Add the rt linux 4.1.3-rt3 as base

Import the rt linux 4.1.3-rt3 as OPNFV kvm base.

It's from git://git.kernel.org/pub/scm/linux/kernel/git/rt/linux-rt-devel.git linux-4.1.y-rt and
the base is:

commit 0917f823c59692d751951bf5ea699a2d1e2f26a2
Author: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Date:   Sat Jul 25 12:13:34 2015 +0200

    Prepare v4.1.3-rt3

    Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>

We lose all the git history this way and it's not good. We
should apply another opnfv project repo in future.

Change-Id: I87543d81c9df70d99c5001fbdf646b202c19f423
Signed-off-by: Yunhong Jiang <yunhong.jiang@intel.com>

1 files changed, 2276 insertions, 0 deletions

diff --git a/kernel/drivers/of/base.c b/kernel/drivers/of/base.c
new file mode 100644
index 000000000..f0650265f
--- /dev/null
+++ b/kernel/drivers/of/base.c
@@ -0,0 +1,2276 @@
+/*
+ * 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 and
+ *  Grant Likely.
+ *
+ *      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/console.h>
+#include <linux/ctype.h>
+#include <linux/cpu.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_graph.h>
+#include <linux/spinlock.h>
+#include <linux/slab.h>
+#include <linux/string.h>
+#include <linux/proc_fs.h>
+
+#include "of_private.h"
+
+LIST_HEAD(aliases_lookup);
+
+struct device_node *of_root;
+EXPORT_SYMBOL(of_root);
+struct device_node *of_chosen;
+struct device_node *of_aliases;
+struct device_node *of_stdout;
+static const char *of_stdout_options;
+
+struct kset *of_kset;
+
+/*
+ * Used to protect the of_aliases, to hold off addition of nodes to sysfs.
+ * This mutex must be held whenever modifications are being made to the
+ * device tree. The of_{attach,detach}_node() and
+ * of_{add,remove,update}_property() helpers make sure this happens.
+ */
+DEFINE_MUTEX(of_mutex);
+
+/* use when traversing tree through the child, sibling,
+ * or parent members of struct device_node.
+ */
+DEFINE_RAW_SPINLOCK(devtree_lock);
+
+int of_n_addr_cells(struct device_node *np)
+{
+	const __be32 *ip;
+
+	do {
+		if (np->parent)
+			np = np->parent;
+		ip = of_get_property(np, "#address-cells", NULL);
+		if (ip)
+			return be32_to_cpup(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 __be32 *ip;
+
+	do {
+		if (np->parent)
+			np = np->parent;
+		ip = of_get_property(np, "#size-cells", NULL);
+		if (ip)
+			return be32_to_cpup(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);
+
+#ifdef CONFIG_NUMA
+int __weak of_node_to_nid(struct device_node *np)
+{
+	return numa_node_id();
+}
+#endif
+
+#ifndef CONFIG_OF_DYNAMIC
+static void of_node_release(struct kobject *kobj)
+{
+	/* Without CONFIG_OF_DYNAMIC, no nodes gets freed */
+}
+#endif /* CONFIG_OF_DYNAMIC */
+
+struct kobj_type of_node_ktype = {
+	.release = of_node_release,
+};
+
+static ssize_t of_node_property_read(struct file *filp, struct kobject *kobj,
+				struct bin_attribute *bin_attr, char *buf,
+				loff_t offset, size_t count)
+{
+	struct property *pp = container_of(bin_attr, struct property, attr);
+	return memory_read_from_buffer(buf, count, &offset, pp->value, pp->length);
+}
+
+static const char *safe_name(struct kobject *kobj, const char *orig_name)
+{
+	const char *name = orig_name;
+	struct kernfs_node *kn;
+	int i = 0;
+
+	/* don't be a hero. After 16 tries give up */
+	while (i < 16 && (kn = sysfs_get_dirent(kobj->sd, name))) {
+		sysfs_put(kn);
+		if (name != orig_name)
+			kfree(name);
+		name = kasprintf(GFP_KERNEL, "%s#%i", orig_name, ++i);
+	}
+
+	if (name != orig_name)
+		pr_warn("device-tree: Duplicate name in %s, renamed to \"%s\"\n",
+			kobject_name(kobj), name);
+	return name;
+}
+
+int __of_add_property_sysfs(struct device_node *np, struct property *pp)
+{
+	int rc;
+
+	/* Important: Don't leak passwords */
+	bool secure = strncmp(pp->name, "security-", 9) == 0;
+
+	if (!IS_ENABLED(CONFIG_SYSFS))
+		return 0;
+
+	if (!of_kset || !of_node_is_attached(np))
+		return 0;
+
+	sysfs_bin_attr_init(&pp->attr);
+	pp->attr.attr.name = safe_name(&np->kobj, pp->name);
+	pp->attr.attr.mode = secure ? S_IRUSR : S_IRUGO;
+	pp->attr.size = secure ? 0 : pp->length;
+	pp->attr.read = of_node_property_read;
+
+	rc = sysfs_create_bin_file(&np->kobj, &pp->attr);
+	WARN(rc, "error adding attribute %s to node %s\n", pp->name, np->full_name);
+	return rc;
+}
+
+int __of_attach_node_sysfs(struct device_node *np)
+{
+	const char *name;
+	struct property *pp;
+	int rc;
+
+	if (!IS_ENABLED(CONFIG_SYSFS))
+		return 0;
+
+	if (!of_kset)
+		return 0;
+
+	np->kobj.kset = of_kset;
+	if (!np->parent) {
+		/* Nodes without parents are new top level trees */
+		rc = kobject_add(&np->kobj, NULL, "%s",
+				 safe_name(&of_kset->kobj, "base"));
+	} else {
+		name = safe_name(&np->parent->kobj, kbasename(np->full_name));
+		if (!name || !name[0])
+			return -EINVAL;
+
+		rc = kobject_add(&np->kobj, &np->parent->kobj, "%s", name);
+	}
+	if (rc)
+		return rc;
+
+	for_each_property_of_node(np, pp)
+		__of_add_property_sysfs(np, pp);
+
+	return 0;
+}
+
+void __init of_core_init(void)
+{
+	struct device_node *np;
+
+	/* Create the kset, and register existing nodes */
+	mutex_lock(&of_mutex);
+	of_kset = kset_create_and_add("devicetree", NULL, firmware_kobj);
+	if (!of_kset) {
+		mutex_unlock(&of_mutex);
+		pr_err("devicetree: failed to register existing nodes\n");
+		return;
+	}
+	for_each_of_allnodes(np)
+		__of_attach_node_sysfs(np);
+	mutex_unlock(&of_mutex);
+
+	/* Symlink in /proc as required by userspace ABI */
+	if (of_root)
