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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