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minix/drivers/audio/es1371/sample_rate_converter.c
Ben Gras 7336a67dfe retire PUBLIC, PRIVATE and FORWARD
2012-03-25 21:58:14 +02:00

240 lines
6.5 KiB
C
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#include "sample_rate_converter.h"
#define SRC_RATE 48000U
#define reg(n) DSP->base + n
/* register/base and control equates for the SRC RAM */
#define SRC_SYNTH_FIFO 0x00
#define SRC_DAC_FIFO 0x20
#define SRC_ADC_FIFO 0x40
#define SRC_SYNTH_LVOL 0x7c
#define SRC_SYNTH_RVOL 0x7d
#define SRC_DAC_LVOL 0x7e
#define SRC_DAC_RVOL 0x7f
#define SRC_ADC_LVOL 0x6c
#define SRC_ADC_RVOL 0x6d
#define SRC_TRUNC_N_OFF 0x00
#define SRC_INT_REGS_OFF 0x01
#define SRC_ACCUM_FRAC_OFF 0x02
#define SRC_VFREQ_FRAC_OFF 0x03
/* miscellaneous control defines */
#define SRC_IOPOLL_COUNT 0x1000UL
#define SRC_SYNTHFREEZE (1UL << 21)
#define SRC_DACFREEZE (1UL << 20)
#define SRC_ADCFREEZE (1UL << 19)
static int src_reg_read(const DEV_STRUCT * DSP, u16_t reg, u16_t
*data);
static int src_reg_write(const DEV_STRUCT * DSP, u16_t reg, u16_t val);
int src_init ( DEV_STRUCT * DSP ) {
u32_t i;
int retVal;
/* Clear all SRC RAM then init - keep SRC disabled until done */
/* Wait till SRC_RAM_BUSY is 0 */
if (WaitBitd (reg(SAMPLE_RATE_CONV), SRC_BUSY_BIT, 0, 1000))
return (SRC_ERR_NOT_BUSY_TIMEOUT);
pci_outl(reg(SAMPLE_RATE_CONV), SRC_DISABLE);
/* from the opensound system driver, no idea where the specification is */
/* there are indeed 7 bits for the addresses of the SRC */
for( i = 0; i < 0x80; ++i ) {
if (SRC_SUCCESS != (retVal = src_reg_write(DSP, (u16_t)i, 0U)))
return (retVal);
}
if (SRC_SUCCESS != (retVal =
src_reg_write(DSP, SRC_SYNTH_BASE + SRC_TRUNC_N_OFF, 16 << 4)))
return (retVal);
if (SRC_SUCCESS != (retVal = src_reg_write(DSP,
SRC_SYNTH_BASE + SRC_INT_REGS_OFF, 16 << 10)))
return (retVal);
if (SRC_SUCCESS != (retVal =
src_reg_write(DSP, SRC_DAC_BASE + SRC_TRUNC_N_OFF, 16 << 4)))
return (retVal);
if (SRC_SUCCESS != (retVal =
src_reg_write(DSP, SRC_DAC_BASE + SRC_INT_REGS_OFF, 16 << 10)))
return (retVal);
if (SRC_SUCCESS != (retVal =
src_reg_write(DSP, SRC_SYNTH_LVOL, 1 << 12)))
return (retVal);
if (SRC_SUCCESS != (retVal =
src_reg_write(DSP, SRC_SYNTH_RVOL, 1 << 12)))
return (retVal);
if (SRC_SUCCESS != (retVal =
src_reg_write(DSP, SRC_DAC_LVOL, 1 << 12)))
return (retVal);
if (SRC_SUCCESS != (retVal =
src_reg_write(DSP, SRC_DAC_RVOL, 1 << 12)))
return (retVal);
if (SRC_SUCCESS != (retVal =
src_reg_write(DSP, SRC_ADC_LVOL, 1 << 12)))
return (retVal);
if (SRC_SUCCESS != (retVal =
src_reg_write(DSP, SRC_ADC_RVOL, 1 << 12)))
return (retVal);
/* default some rates */
src_set_rate(DSP, SRC_SYNTH_BASE, SRC_RATE);
src_set_rate(DSP, SRC_DAC_BASE, SRC_RATE);
src_set_rate(DSP, SRC_ADC_BASE, SRC_RATE);
/* now enable the whole deal */
if (WaitBitd (reg(SAMPLE_RATE_CONV), SRC_BUSY_BIT, 0, 1000))
return (SRC_ERR_NOT_BUSY_TIMEOUT);
pci_outl(reg(SAMPLE_RATE_CONV), 0UL);
return 0;
}
static int src_reg_read(const DEV_STRUCT * DSP, u16_t reg, u16_t *data) {
u32_t dtemp;
/* wait for ready */
if (WaitBitd (reg(SAMPLE_RATE_CONV), SRC_BUSY_BIT, 0, 1000))
return (SRC_ERR_NOT_BUSY_TIMEOUT);
dtemp = pci_inl(reg(SAMPLE_RATE_CONV));
/* assert a read request */
/*pci_outl(reg(SAMPLE_RATE_CONV),
