ISA version of CS4231A

Hopefully someday will be merged with cs4231.c (SPARC version) git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@4741 c046a42c-6fe2-441c-8c8c-71466251a162
2024-11-28 06:13:46 +08:00 · 2008-06-13 10:48:22 +00:00 · 2008-06-13 10:48:22 +00:00 · cc53d26d4d
commit cc53d26d4d
parent 214c465f86
6 changed files with 693 additions and 2 deletions
--- a/Makefile.target
+++ b/Makefile.target
@ -497,6 +497,9 @@ endif
 ifdef CONFIG_GUS
 SOUND_HW += gus.o gusemu_hal.o gusemu_mixer.o
 endif
+ifdef CONFIG_CS4231A
+SOUND_HW += cs4231a.o
+endif

 ifdef CONFIG_VNC_TLS
 CPPFLAGS += $(CONFIG_VNC_TLS_CFLAGS)
--- a/9
+++ b/9
@ -90,6 +90,7 @@ slirp="yes"
 adlib="no"
 ac97="no"
 gus="no"
+cs4231a="no"
 oss="no"
 dsound="no"
 coreaudio="no"
@ -288,6 +289,8 @@ for opt do
  ;;
  --enable-gus) gus="yes"
  ;;
+  --enable-cs4231a) cs4231a="yes"
+  ;;
  --disable-kqemu) kqemu="no"
  ;;
  --disable-brlapi) brlapi="no"
@ -419,6 +422,7 @@ echo "  --enable-mingw32         enable Win32 cross compilation with mingw32"
 echo "  --enable-adlib           enable Adlib emulation"
 echo "  --enable-ac97            enable AC97 emulation"
 echo "  --enable-gus             enable Gravis Ultrasound emulation"
+echo "  --enable-cs4231a         enable CS4231A emulation"
 echo "  --enable-coreaudio       enable Coreaudio audio driver"
 echo "  --enable-alsa            enable ALSA audio driver"
 echo "  --enable-esd             enable EsoundD audio driver"
@ -830,6 +834,7 @@ echo "mingw32 support   $mingw32"
 echo "Adlib support     $adlib"
 echo "AC97 support      $ac97"
 echo "GUS support       $gus"
+echo "CS4231A support   $cs4231a"
 echo "CoreAudio support $coreaudio"
 echo "ALSA support      $alsa"
 echo "EsounD support    $esd"
@ -1038,6 +1043,10 @@ if test "$gus" = "yes" ; then
  echo "CONFIG_GUS=yes" >> $config_mak
  echo "#define CONFIG_GUS 1" >> $config_h
 fi
+if test "$cs4231a" = "yes" ; then
+  echo "CONFIG_CS4231A=yes" >> $config_mak
+  echo "#define CONFIG_CS4231A 1" >> $config_h
+fi
 if test "$oss" = "yes" ; then
  echo "CONFIG_OSS=yes" >> $config_mak
  echo "#define CONFIG_OSS 1" >> $config_h
--- a/hw/audiodev.h
+++ b/hw/audiodev.h
@ -12,3 +12,6 @@ int GUS_init (AudioState *s, qemu_irq *pic);

 /* ac97.c */
 int ac97_init (PCIBus *buf, AudioState *s);
+
+/* cs4231a.c */
+int cs4231a_init (AudioState *s, qemu_irq *pic);
--- a/hw/cs4231a.c
+++ b/hw/cs4231a.c
@ -0,0 +1,661 @@
+/*
+ * QEMU Crystal CS4231 audio chip emulation
+ *
+ * Copyright (c) 2006 Fabrice Bellard
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+#include "hw.h"
+#include "audiodev.h"
+#include "audio/audio.h"
+#include "isa.h"
+#include "qemu-timer.h"
+
+/*
+  Missing features:
+  ADC
+  Loopback
+  Timer
+  ADPCM
+  More...
+*/
+
+/* #define DEBUG */
+#define DEBUG_XLAW
+
+static struct {
+    int irq;
+    int dma;
+    int port;
+    int aci_counter;
+} conf = {9, 3, 0x534, 1};
+
+#ifdef DEBUG
+#define dolog(...) AUD_log ("cs4231a", __VA_ARGS__)
+#else
+#define dolog(...)
