hw/audio/lm4549.c

   1 /*
   2  * LM4549 Audio Codec Interface
   3  *
   4  * Copyright (c) 2011
   5  * Written by Mathieu Sonet - www.elasticsheep.com
   6  *
   7  * This code is licensed under the GPL.
   8  *
   9  * *****************************************************************
  10  *
  11  * This driver emulates the LM4549 codec.
  12  *
  13  * It supports only one playback voice and no record voice.
  14  */
  15
  16 #include "qemu/osdep.h"
  17 #include "hw/hw.h"
  18 #include "audio/audio.h"
  19 #include "lm4549.h"
  20 #include "migration/vmstate.h"
  21
  22 #if 0
  23 #define LM4549_DEBUG  1
  24 #endif
  25
  26 #if 0
  27 #define LM4549_DUMP_DAC_INPUT 1
  28 #endif
  29
  30 #ifdef LM4549_DEBUG
  31 #define DPRINTF(fmt, ...) \
  32 do { printf("lm4549: " fmt , ## __VA_ARGS__); } while (0)
  33 #else
  34 #define DPRINTF(fmt, ...) do {} while (0)
  35 #endif
  36
  37 #if defined(LM4549_DUMP_DAC_INPUT)
  38 static FILE *fp_dac_input;
  39 #endif
  40
  41 /* LM4549 register list */
  42 enum {
  43     LM4549_Reset                    = 0x00,
  44     LM4549_Master_Volume            = 0x02,
  45     LM4549_Line_Out_Volume          = 0x04,
  46     LM4549_Master_Volume_Mono       = 0x06,
  47     LM4549_PC_Beep_Volume           = 0x0A,
  48     LM4549_Phone_Volume             = 0x0C,
  49     LM4549_Mic_Volume               = 0x0E,
  50     LM4549_Line_In_Volume           = 0x10,
  51     LM4549_CD_Volume                = 0x12,
  52     LM4549_Video_Volume             = 0x14,
  53     LM4549_Aux_Volume               = 0x16,
  54     LM4549_PCM_Out_Volume           = 0x18,
  55     LM4549_Record_Select            = 0x1A,
  56     LM4549_Record_Gain              = 0x1C,
  57     LM4549_General_Purpose          = 0x20,
  58     LM4549_3D_Control               = 0x22,
  59     LM4549_Powerdown_Ctrl_Stat      = 0x26,
  60     LM4549_Ext_Audio_ID             = 0x28,
  61     LM4549_Ext_Audio_Stat_Ctrl      = 0x2A,
  62     LM4549_PCM_Front_DAC_Rate       = 0x2C,
  63     LM4549_PCM_ADC_Rate             = 0x32,
  64     LM4549_Vendor_ID1               = 0x7C,
  65     LM4549_Vendor_ID2               = 0x7E
  66 };
  67
  68 static void lm4549_reset(lm4549_state *s)
  69 {
  70     uint16_t *regfile = s->regfile;
  71
  72     regfile[LM4549_Reset]               = 0x0d50;
  73     regfile[LM4549_Master_Volume]       = 0x8008;
  74     regfile[LM4549_Line_Out_Volume]     = 0x8000;
  75     regfile[LM4549_Master_Volume_Mono]  = 0x8000;
  76     regfile[LM4549_PC_Beep_Volume]      = 0x0000;
  77     regfile[LM4549_Phone_Volume]        = 0x8008;
  78     regfile[LM4549_Mic_Volume]          = 0x8008;
  79     regfile[LM4549_Line_In_Volume]      = 0x8808;
  80     regfile[LM4549_CD_Volume]           = 0x8808;
  81     regfile[LM4549_Video_Volume]        = 0x8808;
  82     regfile[LM4549_Aux_Volume]          = 0x8808;
  83     regfile[LM4549_PCM_Out_Volume]      = 0x8808;
  84     regfile[LM4549_Record_Select]       = 0x0000;
  85     regfile[LM4549_Record_Gain]         = 0x8000;
  86     regfile[LM4549_General_Purpose]     = 0x0000;
  87     regfile[LM4549_3D_Control]          = 0x0101;
  88     regfile[LM4549_Powerdown_Ctrl_Stat] = 0x000f;
  89     regfile[LM4549_Ext_Audio_ID]        = 0x0001;
  90     regfile[LM4549_Ext_Audio_Stat_Ctrl] = 0x0000;
  91     regfile[LM4549_PCM_Front_DAC_Rate]  = 0xbb80;
  92     regfile[LM4549_PCM_ADC_Rate]        = 0xbb80;
  93     regfile[LM4549_Vendor_ID1]          = 0x4e53;
  94     regfile[LM4549_Vendor_ID2]          = 0x4331;
  95 }
  96
  97 static void lm4549_audio_transfer(lm4549_state *s)
  98 {
  99     uint32_t written_bytes, written_samples;
 100     uint32_t i;
 101
 102     /* Activate the voice */
