Quelle  trident_main.c   Sprache: C

// SPDX-License-Identifier: GPL-2.0-or-later
/*
 *  Maintained by Jaroslav Kysela <perex@perex.cz>
 *  Originated by audio@tridentmicro.com
 *  Fri Feb 19 15:55:28 MST 1999
 *  Routines for control of Trident 4DWave (DX and NX) chip
 *
 *  BUGS:
 *
 *  TODO:
 *    ---
 *
 *  SiS7018 S/PDIF support by Thomas Winischhofer <thomas@winischhofer.net>
 */

#include <linux/delay.h>
#include <linux/init.h>
#include <linux/interrupt.h>
#include <linux/pci.h>
#include <linux/slab.h>
#include <linux/vmalloc.h>
#include <linux/gameport.h>
#include <linux/dma-mapping.h>
#include <linux/export.h>
#include <linux/io.h>

#include <sound/core.h>
#include <sound/info.h>
#include <sound/control.h>
#include <sound/tlv.h>
#include "trident.h"
#include <sound/asoundef.h>

static int snd_trident_pcm_mixer_build(struct snd_trident *trident,
           struct snd_trident_voice * voice,
           struct snd_pcm_substream *substream);
static int snd_trident_pcm_mixer_free(struct snd_trident *trident,
          struct snd_trident_voice * voice,
          struct snd_pcm_substream *substream);
static irqreturn_t snd_trident_interrupt(int irq, void *dev_id);
static int snd_trident_sis_reset(struct snd_trident *trident);

static void snd_trident_clear_voices(struct snd_trident * trident,
         unsigned short v_min, unsigned short v_max);
static void snd_trident_free(struct snd_card *card);

/*
 *  common I/O routines
 */


#if 0
static void snd_trident_print_voice_regs(struct snd_trident *trident, int voice)
{
 unsigned int val, tmp;

 dev_dbg(trident->card->dev, "Trident voice %i:\n", voice);
 outb(voice, TRID_REG(trident, T4D_LFO_GC_CIR));
 val = inl(TRID_REG(trident, CH_LBA));
 dev_dbg(trident->card->dev, "LBA: 0x%x\n", val);
 val = inl(TRID_REG(trident, CH_GVSEL_PAN_VOL_CTRL_EC));
 dev_dbg(trident->card->dev, "GVSel: %i\n", val >> 31);
 dev_dbg(trident->card->dev, "Pan: 0x%x\n", (val >> 24) & 0x7f);
 dev_dbg(trident->card->dev, "Vol: 0x%x\n", (val >> 16) & 0xff);
 dev_dbg(trident->card->dev, "CTRL: 0x%x\n", (val >> 12) & 0x0f);
 dev_dbg(trident->card->dev, "EC: 0x%x\n", val & 0x0fff);
 if (trident->device != TRIDENT_DEVICE_ID_NX) {
  val = inl(TRID_REG(trident, CH_DX_CSO_ALPHA_FMS));
  dev_dbg(trident->card->dev, "CSO: 0x%x\n", val >> 16);
  dev_dbg(trident->card->dev, "Alpha: 0x%x\n", (val >> 4) & 0x0fff);
  dev_dbg(trident->card->dev, "FMS: 0x%x\n", val & 0x0f);
  val = inl(TRID_REG(trident, CH_DX_ESO_DELTA));
  dev_dbg(trident->card->dev, "ESO: 0x%x\n", val >> 16);
  dev_dbg(trident->card->dev, "Delta: 0x%x\n", val & 0xffff);
  val = inl(TRID_REG(trident, CH_DX_FMC_RVOL_CVOL));
 } else {  // TRIDENT_DEVICE_ID_NX
  val = inl(TRID_REG(trident, CH_NX_DELTA_CSO));
  tmp = (val >> 24) & 0xff;
  dev_dbg(trident->card->dev, "CSO: 0x%x\n", val & 0x00ffffff);
  val = inl(TRID_REG(trident, CH_NX_DELTA_ESO));
  tmp |= (val >> 16) & 0xff00;
  dev_dbg(trident->card->dev, "Delta: 0x%x\n", tmp);
  dev_dbg(trident->card->dev, "ESO: 0x%x\n", val & 0x00ffffff);
  val = inl(TRID_REG(trident, CH_NX_ALPHA_FMS_FMC_RVOL_CVOL));
  dev_dbg(trident->card->dev, "Alpha: 0x%x\n", val >> 20);
  dev_dbg(trident->card->dev, "FMS: 0x%x\n", (val >> 16) & 0x0f);
 }
 dev_dbg(trident->card->dev, "FMC: 0x%x\n", (val >> 14) & 3);
 dev_dbg(trident->card->dev, "RVol: 0x%x\n", (val >> 7) & 0x7f);
 dev_dbg(trident->card->dev, "CVol: 0x%x\n", val & 0x7f);
}
#endif

/*---------------------------------------------------------------------------
   unsigned short snd_trident_codec_read(struct snd_ac97 *ac97, unsigned short reg)
  
   Description: This routine will do all of the reading from the external
                CODEC (AC97).
  
   Parameters:  ac97 - ac97 codec structure
                reg - CODEC register index, from AC97 Hal.
 
   returns:     16 bit value read from the AC97.
  
  ---------------------------------------------------------------------------*/
static unsigned short snd_trident_codec_read(struct snd_ac97 *ac97, unsigned short reg)
{
 unsigned int data = 0, treg;
 unsigned short count = 0xffff;
 unsigned long flags;
 struct snd_trident *trident = ac97->private_data;

 spin_lock_irqsave(&trident->reg_lock, flags);
 if (trident->device == TRIDENT_DEVICE_ID_DX) {
  data = (DX_AC97_BUSY_READ | (reg & 0x000000ff));
  outl(data, TRID_REG(trident, DX_ACR1_AC97_R));
  do {
   data = inl(TRID_REG(trident, DX_ACR1_AC97_R));
   if ((data & DX_AC97_BUSY_READ) == 0)
    break;
  } while (--count);
 } else if (trident->device == TRIDENT_DEVICE_ID_NX) {
  data = (NX_AC97_BUSY_READ | (reg & 0x000000ff));
  treg = ac97->num == 0 ? NX_ACR2_AC97_R_PRIMARY : NX_ACR3_AC97_R_SECONDARY;
  outl(data, TRID_REG(trident, treg));
  do {
   data = inl(TRID_REG(trident, treg));
   if ((data & 0x00000C00) == 0)
    break;
  } while (--count);
 } else if (trident->device == TRIDENT_DEVICE_ID_SI7018) {
  data = SI_AC97_BUSY_READ | SI_AC97_AUDIO_BUSY | (reg & 0x000000ff);
  if (ac97->num == 1)
   data |= SI_AC97_SECONDARY;
  outl(data, TRID_REG(trident, SI_AC97_READ));
  do {
   data = inl(TRID_REG(trident, SI_AC97_READ));
   if ((data & (SI_AC97_BUSY_READ)) == 0)
    break;
  } while (--count);
 }

 if (count == 0 && !trident->ac97_detect) {
  dev_err(trident->card->dev,
   "ac97 codec read TIMEOUT [0x%x/0x%x]!!!\n",
      reg, data);
  data = 0;
 }

 spin_unlock_irqrestore(&trident->reg_lock, flags);
 return ((unsigned short) (data >> 16));
}

/*---------------------------------------------------------------------------
   void snd_trident_codec_write(struct snd_ac97 *ac97, unsigned short reg,
   unsigned short wdata)
  
   Description: This routine will do all of the writing to the external
                CODEC (AC97).
  
   Parameters: ac97 - ac97 codec structure
            reg - CODEC register index, from AC97 Hal.
                data  - Lower 16 bits are the data to write to CODEC.
  
   returns:     TRUE if everything went ok, else FALSE.
  