+#endif
+
+#define lwarn(...) AUD_log ("cs4231a", "warning: " __VA_ARGS__)
+#define lerr(...) AUD_log ("cs4231a", "error: " __VA_ARGS__)
+
+#define CS_REGS 16
+#define CS_DREGS 32
+
+typedef struct CSState {
+    QEMUSoundCard card;
+    qemu_irq *pic;
+    uint32_t regs[CS_REGS];
+    uint8_t dregs[CS_DREGS];
+    int irq;
+    int dma;
+    int port;
+    int shift;
+    int dma_running;
+    int audio_free;
+    int transferred;
+    int aci_counter;
+    SWVoiceOut *voice;
+    int16_t *tab;
+} CSState;
+
+#define IO_READ_PROTO(name)                             \
+    static uint32_t name (void *opaque, uint32_t addr)
+
+#define IO_WRITE_PROTO(name)                                            \
+    static void name (void *opaque, uint32_t addr, uint32_t val)
+
+#define GET_SADDR(addr) (addr & 3)
+
+#define MODE2 (1 << 6)
+#define MCE (1 << 6)
+#define PMCE (1 << 4)
+#define CMCE (1 << 5)
+#define TE (1 << 6)
+#define PEN (1 << 0)
+#define INT (1 << 0)
+#define IEN (1 << 1)
+#define PPIO (1 << 6)
+#define PI (1 << 4)
+#define CI (1 << 5)
+#define TI (1 << 6)
+
+enum {
+    Index_Address,
+    Index_Data,
+    Status,
+    PIO_Data
+};
+
+enum {
+    Left_ADC_Input_Control,
+    Right_ADC_Input_Control,
+    Left_AUX1_Input_Control,
+    Right_AUX1_Input_Control,
+    Left_AUX2_Input_Control,
+    Right_AUX2_Input_Control,
+    Left_DAC_Output_Control,
+    Right_DAC_Output_Control,
+    FS_And_Playback_Data_Format,
+    Interface_Configuration,
+    Pin_Control,
+    Error_Status_And_Initialization,
+    MODE_And_ID,
+    Loopback_Control,
+    Playback_Upper_Base_Count,
+    Playback_Lower_Base_Count,
+    Alternate_Feature_Enable_I,
+    Alternate_Feature_Enable_II,
+    Left_Line_Input_Control,
+    Right_Line_Input_Control,
+    Timer_Low_Base,
+    Timer_High_Base,
+    RESERVED,
+    Alternate_Feature_Enable_III,
+    Alternate_Feature_Status,
+    Version_Chip_ID,
+    Mono_Input_And_Output_Control,
+    RESERVED_2,
+    Capture_Data_Format,
+    RESERVED_3,
+    Capture_Upper_Base_Count,
+    Capture_Lower_Base_Count
+};
+
+static int freqs[2][8] = {
+    { 8000, 16000, 27420, 32000,    -1,    -1, 48000, 9000 },
+    { 5510, 11025, 18900, 22050, 37800, 44100, 33075, 6620 }
+};
+
+/* Tables courtesy http://hazelware.luggle.com/tutorials/mulawcompression.html */
+static int16_t MuLawDecompressTable[256] =
+{
+     -32124,-31100,-30076,-29052,-28028,-27004,-25980,-24956,
+     -23932,-22908,-21884,-20860,-19836,-18812,-17788,-16764,
+     -15996,-15484,-14972,-14460,-13948,-13436,-12924,-12412,
+     -11900,-11388,-10876,-10364, -9852, -9340, -8828, -8316,
+      -7932, -7676, -7420, -7164, -6908, -6652, -6396, -6140,
+      -5884, -5628, -5372, -5116, -4860, -4604, -4348, -4092,
+      -3900, -3772, -3644, -3516, -3388, -3260, -3132, -3004,
+      -2876, -2748, -2620, -2492, -2364, -2236, -2108, -1980,
+      -1884, -1820, -1756, -1692, -1628, -1564, -1500, -1436,
+      -1372, -1308, -1244, -1180, -1116, -1052,  -988,  -924,
+       -876,  -844,  -812,  -780,  -748,  -716,  -684,  -652,
+       -620,  -588,  -556,  -524,  -492,  -460,  -428,  -396,
+       -372,  -356,  -340,  -324,  -308,  -292,  -276,  -260,
+       -244,  -228,  -212,  -196,  -180,  -164,  -148,  -132,
+       -120,  -112,  -104,   -96,   -88,   -80,   -72,   -64,