+		proc_symlink("device-tree", NULL, "/sys/firmware/devicetree/base");
+}
+
+static struct property *__of_find_property(const struct device_node *np,
+					   const char *name, int *lenp)
+{
+	struct property *pp;
+
+	if (!np)
+		return NULL;
+
+	for (pp = np->properties; pp; pp = pp->next) {
+		if (of_prop_cmp(pp->name, name) == 0) {
+			if (lenp)
+				*lenp = pp->length;
+			break;
+		}
+	}
+
+	return pp;
+}
+
+struct property *of_find_property(const struct device_node *np,
+				  const char *name,
+				  int *lenp)
+{
+	struct property *pp;
+	unsigned long flags;
+
+	raw_spin_lock_irqsave(&devtree_lock, flags);
+	pp = __of_find_property(np, name, lenp);
+	raw_spin_unlock_irqrestore(&devtree_lock, flags);
+
+	return pp;
+}
+EXPORT_SYMBOL(of_find_property);
+
+struct device_node *__of_find_all_nodes(struct device_node *prev)
+{
+	struct device_node *np;
+	if (!prev) {
+		np = of_root;
+	} else if (prev->child) {
+		np = prev->child;
+	} else {
+		/* Walk back up looking for a sibling, or the end of the structure */
+		np = prev;
+		while (np->parent && !np->sibling)
+			np = np->parent;
+		np = np->sibling; /* Might be null at the end of the tree */
+	}
+	return np;
+}
+
+/**
+ * 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;
+	unsigned long flags;
+
+	raw_spin_lock_irqsave(&devtree_lock, flags);
+	np = __of_find_all_nodes(prev);
+	of_node_get(np);
+	of_node_put(prev);
+	raw_spin_unlock_irqrestore(&devtree_lock, flags);
+	return np;
+}
+EXPORT_SYMBOL(of_find_all_nodes);
+
+/*
+ * 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;
+}
+
+/*
+ * 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);
+
+/*
+ * arch_match_cpu_phys_id - Match the given logical CPU and physical id
+ *
+ * @cpu: logical cpu index of a core/thread
+ * @phys_id: physical identifier of a core/thread
+ *
+ * CPU logical to physical index mapping is architecture specific.
+ * However this __weak function provides a default match of physical
+ * id to logical cpu index. phys_id provided here is usually values read
+ * from the device tree which must match the hardware internal registers.
+ *
+ * Returns true if the physical identifier and the logical cpu index
+ * correspond to the same core/thread, false otherwise.
+ */
+bool __weak arch_match_cpu_phys_id(int cpu, u64 phys_id)
+{
+	return (u32)phys_id == cpu;
+}
+
+/**
+ * Checks if the given "prop_name" property holds the physical id of the
+ * core/thread corresponding to the logical cpu 'cpu'. If 'thread' is not
+ * NULL, local thread number within the core is returned in it.
+ */
+static bool __of_find_n_match_cpu_property(struct device_node *cpun,
+			const char *prop_name, int cpu, unsigned int *thread)
+{
+	const __be32 *cell;
+	int ac, prop_len, tid;
+	u64 hwid;
+
+	ac = of_n_addr_cells(cpun);
+	cell = of_get_property(cpun, prop_name, &prop_len);
+	if (!cell || !ac)
+		return false;
+	prop_len /= sizeof(*cell) * ac;
+	for (tid = 0; tid < prop_len; tid++) {
+		hwid = of_read_number(cell, ac);
+		if (arch_match_cpu_phys_id(cpu, hwid)) {
+			if (thread)
+				*thread = tid;
+			return true;
+		}
+		cell += ac;
+	}
+	return false;
+}
+
+/*
+ * arch_find_n_match_cpu_physical_id - See if the given device node is
+ * for the cpu corresponding to logical cpu 'cpu'.  Return true if so,
+ * else false.  If 'thread' is non-NULL, the local thread number within the
+ * core is returned in it.
+ */
+bool __weak arch_find_n_match_cpu_physical_id(struct device_node *cpun,
+					      int cpu, unsigned int *thread)
+{
+	/* Check for non-standard "ibm,ppc-interrupt-server#s" property
+	 * for thread ids on PowerPC. If it doesn't exist fallback to
+	 * standard "reg" property.
+	 */
+	if (IS_ENABLED(CONFIG_PPC) &&
+	    __of_find_n_match_cpu_property(cpun,
+					   "ibm,ppc-interrupt-server#s",
+					   cpu, thread))
+		return true;
+
+	if (__of_find_n_match_cpu_property(cpun, "reg", cpu, thread))
+		return true;
+
+	return false;
+}
+
+/**
+ * of_get_cpu_node - Get device node associated with the given logical CPU
+ *
+ * @cpu: CPU number(logical index) for which device node is required
+ * @thread: if not NULL, local thread number within the physical core is
+ *          returned
+ *
+ * The main purpose of this function is to retrieve the device node for the
+ * given logical CPU index. It should be used to initialize the of_node in
+ * cpu device. Once of_node in cpu device is populated, all the further
+ * references can use that instead.
+ *
+ * CPU logical to physical index mapping is architecture specific and is built
+ * before booting secondary cores. This function uses arch_match_cpu_phys_id
+ * which can be overridden by architecture specific implementation.
+ *
+ * Returns a node pointer for the logical cpu if found, else NULL.
+ */
+struct device_node *of_get_cpu_node(int cpu, unsigned int *thread)
+{
+	struct device_node *cpun;
+
+	for_each_node_by_type(cpun, "cpu") {
+		if (arch_find_n_match_cpu_physical_id(cpun, cpu, thread))
+			return cpun;
+	}
+	return NULL;
+}
+EXPORT_SYMBOL(of_get_cpu_node);
+
+/**
+ * __of_device_is_compatible() - Check if the node matches given constraints
+ * @device: pointer to node
+ * @compat: required compatible string, NULL or "" for any match
+ * @type: required device_type value, NULL or "" for any match
+ * @name: required node name, NULL or "" for any match
+ *
+ * Checks if the given @compat, @type and @name strings match the
+ * properties of the given @device. A constraints can be skipped by
+ * passing NULL or an empty string as the constraint.
