X-Git-Url: https://git.ayoreis.com/Adafruit_Blinka-hackapet.git/blobdiff_plain/498d20f05e125c355acf4bfccc9e35bb7461f9d5..99ce0ad895659a2e1ba26003d4b5f78e6471f8e4:/src/adafruit_blinka/microcontroller/am65xx/spi.py

diff --git a/src/adafruit_blinka/microcontroller/am65xx/spi.py b/src/adafruit_blinka/microcontroller/am65xx/spi.py
new file mode 100644
index 0000000..d1fa0b1
--- /dev/null
+++ b/src/adafruit_blinka/microcontroller/am65xx/spi.py
@@ -0,0 +1,144 @@
+# SPDX-FileCopyrightText: 2021 Melissa LeBlanc-Williams for Adafruit Industries
+#
+# SPDX-License-Identifier: MIT
+"""am65xx SPI class using PureIO's SPI class"""
+
+from Adafruit_PureIO import spi
+
+# import Adafruit_PureIO.spi as spi
+from adafruit_blinka.agnostic import detector
+
+
+class SPI:
+    """SPI Class"""
+
+    MSB = 0
+    LSB = 1
+    CPHA = 1
+    CPOL = 2
+
+    baudrate = 100000
+    mode = 0
+    bits = 8
+
+    def __init__(self, portid):
+        if isinstance(portid, tuple):
+            self._spi = spi.SPI(device=portid)
+        else:
+            self._spi = spi.SPI(device=(portid, 0))
+        self.clock_pin = None
+        self.mosi_pin = None
+        self.miso_pin = None
+        self.chip = None
+
+    # 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 SPI"""
+        mode = 0
+        if polarity:
+            mode |= self.CPOL
+        if phase:
+            mode |= self.CPHA
+        self.baudrate = baudrate
+        self.mode = mode
+        self.bits = bits
+        self.chip = detector.chip
+
+        # Pins are not used
+        self.clock_pin = sck
+        self.mosi_pin = mosi
+        self.miso_pin = miso
+
+    # pylint: enable=too-many-arguments,unused-argument
+
+    # pylint: disable=unnecessary-pass
+    def set_no_cs(self):
+        """Setting so that SPI doesn't automatically set the CS pin"""
+        # No kernel seems to support this, so we're just going to pass
+        pass
+
+    # pylint: enable=unnecessary-pass
+
+    @property
+    def frequency(self):
+        """Return the current baudrate"""
+        return self.baudrate
+
+    def write(self, buf, start=0, end=None):
+        """Write data from the buffer to SPI"""
+        if not buf:
+            return
+        if end is None:
+            end = len(buf)
+        try:
+            # self._spi.open(self._port, 0)
+            self.set_no_cs()
+            self._spi.max_speed_hz = self.baudrate
+            self._spi.mode = self.mode
+            self._spi.bits_per_word = self.bits
+            self._spi.writebytes(buf[start:end])
+            # self._spi.close()
+        except FileNotFoundError:
+            print("Could not open SPI device - check if SPI is enabled in kernel!")
+            raise
+
+    def readinto(self, buf, start=0, end=None, write_value=0):
+        """Read data from SPI and into the buffer"""
+        if not buf:
+            return
+        if end is None:
+            end = len(buf)
+        try:
+            # self._spi.open(self._port, 0)
+            # self.set_no_cs()
+            self._spi.max_speed_hz = self.baudrate
+            self._spi.mode = self.mode
+            self._spi.bits_per_word = self.bits
+            data = self._spi.transfer([write_value] * (end - start))
+            for i in range(end - start):  # 'readinto' the given buffer
+                buf[start + i] = data[i]
+            # self._spi.close()
+        except FileNotFoundError:
+            print("Could not open SPI device - check if SPI is enabled in kernel!")
+            raise
+
+    # 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
+        """
+        if not buffer_out or not buffer_in:
+            return
+        if out_end is None:
+            out_end = len(buffer_out)
+        if in_end is None:
+            in_end = len(buffer_in)
+        if out_end - out_start != in_end - in_start:
+            raise RuntimeError("Buffer slices must be of equal length.")
+        try:
+            # self._spi.open(self._port, 0)
+            # self.set_no_cs()
+            self._spi.max_speed_hz = self.baudrate
+            self._spi.mode = self.mode
+            self._spi.bits_per_word = self.bits
+            data = self._spi.transfer(list(buffer_out[out_start : out_end + 1]))
+            for i in range((in_end - in_start)):
+                buffer_in[i + in_start] = data[i]
+            # self._spi.close()
+        except FileNotFoundError:
+            print("Could not open SPI device - check if SPI is enabled in kernel!")
+            raise
+
+    # pylint: enable=too-many-arguments