+        -56,   -48,   -40,   -32,   -24,   -16,    -8,     0,
+      32124, 31100, 30076, 29052, 28028, 27004, 25980, 24956,
+      23932, 22908, 21884, 20860, 19836, 18812, 17788, 16764,
+      15996, 15484, 14972, 14460, 13948, 13436, 12924, 12412,
+      11900, 11388, 10876, 10364,  9852,  9340,  8828,  8316,
+       7932,  7676,  7420,  7164,  6908,  6652,  6396,  6140,
+       5884,  5628,  5372,  5116,  4860,  4604,  4348,  4092,
+       3900,  3772,  3644,  3516,  3388,  3260,  3132,  3004,
+       2876,  2748,  2620,  2492,  2364,  2236,  2108,  1980,
+       1884,  1820,  1756,  1692,  1628,  1564,  1500,  1436,
+       1372,  1308,  1244,  1180,  1116,  1052,   988,   924,
+        876,   844,   812,   780,   748,   716,   684,   652,
+        620,   588,   556,   524,   492,   460,   428,   396,
+        372,   356,   340,   324,   308,   292,   276,   260,
+        244,   228,   212,   196,   180,   164,   148,   132,
+        120,   112,   104,    96,    88,    80,    72,    64,
+         56,    48,    40,    32,    24,    16,     8,     0
+};
+
+static int16_t ALawDecompressTable[256] =
+{
+     -5504, -5248, -6016, -5760, -4480, -4224, -4992, -4736,
+     -7552, -7296, -8064, -7808, -6528, -6272, -7040, -6784,
+     -2752, -2624, -3008, -2880, -2240, -2112, -2496, -2368,
+     -3776, -3648, -4032, -3904, -3264, -3136, -3520, -3392,
+     -22016,-20992,-24064,-23040,-17920,-16896,-19968,-18944,
+     -30208,-29184,-32256,-31232,-26112,-25088,-28160,-27136,
+     -11008,-10496,-12032,-11520,-8960, -8448, -9984, -9472,
+     -15104,-14592,-16128,-15616,-13056,-12544,-14080,-13568,
+     -344,  -328,  -376,  -360,  -280,  -264,  -312,  -296,
+     -472,  -456,  -504,  -488,  -408,  -392,  -440,  -424,
+     -88,   -72,   -120,  -104,  -24,   -8,    -56,   -40,
+     -216,  -200,  -248,  -232,  -152,  -136,  -184,  -168,
+     -1376, -1312, -1504, -1440, -1120, -1056, -1248, -1184,
+     -1888, -1824, -2016, -1952, -1632, -1568, -1760, -1696,
+     -688,  -656,  -752,  -720,  -560,  -528,  -624,  -592,
+     -944,  -912,  -1008, -976,  -816,  -784,  -880,  -848,
+      5504,  5248,  6016,  5760,  4480,  4224,  4992,  4736,
+      7552,  7296,  8064,  7808,  6528,  6272,  7040,  6784,
+      2752,  2624,  3008,  2880,  2240,  2112,  2496,  2368,
+      3776,  3648,  4032,  3904,  3264,  3136,  3520,  3392,
+      22016, 20992, 24064, 23040, 17920, 16896, 19968, 18944,
+      30208, 29184, 32256, 31232, 26112, 25088, 28160, 27136,
+      11008, 10496, 12032, 11520, 8960,  8448,  9984,  9472,
+      15104, 14592, 16128, 15616, 13056, 12544, 14080, 13568,
+      344,   328,   376,   360,   280,   264,   312,   296,
+      472,   456,   504,   488,   408,   392,   440,   424,
+      88,    72,   120,   104,    24,     8,    56,    40,
+      216,   200,   248,   232,   152,   136,   184,   168,
+      1376,  1312,  1504,  1440,  1120,  1056,  1248,  1184,
+      1888,  1824,  2016,  1952,  1632,  1568,  1760,  1696,
+      688,   656,   752,   720,   560,   528,   624,   592,
+      944,   912,  1008,   976,   816,   784,   880,   848
+};
+
+static void cs_reset(void *opaque)
+{
+    CSState *s = opaque;
+
+    s->regs[Index_Address] = 0x40;
+    s->regs[Index_Data]    = 0x00;
+    s->regs[Status]        = 0x00;
+    s->regs[PIO_Data]      = 0x00;
+