+ *
+ * Returns 0 for no match, and a positive integer on match. The return
+ * value is a relative score with larger values indicating better
+ * matches. The score is weighted for the most specific compatible value
+ * to get the highest score. Matching type is next, followed by matching
+ * name. Practically speaking, this results in the following priority
+ * order for matches:
+ *
+ * 1. specific compatible && type && name
+ * 2. specific compatible && type
+ * 3. specific compatible && name
+ * 4. specific compatible
+ * 5. general compatible && type && name
+ * 6. general compatible && type
+ * 7. general compatible && name
+ * 8. general compatible
+ * 9. type && name
+ * 10. type
+ * 11. name
+ */
+static int __of_device_is_compatible(const struct device_node *device,
+				     const char *compat, const char *type, const char *name)
+{
+	struct property *prop;
+	const char *cp;
+	int index = 0, score = 0;
+
+	/* Compatible match has highest priority */
+	if (compat && compat[0]) {
+		prop = __of_find_property(device, "compatible", NULL);
+		for (cp = of_prop_next_string(prop, NULL); cp;
+		     cp = of_prop_next_string(prop, cp), index++) {
+			if (of_compat_cmp(cp, compat, strlen(compat)) == 0) {
+				score = INT_MAX/2 - (index << 2);
+				break;
+			}
+		}
+		if (!score)
+			return 0;
+	}
+
+	/* Matching type is better than matching name */
+	if (type && type[0]) {
+		if (!device->type || of_node_cmp(type, device->type))
+			return 0;
+		score += 2;
+	}
+
+	/* Matching name is a bit better than not */
+	if (name && name[0]) {
+		if (!device->name || of_node_cmp(name, device->name))
+			return 0;
+		score++;
+	}
+
+	return score;
+}
+
+/** 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)
+{
+	unsigned long flags;
+	int res;
+
+	raw_spin_lock_irqsave(&devtree_lock, flags);
+	res = __of_device_is_compatible(device, compat, NULL, NULL);
+	raw_spin_unlock_irqrestore(&devtree_lock, flags);
+	return res;
+}
+EXPORT_SYMBOL(of_device_is_compatible);
+
+/**
+ * of_machine_is_compatible - Test root of device tree for a given compatible value
+ * @compat: compatible string to look for in root node's compatible property.
+ *
+ * Returns a positive integer if the root node has the given value in its
+ * compatible property.
+ */
+int of_machine_is_compatible(const char *compat)
+{
+	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;
+}
+EXPORT_SYMBOL(of_machine_is_compatible);
+
+/**
+ *  __of_device_is_available - check if a device is available for use
+ *
+ *  @device: Node to check for availability, with locks already held
+ *
+ *  Returns true if the status property is absent or set to "okay" or "ok",
+ *  false otherwise
+ */
+static bool __of_device_is_available(const struct device_node *device)
+{
+	const char *status;
+	int statlen;
+
+	if (!device)
+		return false;
+
+	status = __of_get_property(device, "status", &statlen);
+	if (status == NULL)
+		return true;
+
+	if (statlen > 0) {
+		if (!strcmp(status, "okay") || !strcmp(status, "ok"))
+			return true;
+	}
+
+	return false;
+}
+
+/**
+ *  of_device_is_available - check if a device is available for use
+ *
+ *  @device: Node to check for availability
+ *
+ *  Returns true if the status property is absent or set to "okay" or "ok",
+ *  false otherwise
+ */
+bool of_device_is_available(const struct device_node *device)
+{
+	unsigned long flags;
+	bool res;
+
+	raw_spin_lock_irqsave(&devtree_lock, flags);
+	res = __of_device_is_available(device);
+	raw_spin_unlock_irqrestore(&devtree_lock, flags);
+	return res;
+
+}
+EXPORT_SYMBOL(of_device_is_available);
+
+/**
+ *  of_device_is_big_endian - check if a device has BE registers
+ *
+ *  @device: Node to check for endianness
+ *
+ *  Returns true if the device has a "big-endian" property, or if the kernel
+ *  was compiled for BE *and* the device has a "native-endian" property.
+ *  Returns false otherwise.
+ *
+ *  Callers would nominally use ioread32be/iowrite32be if
+ *  of_device_is_big_endian() == true, or readl/writel otherwise.
+ */
+bool of_device_is_big_endian(const struct device_node *device)
+{
+	if (of_property_read_bool(device, "big-endian"))
+		return true;
+	if (IS_ENABLED(CONFIG_CPU_BIG_ENDIAN) &&
+	    of_property_read_bool(device, "native-endian"))
+		return true;
+	return false;
+}
+EXPORT_SYMBOL(of_device_is_big_endian);
+
+/**
+ *	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;
+	unsigned long flags;
+
+	if (!node)
+		return NULL;
+
+	raw_spin_lock_irqsave(&devtree_lock, flags);
+	np = of_node_get(node->parent);
+	raw_spin_unlock_irqrestore(&devtree_lock, flags);
+	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;
+	unsigned long flags;
+
+	if (!node)
+		return NULL;
+
+	raw_spin_lock_irqsave(&devtree_lock, flags);
+	parent = of_node_get(node->parent);
+	of_node_put(node);
+	raw_spin_unlock_irqrestore(&devtree_lock, flags);
+	return parent;
+}
+EXPORT_SYMBOL(of_get_next_parent);
+
+static struct device_node *__of_get_next_child(const struct device_node *node,
+						struct device_node *prev)
+{
+	struct device_node *next;
+
+	if (!node)
+		return NULL;
+
+	next = prev ? prev->sibling : node->child;
+	for (; next; next = next->sibling)
+		if (of_node_get(next))
+			break;
+	of_node_put(prev);
+	return next;
+}
+#define __for_each_child_of_node(parent, child) \
+	for (child = __of_get_next_child(parent, NULL); child != NULL; \
+	     child = __of_get_next_child(parent, child))
+
+/**
+ *	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. Returns NULL when prev is the last child. Decrements the
+ *	refcount of prev.
