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 * Marek Vasut <marex@denx.de>
8 */
9
10 #ifndef _DM_DEVICE_H
11 #define _DM_DEVICE_H
12
13 #include <dm/ofnode.h>
14 #include <dm/uclass-id.h>
15 #include <fdtdec.h>
16 #include <linker_lists.h>
17 #include <linux/kernel.h>
18 #include <linux/list.h>
19 #include <linux/printk.h>
20
21 struct driver_info;
22
23 /* Driver is active (probed). Cleared when it is removed */
24 #define DM_FLAG_ACTIVATED (1 << 0)
25
26 /* DM is responsible for allocating and freeing plat */
27 #define DM_FLAG_ALLOC_PDATA (1 << 1)
28
29 /* DM should init this device prior to relocation */
30 #define DM_FLAG_PRE_RELOC (1 << 2)
31
32 /* DM is responsible for allocating and freeing parent_plat */
33 #define DM_FLAG_ALLOC_PARENT_PDATA (1 << 3)
34
35 /* DM is responsible for allocating and freeing uclass_plat */
36 #define DM_FLAG_ALLOC_UCLASS_PDATA (1 << 4)
37
38 /* Allocate driver private data on a DMA boundary */
39 #define DM_FLAG_ALLOC_PRIV_DMA (1 << 5)
40
41 /* Device is bound */
42 #define DM_FLAG_BOUND (1 << 6)
43
44 /* Device name is allocated and should be freed on unbind() */
45 #define DM_FLAG_NAME_ALLOCED (1 << 7)
46
47 /* Device has platform data provided by of-platdata */
48 #define DM_FLAG_OF_PLATDATA (1 << 8)
49
50 /*
51 * Call driver remove function to stop currently active DMA transfers or
52 * give DMA buffers back to the HW / controller. This may be needed for
53 * some drivers to do some final stage cleanup before the OS is called
54 * (U-Boot exit)
55 */
56 #define DM_FLAG_ACTIVE_DMA (1 << 9)
57
58 /*
59 * Call driver remove function to do some final configuration, before
60 * U-Boot exits and the OS is started
61 */
62 #define DM_FLAG_OS_PREPARE (1 << 10)
63
64 /* DM does not enable/disable the power domains corresponding to this device */
65 #define DM_FLAG_DEFAULT_PD_CTRL_OFF (1 << 11)
66
67 /* Driver plat has been read. Cleared when the device is removed */
68 #define DM_FLAG_PLATDATA_VALID (1 << 12)
69
70 /*
71 * Device is removed without switching off its power domain. This might
72 * be required, i. e. for serial console (debug) output when booting OS.
73 */
74 #define DM_FLAG_LEAVE_PD_ON (1 << 13)
75
76 /*
77 * Device is vital to the operation of other devices. It is possible to remove
78 * removed this device after all regular devices are removed. This is useful
79 * e.g. for clock, which need to be active during the device-removal phase.
80 */
81 #define DM_FLAG_VITAL (1 << 14)
82
83 /*
84 * One or multiple of these flags are passed to device_remove() so that
85 * a selective device removal as specified by the remove-stage and the
86 * driver flags can be done.
87 *
88 * DO NOT use these flags in your driver's @flags value...
89 * use the above DM_FLAG_... values instead
90 */
91 enum {
92 /* Normal remove, remove all devices */
93 DM_REMOVE_NORMAL = 1 << 0,
94
95 /* Remove devices with active DMA */
96 DM_REMOVE_ACTIVE_DMA = DM_FLAG_ACTIVE_DMA,
97
98 /* Remove devices which need some final OS preparation steps */
99 DM_REMOVE_OS_PREPARE = DM_FLAG_OS_PREPARE,
100
101 /* Remove only devices that are not marked vital */
102 DM_REMOVE_NON_VITAL = DM_FLAG_VITAL,
103
104 /* Remove devices with any active flag */
105 DM_REMOVE_ACTIVE_ALL = DM_REMOVE_ACTIVE_DMA | DM_REMOVE_OS_PREPARE,
106
107 /* Don't power down any attached power domains */
108 DM_REMOVE_NO_PD = 1 << 1,
109 };
110
111 /**
112 * struct udevice - An instance of a driver
113 *
114 * This holds information about a device, which is a driver bound to a
115 * particular port or peripheral (essentially a driver instance).
