1 /* SPDX-License-Identifier: GPL-2.0+ */
2 /*
3 * Originally from Linux v4.9
4 * Copyright (C) 1996-2005 Paul Mackerras.
5 *
6 * Updates for PPC64 by Peter Bergner & David Engebretsen, IBM Corp.
7 * Updates for SPARC64 by David S. Miller
8 * Derived from PowerPC and Sparc prom.h files by Stephen Rothwell, IBM Corp.
9 *
10 * Copyright (c) 2017 Google, Inc
11 * Written by Simon Glass <sjg@chromium.org>
12 *
13 * Modified for U-Boot
14 * Copyright (c) 2017 Google, Inc
15 */
16
17 #ifndef _DM_OF_ACCESS_H
18 #define _DM_OF_ACCESS_H
19
20 #include <dm/of.h>
21
22 /**
23 * of_find_all_nodes - Get next node in global list
24 * @prev: Previous node or NULL to start iteration
25 * of_node_put() will be called on it
26 *
27 * Returns a node pointer with refcount incremented, use
28 * of_node_put() on it when done.
29 */
30 struct device_node *of_find_all_nodes(struct device_node *prev);
31
32 #define for_each_of_allnodes_from(from, dn) \
33 for (dn = of_find_all_nodes(from); dn; dn = of_find_all_nodes(dn))
34 #define for_each_of_allnodes(dn) for_each_of_allnodes_from(NULL, dn)
35
36 /* Dummy functions to mirror Linux. These are not used in U-Boot */
37 #define of_node_get(x) (x)
of_node_put(const struct device_node * np)38 static inline void of_node_put(const struct device_node *np) { }
39
40 /**
41 * of_n_addr_cells() - Get the number of address cells for a node
42 *
43 * This walks back up the tree to find the closest #address-cells property
44 * which controls the given node.
45 *
46 * @np: Node pointer to check
47 * @return number of address cells this node uses
48 */
49 int of_n_addr_cells(const struct device_node *np);
50
51 /**
52 * of_n_size_cells() - Get the number of size cells for a node
53 *
54 * This walks back up the tree to find the closest #size-cells property
55 * which controls the given node.
56 *
57 * @np: Node pointer to check
58 * @return number of size cells this node uses
59 */
60 int of_n_size_cells(const struct device_node *np);
61
62 /**
63 * of_simple_addr_cells() - Get the address cells property in a node
64 *
65 * This function matches fdt_address_cells().
66 *
67 * @np: Node pointer to check
68 * @return value of #address-cells property in this node, or 2 if none
69 */
70 int of_simple_addr_cells(const struct device_node *np);
71
72 /**
73 * of_simple_size_cells() - Get the size cells property in a node
74 *
75 * This function matches fdt_size_cells().
76 *
77 * @np: Node pointer to check
78 * @return value of #size-cells property in this node, or 2 if none
79 */
80 int of_simple_size_cells(const struct device_node *np);
81
82 /**
83 * of_find_property() - find a property in a node
84 *
85 * @np: Pointer to device node holding property
86 * @name: Name of property
87 * @lenp: If non-NULL, returns length of property
88 * @return pointer to property, or NULL if not found
89 */
90 struct property *of_find_property(const struct device_node *np,
91 const char *name, int *lenp);
92
93 /**
94 * of_get_property() - get a property value
95 *
96 * Find a property with a given name for a given node and return the value.
97 *
98 * @np: Pointer to device node holding property
99 * @name: Name of property
100 * @lenp: If non-NULL, returns length of property
101 * @return pointer to property value, or NULL if not found
102 */
103 const void *of_get_property(const struct device_node *np, const char *name,
104 int *lenp);
105
106 /**
107 * of_device_is_compatible() - Check if the node matches given constraints
108 * @device: pointer to node
109 * @compat: required compatible string, NULL or "" for any match
110 * @type: required device_type value, NULL or "" for any match
111 * @name: required node name, NULL or "" for any match
112 *
113 * Checks if the given @compat, @type and @name strings match the
114 * properties of the given @device. A constraints can be skipped by
115 * passing NULL or an empty string as the constraint.
