////////////////////////////////////////////////////////////////////////////////
//
//  Microsoft Research Singularity
//
//  Copyright (c) Microsoft Corporation.  All rights reserved.
//
//  File:   Sb16.sg
//

using System;
using System.Text;
using System.Threading;
using System.Runtime.CompilerServices;  //StructAlign attribute
using System.Runtime.InteropServices;   //structLayout attribute
using System.GCs;

using Microsoft.SingSharp;
using Microsoft.SingSharp.Reflection;

using Microsoft.Singularity;
using Microsoft.Singularity.Channels;
using Microsoft.Singularity.Extending;
using Microsoft.Singularity.Directory;
using Microsoft.Singularity.Io;
using Microsoft.Singularity.Configuration;

using Microsoft.Singularity.V1.Services;
using Microsoft.Singularity.V1.Threads;
using Allocation = Microsoft.Singularity.V1.Services.SharedHeapService.Allocation;

using Microsoft.Singularity.Drivers;
[assembly: Transform(typeof(DriverResourceTransform))]

namespace Microsoft.Singularity.Drivers.Sb16
{
    // Declare all resource needs in one place:
    [DriverCategory]
    [Signature("/pnp/PNPB003")]
    internal class Sb16Resources : DriverCategoryDeclaration
    {
        [IoPortRange(0, Default = 0x0220, Length = 0x10)]
        internal readonly IoPortRange basePorts;

        [IoPortRange(1, Default = 0x0380, Length = 0x10)]
        internal readonly IoPortRange gamePorts;

        [IoIrqRange(2, Default = 0x05)]
        internal readonly IoIrqRange irq;

        [IoDmaRange(3, Default = 0x01)]
        internal readonly IoDmaRange dma8;

        [IoDmaRange(4, Default = 0x05)]
        internal readonly IoDmaRange dma16;

        [IoFixedMemoryRange(AddressBits = 24, Alignment = 0x20000, Length = 0x4000)]
        internal readonly IoMemoryRange fixedMem;

        [ExtensionEndpoint]
        internal TRef<ExtensionContract.Exp:Start> ec;

        [ServiceEndpoint(typeof(SoundDeviceContract))]
        internal TRef<ServiceProviderContract.Exp:Start> audiosp;

        internal int DriverMain(string instance) {
            return Sb16Channels.DriverMain(this);
        }

    }

    //////////////////////////////////////////////////////////////////////////
    //
    //  The Sb16Channels class has a single message pump that manages messages
    //  to/from the "/dev" namespace and incoming play requests.
    //
    public class Sb16Channels
    {
        internal static int DriverMain(Sb16Resources! resources)
        {
            // Create and Initialize the device
            Sb16Device device = new Sb16Device(resources);
            device.Initialize();

            // get the endpoints and set up the main switch receive
            ExtensionContract.Exp ec = ((!)resources.ec).Acquire();
            ServiceProviderContract.Exp sp = ((!)resources.audiosp).Acquire();

            // Signal parent that driver is initialized.
            Tracing.Log(Tracing.Audit, "Sb16 Registered");
            ec.SendSuccess();

            // create a set of all client endpoints connected to the sound
            // device
            ESet<SoundDeviceContract.Exp:Ready> clients
                = new ESet<SoundDeviceContract.Exp:Ready>();

            try {
                for (bool run = true; run;) {
                    switch receive {
                        // Listen for new connections
                        case sp.Connect(candidate):
                            SoundDeviceContract.Exp newClient = candidate as SoundDeviceContract.Exp;
                            if (newClient != null) {
                                newClient.SendSuccess();
                                clients.Add(newClient);
                                sp.SendAckConnect();
                            }
                            else {
                                sp.SendNackConnect(candidate);
                            }
                            break;

