Re: [PATCH v3 3/6] platform/x86: lenovo-wmi-{capdata,other}: Support multiple Capability Data

[Armin Wolf <W_Armin@gmx.de>]

Am 31.10.25 um 16:51 schrieb Rong Zhang:

> The current implementation are heavily bound to capdata01. Rewrite it so
> that it is suitable to utilize other Capability Data as well.
>
> No functional change intended.
>
> Signed-off-by: Rong Zhang <i@rong.moe>
> Reviewed-by: Derek J. Clark <derekjohn.clark@gmail.com>
> Tested-by: Derek J. Clark <derekjohn.clark@gmail.com>
> ---
> Changes in v2:
> - Fix function parameter 'type' not described in 'lwmi_cd_match' (thanks
>    kernel test bot)
> ---
>   drivers/platform/x86/lenovo/wmi-capdata.c | 208 +++++++++++++++++-----
>   drivers/platform/x86/lenovo/wmi-capdata.h |   7 +-
>   drivers/platform/x86/lenovo/wmi-other.c   |  27 ++-
>   3 files changed, 190 insertions(+), 52 deletions(-)
>
> diff --git a/drivers/platform/x86/lenovo/wmi-capdata.c b/drivers/platform/x86/lenovo/wmi-capdata.c
> index c5e74b2bfeb3..1f7fc09b7c3f 100644
> --- a/drivers/platform/x86/lenovo/wmi-capdata.c
> +++ b/drivers/platform/x86/lenovo/wmi-capdata.c
> @@ -12,8 +12,13 @@
>    *
>    * Copyright (C) 2025 Derek J. Clark <derekjohn.clark@gmail.com>
>    *   - Initial implementation (formerly named lenovo-wmi-capdata01)
> + *
> + * Copyright (C) 2025 Rong Zhang <i@rong.moe>
> + *   - Unified implementation
>    */
>   
> +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
> +
>   #include <linux/acpi.h>
>   #include <linux/cleanup.h>
>   #include <linux/component.h>
> @@ -36,6 +41,25 @@
>   #define ACPI_AC_CLASS "ac_adapter"
>   #define ACPI_AC_NOTIFY_STATUS 0x80
>   
> +enum lwmi_cd_type {
> +	LENOVO_CAPABILITY_DATA_01,
> +};
> +
> +#define LWMI_CD_TABLE_ITEM(_type)		\
> +	[_type] = {				\
> +		.guid_string = _type##_GUID,	\
> +		.name = #_type,			\
> +		.type = _type,			\
> +	}
> +
> +static const struct lwmi_cd_info {
> +	const char *guid_string;
> +	const char *name;
> +	enum lwmi_cd_type type;
> +} lwmi_cd_table[] = {
> +	LWMI_CD_TABLE_ITEM(LENOVO_CAPABILITY_DATA_01),
> +};
> +
>   struct lwmi_cd_priv {
>   	struct notifier_block acpi_nb; /* ACPI events */
>   	struct wmi_device *wdev;
> @@ -44,15 +68,19 @@ struct lwmi_cd_priv {
>   
>   struct cd_list {
>   	struct mutex list_mutex; /* list R/W mutex */
> +	enum lwmi_cd_type type;
>   	u8 count;
> -	struct capdata01 data[];
> +
> +	union {
> +		DECLARE_FLEX_ARRAY(struct capdata01, cd01);
> +	};
>   };
>   
>   /**
>    * lwmi_cd_component_bind() - Bind component to master device.
>    * @cd_dev: Pointer to the lenovo-wmi-capdata driver parent device.
>    * @om_dev: Pointer to the lenovo-wmi-other driver parent device.
> - * @data: cd_list object pointer used to return the capability data.
> + * @data: lwmi_cd_binder object pointer used to return the capability data.
>    *
>    * On lenovo-wmi-other's master bind, provide a pointer to the local capdata
>    * list. This is used to call lwmi_cd*_get_data to look up attribute data
> @@ -64,9 +92,15 @@ static int lwmi_cd_component_bind(struct device *cd_dev,
