1 /* SPDX-License-Identifier: GPL-2.0+ */
3 * Copyright (c) 2013 Google, Inc
6 * Pavel Herrmann <morpheus.ibis@gmail.com>
7 * Marek Vasut <marex@denx.de>
13 #include <dm/ofnode.h>
14 #include <dm/uclass-id.h>
16 #include <linker_lists.h>
17 #include <linux/kernel.h>
18 #include <linux/list.h>
19 #include <linux/printk.h>
23 /* Driver is active (probed). Cleared when it is removed */
24 #define DM_FLAG_ACTIVATED (1 << 0)
26 /* DM is responsible for allocating and freeing plat */
27 #define DM_FLAG_ALLOC_PDATA (1 << 1)
29 /* DM should init this device prior to relocation */
30 #define DM_FLAG_PRE_RELOC (1 << 2)
32 /* DM is responsible for allocating and freeing parent_plat */
33 #define DM_FLAG_ALLOC_PARENT_PDATA (1 << 3)
35 /* DM is responsible for allocating and freeing uclass_plat */
36 #define DM_FLAG_ALLOC_UCLASS_PDATA (1 << 4)
38 /* Allocate driver private data on a DMA boundary */
39 #define DM_FLAG_ALLOC_PRIV_DMA (1 << 5)
42 #define DM_FLAG_BOUND (1 << 6)
44 /* Device name is allocated and should be freed on unbind() */
45 #define DM_FLAG_NAME_ALLOCED (1 << 7)
47 /* Device has platform data provided by of-platdata */
48 #define DM_FLAG_OF_PLATDATA (1 << 8)
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
56 #define DM_FLAG_ACTIVE_DMA (1 << 9)
59 * Call driver remove function to do some final configuration, before
60 * U-Boot exits and the OS is started
62 #define DM_FLAG_OS_PREPARE (1 << 10)
64 /* DM does not enable/disable the power domains corresponding to this device */
65 #define DM_FLAG_DEFAULT_PD_CTRL_OFF (1 << 11)
67 /* Driver plat has been read. Cleared when the device is removed */
68 #define DM_FLAG_PLATDATA_VALID (1 << 12)
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.
74 #define DM_FLAG_LEAVE_PD_ON (1 << 13)
77 * One or multiple of these flags are passed to device_remove() so that
78 * a selective device removal as specified by the remove-stage and the
79 * driver flags can be done.
81 * DO NOT use these flags in your driver's @flags value...
82 * use the above DM_FLAG_... values instead
85 /* Normal remove, remove all devices */
86 DM_REMOVE_NORMAL = 1 << 0,
88 /* Remove devices with active DMA */
89 DM_REMOVE_ACTIVE_DMA = DM_FLAG_ACTIVE_DMA,
91 /* Remove devices which need some final OS preparation steps */
92 DM_REMOVE_OS_PREPARE = DM_FLAG_OS_PREPARE,
94 /* Add more use cases here */
96 /* Remove devices with any active flag */
97 DM_REMOVE_ACTIVE_ALL = DM_REMOVE_ACTIVE_DMA | DM_REMOVE_OS_PREPARE,
99 /* Don't power down any attached power domains */
100 DM_REMOVE_NO_PD = 1 << 1,
104 * struct udevice - An instance of a driver
106 * This holds information about a device, which is a driver bound to a
107 * particular port or peripheral (essentially a driver instance).
109 * A device will come into existence through a 'bind' call, either due to
110 * a U_BOOT_DRVINFO() macro (in which case plat is non-NULL) or a node
111 * in the device tree (in which case of_offset is >= 0). In the latter case
112 * we translate the device tree information into plat in a function
113 * implemented by the driver of_to_plat method (called just before the
114 * probe method if the device has a device tree node.
116 * All three of plat, priv and uclass_priv can be allocated by the
117 * driver, or you can use the auto members of struct driver and
118 * struct uclass_driver to have driver model do this automatically.
