Merge branch 'dt/property-move' of git://git.kernel.org/pub/scm/linux/kernel/git/robh/linux

Pull DT-related device properties changes from Rob Herring.

* 'dt/property-move' of git://git.kernel.org/pub/scm/linux/kernel/git/robh/linux:
  of: Support const and non-const use for to_of_node()
  of: Make of_fwnode_handle() safer
  of: Move OF property and graph API from base.c to property.c

3 files changed, 767 insertions, 734 deletions

diff --git a/drivers/of/Makefile b/drivers/of/Makefile
index d7efd9d..97dc01c 100644
--- a/drivers/of/Makefile
+++ b/drivers/of/Makefile
@@ -1,4 +1,4 @@
-obj-y = base.o device.o platform.o
+obj-y = base.o device.o platform.o property.o
 obj-$(CONFIG_OF_DYNAMIC) += dynamic.o
 obj-$(CONFIG_OF_FLATTREE) += fdt.o
 obj-$(CONFIG_OF_EARLY_FLATTREE) += fdt_address.o
diff --git a/drivers/of/base.c b/drivers/of/base.c
index 28d5f53..9f70464 100644
--- a/drivers/of/base.c
+++ b/drivers/of/base.c
@@ -1113,458 +1113,6 @@ struct device_node *of_find_node_by_phandle(phandle handle)
 }
 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.
- * @min:	minimum allowed length of property value
- * @max:	maximum allowed length of property value (0 means unlimited)
- * @len:	if !=NULL, actual length is written to here
- *
- * 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 is too small or too large.
- *
- */
-static void *of_find_property_value_of_size(const struct device_node *np,
-			const char *propname, u32 min, u32 max, size_t *len)
-{
-	struct property *prop = of_find_property(np, propname, NULL);
-
-	if (!prop)
-		return ERR_PTR(-EINVAL);
-	if (!prop->value)
-		return ERR_PTR(-ENODATA);
-	if (prop->length < min)
-		return ERR_PTR(-EOVERFLOW);
-	if (max && prop->length > max)
-		return ERR_PTR(-EOVERFLOW);
-
-	if (len)
-		*len = prop->length;
-
-	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)),
-					0,
-					NULL);
-
-	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_u64_index - Find and read a u64 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 u64 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 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_index(const struct device_node *np,
-				       const char *propname,
-				       u32 index, u64 *out_value)
-{
-	const u64 *val = of_find_property_value_of_size(np, propname,
-					((index + 1) * sizeof(*out_value)),
-					0, NULL);
-
-	if (IS_ERR(val))
-		return PTR_ERR(val);
-
-	*out_value = be64_to_cpup(((__be64 *)val) + index);
-	return 0;
-}
-EXPORT_SYMBOL_GPL(of_property_read_u64_index);
-
-/**
- * of_property_read_variable_u8_array - Find and read an array of u8 from a
- * property, with bounds on the minimum and maximum array size.
- *
- * @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_min:	minimum number of array elements to read
- * @sz_max:	maximum number of array elements to read, if zero there is no
- *		upper limit on the number of elements in the dts entry but only
- *		sz_min will be read.
- *
- * Search for a property in a device node and read 8-bit value(s) from
- * it. Returns number of elements read on success, -EINVAL if the property
- * does not exist, -ENODATA if property does not have a value, and -EOVERFLOW
- * if the property data is smaller than sz_min or longer than sz_max.
- *
- * 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_variable_u8_array(const struct device_node *np,
-					const char *propname, u8 *out_values,
-					size_t sz_min, size_t sz_max)
-{
-	size_t sz, count;
-	const u8 *val = of_find_property_value_of_size(np, propname,
-						(sz_min * sizeof(*out_values)),
-						(sz_max * sizeof(*out_values)),
-						&sz);
-
-	if (IS_ERR(val))
-		return PTR_ERR(val);
-
-	if (!sz_max)
-		sz = sz_min;
-	else
-		sz /= sizeof(*out_values);
-
-	count = sz;
-	while (count--)
-		*out_values++ = *val++;
-
-	return sz;
-}
-EXPORT_SYMBOL_GPL(of_property_read_variable_u8_array);
-
-/**
- * of_property_read_variable_u16_array - Find and read an array of u16 from a
- * property, with bounds on the minimum and maximum array size.
- *
- * @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_min:	minimum number of array elements to read
- * @sz_max:	maximum number of array elements to read, if zero there is no
- *		upper limit on the number of elements in the dts entry but only
- *		sz_min will be read.