  ---------------------------------------------------------------------------*/
static void snd_trident_codec_write(struct snd_ac97 *ac97, unsigned short reg,
        unsigned short wdata)
{
 unsigned int address, data;
 unsigned short count = 0xffff;
 unsigned long flags;
 struct snd_trident *trident = ac97->private_data;

 data = ((unsigned long) wdata) << 16;

 spin_lock_irqsave(&trident->reg_lock, flags);
 if (trident->device == TRIDENT_DEVICE_ID_DX) {
  address = DX_ACR0_AC97_W;

  /* read AC-97 write register status */
  do {
   if ((inw(TRID_REG(trident, address)) & DX_AC97_BUSY_WRITE) == 0)
    break;
  } while (--count);

  data |= (DX_AC97_BUSY_WRITE | (reg & 0x000000ff));
 } else if (trident->device == TRIDENT_DEVICE_ID_NX) {
  address = NX_ACR1_AC97_W;

  /* read AC-97 write register status */
  do {
   if ((inw(TRID_REG(trident, address)) & NX_AC97_BUSY_WRITE) == 0)
    break;
  } while (--count);

  data |= (NX_AC97_BUSY_WRITE | (ac97->num << 8) | (reg & 0x000000ff));
 } else if (trident->device == TRIDENT_DEVICE_ID_SI7018) {
  address = SI_AC97_WRITE;

  /* read AC-97 write register status */
  do {
   if ((inw(TRID_REG(trident, address)) & (SI_AC97_BUSY_WRITE)) == 0)
    break;
  } while (--count);

  data |= SI_AC97_BUSY_WRITE | SI_AC97_AUDIO_BUSY | (reg & 0x000000ff);
  if (ac97->num == 1)
   data |= SI_AC97_SECONDARY;
 } else {
  address = 0; /* keep GCC happy */
  count = 0; /* return */
 }

 if (count == 0) {
  spin_unlock_irqrestore(&trident->reg_lock, flags);
  return;
 }
 outl(data, TRID_REG(trident, address));
 spin_unlock_irqrestore(&trident->reg_lock, flags);
}

/*---------------------------------------------------------------------------
   void snd_trident_enable_eso(struct snd_trident *trident)
  
   Description: This routine will enable end of loop interrupts.
                End of loop interrupts will occur when a running
                channel reaches ESO.
                Also enables middle of loop interrupts.
  
   Parameters:  trident - pointer to target device class for 4DWave.
  
  ---------------------------------------------------------------------------*/

static void snd_trident_enable_eso(struct snd_trident * trident)
{
 unsigned int val;

 val = inl(TRID_REG(trident, T4D_LFO_GC_CIR));
 val |= ENDLP_IE;
 val |= MIDLP_IE;
 if (trident->device == TRIDENT_DEVICE_ID_SI7018)
  val |= BANK_B_EN;
 outl(val, TRID_REG(trident, T4D_LFO_GC_CIR));
}

/*---------------------------------------------------------------------------
   void snd_trident_disable_eso(struct snd_trident *trident)
  
   Description: This routine will disable end of loop interrupts.
                End of loop interrupts will occur when a running
                channel reaches ESO.
                Also disables middle of loop interrupts.
  
   Parameters:  
                trident - pointer to target device class for 4DWave.
  
   returns:     TRUE if everything went ok, else FALSE.
  
  ---------------------------------------------------------------------------*/

static void snd_trident_disable_eso(struct snd_trident * trident)
{
 unsigned int tmp;

 tmp = inl(TRID_REG(trident, T4D_LFO_GC_CIR));
 tmp &= ~ENDLP_IE;
 tmp &= ~MIDLP_IE;
 outl(tmp, TRID_REG(trident, T4D_LFO_GC_CIR));
}

/*---------------------------------------------------------------------------
   void snd_trident_start_voice(struct snd_trident * trident, unsigned int voice)

    Description: Start a voice, any channel 0 thru 63.
                 This routine automatically handles the fact that there are
                 more than 32 channels available.

    Parameters : voice - Voice number 0 thru n.
                 trident - pointer to target device class for 4DWave.

    Return Value: None.

  ---------------------------------------------------------------------------*/

void snd_trident_start_voice(struct snd_trident * trident, unsigned int voice)
{
 unsigned int mask = 1 << (voice & 0x1f);
 unsigned int reg = (voice & 0x20) ? T4D_START_B : T4D_START_A;

 outl(mask, TRID_REG(trident, reg));
}

EXPORT_SYMBOL(snd_trident_start_voice);

/*---------------------------------------------------------------------------
   void snd_trident_stop_voice(struct snd_trident * trident, unsigned int voice)

    Description: Stop a voice, any channel 0 thru 63.
                 This routine automatically handles the fact that there are
                 more than 32 channels available.

    Parameters : voice - Voice number 0 thru n.
                 trident - pointer to target device class for 4DWave.

    Return Value: None.

  ---------------------------------------------------------------------------*/

void snd_trident_stop_voice(struct snd_trident * trident, unsigned int voice)
{
 unsigned int mask = 1 << (voice & 0x1f);
 unsigned int reg = (voice & 0x20) ? T4D_STOP_B : T4D_STOP_A;

 outl(mask, TRID_REG(trident, reg));
}

EXPORT_SYMBOL(snd_trident_stop_voice);

/*---------------------------------------------------------------------------
    int snd_trident_allocate_pcm_channel(struct snd_trident *trident)
  
    Description: Allocate hardware channel in Bank B (32-63).
  
    Parameters :  trident - pointer to target device class for 4DWave.
  
    Return Value: hardware channel - 32-63 or -1 when no channel is available
  
  ---------------------------------------------------------------------------*/

static int snd_trident_allocate_pcm_channel(struct snd_trident * trident)
{
 int idx;

 if (trident->ChanPCMcnt >= trident->ChanPCM)
  return -1;
 for (idx = 31; idx >= 0; idx--) {
  if (!(trident->ChanMap[T4D_BANK_B] & (1 << idx))) {
   trident->ChanMap[T4D_BANK_B] |= 1 << idx;
   trident->ChanPCMcnt++;
   return idx + 32;
  }
 }
 return -1;
}

/*---------------------------------------------------------------------------
    void snd_trident_free_pcm_channel(int channel)
  
    Description: Free hardware channel in Bank B (32-63)
  
    Parameters :  trident - pointer to target device class for 4DWave.
          channel - hardware channel number 0-63
  
    Return Value: none
  
  ---------------------------------------------------------------------------*/

static void snd_trident_free_pcm_channel(struct snd_trident *trident, int channel)
{
 if (channel < 32 || channel > 63)
  return;
 channel &= 0x1f;
 if (trident->ChanMap[T4D_BANK_B] & (1 << channel)) {
  trident->ChanMap[T4D_BANK_B] &= ~(1 << channel);
  trident->ChanPCMcnt--;
 }
}

/*---------------------------------------------------------------------------
    unsigned int snd_trident_allocate_synth_channel(void)
  
    Description: Allocate hardware channel in Bank A (0-31).
  
    Parameters :  trident - pointer to target device class for 4DWave.
  
    Return Value: hardware channel - 0-31 or -1 when no channel is available
  
  ---------------------------------------------------------------------------*/

static int snd_trident_allocate_synth_channel(struct snd_trident * trident)
{
 int idx;

 for (idx = 31; idx >= 0; idx--) {
  if (!(trident->ChanMap[T4D_BANK_A] & (1 << idx))) {
   trident->ChanMap[T4D_BANK_A] |= 1 << idx;
   trident->synth.ChanSynthCount++;
   return idx;
  }
 }
 return -1;
}

/*---------------------------------------------------------------------------
    void snd_trident_free_synth_channel( int channel )
  
    Description: Free hardware channel in Bank B (0-31).
  
