base.c 46.3 KB
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/*
 * Procedures for creating, accessing and interpreting the device tree.
 *
 * 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 and sparc64 by David S. Miller davem@davemloft.net
 *
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 *  Reconsolidated from arch/x/kernel/prom.c by Stephen Rothwell and
 *  Grant Likely.
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 *
 *      This program is free software; you can redistribute it and/or
 *      modify it under the terms of the GNU General Public License
 *      as published by the Free Software Foundation; either version
 *      2 of the License, or (at your option) any later version.
 */
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#include <linux/ctype.h>
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#include <linux/module.h>
#include <linux/of.h>
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#include <linux/spinlock.h>
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#include <linux/slab.h>
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#include <linux/proc_fs.h>
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#include "of_private.h"
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LIST_HEAD(aliases_lookup);
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struct device_node *of_allnodes;
EXPORT_SYMBOL(of_allnodes);
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struct device_node *of_chosen;
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struct device_node *of_aliases;

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DEFINE_MUTEX(of_aliases_mutex);
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/* use when traversing tree through the allnext, child, sibling,
 * or parent members of struct device_node.
 */
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DEFINE_RAW_SPINLOCK(devtree_lock);
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int of_n_addr_cells(struct device_node *np)
{
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	const __be32 *ip;
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	do {
		if (np->parent)
			np = np->parent;
		ip = of_get_property(np, "#address-cells", NULL);
		if (ip)
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			return be32_to_cpup(ip);
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	} while (np->parent);
	/* No #address-cells property for the root node */
	return OF_ROOT_NODE_ADDR_CELLS_DEFAULT;
}
EXPORT_SYMBOL(of_n_addr_cells);

int of_n_size_cells(struct device_node *np)
{
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	const __be32 *ip;
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	do {
		if (np->parent)
			np = np->parent;
		ip = of_get_property(np, "#size-cells", NULL);
		if (ip)
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			return be32_to_cpup(ip);
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	} while (np->parent);
	/* No #size-cells property for the root node */
	return OF_ROOT_NODE_SIZE_CELLS_DEFAULT;
}
EXPORT_SYMBOL(of_n_size_cells);

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#if defined(CONFIG_OF_DYNAMIC)
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/**
 *	of_node_get - Increment refcount of a node
 *	@node:	Node to inc refcount, NULL is supported to
 *		simplify writing of callers
 *
 *	Returns node.
 */
struct device_node *of_node_get(struct device_node *node)
{
	if (node)
		kref_get(&node->kref);
	return node;
}
EXPORT_SYMBOL(of_node_get);

static inline struct device_node *kref_to_device_node(struct kref *kref)
{
	return container_of(kref, struct device_node, kref);
}

/**
 *	of_node_release - release a dynamically allocated node
 *	@kref:  kref element of the node to be released
 *
 *	In of_node_put() this function is passed to kref_put()
 *	as the destructor.
 */
static void of_node_release(struct kref *kref)
{
	struct device_node *node = kref_to_device_node(kref);
	struct property *prop = node->properties;

	/* We should never be releasing nodes that haven't been detached. */
	if (!of_node_check_flag(node, OF_DETACHED)) {
		pr_err("ERROR: Bad of_node_put() on %s\n", node->full_name);
		dump_stack();
		kref_init(&node->kref);
		return;
	}

	if (!of_node_check_flag(node, OF_DYNAMIC))
		return;

	while (prop) {
		struct property *next = prop->next;
		kfree(prop->name);
		kfree(prop->value);
		kfree(prop);
		prop = next;

		if (!prop) {
			prop = node->deadprops;
			node->deadprops = NULL;
		}
	}
	kfree(node->full_name);
	kfree(node->data);
	kfree(node);
}

/**
 *	of_node_put - Decrement refcount of a node
 *	@node:	Node to dec refcount, NULL is supported to
 *		simplify writing of callers
 *
 */
void of_node_put(struct device_node *node)
{
	if (node)
		kref_put(&node->kref, of_node_release);
}
EXPORT_SYMBOL(of_node_put);
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#endif /* CONFIG_OF_DYNAMIC */
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static struct property *__of_find_property(const struct device_node *np,
					   const char *name, int *lenp)
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{
	struct property *pp;

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	if (!np)
		return NULL;

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	for (pp = np->properties; pp; pp = pp->next) {
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		if (of_prop_cmp(pp->name, name) == 0) {
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			if (lenp)
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				*lenp = pp->length;
			break;
		}
	}
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	return pp;
}

struct property *of_find_property(const struct device_node *np,
				  const char *name,
				  int *lenp)
{
	struct property *pp;
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	unsigned long flags;
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	raw_spin_lock_irqsave(&devtree_lock, flags);
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	pp = __of_find_property(np, name, lenp);
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	raw_spin_unlock_irqrestore(&devtree_lock, flags);
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	return pp;
}
EXPORT_SYMBOL(of_find_property);

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/**
 * of_find_all_nodes - Get next node in global list
 * @prev:	Previous node or NULL to start iteration
 *		of_node_put() will be called on it
 *
 * Returns a node pointer with refcount incremented, use
 * of_node_put() on it when done.
 */
struct device_node *of_find_all_nodes(struct device_node *prev)
{
	struct device_node *np;
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	unsigned long flags;
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	raw_spin_lock_irqsave(&devtree_lock, flags);
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	np = prev ? prev->allnext : of_allnodes;
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	for (; np != NULL; np = np->allnext)
		if (of_node_get(np))
			break;
	of_node_put(prev);
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	raw_spin_unlock_irqrestore(&devtree_lock, flags);
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	return np;
}
EXPORT_SYMBOL(of_find_all_nodes);

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/*
 * Find a property with a given name for a given node
 * and return the value.
 */
static const void *__of_get_property(const struct device_node *np,
				     const char *name, int *lenp)
{
	struct property *pp = __of_find_property(np, name, lenp);

	return pp ? pp->value : NULL;
}

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/*
 * Find a property with a given name for a given node
 * and return the value.
 */
const void *of_get_property(const struct device_node *np, const char *name,
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			    int *lenp)
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{
	struct property *pp = of_find_property(np, name, lenp);

	return pp ? pp->value : NULL;
}
EXPORT_SYMBOL(of_get_property);
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/** Checks if the given "compat" string matches one of the strings in
 * the device's "compatible" property
 */
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static int __of_device_is_compatible(const struct device_node *device,
				     const char *compat)
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{
	const char* cp;
	int cplen, l;

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	cp = __of_get_property(device, "compatible", &cplen);
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	if (cp == NULL)
		return 0;
	while (cplen > 0) {
		if (of_compat_cmp(cp, compat, strlen(compat)) == 0)
			return 1;
		l = strlen(cp) + 1;
		cp += l;
		cplen -= l;
	}

	return 0;
}
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/** Checks if the given "compat" string matches one of the strings in
 * the device's "compatible" property
 */
int of_device_is_compatible(const struct device_node *device,
		const char *compat)
{
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	unsigned long flags;
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	int res;

