mailbox: apple: Add driver for Apple IOP mailbox
This mailbox driver provides a communication channel with the
Apple IOP controllers found on Apple SoCs. These IOP controllers
are used to implement various functions such as the System
Manegement Controller (SMC) and NVMe storage. It allows sending
and receiving a 96-bit message over a single channel.
The header file with the struct used for mailbox messages is taken
straight from Linux.
Signed-off-by: Mark Kettenis <kettenis@openbsd.org>
Signed-off-by: Sven Peter <sven@svenpeter.dev>
Reviewed-by: Simon Glass <sjg@chromium.org>
Tested on: Macbook Air M1
Tested-by: Simon Glass <sjg@chromium.org>
diff --git a/include/linux/apple-mailbox.h b/include/linux/apple-mailbox.h
new file mode 100644
index 0000000..720fbb7
--- /dev/null
+++ b/include/linux/apple-mailbox.h
@@ -0,0 +1,19 @@
+/* SPDX-License-Identifier: GPL-2.0-only OR MIT */
+/*
+ * Apple mailbox message format
+ *
+ * Copyright (C) 2021 The Asahi Linux Contributors
+ */
+
+#ifndef _LINUX_APPLE_MAILBOX_H_
+#define _LINUX_APPLE_MAILBOX_H_
+
+#include <linux/types.h>
+
+/* encodes a single 96bit message sent over the single channel */
+struct apple_mbox_msg {
+ u64 msg0;
+ u32 msg1;
+};
+
+#endif