of: unify phandle name in struct device_node
[linux-2.6.git] / drivers / of / fdt.c
1 /*
2  * Functions for working with the Flattened Device Tree data format
3  *
4  * Copyright 2009 Benjamin Herrenschmidt, IBM Corp
5  * benh@kernel.crashing.org
6  *
7  * This program is free software; you can redistribute it and/or
8  * modify it under the terms of the GNU General Public License
9  * version 2 as published by the Free Software Foundation.
10  */
11
12 #include <linux/kernel.h>
13 #include <linux/lmb.h>
14 #include <linux/initrd.h>
15 #include <linux/of.h>
16 #include <linux/of_fdt.h>
17
18 #ifdef CONFIG_PPC
19 #include <asm/machdep.h>
20 #endif /* CONFIG_PPC */
21
22 int __initdata dt_root_addr_cells;
23 int __initdata dt_root_size_cells;
24
25 struct boot_param_header *initial_boot_params;
26
27 char *find_flat_dt_string(u32 offset)
28 {
29         return ((char *)initial_boot_params) +
30                 initial_boot_params->off_dt_strings + offset;
31 }
32
33 /**
34  * of_scan_flat_dt - scan flattened tree blob and call callback on each.
35  * @it: callback function
36  * @data: context data pointer
37  *
38  * This function is used to scan the flattened device-tree, it is
39  * used to extract the memory information at boot before we can
40  * unflatten the tree
41  */
42 int __init of_scan_flat_dt(int (*it)(unsigned long node,
43                                      const char *uname, int depth,
44                                      void *data),
45                            void *data)
46 {
47         unsigned long p = ((unsigned long)initial_boot_params) +
48                 initial_boot_params->off_dt_struct;
49         int rc = 0;
50         int depth = -1;
51
52         do {
53                 u32 tag = *((u32 *)p);
54                 char *pathp;
55
56                 p += 4;
57                 if (tag == OF_DT_END_NODE) {
58                         depth--;
59                         continue;
60                 }
61                 if (tag == OF_DT_NOP)
62                         continue;
63                 if (tag == OF_DT_END)
64                         break;
65                 if (tag == OF_DT_PROP) {
66                         u32 sz = *((u32 *)p);
67                         p += 8;
68                         if (initial_boot_params->version < 0x10)
69                                 p = _ALIGN(p, sz >= 8 ? 8 : 4);
70                         p += sz;
71                         p = _ALIGN(p, 4);
72                         continue;
73                 }
74                 if (tag != OF_DT_BEGIN_NODE) {
75                         pr_err("Invalid tag %x in flat device tree!\n", tag);
76                         return -EINVAL;
77                 }
78                 depth++;
79                 pathp = (char *)p;
80                 p = _ALIGN(p + strlen(pathp) + 1, 4);
81                 if ((*pathp) == '/') {
82                         char *lp, *np;
83                         for (lp = NULL, np = pathp; *np; np++)
84                                 if ((*np) == '/')
85                                         lp = np+1;
86                         if (lp != NULL)
87                                 pathp = lp;
88                 }
89                 rc = it(p, pathp, depth, data);
90                 if (rc != 0)
91                         break;
92         } while (1);
93
94         return rc;
95 }
96
97 /**
98  * of_get_flat_dt_root - find the root node in the flat blob
99  */
100 unsigned long __init of_get_flat_dt_root(void)
101 {
102         unsigned long p = ((unsigned long)initial_boot_params) +
103                 initial_boot_params->off_dt_struct;
104
105         while (*((u32 *)p) == OF_DT_NOP)
106                 p += 4;
107         BUG_ON(*((u32 *)p) != OF_DT_BEGIN_NODE);
108         p += 4;
109         return _ALIGN(p + strlen((char *)p) + 1, 4);
110 }
111
112 /**
113  * of_get_flat_dt_prop - Given a node in the flat blob, return the property ptr
114  *
115  * This function can be used within scan_flattened_dt callback to get
116  * access to properties
117  */
118 void *__init of_get_flat_dt_prop(unsigned long node, const char *name,
119                                  unsigned long *size)
120 {
121         unsigned long p = node;
122
123         do {
124                 u32 tag = *((u32 *)p);
125                 u32 sz, noff;
126                 const char *nstr;
127
128                 p += 4;
129                 if (tag == OF_DT_NOP)
130                         continue;
131                 if (tag != OF_DT_PROP)
132                         return NULL;
133
134                 sz = *((u32 *)p);
135                 noff = *((u32 *)(p + 4));
136                 p += 8;
137                 if (initial_boot_params->version < 0x10)
138                         p = _ALIGN(p, sz >= 8 ? 8 : 4);
139
140                 nstr = find_flat_dt_string(noff);
141                 if (nstr == NULL) {
142                         pr_warning("Can't find property index name !\n");
143                         return NULL;
144                 }
145                 if (strcmp(name, nstr) == 0) {
146                         if (size)
147                                 *size = sz;
148                         return (void *)p;
149                 }
150                 p += sz;
151                 p = _ALIGN(p, 4);
152         } while (1);
153 }
154
155 /**
156  * of_flat_dt_is_compatible - Return true if given node has compat in compatible list
157  * @node: node to test
158  * @compat: compatible string to compare with compatible list.
