# GPIO Zero: a library for controlling the Raspberry Pi's GPIO pins
#
# Copyright (c) 2021 Dave Jones <dave@waveform.org.uk>
#
# SPDX-License-Identifier: BSD-3-Clause
from __future__ import (
unicode_literals,
absolute_import,
print_function,
division,
)
str = type('')
import os
import lgpio
from . import SPI
from .pi import spi_port_device
from .local import LocalPiFactory, LocalPiPin
from ..mixins import SharedMixin
from ..exc import (
PinInvalidFunction,
PinSetInput,
PinFixedPull,
PinInvalidPull,
PinInvalidBounce,
PinInvalidState,
SPIBadArgs,
SPIInvalidClockMode,
PinPWMFixedValue,
DeviceClosed
)
[docs]class LGPIOFactory(LocalPiFactory):
"""
Extends :class:`~gpiozero.pins.local.LocalPiFactory`. Uses the `lgpio`_
library to interface to the local computer's GPIO pins. The lgpio library
simply talks to Linux gpiochip devices; it is not specific to the Raspberry
Pi although this class is currently constructed under the assumption that
it is running on a Raspberry Pi.
You can construct lgpio pins manually like so::
from gpiozero.pins.lgpio import LGPIOFactory
from gpiozero import LED
factory = LGPIOFactory(chip=0)
led = LED(12, pin_factory=factory)
The *chip* parameter to the factory constructor specifies which gpiochip
device to attempt to open. It defaults to 0 and thus doesn't normally need
to be specified (the example above only includes it for completeness).
The lgpio library relies on access to the :file:`/dev/gpiochip*` devices.
If you run into issues, please check that your user has read/write access
to the specific gpiochip device you are attempting to open (0 by default).
.. _lgpio: http://abyz.me.uk/lg/py_lgpio.html
"""
def __init__(self, chip=0):
super(LGPIOFactory, self).__init__()
self._handle = lgpio.gpiochip_open(chip)
self._chip = chip
self.pin_class = LGPIOPin
def close(self):
super(LGPIOFactory, self).close()
if self._handle is not None:
lgpio.gpiochip_close(self._handle)
self._handle = None
@property
def chip(self):
return self._chip
def _get_spi_class(self, shared, hardware):
# support via lgpio instead of spidev
if hardware:
return [LGPIOHardwareSPI, LGPIOHardwareSPIShared][shared]
return super(LGPIOFactory, self)._get_spi_class(shared, hardware=False)
[docs]class LGPIOPin(LocalPiPin):
"""
Extends :class:`~gpiozero.pins.local.LocalPiPin`. Pin implementation for
the `lgpio`_ library. See :class:`LGPIOFactory` for more information.
.. _lgpio: http://abyz.me.uk/lg/py_lgpio.html
"""
GPIO_IS_KERNEL = 1 << 0
GPIO_IS_OUT = 1 << 1
GPIO_IS_ACTIVE_LOW = 1 << 2
GPIO_IS_OPEN_DRAIN = 1 << 3
GPIO_IS_OPEN_SOURCE = 1 << 4
GPIO_IS_BIAS_PULL_UP = 1 << 5
GPIO_IS_BIAS_PULL_DOWN = 1 << 6
GPIO_IS_BIAS_DISABLE = 1 << 7
GPIO_IS_LG_INPUT = 1 << 8
GPIO_IS_LG_OUTPUT = 1 << 9
GPIO_IS_LG_ALERT = 1 << 10
GPIO_IS_LG_GROUP = 1 << 11
GPIO_LINE_FLAGS_MASK = (
GPIO_IS_ACTIVE_LOW | GPIO_IS_OPEN_DRAIN | GPIO_IS_OPEN_SOURCE |
GPIO_IS_BIAS_PULL_UP | GPIO_IS_BIAS_PULL_DOWN | GPIO_IS_BIAS_DISABLE)
GPIO_EDGES = {
'both': lgpio.BOTH_EDGES,
'rising': lgpio.RISING_EDGE,
'falling': lgpio.FALLING_EDGE,
}
GPIO_EDGES_NAMES = {v: k for (k, v) in GPIO_EDGES.items()}
def __init__(self, factory, number):
super(LGPIOPin, self).__init__(factory, number)
self._pwm = None
self._bounce = None
