[PATCH v12 4/6] platform/x86: Add Lenovo Capability Data 01 WMI Driver

["Derek J. Clark" <derekjohn.clark@gmail.com>]

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.

Reviewed-by: Alok Tiwari <alok.a.tiwari@oracle.com>
Reviewed-by: Armin Wolf <W_Armin@gmx.de>
Signed-off-by: Derek J. Clark <derekjohn.clark@gmail.com>
---
v12:
 - Fix warnings from make W=1
v11:
 - Formatting
v10: No change
v9:
 - Check result of devm_mutex_init.
v8:
 - Use devm_mutex_init() instead of mutex_init().
 - Check return of devm_add_action_or_reset during probe.
 - Don't check if cd01 list exists in bind as the driver will bail if
   there is a malloc/populating issue prior to bind.
 - Fix typos.
v7:
 - Do memcpy instead of returning pointer in lwmi_cd01_get_data.
 - Put list mutex inside lwmi_cd01_priv struct.
 - Unregister from acpi events on dev remove.
 - Fix typos.
v6:
 - Recache capabiltiy data on ACPI AC events to ensure accutare
   max_value.
 - Fix typos and rewordings from v5 review.
v5:
 - Return to cache at device initialization. On component bind, pass a
   pointer to lenovo-wmi-other.
 - Fixes from v4 review.
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                                 |   1 +
 drivers/platform/x86/Kconfig                |   4 +
 drivers/platform/x86/Makefile               |   1 +
 drivers/platform/x86/lenovo-wmi-capdata01.c | 302 ++++++++++++++++++++
 drivers/platform/x86/lenovo-wmi-capdata01.h |  25 ++
 5 files changed, 333 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 f1df9a07e258..8af1756f39d8 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -13453,6 +13453,7 @@ 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.*
 F:	drivers/platform/x86/lenovo-wmi-events.*
 F:	drivers/platform/x86/lenovo-wmi-helpers.*
 
