Adding upstream version 6.1.76.upstream/6.1.76upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 2208 insertions, 0 deletions

diff --git a/drivers/of/base.c b/drivers/of/base.c
new file mode 100644
index 000000000..f849bbb9e
--- /dev/null
+++ b/drivers/of/base.c
@@ -0,0 +1,2208 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * 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.
+ */
+
+#define pr_fmt(fmt)	"OF: " fmt
+
+#include <linux/console.h>
+#include <linux/ctype.h>
+#include <linux/cpu.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_device.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;
+EXPORT_SYMBOL(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);
+
+bool of_node_name_eq(const struct device_node *np, const char *name)
+{
+	const char *node_name;
+	size_t len;
+
+	if (!np)
+		return false;
+
+	node_name = kbasename(np->full_name);
+	len = strchrnul(node_name, '@') - node_name;
+
+	return (strlen(name) == len) && (strncmp(node_name, name, len) == 0);
+}
+EXPORT_SYMBOL(of_node_name_eq);
+
+bool of_node_name_prefix(const struct device_node *np, const char *prefix)
+{
+	if (!np)
+		return false;
+
+	return strncmp(kbasename(np->full_name), prefix, strlen(prefix)) == 0;
+}
+EXPORT_SYMBOL(of_node_name_prefix);
+
+static bool __of_node_is_type(const struct device_node *np, const char *type)
+{
+	const char *match = __of_get_property(np, "device_type", NULL);
+
+	return np && match && type && !strcmp(match, type);
+}
+
+int of_bus_n_addr_cells(struct device_node *np)
+{
+	u32 cells;
+
+	for (; np; np = np->parent)
+		if (!of_property_read_u32(np, "#address-cells", &cells))
+			return cells;
+
+	/* No #address-cells property for the root node */
+	return OF_ROOT_NODE_ADDR_CELLS_DEFAULT;
+}
+
+int of_n_addr_cells(struct device_node *np)
+{
+	if (np->parent)
+		np = np->parent;
+
+	return of_bus_n_addr_cells(np);
+}
+EXPORT_SYMBOL(of_n_addr_cells);
+
+int of_bus_n_size_cells(struct device_node *np)
+{
+	u32 cells;
+
+	for (; np; np = np->parent)
+		if (!of_property_read_u32(np, "#size-cells", &cells))
+			return cells;
+
+	/* No #size-cells property for the root node */
+	return OF_ROOT_NODE_SIZE_CELLS_DEFAULT;
+}
+
+int of_n_size_cells(struct device_node *np)
+{
+	if (np->parent)
+		np = np->parent;
+
+	return of_bus_n_size_cells(np);
+}
+EXPORT_SYMBOL(of_n_size_cells);
+
+#ifdef CONFIG_NUMA
+int __weak of_node_to_nid(struct device_node *np)
+{
+	return NUMA_NO_NODE;
+}
+#endif
+
+#define OF_PHANDLE_CACHE_BITS	7
+#define OF_PHANDLE_CACHE_SZ	BIT(OF_PHANDLE_CACHE_BITS)
+
+static struct device_node *phandle_cache[OF_PHANDLE_CACHE_SZ];
+
+static u32 of_phandle_cache_hash(phandle handle)
+{
+	return hash_32(handle, OF_PHANDLE_CACHE_BITS);
+}
+
+/*
+ * Caller must hold devtree_lock.
+ */
+void __of_phandle_cache_inv_entry(phandle handle)
+{
+	u32 handle_hash;
+	struct device_node *np;
+
+	if (!handle)
+		return;
+
+	handle_hash = of_phandle_cache_hash(handle);
+
+	np = phandle_cache[handle_hash];
+	if (np && handle == np->phandle)
+		phandle_cache[handle_hash] = NULL;
+}
+
+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("failed to register existing nodes\n");
+		return;
+	}
+	for_each_of_allnodes(np) {
+		__of_attach_node_sysfs(np);
+		if (np->phandle && !phandle_cache[of_phandle_cache_hash(np->phandle)])
+			phandle_cache[of_phandle_cache_hash(np->phandle)] = 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
+ *
+ * Return: 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);
+
+/**
+ * of_get_cpu_hwid - Get the hardware ID from a CPU device node
+ *
+ * @cpun: CPU number(logical index) for which device node is required
+ * @thread: The local thread number to get the hardware ID for.
