# Copyright (C) 2010-2021 Vincent Pelletier # # This library is free software; you can redistribute it and/or # modify it under the terms of the GNU Lesser General Public # License as published by the Free Software Foundation; either # version 2.1 of the License, or (at your option) any later version. # # This library is distributed in the hope that it will be useful, # but WITHOUT ANY WARRANTY; without even the implied warranty of # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU # Lesser General Public License for more details. # # You should have received a copy of the GNU Lesser General Public # License along with this library; if not, write to the Free Software # Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA # pylint: disable=invalid-name, too-many-locals, too-many-arguments # pylint: disable=too-many-public-methods, too-many-instance-attributes # pylint: disable=missing-docstring """ Pythonic wrapper for libusb-1.0. The first thing you must do is to get an "USB context". To do so, create an USBContext instance. Then, you can use it to browse available USB devices and open the one you want to talk to. At this point, you should have a USBDeviceHandle instance (as returned by USBContext or USBDevice instances), and you can start exchanging with the device. Features: - Basic device settings (configuration & interface selection, ...) - String descriptor lookups (ASCII & unicode), and list supported language codes - Synchronous I/O (control, bulk, interrupt) - Asynchronous I/O (control, bulk, interrupt, isochronous) Note: Isochronous support is not well tested. See USBPoller, USBTransfer and USBTransferHelper. All LIBUSB_* constants are available in this module, without the LIBUSB_ prefix - with one exception: LIBUSB_5GBPS_OPERATION is available as SUPER_SPEED_OPERATION, so it is a valid python identifier. All LIBUSB_ERROR_* constants are available in this module as exception classes, subclassing USBError. """ import collections import contextlib from ctypes import byref, c_int, sizeof, POINTER, \ cast, c_uint8, c_uint16, c_ubyte, c_void_p, cdll, addressof, \ c_char from ctypes.util import find_library import functools import inspect import sys import threading import warnings import weakref from . import _libusb1 as libusb1 from ._version import get_versions __version__ = get_versions()['version'] del get_versions # pylint: disable=wrong-import-order,ungrouped-imports if sys.platform == 'win32': from ctypes import get_last_error as get_errno else: from ctypes import get_errno # pylint: enable=wrong-import-order,ungrouped-imports __all__ = [ 'USBContext', 'USBDeviceHandle', 'USBDevice', 'hasCapability', 'USBPoller', 'USBTransfer', 'USBTransferHelper', 'EVENT_CALLBACK_SET', 'USBEndpoint', 'USBInterfaceSetting', 'USBInterface', 'USBConfiguration', 'DoomedTransferError', 'getVersion', 'USBError', 'loadLibrary', ] # Bind libusb1 constants and libusb1.USBError to this module, so user does not # have to import two modules. USBError = libusb1.USBError STATUS_TO_EXCEPTION_DICT = {} def __bindConstants(): global_dict = globals() PREFIX = 'LIBUSB_' for name, value in libusb1.__dict__.items(): if name.startswith(PREFIX): name = name[len(PREFIX):] # Gah. if name == '5GBPS_OPERATION': name = 'SUPER_SPEED_OPERATION' assert name not in global_dict global_dict[name] = value __all__.append(name) # Finer-grained exceptions. for name, value in libusb1.libusb_error.forward_dict.items(): if value: assert name.startswith(PREFIX + 'ERROR_'), name if name == 'LIBUSB_ERROR_IO': name = 'ErrorIO' else: name = ''.join(x.capitalize() for x in name.split('_')[1:]) name = 'USB' + name assert name not in global_dict, name assert value not in STATUS_TO_EXCEPTION_DICT STATUS_TO_EXCEPTION_DICT[value] = global_dict[name] = type( name, (USBError, ), {'value': value}, ) __all__.append(name) __bindConstants() del __bindConstants def raiseUSBError( value, # Avoid globals lookup on call to work during interpreter shutdown. __STATUS_TO_EXCEPTION_DICT=STATUS_TO_EXCEPTION_DICT, __USBError=USBError, ): # pylint: disable=dangerous-default-value raise __STATUS_TO_EXCEPTION_DICT.get(value, __USBError)(value) def mayRaiseUSBError( value, # Avoid globals lookup on call to work during interpreter shutdown. __raiseUSBError=raiseUSBError, ): if value < 0: __raiseUSBError(value) return value Version = collections.namedtuple( 'Version', ['major', 'minor', 'micro', 'nano', 'rc', 'describe'], ) # pylint: disable=undefined-variable CONTROL_SETUP = b'\x00' * CONTROL_SETUP_SIZE # pylint: enable=undefined-variable # Default string length # From a comment in libusb-1.0: "Some devices choke on size > 255" STRING_LENGTH = 255 # As of v3 of USB specs, there cannot be more than 7 hubs from controller to # device. PATH_MAX_DEPTH = 7 EVENT_CALLBACK_SET = frozenset(( # pylint: disable=undefined-variable TRANSFER_COMPLETED, TRANSFER_ERROR, TRANSFER_TIMED_OUT, TRANSFER_CANCELLED, TRANSFER_STALL, TRANSFER_NO_DEVICE, TRANSFER_OVERFLOW, # pylint: enable=undefined-variable )) DEFAULT_ASYNC_TRANSFER_ERROR_CALLBACK = lambda x: False def create_binary_buffer(init_or_size): """ ctypes.create_string_buffer variant which does not add a trailing null when init_or_size is not a size. """ # As per ctypes.create_string_buffer: # - int is a length # - bytes is an initialiser if isinstance(init_or_size, int): init_or_size = bytearray(init_or_size) return create_initialised_buffer(init_or_size) def create_initialised_buffer(init): # raises if init is an integer - this is intentional string_type = c_char * len(init) try: # zero-copy if init is a writable buffer return string_type.from_buffer(init), init # cpython (3.5, 3.9) raises TypeError, pypy 5.4.1 raises ValueError except (TypeError, ValueError): # create our own writable buffer init = bytearray(init) return string_type.from_buffer(init), init class DoomedTransferError(Exception): """Exception raised when altering/submitting a doomed transfer.""" class USBTransfer: """ USB asynchronous transfer control & data. All modification methods will raise if called on a submitted transfer. Methods noted as "should not be called on a submitted transfer" will not prevent you from reading, but returned value is unspecified. Note on user_data: because of pypy's current ctype restrictions, user_data is not provided to C level, but is managed purely in python. It should change nothing for you, unless you are looking at underlying C transfer structure - which you should never have to. """ __transfer = None __initialized = False __submitted_dict = {} __callback = None # Just to silence pylint watnings, this attribute gets overridden after # class definition. __ctypesCallbackWrapper = None __doomed = False __user_data = None __transfer_buffer = None __transfer_py_buffer = None def __init__( self, context, handle, iso_packets, before_submit, after_completion, registerFinalizer, unregisterFinalizer, ): """ You should not instanciate this class directly. Call "getTransfer" method on an USBDeviceHandle instance to get instances of this class. """ if iso_packets < 0: raise ValueError( 'Cannot request a negative number of iso packets.' ) self.__handle = handle self.__before_submit = before_submit self.__after_completion = after_completion self.__num_iso_packets = iso_packets transfer = libusb1.libusb_alloc_transfer(iso_packets) if not transfer: # pylint: disable=undefined-variable raise USBErrorNoMem # pylint: enable=undefined-variable self.__transfer = transfer finalizer_handle = id(self) self.__close = weakref.finalize( self, self.__close, # Note: class method transfer=transfer, context=context, unregisterFinalizer=functools.partial( unregisterFinalizer, handle=finalizer_handle, ), libusb_free_transfer=libusb1.libusb_free_transfer, libusb_cancel_transfer=libusb1.libusb_cancel_transfer, ) registerFinalizer(finalizer_handle, self.__close) def close(self): """ Break reference cycles to allow instance to be garbage-collected. Raises if called on a submitted transfer. """ if self.isSubmitted(): raise ValueError('Cannot close a submitted transfer') self.doom() self.__initialized = False # Break possible external reference cycles self.__callback = None self.__user_data = None # For some reason, overwriting callback is not enough to remove this # reference cycle - though sometimes it works: # self -> self.__dict__ -> libusb_transfer -> dict[x] -> dict[x] -> # CThunkObject -> __callbackWrapper -> self # So free transfer altogether. self.__close() self.__transfer = None self.__transfer_buffer = None # Break USBDeviceHandle reference cycle self.__before_submit = None self.__after_completion = None @classmethod def __close( # pylint: disable=method-hidden cls, transfer, context, unregisterFinalizer, libusb_free_transfer, libusb_cancel_transfer, # pylint: disable=undefined-variable USBErrorInterrupted_=USBErrorInterrupted, # pylint: enable=undefined-variable ): isSubmitted = cls.__isSubmitted # Unlikely to be true if we are triggered by object destruction # (cls.__submitted_dict is precisely here to prevent collection of # submitted transfers). # And if we are called by the user, then they should have the ability # to cancel the transfer cleanly before closing it. if isSubmitted(transfer): libusb_cancel_transfer(transfer) while isSubmitted(transfer): try: context.handleEvents() except USBErrorInterrupted_: pass libusb_free_transfer(transfer) unregisterFinalizer() def doom(self): """ Prevent transfer from being submitted again. """ self.