extcon: optimising the check_mutually_exclusive function

Rather than re-inventing the wheel we can use the hamming function
to calculate the number of bits set to check for violation of
exclusivity.

Signed-off-by: anish kumar <anish198519851985@gmail.com>
Signed-off-by: MyungJoo Ham <myungjoo.ham@samsung.com>

diff --git a/drivers/extcon/extcon-class.c b/drivers/extcon/extcon-class.c
index 1e1a3f17a7828895df6d2cfaac8f984ce393c093..1ce76a8d777b8f1e80cc6769f1b04dcc10954d0d 100644 (file)
--- a/drivers/extcon/extcon-class.c
+++ b/drivers/extcon/extcon-class.c
@@ -89,17 +89,13 @@ static int check_mutually_exclusive(struct extcon_dev *edev, u32 new_state)
                return 0;
 
        for (i = 0; edev->mutually_exclusive[i]; i++) {
-               int count = 0, j;
+               int weight;
                u32 correspondants = new_state & edev->mutually_exclusive[i];
-               u32 exp = 1;
-
-               for (j = 0; j < 32; j++) {
-                       if (exp & correspondants)
-                               count++;
-                       if (count > 1)
-                               return i + 1;
-                       exp <<= 1;
-               }
+
+               /* calculate the total number of bits set */
+               weight = hweight32(correspondants);
+               if (weight > 1)
+                       return i + 1;
        }
 
        return 0;