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 from adafruit_blinka.microcontroller.ftdi_mpsse.mpsse.url import (
   4     get_ft232h_url,
   5     get_ft2232h_url,
   6 )
   7
   8
   9 class I2C:
  10     """Custom I2C Class for FTDI MPSSE"""
  11
  12     MASTER = 0
  13     SLAVE = 1
  14     _mode = None
  15
  16     # pylint: disable=unused-argument
  17     def __init__(self, i2c_id=None, mode=MASTER, baudrate=None, frequency=400000):
  18         if mode != self.MASTER:
  19             raise NotImplementedError("Only I2C Master supported!")
  20         _mode = self.MASTER
  21
  22         # change GPIO controller to I2C
  23         # pylint: disable=import-outside-toplevel
  24         from pyftdi.i2c import I2cController
  25
  26         # pylint: enable=import-outside-toplevel
  27
  28         self._i2c = I2cController()
  29         if i2c_id is None:
  30             self._i2c.configure(get_ft232h_url(), frequency=frequency)
  31         else:
  32             self._i2c.configure(get_ft2232h_url(i2c_id), frequency=frequency)
  33         Pin.mpsse_gpio = self._i2c.get_gpio()
  34
  35     def scan(self):
  36         """Perform an I2C Device Scan"""
  37         return [addr for addr in range(0x79) if self._i2c.poll(addr)]
  38
  39     def writeto(self, address, buffer, *, start=0, end=None, stop=True):
  40         """Write data from the buffer to an address"""
  41         end = end if end else len(buffer)
  42         port = self._i2c.get_port(address)
  43         port.write(buffer[start:end], relax=stop)
  44
  45     def readfrom_into(self, address, buffer, *, start=0, end=None, stop=True):
  46         """Read data from an address and into the buffer"""
  47         end = end if end else len(buffer)
  48         port = self._i2c.get_port(address)
  49         result = port.read(len(buffer[start:end]), relax=stop)
  50         for i, b in enumerate(result):
  51             buffer[start + i] = b
  52
  53     # pylint: disable=unused-argument
  54     def writeto_then_readfrom(
  55         self,
  56         address,
  57         buffer_out,
  58         buffer_in,
  59         *,
  60         out_start=0,
  61         out_end=None,
  62         in_start=0,
  63         in_end=None,
  64         stop=False,
  65     ):
  66         """Write data from buffer_out to an address and then
  67         read data from an address and into buffer_in
  68         """
  69         out_end = out_end if out_end else len(buffer_out)
  70         in_end = in_end if in_end else len(buffer_in)
  71         port = self._i2c.get_port(address)
  72         result = port.exchange(
  73             buffer_out[out_start:out_end], in_end - in_start, relax=True
  74         )
  75         for i, b in enumerate(result):
  76             buffer_in[in_start + i] = b
  77
  78     # pylint: enable=unused-argument