120 * @driver: The driver used by this device
121 * @name: Name of device, typically the FDT node name
122 * @plat_: Configuration data for this device (do not access outside driver
124 * @parent_plat_: The parent bus's configuration data for this device (do not
125 * access outside driver model)
126 * @uclass_plat_: The uclass's configuration data for this device (do not access
127 * outside driver model)
128 * @driver_data: Driver data word for the entry that matched this device with
130 * @parent: Parent of this device, or NULL for the top level device
131 * @priv_: Private data for this device (do not access outside driver model)
132 * @uclass: Pointer to uclass for this device
133 * @uclass_priv_: The uclass's private data for this device (do not access
134 * outside driver model)
135 * @parent_priv_: The parent's private data for this device (do not access
136 * outside driver model)
137 * @uclass_node: Used by uclass to link its devices
138 * @child_head: List of children of this device
139 * @sibling_node: Next device in list of all devices
140 * @flags_: Flags for this device DM_FLAG_... (do not access outside driver
142 * @seq_: Allocated sequence number for this device (-1 = none). This is set up
143 * when the device is bound and is unique within the device's uclass. If the
144 * device has an alias in the devicetree then that is used to set the sequence
145 * number. Otherwise, the next available number is used. Sequence numbers are
146 * used by certain commands that need device to be numbered (e.g. 'mmc dev').
147 * (do not access outside driver model)
148 * @node_: Reference to device tree node for this device (do not access outside
150 * @devres_head: List of memory allocations associated with this device.
151 * When CONFIG_DEVRES is enabled, devm_kmalloc() and friends will
152 * add to this list. Memory so-allocated will be freed
153 * automatically when the device is removed / unbound
156 const struct driver *driver;
162 struct udevice *parent;
164 struct uclass *uclass;
167 struct list_head uclass_node;
168 struct list_head child_head;
169 struct list_head sibling_node;
172 #if !CONFIG_IS_ENABLED(OF_PLATDATA)
176 struct list_head devres_head;
180 /* Maximum sequence number supported */
181 #define DM_MAX_SEQ 999
183 /* Returns the operations for a device */
184 #define device_get_ops(dev) (dev->driver->ops)
186 static inline u32 dev_get_flags(const struct udevice *dev)
191 static inline void dev_or_flags(struct udevice *dev, u32 or)
196 static inline void dev_bic_flags(struct udevice *dev, u32 bic)
202 * dev_ofnode() - get the DT node reference associated with a udevice
204 * @dev: device to check
205 * @return reference of the the device's DT node
207 static inline ofnode dev_ofnode(const struct udevice *dev)
209 #if !CONFIG_IS_ENABLED(OF_PLATDATA)
212 return ofnode_null();
216 /* Returns non-zero if the device is active (probed and not removed) */
217 #define device_active(dev) (dev_get_flags(dev) & DM_FLAG_ACTIVATED)
219 static inline int dev_of_offset(const struct udevice *dev)
221 #if !CONFIG_IS_ENABLED(OF_PLATDATA)
222 return ofnode_to_offset(dev_ofnode(dev));
228 static inline bool dev_has_ofnode(const struct udevice *dev)
230 #if !CONFIG_IS_ENABLED(OF_PLATDATA)
231 return ofnode_valid(dev_ofnode(dev));
237 static inline void dev_set_ofnode(struct udevice *dev, ofnode node)
239 #if !CONFIG_IS_ENABLED(OF_PLATDATA)
244 static inline int dev_seq(const struct udevice *dev)
250 * struct udevice_id - Lists the compatible strings supported by a driver
251 * @compatible: Compatible string
252 * @data: Data for this compatible string
255 const char *compatible;
259 #if CONFIG_IS_ENABLED(OF_CONTROL) && !CONFIG_IS_ENABLED(OF_PLATDATA)
260 #define of_match_ptr(_ptr) (_ptr)
262 #define of_match_ptr(_ptr) NULL
263 #endif /* CONFIG_IS_ENABLED(OF_CONTROL) */
266 * struct driver - A driver for a feature or peripheral
268 * This holds methods for setting up a new device, and also removing it.
