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 * @returns the associated uclass ID, or UCLASS_INVALID if not found
181 enum uclass_id uclass_get_by_name(const char *name);
184 * uclass_get_device() - Get a uclass device based on an ID and index
186 * The device is probed to activate it ready for use.
189 * @index: Device number within that uclass (0=first)
190 * @devp: Returns pointer to device (there is only one per for each ID)
191 * @return 0 if OK, -ve on error
193 int uclass_get_device(enum uclass_id id, int index, struct udevice **devp);
196 * uclass_get_device_by_name() - Get a uclass device by its name
198 * This searches the devices in the uclass for one with the exactly given name.
200 * The device is probed to activate it ready for use.
203 * @name: name of a device to get
204 * @devp: Returns pointer to device (the first one with the name)
205 * @return 0 if OK, -ve on error
207 int uclass_get_device_by_name(enum uclass_id id, const char *name,
208 struct udevice **devp);
211 * uclass_get_device_by_seq() - Get a uclass device based on an ID and sequence
213 * If an active device has this sequence it will be returned. If there is no
214 * such device then this will check for a device that is requesting this
217 * The device is probed to activate it ready for use.
220 * @seq: Sequence number to find (0=first)
221 * @devp: Returns pointer to device (there is only one for each seq)
222 * @return 0 if OK, -ve on error
224 int uclass_get_device_by_seq(enum uclass_id id, int seq, struct udevice **devp);
227 * uclass_get_device_by_of_offset() - Get a uclass device by device tree node
229 * This searches the devices in the uclass for one attached to the given
232 * The device is probed to activate it ready for use.
235 * @node: Device tree offset to search for (if -ve then -ENODEV is returned)
236 * @devp: Returns pointer to device (there is only one for each node)
237 * @return 0 if OK, -ve on error
239 int uclass_get_device_by_of_offset(enum uclass_id id, int node,
240 struct udevice **devp);
243 * uclass_get_device_by_ofnode() - Get a uclass device by device tree node
245 * This searches the devices in the uclass for one attached to the given
248 * The device is probed to activate it ready for use.
251 * @np: Device tree node to search for (if NULL then -ENODEV is returned)
252 * @devp: Returns pointer to device (there is only one for each node)
253 * @return 0 if OK, -ve on error
255 int uclass_get_device_by_ofnode(enum uclass_id id, ofnode node,
256 struct udevice **devp);
259 * uclass_get_device_by_phandle_id() - Get a uclass device by phandle id
261 * This searches the devices in the uclass for one with the given phandle id.
263 * The device is probed to activate it ready for use.
265 * @id: uclass ID to look up
266 * @phandle_id: the phandle id to look up
267 * @devp: Returns pointer to device (there is only one for each node). NULL if
268 * there is no such device.
269 * @return 0 if OK, -ENODEV if there is no device match the phandle, other
272 int uclass_get_device_by_phandle_id(enum uclass_id id, uint phandle_id,
273 struct udevice **devp);
276 * uclass_get_device_by_phandle() - Get a uclass device by phandle
278 * This searches the devices in the uclass for one with the given phandle.
280 * The device is probed to activate it ready for use.
282 * @id: uclass ID to look up
283 * @parent: Parent device containing the phandle pointer
284 * @name: Name of property in the parent device node
285 * @devp: Returns pointer to device (there is only one for each node)
286 * @return 0 if OK, -ENOENT if there is no @name present in the node, other
289 int uclass_get_device_by_phandle(enum uclass_id id, struct udevice *parent,
290 const char *name, struct udevice **devp);
293 * uclass_get_device_by_driver() - Get a uclass device for a driver
295 * This searches the devices in the uclass for one that uses the given
296 * driver. Use DM_DRIVER_GET(name) for the @drv argument, where 'name' is
297 * the driver name - as used in U_BOOT_DRIVER(name).
299 * The device is probed to activate it ready for use.
302 * @drv: Driver to look for
303 * @devp: Returns pointer to the first device with that driver
304 * @return 0 if OK, -ve on error
306 int uclass_get_device_by_driver(enum uclass_id id, const struct driver *drv,
307 struct udevice **devp);
310 * uclass_first_device() - Get the first device in a uclass
312 * The device returned is probed if necessary, and ready for use
314 * This function is useful to start iterating through a list of devices which
315 * are functioning correctly and can be probed.
317 * @id: Uclass ID to look up
318 * @devp: Returns pointer to the first device in that uclass if no error
319 * occurred, or NULL if there is no first device, or an error occurred with
321 * @return 0 if OK (found or not found), other -ve on error
323 int uclass_first_device(enum uclass_id id, struct udevice **devp);
326 * uclass_first_device_err() - Get the first device in a uclass
328 * The device returned is probed if necessary, and ready for use
330 * @id: Uclass ID to look up
331 * @devp: Returns pointer to the first device in that uclass, or NULL if none
332 * @return 0 if found, -ENODEV if not found, other -ve on error
334 int uclass_first_device_err(enum uclass_id id, struct udevice **devp);
337 * uclass_next_device() - Get the next device in a uclass
339 * The device returned is probed if necessary, and ready for use
341 * This function is useful to iterate through a list of devices which
342 * are functioning correctly and can be probed.