+ *
+ * Return: The hardware ID for the CPU node or ~0ULL if not found.
+ */
+u64 of_get_cpu_hwid(struct device_node *cpun, unsigned int thread)
+{
+	const __be32 *cell;
+	int ac, len;
+
+	ac = of_n_addr_cells(cpun);
+	cell = of_get_property(cpun, "reg", &len);
+	if (!cell || !ac || ((sizeof(*cell) * ac * (thread + 1)) > len))
+		return ~0ULL;
+
+	cell += ac * thread;
+	return of_read_number(cell, ac);
+}
+
+/*
+ * 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 && arch_match_cpu_phys_id(cpu, 0))
+		return true;
+	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;
+
+	return __of_find_n_match_cpu_property(cpun, "reg", cpu, thread);
+}
+
+/**
+ * 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.
+ *
+ * Return: A node pointer for the logical cpu with refcount incremented, use
+ * of_node_put() on it when done. Returns NULL if not found.
+ */
+struct device_node *of_get_cpu_node(int cpu, unsigned int *thread)
+{
+	struct device_node *cpun;
+
+	for_each_of_cpu_node(cpun) {
+		if (arch_find_n_match_cpu_physical_id(cpun, cpu, thread))
+			return cpun;
+	}
+	return NULL;
+}
+EXPORT_SYMBOL(of_get_cpu_node);
+
+/**
+ * of_cpu_node_to_id: Get the logical CPU number for a given device_node
+ *
+ * @cpu_node: Pointer to the device_node for CPU.
+ *
+ * Return: The logical CPU number of the given CPU device_node or -ENODEV if the
+ * CPU is not found.
+ */
+int of_cpu_node_to_id(struct device_node *cpu_node)
+{
+	int cpu;
+	bool found = false;
+	struct device_node *np;
+
+	for_each_possible_cpu(cpu) {
+		np = of_cpu_device_node_get(cpu);
+		found = (cpu_node == np);
+		of_node_put(np);
+		if (found)
+			return cpu;
+	}
+
+	return -ENODEV;
+}
+EXPORT_SYMBOL(of_cpu_node_to_id);
+
+/**
+ * of_get_cpu_state_node - Get CPU's idle state node at the given index
+ *
+ * @cpu_node: The device node for the CPU
+ * @index: The index in the list of the idle states
+ *
+ * Two generic methods can be used to describe a CPU's idle states, either via
+ * a flattened description through the "cpu-idle-states" binding or via the
+ * hierarchical layout, using the "power-domains" and the "domain-idle-states"
+ * bindings. This function check for both and returns the idle state node for
+ * the requested index.
+ *
+ * Return: An idle state node if found at @index. The refcount is incremented
+ * for it, so call of_node_put() on it when done. Returns NULL if not found.
+ */
+struct device_node *of_get_cpu_state_node(struct device_node *cpu_node,
+					  int index)
+{
+	struct of_phandle_args args;
+	int err;
+
+	err = of_parse_phandle_with_args(cpu_node, "power-domains",
+					"#power-domain-cells", 0, &args);
+	if (!err) {
+		struct device_node *state_node =
+			of_parse_phandle(args.np, "domain-idle-states", index);
+
+		of_node_put(args.np);
+		if (state_node)
+			return state_node;
+	}
+
+	return of_parse_phandle(cpu_node, "cpu-idle-states", index);
+}
+EXPORT_SYMBOL(of_get_cpu_state_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 (!__of_node_is_type(device, type))
+			return 0;
+		score += 2;
+	}
+
+	/* Matching name is a bit better than not */
+	if (name && name[0]) {
+		if (!of_node_name_eq(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);
+
+/** Checks if the device is compatible with any of the entries in
+ *  a NULL terminated array of strings. Returns the best match
+ *  score or 0.
