[PATCH v3 0/3] of: base: of_parse_phandle() cleanup and new variant

[PATCH v3 0/3] of: base: of_parse_phandle() cleanup and new variant

[Michael Walle]

Convert the smaller variants of of_parse_phandle() to static inline.

It will also introduce a new variant of the function, although it is unused
for now. They will be needed when nvmem phandles are modified to take
additional arguments and need to retain backwards compatibility with older
device trees.

Finally, define of_property_read_u{8,16,32,64}_array() unconditionally,
these are the last ones, which were defined static inline and had an empty
stub if CONFIG_OF wasn't set.

Michael Walle (3):
  of: base: make small of_parse_phandle() variants static inline
  of: property: define of_property_read_u{8,16,32,64}_array()
    unconditionally
  of: base: add of_parse_phandle_with_optional_args()

 drivers/of/base.c  | 128 +------------
 include/linux/of.h | 456 +++++++++++++++++++++++++++------------------
 2 files changed, 284 insertions(+), 300 deletions(-)

-- 
2.30.2

[PATCH v3 1/3] of: base: make small of_parse_phandle() variants static inline

[Michael Walle]

Make all the smaller variants of the of_parse_phandle() static inline.
This also let us remove the empty function stubs if CONFIG_OF is not
defined.

Suggested-by: Rob Herring <robh@kernel.org>
Signed-off-by: Michael Walle <michael@walle.cc>
---
changes since v3:
 - rebased due to now signed index parameter

changes since v2:
 - new patch

 drivers/of/base.c  | 128 ++----------------------------------
 include/linux/of.h | 157 +++++++++++++++++++++++++++++++++++++--------
 2 files changed, 135 insertions(+), 150 deletions(-)

diff --git a/drivers/of/base.c b/drivers/of/base.c
index 8a24d37153b4..b108600b8296 100644
--- a/drivers/of/base.c
+++ b/drivers/of/base.c
@@ -1420,11 +1420,11 @@ int of_phandle_iterator_args(struct of_phandle_iterator *it,
 	return count;
 }
 
-static int __of_parse_phandle_with_args(const struct device_node *np,
-					const char *list_name,
-					const char *cells_name,
-					int cell_count, int index,
-					struct of_phandle_args *out_args)
+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;
@@ -1471,82 +1471,7 @@ static int __of_parse_phandle_with_args(const struct device_node *np,
 	of_node_put(it.node);
 	return rc;
 }
-
-/**
- * of_parse_phandle - Resolve a phandle property to a device_node pointer
- * @np: Pointer to device node holding phandle property
- * @phandle_name: Name of property holding a phandle value
- * @index: For properties holding a table of phandles, this is the index into
- *         the table
- *
- * Return: The device_node pointer with refcount incremented.  Use
- * of_node_put() on it when done.
- */
-struct device_node *of_parse_phandle(const struct device_node *np,
-				     const char *phandle_name, int index)
-{
-	struct of_phandle_args args;
-
-	if (index < 0)
-		return NULL;
-
-	if (__of_parse_phandle_with_args(np, phandle_name, NULL, 0,
-					 index, &args))
-		return NULL;
-
-	return args.np;
-}
-EXPORT_SYMBOL(of_parse_phandle);
-
-/**
- * of_parse_phandle_with_args() - Find a node pointed by phandle in a list
- * @np:		pointer to a device tree node containing a list
- * @list_name:	property name that contains a list
- * @cells_name:	property name that specifies phandles' arguments count
- * @index:	index of a phandle to parse out
- * @out_args:	optional pointer to output arguments structure (will be filled)
- *
- * This function is useful to parse lists of phandles and their arguments.
- * Returns 0 on success and fills out_args, on error returns appropriate
- * errno value.
- *
- * Caller is responsible to call of_node_put() on the returned out_args->np
- * pointer.
- *
- * Example::
- *
- *  phandle1: node1 {
- *	#list-cells = <2>;
- *  };
- *
- *  phandle2: node2 {
- *	#list-cells = <1>;
- *  };
- *
- *  node3 {
- *	list = <&phandle1 1 2 &phandle2 3>;
- *  };
- *
- * To get a device_node of the ``node2`` node you may call this:
- * of_parse_phandle_with_args(node3, "list", "#list-cells", 1, &args);
- */
-int of_parse_phandle_with_args(const struct device_node *np, const char *list_name,
-				const char *cells_name, int index,
-				struct of_phandle_args *out_args)
-{
-	int cell_count = -1;
-
-	if (index < 0)
-		return -EINVAL;
-
-	/* If cells_name is NULL we assume a cell count of 0 */
-	if (!cells_name)
-		cell_count = 0;
-
-	return __of_parse_phandle_with_args(np, list_name, cells_name,
-					    cell_count, index, out_args);
-}
-EXPORT_SYMBOL(of_parse_phandle_with_args);
+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
@@ -1732,47 +1657,6 @@ int of_parse_phandle_with_args_map(const struct device_node *np,
 }
 EXPORT_SYMBOL(of_parse_phandle_with_args_map);
 
