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)
83 /* Device must be probed after it was bound */
84 #define DM_FLAG_PROBE_AFTER_BIND (1 << 15)
87 * One or multiple of these flags are passed to device_remove() so that
88 * a selective device removal as specified by the remove-stage and the
89 * driver flags can be done.
91 * DO NOT use these flags in your driver's @flags value...
92 * use the above DM_FLAG_... values instead
95 /* Normal remove, remove all devices */
96 DM_REMOVE_NORMAL = 1 << 0,
98 /* Remove devices with active DMA */
99 DM_REMOVE_ACTIVE_DMA = DM_FLAG_ACTIVE_DMA,
101 /* Remove devices which need some final OS preparation steps */
102 DM_REMOVE_OS_PREPARE = DM_FLAG_OS_PREPARE,
104 /* Remove only devices that are not marked vital */
105 DM_REMOVE_NON_VITAL = DM_FLAG_VITAL,
107 /* Remove devices with any active flag */
108 DM_REMOVE_ACTIVE_ALL = DM_REMOVE_ACTIVE_DMA | DM_REMOVE_OS_PREPARE,
110 /* Don't power down any attached power domains */
111 DM_REMOVE_NO_PD = 1 << 1,
115 * struct udevice - An instance of a driver
117 * This holds information about a device, which is a driver bound to a
118 * particular port or peripheral (essentially a driver instance).
120 * A device will come into existence through a 'bind' call, either due to
121 * a U_BOOT_DRVINFO() macro (in which case plat is non-NULL) or a node
122 * in the device tree (in which case of_offset is >= 0). In the latter case
123 * we translate the device tree information into plat in a function
124 * implemented by the driver of_to_plat method (called just before the
125 * probe method if the device has a device tree node.
127 * All three of plat, priv and uclass_priv can be allocated by the
128 * driver, or you can use the auto members of struct driver and
129 * struct uclass_driver to have driver model do this automatically.
131 * @driver: The driver used by this device
132 * @name: Name of device, typically the FDT node name
133 * @plat_: Configuration data for this device (do not access outside driver
135 * @parent_plat_: The parent bus's configuration data for this device (do not
136 * access outside driver model)
137 * @uclass_plat_: The uclass's configuration data for this device (do not access
138 * outside driver model)
139 * @driver_data: Driver data word for the entry that matched this device with
141 * @parent: Parent of this device, or NULL for the top level device
142 * @priv_: Private data for this device (do not access outside driver model)
143 * @uclass: Pointer to uclass for this device
144 * @uclass_priv_: The uclass's private data for this device (do not access
145 * outside driver model)
146 * @parent_priv_: The parent's private data for this device (do not access
147 * outside driver model)
148 * @uclass_node: Used by uclass to link its devices
149 * @child_head: List of children of this device
150 * @sibling_node: Next device in list of all devices
151 * @flags_: Flags for this device `DM_FLAG_...` (do not access outside driver
153 * @seq_: Allocated sequence number for this device (-1 = none). This is set up
154 * when the device is bound and is unique within the device's uclass. If the
155 * device has an alias in the devicetree then that is used to set the sequence
156 * number. Otherwise, the next available number is used. Sequence numbers are
157 * used by certain commands that need device to be numbered (e.g. 'mmc dev').
158 * (do not access outside driver model)
159 * @node_: Reference to device tree node for this device (do not access outside
161 * @devres_head: List of memory allocations associated with this device.
162 * When CONFIG_DEVRES is enabled, devm_kmalloc() and friends will
163 * add to this list. Memory so-allocated will be freed
164 * automatically when the device is removed / unbound
165 * @dma_offset: Offset between the physical address space (CPU's) and the
166 * device's bus address space
169 const struct driver *driver;
175 struct udevice *parent;
177 struct uclass *uclass;
180 struct list_head uclass_node;
181 struct list_head child_head;
182 struct list_head sibling_node;
183 #if !CONFIG_IS_ENABLED(OF_PLATDATA_RT)
187 #if CONFIG_IS_ENABLED(OF_REAL)
190 #if CONFIG_IS_ENABLED(DEVRES)
191 struct list_head devres_head;
193 #if CONFIG_IS_ENABLED(DM_DMA)
198 static inline int dm_udevice_size(void)
200 if (CONFIG_IS_ENABLED(OF_PLATDATA_RT))
201 return ALIGN(sizeof(struct udevice), CONFIG_LINKER_LIST_ALIGN);
203 return sizeof(struct udevice);
207 * struct udevice_rt - runtime information set up by U-Boot
209 * This is only used with OF_PLATDATA_RT
211 * There is one of these for every udevice in the linker list, indexed by
212 * the udevice_info idx value.