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	raw_spin_lock_irqsave(&devtree_lock, flags);
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	res = __of_device_is_compatible(device, compat);
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	raw_spin_unlock_irqrestore(&devtree_lock, flags);
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	return res;
}
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EXPORT_SYMBOL(of_device_is_compatible);
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/**
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 * of_machine_is_compatible - Test root of device tree for a given compatible value
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 * @compat: compatible string to look for in root node's compatible property.
 *
 * Returns true if the root node has the given value in its
 * compatible property.
 */
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int of_machine_is_compatible(const char *compat)
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{
	struct device_node *root;
	int rc = 0;

	root = of_find_node_by_path("/");
	if (root) {
		rc = of_device_is_compatible(root, compat);
		of_node_put(root);
	}
	return rc;
}
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EXPORT_SYMBOL(of_machine_is_compatible);
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/**
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 *  __of_device_is_available - check if a device is available for use
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 *
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 *  @device: Node to check for availability, with locks already held
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 *
 *  Returns 1 if the status property is absent or set to "okay" or "ok",
 *  0 otherwise
 */
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static int __of_device_is_available(const struct device_node *device)
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{
	const char *status;
	int statlen;

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	status = __of_get_property(device, "status", &statlen);
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	if (status == NULL)
		return 1;

	if (statlen > 0) {
		if (!strcmp(status, "okay") || !strcmp(status, "ok"))
			return 1;
	}

	return 0;
}
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/**
 *  of_device_is_available - check if a device is available for use
 *
 *  @device: Node to check for availability
 *
 *  Returns 1 if the status property is absent or set to "okay" or "ok",
 *  0 otherwise
 */
int of_device_is_available(const struct device_node *device)
{
	unsigned long flags;
	int res;

	raw_spin_lock_irqsave(&devtree_lock, flags);
	res = __of_device_is_available(device);
	raw_spin_unlock_irqrestore(&devtree_lock, flags);
	return res;

}
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EXPORT_SYMBOL(of_device_is_available);

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/**
 *	of_get_parent - Get a node's parent if any
 *	@node:	Node to get parent
 *
 *	Returns a node pointer with refcount incremented, use
 *	of_node_put() on it when done.
 */
struct device_node *of_get_parent(const struct device_node *node)
{
	struct device_node *np;
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	unsigned long flags;
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	if (!node)
		return NULL;

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	raw_spin_lock_irqsave(&devtree_lock, flags);
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	np = of_node_get(node->parent);
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	raw_spin_unlock_irqrestore(&devtree_lock, flags);
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	return np;
}
EXPORT_SYMBOL(of_get_parent);
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/**
 *	of_get_next_parent - Iterate to a node's parent
 *	@node:	Node to get parent of
 *
 * 	This is like of_get_parent() except that it drops the
 * 	refcount on the passed node, making it suitable for iterating
 * 	through a node's parents.
 *
 *	Returns a node pointer with refcount incremented, use
 *	of_node_put() on it when done.
 */
struct device_node *of_get_next_parent(struct device_node *node)
{
	struct device_node *parent;
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	unsigned long flags;
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	if (!node)
		return NULL;

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	raw_spin_lock_irqsave(&devtree_lock, flags);
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	parent = of_node_get(node->parent);
	of_node_put(node);
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	raw_spin_unlock_irqrestore(&devtree_lock, flags);
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	return parent;
}
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EXPORT_SYMBOL(of_get_next_parent);
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/**
 *	of_get_next_child - Iterate a node childs
 *	@node:	parent node
 *	@prev:	previous child of the parent node, or NULL to get first
 *
 *	Returns a node pointer with refcount incremented, use
 *	of_node_put() on it when done.
 */
struct device_node *of_get_next_child(const struct device_node *node,
	struct device_node *prev)
{
	struct device_node *next;
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	unsigned long flags;
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	raw_spin_lock_irqsave(&devtree_lock, flags);
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	next = prev ? prev->sibling : node->child;
	for (; next; next = next->sibling)
		if (of_node_get(next))
			break;
	of_node_put(prev);
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	raw_spin_unlock_irqrestore(&devtree_lock, flags);
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	return next;
}
EXPORT_SYMBOL(of_get_next_child);
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/**
 *	of_get_next_available_child - Find the next available child node
 *	@node:	parent node
 *	@prev:	previous child of the parent node, or NULL to get first
 *
 *      This function is like of_get_next_child(), except that it
 *      automatically skips any disabled nodes (i.e. status = "disabled").
 */
struct device_node *of_get_next_available_child(const struct device_node *node,
	struct device_node *prev)
{
	struct device_node *next;
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	unsigned long flags;
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	raw_spin_lock_irqsave(&devtree_lock, flags);
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	next = prev ? prev->sibling : node->child;
	for (; next; next = next->sibling) {
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		if (!__of_device_is_available(next))
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			continue;
		if (of_node_get(next))
			break;
	}
	of_node_put(prev);
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	raw_spin_unlock_irqrestore(&devtree_lock, flags);
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	return next;
}
EXPORT_SYMBOL(of_get_next_available_child);

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/**
 *	of_get_child_by_name - Find the child node by name for a given parent
 *	@node:	parent node
 *	@name:	child name to look for.
 *
 *      This function looks for child node for given matching name
 *
 *	Returns a node pointer if found, with refcount incremented, use
 *	of_node_put() on it when done.
 *	Returns NULL if node is not found.
 */
struct device_node *of_get_child_by_name(const struct device_node *node,
				const char *name)
{
	struct device_node *child;

	for_each_child_of_node(node, child)
		if (child->name && (of_node_cmp(child->name, name) == 0))
			break;
	return child;
}
EXPORT_SYMBOL(of_get_child_by_name);

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/**
 *	of_find_node_by_path - Find a node matching a full OF path
 *	@path:	The full path to match
 *
 *	Returns a node pointer with refcount incremented, use
 *	of_node_put() on it when done.
 */
struct device_node *of_find_node_by_path(const char *path)
{
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	struct device_node *np = of_allnodes;
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	unsigned long flags;
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	raw_spin_lock_irqsave(&devtree_lock, flags);
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	for (; np; np = np->allnext) {
		if (np->full_name && (of_node_cmp(np->full_name, path) == 0)
		    && of_node_get(np))
			break;
	}
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	raw_spin_unlock_irqrestore(&devtree_lock, flags);
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	return np;
}
EXPORT_SYMBOL(of_find_node_by_path);

/**
 *	of_find_node_by_name - Find a node by its "name" property
 *	@from:	The node to start searching from or NULL, the node
 *		you pass will not be searched, only the next one
 *		will; typically, you pass what the previous call
 *		returned. of_node_put() will be called on it
 *	@name:	The name string to match against
 *
 *	Returns a node pointer with refcount incremented, use
 *	of_node_put() on it when done.
 */
struct device_node *of_find_node_by_name(struct device_node *from,
	const char *name)
{
	struct device_node *np;
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	unsigned long flags;
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	raw_spin_lock_irqsave(&devtree_lock, flags);
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	np = from ? from->allnext : of_allnodes;
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	for (; np; np = np->allnext)
		if (np->name && (of_node_cmp(np->name, name) == 0)
		    && of_node_get(np))
			break;
	of_node_put(from);
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	raw_spin_unlock_irqrestore(&devtree_lock, flags);
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	return np;
}
EXPORT_SYMBOL(of_find_node_by_name);

/**
 *	of_find_node_by_type - Find a node by its "device_type" property
 *	@from:	The node to start searching from, or NULL to start searching
 *		the entire device tree. The node you pass will not be
 *		searched, only the next one will; typically, you pass
 *		what the previous call returned. of_node_put() will be
 *		called on from for you.
 *	@type:	The type string to match against
 *
 *	Returns a node pointer with refcount incremented, use
 *	of_node_put() on it when done.
 */
struct device_node *of_find_node_by_type(struct device_node *from,
	const char *type)
{
	struct device_node *np;
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	unsigned long flags;
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	raw_spin_lock_irqsave(&devtree_lock, flags);
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	np = from ? from->allnext : of_allnodes;
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	for (; np; np = np->allnext)
		if (np->type && (of_node_cmp(np->type, type) == 0)
		    && of_node_get(np))
			break;
	of_node_put(from);
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	raw_spin_unlock_irqrestore(&devtree_lock, flags);
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	return np;
}
EXPORT_SYMBOL(of_find_node_by_type);