>   				  struct device *om_dev, void *data)
>   {
>   	struct lwmi_cd_priv *priv = dev_get_drvdata(cd_dev);
> -	struct cd_list **cd_list = data;
> +	struct lwmi_cd_binder *binder = data;
>   
> -	*cd_list = priv->list;
> +	switch (priv->list->type) {
> +	case LENOVO_CAPABILITY_DATA_01:
> +		binder->cd01_list = priv->list;
> +		break;
> +	default:
> +		return -EINVAL;
> +	}
>   
>   	return 0;
>   }
> @@ -76,30 +110,33 @@ static const struct component_ops lwmi_cd_component_ops = {
>   };
>   
>   /**
> - * lwmi_cd01_get_data - Get the data of the specified attribute
> + * lwmi_cd*_get_data - Get the data of the specified attribute
>    * @list: The lenovo-wmi-capdata pointer to its cd_list struct.
>    * @attribute_id: The capdata attribute ID to be found.
> - * @output: Pointer to a capdata01 struct to return the data.
> + * @output: Pointer to a capdata* struct to return the data.
>    *
> - * Retrieves the capability data 01 struct pointer for the given
> - * attribute for its specified thermal mode.
> + * Retrieves the capability data struct pointer for the given
> + * attribute.
>    *
>    * Return: 0 on success, or -EINVAL.
>    */
> -int lwmi_cd01_get_data(struct cd_list *list, u32 attribute_id, struct capdata01 *output)
> -{
> -	u8 idx;
> -
> -	guard(mutex)(&list->list_mutex);
> -	for (idx = 0; idx < list->count; idx++) {
> -		if (list->data[idx].id != attribute_id)
> -			continue;
> -		memcpy(output, &list->data[idx], sizeof(list->data[idx]));
> -		return 0;
> +#define DEF_LWMI_CDXX_GET_DATA(_cdxx, _cd_type, _output_t)					\
> +	int lwmi_##_cdxx##_get_data(struct cd_list *list, u32 attribute_id, _output_t *output)	\
> +	{											\
> +		u8 idx;										\
> +		if (WARN_ON(list->type != _cd_type))						\
> +			return -EINVAL;								\
> +		guard(mutex)(&list->list_mutex);						\
> +		for (idx = 0; idx < list->count; idx++) {					\
> +			if (list->_cdxx[idx].id != attribute_id)				\
> +				continue;							\
> +			memcpy(output, &list->_cdxx[idx], sizeof(list->_cdxx[idx]));		\
> +			return 0;								\
> +		}										\
> +		return -EINVAL;									\
>   	}
>   
> -	return -EINVAL;
> -}
> +DEF_LWMI_CDXX_GET_DATA(cd01, LENOVO_CAPABILITY_DATA_01, struct capdata01);
>   EXPORT_SYMBOL_NS_GPL(lwmi_cd01_get_data, "LENOVO_WMI_CD");
>   
>   /**
> @@ -112,10 +149,21 @@ EXPORT_SYMBOL_NS_GPL(lwmi_cd01_get_data, "LENOVO_WMI_CD");
>    */
>   static int lwmi_cd_cache(struct lwmi_cd_priv *priv)
>   {
> +	size_t size;
>   	int idx;
> +	void *p;
> +
> +	switch (priv->list->type) {
> +	case LENOVO_CAPABILITY_DATA_01:
> +		p = &priv->list->cd01[0];
> +		size = sizeof(priv->list->cd01[0]);
> +		break;
> +	default:
> +		return -EINVAL;
> +	}
>   
>   	guard(mutex)(&priv->list->list_mutex);
> -	for (idx = 0; idx < priv->list->count; idx++) {
> +	for (idx = 0; idx < priv->list->count; idx++, p += size) {
>   		union acpi_object *ret_obj __free(kfree) = NULL;
>   
>   		ret_obj = wmidev_block_query(priv->wdev, idx);
> @@ -123,11 +171,10 @@ static int lwmi_cd_cache(struct lwmi_cd_priv *priv)
