Re: [PATCH] hwmon: (adt7475) Convert to use hwmon_device_register_with_groups()

[Guenter Roeck <linux@roeck-us.net>]

On Fri, Jul 19, 2019 at 01:41:30PM +1200, Grant McEwan wrote:
> hwmon_device_register() is a deprecated function and produces a warning.
> 
> Converting the driver to use the hwmon_device_register_with_groups()
> instead.
> 
> Signed-off-by: Grant McEwan <grant.mcewan@alliedtelesis.co.nz>
> ---
>  drivers/hwmon/adt7475.c | 104 +++++++++++++++++++---------------------
>  1 file changed, 48 insertions(+), 56 deletions(-)
> 
> diff --git a/drivers/hwmon/adt7475.c b/drivers/hwmon/adt7475.c
> index c3c6031a7285..4e838555102f 100644
> --- a/drivers/hwmon/adt7475.c
> +++ b/drivers/hwmon/adt7475.c
> @@ -188,6 +188,7 @@ MODULE_DEVICE_TABLE(of, adt7475_of_match);
>  
>  struct adt7475_data {
>  	struct device *hwmon_dev;
> +	struct i2c_client *client;
>  	struct mutex lock;
>  
>  	unsigned long measure_updated;
> @@ -212,6 +213,7 @@ struct adt7475_data {
>  
>  	u8 vid;
>  	u8 vrm;
> +	const struct attribute_group *groups[8];

There are a total of 8 groups, and the list of groups needs to be
terminated with a NULL pointer, so there have to be 9 entries in
this array.