116 *
117 * A device will come into existence through a 'bind' call, either due to
118 * a U_BOOT_DRVINFO() macro (in which case plat is non-NULL) or a node
119 * in the device tree (in which case of_offset is >= 0). In the latter case
120 * we translate the device tree information into plat in a function
121 * implemented by the driver of_to_plat method (called just before the
122 * probe method if the device has a device tree node.
123 *
124 * All three of plat, priv and uclass_priv can be allocated by the
125 * driver, or you can use the auto members of struct driver and
126 * struct uclass_driver to have driver model do this automatically.
127 *
128 * @driver: The driver used by this device
129 * @name: Name of device, typically the FDT node name
130 * @plat_: Configuration data for this device (do not access outside driver
131 * model)
132 * @parent_plat_: The parent bus's configuration data for this device (do not
133 * access outside driver model)
134 * @uclass_plat_: The uclass's configuration data for this device (do not access
135 * outside driver model)
136 * @driver_data: Driver data word for the entry that matched this device with
137 * its driver
138 * @parent: Parent of this device, or NULL for the top level device
139 * @priv_: Private data for this device (do not access outside driver model)
140 * @uclass: Pointer to uclass for this device
141 * @uclass_priv_: The uclass's private data for this device (do not access
142 * outside driver model)
143 * @parent_priv_: The parent's private data for this device (do not access
144 * outside driver model)
145 * @uclass_node: Used by uclass to link its devices
146 * @child_head: List of children of this device
147 * @sibling_node: Next device in list of all devices
148 * @flags_: Flags for this device DM_FLAG_... (do not access outside driver
149 * model)
150 * @seq_: Allocated sequence number for this device (-1 = none). This is set up
151 * when the device is bound and is unique within the device's uclass. If the
152 * device has an alias in the devicetree then that is used to set the sequence
153 * number. Otherwise, the next available number is used. Sequence numbers are
154 * used by certain commands that need device to be numbered (e.g. 'mmc dev').
155 * (do not access outside driver model)
156 * @node_: Reference to device tree node for this device (do not access outside
157 * driver model)
158 * @devres_head: List of memory allocations associated with this device.
159 * When CONFIG_DEVRES is enabled, devm_kmalloc() and friends will
160 * add to this list. Memory so-allocated will be freed
161 * automatically when the device is removed / unbound
162 * @dma_offset: Offset between the physical address space (CPU's) and the
163 * device's bus address space
164 */
165 struct udevice {
166 const struct driver *driver;
167 const char *name;
168 void *plat_;
169 void *parent_plat_;
170 void *uclass_plat_;
171 ulong driver_data;
172 struct udevice *parent;
173 void *priv_;
174 struct uclass *uclass;
175 void *uclass_priv_;
176 void *parent_priv_;
177 struct list_head uclass_node;
178 struct list_head child_head;
179 struct list_head sibling_node;
180 u32 flags_;
181 int seq_;
182 #if !CONFIG_IS_ENABLED(OF_PLATDATA)
183 ofnode node_;
184 #endif
185 #ifdef CONFIG_DEVRES
186 struct list_head devres_head;
187 #endif
188 #if CONFIG_IS_ENABLED(DM_DMA)
189 ulong dma_offset;
190 #endif
191 };
192
193 /* Maximum sequence number supported */
194 #define DM_MAX_SEQ 999
195
196 /* Returns the operations for a device */
197 #define device_get_ops(dev) (dev->driver->ops)
198
dev_get_flags(const struct udevice * dev)199 static inline u32 dev_get_flags(const struct udevice *dev)
200 {
201 return dev->flags_;
202 }
203
dev_or_flags(struct udevice * dev,u32 or)204 static inline void dev_or_flags(struct udevice *dev, u32 or)
205 {
206 dev->flags_ |= or;
207 }
208
dev_bic_flags(struct udevice * dev,u32 bic)209 static inline void dev_bic_flags(struct udevice *dev, u32 bic)
210 {
211 dev->flags_ &= ~bic;
212 }
213
214 /**
