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;
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 int 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 int 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 or 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_index() - get an address from a node
360 * This reads the register address from a node
362 * @node: node to read from
363 * @index: Index of address to read (0 for first)
364 * @return address, or FDT_ADDR_T_NONE if not present or invalid
366 phys_addr_t ofnode_get_addr_index(ofnode node, int index);
369 * ofnode_get_addr() - get an address from a node
371 * This reads the register address from a node
373 * @node: node to read from
374 * @return address, or FDT_ADDR_T_NONE if not present or invalid
376 phys_addr_t ofnode_get_addr(ofnode node);
379 * ofnode_stringlist_search() - find a string in a string list and return index
381 * Note that it is possible for this function to succeed on property values
382 * that are not NUL-terminated. That's because the function will stop after
383 * finding the first occurrence of @string. This can for example happen with
384 * small-valued cell properties, such as #address-cells, when searching for
387 * @node: node to check
388 * @propname: name of the property containing the string list
389 * @string: string to look up in the string list
392 * the index of the string in the list of strings
393 * -ENODATA if the property is not found
394 * -EINVAL on some other error
396 int ofnode_stringlist_search(ofnode node, const char *propname,
400 * ofnode_read_string_index() - obtain an indexed string from a string list
402 * Note that this will successfully extract strings from properties with
403 * non-NUL-terminated values. For example on small-valued cell properties
404 * this function will return the empty string.
406 * If non-NULL, the length of the string (on success) or a negative error-code
407 * (on failure) will be stored in the integer pointer to by lenp.
409 * @node: node to check
410 * @propname: name of the property containing the string list
411 * @index: index of the string to return
412 * @lenp: return location for the string length or an error code on failure
415 * length of string, if found or -ve error value if not found
417 int ofnode_read_string_index(ofnode node, const char *propname, int index,
421 * ofnode_read_string_count() - find the number of strings in a string list
423 * @node: node to check
424 * @propname: name of the property containing the string list
426 * number of strings in the list, or -ve error value if not found
428 int ofnode_read_string_count(ofnode node, const char *property);
431 * ofnode_parse_phandle_with_args() - Find a node pointed by phandle in a list
433 * This function is useful to parse lists of phandles and their arguments.
434 * Returns 0 on success and fills out_args, on error returns appropriate
437 * Caller is responsible to call of_node_put() on the returned out_args->np
451 * list = <&phandle1 1 2 &phandle2 3>;
454 * To get a device_node of the `node2' node you may call this:
455 * ofnode_parse_phandle_with_args(node3, "list", "#list-cells", 0, 1, &args);
457 * @node: device tree node containing a list
458 * @list_name: property name that contains a list
459 * @cells_name: property name that specifies phandles' arguments count
460 * @cells_count: Cell count to use if @cells_name is NULL
461 * @index: index of a phandle to parse out
462 * @out_args: optional pointer to output arguments structure (will be filled)
463 * @return 0 on success (with @out_args filled out if not NULL), -ENOENT if
464 * @list_name does not exist, -EINVAL if a phandle was not found,
465 * @cells_name could not be found, the arguments were truncated or there
466 * were too many arguments.
468 int ofnode_parse_phandle_with_args(ofnode node, const char *list_name,
469 const char *cells_name, int cell_count,
471 struct ofnode_phandle_args *out_args);
474 * ofnode_count_phandle_with_args() - Count number of phandle in a list
476 * This function is useful to count phandles into a list.
477 * Returns number of phandle on success, on error returns appropriate
480 * @node: device tree node containing a list
481 * @list_name: property name that contains a list
482 * @cells_name: property name that specifies phandles' arguments count
483 * @return number of phandle on success, -ENOENT if @list_name does not
484 * exist, -EINVAL if a phandle was not found, @cells_name could not
487 int ofnode_count_phandle_with_args(ofnode node, const char *list_name,
488 const char *cells_name);
491 * ofnode_path() - find a node by full path
493 * @path: Full path to node, e.g. "/bus/spi@1"
494 * @return reference to the node found. Use ofnode_valid() to check if it exists
496 ofnode ofnode_path(const char *path);
499 * ofnode_get_chosen_prop() - get the value of a chosen property
501 * This looks for a property within the /chosen node and returns its value
503 * @propname: Property name to look for
504 * @return property value if found, else NULL
506 const char *ofnode_get_chosen_prop(const char *propname);
509 * ofnode_get_chosen_node() - get the chosen node
511 * @return the chosen node if present, else ofnode_null()
513 ofnode ofnode_get_chosen_node(const char *name);
515 struct display_timing;
517 * ofnode_decode_display_timing() - decode display timings
519 * Decode display timings from the supplied 'display-timings' node.
