61 lines
2.7 KiB
Python
61 lines
2.7 KiB
Python
"""Thin binding to the Balsam-167 physical EEPROM reader in the shared C core.
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No address conversion, endian/CRC codec or memory-size inference in this port.
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The caller owns serial scheduling, timeouts, cancellation and dump file storage.
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"""
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import ctypes as ct
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from .native import get_native_protocol, NativeProtocolUnavailable
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class _State(ct.Structure):
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_fields_ = [(name, ct.c_uint32) for name in ("controller", "start", "length", "received")]
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def _api(name, args, result):
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try:
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function = getattr(get_native_protocol().lib, "pcan_abi_periph28335_eeprom_" + name)
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except AttributeError as error:
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raise NativeProtocolUnavailable("Обновите templates/setprotocol.dll: нет API чтения EEPROM 167") from error
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function.argtypes, function.restype = args, result
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return function
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def capacity():
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return int(_api("capacity", [], ct.c_uint32)())
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class Reader:
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def __init__(self, controller, start, length):
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for value in (controller, start, length):
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if type(value) is not int or not 0 <= value <= 0xffffffff:
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raise ValueError("Адрес и длина должны быть неотрицательными целыми числами")
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self._state = _State()
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result = _api("begin", [ct.c_void_p, ct.c_uint32, ct.c_uint32, ct.c_uint32], ct.c_int)(
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ct.byref(self._state), controller, start, length)
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if result:
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raise ValueError("Диапазон вне EEPROM AT25256B: 0…0x7FFF байт; длина должна быть больше нуля")
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@property
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def received(self): return int(self._state.received)
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@property
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def length(self): return int(self._state.length)
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@property
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def start(self): return int(self._state.start)
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def request(self):
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output = ct.create_string_buffer(8)
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size = _api("request", [ct.c_void_p, ct.c_void_p, ct.c_size_t], ct.c_size_t)(
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ct.byref(self._state), output, len(output))
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return output.raw[:size]
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def accept(self, reply):
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output = ct.create_string_buffer(2)
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reply = bytes(reply)
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size = _api("accept", [ct.c_void_p, ct.c_void_p, ct.c_size_t, ct.c_void_p, ct.c_size_t], ct.c_int)(
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ct.byref(self._state), reply, len(reply), output, len(output))
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if size < 0:
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errors = {-3: "Неверная длина ответа EEPROM", -4: "Ошибка CRC ответа EEPROM",
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-5: "Неверный адрес контроллера или команда ответа EEPROM"}
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raise ValueError(errors.get(size, "Ответ EEPROM не соответствует активному чтению"))
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return output.raw[:size]
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