1 /* SPDX-License-Identifier: GPL-2.0+ */
3 * Copyright (c) 2017 Google, Inc
4 * Written by Simon Glass <sjg@chromium.org>
10 /* TODO(sjg@chromium.org): Drop fdtdec.h include */
14 /* Enable checks to protect against invalid calls */
20 * ofnode - reference to a device tree node
22 * This union can hold either a straightforward pointer to a struct device_node
23 * in the live device tree, or an offset within the flat device tree. In the
24 * latter case, the pointer value is just the integer offset within the flat DT.
26 * Thus we can reference nodes in both the live tree (once available) and the
27 * flat tree (until then). Functions are available to translate between an
28 * ofnode and either an offset or a struct device_node *.
30 * The reference can also hold a null offset, in which case the pointer value
31 * here is NULL. This corresponds to a struct device_node * value of
32 * NULL, or an offset of -1.
34 * There is no ambiguity as to whether ofnode holds an offset or a node
35 * pointer: when the live tree is active it holds a node pointer, otherwise it
36 * holds an offset. The value itself does not need to be unique and in theory
37 * the same value could point to a valid device node or a valid offset. We
38 * could arrange for a unique value to be used (e.g. by making the pointer
39 * point to an offset within the flat device tree in the case of an offset) but
40 * this increases code size slightly due to the subtraction. Since it offers no
41 * real benefit, the approach described here seems best.
43 * For now these points use constant types, since we don't allow writing
46 * @np: Pointer to device node, used for live tree
47 * @of_offset: Pointer into flat device tree, used for flat tree. Note that this
48 * is not a really a pointer to a node: it is an offset value. See above.
50 typedef union ofnode_union {
51 const struct device_node *np; /* will be used for future live tree */
55 struct ofnode_phandle_args {
58 uint32_t args[OF_MAX_PHANDLE_ARGS];
62 * _ofnode_to_np() - convert an ofnode to a live DT node pointer
64 * This cannot be called if the reference contains an offset.
66 * @node: Reference containing struct device_node * (possibly invalid)
67 * @return pointer to device node (can be NULL)
69 static inline const struct device_node *ofnode_to_np(ofnode node)
72 if (!of_live_active())
79 * ofnode_to_offset() - convert an ofnode to a flat DT offset
81 * This cannot be called if the reference contains a node pointer.
83 * @node: Reference containing offset (possibly invalid)
84 * @return DT offset (can be -1)
86 static inline int ofnode_to_offset(ofnode node)
92 return node.of_offset;
96 * ofnode_valid() - check if an ofnode is valid
98 * @return true if the reference contains a valid ofnode, false if it is NULL
100 static inline bool ofnode_valid(ofnode node)
102 if (of_live_active())
103 return node.np != NULL;
105 return node.of_offset != -1;
109 * offset_to_ofnode() - convert a DT offset to an ofnode
111 * @of_offset: DT offset (either valid, or -1)
112 * @return reference to the associated DT offset
114 static inline ofnode offset_to_ofnode(int of_offset)
118 if (of_live_active())
121 node.of_offset = of_offset >= 0 ? of_offset : -1;
127 * np_to_ofnode() - convert a node pointer to an ofnode
129 * @np: Live node pointer (can be NULL)
130 * @return reference to the associated node pointer
132 static inline ofnode np_to_ofnode(const struct device_node *np)
142 * ofnode_is_np() - check if a reference is a node pointer
144 * This function associated that if there is a valid live tree then all
145 * references will use it. This is because using the flat DT when the live tree
146 * is valid is not permitted.
148 * @node: reference to check (possibly invalid)
149 * @return true if the reference is a live node pointer, false if it is a DT
152 static inline bool ofnode_is_np(ofnode node)
156 * Check our assumption that flat tree offsets are not used when a
157 * live tree is in use.
