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authorRasmus Villemoes <linux@rasmusvillemoes.dk>2015-01-22 23:44:14 +0100
committerGuenter Roeck <linux@roeck-us.net>2015-01-25 21:24:00 -0800
commit2c3b1189fdca2f512187a670aeb295f901c10d87 (patch)
treeb977b79ce3df7b3ebcff4c4e2290f2ea72600f01 /drivers/hwmon/adc128d818.c
parent984faa1fb9175720828bf6604f936dff3f17b995 (diff)
hwmon: (adc128d818) Do proper sign extension
data->temp[index] has type s16. Because of C's promotion rules, (data->temp[index] << 7) >> 7 is exactly the same as data->temp[index]. The intention was to use bit 8 as a sign bit, so do that using the existing API. Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk> Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Diffstat (limited to 'drivers/hwmon/adc128d818.c')
-rw-r--r--drivers/hwmon/adc128d818.c3
1 files changed, 2 insertions, 1 deletions
diff --git a/drivers/hwmon/adc128d818.c b/drivers/hwmon/adc128d818.c
index 0625e50d7a6e..ad2b47e40345 100644
--- a/drivers/hwmon/adc128d818.c
+++ b/drivers/hwmon/adc128d818.c
@@ -27,6 +27,7 @@
#include <linux/err.h>
#include <linux/regulator/consumer.h>
#include <linux/mutex.h>
+#include <linux/bitops.h>
/* Addresses to scan
* The chip also supports addresses 0x35..0x37. Don't scan those addresses
@@ -189,7 +190,7 @@ static ssize_t adc128_show_temp(struct device *dev,
if (IS_ERR(data))
return PTR_ERR(data);
- temp = (data->temp[index] << 7) >> 7; /* sign extend */
+ temp = sign_extend32(data->temp[index], 8);
return sprintf(buf, "%d\n", temp * 500);/* 0.5 degrees C resolution */
}