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 "hw/hw.h"
  17 #include "audio/audio.h"
  18 #include "lm4549.h"
  19
  20 #if 0
  21 #define LM4549_DEBUG  1
  22 #endif
  23
  24 #if 0
  25 #define LM4549_DUMP_DAC_INPUT 1
  26 #endif
  27
  28 #ifdef LM4549_DEBUG
  29 #define DPRINTF(fmt, ...) \
  30 do { printf("lm4549: " fmt , ## __VA_ARGS__); } while (0)
  31 #else
  32 #define DPRINTF(fmt, ...) do {} while (0)
  33 #endif
  34
  35 #if defined(LM4549_DUMP_DAC_INPUT)
  36 #include <stdio.h>
  37 static FILE *fp_dac_input;
  38 #endif
  39
  40 /* LM4549 register list */
  41 enum {
  42     LM4549_Reset                    = 0x00,
  43     LM4549_Master_Volume            = 0x02,
  44     LM4549_Line_Out_Volume          = 0x04,
  45     LM4549_Master_Volume_Mono       = 0x06,
  46     LM4549_PC_Beep_Volume           = 0x0A,
  47     LM4549_Phone_Volume             = 0x0C,
  48     LM4549_Mic_Volume               = 0x0E,
  49     LM4549_Line_In_Volume           = 0x10,
  50     LM4549_CD_Volume                = 0x12,
  51     LM4549_Video_Volume             = 0x14,
  52     LM4549_Aux_Volume               = 0x16,
  53     LM4549_PCM_Out_Volume           = 0x18,
  54     LM4549_Record_Select            = 0x1A,
  55     LM4549_Record_Gain              = 0x1C,
  56     LM4549_General_Purpose          = 0x20,
  57     LM4549_3D_Control               = 0x22,
  58     LM4549_Powerdown_Ctrl_Stat      = 0x26,
  59     LM4549_Ext_Audio_ID             = 0x28,
  60     LM4549_Ext_Audio_Stat_Ctrl      = 0x2A,
  61     LM4549_PCM_Front_DAC_Rate       = 0x2C,
  62     LM4549_PCM_ADC_Rate             = 0x32,
  63     LM4549_Vendor_ID1               = 0x7C,
  64     LM4549_Vendor_ID2               = 0x7E
  65 };
  66
  67 static void lm4549_reset(lm4549_state *s)
  68 {
  69     uint16_t *regfile = s->regfile;
  70
  71     regfile[LM4549_Reset]               = 0x0d50;
  72     regfile[LM4549_Master_Volume]       = 0x8008;
  73     regfile[LM4549_Line_Out_Volume]     = 0x8000;
  74     regfile[LM4549_Master_Volume_Mono]  = 0x8000;
  75     regfile[LM4549_PC_Beep_Volume]      = 0x0000;
  76     regfile[LM4549_Phone_Volume]        = 0x8008;
  77     regfile[LM4549_Mic_Volume]          = 0x8008;
  78     regfile[LM4549_Line_In_Volume]      = 0x8808;
  79     regfile[LM4549_CD_Volume]           = 0x8808;
  80     regfile[LM4549_Video_Volume]        = 0x8808;
  81     regfile[LM4549_Aux_Volume]          = 0x8808;
  82     regfile[LM4549_PCM_Out_Volume]      = 0x8808;
  83     regfile[LM4549_Record_Select]       = 0x0000;
  84     regfile[LM4549_Record_Gain]         = 0x8000;
  85     regfile[LM4549_General_Purpose]     = 0x0000;
  86     regfile[LM4549_3D_Control]          = 0x0101;
  87     regfile[LM4549_Powerdown_Ctrl_Stat] = 0x000f;
  88     regfile[LM4549_Ext_Audio_ID]        = 0x0001;
  89     regfile[LM4549_Ext_Audio_Stat_Ctrl] = 0x0000;
  90     regfile[LM4549_PCM_Front_DAC_Rate]  = 0xbb80;
  91     regfile[LM4549_PCM_ADC_Rate]        = 0xbb80;
  92     regfile[LM4549_Vendor_ID1]          = 0x4e53;
  93     regfile[LM4549_Vendor_ID2]          = 0x4331;
  94 }
  95
  96 static void lm4549_audio_transfer(lm4549_state *s)
  97 {
  98     uint32_t written_bytes, written_samples;
  99     uint32_t i;
 100
 101     /* Activate the voice */
 102     AUD_set_active_out(s->voice, 1);
 103     s->voice_is_active = 1;
 104
 105     /* Try to write the buffer content */
 106     written_bytes = AUD_write(s->voice, s->buffer,
 107                               s->buffer_level * sizeof(uint16_t));
