cross-link.c

/*
 * cross-link.c
 *
 * Userspace test program (Xenomai alchemy skin) for RTDM-based UART drivers
 * Copyright 2005 by Joerg Langenberg <joergel75@gmx.net>
 *
 * Updates by Jan Kiszka <jan.kiszka@web.de>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 */
#include <stdio.h>
#include <signal.h>
#include <unistd.h>
#include <sys/mman.h>
#include <alchemy/task.h>
#include <alchemy/timer.h>
#include <rtdm/serial.h>

#define MAIN_PREFIX   "main : "
#define WTASK_PREFIX  "write_task: "
#define RTASK_PREFIX  "read_task: "

#define WRITE_FILE    "/dev/rtdm/rtser0"
#define READ_FILE     "/dev/rtdm/rtser1"

int read_fd  = -1;
int write_fd = -1;

#define STATE_FILE_OPENED         1
#define STATE_TASK_CREATED        2

unsigned int read_state = 0;
unsigned int write_state = 0;

/*                           --s-ms-us-ns */
RTIME write_task_period_ns =    100000000llu;
RT_TASK write_task;
RT_TASK read_task;

static const struct rtser_config read_config = {
        .config_mask       = 0xFFFF,
        .baud_rate         = 115200,
        .parity            = RTSER_DEF_PARITY,
        .data_bits         = RTSER_DEF_BITS,
        .stop_bits         = RTSER_DEF_STOPB,
        .handshake         = RTSER_DEF_HAND,
        .fifo_depth        = RTSER_DEF_FIFO_DEPTH,
        .rx_timeout        = RTSER_DEF_TIMEOUT,
        .tx_timeout        = RTSER_DEF_TIMEOUT,
        .event_timeout     = 1000000000, /* 1 s */
        .timestamp_history = RTSER_RX_TIMESTAMP_HISTORY,
        .event_mask        = RTSER_EVENT_RXPEND,
};

static const struct rtser_config write_config = {
        .config_mask       = RTSER_SET_BAUD | RTSER_SET_TIMESTAMP_HISTORY,
        .baud_rate         = 115200,
        .timestamp_history = RTSER_DEF_TIMESTAMP_HISTORY,
        /* the rest implicitly remains default */
};

static int close_file( int fd, char *name)
{
        int err, i=0;

        do {
                i++;
                err = close(fd);
                switch (err) {
                case -EAGAIN:
                        printf(MAIN_PREFIX "%s -> EAGAIN (%d times)\n",
                               name, i);
                        rt_task_sleep(50000); /* wait 50us */
                        break;
                case 0:
                        printf(MAIN_PREFIX "%s -> closed\n", name);
                        break;
                default:
                        printf(MAIN_PREFIX "%s -> %s\n", name,
                               strerror(errno));
                        break;
                }
        } while (err == -EAGAIN && i < 10);

        return err;
}

static void cleanup_all(void)
{
        if (read_state & STATE_FILE_OPENED) {
                close_file(read_fd, READ_FILE" (read)");
                read_state &= ~STATE_FILE_OPENED;
        }

        if (write_state & STATE_FILE_OPENED) {
                close_file(write_fd, WRITE_FILE " (write)");
                write_state &= ~STATE_FILE_OPENED;
        }

        if (write_state & STATE_TASK_CREATED) {
                printf(MAIN_PREFIX "delete write_task\n");
                rt_task_delete(&write_task);
                write_state &= ~STATE_TASK_CREATED;
        }

        if (read_state & STATE_TASK_CREATED) {
                printf(MAIN_PREFIX "delete read_task\n");
                rt_task_delete(&read_task);
                read_state &= ~STATE_TASK_CREATED;
        }
}

static void catch_signal(int sig)
{
        cleanup_all();
        printf(MAIN_PREFIX "exit\n");
        return;
}

static void write_task_proc(void *arg)
{
        int err;
        RTIME write_time;
        ssize_t sz = sizeof(RTIME);
        int written = 0;

        err = rt_task_set_periodic(NULL, TM_NOW,
                                   rt_timer_ns2ticks(write_task_period_ns));
        if (err) {
                printf(WTASK_PREFIX "error on set periodic, %s\n",
                       strerror(-err));
                goto exit_write_task;
        }

        while (1) {
                err = rt_task_wait_period(NULL);
                if (err) {
                        printf(WTASK_PREFIX
                               "error on rt_task_wait_period, %s\n",
                               strerror(-err));
                        break;
                }

                write_time = rt_timer_read();

                written = write(write_fd, &write_time, sz);
                if (written < 0 ) {
                        printf(WTASK_PREFIX "error on write, %s\n",
                               strerror(errno));
                        break;
                } else if (written != sz) {
                        printf(WTASK_PREFIX "only %d / %zd byte transmitted\n",
                               written, sz);
                        break;
                }
        }

 exit_write_task:
        if ((write_state & STATE_FILE_OPENED) &&
            close_file(write_fd, WRITE_FILE " (write)") == 0)
                write_state &= ~STATE_FILE_OPENED;

        printf(WTASK_PREFIX "exit\n");
}

static void read_task_proc(void *arg)
{
        int err;
        int nr = 0;
        RTIME read_time  = 0;
        RTIME write_time = 0;
        RTIME irq_time   = 0;
        ssize_t sz = sizeof(RTIME);
        int rd = 0;
        struct rtser_event rx_event;

        printf(" Nr |   write->irq    |    irq->read    |   write->read   |\n");
        printf("-----------------------------------------------------------\n");

