Add support for FT2232H "microcontroller"

[Adafruit_Blinka-hackapet.git] / src / adafruit_blinka / microcontroller / ftdi_mpsse / mpsse / spi.py

diff --git a/src/adafruit_blinka/microcontroller/ftdi_mpsse/mpsse/spi.py b/src/adafruit_blinka/microcontroller/ftdi_mpsse/mpsse/spi.py
new file mode 100644 (file)
index 0000000..69fe66f
--- /dev/null
+++ b/src/adafruit_blinka/microcontroller/ftdi_mpsse/mpsse/spi.py
@@ -0,0 +1,93 @@
+"""SPI Class for FTDI MPSSE"""
+from adafruit_blinka.microcontroller.ftdi_mpsse.mpsse.pin import Pin
+
+# pylint: disable=protected-access
+class SPI:
+    """Custom SPI Class for FTDI MPSSE"""
+
+    MSB = 0
+
+    def __init__(self, id=None):
+        # pylint: disable=import-outside-toplevel
+        from pyftdi.spi import SpiController
+
+        # pylint: enable=import-outside-toplevel
+
+        self._spi = SpiController(cs_count=1)
+        if id is None:
+            self._spi.configure("ftdi://ftdi:ft232h/1", frequency=frequency)
+        else
+            self._spi.configure("ftdi://ftdi:ft2232h/{}".format(id+1), frequency=frequency)
+        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.mpsse_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:
+            self._port.write(buf[-1 * rest :])
+
+    # 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