- *
- * Search for a property in a device node and read 16-bit value(s) from
- * it. Returns number of elements read on success, -EINVAL if the property
- * does not exist, -ENODATA if property does not have a value, and -EOVERFLOW
- * if the property data is smaller than sz_min or longer than sz_max.
- *
- * 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_variable_u16_array(const struct device_node *np,
-					const char *propname, u16 *out_values,
-					size_t sz_min, size_t sz_max)
-{
-	size_t sz, count;
-	const __be16 *val = of_find_property_value_of_size(np, propname,
-						(sz_min * sizeof(*out_values)),
-						(sz_max * sizeof(*out_values)),
-						&sz);
-
-	if (IS_ERR(val))
-		return PTR_ERR(val);
-
-	if (!sz_max)
-		sz = sz_min;
-	else
-		sz /= sizeof(*out_values);
-
-	count = sz;
-	while (count--)
-		*out_values++ = be16_to_cpup(val++);
-
-	return sz;
-}
-EXPORT_SYMBOL_GPL(of_property_read_variable_u16_array);
-
-/**
- * of_property_read_variable_u32_array - Find and read an array of 32 bit
- * integers from a property, with bounds on the minimum and maximum array size.
- *
- * @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_min:	minimum number of array elements to read
- * @sz_max:	maximum number of array elements to read, if zero there is no
- *		upper limit on the number of elements in the dts entry but only
- *		sz_min will be read.
- *
- * Search for a property in a device node and read 32-bit value(s) from
- * it. Returns number of elements read on success, -EINVAL if the property
- * does not exist, -ENODATA if property does not have a value, and -EOVERFLOW
- * if the property data is smaller than sz_min or longer than sz_max.
- *
- * The out_values is modified only if a valid u32 value can be decoded.
- */
-int of_property_read_variable_u32_array(const struct device_node *np,
-			       const char *propname, u32 *out_values,
-			       size_t sz_min, size_t sz_max)
-{
-	size_t sz, count;
-	const __be32 *val = of_find_property_value_of_size(np, propname,
-						(sz_min * sizeof(*out_values)),
-						(sz_max * sizeof(*out_values)),
-						&sz);
-
-	if (IS_ERR(val))
-		return PTR_ERR(val);
-
-	if (!sz_max)
-		sz = sz_min;
-	else
-		sz /= sizeof(*out_values);
-
-	count = sz;
-	while (count--)
-		*out_values++ = be32_to_cpup(val++);
-
-	return sz;
-}
-EXPORT_SYMBOL_GPL(of_property_read_variable_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),
-						0,
-						NULL);
-
-	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_variable_u64_array - Find and read an array of 64 bit
- * integers from a property, with bounds on the minimum and maximum array size.
- *
- * @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_min:	minimum number of array elements to read
- * @sz_max:	maximum number of array elements to read, if zero there is no
- *		upper limit on the number of elements in the dts entry but only
- *		sz_min will be read.
- *
- * Search for a property in a device node and read 64-bit value(s) from
- * it. Returns number of elements read on success, -EINVAL if the property
- * does not exist, -ENODATA if property does not have a value, and -EOVERFLOW
- * if the property data is smaller than sz_min or longer than sz_max.
- *
- * The out_values is modified only if a valid u64 value can be decoded.
- */
-int of_property_read_variable_u64_array(const struct device_node *np,
-			       const char *propname, u64 *out_values,
-			       size_t sz_min, size_t sz_max)
-{
-	size_t sz, count;
-	const __be32 *val = of_find_property_value_of_size(np, propname,
-						(sz_min * sizeof(*out_values)),
-						(sz_max * sizeof(*out_values)),
-						&sz);
-
-	if (IS_ERR(val))
-		return PTR_ERR(val);
-
-	if (!sz_max)
-		sz = sz_min;
-	else
-		sz /= sizeof(*out_values);
-
-	count = sz;
-	while (count--) {
-		*out_values++ = of_read_number(val, 2);
-		val += 2;
-	}
-
-	return sz;
-}
-EXPORT_SYMBOL_GPL(of_property_read_variable_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(const struct device_node *np, const char *propname,
-				const char **out_string)
-{
-	const 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(const struct device_node *np, const char *propname,
-			     const char *string)
-{
-	const 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(const struct device_node *np,
-				   const char *propname, const char **out_strs,
-				   size_t sz, int skip)
-{
-	const 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;
@@ -2211,47 +1759,6 @@ int of_alias_get_highest_id(const char *stem)
 }
 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
@@ -2325,243 +1832,3 @@ int of_find_last_cache_level(unsigned int cpu)
 
 	return cache_level;
 }
-
-/**
- * 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("graph: no port node found in %s\n",
-			       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_endpoint_by_regs() - get endpoint node of specific identifiers
- * @parent: pointer to the parent device node
- * @port_reg: identifier (value of reg property) of the parent port node
- * @reg: identifier (value of reg property) of the endpoint node
- *
- * Return: An 'endpoint' node pointer which is identified by reg and at the same
- * is the child of a port node identified by port_reg. reg and port_reg are
- * ignored when they are -1.
