Introduce Virtio-loopback epsilon release:

Epsilon release introduces a new compatibility layer which make virtio-loopback
design to work with QEMU and rust-vmm vhost-user backend without require any
changes.

Signed-off-by: Timos Ampelikiotis <t.ampelikiotis@virtualopensystems.com>
Change-Id: I52e57563e08a7d0bdc002f8e928ee61ba0c53dd9

1 files changed, 336 insertions, 0 deletions

diff --git a/hw/audio/lm4549.c b/hw/audio/lm4549.c
new file mode 100644
index 000000000..32b1481b5
--- /dev/null
+++ b/hw/audio/lm4549.c
@@ -0,0 +1,336 @@
+/*
+ * LM4549 Audio Codec Interface
+ *
+ * Copyright (c) 2011
+ * Written by Mathieu Sonet - www.elasticsheep.com
+ *
+ * This code is licensed under the GPL.
+ *
+ * *****************************************************************
+ *
+ * This driver emulates the LM4549 codec.
+ *
+ * It supports only one playback voice and no record voice.
+ */
+
+#include "qemu/osdep.h"
+#include "hw/hw.h"
+#include "audio/audio.h"
+#include "lm4549.h"
+#include "migration/vmstate.h"
+
+#if 0
+#define LM4549_DEBUG  1
+#endif
+
+#if 0
+#define LM4549_DUMP_DAC_INPUT 1
+#endif
+
+#ifdef LM4549_DEBUG
+#define DPRINTF(fmt, ...) \
+do { printf("lm4549: " fmt , ## __VA_ARGS__); } while (0)
+#else
+#define DPRINTF(fmt, ...) do {} while (0)
+#endif
+
+#if defined(LM4549_DUMP_DAC_INPUT)
+static FILE *fp_dac_input;
+#endif
+
+/* LM4549 register list */
+enum {
+    LM4549_Reset                    = 0x00,
+    LM4549_Master_Volume            = 0x02,
+    LM4549_Line_Out_Volume          = 0x04,
+    LM4549_Master_Volume_Mono       = 0x06,
+    LM4549_PC_Beep_Volume           = 0x0A,
+    LM4549_Phone_Volume             = 0x0C,
+    LM4549_Mic_Volume               = 0x0E,
+    LM4549_Line_In_Volume           = 0x10,
+    LM4549_CD_Volume                = 0x12,
+    LM4549_Video_Volume             = 0x14,
+    LM4549_Aux_Volume               = 0x16,
+    LM4549_PCM_Out_Volume           = 0x18,
+    LM4549_Record_Select            = 0x1A,
+    LM4549_Record_Gain              = 0x1C,
+    LM4549_General_Purpose          = 0x20,
+    LM4549_3D_Control               = 0x22,
+    LM4549_Powerdown_Ctrl_Stat      = 0x26,
+    LM4549_Ext_Audio_ID             = 0x28,
+    LM4549_Ext_Audio_Stat_Ctrl      = 0x2A,
+    LM4549_PCM_Front_DAC_Rate       = 0x2C,
+    LM4549_PCM_ADC_Rate             = 0x32,
+    LM4549_Vendor_ID1               = 0x7C,
+    LM4549_Vendor_ID2               = 0x7E
+};
+
+static void lm4549_reset(lm4549_state *s)
+{
+    uint16_t *regfile = s->regfile;
+
+    regfile[LM4549_Reset]               = 0x0d50;
+    regfile[LM4549_Master_Volume]       = 0x8008;
+    regfile[LM4549_Line_Out_Volume]     = 0x8000;
+    regfile[LM4549_Master_Volume_Mono]  = 0x8000;
+    regfile[LM4549_PC_Beep_Volume]      = 0x0000;
+    regfile[LM4549_Phone_Volume]        = 0x8008;
+    regfile[LM4549_Mic_Volume]          = 0x8008;
+    regfile[LM4549_Line_In_Volume]      = 0x8808;
+    regfile[LM4549_CD_Volume]           = 0x8808;
+    regfile[LM4549_Video_Volume]        = 0x8808;
+    regfile[LM4549_Aux_Volume]          = 0x8808;
+    regfile[LM4549_PCM_Out_Volume]      = 0x8808;
+    regfile[LM4549_Record_Select]       = 0x0000;
+    regfile[LM4549_Record_Gain]         = 0x8000;
+    regfile[LM4549_General_Purpose]     = 0x0000;
+    regfile[LM4549_3D_Control]          = 0x0101;
+    regfile[LM4549_Powerdown_Ctrl_Stat] = 0x000f;
+    regfile[LM4549_Ext_Audio_ID]        = 0x0001;
+    regfile[LM4549_Ext_Audio_Stat_Ctrl] = 0x0000;
+    regfile[LM4549_PCM_Front_DAC_Rate]  = 0xbb80;
