samples: Add mctp host and client samples

Samples work by sending MCTP encoded messages over a uart between two
boards.

Signed-off-by: Tom Burdick <thomas.burdick@intel.com>

samples/modules/mctp/mctp.rst

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+.. zephyr:code-sample-category:: mctp
+   :name: MCTP
+   :show-listing:
+
+   These samples demonstrate how to build communicating firmwares using MCTP in Zephyr.

samples/modules/mctp/mctp_endpoint/CMakeLists.txt

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+cmake_minimum_required(VERSION 3.20.0)
+
+find_package(Zephyr REQUIRED HINTS $ENV{ZEPHYR_BASE})
+
+project(mctp_endpoint)
+
+target_sources(app PRIVATE src/main.c)

samples/modules/mctp/mctp_endpoint/README.rst

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+.. zephyr:code-sample:: mctp_endpoint_sample
+   :name: MCTP Endpoint Sample
+
+   Create an MCTP endpoint over UART.
+
+Overview
+********
+Sets up an MCTP node that listens on a UART for messages targeting a particular
+MCTP endpoint id with the message "hello". Responds to this "hello" message with
+"world".
+
+Requirements
+************
+A board and SoC that provide access to a UART and a driver that implements the
+UART async API.
+
+Wiring
+******
+The listening UART pins should be wired to a board which will run the MCTP host
+sample such that this board's UART tx pin connects to the host board's rx pin,
+and this board's UART rx pin connects to the host board's tx pin. The boards'
+grounds should also be wired together.
+
+Optionally a logic analyzer can be wired up and listening to the UART to inspect
+the data flowing.
+
+Building and Running
+********************
+
+
+.. zephyr-app-commands::
+   :zephyr-app: samples/modules/mctp/mctp_endpoint
+   :host-os: unix
+   :board: nrf52840_nrf52840dk
+   :goals: run
+   :compact:
+
+References
+**********
+
+`MCTP Base Specification 2019 <https://www.dmtf.org/sites/default/files/standards/documents/DSP0236_1.3.1.pdf>`_

samples/modules/mctp/mctp_endpoint/boards/nrf52840dk_nrf52840.overlay

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+&arduino_serial{
+	status = "okay";
+};

samples/modules/mctp/mctp_endpoint/prj.conf

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+CONFIG_SERIAL=y
+CONFIG_UART_ASYNC_API=y
+CONFIG_MCTP=y
+CONFIG_MCTP_UART=y
+CONFIG_LOG=y
+CONFIG_LOG_BUFFER_SIZE=4096
+CONFIG_MCTP_LOG_LEVEL_DBG=y
+CONFIG_ISR_STACK_SIZE=4096

samples/modules/mctp/mctp_endpoint/src/main.c

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+/*
+ * Copyright (c) 2024 Intel Corporation
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#include <stdlib.h>
+#include <stdio.h>
+#include <assert.h>
+#include <unistd.h>
+#include <zephyr/kernel.h>
+#include <zephyr/types.h>
+#include <zephyr/mctp/mctp_uart.h>
+#include <libmctp.h>
+
+#include <zephyr/logging/log.h>
+LOG_MODULE_REGISTER(mctp_endpoint);
+
+#include <zephyr/drivers/uart.h>
+
+static struct mctp *mctp_ctx;
+
+#define LOCAL_HELLO_EID 10
+
+#define REMOTE_HELLO_EID 20
+
+K_SEM_DEFINE(mctp_rx, 0, 1);
+
+static void rx_message(uint8_t eid, bool tag_owner, uint8_t msg_tag, void *data, void *msg,
+		       size_t len)
+{
+	switch (eid) {
+	case REMOTE_HELLO_EID:
+		LOG_INF("got mctp message %s for eid %d, replying to 5 with \"world\"", (char *)msg,
+			eid);
+		mctp_message_tx(mctp_ctx, LOCAL_HELLO_EID, false, 0, "world", sizeof("world"));
+		break;
+	default:
+		LOG_INF("Unknown endpoint %d", eid);
+		break;
+	}
+
+	k_sem_give(&mctp_rx);
+}
+
+MCTP_UART_DT_DEFINE(mctp_endpoint, DEVICE_DT_GET(DT_NODELABEL(arduino_serial)));
+
+#define RX_BUF_SZ 128
+
+int main(void)
+{
+	LOG_INF("MCTP Endpoint EID:%d on %s\n", LOCAL_HELLO_EID, CONFIG_BOARD_TARGET);
+
+	mctp_set_alloc_ops(malloc, free, realloc);
+	mctp_ctx = mctp_init();
+	__ASSERT_NO_MSG(mctp_ctx != NULL);
+	mctp_register_bus(mctp_ctx, &mctp_endpoint.binding, LOCAL_HELLO_EID);
+	mctp_set_rx_all(mctp_ctx, rx_message, NULL);
+
+	/* MCTP poll loop */
+	while (true) {
+		mctp_uart_start_rx(&mctp_endpoint);
+		k_sem_take(&mctp_rx, K_FOREVER);
+	}
+
+	LOG_INF("exiting");
+	return 0;
+}

