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)
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 * @ops: Uclass operations, providing the consistent interface to devices
89 * @flags: Flags for this uclass (DM_UC_...)
91 struct uclass_driver {
94 int (*post_bind)(struct udevice *dev);
95 int (*pre_unbind)(struct udevice *dev);
96 int (*pre_probe)(struct udevice *dev);
97 int (*post_probe)(struct udevice *dev);
98 int (*pre_remove)(struct udevice *dev);
99 int (*child_post_bind)(struct udevice *dev);
100 int (*child_pre_probe)(struct udevice *dev);
101 int (*child_post_probe)(struct udevice *dev);
102 int (*init)(struct uclass *class);
103 int (*destroy)(struct uclass *class);
106 int per_device_plat_auto;
108 int per_child_plat_auto;
113 /* Declare a new uclass_driver */
114 #define UCLASS_DRIVER(__name) \
115 ll_entry_declare(struct uclass_driver, __name, uclass)
118 * uclass_get() - Get a uclass based on an ID, creating it if needed
120 * Every uclass is identified by an ID, a number from 0 to n-1 where n is
121 * the number of uclasses. This function allows looking up a uclass by its
124 * @key: ID to look up
125 * @ucp: Returns pointer to uclass (there is only one per ID)
126 * @return 0 if OK, -ve on error
128 int uclass_get(enum uclass_id key, struct uclass **ucp);
131 * uclass_get_name() - Get the name of a uclass driver
134 * @returns the name of the uclass driver for that ID, or NULL if none
136 const char *uclass_get_name(enum uclass_id id);
139 * uclass_get_by_name() - Look up a uclass by its driver name
141 * @name: Name to look up
142 * @returns the associated uclass ID, or UCLASS_INVALID if not found
144 enum uclass_id uclass_get_by_name(const char *name);
147 * uclass_get_device() - Get a uclass device based on an ID and index
149 * The device is probed to activate it ready for use.
152 * @index: Device number within that uclass (0=first)
153 * @devp: Returns pointer to device (there is only one per for each ID)
154 * @return 0 if OK, -ve on error
156 int uclass_get_device(enum uclass_id id, int index, struct udevice **devp);
159 * uclass_get_device_by_name() - Get a uclass device by its name
161 * This searches the devices in the uclass for one with the exactly given name.
163 * The device is probed to activate it ready for use.
166 * @name: name of a device to get
167 * @devp: Returns pointer to device (the first one with the name)
168 * @return 0 if OK, -ve on error
170 int uclass_get_device_by_name(enum uclass_id id, const char *name,
171 struct udevice **devp);
174 * uclass_get_device_by_seq() - Get a uclass device based on an ID and sequence
176 * If an active device has this sequence it will be returned. If there is no
177 * such device then this will check for a device that is requesting this
180 * The device is probed to activate it ready for use.
183 * @seq: Sequence number to find (0=first)
184 * @devp: Returns pointer to device (there is only one for each seq)
185 * @return 0 if OK, -ve on error
187 int uclass_get_device_by_seq(enum uclass_id id, int seq, struct udevice **devp);
190 * uclass_get_device_by_of_offset() - Get a uclass device by device tree node
192 * This searches the devices in the uclass for one attached to the given
195 * The device is probed to activate it ready for use.
198 * @node: Device tree offset to search for (if -ve then -ENODEV is returned)
199 * @devp: Returns pointer to device (there is only one for each node)
200 * @return 0 if OK, -ve on error
202 int uclass_get_device_by_of_offset(enum uclass_id id, int node,
203 struct udevice **devp);
206 * uclass_get_device_by_ofnode() - Get a uclass device by device tree node
208 * This searches the devices in the uclass for one attached to the given
211 * The device is probed to activate it ready for use.
214 * @np: Device tree node to search for (if NULL then -ENODEV is returned)
215 * @devp: Returns pointer to device (there is only one for each node)
216 * @return 0 if OK, -ve on error
218 int uclass_get_device_by_ofnode(enum uclass_id id, ofnode node,
219 struct udevice **devp);
222 * uclass_get_device_by_phandle_id() - Get a uclass device by phandle id
224 * This searches the devices in the uclass for one with the given phandle id.
226 * The device is probed to activate it ready for use.
228 * @id: uclass ID to look up
229 * @phandle_id: the phandle id to look up
230 * @devp: Returns pointer to device (there is only one for each node). NULL if
231 * there is no such device.
232 * @return 0 if OK, -ENODEV if there is no device match the phandle, other
235 int uclass_get_device_by_phandle_id(enum uclass_id id, uint phandle_id,
236 struct udevice **devp);
239 * uclass_get_device_by_phandle() - Get a uclass device by phandle
241 * This searches the devices in the uclass for one with the given phandle.
243 * The device is probed to activate it ready for use.
245 * @id: uclass ID to look up
246 * @parent: Parent device containing the phandle pointer
247 * @name: Name of property in the parent device node
248 * @devp: Returns pointer to device (there is only one for each node)
249 * @return 0 if OK, -ENOENT if there is no @name present in the node, other
252 int uclass_get_device_by_phandle(enum uclass_id id, struct udevice *parent,
253 const char *name, struct udevice **devp);
256 * uclass_get_device_by_driver() - Get a uclass device for a driver
258 * This searches the devices in the uclass for one that uses the given
259 * driver. Use DM_GET_DRIVER(name) for the @drv argument, where 'name' is
260 * the driver name - as used in U_BOOT_DRIVER(name).
262 * The device is probed to activate it ready for use.
