[PATCH v2] hwmon: adt7410: fix hwmon sysfs attrs not being created

[PATCH v2] hwmon: adt7410: fix hwmon sysfs attrs not being created

[Cosmin Tanislav]

sysfs attrs for adt7410 are supposed to be created under
the hwmon device, but are being created under the i2c
device.
Switch to hwmon_device_register_with_groups to create
the relevant attrs in the correct directory, and
to also fix the deprecation warning created by
hwmon_device_register.

To achieve this, the following changes are also made.

 * pass client name from adt7410 driver to common
   driver and use it to register hwmon device
 * remove attribute_group declaration and use the
   ATTRIBUTE_GROUPS macro to align with other
   usages of hwmon_device_register_with_groups
 * remove name attribute since it is not needed anymore
   after moving away from hwmon_device_register
 * store bus device into private data and use it to call
   the i2c/spi ops both in hwmon sysfs attr contexts and
   outside of them

Signed-off-by: Cosmin Tanislav <demonsingur@gmail.com>
---
 drivers/hwmon/adt7410.c |  2 +-
 drivers/hwmon/adt7x10.c | 56 ++++++++---------------------------------
 2 files changed, 12 insertions(+), 46 deletions(-)

diff --git a/drivers/hwmon/adt7410.c b/drivers/hwmon/adt7410.c
index 80f8a4673315..a5901ecbb347 100644
--- a/drivers/hwmon/adt7410.c
+++ b/drivers/hwmon/adt7410.c
@@ -46,7 +46,7 @@ static int adt7410_i2c_probe(struct i2c_client *client,
 			I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_WORD_DATA))
 		return -ENODEV;
 
-	return adt7x10_probe(&client->dev, NULL, client->irq, &adt7410_i2c_ops);
+	return adt7x10_probe(&client->dev, client->name, client->irq, &adt7410_i2c_ops);
 }
 
 static int adt7410_i2c_remove(struct i2c_client *client)
diff --git a/drivers/hwmon/adt7x10.c b/drivers/hwmon/adt7x10.c
index 3f03b4cf5858..5093911472e8 100644
--- a/drivers/hwmon/adt7x10.c
+++ b/drivers/hwmon/adt7x10.c
@@ -54,8 +54,8 @@
 /* Each client has this additional data */
 struct adt7x10_data {
 	const struct adt7x10_ops *ops;
-	const char		*name;
 	struct device		*hwmon_dev;
+	struct device		*bus_dev;
 	struct mutex		update_lock;
 	u8			config;
 	u8			oldconfig;
@@ -72,25 +72,25 @@ struct adt7x10_data {
 static int adt7x10_read_byte(struct device *dev, u8 reg)
 {
 	struct adt7x10_data *d = dev_get_drvdata(dev);
-	return d->ops->read_byte(dev, reg);
+	return d->ops->read_byte(d->bus_dev, reg);
 }
 
 static int adt7x10_write_byte(struct device *dev, u8 reg, u8 data)
 {
 	struct adt7x10_data *d = dev_get_drvdata(dev);
-	return d->ops->write_byte(dev, reg, data);
+	return d->ops->write_byte(d->bus_dev, reg, data);
 }
 
 static int adt7x10_read_word(struct device *dev, u8 reg)
 {
 	struct adt7x10_data *d = dev_get_drvdata(dev);
-	return d->ops->read_word(dev, reg);
+	return d->ops->read_word(d->bus_dev, reg);
 }
 
 static int adt7x10_write_word(struct device *dev, u8 reg, u16 data)
 {
 	struct adt7x10_data *d = dev_get_drvdata(dev);
-	return d->ops->write_word(dev, reg, data);
+	return d->ops->write_word(d->bus_dev, reg, data);
 }
 
 static const u8 ADT7X10_REG_TEMP[4] = {
@@ -315,14 +315,6 @@ static ssize_t adt7x10_alarm_show(struct device *dev,
 	return sprintf(buf, "%d\n", !!(ret & attr->index));
 }
 
