2 * Procedures for creating, accessing and interpreting the device tree.
4 * Paul Mackerras August 1996.
5 * Copyright (C) 1996-2005 Paul Mackerras.
7 * Adapted for 64bit PowerPC by Dave Engebretsen and Peter Bergner.
8 * {engebret|bergner}@us.ibm.com
10 * Adapted for sparc32 by David S. Miller davem@davemloft.net
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.
18 #include <linux/kernel.h>
19 #include <linux/types.h>
20 #include <linux/string.h>
22 #include <linux/bootmem.h>
23 #include <linux/module.h>
26 #include <asm/oplib.h>
28 extern struct device_node *allnodes; /* temporary while merging */
30 extern rwlock_t devtree_lock; /* temporary while merging */
32 struct device_node *of_find_node_by_phandle(phandle handle)
34 struct device_node *np;
36 for (np = allnodes; np != 0; np = np->allnext)
37 if (np->node == handle)
42 EXPORT_SYMBOL(of_find_node_by_phandle);
44 int of_getintprop_default(struct device_node *np, const char *name, int def)
46 struct property *prop;
49 prop = of_find_property(np, name, &len);
50 if (!prop || len != 4)
53 return *(int *) prop->value;
55 EXPORT_SYMBOL(of_getintprop_default);
57 int of_set_property(struct device_node *dp, const char *name, void *val, int len)
59 struct property **prevp;
63 new_val = kmalloc(len, GFP_KERNEL);
67 memcpy(new_val, val, len);
71 write_lock(&devtree_lock);
72 prevp = &dp->properties;
74 struct property *prop = *prevp;
76 if (!strcasecmp(prop->name, name)) {
77 void *old_val = prop->value;
80 ret = prom_setprop(dp->node, (char *) name, val, len);
83 prop->value = new_val;
86 if (OF_IS_DYNAMIC(prop))
89 OF_MARK_DYNAMIC(prop);
95 prevp = &(*prevp)->next;
97 write_unlock(&devtree_lock);
99 /* XXX Upate procfs if necessary... */
103 EXPORT_SYMBOL(of_set_property);
105 static unsigned int prom_early_allocated;
107 static void * __init prom_early_alloc(unsigned long size)
111 ret = __alloc_bootmem(size, SMP_CACHE_BYTES, 0UL);
113 memset(ret, 0, size);
115 prom_early_allocated += size;
120 static int is_root_node(const struct device_node *dp)
125 return (dp->parent == NULL);
128 /* The following routines deal with the black magic of fully naming a
131 * Certain well known named nodes are just the simple name string.
133 * Actual devices have an address specifier appended to the base name
134 * string, like this "foo@addr". The "addr" can be in any number of
135 * formats, and the platform plus the type of the node determine the
136 * format and how it is constructed.
138 * For children of the ROOT node, the naming convention is fixed and
139 * determined by whether this is a sun4u or sun4v system.
141 * For children of other nodes, it is bus type specific. So
142 * we walk up the tree until we discover a "device_type" property
143 * we recognize and we go from there.
145 static void __init sparc32_path_component(struct device_node *dp, char *tmp_buf)
147 struct linux_prom_registers *regs;
148 struct property *rprop;
150 rprop = of_find_property(dp, "reg", NULL);
155 sprintf(tmp_buf, "%s@%x,%x",
157 regs->which_io, regs->phys_addr);
160 /* "name@slot,offset" */
161 static void __init sbus_path_component(struct device_node *dp, char *tmp_buf)
163 struct linux_prom_registers *regs;
164 struct property *prop;
166 prop = of_find_property(dp, "reg", NULL);
171 sprintf(tmp_buf, "%s@%x,%x",
177 /* "name@devnum[,func]" */
178 static void __init pci_path_component(struct device_node *dp, char *tmp_buf)
180 struct linux_prom_pci_registers *regs;
181 struct property *prop;
184 prop = of_find_property(dp, "reg", NULL);
189 devfn = (regs->phys_hi >> 8) & 0xff;
191 sprintf(tmp_buf, "%s@%x,%x",
196 sprintf(tmp_buf, "%s@%x",
202 /* "name@addrhi,addrlo" */
203 static void __init ebus_path_component(struct device_node *dp, char *tmp_buf)
205 struct linux_prom_registers *regs;
206 struct property *prop;
208 prop = of_find_property(dp, "reg", NULL);
