Re: [PATCH v4 4/6 RESEND] platform/x86: Add Lenovo Capability Data 01 WMI Driver
From: Matthew Schwartz
Date: Wed Mar 26 2025 - 15:52:17 EST
On 3/17/25 7:43 AM, Derek J. Clark wrote:
> Adds lenovo-wmi-capdata01 driver which provides 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.
>
> Signed-off-by: Derek J. Clark <derekjohn.clark@xxxxxxxxx>
All exposed attributes are passed to "Other Mode" on my Legion Go and Legion Go S.
Tested-by: Matthew Schwartz <matthew.schwartz@xxxxxxxxx>
> ---
> v4:
> - Make driver data a private struct, remove references from Other Mode
> driver.
> - Don't cache data at device initialization. Instead, on component bind,
> cache the data on a member variable of the Other Mode driver data
> passed as a void pointer.
> - Add header file for capdata01 structs.
> - Add new struct to pass capdata01 array data and array length to Other
> Mode.
> 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.
> ---
> MAINTAINERS | 2 +
> drivers/platform/x86/Kconfig | 4 +
> drivers/platform/x86/Makefile | 1 +
> drivers/platform/x86/lenovo-wmi-capdata01.c | 136 ++++++++++++++++++++
> drivers/platform/x86/lenovo-wmi-capdata01.h | 29 +++++
> 5 files changed, 172 insertions(+)
> create mode 100644 drivers/platform/x86/lenovo-wmi-capdata01.c
> create mode 100644 drivers/platform/x86/lenovo-wmi-capdata01.h
>
> diff --git a/MAINTAINERS b/MAINTAINERS
> index 6dde75922aaf..56ead241a053 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -13164,6 +13164,8 @@ L: platform-driver-x86@xxxxxxxxxxxxxxx
> 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-capdata01.h
> F: drivers/platform/x86/lenovo-wmi-events.c
> F: drivers/platform/x86/lenovo-wmi-events.h
> F: drivers/platform/x86/lenovo-wmi-helpers.c
> diff --git a/drivers/platform/x86/Kconfig b/drivers/platform/x86/Kconfig
> index 13b8f4ac5dc5..64663667f0cb 100644
> --- a/drivers/platform/x86/Kconfig
> +++ b/drivers/platform/x86/Kconfig
> @@ -467,6 +467,10 @@ config LENOVO_WMI_HELPERS
> tristate
> depends on ACPI_WMI
>
> +config LENOVO_WMI_DATA01
> + 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 fc039839286a..7a35c77221b7 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-$(CONFIG_LENOVO_WMI_DATA01) += lenovo-wmi-capdata01.o
> obj-$(CONFIG_LENOVO_WMI_EVENTS) += lenovo-wmi-events.o
> obj-$(CONFIG_LENOVO_WMI_HELPERS) += lenovo-wmi-helpers.o
>
> diff --git a/drivers/platform/x86/lenovo-wmi-capdata01.c b/drivers/platform/x86/lenovo-wmi-capdata01.c
> new file mode 100644
> index 000000000000..b6876611ffd9
> --- /dev/null
> +++ b/drivers/platform/x86/lenovo-wmi-capdata01.c
> @@ -0,0 +1,136 @@
> +// 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) 2025 Derek J. Clark <derekjohn.clark@xxxxxxxxx>
> + */
> +
> +#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-capdata01.h"
> +
> +/* Interface GUIDs */
> +#define LENOVO_CAPABILITY_DATA_01_GUID "7A8F5407-CB67-4D6E-B547-39B3BE018154"
> +
> +struct lwmi_cd01_priv {
> + struct wmi_device *wdev;
> +};
> +
> +/*
> + * lenovo_cd01_component_bind() - On master bind, caches all capability data on
> + * the master device.
> + * @cd01_dev: Pointer to the capability data 01 parent device.
> + * @om_dev: Pointer to the other mode parent device.
> + * @data: capdata01_list object pointer to return the capability data with.
> + *
> + * Returns: 0, or an error.