    Parameters :  trident - pointer to target device class for 4DWave.
          channel - hardware channel number 0-63
  
    Return Value: none
  
  ---------------------------------------------------------------------------*/

static void snd_trident_free_synth_channel(struct snd_trident *trident, int channel)
{
 if (channel < 0 || channel > 31)
  return;
 channel &= 0x1f;
 if (trident->ChanMap[T4D_BANK_A] & (1 << channel)) {
  trident->ChanMap[T4D_BANK_A] &= ~(1 << channel);
  trident->synth.ChanSynthCount--;
 }
}

/*---------------------------------------------------------------------------
   snd_trident_write_voice_regs
  
   Description: This routine will complete and write the 5 hardware channel
                registers to hardware.
  
   Parameters:  trident - pointer to target device class for 4DWave.
                voice - synthesizer voice structure
                Each register field.
  
  ---------------------------------------------------------------------------*/

void snd_trident_write_voice_regs(struct snd_trident * trident,
      struct snd_trident_voice * voice)
{
 unsigned int FmcRvolCvol;
 unsigned int regs[5];

 regs[1] = voice->LBA;
 regs[4] = (voice->GVSel << 31) |
    ((voice->Pan & 0x0000007f) << 24) |
    ((voice->CTRL & 0x0000000f) << 12);
 FmcRvolCvol = ((voice->FMC & 3) << 14) |
               ((voice->RVol & 0x7f) << 7) |
               (voice->CVol & 0x7f);

 switch (trident->device) {
 case TRIDENT_DEVICE_ID_SI7018:
  regs[4] |= voice->number > 31 ?
    (voice->Vol & 0x000003ff) :
    ((voice->Vol & 0x00003fc) << (16-2)) |
    (voice->EC & 0x00000fff);
  regs[0] = (voice->CSO << 16) | ((voice->Alpha & 0x00000fff) << 4) |
   (voice->FMS & 0x0000000f);
  regs[2] = (voice->ESO << 16) | (voice->Delta & 0x0ffff);
  regs[3] = (voice->Attribute << 16) | FmcRvolCvol;
  break;
 case TRIDENT_DEVICE_ID_DX:
  regs[4] |= ((voice->Vol & 0x000003fc) << (16-2)) |
      (voice->EC & 0x00000fff);
  regs[0] = (voice->CSO << 16) | ((voice->Alpha & 0x00000fff) << 4) |
   (voice->FMS & 0x0000000f);
  regs[2] = (voice->ESO << 16) | (voice->Delta & 0x0ffff);
  regs[3] = FmcRvolCvol;
  break;
 case TRIDENT_DEVICE_ID_NX:
  regs[4] |= ((voice->Vol & 0x000003fc) << (16-2)) |
      (voice->EC & 0x00000fff);
  regs[0] = (voice->Delta << 24) | (voice->CSO & 0x00ffffff);
  regs[2] = ((voice->Delta << 16) & 0xff000000) |
   (voice->ESO & 0x00ffffff);
  regs[3] = (voice->Alpha << 20) |
   ((voice->FMS & 0x0000000f) << 16) | FmcRvolCvol;
  break;
 default:
  snd_BUG();
  return;
 }

 outb(voice->number, TRID_REG(trident, T4D_LFO_GC_CIR));
 outl(regs[0], TRID_REG(trident, CH_START + 0));
 outl(regs[1], TRID_REG(trident, CH_START + 4));
 outl(regs[2], TRID_REG(trident, CH_START + 8));
 outl(regs[3], TRID_REG(trident, CH_START + 12));
 outl(regs[4], TRID_REG(trident, CH_START + 16));

#if 0
 dev_dbg(trident->card->dev, "written %i channel:\n", voice->number);
 dev_dbg(trident->card->dev, " regs[0] = 0x%x/0x%x\n",
        regs[0], inl(TRID_REG(trident, CH_START + 0)));
 dev_dbg(trident->card->dev, " regs[1] = 0x%x/0x%x\n",
        regs[1], inl(TRID_REG(trident, CH_START + 4)));
 dev_dbg(trident->card->dev, " regs[2] = 0x%x/0x%x\n",
        regs[2], inl(TRID_REG(trident, CH_START + 8)));
 dev_dbg(trident->card->dev, " regs[3] = 0x%x/0x%x\n",
        regs[3], inl(TRID_REG(trident, CH_START + 12)));
 dev_dbg(trident->card->dev, " regs[4] = 0x%x/0x%x\n",
        regs[4], inl(TRID_REG(trident, CH_START + 16)));
#endif
}

EXPORT_SYMBOL(snd_trident_write_voice_regs);

/*---------------------------------------------------------------------------
   snd_trident_write_cso_reg
  
   Description: This routine will write the new CSO offset
                register to hardware.
  
   Parameters:  trident - pointer to target device class for 4DWave.
                voice - synthesizer voice structure
                CSO - new CSO value
  
  ---------------------------------------------------------------------------*/

static void snd_trident_write_cso_reg(struct snd_trident * trident,
          struct snd_trident_voice * voice,
          unsigned int CSO)
{
 voice->CSO = CSO;
 outb(voice->number, TRID_REG(trident, T4D_LFO_GC_CIR));
 if (trident->device != TRIDENT_DEVICE_ID_NX) {
  outw(voice->CSO, TRID_REG(trident, CH_DX_CSO_ALPHA_FMS) + 2);
 } else {
  outl((voice->Delta << 24) |
       (voice->CSO & 0x00ffffff), TRID_REG(trident, CH_NX_DELTA_CSO));
 }
}

/*---------------------------------------------------------------------------
   snd_trident_write_eso_reg
  
   Description: This routine will write the new ESO offset
                register to hardware.
  
   Parameters:  trident - pointer to target device class for 4DWave.
                voice - synthesizer voice structure
                ESO - new ESO value
  
  ---------------------------------------------------------------------------*/

static void snd_trident_write_eso_reg(struct snd_trident * trident,
          struct snd_trident_voice * voice,
          unsigned int ESO)
{
 voice->ESO = ESO;
 outb(voice->number, TRID_REG(trident, T4D_LFO_GC_CIR));
 if (trident->device != TRIDENT_DEVICE_ID_NX) {
  outw(voice->ESO, TRID_REG(trident, CH_DX_ESO_DELTA) + 2);
 } else {
  outl(((voice->Delta << 16) & 0xff000000) | (voice->ESO & 0x00ffffff),
       TRID_REG(trident, CH_NX_DELTA_ESO));
 }
}

/*---------------------------------------------------------------------------
   snd_trident_write_vol_reg
  
   Description: This routine will write the new voice volume
                register to hardware.
  
   Parameters:  trident - pointer to target device class for 4DWave.
                voice - synthesizer voice structure
                Vol - new voice volume
  
  ---------------------------------------------------------------------------*/

static void snd_trident_write_vol_reg(struct snd_trident * trident,
          struct snd_trident_voice * voice,
          unsigned int Vol)
{
 voice->Vol = Vol;
 outb(voice->number, TRID_REG(trident, T4D_LFO_GC_CIR));
 switch (trident->device) {
 case TRIDENT_DEVICE_ID_DX:
 case TRIDENT_DEVICE_ID_NX:
  outb(voice->Vol >> 2, TRID_REG(trident, CH_GVSEL_PAN_VOL_CTRL_EC + 2));
  break;
 case TRIDENT_DEVICE_ID_SI7018:
  /* dev_dbg(trident->card->dev, "voice->Vol = 0x%x\n", voice->Vol); */
  outw((voice->CTRL << 12) | voice->Vol,
       TRID_REG(trident, CH_GVSEL_PAN_VOL_CTRL_EC));
  break;
 }
}

/*---------------------------------------------------------------------------
   snd_trident_write_pan_reg
  
   Description: This routine will write the new voice pan
                register to hardware.
  