/**
 *	of_find_compatible_node - Find a node based on type and one of the
 *                                tokens in its "compatible" property
 *	@from:		The node to start searching from or NULL, the node
 *			you pass will not be searched, only the next one
 *			will; typically, you pass what the previous call
 *			returned. of_node_put() will be called on it
 *	@type:		The type string to match "device_type" or NULL to ignore
 *	@compatible:	The string to match to one of the tokens in the device
 *			"compatible" list.
 *
 *	Returns a node pointer with refcount incremented, use
 *	of_node_put() on it when done.
 */
struct device_node *of_find_compatible_node(struct device_node *from,
	const char *type, const char *compatible)
{
	struct device_node *np;
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	unsigned long flags;
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	raw_spin_lock_irqsave(&devtree_lock, flags);
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	np = from ? from->allnext : of_allnodes;
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	for (; np; np = np->allnext) {
		if (type
		    && !(np->type && (of_node_cmp(np->type, type) == 0)))
			continue;
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		if (__of_device_is_compatible(np, compatible) &&
		    of_node_get(np))
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			break;
	}
	of_node_put(from);
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	raw_spin_unlock_irqrestore(&devtree_lock, flags);
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	return np;
}
EXPORT_SYMBOL(of_find_compatible_node);
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/**
 *	of_find_node_with_property - Find a node which has a property with
 *                                   the given name.
 *	@from:		The node to start searching from or NULL, the node
 *			you pass will not be searched, only the next one
 *			will; typically, you pass what the previous call
 *			returned. of_node_put() will be called on it
 *	@prop_name:	The name of the property to look for.
 *
 *	Returns a node pointer with refcount incremented, use
 *	of_node_put() on it when done.
 */
struct device_node *of_find_node_with_property(struct device_node *from,
	const char *prop_name)
{
	struct device_node *np;
	struct property *pp;
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	unsigned long flags;
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	raw_spin_lock_irqsave(&devtree_lock, flags);
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	np = from ? from->allnext : of_allnodes;
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	for (; np; np = np->allnext) {
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		for (pp = np->properties; pp; pp = pp->next) {
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			if (of_prop_cmp(pp->name, prop_name) == 0) {
				of_node_get(np);
				goto out;
			}
		}
	}
out:
	of_node_put(from);
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	raw_spin_unlock_irqrestore(&devtree_lock, flags);
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	return np;
}
EXPORT_SYMBOL(of_find_node_with_property);

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static
const struct of_device_id *__of_match_node(const struct of_device_id *matches,
					   const struct device_node *node)
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{
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	if (!matches)
		return NULL;

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	while (matches->name[0] || matches->type[0] || matches->compatible[0]) {
		int match = 1;
		if (matches->name[0])
			match &= node->name
				&& !strcmp(matches->name, node->name);
		if (matches->type[0])
			match &= node->type
				&& !strcmp(matches->type, node->type);
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		if (matches->compatible[0])
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			match &= __of_device_is_compatible(node,
							   matches->compatible);
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		if (match)
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			return matches;
		matches++;
	}
	return NULL;
}
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/**
 * of_match_node - Tell if an device_node has a matching of_match structure
 *	@matches:	array of of device match structures to search in
 *	@node:		the of device structure to match against
 *
 *	Low level utility function used by device matching.
 */
const struct of_device_id *of_match_node(const struct of_device_id *matches,
					 const struct device_node *node)
{
	const struct of_device_id *match;
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	unsigned long flags;
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	raw_spin_lock_irqsave(&devtree_lock, flags);
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	match = __of_match_node(matches, node);
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	raw_spin_unlock_irqrestore(&devtree_lock, flags);
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	return match;
}
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EXPORT_SYMBOL(of_match_node);

/**
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 *	of_find_matching_node_and_match - Find a node based on an of_device_id
 *					  match table.
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 *	@from:		The node to start searching from or NULL, the node
 *			you pass will not be searched, only the next one
 *			will; typically, you pass what the previous call
 *			returned. of_node_put() will be called on it
 *	@matches:	array of of device match structures to search in
671
 *	@match		Updated to point at the matches entry which matched
672 673 674 675
 *
 *	Returns a node pointer with refcount incremented, use
 *	of_node_put() on it when done.
 */
676 677 678
struct device_node *of_find_matching_node_and_match(struct device_node *from,
					const struct of_device_id *matches,
					const struct of_device_id **match)
679 680
{
	struct device_node *np;
681
	const struct of_device_id *m;
682
	unsigned long flags;
683

684 685 686
	if (match)
		*match = NULL;

687
	raw_spin_lock_irqsave(&devtree_lock, flags);
688
	np = from ? from->allnext : of_allnodes;
689
	for (; np; np = np->allnext) {
690
		m = __of_match_node(matches, np);
691
		if (m && of_node_get(np)) {
692
			if (match)
693
				*match = m;
694
			break;
695
		}
696 697
	}
	of_node_put(from);
698
	raw_spin_unlock_irqrestore(&devtree_lock, flags);
699 700
	return np;
}
701
EXPORT_SYMBOL(of_find_matching_node_and_match);
702 703 704 705 706 707 708

/**
 * of_modalias_node - Lookup appropriate modalias for a device node
 * @node:	pointer to a device tree node
 * @modalias:	Pointer to buffer that modalias value will be copied into
 * @len:	Length of modalias value
 *
709 710 711 712
 * Based on the value of the compatible property, this routine will attempt
 * to choose an appropriate modalias value for a particular device tree node.
 * It does this by stripping the manufacturer prefix (as delimited by a ',')
 * from the first entry in the compatible list property.
713
 *
714
 * This routine returns 0 on success, <0 on failure.
715 716 717
 */
int of_modalias_node(struct device_node *node, char *modalias, int len)
{
718 719
	const char *compatible, *p;
	int cplen;
720 721

	compatible = of_get_property(node, "compatible", &cplen);
722
	if (!compatible || strlen(compatible) > cplen)
723 724
		return -ENODEV;
	p = strchr(compatible, ',');
725
	strlcpy(modalias, p ? p + 1 : compatible, len);
726 727 728 729
	return 0;
}
EXPORT_SYMBOL_GPL(of_modalias_node);

J
Jeremy Kerr 已提交
730 731 732 733 734 735 736 737 738 739
/**
 * of_find_node_by_phandle - Find a node given a phandle
 * @handle:	phandle of the node to find
 *
 * Returns a node pointer with refcount incremented, use
 * of_node_put() on it when done.
 */
struct device_node *of_find_node_by_phandle(phandle handle)
{
	struct device_node *np;
740
	unsigned long flags;
J
Jeremy Kerr 已提交
741

742
	raw_spin_lock_irqsave(&devtree_lock, flags);
743
	for (np = of_allnodes; np; np = np->allnext)
J
Jeremy Kerr 已提交
744 745 746
		if (np->phandle == handle)
			break;
	of_node_get(np);
747
	raw_spin_unlock_irqrestore(&devtree_lock, flags);
J
Jeremy Kerr 已提交
748 749 750 751
	return np;
}
EXPORT_SYMBOL(of_find_node_by_phandle);

