1 files changed, 312 insertions, 0 deletions
diff --git a/drivers/arm/mhu/mhu_wrapper_v2_x.c b/drivers/arm/mhu/mhu_wrapper_v2_x.c
new file mode 100644
index 0000000..60de1d3
--- /dev/null
+++ b/drivers/arm/mhu/mhu_wrapper_v2_x.c
@@ -0,0 +1,312 @@
+/*
+ * Copyright (c) 2022, Arm Limited. All rights reserved.
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+
+#include <assert.h>
+#include <stddef.h>
+#include <stdint.h>
+#include <string.h>
+
+#include <drivers/arm/mhu.h>
+
+#include "mhu_v2_x.h"
+
+#define MHU_NOTIFY_VALUE	(1234u)
+
+/*
+ * MHU devices for host:
+ * HSE: Host to Secure Enclave (sender device)
+ * SEH: Secure Enclave to Host (receiver device)
+ */
+struct mhu_v2_x_dev_t MHU1_HSE_DEV = {0, MHU_V2_X_SENDER_FRAME};
+struct mhu_v2_x_dev_t MHU1_SEH_DEV = {0, MHU_V2_X_RECEIVER_FRAME};
+
+static enum mhu_error_t error_mapping_to_mhu_error_t(enum mhu_v2_x_error_t err)
+{
+	switch (err) {
+	case MHU_V_2_X_ERR_NONE:
+		return MHU_ERR_NONE;
+	case MHU_V_2_X_ERR_NOT_INIT:
+		return MHU_ERR_NOT_INIT;
+	case MHU_V_2_X_ERR_ALREADY_INIT:
+		return MHU_ERR_ALREADY_INIT;
+	case MHU_V_2_X_ERR_UNSUPPORTED_VERSION:
+		return MHU_ERR_UNSUPPORTED_VERSION;
+	case MHU_V_2_X_ERR_INVALID_ARG:
+		return MHU_ERR_INVALID_ARG;
+	case MHU_V_2_X_ERR_GENERAL:
+		return MHU_ERR_GENERAL;
+	default:
+		return MHU_ERR_GENERAL;
+	}
+}
+
+static enum mhu_v2_x_error_t signal_and_wait_for_clear(void)
+{
+	enum mhu_v2_x_error_t err;
+	struct mhu_v2_x_dev_t *dev = &MHU1_HSE_DEV;
+	uint32_t val = MHU_NOTIFY_VALUE;
+	/* Using the last channel for notifications */
+	uint32_t channel_notify = mhu_v2_x_get_num_channel_implemented(dev) - 1;
+
+	err = mhu_v2_x_channel_send(dev, channel_notify, val);
+	if (err != MHU_V_2_X_ERR_NONE) {
+		return err;
+	}
+
+	do {
+		err = mhu_v2_x_channel_poll(dev, channel_notify, &val);
+		if (err != MHU_V_2_X_ERR_NONE) {
+			break;
+		}
+	} while (val != 0);
+
+	return err;
+}
+
+static enum mhu_v2_x_error_t wait_for_signal(void)
+{
+	enum mhu_v2_x_error_t err;
+	struct mhu_v2_x_dev_t *dev = &MHU1_SEH_DEV;
+	uint32_t val = 0;
+	/* Using the last channel for notifications */
+	uint32_t channel_notify = mhu_v2_x_get_num_channel_implemented(dev) - 1;
+
+	do {
+		err = mhu_v2_x_channel_receive(dev, channel_notify, &val);
+		if (err != MHU_V_2_X_ERR_NONE) {
+			break;
+		}
+	} while (val != MHU_NOTIFY_VALUE);
+
+	return err;
+}
+
+static enum mhu_v2_x_error_t clear_and_wait_for_next_signal(void)
+{
+	enum mhu_v2_x_error_t err;
+	struct mhu_v2_x_dev_t *dev = &MHU1_SEH_DEV;
+	uint32_t num_channels = mhu_v2_x_get_num_channel_implemented(dev);
+	uint32_t i;
+
+	/* Clear all channels */
+	for (i = 0; i < num_channels; ++i) {
+		err = mhu_v2_x_channel_clear(dev, i);
+		if (err != MHU_V_2_X_ERR_NONE) {
+			return err;
+		}
+	}
+
+	return wait_for_signal();
+}
+
+enum mhu_error_t mhu_init_sender(uintptr_t mhu_sender_base)
+{
+	enum mhu_v2_x_error_t err;
+
