Added isochronous transfer

usb/config.go

@@ -13,6 +13,7 @@ type EndpointInfo struct {
 	Address       uint8
 	Attributes    uint8
 	MaxPacketSize uint16
+	MaxIsoPacket  uint32
 	PollInterval  uint8
 	RefreshRate   uint8
 	SynchAddress  uint8
@@ -27,11 +28,12 @@ func (e EndpointInfo) Direction() EndpointDirection {
 }
 
 func (e EndpointInfo) String() string {
-	return fmt.Sprintf("Endpoint %d %-3s %s - %s %s",
+	return fmt.Sprintf("Endpoint %d %-3s %s - %s %s [%d %d]",
 		e.Number(), e.Direction(),
 		TransferType(e.Attributes)&TRANSFER_TYPE_MASK,
 		IsoSyncType(e.Attributes)&ISO_SYNC_TYPE_MASK,
 		IsoUsageType(e.Attributes)&ISO_USAGE_TYPE_MASK,
+		e.MaxPacketSize, e.MaxIsoPacket,
 	)
 }
 
@@ -68,7 +70,7 @@ func (c ConfigInfo) String() string {
 	return fmt.Sprintf("Config %02x", c.Config)
 }
 
-func newConfig(cfg *C.struct_libusb_config_descriptor) ConfigInfo {
+func newConfig(dev *C.libusb_device, cfg *C.struct_libusb_config_descriptor) ConfigInfo {
 	c := ConfigInfo{
 		Config:     uint8(cfg.bConfigurationValue),
 		Attributes: uint8(cfg.bmAttributes),
@@ -114,6 +116,7 @@ func newConfig(cfg *C.struct_libusb_config_descriptor) ConfigInfo {
 					Address:       uint8(end.bEndpointAddress),
 					Attributes:    uint8(end.bmAttributes),
 					MaxPacketSize: uint16(end.wMaxPacketSize),
+					//MaxIsoPacket:  uint32(C.libusb_get_max_iso_packet_size(dev, C.uchar(end.bEndpointAddress))),
 					PollInterval:  uint8(end.bInterval),
 					RefreshRate:   uint8(end.bRefresh),
 					SynchAddress:  uint8(end.bSynchAddress),

usb/descriptor.go

@@ -38,7 +38,7 @@ func newDescriptor(dev *C.libusb_device) (*Descriptor, error) {
 		if errno := C.libusb_get_config_descriptor(dev, C.uint8_t(i), &cfg); errno < 0 {
 			return nil, usbError(errno)
 		}
-		cfgs = append(cfgs, newConfig(cfg))
+		cfgs = append(cfgs, newConfig(dev, cfg))
 		C.libusb_free_config_descriptor(cfg)
 	}
 

usb/device.go

@@ -4,6 +4,182 @@ package usb
 import "C"
 
 import (
+	"fmt"
+	"log"
+	"reflect"
+	"runtime"
+	"sync"
+	"time"
+	"unsafe"
 )
 
+var DefaultReadTimeout = 1 * time.Second
+var DefaultWriteTimeout = 1 * time.Second
+var DefaultControlTimeout = 5 * time.Second
 