-/**
- * of_parse_phandle_with_fixed_args() - Find a node pointed by phandle in a list
- * @np:		pointer to a device tree node containing a list
- * @list_name:	property name that contains a list
- * @cell_count: number of argument cells following the phandle
- * @index:	index of a phandle to parse out
- * @out_args:	optional pointer to output arguments structure (will be filled)
- *
- * This function is useful to parse lists of phandles and their arguments.
- * Returns 0 on success and fills out_args, on error returns appropriate
- * errno value.
- *
- * Caller is responsible to call of_node_put() on the returned out_args->np
- * pointer.
- *
- * Example::
- *
- *  phandle1: node1 {
- *  };
- *
- *  phandle2: node2 {
- *  };
- *
- *  node3 {
- *  	list = <&phandle1 0 2 &phandle2 2 3>;
- *  };
- *
- * To get a device_node of the ``node2`` node you may call this:
- * of_parse_phandle_with_fixed_args(node3, "list", 2, 1, &args);
- */
-int of_parse_phandle_with_fixed_args(const struct device_node *np,
-				const char *list_name, int cell_count,
-				int index, struct of_phandle_args *out_args)
-{
-	if (index < 0)
-		return -EINVAL;
-	return __of_parse_phandle_with_args(np, list_name, NULL, cell_count,
-					   index, out_args);
-}
-EXPORT_SYMBOL(of_parse_phandle_with_fixed_args);
-
 /**
  * of_count_phandle_with_args() - Find the number of phandles references in a property
  * @np:		pointer to a device tree node containing a list
diff --git a/include/linux/of.h b/include/linux/of.h
index ff143a027abc..9106eced1ee1 100644
--- a/include/linux/of.h
+++ b/include/linux/of.h
@@ -364,18 +364,12 @@ extern const struct of_device_id *of_match_node(
 	const struct of_device_id *matches, const struct device_node *node);
 extern int of_modalias_node(struct device_node *node, char *modalias, int len);
 extern void of_print_phandle_args(const char *msg, const struct of_phandle_args *args);
-extern struct device_node *of_parse_phandle(const struct device_node *np,
-					    const char *phandle_name,
-					    int index);
-extern int of_parse_phandle_with_args(const struct device_node *np,
-	const char *list_name, const char *cells_name, int index,
-	struct of_phandle_args *out_args);
+extern 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);
 extern 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);
-extern int of_parse_phandle_with_fixed_args(const struct device_node *np,
-	const char *list_name, int cells_count, int index,
-	struct of_phandle_args *out_args);
 extern int of_count_phandle_with_args(const struct device_node *np,
 	const char *list_name, const char *cells_name);
 
@@ -865,18 +859,12 @@ static inline int of_property_read_string_helper(const struct device_node *np,
 	return -ENOSYS;
 }
 
-static inline struct device_node *of_parse_phandle(const struct device_node *np,
-						   const char *phandle_name,
-						   int index)
-{
-	return NULL;
-}
-
-static inline int of_parse_phandle_with_args(const struct device_node *np,
-					     const char *list_name,
-					     const char *cells_name,
-					     int index,
-					     struct of_phandle_args *out_args)
+static inline 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)
 {
 	return -ENOSYS;
 }
@@ -890,13 +878,6 @@ static inline int of_parse_phandle_with_args_map(const struct device_node *np,
 	return -ENOSYS;
 }
 
