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// Copyright (c) 2012 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#ifndef CHROME_BROWSER_USB_USB_DEVICE_H_
#define CHROME_BROWSER_USB_USB_DEVICE_H_
#pragma once
#include <map>
#include "base/memory/ref_counted.h"
#include "base/synchronization/lock.h"
#include "net/base/completion_callback.h"
#include "net/base/io_buffer.h"
#include "third_party/libusb/libusb.h"
typedef libusb_device* PlatformUsbDevice;
typedef libusb_device_handle* PlatformUsbDeviceHandle;
typedef libusb_transfer* PlatformUsbTransferHandle;
class UsbService;
namespace net {
class IOBuffer;
} // namespace net
// A UsbDevice wraps the platform's underlying representation of what a USB
// device actually is, and provides accessors for performing many of the
// standard USB operations.
class UsbDevice : public base::RefCounted<UsbDevice> {
public:
enum TransferDirection { INBOUND, OUTBOUND };
enum TransferRequestType { STANDARD, CLASS, VENDOR, RESERVED };
enum TransferRecipient { DEVICE, INTERFACE, ENDPOINT, OTHER };
// Usually you will not want to directly create a UsbDevice, favoring to let
// the UsbService take care of the logistics of getting a platform device
// handle and handling events for it.
UsbDevice(UsbService* service, PlatformUsbDeviceHandle handle);
PlatformUsbDeviceHandle handle() { return handle_; }
// Close the USB device and release the underlying platform device.
void Close();
void ControlTransfer(const TransferDirection direction,
const TransferRequestType request_type,
const TransferRecipient recipient,
const uint8 request,
const uint16 value,
const uint16 index,
net::IOBuffer* buffer,
const size_t length,
const unsigned int timeout,
const net::CompletionCallback& callback);
void BulkTransfer(const TransferDirection direction,
const uint8 endpoint,
net::IOBuffer* buffer,
const size_t length,
const unsigned int timeout,
const net::CompletionCallback& callback);
void InterruptTransfer(const TransferDirection direction,
const uint8 endpoint,
net::IOBuffer* buffer,
const size_t length,
const unsigned int timeout,
const net::CompletionCallback& callback);
void IsochronousTransfer(const TransferDirection direction,
const uint8 endpoint,
net::IOBuffer* buffer,
const size_t length,
const unsigned int packets,
const unsigned int packet_length,
const unsigned int timeout,
const net::CompletionCallback& callback);
// Normal code should not call this function. It is called by the platform's
// callback mechanism in such a way that it cannot be made private. Invokes
// the callbacks associated with a given transfer, and removes it from the
// in-flight transfer set.
void TransferComplete(PlatformUsbTransferHandle transfer);
private:
struct Transfer {
Transfer();
~Transfer();
scoped_refptr<net::IOBuffer> buffer;
net::CompletionCallback callback;
};
friend class base::RefCounted<UsbDevice>;
virtual ~UsbDevice();
// Checks that the device has not yet been closed.
void CheckDevice();
// Submits a transfer and starts tracking it. Retains the buffer and copies
// the completion callback until the transfer finishes, whereupon it invokes
// the callback then releases the buffer.
void SubmitTransfer(PlatformUsbTransferHandle handle, net::IOBuffer* buffer,
const net::CompletionCallback& callback);
// The UsbService isn't referenced here to prevent a dependency cycle between
// the service and the devices. Since a service owns every device, and is
// responsible for its destruction, there is no case where a UsbDevice can
// have outlived its originating UsbService.
UsbService* const service_;
PlatformUsbDeviceHandle handle_;
// transfers_ tracks all in-flight transfers associated with this device,
// allowing the device to retain the buffer and callback associated with a
// transfer until such time that it completes. It is protected by lock_.
base::Lock lock_;
std::map<PlatformUsbTransferHandle, Transfer> transfers_;
DISALLOW_EVIL_CONSTRUCTORS(UsbDevice);
};
#endif // CHROME_BROWSER_USB_USB_DEVICE_H_
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