752 753 754 755 756 757 758 759 760 761 762 763 764 765 766 767 768 769 770 771 772 773 774 775 776 777 778 779
/**
 * of_find_property_value_of_size
 *
 * @np:		device node from which the property value is to be read.
 * @propname:	name of the property to be searched.
 * @len:	requested length of property value
 *
 * Search for a property in a device node and valid the requested size.
 * Returns the property value on success, -EINVAL if the property does not
 *  exist, -ENODATA if property does not have a value, and -EOVERFLOW if the
 * property data isn't large enough.
 *
 */
static void *of_find_property_value_of_size(const struct device_node *np,
			const char *propname, u32 len)
{
	struct property *prop = of_find_property(np, propname, NULL);

	if (!prop)
		return ERR_PTR(-EINVAL);
	if (!prop->value)
		return ERR_PTR(-ENODATA);
	if (len > prop->length)
		return ERR_PTR(-EOVERFLOW);

	return prop->value;
}

780 781 782 783 784 785 786 787 788 789 790 791 792 793 794 795 796 797 798
/**
 * of_property_read_u32_index - Find and read a u32 from a multi-value property.
 *
 * @np:		device node from which the property value is to be read.
 * @propname:	name of the property to be searched.
 * @index:	index of the u32 in the list of values
 * @out_value:	pointer to return value, modified only if no error.
 *
 * Search for a property in a device node and read nth 32-bit value from
 * it. Returns 0 on success, -EINVAL if the property does not exist,
 * -ENODATA if property does not have a value, and -EOVERFLOW if the
 * property data isn't large enough.
 *
 * The out_value is modified only if a valid u32 value can be decoded.
 */
int of_property_read_u32_index(const struct device_node *np,
				       const char *propname,
				       u32 index, u32 *out_value)
{
799 800
	const u32 *val = of_find_property_value_of_size(np, propname,
					((index + 1) * sizeof(*out_value)));
801

802 803
	if (IS_ERR(val))
		return PTR_ERR(val);
804

805
	*out_value = be32_to_cpup(((__be32 *)val) + index);
806 807 808 809
	return 0;
}
EXPORT_SYMBOL_GPL(of_property_read_u32_index);

810 811 812 813 814
/**
 * of_property_read_u8_array - Find and read an array of u8 from a property.
 *
 * @np:		device node from which the property value is to be read.
 * @propname:	name of the property to be searched.
L
Lad, Prabhakar 已提交
815
 * @out_values:	pointer to return value, modified only if return value is 0.
816 817 818 819 820 821 822 823 824 825
 * @sz:		number of array elements to read
 *
 * Search for a property in a device node and read 8-bit value(s) from
 * it. Returns 0 on success, -EINVAL if the property does not exist,
 * -ENODATA if property does not have a value, and -EOVERFLOW if the
 * property data isn't large enough.
 *
 * dts entry of array should be like:
 *	property = /bits/ 8 <0x50 0x60 0x70>;
 *
L
Lad, Prabhakar 已提交
826
 * The out_values is modified only if a valid u8 value can be decoded.
827 828 829 830
 */
int of_property_read_u8_array(const struct device_node *np,
			const char *propname, u8 *out_values, size_t sz)
{
831 832
	const u8 *val = of_find_property_value_of_size(np, propname,
						(sz * sizeof(*out_values)));
833

834 835
	if (IS_ERR(val))
		return PTR_ERR(val);
836 837 838 839 840 841 842 843 844 845 846 847

	while (sz--)
		*out_values++ = *val++;
	return 0;
}
EXPORT_SYMBOL_GPL(of_property_read_u8_array);

/**
 * of_property_read_u16_array - Find and read an array of u16 from a property.
 *
 * @np:		device node from which the property value is to be read.
 * @propname:	name of the property to be searched.
L
Lad, Prabhakar 已提交
848
 * @out_values:	pointer to return value, modified only if return value is 0.
849 850 851 852 853 854 855 856 857 858
 * @sz:		number of array elements to read
 *
 * Search for a property in a device node and read 16-bit value(s) from
 * it. Returns 0 on success, -EINVAL if the property does not exist,
 * -ENODATA if property does not have a value, and -EOVERFLOW if the
 * property data isn't large enough.
 *
 * dts entry of array should be like:
 *	property = /bits/ 16 <0x5000 0x6000 0x7000>;
 *
L
Lad, Prabhakar 已提交
859
 * The out_values is modified only if a valid u16 value can be decoded.
860 861 862 863
 */
int of_property_read_u16_array(const struct device_node *np,
			const char *propname, u16 *out_values, size_t sz)
{
864 865
	const __be16 *val = of_find_property_value_of_size(np, propname,
						(sz * sizeof(*out_values)));
866

867 868
	if (IS_ERR(val))
		return PTR_ERR(val);
869 870 871 872 873 874 875

	while (sz--)
		*out_values++ = be16_to_cpup(val++);
	return 0;
}
EXPORT_SYMBOL_GPL(of_property_read_u16_array);

876
/**
877 878 879
 * of_property_read_u32_array - Find and read an array of 32 bit integers
 * from a property.
 *
880 881
 * @np:		device node from which the property value is to be read.
 * @propname:	name of the property to be searched.
L
Lad, Prabhakar 已提交
882
 * @out_values:	pointer to return value, modified only if return value is 0.
883
 * @sz:		number of array elements to read
884
 *
885
 * Search for a property in a device node and read 32-bit value(s) from
886 887 888 889
 * it. Returns 0 on success, -EINVAL if the property does not exist,
 * -ENODATA if property does not have a value, and -EOVERFLOW if the
 * property data isn't large enough.
 *
L
Lad, Prabhakar 已提交
890
 * The out_values is modified only if a valid u32 value can be decoded.
891
 */
892 893 894
int of_property_read_u32_array(const struct device_node *np,
			       const char *propname, u32 *out_values,
			       size_t sz)
895
{
896 897
	const __be32 *val = of_find_property_value_of_size(np, propname,
						(sz * sizeof(*out_values)));
898

899 900
	if (IS_ERR(val))
		return PTR_ERR(val);
901 902 903

	while (sz--)
		*out_values++ = be32_to_cpup(val++);
904 905
	return 0;
}
906
EXPORT_SYMBOL_GPL(of_property_read_u32_array);
907

908 909 910 911 912 913 914 915 916 917 918 919 920 921 922 923
/**
 * of_property_read_u64 - Find and read a 64 bit integer from a property
 * @np:		device node from which the property value is to be read.
 * @propname:	name of the property to be searched.
 * @out_value:	pointer to return value, modified only if return value is 0.
 *
 * Search for a property in a device node and read a 64-bit value from
 * it. Returns 0 on success, -EINVAL if the property does not exist,
 * -ENODATA if property does not have a value, and -EOVERFLOW if the
 * property data isn't large enough.
 *
 * The out_value is modified only if a valid u64 value can be decoded.
 */
int of_property_read_u64(const struct device_node *np, const char *propname,
			 u64 *out_value)
{
924 925
	const __be32 *val = of_find_property_value_of_size(np, propname,
						sizeof(*out_value));
926

927 928 929 930
	if (IS_ERR(val))
		return PTR_ERR(val);

	*out_value = of_read_number(val, 2);
931 932 933 934
	return 0;
}
EXPORT_SYMBOL_GPL(of_property_read_u64);