samples/modules/mctp/mctp_host/CMakeLists.txt

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+cmake_minimum_required(VERSION 3.20.0)
+
+find_package(Zephyr REQUIRED HINTS $ENV{ZEPHYR_BASE})
+project(mctp_host)
+
+target_sources(app PRIVATE src/main.c)

samples/modules/mctp/mctp_host/README.rst

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+.. zephyr:code-sample:: mctp_host_sample
+   :name: MCTP Host Sample
+
+   Create an MCTP host over UART.
+
+Overview
+********
+Sets up an MCTP node that sends a request on a UART targeting a particular MCTP
+endpoint id with the message "hello". Expects and waits for a response to this
+"hello" message containing "world".
+
+Requirements
+************
+A board and SoC that provide access to a UART and a driver that implements the
+UART async API.
+
+Wiring
+******
+The UART pins should be wired to a board which will run the MCTP endpoint
+sample such that this board's UART tx pin connects to the endpoint board's rx
+pin, and this board's UART rx pin connects to the endpoint board's tx pin. The
+boards' grounds should also be wired together.
+
+Optionally a logic analyzer can be wired up and listening to the UART to inspect
+the data flowing.
+
+Building and Running
+********************
+
+.. zephyr-app-commands::
+   :zephyr-app: samples/modules/mctp/mctp_host
+   :host-os: unix
+   :board: nrf52840_nrf52840dk
+   :goals: run
+   :compact:
+
+References
+**********
+
+`MCTP Base Specification 2019 <https://www.dmtf.org/sites/default/files/standards/documents/DSP0236_1.3.1.pdf>`_

samples/modules/mctp/mctp_host/boards/nrf52840dk_nrf52840.overlay

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+&arduino_serial{
+	status = "okay";
+};

samples/modules/mctp/mctp_host/prj.conf

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+# nothing here
+CONFIG_SERIAL=y
+CONFIG_UART_ASYNC_API=y
+CONFIG_MCTP=y
+CONFIG_MCTP_UART=y
+CONFIG_MCTP_LOG_LEVEL_DBG=y
+CONFIG_LOG=y
+CONFIG_LOG_BUFFER_SIZE=4096

samples/modules/mctp/mctp_host/src/main.c

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+/*
+ * Copyright (c) 2024 Intel Corporation
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#include <stdlib.h>
+#include <stdio.h>
+#include <assert.h>
+#include <unistd.h>
+#include <zephyr/types.h>
+#include <zephyr/kernel.h>
+#include <libmctp.h>
+#include <zephyr/mctp/mctp_uart.h>
+
+#include <zephyr/logging/log.h>
+LOG_MODULE_REGISTER(mctp_host);
+
+#define LOCAL_HELLO_EID 20
+
+#define REMOTE_HELLO_EID 10
+
+K_SEM_DEFINE(mctp_rx, 0, 1);
+
+static void rx_message(uint8_t eid, bool tag_owner, uint8_t msg_tag, void *data, void *msg,
+		       size_t len)
+{
+	LOG_INF("received message %s for endpoint %d, msg_tag %d, len %zu", (char *)msg, eid,
+		msg_tag, len);
+	k_sem_give(&mctp_rx);
+}
+
+MCTP_UART_DT_DEFINE(mctp_host, DEVICE_DT_GET(DT_NODELABEL(arduino_serial)));
+
+int main(void)
+{
+	int rc;
+	struct mctp *mctp_ctx;
+
+	LOG_INF("MCTP Host EID:%d on %s\n", LOCAL_HELLO_EID, CONFIG_BOARD_TARGET);
+
+	mctp_set_alloc_ops(malloc, free, realloc);
+	mctp_ctx = mctp_init();
+	__ASSERT_NO_MSG(mctp_ctx != NULL);
+	mctp_register_bus(mctp_ctx, &mctp_host.binding, LOCAL_HELLO_EID);
+	mctp_set_rx_all(mctp_ctx, rx_message, NULL);
+	mctp_uart_start_rx(&mctp_host);
+
+	/* MCTP poll loop, send "hello" and get "world" back */
+	while (true) {
+		rc = mctp_message_tx(mctp_ctx, REMOTE_HELLO_EID, false, 0, "hello",
+				     sizeof("hello"));
+		if (rc != 0) {
+			LOG_WRN("Failed to send message, errno %d\n", rc);
+			k_msleep(1000);
+		} else {
+			k_sem_take(&mctp_rx, K_MSEC(10));
+		}
+		rc = 0;
+	}
+
+	return 0;
+}