+ */
+struct device_node *of_get_next_child(const struct device_node *node,
+	struct device_node *prev)
+{
+	struct device_node *next;
+	unsigned long flags;
+
+	raw_spin_lock_irqsave(&devtree_lock, flags);
+	next = __of_get_next_child(node, prev);
+	raw_spin_unlock_irqrestore(&devtree_lock, flags);
+	return next;
+}
+EXPORT_SYMBOL(of_get_next_child);
+
+/**
+ *	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;
+	unsigned long flags;
+
+	if (!node)
+		return NULL;
+
+	raw_spin_lock_irqsave(&devtree_lock, flags);
+	next = prev ? prev->sibling : node->child;
+	for (; next; next = next->sibling) {
+		if (!__of_device_is_available(next))
+			continue;
+		if (of_node_get(next))
+			break;
+	}
+	of_node_put(prev);
+	raw_spin_unlock_irqrestore(&devtree_lock, flags);
+	return next;
+}
+EXPORT_SYMBOL(of_get_next_available_child);
+
+/**
+ *	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);
+
+static struct device_node *__of_find_node_by_path(struct device_node *parent,
+						const char *path)
+{
+	struct device_node *child;
+	int len;
+
+	len = strcspn(path, "/:");
+	if (!len)
+		return NULL;
+
+	__for_each_child_of_node(parent, child) {
+		const char *name = strrchr(child->full_name, '/');
+		if (WARN(!name, "malformed device_node %s\n", child->full_name))
+			continue;
+		name++;
+		if (strncmp(path, name, len) == 0 && (strlen(name) == len))
+			return child;
+	}
+	return NULL;
+}
+
+/**
+ *	of_find_node_opts_by_path - Find a node matching a full OF path
+ *	@path: Either the full path to match, or if the path does not
+ *	       start with '/', the name of a property of the /aliases
+ *	       node (an alias).  In the case of an alias, the node
+ *	       matching the alias' value will be returned.
+ *	@opts: Address of a pointer into which to store the start of
+ *	       an options string appended to the end of the path with
+ *	       a ':' separator.
+ *
+ *	Valid paths:
+ *		/foo/bar	Full path
+ *		foo		Valid alias
+ *		foo/bar		Valid alias + relative path
+ *
+ *	Returns a node pointer with refcount incremented, use
+ *	of_node_put() on it when done.
+ */
+struct device_node *of_find_node_opts_by_path(const char *path, const char **opts)
+{
+	struct device_node *np = NULL;
+	struct property *pp;
+	unsigned long flags;
+	const char *separator = strchr(path, ':');
+
+	if (opts)
+		*opts = separator ? separator + 1 : NULL;
+
+	if (strcmp(path, "/") == 0)
+		return of_node_get(of_root);
+
+	/* The path could begin with an alias */
+	if (*path != '/') {
+		int len;
+		const char *p = separator;
+
+		if (!p)
+			p = strchrnul(path, '/');
+		len = p - path;
+
+		/* of_aliases must not be NULL */
+		if (!of_aliases)
+			return NULL;
+
+		for_each_property_of_node(of_aliases, pp) {
+			if (strlen(pp->name) == len && !strncmp(pp->name, path, len)) {
+				np = of_find_node_by_path(pp->value);
+				break;
+			}
+		}
+		if (!np)
+			return NULL;
+		path = p;
+	}
+
+	/* Step down the tree matching path components */
+	raw_spin_lock_irqsave(&devtree_lock, flags);
+	if (!np)
+		np = of_node_get(of_root);
+	while (np && *path == '/') {
+		path++; /* Increment past '/' delimiter */
+		np = __of_find_node_by_path(np, path);
+		path = strchrnul(path, '/');
+		if (separator && separator < path)
+			break;
+	}
+	raw_spin_unlock_irqrestore(&devtree_lock, flags);
+	return np;
+}
+EXPORT_SYMBOL(of_find_node_opts_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;
+	unsigned long flags;
+
+	raw_spin_lock_irqsave(&devtree_lock, flags);
+	for_each_of_allnodes_from(from, np)
+		if (np->name && (of_node_cmp(np->name, name) == 0)
+		    && of_node_get(np))
+			break;
+	of_node_put(from);
+	raw_spin_unlock_irqrestore(&devtree_lock, flags);
+	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;
+	unsigned long flags;
+
+	raw_spin_lock_irqsave(&devtree_lock, flags);
+	for_each_of_allnodes_from(from, np)
+		if (np->type && (of_node_cmp(np->type, type) == 0)
+		    && of_node_get(np))
+			break;
+	of_node_put(from);
+	raw_spin_unlock_irqrestore(&devtree_lock, flags);
+	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;
+	unsigned long flags;
+
+	raw_spin_lock_irqsave(&devtree_lock, flags);
+	for_each_of_allnodes_from(from, np)
+		if (__of_device_is_compatible(np, compatible, type, NULL) &&
+		    of_node_get(np))
+			break;
+	of_node_put(from);
+	raw_spin_unlock_irqrestore(&devtree_lock, flags);
+	return np;
+}
+EXPORT_SYMBOL(of_find_compatible_node);
+
+/**
+ *	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;
+	unsigned long flags;
+
+	raw_spin_lock_irqsave(&devtree_lock, flags);
+	for_each_of_allnodes_from(from, np) {
+		for (pp = np->properties; pp; pp = pp->next) {
+			if (of_prop_cmp(pp->name, prop_name) == 0) {
+				of_node_get(np);
+				goto out;
+			}
+		}
+	}
+out:
+	of_node_put(from);
+	raw_spin_unlock_irqrestore(&devtree_lock, flags);
+	return np;
+}
+EXPORT_SYMBOL(of_find_node_with_property);
+
+static
+const struct of_device_id *__of_match_node(const struct of_device_id *matches,
+					   const struct device_node *node)
+{
+	const struct of_device_id *best_match = NULL;
+	int score, best_score = 0;
+
+	if (!matches)
+		return NULL;
+
+	for (; matches->name[0] || matches->type[0] || matches->compatible[0]; matches++) {
+		score = __of_device_is_compatible(node, matches->compatible,
+						  matches->type, matches->name);
+		if (score > best_score) {
+			best_match = matches;
+			best_score = score;
+		}
+	}
+
+	return best_match;
+}
+
+/**
+ * of_match_node - Tell if a 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;
+	unsigned long flags;
+
+	raw_spin_lock_irqsave(&devtree_lock, flags);
+	match = __of_match_node(matches, node);
+	raw_spin_unlock_irqrestore(&devtree_lock, flags);
+	return match;
+}
+EXPORT_SYMBOL(of_match_node);
+
+/**
+ *	of_find_matching_node_and_match - 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
+ *	@match		Updated to point at the matches entry which matched
+ *
+ *	Returns a node pointer with refcount incremented, use
+ *	of_node_put() on it when done.
+ */
+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)
+{
+	struct device_node *np;
+	const struct of_device_id *m;
+	unsigned long flags;
+
+	if (match)
+		*match = NULL;
+
+	raw_spin_lock_irqsave(&devtree_lock, flags);
+	for_each_of_allnodes_from(from, np) {
+		m = __of_match_node(matches, np);
+		if (m && of_node_get(np)) {
+			if (match)
+				*match = m;
+			break;
+		}
+	}
+	of_node_put(from);
+	raw_spin_unlock_irqrestore(&devtree_lock, flags);
+	return np;
+}
+EXPORT_SYMBOL(of_find_matching_node_and_match);
+
+/**
+ * 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
+ *
+ * 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.
