per_device_auto_alloc_size: Each device can hold private data owned 66 * by the uclass. If required this will be automatically allocated if this 67 * value is non-zero. 68 * @per_device_platdata_auto_alloc_size: Each device can hold platform data 69 * owned by the uclass as 'dev->uclass_platdata'. If the value is non-zero, 70 * then this will be automatically allocated. 71 * @per_child_auto_alloc_size: Each child device (of a parent in this 72 * uclass) can hold parent data for the device/uclass. This value is only 73 * used as a falback if this member is 0 in the driver. 74 * @per_child_platdata_auto_alloc_size: A bus likes to store information about 75 * its children. If non-zero this is the size of this data, to be allocated 76 * in the child device's parent_platdata pointer. This value is only used as 77 * a falback if this member is 0 in the driver. 78 * @ops: Uclass operations, providing the consistent interface to devices 79 * within the uclass. 80 * @flags: Flags for this uclass (DM_UC_...) 81 */ 82 struct uclass_driver { 83 const char *name; 84 enum uclass_id id; 85 int (*post_bind)(struct udevice *dev); 86 int (*pre_unbind)(struct udevice *dev); 87 int (*pre_probe)(struct udevice *dev); 88 int (*post_probe)(struct udevice *dev); 89 int (*pre_remove)(struct udevice *dev); 90 int (*child_post_bind)(struct udevice *dev); 91 int (*child_pre_probe)(struct udevice *dev); 92 int (*init)(struct uclass *class); 93 int (*destroy)(struct uclass *class); 94 int priv_auto_alloc_size; 95 int per_device_auto_alloc_size; 96 int per_device_platdata_auto_alloc_size; 97 int per_child_auto_alloc_size; 98 int per_child_platdata_auto_alloc_size; 99 const void *ops; 100 uint32_t flags; 101 }; 102 103 /* Declare a new uclass_driver */ 104 #define UCLASS_DRIVER(__name) \ 105 ll_entry_declare(struct uclass_driver, __name, uclass) 106 107 /** 108 * uclass_get() - Get a uclass based on an ID, creating it if needed 109 * 110 * Every uclass is identified by an ID, a number from 0 to n-1 where n is 111 * the number of uclasses. This function allows looking up a uclass by its 112 * ID. 113 * 114 * @key: ID to look up 115 * @ucp: Returns pointer to uclass (there is only one per ID) 116 * @return 0 if OK, -ve on error 117 */ 118 int uclass_get(enum uclass_id key, struct uclass **ucp); 119 120 /** 121 * uclass_get_device() - Get a uclass device based on an ID and index 122 * 123 * The device is probed to activate it ready for use. 124 * 125 * @id: ID to look up 126 * @index: Device number within that uclass (0=first) 127 * @devp: Returns pointer to device (there is only one per for each ID) 128 * @return 0 if OK, -ve on error 129 */ 130 int uclass_get_device(enum uclass_id id, int index, struct udevice **devp); 131 132 /** 133 * uclass_get_device_by_name() - Get a uclass device by it's name 134 * 135 * This searches the devices in the uclass for one with the exactly given name. 136 * 137 * The device is probed to activate it ready for use. 138 * 139 * @id: ID to look up 140 * @name: name of a device to get 141 * @devp: Returns pointer to device (the first one with the name) 142 * @return 0 if OK, -ve on error 143 */ 144 int uclass_get_device_by_name(enum uclass_id id, const char *name, 145 struct udevice **devp); 146 147 /** 148 * uclass_get_device_by_seq() - Get a uclass device based on an ID and sequence 149 * 150 * If an active device has this sequence it will be returned. If there is no 151 * such device then this will check for a device that is requesting this 152 * sequence. 153 * 154 * The device is probed to activate it ready for use. 155 * 156 * @id: ID to look up 157 * @seq: Sequence number to find (0=first) 158 * @devp: Returns pointer to device (there is only one for each seq) 159 * @return 0 if OK, -ve on error 160 */ 161 int uclass_get_device_by_seq(enum uclass_id id, int seq, struct udevice **devp); 162 163 /** 164 * uclass_get_device_by_of_offset() - Get a uclass device by device tree node 165 * 166 * This searches the devices in the uclass for one attached to the given 167 * device tree node. 168 * 169 * The device is probed to activate it ready for use. 170 * 171 * @id: ID to look up 172 * @node: Device tree offset to search for (if -ve then -ENODEV is returned) 173 * @devp: Returns pointer to device (there is only one for each node) 174 * @return 0 if OK, -ve on error 175 */ 176 int uclass_get_device_by_of_offset(enum uclass_id id, int node, 177 struct udevice **devp); 178 179 /** 180 * uclass_first_device() - Get the first device in a uclass 181 * 182 * The device returned is probed if necessary, and ready for use 183 * 184 * @id: Uclass ID to look up 185 * @devp: Returns pointer to the first device in that uclass, or NULL if none 186 * @return 0 if OK (found or not found), -1 on error 187 */ 188 int uclass_first_device(enum uclass_id id, struct udevice **devp); 189 190 /** 191 * uclass_next_device() - Get the next device in a uclass 192 * 193 * The device returned is probed if necessary, and ready for use 194 * 195 * @devp: On entry, pointer to device to lookup. On exit, returns pointer 196 * to the next device in the same uclass, or NULL if none 197 * @return 0 if OK (found or not found), -1 on error 198 */ 199 int uclass_next_device(struct udevice **devp); 200 201 /** 202 * uclass_resolve_seq() - Resolve a device's sequence number 203 * 204 * On entry dev->seq is -1, and dev->req_seq may be -1 (to allocate a 205 * sequence number automatically, or >= 0 to select a particular number. 206 * If the requested sequence number is in use, then this device will 207 * be allocated another one. 208 * 209 * Note that the device's seq value is not changed by this function. 210 * 211 * @dev: Device for which to allocate sequence number 212 * @return sequence number allocated, or -ve on error 213 */ 214 int uclass_resolve_seq(struct udevice *dev); 215 216 /** 217 * uclass_foreach_dev() - Helper function to iteration through devices 218 * 219 * This creates a for() loop which works through the available devices in 220 * a uclass in order from start to end. 221 * 222 * @pos: struct udevice * to hold the current device. Set to NULL when there 223 * are no more devices. 224 * @uc: uclass to scan 225 */ 226 #define uclass_foreach_dev(pos, uc) \ 227 for (pos = list_entry((&(uc)->dev_head)->next, typeof(*pos), \ 228 uclass_node); \ 229 prefetch(pos->uclass_node.next), \ 230 &pos->uclass_node != (&(uc)->dev_head); \ 231 pos = list_entry(pos->uclass_node.next, typeof(*pos), \ 232 uclass_node)) 233 234 #endif 235