   Parameters:  trident - pointer to target device class for 4DWave.
                voice - synthesizer voice structure
                Pan - new pan value
  
  ---------------------------------------------------------------------------*/

static void snd_trident_write_pan_reg(struct snd_trident * trident,
          struct snd_trident_voice * voice,
          unsigned int Pan)
{
 voice->Pan = Pan;
 outb(voice->number, TRID_REG(trident, T4D_LFO_GC_CIR));
 outb(((voice->GVSel & 0x01) << 7) | (voice->Pan & 0x7f),
      TRID_REG(trident, CH_GVSEL_PAN_VOL_CTRL_EC + 3));
}

/*---------------------------------------------------------------------------
   snd_trident_write_rvol_reg
  
   Description: This routine will write the new reverb volume
                register to hardware.
  
   Parameters:  trident - pointer to target device class for 4DWave.
                voice - synthesizer voice structure
                RVol - new reverb volume
  
  ---------------------------------------------------------------------------*/

static void snd_trident_write_rvol_reg(struct snd_trident * trident,
           struct snd_trident_voice * voice,
           unsigned int RVol)
{
 voice->RVol = RVol;
 outb(voice->number, TRID_REG(trident, T4D_LFO_GC_CIR));
 outw(((voice->FMC & 0x0003) << 14) | ((voice->RVol & 0x007f) << 7) |
      (voice->CVol & 0x007f),
      TRID_REG(trident, trident->device == TRIDENT_DEVICE_ID_NX ?
        CH_NX_ALPHA_FMS_FMC_RVOL_CVOL : CH_DX_FMC_RVOL_CVOL));
}

/*---------------------------------------------------------------------------
   snd_trident_write_cvol_reg
  
   Description: This routine will write the new chorus volume
                register to hardware.
  
   Parameters:  trident - pointer to target device class for 4DWave.
                voice - synthesizer voice structure
                CVol - new chorus volume
  
  ---------------------------------------------------------------------------*/

static void snd_trident_write_cvol_reg(struct snd_trident * trident,
           struct snd_trident_voice * voice,
           unsigned int CVol)
{
 voice->CVol = CVol;
 outb(voice->number, TRID_REG(trident, T4D_LFO_GC_CIR));
 outw(((voice->FMC & 0x0003) << 14) | ((voice->RVol & 0x007f) << 7) |
      (voice->CVol & 0x007f),
      TRID_REG(trident, trident->device == TRIDENT_DEVICE_ID_NX ?
        CH_NX_ALPHA_FMS_FMC_RVOL_CVOL : CH_DX_FMC_RVOL_CVOL));
}

/*---------------------------------------------------------------------------
   snd_trident_convert_rate

   Description: This routine converts rate in HZ to hardware delta value.
  
   Parameters:  trident - pointer to target device class for 4DWave.
                rate - Real or Virtual channel number.
  
   Returns:     Delta value.
  
  ---------------------------------------------------------------------------*/
static unsigned int snd_trident_convert_rate(unsigned int rate)
{
 unsigned int delta;

 // We special case 44100 and 8000 since rounding with the equation
 // does not give us an accurate enough value. For 11025 and 22050
 // the equation gives us the best answer. All other frequencies will
 // also use the equation. JDW
 if (rate == 44100)
  delta = 0xeb3;
 else if (rate == 8000)
  delta = 0x2ab;
 else if (rate == 48000)
  delta = 0x1000;
 else
  delta = DIV_ROUND_CLOSEST(rate << 12, 48000) & 0x0000ffff;
 return delta;
}

/*---------------------------------------------------------------------------
   snd_trident_convert_adc_rate

   Description: This routine converts rate in HZ to hardware delta value.
  
   Parameters:  trident - pointer to target device class for 4DWave.
                rate - Real or Virtual channel number.
  
   Returns:     Delta value.
  
  ---------------------------------------------------------------------------*/
static unsigned int snd_trident_convert_adc_rate(unsigned int rate)
{
 unsigned int delta;

 // We special case 44100 and 8000 since rounding with the equation
 // does not give us an accurate enough value. For 11025 and 22050
 // the equation gives us the best answer. All other frequencies will
 // also use the equation. JDW
 if (rate == 44100)
  delta = 0x116a;
 else if (rate == 8000)
  delta = 0x6000;
 else if (rate == 48000)
  delta = 0x1000;
 else
  delta = ((48000 << 12) / rate) & 0x0000ffff;
 return delta;
}

/*---------------------------------------------------------------------------
   snd_trident_spurious_threshold

   Description: This routine converts rate in HZ to spurious threshold.
  
   Parameters:  trident - pointer to target device class for 4DWave.
                rate - Real or Virtual channel number.
  
   Returns:     Delta value.
  
  ---------------------------------------------------------------------------*/
static unsigned int snd_trident_spurious_threshold(unsigned int rate,
         unsigned int period_size)
{
 unsigned int res = (rate * period_size) / 48000;
 if (res < 64)
  res = res / 2;
 else
  res -= 32;
 return res;
}

/*---------------------------------------------------------------------------
   snd_trident_control_mode

   Description: This routine returns a control mode for a PCM channel.
  
   Parameters:  trident - pointer to target device class for 4DWave.
                substream  - PCM substream
  
   Returns:     Control value.
  
  ---------------------------------------------------------------------------*/
static unsigned int snd_trident_control_mode(struct snd_pcm_substream *substream)
{
 unsigned int CTRL;
 struct snd_pcm_runtime *runtime = substream->runtime;

 /* set ctrl mode
   CTRL default: 8-bit (unsigned) mono, loop mode enabled
 */
 CTRL = 0x00000001;
 if (snd_pcm_format_width(runtime->format) == 16)
  CTRL |= 0x00000008; // 16-bit data
 if (snd_pcm_format_signed(runtime->format))
  CTRL |= 0x00000002; // signed data
 if (runtime->channels > 1)
  CTRL |= 0x00000004; // stereo data
 return CTRL;
}

/*
 *  PCM part
 */

/*---------------------------------------------------------------------------
   snd_trident_allocate_pcm_mem
  
   Description: Allocate PCM ring buffer for given substream
  
   Parameters:  substream  - PCM substream class
hw_params  - hardware parameters
  
   Returns:     Error status
  
  ---------------------------------------------------------------------------*/

static int snd_trident_allocate_pcm_mem(struct snd_pcm_substream *substream,
     struct snd_pcm_hw_params *hw_params)
{
 struct snd_trident *trident = snd_pcm_substream_chip(substream);
 struct snd_pcm_runtime *runtime = substream->runtime;
 struct snd_trident_voice *voice = runtime->private_data;

 if (trident->tlb.entries) {
  if (runtime->buffer_changed) {
   if (voice->memblk)
    snd_trident_free_pages(trident, voice->memblk);
   voice->memblk = snd_trident_alloc_pages(trident, substream);
   if (voice->memblk == NULL)
    return -ENOMEM;
  }
 }
 return 0;
}

/*---------------------------------------------------------------------------
   snd_trident_allocate_evoice
  
   Description: Allocate extra voice as interrupt generator
  
   Parameters:  substream  - PCM substream class
hw_params  - hardware parameters
  
   Returns:     Error status
  
  ---------------------------------------------------------------------------*/

static int snd_trident_allocate_evoice(struct snd_pcm_substream *substream,
           struct snd_pcm_hw_params *hw_params)
{
 struct snd_trident *trident = snd_pcm_substream_chip(substream);
 struct snd_pcm_runtime *runtime = substream->runtime;
 struct snd_trident_voice *voice = runtime->private_data;
 struct snd_trident_voice *evoice = voice->extra;

 /* voice management */

 if (params_buffer_size(hw_params) / 2 != params_period_size(hw_params)) {
  if (evoice == NULL) {
   evoice = snd_trident_alloc_voice(trident, SNDRV_TRIDENT_VOICE_TYPE_PCM, 0, 0);
   if (evoice == NULL)
    return -ENOMEM;
   voice->extra = evoice;
   evoice->substream = substream;
  }
 } else {
  if (evoice != NULL) {
   snd_trident_free_voice(trident, evoice);
   voice->extra = evoice = NULL;
  }
 }

 return 0;
}

/*---------------------------------------------------------------------------
   snd_trident_hw_params
  
   Description: Set the hardware parameters for the playback device.
  
