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