dd = 0xab


class NandDmaWriter(Module):

    def __init__(self, lasmim, nandconf):
        self._magic = CSRStatus(16)
        self._reset = CSR()
        self._shoot = CSR()
        self.submodules._dma = DMAWriteController(
            dma_lasmi.Writer(lasmim),
            MODE_EXTERNAL)

        en = Signal()
        en_counter = Signal(lasmim.aw)
        self.comb += en.eq(en_counter != 0)
        self.sync += [
            If(self._shoot.re,
               en_counter.eq(self._dma.length)
               ).Elif(en_counter != 0,
                en_counter.eq(en_counter - 1)
                )
        ]

        ###

        self.comb += self._magic.status.eq(nandread_magic)

        self.sync += [
        # LEDs
            nandconf.io1.o.eq(self._dma.data.stb),
            nandconf.io2.o.eq(self._dma.data.ack),
            nandconf.io7.o.eq(en),
            nandconf.io8.o.eq(en_counter),
            ]

        self.comb += [
            self._dma.trigger.eq(self._shoot.re),
            self._dma.data.stb.eq(en),
            self._dma.data.d.eq(dd)
        ]

    def get_csrs(self):
        return [self._magic, self._reset, self._shoot] + self._dma.get_csrs()