1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 * Lenovo Legion WMI helpers driver. 4 * 5 * The Lenovo Legion WMI interface is broken up into multiple GUID interfaces 6 * that require cross-references between GUID's for some functionality. The 7 * "Custom Mode" interface is a legacy interface for managing and displaying 8 * CPU & GPU power and hwmon settings and readings. The "Other Mode" interface 9 * is a modern interface that replaces or extends the "Custom Mode" interface 10 * methods. The "Gamezone" interface adds advanced features such as fan 11 * profiles and overclocking. The "Lighting" interface adds control of various 12 * status lights related to different hardware components. Each of these 13 * drivers uses a common procedure to get data from the WMI interface, 14 * enumerated here. 15 * 16 * Copyright (C) 2025 Derek J. Clark <derekjohn.clark@gmail.com> 17 */ 18 19 #include <linux/acpi.h> 20 #include <linux/cleanup.h> 21 #include <linux/errno.h> 22 #include <linux/export.h> 23 #include <linux/module.h> 24 #include <linux/wmi.h> 25 26 #include "wmi-helpers.h" 27 28 /** 29 * lwmi_dev_evaluate_int() - Helper function for calling WMI methods that 30 * return an integer. 31 * @wdev: Pointer to the WMI device to be called. 32 * @instance: Instance of the called method. 33 * @method_id: WMI Method ID for the method to be called. 34 * @buf: Buffer of all arguments for the given method_id. 35 * @size: Length of the buffer. 36 * @retval: Pointer for the return value to be assigned. 37 * 38 * Calls wmidev_evaluate_method for Lenovo WMI devices that return an ACPI 39 * integer. Validates the return value type and assigns the value to the 40 * retval pointer. 41 * 42 * Return: 0 on success, or an error code. 43 */ 44 int lwmi_dev_evaluate_int(struct wmi_device *wdev, u8 instance, u32 method_id, 45 unsigned char *buf, size_t size, u32 *retval) 46 { 47 struct acpi_buffer output = { ACPI_ALLOCATE_BUFFER, NULL }; 48 union acpi_object *ret_obj __free(kfree) = NULL; 49 struct acpi_buffer input = { size, buf }; 50 acpi_status status; 51 52 status = wmidev_evaluate_method(wdev, instance, method_id, &input, 53 &output); 54 if (ACPI_FAILURE(status)) 55 return -EIO; 56 57 if (retval) { 58 ret_obj = output.pointer; 59 if (!ret_obj) 60 return -ENODATA; 61 62 if (ret_obj->type != ACPI_TYPE_INTEGER) 63 return -ENXIO; 64 65 *retval = (u32)ret_obj->integer.value; 66 } 67 68 return 0; 69 }; 70 EXPORT_SYMBOL_NS_GPL(lwmi_dev_evaluate_int, "LENOVO_WMI_HELPERS"); 71 72 MODULE_AUTHOR("Derek J. Clark <derekjohn.clark@gmail.com>"); 73 MODULE_DESCRIPTION("Lenovo WMI Helpers Driver"); 74 MODULE_LICENSE("GPL"); 75