1 // SPDX-License-Identifier: GPL-2.0 OR BSD-3-Clause
2 /* Copyright(c) 2021-2023  Realtek Corporation
3  */
4 
5 #include <linux/acpi.h>
6 #include <linux/uuid.h>
7 
8 #include "acpi.h"
9 #include "debug.h"
10 
11 static const guid_t rtw89_guid = GUID_INIT(0xD2A8C3E8, 0x4B69, 0x4F00,
12 					   0x82, 0xBD, 0xFE, 0x86,
13 					   0x07, 0x80, 0x3A, 0xA7);
14 
15 static int rtw89_acpi_dsm_get(struct rtw89_dev *rtwdev, union acpi_object *obj,
16 			      u8 *value)
17 {
18 	switch (obj->type) {
19 	case ACPI_TYPE_INTEGER:
20 		*value = (u8)obj->integer.value;
21 		break;
22 	case ACPI_TYPE_BUFFER:
23 		*value = obj->buffer.pointer[0];
24 		break;
25 	default:
26 		rtw89_debug(rtwdev, RTW89_DBG_UNEXP,
27 			    "acpi dsm return unhandled type: %d\n", obj->type);
28 		return -EINVAL;
29 	}
30 
31 	return 0;
32 }
33 
34 int rtw89_acpi_evaluate_dsm(struct rtw89_dev *rtwdev,
35 			    enum rtw89_acpi_dsm_func func, u8 *value)
36 {
37 	union acpi_object *obj;
38 	int ret;
39 
40 	obj = acpi_evaluate_dsm(ACPI_HANDLE(rtwdev->dev), &rtw89_guid,
41 				0, func, NULL);
42 	if (!obj) {
43 		rtw89_debug(rtwdev, RTW89_DBG_UNEXP,
44 			    "acpi dsm fail to evaluate func: %d\n", func);
45 		return -ENOENT;
46 	}
47 
48 	ret = rtw89_acpi_dsm_get(rtwdev, obj, value);
49 
50 	ACPI_FREE(obj);
51 	return ret;
52 }
53