+	assert(mhu_sender_base != (uintptr_t)NULL);
+
+	MHU1_HSE_DEV.base = mhu_sender_base;
+
+	err = mhu_v2_x_driver_init(&MHU1_HSE_DEV, MHU_REV_READ_FROM_HW);
+	return error_mapping_to_mhu_error_t(err);
+}
+
+enum mhu_error_t mhu_init_receiver(uintptr_t mhu_receiver_base)
+{
+	enum mhu_v2_x_error_t err;
+	uint32_t num_channels, i;
+
+	assert(mhu_receiver_base != (uintptr_t)NULL);
+
+	MHU1_SEH_DEV.base = mhu_receiver_base;
+
+	err = mhu_v2_x_driver_init(&MHU1_SEH_DEV, MHU_REV_READ_FROM_HW);
+	if (err != MHU_V_2_X_ERR_NONE) {
+		return error_mapping_to_mhu_error_t(err);
+	}
+
+	num_channels = mhu_v2_x_get_num_channel_implemented(&MHU1_SEH_DEV);
+
+	/* Mask all channels except the notifying channel */
+	for (i = 0; i < (num_channels - 1); ++i) {
+		err = mhu_v2_x_channel_mask_set(&MHU1_SEH_DEV, i, UINT32_MAX);
+		if (err != MHU_V_2_X_ERR_NONE) {
+			return error_mapping_to_mhu_error_t(err);
+		}
+	}
+
+	/* The last channel is used for notifications */
+	err = mhu_v2_x_channel_mask_clear(
+		&MHU1_SEH_DEV, (num_channels - 1), UINT32_MAX);
+	return error_mapping_to_mhu_error_t(err);
+}
+
+/*
+ * Public function. See mhu.h
+ *
+ * The basic steps of transferring a message:
+ * 1.	Initiate MHU transfer.
+ * 2.	Send over the size of the payload on Channel 1. It is the very first
+ *	4 Bytes of the transfer. Continue with Channel 2.
+ * 3.	Send over the payload, writing the channels one after the other
+ *	(4 Bytes each). The last available channel is reserved for controlling
+ *	the transfer.
+ *	When the last channel is reached or no more data is left, STOP.
+ * 4.	Notify the receiver using the last channel and wait for acknowledge.
+ *	If there is still data to transfer, jump to step 3. Otherwise, proceed.
+ * 5.	Close MHU transfer.
+ *
+ */
+enum mhu_error_t mhu_send_data(const uint8_t *send_buffer, size_t size)
+{
+	enum mhu_v2_x_error_t err;
+	struct mhu_v2_x_dev_t *dev = &MHU1_HSE_DEV;
+	uint32_t num_channels = mhu_v2_x_get_num_channel_implemented(dev);
+	uint32_t chan = 0;
+	uint32_t i;
+	uint32_t *p;
+
+	/* For simplicity, require the send_buffer to be 4-byte aligned */
+	if ((uintptr_t)send_buffer & 0x3U) {
+		return MHU_ERR_INVALID_ARG;
+	}
+
+	err = mhu_v2_x_initiate_transfer(dev);
+	if (err != MHU_V_2_X_ERR_NONE) {
+		return error_mapping_to_mhu_error_t(err);
+	}
+
+	/* First send over the size of the actual message */
+	err = mhu_v2_x_channel_send(dev, chan, (uint32_t)size);
+	if (err != MHU_V_2_X_ERR_NONE) {
+		return error_mapping_to_mhu_error_t(err);
+	}
+	chan++;
+
+	p = (uint32_t *)send_buffer;
+	for (i = 0; i < size; i += 4) {
+		err = mhu_v2_x_channel_send(dev, chan, *p++);
+		if (err != MHU_V_2_X_ERR_NONE) {
+			return error_mapping_to_mhu_error_t(err);
+		}
+		if (++chan == (num_channels - 1)) {
+			err = signal_and_wait_for_clear();
+			if (err != MHU_V_2_X_ERR_NONE) {
+				return error_mapping_to_mhu_error_t(err);
+			}
+			chan = 0;
+		}
+	}
+
+	/* Signal the end of transfer.