520 * See doc/device-tree-bindings/video/display-timing.txt for binding
523 * @node 'display-timing' node containing the timing subnodes
524 * @index Index number to read (0=first timing subnode)
525 * @config Place to put timings
526 * @return 0 if OK, -FDT_ERR_NOTFOUND if not found
528 int ofnode_decode_display_timing(ofnode node, int index,
529 struct display_timing *config);
532 * ofnode_get_property()- - get a pointer to the value of a node property
534 * @node: node to read
535 * @propname: property to read
536 * @lenp: place to put length on success
537 * @return pointer to property, or NULL if not found
539 const void *ofnode_get_property(ofnode node, const char *propname, int *lenp);
542 * ofnode_is_available() - check if a node is marked available
544 * @node: node to check
545 * @return true if node's 'status' property is "okay" (or is missing)
547 bool ofnode_is_available(ofnode node);
550 * ofnode_get_addr_size() - get address and size from a property
552 * This does no address translation. It simply reads an property that contains
553 * an address and a size value, one after the other.
555 * @node: node to read from
556 * @propname: property to read
557 * @sizep: place to put size value (on success)
558 * @return address value, or FDT_ADDR_T_NONE on error
560 phys_addr_t ofnode_get_addr_size(ofnode node, const char *propname,
564 * ofnode_read_u8_array_ptr() - find an 8-bit array
566 * Look up a property in a node and return a pointer to its contents as a
567 * byte array of given length. The property must have at least enough data
568 * for the array (count bytes). It may have more, but this will be ignored.
569 * The data is not copied.
571 * @node node to examine
572 * @propname name of property to find
573 * @sz number of array elements
574 * @return pointer to byte array if found, or NULL if the property is not
575 * found or there is not enough data
577 const uint8_t *ofnode_read_u8_array_ptr(ofnode node, const char *propname,
581 * ofnode_read_pci_addr() - look up a PCI address
583 * Look at an address property in a node and return the PCI address which
584 * corresponds to the given type in the form of fdt_pci_addr.
585 * The property must hold one fdt_pci_addr with a lengh.
587 * @node node to examine
588 * @type pci address type (FDT_PCI_SPACE_xxx)
589 * @propname name of property to find
590 * @addr returns pci address in the form of fdt_pci_addr
591 * @return 0 if ok, -ENOENT if the property did not exist, -EINVAL if the
592 * format of the property was invalid, -ENXIO if the requested
593 * address type was not found
595 int ofnode_read_pci_addr(ofnode node, enum fdt_pci_space type,
596 const char *propname, struct fdt_pci_addr *addr);
599 * ofnode_read_pci_vendev() - look up PCI vendor and device id
601 * Look at the compatible property of a device node that represents a PCI
602 * device and extract pci vendor id and device id from it.
604 * @param node node to examine
605 * @param vendor vendor id of the pci device
606 * @param device device id of the pci device
607 * @return 0 if ok, negative on error
609 int ofnode_read_pci_vendev(ofnode node, u16 *vendor, u16 *device);
612 * ofnode_read_addr_cells() - Get the number of address cells for a node
614 * This walks back up the tree to find the closest #address-cells property
615 * which controls the given node.
617 * @node: Node to check
618 * @return number of address cells this node uses
620 int ofnode_read_addr_cells(ofnode node);
623 * ofnode_read_size_cells() - Get the number of size cells for a node
625 * This walks back up the tree to find the closest #size-cells property
626 * which controls the given node.
628 * @node: Node to check
629 * @return number of size cells this node uses
631 int ofnode_read_size_cells(ofnode node);
634 * ofnode_read_simple_addr_cells() - Get the address cells property in a node
636 * This function matches fdt_address_cells().
638 * @np: Node pointer to check
639 * @return value of #address-cells property in this node, or 2 if none
641 int ofnode_read_simple_addr_cells(ofnode node);
644 * ofnode_read_simple_size_cells() - Get the size cells property in a node
646 * This function matches fdt_size_cells().
648 * @np: Node pointer to check
649 * @return value of #size-cells property in this node, or 2 if none
651 int ofnode_read_simple_size_cells(ofnode node);
654 * ofnode_pre_reloc() - check if a node should be bound before relocation
656 * Device tree nodes can be marked as needing-to-be-bound in the loader stages
657 * via special device tree properties.
659 * Before relocation this function can be used to check if nodes are required
660 * in either SPL or TPL stages.
662 * After relocation and jumping into the real U-Boot binary it is possible to
663 * determine if a node was bound in one of SPL/TPL stages.