+type Device struct {
+	handle *C.libusb_device_handle
+
+	// Embed the device information for easy access
+	*Descriptor
+
+	// Timeouts
+	ReadTimeout    time.Duration
+	WriteTimeout   time.Duration
+	ControlTimeout time.Duration
+
+	// Claimed interfaces
+	lock    *sync.Mutex
+	claimed map[uint8]int
+}
+
+func newDevice(handle *C.libusb_device_handle, desc *Descriptor) *Device {
+	ifaces := 0
+	d := &Device{
+		handle:         handle,
+		Descriptor:     desc,
+		ReadTimeout:    DefaultReadTimeout,
+		WriteTimeout:   DefaultWriteTimeout,
+		ControlTimeout: DefaultControlTimeout,
+		lock:           new(sync.Mutex),
+		claimed:        make(map[uint8]int, ifaces),
+	}
+
+	// This doesn't seem to actually get called
+	runtime.SetFinalizer(d, (*Device).Close)
+
+	return d
+}
+
+func (d *Device) Reset() error {
+	if errno := C.libusb_reset_device(d.handle); errno != 0 {
+		return usbError(errno)
+	}
+	return nil
+}
+
+func (d *Device) Control(rType, request uint8, val, idx uint16, data []byte) (int, error) {
+	dataSlice := (*reflect.SliceHeader)(unsafe.Pointer(&data))
+	n := C.libusb_control_transfer(
+		d.handle,
+		C.uint8_t(rType),
+		C.uint8_t(request),
+		C.uint16_t(val),
+		C.uint16_t(idx),
+		(*C.uchar)(unsafe.Pointer(dataSlice.Data)),
+		C.uint16_t(len(data)),
+		C.uint(d.ControlTimeout/time.Millisecond))
+	if n < 0 {
+		return int(n), usbError(n)
+	}
+	return int(n), nil
+}
+
+// ActiveConfig returns the config id (not the index) of the active configuration.
+// This corresponds to the ConfigInfo.Config field.
+func (d *Device) ActiveConfig() (uint8, error) {
+	var cfg C.int
+	if errno := C.libusb_get_configuration(d.handle, &cfg); errno < 0 {
+		return 0, usbError(errno)
+	}
+	return uint8(cfg), nil
+}
+
+// SetConfig attempts to change the active configuration.
+// The cfg provided is the config id (not the index) of the configuration to set,
+// which corresponds to the ConfigInfo.Config field.
+func (d *Device) SetConfig(cfg uint8) error {
+	if errno := C.libusb_set_configuration(d.handle, C.int(cfg)); errno < 0 {
+		return usbError(errno)
+	}
+	return nil
+}
+
+// Close the device.
+func (d *Device) Close() error {
+	if d.handle == nil {
+		return fmt.Errorf("usb: double close on device")
+	}
+	d.lock.Lock()
+	defer d.lock.Unlock()
+	for iface := range d.claimed {
+		C.libusb_release_interface(d.handle, C.int(iface))
+	}
+	C.libusb_close(d.handle)
+	d.handle = nil
+	return nil
+}
+
+func (d *Device) OpenEndpoint(conf, iface, setup, epoint uint8) (Endpoint, error) {
+	end := &endpoint{
+		Device: d,
+	}
+
+	for _, c := range d.Configs {
+		if c.Config != conf {
+			continue
+		}
+		fmt.Printf("found conf: %#v\n", c)
+		for _, i := range c.Interfaces {
+			if i.Number != iface {
+				continue
+			}
+			fmt.Printf("found iface: %#v\n", i)
+			for _, s := range i.Setups {
+				if s.Alternate != setup {
+					continue
+				}
+				fmt.Printf("found setup: %#v\n", s)
+				for _, e := range s.Endpoints {
+					fmt.Printf("ep %02x search: %#v\n", epoint, s)
+					if e.Address != epoint {
+						continue
+					}
+					end.InterfaceSetup = s
+					end.EndpointInfo = e
+					switch tt := TransferType(e.Attributes) & TRANSFER_TYPE_MASK; tt {
+					case TRANSFER_TYPE_BULK:
+						end.xfer = bulk_xfer
+					case TRANSFER_TYPE_INTERRUPT:
+						end.xfer = interrupt_xfer
+					case TRANSFER_TYPE_ISOCHRONOUS:
+						end.xfer = isochronous_xfer
+					default:
+						return nil, fmt.Errorf("usb: %s transfer is unsupported", tt)
+					}
+					goto found
+				}
+				return nil, fmt.Errorf("usb: unknown endpoint %02x", epoint)
+			}
+			return nil, fmt.Errorf("usb: unknown setup %02x", setup)
+		}
+		return nil, fmt.Errorf("usb: unknown interface %02x", iface)
+	}
+	return nil, fmt.Errorf("usb: unknown configuration %02x", conf)
+
+found:
+
+	// Claim the interface
+	if errno := C.libusb_claim_interface(d.handle, C.int(iface)); errno < 0 {
+		return nil, fmt.Errorf("usb: claim: %s", usbError(errno))
+	}
+
+	// Increment the claim count
+	d.lock.Lock()
+	d.claimed[iface]++
+	d.lock.Unlock() // unlock immediately because the next calls may block
+
+	// Set the configuration
+	if errno := C.libusb_set_configuration(d.handle, C.int(conf)); errno < 0 {
+		return nil, fmt.Errorf("usb: setcfg: %s", usbError(errno))
+	}
+
+	// Choose the alternate
+	// This doesn't seem to work...
+	if errno := C.libusb_set_interface_alt_setting(d.handle, C.int(iface), C.int(setup)); errno < 0 {
+		log.Printf("ignoring altsetting error: %s", usbError(errno))
+		//return nil, fmt.Errorf("usb: setalt: %s", usbError(errno))
+	}
+
+	return end, nil
+}

