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 static struct device_node
*allnodes
;
30 /* use when traversing tree through the allnext, child, sibling,
31 * or parent members of struct device_node.
33 static DEFINE_RWLOCK(devtree_lock
);
35 int of_device_is_compatible(const struct device_node
*device
,
41 cp
= of_get_property(device
, "compatible", &cplen
);
45 if (strncmp(cp
, compat
, strlen(compat
)) == 0)
54 EXPORT_SYMBOL(of_device_is_compatible
);
56 struct device_node
*of_get_parent(const struct device_node
*node
)
58 struct device_node
*np
;
67 EXPORT_SYMBOL(of_get_parent
);
69 struct device_node
*of_get_next_child(const struct device_node
*node
,
70 struct device_node
*prev
)
72 struct device_node
*next
;
74 next
= prev
? prev
->sibling
: node
->child
;
75 for (; next
!= 0; next
= next
->sibling
) {
81 EXPORT_SYMBOL(of_get_next_child
);
83 struct device_node
*of_find_node_by_path(const char *path
)
85 struct device_node
*np
= allnodes
;
87 for (; np
!= 0; np
= np
->allnext
) {
88 if (np
->full_name
!= 0 && strcmp(np
->full_name
, path
) == 0)
94 EXPORT_SYMBOL(of_find_node_by_path
);
96 struct device_node
*of_find_node_by_phandle(phandle handle
)
98 struct device_node
*np
;
100 for (np
= allnodes
; np
!= 0; np
= np
->allnext
)
101 if (np
->node
== handle
)
106 EXPORT_SYMBOL(of_find_node_by_phandle
);
108 struct device_node
*of_find_node_by_name(struct device_node
*from
,
111 struct device_node
*np
;
113 np
= from
? from
->allnext
: allnodes
;
114 for (; np
!= NULL
; np
= np
->allnext
)
115 if (np
->name
!= NULL
&& strcmp(np
->name
, name
) == 0)
120 EXPORT_SYMBOL(of_find_node_by_name
);
122 struct device_node
*of_find_node_by_type(struct device_node
*from
,
125 struct device_node
*np
;
127 np
= from
? from
->allnext
: allnodes
;
128 for (; np
!= 0; np
= np
->allnext
)
129 if (np
->type
!= 0 && strcmp(np
->type
, type
) == 0)
134 EXPORT_SYMBOL(of_find_node_by_type
);
136 struct device_node
*of_find_compatible_node(struct device_node
*from
,
137 const char *type
, const char *compatible
)
139 struct device_node
*np
;
141 np
= from
? from
->allnext
: allnodes
;
142 for (; np
!= 0; np
= np
->allnext
) {
144 && !(np
->type
!= 0 && strcmp(np
->type
, type
) == 0))
146 if (of_device_is_compatible(np
, compatible
))
152 EXPORT_SYMBOL(of_find_compatible_node
);
154 struct property
*of_find_property(const struct device_node
*np
,
160 for (pp
= np
->properties
; pp
!= 0; pp
= pp
->next
) {
161 if (strcasecmp(pp
->name
, name
) == 0) {
169 EXPORT_SYMBOL(of_find_property
);
172 * Find a property with a given name for a given node
173 * and return the value.
