1/*
2 * Procedures for creating, accessing and interpreting the device tree.
3 *
4 * Paul Mackerras	August 1996.
5 * Copyright (C) 1996-2005 Paul Mackerras.
6 *
7 *  Adapted for 64bit PowerPC by Dave Engebretsen and Peter Bergner.
8 *    {engebret|bergner}@us.ibm.com
9 *
10 *  Adapted for sparc32 by David S. Miller davem@davemloft.net
11 *
12 *      This program is free software; you can redistribute it and/or
13 *      modify it under the terms of the GNU General Public License
14 *      as published by the Free Software Foundation; either version
15 *      2 of the License, or (at your option) any later version.
16 */
17
18#include <linux/kernel.h>
19#include <linux/types.h>
20#include <linux/string.h>
21#include <linux/mm.h>
22#include <linux/bootmem.h>
23#include <linux/module.h>
24
25#include <asm/prom.h>
26#include <asm/oplib.h>
27
28static struct device_node *allnodes;
29
30/* use when traversing tree through the allnext, child, sibling,
31 * or parent members of struct device_node.
32 */
33static DEFINE_RWLOCK(devtree_lock);
34
35int of_device_is_compatible(const struct device_node *device,
36			    const char *compat)
37{
38	const char* cp;
39	int cplen, l;
40
41	cp = of_get_property(device, "compatible", &cplen);
42	if (cp == NULL)
43		return 0;
44	while (cplen > 0) {
45		if (strncmp(cp, compat, strlen(compat)) == 0)
46			return 1;
47		l = strlen(cp) + 1;
48		cp += l;
49		cplen -= l;
50	}
51
52	return 0;
53}
54EXPORT_SYMBOL(of_device_is_compatible);
55
56struct device_node *of_get_parent(const struct device_node *node)
57{
58	struct device_node *np;
59
60	if (!node)
61		return NULL;
62
63	np = node->parent;
64
65	return np;
66}
67EXPORT_SYMBOL(of_get_parent);
68
69struct device_node *of_get_next_child(const struct device_node *node,
70	struct device_node *prev)
71{
72	struct device_node *next;
73
74	next = prev ? prev->sibling : node->child;
75	for (; next != 0; next = next->sibling) {
76		break;
77	}
78
79	return next;
80}
81EXPORT_SYMBOL(of_get_next_child);
82
83struct device_node *of_find_node_by_path(const char *path)
84{
85	struct device_node *np = allnodes;
86
87	for (; np != 0; np = np->allnext) {
88		if (np->full_name != 0 && strcmp(np->full_name, path) == 0)
89			break;
90	}
91
92	return np;
93}
94EXPORT_SYMBOL(of_find_node_by_path);
95
96struct device_node *of_find_node_by_phandle(phandle handle)
97{
98	struct device_node *np;
99
100	for (np = allnodes; np != 0; np = np->allnext)
101		if (np->node == handle)
102			break;
103
104	return np;
105}
106EXPORT_SYMBOL(of_find_node_by_phandle);
107
108struct device_node *of_find_node_by_name(struct device_node *from,
109	const char *name)
110{
111	struct device_node *np;
112
113	np = from ? from->allnext : allnodes;
114	for (; np != NULL; np = np->allnext)
115		if (np->name != NULL && strcmp(np->name, name) == 0)
116			break;
117
118	return np;
119}
120EXPORT_SYMBOL(of_find_node_by_name);
121
122struct device_node *of_find_node_by_type(struct device_node *from,
123	const char *type)
124{
125	struct device_node *np;
126
127	np = from ? from->allnext : allnodes;
128	for (; np != 0; np = np->allnext)
129		if (np->type != 0 && strcmp(np->type, type) == 0)
130			break;
131
132	return np;
133}
134EXPORT_SYMBOL(of_find_node_by_type);
135
136struct device_node *of_find_compatible_node(struct device_node *from,
137	const char *type, const char *compatible)
138{
139	struct device_node *np;
140
141	np = from ? from->allnext : allnodes;
142	for (; np != 0; np = np->allnext) {
143		if (type != NULL
144		    && !(np->type != 0 && strcmp(np->type, type) == 0))
145			continue;
146		if (of_device_is_compatible(np, compatible))
147			break;
148	}
149
150	return np;
151}
152EXPORT_SYMBOL(of_find_compatible_node);
153
154struct property *of_find_property(const struct device_node *np,
155				  const char *name,
156				  int *lenp)
157{
158	struct property *pp;
159
160	for (pp = np->properties; pp != 0; pp = pp->next) {
161		if (strcasecmp(pp->name, name) == 0) {
162			if (lenp != 0)
163				*lenp = pp->length;
164			break;
165		}
166	}
167	return pp;
168}
169EXPORT_SYMBOL(of_find_property);
170
171/*
172 * Find a property with a given name for a given node
173 * and return the value.
