sysreset: Add QEMU virtual system controller driver

Introduce a new sysreset driver for the QEMU Virtual System Controller.
This device is found on QEMU "virt" machines (such as the m68k virt
target) and provides a mechanism to trigger system reset and power-off
events.

The driver maps U-Boot sysreset types to the corresponding controller
commands:
- SYSRESET_WARM / SYSRESET_COLD -> VIRT_CTRL_CMD_RESET
- SYSRESET_POWER_OFF -> VIRT_CTRL_CMD_HALT

Signed-off-by: Kuan-Wei Chiu <[email protected]>
Reviewed-by: Simon Glass <[email protected]>

1 files changed, 13 insertions, 0 deletions

diff --git a/include/qemu_virt_ctrl.h b/include/qemu_virt_ctrl.h
new file mode 100644
index 00000000000..05aad82b767
--- /dev/null
+++ b/include/qemu_virt_ctrl.h
@@ -0,0 +1,13 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ * Copyright (C) 2025, Kuan-Wei Chiu <[email protected]>
+ */
+
+#ifndef _QEMU_VIRT_CTRL_H_
+#define _QEMU_VIRT_CTRL_H_
+
+struct qemu_virt_ctrl_plat {
+	phys_addr_t reg;
+};
+
+#endif /* _QEMU_VIRT_CTRL_H_ */