self._callback = None
self._edges = lgpio.BOTH_EDGES
lgpio.gpio_claim_input(
self.factory._handle, self.number, lgpio.SET_BIAS_DISABLE)
def close(self):
if self.factory._handle is not None:
# Closing is really just "resetting" the function of the pin;
# we let the factory close deal with actually freeing stuff
lgpio.gpio_claim_input(
self.factory._handle, self.number, lgpio.SET_BIAS_DISABLE)
def _get_function(self):
mode = lgpio.gpio_get_mode(self.factory._handle, self.number)
return ['input', 'output'][bool(mode & self.GPIO_IS_OUT)]
def _set_function(self, value):
if self._callback is not None:
self._callback.cancel()
self._callback = None
try:
{
'input': lgpio.gpio_claim_input,
'output': lgpio.gpio_claim_output,
}[value](self.factory._handle, self.number)
except KeyError:
raise PinInvalidFunction('invalid function "%s" for pin %r' % (value, self))
def _get_state(self):
if self._pwm:
return self._pwm[1] / 100
else:
return bool(lgpio.gpio_read(self.factory._handle, self.number))
def _set_state(self, value):
if self._pwm:
freq, duty = self._pwm
self._pwm = (freq, int(value * 100))
try:
lgpio.tx_pwm(self.factory._handle, self.number, *self._pwm)
except lgpio.error:
raise PinInvalidState('invalid state "%s" for pin %r' % (value, self))
elif self.function == 'input':
raise PinSetInput('cannot set state of pin %r' % self)
else:
lgpio.gpio_write(self.factory._handle, self.number, bool(value))
def _get_pull(self):
mode = lgpio.gpio_get_mode(self.factory._handle, self.number)
if mode & self.GPIO_IS_BIAS_PULL_UP:
return 'up'
elif mode & self.GPIO_IS_BIAS_PULL_DOWN:
return 'down'
else:
return 'floating'
def _set_pull(self, value):
if self.function != 'input':
raise PinFixedPull('cannot set pull on non-input pin %r' % self)
if value != 'up' and self.factory.pi_info.pulled_up(repr(self)):
raise PinFixedPull('%r has a physical pull-up resistor' % self)
try:
flags = {
'up': lgpio.SET_BIAS_PULL_UP,
'down': lgpio.SET_BIAS_PULL_DOWN,
'floating': lgpio.SET_BIAS_DISABLE,
}[value]
except KeyError:
raise PinInvalidPull('invalid pull "%s" for pin %r' % (value, self))
else:
# Simply calling gpio_claim_input is insufficient to change the
# line flags on a pin; it needs to be freed and re-claimed
lgpio.gpio_free(self.factory._handle, self.number)
lgpio.gpio_claim_input(self.factory._handle, self.number, flags)
def _get_frequency(self):
if self._pwm:
freq, duty = self._pwm
return freq
else:
return None
def _set_frequency(self, value):
if not self._pwm and value is not None and value > 0:
if self.function != 'output':
raise PinPWMFixedValue('cannot start PWM on pin %r' % self)
lgpio.tx_pwm(self.factory._handle, self.number, value, 0)
self._pwm = (value, 0)
elif self._pwm and value is not None and value > 0:
freq, duty = self._pwm
lgpio.tx_pwm(self.factory._handle, self.number, value, duty)
self._pwm = (value, duty)
elif self._pwm and (value is None or value == 0):
lgpio.tx_pwm(self.factory._handle, self.number, 0, 0)
self._pwm = None
def _get_bounce(self):
return None if not self._bounce else self._bounce / 1000000
def _set_bounce(self, value):
if value is None:
value = 0
elif value < 0:
raise PinInvalidBounce('bounce must be 0 or greater')
value = int(value * 1000000)
