hwmon: (adc128d818) Do proper sign extension (2c3b1189) · Commits · 戴 / test

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>

drivers/hwmon/adc128d818.c

+2 −1

Original line number	Diff line number	Diff line
		@@ -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 */
		}

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