+ */
+int of_device_compatible_match(const struct device_node *device,
+			       const char *const *compat)
+{
+	unsigned int tmp, score = 0;
+
+	if (!compat)
+		return 0;
+
+	while (*compat) {
+		tmp = of_device_is_compatible(device, *compat);
+		if (tmp > score)
+			score = tmp;
+		compat++;
+	}
+
+	return score;
+}
+EXPORT_SYMBOL_GPL(of_device_compatible_match);
+
+/**
+ * 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.
+ *
+ * Return: 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
+ *
+ *  Return: 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
+ *
+ *  Return: 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_fail - check if a device has status "fail" or "fail-..."
+ *
+ *  @device: Node to check status for, with locks already held
+ *
+ *  Return: True if the status property is set to "fail" or "fail-..." (for any
+ *  error code suffix), false otherwise
+ */
+static bool __of_device_is_fail(const struct device_node *device)
+{
+	const char *status;
+
+	if (!device)
+		return false;
+
+	status = __of_get_property(device, "status", NULL);
+	if (status == NULL)
+		return false;
+
+	return !strcmp(status, "fail") || !strncmp(status, "fail-", 5);
+}
+
+/**
+ *  of_device_is_big_endian - check if a device has BE registers
+ *
+ *  @device: Node to check for endianness
+ *
+ *  Return: 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
+ *
+ * Return: 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.
+ *
+ * Return: 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;
+	of_node_get(next);
+	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
+ *
+ * Return: 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_next_cpu_node - Iterate on cpu nodes
+ * @prev:	previous child of the /cpus node, or NULL to get first
+ *
+ * Unusable CPUs (those with the status property set to "fail" or "fail-...")
+ * will be skipped.
+ *
+ * Return: A cpu 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_cpu_node(struct device_node *prev)
+{
+	struct device_node *next = NULL;
+	unsigned long flags;
+	struct device_node *node;
+
+	if (!prev)
+		node = of_find_node_by_path("/cpus");
+
+	raw_spin_lock_irqsave(&devtree_lock, flags);
+	if (prev)
+		next = prev->sibling;
+	else if (node) {
+		next = node->child;
+		of_node_put(node);
+	}
+	for (; next; next = next->sibling) {
+		if (__of_device_is_fail(next))
+			continue;
+		if (!(of_node_name_eq(next, "cpu") ||
+		      __of_node_is_type(next, "cpu")))
+			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_cpu_node);
+
+/**
+ * of_get_compatible_child - Find compatible child node
+ * @parent:	parent node
+ * @compatible:	compatible string
+ *
+ * Lookup child node whose compatible property contains the given compatible
+ * string.
+ *
+ * Return: a node pointer with refcount incremented, use of_node_put() on it
+ * when done; or NULL if not found.
+ */
+struct device_node *of_get_compatible_child(const struct device_node *parent,
+				const char *compatible)
+{
+	struct device_node *child;
+
+	for_each_child_of_node(parent, child) {
+		if (of_device_is_compatible(child, compatible))
+			break;
+	}
+
+	return child;
+}
+EXPORT_SYMBOL(of_get_compatible_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
+ *
+ * Return: 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 (of_node_name_eq(child, name))
+			break;
+	return child;
+}
+EXPORT_SYMBOL(of_get_child_by_name);
+
+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 = kbasename(child->full_name);
+		if (strncmp(path, name, len) == 0 && (strlen(name) == len))
+			return child;
+	}
+	return NULL;
+}
+
+struct device_node *__of_find_node_by_full_path(struct device_node *node,
+						const char *path)
+{
+	const char *separator = strchr(path, ':');
+
+	while (node && *path == '/') {
+		struct device_node *tmp = node;
+
+		path++; /* Increment past '/' delimiter */
+		node = __of_find_node_by_path(node, path);
+		of_node_put(tmp);
+		path = strchrnul(path, '/');
+		if (separator && separator < path)
+			break;
+	}
+	return node;
+}
+
+/**
+ * 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
+ *
+ * Return: 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);
+	np = __of_find_node_by_full_path(np, path);
+	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 @from.
+ * @name:	The name string to match against
+ *
+ * Return: 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 (of_node_name_eq(np, name) && 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
+ *
+ * Return: 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 (__of_node_is_type(np, type) && 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.
