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 (do not access outside driver model)
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)
47 /* Members of this uclass without aliases don't get a sequence number */
48 #define DM_UC_FLAG_NO_AUTO_SEQ (1 << 1)
50 /* Same as DM_FLAG_ALLOC_PRIV_DMA */
51 #define DM_UC_FLAG_ALLOC_PRIV_DMA (1 << 5)
54 * struct uclass_driver - Driver for the uclass
56 * A uclass_driver provides a consistent interface to a set of related
59 * @name: Name of uclass driver
60 * @id: ID number of this uclass
61 * @post_bind: Called after a new device is bound to this uclass
62 * @pre_unbind: Called before a device is unbound from this uclass
63 * @pre_probe: Called before a new device is probed
64 * @post_probe: Called after a new device is probed
65 * @pre_remove: Called before a device is removed
66 * @child_post_bind: Called after a child is bound to a device in this uclass
67 * @child_pre_probe: Called before a child in this uclass is probed
68 * @child_post_probe: Called after a child in this uclass is probed
69 * @init: Called to set up the uclass
70 * @destroy: Called to destroy the uclass
71 * @priv_auto: If non-zero this is the size of the private data
72 * to be allocated in the uclass's ->priv pointer. If zero, then the uclass
73 * driver is responsible for allocating any data required.
74 * @per_device_auto: Each device can hold private data owned
75 * by the uclass. If required this will be automatically allocated if this
77 * @per_device_plat_auto: Each device can hold platform data
78 * owned by the uclass as 'dev->uclass_plat'. If the value is non-zero,
79 * then this will be automatically allocated.
80 * @per_child_auto: Each child device (of a parent in this
81 * uclass) can hold parent data for the device/uclass. This value is only
82 * used as a fallback if this member is 0 in the driver.
83 * @per_child_plat_auto: A bus likes to store information about
84 * its children. If non-zero this is the size of this data, to be allocated
85 * in the child device's parent_plat pointer. This value is only used as
86 * a fallback if this member is 0 in the driver.
87 * @flags: Flags for this uclass (DM_UC_...)
89 struct uclass_driver {
92 int (*post_bind)(struct udevice *dev);
93 int (*pre_unbind)(struct udevice *dev);
94 int (*pre_probe)(struct udevice *dev);
95 int (*post_probe)(struct udevice *dev);
96 int (*pre_remove)(struct udevice *dev);
97 int (*child_post_bind)(struct udevice *dev);
98 int (*child_pre_probe)(struct udevice *dev);
99 int (*child_post_probe)(struct udevice *dev);
100 int (*init)(struct uclass *class);
101 int (*destroy)(struct uclass *class);
104 int per_device_plat_auto;
106 int per_child_plat_auto;
110 /* Declare a new uclass_driver */
111 #define UCLASS_DRIVER(__name) \
112 ll_entry_declare(struct uclass_driver, __name, uclass_driver)
115 * These two macros DM_UCLASS_DRIVER_REF and DM_UCLASS_DRIVER_REF are only
116 * allowed in code generated by dtoc, because the ordering is important and if
117 * other instances creep in then they may mess up the ordering expected by dtoc.
119 * It is OK to use them with 'extern' though, since that does not actually
120 * add a new record to the linker_list.
124 * DM_UCLASS_DRIVER_REF() - Get a reference to a uclass driver
126 * This is useful in data structures and code for referencing a uclass_driver at
127 * build time. Before this is used, an extern UCLASS_DRIVER() must have been
132 * extern UCLASS_DRIVER(clk);
134 * struct uclass_driver *drvs[] = {
135 * DM_UCLASS_DRIVER_REF(clk),
138 * @_name: Name of the uclass_driver. This must be a valid C identifier, used by
140 * @returns struct uclass_driver * for the uclass driver
142 #define DM_UCLASS_DRIVER_REF(_name) \
143 ll_entry_ref(struct uclass_driver, _name, uclass_driver)
146 * uclass_get_priv() - Get the private data for a uclass
148 * @uc Uclass to check
149 * @return private data, or NULL if none
151 void *uclass_get_priv(const struct uclass *uc);
154 * uclass_get() - Get a uclass based on an ID, creating it if needed
156 * Every uclass is identified by an ID, a number from 0 to n-1 where n is
157 * the number of uclasses. This function allows looking up a uclass by its
160 * @key: ID to look up
161 * @ucp: Returns pointer to uclass (there is only one per ID)
162 * @return 0 if OK, -EDEADLK if driver model is not yet inited, other -ve on
165 int uclass_get(enum uclass_id key, struct uclass **ucp);
168 * uclass_get_name() - Get the name of a uclass driver
171 * @returns the name of the uclass driver for that ID, or NULL if none
173 const char *uclass_get_name(enum uclass_id id);
176 * uclass_get_by_name() - Look up a uclass by its driver name
178 * @name: Name to look up
179 * @len: Length of name
180 * @returns the associated uclass ID, or UCLASS_INVALID if not found
182 enum uclass_id uclass_get_by_name_len(const char *name, int len);
185 * uclass_get_by_name() - Look up a uclass by its driver name
187 * @name: Name to look up
188 * @returns the associated uclass ID, or UCLASS_INVALID if not found
190 enum uclass_id uclass_get_by_name(const char *name);
193 * uclass_get_device() - Get a uclass device based on an ID and index
195 * The device is probed to activate it ready for use.
