1 files changed, 93 insertions, 0 deletions
diff --git a/ports.go b/ports.go
new file mode 100644
index 0000000..2742e60
--- /dev/null
+++ b/ports.go
@@ -0,0 +1,93 @@
+package userial
+
+import (
+	"math"
+	"os"
+	"time"
+
+	"golang.org/x/sys/unix"
+)
+
+type Port struct{ f *os.File }
+
+// OpenPort opens a named serial device and return a Port data type and error
+func (spops *Serial) OpenPort(path string) (*Port, error) {
+
+	f, err := os.OpenFile(path, unix.O_RDWR|unix.O_NOCTTY|unix.O_NONBLOCK, 0666)
+	if err != nil {
+		return nil, err
+	}
+
+	defer func() {
+		if err != nil && f != nil {
+			f.Close()
+		}
+	}()
+
+	fg := uint32(spops.baud) | uint32(spops.data) | uint32(spops.stop) | spops.cbit
+
+	switch spops.prty {
+	case 1:
+		fg |= unix.PARENB
+	case 2:
+		fg |= unix.PARENB
+		fg |= unix.PARODD
+	}
+
+	t := unix.Termios{
+		Cflag: fg, Iflag: spops.ibit,
+		Ispeed: uint32(spops.baud),
+		Ospeed: uint32(spops.baud),
+	}
+
+	t.Cc[unix.VMIN], t.Cc[unix.VTIME] = timeout(spops.tout)
+
+	if err := unix.IoctlSetTermios(
+		int(f.Fd()), unix.TCSETS, &t); err != nil {
+		return nil, err
+	}
+
+	if err := unix.SetNonblock(int(f.Fd()), false); err != nil {
+		return nil, err
+	}
+
+	return &Port{f: f}, err
+
+}
+
+// Read implement read() method for serial port
+func (p *Port) Read(b []byte) (int, error) { return p.f.Read(b) }
+
+// Write implement write() method for serial port
+func (p *Port) Write(b []byte) (int, error) { return p.f.Write(b) }
+
+// Close implement close() method for serial port
+func (p *Port) Close() error { return p.f.Close() }
+
+// Flush implement flush() method for serial port
+func (p *Port) Flush() error {
+	return unix.IoctlSetInt(int(p.f.Fd()), unix.TCFLSH, unix.TCIOFLUSH)
+}
+
+// SendBreak Sends Break Signal
+func (p *Port) SendBreak(d time.Duration) error {
+	return unix.IoctlSetInt(int(p.f.Fd()), unix.TCSBRKP, int(d))
+}
+
+// Available returns how many bytes are unused in the buffer
+func (p *Port) Available() (int, error) {
+	return unix.IoctlGetInt(int(p.f.Fd()), unix.TIOCINQ)
+}
+
+// Buffered returns the number of bytes that have been written into the current buffer
+func (p *Port) Buffered() (int, error) {
+	return unix.IoctlGetInt(int(p.f.Fd()), unix.TIOCOUTQ)
+}
+
+func timeout(d time.Duration) (byte, byte) {
+	if d > 0x0 {
+		t := math.Min(math.Max(float64(d.Nanoseconds()/1e6/100), 0x01), 0xff)
+		return 0x0, byte(t)
+	}
+	return 0x1, 0x0
+}