>  };
>  
>  static struct i2c_driver adt7475_driver;
> @@ -346,8 +348,8 @@ static ssize_t voltage_store(struct device *dev,
>  {
>  
>  	struct sensor_device_attribute_2 *sattr = to_sensor_dev_attr_2(attr);
> -	struct i2c_client *client = to_i2c_client(dev);
> -	struct adt7475_data *data = i2c_get_clientdata(client);
> +	struct adt7475_data *data = dev_get_drvdata(dev);
> +	struct i2c_client *client = data->client;
>  	unsigned char reg;
>  	long val;
>  
> @@ -440,8 +442,8 @@ static ssize_t temp_store(struct device *dev, struct device_attribute *attr,
>  			  const char *buf, size_t count)
>  {
>  	struct sensor_device_attribute_2 *sattr = to_sensor_dev_attr_2(attr);
> -	struct i2c_client *client = to_i2c_client(dev);
> -	struct adt7475_data *data = i2c_get_clientdata(client);
> +	struct adt7475_data *data = dev_get_drvdata(dev);
> +	struct i2c_client *client = data->client;
>  	unsigned char reg = 0;
>  	u8 out;
>  	int temp;
> @@ -542,8 +544,7 @@ static ssize_t temp_st_show(struct device *dev, struct device_attribute *attr,
>  			    char *buf)
>  {
>  	struct sensor_device_attribute_2 *sattr = to_sensor_dev_attr_2(attr);
> -	struct i2c_client *client = to_i2c_client(dev);
> -	struct adt7475_data *data = i2c_get_clientdata(client);
> +	struct adt7475_data *data = dev_get_drvdata(dev);
>  	long val;
>  
>  	switch (sattr->index) {
> @@ -570,8 +571,8 @@ static ssize_t temp_st_store(struct device *dev,
>  			     size_t count)
>  {
>  	struct sensor_device_attribute_2 *sattr = to_sensor_dev_attr_2(attr);
> -	struct i2c_client *client = to_i2c_client(dev);
> -	struct adt7475_data *data = i2c_get_clientdata(client);
> +	struct adt7475_data *data = dev_get_drvdata(dev);
> +	struct i2c_client *client = data->client;
>  	unsigned char reg;
>  	int shift, idx;
>  	ulong val;
> @@ -647,8 +648,8 @@ static ssize_t point2_show(struct device *dev, struct device_attribute *attr,
>  static ssize_t point2_store(struct device *dev, struct device_attribute *attr,
>  			    const char *buf, size_t count)
>  {
> -	struct i2c_client *client = to_i2c_client(dev);
> -	struct adt7475_data *data = i2c_get_clientdata(client);
> +	struct adt7475_data *data = dev_get_drvdata(dev);
> +	struct i2c_client *client = data->client;
>  	struct sensor_device_attribute_2 *sattr = to_sensor_dev_attr_2(attr);
>  	int temp;
>  	long val;
> @@ -710,8 +711,8 @@ static ssize_t tach_store(struct device *dev, struct device_attribute *attr,
>  {
>  
>  	struct sensor_device_attribute_2 *sattr = to_sensor_dev_attr_2(attr);
> -	struct i2c_client *client = to_i2c_client(dev);
> -	struct adt7475_data *data = i2c_get_clientdata(client);
> +	struct adt7475_data *data = dev_get_drvdata(dev);
> +	struct i2c_client *client = data->client;
>  	unsigned long val;
>  
>  	if (kstrtoul(buf, 10, &val))
> @@ -769,8 +770,8 @@ static ssize_t pwm_store(struct device *dev, struct device_attribute *attr,
>  {
>  
>  	struct sensor_device_attribute_2 *sattr = to_sensor_dev_attr_2(attr);
> -	struct i2c_client *client = to_i2c_client(dev);
> -	struct adt7475_data *data = i2c_get_clientdata(client);
> +	struct adt7475_data *data = dev_get_drvdata(dev);
> +	struct i2c_client *client = data->client;
>  	unsigned char reg = 0;
>  	long val;
>  
> @@ -818,8 +819,8 @@ static ssize_t stall_disable_show(struct device *dev,
>  				  struct device_attribute *attr, char *buf)
>  {
>  	struct sensor_device_attribute_2 *sattr = to_sensor_dev_attr_2(attr);
> -	struct i2c_client *client = to_i2c_client(dev);
> -	struct adt7475_data *data = i2c_get_clientdata(client);
> +	struct adt7475_data *data = dev_get_drvdata(dev);
> +
>  	u8 mask = BIT(5 + sattr->index);
>  
>  	return sprintf(buf, "%d\n", !!(data->enh_acoustics[0] & mask));
> @@ -830,8 +831,8 @@ static ssize_t stall_disable_store(struct device *dev,
>  				   const char *buf, size_t count)
>  {
>  	struct sensor_device_attribute_2 *sattr = to_sensor_dev_attr_2(attr);
> -	struct i2c_client *client = to_i2c_client(dev);
> -	struct adt7475_data *data = i2c_get_clientdata(client);
> +	struct adt7475_data *data = dev_get_drvdata(dev);
> +	struct i2c_client *client = data->client;
>  	long val;
>  	u8 mask = BIT(5 + sattr->index);
>  
> @@ -914,8 +915,8 @@ static ssize_t pwmchan_store(struct device *dev,
>  			     size_t count)
>  {
>  	struct sensor_device_attribute_2 *sattr = to_sensor_dev_attr_2(attr);
> -	struct i2c_client *client = to_i2c_client(dev);
> -	struct adt7475_data *data = i2c_get_clientdata(client);
> +	struct adt7475_data *data = dev_get_drvdata(dev);
> +	struct i2c_client *client = data->client;
>  	int r;
>  	long val;
>  
> @@ -938,8 +939,8 @@ static ssize_t pwmctrl_store(struct device *dev,
>  			     size_t count)
>  {
>  	struct sensor_device_attribute_2 *sattr = to_sensor_dev_attr_2(attr);
> -	struct i2c_client *client = to_i2c_client(dev);
> -	struct adt7475_data *data = i2c_get_clientdata(client);
> +	struct adt7475_data *data = dev_get_drvdata(dev);
> +	struct i2c_client *client = data->client;
>  	int r;
>  	long val;
>  
> @@ -982,8 +983,8 @@ static ssize_t pwmfreq_store(struct device *dev,
>  			     size_t count)
>  {
>  	struct sensor_device_attribute_2 *sattr = to_sensor_dev_attr_2(attr);
> -	struct i2c_client *client = to_i2c_client(dev);
> -	struct adt7475_data *data = i2c_get_clientdata(client);
> +	struct adt7475_data *data = dev_get_drvdata(dev);
> +	struct i2c_client *client = data->client;
>  	int out;
>  	long val;
>  
> @@ -1022,8 +1023,8 @@ static ssize_t pwm_use_point2_pwm_at_crit_store(struct device *dev,
>  					struct device_attribute *devattr,
>  					const char *buf, size_t count)
>  {
> -	struct i2c_client *client = to_i2c_client(dev);
> -	struct adt7475_data *data = i2c_get_clientdata(client);
> +	struct adt7475_data *data = dev_get_drvdata(dev);
> +	struct i2c_client *client = data->client;
>  	long val;
>  
>  	if (kstrtol(buf, 10, &val))
> @@ -1305,6 +1306,9 @@ static const struct attribute_group in4_attr_group = { .attrs = in4_attrs };
>  static const struct attribute_group in5_attr_group = { .attrs = in5_attrs };
>  static const struct attribute_group vid_attr_group = { .attrs = vid_attrs };
>  
> +/* Number of possible attribute groups to add into sysfs */
> +#define ATTR_GROUP_COUNT 8
> +

Not used anywhere.

