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 * 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.
81 #define DM_FLAG_VITAL (1 << 14)
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.
88 * DO NOT use these flags in your driver's @flags value...
89 * use the above DM_FLAG_... values instead
92 /* Normal remove, remove all devices */
93 DM_REMOVE_NORMAL = 1 << 0,
95 /* Remove devices with active DMA */
96 DM_REMOVE_ACTIVE_DMA = DM_FLAG_ACTIVE_DMA,
98 /* Remove devices which need some final OS preparation steps */
99 DM_REMOVE_OS_PREPARE = DM_FLAG_OS_PREPARE,
101 /* Remove only devices that are not marked vital */
102 DM_REMOVE_NON_VITAL = DM_FLAG_VITAL,
104 /* Remove devices with any active flag */
105 DM_REMOVE_ACTIVE_ALL = DM_REMOVE_ACTIVE_DMA | DM_REMOVE_OS_PREPARE,
107 /* Don't power down any attached power domains */
108 DM_REMOVE_NO_PD = 1 << 1,
112 * struct udevice - An instance of a driver
114 * This holds information about a device, which is a driver bound to a
115 * particular port or peripheral (essentially a driver instance).
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.
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.
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
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
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
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
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
166 const struct driver *driver;
172 struct udevice *parent;
174 struct uclass *uclass;
177 struct list_head uclass_node;
178 struct list_head child_head;
179 struct list_head sibling_node;
180 #if !CONFIG_IS_ENABLED(OF_PLATDATA_RT)
184 #if CONFIG_IS_ENABLED(OF_REAL)
188 struct list_head devres_head;
190 #if CONFIG_IS_ENABLED(DM_DMA)
196 * udevice_rt - runtime information set up by U-Boot
198 * This is only used with OF_PLATDATA_RT
200 * There is one of these for every udevice in the linker list, indexed by
201 * the udevice_info idx value.
203 * @flags_: Flags for this device DM_FLAG_... (do not access outside driver
210 /* Maximum sequence number supported and associated string length */
211 #define DM_MAX_SEQ 999
212 #define DM_MAX_SEQ_STR 3
214 /* Returns the operations for a device */
215 #define device_get_ops(dev) (dev->driver->ops)
217 #if CONFIG_IS_ENABLED(OF_PLATDATA_RT)
218 u32 dev_get_flags(const struct udevice *dev);
219 void dev_or_flags(const struct udevice *dev, u32 or);
220 void dev_bic_flags(const struct udevice *dev, u32 bic);
222 static inline u32 dev_get_flags(const struct udevice *dev)
227 static inline void dev_or_flags(struct udevice *dev, u32 or)
232 static inline void dev_bic_flags(struct udevice *dev, u32 bic)
236 #endif /* OF_PLATDATA_RT */
239 * dev_ofnode() - get the DT node reference associated with a udevice
241 * @dev: device to check
242 * @return reference of the the device's DT node
244 static inline ofnode dev_ofnode(const struct udevice *dev)
246 #if CONFIG_IS_ENABLED(OF_REAL)
249 return ofnode_null();
253 /* Returns non-zero if the device is active (probed and not removed) */
254 #define device_active(dev) (dev_get_flags(dev) & DM_FLAG_ACTIVATED)
256 #if CONFIG_IS_ENABLED(DM_DMA)
257 #define dev_set_dma_offset(_dev, _offset) _dev->dma_offset = _offset
258 #define dev_get_dma_offset(_dev) _dev->dma_offset
260 #define dev_set_dma_offset(_dev, _offset)
261 #define dev_get_dma_offset(_dev) 0
264 static inline int dev_of_offset(const struct udevice *dev)
266 #if CONFIG_IS_ENABLED(OF_REAL)
267 return ofnode_to_offset(dev_ofnode(dev));
273 static inline bool dev_has_ofnode(const struct udevice *dev)
275 #if CONFIG_IS_ENABLED(OF_REAL)
276 return ofnode_valid(dev_ofnode(dev));
282 static inline void dev_set_ofnode(struct udevice *dev, ofnode node)
284 #if CONFIG_IS_ENABLED(OF_REAL)
289 static inline int dev_seq(const struct udevice *dev)
295 * struct udevice_id - Lists the compatible strings supported by a driver
296 * @compatible: Compatible string
297 * @data: Data for this compatible string
300 const char *compatible;
304 #if CONFIG_IS_ENABLED(OF_REAL)
305 #define of_match_ptr(_ptr) (_ptr)
307 #define of_match_ptr(_ptr) NULL
308 #endif /* CONFIG_IS_ENABLED(OF_CONTROL) */
311 * struct driver - A driver for a feature or peripheral
313 * This holds methods for setting up a new device, and also removing it.