159  */
160 int __init of_flat_dt_is_compatible(unsigned long node, const char *compat)
161 {
162         const char *cp;
163         unsigned long cplen, l;
164
165         cp = of_get_flat_dt_prop(node, "compatible", &cplen);
166         if (cp == NULL)
167                 return 0;
168         while (cplen > 0) {
169                 if (strncasecmp(cp, compat, strlen(compat)) == 0)
170                         return 1;
171                 l = strlen(cp) + 1;
172                 cp += l;
173                 cplen -= l;
174         }
175
176         return 0;
177 }
178
179 static void *__init unflatten_dt_alloc(unsigned long *mem, unsigned long size,
180                                        unsigned long align)
181 {
182         void *res;
183
184         *mem = _ALIGN(*mem, align);
185         res = (void *)*mem;
186         *mem += size;
187
188         return res;
189 }
190
191 /**
192  * unflatten_dt_node - Alloc and populate a device_node from the flat tree
193  * @p: pointer to node in flat tree
194  * @dad: Parent struct device_node
195  * @allnextpp: pointer to ->allnext from last allocated device_node
196  * @fpsize: Size of the node path up at the current depth.
197  */
198 unsigned long __init unflatten_dt_node(unsigned long mem,
199                                         unsigned long *p,
200                                         struct device_node *dad,
201                                         struct device_node ***allnextpp,
202                                         unsigned long fpsize)
203 {
204         struct device_node *np;
205         struct property *pp, **prev_pp = NULL;
206         char *pathp;
207         u32 tag;
208         unsigned int l, allocl;
209         int has_name = 0;
210         int new_format = 0;
211
212         tag = *((u32 *)(*p));
213         if (tag != OF_DT_BEGIN_NODE) {
214                 pr_err("Weird tag at start of node: %x\n", tag);
215                 return mem;
216         }
217         *p += 4;
218         pathp = (char *)*p;
219         l = allocl = strlen(pathp) + 1;
220         *p = _ALIGN(*p + l, 4);
221
222         /* version 0x10 has a more compact unit name here instead of the full
223          * path. we accumulate the full path size using "fpsize", we'll rebuild
224          * it later. We detect this because the first character of the name is
225          * not '/'.
226          */
227         if ((*pathp) != '/') {
228                 new_format = 1;
229                 if (fpsize == 0) {
230                         /* root node: special case. fpsize accounts for path
231                          * plus terminating zero. root node only has '/', so
232                          * fpsize should be 2, but we want to avoid the first
233                          * level nodes to have two '/' so we use fpsize 1 here
234                          */
235                         fpsize = 1;
236                         allocl = 2;
237                 } else {
238                         /* account for '/' and path size minus terminal 0
239                          * already in 'l'
240                          */
241                         fpsize += l;
242                         allocl = fpsize;
243                 }
244         }
245
246         np = unflatten_dt_alloc(&mem, sizeof(struct device_node) + allocl,
247                                 __alignof__(struct device_node));
248         if (allnextpp) {
249                 memset(np, 0, sizeof(*np));
250                 np->full_name = ((char *)np) + sizeof(struct device_node);
251                 if (new_format) {
252                         char *fn = np->full_name;
253                         /* rebuild full path for new format */
254                         if (dad && dad->parent) {
255                                 strcpy(fn, dad->full_name);
256 #ifdef DEBUG
257                                 if ((strlen(fn) + l + 1) != allocl) {
258                                         pr_debug("%s: p: %d, l: %d, a: %d\n",
259                                                 pathp, (int)strlen(fn),
260                                                 l, allocl);
261                                 }
262 #endif
263                                 fn += strlen(fn);
264                         }
265                         *(fn++) = '/';
266                         memcpy(fn, pathp, l);
267                 } else
268                         memcpy(np->full_name, pathp, l);
269                 prev_pp = &np->properties;
270                 **allnextpp = np;
271                 *allnextpp = &np->allnext;
272                 if (dad != NULL) {
273                         np->parent = dad;
274                         /* we temporarily use the next field as `last_child'*/
275                         if (dad->next == NULL)