 103     AUD_set_active_out(s->voice, 1);
 104     s->voice_is_active = 1;
 105
 106     /* Try to write the buffer content */
 107     written_bytes = AUD_write(s->voice, s->buffer,
 108                               s->buffer_level * sizeof(uint16_t));
 109     written_samples = written_bytes >> 1;
 110
 111 #if defined(LM4549_DUMP_DAC_INPUT)
 112     fwrite(s->buffer, sizeof(uint8_t), written_bytes, fp_dac_input);
 113 #endif
 114
 115     s->buffer_level -= written_samples;
 116
 117     if (s->buffer_level > 0) {
 118         /* Move the data back to the start of the buffer */
 119         for (i = 0; i < s->buffer_level; i++) {
 120             s->buffer[i] = s->buffer[i + written_samples];
 121         }
 122     }
 123 }
 124
 125 static void lm4549_audio_out_callback(void *opaque, int free)
 126 {
 127     lm4549_state *s = (lm4549_state *)opaque;
 128     static uint32_t prev_buffer_level;
 129
 130 #ifdef LM4549_DEBUG
 131     int size = AUD_get_buffer_size_out(s->voice);
 132     DPRINTF("audio_out_callback size = %i free = %i\n", size, free);
 133 #endif
 134
 135     /* Detect that no data are consumed
 136        => disable the voice */
 137     if (s->buffer_level == prev_buffer_level) {
 138         AUD_set_active_out(s->voice, 0);
 139         s->voice_is_active = 0;
 140     }
 141     prev_buffer_level = s->buffer_level;
 142
 143     /* Check if a buffer transfer is pending */
 144     if (s->buffer_level == LM4549_BUFFER_SIZE) {
 145         lm4549_audio_transfer(s);
 146
 147         /* Request more data */
 148         if (s->data_req_cb != NULL) {
 149             (s->data_req_cb)(s->opaque);
 150         }
 151     }
 152 }
 153
 154 uint32_t lm4549_read(lm4549_state *s, hwaddr offset)
 155 {
 156     uint16_t *regfile = s->regfile;
 157     uint32_t value = 0;
 158
 159     /* Read the stored value */
 160     assert(offset < 128);
 161     value = regfile[offset];
 162
 163     DPRINTF("read [0x%02x] = 0x%04x\n", offset, value);
 164
 165     return value;
 166 }
 167
 168 void lm4549_write(lm4549_state *s,
 169                   hwaddr offset, uint32_t value)
 170 {
 171     uint16_t *regfile = s->regfile;
 172
 173     assert(offset < 128);
 174     DPRINTF("write [0x%02x] = 0x%04x\n", offset, value);
 175
 176     switch (offset) {
 177     case LM4549_Reset:
 178         lm4549_reset(s);
 179         break;
 180
 181     case LM4549_PCM_Front_DAC_Rate:
 182         regfile[LM4549_PCM_Front_DAC_Rate] = value;
 183         DPRINTF("DAC rate change = %i\n", value);
 184
 185         /* Re-open a voice with the new sample rate */
 186         struct audsettings as;
 187         as.freq = value;
 188         as.nchannels = 2;
 189         as.fmt = AUDIO_FORMAT_S16;
 190         as.endianness = 0;
 191
 192         s->voice = AUD_open_out(
 193             &s->card,
 194             s->voice,
 195             "lm4549.out",
 196             s,
 197             lm4549_audio_out_callback,
 198             &as
 199         );
 200         break;
 201
 202     case LM4549_Powerdown_Ctrl_Stat:
 203         value &= ~0xf;
 204         value |= regfile[LM4549_Powerdown_Ctrl_Stat] & 0xf;
 205         regfile[LM4549_Powerdown_Ctrl_Stat] = value;
 206         break;
 207
 208     case LM4549_Ext_Audio_ID:
 209     case LM4549_Vendor_ID1:
 210     case LM4549_Vendor_ID2:
 211         DPRINTF("Write to read-only register 0x%x\n", (int)offset);
 212         break;
 213
 214     default:
 215         /* Store the new value */
 216         regfile[offset] = value;
 217         break;
 218     }
 219 }
 220
 221 uint32_t lm4549_write_samples(lm4549_state *s, uint32_t left, uint32_t right)
 222 {
 223     /* The left and right samples are in 20-bit resolution.
