cloudinit/third_party/github.com/tarm/goserial/serial_linux.go
2014-08-15 12:08:34 +03:00

91 lines
1.7 KiB
Go

// +build linux,!cgo
package serial
import (
"io"
"os"
"syscall"
"unsafe"
)
func openPort(name string, baud int) (rwc io.ReadWriteCloser, err error) {
var bauds = map[int]uint32{
50: syscall.B50,
75: syscall.B75,
110: syscall.B110,
134: syscall.B134,
150: syscall.B150,
200: syscall.B200,
300: syscall.B300,
600: syscall.B600,
1200: syscall.B1200,
1800: syscall.B1800,
2400: syscall.B2400,
4800: syscall.B4800,
9600: syscall.B9600,
19200: syscall.B19200,
38400: syscall.B38400,
57600: syscall.B57600,
115200: syscall.B115200,
230400: syscall.B230400,
460800: syscall.B460800,
500000: syscall.B500000,
576000: syscall.B576000,
921600: syscall.B921600,
1000000: syscall.B1000000,
1152000: syscall.B1152000,
1500000: syscall.B1500000,
2000000: syscall.B2000000,
2500000: syscall.B2500000,
3000000: syscall.B3000000,
3500000: syscall.B3500000,
4000000: syscall.B4000000,
}
rate := bauds[baud]
if rate == 0 {
return
}
f, err := os.OpenFile(name, syscall.O_RDWR|syscall.O_NOCTTY|syscall.O_NONBLOCK, 0666)
if err != nil {
return nil, err
}
defer func() {
if err != nil && f != nil {
f.Close()
}
}()
fd := f.Fd()
t := syscall.Termios{
Iflag: syscall.IGNPAR,
Cflag: syscall.CS8 | syscall.CREAD | syscall.CLOCAL | rate,
Cc: [32]uint8{syscall.VMIN: 1},
Ispeed: rate,
Ospeed: rate,
}
if _, _, errno := syscall.Syscall6(
syscall.SYS_IOCTL,
uintptr(fd),
uintptr(syscall.TCSETS),
uintptr(unsafe.Pointer(&t)),
0,
0,
0,
); errno != 0 {
return nil, errno
}
if err = syscall.SetNonblock(int(fd), false); err != nil {
return
}
return f, nil
}