i2c: convert SMBus alert setup function to return an ERRPTR

Only few drivers use this call, so drivers and I2C core are converted at
once with this patch. By simply using i2c_new_client_device() instead of
i2c_new_device(), we easily can return an ERRPTR for this function as
well. To make out of tree users aware that something changed, the
function is renamed to i2c_new_smbus_alert_device().

Signed-off-by: Wolfram Sang <[e-mail]>
Reviewed-by: Luca Ceresoli <[e-mail]>
Signed-off-by: Wolfram Sang <[e-mail]>

Documentation/i2c/smbus-protocol.rst

···
 This is implemented the following way in the Linux kernel:
 
 * I2C bus drivers which support SMBus alert should call
-  i2c_setup_smbus_alert() to setup SMBus alert support.
+  i2c_new_smbus_alert_device() to install SMBus alert support.
 * I2C drivers for devices which can trigger SMBus alerts should implement
   the optional alert() callback.
 

drivers/i2c/busses/i2c-parport.c

···
 
 	/* Setup SMBus alert if supported */
 	if (adapter_parm[type].smbus_alert) {
-		adapter->ara = i2c_setup_smbus_alert(&adapter->adapter,
-						     &adapter->alert_data);
-		if (adapter->ara)
+		struct i2c_client *ara;
+
+		ara = i2c_new_smbus_alert_device(&adapter->adapter,
+						 &adapter->alert_data);
+		if (!IS_ERR(ara)) {
+			adapter->ara = ara;
 			parport_enable_irq(port);
-		else
+		} else {
 			dev_warn(&adapter->pdev->dev,
 				 "Failed to register ARA client\n");
+		}
 	}
 
 	/* Add the new adapter to the list */

drivers/i2c/busses/i2c-thunderx-pcidrv.c

···
 static int thunder_i2c_smbus_setup_of(struct octeon_i2c *i2c,
 				      struct device_node *node)
 {
+	struct i2c_client *ara;
+
 	if (!node)
 		return -EINVAL;
 
···
 	if (!i2c->alert_data.irq)
 		return -EINVAL;
 
-	i2c->ara = i2c_setup_smbus_alert(&i2c->adap, &i2c->alert_data);
-	if (!i2c->ara)
-		return -ENODEV;
+	ara = i2c_new_smbus_alert_device(&i2c->adap, &i2c->alert_data);
+	if (IS_ERR(ara))
+		return PTR_ERR(ara);
+
+	i2c->ara = ara;
+
 	return 0;
 }
 

drivers/i2c/busses/i2c-xlp9xx.c

···
 static int xlp9xx_i2c_smbus_setup(struct xlp9xx_i2c_dev *priv,
 				  struct platform_device *pdev)
 {
+	struct i2c_client *ara;
+
 	if (!priv->alert_data.irq)
 		return -EINVAL;
 
-	priv->ara = i2c_setup_smbus_alert(&priv->adapter, &priv->alert_data);
-	if (!priv->ara)
-		return -ENODEV;
+	ara = i2c_new_smbus_alert_device(&priv->adapter, &priv->alert_data);
+	if (IS_ERR(ara))
+		return PTR_ERR(ara);
+
+	priv->ara = ara;
 
 	return 0;
 }

drivers/i2c/i2c-core-smbus.c

···
 EXPORT_SYMBOL(i2c_smbus_read_i2c_block_data_or_emulated);
 
 /**
- * i2c_setup_smbus_alert - Setup SMBus alert support
+ * i2c_new_smbus_alert_device - get ara client for SMBus alert support
  * @adapter: the target adapter
  * @setup: setup data for the SMBus alert handler
  * Context: can sleep
···
  * should have said it's level triggered.
  *
  * This returns the ara client, which should be saved for later use with
- * i2c_handle_smbus_alert() and ultimately i2c_unregister_device(); or NULL
- * to indicate an error.
+ * i2c_handle_smbus_alert() and ultimately i2c_unregister_device(); or an
+ * ERRPTR to indicate an error.
  */
-struct i2c_client *i2c_setup_smbus_alert(struct i2c_adapter *adapter,
-					 struct i2c_smbus_alert_setup *setup)
+struct i2c_client *i2c_new_smbus_alert_device(struct i2c_adapter *adapter,
+					      struct i2c_smbus_alert_setup *setup)
 {
 	struct i2c_board_info ara_board_info = {
 		I2C_BOARD_INFO("smbus_alert", 0x0c),
 		.platform_data = setup,
 	};
 
-	return i2c_new_device(adapter, &ara_board_info);
+	return i2c_new_client_device(adapter, &ara_board_info);
 }
-EXPORT_SYMBOL_GPL(i2c_setup_smbus_alert);
+EXPORT_SYMBOL_GPL(i2c_new_smbus_alert_device);
 
 #if IS_ENABLED(CONFIG_I2C_SMBUS) && IS_ENABLED(CONFIG_OF)
 int of_i2c_setup_smbus_alert(struct i2c_adapter *adapter)
 {
-	struct i2c_client *client;
 	int irq;
 
 	irq = of_property_match_string(adapter->dev.of_node, "interrupt-names",
···
 	else if (irq < 0)
 		return irq;
 
-	client = i2c_setup_smbus_alert(adapter, NULL);
-	if (!client)
-		return -ENODEV;
-
-	return 0;
+	return PTR_ERR_OR_ZERO(i2c_new_smbus_alert_device(adapter, NULL));
 }
 EXPORT_SYMBOL_GPL(of_i2c_setup_smbus_alert);
 #endif

drivers/i2c/i2c-smbus.c

···
  * corresponding I2C device driver's alert function.
  *
  * It is assumed that ara is a valid i2c client previously returned by
- * i2c_setup_smbus_alert().
+ * i2c_new_smbus_alert_device().
  */
 int i2c_handle_smbus_alert(struct i2c_client *ara)
 {

include/linux/i2c-smbus.h

···
 	int			irq;
 };
 
-struct i2c_client *i2c_setup_smbus_alert(struct i2c_adapter *adapter,
-					 struct i2c_smbus_alert_setup *setup);
+struct i2c_client *i2c_new_smbus_alert_device(struct i2c_adapter *adapter,
+					      struct i2c_smbus_alert_setup *setup);
 int i2c_handle_smbus_alert(struct i2c_client *ara);
 
 #if IS_ENABLED(CONFIG_I2C_SMBUS) && IS_ENABLED(CONFIG_OF)