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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_string() - Read a string from a property
241  *
242  * @ref:	valid node reference to read property from
243  * @propname:	name of the property to read
244  * @return string from property value, or NULL if there is no such property
245  */
246 const char *ofnode_read_string(ofnode node, const char *propname);
247 
248 /**
249  * ofnode_read_u32_array() - Find and read an array of 32 bit integers
250  *
251  * @node:	valid node reference to read property from
252  * @propname:	name of the property to read
253  * @out_values:	pointer to return value, modified only if return value is 0
254  * @sz:		number of array elements to read
255  *
256  * Search for a property in a device node and read 32-bit value(s) from
257  * it. Returns 0 on success, -EINVAL if the property does not exist,
258  * -ENODATA if property does not have a value, and -EOVERFLOW if the
259  * property data isn't large enough.
260  *
261  * The out_values is modified only if a valid u32 value can be decoded.
262  */
263 int ofnode_read_u32_array(ofnode node, const char *propname,
264 			  u32 *out_values, size_t sz);
265 
266 /**
267  * ofnode_read_bool() - read a boolean value from a property
268  *
269  * @node:	valid node reference to read property from
270  * @propname:	name of property to read
271  * @return true if property is present (meaning true), false if not present
272  */
273 bool ofnode_read_bool(ofnode node, const char *propname);
274 
275 /**
276  * ofnode_find_subnode() - find a named subnode of a parent node
277  *
278  * @node:	valid reference to parent node
279  * @subnode_name: name of subnode to find
280  * @return reference to subnode (which can be invalid if there is no such
281  * subnode)
282  */
283 ofnode ofnode_find_subnode(ofnode node, const char *subnode_name);
284 
285 /**
286  * ofnode_first_subnode() - find the first subnode of a parent node
287  *
288  * @node:	valid reference to a valid parent node
289  * @return reference to the first subnode (which can be invalid if the parent
290  * node has no subnodes)
291  */
292 ofnode ofnode_first_subnode(ofnode node);
293 
294 /**
295  * ofnode_next_subnode() - find the next sibling of a subnode
296  *
297  * @node:	valid reference to previous node (sibling)
298  * @return reference to the next subnode (which can be invalid if the node
299  * has no more siblings)
300  */
301 ofnode ofnode_next_subnode(ofnode node);
302 
303 /**
304  * ofnode_get_parent() - get the ofnode's parent (enclosing ofnode)
305  *
306  * @node: valid node to look up
307  * @return ofnode reference of the parent node
308  */
309 ofnode ofnode_get_parent(ofnode node);
310 
311 /**
312  * ofnode_get_name() - get the name of a node
313  *
314  * @node: valid node to look up
315  * @return name or node
316  */
317 const char *ofnode_get_name(ofnode node);
318 
319 /**
320  * ofnode_get_by_phandle() - get ofnode from phandle
321  *
322  * @phandle:	phandle to look up
323  * @return ofnode reference to the phandle
324  */
325 ofnode ofnode_get_by_phandle(uint phandle);
326 
327 /**
328  * ofnode_read_size() - read the size of a property
329  *
330  * @node: node to check
331  * @propname: property to check
332  * @return size of property if present, or -EINVAL if not
333  */
334 int ofnode_read_size(ofnode node, const char *propname);
335 
336 /**
337  * ofnode_get_addr_index() - get an address from a node
338  *
339  * This reads the register address from a node
340  *
341  * @node: node to read from
342  * @index: Index of address to read (0 for first)
343  * @return address, or FDT_ADDR_T_NONE if not present or invalid
344  */
345 phys_addr_t ofnode_get_addr_index(ofnode node, int index);
346 
347 /**
348  * ofnode_get_addr() - get an address from a node
349  *
350  * This reads the register address from a node
351  *
352  * @node: node to read from
353  * @return address, or FDT_ADDR_T_NONE if not present or invalid
354  */
355 phys_addr_t ofnode_get_addr(ofnode node);
356 
357 /**
358  * ofnode_stringlist_search() - find a string in a string list and return index
359  *
360  * Note that it is possible for this function to succeed on property values
361  * that are not NUL-terminated. That's because the function will stop after
362  * finding the first occurrence of @string. This can for example happen with
363  * small-valued cell properties, such as #address-cells, when searching for
364  * the empty string.
