rtc: pcf2123: use sign_extend32() for sign extension

Use sign_extend32() instead of open coding sign extension.

Signed-off-by: Martin Kepplinger <martink@posteo.de>
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
This commit is contained in:
Martin Kepplinger 2016-04-18 12:17:44 +02:00 committed by Alexandre Belloni
parent c5776dec8f
commit 82df3e045d
1 changed files with 2 additions and 2 deletions

View File

@ -96,7 +96,7 @@
#define CD_TMR_TE BIT(3) /* Countdown timer enable */
/* PCF2123_REG_OFFSET BITS */
#define OFFSET_SIGN_BIT BIT(6) /* 2's complement sign bit */
#define OFFSET_SIGN_BIT 6 /* 2's complement sign bit */
#define OFFSET_COARSE BIT(7) /* Coarse mode offset */
#define OFFSET_STEP (2170) /* Offset step in parts per billion */
@ -217,7 +217,7 @@ static int pcf2123_read_offset(struct device *dev, long *offset)
if (reg & OFFSET_COARSE)
reg <<= 1; /* multiply by 2 and sign extend */
else
reg |= (reg & OFFSET_SIGN_BIT) << 1; /* sign extend only */
reg = sign_extend32(reg, OFFSET_SIGN_BIT);
*offset = ((long)reg) * OFFSET_STEP;