of: base: Introduce of_alias_get_alias_list() to check alias IDs

The function travels the lookup table to record alias ids for the given
device match structures and alias stem.
This function will be used by serial drivers to check if requested alias
is allocated or free to use.

Signed-off-by: Michal Simek <michal.simek@xilinx.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 10 insertions, 0 deletions

diff --git a/include/linux/of.h b/include/linux/of.h
index 99b0ebf49632..d51457b40725 100644
--- a/include/linux/of.h
+++ b/include/linux/of.h
@@ -392,6 +392,9 @@ extern int of_phandle_iterator_args(struct of_phandle_iterator *it,
 extern void of_alias_scan(void * (*dt_alloc)(u64 size, u64 align));
 extern int of_alias_get_id(struct device_node *np, const char *stem);
 extern int of_alias_get_highest_id(const char *stem);
+extern int of_alias_get_alias_list(const struct of_device_id *matches,
+                                   const char *stem, unsigned long *bitmap,
+                                   unsigned int nbits);
 
 extern int of_machine_is_compatible(const char *compat);
 
@@ -893,6 +896,13 @@ static inline int of_alias_get_highest_id(const char *stem)
         return -ENOSYS;
 }
 
+static inline int of_alias_get_alias_list(const struct of_device_id *matches,
+                                          const char *stem, unsigned long *bitmap,
+                                          unsigned int nbits)
+{
+        return -ENOSYS;
+}
+
 static inline int of_machine_is_compatible(const char *compat)
 {
         return 0;