platform/x86: intel-wmi-sbl-fw-update: Use new buffer-based WMI API

Use the new buffer-based WMI API to also support ACPI firmware
implementations that return a ACPI buffer instead of a ACPI integer.

Signed-off-by: Armin Wolf <W_Armin@gmx.de>
Link: https://patch.msgid.link/20260116204116.4030-6-W_Armin@gmx.de
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>

Author: Wer-Wolf

drivers/platform/x86/intel/wmi/sbl-fw-update.c

@@ -14,7 +14,6 @@
  * https://slimbootloader.github.io/security/firmware-update.html
  */
 
-#include <linux/acpi.h>
 #include <linux/device.h>
 #include <linux/module.h>
 #include <linux/slab.h>
@@ -25,41 +24,35 @@
 
 static int get_fwu_request(struct device *dev, u32 *out)
 {
-	union acpi_object *obj;
+	struct wmi_buffer buffer;
+	__le32 *result;
+	int ret;
 
-	obj = wmidev_block_query(to_wmi_device(dev), 0);
-	if (!obj)
-		return -ENODEV;
+	ret = wmidev_query_block(to_wmi_device(dev), 0, &buffer);
+	if (ret < 0)
+		return ret;
 
-	if (obj->type != ACPI_TYPE_INTEGER) {
-		dev_warn(dev, "wmidev_block_query returned invalid value\n");
-		kfree(obj);
-		return -EINVAL;
+	if (buffer.length < sizeof(*result)) {
+		kfree(buffer.data);
+		return -ENODATA;
 	}
 
-	*out = obj->integer.value;
-	kfree(obj);
+	result = buffer.data;
+	*out = le32_to_cpu(*result);
+	kfree(result);
 
 	return 0;
 }
 
 static int set_fwu_request(struct device *dev, u32 in)
 {
-	struct acpi_buffer input;
-	acpi_status status;
-	u32 value;
-
-	value = in;
-	input.length = sizeof(u32);
-	input.pointer = &value;
-
-	status = wmidev_block_set(to_wmi_device(dev), 0, &input);
-	if (ACPI_FAILURE(status)) {
-		dev_err(dev, "wmidev_block_set failed\n");
-		return -ENODEV;
-	}
+	__le32 value = cpu_to_le32(in);
+	struct wmi_buffer buffer = {
+		.length = sizeof(value),
+		.data = &value,
+	};
 
-	return 0;
+	return wmidev_set_block(to_wmi_device(dev), 0, &buffer);
 }
 
 static ssize_t firmware_update_request_show(struct device *dev,