1 /* SPDX-License-Identifier: GPL-2.0+ */
3 * Copyright (c) 2013 Google, Inc
6 * Pavel Herrmann <morpheus.ibis@gmail.com>
12 #include <dm/ofnode.h>
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 fallback 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 fallback 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_name() - Get the name of a uclass driver
125 * @returns the name of the uclass driver for that ID, or NULL if none
127 const char *uclass_get_name(enum uclass_id id);
130 * uclass_get_by_name() - Look up a uclass by its driver name
132 * @name: Name to look up
133 * @returns the associated uclass ID, or UCLASS_INVALID if not found
135 enum uclass_id uclass_get_by_name(const char *name);
138 * uclass_get_device() - Get a uclass device based on an ID and index
140 * The device is probed to activate it ready for use.
143 * @index: Device number within that uclass (0=first)
144 * @devp: Returns pointer to device (there is only one per for each ID)
145 * @return 0 if OK, -ve on error
147 int uclass_get_device(enum uclass_id id, int index, struct udevice **devp);
150 * uclass_get_device_by_name() - Get a uclass device by its name
152 * This searches the devices in the uclass for one with the exactly given name.
154 * The device is probed to activate it ready for use.
157 * @name: name of a device to get
158 * @devp: Returns pointer to device (the first one with the name)
159 * @return 0 if OK, -ve on error
161 int uclass_get_device_by_name(enum uclass_id id, const char *name,
162 struct udevice **devp);
165 * uclass_get_device_by_seq() - Get a uclass device based on an ID and sequence
167 * If an active device has this sequence it will be returned. If there is no
168 * such device then this will check for a device that is requesting this
171 * The device is probed to activate it ready for use.
174 * @seq: Sequence number to find (0=first)
175 * @devp: Returns pointer to device (there is only one for each seq)
176 * @return 0 if OK, -ve on error
178 int uclass_get_device_by_seq(enum uclass_id id, int seq, struct udevice **devp);
181 * uclass_get_device_by_of_offset() - Get a uclass device by device tree node
183 * This searches the devices in the uclass for one attached to the given
186 * The device is probed to activate it ready for use.
189 * @node: Device tree offset to search for (if -ve then -ENODEV is returned)
190 * @devp: Returns pointer to device (there is only one for each node)
191 * @return 0 if OK, -ve on error
193 int uclass_get_device_by_of_offset(enum uclass_id id, int node,
194 struct udevice **devp);
197 * uclass_get_device_by_ofnode() - Get a uclass device by device tree node
199 * This searches the devices in the uclass for one attached to the given
202 * The device is probed to activate it ready for use.
205 * @np: Device tree node to search for (if NULL then -ENODEV is returned)
206 * @devp: Returns pointer to device (there is only one for each node)
207 * @return 0 if OK, -ve on error
209 int uclass_get_device_by_ofnode(enum uclass_id id, ofnode node,
210 struct udevice **devp);
213 * uclass_get_device_by_phandle_id() - Get a uclass device by phandle id
215 * This searches the devices in the uclass for one with the given phandle id.
217 * The device is probed to activate it ready for use.
219 * @id: uclass ID to look up
220 * @phandle_id: the phandle id to look up
221 * @devp: Returns pointer to device (there is only one for each node)
222 * @return 0 if OK, -ENODEV if there is no device match the phandle, other
225 int uclass_get_device_by_phandle_id(enum uclass_id id, uint phandle_id,
226 struct udevice **devp);
229 * uclass_get_device_by_phandle() - Get a uclass device by phandle
231 * This searches the devices in the uclass for one with the given phandle.
233 * The device is probed to activate it ready for use.
235 * @id: uclass ID to look up
236 * @parent: Parent device containing the phandle pointer
237 * @name: Name of property in the parent device node
238 * @devp: Returns pointer to device (there is only one for each node)
239 * @return 0 if OK, -ENOENT if there is no @name present in the node, other
242 int uclass_get_device_by_phandle(enum uclass_id id, struct udevice *parent,
243 const char *name, struct udevice **devp);
246 * uclass_get_device_by_driver() - Get a uclass device for a driver
248 * This searches the devices in the uclass for one that uses the given
249 * driver. Use DM_GET_DRIVER(name) for the @drv argument, where 'name' is
250 * the driver name - as used in U_BOOT_DRIVER(name).
