hw/audio/via-ac97: Basic implementation of audio playback

Add basic implementation of the AC'97 sound part used in VIA south
bridge chips. Not all features of the device is emulated, only one
playback channel is supported for now but this is enough to get sound
output from some guests using this device on pegasos2.

Signed-off-by: BALATON Zoltan <balaton@eik.bme.hu>
Reviewed-by: Volker Rümelin <vr_qemu@t-online.de>
Tested-by: Rene Engel <ReneEngel80@emailn.de>
Message-Id: <63b99410895312f40e7be479f581da0805e605a1.1678188711.git.balaton@eik.bme.hu>
Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>

2 files changed, 455 insertions, 6 deletions

diff --git a/hw/audio/trace-events b/hw/audio/trace-events
index e0e71cd..4dec48a 100644
--- a/hw/audio/trace-events
+++ b/hw/audio/trace-events
@@ -11,3 +11,9 @@ hda_audio_running(const char *stream, int nr, bool running) "st %s, nr %d, run %
 hda_audio_format(const char *stream, int chan, const char *fmt, int freq) "st %s, %d x %s @ %d Hz"
 hda_audio_adjust(const char *stream, int pos) "st %s, pos %d"
 hda_audio_overrun(const char *stream) "st %s"
+
+#via-ac97.c
+via_ac97_codec_write(uint8_t addr, uint16_t val) "0x%x <- 0x%x"
+via_ac97_sgd_fetch(uint32_t curr, uint32_t addr, char stop, char eol, char flag, uint32_t len) "curr=0x%x addr=0x%x %c%c%c len=%d"
+via_ac97_sgd_read(uint64_t addr, unsigned size, uint64_t val) "0x%"PRIx64" %d -> 0x%"PRIx64
+via_ac97_sgd_write(uint64_t addr, unsigned size, uint64_t val) "0x%"PRIx64" %d <- 0x%"PRIx64
diff --git a/hw/audio/via-ac97.c b/hw/audio/via-ac97.c
index d1a856f..676254b 100644
--- a/hw/audio/via-ac97.c
+++ b/hw/audio/via-ac97.c
@@ -1,39 +1,482 @@
 /*
  * VIA south bridges sound support
  *
+ * Copyright (c) 2022-2023 BALATON Zoltan
+ *
  * This work is licensed under the GNU GPL license version 2 or later.
  */
 
 /*
- * TODO: This is entirely boiler plate just registering empty PCI devices
- * with the right ID guests expect, functionality should be added here.
+ * TODO: This is only a basic implementation of one audio playback channel
+ *       more functionality should be added here.
  */
 
 #include "qemu/osdep.h"
+#include "qemu/log.h"
 #include "hw/isa/vt82c686.h"
-#include "hw/pci/pci_device.h"
+#include "ac97.h"
+#include "trace.h"
+
+#define CLEN_IS_EOL(x)  ((x)->clen & BIT(31))
+#define CLEN_IS_FLAG(x) ((x)->clen & BIT(30))
+#define CLEN_IS_STOP(x) ((x)->clen & BIT(29))
+#define CLEN_LEN(x)     ((x)->clen & 0xffffff)
+
+#define STAT_ACTIVE BIT(7)
+#define STAT_PAUSED BIT(6)
+#define STAT_TRIG   BIT(3)
+#define STAT_STOP   BIT(2)
+#define STAT_EOL    BIT(1)
+#define STAT_FLAG   BIT(0)
+
+#define CNTL_START  BIT(7)
+#define CNTL_TERM   BIT(6)
+#define CNTL_PAUSE  BIT(3)
+
+static void open_voice_out(ViaAC97State *s);
+
+static uint16_t codec_rates[] = { 8000, 11025, 16000, 22050, 32000, 44100,
+                                  48000 };
+
+#define CODEC_REG(s, o)  ((s)->codec_regs[(o) / 2])
+#define CODEC_VOL(vol, mask)  ((255 * ((vol) & mask)) / mask)
+
+static void codec_volume_set_out(ViaAC97State *s)
