1 /*
2 * Originally from Linux v4.9
3 * Copyright (C) 1996-2005 Paul Mackerras.
4 *
5 * Updates for PPC64 by Peter Bergner & David Engebretsen, IBM Corp.
6 * Updates for SPARC64 by David S. Miller
7 * Derived from PowerPC and Sparc prom.h files by Stephen Rothwell, IBM Corp.
8 *
9 * Copyright (c) 2017 Google, Inc
10 * Written by Simon Glass <sjg@chromium.org>
11 *
12 * Modified for U-Boot
13 * Copyright (c) 2017 Google, Inc
14 *
15 * SPDX-License-Identifier: GPL-2.0+
16 */
17
18 #ifndef _DM_OF_ACCESS_H
19 #define _DM_OF_ACCESS_H
20
21 #include <dm/of.h>
22
23 /**
24 * of_find_all_nodes - Get next node in global list
25 * @prev: Previous node or NULL to start iteration
26 * of_node_put() will be called on it
27 *
28 * Returns a node pointer with refcount incremented, use
29 * of_node_put() on it when done.
30 */
31 struct device_node *of_find_all_nodes(struct device_node *prev);
32
33 #define for_each_of_allnodes_from(from, dn) \
34 for (dn = of_find_all_nodes(from); dn; dn = of_find_all_nodes(dn))
35 #define for_each_of_allnodes(dn) for_each_of_allnodes_from(NULL, dn)
36
37 /* Dummy functions to mirror Linux. These are not used in U-Boot */
38 #define of_node_get(x) (x)
of_node_put(const struct device_node * np)39 static inline void of_node_put(const struct device_node *np) { }
40
41 /**
42 * of_n_addr_cells() - Get the number of address cells for a node
43 *
44 * This walks back up the tree to find the closest #address-cells property
45 * which controls the given node.
46 *
47 * @np: Node pointer to check
48 * @return number of address cells this node uses
49 */
50 int of_n_addr_cells(const struct device_node *np);
51
52 /**
53 * of_n_size_cells() - Get the number of size cells for a node
54 *
55 * This walks back up the tree to find the closest #size-cells property
56 * which controls the given node.
57 *
58 * @np: Node pointer to check
59 * @return number of size cells this node uses
60 */
61 int of_n_size_cells(const struct device_node *np);
62
63 /**
64 * of_simple_addr_cells() - Get the address cells property in a node
65 *
66 * This function matches fdt_address_cells().
67 *
68 * @np: Node pointer to check
69 * @return value of #address-cells property in this node, or 2 if none
70 */
71 int of_simple_addr_cells(const struct device_node *np);
72
73 /**
74 * of_simple_size_cells() - Get the size cells property in a node
75 *
76 * This function matches fdt_size_cells().
77 *
78 * @np: Node pointer to check
79 * @return value of #size-cells property in this node, or 2 if none
80 */
81 int of_simple_size_cells(const struct device_node *np);
82
83 /**
84 * of_find_property() - find a property in a node
85 *
86 * @np: Pointer to device node holding property
87 * @name: Name of property
88 * @lenp: If non-NULL, returns length of property
89 * @return pointer to property, or NULL if not found
90 */
91 struct property *of_find_property(const struct device_node *np,
92 const char *name, int *lenp);
93
94 /**
95 * of_get_property() - get a property value
96 *
97 * Find a property with a given name for a given node and return the value.
98 *
99 * @np: Pointer to device node holding property
100 * @name: Name of property
101 * @lenp: If non-NULL, returns length of property
102 * @return pointer to property value, or NULL if not found
103 */
104 const void *of_get_property(const struct device_node *np, const char *name,
105 int *lenp);
106
107 /**
108 * of_get_first_property()- get to the pointer of the first property
109 *
110 * Get pointer to the first property of the node, it is used to iterate
111 * and read all the property with of_get_next_property_by_prop().
112 *
113 * @np: Pointer to device node
114 * @return pointer to property or NULL if not found
115 */
116 const struct property *of_get_first_property(const struct device_node *np);
117
118 /**
119 * of_get_next_property() - get to the pointer of the next property
120 *
121 * Get pointer to the next property of the node, it is used to iterate
122 * and read all the property with of_get_property_by_prop().
123 *
124 * @np: Pointer to device node
125 * @property: pointer of the current property
126 * @return pointer to next property or NULL if not found
127 */
128 const struct property *of_get_next_property(const struct device_node *np,
129 const struct property *property);
130
131 /**
132 * of_get_property_by_prop() - get a property value of a node property
133 *
134 * Get value for the property identified by node and property pointer.