>   			return -ENODEV;
>   
>   		if (ret_obj->type != ACPI_TYPE_BUFFER ||
> -		    ret_obj->buffer.length < sizeof(priv->list->data[idx]))
> +		    ret_obj->buffer.length < size)
>   			continue;
>   
> -		memcpy(&priv->list->data[idx], ret_obj->buffer.pointer,
> -		       ret_obj->buffer.length);
> +		memcpy(p, ret_obj->buffer.pointer, size);
>   	}
>   
>   	return 0;
> @@ -136,20 +183,28 @@ static int lwmi_cd_cache(struct lwmi_cd_priv *priv)
>   /**
>    * lwmi_cd_alloc() - Allocate a cd_list struct in drvdata
>    * @priv: lenovo-wmi-capdata driver data.
> + * @type: The type of capability data.
>    *
>    * Allocate a cd_list struct large enough to contain data from all WMI data
>    * blocks provided by the interface.
>    *
>    * Return: 0 on success, or an error.
>    */
> -static int lwmi_cd_alloc(struct lwmi_cd_priv *priv)
> +static int lwmi_cd_alloc(struct lwmi_cd_priv *priv, enum lwmi_cd_type type)
>   {
>   	struct cd_list *list;
>   	size_t list_size;
>   	int count, ret;
>   
>   	count = wmidev_instance_count(priv->wdev);
> -	list_size = struct_size(list, data, count);
> +
> +	switch (type) {
> +	case LENOVO_CAPABILITY_DATA_01:
> +		list_size = struct_size(list, cd01, count);
> +		break;
> +	default:
> +		return -EINVAL;
> +	}
>   
>   	list = devm_kzalloc(&priv->wdev->dev, list_size, GFP_KERNEL);
>   	if (!list)
> @@ -159,6 +214,7 @@ static int lwmi_cd_alloc(struct lwmi_cd_priv *priv)
>   	if (ret)
>   		return ret;
>   
> +	list->type = type;
>   	list->count = count;
>   	priv->list = list;
>   
> @@ -168,6 +224,7 @@ static int lwmi_cd_alloc(struct lwmi_cd_priv *priv)
>   /**
>    * lwmi_cd_setup() - Cache all WMI data block information
>    * @priv: lenovo-wmi-capdata driver data.
> + * @type: The type of capability data.
>    *
>    * Allocate a cd_list struct large enough to contain data from all WMI data
>    * blocks provided by the interface. Then loop through each data block and
> @@ -175,11 +232,11 @@ static int lwmi_cd_alloc(struct lwmi_cd_priv *priv)
>    *
>    * Return: 0 on success, or an error code.
>    */
> -static int lwmi_cd_setup(struct lwmi_cd_priv *priv)
> +static int lwmi_cd_setup(struct lwmi_cd_priv *priv, enum lwmi_cd_type type)
>   {
>   	int ret;
>   
> -	ret = lwmi_cd_alloc(priv);
> +	ret = lwmi_cd_alloc(priv, type);
>   	if (ret)
>   		return ret;
>   
> @@ -235,9 +292,13 @@ static void lwmi_cd01_unregister(void *data)
>   
>   static int lwmi_cd_probe(struct wmi_device *wdev, const void *context)
>   {
> +	const struct lwmi_cd_info *info = context;
>   	struct lwmi_cd_priv *priv;
>   	int ret;
>   
> +	if (!info)
> +		return -EINVAL;
> +
>   	priv = devm_kzalloc(&wdev->dev, sizeof(*priv), GFP_KERNEL);
>   	if (!priv)
>   		return -ENOMEM;
> @@ -245,21 +306,34 @@ static int lwmi_cd_probe(struct wmi_device *wdev, const void *context)
>   	priv->wdev = wdev;
>   	dev_set_drvdata(&wdev->dev, priv);
>   
> -	ret = lwmi_cd_setup(priv);
> +	ret = lwmi_cd_setup(priv, info->type);
>   	if (ret)
> -		return ret;
> +		goto out;
>   
