Re: [PATCH 1/4] hwmon: (sch56xx) Use devres functions for watchdog

[Guenter Roeck <linux@xxxxxxxxxxxx>]

On 5/7/21 2:24 PM, W_Armin@xxxxxx wrote:
> From: Armin Wolf <W_Armin@xxxxxx>
>
> Use devm_kzalloc()/devm_watchdog_register() for
> watchdog registration since it allows us to remove
> the sch56xx_watchdog_data struct from the drivers
> own data structs.
> Remove sch56xx_watchdog_unregister since devres
> takes care of that now.
>
> Signed-off-by: Armin Wolf <W_Armin@xxxxxx>
> ---
>   drivers/hwmon/sch5627.c        | 12 +++---------
>   drivers/hwmon/sch5636.c        |  9 ++-------
>   drivers/hwmon/sch56xx-common.c | 13 +++----------
>   3 files changed, 8 insertions(+), 26 deletions(-)
>
> diff --git a/drivers/hwmon/sch5627.c b/drivers/hwmon/sch5627.c
> index 4324a5dbc968..8a71fba33ea0 100644
> --- a/drivers/hwmon/sch5627.c
> +++ b/drivers/hwmon/sch5627.c
> @@ -64,7 +64,6 @@ static const char * const SCH5627_IN_LABELS[SCH5627_NO_IN] = {
>
>   struct sch5627_data {
>   	unsigned short addr;
> -	struct sch56xx_watchdog_data *watchdog;
>   	u8 control;
>   	u8 temp_max[SCH5627_NO_TEMPS];
>   	u8 temp_crit[SCH5627_NO_TEMPS];
> @@ -359,11 +358,6 @@ static const struct hwmon_chip_info sch5627_chip_info = {
>
>   static int sch5627_remove(struct platform_device *pdev)
>   {
> -	struct sch5627_data *data = platform_get_drvdata(pdev);
> -
> -	if (data->watchdog)
> -		sch56xx_watchdog_unregister(data->watchdog);
> -
>   	return 0;
>   }

This function is no longer necessary and can be dropped as well.

> @@ -460,9 +454,9 @@ static int sch5627_probe(struct platform_device *pdev)
>   		return PTR_ERR(hwmon_dev);
>
>   	/* Note failing to register the watchdog is not a fatal error */
> -	data->watchdog = sch56xx_watchdog_register(&pdev->dev, data->addr,
> -			(build_code << 24) | (build_id << 8) | hwmon_rev,
> -			&data->update_lock, 1);
> +	sch56xx_watchdog_register(&pdev->dev, data->addr,
> +				  (build_code << 24) | (build_id << 8) | hwmon_rev,
> +				  &data->update_lock, 1);
>
>   	return 0;
>   }
> diff --git a/drivers/hwmon/sch5636.c b/drivers/hwmon/sch5636.c
> index 5683a38740f6..a5cd4de36575 100644
> --- a/drivers/hwmon/sch5636.c
> +++ b/drivers/hwmon/sch5636.c
> @@ -54,7 +54,6 @@ static const u16 SCH5636_REG_FAN_VAL[SCH5636_NO_FANS] = {
>   struct sch5636_data {
>   	unsigned short addr;
>   	struct device *hwmon_dev;
> -	struct sch56xx_watchdog_data *watchdog;
>
>   	struct mutex update_lock;
>   	char valid;			/* !=0 if following fields are valid */
> @@ -372,9 +371,6 @@ static int sch5636_remove(struct platform_device *pdev)
>   	struct sch5636_data *data = platform_get_drvdata(pdev);
>   	int i;
>
> -	if (data->watchdog)
> -		sch56xx_watchdog_unregister(data->watchdog);
> -
>   	if (data->hwmon_dev)
>   		hwmon_device_unregister(data->hwmon_dev);
>
> @@ -495,9 +491,8 @@ static int sch5636_probe(struct platform_device *pdev)
>   	}
>
>   	/* Note failing to register the watchdog is not a fatal error */
> -	data->watchdog = sch56xx_watchdog_register(&pdev->dev, data->addr,
> -					(revision[0] << 8) | revision[1],
> -					&data->update_lock, 0);
> +	sch56xx_watchdog_register(&pdev->dev, data->addr, (revision[0] << 8) | revision[1],
> +				  &data->update_lock, 0);
>
>   	return 0;
>
> diff --git a/drivers/hwmon/sch56xx-common.c b/drivers/hwmon/sch56xx-common.c
> index 6c84780e358e..9c884fd0beb2 100644
> --- a/drivers/hwmon/sch56xx-common.c
> +++ b/drivers/hwmon/sch56xx-common.c
> @@ -401,7 +401,7 @@ struct sch56xx_watchdog_data *sch56xx_watchdog_register(struct device *parent,
>   		return NULL;
>   	}
>
> -	data = kzalloc(sizeof(struct sch56xx_watchdog_data), GFP_KERNEL);
> +	data = devm_kzalloc(parent, sizeof(struct sch56xx_watchdog_data), GFP_KERNEL);
>   	if (!data)
>   		return NULL;
>
> @@ -438,10 +438,10 @@ struct sch56xx_watchdog_data *sch56xx_watchdog_register(struct device *parent,

Since the return value is no longer used, the function does not need
to return it anymore.

>   	data->watchdog_output_enable = output_enable;
>
>   	watchdog_set_drvdata(&data->wddev, data);
> -	err = watchdog_register_device(&data->wddev);
> +	err = devm_watchdog_register_device(parent, &data->wddev);
>   	if (err) {
>   		pr_err("Registering watchdog chardev: %d\n", err);
> -		kfree(data);
> +		devm_kfree(parent, data);
>   		return NULL;
>   	}
>
> @@ -449,13 +449,6 @@ struct sch56xx_watchdog_data *sch56xx_watchdog_register(struct device *parent,
>   }
>   EXPORT_SYMBOL(sch56xx_watchdog_register);
>
> -void sch56xx_watchdog_unregister(struct sch56xx_watchdog_data *data)
> -{
> -	watchdog_unregister_device(&data->wddev);
> -	kfree(data);
> -}
> -EXPORT_SYMBOL(sch56xx_watchdog_unregister);
> -
>   /*
>    * platform dev find, add and remove functions
>    */
> --
> 2.20.1