135 *
136 * @node: node to read
137 * @property: pointer of the property to read
138 * @propname: place to property name on success
139 * @lenp: place to put length on success
140 * @return pointer to property value or NULL if error
141 */
142 const void *of_get_property_by_prop(const struct device_node *np,
143 const struct property *property,
144 const char **name,
145 int *lenp);
146
147 /**
148 * of_device_is_compatible() - Check if the node matches given constraints
149 * @device: pointer to node
150 * @compat: required compatible string, NULL or "" for any match
151 * @type: required device_type value, NULL or "" for any match
152 * @name: required node name, NULL or "" for any match
153 *
154 * Checks if the given @compat, @type and @name strings match the
155 * properties of the given @device. A constraints can be skipped by
156 * passing NULL or an empty string as the constraint.
157 *
158 * @return 0 for no match, and a positive integer on match. The return
159 * value is a relative score with larger values indicating better
160 * matches. The score is weighted for the most specific compatible value
161 * to get the highest score. Matching type is next, followed by matching
162 * name. Practically speaking, this results in the following priority
163 * order for matches:
164 *
165 * 1. specific compatible && type && name
166 * 2. specific compatible && type
167 * 3. specific compatible && name
168 * 4. specific compatible
169 * 5. general compatible && type && name
170 * 6. general compatible && type
171 * 7. general compatible && name
172 * 8. general compatible
173 * 9. type && name
174 * 10. type
175 * 11. name
176 */
177 int of_device_is_compatible(const struct device_node *np, const char *compat,
178 const char *type, const char *name);
179
180 /**
181 * of_device_is_available() - check if a device is available for use
182 *
183 * @device: Node to check for availability
184 *
185 * @return true if the status property is absent or set to "okay", false
186 * otherwise
187 */
188 bool of_device_is_available(const struct device_node *np);
189
190 /**
191 * of_get_parent() - Get a node's parent, if any
192 *
193 * @node: Node to check
194 * @eturns a node pointer, or NULL if none
195 */
196 struct device_node *of_get_parent(const struct device_node *np);
197
198 /**
199 * of_find_node_opts_by_path() - Find a node matching a full OF path
200 *
201 * @path: Either the full path to match, or if the path does not start with
202 * '/', the name of a property of the /aliases node (an alias). In the
203 * case of an alias, the node matching the alias' value will be returned.
204 * @opts: Address of a pointer into which to store the start of an options
205 * string appended to the end of the path with a ':' separator. Can be NULL
206 *
207 * Valid paths:
208 * /foo/bar Full path
209 * foo Valid alias
210 * foo/bar Valid alias + relative path
211 *
212 * @return a node pointer or NULL if not found
213 */
214 struct device_node *of_find_node_opts_by_path(const char *path,
215 const char **opts);
216
of_find_node_by_path(const char * path)217 static inline struct device_node *of_find_node_by_path(const char *path)
218 {
219 return of_find_node_opts_by_path(path, NULL);
220 }
221
222 /**
223 * of_find_compatible_node() - find a node based on its compatible string
224 *
225 * Find a node based on type and one of the tokens in its "compatible" property
226 * @from: Node to start searching from or NULL. the node you pass will not be
227 * searched, only the next one will; typically, you pass what the previous
228 * call returned.
229 * @type: The type string to match "device_type" or NULL to ignore
230 * @compatible: The string to match to one of the tokens in the device
231 * "compatible" list.
232 * @return node pointer or NULL if not found
233 */
234 struct device_node *of_find_compatible_node(struct device_node *from,
235 const char *type, const char *compatible);
236
237 /**
238 * of_find_node_by_phandle() - Find a node given a phandle
239 *
240 * @handle: phandle of the node to find
241 *
242 * @return node pointer, or NULL if not found
243 */
244 struct device_node *of_find_node_by_phandle(phandle handle);
245
246 /**
247 * of_read_u32() - Find and read a 32-bit integer from a property
248 *
249 * Search for a property in a device node and read a 32-bit value from
250 * it.
251 *
252 * @np: device node from which the property value is to be read.
253 * @propname: name of the property to be searched.
254 * @outp: pointer to return value, modified only if return value is 0.
255 *
256 * @return 0 on success, -EINVAL if the property does not exist,
257 * -ENODATA if property does not have a value, and -EOVERFLOW if the
258 * property data isn't large enough.
