Initial Binho Nova plumbing

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

diff --git a/src/adafruit_blinka/microcontroller/nova/spi.py b/src/adafruit_blinka/microcontroller/nova/spi.py
new file mode 100644 (file)
index 0000000..7882f23
--- /dev/null
+++ b/src/adafruit_blinka/microcontroller/nova/spi.py
@@ -0,0 +1,49 @@
+from adafruit_blinka.microcontroller.nova.pin import Pin
+
+class SPI:
+    MSB = 0
+
+    def __init__(self):
+        from pyftdi.spi import SpiController
+        self._spi = SpiController(cs_count=1)
+        self._spi.configure('ftdi:///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()
+
+    def init(self, baudrate=100000, polarity=0, phase=0, bits=8,
+                  firstbit=MSB, sck=None, mosi=None, miso=None):
+        self._port.set_frequency(baudrate)
+        self._port._cpol = polarity
+        self._port._cpha = phase
+
+    @property
+    def frequency(self):
+        return self._port.frequency
+
+    def write(self, buf, start=0, end=None):
+        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:])
+
+    def readinto(self, buf, start=0, end=None, write_value=0):
+        end = end if end else len(buf)
+        result = self._port.read(end-start)
+        for i, b in enumerate(result):
+            buf[start+i] = b
+
+    def write_readinto(self, buffer_out, buffer_in,  out_start=0, out_end=None, in_start=0, in_end=None):
+        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