xref: /openbmc/u-boot/include/dm/ofnode.h (revision 9450ab2b)
1 /* SPDX-License-Identifier: GPL-2.0+ */
2 /*
3  * Copyright (c) 2017 Google, Inc
4  * Written by Simon Glass <sjg@chromium.org>
5  */
6 
7 #ifndef _DM_OFNODE_H
8 #define _DM_OFNODE_H
9 
10 /* TODO(sjg@chromium.org): Drop fdtdec.h include */
11 #include <fdtdec.h>
12 #include <dm/of.h>
13 
14 /* Enable checks to protect against invalid calls */
15 #undef OF_CHECKS
16 
17 struct resource;
18 
19 /**
20  * ofnode - reference to a device tree node
21  *
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.
25  *
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 *.
29  *
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.
33  *
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.
42  *
43  * For now these points use constant types, since we don't allow writing
44  * the DT.
45  *
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.
49  */
50 typedef union ofnode_union {
51 	const struct device_node *np;	/* will be used for future live tree */
52 	long of_offset;
53 } ofnode;
54 
55 struct ofnode_phandle_args {
56 	ofnode node;
57 	int args_count;
58 	uint32_t args[OF_MAX_PHANDLE_ARGS];
59 };
60 
61 /**
62  * _ofnode_to_np() - convert an ofnode to a live DT node pointer
63  *
64  * This cannot be called if the reference contains an offset.
65  *
66  * @node: Reference containing struct device_node * (possibly invalid)
67  * @return pointer to device node (can be NULL)
68  */
ofnode_to_np(ofnode node)69 static inline const struct device_node *ofnode_to_np(ofnode node)
70 {
71 #ifdef OF_CHECKS
72 	if (!of_live_active())
73 		return NULL;
74 #endif
75 	return node.np;
76 }
77 
78 /**
79  * ofnode_to_offset() - convert an ofnode to a flat DT offset
80  *
81  * This cannot be called if the reference contains a node pointer.
82  *
83  * @node: Reference containing offset (possibly invalid)
84  * @return DT offset (can be -1)
85  */
ofnode_to_offset(ofnode node)86 static inline int ofnode_to_offset(ofnode node)
87 {
88 #ifdef OF_CHECKS
89 	if (of_live_active())
90 		return -1;
91 #endif
92 	return node.of_offset;
93 }
94 
95 /**
96  * ofnode_valid() - check if an ofnode is valid
97  *
98  * @return true if the reference contains a valid ofnode, false if it is NULL
99  */
ofnode_valid(ofnode node)100 static inline bool ofnode_valid(ofnode node)
101 {
102 	if (of_live_active())
103 		return node.np != NULL;
104 	else
105 		return node.of_offset != -1;
106 }
107 
108 /**
109  * offset_to_ofnode() - convert a DT offset to an ofnode
110  *
111  * @of_offset: DT offset (either valid, or -1)
112  * @return reference to the associated DT offset
113  */
offset_to_ofnode(int of_offset)114 static inline ofnode offset_to_ofnode(int of_offset)
115 {
116 	ofnode node;
117 
118 	if (of_live_active())
119 		node.np = NULL;
120 	else
121 		node.of_offset = of_offset;
122 
123 	return node;
124 }
125 
126 /**
127  * np_to_ofnode() - convert a node pointer to an ofnode
128  *
129  * @np: Live node pointer (can be NULL)
130  * @return reference to the associated node pointer
131  */
np_to_ofnode(const struct device_node * np)132 static inline ofnode np_to_ofnode(const struct device_node *np)
133 {
134 	ofnode node;
135 
136 	node.np = np;
137 
138 	return node;
139 }
140 
141 /**
142  * ofnode_is_np() - check if a reference is a node pointer
143  *
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.
147  *
148  * @node: reference to check (possibly invalid)
149  * @return true if the reference is a live node pointer, false if it is a DT
150  * offset
151  */
ofnode_is_np(ofnode node)152 static inline bool ofnode_is_np(ofnode node)
153 {
154 #ifdef OF_CHECKS
155 	/*
156 	 * Check our assumption that flat tree offsets are not used when a
157 	 * live tree is in use.
158 	 */
159 	assert(!ofnode_valid(node) ||
160 	       (of_live_active() ? _ofnode_to_np(node)
161 				  : _ofnode_to_np(node)));
162 #endif
163 	return of_live_active() && ofnode_valid(node);
164 }
165 
166 /**
167  * ofnode_equal() - check if two references are equal
168  *
169  * @return true if equal, else false
170  */
ofnode_equal(ofnode ref1,ofnode ref2)171 static inline bool ofnode_equal(ofnode ref1, ofnode ref2)
172 {
173 	/* We only need to compare the contents */
174 	return ref1.of_offset == ref2.of_offset;
175 }
176 
177 /**
178  * ofnode_null() - Obtain a null ofnode
179  *
180  * This returns an ofnode which points to no node. It works both with the flat
181  * tree and livetree.
