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;
43 /* Members of this uclass sequence themselves with aliases */
44 #define DM_UC_FLAG_SEQ_ALIAS (1 << 0)
47 * struct uclass_driver - Driver for the uclass
49 * A uclass_driver provides a consistent interface to a set of related
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
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
80 * @flags: Flags for this uclass (DM_UC_...)
82 struct uclass_driver {
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;
103 /* Declare a new uclass_driver */
104 #define UCLASS_DRIVER(__name) \
105 ll_entry_declare(struct uclass_driver, __name, uclass)
108 * uclass_get() - Get a uclass based on an ID, creating it if needed
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
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
118 int uclass_get(enum uclass_id key, struct uclass **ucp);
121 * uclass_get_device() - Get a uclass device based on an ID and index
123 * The device is probed to activate it ready for use.
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
130 int uclass_get_device(enum uclass_id id, int index, struct udevice **devp);
133 * uclass_get_device_by_name() - Get a uclass device by its name
135 * This searches the devices in the uclass for one with the exactly given name.
137 * The device is probed to activate it ready for use.
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
144 int uclass_get_device_by_name(enum uclass_id id, const char *name,
145 struct udevice **devp);
148 * uclass_get_device_by_seq() - Get a uclass device based on an ID and sequence
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
154 * The device is probed to activate it ready for use.
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
161 int uclass_get_device_by_seq(enum uclass_id id, int seq, struct udevice **devp);
164 * uclass_get_device_by_of_offset() - Get a uclass device by device tree node
166 * This searches the devices in the uclass for one attached to the given
169 * The device is probed to activate it ready for use.
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
176 int uclass_get_device_by_of_offset(enum uclass_id id, int node,
177 struct udevice **devp);
180 * uclass_get_device_by_phandle() - Get a uclass device by phandle
182 * This searches the devices in the uclass for one with the given phandle.
184 * The device is probed to activate it ready for use.
186 * @id: uclass ID to look up
187 * @parent: Parent device containing the phandle pointer
188 * @name: Name of property in the parent device node
189 * @devp: Returns pointer to device (there is only one for each node)
190 * @return 0 if OK, -ENOENT if there is no @name present in the node, other
193 int uclass_get_device_by_phandle(enum uclass_id id, struct udevice *parent,
194 const char *name, struct udevice **devp);
197 * uclass_first_device() - Get the first device in a uclass
199 * The device returned is probed if necessary, and ready for use
201 * @id: Uclass ID to look up
202 * @devp: Returns pointer to the first device in that uclass, or NULL if none
203 * @return 0 if OK (found or not found), other -ve on error
205 int uclass_first_device(enum uclass_id id, struct udevice **devp);
208 * uclass_first_device_err() - Get the first device in a uclass
210 * The device returned is probed if necessary, and ready for use
212 * @id: Uclass ID to look up
213 * @devp: Returns pointer to the first device in that uclass, or NULL if none
214 * @return 0 if found, -ENODEV if not found, other -ve on error
216 int uclass_first_device_err(enum uclass_id id, struct udevice **devp);
219 * uclass_next_device() - Get the next device in a uclass
221 * The device returned is probed if necessary, and ready for use
223 * @devp: On entry, pointer to device to lookup. On exit, returns pointer
224 * to the next device in the same uclass, or NULL if none
225 * @return 0 if OK (found or not found), other -ve on error
227 int uclass_next_device(struct udevice **devp);
230 * uclass_resolve_seq() - Resolve a device's sequence number
232 * On entry dev->seq is -1, and dev->req_seq may be -1 (to allocate a
233 * sequence number automatically, or >= 0 to select a particular number.
234 * If the requested sequence number is in use, then this device will
235 * be allocated another one.
237 * Note that the device's seq value is not changed by this function.
239 * @dev: Device for which to allocate sequence number
240 * @return sequence number allocated, or -ve on error
242 int uclass_resolve_seq(struct udevice *dev);
245 * uclass_foreach_dev() - Helper function to iteration through devices
247 * This creates a for() loop which works through the available devices in
248 * a uclass in order from start to end.
250 * @pos: struct udevice * to hold the current device. Set to NULL when there
251 * are no more devices.
252 * @uc: uclass to scan
254 #define uclass_foreach_dev(pos, uc) \
255 list_for_each_entry(pos, &uc->dev_head, uclass_node)
258 * uclass_foreach_dev_safe() - Helper function to safely iteration through devs
260 * This creates a for() loop which works through the available devices in
261 * a uclass in order from start to end. Inside the loop, it is safe to remove
264 * @pos: struct udevice * to hold the current device. Set to NULL when there
265 * are no more devices.
266 * @next: struct udevice * to hold the next next
267 * @uc: uclass to scan
269 #define uclass_foreach_dev_safe(pos, next, uc) \
270 list_for_each_entry_safe(pos, next, &uc->dev_head, uclass_node)