Update: After looking through the code a bit, I discovered that the
CAIOC_GETCTRLLINE ioctl exists. This seems to do exactly what I want
it to, in that once the host system opens the ttyACM the DTR and RTS
lines are raised. As long as the host system does not turn off the
DTR line it should be fine.
Sample code(no error checking):
int get_val;
ioctl(fd, CAIOC_GETCTRLLINE, &get_val);
printf("get val: 0x%02X. RTS: %d DTR: %d\n",
get_val,
(get_val & CDCACM_UART_RTS) > 0,
(get_val & CDCACM_UART_DTR) > 0);
-Robert Middleton
