Files
gousb/usb/endpoint.go
Sebastian Zagrodzki c7c647e701 First tests.
2017-02-19 16:04:16 +01:00

106 lines
2.5 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"
"log"
"time"
)
type Endpoint interface {
Read(b []byte) (int, error)
Write(b []byte) (int, error)
Interface() InterfaceSetup
Info() EndpointInfo
}
type transferIntf interface {
submit() error
wait() (int, error)
free() error
}
type endpoint struct {
h *deviceHandle
InterfaceSetup
EndpointInfo
ReadTimeout time.Duration
WriteTimeout time.Duration
newUSBTransfer func([]byte, time.Duration) (transferIntf, error)
}
func (e *endpoint) Read(buf []byte) (int, error) {
if EndpointDirection(e.Address)&ENDPOINT_DIR_MASK != ENDPOINT_DIR_IN {
return 0, fmt.Errorf("usb: read: not an IN endpoint")
}
return e.transfer(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.transfer(buf, e.WriteTimeout)
}
func (e *endpoint) Interface() InterfaceSetup { return e.InterfaceSetup }
func (e *endpoint) Info() EndpointInfo { return e.EndpointInfo }
func (e *endpoint) newRealUSBTransfer(buf []byte, timeout time.Duration) (transferIntf, error) {
return newUSBTransfer(e.h, e.EndpointInfo, buf, timeout)
}
func (e *endpoint) transfer(buf []byte, timeout time.Duration) (int, error) {
if len(buf) == 0 {
return 0, nil
}
tt := e.TransferType()
t, err := e.newUSBTransfer(buf, timeout)
if err != nil {
return 0, err
}
defer t.free()
if err := t.submit(); err != nil {
log.Printf("bulk: %s failed to submit: %s", tt, err)
return 0, err
}
n, err := t.wait()
if err != nil {
log.Printf("bulk: %s failed: %s", tt, err)
return 0, err
}
return n, err
}
func newEndpoint(d *Device) *endpoint {
ep := &endpoint{
h: (*deviceHandle)(d.handle),
ReadTimeout: d.ReadTimeout,
WriteTimeout: d.WriteTimeout,
}
ep.newUSBTransfer = ep.newRealUSBTransfer
return ep
}