diff --git a/drivers/platform/x86/Kconfig b/drivers/platform/x86/Kconfig
index 27881cf00ebf..248384489d36 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 9effb1e3852c..32e72b8b7a6e 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..2bd862a75c71
--- /dev/null
+++ b/drivers/platform/x86/lenovo-wmi-capdata01.c
@@ -0,0 +1,302 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Lenovo Capability Data 01 WMI Data Block driver.
+ *
+ * Lenovo Capability Data 01 provides information on tunable attributes used by
+ * the "Other Mode" WMI interface. The data includes if the attribute is
+ * supported by the hardware, the default_value, max_value, min_value, and step
+ * increment. Each attribute has multiple pages, one for each of the thermal
+ * modes managed by the Gamezone interface.
+ *
+ * Copyright (C) 2025 Derek J. Clark <derekjohn.clark@gmail.com>
+ */
+
+#include <linux/acpi.h>
+#include <linux/cleanup.h>
+#include <linux/component.h>
+#include <linux/container_of.h>
+#include <linux/device.h>
+#include <linux/export.h>
+#include <linux/gfp_types.h>
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include <linux/mutex_types.h>
+#include <linux/notifier.h>
+#include <linux/overflow.h>
+#include <linux/types.h>
+#include <linux/wmi.h>
+
+#include "lenovo-wmi-capdata01.h"
+
+#define LENOVO_CAPABILITY_DATA_01_GUID "7A8F5407-CB67-4D6E-B547-39B3BE018154"
+
+#define ACPI_AC_CLASS "ac_adapter"
+#define ACPI_AC_NOTIFY_STATUS 0x80
+
+struct lwmi_cd01_priv {
+	struct notifier_block acpi_nb; /* ACPI events */
+	struct wmi_device *wdev;
+	struct cd01_list *list;
+};
+
+struct cd01_list {
+	struct mutex list_mutex; /* list R/W mutex */
+	u8 count;
+	struct capdata01 data[];
+};
+
+/**
+ * lwmi_cd01_component_bind() - Bind component to master device.
+ * @cd01_dev: Pointer to the lenovo-wmi-capdata01 driver parent device.
+ * @om_dev: Pointer to the lenovo-wmi-other driver parent device.
+ * @data: capdata01_list object pointer used to return the capability data.
+ *
+ * On lenovo-wmi-other's master bind, provide a pointer to the local capdata01
+ * list. This is used to call lwmi_cd01_get_data to look up attribute data
+ * from the lenovo-wmi-other driver.
+ *
+ * Return: 0
+ */
+static int lwmi_cd01_component_bind(struct device *cd01_dev,
+				    struct device *om_dev, void *data)
+{
+	struct lwmi_cd01_priv *priv = dev_get_drvdata(cd01_dev);
+	struct cd01_list **cd01_list = data;
+
+	*cd01_list = priv->list;
+
+	return 0;
+}
+
+static const struct component_ops lwmi_cd01_component_ops = {
+	.bind = lwmi_cd01_component_bind,
+};
+
+/**
+ * lwmi_cd01_get_data - Get the data of the specified attribute
+ * @list: The lenovo-wmi-capdata01 pointer to its cd01_list struct.
+ * @attribute_id: The capdata attribute ID to be found.
+ * @output: Pointer to a capdata01 struct to return the data.
+ *
+ * Retrieves the capability data 01 struct pointer for the given
+ * attribute for its specified thermal mode.
+ *
+ * Return: 0 on success, or -EINVAL.
+ */
+int lwmi_cd01_get_data(struct cd01_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;
+	};
+
+	return -EINVAL;
+}
+EXPORT_SYMBOL_NS_GPL(lwmi_cd01_get_data, "LENOVO_WMI_CD01");
+
+/**
+ * lwmi_cd01_cache() - Cache all WMI data block information
+ * @priv: lenovo-wmi-capdata01 driver data.
+ *
+ * Loop through each WMI data block and cache the data.
+ *
+ * Return: 0 on success, or an error.
+ */
+static int lwmi_cd01_cache(struct lwmi_cd01_priv *priv)
+{
+	int idx;
+
+	guard(mutex)(&priv->list->list_mutex);
+	for (idx = 0; idx < priv->list->count; idx++) {
+		union acpi_object *ret_obj __free(kfree) = NULL;
+
+		ret_obj = wmidev_block_query(priv->wdev, idx);
+		if (!ret_obj)
+			return -ENODEV;
+
+		if (ret_obj->type != ACPI_TYPE_BUFFER ||
+		    ret_obj->buffer.length < sizeof(priv->list->data[idx]))
+			continue;
+
+		memcpy(&priv->list->data[idx], ret_obj->buffer.pointer,
+		       ret_obj->buffer.length);
+	}
+
+	return 0;
+}
+
+/**
+ * lwmi_cd01_alloc() - Allocate a cd01_list struct in drvdata
+ * @priv: lenovo-wmi-capdata01 driver data.
+ *
+ * Allocate a cd01_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_cd01_alloc(struct lwmi_cd01_priv *priv)
+{
+	struct cd01_list *list;
+	size_t list_size;
+	int count, ret;
+
+	count = wmidev_instance_count(priv->wdev);
+	list_size = struct_size(list, data, count);
+
+	list = devm_kzalloc(&priv->wdev->dev, list_size, GFP_KERNEL);
+	if (!list)
+		return -ENOMEM;
+
+	ret = devm_mutex_init(&priv->wdev->dev, &list->list_mutex);
+	if (ret)
+		return ret;
+
+	list->count = count;
+	priv->list = list;
+
+	return 0;
+}
+
+/**
+ * lwmi_cd01_setup() - Cache all WMI data block information
+ * @priv: lenovo-wmi-capdata01 driver data.
+ *
+ * Allocate a cd01_list struct large enough to contain data from all WMI data
+ * blocks provided by the interface. Then loop through each data block and
+ * cache the data.
+ *
+ * Return: 0 on success, or an error code.
+ */
+static int lwmi_cd01_setup(struct lwmi_cd01_priv *priv)
+{
+	int ret;
+
+	ret = lwmi_cd01_alloc(priv);
+	if (ret)
+		return ret;
+
+	return lwmi_cd01_cache(priv);
+}
+
+/**
+ * lwmi_cd01_notifier_call() - Call method for lenovo-wmi-capdata01 driver notifier.
+ * block call chain.
+ * @nb: The notifier_block registered to lenovo-wmi-events driver.
+ * @action: Unused.
+ * @data: The ACPI event.
+ *
+ * For LWMI_EVENT_THERMAL_MODE, set current_mode and notify platform_profile
+ * of a change.
+ *
+ * Return: notifier_block status.
+ */
+static int lwmi_cd01_notifier_call(struct notifier_block *nb, unsigned long action,
+				   void *data)
+{
+	struct acpi_bus_event *event = data;
+	struct lwmi_cd01_priv *priv;
+	int ret;
+
+	if (strcmp(event->device_class, ACPI_AC_CLASS) != 0)
+		return NOTIFY_DONE;
+
+	priv = container_of(nb, struct lwmi_cd01_priv, acpi_nb);
+
+	switch (event->type) {
+	case ACPI_AC_NOTIFY_STATUS:
+		ret = lwmi_cd01_cache(priv);
+		if (ret)
+			return NOTIFY_BAD;
+
+		return NOTIFY_OK;
+	default:
+		return NOTIFY_DONE;
+	}
+}
+
+/**
+ * lwmi_cd01_unregister() - Unregister the cd01 ACPI notifier_block.
+ * @data: The ACPI event notifier_block to unregister.
+ */
+static void lwmi_cd01_unregister(void *data)
+{
+	struct notifier_block *acpi_nb = data;
+
+	unregister_acpi_notifier(acpi_nb);
+}
+
+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 = lwmi_cd01_setup(priv);
+	if (ret)
+		return ret;
+
+	priv->acpi_nb.notifier_call = lwmi_cd01_notifier_call;
+
+	ret = register_acpi_notifier(&priv->acpi_nb);
+	if (ret)
+		return ret;
+
+	ret = devm_add_action_or_reset(&wdev->dev, lwmi_cd01_unregister, &priv->acpi_nb);
+	if (ret)
+		return ret;
+
+	return component_add(&wdev->dev, &lwmi_cd01_component_ops);
+}
+
+static void lwmi_cd01_remove(struct wmi_device *wdev)
+{
+	component_del(&wdev->dev, &lwmi_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,
+};
+
+/**
+ * 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.
+ *
+ * Return: int.
+ */
+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@gmail.com>");
+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..bd06c5751f68
--- /dev/null
+++ b/drivers/platform/x86/lenovo-wmi-capdata01.h
@@ -0,0 +1,25 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+
+/* Copyright (C) 2025 Derek J. Clark <derekjohn.clark@gmail.com> */
+
+#ifndef _LENOVO_WMI_CAPDATA01_H_
+#define _LENOVO_WMI_CAPDATA01_H_
+
+#include <linux/types.h>
+
+struct device;
+struct cd01_list;
+
+struct capdata01 {
+	u32 id;
+	u32 supported;
+	u32 default_value;
+	u32 step;
+	u32 min_value;
+	u32 max_value;
+};
+
+int lwmi_cd01_get_data(struct cd01_list *list, u32 attribute_id, struct capdata01 *output);
+int lwmi_cd01_match(struct device *dev, void *data);
+
+#endif /* !_LENOVO_WMI_CAPDATA01_H_ */
-- 
2.49.0