test_serial.c

/*
 * c-periphery
 * https://github.com/vsergeev/c-periphery
 * License: MIT
 */

#include "test.h"

#include <stdlib.h>
#include <string.h>

#include <time.h>
#include <unistd.h>

#include "../src/serial.h"

#define ABS(x) ((x < 0) ? -x : x)

const char *device;

void test_arguments(void) {
    serial_t *serial;

    ptest();

    /* Allocate serial */
    serial = serial_new();
    passert(serial != NULL);

    /* Invalid data bits (4 and 9) */
    passert(serial_open_advanced(serial, device, 115200, 4, PARITY_NONE, 1, false, false) == SERIAL_ERROR_ARG);
    passert(serial_open_advanced(serial, device, 115200, 9, PARITY_NONE, 1, false, false) == SERIAL_ERROR_ARG);
    /* Invalid parity */
    passert(serial_open_advanced(serial, device, 115200, 8, PARITY_EVEN+1, 1, false, false) == SERIAL_ERROR_ARG);
    /* Invalid stopbits */
    passert(serial_open_advanced(serial, device, 115200, 8, PARITY_NONE, 0, false, false) == SERIAL_ERROR_ARG);
    passert(serial_open_advanced(serial, device, 115200, 8, PARITY_NONE, 3, false, false) == SERIAL_ERROR_ARG);

    /* Everything else is fair game, although termios might not like it. */

    /* Free serial */
    serial_free(serial);
}

void test_open_config_close(void) {
    serial_t *serial;
    uint32_t baudrate;
    unsigned int databits;
    serial_parity_t parity;
    unsigned int stopbits;
    bool xonxoff;
    bool rtscts;
    unsigned int vmin;
    float vtime;

    ptest();

    /* Allocate serial */
    serial = serial_new();
    passert(serial != NULL);

    passert(serial_open(serial, device, 115200) == 0);

    /* Check default settings */
    passert(serial_get_baudrate(serial, &baudrate) == 0);
    passert(baudrate == 115200);
    passert(serial_get_databits(serial, &databits) == 0);
    passert(databits == 8);
    passert(serial_get_parity(serial, &parity) == 0);
    passert(parity == PARITY_NONE);
    passert(serial_get_stopbits(serial, &stopbits) == 0);
    passert(stopbits == 1);
    passert(serial_get_xonxoff(serial, &xonxoff) == 0);
    passert(xonxoff == false);
    passert(serial_get_rtscts(serial, &rtscts) == 0);
    passert(rtscts == false);
    passert(serial_get_vmin(serial, &vmin) == 0);
    passert(vmin == 0);
    passert(serial_get_vtime(serial, &vtime) == 0);
    passert(vtime == 0);

    /* Change some stuff around */
    passert(serial_set_baudrate(serial, 4800) == 0);
    passert(serial_get_baudrate(serial, &baudrate) == 0);
    passert(baudrate == 4800);
    passert(serial_set_baudrate(serial, 9600) == 0);
    passert(serial_get_baudrate(serial, &baudrate) == 0);
    passert(baudrate == 9600);
    passert(serial_set_databits(serial, 7) == 0);
    passert(serial_get_databits(serial, &databits) == 0);
    passert(databits == 7);
    passert(serial_set_parity(serial, PARITY_ODD) == 0);
    passert(serial_get_parity(serial, &parity) == 0);
    passert(parity == PARITY_ODD);
    passert(serial_set_stopbits(serial, 2) == 0);
    passert(serial_get_stopbits(serial, &stopbits) == 0);
    passert(stopbits == 2);
    passert(serial_set_xonxoff(serial, true) == 0);
    passert(serial_get_xonxoff(serial, &xonxoff) == 0);
    passert(xonxoff == true);
    #if 0 /* Test serial port may not support rtscts */
    passert(serial_set_rtscts(serial, true) == 0);
    passert(serial_get_rtscts(serial, &rtscts) == 0);
    passert(rtscts == true);
    #endif
    passert(serial_set_vmin(serial, 50) == 0);
    passert(serial_get_vmin(serial, &vmin) == 0);
    passert(vmin == 50);
    passert(serial_set_vtime(serial, 15.3) == 0);
    passert(serial_get_vtime(serial, &vtime) == 0);
    passert(ABS(vtime - 15.3) < 0.1);

    passert(serial_close(serial) == 0);