usb/endpoint.go

@@ -6,8 +6,8 @@ import "C"
 import (
 	"fmt"
 	"reflect"
-	"unsafe"
 	"time"
+	"unsafe"
 )
 
 type Endpoint interface {
@@ -25,7 +25,7 @@ type endpoint struct {
 }
 
 func (e *endpoint) Read(buf []byte) (int, error) {
-	if EndpointDirection(e.Address) & ENDPOINT_DIR_MASK != ENDPOINT_DIR_OUT {
+	if EndpointDirection(e.Address)&ENDPOINT_DIR_MASK != ENDPOINT_DIR_OUT {
 		return 0, fmt.Errorf("usb: read: not an IN endpoint")
 	}
 
@@ -33,7 +33,7 @@ func (e *endpoint) Read(buf []byte) (int, error) {
 }
 
 func (e *endpoint) Write(buf []byte) (int, error) {
-	if EndpointDirection(e.Address) & ENDPOINT_DIR_MASK != ENDPOINT_DIR_OUT {
+	if EndpointDirection(e.Address)&ENDPOINT_DIR_MASK != ENDPOINT_DIR_OUT {
 		return 0, fmt.Errorf("usb: write: not an OUT endpoint")
 	}
 
@@ -41,7 +41,7 @@ func (e *endpoint) Write(buf []byte) (int, error) {
 }
 
 func (e *endpoint) Interface() InterfaceSetup { return InterfaceSetup{} }
-func (e *endpoint) Info() EndpointInfo { return EndpointInfo{} }
+func (e *endpoint) Info() EndpointInfo        { return EndpointInfo{} }
 
 // TODO(kevlar): (*Endpoint).Close
 

usb/iso.c

@@ -0,0 +1,9 @@
+#include <libusb-1.0/libusb.h>
+
+void _callback(struct libusb_transfer *xfer) {
+	iso_callback(xfer->user_data);
+}
+
+libusb_transfer_cb_fn callback() {
+  return &_callback;
+}

usb/iso.go

@@ -1,182 +1,107 @@
 package usb
 
-// #include <libusb-1.0/libusb.h>
+/*
+#include <libusb-1.0/libusb.h>
+
+libusb_transfer_cb_fn callback();
+*/
 import "C"
 
 import (
-	"fmt"
+	"log"
 	"reflect"
 	"runtime"
-	"sync"
 	"time"
 	"unsafe"
 )
 
-var DefaultReadTimeout = 1 * time.Second
-var DefaultWriteTimeout = 1 * time.Second
-var DefaultControlTimeout = 5 * time.Second
-
-type Device struct {
-	handle *C.libusb_device_handle
-
-	// Embed the device information for easy access
-	*Descriptor
-
-	// Timeouts
-	ReadTimeout time.Duration
-	WriteTimeout time.Duration
-	ControlTimeout time.Duration
-
-	// Claimed interfaces
-	lock    *sync.Mutex
-	claimed map[uint8]int
+//export iso_callback
+func iso_callback(cptr unsafe.Pointer) {
+	ch := *(*chan struct{})(cptr)
+	close(ch)
 }
 
