drivers/of/base.c - kernel/msm - Gitiles

 /*
  * 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
  *
  *  Reconsolidated from arch/x/kernel/prom.c by Stephen Rothwell.
  *
  *      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.
  */
 #include <linux/module.h>
 #include <linux/of.h>
 #include <linux/spinlock.h>

 struct device_node *allnodes;

 /* use when traversing tree through the allnext, child, sibling,
  * or parent members of struct device_node.
  */
 DEFINE_RWLOCK(devtree_lock);

 int of_n_addr_cells(struct device_node *np)
 {
 	const int *ip;

 	do {
 		if (np->parent)
 			np = np->parent;
 		ip = of_get_property(np, "#address-cells", NULL);
 		if (ip)
 			return *ip;
 	} 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)
 {
 	const int *ip;

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

 struct property *of_find_property(const struct device_node *np,
 				  const char *name,
 				  int *lenp)
 {
 	struct property *pp;

 	if (!np)
 		return NULL;

 	read_lock(&devtree_lock);
 	for (pp = np->properties; pp != 0; pp = pp->next) {
 		if (of_prop_cmp(pp->name, name) == 0) {
 			if (lenp != 0)
 				*lenp = pp->length;
 			break;
 		}
 	}
 	read_unlock(&devtree_lock);

 	return pp;
 }
 EXPORT_SYMBOL(of_find_property);

 /*
  * 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,
 			 int *lenp)
 {
 	struct property *pp = of_find_property(np, name, lenp);

 	return pp ? pp->value : NULL;
 }
 EXPORT_SYMBOL(of_get_property);

 /** 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)
 {
 	const char* cp;
 	int cplen, l;

 	cp = of_get_property(device, "compatible", &cplen);
 	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;
 }
 EXPORT_SYMBOL(of_device_is_compatible);

 /**
  *  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)
 {
 	const char *status;
 	int statlen;

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

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

 	return 0;
 }
 EXPORT_SYMBOL(of_device_is_available);

 /**
  *	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;

 	if (!node)
 		return NULL;

 	read_lock(&devtree_lock);
 	np = of_node_get(node->parent);
 	read_unlock(&devtree_lock);
 	return np;
 }
 EXPORT_SYMBOL(of_get_parent);

 /**
  *	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;

 	if (!node)
 		return NULL;

 	read_lock(&devtree_lock);
 	parent = of_node_get(node->parent);
 	of_node_put(node);
 	read_unlock(&devtree_lock);
 	return parent;
 }

 /**
  *	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;

 	read_lock(&devtree_lock);
 	next = prev ? prev->sibling : node->child;
 	for (; next; next = next->sibling)
 		if (of_node_get(next))
 			break;
 	of_node_put(prev);
 	read_unlock(&devtree_lock);
 	return next;
 }
 EXPORT_SYMBOL(of_get_next_child);

 /**
  *	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)
 {
 	struct device_node *np = allnodes;

 	read_lock(&devtree_lock);
 	for (; np; np = np->allnext) {
 		if (np->full_name && (of_node_cmp(np->full_name, path) == 0)
 		    && of_node_get(np))
 			break;
 	}
 	read_unlock(&devtree_lock);
 	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;

 	read_lock(&devtree_lock);
 	np = from ? from->allnext : allnodes;
 	for (; np; np = np->allnext)
 		if (np->name && (of_node_cmp(np->name, name) == 0)
 		    && of_node_get(np))
 			break;
 	of_node_put(from);
 	read_unlock(&devtree_lock);
 	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;

 	read_lock(&devtree_lock);
 	np = from ? from->allnext : allnodes;
 	for (; np; np = np->allnext)
 		if (np->type && (of_node_cmp(np->type, type) == 0)
 		    && of_node_get(np))
 			break;
 	of_node_put(from);
 	read_unlock(&devtree_lock);
 	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;

 	read_lock(&devtree_lock);
 	np = from ? from->allnext : allnodes;
 	for (; np; np = np->allnext) {
 		if (type
 		    && !(np->type && (of_node_cmp(np->type, type) == 0)))
 			continue;
 		if (of_device_is_compatible(np, compatible) && of_node_get(np))
 			break;
 	}
 	of_node_put(from);
 	read_unlock(&devtree_lock);
 	return np;
 }
 EXPORT_SYMBOL(of_find_compatible_node);

 /**
  * 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)
 {
 	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);
 		if (matches->compatible[0])
 			match &= of_device_is_compatible(node,
 						matches->compatible);
 		if (match)
 			return matches;
 		matches++;
 	}
 	return NULL;
 }
 EXPORT_SYMBOL(of_match_node);

 /**
  *	of_find_matching_node - Find a node based on an of_device_id match
  *				table.
  *	@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
  *
  *	Returns a node pointer with refcount incremented, use
  *	of_node_put() on it when done.
  */
 struct device_node *of_find_matching_node(struct device_node *from,
 					  const struct of_device_id *matches)
 {
 	struct device_node *np;

 	read_lock(&devtree_lock);
 	np = from ? from->allnext : allnodes;
 	for (; np; np = np->allnext) {
 		if (of_match_node(matches, np) && of_node_get(np))
 			break;
 	}
 	of_node_put(from);
 	read_unlock(&devtree_lock);
 	return np;
 }
 EXPORT_SYMBOL(of_find_matching_node);
	/*
	* 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
	*
	* Reconsolidated from arch/x/kernel/prom.c by Stephen Rothwell.
	*
	* 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.
	*/
	#include <linux/module.h>
	#include <linux/of.h>
	#include <linux/spinlock.h>

	struct device_node *allnodes;