   Parameters:  substream  - PCM substream class
hw_params  - hardware parameters
  
   Returns:     Error status
  
  ---------------------------------------------------------------------------*/

static int snd_trident_hw_params(struct snd_pcm_substream *substream,
     struct snd_pcm_hw_params *hw_params)
{
 int err;

 err = snd_trident_allocate_pcm_mem(substream, hw_params);
 if (err >= 0)
  err = snd_trident_allocate_evoice(substream, hw_params);
 return err;
}

/*---------------------------------------------------------------------------
   snd_trident_playback_hw_free
  
   Description: Release the hardware resources for the playback device.
  
   Parameters:  substream  - PCM substream class
  
   Returns:     Error status
  
  ---------------------------------------------------------------------------*/

static int snd_trident_hw_free(struct snd_pcm_substream *substream)
{
 struct snd_trident *trident = snd_pcm_substream_chip(substream);
 struct snd_pcm_runtime *runtime = substream->runtime;
 struct snd_trident_voice *voice = runtime->private_data;
 struct snd_trident_voice *evoice = voice ? voice->extra : NULL;

 if (trident->tlb.entries) {
  if (voice && voice->memblk) {
   snd_trident_free_pages(trident, voice->memblk);
   voice->memblk = NULL;
  }
 }
 if (evoice != NULL) {
  snd_trident_free_voice(trident, evoice);
  voice->extra = NULL;
 }
 return 0;
}

/*---------------------------------------------------------------------------
   snd_trident_playback_prepare
  
   Description: Prepare playback device for playback.
  
   Parameters:  substream  - PCM substream class
  
   Returns:     Error status
  
  ---------------------------------------------------------------------------*/

static int snd_trident_playback_prepare(struct snd_pcm_substream *substream)
{
 struct snd_trident *trident = snd_pcm_substream_chip(substream);
 struct snd_pcm_runtime *runtime = substream->runtime;
 struct snd_trident_voice *voice = runtime->private_data;
 struct snd_trident_voice *evoice = voice->extra;
 struct snd_trident_pcm_mixer *mix = &trident->pcm_mixer[substream->number];

 spin_lock_irq(&trident->reg_lock); 

 /* set delta (rate) value */
 voice->Delta = snd_trident_convert_rate(runtime->rate);
 voice->spurious_threshold = snd_trident_spurious_threshold(runtime->rate, runtime->period_size);

 /* set Loop Begin Address */
 if (voice->memblk)
  voice->LBA = voice->memblk->offset;
 else
  voice->LBA = runtime->dma_addr;
 
 voice->CSO = 0;
 voice->ESO = runtime->buffer_size - 1; /* in samples */
 voice->CTRL = snd_trident_control_mode(substream);
 voice->FMC = 3;
 voice->GVSel = 1;
 voice->EC = 0;
 voice->Alpha = 0;
 voice->FMS = 0;
 voice->Vol = mix->vol;
 voice->RVol = mix->rvol;
 voice->CVol = mix->cvol;
 voice->Pan = mix->pan;
 voice->Attribute = 0;
#if 0
 voice->Attribute = (1<<(30-16))|(2<<(26-16))|
      (0<<(24-16))|(0x1f<<(19-16));
#else
 voice->Attribute = 0;
#endif

 snd_trident_write_voice_regs(trident, voice);

 if (evoice != NULL) {
  evoice->Delta = voice->Delta;
  evoice->spurious_threshold = voice->spurious_threshold;
  evoice->LBA = voice->LBA;
  evoice->CSO = 0;
  evoice->ESO = (runtime->period_size * 2) + 4 - 1; /* in samples */
  evoice->CTRL = voice->CTRL;
  evoice->FMC = 3;
  evoice->GVSel = trident->device == TRIDENT_DEVICE_ID_SI7018 ? 0 : 1;
  evoice->EC = 0;
  evoice->Alpha = 0;
  evoice->FMS = 0;
  evoice->Vol = 0x3ff;   /* mute */
  evoice->RVol = evoice->CVol = 0x7f; /* mute */
  evoice->Pan = 0x7f;   /* mute */
#if 0
  evoice->Attribute = (1<<(30-16))|(2<<(26-16))|
        (0<<(24-16))|(0x1f<<(19-16));
#else
  evoice->Attribute = 0;
#endif
  snd_trident_write_voice_regs(trident, evoice);
  evoice->isync2 = 1;
  evoice->isync_mark = runtime->period_size;
  evoice->ESO = (runtime->period_size * 2) - 1;
 }

 spin_unlock_irq(&trident->reg_lock);

 return 0;
}

/*---------------------------------------------------------------------------
   snd_trident_capture_hw_params
  
   Description: Set the hardware parameters for the capture device.
  
   Parameters:  substream  - PCM substream class
hw_params  - hardware parameters
  
   Returns:     Error status
  
  ---------------------------------------------------------------------------*/

static int snd_trident_capture_hw_params(struct snd_pcm_substream *substream,
      struct snd_pcm_hw_params *hw_params)
{
 return snd_trident_allocate_pcm_mem(substream, hw_params);
}

/*---------------------------------------------------------------------------
   snd_trident_capture_prepare
  
   Description: Prepare capture device for playback.
  
   Parameters:  substream  - PCM substream class
  
   Returns:     Error status
  
  ---------------------------------------------------------------------------*/

static int snd_trident_capture_prepare(struct snd_pcm_substream *substream)
{
 struct snd_trident *trident = snd_pcm_substream_chip(substream);
 struct snd_pcm_runtime *runtime = substream->runtime;
 struct snd_trident_voice *voice = runtime->private_data;
 unsigned int val, ESO_bytes;

 spin_lock_irq(&trident->reg_lock);

 // Initialize the channel and set channel Mode
 outb(0, TRID_REG(trident, LEGACY_DMAR15));

 // Set DMA channel operation mode register
 outb(0x54, TRID_REG(trident, LEGACY_DMAR11));

 // Set channel buffer Address, DMAR0 expects contiguous PCI memory area
 voice->LBA = runtime->dma_addr;
 outl(voice->LBA, TRID_REG(trident, LEGACY_DMAR0));
 if (voice->memblk)
  voice->LBA = voice->memblk->offset;

 // set ESO
 ESO_bytes = snd_pcm_lib_buffer_bytes(substream) - 1;
 outb((ESO_bytes & 0x00ff0000) >> 16, TRID_REG(trident, LEGACY_DMAR6));
 outw((ESO_bytes & 0x0000ffff), TRID_REG(trident, LEGACY_DMAR4));
 ESO_bytes++;

 // Set channel sample rate, 4.12 format
 val = DIV_ROUND_CLOSEST(48000U << 12, runtime->rate);
 outw(val, TRID_REG(trident, T4D_SBDELTA_DELTA_R));

 // Set channel interrupt blk length
 if (snd_pcm_format_width(runtime->format) == 16) {
  val = (unsigned short) ((ESO_bytes >> 1) - 1);
 } else {
  val = (unsigned short) (ESO_bytes - 1);
 }

 outl((val << 16) | val, TRID_REG(trident, T4D_SBBL_SBCL));

