xref: /openbmc/u-boot/include/dm/uclass.h (revision 6bfe3fff)
1 /* SPDX-License-Identifier: GPL-2.0+ */
2 /*
3  * Copyright (c) 2013 Google, Inc
4  *
5  * (C) Copyright 2012
6  * Pavel Herrmann <morpheus.ibis@gmail.com>
7  */
8 
9 #ifndef _DM_UCLASS_H
10 #define _DM_UCLASS_H
11 
12 #include <dm/ofnode.h>
13 #include <dm/uclass-id.h>
14 #include <linker_lists.h>
15 #include <linux/list.h>
16 
17 /**
18  * struct uclass - a U-Boot drive class, collecting together similar drivers
19  *
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.
26  *
27  * @priv: Private data for this uclass
28  * @uc_drv: The driver for the uclass itself, not to be confused with a
29  * 'struct driver'
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
33  */
34 struct uclass {
35 	void *priv;
36 	struct uclass_driver *uc_drv;
37 	struct list_head dev_head;
38 	struct list_head sibling_node;
39 };
40 
41 struct driver;
42 struct udevice;
43 
44 /* Members of this uclass sequence themselves with aliases */
45 #define DM_UC_FLAG_SEQ_ALIAS			(1 << 0)
46 
47 /* Same as DM_FLAG_ALLOC_PRIV_DMA */
48 #define DM_UC_FLAG_ALLOC_PRIV_DMA		(1 << 5)
49 
50 /**
51  * struct uclass_driver - Driver for the uclass
52  *
53  * A uclass_driver provides a consistent interface to a set of related
54  * drivers.
55  *
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
72  * value is non-zero.
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
84  * within the uclass.
85  * @flags: Flags for this uclass (DM_UC_...)
86  */
87 struct uclass_driver {
88 	const char *name;
89 	enum uclass_id id;
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;
104 	const void *ops;
105 	uint32_t flags;
106 };
107 
108 /* Declare a new uclass_driver */
109 #define UCLASS_DRIVER(__name)						\
110 	ll_entry_declare(struct uclass_driver, __name, uclass)
111 
112 /**
113  * uclass_get() - Get a uclass based on an ID, creating it if needed
114  *
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
117  * ID.
118  *
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
122  */
123 int uclass_get(enum uclass_id key, struct uclass **ucp);
124 
125 /**
126  * uclass_get_name() - Get the name of a uclass driver
127  *
128  * @id: ID to look up
129  * @returns the name of the uclass driver for that ID, or NULL if none
130  */
131 const char *uclass_get_name(enum uclass_id id);
132 
133 /**
134  * uclass_get_by_name() - Look up a uclass by its driver name
135  *
136  * @name: Name to look up
137  * @returns the associated uclass ID, or UCLASS_INVALID if not found
138  */
139 enum uclass_id uclass_get_by_name(const char *name);
140 
141 /**
142  * uclass_get_device() - Get a uclass device based on an ID and index
143  *
144  * The device is probed to activate it ready for use.
145  *
146  * @id: ID to look up
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
150  */
151 int uclass_get_device(enum uclass_id id, int index, struct udevice **devp);
152 
153 /**
154  * uclass_get_device_by_name() - Get a uclass device by its name
155  *
156  * This searches the devices in the uclass for one with the exactly given name.
157  *
158  * The device is probed to activate it ready for use.
159  *
160  * @id: ID to look up
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
164  */
165 int uclass_get_device_by_name(enum uclass_id id, const char *name,
166 			      struct udevice **devp);
167 
168 /**
169  * uclass_get_device_by_seq() - Get a uclass device based on an ID and sequence
170  *
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
173  * sequence.
174  *
175  * The device is probed to activate it ready for use.
176  *
177  * @id: ID to look up
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
181  */
182 int uclass_get_device_by_seq(enum uclass_id id, int seq, struct udevice **devp);
183 
184 /**
185  * uclass_get_device_by_of_offset() - Get a uclass device by device tree node
186  *
187  * This searches the devices in the uclass for one attached to the given
188  * device tree node.
189  *
190  * The device is probed to activate it ready for use.
191  *
192  * @id: ID to look up
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
196  */
197 int uclass_get_device_by_of_offset(enum uclass_id id, int node,
198 				   struct udevice **devp);
199 
200 /**
201  * uclass_get_device_by_ofnode() - Get a uclass device by device tree node
202  *
203  * This searches the devices in the uclass for one attached to the given
204  * device tree node.
