dm: core: add ofnode_count_phandle_with_args()

This function is usefull to get phandle number contained
in a property list.
For example,  this allows to allocate the right amount
of memory to keep clock's reference contained into the
"clocks" property.

To implement it, either of_count_phandle_with_args() or
fdtdec_parse_phandle_with_args() are used respectively
for live tree and flat tree.
By passing index = -1, these 2 functions returns the
number of phandle contained into the property list.

Add also the dev_count_phandle_with_args() based on
ofnode_count_phandle_with_args()

Signed-off-by: Patrice Chotard <patrice.chotard@st.com>
Reviewed-by: Simon Glass <sjg@chromium.org>

drivers/core/of_access.c

@@ -665,6 +665,13 @@ int of_parse_phandle_with_args(const struct device_node *np,
 					    index, out_args);
 }
 
+int of_count_phandle_with_args(const struct device_node *np,
+			       const char *list_name, const char *cells_name)
+{
+	return __of_parse_phandle_with_args(np, list_name, cells_name, 0,
+					    -1, NULL);
+}
+
 static void of_alias_add(struct alias_prop *ap, struct device_node *np,
 			 int id, const char *stem, int stem_len)
 {

drivers/core/ofnode.c

@@ -313,6 +313,18 @@ int ofnode_parse_phandle_with_args(ofnode node, const char *list_name,
 	return 0;
 }
 
+int ofnode_count_phandle_with_args(ofnode node, const char *list_name,
+				   const char *cells_name)
+{
+	if (ofnode_is_np(node))
+		return of_count_phandle_with_args(ofnode_to_np(node),
+				list_name, cells_name);
+	else
+		return fdtdec_parse_phandle_with_args(gd->fdt_blob,
+				ofnode_to_offset(node), list_name, cells_name,
+				0, -1, NULL);
+}
+
 ofnode ofnode_path(const char *path)
 {
 	if (of_live_active())

include/dm/of_access.h

@@ -352,6 +352,24 @@ 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);
 
+/**
+ * of_count_phandle_with_args() - Count the number of 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
+ * @return number of phandle found, -ENOENT if
+ *	@list_name does not exist, -EINVAL if a phandle was not found,
+ *	@cells_name could not be found, the arguments were truncated or there
+ *	were too many arguments.
+ *
+ * Returns number of phandle found on success, on error returns appropriate
+ * errno value.
+ *
+ */
+int of_count_phandle_with_args(const struct device_node *np,
+			       const char *list_name, const char *cells_name);
+
 /**
  * of_alias_scan() - Scan all properties of the 'aliases' node
  *

include/dm/ofnode.h

@@ -432,6 +432,23 @@ int ofnode_parse_phandle_with_args(ofnode node, const char *list_name,
 				   int index,
 				   struct ofnode_phandle_args *out_args);
 
+/**
+ * ofnode_count_phandle_with_args() - Count number of phandle in a list
+ *
+ * This function is useful to count phandles into a list.
+ * Returns number of phandle on success, on error returns appropriate
+ * errno value.
+ *
+ * @node:	device tree node containing a list
+ * @list_name:	property name that contains a list
+ * @cells_name:	property name that specifies phandles' arguments count
+ * @return number of phandle on success, -ENOENT if @list_name does not
+ *      exist, -EINVAL if a phandle was not found, @cells_name could not
+ *      be found.
+ */
+int ofnode_count_phandle_with_args(ofnode node, const char *list_name,
+				   const char *cells_name);
+
 /**
  * ofnode_path() - find a node by full path
  *

include/dm/read.h

@@ -208,6 +208,24 @@ int dev_read_phandle_with_args(struct udevice *dev, const char *list_name,
 				int index,
 				struct ofnode_phandle_args *out_args);
 
+/**
+ * dev_count_phandle_with_args() - Return phandle number in a list
+ *
+ * This function is usefull to get phandle number contained in a property list.
+ * For example, this allows to allocate the right amount of memory to keep
+ * clock's reference contained into the "clocks" property.
+ *
+ *
+ * @dev:	device whose node containing a list
+ * @list_name:	property name that contains a list
+ * @cells_name:	property name that specifies phandles' arguments count
+ * @Returns number of phandle found on success, on error returns appropriate
+ * errno value.
+ */
+
+int dev_count_phandle_with_args(struct udevice *dev, const char *list_name,
+				const char *cells_name);
+
 /**
  * dev_read_addr_cells() - Get the number of address cells for a device's node
  *
@@ -416,6 +434,13 @@ static inline int dev_read_phandle_with_args(struct udevice *dev,
 					      out_args);
 }
 
+static inline int dev_count_phandle_with_args(struct udevice *dev,
+		const char *list_name, const char *cells_name)
+{
+	return ofnode_count_phandle_with_args(dev_ofnode(dev), list_name,
+					      cells_name);
+}
+
 static inline int dev_read_addr_cells(struct udevice *dev)
 {
 	/* NOTE: this call should walk up the parent stack */