1 files changed, 82 insertions, 0 deletions
diff --git a/drivers/rpi3/mailbox/rpi3_mbox.c b/drivers/rpi3/mailbox/rpi3_mbox.c
new file mode 100644
index 0000000..aef1f39
--- /dev/null
+++ b/drivers/rpi3/mailbox/rpi3_mbox.c
@@ -0,0 +1,82 @@
+/*
+ * Copyright (c) 2018-2019, ARM Limited and Contributors. All rights reserved.
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+
+#include <platform_def.h>
+
+#include <arch_helpers.h>
+#include <common/debug.h>
+#include <lib/mmio.h>
+
+#include <rpi_hw.h>
+
+#include <drivers/rpi3/mailbox/rpi3_mbox.h>
+
+#define RPI3_MAILBOX_MAX_RETRIES	U(1000000)
+
+/*******************************************************************************
+ * Routine to send requests to the VideoCore using the mailboxes.
+ ******************************************************************************/
+void rpi3_vc_mailbox_request_send(rpi3_mbox_request_t *req, int req_size)
+{
+	uint32_t st, data;
+	uintptr_t resp_addr, addr;
+	unsigned int retries;
+
+	/* This is the location of the request buffer */
+	addr = (uintptr_t)req;
+
+	/* Make sure that the changes are seen by the VideoCore */
+	flush_dcache_range(addr, req_size);
+
+	/* Wait until the outbound mailbox is empty */
+	retries = 0U;
+
+	do {
+		st = mmio_read_32(RPI3_MBOX_BASE + RPI3_MBOX1_STATUS_OFFSET);
+
+		retries++;
+		if (retries == RPI3_MAILBOX_MAX_RETRIES) {
+			ERROR("rpi3: mbox: Send request timeout\n");
+			return;
+		}
+
+	} while ((st & RPI3_MBOX_STATUS_EMPTY_MASK) == 0U);
+
+	/* Send base address of this message to start request */
+	mmio_write_32(RPI3_MBOX_BASE + RPI3_MBOX1_WRITE_OFFSET,
+		      RPI3_CHANNEL_ARM_TO_VC | (uint32_t) addr);
+
+	/* Wait until the inbound mailbox isn't empty */
+	retries = 0U;
+
+	do {
+		st = mmio_read_32(RPI3_MBOX_BASE + RPI3_MBOX0_STATUS_OFFSET);
+
+		retries++;
+		if (retries == RPI3_MAILBOX_MAX_RETRIES) {
+			ERROR("rpi3: mbox: Receive response timeout\n");
+			return;
+		}
+
+	} while ((st & RPI3_MBOX_STATUS_EMPTY_MASK) != 0U);
+
+	/* Get location and channel */
+	data = mmio_read_32(RPI3_MBOX_BASE + RPI3_MBOX0_READ_OFFSET);
+
+	if ((data & RPI3_CHANNEL_MASK) != RPI3_CHANNEL_ARM_TO_VC) {
+		ERROR("rpi3: mbox: Wrong channel: 0x%08x\n", data);
+		panic();
+	}
+
+	resp_addr = (uintptr_t)(data & ~RPI3_CHANNEL_MASK);
+	if (addr != resp_addr) {
+		ERROR("rpi3: mbox: Unexpected address: 0x%08x\n", data);
+		panic();
+	}
+
+	/* Make sure that the data seen by the CPU is up to date */
+	inv_dcache_range(addr, req_size);
+}