365  *
366  * @node: node to check
367  * @propname: name of the property containing the string list
368  * @string: string to look up in the string list
369  *
370  * @return:
371  *   the index of the string in the list of strings
372  *   -ENODATA if the property is not found
373  *   -EINVAL on some other error
374  */
375 int ofnode_stringlist_search(ofnode node, const char *propname,
376 			     const char *string);
377 
378 /**
379  * ofnode_read_string_index() - obtain an indexed string from a string list
380  *
381  * Note that this will successfully extract strings from properties with
382  * non-NUL-terminated values. For example on small-valued cell properties
383  * this function will return the empty string.
384  *
385  * If non-NULL, the length of the string (on success) or a negative error-code
386  * (on failure) will be stored in the integer pointer to by lenp.
387  *
388  * @node: node to check
389  * @propname: name of the property containing the string list
390  * @index: index of the string to return
391  * @lenp: return location for the string length or an error code on failure
392  *
393  * @return:
394  *   length of string, if found or -ve error value if not found
395  */
396 int ofnode_read_string_index(ofnode node, const char *propname, int index,
397 			     const char **outp);
398 
399 /**
400  * ofnode_read_string_count() - find the number of strings in a string list
401  *
402  * @node: node to check
403  * @propname: name of the property containing the string list
404  * @return:
405  *   number of strings in the list, or -ve error value if not found
406  */
407 int ofnode_read_string_count(ofnode node, const char *property);
408 
409 /**
410  * ofnode_parse_phandle_with_args() - Find a node pointed by phandle in a list
411  *
412  * This function is useful to parse lists of phandles and their arguments.
413  * Returns 0 on success and fills out_args, on error returns appropriate
414  * errno value.
415  *
416  * Caller is responsible to call of_node_put() on the returned out_args->np
417  * pointer.
418  *
419  * Example:
420  *
421  * phandle1: node1 {
422  *	#list-cells = <2>;
423  * }
424  *
425  * phandle2: node2 {
426  *	#list-cells = <1>;
427  * }
428  *
429  * node3 {
430  *	list = <&phandle1 1 2 &phandle2 3>;
431  * }
432  *
433  * To get a device_node of the `node2' node you may call this:
434  * ofnode_parse_phandle_with_args(node3, "list", "#list-cells", 0, 1, &args);
435  *
436  * @node:	device tree node containing a list
437  * @list_name:	property name that contains a list
438  * @cells_name:	property name that specifies phandles' arguments count
439  * @cells_count: Cell count to use if @cells_name is NULL
440  * @index:	index of a phandle to parse out
441  * @out_args:	optional pointer to output arguments structure (will be filled)
442  * @return 0 on success (with @out_args filled out if not NULL), -ENOENT if
443  *	@list_name does not exist, -EINVAL if a phandle was not found,
444  *	@cells_name could not be found, the arguments were truncated or there
445  *	were too many arguments.
446  */
447 int ofnode_parse_phandle_with_args(ofnode node, const char *list_name,
448 				   const char *cells_name, int cell_count,
449 				   int index,
450 				   struct ofnode_phandle_args *out_args);
451 
452 /**
453  * ofnode_count_phandle_with_args() - Count number of phandle in a list
454  *
455  * This function is useful to count phandles into a list.
456  * Returns number of phandle on success, on error returns appropriate
457  * errno value.
458  *
459  * @node:	device tree node containing a list
460  * @list_name:	property name that contains a list
461  * @cells_name:	property name that specifies phandles' arguments count
462  * @return number of phandle on success, -ENOENT if @list_name does not
463  *      exist, -EINVAL if a phandle was not found, @cells_name could not
464  *      be found.