+{
+    int lvol, rvol, mute;
+
+    lvol = 255 - CODEC_VOL(CODEC_REG(s, AC97_Master_Volume_Mute) >> 8, 0x1f);
+    lvol *= 255 - CODEC_VOL(CODEC_REG(s, AC97_PCM_Out_Volume_Mute) >> 8, 0x1f);
+    lvol /= 255;
+    rvol = 255 - CODEC_VOL(CODEC_REG(s, AC97_Master_Volume_Mute), 0x1f);
+    rvol *= 255 - CODEC_VOL(CODEC_REG(s, AC97_PCM_Out_Volume_Mute), 0x1f);
+    rvol /= 255;
+    mute = CODEC_REG(s, AC97_Master_Volume_Mute) >> MUTE_SHIFT;
+    mute |= CODEC_REG(s, AC97_PCM_Out_Volume_Mute) >> MUTE_SHIFT;
+    AUD_set_volume_out(s->vo, mute, lvol, rvol);
+}
+
+static void codec_reset(ViaAC97State *s)
+{
+    memset(s->codec_regs, 0, sizeof(s->codec_regs));
+    CODEC_REG(s, AC97_Reset) = 0x6a90;
+    CODEC_REG(s, AC97_Master_Volume_Mute) = 0x8000;
+    CODEC_REG(s, AC97_Headphone_Volume_Mute) = 0x8000;
+    CODEC_REG(s, AC97_Master_Volume_Mono_Mute) = 0x8000;
+    CODEC_REG(s, AC97_Phone_Volume_Mute) = 0x8008;
+    CODEC_REG(s, AC97_Mic_Volume_Mute) = 0x8008;
+    CODEC_REG(s, AC97_Line_In_Volume_Mute) = 0x8808;
+    CODEC_REG(s, AC97_CD_Volume_Mute) = 0x8808;
+    CODEC_REG(s, AC97_Video_Volume_Mute) = 0x8808;
+    CODEC_REG(s, AC97_Aux_Volume_Mute) = 0x8808;
+    CODEC_REG(s, AC97_PCM_Out_Volume_Mute) = 0x8808;
+    CODEC_REG(s, AC97_Record_Gain_Mute) = 0x8000;
+    CODEC_REG(s, AC97_Powerdown_Ctrl_Stat) = 0x000f;
+    CODEC_REG(s, AC97_Extended_Audio_ID) = 0x0a05;
+    CODEC_REG(s, AC97_Extended_Audio_Ctrl_Stat) = 0x0400;
+    CODEC_REG(s, AC97_PCM_Front_DAC_Rate) = 48000;
+    CODEC_REG(s, AC97_PCM_LR_ADC_Rate) = 48000;
+    /* Sigmatel 9766 (STAC9766) */
+    CODEC_REG(s, AC97_Vendor_ID1) = 0x8384;
+    CODEC_REG(s, AC97_Vendor_ID2) = 0x7666;
+}
+
+static uint16_t codec_read(ViaAC97State *s, uint8_t addr)
+{
+    return CODEC_REG(s, addr);
+}
+
+static void codec_write(ViaAC97State *s, uint8_t addr, uint16_t val)
+{
+    trace_via_ac97_codec_write(addr, val);
+    switch (addr) {
+    case AC97_Reset:
+        codec_reset(s);
+        return;
+    case AC97_Master_Volume_Mute:
+    case AC97_PCM_Out_Volume_Mute:
+        if (addr == AC97_Master_Volume_Mute) {
+            if (val & BIT(13)) {
+                val |= 0x1f00;
+            }
+            if (val & BIT(5)) {
+                val |= 0x1f;
+            }
+        }
+        CODEC_REG(s, addr) = val & 0x9f1f;
+        codec_volume_set_out(s);
+        return;
+    case AC97_Extended_Audio_Ctrl_Stat:
+        CODEC_REG(s, addr) &= ~EACS_VRA;
+        CODEC_REG(s, addr) |= val & EACS_VRA;
+        if (!(val & EACS_VRA)) {
+            CODEC_REG(s, AC97_PCM_Front_DAC_Rate) = 48000;
+            CODEC_REG(s, AC97_PCM_LR_ADC_Rate) = 48000;
+            open_voice_out(s);
+        }
+        return;
+    case AC97_PCM_Front_DAC_Rate:
+    case AC97_PCM_LR_ADC_Rate:
+        if (CODEC_REG(s, AC97_Extended_Audio_Ctrl_Stat) & EACS_VRA) {
+            int i;
+            uint16_t rate = val;
+
+            for (i = 0; i < ARRAY_SIZE(codec_rates) - 1; i++) {
+                if (rate < codec_rates[i] +
