micropython-lib/unix-ffi/pyusb/usb/core.py

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7.8 KiB
Python

# MicroPython USB host library, compatible with PyUSB.
# MIT license; Copyright (c) 2021-2024 Damien P. George
import sys
import ffi
import uctypes
if sys.maxsize >> 32:
UINTPTR_SIZE = 8
UINTPTR = uctypes.UINT64
else:
UINTPTR_SIZE = 4
UINTPTR = uctypes.UINT32
def _align_word(x):
return (x + UINTPTR_SIZE - 1) & ~(UINTPTR_SIZE - 1)
ptr_descriptor = (0 | uctypes.ARRAY, 1 | UINTPTR)
libusb_device_descriptor = {
"bLength": 0 | uctypes.UINT8,
"bDescriptorType": 1 | uctypes.UINT8,
"bcdUSB": 2 | uctypes.UINT16,
"bDeviceClass": 4 | uctypes.UINT8,
"bDeviceSubClass": 5 | uctypes.UINT8,
"bDeviceProtocol": 6 | uctypes.UINT8,
"bMaxPacketSize0": 7 | uctypes.UINT8,
"idVendor": 8 | uctypes.UINT16,
"idProduct": 10 | uctypes.UINT16,
"bcdDevice": 12 | uctypes.UINT16,
"iManufacturer": 14 | uctypes.UINT8,
"iProduct": 15 | uctypes.UINT8,
"iSerialNumber": 16 | uctypes.UINT8,
"bNumConfigurations": 17 | uctypes.UINT8,
}
libusb_config_descriptor = {
"bLength": 0 | uctypes.UINT8,
"bDescriptorType": 1 | uctypes.UINT8,
"wTotalLength": 2 | uctypes.UINT16,
"bNumInterfaces": 4 | uctypes.UINT8,
"bConfigurationValue": 5 | uctypes.UINT8,
"iConfiguration": 6 | uctypes.UINT8,
"bmAttributes": 7 | uctypes.UINT8,
"MaxPower": 8 | uctypes.UINT8,
"interface": _align_word(9) | UINTPTR, # array of libusb_interface
"extra": (_align_word(9) + UINTPTR_SIZE) | UINTPTR,
"extra_length": (_align_word(9) + 2 * UINTPTR_SIZE) | uctypes.INT,
}
libusb_interface = {
"altsetting": 0 | UINTPTR, # array of libusb_interface_descriptor
"num_altsetting": UINTPTR_SIZE | uctypes.INT,
}
libusb_interface_descriptor = {
"bLength": 0 | uctypes.UINT8,
"bDescriptorType": 1 | uctypes.UINT8,
"bInterfaceNumber": 2 | uctypes.UINT8,
"bAlternateSetting": 3 | uctypes.UINT8,
"bNumEndpoints": 4 | uctypes.UINT8,
"bInterfaceClass": 5 | uctypes.UINT8,
"bInterfaceSubClass": 6 | uctypes.UINT8,
"bInterfaceProtocol": 7 | uctypes.UINT8,
"iInterface": 8 | uctypes.UINT8,
"endpoint": _align_word(9) | UINTPTR,
"extra": (_align_word(9) + UINTPTR_SIZE) | UINTPTR,
"extra_length": (_align_word(9) + 2 * UINTPTR_SIZE) | uctypes.INT,
}
libusb = ffi.open("libusb-1.0.so")
libusb_init = libusb.func("i", "libusb_init", "p")
libusb_exit = libusb.func("v", "libusb_exit", "p")
libusb_get_device_list = libusb.func("i", "libusb_get_device_list", "pp") # return is ssize_t
libusb_free_device_list = libusb.func("v", "libusb_free_device_list", "pi")
libusb_get_device_descriptor = libusb.func("i", "libusb_get_device_descriptor", "pp")
libusb_get_config_descriptor = libusb.func("i", "libusb_get_config_descriptor", "pBp")
libusb_free_config_descriptor = libusb.func("v", "libusb_free_config_descriptor", "p")
libusb_open = libusb.func("i", "libusb_open", "pp")
libusb_set_configuration = libusb.func("i", "libusb_set_configuration", "pi")
libusb_claim_interface = libusb.func("i", "libusb_claim_interface", "pi")
libusb_control_transfer = libusb.func("i", "libusb_control_transfer", "pBBHHpHI")
def _new(sdesc):
buf = bytearray(uctypes.sizeof(sdesc))
s = uctypes.struct(uctypes.addressof(buf), sdesc)
return s
class Interface:
def __init__(self, descr):