 // Right now, set format and start to run captureing, 
 // continuous run loop enable.
 trident->bDMAStart = 0x19; // 0001 1001b

 if (snd_pcm_format_width(runtime->format) == 16)
  trident->bDMAStart |= 0x80;
 if (snd_pcm_format_signed(runtime->format))
  trident->bDMAStart |= 0x20;
 if (runtime->channels > 1)
  trident->bDMAStart |= 0x40;

 // Prepare capture intr channel

 voice->Delta = snd_trident_convert_rate(runtime->rate);
 voice->spurious_threshold = snd_trident_spurious_threshold(runtime->rate, runtime->period_size);
 voice->isync = 1;
 voice->isync_mark = runtime->period_size;
 voice->isync_max = runtime->buffer_size;

 // Set voice parameters
 voice->CSO = 0;
 voice->ESO = voice->isync_ESO = (runtime->period_size * 2) + 6 - 1;
 voice->CTRL = snd_trident_control_mode(substream);
 voice->FMC = 3;
 voice->RVol = 0x7f;
 voice->CVol = 0x7f;
 voice->GVSel = 1;
 voice->Pan = 0x7f;  /* mute */
 voice->Vol = 0x3ff;  /* mute */
 voice->EC = 0;
 voice->Alpha = 0;
 voice->FMS = 0;
 voice->Attribute = 0;

 snd_trident_write_voice_regs(trident, voice);

 spin_unlock_irq(&trident->reg_lock);
 return 0;
}

/*---------------------------------------------------------------------------
   snd_trident_si7018_capture_hw_params
  
   Description: Set the hardware parameters for the capture device.
  
   Parameters:  substream  - PCM substream class
hw_params  - hardware parameters
  
   Returns:     Error status
  
  ---------------------------------------------------------------------------*/

static int snd_trident_si7018_capture_hw_params(struct snd_pcm_substream *substream,
      struct snd_pcm_hw_params *hw_params)
{
 return snd_trident_allocate_evoice(substream, hw_params);
}

/*---------------------------------------------------------------------------
   snd_trident_si7018_capture_hw_free
  
   Description: Release the hardware resources for the capture device.
  
   Parameters:  substream  - PCM substream class
  
   Returns:     Error status
  
  ---------------------------------------------------------------------------*/

static int snd_trident_si7018_capture_hw_free(struct snd_pcm_substream *substream)
{
 struct snd_trident *trident = snd_pcm_substream_chip(substream);
 struct snd_pcm_runtime *runtime = substream->runtime;
 struct snd_trident_voice *voice = runtime->private_data;
 struct snd_trident_voice *evoice = voice ? voice->extra : NULL;

 if (evoice != NULL) {
  snd_trident_free_voice(trident, evoice);
  voice->extra = NULL;
 }
 return 0;
}

/*---------------------------------------------------------------------------
   snd_trident_si7018_capture_prepare
  
   Description: Prepare capture device for playback.
  
   Parameters:  substream  - PCM substream class
  
   Returns:     Error status
  
  ---------------------------------------------------------------------------*/

static int snd_trident_si7018_capture_prepare(struct snd_pcm_substream *substream)
{
 struct snd_trident *trident = snd_pcm_substream_chip(substream);
 struct snd_pcm_runtime *runtime = substream->runtime;
 struct snd_trident_voice *voice = runtime->private_data;
 struct snd_trident_voice *evoice = voice->extra;

 spin_lock_irq(&trident->reg_lock);

 voice->LBA = runtime->dma_addr;
 voice->Delta = snd_trident_convert_adc_rate(runtime->rate);
 voice->spurious_threshold = snd_trident_spurious_threshold(runtime->rate, runtime->period_size);

 // Set voice parameters
 voice->CSO = 0;
 voice->ESO = runtime->buffer_size - 1;  /* in samples */
 voice->CTRL = snd_trident_control_mode(substream);
 voice->FMC = 0;
 voice->RVol = 0;
 voice->CVol = 0;
 voice->GVSel = 1;
 voice->Pan = T4D_DEFAULT_PCM_PAN;
 voice->Vol = 0;
 voice->EC = 0;
 voice->Alpha = 0;
 voice->FMS = 0;

 voice->Attribute = (2 << (30-16)) |
      (2 << (26-16)) |
      (2 << (24-16)) |
      (1 << (23-16));

 snd_trident_write_voice_regs(trident, voice);

 if (evoice != NULL) {
  evoice->Delta = snd_trident_convert_rate(runtime->rate);
  evoice->spurious_threshold = voice->spurious_threshold;
  evoice->LBA = voice->LBA;
  evoice->CSO = 0;
  evoice->ESO = (runtime->period_size * 2) + 20 - 1; /* in samples, 20 means correction */
  evoice->CTRL = voice->CTRL;
  evoice->FMC = 3;
  evoice->GVSel = 0;
  evoice->EC = 0;
  evoice->Alpha = 0;
  evoice->FMS = 0;
  evoice->Vol = 0x3ff;   /* mute */
  evoice->RVol = evoice->CVol = 0x7f; /* mute */
  evoice->Pan = 0x7f;   /* mute */
  evoice->Attribute = 0;
  snd_trident_write_voice_regs(trident, evoice);
  evoice->isync2 = 1;
  evoice->isync_mark = runtime->period_size;
  evoice->ESO = (runtime->period_size * 2) - 1;
 }
 
 spin_unlock_irq(&trident->reg_lock);
 return 0;
}

/*---------------------------------------------------------------------------
   snd_trident_foldback_prepare
  
   Description: Prepare foldback capture device for playback.
  
   Parameters:  substream  - PCM substream class
  
   Returns:     Error status
  
  ---------------------------------------------------------------------------*/

static int snd_trident_foldback_prepare(struct snd_pcm_substream *substream)
{
 struct snd_trident *trident = snd_pcm_substream_chip(substream);
 struct snd_pcm_runtime *runtime = substream->runtime;
 struct snd_trident_voice *voice = runtime->private_data;
 struct snd_trident_voice *evoice = voice->extra;

 spin_lock_irq(&trident->reg_lock);

 /* Set channel buffer Address */
 if (voice->memblk)
  voice->LBA = voice->memblk->offset;
 else
  voice->LBA = runtime->dma_addr;

 /* set target ESO for channel */
 voice->ESO = runtime->buffer_size - 1; /* in samples */

 /* set sample rate */
 voice->Delta = 0x1000;
 voice->spurious_threshold = snd_trident_spurious_threshold(48000, runtime->period_size);

 voice->CSO = 0;
 voice->CTRL = snd_trident_control_mode(substream);
 voice->FMC = 3;
 voice->RVol = 0x7f;
 voice->CVol = 0x7f;
 voice->GVSel = 1;
 voice->Pan = 0x7f; /* mute */
 voice->Vol = 0x3ff; /* mute */
 voice->EC = 0;
 voice->Alpha = 0;
 voice->FMS = 0;
 voice->Attribute = 0;

 /* set up capture channel */
 outb(((voice->number & 0x3f) | 0x80), TRID_REG(trident, T4D_RCI + voice->foldback_chan));

 snd_trident_write_voice_regs(trident, voice);

 if (evoice != NULL) {
  evoice->Delta = voice->Delta;
  evoice->spurious_threshold = voice->spurious_threshold;
  evoice->LBA = voice->LBA;
  evoice->CSO = 0;
  evoice->ESO = (runtime->period_size * 2) + 4 - 1; /* in samples */
  evoice->CTRL = voice->CTRL;
  evoice->FMC = 3;
  evoice->GVSel = trident->device == TRIDENT_DEVICE_ID_SI7018 ? 0 : 1;
  evoice->EC = 0;
  evoice->Alpha = 0;
  evoice->FMS = 0;
  evoice->Vol = 0x3ff;   /* mute */
  evoice->RVol = evoice->CVol = 0x7f; /* mute */
  evoice->Pan = 0x7f;   /* mute */
  evoice->Attribute = 0;
  snd_trident_write_voice_regs(trident, evoice);
  evoice->isync2 = 1;
  evoice->isync_mark = runtime->period_size;
  evoice->ESO = (runtime->period_size * 2) - 1;
 }

 spin_unlock_irq(&trident->reg_lock);
 return 0;
}

/*---------------------------------------------------------------------------
   snd_trident_spdif_hw_params
  
   Description: Set the hardware parameters for the spdif device.
  
