device property: Add fwnode_property_match_string()

Sometimes it is useful to be able to extract an index of certain string
value from an array of strings. A typical use case is to give a name to a
DMA channel, PWM, clock and so on.

Provide an implementation using unified device property accessors that
follows of_property_match_string() but works for all supported fwnodes.

Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

1 files changed, 4 insertions, 0 deletions

diff --git a/include/linux/property.h b/include/linux/property.h
index a59c6ee566c2..463de52fe891 100644
--- a/include/linux/property.h
+++ b/include/linux/property.h
@@ -40,6 +40,8 @@ int device_property_read_string_array(struct device *dev, const char *propname,
                                       const char **val, size_t nval);
 int device_property_read_string(struct device *dev, const char *propname,
                                 const char **val);
+int device_property_match_string(struct device *dev,
+                                 const char *propname, const char *string);
 
 bool fwnode_property_present(struct fwnode_handle *fwnode, const char *propname);
 int fwnode_property_read_u8_array(struct fwnode_handle *fwnode,
@@ -59,6 +61,8 @@ int fwnode_property_read_string_array(struct fwnode_handle *fwnode,
                                       size_t nval);
 int fwnode_property_read_string(struct fwnode_handle *fwnode,
                                 const char *propname, const char **val);
+int fwnode_property_match_string(struct fwnode_handle *fwnode,
+                                 const char *propname, const char *string);
 
 struct fwnode_handle *device_get_next_child_node(struct device *dev,
                                                  struct fwnode_handle *child);