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>

1 files changed, 6 insertions, 10 deletions

diff --git a/drivers/extcon/extcon-class.c b/drivers/extcon/extcon-class.c
index 1e1a3f17a782..1ce76a8d777b 100644
--- 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;