214 * @flags_: Flags for this device `DM_FLAG_...` (do not access outside driver
221 /* Maximum sequence number supported and associated string length */
222 #define DM_MAX_SEQ 999
223 #define DM_MAX_SEQ_STR 3
225 /* Returns the operations for a device */
226 #define device_get_ops(dev) ((dev)->driver->ops)
228 #if CONFIG_IS_ENABLED(OF_PLATDATA_RT)
229 u32 dev_get_flags(const struct udevice *dev);
230 void dev_or_flags(const struct udevice *dev, u32 or);
231 void dev_bic_flags(const struct udevice *dev, u32 bic);
233 static inline u32 dev_get_flags(const struct udevice *dev)
238 static inline void dev_or_flags(struct udevice *dev, u32 or)
243 static inline void dev_bic_flags(struct udevice *dev, u32 bic)
247 #endif /* OF_PLATDATA_RT */
250 * dev_ofnode() - get the DT node reference associated with a udevice
252 * @dev: device to check
253 * Return: reference of the device's DT node
255 static inline ofnode dev_ofnode(const struct udevice *dev)
257 #if CONFIG_IS_ENABLED(OF_REAL)
260 return ofnode_null();
264 /* Returns non-zero if the device is active (probed and not removed) */
265 #define device_active(dev) (dev_get_flags(dev) & DM_FLAG_ACTIVATED)
267 #if CONFIG_IS_ENABLED(DM_DMA)
268 #define dev_set_dma_offset(_dev, _offset) _dev->dma_offset = _offset
269 #define dev_get_dma_offset(_dev) _dev->dma_offset
271 #define dev_set_dma_offset(_dev, _offset)
272 #define dev_get_dma_offset(_dev) 0
275 static inline int dev_of_offset(const struct udevice *dev)
277 #if CONFIG_IS_ENABLED(OF_REAL)
278 return ofnode_to_offset(dev_ofnode(dev));
284 static inline bool dev_has_ofnode(const struct udevice *dev)
286 #if CONFIG_IS_ENABLED(OF_REAL)
287 return ofnode_valid(dev_ofnode(dev));
293 static inline void dev_set_ofnode(struct udevice *dev, ofnode node)
295 #if CONFIG_IS_ENABLED(OF_REAL)
300 static inline int dev_seq(const struct udevice *dev)
306 * struct udevice_id - Lists the compatible strings supported by a driver
307 * @compatible: Compatible string
308 * @data: Data for this compatible string
311 const char *compatible;
315 #if CONFIG_IS_ENABLED(OF_REAL)
316 #define of_match_ptr(_ptr) (_ptr)
318 #define of_match_ptr(_ptr) NULL
319 #endif /* CONFIG_IS_ENABLED(OF_CONTROL) */
322 * struct driver - A driver for a feature or peripheral
324 * This holds methods for setting up a new device, and also removing it.
325 * The device needs information to set itself up - this is provided either
326 * by plat or a device tree node (which we find by looking up
327 * matching compatible strings with of_match).
329 * Drivers all belong to a uclass, representing a class of devices of the
330 * same type. Common elements of the drivers can be implemented in the uclass,
331 * or the uclass can provide a consistent interface to the drivers within
335 * @id: Identifies the uclass we belong to
336 * @of_match: List of compatible strings to match, and any identifying data
338 * @bind: Called to bind a device to its driver
339 * @probe: Called to probe a device, i.e. activate it
340 * @remove: Called to remove a device, i.e. de-activate it
341 * @unbind: Called to unbind a device from its driver
342 * @of_to_plat: Called before probe to decode device tree data
343 * @child_post_bind: Called after a new child has been bound
344 * @child_pre_probe: Called before a child device is probed. The device has
345 * memory allocated but it has not yet been probed.
346 * @child_post_remove: Called after a child device is removed. The device
347 * has memory allocated but its device_remove() method has been called.
