X-Git-Url: https://git.ayoreis.com/Adafruit_Blinka-hackapet.git/blobdiff_plain/a7bcbc4bc896176070770e9d7834402b4afa3020..c2bc4a90827f28abb6b51eae659a1f80a65c0497:/src/adafruit_blinka/microcontroller/bcm283x/pin.py?ds=inline diff --git a/src/adafruit_blinka/microcontroller/bcm283x/pin.py b/src/adafruit_blinka/microcontroller/bcm283x/pin.py index 10835dc..e31d401 100644 --- a/src/adafruit_blinka/microcontroller/bcm283x/pin.py +++ b/src/adafruit_blinka/microcontroller/bcm283x/pin.py @@ -1,21 +1,67 @@ -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 @@ -26,39 +72,62 @@ class Pin: 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) @@ -80,7 +149,7 @@ MISO = Pin(9) 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) @@ -131,14 +200,19 @@ D44 = Pin(44) 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 = ( - (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! ) -