174 */
175const void *of_get_property(const struct device_node *np, const char *name,
176			    int *lenp)
177{
178	struct property *pp = of_find_property(np,name,lenp);
179	return pp ? pp->value : NULL;
180}
181EXPORT_SYMBOL(of_get_property);
182
183int of_getintprop_default(struct device_node *np, const char *name, int def)
184{
185	struct property *prop;
186	int len;
187
188	prop = of_find_property(np, name, &len);
189	if (!prop || len != 4)
190		return def;
191
192	return *(int *) prop->value;
193}
194EXPORT_SYMBOL(of_getintprop_default);
195
196int of_n_addr_cells(struct device_node *np)
197{
198	const int* ip;
199	do {
200		if (np->parent)
201			np = np->parent;
202		ip = of_get_property(np, "#address-cells", NULL);
203		if (ip != NULL)
204			return *ip;
205	} while (np->parent);
206	/* No #address-cells property for the root node, default to 2 */
207	return 2;
208}
209EXPORT_SYMBOL(of_n_addr_cells);
210
211int of_n_size_cells(struct device_node *np)
212{
213	const int* ip;
214	do {
215		if (np->parent)
216			np = np->parent;
217		ip = of_get_property(np, "#size-cells", NULL);
218		if (ip != NULL)
219			return *ip;
220	} while (np->parent);
221	/* No #size-cells property for the root node, default to 1 */
222	return 1;
223}
224EXPORT_SYMBOL(of_n_size_cells);
225
226int of_set_property(struct device_node *dp, const char *name, void *val, int len)
227{
228	struct property **prevp;
229	void *new_val;
230	int err;
231
232	new_val = kmalloc(len, GFP_KERNEL);
233	if (!new_val)
234		return -ENOMEM;
235
236	memcpy(new_val, val, len);
237
238	err = -ENODEV;
239
240	write_lock(&devtree_lock);
241	prevp = &dp->properties;
242	while (*prevp) {
243		struct property *prop = *prevp;
244
245		if (!strcasecmp(prop->name, name)) {
246			void *old_val = prop->value;
247			int ret;
248
249			ret = prom_setprop(dp->node, (char *) name, val, len);
250			err = -EINVAL;
251			if (ret >= 0) {
252				prop->value = new_val;
253				prop->length = len;
254
255				if (OF_IS_DYNAMIC(prop))
256					kfree(old_val);
257
258				OF_MARK_DYNAMIC(prop);
259
260				err = 0;
261			}
262			break;
263		}
264		prevp = &(*prevp)->next;
265	}
266	write_unlock(&devtree_lock);
267
268
269	return err;
270}
271EXPORT_SYMBOL(of_set_property);
272
273static unsigned int prom_early_allocated;
274
275static void * __init prom_early_alloc(unsigned long size)
276{
277	void *ret;
278
279	ret = __alloc_bootmem(size, SMP_CACHE_BYTES, 0UL);
280	if (ret != NULL)
281		memset(ret, 0, size);
282
283	prom_early_allocated += size;
284
285	return ret;
286}
287
288static int is_root_node(const struct device_node *dp)
289{
290	if (!dp)
291		return 0;
292
293	return (dp->parent == NULL);
294}
295
296/* The following routines deal with the black magic of fully naming a
297 * node.
298 *
299 * Certain well known named nodes are just the simple name string.