__doomed = True @classmethod def __callbackWrapper(cls, transfer_p): """ Makes it possible for user-provided callback to alter transfer when fired (ie, mark transfer as not submitted upon call). """ # pylint: disable=protected-access self = cls.__submitted_dict.pop(addressof(transfer_p.contents)) self.__after_completion(self) callback = self.__callback if callback is not None: callback(self) if self.__doomed: self.close() # pylint: enable=protected-access def setCallback(self, callback): """ Change transfer's callback. """ self.__callback = callback def getCallback(self): """ Get currently set callback. """ return self.__callback def setControl( self, request_type, request, value, index, buffer_or_len, callback=None, user_data=None, timeout=0): """ Setup transfer for control use. request_type, request, value, index See USBDeviceHandle.controlWrite. request_type defines transfer direction (see ENDPOINT_OUT and ENDPOINT_IN)). buffer_or_len Either bytes (when sending data), or expected data length (when receiving data). callback Callback function to be invoked on transfer completion. Called with transfer as parameter, return value ignored. user_data User data to pass to callback function. timeout Transfer timeout in milliseconds. 0 to disable. """ if self.isSubmitted(): raise ValueError('Cannot alter a submitted transfer') if self.__doomed: raise DoomedTransferError('Cannot reuse a doomed transfer') if isinstance(buffer_or_len, int): length = buffer_or_len # pylint: disable=undefined-variable string_buffer, transfer_py_buffer = create_binary_buffer( length + CONTROL_SETUP_SIZE, ) # pylint: enable=undefined-variable else: length = len(buffer_or_len) string_buffer, transfer_py_buffer = create_binary_buffer( CONTROL_SETUP + buffer_or_len, ) self.__initialized = False self.__transfer_buffer = string_buffer # pylint: disable=undefined-variable self.__transfer_py_buffer = memoryview( transfer_py_buffer, )[CONTROL_SETUP_SIZE:] # pylint: enable=undefined-variable self.__user_data = user_data libusb1.libusb_fill_control_setup( string_buffer, request_type, request, value, index, length) libusb1.libusb_fill_control_transfer( self.__transfer, self.__handle, string_buffer, self.__ctypesCallbackWrapper, None, timeout) self.__callback = callback self.__initialized = True def setBulk( self, endpoint, buffer_or_len, callback=None, user_data=None, timeout=0): """ Setup transfer for bulk use. endpoint Endpoint to submit transfer to. Defines transfer direction (see ENDPOINT_OUT and ENDPOINT_IN)). buffer_or_len Either bytes (when sending data), or expected data length (when receiving data) To avoid memory copies, use an object implementing the writeable buffer interface (ex: bytearray). callback Callback function to be invoked on transfer completion. Called with transfer as parameter, return value ignored. user_data User data to pass to callback function. timeout Transfer timeout in milliseconds. 0 to disable. """ if self.isSubmitted(): raise ValueError('Cannot alter a submitted transfer') if self.__doomed: raise DoomedTransferError('Cannot reuse a doomed transfer') string_buffer, self.__transfer_py_buffer = create_binary_buffer( buffer_or_len ) self.__initialized = False self.__transfer_buffer = string_buffer self.__user_data = user_data libusb1.libusb_fill_bulk_transfer( self.__transfer, self.__handle, endpoint, string_buffer, sizeof(string_buffer), self.__ctypesCallbackWrapper, None, timeout) self.__callback = callback self.__initialized = True def setInterrupt( self, endpoint, buffer_or_len, callback=None, user_data=None, timeout=0): """ Setup transfer for interrupt use. endpoint Endpoint to submit transfer to. Defines transfer direction (see ENDPOINT_OUT and ENDPOINT_IN)). buffer_or_len Either bytes (when sending data), or expected data length (when receiving data) To avoid memory copies, use an object implementing the writeable buffer interface (ex: bytearray). callback Callback function to be invoked on transfer completion. Called with transfer as parameter, return value ignored. user_data User data to pass to callback function. timeout Transfer timeout in milliseconds. 0 to disable. """ if self.isSubmitted(): raise ValueError('Cannot alter a submitted transfer') if self.__doomed: raise DoomedTransferError('Cannot reuse a doomed transfer') string_buffer, self.__transfer_py_buffer = create_binary_buffer( buffer_or_len ) self.__initialized = False self.__transfer_buffer = string_buffer self.__user_data = user_data libusb1.libusb_fill_interrupt_transfer( self.__transfer, self.__handle, endpoint, string_buffer, sizeof(string_buffer), self.__ctypesCallbackWrapper, None, timeout) self.__callback = callback self.__initialized = True def setIsochronous( self, endpoint, buffer_or_len, callback=None, user_data=None, timeout=0, iso_transfer_length_list=None): """ Setup transfer for isochronous use. endpoint Endpoint to submit transfer to. Defines transfer direction (see ENDPOINT_OUT and ENDPOINT_IN)). buffer_or_len Either bytes (when sending data), or expected data length (when receiving data) To avoid memory copies, use an object implementing the writeable buffer interface (ex: bytearray). callback Callback function to be invoked on transfer completion. Called with transfer as parameter, return value ignored. user_data User data to pass to callback function. timeout Transfer timeout in milliseconds. 0 to disable. iso_transfer_length_list List of individual transfer sizes. If not provided, buffer_or_len will be divided evenly among available transfers if possible, and raise ValueError otherwise. """ if self.isSubmitted(): raise ValueError('Cannot alter a submitted transfer') num_iso_packets = self.__num_iso_packets if num_iso_packets == 0: raise TypeError( 'This transfer canot be used for isochronous I/O. ' 'You must get another one with a non-zero iso_packets ' 'parameter.' ) if self.__doomed: raise DoomedTransferError('Cannot reuse a doomed transfer') string_buffer, transfer_py_buffer = create_binary_buffer(buffer_or_len) buffer_length = sizeof(string_buffer) if iso_transfer_length_list is None: iso_length, remainder = divmod(buffer_length, num_iso_packets) if remainder: raise ValueError( 'Buffer size %i cannot be evenly distributed among %i ' 'transfers' % ( buffer_length, num_iso_packets, ) ) iso_transfer_length_list = [iso_length] * num_iso_packets configured_iso_packets = len(iso_transfer_length_list) if configured_iso_packets > num_iso_packets: raise ValueError( 'Too many ISO transfer lengths (%i), there are ' 'only %i ISO transfers available' % ( configured_iso_packets, num_iso_packets, ) ) if sum(iso_transfer_length_list) > buffer_length: raise ValueError( 'ISO transfers too long (%i), there are only ' '%i bytes available' % ( sum(iso_transfer_length_list), buffer_length, ) ) transfer_p = self.__transfer self.__initialized = False self.__transfer_buffer = string_buffer self.__transfer_py_buffer = transfer_py_buffer self.__user_data = user_data libusb1.libusb_fill_iso_transfer( transfer_p, self.__handle, endpoint, string_buffer, buffer_length, configured_iso_packets, self.__ctypesCallbackWrapper, None, timeout) for length, iso_packet_desc in zip( iso_transfer_length_list, libusb1.get_iso_packet_list(transfer_p)): if length <= 0: raise ValueError( 'Negative/null length transfers are not possible.' ) iso_packet_desc.length = length self.__callback = callback self.__initialized = True def getType(self): """ Get transfer type. Returns one of: TRANSFER_TYPE_CONTROL TRANSFER_TYPE_ISOCHRONOUS TRANSFER_TYPE_BULK TRANSFER_TYPE_INTERRUPT """ return self.__transfer.contents.type def getEndpoint(self): """ Get endpoint. """ return self.__transfer.contents.endpoint def getStatus(self): """ Get transfer status. Should not be called on a submitted transfer. """ return self.__transfer.contents.status def getActualLength(self): """ Get actually transfered data length. Should not be called on a submitted transfer. """ return self.__transfer.contents.actual_length def getBuffer(self): """ Get data buffer content. Should not be called on a submitted transfer. """ return self.__transfer_py_buffer def getUserData(self): """ Retrieve user data provided on setup. """ return self.__user_data def setUserData(self, user_data): """ Change user data. """ self.__user_data = user_data def getISOBufferList(self): """ Get individual ISO transfer's buffer. Returns a list with one item per ISO transfer, with their individually-configured sizes. Returned list is consistent with getISOSetupList return value. Should not be called on a submitted transfer. See also iterISO. """ transfer_p = self.__transfer transfer = transfer_p.contents # pylint: disable=undefined-variable if transfer.type != TRANSFER_TYPE_ISOCHRONOUS: # pylint: enable=undefined-variable raise TypeError( 'This method cannot be called on non-iso transfers.' ) return libusb1.get_iso_packet_buffer_list(transfer_p) def getISOSetupList(self): """ Get individual ISO transfer's setup. Returns a list of dicts, each containing an individual ISO transfer parameters: - length - actual_length - status (see libusb1's API documentation for their signification) Returned list is consistent with getISOBufferList return value. Should not be called on a submitted transfer (except for 'length' values). """ transfer_p = self.