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authoranish kumar <anish198519851985@gmail.com>2012-08-29 15:05:10 -0400
committerMyungJoo Ham <myungjoo.ham@samsung.com>2012-10-21 22:28:10 -0400
commit28c0ada62d39eaafef03d88a4e6f4c5bcb6e1b6c (patch)
tree6f4f01eab4ad9c1e59265362a3077a50449cba60 /drivers/extcon/extcon-class.c
parent0cf6ad8a18f7f7bdbb81975188d9e0656ef277dd (diff)
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>
Diffstat (limited to 'drivers/extcon/extcon-class.c')
-rw-r--r--drivers/extcon/extcon-class.c16
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)
89 return 0; 89 return 0;
90 90
91 for (i = 0; edev->mutually_exclusive[i]; i++) { 91 for (i = 0; edev->mutually_exclusive[i]; i++) {
92 int count = 0, j; 92 int weight;
93 u32 correspondants = new_state & edev->mutually_exclusive[i]; 93 u32 correspondants = new_state & edev->mutually_exclusive[i];
94 u32 exp = 1; 94
95 95 /* calculate the total number of bits set */
96 for (j = 0; j < 32; j++) { 96 weight = hweight32(correspondants);
97 if (exp & correspondants) 97 if (weight > 1)
98 count++; 98 return i + 1;
99 if (count > 1)
100 return i + 1;
101 exp <<= 1;
102 }
103 } 99 }
104 100
105 return 0; 101 return 0;