+                    (codec_rates[i + 1] - codec_rates[i]) / 2) {
+                    rate = codec_rates[i];
+                    break;
+                }
+            }
+            if (rate > 48000) {
+                rate = 48000;
+            }
+            CODEC_REG(s, addr) = rate;
+            open_voice_out(s);
+        }
+        return;
+    case AC97_Powerdown_Ctrl_Stat:
+        CODEC_REG(s, addr) = (val & 0xff00) | (CODEC_REG(s, addr) & 0xff);
+        return;
+    case AC97_Extended_Audio_ID:
+    case AC97_Vendor_ID1:
+    case AC97_Vendor_ID2:
+        /* Read only registers */
+        return;
+    default:
+        qemu_log_mask(LOG_UNIMP,
+                      "via-ac97: Unimplemented codec register 0x%x\n", addr);
+        CODEC_REG(s, addr) = val;
+    }
+}
+
+static void fetch_sgd(ViaAC97SGDChannel *c, PCIDevice *d)
+{
+    uint32_t b[2];
+
+    if (c->curr < c->base) {
+        c->curr = c->base;
+    }
+    if (unlikely(pci_dma_read(d, c->curr, b, sizeof(b)) != MEMTX_OK)) {
+        qemu_log_mask(LOG_GUEST_ERROR,
+                      "via-ac97: DMA error reading SGD table\n");
+        return;
+    }
+    c->addr = le32_to_cpu(b[0]);
+    c->clen = le32_to_cpu(b[1]);
+    trace_via_ac97_sgd_fetch(c->curr, c->addr, CLEN_IS_STOP(c) ? 'S' : '-',
+                             CLEN_IS_EOL(c) ? 'E' : '-',
+                             CLEN_IS_FLAG(c) ? 'F' : '-', CLEN_LEN(c));
+}
+
+static void out_cb(void *opaque, int avail)
+{
+    ViaAC97State *s = opaque;
+    ViaAC97SGDChannel *c = &s->aur;
+    int temp, to_copy, copied;
+    bool stop = false;
+    uint8_t tmpbuf[4096];
+
+    if (c->stat & STAT_PAUSED) {
+        return;
+    }
+    c->stat |= STAT_ACTIVE;
+    while (avail && !stop) {
+        if (!c->clen) {
+            fetch_sgd(c, &s->dev);
+        }
+        temp = MIN(CLEN_LEN(c), avail);
+        while (temp) {
+            to_copy = MIN(temp, sizeof(tmpbuf));
+            pci_dma_read(&s->dev, c->addr, tmpbuf, to_copy);
+            copied = AUD_write(s->vo, tmpbuf, to_copy);
+            if (!copied) {
+                stop = true;
+                break;
+            }
+            temp -= copied;
+            avail -= copied;
+            c->addr += copied;
+            c->clen -= copied;
+        }
+        if (CLEN_LEN(c) == 0) {
+            c->curr += 8;
+            if (CLEN_IS_EOL(c)) {
+                c->stat |= STAT_EOL;
+                if (c->type & CNTL_START) {
+                    c->curr = c->base;
+                    c->stat |= STAT_PAUSED;
+                } else {
+                    c->stat &= ~STAT_ACTIVE;
+                    AUD_set_active_out(s->vo, 0);
+                }
+                if (c->type & STAT_EOL) {
+                    pci_set_irq(&s->dev, 1);
+                }
+            }
+            if (CLEN_IS_FLAG(c)) {
+                c->stat |= STAT_FLAG;
+                c->stat |= STAT_PAUSED;
+                if (c->type & STAT_FLAG) {
+                    pci_set_irq(&s->dev, 1);
+                }
+            }