__transfer transfer = transfer_p.contents # pylint: disable=undefined-variable if transfer.type != TRANSFER_TYPE_ISOCHRONOUS: # pylint: enable=undefined-variable raise TypeError( 'This method cannot be called on non-iso transfers.' ) return [ { 'length': x.length, 'actual_length': x.actual_length, 'status': x.status, } for x in libusb1.get_iso_packet_list(transfer_p) ] def iterISO(self): """ Generator yielding (status, buffer) for each isochornous transfer. buffer is truncated to actual_length. This is more efficient than calling both getISOBufferList and getISOSetupList when receiving data. Should not be called on a submitted transfer. """ transfer_p = self.__transfer transfer = transfer_p.contents # pylint: disable=undefined-variable if transfer.type != TRANSFER_TYPE_ISOCHRONOUS: # pylint: enable=undefined-variable raise TypeError( 'This method cannot be called on non-iso transfers.' ) buffer_position = transfer.buffer for iso_transfer in libusb1.get_iso_packet_list(transfer_p): yield ( iso_transfer.status, libusb1.buffer_at(buffer_position, iso_transfer.actual_length), ) buffer_position += iso_transfer.length def setBuffer(self, buffer_or_len): """ Replace buffer with a new one. Allows resizing read buffer and replacing data sent. Note: resizing is not allowed for isochronous buffer (use setIsochronous). Note: disallowed on control transfers (use setControl). """ if self.isSubmitted(): raise ValueError('Cannot alter a submitted transfer') transfer = self.__transfer.contents # pylint: disable=undefined-variable if transfer.type == TRANSFER_TYPE_CONTROL: # pylint: enable=undefined-variable raise ValueError( 'To alter control transfer buffer, use setControl' ) buff, transfer_py_buffer = create_binary_buffer(buffer_or_len) # pylint: disable=undefined-variable if transfer.type == TRANSFER_TYPE_ISOCHRONOUS and \ sizeof(buff) != transfer.length: # pylint: enable=undefined-variable raise ValueError( 'To alter isochronous transfer buffer length, use ' 'setIsochronous' ) self.__transfer_buffer = buff self.__transfer_py_buffer = transfer_py_buffer transfer.buffer = cast(buff, c_void_p) transfer.length = sizeof(buff) def isSubmitted(self): """ Tells if this transfer is submitted and still pending. """ transfer = self.__transfer return transfer is not None and self.__isSubmitted(transfer) @classmethod def __isSubmitted(cls, transfer): return addressof(transfer.contents) in cls.__submitted_dict def submit(self): """ Submit transfer for asynchronous handling. """ if self.isSubmitted(): raise ValueError('Cannot submit a submitted transfer') if not self.__initialized: raise ValueError( 'Cannot submit a transfer until it has been initialized' ) if self.__doomed: raise DoomedTransferError('Cannot submit doomed transfer') self.__before_submit(self) transfer = self.__transfer assert transfer is not None self.__submitted_dict[addressof(transfer.contents)] = self result = libusb1.libusb_submit_transfer(transfer) if result: self.__after_completion(self) self.__submitted_dict.pop(addressof(transfer.contents)) raiseUSBError(result) def cancel(self): """ Cancel transfer. Note: cancellation happens asynchronously, so you must wait for TRANSFER_CANCELLED. """ if not self.isSubmitted(): # XXX: Workaround for a bug reported on libusb 1.0.8: calling # libusb_cancel_transfer on a non-submitted transfer might # trigger a segfault. raise USBErrorNotFound # pylint: disable=undefined-variable mayRaiseUSBError(libusb1.libusb_cancel_transfer(self.__transfer)) # XXX: This is very unsightly, but I do not see another way of declaring within # class body both the class method and its ctypes function pointer. # pylint: disable=protected-access,no-member USBTransfer._USBTransfer__ctypesCallbackWrapper = libusb1.libusb_transfer_cb_fn_p( USBTransfer._USBTransfer__callbackWrapper, ) # pylint: enable=protected-access,no-member class USBTransferHelper: """ Simplifies subscribing to the same transfer over and over, and callback handling: - no need to read event status to execute apropriate code, just setup different functions for each status code - just return True instead of calling submit - no need to check if transfer is doomed before submitting it again, DoomedTransferError is caught. Callbacks used in this class must follow the callback API described in USBTransfer, and are expected to return a boolean: - True if transfer is to be submitted again (to receive/send more data) - False otherwise Note: as per libusb1 specifications, isochronous transfer global state might be TRANSFER_COMPLETED although some individual packets might have an error status. You can check individual packet status by calling getISOSetupList on transfer object in your callback. """ def __init__(self, transfer=None): """ Create a transfer callback dispatcher. transfer parameter is deprecated. If provided, it will be equivalent to: helper = USBTransferHelper() transfer.setCallback(helper) and also allows using deprecated methods on this class (otherwise, they raise AttributeError). """ if transfer is not None: # Deprecated: to drop self.__transfer = transfer transfer.setCallback(self) self.__event_callback_dict = {} self.__errorCallback = DEFAULT_ASYNC_TRANSFER_ERROR_CALLBACK def submit(self): """ Submit the asynchronous read request. Deprecated. Use submit on transfer. """ # Deprecated: to drop self.__transfer.submit() def cancel(self): """ Cancel a pending read request. Deprecated. Use cancel on transfer. """ # Deprecated: to drop self.__transfer.cancel() def setEventCallback(self, event, callback): """ Set a function to call for a given event. event must be one of: TRANSFER_COMPLETED TRANSFER_ERROR TRANSFER_TIMED_OUT TRANSFER_CANCELLED TRANSFER_STALL TRANSFER_NO_DEVICE TRANSFER_OVERFLOW """ if event not in EVENT_CALLBACK_SET: raise ValueError('Unknown event %r.' % (event, )) self.__event_callback_dict[event] = callback def setDefaultCallback(self, callback): """ Set the function to call for event which don't have a specific callback registered. The initial default callback does nothing and returns False. """ self.__errorCallback = callback def getEventCallback(self, event, default=None): """ Return the function registered to be called for given event identifier. """ return self.__event_callback_dict.get(event, default) def __call__(self, transfer): """ Callback to set on transfers. """ if self.getEventCallback(transfer.getStatus(), self.__errorCallback)( transfer): try: transfer.submit() except DoomedTransferError: pass def isSubmited(self): """ Returns whether this reader is currently waiting for an event. Deprecatd. Use isSubmitted on transfer. """ # Deprecated: to drop return self.__transfer.isSubmitted() class USBPoller: """ Class allowing integration of USB event polling in a file-descriptor monitoring event loop. WARNING: Do not call "poll" from several threads concurently. Do not use synchronous USB transfers in a thread while "poll" is running. Doing so will result in unnecessarily long pauses in some threads. Opening and/or closing devices while polling can cause race conditions to occur. """ def __init__(self, context, poller): """ Create a poller for given context. Warning: it will not check if another poller instance was already present for that context, and will replace it. poller is a polling instance implementing the following methods: - register(fd, event_flags) event_flags have the same meaning as in poll API (POLLIN & POLLOUT) - unregister(fd) - poll(timeout) timeout being a float in seconds, or negative/None if there is no timeout. It must return a list of (descriptor, event) pairs. Note: USBPoller is itself a valid poller. Note2: select.poll uses a timeout in milliseconds, for some reason (all other select.* classes use seconds for timeout), so you should wrap it to convert & round/truncate timeout. """ self.__context = context self.__poller = poller self.__fd_set = set() context.setPollFDNotifiers(self._registerFD, self._unregisterFD) for fd, events in context.getPollFDList(): self._registerFD(fd, events) def __del__(self): self.__context.setPollFDNotifiers(None, None) def poll(self, timeout=None): """ Poll for events. timeout can be a float in seconds, or None for no timeout. Returns a list of (descriptor, event) pairs. """ next_usb_timeout = self.__context.getNextTimeout() if timeout is None or timeout < 0: usb_timeout = next_usb_timeout elif next_usb_timeout: usb_timeout = min(next_usb_timeout, timeout) else: usb_timeout = timeout event_list = self.__poller.poll(usb_timeout) if event_list: fd_set = self.__fd_set result = [(x, y) for x, y in event_list if x not in fd_set] if len(result) != len(event_list): self.__context.handleEventsTimeout() else: result = event_list self.__context.handleEventsTimeout() return result def register(self, fd, events): """ Register an USB-unrelated fd to poller. Convenience method. """ if fd in self.__fd_set: raise ValueError( 'This fd is a special USB event fd, it cannot be polled.' ) self.