-static inline int of_parse_phandle_with_fixed_args(const struct device_node *np,
-	const char *list_name, int cells_count, int index,
-	struct of_phandle_args *out_args)
-{
-	return -ENOSYS;
-}
-
 static inline int of_count_phandle_with_args(const struct device_node *np,
 					     const char *list_name,
 					     const char *cells_name)
@@ -1077,6 +1058,126 @@ static inline bool of_node_is_type(const struct device_node *np, const char *typ
 	return np && match && type && !strcmp(match, type);
 }
 
+/**
+ * of_parse_phandle - Resolve a phandle property to a device_node pointer
+ * @np: Pointer to device node holding phandle property
+ * @phandle_name: Name of property holding a phandle value
+ * @index: For properties holding a table of phandles, this is the index into
+ *         the table
+ *
+ * Return: The device_node pointer with refcount incremented.  Use
+ * of_node_put() on it when done.
+ */
+static inline struct device_node *of_parse_phandle(const struct device_node *np,
+						   const char *phandle_name,
+						   int index)
+{
+	struct of_phandle_args args;
+
+	if (index < 0)
+		return NULL;
+
+	if (__of_parse_phandle_with_args(np, phandle_name, NULL, 0,
+					 index, &args))
+		return NULL;
+
+	return args.np;
+}
+
+/**
+ * of_parse_phandle_with_args() - Find a node pointed by phandle in a list
+ * @np:		pointer to a device tree node containing a list
+ * @list_name:	property name that contains a list
+ * @cells_name:	property name that specifies phandles' arguments count
+ * @index:	index of a phandle to parse out
+ * @out_args:	optional pointer to output arguments structure (will be filled)
+ *
+ * This function is useful to parse lists of phandles and their arguments.
+ * Returns 0 on success and fills out_args, on error returns appropriate
+ * errno value.
+ *
+ * Caller is responsible to call of_node_put() on the returned out_args->np
+ * pointer.
+ *
+ * Example::
+ *
+ *  phandle1: node1 {
+ *	#list-cells = <2>;
+ *  };
+ *
+ *  phandle2: node2 {
+ *	#list-cells = <1>;
+ *  };
+ *
+ *  node3 {
+ *	list = <&phandle1 1 2 &phandle2 3>;
+ *  };
+ *
+ * To get a device_node of the ``node2`` node you may call this:
+ * of_parse_phandle_with_args(node3, "list", "#list-cells", 1, &args);
+ */
+static inline int of_parse_phandle_with_args(const struct device_node *np,
+					     const char *list_name,
+					     const char *cells_name,
+					     int index,
+					     struct of_phandle_args *out_args)
+{
+	int cell_count = -1;
+
+	if (index < 0)
+		return -EINVAL;
+
+	/* If cells_name is NULL we assume a cell count of 0 */
+	if (!cells_name)
+		cell_count = 0;
+
+	return __of_parse_phandle_with_args(np, list_name, cells_name,
+					    cell_count, index, out_args);
+}
+
+/**
+ * of_parse_phandle_with_fixed_args() - Find a node pointed by phandle in a list
+ * @np:		pointer to a device tree node containing a list
+ * @list_name:	property name that contains a list
+ * @cell_count: number of argument cells following the phandle
+ * @index:	index of a phandle to parse out
+ * @out_args:	optional pointer to output arguments structure (will be filled)
+ *
+ * This function is useful to parse lists of phandles and their arguments.
+ * Returns 0 on success and fills out_args, on error returns appropriate
+ * errno value.
+ *
+ * Caller is responsible to call of_node_put() on the returned out_args->np
+ * pointer.
+ *
+ * Example::
+ *
+ *  phandle1: node1 {
+ *  };
+ *
+ *  phandle2: node2 {
+ *  };
+ *
+ *  node3 {
+ *	list = <&phandle1 0 2 &phandle2 2 3>;
+ *  };
+ *
+ * To get a device_node of the ``node2`` node you may call this:
+ * of_parse_phandle_with_fixed_args(node3, "list", 2, 1, &args);
+ */
+static inline int of_parse_phandle_with_fixed_args(const struct device_node *np,
+						   const char *list_name,
+						   int cell_count,
+						   int index,
+						   struct of_phandle_args *out_args)
+{
+	if (index < 0)
+		return -EINVAL;
+
+	return __of_parse_phandle_with_args(np, list_name, NULL, cell_count,
+					    index, out_args);
+}
+
 /**
  * of_property_count_u8_elems - Count the number of u8 elements in a property
  *
-- 
2.30.2