348 * @priv_auto: If non-zero this is the size of the private data
349 * to be allocated in the device's ->priv pointer. If zero, then the driver
350 * is responsible for allocating any data required.
351 * @plat_auto: If non-zero this is the size of the
352 * platform data to be allocated in the device's ->plat pointer.
353 * This is typically only useful for device-tree-aware drivers (those with
354 * an of_match), since drivers which use plat will have the data
355 * provided in the U_BOOT_DRVINFO() instantiation.
356 * @per_child_auto: Each device can hold private data owned by
357 * its parent. If required this will be automatically allocated if this
359 * @per_child_plat_auto: A bus likes to store information about
360 * its children. If non-zero this is the size of this data, to be allocated
361 * in the child's parent_plat pointer.
362 * @ops: Driver-specific operations. This is typically a list of function
363 * pointers defined by the driver, to implement driver functions required by
365 * @flags: driver flags - see `DM_FLAGS_...`
366 * @acpi_ops: Advanced Configuration and Power Interface (ACPI) operations,
367 * allowing the device to add things to the ACPI tables passed to Linux
372 const struct udevice_id *of_match;
373 int (*bind)(struct udevice *dev);
374 int (*probe)(struct udevice *dev);
375 int (*remove)(struct udevice *dev);
376 int (*unbind)(struct udevice *dev);
377 int (*of_to_plat)(struct udevice *dev);
378 int (*child_post_bind)(struct udevice *dev);
379 int (*child_pre_probe)(struct udevice *dev);
380 int (*child_post_remove)(struct udevice *dev);
384 int per_child_plat_auto;
385 const void *ops; /* driver-specific operations */
387 #if CONFIG_IS_ENABLED(ACPIGEN)
388 struct acpi_ops *acpi_ops;
393 * U_BOOT_DRIVER() - Declare a new U-Boot driver
394 * @__name: name of the driver
396 #define U_BOOT_DRIVER(__name) \
397 ll_entry_declare(struct driver, __name, driver)
400 * DM_DRIVER_GET() - Get a pointer to a given driver
402 * This is useful in code for referencing a driver at build time.
403 * Before this is used, an extern U_BOOT_DRIVER() must have been
406 * @__name: Name of the driver. This must be a valid C identifier,
407 * used by the linker_list
408 * Return: struct driver * for the driver
410 #define DM_DRIVER_GET(__name) \
411 ll_entry_get(struct driver, __name, driver)
414 * DM_DRIVER_REF() - Get a reference to a driver
416 * This is useful in data structures and code for referencing a driver at
417 * build time. Before this is used, an extern U_BOOT_DRIVER() must have been
419 * This is like DM_DRIVER_GET, but without the extra code, so it is suitable
420 * for putting into data structures.
424 * extern U_BOOT_DRIVER(sandbox_fixed_clock);
425 * struct driver *drvs[] = {
426 * DM_DRIVER_REF(sandbox_fixed_clock),
429 * @_name: Name of the driver. This must be a valid C identifier,
430 * used by the linker_list
431 * Return: struct driver * for the driver
433 #define DM_DRIVER_REF(_name) \
434 ll_entry_ref(struct driver, _name, driver)
437 * DM_DRIVER_ALIAS() - Declare a macro to state an alias for a driver name
439 * This macro will produce no code but its information will be parsed by tools
442 * @__name: name of driver
443 * @__alias: alias for the driver name
445 #define DM_DRIVER_ALIAS(__name, __alias)
448 * DM_PHASE() - Declare a macro to indicate which phase of U-Boot this driver is for.
450 * This macro produces no code but its information will be parsed by dtoc. The
451 * macro can be only be used once in a driver. Put it within the U_BOOT_DRIVER()
452 * declaration, e.g.::
454 * U_BOOT_DRIVER(cpu) = {
460 * @_phase: Associated phase of U-Boot ("spl", "tpl")
462 #define DM_PHASE(_phase)
465 * DM_HEADER() - Declare a macro to declare a header needed for a driver.
467 * Often the correct header can be found automatically, but only for struct
468 * declarations. For enums and #defines used in the driver declaration and
469 * declared in a different header from the structs, this macro must be used.
471 * This macro produces no code but its information will be parsed by dtoc. The
472 * macro can be used multiple times with different headers, for the same driver.