259 */
260 int of_read_u32(const struct device_node *np, const char *propname, u32 *outp);
261
262 /**
263 * of_property_read_u64 - Find and read a 64 bit integer from a property
264 * @np: device node from which the property value is to be read.
265 * @propname: name of the property to be searched.
266 * @out_value: pointer to return value, modified only if return value is 0.
267 *
268 * Search for a property in a device node and read a 64-bit value from
269 * it. Returns 0 on success, -EINVAL if the property does not exist,
270 * -ENODATA if property does not have a value, and -EOVERFLOW if the
271 * property data isn't large enough.
272 *
273 * The out_value is modified only if a valid u64 value can be decoded.
274 */
275 int of_property_read_u64(const struct device_node *np, const char *propname,
276 u64 *out_value);
277
278 /**
279 * of_read_u32_array() - Find and read an array of 32 bit integers
280 *
281 * Search for a property in a device node and read 32-bit value(s) from
282 * it.
283 *
284 * @np: device node from which the property value is to be read.
285 * @propname: name of the property to be searched.
286 * @out_values: pointer to return value, modified only if return value is 0.
287 * @sz: number of array elements to read
288 * @return 0 on success, -EINVAL if the property does not exist, -ENODATA
289 * if property does not have a value, and -EOVERFLOW is longer than sz.
290 */
291 int of_read_u32_array(const struct device_node *np, const char *propname,
292 u32 *out_values, size_t sz);
293
294 /**
295 * of_write_u32_array() - Find and write an array of 32 bit integers
296 *
297 * Search for a property in a device node and write 32-bit value(s) to
298 * it.
299 *
300 * @np: device node from which the property value is to be read.
301 * @propname: name of the property to be searched.
302 * @values: pointer to update value, modified only if return value is 0.
303 * @sz: number of array elements to read
304 * @return 0 on success, -EINVAL if the property does not exist, -ENODATA
305 * if property does not have a value, and -EOVERFLOW is longer than sz.
306 */
307 int of_write_u32_array(const struct device_node *np, const char *propname,
308 u32 *values, size_t sz);
309
310 /**
311 * of_property_match_string() - Find string in a list and return index
312 *
313 * This function searches a string list property and returns the index
314 * of a specific string value.
315 *
316 * @np: pointer to node containing string list property
317 * @propname: string list property name
318 * @string: pointer to string to search for in string list
319 * @return 0 on success, -EINVAL if the property does not exist, -ENODATA
320 * if property does not have a value, and -EOVERFLOW is longer than sz.
321 */
322 int of_property_match_string(const struct device_node *np, const char *propname,
323 const char *string);
324
325 int of_property_read_string_helper(const struct device_node *np,
326 const char *propname, const char **out_strs,
327 size_t sz, int index);
328
329 /**
330 * of_property_read_string_index() - Find and read a string from a multiple
331 * strings property.
332 * @np: device node from which the property value is to be read.
333 * @propname: name of the property to be searched.
334 * @index: index of the string in the list of strings
335 * @out_string: pointer to null terminated return string, modified only if
336 * return value is 0.
337 *
338 * Search for a property in a device tree node and retrieve a null
339 * terminated string value (pointer to data, not a copy) in the list of strings
340 * contained in that property.
341 * Returns 0 on success, -EINVAL if the property does not exist, -ENODATA if
342 * property does not have a value, and -EILSEQ if the string is not
343 * null-terminated within the length of the property data.
344 *
345 * The out_string pointer is modified only if a valid string can be decoded.
346 */
of_property_read_string_index(const struct device_node * np,const char * propname,int index,const char ** output)347 static inline int of_property_read_string_index(const struct device_node *np,
348 const char *propname,
349 int index, const char **output)
350 {
351 int rc = of_property_read_string_helper(np, propname, output, 1, index);
352 return rc < 0 ? rc : 0;
353 }
354
355 /**
356 * of_property_count_strings() - Find and return the number of strings from a
357 * multiple strings property.
358 * @np: device node from which the property value is to be read.
359 * @propname: name of the property to be searched.
360 *
361 * Search for a property in a device tree node and retrieve the number of null
362 * terminated string contain in it. Returns the number of strings on
363 * success, -EINVAL if the property does not exist, -ENODATA if property
364 * does not have a value, and -EILSEQ if the string is not null-terminated
365 * within the length of the property data.