+ *
+ * Return: 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.
+ *
+ * Return: 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
+ *
+ * Return: 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.
+ *
+ * Return: 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, ',');
+	strscpy(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
+ *
+ * Return: 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 = NULL;
+	unsigned long flags;
+	u32 handle_hash;
+
+	if (!handle)
+		return NULL;
+
+	handle_hash = of_phandle_cache_hash(handle);
+
+	raw_spin_lock_irqsave(&devtree_lock, flags);
+
+	if (phandle_cache[handle_hash] &&
+	    handle == phandle_cache[handle_hash]->phandle)
+		np = phandle_cache[handle_hash];
+
+	if (!np) {
+		for_each_of_allnodes(np)
+			if (np->phandle == handle &&
+			    !of_node_check_flag(np, OF_DETACHED)) {
+				phandle_cache[handle_hash] = np;
+				break;
+			}
+	}
+
+	of_node_get(np);
+	raw_spin_unlock_irqrestore(&devtree_lock, flags);
+	return np;
+}
+EXPORT_SYMBOL(of_find_node_by_phandle);
+
+void of_print_phandle_args(const char *msg, const struct of_phandle_args *args)
+{
+	int i;
+	printk("%s %pOF", msg, args->np);
+	for (i = 0; i < args->args_count; i++) {
+		const char delim = i ? ',' : ':';
+
+		pr_cont("%c%08x", delim, args->args[i]);
+	}
+	pr_cont("\n");
+}
+
+int of_phandle_iterator_init(struct of_phandle_iterator *it,
+		const struct device_node *np,
+		const char *list_name,
+		const char *cells_name,
+		int cell_count)
+{
+	const __be32 *list;
+	int size;
+
+	memset(it, 0, sizeof(*it));
+
+	/*
+	 * one of cell_count or cells_name must be provided to determine the
+	 * argument length.
+	 */
+	if (cell_count < 0 && !cells_name)
+		return -EINVAL;
+
+	list = of_get_property(np, list_name, &size);
+	if (!list)
+		return -ENOENT;
+
+	it->cells_name = cells_name;
+	it->cell_count = cell_count;
+	it->parent = np;
+	it->list_end = list + size / sizeof(*list);
+	it->phandle_end = list;
+	it->cur = list;
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(of_phandle_iterator_init);
+
+int of_phandle_iterator_next(struct of_phandle_iterator *it)
+{
+	uint32_t count = 0;
+
+	if (it->node) {
+		of_node_put(it->node);
+		it->node = NULL;
+	}
+
+	if (!it->cur || it->phandle_end >= it->list_end)
+		return -ENOENT;
+
+	it->cur = it->phandle_end;
+
+	/* If phandle is 0, then it is an empty entry with no arguments. */
+	it->phandle = be32_to_cpup(it->cur++);
+
+	if (it->phandle) {
+
+		/*
+		 * Find the provider node and parse the #*-cells property to
+		 * determine the argument length.