+    s->dregs[Left_ADC_Input_Control]          = 0x00;
+    s->dregs[Right_ADC_Input_Control]         = 0x00;
+    s->dregs[Left_AUX1_Input_Control]         = 0x88;
+    s->dregs[Right_AUX1_Input_Control]        = 0x88;
+    s->dregs[Left_AUX2_Input_Control]         = 0x88;
+    s->dregs[Right_AUX2_Input_Control]        = 0x88;
+    s->dregs[Left_DAC_Output_Control]         = 0x80;
+    s->dregs[Right_DAC_Output_Control]        = 0x80;
+    s->dregs[FS_And_Playback_Data_Format]     = 0x00;
+    s->dregs[Interface_Configuration]         = 0x08;
+    s->dregs[Pin_Control]                     = 0x00;
+    s->dregs[Error_Status_And_Initialization] = 0x00;
+    s->dregs[MODE_And_ID]                     = 0x8a;
+    s->dregs[Loopback_Control]                = 0x00;
+    s->dregs[Playback_Upper_Base_Count]       = 0x00;
+    s->dregs[Playback_Lower_Base_Count]       = 0x00;
+    s->dregs[Alternate_Feature_Enable_I]      = 0x00;
+    s->dregs[Alternate_Feature_Enable_II]     = 0x00;
+    s->dregs[Left_Line_Input_Control]         = 0x88;
+    s->dregs[Right_Line_Input_Control]        = 0x88;
+    s->dregs[Timer_Low_Base]                  = 0x00;
+    s->dregs[Timer_High_Base]                 = 0x00;
+    s->dregs[RESERVED]                        = 0x00;
+    s->dregs[Alternate_Feature_Enable_III]    = 0x00;
+    s->dregs[Alternate_Feature_Status]        = 0x00;
+    s->dregs[Version_Chip_ID]                 = 0xa0;
+    s->dregs[Mono_Input_And_Output_Control]   = 0xa0;
+    s->dregs[RESERVED_2]                      = 0x00;
+    s->dregs[Capture_Data_Format]             = 0x00;
+    s->dregs[RESERVED_3]                      = 0x00;
+    s->dregs[Capture_Upper_Base_Count]        = 0x00;
+    s->dregs[Capture_Lower_Base_Count]        = 0x00;
+}
+
+static void cs_audio_callback (void *opaque, int free)
+{
+    CSState *s = opaque;
+    s->audio_free = free;
+}
+
+static void cs_reset_voices (CSState *s, uint32_t val)
+{
+    int xtal;
+    audsettings_t as;
+
+#ifdef DEBUG_XLAW
+    if (val == 0 || val == 32)
+        val = (1 << 4) | (1 << 5);
+#endif
+
+    xtal = val & 1;
+    as.freq = freqs[xtal][(val >> 1) & 7];
+
+    if (as.freq == -1) {
+        lerr ("unsupported frequency (val=%#x)\n", val);
+        goto error;
+    }
+
+    as.nchannels = (val & (1 << 4)) ? 2 : 1;
+    as.endianness = 0;
+    s->tab = NULL;
+
+    switch ((val >> 5) & ((s->dregs[MODE_And_ID] & MODE2) ? 7 : 3)) {
+    case 0:
+        as.fmt = AUD_FMT_U8;
+        s->shift = as.nchannels == 2;
+        break;
+
+    case 1:
+        s->tab = MuLawDecompressTable;
+        goto x_law;
+    case 3:
+        s->tab = ALawDecompressTable;
+    x_law:
+        as.fmt = AUD_FMT_S16;
+        as.endianness = AUDIO_HOST_ENDIANNESS;
+        s->shift = as.nchannels == 2;
+        break;
+
+    case 6:
+        as.endianness = 1;
+    case 2:
+        as.fmt = AUD_FMT_S16;
+        s->shift = as.nchannels;
+        break;
+
+    case 7:
+    case 4:
+        lerr ("attempt to use reserved format value (%#x)\n", val);
+        goto error;
+
+    case 5:
+        lerr ("ADPCM 4 bit IMA compatible format is not supported\n");
+        goto error;
+    }
+
+    s->voice = AUD_open_out (
+        &s->card,
+        s->voice,
+        "cs4231a",
+        s,
+        cs_audio_callback,
+        &as
+        );
