[PATCH v5 4/6] platform/x86: Add Lenovo Capability Data 01 WMI Driver

[Derek J. Clark]

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>
---
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                                 |   2 +
 drivers/platform/x86/Kconfig                |   4 +
 drivers/platform/x86/Makefile               |   1 +
 drivers/platform/x86/lenovo-wmi-capdata01.c | 168 ++++++++++++++++++++
 drivers/platform/x86/lenovo-wmi-capdata01.h |  28 ++++
 5 files changed, 203 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..a5255e080e87
--- /dev/null
+++ b/drivers/platform/x86/lenovo-wmi-capdata01.c
@@ -0,0 +1,168 @@
+// 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 attibute has multiple pages, one for each of the thermal
+ * modes managed by the Gamezone interface.
+ *
+ * Copyright(C) 2025 Derek J. Clark <derekjohn.clark@xxxxxxxxx>
+ */
+
+#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/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"
+
+struct lwmi_cd01_priv {
+	struct wmi_device *wdev;
+	struct cd01_list *list;
+};
+
+/**
+ * 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 look up attribute data by the lenovo-wmi-other driver.
+ *
+ * Return: 0 on success, or on error.
+ */
+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;
+
+	if (!priv->list)
+		return -ENODEV;
+
+	*cd01_list = priv->list;
+
+	return 0;
+}
+
+static const struct component_ops lwmi_cd01_component_ops = {
+	.bind = lwmi_cd01_component_bind,
+};
+
+/**
+ * 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 on error.
+ */
+static int lwmi_cd01_setup(struct lwmi_cd01_priv *priv)
+{
+	struct cd01_list *list;
+	size_t list_size;
+	int count, idx;
+
+	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;
+
+	list->count = count;
+
+	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)
+			return -ENODEV;
+
+		if (ret_obj->type != ACPI_TYPE_BUFFER ||
+		    ret_obj->buffer.length < sizeof(struct capdata01))
+			continue;
+
+		memcpy(&list->data[idx], ret_obj->buffer.pointer,
+		       ret_obj->buffer.length);
+	}
+
+	priv->list = list;
+
+	return 0;
+}
+
+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;
+
+	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: bool.
+ */
+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..15974ce5e008
--- /dev/null
+++ b/drivers/platform/x86/lenovo-wmi-capdata01.h
@@ -0,0 +1,28 @@
+/* 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/types.h>
+
+struct device;
+
+struct capdata01 {
+	u32 id;
+	u32 supported;
+	u32 default_value;
+	u32 step;
+	u32 min_value;
+	u32 max_value;
+};
+
+struct cd01_list {
+	u8 count;
+	struct capdata01 data[];
+};
+
+int lwmi_cd01_match(struct device *dev, void *data);
+
+#endif /* !_LENOVO_WMI_CAPDATA01_H_ */
-- 
2.49.0