pypci/pci.py

import numpy as np
from _pciffi import ffi, lib


class Error(Exception):
    pass


class Types(object):
    # This enum also maps directly to the type size for now
    UINT8   = 1
    UINT32  = 4


TYPE_NAMES = {
    Types.UINT8: 'uint8_t',
    Types.UINT32: 'uint32_t',
}

class Device(object):
    def __init__(self, model, device='/dev/fpga0'):
        self.handle = lib.pcilib_open(device, model)
        self.dma_engine = lib.pcilib_find_dma_by_addr(self.handle, lib.PCILIB_DMA_BIDIRECTIONAL, 0xFF)

    def __enter__(self):
        return self

    def __exit__(self, *args):
        self.close()

    def read(self, addr, num, t=Types.UINT32):
        data = ffi.new("{}[]".format(TYPE_NAMES[t]), num)

        if lib.pcilib_read(self.handle, 0, addr, num, t, data) != 0:
            raise Error("Could not read")

        return list(data[0:len(data)])

    def write(self, addr, value, t=Types.UINT32):
        data = ffi.new("{}[]".format(TYPE_NAMES[t]), [value])

        if lib.pcilib_write(self.handle, 0, addr, t, 1, data) != 0:
            raise Error("Could not write")

    def start_dma(self):
        lib.pcilib_start_dma(self.handle, self.dma_engine, lib.PCILIB_DMA_FLAGS_DEFAULT)

    def close(self):
        lib.pcilib_close(self.handle)