-func newDevice(handle *C.libusb_device_handle, desc *Descriptor) *Device {
-	ifaces := 0
-	d := &Device{
-		handle:         handle,
-		Descriptor:     desc,
-		ReadTimeout:    DefaultReadTimeout,
-		WriteTimeout:   DefaultWriteTimeout,
-		ControlTimeout: DefaultControlTimeout,
-		lock:           new(sync.Mutex),
-		claimed:        make(map[uint8]int, ifaces),
+func (end *endpoint) allocTransfer() *Transfer {
+	// Use libusb_get_max_iso_packet_size ?
+	const (
+		iso_packets = 242
+		packet_size = 1760
+	)
+
+	xfer := C.libusb_alloc_transfer(C.int(iso_packets))
+	if xfer == nil {
+		log.Printf("usb: transfer allocation failed?!")
+		return nil
 	}
 
-	// This doesn't seem to actually get called
-	runtime.SetFinalizer(d, (*Device).Close)
+	xfer.dev_handle = end.Device.handle
+	xfer.endpoint = C.uchar(end.Address)
+	xfer._type = C.LIBUSB_TRANSFER_TYPE_ISOCHRONOUS
 
-	return d
+	xfer.callback = C.callback()
+	xfer.timeout = C.uint(5 * time.Second / time.Millisecond)
+
+	buf := make([]byte, iso_packets*packet_size)
+	xfer.num_iso_packets = iso_packets
+	xfer.buffer = (*C.uchar)((unsafe.Pointer)(&buf[0]))
+	xfer.length = C.int(len(buf))
+	C.libusb_set_iso_packet_lengths(xfer, C.uint(len(buf)))
+	pkts := *(*[]C.struct_libusb_packet_descriptor)(unsafe.Pointer(&reflect.SliceHeader{
+		Data: uintptr(unsafe.Pointer(&xfer.iso_packet_desc)),
+		Len:  iso_packets,
+		Cap:  iso_packets,
+	}))
+
+	done := make(chan struct{})
+	xfer.user_data = (unsafe.Pointer)(&done)
+
+	t := &Transfer{
+		xfer: xfer,
+		pkts: pkts,
+		done: done,
+		buf:  buf,
+	}
+
+	runtime.SetFinalizer(t, (*Transfer).Close)
+
+	return t
 }
 
-func (d *Device) Reset() error {
-	if errno := C.libusb_reset_device(d.handle); errno != 0 {
+type Transfer struct {
+	xfer *C.struct_libusb_transfer
+	pkts []C.struct_libusb_packet_descriptor
+	done chan struct{}
+	buf  []byte
+}
+
+func (xfer *Transfer) Submit() error {
+	if errno := C.libusb_submit_transfer(xfer.xfer); errno < 0 {
 		return usbError(errno)
 	}
 	return nil
 }
 
-func (d *Device) Control(rType, request uint8, val, idx uint16, data []byte) (int, error) {
-	dataSlice := (*reflect.SliceHeader)(unsafe.Pointer(&data))
-	n := C.libusb_control_transfer(
-		d.handle,
-		C.uint8_t(rType),
-		C.uint8_t(request),
-		C.uint16_t(val),
-		C.uint16_t(idx),
-		(*C.uchar)(unsafe.Pointer(dataSlice.Data)),
-		C.uint16_t(len(data)),
-		C.uint(d.ControlTimeout/time.Millisecond))
-	if n < 0 {
-		return int(n), usbError(n)
+func (xfer *Transfer) Wait() (n int, err error) {
+	<-xfer.done
+	n = int(xfer.xfer.actual_length)
+	for _, pkt := range xfer.pkts {
+		log.Printf("PACKET[%4d] - %#v", pkt)
 	}
-	return int(n), nil
+	return n, err
 }
 
