1 files changed, 15 insertions, 2 deletions

diff --git a/include/linux/bcd.h b/include/linux/bcd.h
index 22ea563ba3eb..18fff11fb3ea 100644
--- a/include/linux/bcd.h
+++ b/include/linux/bcd.h
@@ -3,7 +3,20 @@
 
 #include <linux/compiler.h>
 
-unsigned bcd2bin(unsigned char val) __attribute_const__;
-unsigned char bin2bcd(unsigned val) __attribute_const__;
+#define bcd2bin(x)                                      \
+                (__builtin_constant_p((u8 )(x)) ?       \
+                const_bcd2bin(x) :                      \
+                _bcd2bin(x))
+
+#define bin2bcd(x)                                      \
+                (__builtin_constant_p((u8 )(x)) ?       \
+                const_bin2bcd(x) :                      \
+                _bin2bcd(x))
+
+#define const_bcd2bin(x)        (((x) & 0x0f) + ((x) >> 4) * 10)
+#define const_bin2bcd(x)        ((((x) / 10) << 4) + (x) % 10)
+
+unsigned _bcd2bin(unsigned char val) __attribute_const__;
+unsigned char _bin2bcd(unsigned val) __attribute_const__;
 
 #endif /* _BCD_H */