2 * Copyright (c) 2013 Google, Inc
5 * Pavel Herrmann <morpheus.ibis@gmail.com>
7 * SPDX-License-Identifier: GPL-2.0+
13 #include <dm/uclass-id.h>
14 #include <linker_lists.h>
15 #include <linux/list.h>
18 * struct uclass - a U-Boot drive class, collecting together similar drivers
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.
27 * @priv: Private data for this uclass
28 * @uc_drv: The driver for the uclass itself, not to be confused with a
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
36 struct uclass_driver *uc_drv;
37 struct list_head dev_head;
38 struct list_head sibling_node;
44 /* Members of this uclass sequence themselves with aliases */
45 #define DM_UC_FLAG_SEQ_ALIAS (1 << 0)
48 * struct uclass_driver - Driver for the uclass
50 * A uclass_driver provides a consistent interface to a set of related
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
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
81 * @flags: Flags for this uclass (DM_UC_...)
83 struct uclass_driver {
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;
104 /* Declare a new uclass_driver */
105 #define UCLASS_DRIVER(__name) \
106 ll_entry_declare(struct uclass_driver, __name, uclass)
109 * uclass_get() - Get a uclass based on an ID, creating it if needed
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
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
119 int uclass_get(enum uclass_id key, struct uclass **ucp);
122 * uclass_get_device() - Get a uclass device based on an ID and index
124 * The device is probed to activate it ready for use.
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
131 int uclass_get_device(enum uclass_id id, int index, struct udevice **devp);
134 * uclass_get_device_by_name() - Get a uclass device by its name
136 * This searches the devices in the uclass for one with the exactly given name.
138 * The device is probed to activate it ready for use.
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
145 int uclass_get_device_by_name(enum uclass_id id, const char *name,
146 struct udevice **devp);
149 * uclass_get_device_by_seq() - Get a uclass device based on an ID and sequence
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
155 * The device is probed to activate it ready for use.
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
162 int uclass_get_device_by_seq(enum uclass_id id, int seq, struct udevice **devp);
165 * uclass_get_device_by_of_offset() - Get a uclass device by device tree node
167 * This searches the devices in the uclass for one attached to the given
170 * The device is probed to activate it ready for use.
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
177 int uclass_get_device_by_of_offset(enum uclass_id id, int node,
178 struct udevice **devp);
181 * uclass_get_device_by_phandle() - Get a uclass device by phandle
183 * This searches the devices in the uclass for one with the given phandle.
185 * The device is probed to activate it ready for use.
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
194 int uclass_get_device_by_phandle(enum uclass_id id, struct udevice *parent,
195 const char *name, struct udevice **devp);
198 * uclass_get_device_by_driver() - Get a uclass device for a driver
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).
204 * The device is probed to activate it ready for use.
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
211 int uclass_get_device_by_driver(enum uclass_id id, const struct driver *drv,
212 struct udevice **devp);
215 * uclass_first_device() - Get the first device in a uclass
217 * The device returned is probed if necessary, and ready for use
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
223 int uclass_first_device(enum uclass_id id, struct udevice **devp);
226 * uclass_first_device_err() - Get the first device in a uclass
228 * The device returned is probed if necessary, and ready for use
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
234 int uclass_first_device_err(enum uclass_id id, struct udevice **devp);
237 * uclass_next_device() - Get the next device in a uclass
239 * The device returned is probed if necessary, and ready for use
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
245 int uclass_next_device(struct udevice **devp);
248 * uclass_resolve_seq() - Resolve a device's sequence number
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.
255 * Note that the device's seq value is not changed by this function.
257 * @dev: Device for which to allocate sequence number
258 * @return sequence number allocated, or -ve on error
260 int uclass_resolve_seq(struct udevice *dev);
263 * uclass_foreach_dev() - Helper function to iteration through devices
265 * This creates a for() loop which works through the available devices in
266 * a uclass in order from start to end.
268 * @pos: struct udevice * to hold the current device. Set to NULL when there
269 * are no more devices.
270 * @uc: uclass to scan
272 #define uclass_foreach_dev(pos, uc) \
273 list_for_each_entry(pos, &uc->dev_head, uclass_node)
276 * uclass_foreach_dev_safe() - Helper function to safely iteration through devs
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
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
287 #define uclass_foreach_dev_safe(pos, next, uc) \
288 list_for_each_entry_safe(pos, next, &uc->dev_head, uclass_node)