269 * The device needs information to set itself up - this is provided either
270 * by plat or a device tree node (which we find by looking up
271 * matching compatible strings with of_match).
273 * Drivers all belong to a uclass, representing a class of devices of the
274 * same type. Common elements of the drivers can be implemented in the uclass,
275 * or the uclass can provide a consistent interface to the drivers within
279 * @id: Identifies the uclass we belong to
280 * @of_match: List of compatible strings to match, and any identifying data
282 * @bind: Called to bind a device to its driver
283 * @probe: Called to probe a device, i.e. activate it
284 * @remove: Called to remove a device, i.e. de-activate it
285 * @unbind: Called to unbind a device from its driver
286 * @of_to_plat: Called before probe to decode device tree data
287 * @child_post_bind: Called after a new child has been bound
288 * @child_pre_probe: Called before a child device is probed. The device has
289 * memory allocated but it has not yet been probed.
290 * @child_post_remove: Called after a child device is removed. The device
291 * has memory allocated but its device_remove() method has been called.
292 * @priv_auto: If non-zero this is the size of the private data
293 * to be allocated in the device's ->priv pointer. If zero, then the driver
294 * is responsible for allocating any data required.
295 * @plat_auto: If non-zero this is the size of the
296 * platform data to be allocated in the device's ->plat pointer.
297 * This is typically only useful for device-tree-aware drivers (those with
298 * an of_match), since drivers which use plat will have the data
299 * provided in the U_BOOT_DRVINFO() instantiation.
300 * @per_child_auto: Each device can hold private data owned by
301 * its parent. If required this will be automatically allocated if this
303 * @per_child_plat_auto: A bus likes to store information about
304 * its children. If non-zero this is the size of this data, to be allocated
305 * in the child's parent_plat pointer.
306 * @ops: Driver-specific operations. This is typically a list of function
307 * pointers defined by the driver, to implement driver functions required by
309 * @flags: driver flags - see DM_FLAGS_...
310 * @acpi_ops: Advanced Configuration and Power Interface (ACPI) operations,
311 * allowing the device to add things to the ACPI tables passed to Linux
316 const struct udevice_id *of_match;
317 int (*bind)(struct udevice *dev);
318 int (*probe)(struct udevice *dev);
319 int (*remove)(struct udevice *dev);
320 int (*unbind)(struct udevice *dev);
321 int (*of_to_plat)(struct udevice *dev);
322 int (*child_post_bind)(struct udevice *dev);
323 int (*child_pre_probe)(struct udevice *dev);
324 int (*child_post_remove)(struct udevice *dev);
328 int per_child_plat_auto;
329 const void *ops; /* driver-specific operations */
331 #if CONFIG_IS_ENABLED(ACPIGEN)
332 struct acpi_ops *acpi_ops;
336 /* Declare a new U-Boot driver */
337 #define U_BOOT_DRIVER(__name) \
338 ll_entry_declare(struct driver, __name, driver)
340 /* Get a pointer to a given driver */
341 #define DM_DRIVER_GET(__name) \
342 ll_entry_get(struct driver, __name, driver)
345 * Declare a macro to state a alias for a driver name. This macro will
346 * produce no code but its information will be parsed by tools like
349 #define DM_DRIVER_ALIAS(__name, __alias)
352 * dev_get_plat() - Get the platform data for a device
354 * This checks that dev is not NULL, but no other checks for now
356 * @dev Device to check
357 * @return platform data, or NULL if none
359 void *dev_get_plat(const struct udevice *dev);
362 * dev_get_parent_plat() - Get the parent platform data for a device
364 * This checks that dev is not NULL, but no other checks for now
366 * @dev Device to check
367 * @return parent's platform data, or NULL if none
369 void *dev_get_parent_plat(const struct udevice *dev);
372 * dev_get_uclass_plat() - Get the uclass platform data for a device
374 * This checks that dev is not NULL, but no other checks for now
376 * @dev Device to check
377 * @return uclass's platform data, or NULL if none
379 void *dev_get_uclass_plat(const struct udevice *dev);
382 * dev_get_priv() - Get the private data for a device
384 * This checks that dev is not NULL, but no other checks for now
386 * @dev Device to check
387 * @return private data, or NULL if none
389 void *dev_get_priv(const struct udevice *dev);
392 * dev_get_parent_priv() - Get the parent private data for a device
394 * The parent private data is data stored in the device but owned by the
395 * parent. For example, a USB device may have parent data which contains
396 * information about how to talk to the device over USB.
