func (bp *baseport) SetReadParams(minread int, timeout float64) error {
inttimeout := int(timeout * 10)
if inttimeout < 0 {
return &ParameterError{"timeout", "needs to be 0 or higher"}
}
// if a timeout is desired but too small for the termios timeout
// granularity, set the minimum timeout
if timeout > 0 && inttimeout == 0 {
inttimeout = 1
}
tio, err := bp.getattr()
if err != nil {
return &Error{"getattr", err}
}
tio.c_cc[C.VMIN] = C.cc_t(minread)
tio.c_cc[C.VTIME] = C.cc_t(inttimeout)
//fmt.Printf("baud rates from termios: %d, %d\n", tio.c_ispeed, tio.c_ospeed)
err = bp.setattr(tio)
if err != nil {
return &Error{"setattr", err}
}
return nil
}
func makeCAttributes(attr *Attributes) C.struct_termios {
var cattr C.struct_termios
cattr.c_iflag = C.tcflag_t(attr.Input)
cattr.c_oflag = C.tcflag_t(attr.Output)
cattr.c_cflag = C.tcflag_t(attr.Control)
cattr.c_lflag = C.tcflag_t(attr.Local)
for i := 0; i < C.NCCS; i++ {
cattr.c_cc[i] = C.cc_t(attr.ControlChars[i])
}
return cattr
}
func cTermios(goTerm *Termios) *C.struct_termios {
var cTerm C.struct_termios
cTerm.c_iflag = C.tcflag_t(goTerm.IFlag)
cTerm.c_oflag = C.tcflag_t(goTerm.OFlag)
cTerm.c_cflag = C.tcflag_t(goTerm.CFlag)
cTerm.c_lflag = C.tcflag_t(goTerm.LFlag)
for idx, ch := range goTerm.CC {
cTerm.c_cc[idx] = C.cc_t(ch)
}
cTerm.c_ispeed = C.speed_t(goTerm.ISpeed)
cTerm.c_ospeed = C.speed_t(goTerm.OSpeed)
return &cTerm
}
func openPort(name string, baud int, readTimeout time.Duration) (p *Port, err error) {
f, err := os.OpenFile(name, syscall.O_RDWR|syscall.O_NOCTTY|syscall.O_NONBLOCK, 0666)
if err != nil {
return
}
fd := C.int(f.Fd())
if C.isatty(fd) != 1 {
f.Close()
return nil, errors.New("File is not a tty")
}
var st C.struct_termios
_, err = C.tcgetattr(fd, &st)
if err != nil {
f.Close()
return nil, err
}
var speed C.speed_t
switch baud {
case 115200:
speed = C.B115200
case 57600:
speed = C.B57600
case 38400:
speed = C.B38400
case 19200:
speed = C.B19200
case 9600:
speed = C.B9600
case 4800:
speed = C.B4800
case 2400:
speed = C.B2400
default:
f.Close()
return nil, fmt.Errorf("Unknown baud rate %v", baud)
}
_, err = C.cfsetispeed(&st, speed)
if err != nil {
f.Close()
return nil, err
}
_, err = C.cfsetospeed(&st, speed)
if err != nil {
f.Close()
return nil, err
}
// Turn off break interrupts, CR->NL, Parity checks, strip, and IXON
st.c_iflag &= ^C.tcflag_t(C.BRKINT | C.ICRNL | C.INPCK | C.ISTRIP | C.IXOFF | C.IXON | C.PARMRK)
// Select local mode, turn off parity, set to 8 bits
st.c_cflag &= ^C.tcflag_t(C.CSIZE | C.PARENB)
st.c_cflag |= (C.CLOCAL | C.CREAD | C.CS8)
// Select raw mode
st.c_lflag &= ^C.tcflag_t(C.ICANON | C.ECHO | C.ECHOE | C.ISIG)
st.c_oflag &= ^C.tcflag_t(C.OPOST)
// set blocking / non-blocking read
/*
* http://man7.org/linux/man-pages/man3/termios.3.html
* - Supports blocking read and read with timeout operations
*/
vmin, vtime := posixTimeoutValues(readTimeout)
st.c_cc[C.VMIN] = C.cc_t(vmin)
st.c_cc[C.VTIME] = C.cc_t(vtime)
_, err = C.tcsetattr(fd, C.TCSANOW, &st)
if err != nil {
f.Close()
return nil, err
}
//fmt.Println("Tweaking", name)
r1, _, e := syscall.Syscall(syscall.SYS_FCNTL,
uintptr(f.Fd()),
uintptr(syscall.F_SETFL),
uintptr(0))
if e != 0 || r1 != 0 {
s := fmt.Sprint("Clearing NONBLOCK syscall error:", e, r1)
f.Close()
return nil, errors.New(s)
}
/*
r1, _, e = syscall.Syscall(syscall.SYS_IOCTL,
uintptr(f.Fd()),
uintptr(0x80045402), // IOSSIOSPEED
uintptr(unsafe.Pointer(&baud)));
if e != 0 || r1 != 0 {
s := fmt.Sprint("Baudrate syscall error:", e, r1)
f.Close()
return nil, os.NewError(s)
}
*/
return &Port{f: f}, nil
}
// SetVMin sets the minimal number of characters for noncanonical read.
func (term *Termios) SetVMin(v uint8) {
term.c_cc[C.VMIN] = C.cc_t(v)
}
// SetVTime sets the timeout in deciseconds for noncanonical read.
func (term *Termios) SetVTime(v uint8) {
term.c_cc[C.VTIME] = C.cc_t(v)
}
// CcSet sets the Termios control character in index idx to c.
func (t *Termios) CcSet(idx int, c Cc) { t.t.c_cc[idx] = C.cc_t(c) }