Isochronous transfer support for USB extension API.

BUG=130190
TEST=none


Review URL: https://chromiumcodereview.appspot.com/10511017

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@140579 0039d316-1c4b-4281-b951-d872f2087c98

2 files changed, 39 insertions, 15 deletions

diff --git a/chrome/browser/usb/usb_device.cc b/chrome/browser/usb/usb_device.cc
index b3ae7ce..519b72e 100644
--- a/chrome/browser/usb/usb_device.cc
+++ b/chrome/browser/usb/usb_device.cc
@@ -113,8 +113,7 @@ void UsbDevice::ControlTransfer(const TransferDirection direction,
   libusb_fill_control_transfer(transfer, handle_, reinterpret_cast<uint8*>(
       buffer->data()), reinterpret_cast<libusb_transfer_cb_fn>(
           &HandleTransferCompletion), this, timeout);
-  AddTransfer(transfer, buffer, callback);
-  libusb_submit_transfer(transfer);
+  SubmitTransfer(transfer, buffer, callback);
 }
 
 void UsbDevice::BulkTransfer(const TransferDirection direction,
@@ -128,8 +127,7 @@ void UsbDevice::BulkTransfer(const TransferDirection direction,
       reinterpret_cast<uint8*>(buffer->data()), length,
       reinterpret_cast<libusb_transfer_cb_fn>(&HandleTransferCompletion), this,
       timeout);
-  AddTransfer(transfer, buffer, callback);
-  libusb_submit_transfer(transfer);
+  SubmitTransfer(transfer, buffer, callback);
 }
 
 void UsbDevice::InterruptTransfer(const TransferDirection direction,
@@ -143,17 +141,35 @@ void UsbDevice::InterruptTransfer(const TransferDirection direction,
       reinterpret_cast<uint8*>(buffer->data()), length,
       reinterpret_cast<libusb_transfer_cb_fn>(&HandleTransferCompletion), this,
       timeout);
-  AddTransfer(transfer, buffer, callback);
-  libusb_submit_transfer(transfer);
+  SubmitTransfer(transfer, buffer, callback);
+}
+
+void UsbDevice::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) {
+  CheckDevice();
+
+  struct libusb_transfer* const transfer = libusb_alloc_transfer(packets);
+  const uint8 new_endpoint = ConvertTransferDirection(direction) | endpoint;
+  libusb_fill_iso_transfer(transfer, handle_, new_endpoint,
+      reinterpret_cast<uint8*>(buffer->data()), length, packets,
+      reinterpret_cast<libusb_transfer_cb_fn>(&HandleTransferCompletion), this,
+      timeout);
+  libusb_set_iso_packet_lengths(transfer, packet_length);
+
+  SubmitTransfer(transfer, buffer, callback);
 }
 
 void UsbDevice::CheckDevice() {
   DCHECK(handle_) << "Device is already closed.";
 }
 
-void UsbDevice::AddTransfer(PlatformUsbTransferHandle handle,
-                            net::IOBuffer* buffer,
-                            const net::CompletionCallback& callback) {
+void UsbDevice::SubmitTransfer(PlatformUsbTransferHandle handle,
+                               net::IOBuffer* buffer,
+                               const net::CompletionCallback& callback) {
+  libusb_submit_transfer(handle);
+
   Transfer transfer;
   transfer.buffer = buffer;
   transfer.callback = callback;
diff --git a/chrome/browser/usb/usb_device.h b/chrome/browser/usb/usb_device.h
index 6ac4030..7343966 100644
--- a/chrome/browser/usb/usb_device.h
+++ b/chrome/browser/usb/usb_device.h
@@ -68,6 +68,15 @@ class UsbDevice : public base::RefCounted<UsbDevice> {
                          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
@@ -89,12 +98,11 @@ class UsbDevice : public base::RefCounted<UsbDevice> {
   // Checks that the device has not yet been closed.
   void CheckDevice();
 
-  // Starts tracking the USB transfer associated with a platform transfer
-  // handle. Retains the buffer and copies the completion callback until the
-  // transfer finishes, whereupon it invokes the callback then releases the
-  // buffer.
-  void AddTransfer(PlatformUsbTransferHandle handle, net::IOBuffer* buffer,
-                   const net::CompletionCallback& callback);
+  // 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