473 * Put it within the U_BOOT_DRIVER() declaration, e.g.::
475 * U_BOOT_DRIVER(cpu) = {
478 * DM_HEADER(<asm/cpu.h>)
481 * @_hdr: header needed for a driver
483 #define DM_HEADER(_hdr)
486 * dev_get_plat() - Get the platform data for a device
488 * This checks that dev is not NULL, but no other checks for now
490 * @dev: Device to check
491 * Return: platform data, or NULL if none
493 void *dev_get_plat(const struct udevice *dev);
496 * dev_get_parent_plat() - Get the parent platform data for a device
498 * This checks that dev is not NULL, but no other checks for now
500 * @dev: Device to check
501 * Return: parent's platform data, or NULL if none
503 void *dev_get_parent_plat(const struct udevice *dev);
506 * dev_get_uclass_plat() - Get the uclass platform data for a device
508 * This checks that dev is not NULL, but no other checks for now
510 * @dev: Device to check
511 * Return: uclass's platform data, or NULL if none
513 void *dev_get_uclass_plat(const struct udevice *dev);
516 * dev_get_priv() - Get the private data for a device
518 * This checks that dev is not NULL, but no other checks for now
520 * @dev: Device to check
521 * Return: private data, or NULL if none
523 void *dev_get_priv(const struct udevice *dev);
526 * dev_get_parent_priv() - Get the parent private data for a device
528 * The parent private data is data stored in the device but owned by the
529 * parent. For example, a USB device may have parent data which contains
530 * information about how to talk to the device over USB.
532 * This checks that dev is not NULL, but no other checks for now
534 * @dev: Device to check
535 * Return: parent data, or NULL if none
537 void *dev_get_parent_priv(const struct udevice *dev);
540 * dev_get_uclass_priv() - Get the private uclass data for a device
542 * This checks that dev is not NULL, but no other checks for now
544 * @dev: Device to check
545 * Return: private uclass data for this device, or NULL if none
547 void *dev_get_uclass_priv(const struct udevice *dev);
550 * dev_get_parent() - Get the parent of a device
552 * @child: Child to check
553 * Return: parent of child, or NULL if this is the root device
555 struct udevice *dev_get_parent(const struct udevice *child);
558 * dev_get_driver_data() - get the driver data used to bind a device
560 * When a device is bound using a device tree node, it matches a
561 * particular compatible string in struct udevice_id. This function
562 * returns the associated data value for that compatible string. This is
563 * the 'data' field in struct udevice_id.
565 * As an example, consider this structure::
567 * static const struct udevice_id tegra_i2c_ids[] = {
568 * { .compatible = "nvidia,tegra114-i2c", .data = TYPE_114 },
569 * { .compatible = "nvidia,tegra20-i2c", .data = TYPE_STD },
570 * { .compatible = "nvidia,tegra20-i2c-dvc", .data = TYPE_DVC },
574 * When driver model finds a driver for this it will store the 'data' value
575 * corresponding to the compatible string it matches. This function returns
576 * that value. This allows the driver to handle several variants of a device.
578 * For USB devices, this is the driver_info field in struct usb_device_id.
580 * @dev: Device to check
581 * Return: driver data (0 if none is provided)
583 ulong dev_get_driver_data(const struct udevice *dev);
586 * dev_get_driver_ops() - get the device's driver's operations
588 * This checks that dev is not NULL, and returns the pointer to device's
589 * driver's operations.
591 * @dev: Device to check
592 * Return: void pointer to driver's operations or NULL for NULL-dev or NULL-ops
594 const void *dev_get_driver_ops(const struct udevice *dev);
597 * device_get_uclass_id() - return the uclass ID of a device
599 * @dev: Device to check
600 * Return: uclass ID for the device
602 enum uclass_id device_get_uclass_id(const struct udevice *dev);
605 * dev_get_uclass_name() - return the uclass name of a device
607 * This checks that dev is not NULL.
609 * @dev: Device to check
610 * Return: pointer to the uclass name for the device
612 const char *dev_get_uclass_name(const struct udevice *dev);
615 * device_get_child() - Get the child of a device by index
617 * Returns the numbered child, 0 being the first. This does not use
618 * sequence numbers, only the natural order.
620 * @parent: Parent device to check
621 * @index: Child index
622 * @devp: Returns pointer to device
624 * 0 if OK, -ENODEV if no such device, other error if the device fails to probe
626 int device_get_child(const struct udevice *parent, int index,
627 struct udevice **devp);
630 * device_get_child_count() - Get the child count of a device
632 * Returns the number of children to a device.
