1 files changed, 105 insertions, 0 deletions
diff --git a/roms/u-boot/drivers/firmware/scmi/mailbox_agent.c b/roms/u-boot/drivers/firmware/scmi/mailbox_agent.c
new file mode 100644
index 000000000..ea35e7e09
--- /dev/null
+++ b/roms/u-boot/drivers/firmware/scmi/mailbox_agent.c
@@ -0,0 +1,105 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright (C) 2020 Linaro Limited.
+ */
+
+#define LOG_CATEGORY UCLASS_SCMI_AGENT
+
+#include <common.h>
+#include <dm.h>
+#include <errno.h>
+#include <mailbox.h>
+#include <scmi_agent.h>
+#include <scmi_agent-uclass.h>
+#include <dm/device_compat.h>
+#include <dm/devres.h>
+#include <linux/compat.h>
+
+#include "smt.h"
+
+#define TIMEOUT_US_10MS			10000
+
+/**
+ * struct scmi_mbox_channel - Description of an SCMI mailbox transport
+ * @smt:	Shared memory buffer
+ * @mbox:	Mailbox channel description
+ * @timeout_us:	Timeout in microseconds for the mailbox transfer
+ */
+struct scmi_mbox_channel {
+	struct scmi_smt smt;
+	struct mbox_chan mbox;
+	ulong timeout_us;
+};
+
+static int scmi_mbox_process_msg(struct udevice *dev, struct scmi_msg *msg)
+{
+	struct scmi_mbox_channel *chan = dev_get_priv(dev);
+	int ret;
+
+	ret = scmi_write_msg_to_smt(dev, &chan->smt, msg);
+	if (ret)
+		return ret;
+
+	/* Give shm addr to mbox in case it is meaningful */
+	ret = mbox_send(&chan->mbox, chan->smt.buf);
+	if (ret) {
+		dev_err(dev, "Message send failed: %d\n", ret);
+		goto out;
+	}
+
+	/* Receive the response */
+	ret = mbox_recv(&chan->mbox, chan->smt.buf, chan->timeout_us);
+	if (ret) {
+		dev_err(dev, "Response failed: %d, abort\n", ret);
+		goto out;
+	}
+
+	ret = scmi_read_resp_from_smt(dev, &chan->smt, msg);
+
+out:
+	scmi_clear_smt_channel(&chan->smt);
+
+	return ret;
+}
+
+int scmi_mbox_probe(struct udevice *dev)
+{
+	struct scmi_mbox_channel *chan = dev_get_priv(dev);
+	int ret;
+
+	chan->timeout_us = TIMEOUT_US_10MS;
+
+	ret = mbox_get_by_index(dev, 0, &chan->mbox);
+	if (ret) {
+		dev_err(dev, "Failed to find mailbox: %d\n", ret);
+		goto out;
+	}
+
+	ret = scmi_dt_get_smt_buffer(dev, &chan->smt);
+	if (ret)
+		dev_err(dev, "Failed to get shm resources: %d\n", ret);
+
+out:
+	if (ret)
+		devm_kfree(dev, chan);
+
+	return ret;
+}
+
+static const struct udevice_id scmi_mbox_ids[] = {
+	{ .compatible = "arm,scmi" },
+	{ }
+};
+
+static const struct scmi_agent_ops scmi_mbox_ops = {
+	.process_msg = scmi_mbox_process_msg,
+};
+
+U_BOOT_DRIVER(scmi_mbox) = {
+	.name		= "scmi-over-mailbox",
+	.id		= UCLASS_SCMI_AGENT,
+	.of_match	= scmi_mbox_ids,
+	.priv_auto	= sizeof(struct scmi_mbox_channel),
+	.probe		= scmi_mbox_probe,
+	.ops		= &scmi_mbox_ops,
+};