344 * @devp: On entry, pointer to device to lookup. On exit, returns pointer
345 * to the next device in the uclass if no error occurred, or NULL if there is
346 * no next device, or an error occurred with that next device.
347 * @return 0 if OK (found or not found), other -ve on error
349 int uclass_next_device(struct udevice **devp);
352 * uclass_next_device_err() - Get the next device in a uclass
354 * The device returned is probed if necessary, and ready for use
356 * @devp: On entry, pointer to device to lookup. On exit, returns pointer
357 * to the next device in the uclass if no error occurred, or NULL if
358 * there is no next device.
359 * @return 0 if found, -ENODEV if not found, other -ve on error
361 int uclass_next_device_err(struct udevice **devp);
364 * uclass_first_device_check() - Get the first device in a uclass
366 * The device returned is probed if necessary, and ready for use
368 * This function is useful to start iterating through a list of devices which
369 * are functioning correctly and can be probed.
371 * @id: Uclass ID to look up
372 * @devp: Returns pointer to the first device in that uclass, or NULL if there
374 * @return 0 if OK (found or not found), other -ve on error. If an error occurs
375 * it is still possible to move to the next device.
377 int uclass_first_device_check(enum uclass_id id, struct udevice **devp);
380 * uclass_next_device_check() - Get the next device in a uclass
382 * The device returned is probed if necessary, and ready for use
384 * This function is useful to start iterating through a list of devices which
385 * are functioning correctly and can be probed.
387 * @devp: On entry, pointer to device to lookup. On exit, returns pointer
388 * to the next device in the uclass if any
389 * @return 0 if OK (found or not found), other -ve on error. If an error occurs
390 * it is still possible to move to the next device.
392 int uclass_next_device_check(struct udevice **devp);
395 * uclass_first_device_drvdata() - Find the first device with given driver data
397 * This searches through the devices for a particular uclass looking for one
398 * that has the given driver data.
400 * @id: Uclass ID to check
401 * @driver_data: Driver data to search for
402 * @devp: Returns pointer to the first matching device in that uclass, if found
403 * @return 0 if found, -ENODEV if not found, other -ve on error
405 int uclass_first_device_drvdata(enum uclass_id id, ulong driver_data,
406 struct udevice **devp);
409 * uclass_probe_all() - Probe all devices based on an uclass ID
411 * This function probes all devices associated with a uclass by
412 * looking for its ID.
414 * @id: uclass ID to look up
415 * @return 0 if OK, other -ve on error
417 int uclass_probe_all(enum uclass_id id);
420 * uclass_id_foreach_dev() - Helper function to iteration through devices
422 * This creates a for() loop which works through the available devices in
423 * a uclass ID in order from start to end.
425 * If for some reason the uclass cannot be found, this does nothing.
427 * @id: enum uclass_id ID to use
428 * @pos: struct udevice * to hold the current device. Set to NULL when there
429 * are no more devices.
430 * @uc: temporary uclass variable (struct uclass *)
432 #define uclass_id_foreach_dev(id, pos, uc) \
433 if (!uclass_get(id, &uc)) \
434 list_for_each_entry(pos, &uc->dev_head, uclass_node)
437 * uclass_foreach_dev() - Helper function to iteration through devices
439 * This creates a for() loop which works through the available devices in
440 * a uclass in order from start to end.
442 * @pos: struct udevice * to hold the current device. Set to NULL when there
443 * are no more devices.
444 * @uc: uclass to scan
446 #define uclass_foreach_dev(pos, uc) \
447 list_for_each_entry(pos, &uc->dev_head, uclass_node)
450 * uclass_foreach_dev_safe() - Helper function to safely iteration through devs
452 * This creates a for() loop which works through the available devices in
453 * a uclass in order from start to end. Inside the loop, it is safe to remove
456 * @pos: struct udevice * to hold the current device. Set to NULL when there
457 * are no more devices.
458 * @next: struct udevice * to hold the next next
459 * @uc: uclass to scan
461 #define uclass_foreach_dev_safe(pos, next, uc) \
462 list_for_each_entry_safe(pos, next, &uc->dev_head, uclass_node)
465 * uclass_foreach_dev_probe() - Helper function to iteration through devices
468 * This creates a for() loop which works through the available devices in
469 * a uclass in order from start to end. Devices are probed if necessary,
473 * @dev: struct udevice * to hold the current device. Set to NULL when there
474 * are no more devices.
476 #define uclass_foreach_dev_probe(id, dev) \
477 for (int _ret = uclass_first_device_err(id, &dev); !_ret && dev; \
478 _ret = uclass_next_device_err(&dev))