-// ActiveConfig returns the config id (not the index) of the active configuration.
-// This corresponds to the ConfigInfo.Config field.
-func (d *Device) ActiveConfig() (uint8, error) {
-	var cfg C.int
-	if errno := C.libusb_get_configuration(d.handle, &cfg); errno < 0 {
-		return 0, usbError(errno)
-	}
-	return uint8(cfg), nil
-}
-
-// SetConfig attempts to change the active configuration.
-// The cfg provided is the config id (not the index) of the configuration to set,
-// which corresponds to the ConfigInfo.Config field.
-func (d *Device) SetConfig(cfg uint8) error {
-	if errno := C.libusb_set_configuration(d.handle, C.int(cfg)); errno < 0 {
-		return usbError(errno)
-	}
+func (xfer *Transfer) Close() error {
+	C.libusb_free_transfer(xfer.xfer)
 	return nil
 }
 
-// Close the device.
-func (d *Device) Close() error {
-	if d.handle == nil {
-		return fmt.Errorf("usb: double close on device")
+func isochronous_xfer(e *endpoint, buf []byte, timeout time.Duration) (int, error) {
+	xfer := e.allocTransfer()
+	defer xfer.Close()
+
+	if err := xfer.Submit(); err != nil {
+		return 0, err
 	}
-	d.lock.Lock()
-	defer d.lock.Unlock()
-	for iface := range d.claimed {
-		C.libusb_release_interface(d.handle, C.int(iface))
-	}
-	C.libusb_close(d.handle)
-	d.handle = nil
-	return nil
-}
-
-func (d *Device) OpenEndpoint(conf, iface, setup, epoint uint8) (Endpoint, error) {
-	end := &endpoint{
-		Device: d,
-	}
-
-	for _, c := range d.Configs {
-		if c.Config != conf {
-			continue
-		}
-		fmt.Printf("found conf: %#v\n", c)
-		for _, i := range c.Interfaces {
-			if i.Number != iface {
-				continue
-			}
-			fmt.Printf("found iface: %#v\n", i)
-			for _, s := range i.Setups {
-				if s.Alternate != setup {
-					continue
-				}
-				fmt.Printf("found setup: %#v\n", s)
-				for _, e := range s.Endpoints {
-					fmt.Printf("ep %02x search: %#v\n", epoint, s)
-					if e.Address != epoint {
-						continue
-					}
-					end.InterfaceSetup = s
-					end.EndpointInfo = e
-					switch tt := TransferType(e.Attributes) & TRANSFER_TYPE_MASK; tt {
-					case TRANSFER_TYPE_BULK:
-						end.xfer = bulk_xfer
-					case TRANSFER_TYPE_INTERRUPT:
-						end.xfer = interrupt_xfer
-					default:
-						return nil, fmt.Errorf("usb: %s transfer is unsupported", tt)
-					}
-					goto found
-				}
-				return nil, fmt.Errorf("usb: unknown endpoint %02x", epoint)
-			}
-			return nil, fmt.Errorf("usb: unknown setup %02x", setup)
-		}
-		return nil, fmt.Errorf("usb: unknown interface %02x", iface)
-	}
-	return nil, fmt.Errorf("usb: unknown configuration %02x", conf)
-
-	found:
-
-	// Claim the interface
-	if errno := C.libusb_claim_interface(d.handle, C.int(iface)); errno < 0 {
-		return nil, fmt.Errorf("usb: claim: %s", usbError(errno))
-	}
-
-	// Increment the claim count
-	d.lock.Lock()
-	d.claimed[iface]++
-	d.lock.Unlock() // unlock immediately because the next calls may block
-
-	// Set the configuration
-	if errno := C.libusb_set_configuration(d.handle, C.int(conf)); errno < 0 {
-		return nil, fmt.Errorf("usb: setcfg: %s", usbError(errno))
-	}
-
-	// Choose the alternate
-	/* This doesn't seem to work...
-	if errno := C.libusb_set_interface_alt_setting(d.handle, C.int(iface), C.int(setup)); errno < 0 {
-		return nil, fmt.Errorf("usb: setalt: %s", usbError(errno))
-	}
-	*/
-
-	return end, nil
+
+	return xfer.Wait()
 }