Re: [PATCH v8 2/6] platform/x86: Add lenovo-wmi-helpers

[ALOK TIWARI <alok.a.tiwari@oracle.com>]

On 05-05-2025 06:36, Derek J. Clark wrote:
> Adds lenovo-wmi-helpers, which provides a common wrapper function for
> wmidev_evaluate_method that does data validation and error handling.
> 
> Reviewed-by: Armin Wolf<W_Armin@gmx.de>
> Reviewed-by: Mario Limonciello<mario.limonciello@amd.com>
> Signed-off-by: Derek J. Clark<derekjohn.clark@gmail.com>
> ---
> v8: No change
> v7:
>   - Fix typos
> v6:
>   - Fix typos and rewordings from v5 review.
> v5:
>   - Fixes from v4 review.
>   - Combine all previous methods into a single function that takes a
>     buffer for the wmi method arguments.
> v4:
>   - Changed namespace to LENOVO_WMI_HELPERS from LENOVO_WMI.
>   - Changed filenames to lenovo-wmi-helpers from lenovo-wmi.
>   - Removed structs and functions implemented by other drivers.
> ---
>   MAINTAINERS                               |  1 +
>   drivers/platform/x86/Kconfig              |  4 ++
>   drivers/platform/x86/Makefile             |  1 +
>   drivers/platform/x86/lenovo-wmi-helpers.c | 74 +++++++++++++++++++++++
>   drivers/platform/x86/lenovo-wmi-helpers.h | 20 ++++++
>   5 files changed, 100 insertions(+)
>   create mode 100644 drivers/platform/x86/lenovo-wmi-helpers.c
>   create mode 100644 drivers/platform/x86/lenovo-wmi-helpers.h
> 
> diff --git a/MAINTAINERS b/MAINTAINERS
> index 675f4b26426d..aab59a777693 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -13164,6 +13164,7 @@ L:	platform-driver-x86@vger.kernel.org
>   S:	Maintained
>   F:	Documentation/wmi/devices/lenovo-wmi-gamezone.rst
>   F:	Documentation/wmi/devices/lenovo-wmi-other.rst
> +F:	drivers/platform/x86/lenovo-wmi-helpers.*
>   
>   LENOVO WMI HOTKEY UTILITIES DRIVER
>   M:	Jackie Dong<xy-jackie@139.com>
> diff --git a/drivers/platform/x86/Kconfig b/drivers/platform/x86/Kconfig
> index 43407e76476b..bece1ba61417 100644
> --- a/drivers/platform/x86/Kconfig
> +++ b/drivers/platform/x86/Kconfig
> @@ -459,6 +459,10 @@ config IBM_RTL
>   	 state = 0 (BIOS SMIs on)
>   	 state = 1 (BIOS SMIs off)
>   
> +config LENOVO_WMI_HELPERS
> +	tristate
> +	depends on ACPI_WMI
> +
>   config IDEAPAD_LAPTOP
>   	tristate "Lenovo IdeaPad Laptop Extras"
>   	depends on ACPI
> diff --git a/drivers/platform/x86/Makefile b/drivers/platform/x86/Makefile
> index 650dfbebb6c8..5a9f4e94f78b 100644
> --- a/drivers/platform/x86/Makefile
> +++ b/drivers/platform/x86/Makefile
> @@ -69,6 +69,7 @@ obj-$(CONFIG_THINKPAD_LMI)	+= think-lmi.o
>   obj-$(CONFIG_YOGABOOK)		+= lenovo-yogabook.o
>   obj-$(CONFIG_YT2_1380)		+= lenovo-yoga-tab2-pro-1380-fastcharger.o
>   obj-$(CONFIG_LENOVO_WMI_CAMERA)	+= lenovo-wmi-camera.o
> +obj-$(CONFIG_LENOVO_WMI_HELPERS)	+= lenovo-wmi-helpers.o
>   
>   # Intel
>   obj-y				+= intel/
> diff --git a/drivers/platform/x86/lenovo-wmi-helpers.c b/drivers/platform/x86/lenovo-wmi-helpers.c
> new file mode 100644
> index 000000000000..93aded3d24e9
> --- /dev/null
> +++ b/drivers/platform/x86/lenovo-wmi-helpers.c
> @@ -0,0 +1,74 @@
> +// SPDX-License-Identifier: GPL-2.0-or-later
> +/*
> + * Lenovo Legion WMI helpers driver.
> + *
> + * The Lenovo Legion WMI interface is broken up into multiple GUID interfaces
> + * that require cross-references between GUID's for some functionality. The
> + * "Custom Mode" interface is a legacy interface for managing and displaying
> + * CPU & GPU power and hwmon settings and readings. The "Other Mode" interface
> + * is a modern interface that replaces or extends the "Custom Mode" interface
> + * methods. The "Gamezone" interface adds advanced features such as fan
> + * profiles and overclocking. The "Lighting" interface adds control of various
> + * status lights related to different hardware components. Each of these
> + * drivers uses a common procedure to get data from the WMI interface,
> + * enumerated here.
> + *
> + * Copyright (C) 2025 Derek J. Clark<derekjohn.clark@gmail.com>
> + */
> +
> +#include <linux/acpi.h>
> +#include <linux/cleanup.h>
> +#include <linux/errno.h>
> +#include <linux/export.h>
> +#include <linux/module.h>
> +#include <linux/wmi.h>
> +
> +#include "lenovo-wmi-helpers.h"
> +
> +/**
> + * lwmi_dev_evaluate_int() - Helper function for calling WMI methods that
> + * return an integer.
> + * @wdev: Pointer to the WMI device to be called.
> + * @instance: Instance of the called method.
> + * @method_id: WMI Method ID for the method to be called.
> + * @buf: Buffer of all arguments for the given method_id.
> + * @size: Length of the buffer.
> + * @retval: Pointer for the return value to be assigned.
> + *
> + * Calls wmidev_evaluate_method for Lenovo WMI devices that return an ACPI
> + * integer. Validates the return value type and assigns the value to the
> + * retval pointer.
> + *
> + * Return: 0 on success, or an error code.
> + */
> +int lwmi_dev_evaluate_int(struct wmi_device *wdev, u8 instance, u32 method_id,
> +			  unsigned char *buf, size_t size, u32 *retval)
> +{
> +	struct acpi_buffer output = { ACPI_ALLOCATE_BUFFER, NULL };
> +	union acpi_object *ret_obj __free(kfree) = NULL;
> +	struct acpi_buffer input = { size, buf };
> +	acpi_status status;
> +
> +	status = wmidev_evaluate_method(wdev, instance, method_id, &input,
> +					&output);
> +
> +	if (ACPI_FAILURE(status))
> +		return -EIO;
> +
> +	if (retval) {
> +		ret_obj = output.pointer;
> +		if (!ret_obj)
> +			return -ENODATA;
> +
> +		if (ret_obj->type != ACPI_TYPE_INTEGER)
> +			return -ENXIO;
> +
> +		*retval = (u32)ret_obj->integer.value;
> +	}

a '\n' before return

> +	return 0;
> +};
> +EXPORT_SYMBOL_NS_GPL(lwmi_dev_evaluate_int, "LENOVO_WMI_HELPERS");
> +


Looks Good To Me.

Reviewed-by: Alok Tiwari <alok.a.tiwari@oracle.com>

Thanks,
Alok