215 * dev_ofnode() - get the DT node reference associated with a udevice
216 *
217 * @dev: device to check
218 * @return reference of the the device's DT node
219 */
dev_ofnode(const struct udevice * dev)220 static inline ofnode dev_ofnode(const struct udevice *dev)
221 {
222 #if !CONFIG_IS_ENABLED(OF_PLATDATA)
223 return dev->node_;
224 #else
225 return ofnode_null();
226 #endif
227 }
228
229 /* Returns non-zero if the device is active (probed and not removed) */
230 #define device_active(dev) (dev_get_flags(dev) & DM_FLAG_ACTIVATED)
231
232 #if CONFIG_IS_ENABLED(DM_DMA)
233 #define dev_set_dma_offset(_dev, _offset) _dev->dma_offset = _offset
234 #define dev_get_dma_offset(_dev) _dev->dma_offset
235 #else
236 #define dev_set_dma_offset(_dev, _offset)
237 #define dev_get_dma_offset(_dev) 0
238 #endif
239
dev_of_offset(const struct udevice * dev)240 static inline int dev_of_offset(const struct udevice *dev)
241 {
242 #if !CONFIG_IS_ENABLED(OF_PLATDATA)
243 return ofnode_to_offset(dev_ofnode(dev));
244 #else
245 return -1;
246 #endif
247 }
248
dev_has_ofnode(const struct udevice * dev)249 static inline bool dev_has_ofnode(const struct udevice *dev)
250 {
251 #if !CONFIG_IS_ENABLED(OF_PLATDATA)
252 return ofnode_valid(dev_ofnode(dev));
253 #else
254 return false;
255 #endif
256 }
257
dev_set_ofnode(struct udevice * dev,ofnode node)258 static inline void dev_set_ofnode(struct udevice *dev, ofnode node)
259 {
260 #if !CONFIG_IS_ENABLED(OF_PLATDATA)
261 dev->node_ = node;
262 #endif
263 }
264
dev_seq(const struct udevice * dev)265 static inline int dev_seq(const struct udevice *dev)
266 {
267 return dev->seq_;
268 }
269
270 /**
271 * struct udevice_id - Lists the compatible strings supported by a driver
272 * @compatible: Compatible string
273 * @data: Data for this compatible string
274 */
275 struct udevice_id {
276 const char *compatible;
277 ulong data;
278 };
279
280 #if CONFIG_IS_ENABLED(OF_CONTROL) && !CONFIG_IS_ENABLED(OF_PLATDATA)
281 #define of_match_ptr(_ptr) (_ptr)
282 #else
283 #define of_match_ptr(_ptr) NULL
284 #endif /* CONFIG_IS_ENABLED(OF_CONTROL) */
285
286 /**
287 * struct driver - A driver for a feature or peripheral
288 *
289 * This holds methods for setting up a new device, and also removing it.
290 * The device needs information to set itself up - this is provided either
291 * by plat or a device tree node (which we find by looking up
292 * matching compatible strings with of_match).
293 *
294 * Drivers all belong to a uclass, representing a class of devices of the
295 * same type. Common elements of the drivers can be implemented in the uclass,
296 * or the uclass can provide a consistent interface to the drivers within
297 * it.
298 *
299 * @name: Device name
300 * @id: Identifies the uclass we belong to
301 * @of_match: List of compatible strings to match, and any identifying data
302 * for each.
303 * @bind: Called to bind a device to its driver
304 * @probe: Called to probe a device, i.e. activate it
305 * @remove: Called to remove a device, i.e. de-activate it
306 * @unbind: Called to unbind a device from its driver
307 * @of_to_plat: Called before probe to decode device tree data
308 * @child_post_bind: Called after a new child has been bound
309 * @child_pre_probe: Called before a child device is probed. The device has
310 * memory allocated but it has not yet been probed.
311 * @child_post_remove: Called after a child device is removed. The device
312 * has memory allocated but its device_remove() method has been called.
313 * @priv_auto: If non-zero this is the size of the private data
314 * to be allocated in the device's ->priv pointer. If zero, then the driver
315 * is responsible for allocating any data required.
316 * @plat_auto: If non-zero this is the size of the
317 * platform data to be allocated in the device's ->plat pointer.
318 * This is typically only useful for device-tree-aware drivers (those with
319 * an of_match), since drivers which use plat will have the data
320 * provided in the U_BOOT_DRVINFO() instantiation.