(dtemp & SRC_CTLMASK) | ((u32_t) reg << 25));*/
pci_outl(reg(SAMPLE_RATE_CONV), (dtemp &
(DIS_REC|DIS_P2|DIS_P1|SRC_DISABLE)) | ((u32_t) reg << 25));
/* now wait for the data */
if (WaitBitd (reg(SAMPLE_RATE_CONV), SRC_BUSY_BIT, 0, 1000))
return (SRC_ERR_NOT_BUSY_TIMEOUT);
if (NULL != data)
*data = (u16_t) pci_inl(reg(SAMPLE_RATE_CONV));
return 0;
}
static int src_reg_write(const DEV_STRUCT * DSP, u16_t reg, u16_t val) {
u32_t dtemp;
/* wait for ready */
if (WaitBitd (reg(SAMPLE_RATE_CONV), SRC_BUSY_BIT, 0, 1000))
return (SRC_ERR_NOT_BUSY_TIMEOUT);
dtemp = pci_inl(reg(SAMPLE_RATE_CONV));
/* assert the write request */
pci_outl(reg(SAMPLE_RATE_CONV),
(dtemp & SRC_CTLMASK) | SRC_RAM_WE | ((u32_t) reg << 25) | val);
return 0;
}
void src_set_rate(const DEV_STRUCT * DSP, char base, u16_t rate) {
u32_t freq, dtemp, i;
u16_t N, truncM, truncStart, wtemp;
if( base != SRC_ADC_BASE )
{
/* freeze the channel */
dtemp = base == SRC_SYNTH_BASE ? SRC_SYNTHFREEZE : SRC_DACFREEZE;
for( i = 0; i < SRC_IOPOLL_COUNT; ++i )
if( !(pci_inl(reg(SAMPLE_RATE_CONV)) & SRC_RAM_BUSY) )
break;
pci_outl(reg(SAMPLE_RATE_CONV),
(pci_inl(reg(SAMPLE_RATE_CONV)) & SRC_CTLMASK) |
dtemp);
/* calculate new frequency and write it - preserve accum */
/* please don't try to understand. */
freq = ((u32_t) rate << 16) / 3000U;
src_reg_read(DSP, base + SRC_INT_REGS_OFF, &wtemp);
src_reg_write(DSP, base + SRC_INT_REGS_OFF,
(wtemp & 0x00ffU) |
((u16_t) (freq >> 6) & 0xfc00));
src_reg_write(DSP, base + SRC_VFREQ_FRAC_OFF, (u16_t) freq >> 1);
/* un-freeze the channel */
dtemp = base == SRC_SYNTH_BASE ? SRC_SYNTHFREEZE : SRC_DACFREEZE;
for( i = 0; i < SRC_IOPOLL_COUNT; ++i )
if( !(pci_inl(reg(SAMPLE_RATE_CONV)) & SRC_RAM_BUSY) )
break;
pci_outl(reg(SAMPLE_RATE_CONV),
(pci_inl(reg(SAMPLE_RATE_CONV)) & SRC_CTLMASK) &
~dtemp);
}
else /* setting ADC rate */
{
/* freeze the channel */
for( i = 0; i < SRC_IOPOLL_COUNT; ++i )
if( !(pci_inl(reg(SAMPLE_RATE_CONV)) & SRC_RAM_BUSY) )
break;
pci_outl(reg(SAMPLE_RATE_CONV),
(pci_inl(reg(SAMPLE_RATE_CONV)) & SRC_CTLMASK) |
SRC_ADCFREEZE);
/* derive oversample ratio */
N = rate/3000U;
if( N == 15 || N == 13 || N == 11 || N == 9 )
--N;
src_reg_write(DSP, SRC_ADC_LVOL, N << 8);
src_reg_write(DSP, SRC_ADC_RVOL, N << 8);
/* truncate the filter and write n/trunc_start */
truncM = (21*N - 1) | 1;
if( rate >= 24000U )
{
if( truncM > 239 )
truncM = 239;
truncStart = (239 - truncM) >> 1;
src_reg_write(DSP, base + SRC_TRUNC_N_OFF,
(truncStart << 9) | (N << 4));
}
else
{
if( truncM > 119 )
truncM = 119;
truncStart = (119 - truncM) >> 1;
src_reg_write(DSP, base + SRC_TRUNC_N_OFF,
0x8000U | (truncStart << 9) | (N << 4));
}
/* calculate new frequency and write it - preserve accum */
freq = ((48000UL << 16) / rate) * N;
src_reg_read(DSP, base + SRC_INT_REGS_OFF, &wtemp);
src_reg_write(DSP, base + SRC_INT_REGS_OFF,
(wtemp & 0x00ffU) |
((u16_t) (freq >> 6) & 0xfc00));
src_reg_write(DSP, base + SRC_VFREQ_FRAC_OFF, (u16_t) freq >> 1);
/* un-freeze the channel */
for( i = 0; i < SRC_IOPOLL_COUNT; ++i )
if( !(pci_inl(reg(SAMPLE_RATE_CONV)) & SRC_RAM_BUSY) )
break;
pci_outl(reg(SAMPLE_RATE_CONV),
(pci_inl(reg(SAMPLE_RATE_CONV)) & SRC_CTLMASK) &
~SRC_ADCFREEZE);
}
return;
}
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