Files
gousb/usb/endpoint.go
Kyle Lemons 71bbb57904 Checkpoint
2012-04-09 17:37:25 -07:00

87 lines
1.8 KiB
Go

package usb
// #include <libusb-1.0/libusb.h>
import "C"
import (
"fmt"
"reflect"
"unsafe"
"time"
)
type Endpoint interface {
Read(b []byte) (int, error)
Write(b []byte) (int, error)
Interface() InterfaceSetup
Info() EndpointInfo
}
type endpoint struct {
*Device
InterfaceSetup
EndpointInfo
xfer func(*endpoint, []byte, time.Duration) (int, error)
}
func (e *endpoint) Read(buf []byte) (int, error) {
if EndpointDirection(e.Address) & ENDPOINT_DIR_MASK != ENDPOINT_DIR_OUT {
return 0, fmt.Errorf("usb: read: not an IN endpoint")
}
return e.xfer(e, buf, e.ReadTimeout)
}
func (e *endpoint) Write(buf []byte) (int, error) {
if EndpointDirection(e.Address) & ENDPOINT_DIR_MASK != ENDPOINT_DIR_OUT {
return 0, fmt.Errorf("usb: write: not an OUT endpoint")
}
return e.xfer(e, buf, e.WriteTimeout)
}
func (e *endpoint) Interface() InterfaceSetup { return InterfaceSetup{} }
func (e *endpoint) Info() EndpointInfo { return EndpointInfo{} }
// TODO(kevlar): (*Endpoint).Close
func bulk_xfer(e *endpoint, buf []byte, timeout time.Duration) (int, error) {
if len(buf) == 0 {
return 0, nil
}
data := (*reflect.SliceHeader)(unsafe.Pointer(&buf)).Data
var cnt C.int
if errno := C.libusb_bulk_transfer(
e.handle,
C.uchar(e.Address),
(*C.uchar)(unsafe.Pointer(data)),
C.int(len(buf)),
&cnt,
C.uint(timeout/time.Millisecond)); errno < 0 {
return 0, usbError(errno)
}
return int(cnt), nil
}
func interrupt_xfer(e *endpoint, buf []byte, timeout time.Duration) (int, error) {
if len(buf) == 0 {
return 0, nil
}
data := (*reflect.SliceHeader)(unsafe.Pointer(&buf)).Data
var cnt C.int
if errno := C.libusb_interrupt_transfer(
e.handle,
C.uchar(e.Address),
(*C.uchar)(unsafe.Pointer(data)),
C.int(len(buf)),
&cnt,
C.uint(timeout/time.Millisecond)); errno < 0 {
return 0, usbError(errno)
}
return int(cnt), nil
}