398 * This checks that dev is not NULL, but no other checks for now
400 * @dev Device to check
401 * @return parent data, or NULL if none
403 void *dev_get_parent_priv(const struct udevice *dev);
406 * dev_get_uclass_priv() - Get the private uclass data for a device
408 * This checks that dev is not NULL, but no other checks for now
410 * @dev Device to check
411 * @return private uclass data for this device, or NULL if none
413 void *dev_get_uclass_priv(const struct udevice *dev);
416 * struct dev_get_parent() - Get the parent of a device
418 * @child: Child to check
419 * @return parent of child, or NULL if this is the root device
421 struct udevice *dev_get_parent(const struct udevice *child);
424 * dev_get_driver_data() - get the driver data used to bind a device
426 * When a device is bound using a device tree node, it matches a
427 * particular compatible string in struct udevice_id. This function
428 * returns the associated data value for that compatible string. This is
429 * the 'data' field in struct udevice_id.
431 * As an example, consider this structure:
432 * static const struct udevice_id tegra_i2c_ids[] = {
433 * { .compatible = "nvidia,tegra114-i2c", .data = TYPE_114 },
434 * { .compatible = "nvidia,tegra20-i2c", .data = TYPE_STD },
435 * { .compatible = "nvidia,tegra20-i2c-dvc", .data = TYPE_DVC },
439 * When driver model finds a driver for this it will store the 'data' value
440 * corresponding to the compatible string it matches. This function returns
441 * that value. This allows the driver to handle several variants of a device.
443 * For USB devices, this is the driver_info field in struct usb_device_id.
445 * @dev: Device to check
446 * @return driver data (0 if none is provided)
448 ulong dev_get_driver_data(const struct udevice *dev);
451 * dev_get_driver_ops() - get the device's driver's operations
453 * This checks that dev is not NULL, and returns the pointer to device's
454 * driver's operations.
456 * @dev: Device to check
457 * @return void pointer to driver's operations or NULL for NULL-dev or NULL-ops
459 const void *dev_get_driver_ops(const struct udevice *dev);
462 * device_get_uclass_id() - return the uclass ID of a device
464 * @dev: Device to check
465 * @return uclass ID for the device
467 enum uclass_id device_get_uclass_id(const struct udevice *dev);
470 * dev_get_uclass_name() - return the uclass name of a device
472 * This checks that dev is not NULL.
474 * @dev: Device to check
475 * @return pointer to the uclass name for the device
477 const char *dev_get_uclass_name(const struct udevice *dev);
480 * device_get_child() - Get the child of a device by index
482 * Returns the numbered child, 0 being the first. This does not use
483 * sequence numbers, only the natural order.
485 * @dev: Parent device to check
486 * @index: Child index
487 * @devp: Returns pointer to device
488 * @return 0 if OK, -ENODEV if no such device, other error if the device fails
491 int device_get_child(const struct udevice *parent, int index,
492 struct udevice **devp);
495 * device_get_child_count() - Get the available child count of a device
497 * Returns the number of children to a device.
499 * @parent: Parent device to check
501 int device_get_child_count(const struct udevice *parent);
504 * device_find_child_by_seq() - Find a child device based on a sequence
506 * This searches for a device with the given seq.
508 * @parent: Parent device
509 * @seq: Sequence number to find (0=first)
510 * @devp: Returns pointer to device (there is only one per for each seq).
