src/adafruit_blinka/microcontroller/generic_linux/libgpiod_pin.py

   1 try:
   2     import gpiod
   3 except ImportError:
   4     raise ImportError("libgpiod Python bindings not found, please install and try again! See https://github.com/adafruit/Raspberry-Pi-Installer-Scripts/blob/master/libgpiod.sh")
   5
   6 # Pins dont exist in CPython so...lets make our own!
   7 class Pin:
   8     IN = 0
   9     OUT = 1
  10     LOW = 0
  11     HIGH = 1
  12     PULL_NONE = 0
  13     PULL_UP = 1
  14     PULL_DOWN = 2
  15     _CONSUMER = 'adafruit_blinka'
  16
  17     id = None
  18     _value = LOW
  19     _mode = IN
  20
  21     def __init__(self, pin_id):
  22         self.id = pin_id
  23         if type(pin_id) is tuple:
  24             self._num = int(pin_id[1])
  25             self._chip = gpiod.Chip(str(pin_id[0]), gpiod.Chip.OPEN_BY_NUMBER)
  26         else:
  27             self._num = int(pin_id)
  28             self._chip = gpiod.Chip("gpiochip0", gpiod.Chip.OPEN_BY_NAME)
  29         self._line = None
  30
  31     def __repr__(self):
  32         return str(self.id)
  33
  34     def __eq__(self, other):
  35         return self.id == other
  36
  37     def init(self, mode=IN, pull=None):
  38         if not self._line:
  39             self._line = self._chip.get_line(int(self._num))
  40             #print("init line: ", self.id, self._line)
  41
  42         if mode != None:
  43             if mode == self.IN:
  44                 flags = 0
  45                 if pull != None:
  46                     if pull == self.PULL_UP:
  47                         raise NotImplementedError("Internal pullups not supported in libgpiod, use physical resistor instead!")
  48                     elif pull == self.PULL_DOWN:
  49                         raise NotImplementedError("Internal pulldowns not supported in libgpiod, use physical resistor instead!")
  50                     else:
  51                         raise RuntimeError("Invalid pull for pin: %s" % self.id)
  52
  53                 self._mode = self.IN
  54                 self._line.release()
  55                 self._line.request(consumer=self._CONSUMER,
  56                                    type=gpiod.LINE_REQ_DIR_IN,
  57                                    flags=flags)
  58
  59             elif mode == self.OUT:
  60                 if pull != None:
  61                     raise RuntimeError("Cannot set pull resistor on output")
  62                 self._mode = self.OUT
  63                 self._line.release()
  64                 self._line.request(consumer=self._CONSUMER,
  65                                    type=gpiod.LINE_REQ_DIR_OUT)
  66
  67             else:
  68                 raise RuntimeError("Invalid mode for pin: %s" % self.id)
  69
  70     def value(self, val=None):
  71         if val != None:
  72             if val in (self.LOW, self.HIGH):
  73                 self._value = val
  74                 self._line.set_value(val)
  75             else:
  76                 raise RuntimeError("Invalid value for pin")
  77         else:
  78             return self._line.get_value()