314 * The device needs information to set itself up - this is provided either
315 * by plat or a device tree node (which we find by looking up
316 * matching compatible strings with of_match).
318 * Drivers all belong to a uclass, representing a class of devices of the
319 * same type. Common elements of the drivers can be implemented in the uclass,
320 * or the uclass can provide a consistent interface to the drivers within
324 * @id: Identifies the uclass we belong to
325 * @of_match: List of compatible strings to match, and any identifying data
327 * @bind: Called to bind a device to its driver
328 * @probe: Called to probe a device, i.e. activate it
329 * @remove: Called to remove a device, i.e. de-activate it
330 * @unbind: Called to unbind a device from its driver
331 * @of_to_plat: Called before probe to decode device tree data
332 * @child_post_bind: Called after a new child has been bound
333 * @child_pre_probe: Called before a child device is probed. The device has
334 * memory allocated but it has not yet been probed.
335 * @child_post_remove: Called after a child device is removed. The device
336 * has memory allocated but its device_remove() method has been called.
337 * @priv_auto: If non-zero this is the size of the private data
338 * to be allocated in the device's ->priv pointer. If zero, then the driver
339 * is responsible for allocating any data required.
340 * @plat_auto: If non-zero this is the size of the
341 * platform data to be allocated in the device's ->plat pointer.
342 * This is typically only useful for device-tree-aware drivers (those with
343 * an of_match), since drivers which use plat will have the data
344 * provided in the U_BOOT_DRVINFO() instantiation.
345 * @per_child_auto: Each device can hold private data owned by
346 * its parent. If required this will be automatically allocated if this
348 * @per_child_plat_auto: A bus likes to store information about
349 * its children. If non-zero this is the size of this data, to be allocated
350 * in the child's parent_plat pointer.
351 * @ops: Driver-specific operations. This is typically a list of function
352 * pointers defined by the driver, to implement driver functions required by
354 * @flags: driver flags - see DM_FLAGS_...
355 * @acpi_ops: Advanced Configuration and Power Interface (ACPI) operations,
356 * allowing the device to add things to the ACPI tables passed to Linux
361 const struct udevice_id *of_match;
362 int (*bind)(struct udevice *dev);
363 int (*probe)(struct udevice *dev);
364 int (*remove)(struct udevice *dev);
365 int (*unbind)(struct udevice *dev);
366 int (*of_to_plat)(struct udevice *dev);
367 int (*child_post_bind)(struct udevice *dev);
368 int (*child_pre_probe)(struct udevice *dev);
369 int (*child_post_remove)(struct udevice *dev);
373 int per_child_plat_auto;
374 const void *ops; /* driver-specific operations */
376 #if CONFIG_IS_ENABLED(ACPIGEN)
377 struct acpi_ops *acpi_ops;
381 /* Declare a new U-Boot driver */
382 #define U_BOOT_DRIVER(__name) \
383 ll_entry_declare(struct driver, __name, driver)
385 /* Get a pointer to a given driver */
386 #define DM_DRIVER_GET(__name) \
387 ll_entry_get(struct driver, __name, driver)
390 * DM_DRIVER_REF() - Get a reference to a driver
392 * This is useful in data structures and code for referencing a driver at
393 * build time. Before this is used, an extern U_BOOT_DRIVER() must have been
398 * extern U_BOOT_DRIVER(sandbox_fixed_clock);
400 * struct driver *drvs[] = {
401 * DM_DRIVER_REF(sandbox_fixed_clock),
404 * @_name: Name of the driver. This must be a valid C identifier, used by the
406 * @returns struct driver * for the driver
408 #define DM_DRIVER_REF(_name) \
409 ll_entry_ref(struct driver, _name, driver)
412 * Declare a macro to state a alias for a driver name. This macro will
413 * produce no code but its information will be parsed by tools like
416 #define DM_DRIVER_ALIAS(__name, __alias)
419 * Declare a macro to indicate which phase of U-Boot this driver is fore.
