power: supply: max17042_battery: Use sign_extend32 instead of DIY code

Use sign_extend32 to sign-extend variables where necessary instead of
DIY code.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Reviewed-by: Krzysztof Kozlowski <krzk@kernel.org>
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.co.uk>

diff --git a/drivers/power/supply/max17042_battery.c b/drivers/power/supply/max17042_battery.c
index da7a75f..790dfa9 100644 (file)
--- a/drivers/power/supply/max17042_battery.c
+++ b/drivers/power/supply/max17042_battery.c
@@ -106,13 +106,7 @@ static int max17042_get_temperature(struct max17042_chip *chip, int *temp)
        if (ret < 0)
                return ret;
 
-       *temp = data;
-       /* The value is signed. */
-       if (*temp & 0x8000) {
-               *temp = (0x7fff & ~*temp) + 1;
-               *temp *= -1;
-       }
-
+       *temp = sign_extend32(data, 15);
        /* The value is converted into deci-centigrade scale */
        /* Units of LSB = 1 / 256 degree Celsius */
        *temp = *temp * 10 / 256;
@@ -302,13 +296,7 @@ static int max17042_get_property(struct power_supply *psy,
                        if (ret < 0)
                                return ret;
 
-                       val->intval = data;
-                       if (val->intval & 0x8000) {
-                               /* Negative */
-                               val->intval = ~val->intval & 0x7fff;
-                               val->intval++;
-                               val->intval *= -1;
-                       }
+                       val->intval = sign_extend32(data, 15);
                        val->intval *= 1562500 / chip->pdata->r_sns;
                } else {
                        return -EINVAL;
@@ -320,13 +308,7 @@ static int max17042_get_property(struct power_supply *psy,
                        if (ret < 0)
                                return ret;
 
-                       val->intval = data;
-                       if (val->intval & 0x8000) {
-                               /* Negative */
-                               val->intval = ~val->intval & 0x7fff;
-                               val->intval++;
-                               val->intval *= -1;
-                       }
+                       val->intval = sign_extend32(data, 15);
                        val->intval *= 1562500 / chip->pdata->r_sns;
                } else {
                        return -EINVAL;