Re: [PATCH v2 5/6] ACPI: NFIT: Replace acpi_driver with platform_driver

["Wilczynski, Michal" <michal.wilczynski@intel.com>]

On 10/6/2023 7:30 PM, Michal Wilczynski wrote:
> NFIT driver uses struct acpi_driver incorrectly to register itself.
> This is wrong as the instances of the ACPI devices are not meant
> to be literal devices, they're supposed to describe ACPI entry of a
> particular device.
>
> Use platform_driver instead of acpi_driver. In relevant places call
> platform devices instances pdev to make a distinction with ACPI
> devices instances.
>
> NFIT driver uses devm_*() family of functions extensively. This change
> has no impact on correct functioning of the whole devm_*() family of
> functions, since the lifecycle of the device stays the same. It is still
> being created during the enumeration, and destroyed on platform device
> removal.
>
> Suggested-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
> Signed-off-by: Michal Wilczynski <michal.wilczynski@intel.com>

Hi Dan,
Rafael already reviewed this patch series and merged patches
that he likes. We're waiting on your input regarding two NFIT
commits in this series.

Thanks a lot !
Michał

> ---
>  drivers/acpi/nfit/core.c | 34 ++++++++++++++++++----------------
>  1 file changed, 18 insertions(+), 16 deletions(-)
>
> diff --git a/drivers/acpi/nfit/core.c b/drivers/acpi/nfit/core.c
> index 942b84d94078..fb0bc16fa186 100644
> --- a/drivers/acpi/nfit/core.c
> +++ b/drivers/acpi/nfit/core.c
> @@ -15,6 +15,7 @@
>  #include <linux/sort.h>
>  #include <linux/io.h>
>  #include <linux/nd.h>
> +#include <linux/platform_device.h>
>  #include <asm/cacheflush.h>
>  #include <acpi/nfit.h>
>  #include "intel.h"
> @@ -98,7 +99,7 @@ static struct acpi_device *to_acpi_dev(struct acpi_nfit_desc *acpi_desc)
>  			|| strcmp(nd_desc->provider_name, "ACPI.NFIT") != 0)
>  		return NULL;
>  
> -	return to_acpi_device(acpi_desc->dev);
> +	return ACPI_COMPANION(acpi_desc->dev);
>  }
>  
>  static int xlat_bus_status(void *buf, unsigned int cmd, u32 status)
> @@ -3284,11 +3285,11 @@ static void acpi_nfit_put_table(void *table)
>  
>  static void acpi_nfit_notify(acpi_handle handle, u32 event, void *data)
>  {
> -	struct acpi_device *adev = data;
> +	struct device *dev = data;
>  
> -	device_lock(&adev->dev);
> -	__acpi_nfit_notify(&adev->dev, handle, event);
> -	device_unlock(&adev->dev);
> +	device_lock(dev);
> +	__acpi_nfit_notify(dev, handle, event);
> +	device_unlock(dev);
>  }
>  
>  static void acpi_nfit_remove_notify_handler(void *data)
> @@ -3329,11 +3330,12 @@ void acpi_nfit_shutdown(void *data)
>  }
>  EXPORT_SYMBOL_GPL(acpi_nfit_shutdown);
>  
> -static int acpi_nfit_add(struct acpi_device *adev)
> +static int acpi_nfit_probe(struct platform_device *pdev)
>  {
>  	struct acpi_buffer buf = { ACPI_ALLOCATE_BUFFER, NULL };
>  	struct acpi_nfit_desc *acpi_desc;
> -	struct device *dev = &adev->dev;
> +	struct device *dev = &pdev->dev;
> +	struct acpi_device *adev = ACPI_COMPANION(dev);
>  	struct acpi_table_header *tbl;
>  	acpi_status status = AE_OK;
>  	acpi_size sz;
> @@ -3360,7 +3362,7 @@ static int acpi_nfit_add(struct acpi_device *adev)
>  	acpi_desc = devm_kzalloc(dev, sizeof(*acpi_desc), GFP_KERNEL);
>  	if (!acpi_desc)
>  		return -ENOMEM;
> -	acpi_nfit_desc_init(acpi_desc, &adev->dev);
> +	acpi_nfit_desc_init(acpi_desc, dev);
>  
>  	/* Save the acpi header for exporting the revision via sysfs */
>  	acpi_desc->acpi_header = *tbl;
> @@ -3391,7 +3393,7 @@ static int acpi_nfit_add(struct acpi_device *adev)
>  		return rc;
>  
>  	rc = acpi_dev_install_notify_handler(adev, ACPI_DEVICE_NOTIFY,
> -					     acpi_nfit_notify, adev);
> +					     acpi_nfit_notify, dev);
>  	if (rc)
>  		return rc;
>  
> @@ -3475,11 +3477,11 @@ static const struct acpi_device_id acpi_nfit_ids[] = {
>  };
>  MODULE_DEVICE_TABLE(acpi, acpi_nfit_ids);
>  
> -static struct acpi_driver acpi_nfit_driver = {
> -	.name = KBUILD_MODNAME,
> -	.ids = acpi_nfit_ids,
> -	.ops = {
> -		.add = acpi_nfit_add,
> +static struct platform_driver acpi_nfit_driver = {
> +	.probe = acpi_nfit_probe,
> +	.driver = {
> +		.name = KBUILD_MODNAME,
> +		.acpi_match_table = acpi_nfit_ids,
>  	},
>  };
>  
> @@ -3517,7 +3519,7 @@ static __init int nfit_init(void)
>  		return -ENOMEM;
>  
>  	nfit_mce_register();
> -	ret = acpi_bus_register_driver(&acpi_nfit_driver);
> +	ret = platform_driver_register(&acpi_nfit_driver);
>  	if (ret) {
>  		nfit_mce_unregister();
>  		destroy_workqueue(nfit_wq);
> @@ -3530,7 +3532,7 @@ static __init int nfit_init(void)
>  static __exit void nfit_exit(void)
>  {
>  	nfit_mce_unregister();
> -	acpi_bus_unregister_driver(&acpi_nfit_driver);
> +	platform_driver_unregister(&acpi_nfit_driver);
>  	destroy_workqueue(nfit_wq);
>  	WARN_ON(!list_empty(&acpi_descs));
>  }