422 * This macro produces no code but its information will be parsed by dtoc. The
423 * macro can be only be used once in a driver. Put it within the U_BOOT_DRIVER()
426 * U_BOOT_DRIVER(cpu) = {
432 #define DM_PHASE(_phase)
435 * Declare a macro to declare a header needed for a driver. Often the correct
436 * header can be found automatically, but only for struct declarations. For
437 * enums and #defines used in the driver declaration and declared in a different
438 * header from the structs, this macro must be used.
440 * This macro produces no code but its information will be parsed by dtoc. The
441 * macro can be used multiple times with different headers, for the same driver.
442 * Put it within the U_BOOT_DRIVER() declaration, e.g.:
444 * U_BOOT_DRIVER(cpu) = {
447 * DM_HEADER(<asm/cpu.h>)
450 #define DM_HEADER(_hdr)
453 * dev_get_plat() - Get the platform data for a device
455 * This checks that dev is not NULL, but no other checks for now
457 * @dev Device to check
458 * @return platform data, or NULL if none
460 void *dev_get_plat(const struct udevice *dev);
463 * dev_get_parent_plat() - Get the parent platform data for a device
465 * This checks that dev is not NULL, but no other checks for now
467 * @dev Device to check
468 * @return parent's platform data, or NULL if none
470 void *dev_get_parent_plat(const struct udevice *dev);
473 * dev_get_uclass_plat() - Get the uclass platform data for a device
475 * This checks that dev is not NULL, but no other checks for now
477 * @dev Device to check
478 * @return uclass's platform data, or NULL if none
480 void *dev_get_uclass_plat(const struct udevice *dev);
483 * dev_get_priv() - Get the private data for a device
485 * This checks that dev is not NULL, but no other checks for now
487 * @dev Device to check
488 * @return private data, or NULL if none
490 void *dev_get_priv(const struct udevice *dev);
493 * dev_get_parent_priv() - Get the parent private data for a device
495 * The parent private data is data stored in the device but owned by the
496 * parent. For example, a USB device may have parent data which contains
497 * information about how to talk to the device over USB.
499 * This checks that dev is not NULL, but no other checks for now
501 * @dev Device to check
502 * @return parent data, or NULL if none
504 void *dev_get_parent_priv(const struct udevice *dev);
507 * dev_get_uclass_priv() - Get the private uclass data for a device
509 * This checks that dev is not NULL, but no other checks for now
511 * @dev Device to check
512 * @return private uclass data for this device, or NULL if none
514 void *dev_get_uclass_priv(const struct udevice *dev);
517 * struct dev_get_parent() - Get the parent of a device
519 * @child: Child to check
520 * @return parent of child, or NULL if this is the root device
522 struct udevice *dev_get_parent(const struct udevice *child);
525 * dev_get_driver_data() - get the driver data used to bind a device
527 * When a device is bound using a device tree node, it matches a
528 * particular compatible string in struct udevice_id. This function
529 * returns the associated data value for that compatible string. This is
530 * the 'data' field in struct udevice_id.
532 * As an example, consider this structure:
533 * static const struct udevice_id tegra_i2c_ids[] = {
534 * { .compatible = "nvidia,tegra114-i2c", .data = TYPE_114 },
535 * { .compatible = "nvidia,tegra20-i2c", .data = TYPE_STD },
536 * { .compatible = "nvidia,tegra20-i2c-dvc", .data = TYPE_DVC },
540 * When driver model finds a driver for this it will store the 'data' value
541 * corresponding to the compatible string it matches. This function returns
542 * that value. This allows the driver to handle several variants of a device.
544 * For USB devices, this is the driver_info field in struct usb_device_id.
546 * @dev: Device to check
547 * @return driver data (0 if none is provided)
549 ulong dev_get_driver_data(const struct udevice *dev);
552 * dev_get_driver_ops() - get the device's driver's operations
554 * This checks that dev is not NULL, and returns the pointer to device's
555 * driver's operations.
557 * @dev: Device to check
558 * @return void pointer to driver's operations or NULL for NULL-dev or NULL-ops
560 const void *dev_get_driver_ops(const struct udevice *dev);
563 * device_get_uclass_id() - return the uclass ID of a device
565 * @dev: Device to check
566 * @return uclass ID for the device
568 enum uclass_id device_get_uclass_id(const struct udevice *dev);
571 * dev_get_uclass_name() - return the uclass name of a device
573 * This checks that dev is not NULL.
