2 * Copyright (c) 2013 Google, Inc
5 * Pavel Herrmann <morpheus.ibis@gmail.com>
7 * SPDX-License-Identifier: GPL-2.0+
13 #include <dm/ofnode.h>
14 #include <dm/uclass-id.h>
15 #include <linker_lists.h>
16 #include <linux/list.h>
19 * struct uclass - a U-Boot drive class, collecting together similar drivers
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.
28 * @priv: Private data for this uclass
29 * @uc_drv: The driver for the uclass itself, not to be confused with a
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
37 struct uclass_driver *uc_drv;
38 struct list_head dev_head;
39 struct list_head sibling_node;
45 /* Members of this uclass sequence themselves with aliases */
46 #define DM_UC_FLAG_SEQ_ALIAS (1 << 0)
49 * struct uclass_driver - Driver for the uclass
51 * A uclass_driver provides a consistent interface to a set of related
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
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 fallback 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 fallback if this member is 0 in the driver.
80 * @ops: Uclass operations, providing the consistent interface to devices
82 * @flags: Flags for this uclass (DM_UC_...)
84 struct uclass_driver {
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;
105 /* Declare a new uclass_driver */
106 #define UCLASS_DRIVER(__name) \
107 ll_entry_declare(struct uclass_driver, __name, uclass)
110 * uclass_get() - Get a uclass based on an ID, creating it if needed
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
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
120 int uclass_get(enum uclass_id key, struct uclass **ucp);
123 * uclass_get_name() - Get the name of a uclass driver
126 * @returns the name of the uclass driver for that ID, or NULL if none
128 const char *uclass_get_name(enum uclass_id id);
131 * uclass_get_by_name() - Look up a uclass by its driver name
133 * @name: Name to look up
134 * @returns the associated uclass ID, or UCLASS_INVALID if not found
136 enum uclass_id uclass_get_by_name(const char *name);
139 * uclass_get_device() - Get a uclass device based on an ID and index
141 * The device is probed to activate it ready for use.
144 * @index: Device number within that uclass (0=first)
145 * @devp: Returns pointer to device (there is only one per for each ID)
146 * @return 0 if OK, -ve on error
148 int uclass_get_device(enum uclass_id id, int index, struct udevice **devp);
151 * uclass_get_device_by_name() - Get a uclass device by its name
153 * This searches the devices in the uclass for one with the exactly given name.
155 * The device is probed to activate it ready for use.
158 * @name: name of a device to get
159 * @devp: Returns pointer to device (the first one with the name)
160 * @return 0 if OK, -ve on error
162 int uclass_get_device_by_name(enum uclass_id id, const char *name,
163 struct udevice **devp);
166 * uclass_get_device_by_seq() - Get a uclass device based on an ID and sequence
168 * If an active device has this sequence it will be returned. If there is no
169 * such device then this will check for a device that is requesting this
172 * The device is probed to activate it ready for use.
175 * @seq: Sequence number to find (0=first)
176 * @devp: Returns pointer to device (there is only one for each seq)
177 * @return 0 if OK, -ve on error
179 int uclass_get_device_by_seq(enum uclass_id id, int seq, struct udevice **devp);
182 * uclass_get_device_by_of_offset() - Get a uclass device by device tree node
184 * This searches the devices in the uclass for one attached to the given
187 * The device is probed to activate it ready for use.
190 * @node: Device tree offset to search for (if -ve then -ENODEV is returned)
191 * @devp: Returns pointer to device (there is only one for each node)
192 * @return 0 if OK, -ve on error
194 int uclass_get_device_by_of_offset(enum uclass_id id, int node,
195 struct udevice **devp);
198 * uclass_get_device_by_ofnode() - Get a uclass device by device tree node
200 * This searches the devices in the uclass for one attached to the given
203 * The device is probed to activate it ready for use.
206 * @np: Device tree node to search for (if NULL then -ENODEV is returned)
207 * @devp: Returns pointer to device (there is only one for each node)
208 * @return 0 if OK, -ve on error
210 int uclass_get_device_by_ofnode(enum uclass_id id, ofnode node,
211 struct udevice **devp);
214 * uclass_get_device_by_phandle() - Get a uclass device by phandle
216 * This searches the devices in the uclass for one with the given phandle.
218 * The device is probed to activate it ready for use.