 108     written_samples = written_bytes >> 1;
 109
 110 #if defined(LM4549_DUMP_DAC_INPUT)
 111     fwrite(s->buffer, sizeof(uint8_t), written_bytes, fp_dac_input);
 112 #endif
 113
 114     s->buffer_level -= written_samples;
 115
 116     if (s->buffer_level > 0) {
 117         /* Move the data back to the start of the buffer */
 118         for (i = 0; i < s->buffer_level; i++) {
 119             s->buffer[i] = s->buffer[i + written_samples];
 120         }
 121     }
 122 }
 123
 124 static void lm4549_audio_out_callback(void *opaque, int free)
 125 {
 126     lm4549_state *s = (lm4549_state *)opaque;
 127     static uint32_t prev_buffer_level;
 128
 129 #ifdef LM4549_DEBUG
 130     int size = AUD_get_buffer_size_out(s->voice);
 131     DPRINTF("audio_out_callback size = %i free = %i\n", size, free);
 132 #endif
 133
 134     /* Detect that no data are consumed
 135        => disable the voice */
 136     if (s->buffer_level == prev_buffer_level) {
 137         AUD_set_active_out(s->voice, 0);
 138         s->voice_is_active = 0;
 139     }
 140     prev_buffer_level = s->buffer_level;
 141
 142     /* Check if a buffer transfer is pending */
 143     if (s->buffer_level == LM4549_BUFFER_SIZE) {
 144         lm4549_audio_transfer(s);
 145
 146         /* Request more data */
 147         if (s->data_req_cb != NULL) {
 148             (s->data_req_cb)(s->opaque);
 149         }
 150     }
 151 }
 152
 153 uint32_t lm4549_read(lm4549_state *s, hwaddr offset)
 154 {
 155     uint16_t *regfile = s->regfile;
 156     uint32_t value = 0;
 157
 158     /* Read the stored value */
 159     assert(offset < 128);
 160     value = regfile[offset];
 161
 162     DPRINTF("read [0x%02x] = 0x%04x\n", offset, value);
 163
 164     return value;
 165 }
 166
 167 void lm4549_write(lm4549_state *s,
 168                   hwaddr offset, uint32_t value)
 169 {
 170     uint16_t *regfile = s->regfile;
 171
 172     assert(offset < 128);
 173     DPRINTF("write [0x%02x] = 0x%04x\n", offset, value);
 174
 175     switch (offset) {
 176     case LM4549_Reset:
 177         lm4549_reset(s);
 178         break;
 179
 180     case LM4549_PCM_Front_DAC_Rate:
 181         regfile[LM4549_PCM_Front_DAC_Rate] = value;
 182         DPRINTF("DAC rate change = %i\n", value);
 183
 184         /* Re-open a voice with the new sample rate */
 185         struct audsettings as;
 186         as.freq = value;
 187         as.nchannels = 2;
 188         as.fmt = AUD_FMT_S16;
 189         as.endianness = 0;
 190
 191         s->voice = AUD_open_out(
 192             &s->card,
 193             s->voice,
 194             "lm4549.out",
 195             s,
 196             lm4549_audio_out_callback,
 197             &as
 198         );
 199         break;
 200
 201     case LM4549_Powerdown_Ctrl_Stat:
 202         value &= ~0xf;
 203         value |= regfile[LM4549_Powerdown_Ctrl_Stat] & 0xf;
 204         regfile[LM4549_Powerdown_Ctrl_Stat] = value;
 205         break;
 206
 207     case LM4549_Ext_Audio_ID:
 208     case LM4549_Vendor_ID1:
 209     case LM4549_Vendor_ID2:
 210         DPRINTF("Write to read-only register 0x%x\n", (int)offset);
 211         break;
 212
 213     default:
 214         /* Store the new value */
 215         regfile[offset] = value;
 216         break;
 217     }
 218 }
 219
 220 uint32_t lm4549_write_samples(lm4549_state *s, uint32_t left, uint32_t right)
 221 {
 222     /* The left and right samples are in 20-bit resolution.
