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>

1 files changed, 18 insertions, 0 deletions

diff --git a/include/dm/of_access.h b/include/dm/of_access.h
index c5ea391aec..c49d287dd6 100644
--- a/include/dm/of_access.h
+++ b/include/dm/of_access.h
@@ -353,6 +353,24 @@ int of_parse_phandle_with_args(const struct device_node *np,
 			       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
  *
  * The function scans all the properties of the 'aliases' node and populates