113 lines
2.6 KiB
Go
113 lines
2.6 KiB
Go
// Copyright 2013 Google Inc. 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 provides a wrapper around libusb-1.0.
|
|
package usb
|
|
|
|
// #cgo LDFLAGS: -lusb-1.0
|
|
// #include <libusb-1.0/libusb.h>
|
|
import "C"
|
|
|
|
import (
|
|
"log"
|
|
"reflect"
|
|
"unsafe"
|
|
)
|
|
|
|
type Context struct {
|
|
ctx *C.libusb_context
|
|
done chan struct{}
|
|
}
|
|
|
|
func (c *Context) Debug(level int) {
|
|
C.libusb_set_debug(c.ctx, C.int(level))
|
|
}
|
|
|
|
func NewContext() *Context {
|
|
c := &Context{
|
|
done: make(chan struct{}),
|
|
}
|
|
|
|
if errno := C.libusb_init(&c.ctx); errno != 0 {
|
|
panic(usbError(errno))
|
|
}
|
|
|
|
go func() {
|
|
for {
|
|
select {
|
|
case <-c.done:
|
|
return
|
|
default:
|
|
}
|
|
if errno := C.libusb_handle_events(c.ctx); errno < 0 {
|
|
log.Printf("handle_events: error: %s", usbError(errno))
|
|
continue
|
|
}
|
|
//log.Printf("handle_events returned")
|
|
}
|
|
}()
|
|
|
|
return c
|
|
}
|
|
|
|
// ListDevices calls each with each enumerated device.
|
|
// If the function returns true, the device is opened and a Device is returned if the operation succeeds.
|
|
// Every Device returned (whether an error is also returned or not) must be closed.
|
|
// If there are any errors enumerating the devices,
|
|
// the final one is returned along with any successfully opened devices.
|
|
func (c *Context) ListDevices(each func(desc *Descriptor) bool) ([]*Device, error) {
|
|
var list **C.libusb_device
|
|
cnt := C.libusb_get_device_list(c.ctx, &list)
|
|
if cnt < 0 {
|
|
return nil, usbError(cnt)
|
|
}
|
|
defer C.libusb_free_device_list(list, 1)
|
|
|
|
var slice []*C.libusb_device
|
|
*(*reflect.SliceHeader)(unsafe.Pointer(&slice)) = reflect.SliceHeader{
|
|
Data: uintptr(unsafe.Pointer(list)),
|
|
Len: int(cnt),
|
|
Cap: int(cnt),
|
|
}
|
|
|
|
var reterr error
|
|
ret := []*Device{}
|
|
for _, dev := range slice {
|
|
desc, err := newDescriptor(dev)
|
|
if err != nil {
|
|
reterr = err
|
|
continue
|
|
}
|
|
|
|
if each(desc) {
|
|
var handle *C.libusb_device_handle
|
|
if errno := C.libusb_open(dev, &handle); errno != 0 {
|
|
reterr = err
|
|
continue
|
|
}
|
|
ret = append(ret, newDevice(handle, desc))
|
|
}
|
|
}
|
|
return ret, reterr
|
|
}
|
|
|
|
func (c *Context) Close() error {
|
|
close(c.done)
|
|
if c.ctx != nil {
|
|
C.libusb_exit(c.ctx)
|
|
}
|
|
c.ctx = nil
|
|
return nil
|
|
}
|