apps/examples: add uart_loopback_test

This is a test example where you can short-circuit the uart tx and rx boards to perform a loopback test.
This test sends "1234567890abcdefghijklmnopqrstuvwxyz" and recive same string

You can use CONIFG_UART_LOOPBACK_PORT to specify the port for the loopback test.

[TEST RESULT]

TASH>>uart_loopback start
TASH>>######################### UART loopback test START #########################
UART RX THREAD START
UART TX THREAD START
SEND UART(1): 1234567890abcdefghijklmnopqrstuvwxyz
RECEIVE(1): 1234567890abcdefghijklmnopqrstuvwxyz
RESULT(1): PASSED
SEND UART(2): 1234567890abcdefghijklmnopqrstuvwxyz
RECEIVE(2): 1234567890abcdefghijklmnopqrstuvwxyz
RESULT(2): PASSED
SEND UART(3): 1234567890abcdefghijklmnopqrstuvwxyz
RECEIVE(3): 1234567890abcdefghijklmnopqrstuvwxyz
RESULT(3): PASSED

apps/examples/uart_loopback/Kconfig

@@ -0,0 +1,21 @@
+#
+# For a description of the syntax of this configuration file,
+# see kconfig-language at https://www.kernel.org/doc/Documentation/kbuild/kconfig-language.txt
+#
+
+config EXAMPLES_UART_LOOPBACK
+	bool "UART loopback test application"
+	default n
+	---help---
+		Enable UART loopback test application
+
+if EXAMPLES_UART_LOOPBACK
+
+config EXAMPLES_UART_LOOPBACK_PORT
+	int "UART loopback tty port "
+	default 2
+	---help---
+		The EXAMPLES_UART_LOOPBACK_PORT sets test UART ttyS* port
+		The default port is ttyS2
+
+endif #EXAMPLES_UART_LOOPBACK

apps/examples/uart_loopback/Kconfig_ENTRY

@@ -0,0 +1,3 @@
+config ENTRY_UART_LOOPBACK
+	bool "uart loop back example"
+	depends on EXAMPLES_UART_LOOPBACK

apps/examples/uart_loopback/Make.defs

@@ -0,0 +1,21 @@
+###########################################################################
+#
+# Copyright 2024 Samsung Electronics All Rights Reserved.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+# http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing,
+# software distributed under the License is distributed on an
+# "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND,
+# either express or implied. See the License for the specific
+# language governing permissions and limitations under the License.
+#
+###########################################################################
+
+ifeq ($(CONFIG_EXAMPLES_UART_LOOPBACK),y)
+CONFIGURED_APPS += examples/uart_loopback
+endif