935 936 937 938 939 940 941 942 943 944 945 946 947 948 949
/**
 * of_property_read_string - Find and read a string from a property
 * @np:		device node from which the property value is to be read.
 * @propname:	name of the property to be searched.
 * @out_string:	pointer to null terminated return string, modified only if
 *		return value is 0.
 *
 * Search for a property in a device tree node and retrieve a null
 * terminated string value (pointer to data, not a copy). Returns 0 on
 * success, -EINVAL if the property does not exist, -ENODATA if property
 * does not have a value, and -EILSEQ if the string is not null-terminated
 * within the length of the property data.
 *
 * The out_string pointer is modified only if a valid string can be decoded.
 */
950
int of_property_read_string(struct device_node *np, const char *propname,
951
				const char **out_string)
952 953 954 955 956 957 958 959 960 961 962 963 964
{
	struct property *prop = of_find_property(np, propname, NULL);
	if (!prop)
		return -EINVAL;
	if (!prop->value)
		return -ENODATA;
	if (strnlen(prop->value, prop->length) >= prop->length)
		return -EILSEQ;
	*out_string = prop->value;
	return 0;
}
EXPORT_SYMBOL_GPL(of_property_read_string);

965 966 967 968 969 970 971 972 973 974 975 976 977 978 979 980 981 982 983 984 985 986 987 988 989 990 991 992 993 994 995 996 997 998 999 1000 1001
/**
 * of_property_read_string_index - Find and read a string from a multiple
 * strings property.
 * @np:		device node from which the property value is to be read.
 * @propname:	name of the property to be searched.
 * @index:	index of the string in the list of strings
 * @out_string:	pointer to null terminated return string, modified only if
 *		return value is 0.
 *
 * Search for a property in a device tree node and retrieve a null
 * terminated string value (pointer to data, not a copy) in the list of strings
 * contained in that property.
 * Returns 0 on success, -EINVAL if the property does not exist, -ENODATA if
 * property does not have a value, and -EILSEQ if the string is not
 * null-terminated within the length of the property data.
 *
 * The out_string pointer is modified only if a valid string can be decoded.
 */
int of_property_read_string_index(struct device_node *np, const char *propname,
				  int index, const char **output)
{
	struct property *prop = of_find_property(np, propname, NULL);
	int i = 0;
	size_t l = 0, total = 0;
	const char *p;

	if (!prop)
		return -EINVAL;
	if (!prop->value)
		return -ENODATA;
	if (strnlen(prop->value, prop->length) >= prop->length)
		return -EILSEQ;

	p = prop->value;

	for (i = 0; total < prop->length; total += l, p += l) {
		l = strlen(p) + 1;
1002
		if (i++ == index) {
1003 1004 1005 1006 1007 1008 1009 1010
			*output = p;
			return 0;
		}
	}
	return -ENODATA;
}
EXPORT_SYMBOL_GPL(of_property_read_string_index);

1011 1012 1013 1014 1015 1016 1017 1018 1019 1020 1021 1022 1023 1024 1025 1026 1027 1028 1029 1030 1031 1032 1033 1034 1035 1036 1037 1038 1039 1040 1041 1042 1043 1044 1045 1046
/**
 * of_property_match_string() - Find string in a list and return index
 * @np: pointer to node containing string list property
 * @propname: string list property name
 * @string: pointer to string to search for in string list
 *
 * This function searches a string list property and returns the index
 * of a specific string value.
 */
int of_property_match_string(struct device_node *np, const char *propname,
			     const char *string)
{
	struct property *prop = of_find_property(np, propname, NULL);
	size_t l;
	int i;
	const char *p, *end;

	if (!prop)
		return -EINVAL;
	if (!prop->value)
		return -ENODATA;

	p = prop->value;
	end = p + prop->length;

	for (i = 0; p < end; i++, p += l) {
		l = strlen(p) + 1;
		if (p + l > end)
			return -EILSEQ;
		pr_debug("comparing %s with %s\n", string, p);
		if (strcmp(string, p) == 0)
			return i; /* Found it; return index */
	}
	return -ENODATA;
}
EXPORT_SYMBOL_GPL(of_property_match_string);
1047 1048 1049 1050 1051 1052 1053 1054 1055 1056 1057 1058 1059 1060 1061 1062 1063 1064 1065 1066 1067 1068 1069 1070 1071 1072 1073 1074 1075

/**
 * of_property_count_strings - Find and return the number of strings from a
 * multiple strings property.
 * @np:		device node from which the property value is to be read.
 * @propname:	name of the property to be searched.
 *
 * Search for a property in a device tree node and retrieve the number of null
 * terminated string contain in it. Returns the number of strings on
 * success, -EINVAL if the property does not exist, -ENODATA if property
 * does not have a value, and -EILSEQ if the string is not null-terminated
 * within the length of the property data.
 */
int of_property_count_strings(struct device_node *np, const char *propname)
{
	struct property *prop = of_find_property(np, propname, NULL);
	int i = 0;
	size_t l = 0, total = 0;
	const char *p;

	if (!prop)
		return -EINVAL;
	if (!prop->value)
		return -ENODATA;
	if (strnlen(prop->value, prop->length) >= prop->length)
		return -EILSEQ;

	p = prop->value;

1076
	for (i = 0; total < prop->length; total += l, p += l, i++)
1077
		l = strlen(p) + 1;
1078

1079 1080 1081 1082
	return i;
}
EXPORT_SYMBOL_GPL(of_property_count_strings);

1083 1084
static int __of_parse_phandle_with_args(const struct device_node *np,
					const char *list_name,
1085 1086
					const char *cells_name,
					int cell_count, int index,
1087
					struct of_phandle_args *out_args)
1088
{
1089
	const __be32 *list, *list_end;
1090
	int rc = 0, size, cur_index = 0;
1091
	uint32_t count = 0;
1092
	struct device_node *node = NULL;
1093
	phandle phandle;
1094

1095
	/* Retrieve the phandle list property */
1096
	list = of_get_property(np, list_name, &size);
1097
	if (!list)
1098
		return -ENOENT;
1099 1100
	list_end = list + size / sizeof(*list);

1101
	/* Loop over the phandles until all the requested entry is found */
1102
	while (list < list_end) {
1103
		rc = -EINVAL;
1104
		count = 0;
1105

1106 1107 1108 1109
		/*
		 * If phandle is 0, then it is an empty entry with no
		 * arguments.  Skip forward to the next entry.
		 */
G
Grant Likely 已提交
1110
		phandle = be32_to_cpup(list++);
1111 1112 1113 1114 1115 1116 1117 1118 1119
		if (phandle) {
			/*
			 * Find the provider node and parse the #*-cells
			 * property to determine the argument length
			 */
			node = of_find_node_by_phandle(phandle);
			if (!node) {
				pr_err("%s: could not find phandle\n",
					 np->full_name);
1120
				goto err;
1121
			}
1122 1123 1124 1125 1126 1127 1128 1129 1130 1131 1132

			if (cells_name) {
				if (of_property_read_u32(node, cells_name,
							 &count)) {
					pr_err("%s: could not get %s for %s\n",
						np->full_name, cells_name,
						node->full_name);
					goto err;
				}
			} else {
				count = cell_count;
1133
			}
1134

1135 1136 1137 1138 1139 1140 1141
			/*
			 * Make sure that the arguments actually fit in the
			 * remaining property data length
			 */
			if (list + count > list_end) {
				pr_err("%s: arguments longer than property\n",
					 np->full_name);
1142
				goto err;
1143
			}
1144 1145
		}