665 * There are 3 settings currently in use
667 * - u-boot,dm-pre-reloc: legacy and indicates any of TPL or SPL
668 * Existing platforms only use it to indicate nodes needed in
669 * SPL. Should probably be replaced by u-boot,dm-spl for
672 * @node: node to check
673 * @return true if node is needed in SPL/TL, false otherwise
675 bool ofnode_pre_reloc(ofnode node);
678 * ofnode_read_resource() - Read a resource from a node
680 * Read resource information from a node at the given index
682 * @node: Node to read from
683 * @index: Index of resource to read (0 = first)
684 * @res: Returns resource that was read, on success
685 * @return 0 if OK, -ve on error
687 int ofnode_read_resource(ofnode node, uint index, struct resource *res);
690 * ofnode_read_resource_byname() - Read a resource from a node by name
692 * Read resource information from a node matching the given name. This uses a
693 * 'reg-names' string list property with the names matching the associated
694 * 'reg' property list.
696 * @node: Node to read from
697 * @name: Name of resource to read
698 * @res: Returns resource that was read, on success
699 * @return 0 if OK, -ve on error
701 int ofnode_read_resource_byname(ofnode node, const char *name,
702 struct resource *res);
705 * ofnode_by_compatible() - Find the next compatible node
707 * Find the next node after @from that is compatible with @compat
709 * @from: ofnode to start from (use ofnode_null() to start at the beginning)
710 * @compat: Compatible string to match
711 * @return ofnode found, or ofnode_null() if none
713 ofnode ofnode_by_compatible(ofnode from, const char *compat);
716 * ofnode_by_prop_value() - Find the next node with given property value
718 * Find the next node after @from that has a @propname with a value
719 * @propval and a length @proplen.
721 * @from: ofnode to start from (use ofnode_null() to start at the
722 * beginning) @propname: property name to check @propval: property value to
723 * search for @proplen: length of the value in propval @return ofnode
724 * found, or ofnode_null() if none
726 ofnode ofnode_by_prop_value(ofnode from, const char *propname,
727 const void *propval, int proplen);
730 * ofnode_for_each_subnode() - iterate over all subnodes of a parent
732 * @node: child node (ofnode, lvalue)
733 * @parent: parent node (ofnode)
735 * This is a wrapper around a for loop and is used like so:
739 * ofnode_for_each_subnode(node, parent) {
744 * Note that this is implemented as a macro and @node is used as
745 * iterator in the loop. The parent variable can be a constant or even a
748 #define ofnode_for_each_subnode(node, parent) \
749 for (node = ofnode_first_subnode(parent); \
750 ofnode_valid(node); \
751 node = ofnode_next_subnode(node))
754 * ofnode_translate_address() - Tranlate a device-tree address
756 * Translate an address from the device-tree into a CPU physical address. This
757 * function walks up the tree and applies the various bus mappings along the
760 * @ofnode: Device tree node giving the context in which to translate the
762 * @in_addr: pointer to the address to translate
763 * @return the translated address; OF_BAD_ADDR on error
765 u64 ofnode_translate_address(ofnode node, const fdt32_t *in_addr);
768 * ofnode_device_is_compatible() - check if the node is compatible with compat
770 * This allows to check whether the node is comaptible with the compat.
772 * @node: Device tree node for which compatible needs to be verified.
773 * @compat: Compatible string which needs to verified in the given node.
774 * @return true if OK, false if the compatible is not found
776 int ofnode_device_is_compatible(ofnode node, const char *compat);
779 * ofnode_write_prop() - Set a property of a ofnode
781 * Note that the value passed to the function is *not* allocated by the
782 * function itself, but must be allocated by the caller if necessary.
784 * @node: The node for whose property should be set
785 * @propname: The name of the property to set
786 * @len: The length of the new value of the property
787 * @value: The new value of the property (must be valid prior to calling
789 * @return 0 if successful, -ve on error
791 int ofnode_write_prop(ofnode node, const char *propname, int len,
795 * ofnode_write_string() - Set a string property of a ofnode
797 * Note that the value passed to the function is *not* allocated by the
798 * function itself, but must be allocated by the caller if necessary.
800 * @node: The node for whose string property should be set
801 * @propname: The name of the string property to set
802 * @value: The new value of the string property (must be valid prior to
803 * calling the function)
804 * @return 0 if successful, -ve on error
806 int ofnode_write_string(ofnode node, const char *propname, const char *value);
809 * ofnode_set_enabled() - Enable or disable a device tree node given by its
812 * This function effectively sets the node's "status" property to either "okay"
813 * or "disable", hence making it available for driver model initialization or
816 * @node: The node to enable
817 * @value: Flag that tells the function to either disable or enable the
819 * @return 0 if successful, -ve on error
821 int ofnode_set_enabled(ofnode node, bool value);