220 * @id: uclass ID to look up
221 * @parent: Parent device containing the phandle pointer
222 * @name: Name of property in the parent device node
223 * @devp: Returns pointer to device (there is only one for each node)
224 * @return 0 if OK, -ENOENT if there is no @name present in the node, other
227 int uclass_get_device_by_phandle(enum uclass_id id, struct udevice *parent,
228 const char *name, struct udevice **devp);
231 * uclass_get_device_by_driver() - Get a uclass device for a driver
233 * This searches the devices in the uclass for one that uses the given
234 * driver. Use DM_GET_DRIVER(name) for the @drv argument, where 'name' is
235 * the driver name - as used in U_BOOT_DRIVER(name).
237 * The device is probed to activate it ready for use.
240 * @drv: Driver to look for
241 * @devp: Returns pointer to the first device with that driver
242 * @return 0 if OK, -ve on error
244 int uclass_get_device_by_driver(enum uclass_id id, const struct driver *drv,
245 struct udevice **devp);
248 * uclass_first_device() - Get the first device in a uclass
250 * The device returned is probed if necessary, and ready for use
252 * This function is useful to start iterating through a list of devices which
253 * are functioning correctly and can be probed.
255 * @id: Uclass ID to look up
256 * @devp: Returns pointer to the first device in that uclass if no error
257 * occurred, or NULL if there is no first device, or an error occurred with
259 * @return 0 if OK (found or not found), other -ve on error
261 int uclass_first_device(enum uclass_id id, struct udevice **devp);
264 * uclass_first_device_err() - Get the first device in a uclass
266 * The device returned is probed if necessary, and ready for use
268 * @id: Uclass ID to look up
269 * @devp: Returns pointer to the first device in that uclass, or NULL if none
270 * @return 0 if found, -ENODEV if not found, other -ve on error
272 int uclass_first_device_err(enum uclass_id id, struct udevice **devp);
275 * uclass_next_device() - Get the next device in a uclass
277 * The device returned is probed if necessary, and ready for use
279 * This function is useful to start iterating through a list of devices which
280 * are functioning correctly and can be probed.
282 * @devp: On entry, pointer to device to lookup. On exit, returns pointer
283 * to the next device in the uclass if no error occurred, or NULL if there is
284 * no next device, or an error occurred with that next device.
285 * @return 0 if OK (found or not found), other -ve on error
287 int uclass_next_device(struct udevice **devp);
290 * uclass_first_device() - Get the first device in a uclass
292 * The device returned is probed if necessary, and ready for use
294 * This function is useful to start iterating through a list of devices which
295 * are functioning correctly and can be probed.
297 * @id: Uclass ID to look up
298 * @devp: Returns pointer to the first device in that uclass, or NULL if there
300 * @return 0 if OK (found or not found), other -ve on error. If an error occurs
301 * it is still possible to move to the next device.
303 int uclass_first_device_check(enum uclass_id id, struct udevice **devp);
306 * uclass_next_device() - Get the next device in a uclass
308 * The device returned is probed if necessary, and ready for use
310 * This function is useful to start iterating through a list of devices which
311 * are functioning correctly and can be probed.
313 * @devp: On entry, pointer to device to lookup. On exit, returns pointer
314 * to the next device in the uclass if any
315 * @return 0 if OK (found or not found), other -ve on error. If an error occurs
316 * it is still possible to move to the next device.
318 int uclass_next_device_check(struct udevice **devp);
321 * uclass_resolve_seq() - Resolve a device's sequence number
323 * On entry dev->seq is -1, and dev->req_seq may be -1 (to allocate a
324 * sequence number automatically, or >= 0 to select a particular number.
325 * If the requested sequence number is in use, then this device will
326 * be allocated another one.
328 * Note that the device's seq value is not changed by this function.
330 * @dev: Device for which to allocate sequence number
331 * @return sequence number allocated, or -ve on error
333 int uclass_resolve_seq(struct udevice *dev);
336 * uclass_foreach_dev() - Helper function to iteration through devices
338 * This creates a for() loop which works through the available devices in
339 * a uclass in order from start to end.
341 * @pos: struct udevice * to hold the current device. Set to NULL when there
342 * are no more devices.
343 * @uc: uclass to scan
345 #define uclass_foreach_dev(pos, uc) \
346 list_for_each_entry(pos, &uc->dev_head, uclass_node)
349 * uclass_foreach_dev_safe() - Helper function to safely iteration through devs
351 * This creates a for() loop which works through the available devices in
352 * a uclass in order from start to end. Inside the loop, it is safe to remove
355 * @pos: struct udevice * to hold the current device. Set to NULL when there
356 * are no more devices.
357 * @next: struct udevice * to hold the next next
358 * @uc: uclass to scan
360 #define uclass_foreach_dev_safe(pos, next, uc) \
361 list_for_each_entry_safe(pos, next, &uc->dev_head, uclass_node)