+ *
+ * This routine returns 0 on success, <0 on failure.
+ */
+int of_modalias_node(struct device_node *node, char *modalias, int len)
+{
+	const char *compatible, *p;
+	int cplen;
+
+	compatible = of_get_property(node, "compatible", &cplen);
+	if (!compatible || strlen(compatible) > cplen)
+		return -ENODEV;
+	p = strchr(compatible, ',');
+	strlcpy(modalias, p ? p + 1 : compatible, len);
+	return 0;
+}
+EXPORT_SYMBOL_GPL(of_modalias_node);
+
+/**
+ * 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;
+	unsigned long flags;
+
+	if (!handle)
+		return NULL;
+
+	raw_spin_lock_irqsave(&devtree_lock, flags);
+	for_each_of_allnodes(np)
+		if (np->phandle == handle)
+			break;
+	of_node_get(np);
+	raw_spin_unlock_irqrestore(&devtree_lock, flags);
+	return np;
+}
+EXPORT_SYMBOL(of_find_node_by_phandle);
+
+/**
+ * of_property_count_elems_of_size - Count the number of elements in a property
+ *
+ * @np:		device node from which the property value is to be read.
+ * @propname:	name of the property to be searched.
+ * @elem_size:	size of the individual element
+ *
+ * Search for a property in a device node and count the number of elements of
+ * size elem_size in it. Returns number of elements on sucess, -EINVAL if the
+ * property does not exist or its length does not match a multiple of elem_size
+ * and -ENODATA if the property does not have a value.
+ */
+int of_property_count_elems_of_size(const struct device_node *np,
+				const char *propname, int elem_size)
+{
+	struct property *prop = of_find_property(np, propname, NULL);
+
+	if (!prop)
+		return -EINVAL;
+	if (!prop->value)
+		return -ENODATA;
+
+	if (prop->length % elem_size != 0) {
+		pr_err("size of %s in node %s is not a multiple of %d\n",
+		       propname, np->full_name, elem_size);
+		return -EINVAL;
+	}
+
+	return prop->length / elem_size;
+}
+EXPORT_SYMBOL_GPL(of_property_count_elems_of_size);
+
+/**
+ * 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;
+}
+
+/**
+ * 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)
+{
+	const u32 *val = of_find_property_value_of_size(np, propname,
+					((index + 1) * sizeof(*out_value)));
+
+	if (IS_ERR(val))
+		return PTR_ERR(val);
+
+	*out_value = be32_to_cpup(((__be32 *)val) + index);
+	return 0;
+}
+EXPORT_SYMBOL_GPL(of_property_read_u32_index);
+
+/**
+ * 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.
+ * @out_values:	pointer to return value, modified only if return value is 0.
+ * @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>;
+ *
+ * The out_values is modified only if a valid u8 value can be decoded.
+ */
+int of_property_read_u8_array(const struct device_node *np,
+			const char *propname, u8 *out_values, size_t sz)
+{
+	const u8 *val = of_find_property_value_of_size(np, propname,
+						(sz * sizeof(*out_values)));
+
+	if (IS_ERR(val))
+		return PTR_ERR(val);
+
+	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.
+ * @out_values:	pointer to return value, modified only if return value is 0.
+ * @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>;
+ *
+ * The out_values is modified only if a valid u16 value can be decoded.
+ */
+int of_property_read_u16_array(const struct device_node *np,
+			const char *propname, u16 *out_values, size_t sz)
+{
+	const __be16 *val = of_find_property_value_of_size(np, propname,
+						(sz * sizeof(*out_values)));
+
+	if (IS_ERR(val))
+		return PTR_ERR(val);
+
+	while (sz--)
+		*out_values++ = be16_to_cpup(val++);
+	return 0;
+}
+EXPORT_SYMBOL_GPL(of_property_read_u16_array);
+
+/**
+ * of_property_read_u32_array - Find and read an array of 32 bit integers
+ * from a property.
+ *
+ * @np:		device node from which the property value is to be read.
+ * @propname:	name of the property to be searched.
+ * @out_values:	pointer to return value, modified only if return value is 0.
+ * @sz:		number of array elements to read
+ *
+ * Search for a property in a device node and read 32-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.
+ *
+ * The out_values is modified only if a valid u32 value can be decoded.
+ */
+int of_property_read_u32_array(const struct device_node *np,
+			       const char *propname, u32 *out_values,
+			       size_t sz)
+{
+	const __be32 *val = of_find_property_value_of_size(np, propname,
+						(sz * sizeof(*out_values)));
+
+	if (IS_ERR(val))
+		return PTR_ERR(val);
+
+	while (sz--)
+		*out_values++ = be32_to_cpup(val++);
+	return 0;
+}
+EXPORT_SYMBOL_GPL(of_property_read_u32_array);
+
+/**
+ * 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)
+{
+	const __be32 *val = of_find_property_value_of_size(np, propname,
+						sizeof(*out_value));
+
+	if (IS_ERR(val))
+		return PTR_ERR(val);
+
+	*out_value = of_read_number(val, 2);
+	return 0;
+}
+EXPORT_SYMBOL_GPL(of_property_read_u64);
+
+/**
+ * of_property_read_u64_array - Find and read an array of 64 bit integers
+ * from a property.
+ *
+ * @np:		device node from which the property value is to be read.
+ * @propname:	name of the property to be searched.
+ * @out_values:	pointer to return value, modified only if return value is 0.
+ * @sz:		number of array elements to read
+ *
+ * Search for a property in a device node and read 64-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.
+ *
+ * The out_values is modified only if a valid u64 value can be decoded.
+ */
+int of_property_read_u64_array(const struct device_node *np,
+			       const char *propname, u64 *out_values,
+			       size_t sz)
+{
+	const __be32 *val = of_find_property_value_of_size(np, propname,
+						(sz * sizeof(*out_values)));
+
+	if (IS_ERR(val))
+		return PTR_ERR(val);
+
+	while (sz--) {
+		*out_values++ = of_read_number(val, 2);
+		val += 2;
+	}
+	return 0;
+}
+EXPORT_SYMBOL_GPL(of_property_read_u64_array);
+
+/**
+ * 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.