116 *
117 * @return 0 for no match, and a positive integer on match. The return
118 * value is a relative score with larger values indicating better
119 * matches. The score is weighted for the most specific compatible value
120 * to get the highest score. Matching type is next, followed by matching
121 * name. Practically speaking, this results in the following priority
122 * order for matches:
123 *
124 * 1. specific compatible && type && name
125 * 2. specific compatible && type
126 * 3. specific compatible && name
127 * 4. specific compatible
128 * 5. general compatible && type && name
129 * 6. general compatible && type
130 * 7. general compatible && name
131 * 8. general compatible
132 * 9. type && name
133 * 10. type
134 * 11. name
135 */
136 int of_device_is_compatible(const struct device_node *np, const char *compat,
137 const char *type, const char *name);
138
139 /**
140 * of_device_is_available() - check if a device is available for use
141 *
142 * @device: Node to check for availability
143 *
144 * @return true if the status property is absent or set to "okay", false
145 * otherwise
146 */
147 bool of_device_is_available(const struct device_node *np);
148
149 /**
150 * of_get_parent() - Get a node's parent, if any
151 *
152 * @node: Node to check
153 * @eturns a node pointer, or NULL if none
154 */
155 struct device_node *of_get_parent(const struct device_node *np);
156
157 /**
158 * of_find_node_opts_by_path() - Find a node matching a full OF path
159 *
160 * @path: Either the full path to match, or if the path does not start with
161 * '/', the name of a property of the /aliases node (an alias). In the
162 * case of an alias, the node matching the alias' value will be returned.
163 * @opts: Address of a pointer into which to store the start of an options
164 * string appended to the end of the path with a ':' separator. Can be NULL
165 *
166 * Valid paths:
167 * /foo/bar Full path
168 * foo Valid alias
169 * foo/bar Valid alias + relative path
170 *
171 * @return a node pointer or NULL if not found
172 */
173 struct device_node *of_find_node_opts_by_path(const char *path,
174 const char **opts);
175
of_find_node_by_path(const char * path)176 static inline struct device_node *of_find_node_by_path(const char *path)
177 {
178 return of_find_node_opts_by_path(path, NULL);
179 }
180
181 /**
182 * of_find_compatible_node() - find a node based on its compatible string
183 *
184 * Find a node based on type and one of the tokens in its "compatible" property
185 * @from: Node to start searching from or NULL. the node you pass will not be
186 * searched, only the next one will; typically, you pass what the previous
187 * call returned.
188 * @type: The type string to match "device_type" or NULL to ignore
189 * @compatible: The string to match to one of the tokens in the device
190 * "compatible" list.
191 * @return node pointer or NULL if not found
192 */
193 struct device_node *of_find_compatible_node(struct device_node *from,
194 const char *type, const char *compatible);
195
196 /**
197 * of_find_node_by_prop_value() - find a node with a given property value
198 *
199 * Find a node based on a property value.
200 * @from: Node to start searching from or NULL. the node you pass will not be
201 * searched, only the next one will; typically, you pass what the previous
202 * call returned.
203 * @propname: property name to check
204 * @propval: property value to search for
205 * @proplen: length of the value in propval
206 * @return node pointer or NULL if not found
207 */
208 struct device_node *of_find_node_by_prop_value(struct device_node *from,
209 const char *propname,
210 const void *propval,
211 int proplen);
212 /**
213 * of_find_node_by_phandle() - Find a node given a phandle
214 *
215 * @handle: phandle of the node to find
216 *
217 * @return node pointer, or NULL if not found
218 */
219 struct device_node *of_find_node_by_phandle(phandle handle);
220
221 /**
222 * of_read_u32() - Find and read a 32-bit integer from a property
223 *
224 * Search for a property in a device node and read a 32-bit value from
225 * it.
226 *
227 * @np: device node from which the property value is to be read.
228 * @propname: name of the property to be searched.
