On Wed, 26 Nov 2025, Rong Zhang wrote: > Add support for LENOVO_FAN_TEST_DATA WMI data block. Provides an > interface for querying the min/max fan speed RPM (reference data) of a > given fan ID. > > This interface is optional. Hence, it does not bind to lenovo-wmi-other > and is not registered as a component for the moment. Appropriate binding > will be implemented in the subsequent patch. > > Signed-off-by: Rong Zhang > Reviewed-by: Derek J. Clark > Tested-by: Derek J. Clark > --- > Changes in v7: > - Rearrange lwmi_cd_fan_list_alloc_cache() to drop gotos (thanks Ilpo > Järvinen) > - Move the declarations of __free()-managed variablesto where thet are > assigned (ditto) > - Prevent back-and-forth changes (ditto) > - Improve the readablity of struct definition (ditto) > - Emit unaligned access to the WMI block > - Properly calculate array index when we truncate the data > > Changes in v4: > - Rebase on top of changes made to [PATCH v4 3/7] > - Do not register it as a component until [PATCH v4 6/7] > > Changes in v2: > - Reword documentation > --- > .../wmi/devices/lenovo-wmi-other.rst | 17 ++++ > drivers/platform/x86/lenovo/wmi-capdata.c | 96 +++++++++++++++++++ > drivers/platform/x86/lenovo/wmi-capdata.h | 7 ++ > 3 files changed, 120 insertions(+) > > diff --git a/Documentation/wmi/devices/lenovo-wmi-other.rst b/Documentation/wmi/devices/lenovo-wmi-other.rst > index fcad595d49af..821282e07d93 100644 > --- a/Documentation/wmi/devices/lenovo-wmi-other.rst > +++ b/Documentation/wmi/devices/lenovo-wmi-other.rst > @@ -62,6 +62,13 @@ The following firmware-attributes are implemented: > - ppt_pl2_sppt: Platform Profile Tracking Slow Package Power Tracking > - ppt_pl3_fppt: Platform Profile Tracking Fast Package Power Tracking > > +LENOVO_FAN_TEST_DATA > +------------------------- > + > +WMI GUID ``B642801B-3D21-45DE-90AE-6E86F164FB21`` > + > +The LENOVO_FAN_TEST_DATA interface provides reference data for self-test of > +cooling fans. > > WMI interface description > ========================= > @@ -115,3 +122,13 @@ data using the `bmfdec `_ utility: > [WmiDataId(3), read, Description("Data Size.")] uint32 DataSize; > [WmiDataId(4), read, Description("Default Value"), WmiSizeIs("DataSize")] uint8 DefaultValue[]; > }; > + > + [WMI, Dynamic, Provider("WmiProv"), Locale("MS\\0x409"), Description("Definition of Fan Test Data"), guid("{B642801B-3D21-45DE-90AE-6E86F164FB21}")] > + class LENOVO_FAN_TEST_DATA { > + [key, read] string InstanceName; > + [read] boolean Active; > + [WmiDataId(1), read, Description("Mode.")] uint32 NumOfFans; > + [WmiDataId(2), read, Description("Fan ID."), WmiSizeIs("NumOfFans")] uint32 FanId[]; > + [WmiDataId(3), read, Description("Maximum Fan Speed."), WmiSizeIs("NumOfFans")] uint32 FanMaxSpeed[]; > + [WmiDataId(4), read, Description("Minumum Fan Speed."), WmiSizeIs("NumOfFans")] uint32 FanMinSpeed[]; > + }; > diff --git a/drivers/platform/x86/lenovo/wmi-capdata.c b/drivers/platform/x86/lenovo/wmi-capdata.c > index 08a78dc490f6..9fed162abd17 100644 > --- a/drivers/platform/x86/lenovo/wmi-capdata.c > +++ b/drivers/platform/x86/lenovo/wmi-capdata.c > @@ -13,6 +13,10 @@ > * attribute has multiple pages, one for each of the thermal modes managed by > * the Gamezone interface. > * > + * Fan Test Data includes the max/min fan speed RPM for each fan. This is > + * reference data for self-test. If the fan is in good condition, it is capable > + * to