lib: import 'bcd' from linux-3.15

Signed-off-by: Antony Pavlov <antonynpavlov@gmail.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

include/linux/bcd.h

@@ -0,0 +1,22 @@
+#ifndef _BCD_H
+#define _BCD_H
+
+#include <linux/compiler.h>
+
+#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 */

lib/Makefile

@@ -1,3 +1,4 @@
+obj-y			+= bcd.o
 obj-$(CONFIG_BOOTSTRAP)	+= bootstrap/
 obj-y			+= ctype.o
 obj-y			+= rbtree.o

lib/bcd.c

@@ -0,0 +1,14 @@
+#include <linux/bcd.h>
+#include <module.h>
+
+unsigned _bcd2bin(unsigned char val)
+{
+	return (val & 0x0f) + (val >> 4) * 10;
+}
+EXPORT_SYMBOL(_bcd2bin);
+
+unsigned char _bin2bcd(unsigned val)
+{
+	return ((val / 10) << 4) + val % 10;
+}
+EXPORT_SYMBOL(_bin2bcd);