-import RPi.GPIO as GPIO
-GPIO.setmode(GPIO.BCM) # Use BCM pins D4 = GPIO #4
-GPIO.setwarnings(False) # shh!
+# SPDX-FileCopyrightText: 2021 Melissa LeBlanc-Williams for Adafruit Industries
+#
+# SPDX-License-Identifier: MIT
+"""Broadcom BCM283x pin names"""
+from pathlib import Path
+import lgpio
+
+
+def _get_gpiochip():
+ """
+ Determines the handle of the GPIO chip device to access.
+
+ iterate through sysfs to find a GPIO chip device with a driver known to be
+ used for userspace GPIO access.
+ """
+ for dev in Path("/sys/bus/gpio/devices").glob("gpiochip*"):
+ drivers = set((dev / "of_node/compatible").read_text().split("\0"))
+ # check if driver names are intended for userspace control
+ if drivers & {
+ "raspberrypi,rp1-gpio",
+ "raspberrypi,bcm2835-gpio",
+ "raspberrypi,bcm2711-gpio",
+ }:
+ return lgpio.gpiochip_open(int(dev.name[-1]))
+ # return chip0 as a fallback
+ return lgpio.gpiochip_open(0)
+
+
+CHIP = _get_gpiochip()
+
-# Pins dont exist in CPython so...lets make our own!
class Pin:
- IN = 0
- OUT = 1
+ """Pins dont exist in CPython so...lets make our own!"""
+
LOW = 0
HIGH = 1
- PULL_NONE = 0
- PULL_UP = 1
- PULL_DOWN = 2
-
+ OFF = LOW
+ ON = HIGH
+
+ # values of lg mode constants
+ PULL_NONE = 0x80
+ PULL_UP = 0x20
+ PULL_DOWN = 0x40
+ ACTIVE_LOW = 0x02
+
+ # drive mode lg constants
+ OPEN_DRAIN = 0x04
+ IN = 0x0100
+ OUT = 0x0200
+
+ # LG mode constants
+ _LG_ALERT = 0x400
+ _LG_GROUP = 0x800
+ _LG_MODES = IN | OUT | _LG_ALERT | _LG_GROUP
+ _LG_PULLS = PULL_NONE | PULL_UP | PULL_NONE | ACTIVE_LOW
+ _LG_DRIVES = OPEN_DRAIN
+
id = None
_value = LOW
_mode = IN
-
+
+ # we want exceptions
+ lgpio.exceptions = True
+
def __init__(self, bcm_number):
self.id = bcm_number
return self.id == other
def init(self, mode=IN, pull=None):
- if mode != None:
- if mode == self.IN:
- self._mode = self.IN
- GPIO.setup(self.id, GPIO.IN)
+ """Initialize the Pin"""
+ if mode is not None:
+ if mode == Pin.IN:
+ self._mode = Pin.IN
+ self._set_gpio_mode_in()
elif mode == self.OUT:
- self._mode = self.OUT
- GPIO.setup(self.id, GPIO.OUT)
+ self._mode = Pin.OUT
+ Pin._check_result(lgpio.gpio_claim_output(CHIP, self.id, Pin.LOW))
else:
- raise RuntimeError("Invalid mode for pin: %s" % self.id)
- if pull != None:
- if self._mode != self.IN:
- raise RuntimeError("Cannot set pull resistor on output")
- if pull == self.PULL_UP:
- GPIO.setup(self.id, GPIO.IN, pull_up_down=GPIO.PUD_UP)
- elif pull == self.PULL_DOWN:
- GPIO.setup(self.id, GPIO.IN, pull_up_down=GPIO.PUD_DOWN)
+ raise RuntimeError(f"Invalid mode for pin: {self.id}")
+ if pull is not None:
+ if self._mode != Pin.IN:
+ raise RuntimeError("Can only set pull resistor on input")
+ if pull in {Pin.PULL_UP, Pin.PULL_DOWN, Pin.PULL_NONE}:
+ self._set_gpio_mode_in(lflags=pull)
else:
- raise RuntimeError("Invalid pull for pin: %s" % self.id)
+ raise RuntimeError(f"Invalid pull for pin: {self.id}")
def value(self, val=None):
- if val != None:
- if val == self.LOW:
+ """Set or return the Pin Value"""
+ if val is not None:
+ if val == Pin.LOW:
self._value = val
- GPIO.output(self.id, val)
- elif val == self.HIGH:
+ Pin._check_result(lgpio.gpio_write(CHIP, self.id, val))
+ elif val == Pin.HIGH:
self._value = val
- GPIO.output(self.id, val)
+ Pin._check_result(lgpio.gpio_write(CHIP, self.id, val))
else:
raise RuntimeError("Invalid value for pin")
- else:
- return GPIO.input(self.id)
+ return None
+ return Pin._check_result(lgpio.gpio_read(CHIP, self.id))
+
+ @staticmethod
+ def _check_result(result):
+ """
+ convert any result other than zero to a text message and pass it back
+ as a runtime exception. Typical usage: use the lgpio call as the
+ argument.
+ """
+ if result < 0:
+ raise RuntimeError(lgpio.error_text(result))
+ return result
+
+ def _set_gpio_mode_in(self, lflags=0):
+ """
+ claim a gpio as input, or modify the flags (PULL_UP, PULL_DOWN, ... )
+ """
+ # This gpio_free may seem redundant, but is required when
+ # changing the line-flags of an already acquired input line
+ try:
+ lgpio.gpio_free(CHIP, self.id)
+ except lgpio.error:
+ pass
+ Pin._check_result(lgpio.gpio_claim_input(CHIP, self.id, lFlags=lflags))
+
-# Pi 1B rev1 only?
D0 = Pin(0)
D1 = Pin(1)
D10 = Pin(10)
MOSI = Pin(10)
D11 = Pin(11)
-SCLK = Pin(11) # Raspberry Pi naming
+SCLK = Pin(11) # Raspberry Pi naming
SCK = Pin(11) # CircuitPython naming
D12 = Pin(12)
D45 = Pin(45)
# ordered as spiId, sckId, mosiId, misoId
-spiPorts = ((0, SCLK, MOSI, MISO), (1, SCLK_1, MOSI_1, MISO_1), (2, SCLK_2, MOSI_2, MISO_2))
+spiPorts = (
+ (0, SCLK, MOSI, MISO),
+ (1, SCLK_1, MOSI_1, MISO_1),
+ (2, SCLK_2, MOSI_2, MISO_2),
+)
# ordered as uartId, txId, rxId
-uartPorts = (
- (1, TXD, RXD),
-)
+uartPorts = ((1, TXD, RXD),)
+# These are the known hardware I2C ports / pins.
+# For software I2C ports created with the i2c-gpio overlay, see:
+# https://github.com/adafruit/Adafruit_Python_Extended_Bus
i2cPorts = (
- (3, SCL, SDA), (1, SCL, SDA), (0, D1, D0), # both pi 1 and pi 2 i2c ports!
+ (1, SCL, SDA),
+ (0, D1, D0), # both pi 1 and pi 2 i2c ports!
)
projects / Adafruit_Blinka-hackapet.git / blobdiff