92 lines
2.2 KiB
Go
92 lines
2.2 KiB
Go
// Copyright 2013 Google Inc. All rights reserved.
|
|
// Copyright 2016 the gousb Authors. All rights reserved.
|
|
//
|
|
// Licensed under the Apache License, Version 2.0 (the "License");
|
|
// you may not use this file except in compliance with the License.
|
|
// You may obtain a copy of the License at
|
|
//
|
|
// http://www.apache.org/licenses/LICENSE-2.0
|
|
//
|
|
// Unless required by applicable law or agreed to in writing, software
|
|
// distributed under the License is distributed on an "AS IS" BASIS,
|
|
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
|
|
// See the License for the specific language governing permissions and
|
|
// limitations under the License.
|
|
|
|
package usb
|
|
|
|
/*
|
|
#include <libusb-1.0/libusb.h>
|
|
*/
|
|
import "C"
|
|
|
|
import (
|
|
"log"
|
|
"time"
|
|
"unsafe"
|
|
)
|
|
|
|
//export iso_callback
|
|
func iso_callback(cptr unsafe.Pointer) {
|
|
ch := *(*chan struct{})(cptr)
|
|
close(ch)
|
|
}
|
|
|
|
func (end *endpoint) allocTransfer() *usbTransfer {
|
|
const (
|
|
iso_packets = 8 // 128 // 242
|
|
)
|
|
|
|
xfer := C.libusb_alloc_transfer(C.int(iso_packets))
|
|
if xfer == nil {
|
|
log.Printf("usb: transfer allocation failed?!")
|
|
return nil
|
|
}
|
|
|
|
buf := make([]byte, iso_packets*end.EndpointInfo.MaxIsoPacket)
|
|
done := make(chan struct{}, 1)
|
|
|
|
xfer.dev_handle = end.Device.handle
|
|
xfer.endpoint = C.uchar(end.Address)
|
|
xfer._type = C.LIBUSB_TRANSFER_TYPE_ISOCHRONOUS
|
|
|
|
xfer.buffer = (*C.uchar)((unsafe.Pointer)(&buf[0]))
|
|
xfer.length = C.int(len(buf))
|
|
xfer.num_iso_packets = iso_packets
|
|
|
|
C.libusb_set_iso_packet_lengths(xfer, C.uint(end.EndpointInfo.MaxIsoPacket))
|
|
/*
|
|
pkts := *(*[]C.struct_libusb_packet_descriptor)(unsafe.Pointer(&reflect.SliceHeader{
|
|
Data: uintptr(unsafe.Pointer(&xfer.iso_packet_desc)),
|
|
Len: iso_packets,
|
|
Cap: iso_packets,
|
|
}))
|
|
*/
|
|
|
|
t := &usbTransfer{
|
|
xfer: xfer,
|
|
done: done,
|
|
buf: buf,
|
|
}
|
|
xfer.user_data = (unsafe.Pointer)(&t.done)
|
|
|
|
return t
|
|
}
|
|
|
|
func isochronous_xfer(e *endpoint, buf []byte, timeout time.Duration) (int, error) {
|
|
t := e.allocTransfer()
|
|
defer t.free()
|
|
|
|
if err := t.submit(timeout); err != nil {
|
|
log.Printf("iso: xfer failed to submit: %s", err)
|
|
return 0, err
|
|
}
|
|
|
|
n, err := t.wait(buf)
|
|
if err != nil {
|
|
log.Printf("iso: xfer failed: %s", err)
|
|
return 0, err
|
|
}
|
|
return n, err
|
|
}
|