                            // Listen for client requests
                            case ep.RecvPlayPcm(data, offset, length, sampleRate, stereo, signed,
                                                eightBit) in clients:
                                {
                                    Tracing.Log(Tracing.Debug, "PlayPcm({0:d})",
                                                (UIntPtr)unchecked((uint)length));
                                    device.PlayPcm((!)data, offset, length, sampleRate,
                                                   stereo, signed, eightBit);
                                    ep.SendAckPlayPcm(data);
                                    // add client endpoint back into set.
                                    clients.Add(ep);
                                    break;
                                }

                            // Listen for client requests
                        case ep.RecvPlayWav(data) in clients:
                            {
                                Tracing.Log(Tracing.Debug, "PlayWav({0:d}",
                                            (UIntPtr)unchecked((uint)data.Length));
                                device.PlayWav(data);

                                ep.SendAckPlayWav(data);
                                // add client endpoint back into set.
                                clients.Add(ep);
                                break;
                            }

                            // Listen for client departure
                        case ep.ChannelClosed() in clients:
                            Tracing.Log(Tracing.Debug, "Client channel closes.");
                            delete ep;
                            break;

                            // Listen for extension parent
                        case ec.Shutdown():
                            ec.SendAckShutdown();
                            run = false;
                            break;

                        case clients.Empty() && sp.ChannelClosed():
                            Tracing.Log(Tracing.Debug, "Sound driver no longer needed.");
                            run = false;
                            break;
                    }
                }
            }
            finally {
                Tracing.Log(Tracing.Debug, "Sb16 finished message pump.");
                delete sp;
                clients.Dispose();
            }

            // Close the device
            device.Finalize();

            Tracing.Log(Tracing.Audit, "Shutdown");
            delete ec;
            return 0;
        }
    }

    public class Sb16Device
    {
        private const ushort    BUFSIZE = 0x4000;
        private const ushort    HALFBUFSIZE = BUFSIZE / 2;

        private IoIrq!          irq;
        private Thread          irqWorker;
        private bool            irqWorkerStop;
        private AutoResetEvent! playEndEvent;

        private IoDma!          dma8;
        private IoDma!          dma16;
        private IoMemory!       fixedBuffer;

        private IoPort!         resetPort;
        private IoPort!         readDataPort;
        private IoPort!         writePort;
        private IoPort!         readStatPort;
        private IoPort!         intAck16Port;
        private IoPort!         mixAddrPort;
        private IoPort!         mixDataPort;

        // Variables re-used for each play request.
        private unsafe SharedHeapService.Allocation *    pcmData;
        private int             pcmLeft = 0;
        private int             pcmOffset = 0;

        //[invariant ((pcmData == null) ||
        //(0 <= pcmOffset && pcmOffset + pcmLeft <= pcmData.Length));]

        private ushort          samplesPerSec;
        private int             halfBufOffset = 0;
        //[invariant (halfBufOffset == 0 || halfBufOffset == HALFBUFSIZE);]

        private bool            done = true;
        private bool            exit = false;
        private ushort          dspVersion = 0;

        const ushort MIX_ADDR_REG       = 0x04; // MIXER CHIP REGISTER ADDRESS PORT : WRITE
        const ushort MIX_DATA_REG       = 0x05; // MIXER CHIP DATA ADDRESS PORT : READ/WRITE
        const ushort DSP_RESET_REG      = 0x06; // DSP RESET : WRITE
        const ushort DSP_READ_DATA_REG  = 0x0A; // DSP READ DATA PORT   : READ
        const ushort DSP_WRITE_REG      = 0x0C; // DSP WRITE COMMAND/DATA PORT  : READ/WRITE
        const ushort DSP_READ_STAT_REG  = 0x0E; // DSP READ BUFFER STATUS PORT  : READ
        const ushort DSP_INT_ACK16_REG  = 0x0F; // Interrupt Ack Port 16bit :READ

        private const byte DSPREADY = 0xAA;// code for DSP READY

        private enum DspMode
        {
            STEREO    = 0x20, // Stereo bit.
            SIGNED    = 0x10, // Signed bit.
            NORMAL    = 0x00, // Neither stereo nor signed.
        }