+    regfile[LM4549_PCM_ADC_Rate]        = 0xbb80;
+    regfile[LM4549_Vendor_ID1]          = 0x4e53;
+    regfile[LM4549_Vendor_ID2]          = 0x4331;
+}
+
+static void lm4549_audio_transfer(lm4549_state *s)
+{
+    uint32_t written_bytes, written_samples;
+    uint32_t i;
+
+    /* Activate the voice */
+    AUD_set_active_out(s->voice, 1);
+    s->voice_is_active = 1;
+
+    /* Try to write the buffer content */
+    written_bytes = AUD_write(s->voice, s->buffer,
+                              s->buffer_level * sizeof(uint16_t));
+    written_samples = written_bytes >> 1;
+
+#if defined(LM4549_DUMP_DAC_INPUT)
+    fwrite(s->buffer, sizeof(uint8_t), written_bytes, fp_dac_input);
+#endif
+
+    s->buffer_level -= written_samples;
+
+    if (s->buffer_level > 0) {
+        /* Move the data back to the start of the buffer */
+        for (i = 0; i < s->buffer_level; i++) {
+            s->buffer[i] = s->buffer[i + written_samples];
+        }
+    }
+}
+
+static void lm4549_audio_out_callback(void *opaque, int free)
+{
+    lm4549_state *s = (lm4549_state *)opaque;
+    static uint32_t prev_buffer_level;
+
+#ifdef LM4549_DEBUG
+    int size = AUD_get_buffer_size_out(s->voice);
+    DPRINTF("audio_out_callback size = %i free = %i\n", size, free);
+#endif
+
+    /* Detect that no data are consumed
+       => disable the voice */
+    if (s->buffer_level == prev_buffer_level) {
+        AUD_set_active_out(s->voice, 0);
+        s->voice_is_active = 0;
+    }
+    prev_buffer_level = s->buffer_level;
+
+    /* Check if a buffer transfer is pending */
+    if (s->buffer_level == LM4549_BUFFER_SIZE) {
+        lm4549_audio_transfer(s);
+
+        /* Request more data */
+        if (s->data_req_cb != NULL) {
+            (s->data_req_cb)(s->opaque);
+        }
+    }
+}
+
+uint32_t lm4549_read(lm4549_state *s, hwaddr offset)
+{
+    uint16_t *regfile = s->regfile;
+    uint32_t value = 0;
+
+    /* Read the stored value */
+    assert(offset < 128);
+    value = regfile[offset];
+
+    DPRINTF("read [0x%02x] = 0x%04x\n", offset, value);
+
+    return value;
+}
+
+void lm4549_write(lm4549_state *s,
+                  hwaddr offset, uint32_t value)
+{
+    uint16_t *regfile = s->regfile;
+
+    assert(offset < 128);
+    DPRINTF("write [0x%02x] = 0x%04x\n", offset, value);
+
+    switch (offset) {
+    case LM4549_Reset:
+        lm4549_reset(s);
+        break;
+
+    case LM4549_PCM_Front_DAC_Rate:
+        regfile[LM4549_PCM_Front_DAC_Rate] = value;
+        DPRINTF("DAC rate change = %i\n", value);
+
+        /* Re-open a voice with the new sample rate */
+        struct audsettings as;
+        as.freq = value;
+        as.nchannels = 2;
+        as.fmt = AUDIO_FORMAT_S16;
+        as.endianness = 0;
+
+        s->voice = AUD_open_out(
+            &s->card,
+            s->voice,
+            "lm4549.out",
+            s,
+            lm4549_audio_out_callback,
+            &as
+        );
+        break;
+
+    case LM4549_Powerdown_Ctrl_Stat:
+        value &= ~0xf;
+        value |= regfile[LM4549_Powerdown_Ctrl_Stat] & 0xf;
+        regfile[LM4549_Powerdown_Ctrl_Stat] = value;
+        break;
+
+    case LM4549_Ext_Audio_ID:
+    case LM4549_Vendor_ID1:
+    case LM4549_Vendor_ID2:
+        DPRINTF("Write to read-only register 0x%x\n", (int)offset);
+        break;
+
+    default:
+        /* Store the new value */
+        regfile[offset] = value;
+        break;
+    }
+}
+
+uint32_t lm4549_write_samples(lm4549_state *s, uint32_t left, uint32_t right)
+{
+    /* The left and right samples are in 20-bit resolution.
