Message ID | 20220118173504.2867523-4-michael@walle.cc |
---|---|
State | Not Applicable, archived |
Headers | show |
Series | of: base: of_parse_phandle() cleanup and new variant | expand |
Context | Check | Description |
---|---|---|
robh/checkpatch | success | |
robh/dtbs-check | success | |
robh/dt-meta-schema | success |
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>
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 *
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(+)