+
+    if (s->dregs[Interface_Configuration] & PEN) {
+        if (!s->dma_running) {
+            DMA_hold_DREQ (s->dma);
+            AUD_set_active_out (s->voice, 1);
+            s->transferred = 0;
+        }
+        s->dma_running = 1;
+    }
+    else {
+        if (s->dma_running) {
+            DMA_release_DREQ (s->dma);
+            AUD_set_active_out (s->voice, 0);
+        }
+        s->dma_running = 0;
+    }
+    return;
+
+ error:
+    if (s->dma_running) {
+        DMA_release_DREQ (s->dma);
+        AUD_set_active_out (s->voice, 0);
+    }
+}
+
+IO_READ_PROTO (cs_read)
+{
+    CSState *s = opaque;
+    uint32_t saddr, iaddr, ret;
+
+    saddr = GET_SADDR (addr);
+    iaddr = ~0U;
+
+    switch (saddr) {
+    case Index_Address:
+        ret = s->regs[saddr] & ~0x80;
+        break;
+
+    case Index_Data:
+        if (!(s->dregs[MODE_And_ID] & MODE2))
+            iaddr = s->regs[Index_Address] & 0x0f;
+        else
+            iaddr = s->regs[Index_Address] & 0x1f;
+
+        ret = s->dregs[iaddr];
+        if (iaddr == Error_Status_And_Initialization) {
+            /* keep SEAL happy */
+            if (s->aci_counter) {
+                ret |= 1 << 5;
+                s->aci_counter -= 1;
+            }
+        }
+        break;
+
+    default:
+        ret = s->regs[saddr];
+        break;
+    }
+    dolog ("read %d:%d -> %d\n", saddr, iaddr, ret);
+    return ret;
+}
+
+IO_WRITE_PROTO (cs_write)
+{
+    CSState *s = opaque;
+    uint32_t saddr, iaddr;
+
+    saddr = GET_SADDR (addr);
+
+    switch (saddr) {
+    case Index_Address:
+        if (!(s->regs[Index_Address] & MCE) && (val & MCE)
+            && (s->dregs[Interface_Configuration] & (3 << 3)))
+            s->aci_counter = conf.aci_counter;
+
+        s->regs[Index_Address] = val & ~(1 << 7);
+        break;
+
+    case Index_Data:
+        if (!(s->dregs[MODE_And_ID] & MODE2))
+            iaddr = s->regs[Index_Address] & 0x0f;
+        else
+            iaddr = s->regs[Index_Address] & 0x1f;
+
+        switch (iaddr) {
+        case RESERVED:
+        case RESERVED_2:
+        case RESERVED_3:
+            lwarn ("attempt to write %#x to reserved indirect register %d\n",
+                   val, iaddr);
+            break;
+
+        case FS_And_Playback_Data_Format:
+            if (s->regs[Index_Address] & MCE) {
+                cs_reset_voices (s, val);
+            }
+            else {
+                if (s->dregs[Alternate_Feature_Status] & PMCE) {
+                    val = (val & ~0x0f) | (s->dregs[iaddr] & 0x0f);
+                    cs_reset_voices (s, val);
+                }
+                else {
+                    lwarn ("[P]MCE(%#x, %#x) is not set, val=%#x\n",
+                           s->regs[Index_Address],
+                           s->dregs[Alternate_Feature_Status],
+                           val);
+                    break;
+                }
+            }
+            s->dregs[iaddr] = val;
+            break;
+
+        case Interface_Configuration:
+            val &= ~(1 << 5);   /* D5 is reserved */
+            s->dregs[iaddr] = val;
+            if (val & PPIO) {
+                lwarn ("PIO is not supported (%#x)\n", val);
+                break;
+            }
+            if (val & PEN) {
+                if (!s->dma_running) {