1146 1147 1148 1149 1150 1151
		/*
		 * All of the error cases above bail out of the loop, so at
		 * this point, the parsing is successful. If the requested
		 * index matches, then fill the out_args structure and return,
		 * or return -ENOENT for an empty entry.
		 */
1152
		rc = -ENOENT;
1153 1154
		if (cur_index == index) {
			if (!phandle)
1155
				goto err;
1156 1157 1158 1159 1160 1161 1162 1163 1164

			if (out_args) {
				int i;
				if (WARN_ON(count > MAX_PHANDLE_ARGS))
					count = MAX_PHANDLE_ARGS;
				out_args->np = node;
				out_args->args_count = count;
				for (i = 0; i < count; i++)
					out_args->args[i] = be32_to_cpup(list++);
1165 1166
			} else {
				of_node_put(node);
1167
			}
1168 1169

			/* Found it! return success */
1170
			return 0;
1171 1172 1173 1174
		}

		of_node_put(node);
		node = NULL;
1175
		list += count;
1176 1177 1178
		cur_index++;
	}

1179 1180 1181 1182
	/*
	 * Unlock node before returning result; will be one of:
	 * -ENOENT : index is for empty phandle
	 * -EINVAL : parsing error on data
1183
	 * [1..n]  : Number of phandle (count mode; when index = -1)
1184
	 */
1185
	rc = index < 0 ? cur_index : -ENOENT;
1186
 err:
1187 1188
	if (node)
		of_node_put(node);
1189
	return rc;
1190
}
1191

S
Stephen Warren 已提交
1192 1193 1194 1195 1196 1197 1198 1199 1200 1201 1202 1203 1204 1205 1206 1207 1208 1209 1210 1211 1212 1213 1214 1215
/**
 * of_parse_phandle - Resolve a phandle property to a device_node pointer
 * @np: Pointer to device node holding phandle property
 * @phandle_name: Name of property holding a phandle value
 * @index: For properties holding a table of phandles, this is the index into
 *         the table
 *
 * Returns the device_node pointer with refcount incremented.  Use
 * of_node_put() on it when done.
 */
struct device_node *of_parse_phandle(const struct device_node *np,
				     const char *phandle_name, int index)
{
	const __be32 *phandle;
	int size;

	phandle = of_get_property(np, phandle_name, &size);
	if ((!phandle) || (size < sizeof(*phandle) * (index + 1)))
		return NULL;

	return of_find_node_by_phandle(be32_to_cpup(phandle + index));
}
EXPORT_SYMBOL(of_parse_phandle);

1216 1217 1218 1219 1220 1221 1222 1223 1224 1225 1226 1227 1228 1229 1230 1231 1232 1233 1234 1235 1236 1237 1238 1239 1240 1241 1242 1243 1244 1245 1246 1247
/**
 * of_parse_phandle_with_args() - Find a node pointed by phandle in a list
 * @np:		pointer to a device tree node containing a list
 * @list_name:	property name that contains a list
 * @cells_name:	property name that specifies phandles' arguments count
 * @index:	index of a phandle to parse out
 * @out_args:	optional pointer to output arguments structure (will be filled)
 *
 * This function is useful to parse lists of phandles and their arguments.
 * Returns 0 on success and fills out_args, on error returns appropriate
 * errno value.
 *
 * Caller is responsible to call of_node_put() on the returned out_args->node
 * pointer.
 *
 * Example:
 *
 * phandle1: node1 {
 * 	#list-cells = <2>;
 * }
 *
 * phandle2: node2 {
 * 	#list-cells = <1>;
 * }
 *
 * node3 {
 * 	list = <&phandle1 1 2 &phandle2 3>;
 * }
 *
 * To get a device_node of the `node2' node you may call this:
 * of_parse_phandle_with_args(node3, "list", "#list-cells", 1, &args);
 */
1248 1249 1250 1251 1252 1253
int of_parse_phandle_with_args(const struct device_node *np, const char *list_name,
				const char *cells_name, int index,
				struct of_phandle_args *out_args)
{
	if (index < 0)
		return -EINVAL;
1254 1255
	return __of_parse_phandle_with_args(np, list_name, cells_name, 0,
					    index, out_args);
1256
}
1257
EXPORT_SYMBOL(of_parse_phandle_with_args);
1258

1259 1260 1261 1262 1263 1264 1265 1266 1267 1268 1269 1270 1271 1272 1273 1274 1275 1276 1277 1278 1279 1280 1281 1282 1283 1284 1285 1286 1287 1288 1289 1290 1291 1292 1293 1294 1295 1296 1297 1298 1299
/**
 * of_parse_phandle_with_fixed_args() - Find a node pointed by phandle in a list
 * @np:		pointer to a device tree node containing a list
 * @list_name:	property name that contains a list
 * @cell_count: number of argument cells following the phandle
 * @index:	index of a phandle to parse out
 * @out_args:	optional pointer to output arguments structure (will be filled)
 *
 * This function is useful to parse lists of phandles and their arguments.
 * Returns 0 on success and fills out_args, on error returns appropriate
 * errno value.
 *
 * Caller is responsible to call of_node_put() on the returned out_args->node
 * pointer.
 *
 * Example:
 *
 * phandle1: node1 {
 * }
 *
 * phandle2: node2 {
 * }
 *
 * node3 {
 * 	list = <&phandle1 0 2 &phandle2 2 3>;
 * }
 *
 * To get a device_node of the `node2' node you may call this:
 * of_parse_phandle_with_fixed_args(node3, "list", 2, 1, &args);
 */
int of_parse_phandle_with_fixed_args(const struct device_node *np,
				const char *list_name, int cell_count,
				int index, struct of_phandle_args *out_args)
{
	if (index < 0)
		return -EINVAL;
	return __of_parse_phandle_with_args(np, list_name, NULL, cell_count,
					   index, out_args);
}
EXPORT_SYMBOL(of_parse_phandle_with_fixed_args);

1300 1301 1302 1303 1304 1305 1306 1307 1308 1309 1310 1311 1312 1313 1314 1315 1316 1317
/**
 * of_count_phandle_with_args() - Find the number of phandles references in a property
 * @np:		pointer to a device tree node containing a list
 * @list_name:	property name that contains a list
 * @cells_name:	property name that specifies phandles' arguments count
 *
 * Returns the number of phandle + argument tuples within a property. It
 * is a typical pattern to encode a list of phandle and variable
 * arguments into a single property. The number of arguments is encoded
 * by a property in the phandle-target node. For example, a gpios
 * property would contain a list of GPIO specifies consisting of a
 * phandle and 1 or more arguments. The number of arguments are
 * determined by the #gpio-cells property in the node pointed to by the
 * phandle.
 */
int of_count_phandle_with_args(const struct device_node *np, const char *list_name,
				const char *cells_name)
{
1318 1319
	return __of_parse_phandle_with_args(np, list_name, cells_name, 0, -1,
					    NULL);
1320 1321 1322
}
EXPORT_SYMBOL(of_count_phandle_with_args);

1323 1324 1325 1326 1327 1328 1329 1330 1331 1332 1333 1334 1335 1336 1337 1338 1339 1340
#if defined(CONFIG_OF_DYNAMIC)
static int of_property_notify(int action, struct device_node *np,
			      struct property *prop)
{
	struct of_prop_reconfig pr;

	pr.dn = np;
	pr.prop = prop;
	return of_reconfig_notify(action, &pr);
}
#else
static int of_property_notify(int action, struct device_node *np,
			      struct property *prop)
{
	return 0;
}
#endif

