# vim: set fileencoding=utf-8:
#
# GPIO Zero: a library for controlling the Raspberry Pi's GPIO pins
#
# Copyright (c) 2016-2023 Dave Jones <dave@waveform.org.uk>
# Copyright (c) 2020 Fangchen Li <fangchen.li@outlook.com>
# Copyright (c) 2016 Andrew Scheller <github@loowis.durge.org>
#
# SPDX-License-Identifier: BSD-3-Clause
import io
import errno
import struct
from collections import defaultdict
from threading import Lock
from time import monotonic
try:
from spidev import SpiDev
except ImportError:
SpiDev = None
from . import SPI
from .pi import PiFactory, PiPin, SPI_HARDWARE_PINS, spi_port_device
from .spi import SPISoftware
from ..devices import Device
from ..mixins import SharedMixin
from ..output_devices import OutputDevice
from ..exc import DeviceClosed, PinUnknownPi, SPIInvalidClockMode
def get_pi_revision():
revision = None
try:
with io.open('/proc/device-tree/system/linux,revision', 'rb') as f:
revision = hex(struct.unpack('>L', f.read(4))[0])[2:]
except IOError as e:
if e.errno != errno.ENOENT:
raise e
with io.open('/proc/cpuinfo', 'r') as f:
for line in f:
if line.startswith('Revision'):
revision = line.split(':')[1].strip().lower()
if revision is not None:
overvolted = revision.startswith('100')
if overvolted:
revision = revision[-4:]
return int(revision, base=16)
raise PinUnknownPi(
'unable to locate Pi revision in /proc/device-tree or /proc/cpuinfo')
[docs]
class LocalPiFactory(PiFactory):
"""
Extends :class:`~gpiozero.pins.pi.PiFactory`. Abstract base class
representing pins attached locally to a Pi. This forms the base class for
local-only pin interfaces (:class:`~gpiozero.pins.rpigpio.RPiGPIOPin`,
:class:`~gpiozero.pins.lgpio.LGPIOPin`, and
:class:`~gpiozero.pins.native.NativePin`).
"""
pins = {}
_reservations = defaultdict(list)
_res_lock = Lock()
def __init__(self):
super().__init__()
# Override the reservations and pins dict to be this class' attributes.
# This is a bit of a dirty hack, but ensures that anyone evil enough to
# mix pin implementations doesn't try and control the same pin with
# different backends
self.pins = LocalPiFactory.pins
self._reservations = LocalPiFactory._reservations
self._res_lock = LocalPiFactory._res_lock
def _get_revision(self):
return get_pi_revision()
def _get_spi_class(self, shared, hardware):
return {
(False, True): LocalPiHardwareSPI,
(True, True): LocalPiHardwareSPIShared,
(False, False): LocalPiSoftwareSPI,
(True, False): LocalPiSoftwareSPIShared,
}[shared, hardware]
[docs]
@staticmethod
def ticks():
return monotonic()
[docs]
@staticmethod
def ticks_diff(later, earlier):
return later - earlier
[docs]
class LocalPiPin(PiPin):
"""
Extends :class:`~gpiozero.pins.pi.PiPin`. Abstract base class representing
a multi-function GPIO pin attached to the local Raspberry Pi.
"""
def _call_when_changed(self, ticks=None, state=None):
"""
Overridden to provide default ticks from the local Pi factory.
.. warning::
The local pin factory uses a seconds-based monotonic value for
its ticks but you *must not* rely upon this behaviour. Ticks are
an opaque value that should only be compared with the associated
:meth:`Factory.ticks_diff` method.
"""
super()._call_when_changed(
self._factory.ticks() if ticks is None else ticks,
self.state if state is None else state)
class LocalPiHardwareSPI(SPI):
def __init__(self, clock_pin, mosi_pin, miso_pin, select_pin, pin_factory):
self._port, self._device = spi_port_device(
clock_pin, mosi_pin, miso_pin, select_pin)
self._bus = None
if SpiDev is None:
raise ImportError('failed to import spidev')
super().__init__(pin_factory=pin_factory)
to_reserve = {clock_pin, select_pin}
if mosi_pin is not None:
to_reserve.add(mosi_pin)
if miso_pin is not None:
to_reserve.add(miso_pin)
self.pin_factory.reserve_pins(self, *to_reserve)
self._bus = SpiDev()
self._bus.open(self._port, self._device)
self._bus.max_speed_hz = 500000
def _conflicts_with(self, other):
if isinstance(other, LocalPiHardwareSPI):
return (
(self._port == other._port) and
(self._device == other._device))
else:
return True
def close(self):
if self._bus is not None:
self._bus.close()
self._bus = None
self.pin_factory.release_all(self)
super().close()
@property
def closed(self):
return self._bus is None
def __repr__(self):
try:
self._check_open()
return 'SPI(port=%d, device=%d)' % (self._port, self._device)
except DeviceClosed:
return 'SPI(closed)'
def transfer(self, data):
"""
Writes data (a list of integer words where each word is assumed to have
:attr:`bits_per_word` bits or less) to the SPI interface, and reads an
equivalent number of words, returning them as a list of integers.
"""
return self._bus.xfer2(data)
def _get_clock_mode(self):
return self._bus.mode
def _set_clock_mode(self, value):
self._bus.mode = value
def _get_lsb_first(self):
return self._bus.lsbfirst
def _set_lsb_first(self, value):
self._bus.lsbfirst = bool(value)
def _get_select_high(self):
return self._bus.cshigh
def _set_select_high(self, value):
self._bus.cshigh = bool(value)
def _get_bits_per_word(self):
return self._bus.bits_per_word
def _set_bits_per_word(self, value):
self._bus.bits_per_word = value
def _get_rate(self):
return self._bus.max_speed_hz
def _set_rate(self, value):
self._bus.max_speed_hz = int(value)
class LocalPiSoftwareSPI(SPISoftware):
pass
class LocalPiHardwareSPIShared(SharedMixin, LocalPiHardwareSPI):
@classmethod
def _shared_key(cls, clock_pin, mosi_pin, miso_pin, select_pin,
pin_factory):
return (clock_pin, select_pin)
class LocalPiSoftwareSPIShared(SharedMixin, LocalPiSoftwareSPI):
@classmethod
def _shared_key(cls, clock_pin, mosi_pin, miso_pin, select_pin,
pin_factory):
return (clock_pin, select_pin)