321 * @per_child_auto: Each device can hold private data owned by
322 * its parent. If required this will be automatically allocated if this
323 * value is non-zero.
324 * @per_child_plat_auto: A bus likes to store information about
325 * its children. If non-zero this is the size of this data, to be allocated
326 * in the child's parent_plat pointer.
327 * @ops: Driver-specific operations. This is typically a list of function
328 * pointers defined by the driver, to implement driver functions required by
329 * the uclass.
330 * @flags: driver flags - see DM_FLAGS_...
331 * @acpi_ops: Advanced Configuration and Power Interface (ACPI) operations,
332 * allowing the device to add things to the ACPI tables passed to Linux
333 */
334 struct driver {
335 char *name;
336 enum uclass_id id;
337 const struct udevice_id *of_match;
338 int (*bind)(struct udevice *dev);
339 int (*probe)(struct udevice *dev);
340 int (*remove)(struct udevice *dev);
341 int (*unbind)(struct udevice *dev);
342 int (*of_to_plat)(struct udevice *dev);
343 int (*child_post_bind)(struct udevice *dev);
344 int (*child_pre_probe)(struct udevice *dev);
345 int (*child_post_remove)(struct udevice *dev);
346 int priv_auto;
347 int plat_auto;
348 int per_child_auto;
349 int per_child_plat_auto;
350 const void *ops; /* driver-specific operations */
351 uint32_t flags;
352 #if CONFIG_IS_ENABLED(ACPIGEN)
353 struct acpi_ops *acpi_ops;
354 #endif
355 };
356
357 /* Declare a new U-Boot driver */
358 #define U_BOOT_DRIVER(__name) \
359 ll_entry_declare(struct driver, __name, driver)
360
361 /* Get a pointer to a given driver */
362 #define DM_DRIVER_GET(__name) \
363 ll_entry_get(struct driver, __name, driver)
364
365 /**
366 * Declare a macro to state a alias for a driver name. This macro will
367 * produce no code but its information will be parsed by tools like
368 * dtoc
369 */
370 #define DM_DRIVER_ALIAS(__name, __alias)
371
372 /**
373 * dev_get_plat() - Get the platform data for a device
374 *
375 * This checks that dev is not NULL, but no other checks for now
376 *
377 * @dev Device to check
378 * @return platform data, or NULL if none
379 */
380 void *dev_get_plat(const struct udevice *dev);
381
382 /**
383 * dev_get_parent_plat() - Get the parent platform data for a device
384 *
385 * This checks that dev is not NULL, but no other checks for now
386 *
387 * @dev Device to check
388 * @return parent's platform data, or NULL if none
389 */
390 void *dev_get_parent_plat(const struct udevice *dev);
391
392 /**
393 * dev_get_uclass_plat() - Get the uclass platform data for a device
394 *
395 * This checks that dev is not NULL, but no other checks for now
396 *
397 * @dev Device to check
398 * @return uclass's platform data, or NULL if none
399 */
400 void *dev_get_uclass_plat(const struct udevice *dev);
401
402 /**
403 * dev_get_priv() - Get the private data for a device
404 *
405 * This checks that dev is not NULL, but no other checks for now
406 *
407 * @dev Device to check
408 * @return private data, or NULL if none
409 */
410 void *dev_get_priv(const struct udevice *dev);
411
412 /**
413 * dev_get_parent_priv() - Get the parent private data for a device
414 *
415 * The parent private data is data stored in the device but owned by the
416 * parent. For example, a USB device may have parent data which contains
417 * information about how to talk to the device over USB.
418 *
419 * This checks that dev is not NULL, but no other checks for now
420 *
421 * @dev Device to check
422 * @return parent data, or NULL if none
423 */
424 void *dev_get_parent_priv(const struct udevice *dev);
425
426 /**
427 * dev_get_uclass_priv() - Get the private uclass data for a device
428 *
429 * This checks that dev is not NULL, but no other checks for now
430 *
431 * @dev Device to check
432 * @return private uclass data for this device, or NULL if none
433 */
434 void *dev_get_uclass_priv(const struct udevice *dev);
435
436 /**
437 * struct dev_get_parent() - Get the parent of a device
438 *
439 * @child: Child to check
440 * @return parent of child, or NULL if this is the root device
441 */
442 struct udevice *dev_get_parent(const struct udevice *child);
443
444 /**
445 * dev_get_driver_data() - get the driver data used to bind a device
446 *
447 * When a device is bound using a device tree node, it matches a
448 * particular compatible string in struct udevice_id. This function
449 * returns the associated data value for that compatible string. This is
450 * the 'data' field in struct udevice_id.