        /*
         * We are in secondary mode now due to printf, the next
         * blocking Xenomai or driver call will switch us back
         * (here: RTSER_RTIOC_WAIT_EVENT).
         */

        while (1) {
                /* waiting for event */
                err = ioctl(read_fd, RTSER_RTIOC_WAIT_EVENT, &rx_event);
                if (err) {
                        printf(RTASK_PREFIX
                               "error on RTSER_RTIOC_WAIT_EVENT, %s\n",
                               strerror(errno));
                        if (err == -ETIMEDOUT)
                                continue;
                        break;
                }

                irq_time = rx_event.rxpend_timestamp;
                rd = read(read_fd, &write_time, sz);
                if (rd == sz) {
                        read_time = rt_timer_read();
                        printf("%3d |%16llu |%16llu |%16llu\n", nr,
                               irq_time  - write_time,
                               read_time - irq_time,
                               read_time - write_time);
                        nr++;
                } else if (rd < 0 ) {
                        printf(RTASK_PREFIX "error on read, code %s\n",
                               strerror(errno));
                        break;
                } else {
                        printf(RTASK_PREFIX "only %d / %zd byte received \n",
                               rd, sz);
                        break;
                }
        }

        if ((read_state & STATE_FILE_OPENED) &&
            close_file(read_fd, READ_FILE " (read)") == 0)
                read_state &= ~STATE_FILE_OPENED;

        printf(RTASK_PREFIX "exit\n");
}

int main(int argc, char* argv[])
{
        int err = 0;

        signal(SIGTERM, catch_signal);
        signal(SIGINT, catch_signal);

        /* open rtser0 */
        write_fd = open( WRITE_FILE, 0);
        if (write_fd < 0) {
                printf(MAIN_PREFIX "can't open %s (write), %s\n", WRITE_FILE,
                       strerror(errno));
                goto error;
        }
        write_state |= STATE_FILE_OPENED;
        printf(MAIN_PREFIX "write-file opened\n");

        /* writing write-config */
        err = ioctl(write_fd, RTSER_RTIOC_SET_CONFIG, &write_config);
        if (err) {
                printf(MAIN_PREFIX "error while RTSER_RTIOC_SET_CONFIG, %s\n",
                       strerror(errno));
                goto error;
        }
        printf(MAIN_PREFIX "write-config written\n");

        /* open rtser1 */
        read_fd = open( READ_FILE, 0 );
        if (read_fd < 0) {
                printf(MAIN_PREFIX "can't open %s (read), %s\n", READ_FILE,
                       strerror(errno));
                goto error;
        }
        read_state |= STATE_FILE_OPENED;
        printf(MAIN_PREFIX "read-file opened\n");

        /* writing read-config */
        err = ioctl(read_fd, RTSER_RTIOC_SET_CONFIG, &read_config);
        if (err) {
                printf(MAIN_PREFIX "error while ioctl, %s\n",
                       strerror(errno));
                goto error;
        }
        printf(MAIN_PREFIX "read-config written\n");

        /* create write_task */
        err = rt_task_create(&write_task, "write_task", 0, 50, 0);
        if (err) {
                printf(MAIN_PREFIX "failed to create write_task, %s\n",
                       strerror(-err));
                goto error;
        }
        write_state |= STATE_TASK_CREATED;
        printf(MAIN_PREFIX "write-task created\n");

        /* create read_task */
        err = rt_task_create(&read_task, "read_task", 0, 51, 0);
        if (err) {
                printf(MAIN_PREFIX "failed to create read_task, %s\n",
                       strerror(-err));
                goto error;
        }
        read_state |= STATE_TASK_CREATED;
        printf(MAIN_PREFIX "read-task created\n");

        /* start write_task */
        printf(MAIN_PREFIX "starting write-task\n");
        err = rt_task_start(&write_task, &write_task_proc, NULL);
        if (err) {
                printf(MAIN_PREFIX "failed to start write_task, %s\n",
                       strerror(-err));
                goto error;
        }

        /* start read_task */
        printf(MAIN_PREFIX "starting read-task\n");
        err = rt_task_start(&read_task,&read_task_proc,NULL);
        if (err) {
                printf(MAIN_PREFIX "failed to start read_task, %s\n",
                       strerror(-err));
                goto error;
        }

        for (;;)
                pause();

        return 0;

 error:
        cleanup_all();
        return err;
}