- */
-struct device_node *of_graph_get_endpoint_by_regs(
-	const struct device_node *parent, int port_reg, int reg)
-{
-	struct of_endpoint endpoint;
-	struct device_node *node = NULL;
-
-	for_each_endpoint_of_node(parent, node) {
-		of_graph_parse_endpoint(node, &endpoint);
-		if (((port_reg == -1) || (endpoint.port == port_reg)) &&
-			((reg == -1) || (endpoint.id == reg)))
-			return node;
-	}
-
-	return NULL;
-}
-EXPORT_SYMBOL(of_graph_get_endpoint_by_regs);
-
-/**
- * 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);
-
-/**
- * of_graph_get_remote_node() - get remote parent device_node for given port/endpoint
- * @node: pointer to parent device_node containing graph port/endpoint
- * @port: identifier (value of reg property) of the parent port node
- * @endpoint: identifier (value of reg property) of the endpoint 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_node(const struct device_node *node,
-					     u32 port, u32 endpoint)
-{
-	struct device_node *endpoint_node, *remote;
-
-	endpoint_node = of_graph_get_endpoint_by_regs(node, port, endpoint);
-	if (!endpoint_node) {
-		pr_debug("no valid endpoint (%d, %d) for node %s\n",
-			 port, endpoint, node->full_name);
-		return NULL;
-	}
-
-	remote = of_graph_get_remote_port_parent(endpoint_node);
-	of_node_put(endpoint_node);
-	if (!remote) {
-		pr_debug("no valid remote node\n");
-		return NULL;
-	}
-
-	if (!of_device_is_available(remote)) {
-		pr_debug("not available for remote node\n");
-		return NULL;
-	}
-
-	return remote;
-}
-EXPORT_SYMBOL(of_graph_get_remote_node);
diff --git a/drivers/of/property.c b/drivers/of/property.c
new file mode 100644
index 0000000..457c313
--- /dev/null
+++ b/drivers/of/property.c
@@ -0,0 +1,766 @@
+/*
+ * drivers/of/property.c - Procedures for accessing and interpreting
+ *			   Devicetree properties and graphs.
+ *
+ * Initially created by copying procedures from drivers/of/base.c. This
+ * file contains the OF property as well as the OF graph interface
+ * functions.
+ *
+ * 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.
+ */
+
+#define pr_fmt(fmt)	"OF: " fmt
+
+#include <linux/of.h>
+#include <linux/of_device.h>
+#include <linux/of_graph.h>
+#include <linux/string.h>
+
+#include "of_private.h"
+
+/**
+ * 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.
+ * @min:	minimum allowed length of property value
+ * @max:	maximum allowed length of property value (0 means unlimited)
+ * @len:	if !=NULL, actual length is written to here
+ *
+ * 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 is too small or too large.
+ *
+ */
+static void *of_find_property_value_of_size(const struct device_node *np,
+			const char *propname, u32 min, u32 max, size_t *len)
+{
+	struct property *prop = of_find_property(np, propname, NULL);
+
+	if (!prop)
+		return ERR_PTR(-EINVAL);
+	if (!prop->value)
+		return ERR_PTR(-ENODATA);
+	if (prop->length < min)
+		return ERR_PTR(-EOVERFLOW);
+	if (max && prop->length > max)
+		return ERR_PTR(-EOVERFLOW);
+
+	if (len)
+		*len = prop->length;
+
+	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)),
+					0,
+					NULL);
+
+	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_u64_index - Find and read a u64 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 u64 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 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_index(const struct device_node *np,
+				       const char *propname,
+				       u32 index, u64 *out_value)
+{
+	const u64 *val = of_find_property_value_of_size(np, propname,
+					((index + 1) * sizeof(*out_value)),
+					0, NULL);
+
+	if (IS_ERR(val))
+		return PTR_ERR(val);
+
+	*out_value = be64_to_cpup(((__be64 *)val) + index);
+	return 0;
+}
+EXPORT_SYMBOL_GPL(of_property_read_u64_index);
+
+/**
+ * of_property_read_variable_u8_array - Find and read an array of u8 from a
+ * property, with bounds on the minimum and maximum array size.