spin faster than max RPM or slower than min RPM. > + * > * Copyright (C) 2025 Derek J. Clark > * - Initial implementation (formerly named lenovo-wmi-capdata01) > * > @@ -45,6 +49,7 @@ > > #define LENOVO_CAPABILITY_DATA_00_GUID "362A3AFE-3D96-4665-8530-96DAD5BB300E" > #define LENOVO_CAPABILITY_DATA_01_GUID "7A8F5407-CB67-4D6E-B547-39B3BE018154" > +#define LENOVO_FAN_TEST_DATA_GUID "B642801B-3D21-45DE-90AE-6E86F164FB21" > > #define ACPI_AC_CLASS "ac_adapter" > #define ACPI_AC_NOTIFY_STATUS 0x80 > @@ -52,6 +57,7 @@ > enum lwmi_cd_type { > LENOVO_CAPABILITY_DATA_00, > LENOVO_CAPABILITY_DATA_01, > + LENOVO_FAN_TEST_DATA, > }; > > #define LWMI_CD_TABLE_ITEM(_type) \ > @@ -66,6 +72,7 @@ static const struct lwmi_cd_info { > } lwmi_cd_table[] = { > LWMI_CD_TABLE_ITEM(LENOVO_CAPABILITY_DATA_00), > LWMI_CD_TABLE_ITEM(LENOVO_CAPABILITY_DATA_01), > + LWMI_CD_TABLE_ITEM(LENOVO_FAN_TEST_DATA), > }; > > struct lwmi_cd_priv { > @@ -82,6 +89,7 @@ struct cd_list { > union { > DECLARE_FLEX_ARRAY(struct capdata00, cd00); > DECLARE_FLEX_ARRAY(struct capdata01, cd01); > + DECLARE_FLEX_ARRAY(struct capdata_fan, cd_fan); > }; > }; > > @@ -121,6 +129,10 @@ void lwmi_cd_match_add_all(struct device *master, struct component_match **match > return; > > for (i = 0; i < ARRAY_SIZE(lwmi_cd_table); i++) { > + /* Skip sub-components. */ > + if (lwmi_cd_table[i].type == LENOVO_FAN_TEST_DATA) > + continue; > + > component_match_add(master, matchptr, lwmi_cd_match, > (void *)&lwmi_cd_table[i].type); > if (IS_ERR(*matchptr)) > @@ -200,6 +212,9 @@ EXPORT_SYMBOL_NS_GPL(lwmi_cd00_get_data, "LENOVO_WMI_CD"); > DEF_LWMI_CDXX_GET_DATA(cd01, LENOVO_CAPABILITY_DATA_01, struct capdata01); > EXPORT_SYMBOL_NS_GPL(lwmi_cd01_get_data, "LENOVO_WMI_CD"); > > +DEF_LWMI_CDXX_GET_DATA(cd_fan, LENOVO_FAN_TEST_DATA, struct capdata_fan); > +EXPORT_SYMBOL_NS_GPL(lwmi_cd_fan_get_data, "LENOVO_WMI_CD"); > + > /** > * lwmi_cd_cache() - Cache all WMI data block information > * @priv: lenovo-wmi-capdata driver data. > @@ -223,6 +238,9 @@ static int lwmi_cd_cache(struct lwmi_cd_priv *priv) > p = &priv->list->cd01[0]; > size = sizeof(priv->list->cd01[0]); > break; > + case LENOVO_FAN_TEST_DATA: > + /* Done by lwmi_cd_alloc() => lwmi_cd_fan_list_alloc_cache(). */ > + return 0; > default: > return -EINVAL; > } > @@ -245,6 +263,72 @@ static int lwmi_cd_cache(struct lwmi_cd_priv *priv) > return 0; > } > > +/** > + * lwmi_cd_fan_list_alloc_cache() - Alloc and cache Fan Test Data list > + * @priv: lenovo-wmi-capdata driver data. > + * @listptr: Pointer to returned cd_list pointer. > + * > + * Return: count of fans found, or an error. > + */ > +static int lwmi_cd_fan_list_alloc_cache(struct lwmi_cd_priv *priv, struct cd_list **listptr) > +{ > + struct cd_list *list; > + size_t size; > + u32 count; > + int idx; > + > + /* Emit unaligned access to u8 buffer with __packed. */ > + struct cd_fan_block { > + u32 nr; > + u32 data[]; /* id[nr], max_rpm[nr], min_rpm[nr] */ > + } __packed * block; > + > + union acpi_object *ret_obj __free(kfree) = wmidev_block_query(priv->wdev, 0); > + if (!ret_obj) > + return -ENODEV; > + > + if (ret_obj->type == ACPI_TYPE_BUFFER) { > + block = (struct cd_fan_block *)ret_obj->buffer.pointer; > + size = ret_obj->buffer.length; > + > + count = size >= sizeof(*block) ? block->nr : 0; > + if (size < struct_size(block, data, count * 3)) { > + dev_warn(&priv->wdev->dev, > + "incomplete fan test data block: %zu < %zu, ignoring\n", > + size, struct_size(block, data, count * 3)); > + count = 0; > + } else if (count > U8_MAX) { + limits.h -- i. > + dev_warn(&priv->wdev->dev, > + "too many fans reported: %u > %u, truncating\n", > + count, U8_MAX); > + count = U8_MAX; > + } > + } else { > + /* > + * This is usually caused by a dummy ACPI method. Do not return an error > + * as failing to probe this device will result in sub-master device being > + * unbound. This behavior aligns with lwmi_cd_cache(). > + */ > + count = 0; > + } > + > + list = devm_kzalloc(&priv->wdev->dev, struct_size(list, cd_fan, count), GFP_KERNEL); > + if (!list) > + return -ENOMEM; > + > + for (idx = 0; idx < count; idx++) { > + /* Do not calculate array index using count, as it may be truncated. */ > + list->cd_fan[idx] = (struct capdata_fan) { > + .id = block->data[idx], > + .max_rpm = block->data[idx + block->nr], > + .min_rpm = block->data[idx + (2 * block->nr)], > + }; > + } > + > + *listptr = list; > + return count; > +} > + > /** > * lwmi_cd_alloc() - Allocate a cd_list struct in drvdata > * @priv: lenovo-wmi-capdata driver data. > @@ -270,6 +354,12 @@ static int lwmi_cd_alloc(struct lwmi_cd_priv *priv, enum lwmi_cd_type type) > case LENOVO_CAPABILITY_DATA_01: > list_size = struct_size(list, cd01, count); > break; > + case LENOVO_FAN_TEST_DATA: > + count = lwmi_cd_fan_list_alloc_cache(priv, &list); > + if (count < 0) > + return count; > + > + goto got_list; > default: > return -EINVAL; > } > @@ -278,6 +368,7 @@ static int lwmi_cd_alloc(struct lwmi_cd_priv *priv, enum lwmi_cd_type type) > if (!list) > return -ENOMEM; > > +got_list: > ret = devm_mutex_init(&priv->wdev->dev, &list->list_mutex); > if (ret) > return ret; > @@ -396,6 +487,8 @@ static int lwmi_cd_probe(struct wmi_device *wdev, const void *context) > > ret = component_add(&wdev->dev, &lwmi_cd_component_ops); > goto out; > + case LENOVO_FAN_TEST_DATA: > + goto out; > default: > return -EINVAL; > } > @@ -419,6 +512,8 @@ static void lwmi_cd_remove(struct wmi_device *wdev) > case LENOVO_CAPABILITY_DATA_01: > component_del(&wdev->dev, &lwmi_cd_component_ops); > break; > + case LENOVO_FAN_TEST_DATA: > + break; > default: > WARN_ON(1); > } > @@ -431,6 +526,7 @@ static void lwmi_cd_remove(struct wmi_device *wdev) > static const struct wmi_device_id lwmi_cd_id_table[] = { > { LWMI_CD_WDEV_ID(LENOVO_CAPABILITY_DATA_00) }, > { LWMI_CD_WDEV_ID(LENOVO_CAPABILITY_DATA_01) }, > + { LWMI_CD_WDEV_ID(LENOVO_FAN_TEST_DATA) }, > {} > }; > > diff --git a/drivers/platform/x86/lenovo/wmi-capdata.h b/drivers/platform/x86/lenovo/wmi-capdata.h > index a6d006ef458f..38af4c4e4ef4 100644 > --- a/drivers/platform/x86/lenovo/wmi-capdata.h > +++ b/drivers/platform/x86/lenovo/wmi-capdata.h > @@ -26,6 +26,12 @@ struct capdata01 { > u32 max_value; > }; > > +struct capdata_fan { > + u32 id; > + u32 min_rpm; > + u32 max_rpm; > +}; > + > struct lwmi_cd_binder { > struct cd_list *cd00_list; > struct cd_list *cd01_list; > @@ -34,5 +40,6 @@ struct lwmi_cd_binder { > void lwmi_cd_match_add_all(struct device *master, struct component_match **matchptr); > int lwmi_cd00_get_data(struct cd_list *list, u32 attribute_id, struct capdata00 *output); > int lwmi_cd01_get_data(struct cd_list *list, u32 attribute_id, struct capdata01 *output); > +int lwmi_cd_fan_get_data(struct cd_list *list, u32 attribute_id, struct capdata_fan *output); > > #endif /* !_LENOVO_WMI_CAPDATA_H_ */ >