part: Export part_driver_lookup_type for external use

Make part_driver_lookup_type non-static so it can be used outside
part.c. This allows external callers to determine the appropriate
partition driver for a block device, enabling more flexible handling of
partition types.

Add a prototype and kernel-doc comment in part.h to document the
function contract. Provide a stub inline implementation returning NULL
when partition support is disabled, ensuring build consistency across
configurations.

Signed-off-by: Javier Tia <[email protected]>
Reviewed-by: Ilias Apalodimas <[email protected]>
Signed-off-by: Ilias Apalodimas <[email protected]>

1 files changed, 21 insertions, 0 deletions

diff --git a/include/part.h b/include/part.h
index b772fb34c8a..6caaa6526aa 100644
--- a/include/part.h
+++ b/include/part.h
@@ -727,6 +727,24 @@ int part_get_type_by_name(const char *name);
  */
 int part_get_bootable(struct blk_desc *desc);
 
+/**
+ * part_driver_lookup_type() - Look up the partition driver for a blk device
+ *
+ * If @desc->part_type is PART_TYPE_UNKNOWN, this checks each partition driver
+ * against the blk device to see if there is a valid partition table acceptable
+ * to that driver.
+ *
+ * If @desc->part_type is already set, it just returns the driver for that
+ * type, without testing if the driver can find a valid partition on the
+ * descriptor.
+ *
+ * On success it updates @desc->part_type if set to PART_TYPE_UNKNOWN on entry
+ *
+ * @desc: Device descriptor
+ * Return: Driver found, or NULL if none
+ */
+struct part_driver *part_driver_lookup_type(struct blk_desc *desc);
+
 #else
 static inline int part_driver_get_count(void)
 { return 0; }
@@ -737,6 +755,9 @@ static inline struct part_driver *part_driver_get_first(void)
 static inline bool part_get_bootable(struct blk_desc *desc)
 { return false; }
 
+static inline struct part_driver *part_driver_lookup_type(struct blk_desc *desc)
+{ return NULL; }
+
 #endif /* CONFIG_PARTITIONS */
 
 #endif /* _PART_H */