634 * @parent: Parent device to check
636 int device_get_child_count(const struct udevice *parent);
639 * device_get_decendent_count() - Get the total number of decendents of a device
641 * Returns the total number of decendents, including all children
643 * @parent: Parent device to check
645 int device_get_decendent_count(const struct udevice *parent);
648 * device_find_child_by_seq() - Find a child device based on a sequence
650 * This searches for a device with the given seq.
652 * @parent: Parent device
653 * @seq: Sequence number to find (0=first)
654 * @devp: Returns pointer to device (there is only one per for each seq).
655 * Set to NULL if none is found
656 * Return: 0 if OK, -ENODEV if not found
658 int device_find_child_by_seq(const struct udevice *parent, int seq,
659 struct udevice **devp);
662 * device_get_child_by_seq() - Get a child device based on a sequence
664 * If an active device has this sequence it will be returned. If there is no
665 * such device then this will check for a device that is requesting this
668 * The device is probed to activate it ready for use.
670 * @parent: Parent device
671 * @seq: Sequence number to find (0=first)
672 * @devp: Returns pointer to device (there is only one per for each seq)
673 * Set to NULL if none is found
674 * Return: 0 if OK, -ve on error
676 int device_get_child_by_seq(const struct udevice *parent, int seq,
677 struct udevice **devp);
680 * device_find_child_by_of_offset() - Find a child device based on FDT offset
682 * Locates a child device by its device tree offset.
684 * @parent: Parent device
685 * @of_offset: Device tree offset to find
686 * @devp: Returns pointer to device if found, otherwise this is set to NULL
687 * Return: 0 if OK, -ve on error
689 int device_find_child_by_of_offset(const struct udevice *parent, int of_offset,
690 struct udevice **devp);
693 * device_get_child_by_of_offset() - Get a child device based on FDT offset
695 * Locates a child device by its device tree offset.
697 * The device is probed to activate it ready for use.
699 * @parent: Parent device
700 * @of_offset: Device tree offset to find
701 * @devp: Returns pointer to device if found, otherwise this is set to NULL
702 * Return: 0 if OK, -ve on error
704 int device_get_child_by_of_offset(const struct udevice *parent, int of_offset,
705 struct udevice **devp);
708 * device_find_global_by_ofnode() - Get a device based on ofnode
710 * Locates a device by its device tree ofnode, searching globally throughout
711 * the all driver model devices.
713 * The device is NOT probed
715 * @node: Device tree ofnode to find
716 * @devp: Returns pointer to device if found, otherwise this is set to NULL
717 * Return: 0 if OK, -ve on error
720 int device_find_global_by_ofnode(ofnode node, struct udevice **devp);
723 * device_get_global_by_ofnode() - Get a device based on ofnode
725 * Locates a device by its device tree ofnode, searching globally throughout
726 * the all driver model devices.
728 * The device is probed to activate it ready for use.
730 * @node: Device tree ofnode to find
731 * @devp: Returns pointer to device if found, otherwise this is set to NULL
732 * Return: 0 if OK, -ve on error
734 int device_get_global_by_ofnode(ofnode node, struct udevice **devp);
737 * device_get_by_ofplat_idx() - Get a device based on of-platdata index
739 * Locates a device by either its struct driver_info index, or its
740 * struct udevice index. The latter is used with OF_PLATDATA_INST, since we have
741 * a list of build-time instantiated struct udevice records, The former is used
742 * with !OF_PLATDATA_INST since in that case we have a list of
743 * struct driver_info records.
745 * The index number is written into the idx field of struct phandle_1_arg, etc.
746 * It is the position of this driver_info/udevice in its linker list.
748 * The device is probed to activate it ready for use.