	/* use when traversing tree through the allnext, child, sibling,
	* or parent members of struct device_node.
	*/
	DEFINE_RWLOCK(devtree_lock);

	int of_n_addr_cells(struct device_node *np)
	{
	const int *ip;

	do {
	if (np->parent)
	np = np->parent;
	ip = of_get_property(np, "#address-cells", NULL);
	if (ip)
	return *ip;
	} 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)
	{
	const int *ip;

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

	struct property of_find_property(const struct device_node np,
	const char *name,
	int *lenp)
	{
	struct property *pp;

	if (!np)
	return NULL;

	read_lock(&devtree_lock);
	for (pp = np->properties; pp != 0; pp = pp->next) {
	if (of_prop_cmp(pp->name, name) == 0) {
	if (lenp != 0)
	*lenp = pp->length;
	break;
	}
	}
	read_unlock(&devtree_lock);

	return pp;
	}
	EXPORT_SYMBOL(of_find_property);

	/*
	* 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,
	int *lenp)
	{
	struct property *pp = of_find_property(np, name, lenp);

	return pp ? pp->value : NULL;
	}
	EXPORT_SYMBOL(of_get_property);

	/** 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)
	{
	const char* cp;
	int cplen, l;

	cp = of_get_property(device, "compatible", &cplen);
	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;
	}
	EXPORT_SYMBOL(of_device_is_compatible);

	/**
	* 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)
	{
	const char *status;
	int statlen;

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

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

	return 0;
	}
	EXPORT_SYMBOL(of_device_is_available);

	/**
	* 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;

	if (!node)
	return NULL;

	read_lock(&devtree_lock);
	np = of_node_get(node->parent);
	read_unlock(&devtree_lock);
	return np;
	}
	EXPORT_SYMBOL(of_get_parent);

	/**
	* 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;

	if (!node)
	return NULL;

	read_lock(&devtree_lock);
	parent = of_node_get(node->parent);
	of_node_put(node);
	read_unlock(&devtree_lock);
	return parent;
	}

	/**
	* 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;

	read_lock(&devtree_lock);
	next = prev ? prev->sibling : node->child;
	for (; next; next = next->sibling)
	if (of_node_get(next))
	break;
	of_node_put(prev);
	read_unlock(&devtree_lock);
	return next;
	}
	EXPORT_SYMBOL(of_get_next_child);

	/**
	* 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)
	{
	struct device_node *np = allnodes;

	read_lock(&devtree_lock);
	for (; np; np = np->allnext) {
	if (np->full_name && (of_node_cmp(np->full_name, path) == 0)
	&& of_node_get(np))
	break;
	}
	read_unlock(&devtree_lock);
	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;

	read_lock(&devtree_lock);
	np = from ? from->allnext : allnodes;
	for (; np; np = np->allnext)
	if (np->name && (of_node_cmp(np->name, name) == 0)
	&& of_node_get(np))
	break;
	of_node_put(from);
	read_unlock(&devtree_lock);
	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;

	read_lock(&devtree_lock);
	np = from ? from->allnext : allnodes;
	for (; np; np = np->allnext)
	if (np->type && (of_node_cmp(np->type, type) == 0)
	&& of_node_get(np))
	break;
	of_node_put(from);
	read_unlock(&devtree_lock);
	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;

	read_lock(&devtree_lock);
	np = from ? from->allnext : allnodes;
	for (; np; np = np->allnext) {
	if (type
	&& !(np->type && (of_node_cmp(np->type, type) == 0)))
	continue;
	if (of_device_is_compatible(np, compatible) && of_node_get(np))
	break;
	}
	of_node_put(from);
	read_unlock(&devtree_lock);
	return np;
	}
	EXPORT_SYMBOL(of_find_compatible_node);

	/**
	* 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)
	{
	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);
	if (matches->compatible[0])
	match &= of_device_is_compatible(node,
	matches->compatible);
	if (match)
	return matches;
	matches++;
	}
	return NULL;
	}
	EXPORT_SYMBOL(of_match_node);

	/**
	* of_find_matching_node - Find a node based on an of_device_id match
	* table.
	* @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
	*
	* Returns a node pointer with refcount incremented, use
	* of_node_put() on it when done.
	*/
	struct device_node of_find_matching_node(struct device_node from,
	const struct of_device_id *matches)
	{
	struct device_node *np;

	read_lock(&devtree_lock);
	np = from ? from->allnext : allnodes;
	for (; np; np = np->allnext) {
	if (of_match_node(matches, np) && of_node_get(np))
	break;
	}
	of_node_put(from);
	read_unlock(&devtree_lock);
	return np;
	}
	EXPORT_SYMBOL(of_find_matching_node);