+                    cs_reset_voices (s, s->dregs[FS_And_Playback_Data_Format]);
+                }
+            }
+            else {
+                if (s->dma_running) {
+                    DMA_release_DREQ (s->dma);
+                    AUD_set_active_out (s->voice, 0);
+                    s->dma_running = 0;
+                }
+            }
+            break;
+
+        case Error_Status_And_Initialization:
+            lwarn ("attempt to write to read only register %d\n", iaddr);
+            break;
+
+        case MODE_And_ID:
+            dolog ("val=%#x\n", val);
+            if (val & MODE2)
+                s->dregs[iaddr] |= MODE2;
+            else
+                s->dregs[iaddr] &= ~MODE2;
+            break;
+
+        case Alternate_Feature_Enable_I:
+            if (val & TE)
+                lerr ("timer is not yet supported\n");
+            s->dregs[iaddr] = val;
+            break;
+
+        case Alternate_Feature_Status:
+            if ((s->dregs[iaddr] & PI) && !(val & PI)) {
+                /* XXX: TI CI */
+                qemu_irq_lower (s->pic[s->irq]);
+                s->regs[Status] &= ~INT;
+            }
+            s->dregs[iaddr] = val;
+            break;
+
+        case Version_Chip_ID:
+            lwarn ("write to Version_Chip_ID register %#x\n", val);
+            s->dregs[iaddr] = val;
+            break;
+
+        default:
+            s->dregs[iaddr] = val;
+            break;
+        }
+        dolog ("written value %#x to indirect register %d\n", val, iaddr);
+        break;
+
+    case Status:
+        if (s->regs[Status] & INT) {
+            qemu_irq_lower (s->pic[s->irq]);
+        }
+        s->regs[Status] &= ~INT;
+        s->dregs[Alternate_Feature_Status] &= ~(PI | CI | TI);
+        break;
+
+    case PIO_Data:
+        lwarn ("attempt to write value %#x to PIO register\n", val);
+        break;
+    }
+}
+
+static int cs_write_audio (CSState *s, int nchan, int dma_pos,
+                           int dma_len, int len)
+{
+    int temp, net;
+    uint8_t tmpbuf[4096];
+
+    temp = len;
+    net = 0;
+
+    while (temp) {
+        int left = dma_len - dma_pos;
+        int copied;
+        size_t to_copy;
+
+        to_copy = audio_MIN (temp, left);
+        if (to_copy > sizeof (tmpbuf)) {
+            to_copy = sizeof (tmpbuf);
+        }
+
+        copied = DMA_read_memory (nchan, tmpbuf, dma_pos, to_copy);
+        if (s->tab) {
+            int i;
+            int16_t linbuf[4096];
+
+            for (i = 0; i < copied; ++i)
+                linbuf[i] = s->tab[tmpbuf[i]];
+            copied = AUD_write (s->voice, linbuf, copied << 1);
+            copied >>= 1;
+        }
+        else {
+            copied = AUD_write (s->voice, tmpbuf, copied);
+        }
+
+        temp -= copied;
+        dma_pos = (dma_pos + copied) % dma_len;
+        net += copied;
+
+        if (!copied) {
+            break;
+        }
+    }
+
+    return net;
+}
+
+static int cs_dma_read (void *opaque, int nchan, int dma_pos, int dma_len)
+{
+    CSState *s = opaque;
+    int copy, written;
+    int till = -1;
+
+    copy = s->voice ? (s->audio_free >> (s->tab != NULL)) : dma_len;
+
+    if (s->dregs[Pin_Control] & IEN) {
+        till = (s->dregs[Playback_Lower_Base_Count]