+ */
+int of_property_read_string(struct device_node *np, const char *propname,
+				const char **out_string)
+{
+	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);
+
+/**
+ * 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 = strnlen(p, end - 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);
+
+/**
+ * of_property_read_string_helper() - Utility helper for parsing string properties
+ * @np:		device node from which the property value is to be read.
+ * @propname:	name of the property to be searched.
+ * @out_strs:	output array of string pointers.
+ * @sz:		number of array elements to read.
+ * @skip:	Number of strings to skip over at beginning of list.
+ *
+ * Don't call this function directly. It is a utility helper for the
+ * of_property_read_string*() family of functions.
+ */
+int of_property_read_string_helper(struct device_node *np, const char *propname,
+				   const char **out_strs, size_t sz, int skip)
+{
+	struct property *prop = of_find_property(np, propname, NULL);
+	int l = 0, i = 0;
+	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 && (!out_strs || i < skip + sz); i++, p += l) {
+		l = strnlen(p, end - p) + 1;
+		if (p + l > end)
+			return -EILSEQ;
+		if (out_strs && i >= skip)
+			*out_strs++ = p;
+	}
+	i -= skip;
+	return i <= 0 ? -ENODATA : i;
+}
+EXPORT_SYMBOL_GPL(of_property_read_string_helper);
+
+void of_print_phandle_args(const char *msg, const struct of_phandle_args *args)
+{
+	int i;
+	printk("%s %s", msg, of_node_full_name(args->np));
+	for (i = 0; i < args->args_count; i++)
+		printk(i ? ",%08x" : ":%08x", args->args[i]);
+	printk("\n");
+}
+
+static int __of_parse_phandle_with_args(const struct device_node *np,
+					const char *list_name,
+					const char *cells_name,
+					int cell_count, int index,
+					struct of_phandle_args *out_args)
+{
+	const __be32 *list, *list_end;
+	int rc = 0, size, cur_index = 0;
+	uint32_t count = 0;
+	struct device_node *node = NULL;
+	phandle phandle;
+
+	/* Retrieve the phandle list property */
+	list = of_get_property(np, list_name, &size);
+	if (!list)
+		return -ENOENT;
+	list_end = list + size / sizeof(*list);
+
+	/* Loop over the phandles until all the requested entry is found */
+	while (list < list_end) {
+		rc = -EINVAL;
+		count = 0;
+
+		/*
+		 * If phandle is 0, then it is an empty entry with no
+		 * arguments.  Skip forward to the next entry.
+		 */
+		phandle = be32_to_cpup(list++);
+		if (phandle) {
+			/*
+			 * Find the provider node and parse the #*-cells
+			 * property to determine the argument length.
+			 *
+			 * This is not needed if the cell count is hard-coded
+			 * (i.e. cells_name not set, but cell_count is set),
+			 * except when we're going to return the found node
+			 * below.
+			 */
+			if (cells_name || cur_index == index) {
+				node = of_find_node_by_phandle(phandle);
+				if (!node) {
+					pr_err("%s: could not find phandle\n",
+						np->full_name);
+					goto err;
+				}
+			}
+
+			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;
+			}
+
+			/*
+			 * 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);
+				goto err;
+			}
+		}
+
+		/*
+		 * 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.
+		 */
+		rc = -ENOENT;
+		if (cur_index == index) {
+			if (!phandle)
+				goto err;
+
+			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++);
+			} else {
+				of_node_put(node);
+			}
+
+			/* Found it! return success */
+			return 0;
+		}
+
+		of_node_put(node);
+		node = NULL;
+		list += count;
+		cur_index++;
+	}
+
+	/*
+	 * Unlock node before returning result; will be one of:
+	 * -ENOENT : index is for empty phandle
+	 * -EINVAL : parsing error on data
+	 * [1..n]  : Number of phandle (count mode; when index = -1)
+	 */
+	rc = index < 0 ? cur_index : -ENOENT;
+ err:
+	if (node)
+		of_node_put(node);
+	return rc;
+}
+
+/**
+ * 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)
+{
+	struct of_phandle_args args;
+
+	if (index < 0)
+		return NULL;
+
+	if (__of_parse_phandle_with_args(np, phandle_name, NULL, 0,
+					 index, &args))
+		return NULL;
+
+	return args.np;
+}
+EXPORT_SYMBOL(of_parse_phandle);
+
+/**
+ * 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->np
+ * 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);
+ */
+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;
+	return __of_parse_phandle_with_args(np, list_name, cells_name, 0,
+					    index, out_args);
+}
+EXPORT_SYMBOL(of_parse_phandle_with_args);
+
+/**
+ * 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->np
+ * 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);
+
+/**
+ * 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)
+{
+	return __of_parse_phandle_with_args(np, list_name, cells_name, 0, -1,
+					    NULL);
+}
+EXPORT_SYMBOL(of_count_phandle_with_args);
+
+/**
+ * __of_add_property - Add a property to a node without lock operations
+ */
+int __of_add_property(struct device_node *np, struct property *prop)
+{
+	struct property **next;
+
+	prop->next = NULL;
+	next = &np->properties;
+	while (*next) {
+		if (strcmp(prop->name, (*next)->name) == 0)
+			/* duplicate ! don't insert it */
+			return -EEXIST;
+
+		next = &(*next)->next;
+	}
+	*next = prop;
+
+	return 0;
+}
+
+/**
+ * of_add_property - Add a property to a node
+ */
+int of_add_property(struct device_node *np, struct property *prop)
+{
+	unsigned long flags;
+	int rc;
+
+	mutex_lock(&of_mutex);
+
+	raw_spin_lock_irqsave(&devtree_lock, flags);
+	rc = __of_add_property(np, prop);
+	raw_spin_unlock_irqrestore(&devtree_lock, flags);
+
+	if (!rc)
+		__of_add_property_sysfs(np, prop);
+
+	mutex_unlock(&of_mutex);
+
+	if (!rc)
+		of_property_notify(OF_RECONFIG_ADD_PROPERTY, np, prop, NULL);
+
+	return rc;
+}
+
+int __of_remove_property(struct device_node *np, struct property *prop)
+{
+	struct property **next;
+
+	for (next = &np->properties; *next; next = &(*next)->next) {
+		if (*next == prop)
+			break;
+	}
+	if (*next == NULL)
+		return -ENODEV;
+
+	/* found the node */
+	*next = prop->next;
+	prop->next = np->deadprops;
+	np->deadprops = prop;
+
+	return 0;
+}
+
+void __of_remove_property_sysfs(struct device_node *np, struct property *prop)
+{
+	if (!IS_ENABLED(CONFIG_SYSFS))
+		return;
+
+	/* at early boot, bail here and defer setup to of_init() */
+	if (of_kset && of_node_is_attached(np))
+		sysfs_remove_bin_file(&np->kobj, &prop->attr);
+}
+
+/**
+ * of_remove_property - Remove a property from a node.