Re: [PATCH v3 1/3] of: base: make small of_parse_phandle() variants static inline

[Rob Herring]

On Tue, 18 Jan 2022 18:35:02 +0100, Michael Walle wrote:
> Make all the smaller variants of the of_parse_phandle() static inline.
> This also let us remove the empty function stubs if CONFIG_OF is not
> defined.
> 
> Suggested-by: Rob Herring <robh@kernel.org>
> Signed-off-by: Michael Walle <michael@walle.cc>
> ---
> changes since v3:
>  - rebased due to now signed index parameter
> 
> changes since v2:
>  - new patch
> 
>  drivers/of/base.c  | 128 ++----------------------------------
>  include/linux/of.h | 157 +++++++++++++++++++++++++++++++++++++--------
>  2 files changed, 135 insertions(+), 150 deletions(-)
> 

I moved the index < 0 checks into __of_parse_phandle_with_args 
and applied, thanks!

[PATCH v3 2/3] of: property: define of_property_read_u{8,16,32,64}_array() unconditionally

[Michael Walle]

We can get rid of all the empty stubs because all these functions call
of_property_read_variable_u{8,16,32,64}_array() which already have an
empty stub if CONFIG_OF is not defined.

Signed-off-by: Michael Walle <michael@walle.cc>
---
changes since v2:
 - none

changes since v1:
 - new patch

 include/linux/of.h | 274 ++++++++++++++++++++-------------------------
 1 file changed, 124 insertions(+), 150 deletions(-)

diff --git a/include/linux/of.h b/include/linux/of.h
index 9106eced1ee1..c64af2efbc3a 100644
--- a/include/linux/of.h
+++ b/include/linux/of.h
@@ -410,130 +410,6 @@ extern int of_detach_node(struct device_node *);
 
 #define of_match_ptr(_ptr)	(_ptr)
 