    /* Free serial */
    serial_free(serial);
}

void test_loopback(void) {
    serial_t *serial;
    unsigned int count;
    time_t start, stop;
    uint8_t lorem_ipsum[] = "Lorem ipsum dolor sit amet, consectetur adipisicing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat. Duis aute irure dolor in reprehenderit in voluptate velit esse cillum dolore eu fugiat nulla pariatur. Excepteur sint occaecat cupidatat non proident, sunt in culpa qui officia deserunt mollit anim id est laborum.";
    uint8_t lorem_hugesum[4096*3];
    uint8_t buf[sizeof(lorem_hugesum)];

    ptest();

    /* Allocate serial */
    serial = serial_new();
    passert(serial != NULL);

    passert(serial_open(serial, device, 115200) == 0);

    /* Test write/flush/read */
    passert(serial_write(serial, lorem_ipsum, sizeof(lorem_ipsum)) == sizeof(lorem_ipsum));
    passert(serial_flush(serial) == 0);
    passert(serial_read(serial, buf, sizeof(lorem_ipsum), -1) == sizeof(lorem_ipsum));
    passert(memcmp(lorem_ipsum, buf, sizeof(lorem_ipsum)) == 0);

    /* Test poll/write/flush/poll/input waiting/read */
    passert(serial_poll(serial, 500) == 0); /* Should timeout */
    passert(serial_write(serial, lorem_ipsum, sizeof(lorem_ipsum)) == sizeof(lorem_ipsum));
    passert(serial_flush(serial) == 0);
    passert(serial_poll(serial, 500) == 1);
    usleep(500000);
    passert(serial_input_waiting(serial, &count) == 0);
    passert(count == sizeof(lorem_ipsum));
    passert(serial_read(serial, buf, sizeof(lorem_ipsum), -1) == sizeof(lorem_ipsum));
    passert(memcmp(lorem_ipsum, buf, sizeof(lorem_ipsum)) == 0);

    /* Test non-blocking poll */
    passert(serial_poll(serial, 0) == 0);

    /* Test a very large read-write (likely to exceed internal buffer size (~4096)) */
    memset(lorem_hugesum, 0xAA, sizeof(lorem_hugesum));
    passert(serial_write(serial, lorem_hugesum, sizeof(lorem_hugesum)) == sizeof(lorem_hugesum));
    passert(serial_flush(serial) == 0);
    passert(serial_read(serial, buf, sizeof(lorem_hugesum), -1) == sizeof(lorem_hugesum));
    passert(memcmp(lorem_hugesum, buf, sizeof(lorem_hugesum)) == 0);

    /* Test read timeout */
    start = time(NULL);
    passert(serial_read(serial, buf, sizeof(buf), 2000) == 0);
    stop = time(NULL);
    passert((stop - start) > 1);

    /* Test non-blocking read */
    start = time(NULL);
    passert(serial_read(serial, buf, sizeof(buf), 0) == 0);
    stop = time(NULL);
    /* Assuming we weren't context switched out for a second and weren't on a
     * thin time boundary ;) */
    passert((stop - start) == 0);

    /* Test blocking read with vmin=5 termios timeout */
    passert(serial_set_vmin(serial, 5) == 0);
    /* Write 5, read back 5 (== vmin) */
    passert(serial_write(serial, lorem_ipsum, 5) == 5);
    passert(serial_flush(serial) == 0);
    passert(serial_read(serial, buf, sizeof(buf), -1) == 5);
    passert(memcmp(lorem_ipsum, buf, 5) == 0);