-static ssize_t name_show(struct device *dev, struct device_attribute *da,
-			 char *buf)
-{
-	struct adt7x10_data *data = dev_get_drvdata(dev);
-
-	return sprintf(buf, "%s\n", data->name);
-}
-
 static SENSOR_DEVICE_ATTR_RO(temp1_input, adt7x10_temp, 0);
 static SENSOR_DEVICE_ATTR_RW(temp1_max, adt7x10_temp, 1);
 static SENSOR_DEVICE_ATTR_RW(temp1_min, adt7x10_temp, 2);
@@ -336,9 +328,8 @@ static SENSOR_DEVICE_ATTR_RO(temp1_max_alarm, adt7x10_alarm,
 			     ADT7X10_STAT_T_HIGH);
 static SENSOR_DEVICE_ATTR_RO(temp1_crit_alarm, adt7x10_alarm,
 			     ADT7X10_STAT_T_CRIT);
-static DEVICE_ATTR_RO(name);
 
-static struct attribute *adt7x10_attributes[] = {
+static struct attribute *adt7x10_attrs[] = {
 	&sensor_dev_attr_temp1_input.dev_attr.attr,
 	&sensor_dev_attr_temp1_max.dev_attr.attr,
 	&sensor_dev_attr_temp1_min.dev_attr.attr,
@@ -352,9 +343,7 @@ static struct attribute *adt7x10_attributes[] = {
 	NULL
 };
 
-static const struct attribute_group adt7x10_group = {
-	.attrs = adt7x10_attributes,
-};
+ATTRIBUTE_GROUPS(adt7x10);
 
 int adt7x10_probe(struct device *dev, const char *name, int irq,
 		  const struct adt7x10_ops *ops)
@@ -367,7 +356,7 @@ int adt7x10_probe(struct device *dev, const char *name, int irq,
 		return -ENOMEM;
 
 	data->ops = ops;
-	data->name = name;
+	data->bus_dev = dev;
 
 	dev_set_drvdata(dev, data);
 	mutex_init(&data->update_lock);
@@ -399,26 +388,11 @@ int adt7x10_probe(struct device *dev, const char *name, int irq,
 	if (ret)
 		goto exit_restore;
 
-	/* Register sysfs hooks */
-	ret = sysfs_create_group(&dev->kobj, &adt7x10_group);
-	if (ret)
-		goto exit_restore;
-
-	/*
-	 * The I2C device will already have it's own 'name' attribute, but for
-	 * the SPI device we need to register it. name will only be non NULL if
-	 * the device doesn't register the 'name' attribute on its own.
-	 */
-	if (name) {
-		ret = device_create_file(dev, &dev_attr_name);
-		if (ret)
-			goto exit_remove;
-	}
-
-	data->hwmon_dev = hwmon_device_register(dev);
+	data->hwmon_dev = hwmon_device_register_with_groups(dev, name, data,
+							    adt7x10_groups);
 	if (IS_ERR(data->hwmon_dev)) {
 		ret = PTR_ERR(data->hwmon_dev);
-		goto exit_remove_name;
+		goto exit_restore;
 	}
 
 	if (irq > 0) {
@@ -433,11 +407,6 @@ int adt7x10_probe(struct device *dev, const char *name, int irq,
 
 exit_hwmon_device_unregister:
 	hwmon_device_unregister(data->hwmon_dev);
-exit_remove_name:
-	if (name)
-		device_remove_file(dev, &dev_attr_name);
-exit_remove:
-	sysfs_remove_group(&dev->kobj, &adt7x10_group);
 exit_restore:
 	adt7x10_write_byte(dev, ADT7X10_CONFIG, data->oldconfig);
 	return ret;
@@ -452,9 +421,6 @@ int adt7x10_remove(struct device *dev, int irq)
 		free_irq(irq, dev);
 
 	hwmon_device_unregister(data->hwmon_dev);
-	if (data->name)
-		device_remove_file(dev, &dev_attr_name);
-	sysfs_remove_group(&dev->kobj, &adt7x10_group);
 	if (data->oldconfig != data->config)
 		adt7x10_write_byte(dev, ADT7X10_CONFIG, data->oldconfig);
 	return 0;
-- 
2.33.0

Re: [PATCH v2] hwmon: adt7410: fix hwmon sysfs attrs not being created

[Guenter Roeck]

On Wed, Aug 25, 2021 at 10:42:27AM +0300, Cosmin Tanislav wrote:
> sysfs attrs for adt7410 are supposed to be created under
> the hwmon device, but are being created under the i2c
> device.

This is not correct. hwmon sysfs attributes may exist in either location,
and the lm-sensors userspace library handles both just fine.

> Switch to hwmon_device_register_with_groups to create
> the relevant attrs in the correct directory, and
> to also fix the deprecation warning created by
> hwmon_device_register.
> 

There is no "correct" directory. The reason for introducing the
new API was to simplify attribute creation and to avoid potential
race conditions by attaching the attributes to the hwmon device,
and by attaching them during device creation and not independently.
The new APIs also ensure that the "name' attribute exists,
which was not previously the case.