-/**
- * of_property_read_u8_array - Find and read an array of u8 from a property.
- *
- * @np:		device node from which the property value is to be read.
- * @propname:	name of the property to be searched.
- * @out_values:	pointer to return value, modified only if return value is 0.
- * @sz:		number of array elements to read
- *
- * Search for a property in a device node and read 8-bit value(s) from
- * it.
- *
- * dts entry of array should be like:
- *  ``property = /bits/ 8 <0x50 0x60 0x70>;``
- *
- * Return: 0 on success, -EINVAL if the property does not exist,
- * -ENODATA if property does not have a value, and -EOVERFLOW if the
- * property data isn't large enough.
- *
- * The out_values is modified only if a valid u8 value can be decoded.
- */
-static inline int of_property_read_u8_array(const struct device_node *np,
-					    const char *propname,
-					    u8 *out_values, size_t sz)
-{
-	int ret = of_property_read_variable_u8_array(np, propname, out_values,
-						     sz, 0);
-	if (ret >= 0)
-		return 0;
-	else
-		return ret;
-}
-
-/**
- * of_property_read_u16_array - Find and read an array of u16 from a property.
- *
- * @np:		device node from which the property value is to be read.
- * @propname:	name of the property to be searched.
- * @out_values:	pointer to return value, modified only if return value is 0.
- * @sz:		number of array elements to read
- *
- * Search for a property in a device node and read 16-bit value(s) from
- * it.
- *
- * dts entry of array should be like:
- *  ``property = /bits/ 16 <0x5000 0x6000 0x7000>;``
- *
- * Return: 0 on success, -EINVAL if the property does not exist,
- * -ENODATA if property does not have a value, and -EOVERFLOW if the
- * property data isn't large enough.
- *
- * The out_values is modified only if a valid u16 value can be decoded.
- */
-static inline int of_property_read_u16_array(const struct device_node *np,
-					     const char *propname,
-					     u16 *out_values, size_t sz)
-{
-	int ret = of_property_read_variable_u16_array(np, propname, out_values,
-						      sz, 0);
-	if (ret >= 0)
-		return 0;
-	else
-		return ret;
-}
-
-/**
- * of_property_read_u32_array - Find and read an array of 32 bit integers
- * from a property.
- *
- * @np:		device node from which the property value is to be read.
- * @propname:	name of the property to be searched.
- * @out_values:	pointer to return value, modified only if return value is 0.
- * @sz:		number of array elements to read
- *
- * Search for a property in a device node and read 32-bit value(s) from
- * it.
- *
- * Return: 0 on success, -EINVAL if the property does not exist,
- * -ENODATA if property does not have a value, and -EOVERFLOW if the
- * property data isn't large enough.
- *
- * The out_values is modified only if a valid u32 value can be decoded.
- */
-static inline int of_property_read_u32_array(const struct device_node *np,
-					     const char *propname,
-					     u32 *out_values, size_t sz)
-{
-	int ret = of_property_read_variable_u32_array(np, propname, out_values,
-						      sz, 0);
-	if (ret >= 0)
-		return 0;
-	else
-		return ret;
-}
-
-/**
- * of_property_read_u64_array - Find and read an array of 64 bit integers
- * from a property.
- *
- * @np:		device node from which the property value is to be read.
- * @propname:	name of the property to be searched.
- * @out_values:	pointer to return value, modified only if return value is 0.
- * @sz:		number of array elements to read
- *
- * Search for a property in a device node and read 64-bit value(s) from
- * it.
- *
- * Return: 0 on success, -EINVAL if the property does not exist,
- * -ENODATA if property does not have a value, and -EOVERFLOW if the
- * property data isn't large enough.
- *
- * The out_values is modified only if a valid u64 value can be decoded.
- */
-static inline int of_property_read_u64_array(const struct device_node *np,
-					     const char *propname,
-					     u64 *out_values, size_t sz)
-{
-	int ret = of_property_read_variable_u64_array(np, propname, out_values,
-						      sz, 0);
-	if (ret >= 0)
-		return 0;
-	else
-		return ret;
-}
-
 /*
  * struct property *prop;
  * const __be32 *p;
@@ -728,32 +604,6 @@ static inline int of_property_count_elems_of_size(const struct device_node *np,
 	return -ENOSYS;
 }
 
-static inline int of_property_read_u8_array(const struct device_node *np,
-			const char *propname, u8 *out_values, size_t sz)
-{
-	return -ENOSYS;
-}
-
-static inline int of_property_read_u16_array(const struct device_node *np,
-			const char *propname, u16 *out_values, size_t sz)
-{
-	return -ENOSYS;
-}
-
-static inline int of_property_read_u32_array(const struct device_node *np,
-					     const char *propname,
-					     u32 *out_values, size_t sz)
-{
-	return -ENOSYS;
-}
-
-static inline int of_property_read_u64_array(const struct device_node *np,
-					     const char *propname,
-					     u64 *out_values, size_t sz)
-{
-	return -ENOSYS;
-}
-
 static inline int of_property_read_u32_index(const struct device_node *np,
 			const char *propname, u32 index, u32 *out_value)
 {
@@ -1337,6 +1187,130 @@ static inline bool of_property_read_bool(const struct device_node *np,
 	return prop ? true : false;
 }
 