> -	priv->acpi_nb.notifier_call = lwmi_cd01_notifier_call;
> +	if (info->type == LENOVO_CAPABILITY_DATA_01) {
> +		priv->acpi_nb.notifier_call = lwmi_cd01_notifier_call;
>   
> -	ret = register_acpi_notifier(&priv->acpi_nb);
> -	if (ret)
> -		return ret;
> +		ret = register_acpi_notifier(&priv->acpi_nb);
> +		if (ret)
> +			goto out;
>   
> -	ret = devm_add_action_or_reset(&wdev->dev, lwmi_cd01_unregister, &priv->acpi_nb);
> -	if (ret)
> -		return ret;
> +		ret = devm_add_action_or_reset(&wdev->dev, lwmi_cd01_unregister,
> +					       &priv->acpi_nb);
> +		if (ret)
> +			goto out;
> +	}
> +
> +	ret = component_add(&wdev->dev, &lwmi_cd_component_ops);
>   
> -	return component_add(&wdev->dev, &lwmi_cd_component_ops);
> +out:
> +	if (ret) {
> +		dev_err(&wdev->dev, "failed to register %s: %d\n",
> +			info->name, ret);
> +	} else {
> +		dev_info(&wdev->dev, "registered %s with %u items\n",
> +			 info->name, priv->list->count);
> +	}
> +	return ret;
>   }
>   
>   static void lwmi_cd_remove(struct wmi_device *wdev)
> @@ -267,8 +341,12 @@ static void lwmi_cd_remove(struct wmi_device *wdev)
>   	component_del(&wdev->dev, &lwmi_cd_component_ops);
>   }
>   
> +#define LWMI_CD_WDEV_ID(_type)				\
> +	.guid_string = _type##_GUID,			\
> +	.context = &lwmi_cd_table[_type]
> +
>   static const struct wmi_device_id lwmi_cd_id_table[] = {
> -	{ LENOVO_CAPABILITY_DATA_01_GUID, NULL },
> +	{ LWMI_CD_WDEV_ID(LENOVO_CAPABILITY_DATA_01) },
>   	{}
>   };
>   
> @@ -284,21 +362,61 @@ static struct wmi_driver lwmi_cd_driver = {
>   };
>   
>   /**
> - * lwmi_cd01_match() - Match rule for the master driver.
> - * @dev: Pointer to the capability data 01 parent device.
> - * @data: Unused void pointer for passing match criteria.
> + * lwmi_cd_match() - Match rule for the master driver.
> + * @dev: Pointer to the capability data parent device.
> + * @type: Pointer to capability data type (enum lwmi_cd_type *) to match.
>    *
>    * Return: int.
>    */
> -int lwmi_cd01_match(struct device *dev, void *data)
> +static int lwmi_cd_match(struct device *dev, void *type)
> +{
> +	struct lwmi_cd_priv *priv;
> +
> +	if (dev->driver != &lwmi_cd_driver.driver)
> +		return false;
> +
> +	priv = dev_get_drvdata(dev);
> +	return priv->list->type == *(enum lwmi_cd_type *)type;
> +}
> +
> +/**
> + * lwmi_cd_match_add_all() - Add all match rule for the master driver.
> + * @master: Pointer to the master device.
> + * @matchptr: Pointer to the returned component_match pointer.
> + *
> + * Adds all component matches to the list stored in @matchptr for the @master
> + * device. @matchptr must be initialized to NULL. This matches all available
> + * capdata types on the machine.
> + */
> +void lwmi_cd_match_add_all(struct device *master, struct component_match **matchptr)
>   {
> -	return dev->driver == &lwmi_cd_driver.driver;
> +	int i;
> +
> +	if (WARN_ON(*matchptr))
> +		return;
> +
> +	for (i = 0; i < ARRAY_SIZE(lwmi_cd_table); i++) {
> +		if (!lwmi_cd_table[i].guid_string ||
> +		    !wmi_has_guid(lwmi_cd_table[i].guid_string))
> +			continue;