465  */
466 int ofnode_count_phandle_with_args(ofnode node, const char *list_name,
467 				   const char *cells_name);
468 
469 /**
470  * ofnode_path() - find a node by full path
471  *
472  * @path: Full path to node, e.g. "/bus/spi@1"
473  * @return reference to the node found. Use ofnode_valid() to check if it exists
474  */
475 ofnode ofnode_path(const char *path);
476 
477 /**
478  * ofnode_get_chosen_prop() - get the value of a chosen property
479  *
480  * This looks for a property within the /chosen node and returns its value
481  *
482  * @propname: Property name to look for
483  */
484 const char *ofnode_get_chosen_prop(const char *propname);
485 
486 /**
487  * ofnode_get_chosen_node() - get the chosen node
488  *
489  * @return the chosen node if present, else ofnode_null()
490  */
491 ofnode ofnode_get_chosen_node(const char *name);
492 
493 struct display_timing;
494 /**
495  * ofnode_decode_display_timing() - decode display timings
496  *
497  * Decode display timings from the supplied 'display-timings' node.
498  * See doc/device-tree-bindings/video/display-timing.txt for binding
499  * information.
500  *
501  * @node	'display-timing' node containing the timing subnodes
502  * @index	Index number to read (0=first timing subnode)
503  * @config	Place to put timings
504  * @return 0 if OK, -FDT_ERR_NOTFOUND if not found
505  */
506 int ofnode_decode_display_timing(ofnode node, int index,
507 				 struct display_timing *config);
508 
509 /**
510  * ofnode_get_property()- - get a pointer to the value of a node property
511  *
512  * @node: node to read
513  * @propname: property to read
514  * @lenp: place to put length on success
515  * @return pointer to property, or NULL if not found
516  */
517 const void *ofnode_get_property(ofnode node, const char *propname, int *lenp);
518 
519 /**
520  * ofnode_is_available() - check if a node is marked available
521  *
522  * @node: node to check
523  * @return true if node's 'status' property is "okay" (or is missing)
524  */
525 bool ofnode_is_available(ofnode node);
526 
527 /**
528  * ofnode_get_addr_size() - get address and size from a property
529  *
530  * This does no address translation. It simply reads an property that contains
531  * an address and a size value, one after the other.
532  *
533  * @node: node to read from
534  * @propname: property to read
535  * @sizep: place to put size value (on success)
536  * @return address value, or FDT_ADDR_T_NONE on error
537  */
538 phys_addr_t ofnode_get_addr_size(ofnode node, const char *propname,
539 				 phys_size_t *sizep);
540 
541 /**
542  * ofnode_read_u8_array_ptr() - find an 8-bit array
543  *
544  * Look up a property in a node and return a pointer to its contents as a
545  * byte array of given length. The property must have at least enough data
546  * for the array (count bytes). It may have more, but this will be ignored.
547  * The data is not copied.
548  *
549  * @node	node to examine
550  * @propname	name of property to find
551  * @sz		number of array elements
552  * @return pointer to byte array if found, or NULL if the property is not
553  *		found or there is not enough data
554  */
555 const uint8_t *ofnode_read_u8_array_ptr(ofnode node, const char *propname,
556 					size_t sz);
557 
558 /**
559  * ofnode_read_pci_addr() - look up a PCI address
560  *
561  * Look at an address property in a node and return the PCI address which
562  * corresponds to the given type in the form of fdt_pci_addr.
563  * The property must hold one fdt_pci_addr with a lengh.
564  *
565  * @node	node to examine
566  * @type	pci address type (FDT_PCI_SPACE_xxx)
567  * @propname	name of property to find
568  * @addr	returns pci address in the form of fdt_pci_addr
569  * @return 0 if ok, -ENOENT if the property did not exist, -EINVAL if the
570  *		format of the property was invalid, -ENXIO if the requested
571  *		address type was not found
572  */
573 int ofnode_read_pci_addr(ofnode node, enum fdt_pci_space type,
574 			 const char *propname, struct fdt_pci_addr *addr);
575 
576 /**
577  * ofnode_read_addr_cells() - Get the number of address cells for a node
578  *
579  * This walks back up the tree to find the closest #address-cells property
580  * which controls the given node.