+/**
+ * of_property_read_u8_array - Find and read an array of u8 from a property.
+ *
+ * @np:		device node from which the property value is to be read.
+ * @propname:	name of the property to be searched.
+ * @out_values:	pointer to return value, modified only if return value is 0.
+ * @sz:		number of array elements to read
+ *
+ * Search for a property in a device node and read 8-bit value(s) from
+ * it.
+ *
+ * dts entry of array should be like:
+ *  ``property = /bits/ 8 <0x50 0x60 0x70>;``
+ *
+ * Return: 0 on success, -EINVAL if the property does not exist,
+ * -ENODATA if property does not have a value, and -EOVERFLOW if the
+ * property data isn't large enough.
+ *
+ * The out_values is modified only if a valid u8 value can be decoded.
+ */
+static inline int of_property_read_u8_array(const struct device_node *np,
+					    const char *propname,
+					    u8 *out_values, size_t sz)
+{
+	int ret = of_property_read_variable_u8_array(np, propname, out_values,
+						     sz, 0);
+	if (ret >= 0)
+		return 0;
+	else
+		return ret;
+}
+
+/**
+ * of_property_read_u16_array - Find and read an array of u16 from a property.
+ *
+ * @np:		device node from which the property value is to be read.
+ * @propname:	name of the property to be searched.
+ * @out_values:	pointer to return value, modified only if return value is 0.
+ * @sz:		number of array elements to read
+ *
+ * Search for a property in a device node and read 16-bit value(s) from
+ * it.
+ *
+ * dts entry of array should be like:
+ *  ``property = /bits/ 16 <0x5000 0x6000 0x7000>;``
+ *
+ * Return: 0 on success, -EINVAL if the property does not exist,
+ * -ENODATA if property does not have a value, and -EOVERFLOW if the
+ * property data isn't large enough.
+ *
+ * The out_values is modified only if a valid u16 value can be decoded.
+ */
+static inline int of_property_read_u16_array(const struct device_node *np,
+					     const char *propname,
+					     u16 *out_values, size_t sz)
+{
+	int ret = of_property_read_variable_u16_array(np, propname, out_values,
+						      sz, 0);
+	if (ret >= 0)
+		return 0;
+	else
+		return ret;
+}
+
+/**
+ * of_property_read_u32_array - Find and read an array of 32 bit integers
+ * from a property.
+ *
+ * @np:		device node from which the property value is to be read.
+ * @propname:	name of the property to be searched.
+ * @out_values:	pointer to return value, modified only if return value is 0.
+ * @sz:		number of array elements to read
+ *
+ * Search for a property in a device node and read 32-bit value(s) from
+ * it.
+ *
+ * Return: 0 on success, -EINVAL if the property does not exist,
+ * -ENODATA if property does not have a value, and -EOVERFLOW if the
+ * property data isn't large enough.
+ *
+ * The out_values is modified only if a valid u32 value can be decoded.
+ */
+static inline int of_property_read_u32_array(const struct device_node *np,
+					     const char *propname,
+					     u32 *out_values, size_t sz)
+{
+	int ret = of_property_read_variable_u32_array(np, propname, out_values,
+						      sz, 0);
+	if (ret >= 0)
+		return 0;
+	else
+		return ret;
+}
+
+/**
+ * of_property_read_u64_array - Find and read an array of 64 bit integers
+ * from a property.
+ *
+ * @np:		device node from which the property value is to be read.
+ * @propname:	name of the property to be searched.
+ * @out_values:	pointer to return value, modified only if return value is 0.
+ * @sz:		number of array elements to read
+ *
+ * Search for a property in a device node and read 64-bit value(s) from
+ * it.
+ *
+ * Return: 0 on success, -EINVAL if the property does not exist,
+ * -ENODATA if property does not have a value, and -EOVERFLOW if the
+ * property data isn't large enough.
+ *
+ * The out_values is modified only if a valid u64 value can be decoded.
+ */
+static inline int of_property_read_u64_array(const struct device_node *np,
+					     const char *propname,
+					     u64 *out_values, size_t sz)
+{
+	int ret = of_property_read_variable_u64_array(np, propname, out_values,
+						      sz, 0);
+	if (ret >= 0)
+		return 0;
+	else
+		return ret;
+}
+
 static inline int of_property_read_u8(const struct device_node *np,
 				       const char *propname,
 				       u8 *out_value)
-- 
2.30.2

