// 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" ) type Endpoint interface { Read(b []byte) (int, error) Write(b []byte) (int, error) Interface() InterfaceSetup Info() EndpointInfo } type endpoint struct { h *libusbDevHandle InterfaceSetup EndpointInfo readTimeout time.Duration writeTimeout time.Duration } 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) transfer(buf []byte, timeout time.Duration) (int, error) { if len(buf) == 0 { return 0, nil } t, err := newUSBTransfer(e.h, e.EndpointInfo, 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 InterfaceSetup, e EndpointInfo, rt, wt time.Duration) *endpoint { return &endpoint{ InterfaceSetup: s, EndpointInfo: e, h: h, readTimeout: rt, writeTimeout: wt, } }