276                                 dad->child = np;
277                         else
278                                 dad->next->sibling = np;
279                         dad->next = np;
280                 }
281                 kref_init(&np->kref);
282         }
283         while (1) {
284                 u32 sz, noff;
285                 char *pname;
286
287                 tag = *((u32 *)(*p));
288                 if (tag == OF_DT_NOP) {
289                         *p += 4;
290                         continue;
291                 }
292                 if (tag != OF_DT_PROP)
293                         break;
294                 *p += 4;
295                 sz = *((u32 *)(*p));
296                 noff = *((u32 *)((*p) + 4));
297                 *p += 8;
298                 if (initial_boot_params->version < 0x10)
299                         *p = _ALIGN(*p, sz >= 8 ? 8 : 4);
300
301                 pname = find_flat_dt_string(noff);
302                 if (pname == NULL) {
303                         pr_info("Can't find property name in list !\n");
304                         break;
305                 }
306                 if (strcmp(pname, "name") == 0)
307                         has_name = 1;
308                 l = strlen(pname) + 1;
309                 pp = unflatten_dt_alloc(&mem, sizeof(struct property),
310                                         __alignof__(struct property));
311                 if (allnextpp) {
312                         if (strcmp(pname, "linux,phandle") == 0) {
313                                 if (np->phandle == 0)
314                                         np->phandle = *((u32 *)*p);
315                         }
316                         if (strcmp(pname, "ibm,phandle") == 0)
317                                 np->phandle = *((u32 *)*p);
318                         pp->name = pname;
319                         pp->length = sz;
320                         pp->value = (void *)*p;
321                         *prev_pp = pp;
322                         prev_pp = &pp->next;
323                 }
324                 *p = _ALIGN((*p) + sz, 4);
325         }
326         /* with version 0x10 we may not have the name property, recreate
327          * it here from the unit name if absent
328          */
329         if (!has_name) {
330                 char *p1 = pathp, *ps = pathp, *pa = NULL;
331                 int sz;
332
333                 while (*p1) {
334                         if ((*p1) == '@')
335                                 pa = p1;
336                         if ((*p1) == '/')
337                                 ps = p1 + 1;
338                         p1++;
339                 }
340                 if (pa < ps)
341                         pa = p1;
342                 sz = (pa - ps) + 1;
343                 pp = unflatten_dt_alloc(&mem, sizeof(struct property) + sz,
344                                         __alignof__(struct property));
345                 if (allnextpp) {
346                         pp->name = "name";
347                         pp->length = sz;
348                         pp->value = pp + 1;
349                         *prev_pp = pp;
350                         prev_pp = &pp->next;
351                         memcpy(pp->value, ps, sz - 1);
352                         ((char *)pp->value)[sz - 1] = 0;
353                         pr_debug("fixed up name for %s -> %s\n", pathp,
354                                 (char *)pp->value);
355                 }
356         }
357         if (allnextpp) {
358                 *prev_pp = NULL;
359                 np->name = of_get_property(np, "name", NULL);
360                 np->type = of_get_property(np, "device_type", NULL);
361
362                 if (!np->name)
363                         np->name = "<NULL>";
364                 if (!np->type)
365                         np->type = "<NULL>";
366         }
367         while (tag == OF_DT_BEGIN_NODE) {
368                 mem = unflatten_dt_node(mem, p, np, allnextpp, fpsize);
369                 tag = *((u32 *)(*p));
370         }
371         if (tag != OF_DT_END_NODE) {
372                 pr_err("Weird tag at end of node: %x\n", tag);
373                 return mem;
374         }
375         *p += 4;
376         return mem;
377 }
378
379 #ifdef CONFIG_BLK_DEV_INITRD
380 /**
381  * early_init_dt_check_for_initrd - Decode initrd location from flat tree
382  * @node: reference to node containing initrd location ('chosen')
383  */
384 void __init early_init_dt_check_for_initrd(unsigned long node)
385 {
386         unsigned long len;
387         u32 *prop;
388
389         pr_debug("Looking for initrd properties... ");
390
391         prop = of_get_flat_dt_prop(node, "linux,initrd-start", &len);
392         if (prop) {
393                 initrd_start = (unsigned long)