+            if (CLEN_IS_STOP(c)) {
+                c->stat |= STAT_STOP;
+                c->stat |= STAT_PAUSED;
+            }
+            c->clen = 0;
+            stop = true;
+        }
+    }
+}
+
+static void open_voice_out(ViaAC97State *s)
+{
+    struct audsettings as = {
+        .freq = CODEC_REG(s, AC97_PCM_Front_DAC_Rate),
+        .nchannels = s->aur.type & BIT(4) ? 2 : 1,
+        .fmt = s->aur.type & BIT(5) ? AUDIO_FORMAT_S16 : AUDIO_FORMAT_S8,
+        .endianness = 0,
+    };
+    s->vo = AUD_open_out(&s->card, s->vo, "via-ac97.out", s, out_cb, &as);
+}
+
+static uint64_t sgd_read(void *opaque, hwaddr addr, unsigned size)
+{
+    ViaAC97State *s = opaque;
+    uint64_t val = 0;
+
+    switch (addr) {
+    case 0:
+        val = s->aur.stat;
+        if (s->aur.type & CNTL_START) {
+            val |= STAT_TRIG;
+        }
+        break;
+    case 1:
+        val = s->aur.stat & STAT_PAUSED ? BIT(3) : 0;
+        break;
+    case 2:
+        val = s->aur.type;
+        break;
+    case 4:
+        val = s->aur.curr;
+        break;
+    case 0xc:
+        val = CLEN_LEN(&s->aur);
+        break;
+    case 0x10:
+        /* silence unimplemented log message that happens at every IRQ */
+        break;
+    case 0x80:
+        val = s->ac97_cmd;
+        break;
+    case 0x84:
+        val = s->aur.stat & STAT_FLAG;
+        if (s->aur.stat & STAT_EOL) {
+            val |= BIT(4);
+        }
+        if (s->aur.stat & STAT_STOP) {
+            val |= BIT(8);
+        }
+        if (s->aur.stat & STAT_ACTIVE) {
+            val |= BIT(12);
+        }
+        break;
+    default:
+        qemu_log_mask(LOG_UNIMP, "via-ac97: Unimplemented register read 0x%"
+                      HWADDR_PRIx"\n", addr);
+    }
+    trace_via_ac97_sgd_read(addr, size, val);
+    return val;
+}
+
+static void sgd_write(void *opaque, hwaddr addr, uint64_t val, unsigned size)
+{
+    ViaAC97State *s = opaque;
+
+    trace_via_ac97_sgd_write(addr, size, val);
+    switch (addr) {
+    case 0:
+        if (val & STAT_STOP) {
+            s->aur.stat &= ~STAT_PAUSED;
+        }
+        if (val & STAT_EOL) {
+            s->aur.stat &= ~(STAT_EOL | STAT_PAUSED);
+            if (s->aur.type & STAT_EOL) {
+                pci_set_irq(&s->dev, 0);
+            }
+        }
+        if (val & STAT_FLAG) {
+            s->aur.stat &= ~(STAT_FLAG | STAT_PAUSED);
+            if (s->aur.type & STAT_FLAG) {
+                pci_set_irq(&s->dev, 0);
+            }
+        }
+        break;
+    case 1:
+        if (val & CNTL_START) {
+            AUD_set_active_out(s->vo, 1);
+            s->aur.stat = STAT_ACTIVE;
+        }
+        if (val & CNTL_TERM) {
+            AUD_set_active_out(s->vo, 0);
+            s->aur.stat &= ~(STAT_ACTIVE | STAT_PAUSED);
+            s->aur.clen = 0;
+        }
+        if (val & CNTL_PAUSE) {
+            AUD_set_active_out(s->vo, 0);
+            s->aur.stat &= ~STAT_ACTIVE;
+            s->aur.stat |= STAT_PAUSED;
+        } else if (!(val & CNTL_PAUSE) && (s->aur.stat & STAT_PAUSED)) {