265 * @drv: Driver to look for
266 * @devp: Returns pointer to the first device with that driver
267 * @return 0 if OK, -ve on error
269 int uclass_get_device_by_driver(enum uclass_id id, const struct driver *drv,
270 struct udevice **devp);
273 * uclass_first_device() - Get the first device in a uclass
275 * The device returned is probed if necessary, and ready for use
277 * This function is useful to start iterating through a list of devices which
278 * are functioning correctly and can be probed.
280 * @id: Uclass ID to look up
281 * @devp: Returns pointer to the first device in that uclass if no error
282 * occurred, or NULL if there is no first device, or an error occurred with
284 * @return 0 if OK (found or not found), other -ve on error
286 int uclass_first_device(enum uclass_id id, struct udevice **devp);
289 * uclass_first_device_err() - Get the first device in a uclass
291 * The device returned is probed if necessary, and ready for use
293 * @id: Uclass ID to look up
294 * @devp: Returns pointer to the first device in that uclass, or NULL if none
295 * @return 0 if found, -ENODEV if not found, other -ve on error
297 int uclass_first_device_err(enum uclass_id id, struct udevice **devp);
300 * uclass_next_device() - Get the next device in a uclass
302 * The device returned is probed if necessary, and ready for use
304 * This function is useful to iterate through a list of devices which
305 * are functioning correctly and can be probed.
307 * @devp: On entry, pointer to device to lookup. On exit, returns pointer
308 * to the next device in the uclass if no error occurred, or NULL if there is
309 * no next device, or an error occurred with that next device.
310 * @return 0 if OK (found or not found), other -ve on error
312 int uclass_next_device(struct udevice **devp);
315 * uclass_next_device_err() - Get the next device in a uclass
317 * The device returned is probed if necessary, and ready for use
319 * @devp: On entry, pointer to device to lookup. On exit, returns pointer
320 * to the next device in the uclass if no error occurred, or -ENODEV if
321 * there is no next device.
322 * @return 0 if found, -ENODEV if not found, other -ve on error
324 int uclass_next_device_err(struct udevice **devp);
327 * uclass_first_device_check() - Get the first device in a uclass
329 * The device returned is probed if necessary, and ready for use
331 * This function is useful to start iterating through a list of devices which
332 * are functioning correctly and can be probed.
334 * @id: Uclass ID to look up
335 * @devp: Returns pointer to the first device in that uclass, or NULL if there
337 * @return 0 if OK (found or not found), other -ve on error. If an error occurs
338 * it is still possible to move to the next device.
340 int uclass_first_device_check(enum uclass_id id, struct udevice **devp);
343 * uclass_next_device_check() - Get the next device in a uclass
345 * The device returned is probed if necessary, and ready for use
347 * This function is useful to start iterating through a list of devices which
348 * are functioning correctly and can be probed.
350 * @devp: On entry, pointer to device to lookup. On exit, returns pointer
351 * to the next device in the uclass if any
352 * @return 0 if OK (found or not found), other -ve on error. If an error occurs
353 * it is still possible to move to the next device.
355 int uclass_next_device_check(struct udevice **devp);
358 * uclass_first_device_drvdata() - Find the first device with given driver data
360 * This searches through the devices for a particular uclass looking for one
361 * that has the given driver data.
363 * @id: Uclass ID to check
364 * @driver_data: Driver data to search for
365 * @devp: Returns pointer to the first matching device in that uclass, if found
366 * @return 0 if found, -ENODEV if not found, other -ve on error
368 int uclass_first_device_drvdata(enum uclass_id id, ulong driver_data,
369 struct udevice **devp);
372 * uclass_id_foreach_dev() - Helper function to iteration through devices
374 * This creates a for() loop which works through the available devices in
375 * a uclass ID in order from start to end.
377 * If for some reason the uclass cannot be found, this does nothing.
379 * @id: enum uclass_id ID to use
380 * @pos: struct udevice * to hold the current device. Set to NULL when there
381 * are no more devices.
382 * @uc: temporary uclass variable (struct uclass *)
384 #define uclass_id_foreach_dev(id, pos, uc) \
385 if (!uclass_get(id, &uc)) \
386 list_for_each_entry(pos, &uc->dev_head, uclass_node)
389 * uclass_foreach_dev() - Helper function to iteration through devices
391 * This creates a for() loop which works through the available devices in
392 * a uclass in order from start to end.
394 * @pos: struct udevice * to hold the current device. Set to NULL when there
395 * are no more devices.
396 * @uc: uclass to scan
398 #define uclass_foreach_dev(pos, uc) \
399 list_for_each_entry(pos, &uc->dev_head, uclass_node)
402 * uclass_foreach_dev_safe() - Helper function to safely iteration through devs
404 * This creates a for() loop which works through the available devices in
405 * a uclass in order from start to end. Inside the loop, it is safe to remove
408 * @pos: struct udevice * to hold the current device. Set to NULL when there
409 * are no more devices.
410 * @next: struct udevice * to hold the next next
411 * @uc: uclass to scan
413 #define uclass_foreach_dev_safe(pos, next, uc) \
414 list_for_each_entry_safe(pos, next, &uc->dev_head, uclass_node)
417 * uclass_foreach_dev_probe() - Helper function to iteration through devices
420 * This creates a for() loop which works through the available devices in
421 * a uclass in order from start to end. Devices are probed if necessary,
425 * @dev: struct udevice * to hold the current device. Set to NULL when there
426 * are no more devices.
428 #define uclass_foreach_dev_probe(id, dev) \
429 for (int _ret = uclass_first_device_err(id, &dev); !_ret && dev; \
430 _ret = uclass_next_device_err(&dev))