Add virtio_rtc.h from the upstream Linux kernel using
scripts/update-linux-headers.sh.

Source:
- Linux commit 6de23f81a5e08be8fbf5e8d7e9febc72a5b5f27f (v7.0-rc1)
- Author: Linus Torvalds <torvalds@linux-foundation.org>
- Date:   Sun Feb 22 13:18:59 2026 -0800

Signed-off-by: Kuan-Wei Chiu <visitorckw@gmail.com>
---
 include/standard-headers/linux/virtio_rtc.h | 237 ++++++++++++++++++++
 1 file changed, 237 insertions(+)
 create mode 100644 include/standard-headers/linux/virtio_rtc.h

diff --git a/include/standard-headers/linux/virtio_rtc.h b/include/standard-headers/linux/virtio_rtc.h
new file mode 100644
index 0000000000..7e2c21ebff
--- /dev/null
+++ b/include/standard-headers/linux/virtio_rtc.h
@@ -0,0 +1,237 @@
+/* SPDX-License-Identifier: ((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause) */
+/*
+ * Copyright (C) 2022-2024 OpenSynergy GmbH
+ * Copyright (c) 2024 Qualcomm Innovation Center, Inc. All rights reserved.
+ */
+
+#ifndef _LINUX_VIRTIO_RTC_H
+#define _LINUX_VIRTIO_RTC_H
+
+#include "standard-headers/linux/types.h"
+
+/* alarm feature */
+#define VIRTIO_RTC_F_ALARM	0
+
+/* read request message types */
+
+#define VIRTIO_RTC_REQ_READ			0x0001
+#define VIRTIO_RTC_REQ_READ_CROSS		0x0002
+
+/* control request message types */
+
+#define VIRTIO_RTC_REQ_CFG			0x1000
+#define VIRTIO_RTC_REQ_CLOCK_CAP		0x1001
+#define VIRTIO_RTC_REQ_CROSS_CAP		0x1002
+#define VIRTIO_RTC_REQ_READ_ALARM		0x1003
+#define VIRTIO_RTC_REQ_SET_ALARM		0x1004
+#define VIRTIO_RTC_REQ_SET_ALARM_ENABLED	0x1005
+
+/* alarmq message types */
+
+#define VIRTIO_RTC_NOTIF_ALARM			0x2000
+
+/* Message headers */
+
+/** common request header */
+struct virtio_rtc_req_head {
+	uint16_t msg_type;
+	uint8_t reserved[6];
+};
+
+/** common response header */
+struct virtio_rtc_resp_head {
+#define VIRTIO_RTC_S_OK			0
+#define VIRTIO_RTC_S_EOPNOTSUPP		2
+#define VIRTIO_RTC_S_ENODEV		3
+#define VIRTIO_RTC_S_EINVAL		4
+#define VIRTIO_RTC_S_EIO		5
+	uint8_t status;
+	uint8_t reserved[7];
+};
+
+/** common notification header */
+struct virtio_rtc_notif_head {
+	uint16_t msg_type;
+	uint8_t reserved[6];
+};
+
+/* read requests */
+
+/* VIRTIO_RTC_REQ_READ message */
+
+struct virtio_rtc_req_read {
+	struct virtio_rtc_req_head head;
+	uint16_t clock_id;
+	uint8_t reserved[6];
+};
+
+struct virtio_rtc_resp_read {
+	struct virtio_rtc_resp_head head;
+	uint64_t clock_reading;
+};
+
+/* VIRTIO_RTC_REQ_READ_CROSS message */
+
+struct virtio_rtc_req_read_cross {
+	struct virtio_rtc_req_head head;
+	uint16_t clock_id;
+/* Arm Generic Timer Counter-timer Virtual Count Register (CNTVCT_EL0) */
+#define VIRTIO_RTC_COUNTER_ARM_VCT	0
+/* x86 Time-Stamp Counter */
+#define VIRTIO_RTC_COUNTER_X86_TSC	1
+/* Invalid */
+#define VIRTIO_RTC_COUNTER_INVALID	0xFF
+	uint8_t hw_counter;
+	uint8_t reserved[5];
+};
+
+struct virtio_rtc_resp_read_cross {
+	struct virtio_rtc_resp_head head;
+	uint64_t clock_reading;
+	uint64_t counter_cycles;
+};
+
+/* control requests */
+
+/* VIRTIO_RTC_REQ_CFG message */
+
+struct virtio_rtc_req_cfg {
+	struct virtio_rtc_req_head head;
+	/* no request params */
+};
+
+struct virtio_rtc_resp_cfg {
+	struct virtio_rtc_resp_head head;
+	/** # of clocks -> clock ids < num_clocks are valid */
+	uint16_t num_clocks;
+	uint8_t reserved[6];
+};
+
+/* VIRTIO_RTC_REQ_CLOCK_CAP message */