252 * The device is probed to activate it ready for use.
255 * @drv: Driver to look for
256 * @devp: Returns pointer to the first device with that driver
257 * @return 0 if OK, -ve on error
259 int uclass_get_device_by_driver(enum uclass_id id, const struct driver *drv,
260 struct udevice **devp);
263 * uclass_first_device() - Get the first device in a uclass
265 * The device returned is probed if necessary, and ready for use
267 * This function is useful to start iterating through a list of devices which
268 * are functioning correctly and can be probed.
270 * @id: Uclass ID to look up
271 * @devp: Returns pointer to the first device in that uclass if no error
272 * occurred, or NULL if there is no first device, or an error occurred with
274 * @return 0 if OK (found or not found), other -ve on error
276 int uclass_first_device(enum uclass_id id, struct udevice **devp);
279 * uclass_first_device_err() - Get the first device in a uclass
281 * The device returned is probed if necessary, and ready for use
283 * @id: Uclass ID to look up
284 * @devp: Returns pointer to the first device in that uclass, or NULL if none
285 * @return 0 if found, -ENODEV if not found, other -ve on error
287 int uclass_first_device_err(enum uclass_id id, struct udevice **devp);
290 * uclass_next_device() - Get the next 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 * @devp: On entry, pointer to device to lookup. On exit, returns pointer
298 * to the next device in the uclass if no error occurred, or NULL if there is
299 * no next device, or an error occurred with that next device.
300 * @return 0 if OK (found or not found), other -ve on error
302 int uclass_next_device(struct udevice **devp);
305 * uclass_first_device() - Get the first device in a uclass
307 * The device returned is probed if necessary, and ready for use
309 * This function is useful to start iterating through a list of devices which
310 * are functioning correctly and can be probed.
312 * @id: Uclass ID to look up
313 * @devp: Returns pointer to the first device in that uclass, or NULL if there
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_first_device_check(enum uclass_id id, struct udevice **devp);
321 * uclass_next_device() - Get the next device in a uclass
323 * The device returned is probed if necessary, and ready for use
325 * This function is useful to start iterating through a list of devices which
326 * are functioning correctly and can be probed.
328 * @devp: On entry, pointer to device to lookup. On exit, returns pointer
329 * to the next device in the uclass if any
330 * @return 0 if OK (found or not found), other -ve on error. If an error occurs
331 * it is still possible to move to the next device.
333 int uclass_next_device_check(struct udevice **devp);
336 * uclass_resolve_seq() - Resolve a device's sequence number
338 * On entry dev->seq is -1, and dev->req_seq may be -1 (to allocate a
339 * sequence number automatically, or >= 0 to select a particular number.
340 * If the requested sequence number is in use, then this device will
341 * be allocated another one.
343 * Note that the device's seq value is not changed by this function.
345 * @dev: Device for which to allocate sequence number
346 * @return sequence number allocated, or -ve on error
348 int uclass_resolve_seq(struct udevice *dev);
351 * uclass_foreach_dev() - Helper function to iteration through devices
353 * This creates a for() loop which works through the available devices in
354 * a uclass in order from start to end.
356 * @pos: struct udevice * to hold the current device. Set to NULL when there
357 * are no more devices.
358 * @uc: uclass to scan
360 #define uclass_foreach_dev(pos, uc) \
361 list_for_each_entry(pos, &uc->dev_head, uclass_node)
364 * uclass_foreach_dev_safe() - Helper function to safely iteration through devs
366 * This creates a for() loop which works through the available devices in
367 * a uclass in order from start to end. Inside the loop, it is safe to remove
370 * @pos: struct udevice * to hold the current device. Set to NULL when there
371 * are no more devices.
372 * @next: struct udevice * to hold the next next
373 * @uc: uclass to scan
375 #define uclass_foreach_dev_safe(pos, next, uc) \
376 list_for_each_entry_safe(pos, next, &uc->dev_head, uclass_node)