>  static int adt7475_detect(struct i2c_client *client,
>  			  struct i2c_board_info *info)
>  {
> @@ -1489,7 +1493,7 @@ static int adt7475_probe(struct i2c_client *client,
>  	};
>  
>  	struct adt7475_data *data;
> -	int i, ret = 0, revision;
> +	int i, ret = 0, revision, group_num = 0;
>  	u8 config2, config3;
>  
>  	data = devm_kzalloc(&client->dev, sizeof(*data), GFP_KERNEL);
> @@ -1497,6 +1501,7 @@ static int adt7475_probe(struct i2c_client *client,
>  		return -ENOMEM;
>  
>  	mutex_init(&data->lock);
> +	data->client = client;
>  	i2c_set_clientdata(client, data);
>  
>  	if (client->dev.of_node)
> @@ -1590,49 +1595,37 @@ static int adt7475_probe(struct i2c_client *client,
>  		break;
>  	}
>  
> -	ret = sysfs_create_group(&client->dev.kobj, &adt7475_attr_group);
> -	if (ret)
> -		return ret;
> +	data->groups[group_num++] = &adt7475_attr_group;
>  
>  	/* Features that can be disabled individually */
>  	if (data->has_fan4) {
> -		ret = sysfs_create_group(&client->dev.kobj, &fan4_attr_group);
> -		if (ret)
> -			goto eremove;
> +		data->groups[group_num++] = &fan4_attr_group;
>  	}
>  	if (data->has_pwm2) {
> -		ret = sysfs_create_group(&client->dev.kobj, &pwm2_attr_group);
> -		if (ret)
> -			goto eremove;
> +		data->groups[group_num++] = &pwm2_attr_group;
>  	}
>  	if (data->has_voltage & (1 << 0)) {
> -		ret = sysfs_create_group(&client->dev.kobj, &in0_attr_group);
> -		if (ret)
> -			goto eremove;
> +		data->groups[group_num++] = &in0_attr_group;
>  	}
>  	if (data->has_voltage & (1 << 3)) {
> -		ret = sysfs_create_group(&client->dev.kobj, &in3_attr_group);
> -		if (ret)
> -			goto eremove;
> +		data->groups[group_num++] = &in3_attr_group;
>  	}
>  	if (data->has_voltage & (1 << 4)) {
> -		ret = sysfs_create_group(&client->dev.kobj, &in4_attr_group);
> -		if (ret)
> -			goto eremove;
> +		data->groups[group_num++] = &in4_attr_group;
>  	}
>  	if (data->has_voltage & (1 << 5)) {
> -		ret = sysfs_create_group(&client->dev.kobj, &in5_attr_group);
> -		if (ret)
> -			goto eremove;
> +		data->groups[group_num++] = &in5_attr_group;
>  	}
>  	if (data->has_vid) {
>  		data->vrm = vid_which_vrm();
> -		ret = sysfs_create_group(&client->dev.kobj, &vid_attr_group);
> -		if (ret)
> -			goto eremove;
> +		data->groups[group_num] = &vid_attr_group;
>  	}
>  
> -	data->hwmon_dev = hwmon_device_register(&client->dev);
> +	/* register device with all the acquired attributes */
> +	data->hwmon_dev = hwmon_device_register_with_groups(&client->dev,
> +							    client->name, data,
> +							    data->groups);
> +

You could call devm_hwmon_device_register_with_groups() here, drop the
remove function, and drop hwmon_dev from struct adt7475_data.

Also, adt7475_remove_files() is no longer necessary. With the new API,
attribute files are owned by the hwmon subsystem.

>  	if (IS_ERR(data->hwmon_dev)) {
>  		ret = PTR_ERR(data->hwmon_dev);
>  		goto eremove;
> @@ -1757,8 +1750,8 @@ static void adt7475_read_pwm(struct i2c_client *client, int index)
>  
>  static int adt7475_update_measure(struct device *dev)
>  {
> -	struct i2c_client *client = to_i2c_client(dev);
> -	struct adt7475_data *data = i2c_get_clientdata(client);
> +	struct adt7475_data *data = dev_get_drvdata(dev);
> +	struct i2c_client *client = data->client;
>  	u16 ext;
>  	int i;
>  	int ret;
> @@ -1854,8 +1847,7 @@ static int adt7475_update_measure(struct device *dev)
>  
>  static struct adt7475_data *adt7475_update_device(struct device *dev)
>  {
> -	struct i2c_client *client = to_i2c_client(dev);
> -	struct adt7475_data *data = i2c_get_clientdata(client);
> +	struct adt7475_data *data = dev_get_drvdata(dev);
>  	int ret;
>  
>  	mutex_lock(&data->lock);