159 assert(!ofnode_valid(node) ||
160 (of_live_active() ? _ofnode_to_np(node)
161 : _ofnode_to_np(node)));
163 return of_live_active() && ofnode_valid(node);
167 * ofnode_equal() - check if two references are equal
169 * @return true if equal, else false
171 static inline bool ofnode_equal(ofnode ref1, ofnode ref2)
173 /* We only need to compare the contents */
174 return ref1.of_offset == ref2.of_offset;
178 * ofnode_null() - Obtain a null ofnode
180 * This returns an ofnode which points to no node. It works both with the flat
183 static inline ofnode ofnode_null(void)
187 if (of_live_active())
196 * ofnode_read_u32() - Read a 32-bit integer from a property
198 * @ref: valid node reference to read property from
199 * @propname: name of the property to read from
200 * @outp: place to put value (if found)
201 * @return 0 if OK, -ve on error
203 int ofnode_read_u32(ofnode node, const char *propname, u32 *outp);
206 * ofnode_read_s32() - Read a 32-bit integer from a property
208 * @ref: valid node reference to read property from
209 * @propname: name of the property to read from
210 * @outp: place to put value (if found)
211 * @return 0 if OK, -ve on error
213 static inline int ofnode_read_s32(ofnode node, const char *propname,
216 return ofnode_read_u32(node, propname, (u32 *)out_value);
220 * ofnode_read_u32_default() - Read a 32-bit integer from a property
222 * @ref: valid node reference to read property from
223 * @propname: name of the property to read from
224 * @def: default value to return if the property has no value
225 * @return property value, or @def if not found
227 u32 ofnode_read_u32_default(ofnode ref, const char *propname, u32 def);
230 * ofnode_read_s32_default() - Read a 32-bit integer from a property
232 * @ref: valid node reference to read property from
233 * @propname: name of the property to read from
234 * @def: default value to return if the property has no value
235 * @return property value, or @def if not found
237 int ofnode_read_s32_default(ofnode node, const char *propname, s32 def);
240 * ofnode_read_u64() - Read a 64-bit integer from a property
242 * @node: valid node reference to read property from
243 * @propname: name of the property to read from
244 * @outp: place to put value (if found)
245 * @return 0 if OK, -ve on error
247 int ofnode_read_u64(ofnode node, const char *propname, u64 *outp);
250 * ofnode_read_u64_default() - Read a 64-bit integer from a property
252 * @ref: valid node reference to read property from
253 * @propname: name of the property to read from
254 * @def: default value to return if the property has no value
255 * @return property value, or @def if not found
257 u64 ofnode_read_u64_default(ofnode node, const char *propname, u64 def);
260 * ofnode_read_string() - Read a string from a property
262 * @ref: valid node reference to read property from
263 * @propname: name of the property to read
264 * @return string from property value, or NULL if there is no such property
266 const char *ofnode_read_string(ofnode node, const char *propname);
269 * ofnode_read_u32_array() - Find and read an array of 32 bit integers
271 * @node: valid node reference to read property from
272 * @propname: name of the property to read
273 * @out_values: pointer to return value, modified only if return value is 0
274 * @sz: number of array elements to read
275 * @return 0 if OK, -ve on error
277 * Search for a property in a device node and read 32-bit value(s) from
278 * it. Returns 0 on success, -EINVAL if the property does not exist,
279 * -ENODATA if property does not have a value, and -EOVERFLOW if the
280 * property data isn't large enough.
282 * The out_values is modified only if a valid u32 value can be decoded.
