hwmon: (lm95245) Fix hysteresis temperatures

Hysteresis temperatures are defined as absolute temperatures,
not as delta value from the critical temperatures.
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Reviewed-by: Jean Delvare <jdelvare@suse.de>

drivers/hwmon/lm95245.c

@@ -272,27 +272,38 @@ static ssize_t set_limit(struct device *dev, struct device_attribute *attr,
 	return count;
 }
 
+static ssize_t show_crit_hyst(struct device *dev, struct device_attribute *attr,
+			char *buf)
+{
+	struct lm95245_data *data = lm95245_update_device(dev);
+	int index = to_sensor_dev_attr(attr)->index;
+	int hyst = data->regs[index] - data->regs[8];
+
+	return snprintf(buf, PAGE_SIZE - 1, "%d\n", hyst * 1000);
+}
+
 static ssize_t set_crit_hyst(struct device *dev, struct device_attribute *attr,
 			const char *buf, size_t count)
 {
 	struct i2c_client *client = to_i2c_client(dev);
 	struct lm95245_data *data = i2c_get_clientdata(client);
+	int index = to_sensor_dev_attr(attr)->index;
 	unsigned long val;
+	int hyst, limit;
 
 	if (kstrtoul(buf, 10, &val) < 0)
 		return -EINVAL;
 
-	val /= 1000;
-
-	val = clamp_val(val, 0, 31);
-
 	mutex_lock(&data->update_lock);
 
-	data->valid = 0;
+	limit = i2c_smbus_read_byte_data(client, lm95245_reg_address[index]);
+	hyst = limit - val / 1000;
+	hyst = clamp_val(hyst, 0, 31);
+	data->regs[8] = hyst;
 
 	/* shared crit hysteresis */
 	i2c_smbus_write_byte_data(client, LM95245_REG_RW_COMMON_HYSTERESIS,
-		val);
+		hyst);
 
 	mutex_unlock(&data->update_lock);
 
@@ -378,16 +389,16 @@ static ssize_t set_interval(struct device *dev, struct device_attribute *attr,
 static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, show_input, NULL, 0);
 static SENSOR_DEVICE_ATTR(temp1_crit, S_IWUSR | S_IRUGO, show_limit,
 		set_limit, 6);
-static SENSOR_DEVICE_ATTR(temp1_crit_hyst, S_IWUSR | S_IRUGO, show_limit,
-		set_crit_hyst, 8);
+static SENSOR_DEVICE_ATTR(temp1_crit_hyst, S_IWUSR | S_IRUGO, show_crit_hyst,
+		set_crit_hyst, 6);
 static SENSOR_DEVICE_ATTR(temp1_crit_alarm, S_IRUGO, show_alarm, NULL,
 		STATUS1_LOC);
 
 static SENSOR_DEVICE_ATTR(temp2_input, S_IRUGO, show_input, NULL, 2);
 static SENSOR_DEVICE_ATTR(temp2_crit, S_IWUSR | S_IRUGO, show_limit,
 		set_limit, 7);
-static SENSOR_DEVICE_ATTR(temp2_crit_hyst, S_IWUSR | S_IRUGO, show_limit,
-		set_crit_hyst, 8);
+static SENSOR_DEVICE_ATTR(temp2_crit_hyst, S_IWUSR | S_IRUGO, show_crit_hyst,
+		set_crit_hyst, 7);
 static SENSOR_DEVICE_ATTR(temp2_crit_alarm, S_IRUGO, show_alarm, NULL,
 		STATUS1_RTCRIT);
 static SENSOR_DEVICE_ATTR(temp2_type, S_IWUSR | S_IRUGO, show_type,