Hi Armin,
On Tue, 2025-11-04 at 21:20 +0100, Armin Wolf wrote:
> 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 <[email protected]>
> > Reviewed-by: Derek J. Clark <[email protected]>
> > Tested-by: Derek J. Clark <[email protected]>
> > ---
> > 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 <[email protected]>
> > * - Initial implementation (formerly named lenovo-wmi-capdata01)
> > + *
> > + * Copyright (C) 2025 Rong Zhang <[email protected]>
> > + * - 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?
I tried your approach. I looks pretty well except for step 4:
debugfs: 'DC2A8805-3A8C-41BA-A6F7-092E0089CD3B-21' already exists in
'device_component'
Moreover, component_[un]bind_all() calls __aggregate_find() with ops ==
NULL, which implies that it can't really distinguish the two aggregate
devices we have. Thus, we are rely on the insertion sequence of
aggregate_devices (see component_master_add_with_match()) to make it
just work. Pseudo code:
lwmi_other_probe()
{
component_match_add(..., lwmi_cd00_match, ...);
component_match_add(..., lwmi_cd01_match, ...);
component_master_add_with_match(..., &ops1, ...);
component_match_add(..., lwmi_cd_fan_match, ...);
component_master_add_with_match(..., &ops2, ...);
}
lwmi_other_remove()
{
/* This just works (TM). */
component_master_del(..., &ops2); /* unbinds cd_fan */
component_master_del(..., &ops1); /* unbinds cd00/01 */
/* WARNING: at drivers/base/component.c:589 */
/*
component_master_del(..., &ops1); /* unbinds cd_fan!!! */
component_master_del(..., &ops2); /* unbinds cd_fan!!! */
*/
}
It seems that the component framework is not prepared to allow multi-
aggregation master device.
Since we are talking about the component framework: all efforts we made
here is to work around one of its limitations -- all components must be
found or else it won't bring up the aggregate device. Do you think
allowing partially bound aggregate device a good idea? E.g., adding a
flag, indicating the master device opts in to such behavior, to the
definition of struct component_master_ops. I can prepare a separate
patch for that.
CC'ing maintainers and lists of driver core and component framework.
> Thanks,
> Armin Wolf
Thanks,
Rong
> > +
> > + 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 <[email protected]>");
> > +MODULE_AUTHOR("Rong Zhang <[email protected]>");
> > 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)