284 int ofnode_read_u32_array(ofnode node, const char *propname,
285 u32 *out_values, size_t sz);
288 * ofnode_read_bool() - read a boolean value from a property
290 * @node: valid node reference to read property from
291 * @propname: name of property to read
292 * @return true if property is present (meaning true), false if not present
294 bool ofnode_read_bool(ofnode node, const char *propname);
297 * ofnode_find_subnode() - find a named subnode of a parent node
299 * @node: valid reference to parent node
300 * @subnode_name: name of subnode to find
301 * @return reference to subnode (which can be invalid if there is no such
304 ofnode ofnode_find_subnode(ofnode node, const char *subnode_name);
307 * ofnode_first_subnode() - find the first subnode of a parent node
309 * @node: valid reference to a valid parent node
310 * @return reference to the first subnode (which can be invalid if the parent
311 * node has no subnodes)
313 ofnode ofnode_first_subnode(ofnode node);
316 * ofnode_next_subnode() - find the next sibling of a subnode
318 * @node: valid reference to previous node (sibling)
319 * @return reference to the next subnode (which can be invalid if the node
320 * has no more siblings)
322 ofnode ofnode_next_subnode(ofnode node);
325 * ofnode_get_parent() - get the ofnode's parent (enclosing ofnode)
327 * @node: valid node to look up
328 * @return ofnode reference of the parent node
330 ofnode ofnode_get_parent(ofnode node);
333 * ofnode_get_name() - get the name of a node
335 * @node: valid node to look up
336 * @return name of node
338 const char *ofnode_get_name(ofnode node);
341 * ofnode_get_by_phandle() - get ofnode from phandle
343 * @phandle: phandle to look up
344 * @return ofnode reference to the phandle
346 ofnode ofnode_get_by_phandle(uint phandle);
349 * ofnode_read_size() - read the size of a property
351 * @node: node to check
352 * @propname: property to check
353 * @return size of property if present, or -EINVAL if not
355 int ofnode_read_size(ofnode node, const char *propname);
358 * ofnode_get_addr_size_index() - get an address/size from a node
361 * This reads the register address/size from a node based on index
363 * @node: node to read from
364 * @index: Index of address to read (0 for first)
365 * @size: Pointer to size of the address
366 * @return address, or FDT_ADDR_T_NONE if not present or invalid
368 phys_addr_t ofnode_get_addr_size_index(ofnode node, int index,
372 * ofnode_get_addr_index() - get an address from a node
374 * This reads the register address from a node
376 * @node: node to read from
377 * @index: Index of address to read (0 for first)
378 * @return address, or FDT_ADDR_T_NONE if not present or invalid
380 phys_addr_t ofnode_get_addr_index(ofnode node, int index);
383 * ofnode_get_addr() - get an address from a node
385 * This reads the register address from a node
387 * @node: node to read from
388 * @return address, or FDT_ADDR_T_NONE if not present or invalid
390 phys_addr_t ofnode_get_addr(ofnode node);
393 * ofnode_stringlist_search() - find a string in a string list and return index
395 * Note that it is possible for this function to succeed on property values
396 * that are not NUL-terminated. That's because the function will stop after
397 * finding the first occurrence of @string. This can for example happen with
398 * small-valued cell properties, such as #address-cells, when searching for
401 * @node: node to check
402 * @propname: name of the property containing the string list
403 * @string: string to look up in the string list
406 * the index of the string in the list of strings
407 * -ENODATA if the property is not found
408 * -EINVAL on some other error
410 int ofnode_stringlist_search(ofnode node, const char *propname,
414 * ofnode_read_string_index() - obtain an indexed string from a string list
416 * Note that this will successfully extract strings from properties with
417 * non-NUL-terminated values. For example on small-valued cell properties
418 * this function will return the empty string.
420 * If non-NULL, the length of the string (on success) or a negative error-code
421 * (on failure) will be stored in the integer pointer to by lenp.
423 * @node: node to check
424 * @propname: name of the property containing the string list
425 * @index: index of the string to return
426 * @lenp: return location for the string length or an error code on failure
429 * length of string, if found or -ve error value if not found
431 int ofnode_read_string_index(ofnode node, const char *propname, int index,
435 * ofnode_read_string_count() - find the number of strings in a string list
437 * @node: node to check
438 * @propname: name of the property containing the string list
440 * number of strings in the list, or -ve error value if not found
442 int ofnode_read_string_count(ofnode node, const char *property);
445 * ofnode_parse_phandle_with_args() - Find a node pointed by phandle in a list
447 * This function is useful to parse lists of phandles and their arguments.
