hwmon: (jc42) Allow negative hysteresis temperatures

The driver supports negative high and critical limits, it can return
negative hysteresis values, so there is no good reason to not let the
user write negative hysteresis values.

Signed-off-by: Jean Delvare <jdelvare@suse.de>
Cc: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
diff --git a/drivers/hwmon/jc42.c b/drivers/hwmon/jc42.c
index a46cb65..996bdfd 100644
--- a/drivers/hwmon/jc42.c
+++ b/drivers/hwmon/jc42.c
@@ -304,15 +304,16 @@
 				  const char *buf, size_t count)
 {
 	struct jc42_data *data = dev_get_drvdata(dev);
-	unsigned long val;
+	long val;
 	int diff, hyst;
 	int err;
 	int ret = count;
 
-	if (kstrtoul(buf, 10, &val) < 0)
+	if (kstrtol(buf, 10, &val) < 0)
 		return -EINVAL;
 
-	val = clamp_val(val, 0, JC42_TEMP_MAX);
+	val = clamp_val(val, (data->extended ? JC42_TEMP_MIN_EXTENDED :
+			      JC42_TEMP_MIN) - 6000, JC42_TEMP_MAX);
 	diff = jc42_temp_from_reg(data->temp[t_crit]) - val;
 
 	hyst = 0;