    /* Test blocking read with vmin=5, vtime=2 termios timeout */
    passert(serial_set_vtime(serial, 2) == 0);
    /* Write 3, read back 3 (< vmin, but > vtime interbyte timeout) */
    passert(serial_write(serial, lorem_ipsum, 3) == 3);
    passert(serial_flush(serial) == 0);
    start = time(NULL);
    passert(serial_read(serial, buf, sizeof(buf), -1) == 3);
    stop = time(NULL);
    passert(memcmp(lorem_ipsum, buf, 3) == 0);
    passert((stop - start) > 1);

    passert(serial_close(serial) == 0);

    /* Free serial */
    serial_free(serial);
}

bool getc_yes(void) {
    char buf[4];
    fgets(buf, sizeof(buf), stdin);
    return (buf[0] == 'y' || buf[0] == 'Y');
}

void test_interactive(void) {
    char str[256];
    serial_t *serial;
    uint8_t buf[] = "Hello World";

    ptest();

    /* Allocate serial */
    serial = serial_new();
    passert(serial != NULL);
    passert(serial_open(serial, device, 4800) == 0);

    printf("Starting interactive test. Get out your logic analyzer, buddy!\n");
    printf("Press enter to continue...\n");
    getc(stdin);

    /* Check tostring */
    passert(serial_tostring(serial, str, sizeof(str)) > 0);
    printf("Serial description: %s\n", str);
    printf("Serial description looks OK? y/n\n");
    passert(getc_yes());

    printf("Press enter to start transfer...");
    getc(stdin);
    passert(serial_write(serial, buf, sizeof(buf)) == sizeof(buf));
    printf("Serial transfer baudrate 4800, 8n1 occurred? y/n\n");
    passert(getc_yes());

    passert(serial_set_baudrate(serial, 9600) == 0);

    printf("Press enter to start transfer...");
    getc(stdin);
    passert(serial_write(serial, buf, sizeof(buf)) == sizeof(buf));
    printf("Serial transfer baudrate 9600, 8n1 occurred? y/n\n");
    passert(getc_yes());

    passert(serial_set_baudrate(serial, 115200) == 0);

    printf("Press enter to start transfer...");
    getc(stdin);
    passert(serial_write(serial, buf, sizeof(buf)) == sizeof(buf));
    printf("Serial transfer baudrate 115200, 8n1 occurred? y/n\n");
    passert(getc_yes());

    passert(serial_close(serial) == 0);

    /* Free serial */
    serial_free(serial);
}

int main(int argc, char *argv[]) {
    if (argc < 2) {
        fprintf(stderr, "Usage: %s <serial port device>\n\n", argv[0]);
        fprintf(stderr, "[1/4] Arguments test: No requirements.\n");
        fprintf(stderr, "[2/4] Open/close test: Serial port device should be real.\n");
        fprintf(stderr, "[3/4] Loopback test: Serial TX and RX should be connected with a wire.\n");
        fprintf(stderr, "[4/4] Interactive test: Serial TX should be observed with an oscilloscope or logic analyzer.\n\n");
        fprintf(stderr, "Hint: for Raspberry Pi 3, enable UART0 with:\n");
        fprintf(stderr, "   $ echo \"dtoverlay=pi3-disable-bt\" | sudo tee -a /boot/config.txt\n");
        fprintf(stderr, "   $ sudo systemctl disable hciuart\n");
        fprintf(stderr, "   $ sudo reboot\n");
        fprintf(stderr, "   (Note that this will disable Bluetooth)\n");
        fprintf(stderr, "Use pins UART0 TXD (header pin 8) and UART0 RXD (header pin 10),\n");
        fprintf(stderr, "connect a loopback between TXD and RXD, and run this test with:\n");
        fprintf(stderr, "    %s /dev/ttyAMA0\n\n", argv[0]);
        exit(1);
    }

    device = argv[1];

    test_arguments();
    printf(" " STR_OK "  Arguments test passed.\n\n");
    test_open_config_close();
    printf(" " STR_OK "  Open/close test passed.\n\n");
    test_loopback();
    printf(" " STR_OK "  Loopback test passed.\n\n");
    test_interactive();
    printf(" " STR_OK "  Interactive test passed.\n\n");

    printf("All tests passed!\n");
    return 0;
}