581  *
582  * @node: Node to check
583  * @return number of address cells this node uses
584  */
585 int ofnode_read_addr_cells(ofnode node);
586 
587 /**
588  * ofnode_read_size_cells() - Get the number of size cells for a node
589  *
590  * This walks back up the tree to find the closest #size-cells property
591  * which controls the given node.
592  *
593  * @node: Node to check
594  * @return number of size cells this node uses
595  */
596 int ofnode_read_size_cells(ofnode node);
597 
598 /**
599  * ofnode_read_simple_addr_cells() - Get the address cells property in a node
600  *
601  * This function matches fdt_address_cells().
602  *
603  * @np: Node pointer to check
604  * @return value of #address-cells property in this node, or 2 if none
605  */
606 int ofnode_read_simple_addr_cells(ofnode node);
607 
608 /**
609  * ofnode_read_simple_size_cells() - Get the size cells property in a node
610  *
611  * This function matches fdt_size_cells().
612  *
613  * @np: Node pointer to check
614  * @return value of #size-cells property in this node, or 2 if none
615  */
616 int ofnode_read_simple_size_cells(ofnode node);
617 
618 /**
619  * ofnode_pre_reloc() - check if a node should be bound before relocation
620  *
621  * Device tree nodes can be marked as needing-to-be-bound in the loader stages
622  * via special device tree properties.
623  *
624  * Before relocation this function can be used to check if nodes are required
625  * in either SPL or TPL stages.
626  *
627  * After relocation and jumping into the real U-Boot binary it is possible to
628  * determine if a node was bound in one of SPL/TPL stages.
629  *
630  * There are 3 settings currently in use
631  * -
632  * - u-boot,dm-pre-reloc: legacy and indicates any of TPL or SPL
633  *   Existing platforms only use it to indicate nodes needed in
634  *   SPL. Should probably be replaced by u-boot,dm-spl for
635  *   new platforms.
636  *
637  * @node: node to check
638  * @eturns true if node is needed in SPL/TL, false otherwise
639  */
640 bool ofnode_pre_reloc(ofnode node);
641 
642 int ofnode_read_resource(ofnode node, uint index, struct resource *res);
643 int ofnode_read_resource_byname(ofnode node, const char *name,
644 				struct resource *res);
645 
646 /**
647  * ofnode_for_each_subnode() - iterate over all subnodes of a parent
648  *
649  * @node:       child node (ofnode, lvalue)
650  * @parent:     parent node (ofnode)
651  *
652  * This is a wrapper around a for loop and is used like so:
653  *
654  *	ofnode node;
655  *
656  *	ofnode_for_each_subnode(node, parent) {
657  *		Use node
658  *		...
659  *	}
660  *
661  * Note that this is implemented as a macro and @node is used as
662  * iterator in the loop. The parent variable can be a constant or even a
663  * literal.
664  */
665 #define ofnode_for_each_subnode(node, parent) \
666 	for (node = ofnode_first_subnode(parent); \
667 	     ofnode_valid(node); \
668 	     node = ofnode_next_subnode(node))
669 
670 /**
671  * ofnode_translate_address() - Tranlate a device-tree address
672  *
673  * Translate an address from the device-tree into a CPU physical address. This
674  * function walks up the tree and applies the various bus mappings along the
675  * way.
676  *
677  * @ofnode: Device tree node giving the context in which to translate the
678  *          address
679  * @in_addr: pointer to the address to translate
680  * @return the translated address; OF_BAD_ADDR on error
681  */
682 u64 ofnode_translate_address(ofnode node, const fdt32_t *in_addr);
683 
684 /**
685  * ofnode_device_is_compatible() - check if the node is compatible with compat
686  *
687  * This allows to check whether the node is comaptible with the compat.
688  *
689  * @node:	Device tree node for which compatible needs to be verified.
690  * @compat:	Compatible string which needs to verified in the given node.
691  * @return true if OK, false if the compatible is not found
692  */
693 int ofnode_device_is_compatible(ofnode node, const char *compat);
694 #endif
695