hwmon: (w83793) Implement the standard intrusion detection interface

We have a standard intrusion detection interface now, drivers should
implement it. I've left the old interface in place for the time being,
with a deprecation warning, it will be removed later.

Signed-off-by: Jean Delvare <[e-mail]>
Acked-by: Guenter Roeck <[e-mail]>

Documentation/hwmon/w83793

···
 
 * Chassis
   If the case open alarm triggers, it will stay in this state unless cleared
-  by any write to the sysfs file "chassis".
+  by writing 0 to the sysfs file "intrusion0_alarm".
 
 * VID and VRM
   The VRM version is detected automatically, don't modify the it unless you

drivers/hwmon/w83793.c

···
 
 /* Write any value to clear chassis alarm */
 static ssize_t
+store_chassis_clear_legacy(struct device *dev,
+			   struct device_attribute *attr, const char *buf,
+			   size_t count)
+{
+	struct i2c_client *client = to_i2c_client(dev);
+	struct w83793_data *data = i2c_get_clientdata(client);
+	u8 val;
+
+	dev_warn(dev, "Attribute chassis is deprecated, "
+		 "use intrusion0_alarm instead\n");
+
+	mutex_lock(&data->update_lock);
+	val = w83793_read_value(client, W83793_REG_CLR_CHASSIS);
+	val |= 0x80;
+	w83793_write_value(client, W83793_REG_CLR_CHASSIS, val);
+	mutex_unlock(&data->update_lock);
+	return count;
+}
+
+/* Write 0 to clear chassis alarm */
+static ssize_t
 store_chassis_clear(struct device *dev,
 		    struct device_attribute *attr, const char *buf,
 		    size_t count)
 {
 	struct i2c_client *client = to_i2c_client(dev);
 	struct w83793_data *data = i2c_get_clientdata(client);
-	u8 val;
+	unsigned long val;
+	u8 reg;
+
+	if (strict_strtoul(buf, 10, &val) || val != 0)
+		return -EINVAL;
 
 	mutex_lock(&data->update_lock);
-	val = w83793_read_value(client, W83793_REG_CLR_CHASSIS);
-	val |= 0x80;
-	w83793_write_value(client, W83793_REG_CLR_CHASSIS, val);
+	reg = w83793_read_value(client, W83793_REG_CLR_CHASSIS);
+	w83793_write_value(client, W83793_REG_CLR_CHASSIS, reg | 0x80);
+	data->valid = 0;		/* Force cache refresh */
 	mutex_unlock(&data->update_lock);
 	return count;
 }
···
 
 static struct sensor_device_attribute_2 sda_single_files[] = {
 	SENSOR_ATTR_2(chassis, S_IWUSR | S_IRUGO, show_alarm_beep,
+		      store_chassis_clear_legacy, ALARM_STATUS, 30),
+	SENSOR_ATTR_2(intrusion0_alarm, S_IWUSR | S_IRUGO, show_alarm_beep,
 		      store_chassis_clear, ALARM_STATUS, 30),
 	SENSOR_ATTR_2(beep_enable, S_IWUSR | S_IRUGO, show_beep_enable,
 		      store_beep_enable, NOT_USED, NOT_USED),