rtc: BCD codeshrink

This updates <linux/bcd.h> to define the key routines as constant
functions, which the macros will then call.  Newer code can now call
bcd2bin() instead of SCREAMING BCD2BIN() TO THE FOUR WINDS.

This lets each driver shrink their codespace by using N function calls to
a single (global) copy of those routines, instead of N inlined copies of
these functions per driver.

These routines aren't used in speed-critical code.  Almost all callers are
in the RTC framework.  Typical per-driver savings is near 300 bytes.

Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Acked-by: Adrian Bunk <bunk@kernel.org>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
David Brownell 2008-07-23 21:30:37 -07:00 committed by Linus Torvalds
parent 53e84b672c
commit d3de851a44
3 changed files with 22 additions and 3 deletions

View File

@ -10,8 +10,13 @@
#ifndef _BCD_H
#define _BCD_H
#define BCD2BIN(val) (((val) & 0x0f) + ((val)>>4)*10)
#define BIN2BCD(val) ((((val)/10)<<4) + (val)%10)
#include <linux/compiler.h>
unsigned bcd2bin(unsigned char val) __attribute_const__;
unsigned char bin2bcd(unsigned val) __attribute_const__;
#define BCD2BIN(val) bcd2bin(val)
#define BIN2BCD(val) bin2bcd(val)
/* backwards compat */
#define BCD_TO_BIN(val) ((val)=BCD2BIN(val))

View File

@ -18,7 +18,7 @@ lib-$(CONFIG_SMP) += cpumask.o
lib-y += kobject.o kref.o klist.o
obj-y += div64.o sort.o parser.o halfmd4.o debug_locks.o random32.o \
obj-y += bcd.o div64.o sort.o parser.o halfmd4.o debug_locks.o random32.o \
bust_spinlocks.o hexdump.o kasprintf.o bitmap.o scatterlist.o
ifeq ($(CONFIG_DEBUG_KOBJECT),y)

14
lib/bcd.c Normal file
View File

@ -0,0 +1,14 @@
#include <linux/bcd.h>
#include <linux/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);