@@ -667,28 +667,24 @@ static inline int w1_DS18B20_get_resolut
*/
static inline int w1_DS18B20_convert_temp(u8 rom[9])
{
- int t;
- u32 bv;
+ u16 bv;
+ s16 t;
+
+ /* Signed 16-bit value to unsigned, cpu order */
+ bv = le16_to_cpup((__le16 *)rom);
/* Config register bit R2 = 1 - GX20MH01 in 13 or 14 bit resolution mode */
if (rom[4] & 0x80) {
- /* Signed 16-bit value to unsigned, cpu order */
- bv = le16_to_cpup((__le16 *)rom);
-
/* Insert two temperature bits from config register */
/* Avoid arithmetic shift of signed value */
bv = (bv << 2) | (rom[4] & 3);
-
- t = (int) sign_extend32(bv, 17); /* Degrees, lowest bit is 2^-6 */
- return (t*1000)/64; /* Millidegrees */
+ t = (s16) bv; /* Degrees, lowest bit is 2^-6 */
+ return (int)t * 1000 / 64; /* Sign-extend to int; millidegrees */
}
-
- t = (int)le16_to_cpup((__le16 *)rom);
- return t*1000/16;
+ t = (s16)bv; /* Degrees, lowest bit is 2^-4 */
+ return (int)t * 1000 / 16; /* Sign-extend to int; millidegrees */
}
-
-
/**
* w1_DS18S20_convert_temp() - temperature computation for DS18S20
* @rom: data read from device RAM (8 data bytes + 1 CRC byte)