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