lgpio.gpio_set_debounce_micros(self.factory._handle, self.number, value)
self._bounce = value
def _get_edges(self):
return self.GPIO_EDGES_NAMES[self._edges]
def _set_edges(self, value):
f = self.when_changed
self.when_changed = None
try:
self._edges = self.GPIO_EDGES[value]
finally:
self.when_changed = f
def _call_when_changed(self, chip, gpio, level, ticks):
super(LGPIOPin, self)._call_when_changed(ticks / 1000000000, level)
def _enable_event_detect(self):
lgpio.gpio_claim_alert(
self.factory._handle, self.number, self._edges,
lgpio.gpio_get_mode(self.factory._handle, self.number) &
self.GPIO_LINE_FLAGS_MASK)
self._callback = lgpio.callback(
self.factory._handle, self.number, self._edges,
self._call_when_changed)
def _disable_event_detect(self):
if self._callback is not None:
self._callback.cancel()
self._callback = None
lgpio.gpio_claim_input(
self.factory._handle, self.number,
lgpio.gpio_get_mode(self.factory._handle, self.number) &
self.GPIO_LINE_FLAGS_MASK)
class LGPIOHardwareSPI(SPI):
"""
Hardware SPI implementation for the `lgpio`_ library. Uses the ``spi_*``
functions from the lgpio API.
.. _lgpio: http://abyz.me.uk/lg/py_lgpio.html
"""
def __init__(self, clock_pin, mosi_pin, miso_pin, select_pin, pin_factory):
port, device = spi_port_device(
clock_pin, mosi_pin, miso_pin, select_pin)
self._port = port
self._device = device
self._baud = 500000
self._spi_flags = 0
self._handle = None
super(LGPIOHardwareSPI, self).__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._handle = lgpio.spi_open(port, device, self._baud, self._spi_flags)
def _conflicts_with(self, other):
return not (
isinstance(other, LGPIOHardwareSPI) and
(self._port, self._device) != (other._port, other._device)
)
def close(self):
if not self.closed:
lgpio.spi_close(self._handle)
self._handle = None
self.pin_factory.release_all(self)
super(LGPIOHardwareSPI, self).close()
@property
def closed(self):
return self._handle 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 _get_clock_mode(self):
return self._spi_flags
def _set_clock_mode(self, value):
self._check_open()
if not 0 <= value < 4:
raise SPIInvalidClockMode("%d is not a valid SPI clock mode" % value)
lgpio.spi_close(self._handle)
self._spi_flags = value
self._handle = lgpio.spi_open(
self._port, self._device, self._baud, self._spi_flags)
def _get_rate(self):
return self._baud
def _set_rate(self, value):
self._check_open()
value = int(value)
lgpio.spi_close(self._handle)
self._baud = value
self._handle = lgpio.spi_open(
self._port, self._device, self._baud, self._spi_flags)
def read(self, n):
self._check_open()
count, data = lgpio.spi_read(self._handle, n)
if count < 0:
raise IOError('SPI transfer error %d' % count)
return [int(b) for b in data]
def write(self, data):
self._check_open()
count = lgpio.spi_write(self._handle, data)
if count < 0:
raise IOError('SPI transfer error %d' % count)
return len(data)
def transfer(self, data):
self._check_open()
count, data = lgpio.spi_xfer(self._handle, data)
if count < 0:
raise IOError('SPI transfer error %d' % count)
return [int(b) for b in data]
class LGPIOHardwareSPIShared(SharedMixin, LGPIOHardwareSPI):
@classmethod
def _shared_key(cls, clock_pin, mosi_pin, miso_pin, select_pin, pin_factory):
return (clock_pin, select_pin)