Added isochronous transfer

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
+}