88 lines
2.1 KiB
Go
88 lines
2.1 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
|
|
|
|
import (
|
|
"fmt"
|
|
"time"
|
|
)
|
|
|
|
// Endpoint identifies a USB endpoint opened for transfer.
|
|
type Endpoint struct {
|
|
h *libusbDevHandle
|
|
|
|
InterfaceSetting
|
|
Info EndpointInfo
|
|
|
|
readTimeout time.Duration
|
|
writeTimeout time.Duration
|
|
}
|
|
|
|
// String returns a human-readable description of the endpoint.
|
|
func (e *Endpoint) String() string {
|
|
return e.Info.String()
|
|
}
|
|
|
|
// Read reads data from an IN endpoint.
|
|
func (e *Endpoint) Read(buf []byte) (int, error) {
|
|
if e.Info.Direction != EndpointDirectionIn {
|
|
return 0, fmt.Errorf("usb: read: not an IN endpoint")
|
|
}
|
|
|
|
return e.transfer(buf, e.readTimeout)
|
|
}
|
|
|
|
// Write writes data to an OUT endpoint.
|
|
func (e *Endpoint) Write(buf []byte) (int, error) {
|
|
if e.Info.Direction != EndpointDirectionOut {
|
|
return 0, fmt.Errorf("usb: write: not an OUT endpoint")
|
|
}
|
|
|
|
return e.transfer(buf, e.writeTimeout)
|
|
}
|
|
|
|
func (e *Endpoint) transfer(buf []byte, timeout time.Duration) (int, error) {
|
|
if len(buf) == 0 {
|
|
return 0, nil
|
|
}
|
|
|
|
t, err := newUSBTransfer(e.h, &e.Info, buf, timeout)
|
|
if err != nil {
|
|
return 0, err
|
|
}
|
|
defer t.free()
|
|
|
|
if err := t.submit(); err != nil {
|
|
return 0, err
|
|
}
|
|
|
|
n, err := t.wait()
|
|
if err != nil {
|
|
return n, err
|
|
}
|
|
return n, nil
|
|
}
|
|
|
|
func newEndpoint(h *libusbDevHandle, s InterfaceSetting, e EndpointInfo, rt, wt time.Duration) *Endpoint {
|
|
return &Endpoint{
|
|
InterfaceSetting: s,
|
|
Info: e,
|
|
h: h,
|
|
readTimeout: rt,
|
|
writeTimeout: wt,
|
|
}
|
|
}
|