511 * Set to NULL if none is found
512 * @return 0 if OK, -ENODEV if not found
514 int device_find_child_by_seq(const struct udevice *parent, int seq,
515 struct udevice **devp);
518 * device_get_child_by_seq() - Get a child device based on a sequence
520 * If an active device has this sequence it will be returned. If there is no
521 * such device then this will check for a device that is requesting this
524 * The device is probed to activate it ready for use.
526 * @parent: Parent device
527 * @seq: Sequence number to find (0=first)
528 * @devp: Returns pointer to device (there is only one per for each seq)
529 * Set to NULL if none is found
530 * @return 0 if OK, -ve on error
532 int device_get_child_by_seq(const struct udevice *parent, int seq,
533 struct udevice **devp);
536 * device_find_child_by_of_offset() - Find a child device based on FDT offset
538 * Locates a child device by its device tree offset.
540 * @parent: Parent device
541 * @of_offset: Device tree offset to find
542 * @devp: Returns pointer to device if found, otherwise this is set to NULL
543 * @return 0 if OK, -ve on error
545 int device_find_child_by_of_offset(const struct udevice *parent, int of_offset,
546 struct udevice **devp);
549 * device_get_child_by_of_offset() - Get a child device based on FDT offset
551 * Locates a child device by its device tree offset.
553 * The device is probed to activate it ready for use.
555 * @parent: Parent device
556 * @of_offset: Device tree offset to find
557 * @devp: Returns pointer to device if found, otherwise this is set to NULL
558 * @return 0 if OK, -ve on error
560 int device_get_child_by_of_offset(const struct udevice *parent, int of_offset,
561 struct udevice **devp);
564 * device_find_global_by_ofnode() - Get a device based on ofnode
566 * Locates a device by its device tree ofnode, searching globally throughout
567 * the all driver model devices.
569 * The device is NOT probed
571 * @node: Device tree ofnode to find
572 * @devp: Returns pointer to device if found, otherwise this is set to NULL
573 * @return 0 if OK, -ve on error
576 int device_find_global_by_ofnode(ofnode node, struct udevice **devp);
579 * device_get_global_by_ofnode() - Get a device based on ofnode
581 * Locates a device by its device tree ofnode, searching globally throughout
582 * the all driver model devices.
584 * The device is probed to activate it ready for use.
586 * @node: Device tree ofnode to find
587 * @devp: Returns pointer to device if found, otherwise this is set to NULL
588 * @return 0 if OK, -ve on error
590 int device_get_global_by_ofnode(ofnode node, struct udevice **devp);
593 * device_get_by_driver_info() - Get a device based on driver_info
595 * Locates a device by its struct driver_info, by using its reference which
596 * is updated during the bind process.
598 * The device is probed to activate it ready for use.
600 * @info: Struct driver_info
601 * @devp: Returns pointer to device if found, otherwise this is set to NULL
602 * @return 0 if OK, -ve on error
604 int device_get_by_driver_info(const struct driver_info *info,
605 struct udevice **devp);
608 * device_get_by_driver_info_idx() - Get a device based on driver_info index
610 * Locates a device by its struct driver_info, by using its index number which
611 * is written into the idx field of struct phandle_1_arg, etc.
613 * The device is probed to activate it ready for use.
