src/adafruit_blinka/microcontroller/nova/spi.py

   1 #from adafruit_blinka.microcontroller.nova.pin import Pin
   2
   3 class SPI:
   4     PAYLOAD_MAX_LENGTH = 64
   5
   6     def __init__(self, clock):
   7         from binhoHostAdapter import binhoHostAdapter
   8         from binhoHostAdapter import binhoUtilities
   9
  10         utilities = binhoUtilities.binhoUtilities()
  11         devices = utilities.listAvailableDevices()
  12
  13         if len(devices) > 0:
  14             self._nova = binhoHostAdapter.binhoHostAdapter(devices[0])
  15             self._nova.setOperationMode(0, 'SPI')
  16             self._nova.setClockSPI(0, clock)
  17             self._nova.setModeSPI(0, 0)
  18             self._nova.setIOpinMode(0, 'DOUT')
  19             self._nova.setIOpinValue(0, 'HIGH')
  20             self._nova.beginSPI(0)
  21             # Cpol and Cpha set by mode
  22             # Mode  Cpol Cpha
  23             #  0     0    0
  24             #  1     0    1
  25             #  2     1    0
  26             #  3     1    1
  27
  28         else:
  29             raise RuntimeError('No Binho host adapter found!')
  30
  31     def init(self, baudrate=100000, polarity=0, phase=0, bits=8,
  32                   firstbit=MSB, sck=None, mosi=None, miso=None):
  33         print("baudrate: " + baudrate)
  34         print("mode: " + (polarity<<1) | (phase))
  35         self._nova.setClockSPI(0, baudrate)
  36         self._nova.setModeSPI(0, (polarity<<1) | (phase))
  37
  38     @staticmethod
  39     def getSpiReceivedData(lineOutput):
  40         return (lineOutput.split('RXD ')[1])
  41
  42     @property
  43     def frequency(self):
  44         return self._nova.getClockSPI(0).split('CLK ')[1]
  45
  46     def write(self, buf, start=0, end=None):
  47         end = end if end else len(buf)
  48         chunks, rest = divmod(end - start, self.PAYLOAD_MAX_LENGTH)
  49         self._nova.setIOpinValue(0, 'LOW')
  50         for i in range(chunks):
  51             chunk_start = start + i * self.PAYLOAD_MAX_LENGTH
  52             chunk_end = chunk_start + self.PAYLOAD_MAX_LENGTH
  53             buffer_data = buf[chunk_start:chunk_end]
  54             self._nova.clearBuffer(0)
  55             self._nova.writeToBuffer(0, 0, buffer_data)
  56             self._nova.transferBufferSPI(0, chunk_end - chunk_start + 1)
  57         if rest:
  58             buffer_data = buf[-1*rest:]
  59             self._nova.clearBuffer(0)
  60             self._nova.writeToBuffer(0, 0, buffer_data)
  61             self._nova.transferBufferSPI(0, rest)
  62         self._nova.setIOpinValue(0, 'HIGH')
  63         print(self._nova.readBuffer(0, 4))
  64
  65     def readinto(self, buf, start=0, end=None, write_value=0):
  66         end = end if end else len(buf)
  67         self._nova.setIOpinValue(0, 'LOW')
  68         for i in range(start, end):
  69             buf[start+i] = int(self.getSpiReceivedData(self._nova.transferSPI(0, write_value)), 16)
  70         self._nova.setIOpinValue(0, 'HIGH')
  71
  72     def write_readinto(self, buffer_out, buffer_in,  out_start=0, out_end=None, in_start=0, in_end=None):
  73         out_end = out_end if out_end else len(buffer_out)
  74         in_end = in_end if in_end else len(buffer_in)
  75         readlen = in_end-in_start
  76         writelen = out_end-out_start
  77         if readlen > writelen:
  78             # resize out and pad with 0's
  79             tmp = bytearray(buffer_out)
  80             tmp.extend([0] * (readlen - len(buffer_out)))
  81             buffer_out = tmp
  82         i = 0
  83         self._nova.setIOpinValue(0, 'LOW')
  84         for data_out in buffer_out:
  85             data_in = int(self.getSpiReceivedData(self._nova.transferSPI(0, data_out)), 16)
  86             if i < readlen:
  87                 buffer_in[in_start+i] = data_in
  88             i += 1
  89         self._nova.setIOpinValue(0, 'HIGH')