448 * Returns 0 on success and fills out_args, on error returns appropriate
451 * Caller is responsible to call of_node_put() on the returned out_args->np
465 * list = <&phandle1 1 2 &phandle2 3>;
468 * To get a device_node of the `node2' node you may call this:
469 * ofnode_parse_phandle_with_args(node3, "list", "#list-cells", 0, 1, &args);
471 * @node: device tree node containing a list
472 * @list_name: property name that contains a list
473 * @cells_name: property name that specifies phandles' arguments count
474 * @cells_count: Cell count to use if @cells_name is NULL
475 * @index: index of a phandle to parse out
476 * @out_args: optional pointer to output arguments structure (will be filled)
477 * @return 0 on success (with @out_args filled out if not NULL), -ENOENT if
478 * @list_name does not exist, -EINVAL if a phandle was not found,
479 * @cells_name could not be found, the arguments were truncated or there
480 * were too many arguments.
482 int ofnode_parse_phandle_with_args(ofnode node, const char *list_name,
483 const char *cells_name, int cell_count,
485 struct ofnode_phandle_args *out_args);
488 * ofnode_count_phandle_with_args() - Count number of phandle in a list
490 * This function is useful to count phandles into a list.
491 * Returns number of phandle on success, on error returns appropriate
494 * @node: device tree node containing a list
495 * @list_name: property name that contains a list
496 * @cells_name: property name that specifies phandles' arguments count
497 * @return number of phandle on success, -ENOENT if @list_name does not
498 * exist, -EINVAL if a phandle was not found, @cells_name could not
501 int ofnode_count_phandle_with_args(ofnode node, const char *list_name,
502 const char *cells_name);
505 * ofnode_path() - find a node by full path
507 * @path: Full path to node, e.g. "/bus/spi@1"
508 * @return reference to the node found. Use ofnode_valid() to check if it exists
510 ofnode ofnode_path(const char *path);
513 * ofnode_get_chosen_prop() - get the value of a chosen property
515 * This looks for a property within the /chosen node and returns its value
517 * @propname: Property name to look for
518 * @return property value if found, else NULL
520 const char *ofnode_get_chosen_prop(const char *propname);
523 * ofnode_get_chosen_node() - get a referenced node from the chosen node
525 * This looks up a named property in the chosen node and uses that as a path to
528 * @return the referenced node if present, else ofnode_null()
530 ofnode ofnode_get_chosen_node(const char *propname);
532 struct display_timing;
534 * ofnode_decode_display_timing() - decode display timings
536 * Decode display timings from the supplied 'display-timings' node.
537 * See doc/device-tree-bindings/video/display-timing.txt for binding
540 * @node 'display-timing' node containing the timing subnodes
541 * @index Index number to read (0=first timing subnode)
542 * @config Place to put timings
543 * @return 0 if OK, -FDT_ERR_NOTFOUND if not found
545 int ofnode_decode_display_timing(ofnode node, int index,
546 struct display_timing *config);
549 * ofnode_get_property()- - get a pointer to the value of a node property
551 * @node: node to read
552 * @propname: property to read
553 * @lenp: place to put length on success
554 * @return pointer to property, or NULL if not found
556 const void *ofnode_get_property(ofnode node, const char *propname, int *lenp);
559 * ofnode_is_available() - check if a node is marked available
561 * @node: node to check
562 * @return true if node's 'status' property is "okay" (or is missing)
564 bool ofnode_is_available(ofnode node);
567 * ofnode_get_addr_size() - get address and size from a property
569 * This does no address translation. It simply reads an property that contains
570 * an address and a size value, one after the other.
572 * @node: node to read from
573 * @propname: property to read
574 * @sizep: place to put size value (on success)
575 * @return address value, or FDT_ADDR_T_NONE on error
577 phys_addr_t ofnode_get_addr_size(ofnode node, const char *propname,
581 * ofnode_read_u8_array_ptr() - find an 8-bit array
583 * Look up a property in a node and return a pointer to its contents as a
584 * byte array of given length. The property must have at least enough data
585 * for the array (count bytes). It may have more, but this will be ignored.
586 * The data is not copied.
588 * @node node to examine
589 * @propname name of property to find
590 * @sz number of array elements
591 * @return pointer to byte array if found, or NULL if the property is not
592 * found or there is not enough data
594 const uint8_t *ofnode_read_u8_array_ptr(ofnode node, const char *propname,
598 * ofnode_read_pci_addr() - look up a PCI address
600 * Look at an address property in a node and return the PCI address which
601 * corresponds to the given type in the form of fdt_pci_addr.