615 * @idx: Index number of the driver_info structure (0=first)
616 * @devp: Returns pointer to device if found, otherwise this is set to NULL
617 * @return 0 if OK, -ve on error
619 int device_get_by_driver_info_idx(uint idx, struct udevice **devp);
622 * device_find_first_child() - Find the first child of a device
624 * @parent: Parent device to search
625 * @devp: Returns first child device, or NULL if none
628 int device_find_first_child(const struct udevice *parent,
629 struct udevice **devp);
632 * device_find_next_child() - Find the next child of a device
634 * @devp: Pointer to previous child device on entry. Returns pointer to next
635 * child device, or NULL if none
638 int device_find_next_child(struct udevice **devp);
641 * device_find_first_inactive_child() - Find the first inactive child
643 * This is used to locate an existing child of a device which is of a given
646 * The device is NOT probed
648 * @parent: Parent device to search
649 * @uclass_id: Uclass to look for
650 * @devp: Returns device found, if any
651 * @return 0 if found, else -ENODEV
653 int device_find_first_inactive_child(const struct udevice *parent,
654 enum uclass_id uclass_id,
655 struct udevice **devp);
658 * device_find_first_child_by_uclass() - Find the first child of a device in uc
660 * @parent: Parent device to search
661 * @uclass_id: Uclass to look for
662 * @devp: Returns first child device in that uclass, if any
663 * @return 0 if found, else -ENODEV
665 int device_find_first_child_by_uclass(const struct udevice *parent,
666 enum uclass_id uclass_id,
667 struct udevice **devp);
670 * device_find_child_by_name() - Find a child by device name
672 * @parent: Parent device to search
673 * @name: Name to look for
674 * @devp: Returns device found, if any
675 * @return 0 if found, else -ENODEV
677 int device_find_child_by_name(const struct udevice *parent, const char *name,
678 struct udevice **devp);
681 * device_first_child_ofdata_err() - Find the first child and reads its plat
683 * The of_to_plat() method is called on the child before it is returned,
684 * but the child is not probed.
686 * @parent: Parent to check
687 * @devp: Returns child that was found, if any
688 * @return 0 on success, -ENODEV if no children, other -ve on error
690 int device_first_child_ofdata_err(struct udevice *parent,
691 struct udevice **devp);
694 * device_next_child_ofdata_err() - Find the next child and read its plat
696 * The of_to_plat() method is called on the child before it is returned,
697 * but the child is not probed.
699 * @devp: On entry, points to the previous child; on exit returns the child that
701 * @return 0 on success, -ENODEV if no children, other -ve on error
703 int device_next_child_ofdata_err(struct udevice **devp);
706 * device_first_child_err() - Get the first child of a device
708 * The device returned is probed if necessary, and ready for use
710 * @parent: Parent device to search
711 * @devp: Returns device found, if any
712 * @return 0 if found, -ENODEV if not, -ve error if device failed to probe
714 int device_first_child_err(struct udevice *parent, struct udevice **devp);
717 * device_next_child_err() - Get the next child of a parent device
719 * The device returned is probed if necessary, and ready for use
721 * @devp: On entry, pointer to device to lookup. On exit, returns pointer
722 * to the next sibling if no error occurred
723 * @return 0 if found, -ENODEV if not, -ve error if device failed to probe
725 int device_next_child_err(struct udevice **devp);
728 * device_has_children() - check if a device has any children
730 * @dev: Device to check
731 * @return true if the device has one or more children
733 bool device_has_children(const struct udevice *dev);
736 * device_has_active_children() - check if a device has any active children
738 * @dev: Device to check
739 * @return true if the device has one or more children and at least one of
740 * them is active (probed).
742 bool device_has_active_children(const struct udevice *dev);
745 * device_is_last_sibling() - check if a device is the last sibling
747 * This function can be useful for display purposes, when special action needs
748 * to be taken when displaying the last sibling. This can happen when a tree
749 * view of devices is being displayed.
751 * @dev: Device to check
752 * @return true if there are no more siblings after this one - i.e. is it
755 bool device_is_last_sibling(const struct udevice *dev);
758 * device_set_name() - set the name of a device
760 * This must be called in the device's bind() method and no later. Normally
761 * this is unnecessary but for probed devices which don't get a useful name
762 * this function can be helpful.
764 * The name is allocated and will be freed automatically when the device is
767 * @dev: Device to update
768 * @name: New name (this string is allocated new memory and attached to
770 * @return 0 if OK, -ENOMEM if there is not enough memory to allocate the
773 int device_set_name(struct udevice *dev, const char *name);
776 * device_set_name_alloced() - note that a device name is allocated
778 * This sets the DM_FLAG_NAME_ALLOCED flag for the device, so that when it is
779 * unbound the name will be freed. This avoids memory leaks.
