hwmon: (f75375s) Add new style bindings

Following the example of David Brownell's work on lm75:

 - Create a second driver struct, using new-style driver binding methods.

 - Rename the old driver struct as f75375_legacy_driver.

 - Make the legacy bind/unbind logic delegate all its work.
Signed-off-by: Riku Voipio <riku.voipio@movial.fi>
Signed-off-by: Mark M. Hoffman <mhoffman@lightlink.com>

drivers/hwmon/f75375s.c

@@ -86,7 +86,7 @@ I2C_CLIENT_INSMOD_2(f75373, f75375);
 
 struct f75375_data {
 	unsigned short addr;
-	struct i2c_client client;
+	struct i2c_client *client;
 	struct device *hwmon_dev;
 
 	const char *name;
@@ -116,15 +116,25 @@ struct f75375_data {
 static int f75375_attach_adapter(struct i2c_adapter *adapter);
 static int f75375_detect(struct i2c_adapter *adapter, int address, int kind);
 static int f75375_detach_client(struct i2c_client *client);
+static int f75375_probe(struct i2c_client *client);
+static int f75375_remove(struct i2c_client *client);
 
-static struct i2c_driver f75375_driver = {
+static struct i2c_driver f75375_legacy_driver = {
 	.driver = {
-		.name = "f75375",
+		.name = "f75375_legacy",
 	},
 	.attach_adapter = f75375_attach_adapter,
 	.detach_client = f75375_detach_client,
 };
 
+static struct i2c_driver f75375_driver = {
+	.driver = {
+		.name = "f75375",
+	},
+	.probe = f75375_probe,
+	.remove = f75375_remove,
+};
+
 static inline int f75375_read8(struct i2c_client *client, u8 reg)
 {
 	return i2c_smbus_read_byte_data(client, reg);
@@ -580,12 +590,9 @@ static const struct attribute_group f75375_group = {
 
 static int f75375_detach_client(struct i2c_client *client)
 {
-	struct f75375_data *data = i2c_get_clientdata(client);
 	int err;
 
-	hwmon_device_unregister(data->hwmon_dev);
-	sysfs_remove_group(&client->dev.kobj, &f75375_group);
-
+	f75375_remove(client);
 	err = i2c_detach_client(client);
 	if (err) {
 		dev_err(&client->dev,
@@ -593,7 +600,60 @@ static int f75375_detach_client(struct i2c_client *client)
 			"client not detached.\n");
 		return err;
 	}
+	kfree(client);
+	return 0;
+}
+
+static int f75375_probe(struct i2c_client *client)
+{
+	struct f75375_data *data = i2c_get_clientdata(client);
+	int err;
+
+	if (!i2c_check_functionality(client->adapter,
+				I2C_FUNC_SMBUS_BYTE_DATA))
+		return -EIO;
+	if (!(data = kzalloc(sizeof(struct f75375_data), GFP_KERNEL)))
+		return -ENOMEM;
+
+	i2c_set_clientdata(client, data);
+	data->client = client;
+	mutex_init(&data->update_lock);
+
+	if (strcmp(client->name, "f75375") == 0)
+		data->kind = f75375;
+	else if (strcmp(client->name, "f75373") == 0)
+		data->kind = f75373;
+	else {
+		dev_err(&client->dev, "Unsupported device: %s\n", client->name);
+		return -ENODEV;
+	}
+
+	if ((err = sysfs_create_group(&client->dev.kobj, &f75375_group)))
+		goto exit_free;
+
+	data->hwmon_dev = hwmon_device_register(&client->dev);
+	if (IS_ERR(data->hwmon_dev)) {
+		err = PTR_ERR(data->hwmon_dev);
+		goto exit_remove;
+	}
+
+	return 0;
+
+exit_remove:
+	sysfs_remove_group(&client->dev.kobj, &f75375_group);
+exit_free:
+	kfree(data);
+	i2c_set_clientdata(client, NULL);
+	return err;
+}
+
+static int f75375_remove(struct i2c_client *client)
+{
+	struct f75375_data *data = i2c_get_clientdata(client);
+	hwmon_device_unregister(data->hwmon_dev);
+	sysfs_remove_group(&client->dev.kobj, &f75375_group);
 	kfree(data);
+	i2c_set_clientdata(client, NULL);
 	return 0;
 }
 
@@ -608,20 +668,17 @@ static int f75375_attach_adapter(struct i2c_adapter *adapter)
 static int f75375_detect(struct i2c_adapter *adapter, int address, int kind)
 {
 	struct i2c_client *client;
-	struct f75375_data *data;
 	u8 version = 0;
 	int err = 0;
 	const char *name = "";
 
-	if (!(data = kzalloc(sizeof(struct f75375_data), GFP_KERNEL))) {
+	if (!(client = kzalloc(sizeof(*client), GFP_KERNEL))) {
 		err = -ENOMEM;
 		goto exit;
 	}
-	client = &data->client;
-	i2c_set_clientdata(client, data);
 	client->addr = address;
 	client->adapter = adapter;
-	client->driver = &f75375_driver;
+	client->driver = &f75375_legacy_driver;
 
 	if (kind < 0) {
 		u16 vendid = f75375_read16(client, F75375_REG_VENDOR);
@@ -644,42 +701,42 @@ static int f75375_detect(struct i2c_adapter *adapter, int address, int kind)
 	} else if (kind == f75373) {
 		name = "f75373";
 	}
-
 	dev_info(&adapter->dev, "found %s version: %02X\n", name, version);
 	strlcpy(client->name, name, I2C_NAME_SIZE);
-	data->kind = kind;
-	mutex_init(&data->update_lock);
+
 	if ((err = i2c_attach_client(client)))
 		goto exit_free;
 
-	if ((err = sysfs_create_group(&client->dev.kobj, &f75375_group)))
+	if ((err = f75375_probe(client)) < 0)
 		goto exit_detach;
 
-	data->hwmon_dev = hwmon_device_register(&client->dev);
-	if (IS_ERR(data->hwmon_dev)) {
-		err = PTR_ERR(data->hwmon_dev);
-		goto exit_remove;
-	}
-
 	return 0;
 
-exit_remove:
-	sysfs_remove_group(&client->dev.kobj, &f75375_group);
 exit_detach:
 	i2c_detach_client(client);
 exit_free:
-	kfree(data);
+	kfree(client);
 exit:
 	return err;
 }
 
 static int __init sensors_f75375_init(void)
 {
-	return i2c_add_driver(&f75375_driver);
+	int status;
+	status = i2c_add_driver(&f75375_driver);
+	if (status)
+		return status;
+
+	status = i2c_add_driver(&f75375_legacy_driver);
+	if (status)
+		i2c_del_driver(&f75375_driver);
+
+	return status;
 }
 
 static void __exit sensors_f75375_exit(void)
 {
+	i2c_del_driver(&f75375_legacy_driver);
 	i2c_del_driver(&f75375_driver);
 }