[PATCH] bitops: move BITS() macro to the bitops file

From: Linus Walleij
Date: Wed Aug 07 2013 - 05:06:31 EST

This macro was invented by Mattias Nilsson for the usecase
where you want to set a sequence of bits inside a n-bit
word, while leaving the head and tail of the sequence all
zeroes. For example:

#include <linux/bitops.h>

u16 mask = BITS(4, 12);

Yields a mask like this:


This patch moves the construct out of the MFD PRCMU driver
and make it available for common use, after noticing in a
review or two that it would be useful for others.

Cc: Akinobu Mita <mita@xxxxxxxxxxxxxxxx>
Signed-off-by: Linus Walleij <linus.walleij@xxxxxxxxxx>
drivers/mfd/dbx500-prcmu-regs.h | 2 --
include/linux/bitops.h | 1 +
2 files changed, 1 insertion(+), 2 deletions(-)

diff --git a/drivers/mfd/dbx500-prcmu-regs.h b/drivers/mfd/dbx500-prcmu-regs.h
index 4f6f0fa..906e75e 100644
--- a/drivers/mfd/dbx500-prcmu-regs.h
+++ b/drivers/mfd/dbx500-prcmu-regs.h
@@ -13,8 +13,6 @@
#ifndef __DB8500_PRCMU_REGS_H
#define __DB8500_PRCMU_REGS_H

-#define BITS(_start, _end) ((BIT(_end) - BIT(_start)) + BIT(_end))
#define PRCM_ACLK_MGT (0x004)
#define PRCM_SVAMMCSPCLK_MGT (0x008)
diff --git a/include/linux/bitops.h b/include/linux/bitops.h
index a3b6b82..1f9d78b 100644
--- a/include/linux/bitops.h
+++ b/include/linux/bitops.h
@@ -6,6 +6,7 @@
#define BIT(nr) (1UL << (nr))
#define BIT_MASK(nr) (1UL << ((nr) % BITS_PER_LONG))
#define BIT_WORD(nr) ((nr) / BITS_PER_LONG)
+#define BITS(_start, _end) ((BIT(_end) - BIT(_start)) + BIT(_end))
#define BITS_PER_BYTE 8
#define BITS_TO_LONGS(nr) DIV_ROUND_UP(nr, BITS_PER_BYTE * sizeof(long))

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