Commit c5d264d4 authored by Michael Walle's avatar Michael Walle Committed by Greg Kroah-Hartman
Browse files

of: base: add of_parse_phandle_with_optional_args() 



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: default avatarMichael Walle <michael@walle.cc>
Reviewed-by: default avatarRob Herring <robh@kernel.org>
Signed-off-by: default avatarSrinivas Kandagatla <srinivas.kandagatla@linaro.org>
Link: https://lore.kernel.org/r/20230206134356.839737-10-srinivas.kandagatla@linaro.org


Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 7390609b

include/linux/of.h

+25 −0
Original line number Diff line number Diff line
@@ -1008,6 +1008,31 @@ 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

 *