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 /* Same as DM_FLAG_ALLOC_PRIV_DMA */
48 #define DM_UC_FLAG_ALLOC_PRIV_DMA (1 << 5)
51 * struct uclass_driver - Driver for the uclass
53 * A uclass_driver provides a consistent interface to a set of related
56 * @name: Name of uclass driver
57 * @id: ID number of this uclass
58 * @post_bind: Called after a new device is bound to this uclass
59 * @pre_unbind: Called before a device is unbound from this uclass
60 * @pre_probe: Called before a new device is probed
61 * @post_probe: Called after a new device is probed
62 * @pre_remove: Called before a device is removed
63 * @child_post_bind: Called after a child is bound to a device in this uclass
64 * @child_pre_probe: Called before a child is probed in this uclass
65 * @init: Called to set up the uclass
66 * @destroy: Called to destroy the uclass
67 * @priv_auto_alloc_size: If non-zero this is the size of the private data
68 * to be allocated in the uclass's ->priv pointer. If zero, then the uclass
69 * driver is responsible for allocating any data required.
70 * @per_device_auto_alloc_size: Each device can hold private data owned
71 * by the uclass. If required this will be automatically allocated if this
73 * @per_device_platdata_auto_alloc_size: Each device can hold platform data
74 * owned by the uclass as 'dev->uclass_platdata'. If the value is non-zero,
75 * then this will be automatically allocated.
76 * @per_child_auto_alloc_size: Each child device (of a parent in this
77 * uclass) can hold parent data for the device/uclass. This value is only
78 * used as a fallback if this member is 0 in the driver.
79 * @per_child_platdata_auto_alloc_size: A bus likes to store information about
80 * its children. If non-zero this is the size of this data, to be allocated
81 * in the child device's parent_platdata pointer. This value is only used as
82 * a fallback if this member is 0 in the driver.
83 * @ops: Uclass operations, providing the consistent interface to devices
85 * @flags: Flags for this uclass (DM_UC_...)
87 struct uclass_driver {
90 int (*post_bind)(struct udevice *dev);
91 int (*pre_unbind)(struct udevice *dev);
92 int (*pre_probe)(struct udevice *dev);
93 int (*post_probe)(struct udevice *dev);
94 int (*pre_remove)(struct udevice *dev);
95 int (*child_post_bind)(struct udevice *dev);
96 int (*child_pre_probe)(struct udevice *dev);
97 int (*init)(struct uclass *class);
98 int (*destroy)(struct uclass *class);
99 int priv_auto_alloc_size;
100 int per_device_auto_alloc_size;
101 int per_device_platdata_auto_alloc_size;
102 int per_child_auto_alloc_size;
103 int per_child_platdata_auto_alloc_size;
108 /* Declare a new uclass_driver */
109 #define UCLASS_DRIVER(__name) \
110 ll_entry_declare(struct uclass_driver, __name, uclass)
113 * uclass_get() - Get a uclass based on an ID, creating it if needed
115 * Every uclass is identified by an ID, a number from 0 to n-1 where n is
116 * the number of uclasses. This function allows looking up a uclass by its
119 * @key: ID to look up
120 * @ucp: Returns pointer to uclass (there is only one per ID)
121 * @return 0 if OK, -ve on error
123 int uclass_get(enum uclass_id key, struct uclass **ucp);
126 * uclass_get_name() - Get the name of a uclass driver
129 * @returns the name of the uclass driver for that ID, or NULL if none
131 const char *uclass_get_name(enum uclass_id id);
134 * uclass_get_by_name() - Look up a uclass by its driver name
136 * @name: Name to look up
137 * @returns the associated uclass ID, or UCLASS_INVALID if not found
139 enum uclass_id uclass_get_by_name(const char *name);
142 * uclass_get_device() - Get a uclass device based on an ID and index
144 * The device is probed to activate it ready for use.