__poller.register(fd, events) def unregister(self, fd): """ Unregister an USB-unrelated fd from poller. Convenience method. """ if fd in self.__fd_set: raise ValueError( 'This fd is a special USB event fd, it must stay registered.' ) self.__poller.unregister(fd) # pylint: disable=unused-argument def _registerFD(self, fd, events, user_data=None): self.register(fd, events) self.__fd_set.add(fd) # pylint: enable=unused-argument # pylint: disable=unused-argument def _unregisterFD(self, fd, user_data=None): self.__fd_set.discard(fd) self.unregister(fd) # pylint: enable=unused-argument class _ReleaseInterface: def __init__(self, handle, interface): self._handle = handle self._interface = interface def __enter__(self): # USBDeviceHandle.claimInterface already claimed the interface. pass def __exit__(self, exc_type, exc_val, exc_tb): self._handle.releaseInterface(self._interface) class USBDeviceHandle: """ Represents an opened USB device. """ __handle = None def __init__( self, context, handle, device, registerFinalizer, unregisterFinalizer, ): """ You should not instanciate this class directly. Call "open" method on an USBDevice instance to get an USBDeviceHandle instance. """ self.__context = context self.__finalizer_dict = {} # Strong references to inflight transfers so they do not get freed # even if user drops all strong references to them. If this instance # is garbage-collected, we close all transfers, so it's fine. self.__inflight = inflight = set() # XXX: For some reason, doing self.__inflight.{add|remove} inside # getTransfer causes extra intermediate python objects for each # allocated transfer. Storing them as properties solves this. Found # with objgraph. self.__inflight_add = inflight.add self.__inflight_remove = inflight.remove self.__handle = handle self.__device = device finalizer_handle = id(self) self.close = weakref.finalize( self, self.close, # Note: static method context=context, handle=handle, inflight=inflight, finalizer_dict=self.__finalizer_dict, unregisterFinalizer=functools.partial( unregisterFinalizer, handle=finalizer_handle, ), libusb_close=libusb1.libusb_close, ) registerFinalizer(finalizer_handle, self.close) def __registerFinalizer(self, handle, finalizer): if handle in self.__finalizer_dict: finalizer.detach() raise ValueError self.__finalizer_dict[handle] = finalizer def __unregisterFinalizer(self, handle): self.__finalizer_dict.pop(handle) @staticmethod def close( # pylint: disable=method-hidden context, handle, inflight, finalizer_dict, unregisterFinalizer, libusb_close, set_=set, # pylint: disable=undefined-variable USBErrorNotFound_=USBErrorNotFound, USBErrorNoDevice_=USBErrorNoDevice, USBErrorInterrupted_=USBErrorInterrupted, # pylint: enable=undefined-variable ): """ Close this handle. If not called explicitely, will be called by destructor. This method cancels any in-flight transfer when it is called. As cancellation is not immediate, this method needs to let libusb handle events until transfers are actually cancelled. In multi-threaded programs, this can lead to stalls. To avoid this, do not close nor let GC collect a USBDeviceHandle which has in-flight transfers. """ cancelled_set = set_() while inflight: for transfer in tuple(inflight): if transfer not in cancelled_set: try: transfer.cancel() except (USBErrorNotFound_, USBErrorNoDevice_): pass cancelled_set.add(transfer) try: context.handleEvents() except USBErrorInterrupted_: pass while finalizer_dict: for finalizer_handle, finalizer in list(finalizer_dict.items()): finalizer() assert finalizer_handle not in finalizer_dict libusb_close(handle) unregisterFinalizer() def getDevice(self): """ Get an USBDevice instance for the device accessed through this handle, to access to the descriptors available in OS cache. """ return self.__device def getConfiguration(self): """ Get the current configuration number for this device. """ configuration = c_int() mayRaiseUSBError(libusb1.libusb_get_configuration( self.__handle, byref(configuration), )) return configuration.value def setConfiguration(self, configuration): """ Set the configuration number for this device. """ mayRaiseUSBError( libusb1.libusb_set_configuration(self.__handle, configuration), ) def getManufacturer(self): """ Get device's manufaturer name. """ return self.getASCIIStringDescriptor( self.__device.device_descriptor.iManufacturer, ) def getProduct(self): """ Get device's product name. """ return self.getASCIIStringDescriptor( self.__device.device_descriptor.iProduct, ) def getSerialNumber(self): """ Get device's serial number. """ return self.getASCIIStringDescriptor( self.__device.device_descriptor.iSerialNumber, ) def claimInterface(self, interface): """ Claim (= get exclusive access to) given interface number. Required to receive/send data. Can be used as a context manager: with handle.claimInterface(0): # do stuff # handle.releaseInterface(0) gets automatically called """ mayRaiseUSBError( libusb1.libusb_claim_interface(self.__handle, interface), ) return _ReleaseInterface(self, interface) def releaseInterface(self, interface): """ Release interface, allowing another process to use it. """ mayRaiseUSBError( libusb1.libusb_release_interface(self.__handle, interface), ) def setInterfaceAltSetting(self, interface, alt_setting): """ Set interface's alternative setting (both parameters are integers). """ mayRaiseUSBError(libusb1.libusb_set_interface_alt_setting( self.__handle, interface, alt_setting, )) def clearHalt(self, endpoint): """ Clear a halt state on given endpoint number. """ mayRaiseUSBError(libusb1.libusb_clear_halt(self.__handle, endpoint)) def resetDevice(self): """ Reinitialise current device. Attempts to restore current configuration & alt settings. If this fails, will result in a device disconnect & reconnect, so you have to close current device and rediscover it (notified by an USBErrorNotFound exception). """ mayRaiseUSBError(libusb1.libusb_reset_device(self.__handle)) def kernelDriverActive(self, interface): """ Tell whether a kernel driver is active on given interface number. """ result = libusb1.libusb_kernel_driver_active(self.__handle, interface) if result == 0: return False if result == 1: return True raiseUSBError(result) return None # unreachable, to make pylint happy def detachKernelDriver(self, interface): """ Ask kernel driver to detach from given interface number. """ mayRaiseUSBError( libusb1.libusb_detach_kernel_driver(self.__handle, interface), ) def attachKernelDriver(self, interface): """ Ask kernel driver to re-attach to given interface number. """ mayRaiseUSBError( libusb1.libusb_attach_kernel_driver(self.__handle, interface), ) def setAutoDetachKernelDriver(self, enable): """ Control automatic kernel driver detach. enable (bool) True to enable auto-detach, False to disable it. """ mayRaiseUSBError(libusb1.libusb_set_auto_detach_kernel_driver( self.__handle, bool(enable), )) def getSupportedLanguageList(self): """ Return a list of USB language identifiers (as integers) supported by current device for its string descriptors. Note: language identifiers seem (I didn't check them all...) very similar to windows language identifiers, so you may want to use locales.windows_locale to get an rfc3066 representation. The 5 standard HID language codes are missing though. """ descriptor_string, _ = create_binary_buffer(STRING_LENGTH) result = libusb1.libusb_get_string_descriptor( self.__handle, 0, 0, descriptor_string, sizeof(descriptor_string), ) # pylint: disable=undefined-variable if result == ERROR_PIPE: # pylint: enable=undefined-variable # From libusb_control_transfer doc: # control request not supported by the device return [] mayRaiseUSBError(result) langid_list = cast(descriptor_string, POINTER(c_uint16)) return [ libusb1.libusb_le16_to_cpu(langid_list[offset]) for offset in range(1, cast(descriptor_string, POINTER(c_ubyte))[0] // 2) ] def getStringDescriptor(self, descriptor, lang_id, errors='strict'): """ Fetch description string for given descriptor and in given language. Use getSupportedLanguageList to know which languages are available. Return value is a unicode string. Return None if there is no such descriptor on device. """ if descriptor == 0: return None descriptor_string = bytearray(STRING_LENGTH) try: received = mayRaiseUSBError(libusb1.libusb_get_string_descriptor( self.__handle, descriptor, lang_id, create_binary_buffer(descriptor_string)[0], STRING_LENGTH, )) # pylint: disable=undefined-variable except USBErrorNotFound: # pylint: enable=undefined-variable return None # pylint: disable=undefined-variable if received < 2 or descriptor_string[1] != DT_STRING: # pylint: enable=undefined-variable raise ValueError('Invalid string descriptor') return descriptor_string[2:min( received, descriptor_string[0], )].decode('UTF-16-LE', errors=errors) def getASCIIStringDescriptor(self, descriptor, errors='strict'): """ Fetch description string for given descriptor in first available language. Return value is a unicode string. Return None if there is no such descriptor on device. """ if descriptor == 0: return None descriptor_string = bytearray(STRING_LENGTH) try: received = mayRaiseUSBError(libusb1.libusb_get_string_descriptor_ascii( self.