214 sprintf(tmp_buf, "%s@%x,%x",
216 regs->which_io, regs->phys_addr);
219 static void __init __build_path_component(struct device_node *dp, char *tmp_buf)
221 struct device_node *parent = dp->parent;
223 if (parent != NULL) {
224 if (!strcmp(parent->type, "pci") ||
225 !strcmp(parent->type, "pciex"))
226 return pci_path_component(dp, tmp_buf);
227 if (!strcmp(parent->type, "sbus"))
228 return sbus_path_component(dp, tmp_buf);
229 if (!strcmp(parent->type, "ebus"))
230 return ebus_path_component(dp, tmp_buf);
232 /* "isa" is handled with platform naming */
235 /* Use platform naming convention. */
236 return sparc32_path_component(dp, tmp_buf);
239 static char * __init build_path_component(struct device_node *dp)
241 char tmp_buf[64], *n;
244 __build_path_component(dp, tmp_buf);
245 if (tmp_buf[0] == '\0')
246 strcpy(tmp_buf, dp->name);
248 n = prom_early_alloc(strlen(tmp_buf) + 1);
254 static char * __init build_full_name(struct device_node *dp)
256 int len, ourlen, plen;
259 plen = strlen(dp->parent->full_name);
260 ourlen = strlen(dp->path_component_name);
261 len = ourlen + plen + 2;
263 n = prom_early_alloc(len);
264 strcpy(n, dp->parent->full_name);
265 if (!is_root_node(dp->parent)) {
266 strcpy(n + plen, "/");
269 strcpy(n + plen, dp->path_component_name);
274 static unsigned int unique_id;
276 static struct property * __init build_one_prop(phandle node, char *prev, char *special_name, void *special_val, int special_len)
278 static struct property *tmp = NULL;
285 memset(p, 0, sizeof(*p) + 32);
288 p = prom_early_alloc(sizeof(struct property) + 32);
289 p->unique_id = unique_id++;
292 p->name = (char *) (p + 1);
294 strcpy(p->name, special_name);
295 p->length = special_len;
296 p->value = prom_early_alloc(special_len);
297 memcpy(p->value, special_val, special_len);
300 name = prom_firstprop(node, NULL);
302 name = prom_nextprop(node, prev, NULL);
304 if (strlen(name) == 0) {
308 strcpy(p->name, name);
309 p->length = prom_getproplen(node, p->name);
310 if (p->length <= 0) {
313 p->value = prom_early_alloc(p->length + 1);
314 len = prom_getproperty(node, p->name, p->value,
318 ((unsigned char *)p->value)[p->length] = '\0';
324 static struct property * __init build_prop_list(phandle node)
326 struct property *head, *tail;
328 head = tail = build_one_prop(node, NULL,
329 ".node", &node, sizeof(node));
331 tail->next = build_one_prop(node, NULL, NULL, NULL, 0);
334 tail->next = build_one_prop(node, tail->name,
342 static char * __init get_one_property(phandle node, char *name)
344 char *buf = "<NULL>";
347 len = prom_getproplen(node, name);
349 buf = prom_early_alloc(len);
350 len = prom_getproperty(node, name, buf, len);
356 static struct device_node * __init create_node(phandle node)
358 struct device_node *dp;
363 dp = prom_early_alloc(sizeof(*dp));
364 dp->unique_id = unique_id++;
366 kref_init(&dp->kref);
368 dp->name = get_one_property(node, "name");
369 dp->type = get_one_property(node, "device_type");
372 /* Build interrupts later... */
374 dp->properties = build_prop_list(node);
379 static struct device_node * __init build_tree(struct device_node *parent, phandle node, struct device_node ***nextp)
381 struct device_node *dp;
383 dp = create_node(node);
386 *nextp = &dp->allnext;
389 dp->path_component_name = build_path_component(dp);
390 dp->full_name = build_full_name(dp);
392 dp->child = build_tree(dp, prom_getchild(node), nextp);
394 dp->sibling = build_tree(parent, prom_getsibling(node), nextp);
400 void __init prom_build_devicetree(void)
402 struct device_node **nextp;
404 allnodes = create_node(prom_root_node);
405 allnodes->path_component_name = "";
406 allnodes->full_name = "/";
408 nextp = &allnodes->allnext;
409 allnodes->child = build_tree(allnodes,
410 prom_getchild(allnodes->node),
412 printk("PROM: Built device tree with %u bytes of memory.\n",
413 prom_early_allocated);