+		 */
+		it->node = of_find_node_by_phandle(it->phandle);
+
+		if (it->cells_name) {
+			if (!it->node) {
+				pr_err("%pOF: could not find phandle %d\n",
+				       it->parent, it->phandle);
+				goto err;
+			}
+
+			if (of_property_read_u32(it->node, it->cells_name,
+						 &count)) {
+				/*
+				 * If both cell_count and cells_name is given,
+				 * fall back to cell_count in absence
+				 * of the cells_name property
+				 */
+				if (it->cell_count >= 0) {
+					count = it->cell_count;
+				} else {
+					pr_err("%pOF: could not get %s for %pOF\n",
+					       it->parent,
+					       it->cells_name,
+					       it->node);
+					goto err;
+				}
+			}
+		} else {
+			count = it->cell_count;
+		}
+
+		/*
+		 * Make sure that the arguments actually fit in the remaining
+		 * property data length
+		 */
+		if (it->cur + count > it->list_end) {
+			if (it->cells_name)
+				pr_err("%pOF: %s = %d found %td\n",
+					it->parent, it->cells_name,
+					count, it->list_end - it->cur);
+			else
+				pr_err("%pOF: phandle %s needs %d, found %td\n",
+					it->parent, of_node_full_name(it->node),
+					count, it->list_end - it->cur);
+			goto err;
+		}
+	}
+
+	it->phandle_end = it->cur + count;
+	it->cur_count = count;
+
+	return 0;
+
+err:
+	if (it->node) {
+		of_node_put(it->node);
+		it->node = NULL;
+	}
+
+	return -EINVAL;
+}
+EXPORT_SYMBOL_GPL(of_phandle_iterator_next);
+
+int of_phandle_iterator_args(struct of_phandle_iterator *it,
+			     uint32_t *args,
+			     int size)
+{
+	int i, count;
+
+	count = it->cur_count;
+
+	if (WARN_ON(size < count))
+		count = size;
+
+	for (i = 0; i < count; i++)
+		args[i] = be32_to_cpup(it->cur++);
+
+	return count;
+}
+
+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)
+{
+	struct of_phandle_iterator it;
+	int rc, cur_index = 0;
+
+	if (index < 0)
+		return -EINVAL;
+
+	/* Loop over the phandles until all the requested entry is found */
+	of_for_each_phandle(&it, rc, np, list_name, cells_name, cell_count) {
+		/*
+		 * All of the error cases 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 (!it.phandle)
+				goto err;
+
+			if (out_args) {
+				int c;
+
+				c = of_phandle_iterator_args(&it,
+							     out_args->args,
+							     MAX_PHANDLE_ARGS);
+				out_args->np = it.node;
+				out_args->args_count = c;
+			} else {
+				of_node_put(it.node);
+			}
+
+			/* Found it! return success */
+			return 0;
+		}
+
+		cur_index++;
+	}
+
+	/*
+	 * Unlock node before returning result; will be one of:
+	 * -ENOENT : index is for empty phandle
+	 * -EINVAL : parsing error on data
+	 */
+
+ err:
+	of_node_put(it.node);
+	return rc;
+}
+EXPORT_SYMBOL(__of_parse_phandle_with_args);
+
+/**
+ * of_parse_phandle_with_args_map() - Find a node pointed by phandle in a list and remap it
+ * @np:		pointer to a device tree node containing a list
+ * @list_name:	property name that contains a list
+ * @stem_name:	stem of property names that specify 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. The difference between this function and of_parse_phandle_with_args()
+ * is that this API remaps a phandle if the node the phandle points to has
+ * a <@stem_name>-map property.
+ *
+ * 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>;
+ *  };
+ *
+ *  phandle3: node3 {
+ *  	#list-cells = <1>;
+ *  	list-map = <0 &phandle2 3>,
+ *  		   <1 &phandle2 2>,
+ *  		   <2 &phandle1 5 1>;
+ *  	list-map-mask = <0x3>;
+ *  };
+ *
+ *  node4 {
+ *  	list = <&phandle1 1 2 &phandle3 0>;
+ *  };
+ *
+ * To get a device_node of the ``node2`` node you may call this:
+ * of_parse_phandle_with_args(node4, "list", "list", 1, &args);
+ */
+int of_parse_phandle_with_args_map(const struct device_node *np,
+				   const char *list_name,
+				   const char *stem_name,
+				   int index, struct of_phandle_args *out_args)
+{
+	char *cells_name, *map_name = NULL, *mask_name = NULL;
+	char *pass_name = NULL;
