src/adafruit_blinka/microcontroller/rp2040/spi.py

   1 """SPI Class for RP2040"""
   2 from machine import SPI as _SPI
   3 from machine import Pin
   4 from microcontroller.pin import spiPorts
   5
   6 # pylint: disable=protected-access, no-self-use
   7 class SPI:
   8     """Custom SPI Class for RP2040"""
   9
  10     MSB = _SPI.MSB
  11
  12     def __init__(self, clock, MOSI=None, MISO=None, *, baudrate=1000000):
  13         self._frequency = baudrate
  14         for portId, portSck, portMosi, portMiso in spiPorts:
  15             if (
  16                 (clock == portSck)
  17                 and MOSI in (portMosi, None)  # Clock is required!
  18                 and MISO in (portMiso, None)  # But can do with just output
  19             ):  # Or just input
  20                 mosiPin = Pin(portMosi.id) if MOSI else None
  21                 misoPin = Pin(portMiso.id) if MISO else None
  22                 self._spi = _SPI(
  23                     portId,
  24                     sck=Pin(portSck.id),
  25                     mosi=mosiPin,
  26                     miso=misoPin,
  27                     baudrate=baudrate,
  28                 )
  29                 break
  30         else:
  31             raise ValueError(
  32                 "No Hardware SPI on (SCLK, MOSI, MISO)={}\nValid SPI ports:{}".format(
  33                     (clock, MOSI, MISO), spiPorts
  34                 )
  35             )
  36
  37     # pylint: disable=too-many-arguments,unused-argument
  38     def init(
  39         self,
  40         baudrate=1000000,
  41         polarity=0,
  42         phase=0,
  43         bits=8,
  44         firstbit=_SPI.MSB,
  45         sck=None,
  46         mosi=None,
  47         miso=None,
  48     ):
  49         """Initialize the Port"""
  50         self._frequency = baudrate
  51         self._spi.init(
  52             baudrate=baudrate,
  53             polarity=polarity,
  54             phase=phase,
  55             bits=bits,
  56             firstbit=firstbit,
  57         )
  58
  59     # pylint: enable=too-many-arguments
  60
  61     @property
  62     def frequency(self):
  63         """Return the current frequency"""
  64         return self._frequency
  65
  66     def write(self, buf, start=0, end=None):
  67         """Write data from the buffer to SPI"""
  68         self._spi.write(buf)
  69
  70     def readinto(self, buf, start=0, end=None, write_value=0):
  71         """Read data from SPI and into the buffer"""
  72         self._spi.readinto(buf)
  73
  74     # pylint: disable=too-many-arguments
  75     def write_readinto(
  76         self, buffer_out, buffer_in, out_start=0, out_end=None, in_start=0, in_end=None
  77     ):
  78         """Perform a half-duplex write from buffer_out and then
  79         read data into buffer_in
  80         """
  81         self._spi.write_readinto(
  82             buffer_out,
  83             buffer_in,
  84             out_start=out_start,
  85             out_end=out_end,
  86             in_start=in_start,
  87             in_end=in_end,
  88         )
  89
  90     # pylint: enable=too-many-arguments