76 lines
2.0 KiB
Go
76 lines
2.0 KiB
Go
// Copyright 2016 the gousb Authors. All rights reserved.
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//
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// Licensed under the Apache License, Version 2.0 (the "License");
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// you may not use this file except in compliance with the License.
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// You may obtain a copy of the License at
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//
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// http://www.apache.org/licenses/LICENSE-2.0
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//
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// Unless required by applicable law or agreed to in writing, software
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// distributed under the License is distributed on an "AS IS" BASIS,
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// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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// See the License for the specific language governing permissions and
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// limitations under the License.
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package usb
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/*
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#include <libusb-1.0/libusb.h>
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int extract_data(struct libusb_transfer *xfer, void *data, int max, unsigned char *status);
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int extract_iso_data(struct libusb_transfer *xfer, void *data, int max, unsigned char *status);
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int submit(struct libusb_transfer *xfer);
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*/
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import "C"
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import (
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"fmt"
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"time"
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"unsafe"
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)
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//export xfer_callback
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func xfer_callback(cptr unsafe.Pointer) {
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ch := *(*chan struct{})(cptr)
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close(ch)
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}
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type usbTransfer struct {
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xfer *C.struct_libusb_transfer
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pkts []*C.struct_libusb_packet_descriptor
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done chan struct{}
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buf []byte
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}
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func (t *usbTransfer) submit(timeout time.Duration) error {
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t.xfer.timeout = C.uint(timeout / time.Millisecond)
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if errno := C.submit(t.xfer); errno < 0 {
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return usbError(errno)
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}
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return nil
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}
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func (t *usbTransfer) wait() (n int, err error) {
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select {
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case <-time.After(10 * time.Second):
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return 0, fmt.Errorf("wait timed out after 10s")
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case <-t.done:
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}
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var status uint8
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switch TransferType(t.xfer._type) {
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case TRANSFER_TYPE_ISOCHRONOUS:
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n = int(C.extract_iso_data(t.xfer, unsafe.Pointer(&t.buf[0]), C.int(len(t.buf)), (*C.uchar)(unsafe.Pointer(&status))))
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default:
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n = int(C.extract_data(t.xfer, unsafe.Pointer(&t.buf[0]), C.int(len(t.buf)), (*C.uchar)(unsafe.Pointer(&status))))
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}
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if status != 0 {
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err = TransferStatus(status)
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}
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return n, err
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}
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func (t *usbTransfer) free() error {
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C.libusb_free_transfer(t.xfer)
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return nil
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}
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