> + */
> +static int lenovo_cd01_component_bind(struct device *cd01_dev,
> + struct device *om_dev, void *data)
> +{
> + struct lwmi_cd01_priv *priv = dev_get_drvdata(cd01_dev);
> + int count, idx;
> +
> + if (!priv)
> + return -ENODEV;
> +
> + count = wmidev_instance_count(priv->wdev);
> +
> + if (count == 0)
> + return -EINVAL;
> +
> + ((struct cd01_list *)data)->count = count;
> + ((struct cd01_list *)data)->data = devm_kmalloc_array(om_dev, count,
> + sizeof(struct capdata01 *),
> + GFP_KERNEL);
> + if (!data)
> + return -ENOMEM;
> +
> + for (idx = 0; idx < count; idx++) {
> + union acpi_object *ret_obj __free(kfree) = NULL;
> +
> + ret_obj = wmidev_block_query(priv->wdev, idx);
> + if (!ret_obj) {
> + ((struct cd01_list *)data)->data[idx] = NULL;
> + continue;
> + }
> + if (ret_obj->type != ACPI_TYPE_BUFFER) {
> + ((struct cd01_list *)data)->data[idx] = NULL;
> + continue;
> + }
> +
> + if (ret_obj->buffer.length != sizeof(struct capdata01)) {
> + ((struct cd01_list *)data)->data[idx] = NULL;
> + continue;
> + }
> +
> + ((struct cd01_list *)data)->data[idx] =
> + devm_kmemdup(om_dev, ret_obj->buffer.pointer,
> + ret_obj->buffer.length, GFP_KERNEL);
> + }
> + return 0;
> +}
> +
> +static const struct component_ops lenovo_cd01_component_ops = {
> + .bind = lenovo_cd01_component_bind,
> +};
> +
> +static int lwmi_cd01_probe(struct wmi_device *wdev, const void *context)
> +
> +{
> + struct lwmi_cd01_priv *priv;
> + int ret;
> +
> + priv = devm_kzalloc(&wdev->dev, sizeof(*priv), GFP_KERNEL);
> + if (!priv)
> + return -ENOMEM;
> +
> + priv->wdev = wdev;
> + dev_set_drvdata(&wdev->dev, priv);
> +
> + ret = component_add(&wdev->dev, &lenovo_cd01_component_ops);
> +
> + return ret;
> +}
> +
> +static void lwmi_cd01_remove(struct wmi_device *wdev)
> +{
> + component_del(&wdev->dev, &lenovo_cd01_component_ops);
> +}
> +
> +static const struct wmi_device_id lwmi_cd01_id_table[] = {
> + { LENOVO_CAPABILITY_DATA_01_GUID, NULL },
> + {}
> +};
> +
> +static struct wmi_driver lwmi_cd01_driver = {
> + .driver = {
> + .name = "lenovo_wmi_cd01",
> + .probe_type = PROBE_PREFER_ASYNCHRONOUS,
> + },
> + .id_table = lwmi_cd01_id_table,
> + .probe = lwmi_cd01_probe,
> + .remove = lwmi_cd01_remove,
> + .no_singleton = true,
> +};
> +
> +int lwmi_cd01_match(struct device *dev, void *data)
> +{
> + return dev->driver == &lwmi_cd01_driver.driver;
> +}
> +EXPORT_SYMBOL_NS_GPL(lwmi_cd01_match, "LENOVO_WMI_CD01");
> +
> +module_wmi_driver(lwmi_cd01_driver);
> +
> +MODULE_DEVICE_TABLE(wmi, lwmi_cd01_id_table);
> +MODULE_AUTHOR("Derek J. Clark <derekjohn.clark@xxxxxxxxx>");
> +MODULE_DESCRIPTION("Lenovo Capability Data 01 WMI Driver");
> +MODULE_LICENSE("GPL");
> diff --git a/drivers/platform/x86/lenovo-wmi-capdata01.h b/drivers/platform/x86/lenovo-wmi-capdata01.h
> new file mode 100644
> index 000000000000..c7067a8d0398
> --- /dev/null
> +++ b/drivers/platform/x86/lenovo-wmi-capdata01.h
> @@ -0,0 +1,29 @@
> +/* SPDX-License-Identifier: GPL-2.0-or-later
> + *
> + * Copyright(C) 2025 Derek J. Clark <derekjohn.clark@xxxxxxxxx>
> + *
> + */
> +
> +#ifndef _LENOVO_WMI_CAPDATA01_H_
> +#define _LENOVO_WMI_CAPDATA01_H_
> +
> +#include <linux/device.h>
> +#include <linux/types.h>
> +
> +struct capdata01 {
> + u32 id;
> + u32 supported;
> + u32 default_value;
> + u32 step;
> + u32 min_value;
> + u32 max_value;
> +};
> +
> +struct cd01_list {
> + struct capdata01 **data;
> + int count;
> +};
> +
> +int lwmi_cd01_match(struct device *dev, void *data);
> +
> +#endif /* !_LENOVO_WMI_CAPDATA01_H_ */