175 const void *of_get_property(const struct device_node
*np
, const char *name
,
178 struct property
*pp
= of_find_property(np
,name
,lenp
);
179 return pp
? pp
->value
: NULL
;
181 EXPORT_SYMBOL(of_get_property
);
183 int of_getintprop_default(struct device_node
*np
, const char *name
, int def
)
185 struct property
*prop
;
188 prop
= of_find_property(np
, name
, &len
);
189 if (!prop
|| len
!= 4)
192 return *(int *) prop
->value
;
194 EXPORT_SYMBOL(of_getintprop_default
);
196 int of_n_addr_cells(struct device_node
*np
)
202 ip
= of_get_property(np
, "#address-cells", NULL
);
205 } while (np
->parent
);
206 /* No #address-cells property for the root node, default to 2 */
209 EXPORT_SYMBOL(of_n_addr_cells
);
211 int of_n_size_cells(struct device_node
*np
)
217 ip
= of_get_property(np
, "#size-cells", NULL
);
220 } while (np
->parent
);
221 /* No #size-cells property for the root node, default to 1 */
224 EXPORT_SYMBOL(of_n_size_cells
);
226 int of_set_property(struct device_node
*dp
, const char *name
, void *val
, int len
)
228 struct property
**prevp
;
232 new_val
= kmalloc(len
, GFP_KERNEL
);
236 memcpy(new_val
, val
, len
);
240 write_lock(&devtree_lock
);
241 prevp
= &dp
->properties
;
243 struct property
*prop
= *prevp
;
245 if (!strcasecmp(prop
->name
, name
)) {
246 void *old_val
= prop
->value
;
249 ret
= prom_setprop(dp
->node
, (char *) name
, val
, len
);
252 prop
->value
= new_val
;
255 if (OF_IS_DYNAMIC(prop
))
258 OF_MARK_DYNAMIC(prop
);
264 prevp
= &(*prevp
)->next
;
266 write_unlock(&devtree_lock
);
268 /* XXX Upate procfs if necessary... */
272 EXPORT_SYMBOL(of_set_property
);
274 static unsigned int prom_early_allocated
;
276 static void * __init
prom_early_alloc(unsigned long size
)
280 ret
= __alloc_bootmem(size
, SMP_CACHE_BYTES
, 0UL);
282 memset(ret
, 0, size
);
284 prom_early_allocated
+= size
;
289 static int is_root_node(const struct device_node
*dp
)
294 return (dp
->parent
== NULL
);
297 /* The following routines deal with the black magic of fully naming a
300 * Certain well known named nodes are just the simple name string.
302 * Actual devices have an address specifier appended to the base name
303 * string, like this "foo@addr". The "addr" can be in any number of
304 * formats, and the platform plus the type of the node determine the
305 * format and how it is constructed.
307 * For children of the ROOT node, the naming convention is fixed and
308 * determined by whether this is a sun4u or sun4v system.
310 * For children of other nodes, it is bus type specific. So
311 * we walk up the tree until we discover a "device_type" property
312 * we recognize and we go from there.
314 static void __init
sparc32_path_component(struct device_node
*dp
, char *tmp_buf
)
316 struct linux_prom_registers
*regs
;
317 struct property
*rprop
;
319 rprop
= of_find_property(dp
, "reg", NULL
);
324 sprintf(tmp_buf
, "%s@%x,%x",
326 regs
->which_io
, regs
->phys_addr
);
329 /* "name@slot,offset" */
330 static void __init
sbus_path_component(struct device_node
*dp
, char *tmp_buf
)
332 struct linux_prom_registers
*regs
;
333 struct property
*prop
;
335 prop
= of_find_property(dp
, "reg", NULL
);
340 sprintf(tmp_buf
, "%s@%x,%x",
346 /* "name@devnum[,func]" */
347 static void __init
pci_path_component(struct device_node
*dp
, char *tmp_buf
)
349 struct linux_prom_pci_registers
*regs
;
350 struct property
*prop
;
353 prop
= of_find_property(dp
, "reg", NULL
);
358 devfn
= (regs
->phys_hi
>> 8) & 0xff;
360 sprintf(tmp_buf
, "%s@%x,%x",
365 sprintf(tmp_buf
, "%s@%x",
371 /* "name@addrhi,addrlo" */
372 static void __init
ebus_path_component(struct device_node
*dp
, char *tmp_buf
)
374 struct linux_prom_registers
*regs
;
375 struct property
*prop
;
377 prop
= of_find_property(dp
, "reg", NULL
);
383 sprintf(tmp_buf
, "%s@%x,%x",
385 regs
->which_io
, regs
->phys_addr
);
388 static void __init
__build_path_component(struct device_node
*dp
, char *tmp_buf
)