750 * @idx: Index number of the driver_info/udevice structure (0=first)
751 * @devp: Returns pointer to device if found, otherwise this is set to NULL
752 * Return: 0 if OK, -ve on error
754 int device_get_by_ofplat_idx(uint idx, struct udevice **devp);
757 * device_find_first_child() - Find the first child of a device
759 * @parent: Parent device to search
760 * @devp: Returns first child device, or NULL if none
763 int device_find_first_child(const struct udevice *parent,
764 struct udevice **devp);
767 * device_find_next_child() - Find the next child of a device
769 * @devp: Pointer to previous child device on entry. Returns pointer to next
770 * child device, or NULL if none
773 int device_find_next_child(struct udevice **devp);
776 * device_find_first_inactive_child() - Find the first inactive child
778 * This is used to locate an existing child of a device which is of a given
781 * The device is NOT probed
783 * @parent: Parent device to search
784 * @uclass_id: Uclass to look for
785 * @devp: Returns device found, if any, else NULL
786 * Return: 0 if found, else -ENODEV
788 int device_find_first_inactive_child(const struct udevice *parent,
789 enum uclass_id uclass_id,
790 struct udevice **devp);
793 * device_find_first_child_by_uclass() - Find the first child of a device in uc
795 * @parent: Parent device to search
796 * @uclass_id: Uclass to look for
797 * @devp: Returns first child device in that uclass, if any, else NULL
798 * Return: 0 if found, else -ENODEV
800 int device_find_first_child_by_uclass(const struct udevice *parent,
801 enum uclass_id uclass_id,
802 struct udevice **devp);
805 * device_find_child_by_namelen() - Find a child by device name
807 * @parent: Parent device to search
808 * @name: Name to look for
809 * @len: Length of the name
810 * @devp: Returns device found, if any
811 * Return: 0 if found, else -ENODEV
813 int device_find_child_by_namelen(const struct udevice *parent, const char *name,
814 int len, struct udevice **devp);
817 * device_find_child_by_name() - Find a child by device name
819 * @parent: Parent device to search
820 * @name: Name to look for
821 * @devp: Returns device found, if any
822 * Return: 0 if found, else -ENODEV
824 int device_find_child_by_name(const struct udevice *parent, const char *name,
825 struct udevice **devp);
828 * device_first_child_ofdata_err() - Find the first child and reads its plat
830 * The of_to_plat() method is called on the child before it is returned,
831 * but the child is not probed.
833 * @parent: Parent to check
834 * @devp: Returns child that was found, if any
835 * Return: 0 on success, -ENODEV if no children, other -ve on error
837 int device_first_child_ofdata_err(struct udevice *parent,
838 struct udevice **devp);
841 * device_next_child_ofdata_err() - Find the next child and read its plat
843 * The of_to_plat() method is called on the child before it is returned,
844 * but the child is not probed.
846 * @devp: On entry, points to the previous child; on exit returns the child that
848 * Return: 0 on success, -ENODEV if no children, other -ve on error
850 int device_next_child_ofdata_err(struct udevice **devp);
853 * device_first_child_err() - Get the first child of a device
855 * The device returned is probed if necessary, and ready for use
857 * @parent: Parent device to search
858 * @devp: Returns device found, if any
859 * Return: 0 if found, -ENODEV if not, -ve error if device failed to probe
861 int device_first_child_err(struct udevice *parent, struct udevice **devp);
864 * device_next_child_err() - Get the next child of a parent device
866 * The device returned is probed if necessary, and ready for use
868 * @devp: On entry, pointer to device to lookup. On exit, returns pointer
869 * to the next sibling if no error occurred
870 * Return: 0 if found, -ENODEV if not, -ve error if device failed to probe
872 int device_next_child_err(struct udevice **devp);
875 * device_has_children() - check if a device has any children
877 * @dev: Device to check
878 * Return: true if the device has one or more children
880 bool device_has_children(const struct udevice *dev);
883 * device_has_active_children() - check if a device has any active children
885 * @dev: Device to check
886 * Return: true if the device has one or more children and at least one of
887 * them is active (probed).
889 bool device_has_active_children(const struct udevice *dev);
892 * device_is_last_sibling() - check if a device is the last sibling
894 * This function can be useful for display purposes, when special action needs
895 * to be taken when displaying the last sibling. This can happen when a tree
896 * view of devices is being displayed.
898 * @dev: Device to check
899 * Return: true if there are no more siblings after this one - i.e. is it
902 bool device_is_last_sibling(const struct udevice *dev);
905 * device_set_name() - set the name of a device
907 * This must be called in the device's bind() method and no later. Normally
908 * this is unnecessary but for probed devices which don't get a useful name
909 * this function can be helpful.
