i2c: Add support for software nodes

This makes it possible for the drivers to assign complete
software fwnodes to the devices instead of only the device
properties in those nodes.
Signed-off-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

drivers/i2c/i2c-core-base.c

@@ -919,15 +919,27 @@ i2c_new_client_device(struct i2c_adapter *adap, struct i2c_board_info const *inf
 		}
 	}
 
+	if (info->swnode) {
+		status = device_add_software_node(&client->dev, info->swnode);
+		if (status) {
+			dev_err(&adap->dev,
+				"Failed to add software node to client %s: %d\n",
+				client->name, status);
+			goto out_free_props;
+		}
+	}
+
 	status = device_register(&client->dev);
 	if (status)
-		goto out_free_props;
+		goto out_remove_swnode;
 
 	dev_dbg(&adap->dev, "client [%s] registered with bus id %s\n",
 		client->name, dev_name(&client->dev));
 
 	return client;
 
+out_remove_swnode:
+	device_remove_software_node(&client->dev);
 out_free_props:
 	if (info->properties)
 		device_remove_properties(&client->dev);
@@ -960,6 +972,7 @@ void i2c_unregister_device(struct i2c_client *client)
 
 	if (ACPI_COMPANION(&client->dev))
 		acpi_device_clear_enumerated(ACPI_COMPANION(&client->dev));
+	device_remove_software_node(&client->dev);
 	device_unregister(&client->dev);
 }
 EXPORT_SYMBOL_GPL(i2c_unregister_device);

include/linux/i2c.h

@@ -391,7 +391,8 @@ static inline bool i2c_detect_slave_mode(struct device *dev) { return false; }
  * @platform_data: stored in i2c_client.dev.platform_data
  * @of_node: pointer to OpenFirmware device node
  * @fwnode: device node supplied by the platform firmware
- * @properties: additional device properties for the device
+ * @properties: Deprecated - use swnode instead
+ * @swnode: software node for the device
  * @resources: resources associated with the device
  * @num_resources: number of resources in the @resources array
  * @irq: stored in i2c_client.irq
@@ -416,6 +417,7 @@ struct i2c_board_info {
 	struct device_node *of_node;
 	struct fwnode_handle *fwnode;
 	const struct property_entry *properties;
+	const struct software_node *swnode;
 	const struct resource *resources;
 	unsigned int	num_resources;
 	int		irq;