+	struct device_node *cur, *new = NULL;
+	const __be32 *map, *mask, *pass;
+	static const __be32 dummy_mask[] = { [0 ... MAX_PHANDLE_ARGS] = ~0 };
+	static const __be32 dummy_pass[] = { [0 ... MAX_PHANDLE_ARGS] = 0 };
+	__be32 initial_match_array[MAX_PHANDLE_ARGS];
+	const __be32 *match_array = initial_match_array;
+	int i, ret, map_len, match;
+	u32 list_size, new_size;
+
+	if (index < 0)
+		return -EINVAL;
+
+	cells_name = kasprintf(GFP_KERNEL, "#%s-cells", stem_name);
+	if (!cells_name)
+		return -ENOMEM;
+
+	ret = -ENOMEM;
+	map_name = kasprintf(GFP_KERNEL, "%s-map", stem_name);
+	if (!map_name)
+		goto free;
+
+	mask_name = kasprintf(GFP_KERNEL, "%s-map-mask", stem_name);
+	if (!mask_name)
+		goto free;
+
+	pass_name = kasprintf(GFP_KERNEL, "%s-map-pass-thru", stem_name);
+	if (!pass_name)
+		goto free;
+
+	ret = __of_parse_phandle_with_args(np, list_name, cells_name, -1, index,
+					   out_args);
+	if (ret)
+		goto free;
+
+	/* Get the #<list>-cells property */
+	cur = out_args->np;
+	ret = of_property_read_u32(cur, cells_name, &list_size);
+	if (ret < 0)
+		goto put;
+
+	/* Precalculate the match array - this simplifies match loop */
+	for (i = 0; i < list_size; i++)
+		initial_match_array[i] = cpu_to_be32(out_args->args[i]);
+
+	ret = -EINVAL;
+	while (cur) {
+		/* Get the <list>-map property */
+		map = of_get_property(cur, map_name, &map_len);
+		if (!map) {
+			ret = 0;
+			goto free;
+		}
+		map_len /= sizeof(u32);
+
+		/* Get the <list>-map-mask property (optional) */
+		mask = of_get_property(cur, mask_name, NULL);
+		if (!mask)
+			mask = dummy_mask;
+		/* Iterate through <list>-map property */
+		match = 0;
+		while (map_len > (list_size + 1) && !match) {
+			/* Compare specifiers */
+			match = 1;
+			for (i = 0; i < list_size; i++, map_len--)
+				match &= !((match_array[i] ^ *map++) & mask[i]);
+
+			of_node_put(new);
+			new = of_find_node_by_phandle(be32_to_cpup(map));
+			map++;
+			map_len--;
+
+			/* Check if not found */
+			if (!new)
+				goto put;
+
+			if (!of_device_is_available(new))
+				match = 0;
+
+			ret = of_property_read_u32(new, cells_name, &new_size);
+			if (ret)
+				goto put;
+
+			/* Check for malformed properties */
+			if (WARN_ON(new_size > MAX_PHANDLE_ARGS))
+				goto put;
+			if (map_len < new_size)
+				goto put;
+
+			/* Move forward by new node's #<list>-cells amount */
+			map += new_size;
+			map_len -= new_size;
+		}
+		if (!match)
+			goto put;
+
+		/* Get the <list>-map-pass-thru property (optional) */
+		pass = of_get_property(cur, pass_name, NULL);
+		if (!pass)
+			pass = dummy_pass;
+
+		/*
+		 * Successfully parsed a <list>-map translation; copy new
+		 * specifier into the out_args structure, keeping the
+		 * bits specified in <list>-map-pass-thru.
+		 */
+		match_array = map - new_size;
+		for (i = 0; i < new_size; i++) {
+			__be32 val = *(map - new_size + i);
+
+			if (i < list_size) {
+				val &= ~pass[i];
+				val |= cpu_to_be32(out_args->args[i]) & pass[i];
+			}
+
+			out_args->args[i] = be32_to_cpu(val);
+		}
+		out_args->args_count = list_size = new_size;
+		/* Iterate again with new provider */
+		out_args->np = new;
+		of_node_put(cur);
+		cur = new;
+		new = NULL;
+	}
+put:
+	of_node_put(cur);
+	of_node_put(new);
+free:
+	kfree(mask_name);
+	kfree(map_name);
+	kfree(cells_name);
+	kfree(pass_name);
+
+	return ret;
+}
+EXPORT_SYMBOL(of_parse_phandle_with_args_map);
+
+/**
+ * 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
+ *
+ * Return: 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)
+{
+	struct of_phandle_iterator it;
+	int rc, cur_index = 0;
+
+	/*
+	 * If cells_name is NULL we assume a cell count of 0. This makes
+	 * counting the phandles trivial as each 32bit word in the list is a
+	 * phandle and no arguments are to consider. So we don't iterate through
+	 * the list but just use the length to determine the phandle count.
