device_crow.c

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <errno.h>
#include <fcntl.h>
#include <termios.h>
#include <unistd.h>
#include <linux/input.h>
#include <sys/types.h>
#include <sys/stat.h>

#include "device_crow.h"
#include "events.h"

#pragma GCC diagnostic push
#pragma GCC diagnostic ignored "-Wunused-result"

#define TEST_NULL_AND_FREE(p) if( (p) != NULL ) { free(p); } \
    else { fprintf(stderr, "error: double free in device_crow.c\n"); }

#define CROW_RETRIES 10

int dev_crow_init(void *self) {
    struct dev_crow *d = (struct dev_crow *)self;
    struct dev_common *base = (struct dev_common *)self;

    d->fd = open(d->base.path, O_RDWR | O_NOCTTY | O_SYNC);

    if (d->fd < 0) {
        fprintf(stderr, "failed to open crow device: %s\n", d->base.path);
        return -1;
    }

    tcgetattr(d->fd,&d->oldtio);
    //d->newtio.c_cflag = CROW_BAUDRATE | CRTSCTS | CS8 | CLOCAL | CREAD;
    d->newtio.c_cflag = CROW_BAUDRATE | CS8 | CLOCAL | CREAD;
    //d->newtio.c_iflag = IGNPAR | ICRNL;
    d->newtio.c_iflag &= ~(IXON | IXOFF | IXANY);
    d->newtio.c_oflag = 0;
    //d->newtio.c_lflag = ICANON;
    d->newtio.c_lflag = 0;
    d->newtio.c_cc[VMIN]=0;
    d->newtio.c_cc[VTIME]=5;
    tcflush(d->fd, TCIFLUSH);
    tcsetattr(d->fd,TCSANOW,&d->newtio);

    // check if modem is a crow
    char s[256];
    read(d->fd, s, 255); // clear buffer
    write(d->fd,"^^i\n\0",5);    
    usleep(1000);
    int retry = 0;
    while(retry < CROW_RETRIES) {
      retry++;
      memset(s,0,sizeof(s));
      read(d->fd, s, 255);
      //fprintf(stderr,"crow init> %i %s",sizeof(s),s);
      if(strstr(s,"^^identity")!=NULL) break;
    }
    if(retry >= CROW_RETRIES) {
        fprintf(stderr,">> ttyACM found, but not a crow\n");
        return -1;
    }

    base->start = &dev_crow_start;
    base->deinit = &dev_crow_deinit;

    return 0;
}

static void handle_event(void *dev, uint8_t id) {
    union event_data *ev = event_data_new(EVENT_CROW_EVENT);
    ev->crow_event.dev = dev;
    ev->crow_event.id = id;
    event_post(ev);
}

void *dev_crow_start(void *self) {
    struct dev_crow *di = (struct dev_crow *)self;
    struct dev_common *base = (struct dev_common *)self;

    uint8_t len;

    while(1) {
        len = read(di->fd, di->line, 255);
        if(len > 0) {
            di->line[len] = 0; // add null to end of string
            if(len>1) {
                //fprintf(stderr,"crow> %s", di->line);
                handle_event(self, base->id);
            }
            len = 0;
        }
        usleep(1000); // 1ms
    }
    return NULL;
}

void dev_crow_deinit(void *self) {
    struct dev_crow *di = (struct dev_crow *)self;
    tcsetattr(di->fd,TCSANOW,&di->oldtio);
}

void dev_crow_send(struct dev_crow *d, const char *line) {
    char s[256];
    strcpy(s,line);
    strcat(s,"\n\0");
    //fprintf(stderr,"crow_send: %s",line);
    write(d->fd, s, strlen(s));
}


#pragma GCC diagnostic pop