+            | (s->dregs[Playback_Upper_Base_Count] << 8)) << s->shift;
+        till -= s->transferred;
+        copy = audio_MIN (till, copy);
+    }
+
+    if ((copy <= 0) || (dma_len <= 0)) {
+        return dma_pos;
+    }
+
+    written = cs_write_audio (s, nchan, dma_pos, dma_len, copy);
+
+    dma_pos = (dma_pos + written) % dma_len;
+    s->audio_free -= (written << (s->tab != NULL));
+
+    if (written == till) {
+        s->regs[Status] |= INT;
+        s->dregs[Alternate_Feature_Status] |= PI;
+        s->transferred = 0;
+        qemu_irq_raise (s->pic[s->irq]);
+    }
+    else {
+        s->transferred += written;
+    }
+
+    return dma_pos;
+}
+
+static void cs_save(QEMUFile *f, void *opaque)
+{
+    CSState *s = opaque;
+    unsigned int i;
+
+    for (i = 0; i < CS_REGS; i++)
+        qemu_put_be32s(f, &s->regs[i]);
+
+    qemu_put_buffer(f, s->dregs, CS_DREGS);
+}
+
+static int cs_load(QEMUFile *f, void *opaque, int version_id)
+{
+    CSState *s = opaque;
+    unsigned int i;
+
+    if (version_id > 1)
+        return -EINVAL;
+
+    for (i = 0; i < CS_REGS; i++)
+        qemu_get_be32s(f, &s->regs[i]);
+
+    qemu_get_buffer(f, s->dregs, CS_DREGS);
+    return 0;
+}
+
+int cs4231a_init (AudioState *audio, qemu_irq *pic)
+{
+    int i;
+    CSState *s;
+
+    if (!audio) {
+        lerr ("No audio state\n");
+        return -1;
+    }
+
+    s = qemu_mallocz (sizeof (*s));
+    if (!s) {
+        lerr ("Could not allocate memory for cs4231a (%zu bytes)\n",
+               sizeof (*s));
+        return -1;
+    }
+
+    s->pic = pic;
+    s->irq = conf.irq;
+    s->dma = conf.dma;
+    s->port = conf.port;
+
+    for (i = 0; i < 4; i++) {
+        register_ioport_write (s->port + i, 1, 1, cs_write, s);
+        register_ioport_read (s->port + i, 1, 1, cs_read, s);
+    }
+
+    DMA_register_channel (s->dma, cs_dma_read, s);
+
+    register_savevm ("cs4231a", 0, 1, cs_save, cs_load, s);
+    qemu_register_reset (cs_reset, s);
+    cs_reset (s);
+
+    AUD_register_card (audio,"cs4231a", &s->card);
+    return 0;
+}
--- a/qemu-doc.texi
+++ b/qemu-doc.texi
@ -175,13 +175,16 @@ Adlib(OPL2) - Yamaha YM3812 compatible chip
@item
 Gravis Ultrasound GF1 sound card
@item
+CS4231A compatible sound card
+@item
 PCI UHCI USB controller and a virtual USB hub.
@end itemize

 SMP is supported with up to 255 CPUs.

-Note that adlib, ac97 and gus are only available when QEMU was configured
-with --enable-adlib, --enable-ac97 or --enable-gus respectively.
+Note that adlib, ac97, gus and cs4231a are only available when QEMU
+was configured with --enable-adlib, --enable-ac97, --enable-gus or
+--enable-cs4231a respectively.

 QEMU uses the PC BIOS from the Bochs project and the Plex86/Bochs LGPL
 VGA BIOS.
@ -191,6 +194,8 @@ QEMU uses YM3812 emulation by Tatsuyuki Satoh.
 QEMU uses GUS emulation(GUSEMU32 @url{http://www.deinmeister.de/gusemu/})
 by Tibor "TS" Schütz.

+CS4231A is the chip used in Windows Sound System and GUSMAX products
+
@c man end

@node pcsys_quickstart
--- a/vl.c
+++ b/vl.c
@ -7552,6 +7552,16 @@ struct soundhw soundhw[] = {
        { .init_isa = SB16_init }
    },

+#ifdef CONFIG_CS4231A
+    {
+        "cs4231a",
+        "CS4231A",
+        0,
+        1,
+        { .init_isa = cs4231a_init }
+    },
+#endif
+
 #ifdef CONFIG_ADLIB
    {
        "adlib",