+	 */
+	if (!cells_name) {
+		const __be32 *list;
+		int size;
+
+		list = of_get_property(np, list_name, &size);
+		if (!list)
+			return -ENOENT;
+
+		return size / sizeof(*list);
+	}
+
+	rc = of_phandle_iterator_init(&it, np, list_name, cells_name, -1);
+	if (rc)
+		return rc;
+
+	while ((rc = of_phandle_iterator_next(&it)) == 0)
+		cur_index += 1;
+
+	if (rc != -ENOENT)
+		return rc;
+
+	return cur_index;
+}
+EXPORT_SYMBOL(of_count_phandle_with_args);
+
+/**
+ * __of_add_property - Add a property to a node without lock operations
+ * @np:		Caller's Device Node
+ * @prop:	Property to add
+ */
+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
+ * @np:		Caller's Device Node
+ * @prop:	Property to add
+ */
+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;
+}
+EXPORT_SYMBOL_GPL(of_add_property);
+
+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;
+}
+
+/**
+ * of_remove_property - Remove a property from a node.
+ * @np:		Caller's Device Node
+ * @prop:	Property to remove
+ *
+ * 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;
+
+	if (!prop)
+		return -ENODEV;
+
+	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;
+}
+EXPORT_SYMBOL_GPL(of_remove_property);
+
+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;
+}
+
+/*
+ * 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=%pOF\n",
+		 ap->alias, ap->stem, ap->id, np);
+}
+
+/**
+ * of_alias_scan - Scan all properties of the 'aliases' node
+ * @dt_alloc:	An allocator that provides a virtual address to memory
+ *		for storing the resulting tree
+ *
+ * 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.
+ */
+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 = NULL;
+
+		if (of_property_read_string(of_chosen, "stdout-path", &name))
+			of_property_read_string(of_chosen, "linux,stdout-path",
+						&name);
+		if (IS_ENABLED(CONFIG_PPC) && !name)
+			of_property_read_string(of_aliases, "stdout", &name);
+		if (name)
+			of_stdout = of_find_node_opts_by_path(name, &of_stdout_options);
+		if (of_stdout)
+			of_stdout->fwnode.flags |= FWNODE_FLAG_BEST_EFFORT;
+	}
+
+	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, __alignof__(*ap));
+		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.
+ *
+ * Return: 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);
+
+/**
+ * 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.
+ *
+ * Return: TRUE if console successfully setup. 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;
+
+	/*
+	 * XXX: cast `options' to char pointer to suppress complication
+	 * warnings: printk, UART and console drivers expect char pointer.
+	 */
+	return !add_preferred_console(name, index, (char *)of_stdout_options);
+}
+EXPORT_SYMBOL_GPL(of_console_check);
+
+/**
+ * of_find_next_cache_node - Find a node's subsidiary cache
+ * @np:	node of type "cpu" or "cache"
+ *
+ * Return: 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, *cache_node;
+
+	cache_node = of_parse_phandle(np, "l2-cache", 0);
+	if (!cache_node)
+		cache_node = of_parse_phandle(np, "next-level-cache", 0);
+
+	if (cache_node)
+		return cache_node;
+
+	/* OF on pmac has nodes instead of properties named "l2-cache"
+	 * beneath CPU nodes.
+	 */
+	if (IS_ENABLED(CONFIG_PPC_PMAC) && of_node_is_type(np, "cpu"))
+		for_each_child_of_node(np, child)
+			if (of_node_is_type(child, "cache"))
+				return child;
+
+	return NULL;
+}
+
+/**
+ * of_find_last_cache_level - Find the level at which the last cache is
+ * 		present for the given logical cpu
+ *
+ * @cpu: cpu number(logical index) for which the last cache level is needed
+ *
+ * Return: The level at which the last cache is present. It is exactly
+ * same as  the total number of cache levels for the given logical cpu.