229 * @outp: pointer to return value, modified only if return value is 0.
230 *
231 * @return 0 on success, -EINVAL if the property does not exist,
232 * -ENODATA if property does not have a value, and -EOVERFLOW if the
233 * property data isn't large enough.
234 */
235 int of_read_u32(const struct device_node *np, const char *propname, u32 *outp);
236
237 /**
238 * of_read_u64() - Find and read a 64-bit integer from a property
239 *
240 * Search for a property in a device node and read a 64-bit value from
241 * it.
242 *
243 * @np: device node from which the property value is to be read.
244 * @propname: name of the property to be searched.
245 * @outp: pointer to return value, modified only if return value is 0.
246 *
247 * @return 0 on success, -EINVAL if the property does not exist,
248 * -ENODATA if property does not have a value, and -EOVERFLOW if the
249 * property data isn't large enough.
250 */
251 int of_read_u64(const struct device_node *np, const char *propname, u64 *outp);
252
253 /**
254 * of_read_u32_array() - Find and read an array of 32 bit integers
255 *
256 * Search for a property in a device node and read 32-bit value(s) from
257 * it.
258 *
259 * @np: device node from which the property value is to be read.
260 * @propname: name of the property to be searched.
261 * @out_values: pointer to return value, modified only if return value is 0.
262 * @sz: number of array elements to read
263 * @return 0 on success, -EINVAL if the property does not exist, -ENODATA
264 * if property does not have a value, and -EOVERFLOW is longer than sz.
265 */
266 int of_read_u32_array(const struct device_node *np, const char *propname,
267 u32 *out_values, size_t sz);
268
269 /**
270 * of_property_match_string() - Find string in a list and return index
271 *
272 * This function searches a string list property and returns the index
273 * of a specific string value.
274 *
275 * @np: pointer to node containing string list property
276 * @propname: string list property name
277 * @string: pointer to string to search for in string list
278 * @return 0 on success, -EINVAL if the property does not exist, -ENODATA
279 * if property does not have a value, and -EOVERFLOW is longer than sz.
280 */
281 int of_property_match_string(const struct device_node *np, const char *propname,
282 const char *string);
283
284 int of_property_read_string_helper(const struct device_node *np,
285 const char *propname, const char **out_strs,
286 size_t sz, int index);
287
288 /**
289 * of_property_read_string_index() - Find and read a string from a multiple
290 * strings property.
291 * @np: device node from which the property value is to be read.
292 * @propname: name of the property to be searched.
293 * @index: index of the string in the list of strings
294 * @out_string: pointer to null terminated return string, modified only if
295 * return value is 0.
296 *
297 * Search for a property in a device tree node and retrieve a null
298 * terminated string value (pointer to data, not a copy) in the list of strings
299 * contained in that property.
300 * Returns 0 on success, -EINVAL if the property does not exist, -ENODATA if
301 * property does not have a value, and -EILSEQ if the string is not
302 * null-terminated within the length of the property data.
303 *
304 * The out_string pointer is modified only if a valid string can be decoded.
305 */
of_property_read_string_index(const struct device_node * np,const char * propname,int index,const char ** output)306 static inline int of_property_read_string_index(const struct device_node *np,
307 const char *propname,
308 int index, const char **output)
309 {
310 int rc = of_property_read_string_helper(np, propname, output, 1, index);
311 return rc < 0 ? rc : 0;
312 }
313
314 /**
315 * of_property_count_strings() - Find and return the number of strings from a
316 * multiple strings property.
317 * @np: device node from which the property value is to be read.
318 * @propname: name of the property to be searched.
319 *
320 * Search for a property in a device tree node and retrieve the number of null
321 * terminated string contain in it. Returns the number of strings on
322 * success, -EINVAL if the property does not exist, -ENODATA if property
323 * does not have a value, and -EILSEQ if the string is not null-terminated
324 * within the length of the property data.
