src/adafruit_blinka/microcontroller/rp2040/spi.py

   1 # SPDX-FileCopyrightText: 2021 Melissa LeBlanc-Williams for Adafruit Industries
   2 #
   3 # SPDX-License-Identifier: MIT
   4 """SPI Class for RP2040"""
   5 from machine import SPI as _SPI
   6 from machine import Pin
   7 from microcontroller.pin import spiPorts
   8
   9 # pylint: disable=protected-access, no-self-use
  10 class SPI:
  11     """Custom SPI Class for RP2040"""
  12
  13     MSB = _SPI.MSB
  14
  15     def __init__(self, clock, MOSI=None, MISO=None, *, baudrate=1000000):
  16         self._frequency = baudrate
  17         for portId, portSck, portMosi, portMiso in spiPorts:
  18             if (
  19                 (clock == portSck)
  20                 and MOSI in (portMosi, None)  # Clock is required!
  21                 and MISO in (portMiso, None)  # But can do with just output
  22             ):  # Or just input
  23                 mosiPin = Pin(portMosi.id) if MOSI else None
  24                 misoPin = Pin(portMiso.id) if MISO else None
  25                 self._spi = _SPI(
  26                     portId,
  27                     sck=Pin(portSck.id),
  28                     mosi=mosiPin,
  29                     miso=misoPin,
  30                     baudrate=baudrate,
  31                 )
  32                 break
  33         else:
  34             raise ValueError(
  35                 "No Hardware SPI on (SCLK, MOSI, MISO)={}\nValid SPI ports:{}".format(
  36                     (clock, MOSI, MISO), spiPorts
  37                 )
  38             )
  39
  40     # pylint: disable=too-many-arguments,unused-argument
  41     def init(
  42         self,
  43         baudrate=1000000,
  44         polarity=0,
  45         phase=0,
  46         bits=8,
  47         firstbit=_SPI.MSB,
  48         sck=None,
  49         mosi=None,
  50         miso=None,
  51     ):
  52         """Initialize the Port"""
  53         self._frequency = baudrate
  54         self._spi.init(
  55             baudrate=baudrate,
  56             polarity=polarity,
  57             phase=phase,
  58             bits=bits,
  59             firstbit=firstbit,
  60         )
  61
  62     # pylint: enable=too-many-arguments
  63
  64     @property
  65     def frequency(self):
  66         """Return the current frequency"""
  67         return self._frequency
  68
  69     def write(self, buf, start=0, end=None):
  70         """Write data from the buffer to SPI"""
  71         self._spi.write(buf)
  72
  73     def readinto(self, buf, start=0, end=None, write_value=0):
  74         """Read data from SPI and into the buffer"""
  75         self._spi.readinto(buf)
  76
  77     # pylint: disable=too-many-arguments
  78     def write_readinto(
  79         self, buffer_out, buffer_in, out_start=0, out_end=None, in_start=0, in_end=None
  80     ):
  81         """Perform a half-duplex write from buffer_out and then
  82         read data into buffer_in
  83         """
  84         self._spi.write_readinto(
  85             buffer_out,
  86             buffer_in,
  87             out_start=out_start,
  88             out_end=out_end,
  89             in_start=in_start,
  90             in_end=in_end,
  91         )
  92
  93     # pylint: enable=too-many-arguments