        private enum DspCommand
        {
            SETSAMPRATE     = 0x41, // Set sample rate ( only available in 4.xx)
            PROGAUTOINIT16  = 0xb6, // program 16 bit digital input output
            PROGAUTOINIT8   = 0xc6, // program 8 bit digital input output
            SPKRON          = 0xd1, // turn speaker on
            SPKROFF         = 0xd3, // turn off speaker
            EXITAUTOINIT16  = 0xd9, // exit 16-bit auto init DMA mode
            EXITAUTOINIT8   = 0xda, // exit 8 bit auto init DMA mode
            GETDSPVERSION   = 0xe1, // Get DSP version number
        }

        private enum DspRegisters
        {
            IntStatPort = 0x82,
        }

        ///////////////////////////////////////////////////////////////////////
        //
        internal Sb16Device(Sb16Resources! res)
        {
            // Ranges[0]: Fixed I/O Port bas=0220 len=10  0220..022f
            // Ranges[1]: Fixed I/O Port bas=0380 len=10  0380..038f
            // Ranges[2]: IRQ 5
            // Ranges[3]: DMA 1 - 8-bit DMA
            // Ranges[4]: DMA 5 - 16-bit DMA

            playEndEvent = new AutoResetEvent(false);

            assume res.irq != null;
            assume res.dma8 != null;
            assume res.dma16 != null;
            assume res.fixedMem != null;
            assume res.basePorts != null;

            // get Irq and Dma channels from the resources
            irq = (!)res.irq.IrqAtOffset(0);
            dma8 = (!)res.dma8.DmaAtOffset(0);
            dma16 = (!)res.dma16.DmaAtOffset(0);

            mixAddrPort  = (!)res.basePorts.PortAtOffset(MIX_ADDR_REG, 1,
                                                         Access.Write);
            mixDataPort  = (!)res.basePorts.PortAtOffset(MIX_DATA_REG, 1,
                                                         Access.ReadWrite);
            resetPort    = (!)res.basePorts.PortAtOffset(DSP_RESET_REG, 1,
                                                         Access.Write);
            readDataPort = (!)res.basePorts.PortAtOffset(DSP_READ_DATA_REG, 1,
                                                         Access.Read);
            writePort    = (!)res.basePorts.PortAtOffset(DSP_WRITE_REG, 1,
                                                         Access.ReadWrite);
            readStatPort = (!)res.basePorts.PortAtOffset(DSP_READ_STAT_REG, 1,
                                                         Access.Read);
            intAck16Port = (!)res.basePorts.PortAtOffset(DSP_INT_ACK16_REG, 1,
                                                         Access.Read);

            base();

            // Now get the fixed memory region out of the resources:
            fixedBuffer = (!)res.fixedMem.MemoryAtOffset(0, BUFSIZE,
                                                         true, true);

        }

        public void Initialize()
        {
            Tracing.Log(Tracing.Debug, "Initialize");

            Tracing.Log(Tracing.Debug, "Fixed Buffer: {0,8:x8}",
                        fixedBuffer.PhysicalAddress.Value);

            bool iflag = PrivilegedGate.DisableInterrupts();
            try {
                irq.RegisterInterrupt();

                DspReset();
                DspWrite(DspCommand.SPKRON);
            }
            finally {
                PrivilegedGate.RestoreInterrupts(iflag);
            }

            irqWorker     = new Thread(new ThreadStart(IrqWorkerPump));
            irqWorkerStop = false;
            irqWorker.Start();
        }

        public void Finalize()
        {
            bool iflag = PrivilegedGate.DisableInterrupts();
            try {
                DspWrite(DspCommand.SPKROFF);
                irqWorkerStop = true;
                irq.ReleaseInterrupt();
            }
            finally {
                PrivilegedGate.RestoreInterrupts(iflag);
            }

