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Add support for ESS mixer volume commands
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Co-authored-by: John Novak <john@johnnovak.net>

Imported-from:
https://github.com/joncampbell123/dosbox-x/blob/d5743d42a7a891426062d0025e7e24a6991d1df7/src/hardware/s
blaster.cpp
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@joncampbell123 @johnnovak
joncampbell123 authored and johnnovak committed May 26, 2024
1 parent e78b314 commit c52451f
Showing 1 changed file with 106 additions and 9 deletions.
115 changes: 106 additions & 9 deletions src/hardware/sblaster.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -2225,6 +2225,45 @@ static void dsp_change_stereo(const bool stereo)
sb.dma.stereo = stereo;
}

static inline uint8_t map_nibble_to_5bit(const uint8_t v)
{
assert(v <= 0x0f);

// Nibble (4-bit, 0-15) to 5-bit (0-31) mapping:
//
// 0 -> 0
// 1 -> 2
// 2 -> 4
// 3 -> 6
// ....
// 7 -> 14
// 8 -> 17
// 9 -> 19
// 10 -> 21
// 11 -> 23
// ....
// 15 -> 31
//
return (v << 1) | (v >> 3);
}

static void map_nibble_to_5bit_stereo(const uint8_t val, uint8_t *out)
{
out[0] = map_nibble_to_5bit(high_nibble(val));
out[1] = map_nibble_to_5bit(low_nibble(val));
}

static uint8_t map_5bit_to_nibble_stereo(const uint8_t v[2])
{
assert(v[0] <= 0x1f);
assert(v[1] <= 0x1f);

// 5-bit (0-31) to nibble (4-bit, 0-15) mapping
const auto high_nibble = v[0] >> 1;
const auto low_nibble = v[1] >> 1;
return (high_nibble << 4) + low_nibble;
}

static void ctmixer_write(const uint8_t val)
{
switch (sb.mixer.index) {
Expand Down Expand Up @@ -2289,6 +2328,13 @@ static void ctmixer_write(const uint8_t val)
("Mixer set to %s", sb.dma.stereo ? "STEREO" : "MONO");
break;

case 0x14: // Audio 1 Play Volume (ESS)
if (sb.ess_type != EssType::None) {
map_nibble_to_5bit_stereo(val, sb.mixer.dac);
ctmixer_update_volumes();
}
break;

case 0x22: // Master Volume (SBPRO)
set_sb_pro_volume(sb.mixer.master, val);
ctmixer_update_volumes();
Expand Down Expand Up @@ -2324,10 +2370,16 @@ static void ctmixer_write(const uint8_t val)
}
break;

case 0x32: // DAC Volume Left (SB16)
case 0x32:
// DAC Volume Left (SB16)
// Master Volume (ESS)
if (sb.type == SbType::SB16) {
sb.mixer.dac[0] = val >> 3;
ctmixer_update_volumes();

} else if (sb.ess_type != EssType::None) {
map_nibble_to_5bit_stereo(val, sb.mixer.master);
ctmixer_update_volumes();
}
break;

Expand All @@ -2352,10 +2404,16 @@ static void ctmixer_write(const uint8_t val)
}
break;

case 0x36: // CD Volume Left (SB16)
case 0x36:
// CD Volume Left (SB16)
// FM Volume (ESS)
if (sb.type == SbType::SB16) {
sb.mixer.cda[0] = val >> 3;
ctmixer_update_volumes();

} else if (sb.ess_type != EssType::None) {
map_nibble_to_5bit_stereo(val, sb.mixer.fm);
ctmixer_update_volumes();
}
break;

Expand All @@ -2366,9 +2424,15 @@ static void ctmixer_write(const uint8_t val)
}
break;

case 0x38: // Line-in Volume Left (SB16)
case 0x38:
// Line-in Volume Left (SB16)
// AuxA (CD) Volume Register (ESS)
if (sb.type == SbType::SB16) {
sb.mixer.lin[0] = val >> 3;

} else if (sb.ess_type != EssType::None) {
map_nibble_to_5bit_stereo(val, sb.mixer.cda);
ctmixer_update_volumes();
}
break;

Expand All @@ -2378,12 +2442,18 @@ static void ctmixer_write(const uint8_t val)
}
break;

case 0x3a:
case 0x3a: // Mic Volume (SB16)
if (sb.type == SbType::SB16) {
sb.mixer.mic = val >> 3;
}
break;

case 0x3e: // Line Volume (ESS)
if (sb.ess_type != EssType::None) {
map_nibble_to_5bit_stereo(val, sb.mixer.lin);
}
break;

case 0x80: // IRQ Select
sb.hw.irq = 0xff;

Expand Down Expand Up @@ -2437,7 +2507,7 @@ static void ctmixer_write(const uint8_t val)

static uint8_t ctmixer_read()
{
uint8_t ret;
uint8_t ret = 0;
// if ( sb.mixer.index< 0x80) LOG_MSG("Read mixer %x",sb.mixer.index);

switch (sb.mixer.index) {
Expand All @@ -2447,6 +2517,12 @@ static uint8_t ctmixer_read()
case 0x02: // Master Volume (SB2 only)
return ((sb.mixer.master[1] >> 1) & 0xe);

case 0x14: // Audio 1 Play Volume (ESS)
if (sb.ess_type != EssType::None) {
return map_5bit_to_nibble_stereo(sb.mixer.dac);
}
break;

case 0x22: // Master Volume (SB Pro)
return make_sb_pro_volume(sb.mixer.master);

Expand Down Expand Up @@ -2493,10 +2569,15 @@ static uint8_t ctmixer_read()
ret = 0xa;
break;

case 0x32: // DAC Volume Left (SB16)
case 0x32:
// DAC Volume Left (SB16)
// Master Volume (ESS)
if (sb.type == SbType::SB16) {
return sb.mixer.dac[0] << 3;
}
if (sb.ess_type != EssType::None) {
return map_5bit_to_nibble_stereo(sb.mixer.master);
}
ret = 0xa;
break;

Expand All @@ -2507,10 +2588,15 @@ static uint8_t ctmixer_read()
ret = 0xa;
break;

case 0x34: // FM Volume Left (SB16)
case 0x34:
// FM Volume Left (SB16)
// FM Volume (ESS)
if (sb.type == SbType::SB16) {
return sb.mixer.fm[0] << 3;
}
if (sb.ess_type != EssType::None) {
return map_5bit_to_nibble_stereo(sb.mixer.fm);
}
ret = 0xa;
break;

Expand All @@ -2535,10 +2621,15 @@ static uint8_t ctmixer_read()
ret = 0xa;
break;

case 0x38: // Line-in Volume Left (SB16)
case 0x38:
// Line-in Volume Left (SB16)
// AuxA (CD) Volume Register (ESS)
if (sb.type == SbType::SB16) {
return sb.mixer.lin[0] << 3;
}
if (sb.ess_type != EssType::None) {
return map_5bit_to_nibble_stereo(sb.mixer.cda);
}
ret = 0xa;
break;

Expand All @@ -2556,7 +2647,13 @@ static uint8_t ctmixer_read()
ret = 0xa;
break;

case 0x40: // ESS Identification Value (ES1488 and later)
case 0x3e: // Line Volume (ESS)
if (sb.ess_type != EssType::None) {
return map_5bit_to_nibble_stereo(sb.mixer.lin);
}
break;

case 0x40: // ESS Identification Value (ES1488 and later)
switch (sb.ess_type) {
case EssType::None:
case EssType::Es1688:
Expand Down

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