Untangle code and remove pylint disables

[Adafruit_Blinka-hackapet.git] / src / adafruit_blinka / microcontroller / bcm283x / pin.py

diff --git a/src/adafruit_blinka/microcontroller/bcm283x/pin.py b/src/adafruit_blinka/microcontroller/bcm283x/pin.py
index 3db76dfec133425357f34ada784f2c8d0f2a676e..e31d401249d68f12fac8a63460b1046af3ba163a 100644 (file)
--- 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:
 class Pin:

-    IN = 0
-    OUT = 1
+    """Pins dont exist in CPython so...lets make our own!"""
+

     LOW = 0
     HIGH = 1
     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
     id = None
     _value = LOW
     _mode = IN

-    
+
+    # we want exceptions
+    lgpio.exceptions = True
+

     def __init__(self, bcm_number):
         self.id = bcm_number
 
     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):
         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:
             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:
             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:
             else:

-                raise RuntimeError("Invalid pull for pin: %s" % self.id)       
+                raise RuntimeError(f"Invalid pull for pin: {self.id}")

 
     def value(self, val=None):
 
     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
                 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
                 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:
                 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)
 
 D0 = Pin(0)
 D1 = Pin(1)
 


@@ -80,7 +149,7 @@ MISO = Pin(9)
 D10 = Pin(10)
 MOSI = Pin(10)
 D11 = Pin(11)
 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)
 SCK = Pin(11)  # CircuitPython naming
 
 D12 = Pin(12)


@@ -131,13 +200,19 @@ D44 = Pin(44)
 D45 = Pin(45)
 
 # ordered as spiId, sckId, mosiId, misoId
 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
 
 # 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 = (
 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!

 )
 )