"""SPI Class for FT232H""" from adafruit_blinka.microcontroller.ft232h.pin import Pin # pylint: disable=protected-access class SPI: """Custom SPI Class for FT232H""" MSB = 0 def __init__(self): # pylint: disable=import-outside-toplevel from pyftdi.spi import SpiController # pylint: enable=import-outside-toplevel self._spi = SpiController(cs_count=1) self._spi.configure("ftdi://ftdi:ft232h/1") self._port = self._spi.get_port(0) self._port.set_frequency(100000) self._port._cpol = 0 self._port._cpha = 0 # Change GPIO controller to SPI Pin.ft232h_gpio = self._spi.get_gpio() # pylint: disable=too-many-arguments,unused-argument def init( self, baudrate=100000, polarity=0, phase=0, bits=8, firstbit=MSB, sck=None, mosi=None, miso=None, ): """Initialize the Port""" self._port.set_frequency(baudrate) # FTDI device can only support mode 0 and mode 2 # due to the limitation of MPSSE engine. # This means CPHA must = 0 self._port._cpol = polarity if phase != 0: raise ValueError("Only SPI phase 0 is supported by FT232H.") self._port._cpha = phase # pylint: enable=too-many-arguments @property def frequency(self): """Return the current frequency""" return self._port.frequency def write(self, buf, start=0, end=None): """Write data from the buffer to SPI""" end = end if end else len(buf) chunks, rest = divmod(end - start, self._spi.PAYLOAD_MAX_LENGTH) for i in range(chunks): chunk_start = start + i * self._spi.PAYLOAD_MAX_LENGTH chunk_end = chunk_start + self._spi.PAYLOAD_MAX_LENGTH self._port.write(buf[chunk_start:chunk_end]) if rest: rest_start = start + chunks * self._spi.PAYLOAD_MAX_LENGTH self._port.write(buf[rest_start:end]) # pylint: disable=unused-argument def readinto(self, buf, start=0, end=None, write_value=0): """Read data from SPI and into the buffer""" end = end if end else len(buf) result = self._port.read(end - start) for i, b in enumerate(result): buf[start + i] = b # pylint: enable=unused-argument # pylint: disable=too-many-arguments def write_readinto( self, buffer_out, buffer_in, out_start=0, out_end=None, in_start=0, in_end=None ): """Perform a half-duplex write from buffer_out and then read data into buffer_in """ out_end = out_end if out_end else len(buffer_out) in_end = in_end if in_end else len(buffer_in) result = self._port.exchange( buffer_out[out_start:out_end], in_end - in_start, duplex=True ) for i, b in enumerate(result): buffer_in[in_start + i] = b # pylint: enable=too-many-arguments