198 * @index: Device number within that uclass (0=first)
199 * @devp: Returns pointer to device (there is only one per for each ID)
200 * @return 0 if OK, -ve on error
202 int uclass_get_device(enum uclass_id id, int index, struct udevice **devp);
205 * uclass_get_device_by_name() - Get a uclass device by its name
207 * This searches the devices in the uclass for one with the exactly given name.
209 * The device is probed to activate it ready for use.
212 * @name: name of a device to get
213 * @devp: Returns pointer to device (the first one with the name)
214 * @return 0 if OK, -ve on error
216 int uclass_get_device_by_name(enum uclass_id id, const char *name,
217 struct udevice **devp);
220 * uclass_get_device_by_seq() - Get a uclass device based on an ID and sequence
222 * If an active device has this sequence it will be returned. If there is no
223 * such device then this will check for a device that is requesting this
226 * The device is probed to activate it ready for use.
229 * @seq: Sequence number to find (0=first)
230 * @devp: Returns pointer to device (there is only one for each seq)
231 * @return 0 if OK, -ve on error
233 int uclass_get_device_by_seq(enum uclass_id id, int seq, struct udevice **devp);
236 * uclass_get_device_by_of_offset() - Get a uclass device by device tree node
238 * This searches the devices in the uclass for one attached to the given
241 * The device is probed to activate it ready for use.
244 * @node: Device tree offset to search for (if -ve then -ENODEV is returned)
245 * @devp: Returns pointer to device (there is only one for each node)
246 * @return 0 if OK, -ve on error
248 int uclass_get_device_by_of_offset(enum uclass_id id, int node,
249 struct udevice **devp);
252 * uclass_get_device_by_ofnode() - Get a uclass device by device tree node
254 * This searches the devices in the uclass for one attached to the given
257 * The device is probed to activate it ready for use.
260 * @np: Device tree node to search for (if NULL then -ENODEV is returned)
261 * @devp: Returns pointer to device (there is only one for each node)
262 * @return 0 if OK, -ve on error
264 int uclass_get_device_by_ofnode(enum uclass_id id, ofnode node,
265 struct udevice **devp);
268 * uclass_get_device_by_phandle_id() - Get a uclass device by phandle id
270 * This searches the devices in the uclass for one with the given phandle id.
272 * The device is probed to activate it ready for use.
274 * @id: uclass ID to look up
275 * @phandle_id: the phandle id to look up
276 * @devp: Returns pointer to device (there is only one for each node). NULL if
277 * there is no such device.
278 * @return 0 if OK, -ENODEV if there is no device match the phandle, other
281 int uclass_get_device_by_phandle_id(enum uclass_id id, uint phandle_id,
282 struct udevice **devp);
285 * uclass_get_device_by_phandle() - Get a uclass device by phandle
287 * This searches the devices in the uclass for one with the given phandle.
289 * The device is probed to activate it ready for use.
291 * @id: uclass ID to look up
292 * @parent: Parent device containing the phandle pointer
293 * @name: Name of property in the parent device node
294 * @devp: Returns pointer to device (there is only one for each node)
295 * @return 0 if OK, -ENOENT if there is no @name present in the node, other
298 int uclass_get_device_by_phandle(enum uclass_id id, struct udevice *parent,
299 const char *name, struct udevice **devp);
302 * uclass_get_device_by_driver() - Get a uclass device for a driver
304 * This searches the devices in the uclass for one that uses the given
305 * driver. Use DM_DRIVER_GET(name) for the @drv argument, where 'name' is
306 * the driver name - as used in U_BOOT_DRIVER(name).
308 * The device is probed to activate it ready for use.
311 * @drv: Driver to look for
312 * @devp: Returns pointer to the first device with that driver
313 * @return 0 if OK, -ve on error
315 int uclass_get_device_by_driver(enum uclass_id id, const struct driver *drv,
316 struct udevice **devp);
319 * uclass_first_device() - Get the first device in a uclass
321 * The device returned is probed if necessary, and ready for use
323 * This function is useful to start iterating through a list of devices which
324 * are functioning correctly and can be probed.
326 * @id: Uclass ID to look up
327 * @devp: Returns pointer to the first device in that uclass if no error
328 * occurred, or NULL if there is no first device, or an error occurred with
330 * @return 0 if OK (found or not found), other -ve on error
332 int uclass_first_device(enum uclass_id id, struct udevice **devp);
335 * uclass_first_device_err() - Get the first device in a uclass
337 * The device returned is probed if necessary, and ready for use
339 * @id: Uclass ID to look up
340 * @devp: Returns pointer to the first device in that uclass, or NULL if none
341 * @return 0 if found, -ENODEV if not found, other -ve on error
343 int uclass_first_device_err(enum uclass_id id, struct udevice **devp);
346 * uclass_next_device() - Get the next device in a uclass
348 * The device returned is probed if necessary, and ready for use
350 * This function is useful to iterate through a list of devices which
351 * are functioning correctly and can be probed.