 223        The LM4549 has 18-bit resolution and only uses the bits [19:2].
 224        This model supports 16-bit playback.
 225     */
 226
 227     if (s->buffer_level > LM4549_BUFFER_SIZE - 2) {
 228         DPRINTF("write_sample Buffer full\n");
 229         return 0;
 230     }
 231
 232     /* Store 16-bit samples in the buffer */
 233     s->buffer[s->buffer_level++] = (left >> 4);
 234     s->buffer[s->buffer_level++] = (right >> 4);
 235
 236     if (s->buffer_level == LM4549_BUFFER_SIZE) {
 237         /* Trigger the transfer of the buffer to the audio host */
 238         lm4549_audio_transfer(s);
 239     }
 240
 241     return 1;
 242 }
 243
 244 static int lm4549_post_load(void *opaque, int version_id)
 245 {
 246     lm4549_state *s = (lm4549_state *)opaque;
 247     uint16_t *regfile = s->regfile;
 248
 249     /* Re-open a voice with the current sample rate */
 250     uint32_t freq = regfile[LM4549_PCM_Front_DAC_Rate];
 251
 252     DPRINTF("post_load freq = %i\n", freq);
 253     DPRINTF("post_load voice_is_active = %i\n", s->voice_is_active);
 254
 255     struct audsettings as;
 256     as.freq = freq;
 257     as.nchannels = 2;
 258     as.fmt = AUD_FMT_S16;
 259     as.endianness = 0;
 260
 261     s->voice = AUD_open_out(
 262         &s->card,
 263         s->voice,
 264         "lm4549.out",
 265         s,
 266         lm4549_audio_out_callback,
 267         &as
 268     );
 269
 270     /* Request data */
 271     if (s->voice_is_active == 1) {
 272         lm4549_audio_out_callback(s, AUD_get_buffer_size_out(s->voice));
 273     }
 274
 275     return 0;
 276 }
 277
 278 void lm4549_init(lm4549_state *s, lm4549_callback data_req_cb, void* opaque)
 279 {
 280     struct audsettings as;
 281
 282     /* Store the callback and opaque pointer */
 283     s->data_req_cb = data_req_cb;
 284     s->opaque = opaque;
 285
 286     /* Init the registers */
 287     lm4549_reset(s);
 288
 289     /* Register an audio card */
 290     AUD_register_card("lm4549", &s->card);
 291
 292     /* Open a default voice */
 293     as.freq = 48000;
 294     as.nchannels = 2;
 295     as.fmt = AUD_FMT_S16;
 296     as.endianness = 0;
 297
 298     s->voice = AUD_open_out(
 299         &s->card,
 300         s->voice,
 301         "lm4549.out",
 302         s,
 303         lm4549_audio_out_callback,
 304         &as
 305     );
 306
 307     AUD_set_volume_out(s->voice, 0, 255, 255);
 308
 309     s->voice_is_active = 0;
 310
 311     /* Reset the input buffer */
 312     memset(s->buffer, 0x00, sizeof(s->buffer));
 313     s->buffer_level = 0;
 314
 315 #if defined(LM4549_DUMP_DAC_INPUT)
 316     fp_dac_input = fopen("lm4549_dac_input.pcm", "wb");
 317     if (!fp_dac_input) {
 318         hw_error("Unable to open lm4549_dac_input.pcm for writing\n");
 319     }
 320 #endif
 321 }
 322
 323 const VMStateDescription vmstate_lm4549_state = {
 324     .name = "lm4549_state",
 325     .version_id = 1,
 326     .minimum_version_id = 1,
 327     .post_load = lm4549_post_load,
 328     .fields = (VMStateField[]) {
 329         VMSTATE_UINT32(voice_is_active, lm4549_state),
 330         VMSTATE_UINT16_ARRAY(regfile, lm4549_state, 128),
 331         VMSTATE_UINT16_ARRAY(buffer, lm4549_state, LM4549_BUFFER_SIZE),
 332         VMSTATE_UINT32(buffer_level, lm4549_state),
 333         VMSTATE_END_OF_LIST()
 334     }
 335 };