+            AUD_set_active_out(s->vo, 1);
+            s->aur.stat |= STAT_ACTIVE;
+            s->aur.stat &= ~STAT_PAUSED;
+        }
+        break;
+    case 2:
+    {
+        uint32_t oldval = s->aur.type;
+        s->aur.type = val;
+        if ((oldval & 0x30) != (val & 0x30)) {
+            open_voice_out(s);
+        }
+        break;
+    }
+    case 4:
+        s->aur.base = val & ~1ULL;
+        s->aur.curr = s->aur.base;
+        break;
+    case 0x80:
+        if (val >> 30) {
+            /* we only have primary codec */
+            break;
+        }
+        if (val & BIT(23)) { /* read reg */
+            s->ac97_cmd = val & 0xc0ff0000ULL;
+            s->ac97_cmd |= codec_read(s, (val >> 16) & 0x7f);
+            s->ac97_cmd |= BIT(25); /* data valid */
+        } else {
+            s->ac97_cmd = val & 0xc0ffffffULL;
+            codec_write(s, (val >> 16) & 0x7f, val);
+        }
+        break;
+    case 0xc:
+    case 0x84:
+        /* Read only */
+        break;
+    default:
+        qemu_log_mask(LOG_UNIMP, "via-ac97: Unimplemented register write 0x%"
+                      HWADDR_PRIx"\n", addr);
+    }
+}
+
+static const MemoryRegionOps sgd_ops = {
+    .read = sgd_read,
+    .write = sgd_write,
+    .endianness = DEVICE_LITTLE_ENDIAN,
+};
+
+static uint64_t fm_read(void *opaque, hwaddr addr, unsigned size)
+{
+    qemu_log_mask(LOG_UNIMP, "%s: 0x%"HWADDR_PRIx" %d\n", __func__, addr, size);
+    return 0;
+}
+
+static void fm_write(void *opaque, hwaddr addr, uint64_t val, unsigned size)
+{
+    qemu_log_mask(LOG_UNIMP, "%s: 0x%"HWADDR_PRIx" %d <= 0x%"PRIX64"\n",
+                  __func__, addr, size, val);
+}
+
+static const MemoryRegionOps fm_ops = {
+    .read = fm_read,
+    .write = fm_write,
+    .endianness = DEVICE_LITTLE_ENDIAN,
+};
+
+static uint64_t midi_read(void *opaque, hwaddr addr, unsigned size)
+{
+    qemu_log_mask(LOG_UNIMP, "%s: 0x%"HWADDR_PRIx" %d\n", __func__, addr, size);
+    return 0;
+}
+
+static void midi_write(void *opaque, hwaddr addr, uint64_t val, unsigned size)
+{
+    qemu_log_mask(LOG_UNIMP, "%s: 0x%"HWADDR_PRIx" %d <= 0x%"PRIX64"\n",
+                  __func__, addr, size, val);
+}
+
+static const MemoryRegionOps midi_ops = {
+    .read = midi_read,
+    .write = midi_write,
+    .endianness = DEVICE_LITTLE_ENDIAN,
+};
+
+static void via_ac97_reset(DeviceState *dev)
+{
+    ViaAC97State *s = VIA_AC97(dev);
+
+    codec_reset(s);
+}
 
 static void via_ac97_realize(PCIDevice *pci_dev, Error **errp)
 {
-    pci_set_word(pci_dev->config + PCI_COMMAND,
-                 PCI_COMMAND_INVALIDATE | PCI_COMMAND_PARITY);
+    ViaAC97State *s = VIA_AC97(pci_dev);
+    Object *o = OBJECT(s);
+
+    /*
+     * Command register Bus Master bit is documented to be fixed at 0 but it's
+     * needed for PCI DMA to work in QEMU. The pegasos2 firmware writes 0 here
+     * and the AmigaOS driver writes 1 only enabling IO bit which works on
+     * real hardware. So set it here and fix it to 1 to allow DMA.