__handle, descriptor, create_binary_buffer(descriptor_string)[0], STRING_LENGTH, )) # pylint: disable=undefined-variable except USBErrorNotFound: # pylint: enable=undefined-variable return None return descriptor_string[:received].decode('ASCII', errors=errors) # Sync I/O def _controlTransfer( self, request_type, request, value, index, data, length, timeout): result = libusb1.libusb_control_transfer( self.__handle, request_type, request, value, index, data, length, timeout, ) mayRaiseUSBError(result) return result def controlWrite( self, request_type, request, value, index, data, timeout=0): """ Synchronous control write. request_type: request type bitmask (bmRequestType), see constants TYPE_* and RECIPIENT_*. request: request id (some values are standard). value, index, data: meaning is request-dependent. timeout: in milliseconds, how long to wait for device acknowledgement. Set to 0 to disable. To avoid memory copies, use an object implementing the writeable buffer interface (ex: bytearray) for the "data" parameter. Returns the number of bytes actually sent. """ # pylint: disable=undefined-variable request_type = (request_type & ~ENDPOINT_DIR_MASK) | ENDPOINT_OUT # pylint: enable=undefined-variable data, _ = create_initialised_buffer(data) return self._controlTransfer(request_type, request, value, index, data, sizeof(data), timeout) def controlRead( self, request_type, request, value, index, length, timeout=0): """ Synchronous control read. timeout: in milliseconds, how long to wait for data. Set to 0 to disable. See controlWrite for other parameters description. To avoid memory copies, use an object implementing the writeable buffer interface (ex: bytearray) for the "data" parameter. Returns received data. """ # pylint: disable=undefined-variable request_type = (request_type & ~ENDPOINT_DIR_MASK) | ENDPOINT_IN # pylint: enable=undefined-variable data, data_buffer = create_binary_buffer(length) transferred = self._controlTransfer( request_type, request, value, index, data, length, timeout, ) return data_buffer[:transferred] def _bulkTransfer(self, endpoint, data, length, timeout): transferred = c_int() try: mayRaiseUSBError(libusb1.libusb_bulk_transfer( self.__handle, endpoint, data, length, byref(transferred), timeout, )) # pylint: disable=undefined-variable except USBErrorTimeout as exception: # pylint: enable=undefined-variable exception.transferred = transferred.value raise return transferred.value def bulkWrite(self, endpoint, data, timeout=0): """ Synchronous bulk write. endpoint: endpoint to send data to. data: data to send. timeout: in milliseconds, how long to wait for device acknowledgement. Set to 0 to disable. To avoid memory copies, use an object implementing the writeable buffer interface (ex: bytearray) for the "data" parameter. Returns the number of bytes actually sent. May raise an exception from the USBError family. USBErrorTimeout exception has a "transferred" property giving the number of bytes sent up to the timeout. """ # pylint: disable=undefined-variable endpoint = (endpoint & ~ENDPOINT_DIR_MASK) | ENDPOINT_OUT # pylint: enable=undefined-variable data, _ = create_initialised_buffer(data) return self._bulkTransfer(endpoint, data, sizeof(data), timeout) def bulkRead(self, endpoint, length, timeout=0): """ Synchronous bulk read. timeout: in milliseconds, how long to wait for data. Set to 0 to disable. See bulkWrite for other parameters description. To avoid memory copies, use an object implementing the writeable buffer interface (ex: bytearray) for the "data" parameter. Returns received data. May raise an exception from the USBError family. USBErrorTimeout exception has a "received" property giving the bytes received up to the timeout. """ # pylint: disable=undefined-variable endpoint = (endpoint & ~ENDPOINT_DIR_MASK) | ENDPOINT_IN # pylint: enable=undefined-variable data, data_buffer = create_binary_buffer(length) try: transferred = self._bulkTransfer(endpoint, data, length, timeout) # pylint: disable=undefined-variable except USBErrorTimeout as exception: # pylint: enable=undefined-variable exception.received = data_buffer[:exception.transferred] raise return data_buffer[:transferred] def _interruptTransfer(self, endpoint, data, length, timeout): transferred = c_int() try: mayRaiseUSBError(libusb1.libusb_interrupt_transfer( self.__handle, endpoint, data, length, byref(transferred), timeout, )) # pylint: disable=undefined-variable except USBErrorTimeout as exception: # pylint: enable=undefined-variable exception.transferred = transferred.value raise return transferred.value def interruptWrite(self, endpoint, data, timeout=0): """ Synchronous interrupt write. endpoint: endpoint to send data to. data: data to send. timeout: in milliseconds, how long to wait for device acknowledgement. Set to 0 to disable. To avoid memory copies, use an object implementing the writeable buffer interface (ex: bytearray) for the "data" parameter. Returns the number of bytes actually sent. May raise an exception from the USBError family. USBErrorTimeout exception has a "transferred" property giving the number of bytes sent up to the timeout. """ # pylint: disable=undefined-variable endpoint = (endpoint & ~ENDPOINT_DIR_MASK) | ENDPOINT_OUT # pylint: enable=undefined-variable data, _ = create_initialised_buffer(data) return self._interruptTransfer(endpoint, data, sizeof(data), timeout) def interruptRead(self, endpoint, length, timeout=0): """ Synchronous interrupt write. timeout: in milliseconds, how long to wait for data. Set to 0 to disable. See interruptWrite for other parameters description. To avoid memory copies, use an object implementing the writeable buffer interface (ex: bytearray) for the "data" parameter. Returns received data. May raise an exception from the USBError family. USBErrorTimeout exception has a "received" property giving the bytes received up to the timeout. """ # pylint: disable=undefined-variable endpoint = (endpoint & ~ENDPOINT_DIR_MASK) | ENDPOINT_IN # pylint: enable=undefined-variable data, data_buffer = create_binary_buffer(length) try: transferred = self._interruptTransfer( endpoint, data, length, timeout, ) # pylint: disable=undefined-variable except USBErrorTimeout as exception: # pylint: enable=undefined-variable exception.received = data_buffer[:exception.transferred] raise return data_buffer[:transferred] def getTransfer(self, iso_packets=0): """ Get an USBTransfer instance for asynchronous use. iso_packets: the number of isochronous transfer descriptors to allocate. """ return USBTransfer( context=self.__context, handle=self.__handle, iso_packets=iso_packets, before_submit=self.__inflight_add, after_completion=self.__inflight_remove, registerFinalizer=self.__registerFinalizer, unregisterFinalizer=self.__unregisterFinalizer, ) class USBConfiguration: def __init__(self, context, config, device_speed): """ You should not instanciate this class directly. Call USBDevice methods to get instances of this class. """ if not isinstance(config, libusb1.libusb_config_descriptor): raise TypeError('Unexpected descriptor type.') self.__config = config self.__context = context self.__device_speed = device_speed def getNumInterfaces(self): return self.__config.bNumInterfaces __len__ = getNumInterfaces def getConfigurationValue(self): return self.__config.bConfigurationValue def getDescriptor(self): return self.__config.iConfiguration def getAttributes(self): return self.__config.bmAttributes def getMaxPower(self): """ Returns device's power consumption in mA. USB descriptor is expressed in units of 2 mA when the device is operating in high-speed mode and in units of 8 mA when the device is operating in super-speed mode. This function scales the descriptor value appropriately. """ # pylint: disable=undefined-variable return self.__config.MaxPower * (8 if self.__device_speed == SPEED_SUPER else 2) # pylint: enable=undefined-variable def getExtra(self): """ Returns a list of extra (non-basic) descriptors (DFU, HID, ...). """ return libusb1.get_extra(self.__config) def __iter__(self): """ Iterates over interfaces available in this configuration, yielding USBInterface instances. """ context = self.__context interface_list = self.__config.interface for interface_num in range(self.getNumInterfaces()): yield USBInterface(context, interface_list[interface_num]) # BBB iterInterfaces = __iter__ def __getitem__(self, interface): """ Returns an USBInterface instance. """ if not isinstance(interface, int): raise TypeError('interface parameter must be an integer') if not 0 <= interface < self.getNumInterfaces(): raise IndexError('No such interface: %r' % (interface, )) return USBInterface(self.__context, self.__config.interface[interface]) class USBInterface: def __init__(self, context, interface): """ You should not instanciate this class directly. Call USBConfiguration methods to get instances of this class. """ if not isinstance(interface, libusb1.libusb_interface): raise TypeError('Unexpected descriptor type.') self.__interface = interface self.__context = context def getNumSettings(self): return self.__interface.num_altsetting __len__ = getNumSettings def __iter__(self): """ Iterates over settings in this insterface, yielding USBInterfaceSetting instances. """ context = self.__context alt_setting_list = self.