Re: [PATCH v3 3/4] platform/x86: Add Lenovo Capability Data 01 WMI Driver

[Armin Wolf <W_Armin@gmx.de>]

Am 25.02.25 um 22:59 schrieb Derek J. Clark:

> Adds lenovo-wmi-capdata01.c which provides a driver for the
> LENOVO_CAPABILITY_DATA_01 WMI data block that comes on "Other Mode"
> enabled hardware. Provides an interface for querying if a given
> attribute is supported by the hardware, as well as its default_value,
> max_value, min_value, and step increment.
> v3:
> - Add as component to lenovo-wmi-other driver.
> v2:
> - Use devm_kmalloc to ensure driver can be instanced, remove global
>    reference.
> - Ensure reverse Christmas tree for all variable declarations.
> - Remove extra whitespace.
> - Use guard(mutex) in all mutex instances, global mutex.
> - Use pr_fmt instead of adding the driver name to each pr_err.
> - Remove noisy pr_info usage.
> - Rename capdata_wmi to lenovo_wmi_cd01_priv and cd01_wmi to priv.
> - Use list to get the lenovo_wmi_cd01_priv instance in
>    lenovo_wmi_capdata01_get as none of the data provided by the macros
>    that will use it can pass a member of the struct for use in
>    container_of.
>
> Signed-off-by: Derek J. Clark <derekjohn.clark@gmail.com>
> ---
>   MAINTAINERS                                 |   1 +
>   drivers/platform/x86/Kconfig                |   5 +
>   drivers/platform/x86/Makefile               |   1 +
>   drivers/platform/x86/lenovo-wmi-capdata01.c | 140 ++++++++++++++++++++
>   drivers/platform/x86/lenovo-wmi.h           |  19 +++
>   5 files changed, 166 insertions(+)
>   create mode 100644 drivers/platform/x86/lenovo-wmi-capdata01.c
>
> diff --git a/MAINTAINERS b/MAINTAINERS
> index cf7f4fce1a25..f6d3e79e50ce 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -13157,6 +13157,7 @@ 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-capdata01.c
>   F:	drivers/platform/x86/lenovo-wmi-gamezone.c
>   F:	drivers/platform/x86/lenovo-wmi.c
>   F:	drivers/platform/x86/lenovo-wmi.h
> diff --git a/drivers/platform/x86/Kconfig b/drivers/platform/x86/Kconfig
> index 875822e6bd65..56336dc3c2d0 100644
> --- a/drivers/platform/x86/Kconfig
> +++ b/drivers/platform/x86/Kconfig
> @@ -475,6 +475,11 @@ config LENOVO_WMI_GAMEZONE
>   	  To compile this driver as a module, choose M here: the module will
>   	  be called lenovo-wmi-gamezone.
>
> +config LENOVO_WMI_DATA01
> +	tristate
> +	depends on ACPI_WMI
> +	select LENOVO_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 4a7b2d14eb82..be9031bea090 100644
> --- a/drivers/platform/x86/Makefile
> +++ b/drivers/platform/x86/Makefile
> @@ -70,6 +70,7 @@ obj-$(CONFIG_YT2_1380)		+= lenovo-yoga-tab2-pro-1380-fastcharger.o
>   obj-$(CONFIG_LENOVO_WMI)	+= lenovo-wmi.o
>   obj-$(CONFIG_LENOVO_WMI_CAMERA)	+= lenovo-wmi-camera.o
>   obj-$(CONFIG_LENOVO_WMI_GAMEZONE)	+= lenovo-wmi-gamezone.o
> +obj-$(CONFIG_LENOVO_WMI_DATA01)	+= lenovo-wmi-capdata01.o
>
>   # Intel
>   obj-y				+= intel/
> diff --git a/drivers/platform/x86/lenovo-wmi-capdata01.c b/drivers/platform/x86/lenovo-wmi-capdata01.c
> new file mode 100644
> index 000000000000..0fe156d5d770
> --- /dev/null
> +++ b/drivers/platform/x86/lenovo-wmi-capdata01.c
> @@ -0,0 +1,140 @@
> +// SPDX-License-Identifier: GPL-2.0-or-later
> +/*
> + * LENOVO_CAPABILITY_DATA_01 WMI data block driver. This interface provides
> + * information on tunable attributes used by the "Other Mode" WMI interface,
> + * including if it is supported by the hardware, the default_value, max_value,
> + * min_value, and step increment.
> + *
> + * Copyright(C) 2024 Derek J. Clark <derekjohn.clark@gmail.com>