#if CAN_JOIN
            if (irqWorker != null) {
                irqWorker.Join();
                irqWorker = null;
            }
#endif
        }

        public void PlayWav(byte[]! in ExHeap data)
        {
            if (data.Length < 64) {
                Tracing.Log(Tracing.Warning, "File too short for WAV");
                return;
            }

            if (data[0] != 'R' || data[1] != 'I' || data[2] != 'F' || data[3] != 'F' ||
                data[8] != 'W' || data[9] != 'A' || data[10] != 'V' || data[11] != 'E' ||
                data[12] != 'f' || data[13] != 'm' || data[14] != 't' || data[15] != ' ' ||
                data[20] != 1 || data[21] != 0) {
                Tracing.Log(Tracing.Warning, "No WAVE signature");
                return;
            }

            ushort numChannels = Bitter.ToUInt16(data, 22);
            ushort samplesPerSec = (ushort)Bitter.ToUInt32(data, 24);
            ushort bitsPerSample = Bitter.ToUInt16(data, 34);

            if ((numChannels != 1 && numChannels != 2) ||
                (samplesPerSec > 48000) ||
                (bitsPerSample != 8 && bitsPerSample != 16)) {
                Tracing.Log(Tracing.Warning, "Unrecognized WAV fmt parameters.");
                return;
            }

            for (int offset = 12;;) {
                if (data.Length < offset + 8) {
                    Tracing.Log(Tracing.Warning, "Malformed WAV file at {0}.",
                                (UIntPtr)offset);
                    return;
                }

                if (data[offset] == 'd' &&
                    data[offset+1] == 'a' &&
                    data[offset+2] == 't' &&
                    data[offset+3] == 'a') {

                    PlayPcm(data,
                            offset + 8,
                            Bitter.ToInt32(data, offset + 4),
                            samplesPerSec,
                            numChannels == 2,
                            bitsPerSample != 8,
                            bitsPerSample == 8);
                    return;
                }

                offset += 8 + Bitter.ToInt32(data, offset + 4);
            }
        }

        public unsafe void PlayPcm(byte[]! in ExHeap buffer,
                                   int offset,
                                   int length,
                                   ushort sampleRate,
                                   bool stereo,
                                   bool signed,
                                   bool eightBit)
            //[requires offset >= 0 && offset + length <= data.Length;]
        {
            Tracing.Log(Tracing.Debug, "buff.Length={0}, offset={1}, length={2} ={3}",
                        (UIntPtr)unchecked((uint)buffer.Length),
                        (UIntPtr)unchecked((uint)offset),
                        (UIntPtr)unchecked((uint)length),
                        (UIntPtr)unchecked((uint)offset + length));

            done = false;
            exit = false;

            pcmData = (Allocation *)buffer;
            pcmOffset = offset;
            pcmLeft = length;
            samplesPerSec = sampleRate;

            if (eightBit) {
                Tracing.Log(Tracing.Debug, "Playing 8-bit sound (byte={0}, {1} Hz, {2})",
                            (UIntPtr)length, sampleRate, (UIntPtr)(stereo ? 2 : 1));
                PlayDmaAutoInit8(stereo, signed);
            }
            else {
                Tracing.Log(Tracing.Debug, "Playing 16-bit sound (byte={0}, {1} Hz, {2})",
                            (UIntPtr)length, sampleRate, (UIntPtr)(stereo ? 2 : 1));
                PlayDmaAutoInit16(stereo, signed);
            }

            playEndEvent.WaitOne();
        }

        private void PlayDmaAutoInit8(bool stereo, bool signed)
        {
            halfBufOffset = 0;

            bool iflag = PrivilegedGate.DisableInterrupts();
            try {
                dma8.DisableChannel(); //Disable DMA channel while programming it
                dma8.SetControlByteMask(IoDma.Settings.SingleMode |
                                        IoDma.Settings.AddressIncrement |
                                        IoDma.Settings.AutoInit |
                                        IoDma.Settings.ReadTransfer);
                dma8.ClearFlipFlop(); //Clear Flip-Flop [ref]swap clear and control statement
                dma8.SetControlByte(); //Put into 8-bit Single Cycle mode
                dma8.SetBuffer(fixedBuffer);
                dma8.SetTransferLength(BUFSIZE - 1);
                dma8.EnableChannel(); //enable DMA channelFillBuffer();