+ *
+ * @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_min:	minimum number of array elements to read
+ * @sz_max:	maximum number of array elements to read, if zero there is no
+ *		upper limit on the number of elements in the dts entry but only
+ *		sz_min will be read.
+ *
+ * Search for a property in a device node and read 8-bit value(s) from
+ * it. Returns number of elements read on success, -EINVAL if the property
+ * does not exist, -ENODATA if property does not have a value, and -EOVERFLOW
+ * if the property data is smaller than sz_min or longer than sz_max.
+ *
+ * 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_variable_u8_array(const struct device_node *np,
+					const char *propname, u8 *out_values,
+					size_t sz_min, size_t sz_max)
+{
+	size_t sz, count;
+	const u8 *val = of_find_property_value_of_size(np, propname,
+						(sz_min * sizeof(*out_values)),
+						(sz_max * sizeof(*out_values)),
+						&sz);
+
+	if (IS_ERR(val))
+		return PTR_ERR(val);
+
+	if (!sz_max)
+		sz = sz_min;
+	else
+		sz /= sizeof(*out_values);
+
+	count = sz;
+	while (count--)
+		*out_values++ = *val++;
+
+	return sz;
+}
+EXPORT_SYMBOL_GPL(of_property_read_variable_u8_array);
+
+/**
+ * of_property_read_variable_u16_array - Find and read an array of u16 from a
+ * property, with bounds on the minimum and maximum array size.
+ *
+ * @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_min:	minimum number of array elements to read
+ * @sz_max:	maximum number of array elements to read, if zero there is no
+ *		upper limit on the number of elements in the dts entry but only
+ *		sz_min will be read.
+ *
+ * Search for a property in a device node and read 16-bit value(s) from
+ * it. Returns number of elements read on success, -EINVAL if the property
+ * does not exist, -ENODATA if property does not have a value, and -EOVERFLOW
+ * if the property data is smaller than sz_min or longer than sz_max.
+ *
+ * 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_variable_u16_array(const struct device_node *np,
+					const char *propname, u16 *out_values,
+					size_t sz_min, size_t sz_max)
+{
+	size_t sz, count;
+	const __be16 *val = of_find_property_value_of_size(np, propname,
+						(sz_min * sizeof(*out_values)),
+						(sz_max * sizeof(*out_values)),
+						&sz);
+
+	if (IS_ERR(val))
+		return PTR_ERR(val);
+
+	if (!sz_max)
+		sz = sz_min;
+	else
+		sz /= sizeof(*out_values);
+
+	count = sz;
+	while (count--)
+		*out_values++ = be16_to_cpup(val++);
+
+	return sz;
+}
+EXPORT_SYMBOL_GPL(of_property_read_variable_u16_array);
+
+/**
+ * of_property_read_variable_u32_array - Find and read an array of 32 bit
+ * integers from a property, with bounds on the minimum and maximum array size.
+ *
+ * @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_min:	minimum number of array elements to read
+ * @sz_max:	maximum number of array elements to read, if zero there is no
+ *		upper limit on the number of elements in the dts entry but only
+ *		sz_min will be read.
+ *
+ * Search for a property in a device node and read 32-bit value(s) from
+ * it. Returns number of elements read on success, -EINVAL if the property
+ * does not exist, -ENODATA if property does not have a value, and -EOVERFLOW
+ * if the property data is smaller than sz_min or longer than sz_max.
+ *
+ * The out_values is modified only if a valid u32 value can be decoded.
+ */
+int of_property_read_variable_u32_array(const struct device_node *np,
+			       const char *propname, u32 *out_values,
+			       size_t sz_min, size_t sz_max)
+{
+	size_t sz, count;
+	const __be32 *val = of_find_property_value_of_size(np, propname,
+						(sz_min * sizeof(*out_values)),
+						(sz_max * sizeof(*out_values)),
+						&sz);
+
+	if (IS_ERR(val))
+		return PTR_ERR(val);
+
+	if (!sz_max)
+		sz = sz_min;
+	else
+		sz /= sizeof(*out_values);
+
+	count = sz;
+	while (count--)
+		*out_values++ = be32_to_cpup(val++);
+
+	return sz;
+}
+EXPORT_SYMBOL_GPL(of_property_read_variable_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),
+						0,
+						NULL);
+
+	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_variable_u64_array - Find and read an array of 64 bit
+ * integers from a property, with bounds on the minimum and maximum array size.