+	 *   It's not required to send a signal when the message was
+	 *   perfectly-aligned (num_channels - 1 channels were used in the last
+	 *   round) preventing it from signaling twice at the end of transfer.
+	 */
+	if (chan != 0) {
+		err = signal_and_wait_for_clear();
+		if (err != MHU_V_2_X_ERR_NONE) {
+			return error_mapping_to_mhu_error_t(err);
+		}
+	}
+
+	err = mhu_v2_x_close_transfer(dev);
+	return error_mapping_to_mhu_error_t(err);
+}
+
+/*
+ * Public function. See mhu.h
+ *
+ * The basic steps of receiving a message:
+ * 1.	Read the size of the payload from Channel 1. It is the very first
+ *	4 Bytes of the transfer. Continue with Channel 2.
+ * 2.	Receive the payload, read the channels one after the other
+ *	(4 Bytes each). The last available channel is reserved for controlling
+ *	the transfer.
+ *	When the last channel is reached clear all the channels
+ *	(also sending an acknowledge on the last channel).
+ * 3.	If there is still data to receive wait for a notification on the last
+ *	channel and jump to step 2 as soon as it arrived. Otherwise, proceed.
+ * 4.	End of transfer.
+ *
+ */
+enum mhu_error_t mhu_receive_data(uint8_t *receive_buffer, size_t *size)
+{
+	enum mhu_v2_x_error_t err;
+	struct mhu_v2_x_dev_t *dev = &MHU1_SEH_DEV;
+	uint32_t num_channels = mhu_v2_x_get_num_channel_implemented(dev);
+	uint32_t chan = 0;
+	uint32_t message_len;
+	uint32_t i;
+	uint32_t *p;
+
+	/* For simplicity, require:
+	 * - the receive_buffer to be 4-byte aligned,
+	 * - the buffer size to be a multiple of 4.
+	 */
+	if (((uintptr_t)receive_buffer & 0x3U) || (*size & 0x3U)) {
+		return MHU_ERR_INVALID_ARG;
+	}
+
+	/* Busy wait for incoming reply */
+	err = wait_for_signal();
+	if (err != MHU_V_2_X_ERR_NONE) {
+		return error_mapping_to_mhu_error_t(err);
+	}
+
+	/* The first word is the length of the actual message */
+	err = mhu_v2_x_channel_receive(dev, chan, &message_len);
+	if (err != MHU_V_2_X_ERR_NONE) {
+		return error_mapping_to_mhu_error_t(err);
+	}
+	chan++;
+
+	if (message_len > *size) {
+		/* Message buffer too small */
+		*size = message_len;
+		return MHU_ERR_BUFFER_TOO_SMALL;
+	}
+
+	p = (uint32_t *)receive_buffer;
+	for (i = 0; i < message_len; i += 4) {
+		err = mhu_v2_x_channel_receive(dev, chan, p++);
+		if (err != MHU_V_2_X_ERR_NONE) {
+			return error_mapping_to_mhu_error_t(err);
+		}
+
+		/* Only wait for next transfer if there is still missing data */
+		if (++chan == (num_channels - 1) && (message_len - i) > 4) {
+			/* Busy wait for next transfer */
+			err = clear_and_wait_for_next_signal();
+			if (err != MHU_V_2_X_ERR_NONE) {
+				return error_mapping_to_mhu_error_t(err);
+			}
+			chan = 0;
+		}
+	}
+
+	/* Clear all channels */
+	for (i = 0; i < num_channels; ++i) {
+		err = mhu_v2_x_channel_clear(dev, i);
+		if (err != MHU_V_2_X_ERR_NONE) {
+			return error_mapping_to_mhu_error_t(err);
+		}
+	}
+
+	*size = message_len;
+
+	return MHU_ERR_NONE;
+}
+
+size_t mhu_get_max_message_size(void)
+{
+	struct mhu_v2_x_dev_t *dev = &MHU1_SEH_DEV;
+	uint32_t num_channels = mhu_v2_x_get_num_channel_implemented(dev);
+
+	assert(num_channels != 0);
+
+	return num_channels * sizeof(uint32_t);
+}