2025

> + */
> +
> +#include <linux/cleanup.h>
> +#include <linux/component.h>
> +#include <linux/container_of.h>
> +#include <linux/device.h>
> +#include <linux/gfp_types.h>
> +#include <linux/types.h>
> +#include <linux/wmi.h>
> +#include "lenovo-wmi.h"
> +
> +/* Interface GUIDs */
> +#define LENOVO_CAPABILITY_DATA_01_GUID "7A8F5407-CB67-4D6E-B547-39B3BE018154"
> +
> +static int lenovo_cd01_component_bind(struct device *cd01_dev,
> +				      struct device *om_dev, void *data)
> +{
> +	struct lenovo_wmi_cd01 *cd01 = dev_get_drvdata(cd01_dev);
> +	struct lenovo_wmi_om *om = dev_get_drvdata(om_dev);

Why not using the *data pointer to pass the cd01 data? This way the capdata driver
does not need to know the structure of the private data of the lenovo-wmi-other driver.

> +
> +	om->cd01 = cd01;
> +	return 0;
> +}
> +
> +static void lenovo_cd01_component_unbind(struct device *cd01_dev,
> +					 struct device *om_dev, void *data)
> +
> +{
> +	struct wmi_device *om_wdev =
> +		container_of(om_dev, struct wmi_device, dev);
> +	struct lenovo_wmi_om *om =
> +		container_of(&om_wdev, struct lenovo_wmi_om, wdev);
> +
> +	om->cd01 = NULL;

I think this is unnecessary, please remove the unbind callback.

> +}
> +
> +static const struct component_ops lenovo_cd01_component_ops = {
> +	.bind = lenovo_cd01_component_bind,
> +	.unbind = lenovo_cd01_component_unbind,
> +};
> +
> +static int lenovo_wmi_cd01_setup(struct lenovo_wmi_cd01 *cd01)
> +{
> +	size_t cd_size = sizeof(struct capdata01);
> +	int count, idx;
> +
> +	count = wmidev_instance_count(cd01->wdev);
> +
> +	cd01->capdata = devm_kmalloc_array(&cd01->wdev->dev, (size_t)count,
> +					   sizeof(*cd01->capdata), GFP_KERNEL);

Cast to size_t is unnecessary here.

> +	if (!cd01->capdata)
> +		return -ENOMEM;
> +
> +	cd01->instance_count = count;
> +
> +	for (idx = 0; idx < count; idx++) {
> +		union acpi_object *ret_obj __free(kfree) = NULL;

I am not sure if the compiler frees ret_obj after each loop iteration. Did you test this?

> +		struct capdata01 *cap_ptr =
> +			devm_kmalloc(&cd01->wdev->dev, cd_size, GFP_KERNEL);

Please call devm_kmalloc() on a separate line.

> +		ret_obj = wmidev_block_query(cd01->wdev, idx);
> +		if (!ret_obj)
> +			continue;
> +
> +		if (ret_obj->type != ACPI_TYPE_BUFFER)
> +			continue;
> +
> +		if (ret_obj->buffer.length != cd_size)
> +			continue;
> +
> +		memcpy(cap_ptr, ret_obj->buffer.pointer,
> +		       ret_obj->buffer.length);

Using devm_kmemdup() would make sense here.