+     */
+    pci_set_word(pci_dev->config + PCI_COMMAND, PCI_COMMAND_MASTER);
+    pci_set_word(pci_dev->wmask + PCI_COMMAND, PCI_COMMAND_IO);
     pci_set_word(pci_dev->config + PCI_STATUS,
                  PCI_STATUS_CAP_LIST | PCI_STATUS_DEVSEL_MEDIUM);
     pci_set_long(pci_dev->config + PCI_INTERRUPT_PIN, 0x03);
+    pci_set_byte(pci_dev->config + 0x40, 1); /* codec ready */
+
+    memory_region_init_io(&s->sgd, o, &sgd_ops, s, "via-ac97.sgd", 256);
+    pci_register_bar(pci_dev, 0, PCI_BASE_ADDRESS_SPACE_IO, &s->sgd);
+    memory_region_init_io(&s->fm, o, &fm_ops, s, "via-ac97.fm", 4);
+    pci_register_bar(pci_dev, 1, PCI_BASE_ADDRESS_SPACE_IO, &s->fm);
+    memory_region_init_io(&s->midi, o, &midi_ops, s, "via-ac97.midi", 4);
+    pci_register_bar(pci_dev, 2, PCI_BASE_ADDRESS_SPACE_IO, &s->midi);
+
+    AUD_register_card ("via-ac97", &s->card);
 }
 
+static void via_ac97_exit(PCIDevice *dev)
+{
+    ViaAC97State *s = VIA_AC97(dev);
+
+    AUD_close_out(&s->card, s->vo);
+    AUD_remove_card(&s->card);
+}
+
+static Property via_ac97_properties[] = {
+    DEFINE_AUDIO_PROPERTIES(ViaAC97State, card),
+    DEFINE_PROP_END_OF_LIST(),
+};
+
 static void via_ac97_class_init(ObjectClass *klass, void *data)
 {
     DeviceClass *dc = DEVICE_CLASS(klass);
     PCIDeviceClass *k = PCI_DEVICE_CLASS(klass);
 
     k->realize = via_ac97_realize;
+    k->exit = via_ac97_exit;
     k->vendor_id = PCI_VENDOR_ID_VIA;
     k->device_id = PCI_DEVICE_ID_VIA_AC97;
     k->revision = 0x50;
     k->class_id = PCI_CLASS_MULTIMEDIA_AUDIO;
+    device_class_set_props(dc, via_ac97_properties);
     set_bit(DEVICE_CATEGORY_SOUND, dc->categories);
     dc->desc = "VIA AC97";
+    dc->reset = via_ac97_reset;
     /* Reason: Part of a south bridge chip */
     dc->user_creatable = false;
 }
@@ -41,7 +484,7 @@ static void via_ac97_class_init(ObjectClass *klass, void *data)
 static const TypeInfo via_ac97_info = {
     .name          = TYPE_VIA_AC97,
     .parent        = TYPE_PCI_DEVICE,
-    .instance_size = sizeof(PCIDevice),
+    .instance_size = sizeof(ViaAC97State),
     .class_init    = via_ac97_class_init,
     .interfaces = (InterfaceInfo[]) {
         { INTERFACE_CONVENTIONAL_PCI_DEVICE },