from migen import *

from litex.soc.interconnect.csr import *
from migen.genlib.fifo import AsyncFIFO as MigenAsyncFIFO
from litex.soc.integration.doc import ModuleDoc

class GenerateWave(Module, AutoCSR, ModuleDoc):
    """
    Multi Wave Generation Module

    Set the target frequency and waveform outpput for each of 128 oscillators.
    Outputs samples normalised in range 0.5-1x max amplitude.
    """
    def __init__(self, platform, pads):
        platform.add_source("rtl/cordic.sv")
        platform.add_source("rtl/saw2sin.sv")
        platform.add_source("rtl/genWave.sv")
        platform.add_source("rtl/dacDriver.sv")

        self.pads = pads
        self.osc = CSRStorage(size = 6, description = "Index of the Oscillator to Configure (0-63)")
        self.tf = CSRStorage(size = 24, description = "Target Frequency of the phase accumulator")
        self.wav = CSRStorage(size = 8, description = "Waveform to Output (Saw, Square, Triangle, Sine)")

        # 48MHz Domain Signals
        self.backpressure_48 = Signal()
        self.sample_48       = Signal(16)
        self.audioready_48   = Signal()

        # 36.864MHz Domain Signals
        self.readrequest_36  = Signal()
        self.sample_36       = Signal(16)
        self.fifoempty_36    = Signal()
        self.dac_lrck        = Signal()
        self.dac_bck         = Signal()
        self.dac_data        = Signal()

        # # #

        self.specials += Instance("genWave",
            i_i_clk48    = ClockSignal(),
            i_i_rst48_n  = ~ResetSignal(),
            i_i_pause    = self.backpressure_48,
            i_i_osc_sel  = self.osc.storage,
            i_i_t_freq   = self.tf.storage,
            i_i_tf_valid = self.tf.re,
            i_i_wav_sel  = self.wav.storage,
            i_i_ws_valid = self.wav.re,
            o_o_sample   = self.sample_48,
            o_o_pulse    = self.audioready_48,
        )

        sample_fifo = ClockDomainsRenamer({"write": "sys", "read": "dac"})(MigenAsyncFIFO(48, 4))
        self.comb += self.backpressure_48.eq(~sample_fifo.writable)
        self.comb += sample_fifo.we.eq(self.audioready_48)
        self.comb += sample_fifo.din.eq(self.sample_48)
        self.comb += self.fifoempty_36.eq(~sample_fifo.readable)
        self.comb += sample_fifo.re.eq(self.readrequest_36)
        self.comb += self.sample_36.eq(sample_fifo.dout)
        self.submodules += sample_fifo

        self.specials += Instance("dacDriver",
            i_i_clk36   = ClockSignal("dac"),
            i_i_rst36_n = ~ResetSignal("dac"),
            i_i_wait    = self.fifoempty_36,
            i_i_sample  = self.sample_36,
            o_o_rdreq   = self.readrequest_36,
            o_o_lrck    = self.dac_lrck,
            o_o_bck     = self.dac_bck,
            o_o_data    = self.dac_data,
        )

        self.comb += self.pads.sck.eq(ClockSignal("dac"))
        self.comb += self.pads.bck.eq(self.dac_bck)
        self.comb += self.pads.lrck.eq(self.dac_lrck)
        self.comb += self.pads.data.eq(self.dac_data)