diff options
Diffstat (limited to 'vendor/github.com/karalabe/gousb/usb/iso.go')
-rw-r--r-- | vendor/github.com/karalabe/gousb/usb/iso.go | 148 |
1 files changed, 148 insertions, 0 deletions
diff --git a/vendor/github.com/karalabe/gousb/usb/iso.go b/vendor/github.com/karalabe/gousb/usb/iso.go new file mode 100644 index 000000000..1ba694e0e --- /dev/null +++ b/vendor/github.com/karalabe/gousb/usb/iso.go @@ -0,0 +1,148 @@ +// 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 + +/* +#include "libusb.h" + +int submit(struct libusb_transfer *xfer); +void print_xfer(struct libusb_transfer *xfer); +int extract_data(struct libusb_transfer *xfer, void *data, int max, unsigned char *status); +*/ +import "C" + +import ( + "fmt" + "log" + "time" + "unsafe" +) + +//export iso_callback +func iso_callback(cptr unsafe.Pointer) { + ch := *(*chan struct{})(cptr) + close(ch) +} + +func (end *endpoint) allocTransfer() *Transfer { + // Use libusb_get_max_iso_packet_size ? + const ( + iso_packets = 8 // 128 // 242 + packet_size = 2 * 960 // 1760 + ) + + xfer := C.libusb_alloc_transfer(C.int(iso_packets)) + if xfer == nil { + log.Printf("usb: transfer allocation failed?!") + return nil + } + + buf := make([]byte, iso_packets*packet_size) + done := make(chan struct{}, 1) + + xfer.dev_handle = end.Device.handle + xfer.endpoint = C.uchar(end.Address) + xfer._type = C.LIBUSB_TRANSFER_TYPE_ISOCHRONOUS + + xfer.buffer = (*C.uchar)((unsafe.Pointer)(&buf[0])) + xfer.length = C.int(len(buf)) + xfer.num_iso_packets = iso_packets + + C.libusb_set_iso_packet_lengths(xfer, packet_size) + /* + pkts := *(*[]C.struct_libusb_packet_descriptor)(unsafe.Pointer(&reflect.SliceHeader{ + Data: uintptr(unsafe.Pointer(&xfer.iso_packet_desc)), + Len: iso_packets, + Cap: iso_packets, + })) + */ + + t := &Transfer{ + xfer: xfer, + done: done, + buf: buf, + } + xfer.user_data = (unsafe.Pointer)(&t.done) + + return t +} + +type Transfer struct { + xfer *C.struct_libusb_transfer + pkts []*C.struct_libusb_packet_descriptor + done chan struct{} + buf []byte +} + +func (t *Transfer) Submit(timeout time.Duration) error { + //log.Printf("iso: submitting %#v", t.xfer) + t.xfer.timeout = C.uint(timeout / time.Millisecond) + if errno := C.submit(t.xfer); errno < 0 { + return usbError(errno) + } + return nil +} + +func (t *Transfer) Wait(b []byte) (n int, err error) { + select { + case <-time.After(10 * time.Second): + return 0, fmt.Errorf("wait timed out after 10s") + case <-t.done: + } + // Non-iso transfers: + //n = int(t.xfer.actual_length) + //copy(b, ((*[1 << 16]byte)(unsafe.Pointer(t.xfer.buffer)))[:n]) + + //C.print_xfer(t.xfer) + /* + buf, offset := ((*[1 << 16]byte)(unsafe.Pointer(t.xfer.buffer))), 0 + for i, pkt := range *t.pkts { + log.Printf("Type is %T", t.pkts) + n += copy(b[n:], buf[offset:][:pkt.actual_length]) + offset += pkt.Length + if pkt.status != 0 && err == nil { + err = error(TransferStatus(pkt.status)) + } + } + */ + var status uint8 + n = int(C.extract_data(t.xfer, unsafe.Pointer(&b[0]), C.int(len(b)), (*C.uchar)(unsafe.Pointer(&status)))) + if status != 0 { + err = TransferStatus(status) + } + return n, err +} + +func (t *Transfer) Close() error { + C.libusb_free_transfer(t.xfer) + return nil +} + +func isochronous_xfer(e *endpoint, buf []byte, timeout time.Duration) (int, error) { + t := e.allocTransfer() + defer t.Close() + + if err := t.Submit(timeout); err != nil { + log.Printf("iso: xfer failed to submit: %s", err) + return 0, err + } + + n, err := t.Wait(buf) + if err != nil { + log.Printf("iso: xfer failed: %s", err) + return 0, err + } + return n, err +} |