1341
/**
1342
 * of_add_property - Add a property to a node
1343
 */
1344
int of_add_property(struct device_node *np, struct property *prop)
1345 1346 1347
{
	struct property **next;
	unsigned long flags;
1348 1349 1350 1351 1352
	int rc;

	rc = of_property_notify(OF_RECONFIG_ADD_PROPERTY, np, prop);
	if (rc)
		return rc;
1353 1354

	prop->next = NULL;
1355
	raw_spin_lock_irqsave(&devtree_lock, flags);
1356 1357 1358 1359
	next = &np->properties;
	while (*next) {
		if (strcmp(prop->name, (*next)->name) == 0) {
			/* duplicate ! don't insert it */
1360
			raw_spin_unlock_irqrestore(&devtree_lock, flags);
1361 1362 1363 1364 1365
			return -1;
		}
		next = &(*next)->next;
	}
	*next = prop;
1366
	raw_spin_unlock_irqrestore(&devtree_lock, flags);
1367 1368 1369 1370 1371 1372 1373 1374 1375 1376 1377

#ifdef CONFIG_PROC_DEVICETREE
	/* try to add to proc as well if it was initialized */
	if (np->pde)
		proc_device_tree_add_prop(np->pde, prop);
#endif /* CONFIG_PROC_DEVICETREE */

	return 0;
}

/**
1378
 * of_remove_property - Remove a property from a node.
1379 1380 1381 1382 1383 1384
 *
 * Note that we don't actually remove it, since we have given out
 * who-knows-how-many pointers to the data using get-property.
 * Instead we just move the property to the "dead properties"
 * list, so it won't be found any more.
 */
1385
int of_remove_property(struct device_node *np, struct property *prop)
1386 1387 1388 1389
{
	struct property **next;
	unsigned long flags;
	int found = 0;
1390 1391 1392 1393 1394
	int rc;

	rc = of_property_notify(OF_RECONFIG_REMOVE_PROPERTY, np, prop);
	if (rc)
		return rc;
1395

1396
	raw_spin_lock_irqsave(&devtree_lock, flags);
1397 1398 1399 1400 1401 1402 1403 1404 1405 1406 1407 1408
	next = &np->properties;
	while (*next) {
		if (*next == prop) {
			/* found the node */
			*next = prop->next;
			prop->next = np->deadprops;
			np->deadprops = prop;
			found = 1;
			break;
		}
		next = &(*next)->next;
	}
1409
	raw_spin_unlock_irqrestore(&devtree_lock, flags);
1410 1411 1412 1413 1414 1415 1416 1417 1418 1419 1420 1421 1422 1423

	if (!found)
		return -ENODEV;

#ifdef CONFIG_PROC_DEVICETREE
	/* try to remove the proc node as well */
	if (np->pde)
		proc_device_tree_remove_prop(np->pde, prop);
#endif /* CONFIG_PROC_DEVICETREE */

	return 0;
}

/*
1424
 * of_update_property - Update a property in a node, if the property does
1425
 * not exist, add it.
1426 1427 1428 1429 1430 1431
 *
 * Note that we don't actually remove it, since we have given out
 * who-knows-how-many pointers to the data using get-property.
 * Instead we just move the property to the "dead properties" list,
 * and add the new property to the property list
 */
1432
int of_update_property(struct device_node *np, struct property *newprop)
1433
{
1434
	struct property **next, *oldprop;
1435
	unsigned long flags;
1436 1437 1438 1439 1440
	int rc, found = 0;

	rc = of_property_notify(OF_RECONFIG_UPDATE_PROPERTY, np, newprop);
	if (rc)
		return rc;
1441

1442 1443 1444 1445 1446
	if (!newprop->name)
		return -EINVAL;

	oldprop = of_find_property(np, newprop->name, NULL);
	if (!oldprop)
1447
		return of_add_property(np, newprop);
1448

1449
	raw_spin_lock_irqsave(&devtree_lock, flags);
1450 1451 1452 1453 1454 1455 1456 1457 1458 1459 1460 1461 1462
	next = &np->properties;
	while (*next) {
		if (*next == oldprop) {
			/* found the node */
			newprop->next = oldprop->next;
			*next = newprop;
			oldprop->next = np->deadprops;
			np->deadprops = oldprop;
			found = 1;
			break;
		}
		next = &(*next)->next;
	}
1463
	raw_spin_unlock_irqrestore(&devtree_lock, flags);
1464 1465 1466 1467 1468 1469 1470 1471 1472 1473 1474 1475

	if (!found)
		return -ENODEV;

#ifdef CONFIG_PROC_DEVICETREE
	/* try to add to proc as well if it was initialized */
	if (np->pde)
		proc_device_tree_update_prop(np->pde, newprop, oldprop);
#endif /* CONFIG_PROC_DEVICETREE */

	return 0;
}
1476 1477 1478 1479 1480 1481 1482 1483 1484 1485

#if defined(CONFIG_OF_DYNAMIC)
/*
 * Support for dynamic device trees.
 *
 * On some platforms, the device tree can be manipulated at runtime.
 * The routines in this section support adding, removing and changing
 * device tree nodes.
 */

1486 1487 1488 1489 1490 1491
static BLOCKING_NOTIFIER_HEAD(of_reconfig_chain);

int of_reconfig_notifier_register(struct notifier_block *nb)
{
	return blocking_notifier_chain_register(&of_reconfig_chain, nb);
}
1492
EXPORT_SYMBOL_GPL(of_reconfig_notifier_register);
1493 1494 1495 1496 1497

int of_reconfig_notifier_unregister(struct notifier_block *nb)
{
	return blocking_notifier_chain_unregister(&of_reconfig_chain, nb);
}
1498
EXPORT_SYMBOL_GPL(of_reconfig_notifier_unregister);
1499 1500 1501 1502 1503 1504 1505 1506 1507

int of_reconfig_notify(unsigned long action, void *p)
{
	int rc;

	rc = blocking_notifier_call_chain(&of_reconfig_chain, action, p);
	return notifier_to_errno(rc);
}

1508 1509 1510 1511 1512 1513 1514 1515 1516 1517 1518 1519 1520 1521 1522 1523
#ifdef CONFIG_PROC_DEVICETREE
static void of_add_proc_dt_entry(struct device_node *dn)
{
	struct proc_dir_entry *ent;

	ent = proc_mkdir(strrchr(dn->full_name, '/') + 1, dn->parent->pde);
	if (ent)
		proc_device_tree_add_node(dn, ent);
}
#else
static void of_add_proc_dt_entry(struct device_node *dn)
{
	return;
}
#endif

1524 1525 1526
/**
 * of_attach_node - Plug a device node into the tree and global list.
 */
1527
int of_attach_node(struct device_node *np)
1528 1529
{
	unsigned long flags;
1530 1531 1532 1533 1534
	int rc;

	rc = of_reconfig_notify(OF_RECONFIG_ATTACH_NODE, np);
	if (rc)
		return rc;
1535

1536
	raw_spin_lock_irqsave(&devtree_lock, flags);
1537
	np->sibling = np->parent->child;
1538
	np->allnext = of_allnodes;
1539
	np->parent->child = np;
1540
	of_allnodes = np;
1541
	raw_spin_unlock_irqrestore(&devtree_lock, flags);
1542 1543

	of_add_proc_dt_entry(np);
1544
	return 0;
1545 1546
}

1547 1548 1549
#ifdef CONFIG_PROC_DEVICETREE
static void of_remove_proc_dt_entry(struct device_node *dn)
{
1550
	proc_remove(dn->pde);
1551 1552 1553 1554 1555 1556 1557 1558
}
#else
static void of_remove_proc_dt_entry(struct device_node *dn)
{
	return;
}
#endif