390 struct device_node
*parent
= dp
->parent
;
392 if (parent
!= NULL
) {
393 if (!strcmp(parent
->type
, "pci") ||
394 !strcmp(parent
->type
, "pciex"))
395 return pci_path_component(dp
, tmp_buf
);
396 if (!strcmp(parent
->type
, "sbus"))
397 return sbus_path_component(dp
, tmp_buf
);
398 if (!strcmp(parent
->type
, "ebus"))
399 return ebus_path_component(dp
, tmp_buf
);
401 /* "isa" is handled with platform naming */
404 /* Use platform naming convention. */
405 return sparc32_path_component(dp
, tmp_buf
);
408 static char * __init
build_path_component(struct device_node
*dp
)
410 char tmp_buf
[64], *n
;
413 __build_path_component(dp
, tmp_buf
);
414 if (tmp_buf
[0] == '\0')
415 strcpy(tmp_buf
, dp
->name
);
417 n
= prom_early_alloc(strlen(tmp_buf
) + 1);
423 static char * __init
build_full_name(struct device_node
*dp
)
425 int len
, ourlen
, plen
;
428 plen
= strlen(dp
->parent
->full_name
);
429 ourlen
= strlen(dp
->path_component_name
);
430 len
= ourlen
+ plen
+ 2;
432 n
= prom_early_alloc(len
);
433 strcpy(n
, dp
->parent
->full_name
);
434 if (!is_root_node(dp
->parent
)) {
435 strcpy(n
+ plen
, "/");
438 strcpy(n
+ plen
, dp
->path_component_name
);
443 static unsigned int unique_id
;
445 static struct property
* __init
build_one_prop(phandle node
, char *prev
, char *special_name
, void *special_val
, int special_len
)
447 static struct property
*tmp
= NULL
;
454 memset(p
, 0, sizeof(*p
) + 32);
457 p
= prom_early_alloc(sizeof(struct property
) + 32);
458 p
->unique_id
= unique_id
++;
461 p
->name
= (char *) (p
+ 1);
463 strcpy(p
->name
, special_name
);
464 p
->length
= special_len
;
465 p
->value
= prom_early_alloc(special_len
);
466 memcpy(p
->value
, special_val
, special_len
);
469 name
= prom_firstprop(node
, NULL
);
471 name
= prom_nextprop(node
, prev
, NULL
);
473 if (strlen(name
) == 0) {
477 strcpy(p
->name
, name
);
478 p
->length
= prom_getproplen(node
, p
->name
);
479 if (p
->length
<= 0) {
482 p
->value
= prom_early_alloc(p
->length
+ 1);
483 len
= prom_getproperty(node
, p
->name
, p
->value
,
487 ((unsigned char *)p
->value
)[p
->length
] = '\0';
493 static struct property
* __init
build_prop_list(phandle node
)
495 struct property
*head
, *tail
;
497 head
= tail
= build_one_prop(node
, NULL
,
498 ".node", &node
, sizeof(node
));
500 tail
->next
= build_one_prop(node
, NULL
, NULL
, NULL
, 0);
503 tail
->next
= build_one_prop(node
, tail
->name
,
511 static char * __init
get_one_property(phandle node
, char *name
)
513 char *buf
= "<NULL>";
516 len
= prom_getproplen(node
, name
);
518 buf
= prom_early_alloc(len
);
519 len
= prom_getproperty(node
, name
, buf
, len
);
525 static struct device_node
* __init
create_node(phandle node
)
527 struct device_node
*dp
;
532 dp
= prom_early_alloc(sizeof(*dp
));
533 dp
->unique_id
= unique_id
++;
535 kref_init(&dp
->kref
);
537 dp
->name
= get_one_property(node
, "name");
538 dp
->type
= get_one_property(node
, "device_type");
541 /* Build interrupts later... */
543 dp
->properties
= build_prop_list(node
);
548 static struct device_node
* __init
build_tree(struct device_node
*parent
, phandle node
, struct device_node
***nextp
)
550 struct device_node
*dp
;
552 dp
= create_node(node
);
555 *nextp
= &dp
->allnext
;
558 dp
->path_component_name
= build_path_component(dp
);
559 dp
->full_name
= build_full_name(dp
);
561 dp
->child
= build_tree(dp
, prom_getchild(node
), nextp
);
563 dp
->sibling
= build_tree(parent
, prom_getsibling(node
), nextp
);
569 void __init
prom_build_devicetree(void)
571 struct device_node
**nextp
;
573 allnodes
= create_node(prom_root_node
);
574 allnodes
->path_component_name
= "";
575 allnodes
->full_name
= "/";
577 nextp
= &allnodes
->allnext
;
578 allnodes
->child
= build_tree(allnodes
,
579 prom_getchild(allnodes
->node
),
581 printk("PROM: Built device tree with %u bytes of memory.\n",
582 prom_early_allocated
);
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