+ *
+ * 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.
+ */
+int of_remove_property(struct device_node *np, struct property *prop)
+{
+	unsigned long flags;
+	int rc;
+
+	mutex_lock(&of_mutex);
+
+	raw_spin_lock_irqsave(&devtree_lock, flags);
+	rc = __of_remove_property(np, prop);
+	raw_spin_unlock_irqrestore(&devtree_lock, flags);
+
+	if (!rc)
+		__of_remove_property_sysfs(np, prop);
+
+	mutex_unlock(&of_mutex);
+
+	if (!rc)
+		of_property_notify(OF_RECONFIG_REMOVE_PROPERTY, np, prop, NULL);
+
+	return rc;
+}
+
+int __of_update_property(struct device_node *np, struct property *newprop,
+		struct property **oldpropp)
+{
+	struct property **next, *oldprop;
+
+	for (next = &np->properties; *next; next = &(*next)->next) {
+		if (of_prop_cmp((*next)->name, newprop->name) == 0)
+			break;
+	}
+	*oldpropp = oldprop = *next;
+
+	if (oldprop) {
+		/* replace the node */
+		newprop->next = oldprop->next;
+		*next = newprop;
+		oldprop->next = np->deadprops;
+		np->deadprops = oldprop;
+	} else {
+		/* new node */
+		newprop->next = NULL;
+		*next = newprop;
+	}
+
+	return 0;
+}
+
+void __of_update_property_sysfs(struct device_node *np, struct property *newprop,
+		struct property *oldprop)
+{
+	if (!IS_ENABLED(CONFIG_SYSFS))
+		return;
+
+	/* At early boot, bail out and defer setup to of_init() */
+	if (!of_kset)
+		return;
+
+	if (oldprop)
+		sysfs_remove_bin_file(&np->kobj, &oldprop->attr);
+	__of_add_property_sysfs(np, newprop);
+}
+
+/*
+ * of_update_property - Update a property in a node, if the property does
+ * not exist, add it.
+ *
+ * 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
+ */
+int of_update_property(struct device_node *np, struct property *newprop)
+{
+	struct property *oldprop;
+	unsigned long flags;
+	int rc;
+
+	if (!newprop->name)
+		return -EINVAL;
+
+	mutex_lock(&of_mutex);
+
+	raw_spin_lock_irqsave(&devtree_lock, flags);
+	rc = __of_update_property(np, newprop, &oldprop);
+	raw_spin_unlock_irqrestore(&devtree_lock, flags);
+
+	if (!rc)
+		__of_update_property_sysfs(np, newprop, oldprop);
+
+	mutex_unlock(&of_mutex);
+
+	if (!rc)
+		of_property_notify(OF_RECONFIG_UPDATE_PROPERTY, np, newprop, oldprop);
+
+	return rc;
+}
+
+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",
+		 ap->alias, ap->stem, ap->id, of_node_full_name(np));
+}
+
+/**
+ * of_alias_scan - Scan all properties of the 'aliases' node
+ *
+ * The function scans all the properties of the 'aliases' node and populates
+ * the global lookup table with the properties.  It returns the
+ * number of alias properties found, or an error code in case of failure.
+ *
+ * @dt_alloc:	An allocator that provides a virtual address to memory
+ *		for storing the resulting tree
+ */
+void of_alias_scan(void * (*dt_alloc)(u64 size, u64 align))
+{
+	struct property *pp;
+
+	of_aliases = of_find_node_by_path("/aliases");
+	of_chosen = of_find_node_by_path("/chosen");
+	if (of_chosen == NULL)
+		of_chosen = of_find_node_by_path("/chosen@0");
+
+	if (of_chosen) {
+		/* linux,stdout-path and /aliases/stdout are for legacy compatibility */
+		const char *name = of_get_property(of_chosen, "stdout-path", NULL);
+		if (!name)
+			name = of_get_property(of_chosen, "linux,stdout-path", NULL);
+		if (IS_ENABLED(CONFIG_PPC) && !name)
+			name = of_get_property(of_aliases, "stdout", NULL);
+		if (name)
+			of_stdout = of_find_node_opts_by_path(name, &of_stdout_options);
+	}
+
+	if (!of_aliases)
+		return;
+
+	for_each_property_of_node(of_aliases, pp) {
+		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;
+		memset(ap, 0, sizeof(*ap) + len + 1);
+		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 the alias id for the given
+ * device_node and alias stem.  It returns the alias id if found.
+ */
+int of_alias_get_id(struct device_node *np, const char *stem)
+{
+	struct alias_prop *app;
+	int id = -ENODEV;
+
+	mutex_lock(&of_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_mutex);
+
+	return id;
+}
+EXPORT_SYMBOL_GPL(of_alias_get_id);
+
+/**
+ * of_alias_get_highest_id - Get highest alias id for the given stem
+ * @stem:	Alias stem to be examined
+ *
+ * The function travels the lookup table to get the highest alias id for the
+ * given alias stem.  It returns the alias id if found.
+ */
+int of_alias_get_highest_id(const char *stem)
+{
+	struct alias_prop *app;
+	int id = -ENODEV;
+
+	mutex_lock(&of_mutex);
+	list_for_each_entry(app, &aliases_lookup, link) {
+		if (strcmp(app->stem, stem) != 0)
+			continue;
+
+		if (app->id > id)
+			id = app->id;
+	}
+	mutex_unlock(&of_mutex);
+
+	return id;
+}
+EXPORT_SYMBOL_GPL(of_alias_get_highest_id);
+
+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);
+
+/**
+ * of_console_check() - Test and setup console for DT setup
+ * @dn - Pointer to device node
+ * @name - Name to use for preferred console without index. ex. "ttyS"
+ * @index - Index to use for preferred console.
+ *
+ * Check if the given device node matches the stdout-path property in the
+ * /chosen node. If it does then register it as the preferred console and return
+ * TRUE. Otherwise return FALSE.