   Parameters:  substream  - PCM substream class
hw_params  - hardware parameters
  
   Returns:     Error status
  
  ---------------------------------------------------------------------------*/

static int snd_trident_spdif_hw_params(struct snd_pcm_substream *substream,
           struct snd_pcm_hw_params *hw_params)
{
 struct snd_trident *trident = snd_pcm_substream_chip(substream);
 unsigned int old_bits = 0, change = 0;
 int err;

 err = snd_trident_allocate_pcm_mem(substream, hw_params);
 if (err < 0)
  return err;

 if (trident->device == TRIDENT_DEVICE_ID_SI7018) {
  err = snd_trident_allocate_evoice(substream, hw_params);
  if (err < 0)
   return err;
 }

 /* prepare SPDIF channel */
 spin_lock_irq(&trident->reg_lock);
 old_bits = trident->spdif_pcm_bits;
 if (old_bits & IEC958_AES0_PROFESSIONAL)
  trident->spdif_pcm_bits &= ~IEC958_AES0_PRO_FS;
 else
  trident->spdif_pcm_bits &= ~(IEC958_AES3_CON_FS << 24);
 if (params_rate(hw_params) >= 48000) {
  trident->spdif_pcm_ctrl = 0x3c; // 48000 Hz
  trident->spdif_pcm_bits |=
   trident->spdif_bits & IEC958_AES0_PROFESSIONAL ?
    IEC958_AES0_PRO_FS_48000 :
    (IEC958_AES3_CON_FS_48000 << 24);
 }
 else if (params_rate(hw_params) >= 44100) {
  trident->spdif_pcm_ctrl = 0x3e; // 44100 Hz
  trident->spdif_pcm_bits |=
   trident->spdif_bits & IEC958_AES0_PROFESSIONAL ?
    IEC958_AES0_PRO_FS_44100 :
    (IEC958_AES3_CON_FS_44100 << 24);
 }
 else {
  trident->spdif_pcm_ctrl = 0x3d; // 32000 Hz
  trident->spdif_pcm_bits |=
   trident->spdif_bits & IEC958_AES0_PROFESSIONAL ?
    IEC958_AES0_PRO_FS_32000 :
    (IEC958_AES3_CON_FS_32000 << 24);
 }
 change = old_bits != trident->spdif_pcm_bits;
 spin_unlock_irq(&trident->reg_lock);

 if (change)
  snd_ctl_notify(trident->card, SNDRV_CTL_EVENT_MASK_VALUE, &trident->spdif_pcm_ctl->id);

 return 0;
}

/*---------------------------------------------------------------------------
   snd_trident_spdif_prepare
  
   Description: Prepare SPDIF device for playback.
  
   Parameters:  substream  - PCM substream class
  
   Returns:     Error status
  
  ---------------------------------------------------------------------------*/

static int snd_trident_spdif_prepare(struct snd_pcm_substream *substream)
{
 struct snd_trident *trident = snd_pcm_substream_chip(substream);
 struct snd_pcm_runtime *runtime = substream->runtime;
 struct snd_trident_voice *voice = runtime->private_data;
 struct snd_trident_voice *evoice = voice->extra;
 struct snd_trident_pcm_mixer *mix = &trident->pcm_mixer[substream->number];
 unsigned int RESO, LBAO;
 unsigned int temp;

 spin_lock_irq(&trident->reg_lock);

 if (trident->device != TRIDENT_DEVICE_ID_SI7018) {

  /* set delta (rate) value */
  voice->Delta = snd_trident_convert_rate(runtime->rate);
  voice->spurious_threshold = snd_trident_spurious_threshold(runtime->rate, runtime->period_size);

  /* set Loop Back Address */
  LBAO = runtime->dma_addr;
  if (voice->memblk)
   voice->LBA = voice->memblk->offset;
  else
   voice->LBA = LBAO;

  voice->isync = 1;
  voice->isync3 = 1;
  voice->isync_mark = runtime->period_size;
  voice->isync_max = runtime->buffer_size;

  /* set target ESO for channel */
  RESO = runtime->buffer_size - 1;
  voice->ESO = voice->isync_ESO = (runtime->period_size * 2) + 6 - 1;

  /* set ctrl mode */
  voice->CTRL = snd_trident_control_mode(substream);

  voice->FMC = 3;
  voice->RVol = 0x7f;
  voice->CVol = 0x7f;
  voice->GVSel = 1;
  voice->Pan = 0x7f;
  voice->Vol = 0x3ff;
  voice->EC = 0;
  voice->CSO = 0;
  voice->Alpha = 0;
  voice->FMS = 0;
  voice->Attribute = 0;

  /* prepare surrogate IRQ channel */
  snd_trident_write_voice_regs(trident, voice);

  outw((RESO & 0xffff), TRID_REG(trident, NX_SPESO));
  outb((RESO >> 16), TRID_REG(trident, NX_SPESO + 2));
  outl((LBAO & 0xfffffffc), TRID_REG(trident, NX_SPLBA));
  outw((voice->CSO & 0xffff), TRID_REG(trident, NX_SPCTRL_SPCSO));
  outb((voice->CSO >> 16), TRID_REG(trident, NX_SPCTRL_SPCSO + 2));

  /* set SPDIF setting */
  outb(trident->spdif_pcm_ctrl, TRID_REG(trident, NX_SPCTRL_SPCSO + 3));
  outl(trident->spdif_pcm_bits, TRID_REG(trident, NX_SPCSTATUS));

 } else { /* SiS */
 
  /* set delta (rate) value */
  voice->Delta = 0x800;
  voice->spurious_threshold = snd_trident_spurious_threshold(48000, runtime->period_size);

  /* set Loop Begin Address */
  if (voice->memblk)
   voice->LBA = voice->memblk->offset;
  else
   voice->LBA = runtime->dma_addr;

  voice->CSO = 0;
  voice->ESO = runtime->buffer_size - 1; /* in samples */
  voice->CTRL = snd_trident_control_mode(substream);
  voice->FMC = 3;
  voice->GVSel = 1;
  voice->EC = 0;
  voice->Alpha = 0;
  voice->FMS = 0;
  voice->Vol = mix->vol;
  voice->RVol = mix->rvol;
  voice->CVol = mix->cvol;
  voice->Pan = mix->pan;
  voice->Attribute = (1<<(30-16))|(7<<(26-16))|
       (0<<(24-16))|(0<<(19-16));

  snd_trident_write_voice_regs(trident, voice);

  if (evoice != NULL) {
   evoice->Delta = voice->Delta;
   evoice->spurious_threshold = voice->spurious_threshold;
   evoice->LBA = voice->LBA;
   evoice->CSO = 0;
   evoice->ESO = (runtime->period_size * 2) + 4 - 1; /* in samples */
   evoice->CTRL = voice->CTRL;
   evoice->FMC = 3;
   evoice->GVSel = trident->device == TRIDENT_DEVICE_ID_SI7018 ? 0 : 1;
   evoice->EC = 0;
   evoice->Alpha = 0;
   evoice->FMS = 0;
   evoice->Vol = 0x3ff;   /* mute */
   evoice->RVol = evoice->CVol = 0x7f; /* mute */
   evoice->Pan = 0x7f;   /* mute */
   evoice->Attribute = 0;
   snd_trident_write_voice_regs(trident, evoice);
   evoice->isync2 = 1;
   evoice->isync_mark = runtime->period_size;
   evoice->ESO = (runtime->period_size * 2) - 1;
  }