 224        The LM4549 has 18-bit resolution and only uses the bits [19:2].
 225        This model supports 16-bit playback.
 226     */
 227
 228     if (s->buffer_level > LM4549_BUFFER_SIZE - 2) {
 229         DPRINTF("write_sample Buffer full\n");
 230         return 0;
 231     }
 232
 233     /* Store 16-bit samples in the buffer */
 234     s->buffer[s->buffer_level++] = (left >> 4);
 235     s->buffer[s->buffer_level++] = (right >> 4);
 236
 237     if (s->buffer_level == LM4549_BUFFER_SIZE) {
 238         /* Trigger the transfer of the buffer to the audio host */
 239         lm4549_audio_transfer(s);
 240     }
 241
 242     return 1;
 243 }
 244
 245 static int lm4549_post_load(void *opaque, int version_id)
 246 {
 247     lm4549_state *s = (lm4549_state *)opaque;
 248     uint16_t *regfile = s->regfile;
 249
 250     /* Re-open a voice with the current sample rate */
 251     uint32_t freq = regfile[LM4549_PCM_Front_DAC_Rate];
 252
 253     DPRINTF("post_load freq = %i\n", freq);
 254     DPRINTF("post_load voice_is_active = %i\n", s->voice_is_active);
 255
 256     struct audsettings as;
 257     as.freq = freq;
 258     as.nchannels = 2;
 259     as.fmt = AUDIO_FORMAT_S16;
 260     as.endianness = 0;
 261
 262     s->voice = AUD_open_out(
 263         &s->card,
 264         s->voice,
 265         "lm4549.out",
 266         s,
 267         lm4549_audio_out_callback,
 268         &as
 269     );
 270
 271     /* Request data */
 272     if (s->voice_is_active == 1) {
 273         lm4549_audio_out_callback(s, AUD_get_buffer_size_out(s->voice));
 274     }
 275
 276     return 0;
 277 }
 278
 279 void lm4549_init(lm4549_state *s, lm4549_callback data_req_cb, void* opaque)
 280 {
 281     struct audsettings as;
 282
 283     /* Store the callback and opaque pointer */
 284     s->data_req_cb = data_req_cb;
 285     s->opaque = opaque;
 286
 287     /* Init the registers */
 288     lm4549_reset(s);
 289
 290     /* Register an audio card */
 291     AUD_register_card("lm4549", &s->card);
 292
 293     /* Open a default voice */
 294     as.freq = 48000;
 295     as.nchannels = 2;
 296     as.fmt = AUDIO_FORMAT_S16;
 297     as.endianness = 0;
 298
 299     s->voice = AUD_open_out(
 300         &s->card,
 301         s->voice,
 302         "lm4549.out",
 303         s,
 304         lm4549_audio_out_callback,
 305         &as
 306     );
 307
 308     AUD_set_volume_out(s->voice, 0, 255, 255);
 309
 310     s->voice_is_active = 0;
 311
 312     /* Reset the input buffer */
 313     memset(s->buffer, 0x00, sizeof(s->buffer));
 314     s->buffer_level = 0;
 315
 316 #if defined(LM4549_DUMP_DAC_INPUT)
 317     fp_dac_input = fopen("lm4549_dac_input.pcm", "wb");
 318     if (!fp_dac_input) {
 319         hw_error("Unable to open lm4549_dac_input.pcm for writing\n");
 320     }
 321 #endif
 322 }
 323
 324 const VMStateDescription vmstate_lm4549_state = {
 325     .name = "lm4549_state",
 326     .version_id = 1,
 327     .minimum_version_id = 1,
 328     .post_load = lm4549_post_load,
 329     .fields = (VMStateField[]) {
 330         VMSTATE_UINT32(voice_is_active, lm4549_state),
 331         VMSTATE_UINT16_ARRAY(regfile, lm4549_state, 128),
 332         VMSTATE_UINT16_ARRAY(buffer, lm4549_state, LM4549_BUFFER_SIZE),
 333         VMSTATE_UINT32(buffer_level, lm4549_state),
 334         VMSTATE_END_OF_LIST()
 335     }
 336 };