300 *
301 * Actual devices have an address specifier appended to the base name
302 * string, like this "foo@addr".  The "addr" can be in any number of
303 * formats, and the platform plus the type of the node determine the
304 * format and how it is constructed.
305 *
306 * For children of the ROOT node, the naming convention is fixed and
307 * determined by whether this is a sun4u or sun4v system.
308 *
309 * For children of other nodes, it is bus type specific.  So
310 * we walk up the tree until we discover a "device_type" property
311 * we recognize and we go from there.
312 */
313static void __init sparc32_path_component(struct device_node *dp, char *tmp_buf)
314{
315	struct linux_prom_registers *regs;
316	struct property *rprop;
317
318	rprop = of_find_property(dp, "reg", NULL);
319	if (!rprop)
320		return;
321
322	regs = rprop->value;
323	sprintf(tmp_buf, "%s@%x,%x",
324		dp->name,
325		regs->which_io, regs->phys_addr);
326}
327
328/* "name@slot,offset"  */
329static void __init sbus_path_component(struct device_node *dp, char *tmp_buf)
330{
331	struct linux_prom_registers *regs;
332	struct property *prop;
333
334	prop = of_find_property(dp, "reg", NULL);
335	if (!prop)
336		return;
337
338	regs = prop->value;
339	sprintf(tmp_buf, "%s@%x,%x",
340		dp->name,
341		regs->which_io,
342		regs->phys_addr);
343}
344
345/* "name@devnum[,func]" */
346static void __init pci_path_component(struct device_node *dp, char *tmp_buf)
347{
348	struct linux_prom_pci_registers *regs;
349	struct property *prop;
350	unsigned int devfn;
351
352	prop = of_find_property(dp, "reg", NULL);
353	if (!prop)
354		return;
355
356	regs = prop->value;
357	devfn = (regs->phys_hi >> 8) & 0xff;
358	if (devfn & 0x07) {
359		sprintf(tmp_buf, "%s@%x,%x",
360			dp->name,
361			devfn >> 3,
362			devfn & 0x07);
363	} else {
364		sprintf(tmp_buf, "%s@%x",
365			dp->name,
366			devfn >> 3);
367	}
368}
369
370/* "name@addrhi,addrlo" */
371static void __init ebus_path_component(struct device_node *dp, char *tmp_buf)
372{
373	struct linux_prom_registers *regs;
374	struct property *prop;
375
376	prop = of_find_property(dp, "reg", NULL);
377	if (!prop)
378		return;
379
380	regs = prop->value;
381
382	sprintf(tmp_buf, "%s@%x,%x",
383		dp->name,
384		regs->which_io, regs->phys_addr);
385}
386
387static void __init __build_path_component(struct device_node *dp, char *tmp_buf)
388{
389	struct device_node *parent = dp->parent;
390
391	if (parent != NULL) {
392		if (!strcmp(parent->type, "pci") ||
393		    !strcmp(parent->type, "pciex"))
394			return pci_path_component(dp, tmp_buf);
395		if (!strcmp(parent->type, "sbus"))
396			return sbus_path_component(dp, tmp_buf);
397		if (!strcmp(parent->type, "ebus"))
398			return ebus_path_component(dp, tmp_buf);
399
400		/* "isa" is handled with platform naming */
401	}
402
403	/* Use platform naming convention.  */
404	return sparc32_path_component(dp, tmp_buf);
405}
406
407static char * __init build_path_component(struct device_node *dp)
408{
409	char tmp_buf[64], *n;
410
411	tmp_buf[0] = '\0';
412	__build_path_component(dp, tmp_buf);
413	if (tmp_buf[0] == '\0')
414		strcpy(tmp_buf, dp->name);
415
416	n = prom_early_alloc(strlen(tmp_buf) + 1);
417	strcpy(n, tmp_buf);
418
419	return n;
420}
421
422static char * __init build_full_name(struct device_node *dp)
423{
424	int len, ourlen, plen;
425	char *n;
426
427	plen = strlen(dp->parent->full_name);
428	ourlen = strlen(dp->path_component_name);
429	len = ourlen + plen + 2;
430
431	n = prom_early_alloc(len);
432	strcpy(n, dp->parent->full_name);
433	if (!is_root_node(dp->parent)) {
434		strcpy(n + plen, "/");