+ */
+bool of_console_check(struct device_node *dn, char *name, int index)
+{
+	if (!dn || dn != of_stdout || console_set_on_cmdline)
+		return false;
+	return !add_preferred_console(name, index,
+				      kstrdup(of_stdout_options, GFP_KERNEL));
+}
+EXPORT_SYMBOL_GPL(of_console_check);
+
+/**
+ *	of_find_next_cache_node - Find a node's subsidiary cache
+ *	@np:	node of type "cpu" or "cache"
+ *
+ *	Returns a node pointer with refcount incremented, use
+ *	of_node_put() on it when done.  Caller should hold a reference
+ *	to np.
+ */
+struct device_node *of_find_next_cache_node(const struct device_node *np)
+{
+	struct device_node *child;
+	const phandle *handle;
+
+	handle = of_get_property(np, "l2-cache", NULL);
+	if (!handle)
+		handle = of_get_property(np, "next-level-cache", NULL);
+
+	if (handle)
+		return of_find_node_by_phandle(be32_to_cpup(handle));
+
+	/* OF on pmac has nodes instead of properties named "l2-cache"
+	 * beneath CPU nodes.
+	 */
+	if (!strcmp(np->type, "cpu"))
+		for_each_child_of_node(np, child)
+			if (!strcmp(child->type, "cache"))
+				return child;
+
+	return NULL;
+}
+
+/**
+ * of_graph_parse_endpoint() - parse common endpoint node properties
+ * @node: pointer to endpoint device_node
+ * @endpoint: pointer to the OF endpoint data structure
+ *
+ * The caller should hold a reference to @node.
+ */
+int of_graph_parse_endpoint(const struct device_node *node,
+			    struct of_endpoint *endpoint)
+{
+	struct device_node *port_node = of_get_parent(node);
+
+	WARN_ONCE(!port_node, "%s(): endpoint %s has no parent node\n",
+		  __func__, node->full_name);
+
+	memset(endpoint, 0, sizeof(*endpoint));
+
+	endpoint->local_node = node;
+	/*
+	 * It doesn't matter whether the two calls below succeed.
+	 * If they don't then the default value 0 is used.
+	 */
+	of_property_read_u32(port_node, "reg", &endpoint->port);
+	of_property_read_u32(node, "reg", &endpoint->id);
+
+	of_node_put(port_node);
+
+	return 0;
+}
+EXPORT_SYMBOL(of_graph_parse_endpoint);
+
+/**
+ * of_graph_get_port_by_id() - get the port matching a given id
+ * @parent: pointer to the parent device node
+ * @id: id of the port
+ *
+ * Return: A 'port' node pointer with refcount incremented. The caller
+ * has to use of_node_put() on it when done.
+ */
+struct device_node *of_graph_get_port_by_id(struct device_node *parent, u32 id)
+{
+	struct device_node *node, *port;
+
+	node = of_get_child_by_name(parent, "ports");
+	if (node)
+		parent = node;
+
+	for_each_child_of_node(parent, port) {
+		u32 port_id = 0;
+
+		if (of_node_cmp(port->name, "port") != 0)
+			continue;
+		of_property_read_u32(port, "reg", &port_id);
+		if (id == port_id)
+			break;
+	}
+
+	of_node_put(node);
+
+	return port;
+}
+EXPORT_SYMBOL(of_graph_get_port_by_id);
+
+/**
+ * of_graph_get_next_endpoint() - get next endpoint node
+ * @parent: pointer to the parent device node
+ * @prev: previous endpoint node, or NULL to get first
+ *
+ * Return: An 'endpoint' node pointer with refcount incremented. Refcount
+ * of the passed @prev node is decremented.
+ */
+struct device_node *of_graph_get_next_endpoint(const struct device_node *parent,
+					struct device_node *prev)
+{
+	struct device_node *endpoint;
+	struct device_node *port;
+
+	if (!parent)
+		return NULL;
+
+	/*
+	 * Start by locating the port node. If no previous endpoint is specified
+	 * search for the first port node, otherwise get the previous endpoint
+	 * parent port node.
+	 */
+	if (!prev) {
+		struct device_node *node;
+
+		node = of_get_child_by_name(parent, "ports");
+		if (node)
+			parent = node;
+
+		port = of_get_child_by_name(parent, "port");
+		of_node_put(node);
+
+		if (!port) {
+			pr_err("%s(): no port node found in %s\n",
+			       __func__, parent->full_name);
+			return NULL;
+		}
+	} else {
+		port = of_get_parent(prev);
+		if (WARN_ONCE(!port, "%s(): endpoint %s has no parent node\n",
+			      __func__, prev->full_name))
+			return NULL;
+	}
+
+	while (1) {
+		/*
+		 * Now that we have a port node, get the next endpoint by
+		 * getting the next child. If the previous endpoint is NULL this
+		 * will return the first child.
+		 */
+		endpoint = of_get_next_child(port, prev);
+		if (endpoint) {
+			of_node_put(port);
+			return endpoint;
+		}
+
+		/* No more endpoints under this port, try the next one. */
+		prev = NULL;
+
+		do {
+			port = of_get_next_child(parent, port);
+			if (!port)
+				return NULL;
+		} while (of_node_cmp(port->name, "port"));
+	}
+}
+EXPORT_SYMBOL(of_graph_get_next_endpoint);
+
+/**
+ * of_graph_get_remote_port_parent() - get remote port's parent node
+ * @node: pointer to a local endpoint device_node
+ *
+ * Return: Remote device node associated with remote endpoint node linked
+ *	   to @node. Use of_node_put() on it when done.
+ */
+struct device_node *of_graph_get_remote_port_parent(
+			       const struct device_node *node)
+{
+	struct device_node *np;
+	unsigned int depth;
+
+	/* Get remote endpoint node. */
+	np = of_parse_phandle(node, "remote-endpoint", 0);
+
+	/* Walk 3 levels up only if there is 'ports' node. */
+	for (depth = 3; depth && np; depth--) {
+		np = of_get_next_parent(np);
+		if (depth == 2 && of_node_cmp(np->name, "ports"))
+			break;
+	}
+	return np;
+}
+EXPORT_SYMBOL(of_graph_get_remote_port_parent);
+
+/**
+ * of_graph_get_remote_port() - get remote port node
+ * @node: pointer to a local endpoint device_node
+ *
+ * Return: Remote port node associated with remote endpoint node linked
+ *	   to @node. Use of_node_put() on it when done.
+ */
+struct device_node *of_graph_get_remote_port(const struct device_node *node)
+{
+	struct device_node *np;
+
+	/* Get remote endpoint node. */
+	np = of_parse_phandle(node, "remote-endpoint", 0);
+	if (!np)
+		return NULL;
+	return of_get_next_parent(np);
+}
+EXPORT_SYMBOL(of_graph_get_remote_port);