1559 1560 1561 1562 1563 1564
/**
 * of_detach_node - "Unplug" a node from the device tree.
 *
 * The caller must hold a reference to the node.  The memory associated with
 * the node is not freed until its refcount goes to zero.
 */
1565
int of_detach_node(struct device_node *np)
1566 1567 1568
{
	struct device_node *parent;
	unsigned long flags;
1569 1570 1571 1572 1573
	int rc = 0;

	rc = of_reconfig_notify(OF_RECONFIG_DETACH_NODE, np);
	if (rc)
		return rc;
1574

1575
	raw_spin_lock_irqsave(&devtree_lock, flags);
1576

1577 1578
	if (of_node_check_flag(np, OF_DETACHED)) {
		/* someone already detached it */
1579
		raw_spin_unlock_irqrestore(&devtree_lock, flags);
1580
		return rc;
1581 1582
	}

1583
	parent = np->parent;
1584
	if (!parent) {
1585
		raw_spin_unlock_irqrestore(&devtree_lock, flags);
1586
		return rc;
1587
	}
1588

1589 1590
	if (of_allnodes == np)
		of_allnodes = np->allnext;
1591 1592
	else {
		struct device_node *prev;
1593
		for (prev = of_allnodes;
1594 1595 1596 1597 1598 1599 1600 1601 1602 1603 1604 1605 1606 1607 1608 1609 1610 1611
		     prev->allnext != np;
		     prev = prev->allnext)
			;
		prev->allnext = np->allnext;
	}

	if (parent->child == np)
		parent->child = np->sibling;
	else {
		struct device_node *prevsib;
		for (prevsib = np->parent->child;
		     prevsib->sibling != np;
		     prevsib = prevsib->sibling)
			;
		prevsib->sibling = np->sibling;
	}

	of_node_set_flag(np, OF_DETACHED);
1612
	raw_spin_unlock_irqrestore(&devtree_lock, flags);
1613 1614

	of_remove_proc_dt_entry(np);
1615
	return rc;
1616 1617 1618
}
#endif /* defined(CONFIG_OF_DYNAMIC) */

1619 1620 1621 1622 1623 1624 1625 1626 1627
static void of_alias_add(struct alias_prop *ap, struct device_node *np,
			 int id, const char *stem, int stem_len)
{
	ap->np = np;
	ap->id = id;
	strncpy(ap->stem, stem, stem_len);
	ap->stem[stem_len] = 0;
	list_add_tail(&ap->link, &aliases_lookup);
	pr_debug("adding DT alias:%s: stem=%s id=%i node=%s\n",
1628
		 ap->alias, ap->stem, ap->id, of_node_full_name(np));
1629 1630 1631 1632 1633 1634 1635 1636 1637 1638 1639 1640 1641 1642 1643 1644 1645 1646 1647 1648 1649 1650 1651
}

/**
 * of_alias_scan - Scan all properties of 'aliases' node
 *
 * The function scans all the properties of 'aliases' node and populate
 * the the global lookup table with the properties.  It returns the
 * number of alias_prop found, or error code in error case.
 *
 * @dt_alloc:	An allocator that provides a virtual address to memory
 *		for the resulting tree
 */
void of_alias_scan(void * (*dt_alloc)(u64 size, u64 align))
{
	struct property *pp;

	of_chosen = of_find_node_by_path("/chosen");
	if (of_chosen == NULL)
		of_chosen = of_find_node_by_path("/chosen@0");
	of_aliases = of_find_node_by_path("/aliases");
	if (!of_aliases)
		return;

1652
	for_each_property_of_node(of_aliases, pp) {
1653 1654 1655 1656 1657 1658 1659 1660 1661 1662 1663 1664 1665 1666 1667 1668 1669 1670 1671 1672 1673 1674 1675 1676 1677 1678 1679 1680 1681
		const char *start = pp->name;
		const char *end = start + strlen(start);
		struct device_node *np;
		struct alias_prop *ap;
		int id, len;

		/* Skip those we do not want to proceed */
		if (!strcmp(pp->name, "name") ||
		    !strcmp(pp->name, "phandle") ||
		    !strcmp(pp->name, "linux,phandle"))
			continue;

		np = of_find_node_by_path(pp->value);
		if (!np)
			continue;

		/* walk the alias backwards to extract the id and work out
		 * the 'stem' string */
		while (isdigit(*(end-1)) && end > start)
			end--;
		len = end - start;

		if (kstrtoint(end, 10, &id) < 0)
			continue;

		/* Allocate an alias_prop with enough space for the stem */
		ap = dt_alloc(sizeof(*ap) + len + 1, 4);
		if (!ap)
			continue;
1682
		memset(ap, 0, sizeof(*ap) + len + 1);
1683 1684 1685 1686 1687 1688 1689 1690 1691 1692 1693 1694 1695 1696 1697 1698 1699 1700 1701 1702 1703 1704 1705 1706 1707 1708 1709 1710 1711 1712 1713 1714 1715
		ap->alias = start;
		of_alias_add(ap, np, id, start, len);
	}
}

/**
 * of_alias_get_id - Get alias id for the given device_node
 * @np:		Pointer to the given device_node
 * @stem:	Alias stem of the given device_node
 *
 * The function travels the lookup table to get alias id for the given
 * device_node and alias stem.  It returns the alias id if find it.
 */
int of_alias_get_id(struct device_node *np, const char *stem)
{
	struct alias_prop *app;
	int id = -ENODEV;

	mutex_lock(&of_aliases_mutex);
	list_for_each_entry(app, &aliases_lookup, link) {
		if (strcmp(app->stem, stem) != 0)
			continue;

		if (np == app->np) {
			id = app->id;
			break;
		}
	}
	mutex_unlock(&of_aliases_mutex);

	return id;
}
EXPORT_SYMBOL_GPL(of_alias_get_id);
1716 1717 1718 1719 1720 1721 1722 1723 1724 1725 1726 1727 1728 1729 1730 1731 1732 1733 1734 1735 1736 1737 1738 1739 1740 1741 1742 1743 1744 1745 1746 1747 1748 1749 1750 1751 1752 1753 1754 1755 1756

const __be32 *of_prop_next_u32(struct property *prop, const __be32 *cur,
			       u32 *pu)
{
	const void *curv = cur;

	if (!prop)
		return NULL;

	if (!cur) {
		curv = prop->value;
		goto out_val;
	}

	curv += sizeof(*cur);
	if (curv >= prop->value + prop->length)
		return NULL;

out_val:
	*pu = be32_to_cpup(curv);
	return curv;
}
EXPORT_SYMBOL_GPL(of_prop_next_u32);

const char *of_prop_next_string(struct property *prop, const char *cur)
{
	const void *curv = cur;

	if (!prop)
		return NULL;

	if (!cur)
		return prop->value;

	curv += strlen(cur) + 1;
	if (curv >= prop->value + prop->length)
		return NULL;

	return curv;
}
EXPORT_SYMBOL_GPL(of_prop_next_string);