--- /dev/null
+# 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