182  */
ofnode_null(void)183 static inline ofnode ofnode_null(void)
184 {
185 	ofnode node;
186 
187 	if (of_live_active())
188 		node.np = NULL;
189 	else
190 		node.of_offset = -1;
191 
192 	return node;
193 }
194 
195 /**
196  * ofnode_read_u32() - Read a 32-bit integer from a property
197  *
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
202  */
203 int ofnode_read_u32(ofnode node, const char *propname, u32 *outp);
204 
205 /**
206  * ofnode_read_s32() - Read a 32-bit integer from a property
207  *
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
212  */
ofnode_read_s32(ofnode node,const char * propname,s32 * out_value)213 static inline int ofnode_read_s32(ofnode node, const char *propname,
214 				  s32 *out_value)
215 {
216 	return ofnode_read_u32(node, propname, (u32 *)out_value);
217 }
218 
219 /**
220  * ofnode_read_u32_default() - Read a 32-bit integer from a property
221  *
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
226  */
227 int ofnode_read_u32_default(ofnode ref, const char *propname, u32 def);
228 
229 /**
230  * ofnode_read_s32_default() - Read a 32-bit integer from a property
231  *
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
236  */
237 int ofnode_read_s32_default(ofnode node, const char *propname, s32 def);
238 
239 /**
240  * ofnode_read_u64() - Read a 64-bit integer from a property
241  *
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
246  */
247 int ofnode_read_u64(ofnode node, const char *propname, u64 *outp);
248 
249 /**
250  * ofnode_read_u64_default() - Read a 64-bit integer from a property
251  *
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
256  */
257 int ofnode_read_u64_default(ofnode node, const char *propname, u64 def);
258 
259 /**
260  * ofnode_read_string() - Read a string from a property
261  *
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
265  */
266 const char *ofnode_read_string(ofnode node, const char *propname);
267 
268 /**
269  * ofnode_read_u32_array() - Find and read an array of 32 bit integers
270  *
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
276  *
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.
281  *
282  * The out_values is modified only if a valid u32 value can be decoded.
283  */
284 int ofnode_read_u32_array(ofnode node, const char *propname,
285 			  u32 *out_values, size_t sz);
286 
287 /**
288  * ofnode_read_bool() - read a boolean value from a property
289  *
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
293  */
294 bool ofnode_read_bool(ofnode node, const char *propname);
295 
296 /**
297  * ofnode_find_subnode() - find a named subnode of a parent node
298  *
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
302  * subnode)
303  */
304 ofnode ofnode_find_subnode(ofnode node, const char *subnode_name);
305 
306 /**
307  * ofnode_first_subnode() - find the first subnode of a parent node
308  *
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)
312  */
313 ofnode ofnode_first_subnode(ofnode node);
314 
315 /**
316  * ofnode_next_subnode() - find the next sibling of a subnode
317  *
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)
321  */
322 ofnode ofnode_next_subnode(ofnode node);
323 
324 /**
325  * ofnode_get_parent() - get the ofnode's parent (enclosing ofnode)
326  *
327  * @node: valid node to look up
328  * @return ofnode reference of the parent node
329  */
330 ofnode ofnode_get_parent(ofnode node);
331 
332 /**
333  * ofnode_get_name() - get the name of a node
334  *
335  * @node: valid node to look up
336  * @return name of node
337  */
338 const char *ofnode_get_name(ofnode node);
339 
340 /**
341  * ofnode_get_by_phandle() - get ofnode from phandle
342  *
343  * @phandle:	phandle to look up
344  * @return ofnode reference to the phandle
345  */
346 ofnode ofnode_get_by_phandle(uint phandle);
347 
348 /**
349  * ofnode_read_size() - read the size of a property
350  *
351  * @node: node to check
352  * @propname: property to check
353  * @return size of property if present, or -EINVAL if not
354  */
355 int ofnode_read_size(ofnode node, const char *propname);
356 
357 /**
358  * ofnode_get_addr_index() - get an address from a node
359  *
360  * This reads the register address from a node
361  *
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
365  */
366 phys_addr_t ofnode_get_addr_index(ofnode node, int index);
367 
368 /**
369  * ofnode_get_addr() - get an address from a node
370  *
371  * This reads the register address from a node
372  *
373  * @node: node to read from
374  * @return address, or FDT_ADDR_T_NONE if not present or invalid
375  */
376 phys_addr_t ofnode_get_addr(ofnode node);
377 
378 /**
379  * ofnode_stringlist_search() - find a string in a string list and return index
380  *
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
385  * the empty string.
