1 files changed, 52 insertions, 0 deletions
diff --git a/drivers/net/wireless/realtek/rtw89/acpi.c b/drivers/net/wireless/realtek/rtw89/acpi.c
new file mode 100644
index 000000000000..8aaf83a2a6b4
--- /dev/null
+++ b/drivers/net/wireless/realtek/rtw89/acpi.c
@@ -0,0 +1,52 @@
+// SPDX-License-Identifier: GPL-2.0 OR BSD-3-Clause
+/* Copyright(c) 2021-2023  Realtek Corporation
+ */
+
+#include <linux/acpi.h>
+#include <linux/uuid.h>
+
+#include "acpi.h"
+#include "debug.h"
+
+static const guid_t rtw89_guid = GUID_INIT(0xD2A8C3E8, 0x4B69, 0x4F00,
+					   0x82, 0xBD, 0xFE, 0x86,
+					   0x07, 0x80, 0x3A, 0xA7);
+
+static int rtw89_acpi_dsm_get(struct rtw89_dev *rtwdev, union acpi_object *obj,
+			      u8 *value)
+{
+	switch (obj->type) {
+	case ACPI_TYPE_INTEGER:
+		*value = (u8)obj->integer.value;
+		break;
+	case ACPI_TYPE_BUFFER:
+		*value = obj->buffer.pointer[0];
+		break;
+	default:
+		rtw89_debug(rtwdev, RTW89_DBG_UNEXP,
+			    "acpi dsm return unhandled type: %d\n", obj->type);
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+int rtw89_acpi_evaluate_dsm(struct rtw89_dev *rtwdev,
+			    enum rtw89_acpi_dsm_func func, u8 *value)
+{
+	union acpi_object *obj;
+	int ret;
+
+	obj = acpi_evaluate_dsm(ACPI_HANDLE(rtwdev->dev), &rtw89_guid,
+				0, func, NULL);
+	if (!obj) {
+		rtw89_debug(rtwdev, RTW89_DBG_UNEXP,
+			    "acpi dsm fail to evaluate func: %d\n", func);
+		return -ENOENT;
+	}
+
+	ret = rtw89_acpi_dsm_get(rtwdev, obj, value);
+
+	ACPI_FREE(obj);
+	return ret;
+}