__interface.altsetting for alt_setting_num in range(self.getNumSettings()): yield USBInterfaceSetting( context, alt_setting_list[alt_setting_num]) # BBB iterSettings = __iter__ def __getitem__(self, alt_setting): """ Returns an USBInterfaceSetting instance. """ if not isinstance(alt_setting, int): raise TypeError('alt_setting parameter must be an integer') if not 0 <= alt_setting < self.getNumSettings(): raise IndexError('No such setting: %r' % (alt_setting, )) return USBInterfaceSetting( self.__context, self.__interface.altsetting[alt_setting]) class USBInterfaceSetting: def __init__(self, context, alt_setting): """ You should not instanciate this class directly. Call USBDevice or USBInterface methods to get instances of this class. """ if not isinstance(alt_setting, libusb1.libusb_interface_descriptor): raise TypeError('Unexpected descriptor type.') self.__alt_setting = alt_setting self.__context = context def getNumber(self): return self.__alt_setting.bInterfaceNumber def getAlternateSetting(self): return self.__alt_setting.bAlternateSetting def getNumEndpoints(self): return self.__alt_setting.bNumEndpoints __len__ = getNumEndpoints def getClass(self): return self.__alt_setting.bInterfaceClass def getSubClass(self): return self.__alt_setting.bInterfaceSubClass def getClassTuple(self): """ For convenience: class and subclass are probably often matched simultaneously. """ alt_setting = self.__alt_setting return (alt_setting.bInterfaceClass, alt_setting.bInterfaceSubClass) # BBB getClassTupple = getClassTuple def getProtocol(self): return self.__alt_setting.bInterfaceProtocol def getDescriptor(self): return self.__alt_setting.iInterface def getExtra(self): return libusb1.get_extra(self.__alt_setting) def __iter__(self): """ Iterates over endpoints in this interface setting , yielding USBEndpoint instances. """ context = self.__context endpoint_list = self.__alt_setting.endpoint for endpoint_num in range(self.getNumEndpoints()): yield USBEndpoint(context, endpoint_list[endpoint_num]) # BBB iterEndpoints = __iter__ def __getitem__(self, endpoint): """ Returns an USBEndpoint instance. """ if not isinstance(endpoint, int): raise TypeError('endpoint parameter must be an integer') if not 0 <= endpoint < self.getNumEndpoints(): raise ValueError('No such endpoint: %r' % (endpoint, )) return USBEndpoint( self.__context, self.__alt_setting.endpoint[endpoint]) class USBEndpoint: def __init__(self, context, endpoint): if not isinstance(endpoint, libusb1.libusb_endpoint_descriptor): raise TypeError('Unexpected descriptor type.') self.__endpoint = endpoint self.__context = context def getAddress(self): return self.__endpoint.bEndpointAddress def getAttributes(self): return self.__endpoint.bmAttributes def getMaxPacketSize(self): return self.__endpoint.wMaxPacketSize def getInterval(self): return self.__endpoint.bInterval def getRefresh(self): return self.__endpoint.bRefresh def getSyncAddress(self): return self.__endpoint.bSynchAddress def getExtra(self): return libusb1.get_extra(self.__endpoint) class USBDevice: """ Represents a USB device. Exposes USB descriptors which are available from OS without needing to get a USBDeviceHandle: device descriptor, configuration descriptors, interface descriptors, setting descritptors, endpoint descriptors. """ __configuration_descriptor_list = () def __init__( self, context, device_p, registerFinalizer, unregisterFinalizer, can_load_configuration, ): """ You should not instanciate this class directly. Call USBContext methods to receive instances of this class. """ self.__context = context self.__finalizer_dict = finalizer_dict = {} self.__configuration_descriptor_list = descriptor_list = [] libusb1.libusb_ref_device(device_p) finalizer_handle = id(self) self.close = weakref.finalize( self, self.close, # Note: static method device_p=device_p, finalizer_dict=finalizer_dict, unregisterFinalizer=functools.partial( unregisterFinalizer, handle=finalizer_handle, ), descriptor_list=descriptor_list, libusb_unref_device=libusb1.libusb_unref_device, libusb_free_config_descriptor=libusb1.libusb_free_config_descriptor, ) registerFinalizer(finalizer_handle, self.close) self.device_p = device_p # Fetch device descriptor # Note: if this is made lazy, access errors will happen later, breaking # getDeviceIterator exception handling. device_descriptor = libusb1.libusb_device_descriptor() result = libusb1.libusb_get_device_descriptor( device_p, byref(device_descriptor)) mayRaiseUSBError(result) self.device_descriptor = device_descriptor if can_load_configuration: append = descriptor_list.append for configuration_id in range( self.device_descriptor.bNumConfigurations): config = libusb1.libusb_config_descriptor_p() result = libusb1.libusb_get_config_descriptor( device_p, configuration_id, byref(config)) # pylint: disable=undefined-variable if result == ERROR_NOT_FOUND: # pylint: enable=undefined-variable # Some devices (ex windows' root hubs) tell they have # one configuration, but they have no configuration # descriptor. continue mayRaiseUSBError(result) append(config.contents) self.__bus_number = libusb1.libusb_get_bus_number(device_p) self.__port_number = libusb1.libusb_get_port_number(device_p) self.__device_address = libusb1.libusb_get_device_address(device_p) def __registerFinalizer(self, handle, finalizer): if handle in self.__finalizer_dict: finalizer.detach() raise ValueError self.__finalizer_dict[handle] = finalizer def __unregisterFinalizer(self, handle): self.__finalizer_dict.pop(handle) @staticmethod def close( # pylint: disable=method-hidden device_p, finalizer_dict, unregisterFinalizer, descriptor_list, libusb_unref_device, libusb_free_config_descriptor, byref_=byref, ): while finalizer_dict: for handle, finalizer in list(finalizer_dict.items()): finalizer() assert handle not in finalizer_dict libusb_unref_device(device_p) while descriptor_list: libusb_free_config_descriptor( byref_(descriptor_list.pop()), ) unregisterFinalizer() def __str__(self): return 'Bus %03i Device %03i: ID %04x:%04x' % ( self.getBusNumber(), self.getDeviceAddress(), self.getVendorID(), self.getProductID(), ) def __len__(self): return len(self.__configuration_descriptor_list) def __getitem__(self, index): return USBConfiguration( self.__context, self.__configuration_descriptor_list[index], self.getDeviceSpeed()) def __key(self): return ( id(self.__context), self.__bus_number, self.__device_address, self.device_descriptor.idVendor, self.device_descriptor.idProduct, ) def __hash__(self): return hash(self.__key()) def __eq__(self, other): # pylint: disable=unidiomatic-typecheck return type(self) == type(other) and ( # pylint: enable=unidiomatic-typecheck self.device_p == other.device_p or # pylint: disable=protected-access self.__key() == other.__key() # pylint: enable=protected-access ) def iterConfigurations(self): context = self.__context for config in self.__configuration_descriptor_list: yield USBConfiguration(context, config, self.getDeviceSpeed()) # BBB iterConfiguations = iterConfigurations def iterSettings(self): for config in self.iterConfigurations(): for interface in config: for setting in interface: yield setting def getBusNumber(self): """ Get device's bus number. """ return self.__bus_number def getPortNumber(self): """ Get device's port number. """ return self.__port_number def getPortNumberList(self): """ Get the port number of each hub toward device. """ port_list = (c_uint8 * PATH_MAX_DEPTH)() result = libusb1.libusb_get_port_numbers( self.device_p, port_list, len(port_list)) mayRaiseUSBError(result) return list(port_list[:result]) # TODO: wrap libusb_get_parent when/if libusb removes the need to be inside # a libusb_(get|free)_device_list block. def getDeviceAddress(self): """ Get device's address on its bus. """ return self.__device_address def getbcdUSB(self): """ Get the USB spec version device complies to, in BCD format. """ return self.device_descriptor.bcdUSB def getDeviceClass(self): """ Get device's class id. """ return self.device_descriptor.bDeviceClass def getDeviceSubClass(self): """ Get device's subclass id. """ return self.device_descriptor.bDeviceSubClass def getDeviceProtocol(self): """ Get device's protocol id. """ return self.device_descriptor.bDeviceProtocol def getMaxPacketSize0(self): """ Get device's max packet size for endpoint 0 (control). """ return self.device_descriptor.bMaxPacketSize0 def getMaxPacketSize(self, endpoint): """ Get device's max packet size for given endpoint. Warning: this function will not always give you the expected result. See https://libusb.org/ticket/77 . You should instead consult the endpoint descriptor of current configuration and alternate setting. """ result = libusb1.libusb_get_max_packet_size(self.device_p, endpoint) mayRaiseUSBError(result) return result def getMaxISOPacketSize(self, endpoint): """ Get the maximum size for a single isochronous packet for given endpoint. Warning: this function will not always give you the expected result. See https://libusb.org/ticket/77 . You should instead consult the endpoint descriptor of current configuration and alternate setting. """ result = libusb1.libusb_get_max_iso_packet_size(self.device_p, endpoint) mayRaiseUSBError(result) return result def getVendorID(self): """ Get device's vendor id. """ return self.device_descriptor.idVendor def getProductID(self): """ Get device's product id. """ return self.device_descriptor.idProduct def getbcdDevice(self): """ Get device's release number. """ return self.device_descriptor.bcdDevice def getSupportedLanguageList(self): """ Get the list of language ids device has string descriptors for. Note: opens the device temporarily and uses synchronous API. """ return self.open().getSupportedLanguageList() def getManufacturer(self): """ Get device's manufaturer name. Shortcut for .open().getManufacturer() . """ return self.open().getManufacturer() def getManufacturerDescriptor(self): """ Get the string index of device's manufacturer. You can pass this value to USBHandle.getASCIIStringDescriptor to get the actual manufacturer string. """ return self.device_descriptor.iManufacturer def getProduct(self): """ Get device's product name. Shortcut for .open().getProduct() . """ return self.open().getProduct() def getProductDescriptor(self): """ Get the string index of device's product name. You can pass this value to USBHandle.getASCIIStringDescriptor to get the actual product name string. """ return self.device_descriptor.iProduct def getSerialNumber(self): """ Get device's serial number. Shortcut for .open().getSerialNumber() . """ return self.open().getSerialNumber() def getSerialNumberDescriptor(self): """ Get the string index of device's serial number. You can pass this value to USBHandle.getASCIIStringDescriptor to get the actual serial number string. """ return self.device_descriptor.iSerialNumber def getNumConfigurations(self): """ Get device's number of possible configurations. """ return self.device_descriptor.bNumConfigurations def getDeviceSpeed(self): """ Get device's speed. Returns one of: SPEED_UNKNOWN SPEED_LOW SPEED_FULL SPEED_HIGH SPEED_SUPER SPEED_SUPER_PLUS """ return libusb1.libusb_get_device_speed(self.device_p) def open(self): """ Open device. Returns an USBDeviceHandle instance. """ handle = libusb1.libusb_device_handle_p() mayRaiseUSBError(libusb1.libusb_open(self.device_p, byref(handle))) return USBDeviceHandle( context=self.__context, handle=handle, device=self, registerFinalizer=self.__registerFinalizer, unregisterFinalizer=self.__unregisterFinalizer, ) _zero_tv = libusb1.timeval(0, 0) _zero_tv_p = byref(_zero_tv) _null_pointer = c_void_p() class USBContext: """ libusb1 USB context. Provides methods to enumerate & look up USB devices. Also provides access to global (device-independent) libusb1 functions. """ __context_p = None __added_cb = None __removed_cb = None __poll_cb_user_data = None __auto_open = True __has_pollfd_finalizer = False __mayRaiseUSBError = staticmethod(mayRaiseUSBError) __libusb_handle_events = None # pylint: disable=no-self-argument,protected-access def _validContext(func): # Defined inside USBContext so we can access "self.__*". @contextlib.contextmanager def refcount(self): with self.__context_cond: if not self.__context_p and self.__auto_open: # BBB warnings.warn( 'Use "with USBContext() as context:" for safer cleanup' ' on interpreter shutdown. See also USBContext.open().', DeprecationWarning, ) self.open() self.__context_refcount += 1 try: yield finally: with self.__context_cond: self.__context_refcount -= 1 if not self.__context_refcount: self.__context_cond.notify_all() if inspect.isgeneratorfunction(func): def wrapper(self, *args, **kw): with refcount(self): if self.__context_p: # pylint: disable=not-callable generator = func(self, *args, **kw) # pylint: enable=not-callable try: for value in generator: yield value finally: generator.close() else: def wrapper(self, *args, **kw): with refcount(self): if self.__context_p: # pylint: disable=not-callable return func(self, *args, **kw) # pylint: enable=not-callable return None functools.update_wrapper(wrapper, func) return wrapper # pylint: enable=no-self-argument,protected-access def __init__(self): """ Create a new USB context. """ # Used to prevent an exit to cause a segfault if a concurrent thread # is still in libusb. self.__context_refcount = 0 self.__context_cond = threading.Condition() self.__context_p = libusb1.libusb_context_p() assert not self.__context_p self.__hotplug_callback_dict = {} self.__finalizer_dict = {} def __enter__(self): return self.open() def __exit__(self, exc_type, exc_val, exc_tb): self.close() def __registerFinalizer(self, handle, finalizer): if handle in self.__finalizer_dict: finalizer.detach() raise ValueError self.__finalizer_dict[handle] = finalizer def __unregisterFinalizer(self, handle): self.__finalizer_dict.pop(handle) def open(self): """ Finish context initialisation, as is normally done in __enter__ . This happens automatically on the first method call needing access to the uninitialised properties, but with a warning. Call this method ONLY if your usage pattern prevents you from using the with USBContext() as contewt: form: this means there are ways to avoid calling close(), which can cause issues particularly hard to debug (ex: interpreter hangs on exit). Calls loadLibrary. """ assert self.__context_refcount == 0 assert not self.__context_p loadLibrary() self.__libusb_handle_events = libusb1.libusb_handle_events mayRaiseUSBError(libusb1.libusb_init(byref(self.__context_p))) self.__close = weakref.finalize( self, self.___close, # Note: static method context_p=self.__context_p, hotplug_callback_dict=self.__hotplug_callback_dict, finalizer_dict=self.__finalizer_dict, libusb_exit=libusb1.libusb_exit, libusb_hotplug_deregister_callback=libusb1.libusb_hotplug_deregister_callback, ) return self def close(self): """ Close (destroy) this USB context, and all related instances. When this method has been called, methods on its instance will become mosty no-ops, returning None until explicitly re-opened (by calling open() or __enter__()). Note: "exit" is a deprecated alias of "close". """ self.__auto_open = False self.__context_cond.acquire() try: while self.__context_refcount and self.__context_p: self.__context_cond.wait() self.__close() self.__added_cb = None self.__removed_cb = None self.__poll_cb_user_data = None finally: self.__context_cond.notify_all() self.__context_cond.release() # BBB exit = close @staticmethod def __close(): # pylint: disable=method-hidden # Placeholder, masked on open() pass @staticmethod def ___close( # pylint: disable=method-hidden context_p, hotplug_callback_dict, finalizer_dict, libusb_exit, libusb_hotplug_deregister_callback, ): while hotplug_callback_dict: # Duplicates hotplugDeregisterCallback logic, to avoid finalizer # referencing its own instance. handle, _ = hotplug_callback_dict.popitem() libusb_hotplug_deregister_callback(context_p, handle) while finalizer_dict: for handle, finalizer in list(finalizer_dict.items()): finalizer() assert handle not in finalizer_dict libusb_exit(context_p) context_p.value = None @_validContext def getDeviceIterator(self, skip_on_error=False): """ Return an iterator over all USB devices currently plugged in, as USBDevice instances. skip_on_error (bool) If True, ignore devices which raise USBError. """ libusb_free_device_list = libusb1.libusb_free_device_list device_p_p = libusb1.libusb_device_p_p() libusb_device_p = libusb1.libusb_device_p device_list_len = libusb1.libusb_get_device_list(self.__context_p, byref(device_p_p)) mayRaiseUSBError(device_list_len) try: for device_p in device_p_p[:device_list_len]: try: device = USBDevice( context=self, device_p=device_p, registerFinalizer=self.__registerFinalizer, unregisterFinalizer=self.__unregisterFinalizer, can_load_configuration=True, ) except USBError: if not skip_on_error: raise else: yield device finally: libusb_free_device_list(device_p_p, 1) def getDeviceList(self, skip_on_access_error=False, skip_on_error=False): """ Return a list of all USB devices currently plugged in, as USBDevice instances. skip_on_error (bool) If True, ignore devices which raise USBError. skip_on_access_error (bool) DEPRECATED. Alias for skip_on_error. """ return list( self.getDeviceIterator( skip_on_error=skip_on_access_error or skip_on_error, ), ) def getByVendorIDAndProductID( self, vendor_id, product_id, skip_on_access_error=False, skip_on_error=False): """ Get the first USB device matching given vendor and product ids. Returns an USBDevice instance, or None if no present device match. skip_on_error (bool) (see getDeviceList) skip_on_access_error (bool) (see getDeviceList) """ device_iterator = self.getDeviceIterator( skip_on_error=skip_on_access_error or skip_on_error, ) try: for device in device_iterator: if device.getVendorID() == vendor_id and \ device.getProductID() == product_id: return device device.close() finally: device_iterator.close() return None def openByVendorIDAndProductID( self, vendor_id, product_id, skip_on_access_error=False, skip_on_error=False): """ Get the first USB device matching given vendor and product ids. Returns an USBDeviceHandle instance, or None if no present device match. skip_on_error (bool) (see getDeviceList) skip_on_access_error (bool) (see getDeviceList) """ result = self.getByVendorIDAndProductID( vendor_id, product_id, skip_on_access_error=skip_on_access_error, skip_on_error=skip_on_error) if result is not None: return result.open() return None @_validContext def getPollFDList(self): """ Return file descriptors to be used to poll USB events. You should not have to call this method, unless you are integrating this class with a polling mechanism. """ pollfd_p_p = libusb1.libusb_get_pollfds(self.