602 * The property must hold one fdt_pci_addr with a lengh.
604 * @node node to examine
605 * @type pci address type (FDT_PCI_SPACE_xxx)
606 * @propname name of property to find
607 * @addr returns pci address in the form of fdt_pci_addr
608 * @return 0 if ok, -ENOENT if the property did not exist, -EINVAL if the
609 * format of the property was invalid, -ENXIO if the requested
610 * address type was not found
612 int ofnode_read_pci_addr(ofnode node, enum fdt_pci_space type,
613 const char *propname, struct fdt_pci_addr *addr);
616 * ofnode_read_pci_vendev() - look up PCI vendor and device id
618 * Look at the compatible property of a device node that represents a PCI
619 * device and extract pci vendor id and device id from it.
621 * @param node node to examine
622 * @param vendor vendor id of the pci device
623 * @param device device id of the pci device
624 * @return 0 if ok, negative on error
626 int ofnode_read_pci_vendev(ofnode node, u16 *vendor, u16 *device);
629 * ofnode_read_addr_cells() - Get the number of address cells for a node
631 * This walks back up the tree to find the closest #address-cells property
632 * which controls the given node.
634 * @node: Node to check
635 * @return number of address cells this node uses
637 int ofnode_read_addr_cells(ofnode node);
640 * ofnode_read_size_cells() - Get the number of size cells for a node
642 * This walks back up the tree to find the closest #size-cells property
643 * which controls the given node.
645 * @node: Node to check
646 * @return number of size cells this node uses
648 int ofnode_read_size_cells(ofnode node);
651 * ofnode_read_simple_addr_cells() - Get the address cells property in a node
653 * This function matches fdt_address_cells().
655 * @np: Node pointer to check
656 * @return value of #address-cells property in this node, or 2 if none
658 int ofnode_read_simple_addr_cells(ofnode node);
661 * ofnode_read_simple_size_cells() - Get the size cells property in a node
663 * This function matches fdt_size_cells().
665 * @np: Node pointer to check
666 * @return value of #size-cells property in this node, or 2 if none
668 int ofnode_read_simple_size_cells(ofnode node);
671 * ofnode_pre_reloc() - check if a node should be bound before relocation
673 * Device tree nodes can be marked as needing-to-be-bound in the loader stages
674 * via special device tree properties.
676 * Before relocation this function can be used to check if nodes are required
677 * in either SPL or TPL stages.
679 * After relocation and jumping into the real U-Boot binary it is possible to
680 * determine if a node was bound in one of SPL/TPL stages.
682 * There are 4 settings currently in use
683 * - u-boot,dm-pre-proper: U-Boot proper pre-relocation only
684 * - u-boot,dm-pre-reloc: legacy and indicates any of TPL or SPL
685 * Existing platforms only use it to indicate nodes needed in
686 * SPL. Should probably be replaced by u-boot,dm-spl for
688 * - u-boot,dm-spl: SPL and U-Boot pre-relocation
689 * - u-boot,dm-tpl: TPL and U-Boot pre-relocation
691 * @node: node to check
692 * @return true if node is needed in SPL/TL, false otherwise
694 bool ofnode_pre_reloc(ofnode node);
697 * ofnode_read_resource() - Read a resource from a node
699 * Read resource information from a node at the given index
701 * @node: Node to read from
702 * @index: Index of resource to read (0 = first)
703 * @res: Returns resource that was read, on success
704 * @return 0 if OK, -ve on error
706 int ofnode_read_resource(ofnode node, uint index, struct resource *res);
709 * ofnode_read_resource_byname() - Read a resource from a node by name
711 * Read resource information from a node matching the given name. This uses a
712 * 'reg-names' string list property with the names matching the associated
713 * 'reg' property list.