386  *
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
390  *
391  * @return:
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
395  */
396 int ofnode_stringlist_search(ofnode node, const char *propname,
397 			     const char *string);
398 
399 /**
400  * ofnode_read_string_index() - obtain an indexed string from a string list
401  *
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.
405  *
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.
408  *
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
413  *
414  * @return:
415  *   length of string, if found or -ve error value if not found
416  */
417 int ofnode_read_string_index(ofnode node, const char *propname, int index,
418 			     const char **outp);
419 
420 /**
421  * ofnode_read_string_count() - find the number of strings in a string list
422  *
423  * @node: node to check
424  * @propname: name of the property containing the string list
425  * @return:
426  *   number of strings in the list, or -ve error value if not found
427  */
428 int ofnode_read_string_count(ofnode node, const char *property);
429 
430 /**
431  * ofnode_parse_phandle_with_args() - Find a node pointed by phandle in a list
432  *
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
435  * errno value.
436  *
437  * Caller is responsible to call of_node_put() on the returned out_args->np
438  * pointer.
439  *
440  * Example:
441  *
442  * phandle1: node1 {
443  *	#list-cells = <2>;
444  * }
445  *
446  * phandle2: node2 {
447  *	#list-cells = <1>;
448  * }
449  *
450  * node3 {
451  *	list = <&phandle1 1 2 &phandle2 3>;
452  * }
453  *
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);
456  *
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.
467  */
468 int ofnode_parse_phandle_with_args(ofnode node, const char *list_name,
469 				   const char *cells_name, int cell_count,
470 				   int index,
471 				   struct ofnode_phandle_args *out_args);
472 
473 /**
474  * ofnode_count_phandle_with_args() - Count number of phandle in a list
475  *
476  * This function is useful to count phandles into a list.
477  * Returns number of phandle on success, on error returns appropriate
478  * errno value.
479  *
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
485  *      be found.
486  */
487 int ofnode_count_phandle_with_args(ofnode node, const char *list_name,
488 				   const char *cells_name);
489 
490 /**
491  * ofnode_path() - find a node by full path
492  *
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
495  */
496 ofnode ofnode_path(const char *path);
497 
498 /**
499  * ofnode_get_chosen_prop() - get the value of a chosen property
500  *
501  * This looks for a property within the /chosen node and returns its value
502  *
503  * @propname: Property name to look for
504  * @return property value if found, else NULL
505  */
506 const char *ofnode_get_chosen_prop(const char *propname);
507 
508 /**
509  * ofnode_get_chosen_node() - get the chosen node
510  *
511  * @return the chosen node if present, else ofnode_null()
512  */
513 ofnode ofnode_get_chosen_node(const char *name);
514 
515 struct display_timing;
516 /**
517  * ofnode_decode_display_timing() - decode display timings
518  *
519  * Decode display timings from the supplied 'display-timings' node.
520  * See doc/device-tree-bindings/video/display-timing.txt for binding
521  * information.
522  *
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
527  */
528 int ofnode_decode_display_timing(ofnode node, int index,
529 				 struct display_timing *config);
530 
531 /**
532  * ofnode_get_property()- - get a pointer to the value of a node property
533  *
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
538  */
539 const void *ofnode_get_property(ofnode node, const char *propname, int *lenp);
540 
541 /**
542  * ofnode_is_available() - check if a node is marked available
543  *
544  * @node: node to check
545  * @return true if node's 'status' property is "okay" (or is missing)
546  */
547 bool ofnode_is_available(ofnode node);
548 
549 /**
550  * ofnode_get_addr_size() - get address and size from a property
551  *
552  * This does no address translation. It simply reads an property that contains
553  * an address and a size value, one after the other.
554  *
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
559  */
560 phys_addr_t ofnode_get_addr_size(ofnode node, const char *propname,
561 				 phys_size_t *sizep);
562 
563 /**
564  * ofnode_read_u8_array_ptr() - find an 8-bit array
565  *
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.
570  *
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
576  */
577 const uint8_t *ofnode_read_u8_array_ptr(ofnode node, const char *propname,
578 					size_t sz);
579 
580 /**
581  * ofnode_read_pci_addr() - look up a PCI address
582  *
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.
586  *
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
594  */
595 int ofnode_read_pci_addr(ofnode node, enum fdt_pci_space type,
596 			 const char *propname, struct fdt_pci_addr *addr);
597 
598 /**
599  * ofnode_read_pci_vendev() - look up PCI vendor and device id
600  *
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.
603  *
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
608  */
609 int ofnode_read_pci_vendev(ofnode node, u16 *vendor, u16 *device);
610 
611 /**
612  * ofnode_read_addr_cells() - Get the number of address cells for a node
613  *
614  * This walks back up the tree to find the closest #address-cells property
615  * which controls the given node.