> +		cd01->capdata[idx] = cap_ptr;
> +	}
> +	return 0;
> +}
> +
> +static int lenovo_wmi_cd01_probe(struct wmi_device *wdev, const void *context)
> +
> +{
> +	struct lenovo_wmi_cd01 *cd01;
> +	int ret;
> +
> +	cd01 = devm_kzalloc(&wdev->dev, sizeof(*cd01), GFP_KERNEL);
> +	if (!cd01)
> +		return -ENOMEM;
> +
> +	cd01->wdev = wdev;
> +
> +	ret = lenovo_wmi_cd01_setup(cd01);
> +	if (ret)
> +		return ret;
> +
> +	dev_set_drvdata(&wdev->dev, cd01);
> +
> +	ret = component_add(&wdev->dev, &lenovo_cd01_component_ops);
> +
> +	return ret;
> +}
> +
> +static void lenovo_wmi_cd01_remove(struct wmi_device *wdev)
> +{
> +	component_del(&wdev->dev, &lenovo_cd01_component_ops);
> +}
> +
> +static const struct wmi_device_id lenovo_wmi_cd01_id_table[] = {
> +	{ LENOVO_CAPABILITY_DATA_01_GUID, NULL },
> +	{}
> +};
> +
> +static struct wmi_driver lenovo_wmi_cd01_driver = {
> +	.driver = {
> +		.name = "lenovo_wmi_cd01",
> +		.probe_type = PROBE_PREFER_ASYNCHRONOUS,
> +	},
> +	.id_table = lenovo_wmi_cd01_id_table,
> +	.probe = lenovo_wmi_cd01_probe,
> +	.remove = lenovo_wmi_cd01_remove,
> +	.no_singleton = true,
> +};
> +
> +int lenovo_wmi_cd01_match(struct device *dev, void *data)
> +{
> +	return dev->driver == &lenovo_wmi_cd01_driver.driver;
> +}
> +EXPORT_SYMBOL_GPL(lenovo_wmi_cd01_match);

Please put this symbol into a namespace too.

> +
> +module_wmi_driver(lenovo_wmi_cd01_driver);
> +
> +MODULE_DEVICE_TABLE(wmi, lenovo_wmi_cd01_id_table);
> +MODULE_AUTHOR("Derek J. Clark <derekjohn.clark@gmail.com>");
> +MODULE_DESCRIPTION("Lenovo Capability Data 01 WMI Driver");
> +MODULE_LICENSE("GPL");
> diff --git a/drivers/platform/x86/lenovo-wmi.h b/drivers/platform/x86/lenovo-wmi.h
> index 113928b4fc0f..07fa67ed89d6 100644
> --- a/drivers/platform/x86/lenovo-wmi.h
> +++ b/drivers/platform/x86/lenovo-wmi.h
> @@ -45,6 +45,22 @@ enum lenovo_wmi_action {
>   	THERMAL_MODE_EVENT = 1,
>   };
>
> +/* capdata01 structs */
> +struct lenovo_wmi_cd01 {
> +	struct capdata01 **capdata;
> +	struct wmi_device *wdev;
> +	int instance_count;
> +};
> +
> +struct capdata01 {
> +	u32 id;
> +	u32 supported;
> +	u32 default_value;
> +	u32 step;
> +	u32 min_value;
> +	u32 max_value;
> +};

Please put those struct definitions into a separate header file.

Thanks,
Armin Wolf

> +
>   /* wmidev_evaluate_method helper functions */
>   int lenovo_wmidev_evaluate_method_2(struct wmi_device *wdev, u8 instance,
>   				    u32 method_id, u32 arg0, u32 arg1,
> @@ -52,6 +68,9 @@ int lenovo_wmidev_evaluate_method_2(struct wmi_device *wdev, u8 instance,
>   int lenovo_wmidev_evaluate_method_1(struct wmi_device *wdev, u8 instance,
>   				    u32 method_id, u32 arg0, u32 *retval);
>
> +/* lenovo_wmi_cd01_driver match function */
> +int lenovo_wmi_cd01_match(struct device *dev, void *data);
> +
>   /* lenovo_wmi_gz_driver notifier functions */
>   int lenovo_wmi_gz_notifier_call(struct notifier_block *nb, unsigned long action,
>   				enum platform_profile_option *profile);