# Public attributes.
self.bInterfaceClass = descr.bInterfaceClass
self.bInterfaceSubClass = descr.bInterfaceSubClass
self.iInterface = descr.iInterface
self.extra_descriptors = uctypes.bytes_at(descr.extra, descr.extra_length)
class Configuration:
def __init__(self, dev, cfg_idx):
cfgs = _new(ptr_descriptor)
if libusb_get_config_descriptor(dev._dev, cfg_idx, cfgs) != 0:
libusb_exit(0)
raise Exception
descr = uctypes.struct(cfgs[0], libusb_config_descriptor)
# Extract all needed info because descr is going to be free'd at the end.
self._itfs = []
itf_array = uctypes.struct(
descr.interface, (0 | uctypes.ARRAY, descr.bNumInterfaces, libusb_interface)
)
for i in range(descr.bNumInterfaces):
itf = itf_array[i]
alt_array = uctypes.struct(
itf.altsetting,
(0 | uctypes.ARRAY, itf.num_altsetting, libusb_interface_descriptor),
)
for j in range(itf.num_altsetting):
alt = alt_array[j]
self._itfs.append(Interface(alt))
# Public attributes.
self.bNumInterfaces = descr.bNumInterfaces
self.bConfigurationValue = descr.bConfigurationValue
self.bmAttributes = descr.bmAttributes
self.bMaxPower = descr.MaxPower
self.extra_descriptors = uctypes.bytes_at(descr.extra, descr.extra_length)
# Free descr memory in the driver.
libusb_free_config_descriptor(cfgs[0])
def __iter__(self):
return iter(self._itfs)
class Device:
_TIMEOUT_DEFAULT = 1000
def __init__(self, dev, descr):
self._dev = dev
self._num_cfg = descr.bNumConfigurations
self._handle = None
self._claim_itf = set()
# Public attributes.
self.idVendor = descr.idVendor
self.idProduct = descr.idProduct
def __iter__(self):
for i in range(self._num_cfg):
yield Configuration(self, i)
def __getitem__(self, i):
return Configuration(self, i)
def _open(self):
if self._handle is None:
# Open the USB device.
handle = _new(ptr_descriptor)
if libusb_open(self._dev, handle) != 0:
libusb_exit(0)
raise Exception
self._handle = handle[0]
def _claim_interface(self, i):
if libusb_claim_interface(self._handle, i) != 0:
libusb_exit(0)
raise Exception
def set_configuration(self):
# Select default configuration.
self._open()
cfg = Configuration(self, 0).bConfigurationValue
ret = libusb_set_configuration(self._handle, cfg)
if ret != 0:
libusb_exit(0)
raise Exception
def ctrl_transfer(
self, bmRequestType, bRequest, wValue=0, wIndex=0, data_or_wLength=None, timeout=None
):
if data_or_wLength is None:
l = 0
data = bytes()
elif isinstance(data_or_wLength, int):
l = data_or_wLength
data = bytearray(l)
else:
l = len(data_or_wLength)
data = data_or_wLength
self._open()
if wIndex & 0xFF not in self._claim_itf:
self._claim_interface(wIndex & 0xFF)
self._claim_itf.add(wIndex & 0xFF)
if timeout is None:
timeout = self._TIMEOUT_DEFAULT
ret = libusb_control_transfer(
self._handle, bmRequestType, bRequest, wValue, wIndex, data, l, timeout * 1000
)
if ret < 0:
libusb_exit(0)
raise Exception
if isinstance(data_or_wLength, int):
return data
else:
return ret
def find(*, find_all=False, custom_match=None, idVendor=None, idProduct=None):
if libusb_init(0) < 0:
raise Exception
devs = _new(ptr_descriptor)
count = libusb_get_device_list(0, devs)
if count < 0:
libusb_exit(0)
raise Exception
dev_array = uctypes.struct(devs[0], (0 | uctypes.ARRAY, count | UINTPTR))
descr = _new(libusb_device_descriptor)
devices = None
for i in range(count):
libusb_get_device_descriptor(dev_array[i], descr)
if idVendor and descr.idVendor != idVendor:
continue
if idProduct and descr.idProduct != idProduct:
continue
device = Device(dev_array[i], descr)
if custom_match and not custom_match(device):
continue
if not find_all:
return device
if not devices:
devices = []
devices.append(device)
return devices