575 * @dev: Device to check
576 * @return pointer to the uclass name for the device
578 const char *dev_get_uclass_name(const struct udevice *dev);
581 * device_get_child() - Get the child of a device by index
583 * Returns the numbered child, 0 being the first. This does not use
584 * sequence numbers, only the natural order.
586 * @dev: Parent device to check
587 * @index: Child index
588 * @devp: Returns pointer to device
589 * @return 0 if OK, -ENODEV if no such device, other error if the device fails
592 int device_get_child(const struct udevice *parent, int index,
593 struct udevice **devp);
596 * device_get_child_count() - Get the available child count of a device
598 * Returns the number of children to a device.
600 * @parent: Parent device to check
602 int device_get_child_count(const struct udevice *parent);
605 * device_find_child_by_seq() - Find a child device based on a sequence
607 * This searches for a device with the given seq.
609 * @parent: Parent device
610 * @seq: Sequence number to find (0=first)
611 * @devp: Returns pointer to device (there is only one per for each seq).
612 * Set to NULL if none is found
613 * @return 0 if OK, -ENODEV if not found
615 int device_find_child_by_seq(const struct udevice *parent, int seq,
616 struct udevice **devp);
619 * device_get_child_by_seq() - Get a child device based on a sequence
621 * If an active device has this sequence it will be returned. If there is no
622 * such device then this will check for a device that is requesting this
625 * The device is probed to activate it ready for use.
627 * @parent: Parent device
628 * @seq: Sequence number to find (0=first)
629 * @devp: Returns pointer to device (there is only one per for each seq)
630 * Set to NULL if none is found
631 * @return 0 if OK, -ve on error
633 int device_get_child_by_seq(const struct udevice *parent, int seq,
634 struct udevice **devp);
637 * device_find_child_by_of_offset() - Find a child device based on FDT offset
639 * Locates a child device by its device tree offset.
641 * @parent: Parent device
642 * @of_offset: Device tree offset to find
643 * @devp: Returns pointer to device if found, otherwise this is set to NULL
644 * @return 0 if OK, -ve on error
646 int device_find_child_by_of_offset(const struct udevice *parent, int of_offset,
647 struct udevice **devp);
650 * device_get_child_by_of_offset() - Get a child device based on FDT offset
652 * Locates a child device by its device tree offset.
654 * The device is probed to activate it ready for use.
656 * @parent: Parent device
657 * @of_offset: Device tree offset to find
658 * @devp: Returns pointer to device if found, otherwise this is set to NULL
659 * @return 0 if OK, -ve on error
661 int device_get_child_by_of_offset(const struct udevice *parent, int of_offset,
662 struct udevice **devp);
665 * device_find_global_by_ofnode() - Get a device based on ofnode
667 * Locates a device by its device tree ofnode, searching globally throughout
668 * the all driver model devices.
670 * The device is NOT probed
672 * @node: Device tree ofnode to find
673 * @devp: Returns pointer to device if found, otherwise this is set to NULL
674 * @return 0 if OK, -ve on error
677 int device_find_global_by_ofnode(ofnode node, struct udevice **devp);
680 * device_get_global_by_ofnode() - Get a device based on ofnode
682 * Locates a device by its device tree ofnode, searching globally throughout
683 * the all driver model devices.
685 * The device is probed to activate it ready for use.
687 * @node: Device tree ofnode to find
688 * @devp: Returns pointer to device if found, otherwise this is set to NULL
689 * @return 0 if OK, -ve on error
691 int device_get_global_by_ofnode(ofnode node, struct udevice **devp);
694 * device_get_by_ofplat_idx() - Get a device based on of-platdata index
696 * Locates a device by either its struct driver_info index, or its
697 * struct udevice index. The latter is used with OF_PLATDATA_INST, since we have
698 * a list of build-time instantiated struct udevice records, The former is used
699 * with !OF_PLATDATA_INST since in that case we have a list of
700 * struct driver_info records.
702 * The index number is written into the idx field of struct phandle_1_arg, etc.
703 * It is the position of this driver_info/udevice in its linker list.
705 * The device is probed to activate it ready for use.