I am still not happy about this. AFAIK as soon as the ordinary capdata WMI devices are bound together,
the firmware tells you whether or not the additional fan data WMI device is available. Maybe you can do
something like this:

1. Bind both capdata WMI devices as usual.
2. Check if a fan data WMI device is available (you can use a DMI-based quirk list for devices were
    the firmware reports invalid data).
3. Register an additional component that binds to the fan data WMI device.
4. Bind both the additional component and the component registered by the fan data WMI device.
5. Register the hwmon device with additional fan data.

If the fan data WMI device is not available, you can simply skip steps 3 and 4 and simply
register the hwmon device with any additional fan data.

What do you think?

Thanks,
Armin Wolf

> +
> +		component_match_add(master, matchptr, lwmi_cd_match,
> +				    (void *)&lwmi_cd_table[i].type);
> +		if (IS_ERR(matchptr))
> +			return;
> +	}
> +
> +	if (!*matchptr) {
> +		pr_warn("a master driver requested capability data, but nothing is available\n");
> +		*matchptr = ERR_PTR(-ENODEV);
> +	}
>   }
> -EXPORT_SYMBOL_NS_GPL(lwmi_cd01_match, "LENOVO_WMI_CD");
> +EXPORT_SYMBOL_NS_GPL(lwmi_cd_match_add_all, "LENOVO_WMI_CD");
>   
>   module_wmi_driver(lwmi_cd_driver);
>   
>   MODULE_DEVICE_TABLE(wmi, lwmi_cd_id_table);
>   MODULE_AUTHOR("Derek J. Clark <derekjohn.clark@gmail.com>");
> +MODULE_AUTHOR("Rong Zhang <i@rong.moe>");
>   MODULE_DESCRIPTION("Lenovo Capability Data WMI Driver");
>   MODULE_LICENSE("GPL");
> diff --git a/drivers/platform/x86/lenovo/wmi-capdata.h b/drivers/platform/x86/lenovo/wmi-capdata.h
> index 2a4746e38ad4..1e5fce7836cb 100644
> --- a/drivers/platform/x86/lenovo/wmi-capdata.h
> +++ b/drivers/platform/x86/lenovo/wmi-capdata.h
> @@ -7,6 +7,7 @@
>   
>   #include <linux/types.h>
>   
> +struct component_match;
>   struct device;
>   struct cd_list;
>   
> @@ -19,7 +20,11 @@ struct capdata01 {
>   	u32 max_value;
>   };
>   
> +struct lwmi_cd_binder {
> +	struct cd_list *cd01_list;
> +};
> +
>   int lwmi_cd01_get_data(struct cd_list *list, u32 attribute_id, struct capdata01 *output);
> -int lwmi_cd01_match(struct device *dev, void *data);
> +void lwmi_cd_match_add_all(struct device *master, struct component_match **matchptr);
>   
>   #endif /* !_LENOVO_WMI_CAPDATA_H_ */
> diff --git a/drivers/platform/x86/lenovo/wmi-other.c b/drivers/platform/x86/lenovo/wmi-other.c
> index c6dc1b4cff84..20c6ff0be37a 100644
> --- a/drivers/platform/x86/lenovo/wmi-other.c
> +++ b/drivers/platform/x86/lenovo/wmi-other.c
> @@ -579,14 +579,14 @@ static void lwmi_om_fw_attr_remove(struct lwmi_om_priv *priv)
>   static int lwmi_om_master_bind(struct device *dev)
>   {
>   	struct lwmi_om_priv *priv = dev_get_drvdata(dev);
> -	struct cd_list *tmp_list;
> +	struct lwmi_cd_binder binder = { 0 };
>   	int ret;
>   
> -	ret = component_bind_all(dev, &tmp_list);
> +	ret = component_bind_all(dev, &binder);
>   	if (ret)
>   		return ret;
>   
> -	priv->cd01_list = tmp_list;
> +	priv->cd01_list = binder.cd01_list;
>   	if (!priv->cd01_list)
>   		return -ENODEV;
>   
> @@ -618,6 +618,7 @@ static int lwmi_other_probe(struct wmi_device *wdev, const void *context)
>   {
>   	struct component_match *master_match = NULL;
>   	struct lwmi_om_priv *priv;
> +	int ret;
>   
>   	priv = devm_kzalloc(&wdev->dev, sizeof(*priv), GFP_KERNEL);
>   	if (!priv)
> @@ -626,12 +627,26 @@ static int lwmi_other_probe(struct wmi_device *wdev, const void *context)
>   	priv->wdev = wdev;
>   	dev_set_drvdata(&wdev->dev, priv);
>   
> -	component_match_add(&wdev->dev, &master_match, lwmi_cd01_match, NULL);
> +	lwmi_cd_match_add_all(&wdev->dev, &master_match);
>   	if (IS_ERR(master_match))
>   		return PTR_ERR(master_match);
>   
> -	return component_master_add_with_match(&wdev->dev, &lwmi_om_master_ops,
> -					       master_match);
> +	ret = component_master_add_with_match(&wdev->dev, &lwmi_om_master_ops,
> +					      master_match);
> +	if (ret)
> +		return ret;
> +
> +	if (likely(component_master_is_bound(&wdev->dev, &lwmi_om_master_ops)))
> +		return 0;
> +
> +	/*
> +	 * The bind callbacks of both master and components were never called in
> +	 * this case - this driver won't work at all. Failing...
> +	 */
> +	dev_err(&wdev->dev, "unbound master; is any component failing to be probed?");
> +
> +	component_master_del(&wdev->dev, &lwmi_om_master_ops);
> +	return -EXDEV;
>   }
>   
>   static void lwmi_other_remove(struct wmi_device *wdev)