325 */
of_property_count_strings(const struct device_node * np,const char * propname)326 static inline int of_property_count_strings(const struct device_node *np,
327 const char *propname)
328 {
329 return of_property_read_string_helper(np, propname, NULL, 0, 0);
330 }
331
332 /**
333 * of_parse_phandle - Resolve a phandle property to a device_node pointer
334 * @np: Pointer to device node holding phandle property
335 * @phandle_name: Name of property holding a phandle value
336 * @index: For properties holding a table of phandles, this is the index into
337 * the table
338 *
339 * Returns the device_node pointer with refcount incremented. Use
340 * of_node_put() on it when done.
341 */
342 struct device_node *of_parse_phandle(const struct device_node *np,
343 const char *phandle_name, int index);
344
345 /**
346 * of_parse_phandle_with_args() - Find a node pointed by phandle in a list
347 *
348 * @np: pointer to a device tree node containing a list
349 * @list_name: property name that contains a list
350 * @cells_name: property name that specifies phandles' arguments count
351 * @index: index of a phandle to parse out
352 * @out_args: optional pointer to output arguments structure (will be filled)
353 * @return 0 on success (with @out_args filled out if not NULL), -ENOENT if
354 * @list_name does not exist, -EINVAL if a phandle was not found,
355 * @cells_name could not be found, the arguments were truncated or there
356 * were too many arguments.
357 *
358 * This function is useful to parse lists of phandles and their arguments.
359 * Returns 0 on success and fills out_args, on error returns appropriate
360 * errno value.
361 *
362 * Caller is responsible to call of_node_put() on the returned out_args->np
363 * pointer.
364 *
365 * Example:
366 *
367 * phandle1: node1 {
368 * #list-cells = <2>;
369 * }
370 *
371 * phandle2: node2 {
372 * #list-cells = <1>;
373 * }
374 *
375 * node3 {
376 * list = <&phandle1 1 2 &phandle2 3>;
377 * }
378 *
379 * To get a device_node of the `node2' node you may call this:
380 * of_parse_phandle_with_args(node3, "list", "#list-cells", 1, &args);
381 */
382 int of_parse_phandle_with_args(const struct device_node *np,
383 const char *list_name, const char *cells_name,
384 int index, struct of_phandle_args *out_args);
385
386 /**
387 * of_count_phandle_with_args() - Count the number of 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 * @return number of phandle found, -ENOENT if
393 * @list_name does not exist, -EINVAL if a phandle was not found,
394 * @cells_name could not be found, the arguments were truncated or there
395 * were too many arguments.
396 *
397 * Returns number of phandle found on success, on error returns appropriate
398 * errno value.
399 *
400 */
401 int of_count_phandle_with_args(const struct device_node *np,
402 const char *list_name, const char *cells_name);
403
404 /**
405 * of_alias_scan() - Scan all properties of the 'aliases' node
406 *
407 * The function scans all the properties of the 'aliases' node and populates
408 * the lookup table with the properties. It returns the number of alias
409 * properties found, or an error code in case of failure.
410 *
411 * @return 9 if OK, -ENOMEM if not enough memory
412 */
413 int of_alias_scan(void);
414
415 /**
416 * of_alias_get_id - Get alias id for the given device_node
417 *
418 * Travels the lookup table to get the alias id for the given device_node and
419 * alias stem.
420 *
421 * @np: Pointer to the given device_node
422 * @stem: Alias stem of the given device_node
423 * @return alias ID, if found, else -ENODEV
424 */
425 int of_alias_get_id(const struct device_node *np, const char *stem);
426
427 /**
428 * of_alias_get_highest_id - Get highest alias id for the given stem
429 * @stem: Alias stem to be examined
430 *
431 * The function travels the lookup table to get the highest alias id for the
432 * given alias stem.
433 * @return alias ID, if found, else -1
434 */
435 int of_alias_get_highest_id(const char *stem);
436
437 /**
438 * of_get_stdout() - Get node to use for stdout
439 *
440 * @return node referred to by stdout-path alias, or NULL if none
441 */
442 struct device_node *of_get_stdout(void);
443
444 #endif
445