435		plen++;
436	}
437	strcpy(n + plen, dp->path_component_name);
438
439	return n;
440}
441
442static unsigned int unique_id;
443
444static struct property * __init build_one_prop(phandle node, char *prev, char *special_name, void *special_val, int special_len)
445{
446	static struct property *tmp = NULL;
447	struct property *p;
448	int len;
449	const char *name;
450
451	if (tmp) {
452		p = tmp;
453		memset(p, 0, sizeof(*p) + 32);
454		tmp = NULL;
455	} else {
456		p = prom_early_alloc(sizeof(struct property) + 32);
457		p->unique_id = unique_id++;
458	}
459
460	p->name = (char *) (p + 1);
461	if (special_name) {
462		strcpy(p->name, special_name);
463		p->length = special_len;
464		p->value = prom_early_alloc(special_len);
465		memcpy(p->value, special_val, special_len);
466	} else {
467		if (prev == NULL) {
468			name = prom_firstprop(node, NULL);
469		} else {
470			name = prom_nextprop(node, prev, NULL);
471		}
472		if (strlen(name) == 0) {
473			tmp = p;
474			return NULL;
475		}
476		strcpy(p->name, name);
477		p->length = prom_getproplen(node, p->name);
478		if (p->length <= 0) {
479			p->length = 0;
480		} else {
481			p->value = prom_early_alloc(p->length + 1);
482			len = prom_getproperty(node, p->name, p->value,
483					       p->length);
484			if (len <= 0)
485				p->length = 0;
486			((unsigned char *)p->value)[p->length] = '\0';
487		}
488	}
489	return p;
490}
491
492static struct property * __init build_prop_list(phandle node)
493{
494	struct property *head, *tail;
495
496	head = tail = build_one_prop(node, NULL,
497				     ".node", &node, sizeof(node));
498
499	tail->next = build_one_prop(node, NULL, NULL, NULL, 0);
500	tail = tail->next;
501	while(tail) {
502		tail->next = build_one_prop(node, tail->name,
503					    NULL, NULL, 0);
504		tail = tail->next;
505	}
506
507	return head;
508}
509
510static char * __init get_one_property(phandle node, char *name)
511{
512	char *buf = "<NULL>";
513	int len;
514
515	len = prom_getproplen(node, name);
516	if (len > 0) {
517		buf = prom_early_alloc(len);
518		len = prom_getproperty(node, name, buf, len);
519	}
520
521	return buf;
522}
523
524static struct device_node * __init create_node(phandle node)
525{
526	struct device_node *dp;
527
528	if (!node)
529		return NULL;
530
531	dp = prom_early_alloc(sizeof(*dp));
532	dp->unique_id = unique_id++;
533
534	kref_init(&dp->kref);
535
536	dp->name = get_one_property(node, "name");
537	dp->type = get_one_property(node, "device_type");
538	dp->node = node;
539
540	/* Build interrupts later... */
541
542	dp->properties = build_prop_list(node);
543
544	return dp;
545}
546
547static struct device_node * __init build_tree(struct device_node *parent, phandle node, struct device_node ***nextp)
548{
549	struct device_node *dp;
550
551	dp = create_node(node);
552	if (dp) {
553		*(*nextp) = dp;
554		*nextp = &dp->allnext;
555
556		dp->parent = parent;
557		dp->path_component_name = build_path_component(dp);
558		dp->full_name = build_full_name(dp);
559
560		dp->child = build_tree(dp, prom_getchild(node), nextp);
561
562		dp->sibling = build_tree(parent, prom_getsibling(node), nextp);
563	}
564
565	return dp;
566}
567
568void __init prom_build_devicetree(void)
569{
570	struct device_node **nextp;
571
572	allnodes = create_node(prom_root_node);
573	allnodes->path_component_name = "";
574	allnodes->full_name = "/";
575
576	nextp = &allnodes->allnext;
577	allnodes->child = build_tree(allnodes,
578				     prom_getchild(allnodes->node),
579				     &nextp);
580	printk("PROM: Built device tree with %u bytes of memory.\n",
581	       prom_early_allocated);
582}
583