394                                 __va(of_read_ulong(prop, len/4));
395
396                 prop = of_get_flat_dt_prop(node, "linux,initrd-end", &len);
397                 if (prop) {
398                         initrd_end = (unsigned long)
399                                 __va(of_read_ulong(prop, len/4));
400                         initrd_below_start_ok = 1;
401                 } else {
402                         initrd_start = 0;
403                 }
404         }
405
406         pr_debug("initrd_start=0x%lx  initrd_end=0x%lx\n",
407                  initrd_start, initrd_end);
408 }
409 #else
410 inline void early_init_dt_check_for_initrd(unsigned long node)
411 {
412 }
413 #endif /* CONFIG_BLK_DEV_INITRD */
414
415 /**
416  * early_init_dt_scan_root - fetch the top level address and size cells
417  */
418 int __init early_init_dt_scan_root(unsigned long node, const char *uname,
419                                    int depth, void *data)
420 {
421         u32 *prop;
422
423         if (depth != 0)
424                 return 0;
425
426         prop = of_get_flat_dt_prop(node, "#size-cells", NULL);
427         dt_root_size_cells = (prop == NULL) ? 1 : *prop;
428         pr_debug("dt_root_size_cells = %x\n", dt_root_size_cells);
429
430         prop = of_get_flat_dt_prop(node, "#address-cells", NULL);
431         dt_root_addr_cells = (prop == NULL) ? 2 : *prop;
432         pr_debug("dt_root_addr_cells = %x\n", dt_root_addr_cells);
433
434         /* break now */
435         return 1;
436 }
437
438 u64 __init dt_mem_next_cell(int s, u32 **cellp)
439 {
440         u32 *p = *cellp;
441
442         *cellp = p + s;
443         return of_read_number(p, s);
444 }
445
446 int __init early_init_dt_scan_chosen(unsigned long node, const char *uname,
447                                      int depth, void *data)
448 {
449         unsigned long l;
450         char *p;
451
452         pr_debug("search \"chosen\", depth: %d, uname: %s\n", depth, uname);
453
454         if (depth != 1 ||
455             (strcmp(uname, "chosen") != 0 && strcmp(uname, "chosen@0") != 0))
456                 return 0;
457
458         early_init_dt_check_for_initrd(node);
459
460         /* Retreive command line */
461         p = of_get_flat_dt_prop(node, "bootargs", &l);
462         if (p != NULL && l > 0)
463                 strlcpy(cmd_line, p, min((int)l, COMMAND_LINE_SIZE));
464
465 #ifdef CONFIG_CMDLINE
466 #ifndef CONFIG_CMDLINE_FORCE
467         if (p == NULL || l == 0 || (l == 1 && (*p) == 0))
468 #endif
469                 strlcpy(cmd_line, CONFIG_CMDLINE, COMMAND_LINE_SIZE);
470 #endif /* CONFIG_CMDLINE */
471
472         early_init_dt_scan_chosen_arch(node);
473
474         pr_debug("Command line is: %s\n", cmd_line);
475
476         /* break now */
477         return 1;
478 }
479
480 /**
481  * unflatten_device_tree - create tree of device_nodes from flat blob
482  *
483  * unflattens the device-tree passed by the firmware, creating the
484  * tree of struct device_node. It also fills the "name" and "type"
485  * pointers of the nodes so the normal device-tree walking functions
486  * can be used.
487  */
488 void __init unflatten_device_tree(void)
489 {
490         unsigned long start, mem, size;
491         struct device_node **allnextp = &allnodes;
492
493         pr_debug(" -> unflatten_device_tree()\n");
494
495         /* First pass, scan for size */
496         start = ((unsigned long)initial_boot_params) +
497                 initial_boot_params->off_dt_struct;
498         size = unflatten_dt_node(0, &start, NULL, NULL, 0);
499         size = (size | 3) + 1;
500
501         pr_debug("  size is %lx, allocating...\n", size);
502
503         /* Allocate memory for the expanded device tree */
504         mem = lmb_alloc(size + 4, __alignof__(struct device_node));
505         mem = (unsigned long) __va(mem);
506
507         ((u32 *)mem)[size / 4] = 0xdeadbeef;
508
509         pr_debug("  unflattening %lx...\n", mem);
510
511         /* Second pass, do actual unflattening */
512         start = ((unsigned long)initial_boot_params) +
513                 initial_boot_params->off_dt_struct;
514         unflatten_dt_node(mem, &start, NULL, &allnextp, 0);
515         if (*((u32 *)start) != OF_DT_END)
516                 pr_warning("Weird tag at end of tree: %08x\n", *((u32 *)start));
517         if (((u32 *)mem)[size / 4] != 0xdeadbeef)
518                 pr_warning("End of tree marker overwritten: %08x\n",
519                            ((u32 *)mem)[size / 4]);
520         *allnextp = NULL;
521
522         /* Get pointer to OF "/chosen" node for use everywhere */
523         of_chosen = of_find_node_by_path("/chosen");
524         if (of_chosen == NULL)
525                 of_chosen = of_find_node_by_path("/chosen@0");
526
527         pr_debug(" <- unflatten_device_tree()\n");
528 }