                DspWrite(DspCommand.SETSAMPRATE);
                DspWriteBig(samplesPerSec);

                done = FillHalfBuffer();
                DspWrite(DspCommand.PROGAUTOINIT8);
                DspWriteBMode(stereo, signed);
                DspWriteLittle(HALFBUFSIZE - 1);

                if (done) {
                    DspWrite(DspCommand.EXITAUTOINIT8);
                    exit = true;
                }
                else {
                    done = FillHalfBuffer();
                }
            }
            finally {
                PrivilegedGate.RestoreInterrupts(iflag);
            }
        }

        private void PlayDmaAutoInit16(bool stereo, bool signed)
        {
            halfBufOffset = 0;

            bool iflag = PrivilegedGate.DisableInterrupts();
            try {
                dma16.DisableChannel(); //Disable DMA channel while programming it
                dma16.SetControlByteMask(IoDma.Settings.SingleMode |
                                         IoDma.Settings.AddressIncrement |
                                         IoDma.Settings.AutoInit |
                                         IoDma.Settings.ReadTransfer);
                dma16.ClearFlipFlop(); //Clear Flip-Flop [ref]swap clear and control statement
                dma16.SetControlByte(); //Put into 8-bit Single Cycle mode
                dma16.SetBuffer(fixedBuffer);
                dma16.SetTransferLength((BUFSIZE / 2) - 1);
                dma16.EnableChannel(); //enable DMA channelFillBuffer();

                DspWrite(DspCommand.SETSAMPRATE);
                DspWriteBig(samplesPerSec);

                done = FillHalfBuffer();
                DspWrite(DspCommand.PROGAUTOINIT16);
                DspWriteBMode(stereo, signed);
                DspWriteLittle((HALFBUFSIZE / 2) - 1);

                if (done) {
                    DspWrite(DspCommand.EXITAUTOINIT16);
                    exit = true;
                }
                else {
                    done = FillHalfBuffer();
                }
            }
            finally {
                PrivilegedGate.RestoreInterrupts(iflag);
            }
        }

        private unsafe bool FillHalfBuffer()
        {
            //transfer data from snddat.Sound to Buffer
            int use = Math.Min(pcmLeft, HALFBUFSIZE);
            if (use != 0) {
                byte[] in ExHeap buffer = (byte[] in ExHeap)pcmData;

                Bitter.ToIoMemory(buffer, pcmOffset, use,
                                  fixedBuffer, halfBufOffset);


                if (use < HALFBUFSIZE) {
                    // Pad with empty sound as needed.
                    fixedBuffer.Write8(halfBufOffset + use, 0, HALFBUFSIZE - use);
                }

                pcmOffset += use;
                pcmLeft -= use;

                if (halfBufOffset > 0) {
                    halfBufOffset = 0;
                }
                else {
                    halfBufOffset = HALFBUFSIZE;
                }
            }
            Tracing.Log(Tracing.Debug,
                        "offset:{0,6}, left:{1,6}, use:{2,5}, buffer:{3,5}",
                        (UIntPtr)unchecked((uint)pcmOffset),
                        (UIntPtr)unchecked((uint)pcmLeft),
                        (UIntPtr)unchecked((uint)use),
                        (UIntPtr)unchecked((uint)halfBufOffset));
            return (use < HALFBUFSIZE);
        }

        private void IrqWorkerPump()
        {
            //  When this IRQ is signaled, there may be two half-buffers
            //  at play.  The first just finished (thus triggering the IRQ);
            //  the second is going out the DSP as we process.
            //  If the done flag is set, the last half-buffer has been filled.
            //  If the exit flag is set, then this *IS* the last half-buffer.
            //
            Tracing.Log(Tracing.Audit, "Start worker thread.");
            while (irqWorkerStop == false) {
                irq.WaitForInterrupt();