+       The LM4549 has 18-bit resolution and only uses the bits [19:2].
+       This model supports 16-bit playback.
+    */
+
+    if (s->buffer_level > LM4549_BUFFER_SIZE - 2) {
+        DPRINTF("write_sample Buffer full\n");
+        return 0;
+    }
+
+    /* Store 16-bit samples in the buffer */
+    s->buffer[s->buffer_level++] = (left >> 4);
+    s->buffer[s->buffer_level++] = (right >> 4);
+
+    if (s->buffer_level == LM4549_BUFFER_SIZE) {
+        /* Trigger the transfer of the buffer to the audio host */
+        lm4549_audio_transfer(s);
+    }
+
+    return 1;
+}
+
+static int lm4549_post_load(void *opaque, int version_id)
+{
+    lm4549_state *s = (lm4549_state *)opaque;
+    uint16_t *regfile = s->regfile;
+
+    /* Re-open a voice with the current sample rate */
+    uint32_t freq = regfile[LM4549_PCM_Front_DAC_Rate];
+
+    DPRINTF("post_load freq = %i\n", freq);
+    DPRINTF("post_load voice_is_active = %i\n", s->voice_is_active);
+
+    struct audsettings as;
+    as.freq = freq;
+    as.nchannels = 2;
+    as.fmt = AUDIO_FORMAT_S16;
+    as.endianness = 0;
+
+    s->voice = AUD_open_out(
+        &s->card,
+        s->voice,
+        "lm4549.out",
+        s,
+        lm4549_audio_out_callback,
+        &as
+    );
+
+    /* Request data */
+    if (s->voice_is_active == 1) {
+        lm4549_audio_out_callback(s, AUD_get_buffer_size_out(s->voice));
+    }
+
+    return 0;
+}
+
+void lm4549_init(lm4549_state *s, lm4549_callback data_req_cb, void* opaque)
+{
+    struct audsettings as;
+
+    /* Store the callback and opaque pointer */
+    s->data_req_cb = data_req_cb;
+    s->opaque = opaque;
+
+    /* Init the registers */
+    lm4549_reset(s);
+
+    /* Register an audio card */
+    AUD_register_card("lm4549", &s->card);
+
+    /* Open a default voice */
+    as.freq = 48000;
+    as.nchannels = 2;
+    as.fmt = AUDIO_FORMAT_S16;
+    as.endianness = 0;
+
+    s->voice = AUD_open_out(
+        &s->card,
+        s->voice,
+        "lm4549.out",
+        s,
+        lm4549_audio_out_callback,
+        &as
+    );
+
+    AUD_set_volume_out(s->voice, 0, 255, 255);
+
+    s->voice_is_active = 0;
+
+    /* Reset the input buffer */
+    memset(s->buffer, 0x00, sizeof(s->buffer));
+    s->buffer_level = 0;
+
+#if defined(LM4549_DUMP_DAC_INPUT)
+    fp_dac_input = fopen("lm4549_dac_input.pcm", "wb");
+    if (!fp_dac_input) {
+        hw_error("Unable to open lm4549_dac_input.pcm for writing\n");
+    }
+#endif
+}
+
+const VMStateDescription vmstate_lm4549_state = {
+    .name = "lm4549_state",
+    .version_id = 1,
+    .minimum_version_id = 1,
+    .post_load = lm4549_post_load,
+    .fields = (VMStateField[]) {
+        VMSTATE_UINT32(voice_is_active, lm4549_state),
+        VMSTATE_UINT16_ARRAY(regfile, lm4549_state, 128),
+        VMSTATE_UINT16_ARRAY(buffer, lm4549_state, LM4549_BUFFER_SIZE),
+        VMSTATE_UINT32(buffer_level, lm4549_state),
+        VMSTATE_END_OF_LIST()
+    }
+};