451 *
452 * As an example, consider this structure:
453 * static const struct udevice_id tegra_i2c_ids[] = {
454 * { .compatible = "nvidia,tegra114-i2c", .data = TYPE_114 },
455 * { .compatible = "nvidia,tegra20-i2c", .data = TYPE_STD },
456 * { .compatible = "nvidia,tegra20-i2c-dvc", .data = TYPE_DVC },
457 * { }
458 * };
459 *
460 * When driver model finds a driver for this it will store the 'data' value
461 * corresponding to the compatible string it matches. This function returns
462 * that value. This allows the driver to handle several variants of a device.
463 *
464 * For USB devices, this is the driver_info field in struct usb_device_id.
465 *
466 * @dev: Device to check
467 * @return driver data (0 if none is provided)
468 */
469 ulong dev_get_driver_data(const struct udevice *dev);
470
471 /**
472 * dev_get_driver_ops() - get the device's driver's operations
473 *
474 * This checks that dev is not NULL, and returns the pointer to device's
475 * driver's operations.
476 *
477 * @dev: Device to check
478 * @return void pointer to driver's operations or NULL for NULL-dev or NULL-ops
479 */
480 const void *dev_get_driver_ops(const struct udevice *dev);
481
482 /**
483 * device_get_uclass_id() - return the uclass ID of a device
484 *
485 * @dev: Device to check
486 * @return uclass ID for the device
487 */
488 enum uclass_id device_get_uclass_id(const struct udevice *dev);
489
490 /**
491 * dev_get_uclass_name() - return the uclass name of a device
492 *
493 * This checks that dev is not NULL.
494 *
495 * @dev: Device to check
496 * @return pointer to the uclass name for the device
497 */
498 const char *dev_get_uclass_name(const struct udevice *dev);
499
500 /**
501 * device_get_child() - Get the child of a device by index
502 *
503 * Returns the numbered child, 0 being the first. This does not use
504 * sequence numbers, only the natural order.
505 *
506 * @dev: Parent device to check
507 * @index: Child index
508 * @devp: Returns pointer to device
509 * @return 0 if OK, -ENODEV if no such device, other error if the device fails
510 * to probe
511 */
512 int device_get_child(const struct udevice *parent, int index,
513 struct udevice **devp);
514
515 /**
516 * device_get_child_count() - Get the available child count of a device
517 *
518 * Returns the number of children to a device.
519 *
520 * @parent: Parent device to check
521 */
522 int device_get_child_count(const struct udevice *parent);
523
524 /**
525 * device_find_child_by_seq() - Find a child device based on a sequence
526 *
527 * This searches for a device with the given seq.
528 *
529 * @parent: Parent device
530 * @seq: Sequence number to find (0=first)
531 * @devp: Returns pointer to device (there is only one per for each seq).
532 * Set to NULL if none is found
533 * @return 0 if OK, -ENODEV if not found
534 */
535 int device_find_child_by_seq(const struct udevice *parent, int seq,
536 struct udevice **devp);
537
538 /**
539 * device_get_child_by_seq() - Get a child device based on a sequence
540 *
541 * If an active device has this sequence it will be returned. If there is no
542 * such device then this will check for a device that is requesting this
543 * sequence.
544 *
545 * The device is probed to activate it ready for use.
546 *
547 * @parent: Parent device
548 * @seq: Sequence number to find (0=first)
549 * @devp: Returns pointer to device (there is only one per for each seq)
550 * Set to NULL if none is found
551 * @return 0 if OK, -ve on error
552 */
553 int device_get_child_by_seq(const struct udevice *parent, int seq,
554 struct udevice **devp);
555
556 /**
557 * device_find_child_by_of_offset() - Find a child device based on FDT offset
558 *
559 * Locates a child device by its device tree offset.
