mailbox: Add support for Armada 37xx rWTM mailbox

This adds support for the mailbox via which the kernel can communicate
with the firmware running on the secure processor of the Armada 37xx
SOC.

The rWTM secure processor has access to internal eFuses and
cryptographic circuits, such as the Entropy Bit Generator to generate
true random numbers.

Signed-off-by: Marek Behun <marek.behun@nic.cz>
Signed-off-by: Jassi Brar <jaswinder.singh@linaro.org>

1 files changed, 23 insertions, 0 deletions

diff --git a/include/linux/armada-37xx-rwtm-mailbox.h b/include/linux/armada-37xx-rwtm-mailbox.h
new file mode 100644
index 000000000000..57bb54f6767a
--- /dev/null
+++ b/include/linux/armada-37xx-rwtm-mailbox.h
@@ -0,0 +1,23 @@
+/* SPDX-License-Identifier: GPL-2.0+ */
+/*
+ * rWTM BIU Mailbox driver for Armada 37xx
+ *
+ * Author: Marek Behun <marek.behun@nic.cz>
+ */
+
+#ifndef _LINUX_ARMADA_37XX_RWTM_MAILBOX_H_
+#define _LINUX_ARMADA_37XX_RWTM_MAILBOX_H_
+
+#include <linux/types.h>
+
+struct armada_37xx_rwtm_tx_msg {
+	u16 command;
+	u32 args[16];
+};
+
+struct armada_37xx_rwtm_rx_msg {
+	u32 retval;
+	u32 status[16];
+};
+
+#endif /* _LINUX_ARMADA_37XX_RWTM_MAILBOX_H_ */