205  *
206  * The device is probed to activate it ready for use.
207  *
208  * @id: ID to look up
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
212  */
213 int uclass_get_device_by_ofnode(enum uclass_id id, ofnode node,
214 				struct udevice **devp);
215 
216 /**
217  * uclass_get_device_by_phandle_id() - Get a uclass device by phandle id
218  *
219  * This searches the devices in the uclass for one with the given phandle id.
220  *
221  * The device is probed to activate it ready for use.
222  *
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
227  *	-ve on error
228  */
229 int uclass_get_device_by_phandle_id(enum uclass_id id, uint phandle_id,
230 				    struct udevice **devp);
231 
232 /**
233  * uclass_get_device_by_phandle() - Get a uclass device by phandle
234  *
235  * This searches the devices in the uclass for one with the given phandle.
236  *
237  * The device is probed to activate it ready for use.
238  *
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
244  *	-ve on error
245  */
246 int uclass_get_device_by_phandle(enum uclass_id id, struct udevice *parent,
247 				 const char *name, struct udevice **devp);
248 
249 /**
250  * uclass_get_device_by_driver() - Get a uclass device for a driver
251  *
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).
255  *
256  * The device is probed to activate it ready for use.
257  *
258  * @id: ID to look up
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
262  */
263 int uclass_get_device_by_driver(enum uclass_id id, const struct driver *drv,
264 				struct udevice **devp);
265 
266 /**
267  * uclass_first_device() - Get the first device in a uclass
268  *
269  * The device returned is probed if necessary, and ready for use
270  *
271  * This function is useful to start iterating through a list of devices which
272  * are functioning correctly and can be probed.
273  *
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
277  * that device.
278  * @return 0 if OK (found or not found), other -ve on error
279  */
280 int uclass_first_device(enum uclass_id id, struct udevice **devp);
281 
282 /**
283  * uclass_first_device_err() - Get the first device in a uclass
284  *
285  * The device returned is probed if necessary, and ready for use
286  *
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
290  */
291 int uclass_first_device_err(enum uclass_id id, struct udevice **devp);
292 
293 /**
294  * uclass_next_device() - Get the next device in a uclass
295  *
296  * The device returned is probed if necessary, and ready for use
297  *
298  * This function is useful to start iterating through a list of devices which
299  * are functioning correctly and can be probed.
300  *
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
305  */
306 int uclass_next_device(struct udevice **devp);
307 
308 /**
309  * uclass_first_device_check() - Get the first device in a uclass
310  *
311  * The device returned is probed if necessary, and ready for use
312  *
313  * This function is useful to start iterating through a list of devices which
314  * are functioning correctly and can be probed.
315  *
316  * @id: Uclass ID to look up
317  * @devp: Returns pointer to the first device in that uclass, or NULL if there
318  * is no first device
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.
321  */
322 int uclass_first_device_check(enum uclass_id id, struct udevice **devp);
323 
324 /**
325  * uclass_next_device_check() - Get the next device in a uclass
326  *
327  * The device returned is probed if necessary, and ready for use
328  *
329  * This function is useful to start iterating through a list of devices which
330  * are functioning correctly and can be probed.
331  *
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.
336  */
337 int uclass_next_device_check(struct udevice **devp);
338 
339 /**
340  * uclass_resolve_seq() - Resolve a device's sequence number
341  *
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.
346  *
347  * Note that the device's seq value is not changed by this function.
348  *
349  * @dev: Device for which to allocate sequence number
350  * @return sequence number allocated, or -ve on error
351  */
352 int uclass_resolve_seq(struct udevice *dev);
353 
354 /**
355  * uclass_foreach_dev() - Helper function to iteration through devices
356  *
357  * This creates a for() loop which works through the available devices in
358  * a uclass in order from start to end.
359  *
360  * @pos: struct udevice * to hold the current device. Set to NULL when there
361  * are no more devices.
362  * @uc: uclass to scan
363  */
364 #define uclass_foreach_dev(pos, uc)	\
365 	list_for_each_entry(pos, &uc->dev_head, uclass_node)
366 
367 /**
368  * uclass_foreach_dev_safe() - Helper function to safely iteration through devs
369  *
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
372  * @pos if required.
373  *
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
378  */
379 #define uclass_foreach_dev_safe(pos, next, uc)	\
380 	list_for_each_entry_safe(pos, next, &uc->dev_head, uclass_node)
381 
382 #endif
383