+ */
+int of_find_last_cache_level(unsigned int cpu)
+{
+	u32 cache_level = 0;
+	struct device_node *prev = NULL, *np = of_cpu_device_node_get(cpu);
+
+	while (np) {
+		of_node_put(prev);
+		prev = np;
+		np = of_find_next_cache_node(np);
+	}
+
+	of_property_read_u32(prev, "cache-level", &cache_level);
+	of_node_put(prev);
+
+	return cache_level;
+}
+
+/**
+ * of_map_id - Translate an ID through a downstream mapping.
+ * @np: root complex device node.
+ * @id: device ID to map.
+ * @map_name: property name of the map to use.
+ * @map_mask_name: optional property name of the mask to use.
+ * @target: optional pointer to a target device node.
+ * @id_out: optional pointer to receive the translated ID.
+ *
+ * Given a device ID, look up the appropriate implementation-defined
+ * platform ID and/or the target device which receives transactions on that
+ * ID, as per the "iommu-map" and "msi-map" bindings. Either of @target or
+ * @id_out may be NULL if only the other is required. If @target points to
+ * a non-NULL device node pointer, only entries targeting that node will be
+ * matched; if it points to a NULL value, it will receive the device node of
+ * the first matching target phandle, with a reference held.
+ *
+ * Return: 0 on success or a standard error code on failure.
+ */
+int of_map_id(struct device_node *np, u32 id,
+	       const char *map_name, const char *map_mask_name,
+	       struct device_node **target, u32 *id_out)
+{
+	u32 map_mask, masked_id;
+	int map_len;
+	const __be32 *map = NULL;
+
+	if (!np || !map_name || (!target && !id_out))
+		return -EINVAL;
+
+	map = of_get_property(np, map_name, &map_len);
+	if (!map) {
+		if (target)
+			return -ENODEV;
+		/* Otherwise, no map implies no translation */
+		*id_out = id;
+		return 0;
+	}
+
+	if (!map_len || map_len % (4 * sizeof(*map))) {
+		pr_err("%pOF: Error: Bad %s length: %d\n", np,
+			map_name, map_len);
+		return -EINVAL;
+	}
+
+	/* The default is to select all bits. */
+	map_mask = 0xffffffff;
+
+	/*
+	 * Can be overridden by "{iommu,msi}-map-mask" property.
+	 * If of_property_read_u32() fails, the default is used.
+	 */
+	if (map_mask_name)
+		of_property_read_u32(np, map_mask_name, &map_mask);
+
+	masked_id = map_mask & id;
+	for ( ; map_len > 0; map_len -= 4 * sizeof(*map), map += 4) {
+		struct device_node *phandle_node;
+		u32 id_base = be32_to_cpup(map + 0);
+		u32 phandle = be32_to_cpup(map + 1);
+		u32 out_base = be32_to_cpup(map + 2);
+		u32 id_len = be32_to_cpup(map + 3);
+
+		if (id_base & ~map_mask) {
+			pr_err("%pOF: Invalid %s translation - %s-mask (0x%x) ignores id-base (0x%x)\n",
+				np, map_name, map_name,
+				map_mask, id_base);
+			return -EFAULT;
+		}
+
+		if (masked_id < id_base || masked_id >= id_base + id_len)
+			continue;
+
+		phandle_node = of_find_node_by_phandle(phandle);
+		if (!phandle_node)
+			return -ENODEV;
+
+		if (target) {
+			if (*target)
+				of_node_put(phandle_node);
+			else
+				*target = phandle_node;
+
+			if (*target != phandle_node)
+				continue;
+		}
+
+		if (id_out)
+			*id_out = masked_id - id_base + out_base;
+
+		pr_debug("%pOF: %s, using mask %08x, id-base: %08x, out-base: %08x, length: %08x, id: %08x -> %08x\n",
+			np, map_name, map_mask, id_base, out_base,
+			id_len, id, masked_id - id_base + out_base);
+		return 0;
+	}
+
+	pr_info("%pOF: no %s translation for id 0x%x on %pOF\n", np, map_name,
+		id, target && *target ? *target : NULL);
+
+	/* Bypasses translation */
+	if (id_out)
+		*id_out = id;
+	return 0;
+}
+EXPORT_SYMBOL_GPL(of_map_id);