707 * @idx: Index number of the driver_info/udevice structure (0=first)
708 * @devp: Returns pointer to device if found, otherwise this is set to NULL
709 * @return 0 if OK, -ve on error
711 int device_get_by_ofplat_idx(uint idx, struct udevice **devp);
714 * device_find_first_child() - Find the first child of a device
716 * @parent: Parent device to search
717 * @devp: Returns first child device, or NULL if none
720 int device_find_first_child(const struct udevice *parent,
721 struct udevice **devp);
724 * device_find_next_child() - Find the next child of a device
726 * @devp: Pointer to previous child device on entry. Returns pointer to next
727 * child device, or NULL if none
730 int device_find_next_child(struct udevice **devp);
733 * device_find_first_inactive_child() - Find the first inactive child
735 * This is used to locate an existing child of a device which is of a given
738 * The device is NOT probed
740 * @parent: Parent device to search
741 * @uclass_id: Uclass to look for
742 * @devp: Returns device found, if any, else NULL
743 * @return 0 if found, else -ENODEV
745 int device_find_first_inactive_child(const struct udevice *parent,
746 enum uclass_id uclass_id,
747 struct udevice **devp);
750 * device_find_first_child_by_uclass() - Find the first child of a device in uc
752 * @parent: Parent device to search
753 * @uclass_id: Uclass to look for
754 * @devp: Returns first child device in that uclass, if any, else NULL
755 * @return 0 if found, else -ENODEV
757 int device_find_first_child_by_uclass(const struct udevice *parent,
758 enum uclass_id uclass_id,
759 struct udevice **devp);
762 * device_find_child_by_name() - Find a child by device name
764 * @parent: Parent device to search
765 * @name: Name to look for
766 * @devp: Returns device found, if any
767 * @return 0 if found, else -ENODEV
769 int device_find_child_by_name(const struct udevice *parent, const char *name,
770 struct udevice **devp);
773 * device_first_child_ofdata_err() - Find the first child and reads its plat
775 * The of_to_plat() method is called on the child before it is returned,
776 * but the child is not probed.
778 * @parent: Parent to check
779 * @devp: Returns child that was found, if any
780 * @return 0 on success, -ENODEV if no children, other -ve on error
782 int device_first_child_ofdata_err(struct udevice *parent,
783 struct udevice **devp);
786 * device_next_child_ofdata_err() - Find the next child and read its plat
788 * The of_to_plat() method is called on the child before it is returned,
789 * but the child is not probed.
791 * @devp: On entry, points to the previous child; on exit returns the child that
793 * @return 0 on success, -ENODEV if no children, other -ve on error
795 int device_next_child_ofdata_err(struct udevice **devp);
798 * device_first_child_err() - Get the first child of a device
800 * The device returned is probed if necessary, and ready for use
802 * @parent: Parent device to search
803 * @devp: Returns device found, if any
804 * @return 0 if found, -ENODEV if not, -ve error if device failed to probe
806 int device_first_child_err(struct udevice *parent, struct udevice **devp);
809 * device_next_child_err() - Get the next child of a parent device
811 * The device returned is probed if necessary, and ready for use
813 * @devp: On entry, pointer to device to lookup. On exit, returns pointer
814 * to the next sibling if no error occurred
815 * @return 0 if found, -ENODEV if not, -ve error if device failed to probe
817 int device_next_child_err(struct udevice **devp);
820 * device_has_children() - check if a device has any children
822 * @dev: Device to check
823 * @return true if the device has one or more children
825 bool device_has_children(const struct udevice *dev);
828 * device_has_active_children() - check if a device has any active children
830 * @dev: Device to check
831 * @return true if the device has one or more children and at least one of
832 * them is active (probed).
834 bool device_has_active_children(const struct udevice *dev);
837 * device_is_last_sibling() - check if a device is the last sibling
839 * This function can be useful for display purposes, when special action needs
840 * to be taken when displaying the last sibling. This can happen when a tree
841 * view of devices is being displayed.
843 * @dev: Device to check
844 * @return true if there are no more siblings after this one - i.e. is it
847 bool device_is_last_sibling(const struct udevice *dev);
850 * device_set_name() - set the name of a device
852 * This must be called in the device's bind() method and no later. Normally
853 * this is unnecessary but for probed devices which don't get a useful name
854 * this function can be helpful.