616  *
617  * @node: Node to check
618  * @return number of address cells this node uses
619  */
620 int ofnode_read_addr_cells(ofnode node);
621 
622 /**
623  * ofnode_read_size_cells() - Get the number of size cells for a node
624  *
625  * This walks back up the tree to find the closest #size-cells property
626  * which controls the given node.
627  *
628  * @node: Node to check
629  * @return number of size cells this node uses
630  */
631 int ofnode_read_size_cells(ofnode node);
632 
633 /**
634  * ofnode_read_simple_addr_cells() - Get the address cells property in a node
635  *
636  * This function matches fdt_address_cells().
637  *
638  * @np: Node pointer to check
639  * @return value of #address-cells property in this node, or 2 if none
640  */
641 int ofnode_read_simple_addr_cells(ofnode node);
642 
643 /**
644  * ofnode_read_simple_size_cells() - Get the size cells property in a node
645  *
646  * This function matches fdt_size_cells().
647  *
648  * @np: Node pointer to check
649  * @return value of #size-cells property in this node, or 2 if none
650  */
651 int ofnode_read_simple_size_cells(ofnode node);
652 
653 /**
654  * ofnode_pre_reloc() - check if a node should be bound before relocation
655  *
656  * Device tree nodes can be marked as needing-to-be-bound in the loader stages
657  * via special device tree properties.
658  *
659  * Before relocation this function can be used to check if nodes are required
660  * in either SPL or TPL stages.
661  *
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.
664  *
665  * There are 3 settings currently in use
666  * -
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
670  *   new platforms.
671  *
672  * @node: node to check
673  * @return true if node is needed in SPL/TL, false otherwise
674  */
675 bool ofnode_pre_reloc(ofnode node);
676 
677 /**
678  * ofnode_read_resource() - Read a resource from a node
679  *
680  * Read resource information from a node at the given index
681  *
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
686  */
687 int ofnode_read_resource(ofnode node, uint index, struct resource *res);
688 
689 /**
690  * ofnode_read_resource_byname() - Read a resource from a node by name
691  *
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.
695  *
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
700  */
701 int ofnode_read_resource_byname(ofnode node, const char *name,
702 				struct resource *res);
703 
704 /**
705  * ofnode_by_compatible() - Find the next compatible node
706  *
707  * Find the next node after @from that is compatible with @compat
708  *
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
712  */
713 ofnode ofnode_by_compatible(ofnode from, const char *compat);
714 
715 /**
716  * ofnode_by_prop_value() - Find the next node with given property value
717  *
718  * Find the next node after @from that has a @propname with a value
719  * @propval and a length @proplen.
720  *
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
725  */
726 ofnode ofnode_by_prop_value(ofnode from, const char *propname,
727 			    const void *propval, int proplen);
728 
729 /**
730  * ofnode_for_each_subnode() - iterate over all subnodes of a parent
731  *
732  * @node:       child node (ofnode, lvalue)
733  * @parent:     parent node (ofnode)
734  *
735  * This is a wrapper around a for loop and is used like so:
736  *
737  *	ofnode node;
738  *
739  *	ofnode_for_each_subnode(node, parent) {
740  *		Use node
741  *		...
742  *	}
743  *
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
746  * literal.
747  */
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))
752 
753 /**
754  * ofnode_translate_address() - Tranlate a device-tree address
755  *
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
758  * way.
759  *
760  * @ofnode: Device tree node giving the context in which to translate the
761  *          address
762  * @in_addr: pointer to the address to translate
763  * @return the translated address; OF_BAD_ADDR on error
764  */
765 u64 ofnode_translate_address(ofnode node, const fdt32_t *in_addr);
766 
767 /**
768  * ofnode_device_is_compatible() - check if the node is compatible with compat
769  *
770  * This allows to check whether the node is comaptible with the compat.
771  *
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
775  */
776 int ofnode_device_is_compatible(ofnode node, const char *compat);
777 
778 /**
779  * ofnode_write_prop() - Set a property of a ofnode
780  *
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.
783  *
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
788  *		the function)
789  * @return 0 if successful, -ve on error
790  */
791 int ofnode_write_prop(ofnode node, const char *propname, int len,
792 		      const void *value);
793 
794 /**
795  * ofnode_write_string() - Set a string property of a ofnode
796  *
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.
799  *
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
805  */
806 int ofnode_write_string(ofnode node, const char *propname, const char *value);
807 
808 /**
809  * ofnode_set_enabled() - Enable or disable a device tree node given by its
810  *			  ofnode
811  *
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
814  * not.
815  *
816  * @node:	The node to enable
817  * @value:	Flag that tells the function to either disable or enable the
818  *		node
819  * @return 0 if successful, -ve on error
820  */
821 int ofnode_set_enabled(ofnode node, bool value);
822 
823 #endif
824