summaryrefslogtreecommitdiffstats
path: root/drivers/rtc/rtc-x1205.c
diff options
context:
space:
mode:
authorMartin Kepplinger <martink@posteo.de>2015-04-16 12:45:09 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2015-04-17 09:03:59 -0400
commit86e66604fca053e5ecb2427538aa233637119409 (patch)
tree62499fe6e2d21a0fc75d3ad6dce735ea183cffe8 /drivers/rtc/rtc-x1205.c
parente706974dc3e2f44891e736f4a96eb88b60356178 (diff)
downloadlinux-stable-86e66604fca053e5ecb2427538aa233637119409.tar.gz
linux-stable-86e66604fca053e5ecb2427538aa233637119409.tar.bz2
linux-stable-86e66604fca053e5ecb2427538aa233637119409.zip
drivers/rtc/rtc-x1205.c: use sign_extend32() for sign extension
Despite its name, sign_extend32() is safe to use for 8 bit types too. (See https://lkml.org/lkml/2015/1/18/289). Signed-off-by: Martin Kepplinger <martink@posteo.de> 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>
Diffstat (limited to 'drivers/rtc/rtc-x1205.c')
-rw-r--r--drivers/rtc/rtc-x1205.c4
1 files changed, 2 insertions, 2 deletions
diff --git a/drivers/rtc/rtc-x1205.c b/drivers/rtc/rtc-x1205.c
index b1de58e0b3d0..5638b7ba8b06 100644
--- a/drivers/rtc/rtc-x1205.c
+++ b/drivers/rtc/rtc-x1205.c
@@ -22,6 +22,7 @@
#include <linux/rtc.h>
#include <linux/delay.h>
#include <linux/module.h>
+#include <linux/bitops.h>
#define DRV_VERSION "1.0.8"
@@ -366,8 +367,7 @@ static int x1205_get_atrim(struct i2c_client *client, int *trim)
* perform sign extension. The formula is
* Catr = (atr * 0.25pF) + 11.00pF.
*/
- if (atr & 0x20)
- atr |= 0xC0;
+ atr = sign_extend32(atr, 5);
dev_dbg(&client->dev, "%s: raw atr=%x (%d)\n", __func__, atr, atr);