+
+struct virtio_rtc_req_clock_cap {
+	struct virtio_rtc_req_head head;
+	uint16_t clock_id;
+	uint8_t reserved[6];
+};
+
+struct virtio_rtc_resp_clock_cap {
+	struct virtio_rtc_resp_head head;
+#define VIRTIO_RTC_CLOCK_UTC			0
+#define VIRTIO_RTC_CLOCK_TAI			1
+#define VIRTIO_RTC_CLOCK_MONOTONIC		2
+#define VIRTIO_RTC_CLOCK_UTC_SMEARED		3
+#define VIRTIO_RTC_CLOCK_UTC_MAYBE_SMEARED	4
+	uint8_t type;
+#define VIRTIO_RTC_SMEAR_UNSPECIFIED	0
+#define VIRTIO_RTC_SMEAR_NOON_LINEAR	1
+#define VIRTIO_RTC_SMEAR_UTC_SLS	2
+	uint8_t leap_second_smearing;
+#define VIRTIO_RTC_FLAG_ALARM_CAP		(1 << 0)
+	uint8_t flags;
+	uint8_t reserved[5];
+};
+
+/* VIRTIO_RTC_REQ_CROSS_CAP message */
+
+struct virtio_rtc_req_cross_cap {
+	struct virtio_rtc_req_head head;
+	uint16_t clock_id;
+	uint8_t hw_counter;
+	uint8_t reserved[5];
+};
+
+struct virtio_rtc_resp_cross_cap {
+	struct virtio_rtc_resp_head head;
+#define VIRTIO_RTC_FLAG_CROSS_CAP	(1 << 0)
+	uint8_t flags;
+	uint8_t reserved[7];
+};
+
+/* VIRTIO_RTC_REQ_READ_ALARM message */
+
+struct virtio_rtc_req_read_alarm {
+	struct virtio_rtc_req_head head;
+	uint16_t clock_id;
+	uint8_t reserved[6];
+};
+
+struct virtio_rtc_resp_read_alarm {
+	struct virtio_rtc_resp_head head;
+	uint64_t alarm_time;
+#define VIRTIO_RTC_FLAG_ALARM_ENABLED	(1 << 0)
+	uint8_t flags;
+	uint8_t reserved[7];
+};
+
+/* VIRTIO_RTC_REQ_SET_ALARM message */
+
+struct virtio_rtc_req_set_alarm {
+	struct virtio_rtc_req_head head;
+	uint64_t alarm_time;
+	uint16_t clock_id;
+	/* flag VIRTIO_RTC_FLAG_ALARM_ENABLED */
+	uint8_t flags;
+	uint8_t reserved[5];
+};
+
+struct virtio_rtc_resp_set_alarm {
+	struct virtio_rtc_resp_head head;
+	/* no response params */
+};
+
+/* VIRTIO_RTC_REQ_SET_ALARM_ENABLED message */
+
+struct virtio_rtc_req_set_alarm_enabled {
+	struct virtio_rtc_req_head head;
+	uint16_t clock_id;
+	/* flag VIRTIO_RTC_ALARM_ENABLED */
+	uint8_t flags;
+	uint8_t reserved[5];
+};
+
+struct virtio_rtc_resp_set_alarm_enabled {
+	struct virtio_rtc_resp_head head;
+	/* no response params */
+};
+
+/** Union of request types for requestq */
+union virtio_rtc_req_requestq {
+	struct virtio_rtc_req_read read;
+	struct virtio_rtc_req_read_cross read_cross;
+	struct virtio_rtc_req_cfg cfg;
+	struct virtio_rtc_req_clock_cap clock_cap;
+	struct virtio_rtc_req_cross_cap cross_cap;
+	struct virtio_rtc_req_read_alarm read_alarm;
+	struct virtio_rtc_req_set_alarm set_alarm;
+	struct virtio_rtc_req_set_alarm_enabled set_alarm_enabled;
+};
+
+/** Union of response types for requestq */
+union virtio_rtc_resp_requestq {
+	struct virtio_rtc_resp_read read;
+	struct virtio_rtc_resp_read_cross read_cross;
+	struct virtio_rtc_resp_cfg cfg;
+	struct virtio_rtc_resp_clock_cap clock_cap;
+	struct virtio_rtc_resp_cross_cap cross_cap;
+	struct virtio_rtc_resp_read_alarm read_alarm;
+	struct virtio_rtc_resp_set_alarm set_alarm;
+	struct virtio_rtc_resp_set_alarm_enabled set_alarm_enabled;
+};
+
+/* alarmq notifications */
+
+/* VIRTIO_RTC_NOTIF_ALARM notification */
+
+struct virtio_rtc_notif_alarm {
+	struct virtio_rtc_notif_head head;
+	uint16_t clock_id;
+	uint8_t reserved[6];
+};
+
+/** Union of notification types for alarmq */
+union virtio_rtc_notif_alarmq {
+	struct virtio_rtc_notif_alarm alarm;
+};
+
+#endif /* _LINUX_VIRTIO_RTC_H */
-- 
2.53.0.473.g4a7958ca14-goog