The scope of this patch should simply be the conversion
to a non-deprecated API.

On a side note, conversion to use the with_info API would
reduce driver size significantly and be even more valuable.

> To achieve this, the following changes are also made.
> 
>  * pass client name from adt7410 driver to common
>    driver and use it to register hwmon device
>  * remove attribute_group declaration and use the
>    ATTRIBUTE_GROUPS macro to align with other
>    usages of hwmon_device_register_with_groups
>  * remove name attribute since it is not needed anymore
>    after moving away from hwmon_device_register
>  * store bus device into private data and use it to call
>    the i2c/spi ops both in hwmon sysfs attr contexts and
>    outside of them

This is just mechanics and really not relevant for the
patch description.

> 
> Signed-off-by: Cosmin Tanislav <demonsingur@gmail.com>
> ---

FWIW:

<Formletter>  
Change log goes here. If it is missing, I won't know what changed.
That means I will have to dig out older patch versions to compare.
That costs time and would hold up both this patch as well as all other
patches which I still have to review.

For this reason, I will not review patches without change log.
</Formletter>

Thanks,
Guenter

>  drivers/hwmon/adt7410.c |  2 +-
>  drivers/hwmon/adt7x10.c | 56 ++++++++---------------------------------
>  2 files changed, 12 insertions(+), 46 deletions(-)
> 
> diff --git a/drivers/hwmon/adt7410.c b/drivers/hwmon/adt7410.c
> index 80f8a4673315..a5901ecbb347 100644
> --- a/drivers/hwmon/adt7410.c
> +++ b/drivers/hwmon/adt7410.c
> @@ -46,7 +46,7 @@ static int adt7410_i2c_probe(struct i2c_client *client,
>  			I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_WORD_DATA))
>  		return -ENODEV;
>  
> -	return adt7x10_probe(&client->dev, NULL, client->irq, &adt7410_i2c_ops);
> +	return adt7x10_probe(&client->dev, client->name, client->irq, &adt7410_i2c_ops);
>  }
>  
>  static int adt7410_i2c_remove(struct i2c_client *client)
> diff --git a/drivers/hwmon/adt7x10.c b/drivers/hwmon/adt7x10.c
> index 3f03b4cf5858..5093911472e8 100644
> --- a/drivers/hwmon/adt7x10.c
> +++ b/drivers/hwmon/adt7x10.c
> @@ -54,8 +54,8 @@
>  /* Each client has this additional data */
>  struct adt7x10_data {
>  	const struct adt7x10_ops *ops;
> -	const char		*name;
>  	struct device		*hwmon_dev;
> +	struct device		*bus_dev;
>  	struct mutex		update_lock;
>  	u8			config;
>  	u8			oldconfig;
> @@ -72,25 +72,25 @@ struct adt7x10_data {
>  static int adt7x10_read_byte(struct device *dev, u8 reg)
>  {
>  	struct adt7x10_data *d = dev_get_drvdata(dev);
> -	return d->ops->read_byte(dev, reg);
> +	return d->ops->read_byte(d->bus_dev, reg);
>  }
>  
>  static int adt7x10_write_byte(struct device *dev, u8 reg, u8 data)
>  {
>  	struct adt7x10_data *d = dev_get_drvdata(dev);
> -	return d->ops->write_byte(dev, reg, data);
> +	return d->ops->write_byte(d->bus_dev, reg, data);
>  }
>  
>  static int adt7x10_read_word(struct device *dev, u8 reg)
>  {
>  	struct adt7x10_data *d = dev_get_drvdata(dev);
> -	return d->ops->read_word(dev, reg);
> +	return d->ops->read_word(d->bus_dev, reg);
>  }
>  
>  static int adt7x10_write_word(struct device *dev, u8 reg, u16 data)
>  {
>  	struct adt7x10_data *d = dev_get_drvdata(dev);
> -	return d->ops->write_word(dev, reg, data);
> +	return d->ops->write_word(d->bus_dev, reg, data);
>  }