715 * @node: Node to read from
716 * @name: Name of resource to read
717 * @res: Returns resource that was read, on success
718 * @return 0 if OK, -ve on error
720 int ofnode_read_resource_byname(ofnode node, const char *name,
721 struct resource *res);
724 * ofnode_by_compatible() - Find the next compatible node
726 * Find the next node after @from that is compatible with @compat
728 * @from: ofnode to start from (use ofnode_null() to start at the beginning)
729 * @compat: Compatible string to match
730 * @return ofnode found, or ofnode_null() if none
732 ofnode ofnode_by_compatible(ofnode from, const char *compat);
735 * ofnode_by_prop_value() - Find the next node with given property value
737 * Find the next node after @from that has a @propname with a value
738 * @propval and a length @proplen.
740 * @from: ofnode to start from (use ofnode_null() to start at the
741 * beginning) @propname: property name to check @propval: property value to
742 * search for @proplen: length of the value in propval @return ofnode
743 * found, or ofnode_null() if none
745 ofnode ofnode_by_prop_value(ofnode from, const char *propname,
746 const void *propval, int proplen);
749 * ofnode_for_each_subnode() - iterate over all subnodes of a parent
751 * @node: child node (ofnode, lvalue)
752 * @parent: parent node (ofnode)
754 * This is a wrapper around a for loop and is used like so:
758 * ofnode_for_each_subnode(node, parent) {
763 * Note that this is implemented as a macro and @node is used as
764 * iterator in the loop. The parent variable can be a constant or even a
767 #define ofnode_for_each_subnode(node, parent) \
768 for (node = ofnode_first_subnode(parent); \
769 ofnode_valid(node); \
770 node = ofnode_next_subnode(node))
773 * ofnode_translate_address() - Translate a device-tree address
775 * Translate an address from the device-tree into a CPU physical address. This
776 * function walks up the tree and applies the various bus mappings along the
779 * @ofnode: Device tree node giving the context in which to translate the
781 * @in_addr: pointer to the address to translate
782 * @return the translated address; OF_BAD_ADDR on error
784 u64 ofnode_translate_address(ofnode node, const fdt32_t *in_addr);
787 * ofnode_translate_dma_address() - Translate a device-tree DMA address
789 * Translate a DMA address from the device-tree into a CPU physical address.
790 * This function walks up the tree and applies the various bus mappings along
793 * @ofnode: Device tree node giving the context in which to translate the
795 * @in_addr: pointer to the DMA address to translate
796 * @return the translated DMA address; OF_BAD_ADDR on error
798 u64 ofnode_translate_dma_address(ofnode node, const fdt32_t *in_addr);
801 * ofnode_device_is_compatible() - check if the node is compatible with compat
803 * This allows to check whether the node is comaptible with the compat.
805 * @node: Device tree node for which compatible needs to be verified.
806 * @compat: Compatible string which needs to verified in the given node.
807 * @return true if OK, false if the compatible is not found
809 int ofnode_device_is_compatible(ofnode node, const char *compat);
812 * ofnode_write_prop() - Set a property of a ofnode
814 * Note that the value passed to the function is *not* allocated by the
815 * function itself, but must be allocated by the caller if necessary.
817 * @node: The node for whose property should be set
818 * @propname: The name of the property to set
819 * @len: The length of the new value of the property
820 * @value: The new value of the property (must be valid prior to calling
822 * @return 0 if successful, -ve on error
824 int ofnode_write_prop(ofnode node, const char *propname, int len,
828 * ofnode_write_string() - Set a string property of a ofnode
830 * Note that the value passed to the function is *not* allocated by the
831 * function itself, but must be allocated by the caller if necessary.
833 * @node: The node for whose string property should be set
834 * @propname: The name of the string property to set
835 * @value: The new value of the string property (must be valid prior to
836 * calling the function)
837 * @return 0 if successful, -ve on error
839 int ofnode_write_string(ofnode node, const char *propname, const char *value);
842 * ofnode_set_enabled() - Enable or disable a device tree node given by its
845 * This function effectively sets the node's "status" property to either "okay"
846 * or "disable", hence making it available for driver model initialization or
849 * @node: The node to enable
850 * @value: Flag that tells the function to either disable or enable the
852 * @return 0 if successful, -ve on error
854 int ofnode_set_enabled(ofnode node, bool value);