781 * @dev: Device to update
783 void device_set_name_alloced(struct udevice *dev);
786 * device_is_compatible() - check if the device is compatible with the compat
788 * This allows to check whether the device is comaptible with the compat.
790 * @dev: udevice pointer for which compatible needs to be verified.
791 * @compat: Compatible string which needs to verified in the given
793 * @return true if OK, false if the compatible is not found
795 bool device_is_compatible(const struct udevice *dev, const char *compat);
798 * of_machine_is_compatible() - check if the machine is compatible with
801 * This allows to check whether the machine is comaptible with the compat.
803 * @compat: Compatible string which needs to verified
804 * @return true if OK, false if the compatible is not found
806 bool of_machine_is_compatible(const char *compat);
809 * dev_disable_by_path() - Disable a device given its device tree path
811 * @path: The device tree path identifying the device to be disabled
812 * @return 0 on success, -ve on error
814 int dev_disable_by_path(const char *path);
817 * dev_enable_by_path() - Enable a device given its device tree path
819 * @path: The device tree path identifying the device to be enabled
820 * @return 0 on success, -ve on error
822 int dev_enable_by_path(const char *path);
825 * device_is_on_pci_bus - Test if a device is on a PCI bus
827 * @dev: device to test
828 * @return: true if it is on a PCI bus, false otherwise
830 static inline bool device_is_on_pci_bus(const struct udevice *dev)
832 return dev->parent && device_get_uclass_id(dev->parent) == UCLASS_PCI;
836 * device_foreach_child_safe() - iterate through child devices safely
838 * This allows the @pos child to be removed in the loop if required.
840 * @pos: struct udevice * for the current device
841 * @next: struct udevice * for the next device
842 * @parent: parent device to scan
844 #define device_foreach_child_safe(pos, next, parent) \
845 list_for_each_entry_safe(pos, next, &parent->child_head, sibling_node)
848 * device_foreach_child() - iterate through child devices
850 * @pos: struct udevice * for the current device
851 * @parent: parent device to scan
853 #define device_foreach_child(pos, parent) \
854 list_for_each_entry(pos, &parent->child_head, sibling_node)
857 * device_foreach_child_of_to_plat() - iterate through children
859 * This stops when it gets an error, with @pos set to the device that failed to
862 * This creates a for() loop which works through the available children of
863 * a device in order from start to end. Device ofdata is read by calling
864 * device_of_to_plat() on each one. The devices are not probed.
866 * @pos: struct udevice * for the current device
867 * @parent: parent device to scan
869 #define device_foreach_child_of_to_plat(pos, parent) \
870 for (int _ret = device_first_child_ofdata_err(parent, &dev); !_ret; \
871 _ret = device_next_child_ofdata_err(&dev))
874 * device_foreach_child_probe() - iterate through children, probing them
876 * This creates a for() loop which works through the available children of
877 * a device in order from start to end. Devices are probed if necessary,
880 * This stops when it gets an error, with @pos set to the device that failed to
883 * @pos: struct udevice * for the current device
884 * @parent: parent device to scan
886 #define device_foreach_child_probe(pos, parent) \
887 for (int _ret = device_first_child_err(parent, &dev); !_ret; \
888 _ret = device_next_child_err(&dev))
891 * dm_scan_fdt_dev() - Bind child device in the device tree
893 * This handles device which have sub-nodes in the device tree. It scans all
894 * sub-nodes and binds drivers for each node where a driver can be found.
896 * If this is called prior to relocation, only pre-relocation devices will be
897 * bound (those marked with u-boot,dm-pre-reloc in the device tree, or where
898 * the driver has the DM_FLAG_PRE_RELOC flag set). Otherwise, all devices will
901 * @dev: Device to scan
902 * @return 0 if OK, -ve on error
904 int dm_scan_fdt_dev(struct udevice *dev);