856 * The name is allocated and will be freed automatically when the device is
859 * @dev: Device to update
860 * @name: New name (this string is allocated new memory and attached to
862 * @return 0 if OK, -ENOMEM if there is not enough memory to allocate the
865 int device_set_name(struct udevice *dev, const char *name);
868 * device_set_name_alloced() - note that a device name is allocated
870 * This sets the DM_FLAG_NAME_ALLOCED flag for the device, so that when it is
871 * unbound the name will be freed. This avoids memory leaks.
873 * @dev: Device to update
875 void device_set_name_alloced(struct udevice *dev);
878 * device_is_compatible() - check if the device is compatible with the compat
880 * This allows to check whether the device is comaptible with the compat.
882 * @dev: udevice pointer for which compatible needs to be verified.
883 * @compat: Compatible string which needs to verified in the given
885 * @return true if OK, false if the compatible is not found
887 bool device_is_compatible(const struct udevice *dev, const char *compat);
890 * of_machine_is_compatible() - check if the machine is compatible with
893 * This allows to check whether the machine is comaptible with the compat.
895 * @compat: Compatible string which needs to verified
896 * @return true if OK, false if the compatible is not found
898 bool of_machine_is_compatible(const char *compat);
901 * dev_disable_by_path() - Disable a device given its device tree path
903 * @path: The device tree path identifying the device to be disabled
904 * @return 0 on success, -ve on error
906 int dev_disable_by_path(const char *path);
909 * dev_enable_by_path() - Enable a device given its device tree path
911 * @path: The device tree path identifying the device to be enabled
912 * @return 0 on success, -ve on error
914 int dev_enable_by_path(const char *path);
917 * device_is_on_pci_bus - Test if a device is on a PCI bus
919 * @dev: device to test
920 * @return: true if it is on a PCI bus, false otherwise
922 static inline bool device_is_on_pci_bus(const struct udevice *dev)
924 return dev->parent && device_get_uclass_id(dev->parent) == UCLASS_PCI;
928 * device_foreach_child_safe() - iterate through child devices safely
930 * This allows the @pos child to be removed in the loop if required.
932 * @pos: struct udevice * for the current device
933 * @next: struct udevice * for the next device
934 * @parent: parent device to scan
936 #define device_foreach_child_safe(pos, next, parent) \
937 list_for_each_entry_safe(pos, next, &parent->child_head, sibling_node)
940 * device_foreach_child() - iterate through child devices
942 * @pos: struct udevice * for the current device
943 * @parent: parent device to scan
945 #define device_foreach_child(pos, parent) \
946 list_for_each_entry(pos, &parent->child_head, sibling_node)
949 * device_foreach_child_of_to_plat() - iterate through children
951 * This stops when it gets an error, with @pos set to the device that failed to
954 * This creates a for() loop which works through the available children of
955 * a device in order from start to end. Device ofdata is read by calling
956 * device_of_to_plat() on each one. The devices are not probed.
958 * @pos: struct udevice * for the current device
959 * @parent: parent device to scan
961 #define device_foreach_child_of_to_plat(pos, parent) \
962 for (int _ret = device_first_child_ofdata_err(parent, &dev); !_ret; \
963 _ret = device_next_child_ofdata_err(&dev))
966 * device_foreach_child_probe() - iterate through children, probing them
968 * This creates a for() loop which works through the available children of
969 * a device in order from start to end. Devices are probed if necessary,
972 * This stops when it gets an error, with @pos set to the device that failed to
975 * @pos: struct udevice * for the current device
976 * @parent: parent device to scan
978 #define device_foreach_child_probe(pos, parent) \
979 for (int _ret = device_first_child_err(parent, &dev); !_ret; \
980 _ret = device_next_child_err(&dev))
983 * dm_scan_fdt_dev() - Bind child device in the device tree
985 * This handles device which have sub-nodes in the device tree. It scans all
986 * sub-nodes and binds drivers for each node where a driver can be found.
988 * If this is called prior to relocation, only pre-relocation devices will be
989 * bound (those marked with u-boot,dm-pre-reloc in the device tree, or where
990 * the driver has the DM_FLAG_PRE_RELOC flag set). Otherwise, all devices will
993 * @dev: Device to scan
994 * @return 0 if OK, -ve on error
996 int dm_scan_fdt_dev(struct udevice *dev);