560 *
561 * @parent: Parent device
562 * @of_offset: Device tree offset to find
563 * @devp: Returns pointer to device if found, otherwise this is set to NULL
564 * @return 0 if OK, -ve on error
565 */
566 int device_find_child_by_of_offset(const struct udevice *parent, int of_offset,
567 struct udevice **devp);
568
569 /**
570 * device_get_child_by_of_offset() - Get a child device based on FDT offset
571 *
572 * Locates a child device by its device tree offset.
573 *
574 * The device is probed to activate it ready for use.
575 *
576 * @parent: Parent device
577 * @of_offset: Device tree offset to find
578 * @devp: Returns pointer to device if found, otherwise this is set to NULL
579 * @return 0 if OK, -ve on error
580 */
581 int device_get_child_by_of_offset(const struct udevice *parent, int of_offset,
582 struct udevice **devp);
583
584 /**
585 * device_find_global_by_ofnode() - Get a device based on ofnode
586 *
587 * Locates a device by its device tree ofnode, searching globally throughout
588 * the all driver model devices.
589 *
590 * The device is NOT probed
591 *
592 * @node: Device tree ofnode to find
593 * @devp: Returns pointer to device if found, otherwise this is set to NULL
594 * @return 0 if OK, -ve on error
595 */
596
597 int device_find_global_by_ofnode(ofnode node, struct udevice **devp);
598
599 /**
600 * device_get_global_by_ofnode() - Get a device based on ofnode
601 *
602 * Locates a device by its device tree ofnode, searching globally throughout
603 * the all driver model devices.
604 *
605 * The device is probed to activate it ready for use.
606 *
607 * @node: Device tree ofnode to find
608 * @devp: Returns pointer to device if found, otherwise this is set to NULL
609 * @return 0 if OK, -ve on error
610 */
611 int device_get_global_by_ofnode(ofnode node, struct udevice **devp);
612
613 /**
614 * device_get_by_driver_info() - Get a device based on driver_info
615 *
616 * Locates a device by its struct driver_info, by using its reference which
617 * is updated during the bind process.
618 *
619 * The device is probed to activate it ready for use.
620 *
621 * @info: Struct driver_info
622 * @devp: Returns pointer to device if found, otherwise this is set to NULL
623 * @return 0 if OK, -ve on error
624 */
625 int device_get_by_driver_info(const struct driver_info *info,
626 struct udevice **devp);
627
628 /**
629 * device_get_by_driver_info_idx() - Get a device based on driver_info index
630 *
631 * Locates a device by its struct driver_info, by using its index number which
632 * is written into the idx field of struct phandle_1_arg, etc.
633 *
634 * The device is probed to activate it ready for use.
635 *
636 * @idx: Index number of the driver_info structure (0=first)
637 * @devp: Returns pointer to device if found, otherwise this is set to NULL
638 * @return 0 if OK, -ve on error
639 */
640 int device_get_by_driver_info_idx(uint idx, struct udevice **devp);
641
642 /**
643 * device_find_first_child() - Find the first child of a device
644 *
645 * @parent: Parent device to search
646 * @devp: Returns first child device, or NULL if none
647 * @return 0
648 */
649 int device_find_first_child(const struct udevice *parent,
650 struct udevice **devp);
651
652 /**
653 * device_find_next_child() - Find the next child of a device
654 *
655 * @devp: Pointer to previous child device on entry. Returns pointer to next
656 * child device, or NULL if none
657 * @return 0
658 */
659 int device_find_next_child(struct udevice **devp);
660
661 /**
662 * device_find_first_inactive_child() - Find the first inactive child
663 *
664 * This is used to locate an existing child of a device which is of a given
665 * uclass.