                if (irqWorkerStop) {
                    break;
                }

                bool iflag = PrivilegedGate.DisableInterrupts();
                try {
                    byte bt = (byte)ReadMixPort((byte)DspRegisters.IntStatPort);
                    bt &= 0x7u;

                    if (bt == 1) {
                        readStatPort.Read8();
                        if (exit) {
                            playEndEvent.Set();
                            continue;
                        }
                        if (done) {
                            DspWrite(DspCommand.EXITAUTOINIT8);
                            exit = true;
                        }
                    }
                    else if (bt == 2) {
                        intAck16Port.Read8();
                        if (exit) {
                            playEndEvent.Set();
                            continue;
                        }
                        if (done) {
                            DspWrite(DspCommand.EXITAUTOINIT16);
                            exit = true;
                        }
                    }
                    else if (irqWorkerStop == false) {
                        Tracing.Log(Tracing.Error, "Interrupt status {0}", bt);
                        DebugStub.Break();
                    }

                    done = FillHalfBuffer();
                }
                finally {
                    irq.AckInterrupt();
                    PrivilegedGate.RestoreInterrupts(iflag);
                }
            }
        }

#region DSP

        private void DspWaitForData()
        {
            for (int i = 0; i < 100; i++) {
                if ((readStatPort.Read8() & 0x80) != 0) {
                    return;
                }
            }
            Tracing.Log(Tracing.Error, "DSP Data Avail FAILED");
            DebugStub.Break();
        }

        private byte DspRead()
        {
            DspWaitForData(); // wait for data to be available
            return readDataPort.Read8();
        }

        private void DspGetVersion()
        {
            byte VersionMaj;
            byte VersionMin;

            DspWrite(DspCommand.GETDSPVERSION); //send instruction
            DspWaitForData(); //wait for dsp to flag u for instruction

            VersionMaj = DspRead();
            VersionMin = DspRead();

            dspVersion = (ushort)((VersionMaj << 8) | VersionMin);
            Tracing.Log(Tracing.Debug, "Hardware Version : {0:x4}", dspVersion);
        }

        private bool DspReset()
        {
            resetPort.Write8(0x01);
            Thread.SpinWait(10000);
            resetPort.Write8(0x00);

            for (int i = 0; i < 0xffff; i++) {
                DspWaitForData();
                byte bt = DspRead();

                if (bt == DSPREADY) {
                    DspGetVersion();
                    return true;
                }
                else {
                    Tracing.Log(Tracing.Warning, "BT {0} is not DSP_READY", bt);
                }
            }

            return false;
        }

        private void DspWait()
        {
            for (int i = 0; i < 100; i++) {
                if ((writePort.Read8() & 0x80) == 0) {
                    return;
                }
            }
            Tracing.Log(Tracing.Error, "DSP Wait FAlLED.");
            DebugStub.Break();

        }

        private void DspWrite(DspCommand cmd)
        {
            DspWait();
            writePort.Write8((byte)cmd);
        }

        private void DspWriteBMode(bool stereo, bool signed)
        {
            DspWait();
            DspMode mode = DspMode.NORMAL;
            if (stereo) {
                mode |= DspMode.STEREO;
            }
            if (signed) {
                mode |= DspMode.SIGNED;
            }

            writePort.Write8((byte)mode);
        }

        // Little-endian write.
        private void DspWriteLittle(ushort value)
        {
            DspWait();
            writePort.Write8((byte)(value & 0xff));
            DspWait();
            writePort.Write8((byte)(value >> 8));
        }

        // Big-endian write.
        private void DspWriteBig(ushort value)
        {
            DspWait();
            writePort.Write8((byte)(value >> 8));
            DspWait();
            writePort.Write8((byte)(value & 0xff));
        }

        private void WriteMixPort(byte Add,byte data)
        {
            mixAddrPort.Write8(Add);
            mixDataPort.Write8(data);
        }

        private byte ReadMixPort(byte Add)
        {
            mixAddrPort.Write8(Add);
            return mixDataPort.Read8();
        }

#endregion // DSP
    }
}