353 * @devp: On entry, pointer to device to lookup. On exit, returns pointer
354 * to the next device in the uclass if no error occurred, or NULL if there is
355 * no next device, or an error occurred with that next device.
356 * @return 0 if OK (found or not found), other -ve on error
358 int uclass_next_device(struct udevice **devp);
361 * uclass_next_device_err() - Get the next device in a uclass
363 * The device returned is probed if necessary, and ready for use
365 * @devp: On entry, pointer to device to lookup. On exit, returns pointer
366 * to the next device in the uclass if no error occurred, or NULL if
367 * there is no next device.
368 * @return 0 if found, -ENODEV if not found, other -ve on error
370 int uclass_next_device_err(struct udevice **devp);
373 * uclass_first_device_check() - Get the first device in a uclass
375 * The device returned is probed if necessary, and ready for use
377 * This function is useful to start iterating through a list of devices which
378 * are functioning correctly and can be probed.
380 * @id: Uclass ID to look up
381 * @devp: Returns pointer to the first device in that uclass, or NULL if there
383 * @return 0 if OK (found or not found), other -ve on error. If an error occurs
384 * it is still possible to move to the next device.
386 int uclass_first_device_check(enum uclass_id id, struct udevice **devp);
389 * uclass_next_device_check() - Get the next device in a uclass
391 * The device returned is probed if necessary, and ready for use
393 * This function is useful to start iterating through a list of devices which
394 * are functioning correctly and can be probed.
396 * @devp: On entry, pointer to device to lookup. On exit, returns pointer
397 * to the next device in the uclass if any
398 * @return 0 if OK (found or not found), other -ve on error. If an error occurs
399 * it is still possible to move to the next device.
401 int uclass_next_device_check(struct udevice **devp);
404 * uclass_first_device_drvdata() - Find the first device with given driver data
406 * This searches through the devices for a particular uclass looking for one
407 * that has the given driver data.
409 * @id: Uclass ID to check
410 * @driver_data: Driver data to search for
411 * @devp: Returns pointer to the first matching device in that uclass, if found
412 * @return 0 if found, -ENODEV if not found, other -ve on error
414 int uclass_first_device_drvdata(enum uclass_id id, ulong driver_data,
415 struct udevice **devp);
418 * uclass_probe_all() - Probe all devices based on an uclass ID
420 * This function probes all devices associated with a uclass by
421 * looking for its ID.
423 * @id: uclass ID to look up
424 * @return 0 if OK, other -ve on error
426 int uclass_probe_all(enum uclass_id id);
429 * uclass_id_count() - Count the number of devices in a uclass
431 * @id: uclass ID to look up
432 * @return number of devices in that uclass (0 if none)
434 int uclass_id_count(enum uclass_id id);
437 * uclass_id_foreach_dev() - Helper function to iteration through devices
439 * This creates a for() loop which works through the available devices in
440 * a uclass ID in order from start to end.
442 * If for some reason the uclass cannot be found, this does nothing.
444 * @id: enum uclass_id ID to use
445 * @pos: struct udevice * to hold the current device. Set to NULL when there
446 * are no more devices.
447 * @uc: temporary uclass variable (struct uclass *)
449 #define uclass_id_foreach_dev(id, pos, uc) \
450 if (!uclass_get(id, &uc)) \
451 list_for_each_entry(pos, &uc->dev_head, uclass_node)
454 * uclass_foreach_dev() - Helper function to iteration through devices
456 * This creates a for() loop which works through the available devices in
457 * a uclass in order from start to end.
459 * @pos: struct udevice * to hold the current device. Set to NULL when there
460 * are no more devices.
461 * @uc: uclass to scan
463 #define uclass_foreach_dev(pos, uc) \
464 list_for_each_entry(pos, &uc->dev_head, uclass_node)
467 * uclass_foreach_dev_safe() - Helper function to safely iteration through devs
469 * This creates a for() loop which works through the available devices in
470 * a uclass in order from start to end. Inside the loop, it is safe to remove
473 * @pos: struct udevice * to hold the current device. Set to NULL when there
474 * are no more devices.
475 * @next: struct udevice * to hold the next next
476 * @uc: uclass to scan
478 #define uclass_foreach_dev_safe(pos, next, uc) \
479 list_for_each_entry_safe(pos, next, &uc->dev_head, uclass_node)
482 * uclass_foreach_dev_probe() - Helper function to iteration through devices
485 * This creates a for() loop which works through the available devices in
486 * a uclass in order from start to end. Devices are probed if necessary,
490 * @dev: struct udevice * to hold the current device. Set to NULL when there
491 * are no more devices.
493 #define uclass_foreach_dev_probe(id, dev) \
494 for (int _ret = uclass_first_device_err(id, &dev); !_ret && dev; \
495 _ret = uclass_next_device_err(&dev))