147 * @index: Device number within that uclass (0=first)
148 * @devp: Returns pointer to device (there is only one per for each ID)
149 * @return 0 if OK, -ve on error
151 int uclass_get_device(enum uclass_id id, int index, struct udevice **devp);
154 * uclass_get_device_by_name() - Get a uclass device by its name
156 * This searches the devices in the uclass for one with the exactly given name.
158 * The device is probed to activate it ready for use.
161 * @name: name of a device to get
162 * @devp: Returns pointer to device (the first one with the name)
163 * @return 0 if OK, -ve on error
165 int uclass_get_device_by_name(enum uclass_id id, const char *name,
166 struct udevice **devp);
169 * uclass_get_device_by_seq() - Get a uclass device based on an ID and sequence
171 * If an active device has this sequence it will be returned. If there is no
172 * such device then this will check for a device that is requesting this
175 * The device is probed to activate it ready for use.
178 * @seq: Sequence number to find (0=first)
179 * @devp: Returns pointer to device (there is only one for each seq)
180 * @return 0 if OK, -ve on error
182 int uclass_get_device_by_seq(enum uclass_id id, int seq, struct udevice **devp);
185 * uclass_get_device_by_of_offset() - Get a uclass device by device tree node
187 * This searches the devices in the uclass for one attached to the given
190 * The device is probed to activate it ready for use.
193 * @node: Device tree offset to search for (if -ve then -ENODEV is returned)
194 * @devp: Returns pointer to device (there is only one for each node)
195 * @return 0 if OK, -ve on error
197 int uclass_get_device_by_of_offset(enum uclass_id id, int node,
198 struct udevice **devp);
201 * uclass_get_device_by_ofnode() - Get a uclass device by device tree node
203 * This searches the devices in the uclass for one attached to the given
206 * The device is probed to activate it ready for use.
209 * @np: Device tree node to search for (if NULL then -ENODEV is returned)
210 * @devp: Returns pointer to device (there is only one for each node)
211 * @return 0 if OK, -ve on error
213 int uclass_get_device_by_ofnode(enum uclass_id id, ofnode node,
214 struct udevice **devp);
217 * uclass_get_device_by_phandle_id() - Get a uclass device by phandle id
219 * This searches the devices in the uclass for one with the given phandle id.
221 * The device is probed to activate it ready for use.
223 * @id: uclass ID to look up
224 * @phandle_id: the phandle id to look up
225 * @devp: Returns pointer to device (there is only one for each node)
226 * @return 0 if OK, -ENODEV if there is no device match the phandle, other
229 int uclass_get_device_by_phandle_id(enum uclass_id id, uint phandle_id,
230 struct udevice **devp);
233 * uclass_get_device_by_phandle() - Get a uclass device by phandle
235 * This searches the devices in the uclass for one with the given phandle.
237 * The device is probed to activate it ready for use.
239 * @id: uclass ID to look up
240 * @parent: Parent device containing the phandle pointer
241 * @name: Name of property in the parent device node
242 * @devp: Returns pointer to device (there is only one for each node)
243 * @return 0 if OK, -ENOENT if there is no @name present in the node, other
246 int uclass_get_device_by_phandle(enum uclass_id id, struct udevice *parent,
247 const char *name, struct udevice **devp);
250 * uclass_get_device_by_driver() - Get a uclass device for a driver
252 * This searches the devices in the uclass for one that uses the given
253 * driver. Use DM_GET_DRIVER(name) for the @drv argument, where 'name' is
254 * the driver name - as used in U_BOOT_DRIVER(name).
256 * The device is probed to activate it ready for use.
259 * @drv: Driver to look for
260 * @devp: Returns pointer to the first device with that driver
261 * @return 0 if OK, -ve on error
263 int uclass_get_device_by_driver(enum uclass_id id, const struct driver *drv,
264 struct udevice **devp);
267 * uclass_first_device() - Get the first device in a uclass
269 * The device returned is probed if necessary, and ready for use
271 * This function is useful to start iterating through a list of devices which
272 * are functioning correctly and can be probed.
