linux-zen-desktop/drivers/of/pdt.c

214 lines
4.8 KiB
C

// SPDX-License-Identifier: GPL-2.0+
/* pdt.c: OF PROM device tree support code.
*
* Paul Mackerras August 1996.
* Copyright (C) 1996-2005 Paul Mackerras.
*
* Adapted for 64bit PowerPC by Dave Engebretsen and Peter Bergner.
* {engebret|bergner}@us.ibm.com
*
* Adapted for sparc by David S. Miller davem@davemloft.net
* Adapted for multiple architectures by Andres Salomon <dilinger@queued.net>
*/
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/errno.h>
#include <linux/mutex.h>
#include <linux/slab.h>
#include <linux/of.h>
#include <linux/of_pdt.h>
static struct of_pdt_ops *of_pdt_prom_ops __initdata;
#if defined(CONFIG_SPARC)
unsigned int of_pdt_unique_id __initdata;
#define of_pdt_incr_unique_id(p) do { \
(p)->unique_id = of_pdt_unique_id++; \
} while (0)
static char * __init of_pdt_build_full_name(struct device_node *dp)
{
return build_path_component(dp);
}
#else /* CONFIG_SPARC */
static inline void of_pdt_incr_unique_id(void *p) { }
static inline void irq_trans_init(struct device_node *dp) { }
static char * __init of_pdt_build_full_name(struct device_node *dp)
{
static int failsafe_id = 0; /* for generating unique names on failure */
const char *name;
char path[256];
char *buf;
int len;
if (!of_pdt_prom_ops->pkg2path(dp->phandle, path, sizeof(path), &len)) {
name = kbasename(path);
buf = prom_early_alloc(strlen(name) + 1);
strcpy(buf, name);
return buf;
}
name = of_get_property(dp, "name", &len);
buf = prom_early_alloc(len + 16);
sprintf(buf, "%s@unknown%i", name, failsafe_id++);
pr_err("%s: pkg2path failed; assigning %s\n", __func__, buf);
return buf;
}
#endif /* !CONFIG_SPARC */
static struct property * __init of_pdt_build_one_prop(phandle node, char *prev,
char *special_name,
void *special_val,
int special_len)
{
static struct property *tmp = NULL;
struct property *p;
int err;
if (tmp) {
p = tmp;
memset(p, 0, sizeof(*p) + 32);
tmp = NULL;
} else {
p = prom_early_alloc(sizeof(struct property) + 32);
of_pdt_incr_unique_id(p);
}
p->name = (char *) (p + 1);
if (special_name) {
strcpy(p->name, special_name);
p->length = special_len;
p->value = prom_early_alloc(special_len);
memcpy(p->value, special_val, special_len);
} else {
err = of_pdt_prom_ops->nextprop(node, prev, p->name);
if (err) {
tmp = p;
return NULL;
}
p->length = of_pdt_prom_ops->getproplen(node, p->name);
if (p->length <= 0) {
p->length = 0;
} else {
int len;
p->value = prom_early_alloc(p->length + 1);
len = of_pdt_prom_ops->getproperty(node, p->name,
p->value, p->length);
if (len <= 0)
p->length = 0;
((unsigned char *)p->value)[p->length] = '\0';
}
}
return p;
}
static struct property * __init of_pdt_build_prop_list(phandle node)
{
struct property *head, *tail;
head = tail = of_pdt_build_one_prop(node, NULL,
".node", &node, sizeof(node));
tail->next = of_pdt_build_one_prop(node, NULL, NULL, NULL, 0);
tail = tail->next;
while(tail) {
tail->next = of_pdt_build_one_prop(node, tail->name,
NULL, NULL, 0);
tail = tail->next;
}
return head;
}
static char * __init of_pdt_get_one_property(phandle node, const char *name)
{
char *buf = "<NULL>";
int len;
len = of_pdt_prom_ops->getproplen(node, name);
if (len > 0) {
buf = prom_early_alloc(len);
len = of_pdt_prom_ops->getproperty(node, name, buf, len);
}
return buf;
}
static struct device_node * __init of_pdt_create_node(phandle node,
struct device_node *parent)
{
struct device_node *dp;
if (!node)
return NULL;
dp = prom_early_alloc(sizeof(*dp));
of_node_init(dp);
of_pdt_incr_unique_id(dp);
dp->parent = parent;
dp->name = of_pdt_get_one_property(node, "name");
dp->phandle = node;
dp->properties = of_pdt_build_prop_list(node);
dp->full_name = of_pdt_build_full_name(dp);
irq_trans_init(dp);
return dp;
}
static struct device_node * __init of_pdt_build_tree(struct device_node *parent,
phandle node)
{
struct device_node *ret = NULL, *prev_sibling = NULL;
struct device_node *dp;
while (1) {
dp = of_pdt_create_node(node, parent);
if (!dp)
break;
if (prev_sibling)
prev_sibling->sibling = dp;
if (!ret)
ret = dp;
prev_sibling = dp;
dp->child = of_pdt_build_tree(dp, of_pdt_prom_ops->getchild(node));
node = of_pdt_prom_ops->getsibling(node);
}
return ret;
}
static void * __init kernel_tree_alloc(u64 size, u64 align)
{
return prom_early_alloc(size);
}
void __init of_pdt_build_devicetree(phandle root_node, struct of_pdt_ops *ops)
{
BUG_ON(!ops);
of_pdt_prom_ops = ops;
of_root = of_pdt_create_node(root_node, NULL);
of_root->full_name = "/";
of_root->child = of_pdt_build_tree(of_root,
of_pdt_prom_ops->getchild(of_root->phandle));
/* Get pointer to "/chosen" and "/aliases" nodes for use everywhere */
of_alias_scan(kernel_tree_alloc);
}