__context_p) if not pollfd_p_p: errno = get_errno() if errno: raise OSError(errno) # Assume not implemented raise NotImplementedError( 'Your libusb does not seem to implement pollable FDs') try: result = [] append = result.append fd_index = 0 while pollfd_p_p[fd_index]: append(( pollfd_p_p[fd_index].contents.fd, pollfd_p_p[fd_index].contents.events, )) fd_index += 1 finally: libusb1.libusb_free_pollfds(pollfd_p_p) return result @_validContext def handleEvents(self): """ Handle any pending event (blocking). See libusb1 documentation for details (there is a timeout, so it's not "really" blocking). """ self.__mayRaiseUSBError( self.__libusb_handle_events(self.__context_p), ) # TODO: handleEventsCompleted @_validContext def handleEventsTimeout(self, tv=0): """ Handle any pending event. If tv is 0, will return immediately after handling already-pending events. Otherwise, defines the maximum amount of time to wait for events, in seconds. """ if tv is None: tv = 0 tv_s = int(tv) real_tv = libusb1.timeval(tv_s, int((tv - tv_s) * 1000000)) mayRaiseUSBError( libusb1.libusb_handle_events_timeout( self.__context_p, byref(real_tv), ), ) # TODO: handleEventsTimeoutCompleted @_validContext def setPollFDNotifiers( self, added_cb=None, removed_cb=None, user_data=None): """ Give libusb1 methods to call when it should add/remove file descriptor for polling. You should not have to call this method, unless you are integrating this class with a polling mechanism. """ if added_cb is None: added_cb = _null_pointer else: added_cb = libusb1.libusb_pollfd_added_cb_p(added_cb) if removed_cb is None: removed_cb = _null_pointer else: removed_cb = libusb1.libusb_pollfd_removed_cb_p(removed_cb) if user_data is None: user_data = _null_pointer self.__added_cb = added_cb self.__removed_cb = removed_cb self.__poll_cb_user_data = user_data libusb1.libusb_set_pollfd_notifiers( self.__context_p, cast(added_cb, libusb1.libusb_pollfd_added_cb_p), cast(removed_cb, libusb1.libusb_pollfd_removed_cb_p), user_data, ) if not self.__has_pollfd_finalizer: self.__has_pollfd_finalizer = True try: self.__registerFinalizer( handle=id(self), finalizer=weakref.finalize( self, self.__finalizePollFDNotifiers, # Note: staticmethod context_p=self.__context_p, libusb_set_pollfd_notifiers=libusb1.libusb_set_pollfd_notifiers, ), ) except ValueError: # Already registered pass @staticmethod def __finalizePollFDNotifiers( context_p, libusb_set_pollfd_notifiers, null_pointer=_null_pointer, added_cb_p=cast(_null_pointer, libusb1.libusb_pollfd_added_cb_p), removed_cb_p=cast(_null_pointer, libusb1.libusb_pollfd_removed_cb_p), ): libusb_set_pollfd_notifiers( context_p, added_cb_p, removed_cb_p, null_pointer, ) @_validContext def getNextTimeout(self): """ Returns the next internal timeout that libusb needs to handle, in seconds, or None if no timeout is needed. You should not have to call this method, unless you are integrating this class with a polling mechanism. """ timeval = libusb1.timeval() result = libusb1.libusb_get_next_timeout( self.__context_p, byref(timeval)) if result == 0: return None if result == 1: return timeval.tv_sec + (timeval.tv_usec * 0.000001) raiseUSBError(result) return None # unreachable, to make pylint happy @_validContext def setDebug(self, level): """ Set debugging level. See LOG_LEVEL_* constants. Note: depending on libusb compilation settings, this might have no effect. """ libusb1.libusb_set_debug(self.__context_p, level) @_validContext def tryLockEvents(self): warnings.warn( 'You may not be able to unlock in the event of USBContext exit. ' 'Consider looping over handleEvents() in a thread.', DeprecationWarning, ) return libusb1.libusb_try_lock_events(self.__context_p) @_validContext def lockEvents(self): warnings.warn( 'You may not be able to unlock in the event of USBContext exit. ' 'Consider looping over handleEvents() in a thread.', DeprecationWarning, ) libusb1.libusb_lock_events(self.__context_p) @_validContext def lockEventWaiters(self): warnings.warn( 'You may not be able to unlock in the event of USBContext exit. ' 'Consider looping over handleEvents() in a thread.', DeprecationWarning, ) libusb1.libusb_lock_event_waiters(self.__context_p) @_validContext def waitForEvent(self, tv=0): warnings.warn( 'Consider looping over handleEvents() in a thread.', DeprecationWarning, ) if tv is None: tv = 0 tv_s = int(tv) real_tv = libusb1.timeval(tv_s, int((tv - tv_s) * 1000000)) libusb1.libusb_wait_for_event(self.__context_p, byref(real_tv)) @_validContext def unlockEventWaiters(self): warnings.warn( 'This method will lock in the event of USBContext exit, ' 'preventing libusb lock release. ' 'Consider looping over handleEvents() in a thread.', DeprecationWarning, ) libusb1.libusb_unlock_event_waiters(self.__context_p) @_validContext def eventHandlingOK(self): warnings.warn( 'Consider looping over handleEvents() in a thread.', DeprecationWarning, ) return libusb1.libusb_event_handling_ok(self.__context_p) @_validContext def unlockEvents(self): warnings.warn( 'This method will lock in the event of USBContext exit, ' 'preventing libusb lock release. ' 'Consider looping over handleEvents() in a thread.', DeprecationWarning, ) libusb1.libusb_unlock_events(self.__context_p) @_validContext def handleEventsLocked(self): warnings.warn( 'Consider looping over handleEvents() in a thread.', DeprecationWarning, ) # XXX: does tv parameter need to be exposed ? mayRaiseUSBError(libusb1.libusb_handle_events_locked( self.__context_p, _zero_tv_p, )) @_validContext def eventHandlerActive(self): warnings.warn( 'Consider looping over handleEvents() in a thread.', DeprecationWarning, ) return libusb1.libusb_event_handler_active(self.__context_p) @staticmethod def hasCapability(capability): """ Backward-compatibility alias for module-level hasCapability. """ return hasCapability(capability) @_validContext def hotplugRegisterCallback( self, callback, # pylint: disable=undefined-variable events=HOTPLUG_EVENT_DEVICE_ARRIVED | HOTPLUG_EVENT_DEVICE_LEFT, flags=HOTPLUG_ENUMERATE, vendor_id=HOTPLUG_MATCH_ANY, product_id=HOTPLUG_MATCH_ANY, dev_class=HOTPLUG_MATCH_ANY, # pylint: enable=undefined-variable ): """ Registers an hotplug callback. On success, returns an opaque value which can be passed to hotplugDeregisterCallback. Callback must accept the following positional arguments: - this USBContext instance - an USBDevice instance If device has left, configuration descriptors may not be available. Its device descriptor will be available. - event type, one of: HOTPLUG_EVENT_DEVICE_ARRIVED HOTPLUG_EVENT_DEVICE_LEFT Callback must return whether it must be unregistered (any true value to be unregistered, any false value to be kept registered). Note: given callback will be invoked during event handling, meaning it cannot call any synchronous libusb function. """ def wrapped_callback(context_p, device_p, event, _): assert context_p == self.__context_p.value, ( context_p, self.__context_p, ) device = USBDevice( context=self, device_p=device_p, registerFinalizer=self.__registerFinalizer, unregisterFinalizer=self.__unregisterFinalizer, # pylint: disable=undefined-variable can_load_configuration=event != HOTPLUG_EVENT_DEVICE_LEFT, # pylint: enable=undefined-variable ) unregister = bool(callback( self, device, event, )) if unregister: del self.__hotplug_callback_dict[handle] return unregister handle = c_int() callback_p = libusb1.libusb_hotplug_callback_fn_p(wrapped_callback) mayRaiseUSBError(libusb1.libusb_hotplug_register_callback( self.__context_p, events, flags, vendor_id, product_id, dev_class, callback_p, None, byref(handle), )) handle = handle.value # Keep strong references assert handle not in self.__hotplug_callback_dict, ( handle, self.__hotplug_callback_dict, ) self.__hotplug_callback_dict[handle] = (callback_p, wrapped_callback) return handle @_validContext def hotplugDeregisterCallback(self, handle): """ Deregisters an hotplug callback. handle (opaque) Return value of a former hotplugRegisterCallback call. """ del self.__hotplug_callback_dict[handle] libusb1.libusb_hotplug_deregister_callback(self.__context_p, handle) del USBContext._validContext def getVersion(): """ Returns underlying libusb's version information as a 6-namedtuple (or 6-tuple if namedtuples are not avaiable): - major - minor - micro - nano - rc - describe Returns (0, 0, 0, 0, '', '') if libusb doesn't have required entry point. Calls loadLibrary. """ loadLibrary() version = libusb1.libusb_get_version().contents return Version( version.major, version.minor, version.micro, version.nano, version.rc, version.describe, ) def hasCapability(capability): """ Tests feature presence. capability should be one of: CAP_HAS_CAPABILITY CAP_HAS_HOTPLUG CAP_HAS_HID_ACCESS CAP_SUPPORTS_DETACH_KERNEL_DRIVER Calls loadLibrary. """ loadLibrary() return libusb1.libusb_has_capability(capability) class LibUSBContext(USBContext): """ Backward-compatibility alias for USBContext. """ def __init__(self): warnings.warn( 'LibUSBContext is being renamed to USBContext', DeprecationWarning, ) super().__init__() loadLibrary = libusb1.loadLibrary