+ *
+ * @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_min:	minimum number of array elements to read
+ * @sz_max:	maximum number of array elements to read, if zero there is no
+ *		upper limit on the number of elements in the dts entry but only
+ *		sz_min will be read.
+ *
+ * Search for a property in a device node and read 64-bit value(s) from
+ * it. Returns number of elements read on success, -EINVAL if the property
+ * does not exist, -ENODATA if property does not have a value, and -EOVERFLOW
+ * if the property data is smaller than sz_min or longer than sz_max.
+ *
+ * The out_values is modified only if a valid u64 value can be decoded.
+ */
+int of_property_read_variable_u64_array(const struct device_node *np,
+			       const char *propname, u64 *out_values,
+			       size_t sz_min, size_t sz_max)
+{
+	size_t sz, count;
+	const __be32 *val = of_find_property_value_of_size(np, propname,
+						(sz_min * sizeof(*out_values)),
+						(sz_max * sizeof(*out_values)),
+						&sz);
+
+	if (IS_ERR(val))
+		return PTR_ERR(val);
+
+	if (!sz_max)
+		sz = sz_min;
+	else
+		sz /= sizeof(*out_values);
+
+	count = sz;
+	while (count--) {
+		*out_values++ = of_read_number(val, 2);
+		val += 2;
+	}
+
+	return sz;
+}
+EXPORT_SYMBOL_GPL(of_property_read_variable_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(const struct device_node *np, const char *propname,
+				const char **out_string)
+{
+	const 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(const struct device_node *np, const char *propname,
+			     const char *string)
+{
+	const 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(const struct device_node *np,
+				   const char *propname, const char **out_strs,
+				   size_t sz, int skip)
+{
+	const 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);
+
+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_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("graph: no port node found in %s\n",
+			       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_endpoint_by_regs() - get endpoint node of specific identifiers
+ * @parent: pointer to the parent device node
+ * @port_reg: identifier (value of reg property) of the parent port node
+ * @reg: identifier (value of reg property) of the endpoint node
+ *
+ * Return: An 'endpoint' node pointer which is identified by reg and at the same
+ * is the child of a port node identified by port_reg. reg and port_reg are
+ * ignored when they are -1.
+ */
+struct device_node *of_graph_get_endpoint_by_regs(
+	const struct device_node *parent, int port_reg, int reg)
+{
+	struct of_endpoint endpoint;
+	struct device_node *node = NULL;
+
+	for_each_endpoint_of_node(parent, node) {
+		of_graph_parse_endpoint(node, &endpoint);
+		if (((port_reg == -1) || (endpoint.port == port_reg)) &&
+			((reg == -1) || (endpoint.id == reg)))
+			return node;
+	}
+
+	return NULL;
+}
+EXPORT_SYMBOL(of_graph_get_endpoint_by_regs);
+
+/**
+ * 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);
+
+/**
+ * of_graph_get_remote_node() - get remote parent device_node for given port/endpoint
+ * @node: pointer to parent device_node containing graph port/endpoint
+ * @port: identifier (value of reg property) of the parent port node
+ * @endpoint: identifier (value of reg property) of the endpoint 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_node(const struct device_node *node,
+					     u32 port, u32 endpoint)
+{
+	struct device_node *endpoint_node, *remote;
+
+	endpoint_node = of_graph_get_endpoint_by_regs(node, port, endpoint);
+	if (!endpoint_node) {
+		pr_debug("no valid endpoint (%d, %d) for node %s\n",
+			 port, endpoint, node->full_name);
+		return NULL;
+	}
+
+	remote = of_graph_get_remote_port_parent(endpoint_node);
+	of_node_put(endpoint_node);
+	if (!remote) {
+		pr_debug("no valid remote node\n");
+		return NULL;
+	}
+
+	if (!of_device_is_available(remote)) {
+		pr_debug("not available for remote node\n");
+		return NULL;
+	}
+
+	return remote;
+}
+EXPORT_SYMBOL(of_graph_get_remote_node);