366 */
of_property_count_strings(const struct device_node * np,const char * propname)367 static inline int of_property_count_strings(const struct device_node *np,
368 const char *propname)
369 {
370 return of_property_read_string_helper(np, propname, NULL, 0, 0);
371 }
372
373 /**
374 * of_parse_phandle - Resolve a phandle property to a device_node pointer
375 * @np: Pointer to device node holding phandle property
376 * @phandle_name: Name of property holding a phandle value
377 * @index: For properties holding a table of phandles, this is the index into
378 * the table
379 *
380 * Returns the device_node pointer with refcount incremented. Use
381 * of_node_put() on it when done.
382 */
383 struct device_node *of_parse_phandle(const struct device_node *np,
384 const char *phandle_name, int index);
385
386 /**
387 * of_parse_phandle_with_args() - Find a node pointed by phandle in a list
388 *
389 * @np: pointer to a device tree node containing a list
390 * @list_name: property name that contains a list
391 * @cells_name: property name that specifies phandles' arguments count
392 * @index: index of a phandle to parse out
393 * @out_args: optional pointer to output arguments structure (will be filled)
394 * @return 0 on success (with @out_args filled out if not NULL), -ENOENT if
395 * @list_name does not exist, -EINVAL if a phandle was not found,
396 * @cells_name could not be found, the arguments were truncated or there
397 * were too many arguments.
398 *
399 * This function is useful to parse lists of phandles and their arguments.
400 * Returns 0 on success and fills out_args, on error returns appropriate
401 * errno value.
402 *
403 * Caller is responsible to call of_node_put() on the returned out_args->np
404 * pointer.
405 *
406 * Example:
407 *
408 * phandle1: node1 {
409 * #list-cells = <2>;
410 * }
411 *
412 * phandle2: node2 {
413 * #list-cells = <1>;
414 * }
415 *
416 * node3 {
417 * list = <&phandle1 1 2 &phandle2 3>;
418 * }
419 *
420 * To get a device_node of the `node2' node you may call this:
421 * of_parse_phandle_with_args(node3, "list", "#list-cells", 1, &args);
422 */
423 int of_parse_phandle_with_args(const struct device_node *np,
424 const char *list_name, const char *cells_name,
425 int index, struct of_phandle_args *out_args);
426
427 /**
428 * of_count_phandle_with_args() - Count the number of phandle in a list
429 *
430 * @np: pointer to a device tree node containing a list
431 * @list_name: property name that contains a list
432 * @cells_name: property name that specifies phandles' arguments count
433 * @return number of phandle found, -ENOENT if
434 * @list_name does not exist, -EINVAL if a phandle was not found,
435 * @cells_name could not be found, the arguments were truncated or there
436 * were too many arguments.
437 *
438 * Returns number of phandle found on success, on error returns appropriate
439 * errno value.
440 *
441 */
442 int of_count_phandle_with_args(const struct device_node *np,
443 const char *list_name, const char *cells_name);
444
445 /**
446 * of_alias_scan() - Scan all properties of the 'aliases' node
447 *
448 * The function scans all the properties of the 'aliases' node and populates
449 * the lookup table with the properties. It returns the number of alias
450 * properties found, or an error code in case of failure.
451 *
452 * @return 9 if OK, -ENOMEM if not enough memory
453 */
454 int of_alias_scan(void);
455
456 /**
457 * of_alias_get_id - Get alias id for the given device_node
458 *
459 * Travels the lookup table to get the alias id for the given device_node and
460 * alias stem.
461 *
462 * @np: Pointer to the given device_node
463 * @stem: Alias stem of the given device_node
464 * @return alias ID, if found, else -ENODEV
465 */
466 int of_alias_get_id(const struct device_node *np, const char *stem);
467
468 /**
469 * of_alias_get_dev - Get device_node by given stem and alias id
470 *
471 * Travels the lookup table to get the device_node by given stem and alias id.
472 *
473 * @stem: Alias stem of the given device_node
474 * @id: Alias id of the given device_node
475 * @return device_node, if found, else NULL
476 */
477 struct device_node *of_alias_get_dev(const char *stem, int id);
478
479 /**
480 * of_alias_dump - Dump of alias nodes added in aliases_lookup.
481 */
482 struct device_node *of_alias_dump(void);
483
484 /**
485 * of_get_stdout() - Get node to use for stdout
486 *
487 * @return node referred to by stdout-path alias, or NULL if none
488 */
489 struct device_node *of_get_stdout(void);
490
491 #endif
492