Re: [PATCH v3 2/3] of: property: define of_property_read_u{8,16,32,64}_array() unconditionally

[Rob Herring]

On Tue, 18 Jan 2022 18:35:03 +0100, Michael Walle wrote:
> We can get rid of all the empty stubs because all these functions call
> of_property_read_variable_u{8,16,32,64}_array() which already have an
> empty stub if CONFIG_OF is not defined.
> 
> Signed-off-by: Michael Walle <michael@walle.cc>
> ---
> changes since v2:
>  - none
> 
> changes since v1:
>  - new patch
> 
>  include/linux/of.h | 274 ++++++++++++++++++++-------------------------
>  1 file changed, 124 insertions(+), 150 deletions(-)
> 

Applied, thanks!

[PATCH v3 3/3] of: base: add of_parse_phandle_with_optional_args()

[Michael Walle]

Add a new variant of the of_parse_phandle_with_args() which treats the
cells name as optional. If it's missing, it is assumed that the phandle
has no arguments.

Up until now, a nvmem node didn't have any arguments, so all the device
trees haven't any '#*-cells' property. But there is a need for an
additional argument for the phandle, for which we need a '#*-cells'
property. Therefore, we need to support nvmem nodes with and without
this property.

Signed-off-by: Michael Walle <michael@walle.cc>
---
changes since v2:
 - make index signed
 - add missing function parameter doc

changes since v1:
 - new patch

 include/linux/of.h | 25 +++++++++++++++++++++++++
 1 file changed, 25 insertions(+)

diff --git a/include/linux/of.h b/include/linux/of.h
index c64af2efbc3a..a0880c43d435 100644
--- a/include/linux/of.h
+++ b/include/linux/of.h
@@ -1028,6 +1028,31 @@ static inline int of_parse_phandle_with_fixed_args(const struct device_node *np,
 					    index, out_args);
 }
 
+/**
+ * of_parse_phandle_with_optional_args() - Find a node pointed by phandle in a list
+ * @np:		pointer to a device tree node containing a list
+ * @list_name:	property name that contains a list
+ * @cells_name:	property name that specifies phandles' arguments count
+ * @index:	index of a phandle to parse out
+ * @out_args:	optional pointer to output arguments structure (will be filled)
+ *
+ * Same as of_parse_phandle_with_args() except that if the cells_name property
+ * is not found, cell_count of 0 is assumed.
+ *
+ * This is used to useful, if you have a phandle which didn't have arguments
+ * before and thus doesn't have a '#*-cells' property but is now migrated to
+ * having arguments while retaining backwards compatibility.
+ */
+static inline int of_parse_phandle_with_optional_args(const struct device_node *np,
+						      const char *list_name,
+						      const char *cells_name,
+						      int index,
+						      struct of_phandle_args *out_args)
+{
+	return __of_parse_phandle_with_args(np, list_name, cells_name,
+					    0, index, out_args);
+}
+
 /**
  * of_property_count_u8_elems - Count the number of u8 elements in a property
  *
-- 
2.30.2

Re: [PATCH v3 3/3] of: base: add of_parse_phandle_with_optional_args()

[Rob Herring]

On Tue, 18 Jan 2022 18:35:04 +0100, Michael Walle wrote:
> Add a new variant of the of_parse_phandle_with_args() which treats the
> cells name as optional. If it's missing, it is assumed that the phandle
> has no arguments.
> 
> Up until now, a nvmem node didn't have any arguments, so all the device
> trees haven't any '#*-cells' property. But there is a need for an
> additional argument for the phandle, for which we need a '#*-cells'
> property. Therefore, we need to support nvmem nodes with and without
> this property.
> 
> Signed-off-by: Michael Walle <michael@walle.cc>
> ---
> changes since v2:
>  - make index signed
>  - add missing function parameter doc
> 
> changes since v1:
>  - new patch
> 
>  include/linux/of.h | 25 +++++++++++++++++++++++++
>  1 file changed, 25 insertions(+)
> 

Reviewed-by: Rob Herring <robh@kernel.org>