src/adafruit_blinka/microcontroller/ftdi_mpsse/mpsse/i2c.py

   1 """I2C Class for FTDI MPSSE"""
   2 from adafruit_blinka.microcontroller.ftdi_mpsse.mpsse.pin import Pin
   3
   4
   5 class I2C:
   6     """Custom I2C Class for FTDI MPSSE"""
   7
   8     MASTER = 0
   9     SLAVE = 1
  10     _mode = None
  11
  12     # pylint: disable=unused-argument
  13     def __init__(self, i2c_id=None, mode=MASTER, baudrate=None, frequency=400000):
  14         if mode != self.MASTER:
  15             raise NotImplementedError("Only I2C Master supported!")
  16         _mode = self.MASTER
  17
  18         # change GPIO controller to I2C
  19         # pylint: disable=import-outside-toplevel
  20         from pyftdi.i2c import I2cController
  21
  22         # pylint: enable=import-outside-toplevel
  23
  24         self._i2c = I2cController()
  25         if i2c_id is None:
  26             self._i2c.configure("ftdi://ftdi:ft232h/1", frequency=frequency)
  27         else:
  28             self._i2c.configure(
  29                 "ftdi://ftdi:ft2232h/{}".format(i2c_id + 1), frequency=frequency
  30             )
  31         Pin.mpsse_gpio = self._i2c.get_gpio()
  32
  33     def scan(self):
  34         """Perform an I2C Device Scan"""
  35         return [addr for addr in range(0x79) if self._i2c.poll(addr)]
  36
  37     def writeto(self, address, buffer, *, start=0, end=None, stop=True):
  38         """Write data from the buffer to an address"""
  39         end = end if end else len(buffer)
  40         port = self._i2c.get_port(address)
  41         port.write(buffer[start:end], relax=stop)
  42
  43     def readfrom_into(self, address, buffer, *, start=0, end=None, stop=True):
  44         """Read data from an address and into the buffer"""
  45         end = end if end else len(buffer)
  46         port = self._i2c.get_port(address)
  47         result = port.read(len(buffer[start:end]), relax=stop)
  48         for i, b in enumerate(result):
  49             buffer[start + i] = b
  50
  51     # pylint: disable=unused-argument
  52     def writeto_then_readfrom(
  53         self,
  54         address,
  55         buffer_out,
  56         buffer_in,
  57         *,
  58         out_start=0,
  59         out_end=None,
  60         in_start=0,
  61         in_end=None,
  62         stop=False,
  63     ):
  64         """Write data from buffer_out to an address and then
  65         read data from an address and into buffer_in
  66         """
  67         out_end = out_end if out_end else len(buffer_out)
  68         in_end = in_end if in_end else len(buffer_in)
  69         port = self._i2c.get_port(address)
  70         result = port.exchange(
  71             buffer_out[out_start:out_end], in_end - in_start, relax=True
  72         )
  73         for i, b in enumerate(result):
  74             buffer_in[in_start + i] = b
  75
  76     # pylint: enable=unused-argument