666 *
667 * The device is NOT probed
668 *
669 * @parent: Parent device to search
670 * @uclass_id: Uclass to look for
671 * @devp: Returns device found, if any
672 * @return 0 if found, else -ENODEV
673 */
674 int device_find_first_inactive_child(const struct udevice *parent,
675 enum uclass_id uclass_id,
676 struct udevice **devp);
677
678 /**
679 * device_find_first_child_by_uclass() - Find the first child of a device in uc
680 *
681 * @parent: Parent device to search
682 * @uclass_id: Uclass to look for
683 * @devp: Returns first child device in that uclass, if any
684 * @return 0 if found, else -ENODEV
685 */
686 int device_find_first_child_by_uclass(const struct udevice *parent,
687 enum uclass_id uclass_id,
688 struct udevice **devp);
689
690 /**
691 * device_find_child_by_name() - Find a child by device name
692 *
693 * @parent: Parent device to search
694 * @name: Name to look for
695 * @devp: Returns device found, if any
696 * @return 0 if found, else -ENODEV
697 */
698 int device_find_child_by_name(const struct udevice *parent, const char *name,
699 struct udevice **devp);
700
701 /**
702 * device_first_child_ofdata_err() - Find the first child and reads its plat
703 *
704 * The of_to_plat() method is called on the child before it is returned,
705 * but the child is not probed.
706 *
707 * @parent: Parent to check
708 * @devp: Returns child that was found, if any
709 * @return 0 on success, -ENODEV if no children, other -ve on error
710 */
711 int device_first_child_ofdata_err(struct udevice *parent,
712 struct udevice **devp);
713
714 /*
715 * device_next_child_ofdata_err() - Find the next child and read its plat
716 *
717 * The of_to_plat() method is called on the child before it is returned,
718 * but the child is not probed.
719 *
720 * @devp: On entry, points to the previous child; on exit returns the child that
721 * was found, if any
722 * @return 0 on success, -ENODEV if no children, other -ve on error
723 */
724 int device_next_child_ofdata_err(struct udevice **devp);
725
726 /**
727 * device_first_child_err() - Get the first child of a device
728 *
729 * The device returned is probed if necessary, and ready for use
730 *
731 * @parent: Parent device to search
732 * @devp: Returns device found, if any
733 * @return 0 if found, -ENODEV if not, -ve error if device failed to probe
734 */
735 int device_first_child_err(struct udevice *parent, struct udevice **devp);
736
737 /**
738 * device_next_child_err() - Get the next child of a parent device
739 *
740 * The device returned is probed if necessary, and ready for use
741 *
742 * @devp: On entry, pointer to device to lookup. On exit, returns pointer
743 * to the next sibling if no error occurred
744 * @return 0 if found, -ENODEV if not, -ve error if device failed to probe
745 */
746 int device_next_child_err(struct udevice **devp);
747
748 /**
749 * device_has_children() - check if a device has any children
750 *
751 * @dev: Device to check
752 * @return true if the device has one or more children
753 */
754 bool device_has_children(const struct udevice *dev);
755
756 /**
757 * device_has_active_children() - check if a device has any active children
758 *
759 * @dev: Device to check
760 * @return true if the device has one or more children and at least one of
761 * them is active (probed).
762 */
763 bool device_has_active_children(const struct udevice *dev);
764
765 /**
766 * device_is_last_sibling() - check if a device is the last sibling
767 *
768 * This function can be useful for display purposes, when special action needs
769 * to be taken when displaying the last sibling. This can happen when a tree
770 * view of devices is being displayed.
771 *
772 * @dev: Device to check
773 * @return true if there are no more siblings after this one - i.e. is it
774 * last in the list.
775 */
776 bool device_is_last_sibling(const struct udevice *dev);
777
778 /**
779 * device_set_name() - set the name of a device
780 *
781 * This must be called in the device's bind() method and no later. Normally
782 * this is unnecessary but for probed devices which don't get a useful name
783 * this function can be helpful.
784 *
785 * The name is allocated and will be freed automatically when the device is
786 * unbound.
787 *
788 * @dev: Device to update
789 * @name: New name (this string is allocated new memory and attached to
790 * the device)
791 * @return 0 if OK, -ENOMEM if there is not enough memory to allocate the
792 * string
793 */
794 int device_set_name(struct udevice *dev, const char *name);
795
796 /**
797 * device_set_name_alloced() - note that a device name is allocated
798 *
799 * This sets the DM_FLAG_NAME_ALLOCED flag for the device, so that when it is
800 * unbound the name will be freed. This avoids memory leaks.
801 *
802 * @dev: Device to update
803 */
804 void device_set_name_alloced(struct udevice *dev);
805
806 /**
807 * device_is_compatible() - check if the device is compatible with the compat
808 *
809 * This allows to check whether the device is comaptible with the compat.