274 * @id: Uclass ID to look up
275 * @devp: Returns pointer to the first device in that uclass if no error
276 * occurred, or NULL if there is no first device, or an error occurred with
278 * @return 0 if OK (found or not found), other -ve on error
280 int uclass_first_device(enum uclass_id id, struct udevice **devp);
283 * uclass_first_device_err() - Get the first device in a uclass
285 * The device returned is probed if necessary, and ready for use
287 * @id: Uclass ID to look up
288 * @devp: Returns pointer to the first device in that uclass, or NULL if none
289 * @return 0 if found, -ENODEV if not found, other -ve on error
291 int uclass_first_device_err(enum uclass_id id, struct udevice **devp);
294 * uclass_next_device() - Get the next device in a uclass
296 * The device returned is probed if necessary, and ready for use
298 * This function is useful to start iterating through a list of devices which
299 * are functioning correctly and can be probed.
301 * @devp: On entry, pointer to device to lookup. On exit, returns pointer
302 * to the next device in the uclass if no error occurred, or NULL if there is
303 * no next device, or an error occurred with that next device.
304 * @return 0 if OK (found or not found), other -ve on error
306 int uclass_next_device(struct udevice **devp);
309 * uclass_first_device_check() - Get the first device in a uclass
311 * The device returned is probed if necessary, and ready for use
313 * This function is useful to start iterating through a list of devices which
314 * are functioning correctly and can be probed.
316 * @id: Uclass ID to look up
317 * @devp: Returns pointer to the first device in that uclass, or NULL if there
319 * @return 0 if OK (found or not found), other -ve on error. If an error occurs
320 * it is still possible to move to the next device.
322 int uclass_first_device_check(enum uclass_id id, struct udevice **devp);
325 * uclass_next_device_check() - Get the next device in a uclass
327 * The device returned is probed if necessary, and ready for use
329 * This function is useful to start iterating through a list of devices which
330 * are functioning correctly and can be probed.
332 * @devp: On entry, pointer to device to lookup. On exit, returns pointer
333 * to the next device in the uclass if any
334 * @return 0 if OK (found or not found), other -ve on error. If an error occurs
335 * it is still possible to move to the next device.
337 int uclass_next_device_check(struct udevice **devp);
340 * uclass_resolve_seq() - Resolve a device's sequence number
342 * On entry dev->seq is -1, and dev->req_seq may be -1 (to allocate a
343 * sequence number automatically, or >= 0 to select a particular number.
344 * If the requested sequence number is in use, then this device will
345 * be allocated another one.
347 * Note that the device's seq value is not changed by this function.
349 * @dev: Device for which to allocate sequence number
350 * @return sequence number allocated, or -ve on error
352 int uclass_resolve_seq(struct udevice *dev);
355 * uclass_foreach_dev() - Helper function to iteration through devices
357 * This creates a for() loop which works through the available devices in
358 * a uclass in order from start to end.
360 * @pos: struct udevice * to hold the current device. Set to NULL when there
361 * are no more devices.
362 * @uc: uclass to scan
364 #define uclass_foreach_dev(pos, uc) \
365 list_for_each_entry(pos, &uc->dev_head, uclass_node)
368 * uclass_foreach_dev_safe() - Helper function to safely iteration through devs
370 * This creates a for() loop which works through the available devices in
371 * a uclass in order from start to end. Inside the loop, it is safe to remove
374 * @pos: struct udevice * to hold the current device. Set to NULL when there
375 * are no more devices.
376 * @next: struct udevice * to hold the next next
377 * @uc: uclass to scan
379 #define uclass_foreach_dev_safe(pos, next, uc) \
380 list_for_each_entry_safe(pos, next, &uc->dev_head, uclass_node)