911 * The name is allocated and will be freed automatically when the device is
914 * @dev: Device to update
915 * @name: New name (this string is allocated new memory and attached to
917 * Return: 0 if OK, -ENOMEM if there is not enough memory to allocate the
920 int device_set_name(struct udevice *dev, const char *name);
923 * device_set_name_alloced() - note that a device name is allocated
925 * This sets the DM_FLAG_NAME_ALLOCED flag for the device, so that when it is
926 * unbound the name will be freed. This avoids memory leaks.
928 * @dev: Device to update
930 void device_set_name_alloced(struct udevice *dev);
933 * device_is_compatible() - check if the device is compatible with the compat
935 * This allows to check whether the device is comaptible with the compat.
937 * @dev: udevice pointer for which compatible needs to be verified.
938 * @compat: Compatible string which needs to verified in the given
940 * Return: true if OK, false if the compatible is not found
942 bool device_is_compatible(const struct udevice *dev, const char *compat);
945 * of_machine_is_compatible() - check if the machine is compatible with
948 * This allows to check whether the machine is comaptible with the compat.
950 * @compat: Compatible string which needs to verified
951 * Return: true if OK, false if the compatible is not found
953 bool of_machine_is_compatible(const char *compat);
956 * dev_disable_by_path() - Disable a device given its device tree path
958 * @path: The device tree path identifying the device to be disabled
959 * Return: 0 on success, -ve on error
961 int dev_disable_by_path(const char *path);
964 * dev_enable_by_path() - Enable a device given its device tree path
966 * @path: The device tree path identifying the device to be enabled
967 * Return: 0 on success, -ve on error
969 int dev_enable_by_path(const char *path);
972 * device_is_on_pci_bus - Test if a device is on a PCI bus
974 * @dev: device to test
975 * Return: true if it is on a PCI bus, false otherwise
977 static inline bool device_is_on_pci_bus(const struct udevice *dev)
979 return dev->parent && device_get_uclass_id(dev->parent) == UCLASS_PCI;
983 * device_foreach_child_safe() - iterate through child devices safely
985 * This allows the @pos child to be removed in the loop if required.
987 * @pos: struct udevice * for the current device
988 * @next: struct udevice * for the next device
989 * @parent: parent device to scan
991 #define device_foreach_child_safe(pos, next, parent) \
992 list_for_each_entry_safe(pos, next, &parent->child_head, sibling_node)
995 * device_foreach_child() - iterate through child devices
997 * @pos: struct udevice * for the current device
998 * @parent: parent device to scan
1000 #define device_foreach_child(pos, parent) \
1001 list_for_each_entry(pos, &parent->child_head, sibling_node)
1004 * device_foreach_child_of_to_plat() - iterate through children
1006 * This stops when it gets an error, with @pos set to the device that failed to
1009 * This creates a for() loop which works through the available children of
1010 * a device in order from start to end. Device ofdata is read by calling
1011 * device_of_to_plat() on each one. The devices are not probed.
1013 * @pos: struct udevice * for the current device
1014 * @parent: parent device to scan
1016 #define device_foreach_child_of_to_plat(pos, parent) \
1017 for (int _ret = device_first_child_ofdata_err(parent, &pos); !_ret; \
1018 _ret = device_next_child_ofdata_err(&pos))
1021 * device_foreach_child_probe() - iterate through children, probing them
1023 * This creates a for() loop which works through the available children of
1024 * a device in order from start to end. Devices are probed if necessary,
1025 * and ready for use.
1027 * This stops when it gets an error, with @pos set to the device that failed to
1030 * @pos: struct udevice * for the current device
1031 * @parent: parent device to scan
1033 #define device_foreach_child_probe(pos, parent) \
1034 for (int _ret = device_first_child_err(parent, &pos); !_ret; \
1035 _ret = device_next_child_err(&pos))
1038 * dm_scan_fdt_dev() - Bind child device in the device tree
1040 * This handles device which have sub-nodes in the device tree. It scans all
1041 * sub-nodes and binds drivers for each node where a driver can be found.
1043 * If this is called prior to relocation, only pre-relocation devices will be
1044 * bound (those marked with u-boot,dm-pre-reloc in the device tree, or where
1045 * the driver has the DM_FLAG_PRE_RELOC flag set). Otherwise, all devices will
1048 * @dev: Device to scan
1049 * Return: 0 if OK, -ve on error
1051 int dm_scan_fdt_dev(struct udevice *dev);