apps/examples/uart_loopback/Makefile

@@ -0,0 +1,121 @@
+###########################################################################
+#
+# Copyright 2024 Samsung Electronics All Rights Reserved.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+# http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing,
+# software distributed under the License is distributed on an
+# "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND,
+# either express or implied. See the License for the specific
+# language governing permissions and limitations under the License.
+#
+###########################################################################
+-include $(TOPDIR)/.config
+-include $(TOPDIR)/Make.defs
+include $(APPDIR)/Make.defs
+
+APPNAME = uart_loopback
+FUNCNAME = $(APPNAME)_main
+THREADEXEC = TASH_EXECMD_ASYNC
+PRIORITY = 100
+STACKSIZE = 2048
+
+ASRCS =
+CSRCS =
+MAINSRC = uart_loopback.c
+
+AOBJS = $(ASRCS:.S=$(OBJEXT))
+COBJS = $(CSRCS:.c=$(OBJEXT))
+MAINOBJ = $(MAINSRC:.c=$(OBJEXT))
+
+SRCS = $(ASRCS) $(CSRCS) $(MAINSRC)
+OBJS = $(AOBJS) $(COBJS)
+
+ifneq ($(CONFIG_BUILD_KERNEL),y)
+  OBJS += $(MAINOBJ)
+endif
+
+ifeq ($(CONFIG_WINDOWS_NATIVE),y)
+  BIN = $(APPDIR)\libapps$(LIBEXT)
+else
+ifeq ($(WINTOOL),y)
+  BIN = $(APPDIR)\\libapps$(LIBEXT)
+else
+  BIN = $(APPDIR)/libapps$(LIBEXT)
+endif
+endif
+
+ifeq ($(WINTOOL),y)
+  INSTALL_DIR = "${shell cygpath -w $(BIN_DIR)}"
+else
+  INSTALL_DIR = $(BIN_DIR)
+endif
+
+CONFIG_EXAMPLES_TEST_PROGNAME ?= uart_loopback(EXEEXT)
+PROGNAME = $(CONFIG_EXAMPLES_TEST_PROGNAME)
+
+ROOTDEPPATH = --dep-path .
+
+# Common build
+
+VPATH =
+
+all: .built
+.PHONY: clean depend distclean
+
+$(AOBJS): %$(OBJEXT): %.S
+	$(call ASSEMBLE, $<, $@)
+
+$(COBJS) $(MAINOBJ): %$(OBJEXT): %.c
+	$(call COMPILE, $<, $@)
+
+.built: $(OBJS)
+	$(call ARCHIVE, $(BIN), $(OBJS))
+	@touch .built
+
+ifeq ($(CONFIG_BUILD_KERNEL),y)
+$(BIN_DIR)$(DELIM)$(PROGNAME): $(OBJS) $(MAINOBJ)
+	@echo "LD: $(PROGNAME)"
+	$(Q) $(LD) $(LDELFFLAGS) $(LDLIBPATH) -o $(INSTALL_DIR)$(DELIM)$(PROGNAME) $(ARCHCRT0OBJ) $(MAINOBJ) $(LDLIBS)
+	$(Q) $(NM) -u  $(INSTALL_DIR)$(DELIM)$(PROGNAME)
+
+install: $(BIN_DIR)$(DELIM)$(PROGNAME)
+
+else
+install:
+
+endif
+
+
+ifeq ($(CONFIG_BUILTIN_APPS)$(CONFIG_EXAMPLES_UART_LOOPBACK),yy)
+$(BUILTIN_REGISTRY)$(DELIM)$(FUNCNAME).bdat: $(DEPCONFIG) Makefile
+	$(Q) $(call REGISTER,$(APPNAME),$(FUNCNAME),$(THREADEXEC),$(PRIORITY),$(STACKSIZE))
+context: $(BUILTIN_REGISTRY)$(DELIM)$(FUNCNAME).bdat
+
+else
+context:
+
+endif
+
+.depend: Makefile $(SRCS)
+	@$(MKDEP) $(ROOTDEPPATH) "$(CC)" -- $(CFLAGS) -- $(SRCS) >Make.dep
+	@touch $@
+
+depend: .depend
+
+clean:
+	$(call DELFILE, .built)
+	$(call CLEAN)
+
+distclean: clean
+	$(call DELFILE, Make.dep)
+	$(call DELFILE, .depend)
+
+-include Make.dep
+.PHONY: preconfig
+preconfig:

apps/examples/uart_loopback/uart_loopback.c

@@ -0,0 +1,205 @@
+/****************************************************************************
+ *
+ * Copyright 2024 Samsung Electronics All Rights Reserved.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND,
+ * either express or implied. See the License for the specific
+ * language governing permissions and limitations under the License.
+ *
+ ****************************************************************************/
+
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+#include <tinyara/config.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <fcntl.h>
+#include <errno.h>
+#include <unistd.h>
+#include <pthread.h>
+#ifndef CONFIG_DISABLE_POLL
+#include <poll.h>
+#endif
+#include <sys/types.h>
+#include <sys/stat.h>
+/****************************************************************************
+ * Pre-processor Definitions
+ ****************************************************************************/
+#ifndef CONFIG_EXAMPLES_UART_LOOPBACK_PORT
+#define CONFIG_EXAMPLES_UART_LOOPBACK_PORT 2
+#endif
+
+#define UART_DEV_PATH		"/dev/ttyS%d"
+
+#define UART_POLL_TIMEOUT_MS	10000
+
+#define TEST_STR		"1234567890abcdefghijklmnopqrstuvwxyz"
+#define TEST_STR_LEN	37
+
+static int is_running;
+static pthread_t g_tx_tid;
+static pthread_t g_rx_tid;
+
+static int uart_tx_loop(void)
+{
+	printf("UART TX THREAD START\n");
+	int fd = 0;
+	int tx_test_count = 0;
+	char port[20] = {'\0'};
+	sprintf(port, UART_DEV_PATH, CONFIG_EXAMPLES_UART_LOOPBACK_PORT);
+	fd = open(port, O_RDWR | O_SYNC, 0666);
+	if (fd < 0) {
+		printf("ERROR: Failed to open Tx UART(%d):\n", get_errno());
+		return -1;
+	}
+
+	while (is_running) {
+		tx_test_count++;
+		usleep(200*1000);
+
+		char test_data[TEST_STR_LEN] = TEST_STR;
+		write(fd, (void *)test_data, TEST_STR_LEN);
+		printf("SEND UART(%d): %s\n", tx_test_count, TEST_STR, TEST_STR_LEN);
+	}
+
+	close(fd);
+	return 0;
+}
+
+static int uart_rx_loop(void)
+{
+	int fd = 0;
+	char port[20] = {'\0'};
+	ssize_t ret_size;
+	int remain_size;
+	char *read_ptr;
+	int rx_test_count = 0;
+	char read_buf[TEST_STR_LEN];
+
+	printf("UART RX THREAD START\n");
+
+	sprintf(port, UART_DEV_PATH, CONFIG_EXAMPLES_UART_LOOPBACK_PORT);
+	fd = open(port, O_RDWR | O_SYNC, 0666);
+	if (fd < 0) {
+		printf("ERROR: Failed to open Rx UART(%d):\n", get_errno());
+		return -1;
+	}
+
+	while (is_running) {
+		rx_test_count++;
+		read_ptr = &read_buf;
+		remain_size = TEST_STR_LEN;
+
+		while (0 < remain_size) {
+
+#ifndef CONFIG_DISABLE_POLL
+			struct pollfd fds[1];
+			fds[0].fd = fd;
+			fds[0].events = POLLIN;
+			if (poll(fds, 1, UART_POLL_TIMEOUT_MS) < 0) {
+				printf("Fail to poll(%d):\n", get_errno());
+				close(fd);
+				return -1;
+			}
+			if (!(fds[0].revents & POLLIN)) {
+				printf("RESULT(%d): FAILED (Timeout)\n");
+				continue;
+			}
+#endif
+			ret_size = read(fd, (void *)read_ptr, remain_size);
+			remain_size -= ret_size;
+			read_ptr += ret_size;
+		}
+		printf("RECEIVE(%d): %s\n", rx_test_count, read_buf);
+		if (strncmp(read_buf, TEST_STR, TEST_STR_LEN) == 0) {
+			printf("RESULT(%d): PASSED\n", rx_test_count);
+		} else {
+			printf("RESULT(%d): FAILED (It does not match)\n", rx_test_count);
+		}
+	}
+
+	close(fd);
+	return 0;
+}
+
+static void help_func(void)
+{
+	printf("usage: uart_loopback start/stop \n\n");
+	printf("This test is to check if the same data is read as it was written through uart.\n");
+	printf("For this test, you need to short-circuit the UART TX PIN and the UART RX PIN.\n");
+	printf("This default uart port is /dev/ttyS2, you can change CONFIG_EXAMPLES_UART_LOOPBACK_PORT.\n\n");
+	printf("  start\t\t Start uart loopback test\n");
+	printf("  stop\t\t stop uart loopback test\n");	
+}
+
+/****************************************************************************
+ * Public functions
+ ****************************************************************************/
+#ifdef CONFIG_BUILD_KERNEL
+int main(int argc, FAR char *argv[])
+#else
+int uart_loopback_main(int argc, char **argv)
+#endif
+{
+
+	if (argc != 2 || strncmp(argv[1], "help", 5) == 0) {
+		help_func();
+		return 0;
+	}
+
+	if (strncmp(argv[1], "start", 6) == 0) {
+
+		if (is_running) {
+			printf("uart_loopback is already running\n");
+			return 0;
+		}
+
+		printf("######################### UART loopback test START #########################\n");
+
+		is_running = 1;
+
+		if (pthread_create(&g_rx_tid, NULL, (pthread_startroutine_t)uart_rx_loop, NULL) < 0) {
+			printf("Failed to create rx pthread(%d):\n", get_errno());
+			return -1;
+		}
+		(void)pthread_setname_np(g_rx_tid, "uart_loopback_rx");
+
+		if (pthread_create(&g_tx_tid, NULL, (pthread_startroutine_t)uart_tx_loop, NULL) < 0) {
+			printf("Failed to create tx pthread(%d):\n", get_errno());
+			pthread_cancel(g_rx_tid);
+			return -1;
+		}
+		(void)pthread_setname_np(g_tx_tid, "uart_loopback_tx");
+
+	} else if (strncmp(argv[1], "stop", 5) == 0) {
+		if (!is_running) {
+			printf("uart_loopback was not running\n");
+			return 0;
+		}
+
+		is_running = 0;
+
+		if (pthread_join(g_rx_tid, NULL) < 0) {
+			printf("Fail to join rx thread(%d):\n", get_errno());
+		}
+		if (pthread_join(g_rx_tid, NULL) < 0) {
+			printf("Fail to join tx thread(%d):\n", get_errno());
+		}
+
+		printf("######################### UART loopback test END ###########################\n");
+
+	} else {
+		help_func();
+	}
+
+	return 0;
+}