HelenOS sources

batch_control     374 uspace/drv/bus/usb/ehci/ehci_batch.c 	[USB_TRANSFER_CONTROL] = batch_control,
batch_control     382 uspace/drv/bus/usb/ohci/ohci_batch.c 	[USB_TRANSFER_CONTROL] = batch_control,
batch_control     332 uspace/drv/bus/usb/uhci/uhci_batch.c 	[USB_TRANSFER_CONTROL] = batch_control,
HelenOS homepage, sources at GitHub