>  
>  static const u8 ADT7X10_REG_TEMP[4] = {
> @@ -315,14 +315,6 @@ static ssize_t adt7x10_alarm_show(struct device *dev,
>  	return sprintf(buf, "%d\n", !!(ret & attr->index));
>  }
>  
> -static ssize_t name_show(struct device *dev, struct device_attribute *da,
> -			 char *buf)
> -{
> -	struct adt7x10_data *data = dev_get_drvdata(dev);
> -
> -	return sprintf(buf, "%s\n", data->name);
> -}
> -
>  static SENSOR_DEVICE_ATTR_RO(temp1_input, adt7x10_temp, 0);
>  static SENSOR_DEVICE_ATTR_RW(temp1_max, adt7x10_temp, 1);
>  static SENSOR_DEVICE_ATTR_RW(temp1_min, adt7x10_temp, 2);
> @@ -336,9 +328,8 @@ static SENSOR_DEVICE_ATTR_RO(temp1_max_alarm, adt7x10_alarm,
>  			     ADT7X10_STAT_T_HIGH);
>  static SENSOR_DEVICE_ATTR_RO(temp1_crit_alarm, adt7x10_alarm,
>  			     ADT7X10_STAT_T_CRIT);
> -static DEVICE_ATTR_RO(name);
>  
> -static struct attribute *adt7x10_attributes[] = {
> +static struct attribute *adt7x10_attrs[] = {
>  	&sensor_dev_attr_temp1_input.dev_attr.attr,
>  	&sensor_dev_attr_temp1_max.dev_attr.attr,
>  	&sensor_dev_attr_temp1_min.dev_attr.attr,
> @@ -352,9 +343,7 @@ static struct attribute *adt7x10_attributes[] = {
>  	NULL
>  };
>  
> -static const struct attribute_group adt7x10_group = {
> -	.attrs = adt7x10_attributes,
> -};
> +ATTRIBUTE_GROUPS(adt7x10);
>  
>  int adt7x10_probe(struct device *dev, const char *name, int irq,
>  		  const struct adt7x10_ops *ops)
> @@ -367,7 +356,7 @@ int adt7x10_probe(struct device *dev, const char *name, int irq,
>  		return -ENOMEM;
>  
>  	data->ops = ops;
> -	data->name = name;
> +	data->bus_dev = dev;
>  
>  	dev_set_drvdata(dev, data);
>  	mutex_init(&data->update_lock);
> @@ -399,26 +388,11 @@ int adt7x10_probe(struct device *dev, const char *name, int irq,
>  	if (ret)
>  		goto exit_restore;
>  
> -	/* Register sysfs hooks */
> -	ret = sysfs_create_group(&dev->kobj, &adt7x10_group);
> -	if (ret)
> -		goto exit_restore;
> -
> -	/*
> -	 * The I2C device will already have it's own 'name' attribute, but for
> -	 * the SPI device we need to register it. name will only be non NULL if
> -	 * the device doesn't register the 'name' attribute on its own.
> -	 */
> -	if (name) {
> -		ret = device_create_file(dev, &dev_attr_name);
> -		if (ret)
> -			goto exit_remove;
> -	}
> -
> -	data->hwmon_dev = hwmon_device_register(dev);
> +	data->hwmon_dev = hwmon_device_register_with_groups(dev, name, data,
> +							    adt7x10_groups);
>  	if (IS_ERR(data->hwmon_dev)) {
>  		ret = PTR_ERR(data->hwmon_dev);
> -		goto exit_remove_name;
> +		goto exit_restore;
>  	}
>  
>  	if (irq > 0) {
> @@ -433,11 +407,6 @@ int adt7x10_probe(struct device *dev, const char *name, int irq,
>  
>  exit_hwmon_device_unregister:
>  	hwmon_device_unregister(data->hwmon_dev);
> -exit_remove_name:
> -	if (name)
> -		device_remove_file(dev, &dev_attr_name);
> -exit_remove:
> -	sysfs_remove_group(&dev->kobj, &adt7x10_group);
>  exit_restore:
>  	adt7x10_write_byte(dev, ADT7X10_CONFIG, data->oldconfig);
>  	return ret;
> @@ -452,9 +421,6 @@ int adt7x10_remove(struct device *dev, int irq)
>  		free_irq(irq, dev);
>  
>  	hwmon_device_unregister(data->hwmon_dev);
> -	if (data->name)
> -		device_remove_file(dev, &dev_attr_name);
> -	sysfs_remove_group(&dev->kobj, &adt7x10_group);
>  	if (data->oldconfig != data->config)
>  		adt7x10_write_byte(dev, ADT7X10_CONFIG, data->oldconfig);
>  	return 0;
> -- 
> 2.33.0
>