810 *
811 * @dev: udevice pointer for which compatible needs to be verified.
812 * @compat: Compatible string which needs to verified in the given
813 * device
814 * @return true if OK, false if the compatible is not found
815 */
816 bool device_is_compatible(const struct udevice *dev, const char *compat);
817
818 /**
819 * of_machine_is_compatible() - check if the machine is compatible with
820 * the compat
821 *
822 * This allows to check whether the machine is comaptible with the compat.
823 *
824 * @compat: Compatible string which needs to verified
825 * @return true if OK, false if the compatible is not found
826 */
827 bool of_machine_is_compatible(const char *compat);
828
829 /**
830 * dev_disable_by_path() - Disable a device given its device tree path
831 *
832 * @path: The device tree path identifying the device to be disabled
833 * @return 0 on success, -ve on error
834 */
835 int dev_disable_by_path(const char *path);
836
837 /**
838 * dev_enable_by_path() - Enable a device given its device tree path
839 *
840 * @path: The device tree path identifying the device to be enabled
841 * @return 0 on success, -ve on error
842 */
843 int dev_enable_by_path(const char *path);
844
845 /**
846 * device_is_on_pci_bus - Test if a device is on a PCI bus
847 *
848 * @dev: device to test
849 * @return: true if it is on a PCI bus, false otherwise
850 */
device_is_on_pci_bus(const struct udevice * dev)851 static inline bool device_is_on_pci_bus(const struct udevice *dev)
852 {
853 return dev->parent && device_get_uclass_id(dev->parent) == UCLASS_PCI;
854 }
855
856 /**
857 * device_foreach_child_safe() - iterate through child devices safely
858 *
859 * This allows the @pos child to be removed in the loop if required.
860 *
861 * @pos: struct udevice * for the current device
862 * @next: struct udevice * for the next device
863 * @parent: parent device to scan
864 */
865 #define device_foreach_child_safe(pos, next, parent) \
866 list_for_each_entry_safe(pos, next, &parent->child_head, sibling_node)
867
868 /**
869 * device_foreach_child() - iterate through child devices
870 *
871 * @pos: struct udevice * for the current device
872 * @parent: parent device to scan
873 */
874 #define device_foreach_child(pos, parent) \
875 list_for_each_entry(pos, &parent->child_head, sibling_node)
876
877 /**
878 * device_foreach_child_of_to_plat() - iterate through children
879 *
880 * This stops when it gets an error, with @pos set to the device that failed to
881 * read ofdata.
882
883 * This creates a for() loop which works through the available children of
884 * a device in order from start to end. Device ofdata is read by calling
885 * device_of_to_plat() on each one. The devices are not probed.
886 *
887 * @pos: struct udevice * for the current device
888 * @parent: parent device to scan
889 */
890 #define device_foreach_child_of_to_plat(pos, parent) \
891 for (int _ret = device_first_child_ofdata_err(parent, &dev); !_ret; \
892 _ret = device_next_child_ofdata_err(&dev))
893
894 /**
895 * device_foreach_child_probe() - iterate through children, probing them
896 *
897 * This creates a for() loop which works through the available children of
898 * a device in order from start to end. Devices are probed if necessary,
899 * and ready for use.
900 *
901 * This stops when it gets an error, with @pos set to the device that failed to
902 * probe
903 *
904 * @pos: struct udevice * for the current device
905 * @parent: parent device to scan
906 */
907 #define device_foreach_child_probe(pos, parent) \
908 for (int _ret = device_first_child_err(parent, &dev); !_ret; \
909 _ret = device_next_child_err(&dev))
910
911 /**
912 * dm_scan_fdt_dev() - Bind child device in the device tree
913 *
914 * This handles device which have sub-nodes in the device tree. It scans all
915 * sub-nodes and binds drivers for each node where a driver can be found.
916 *
917 * If this is called prior to relocation, only pre-relocation devices will be
918 * bound (those marked with u-boot,dm-pre-reloc in the device tree, or where
919 * the driver has the DM_FLAG_PRE_RELOC flag set). Otherwise, all devices will
920 * be bound.
921 *
922 * @dev: Device to scan
923 * @return 0 if OK, -ve on error
924 */
925 int dm_scan_fdt_dev(struct udevice *dev);
926
927 #endif
928