  outl(trident->spdif_pcm_bits, TRID_REG(trident, SI_SPDIF_CS));
  temp = inl(TRID_REG(trident, T4D_LFO_GC_CIR));
  temp &= ~(1<<19);
  outl(temp, TRID_REG(trident, T4D_LFO_GC_CIR));
  temp = inl(TRID_REG(trident, SI_SERIAL_INTF_CTRL));
  temp |= SPDIF_EN;
  outl(temp, TRID_REG(trident, SI_SERIAL_INTF_CTRL));
 }

 spin_unlock_irq(&trident->reg_lock);

 return 0;
}

/*---------------------------------------------------------------------------
   snd_trident_trigger
  
   Description: Start/stop devices
  
   Parameters:  substream  - PCM substream class
    cmd - trigger command (STOP, GO)
  
   Returns:     Error status
  
  ---------------------------------------------------------------------------*/

static int snd_trident_trigger(struct snd_pcm_substream *substream,
          int cmd)
        
{
 struct snd_trident *trident = snd_pcm_substream_chip(substream);
 struct snd_pcm_substream *s;
 unsigned int what, whati, capture_flag, spdif_flag;
 struct snd_trident_voice *voice, *evoice;
 unsigned int val, go;

 switch (cmd) {
 case SNDRV_PCM_TRIGGER_START:
 case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
 case SNDRV_PCM_TRIGGER_RESUME:
  go = 1;
  break;
 case SNDRV_PCM_TRIGGER_STOP:
 case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
 case SNDRV_PCM_TRIGGER_SUSPEND:
  go = 0;
  break;
 default:
  return -EINVAL;
 }
 what = whati = capture_flag = spdif_flag = 0;
 spin_lock(&trident->reg_lock);
 val = inl(TRID_REG(trident, T4D_STIMER)) & 0x00ffffff;
 snd_pcm_group_for_each_entry(s, substream) {
  if ((struct snd_trident *) snd_pcm_substream_chip(s) == trident) {
   voice = s->runtime->private_data;
   evoice = voice->extra;
   what |= 1 << (voice->number & 0x1f);
   if (evoice == NULL) {
    whati |= 1 << (voice->number & 0x1f);
   } else {
    what |= 1 << (evoice->number & 0x1f);
    whati |= 1 << (evoice->number & 0x1f);
    if (go)
     evoice->stimer = val;
   }
   if (go) {
    voice->running = 1;
    voice->stimer = val;
   } else {
    voice->running = 0;
   }
   snd_pcm_trigger_done(s, substream);
   if (voice->capture)
    capture_flag = 1;
   if (voice->spdif)
    spdif_flag = 1;
  }
 }
 if (spdif_flag) {
  if (trident->device != TRIDENT_DEVICE_ID_SI7018) {
   outl(trident->spdif_pcm_bits, TRID_REG(trident, NX_SPCSTATUS));
   val = trident->spdif_pcm_ctrl;
   if (!go)
    val &= ~(0x28);
   outb(val, TRID_REG(trident, NX_SPCTRL_SPCSO + 3));
  } else {
   outl(trident->spdif_pcm_bits, TRID_REG(trident, SI_SPDIF_CS));
   val = inl(TRID_REG(trident, SI_SERIAL_INTF_CTRL)) | SPDIF_EN;
   outl(val, TRID_REG(trident, SI_SERIAL_INTF_CTRL));
  }
 }
 if (!go)
  outl(what, TRID_REG(trident, T4D_STOP_B));
 val = inl(TRID_REG(trident, T4D_AINTEN_B));
 if (go) {
  val |= whati;
 } else {
  val &= ~whati;
 }
 outl(val, TRID_REG(trident, T4D_AINTEN_B));
 if (go) {
  outl(what, TRID_REG(trident, T4D_START_B));

  if (capture_flag && trident->device != TRIDENT_DEVICE_ID_SI7018)
   outb(trident->bDMAStart, TRID_REG(trident, T4D_SBCTRL_SBE2R_SBDD));
 } else {
  if (capture_flag && trident->device != TRIDENT_DEVICE_ID_SI7018)
   outb(0x00, TRID_REG(trident, T4D_SBCTRL_SBE2R_SBDD));
 }
 spin_unlock(&trident->reg_lock);
 return 0;
}

/*---------------------------------------------------------------------------
   snd_trident_playback_pointer
  
   Description: This routine return the playback position
                
   Parameters: substream  - PCM substream class

   Returns:     position of buffer
  
  ---------------------------------------------------------------------------*/

static snd_pcm_uframes_t snd_trident_playback_pointer(struct snd_pcm_substream *substream)
{
 struct snd_trident *trident = snd_pcm_substream_chip(substream);
 struct snd_pcm_runtime *runtime = substream->runtime;
 struct snd_trident_voice *voice = runtime->private_data;
 unsigned int cso;

 if (!voice->running)
  return 0;

 spin_lock(&trident->reg_lock);

 outb(voice->number, TRID_REG(trident, T4D_LFO_GC_CIR));

 if (trident->device != TRIDENT_DEVICE_ID_NX) {
  cso = inw(TRID_REG(trident, CH_DX_CSO_ALPHA_FMS + 2));
 } else {  // ID_4DWAVE_NX
  cso = (unsigned int) inl(TRID_REG(trident, CH_NX_DELTA_CSO)) & 0x00ffffff;
 }

 spin_unlock(&trident->reg_lock);

 if (cso >= runtime->buffer_size)
  cso = 0;

 return cso;
}

/*---------------------------------------------------------------------------
   snd_trident_capture_pointer
  
   Description: This routine return the capture position
                
   Parameters:   pcm1    - PCM device class

   Returns:     position of buffer
  
  ---------------------------------------------------------------------------*/

static snd_pcm_uframes_t snd_trident_capture_pointer(struct snd_pcm_substream *substream)
{
 struct snd_trident *trident = snd_pcm_substream_chip(substream);
 struct snd_pcm_runtime *runtime = substream->runtime;
 struct snd_trident_voice *voice = runtime->private_data;
 unsigned int result;

 if (!voice->running)
  return 0;

 result = inw(TRID_REG(trident, T4D_SBBL_SBCL));
 if (runtime->channels > 1)
  result >>= 1;
 if (result > 0)
  result = runtime->buffer_size - result;

 return result;
}

/*---------------------------------------------------------------------------
   snd_trident_spdif_pointer
  
   Description: This routine return the SPDIF playback position
                
   Parameters: substream  - PCM substream class

   Returns:     position of buffer
  
  ---------------------------------------------------------------------------*/

static snd_pcm_uframes_t snd_trident_spdif_pointer(struct snd_pcm_substream *substream)
{
 struct snd_trident *trident = snd_pcm_substream_chip(substream);
 struct snd_pcm_runtime *runtime = substream->runtime;
 struct snd_trident_voice *voice = runtime->private_data;
 unsigned int result;

 if (!voice->running)
  return 0;

 result = inl(TRID_REG(trident, NX_SPCTRL_SPCSO)) & 0x00ffffff;

 return result;
}

/*
 *  Playback support device description
 */

static const struct snd_pcm_hardware snd_trident_playback =
{
 .info =   (SNDRV_PCM_INFO_MMAP | SNDRV_PCM_INFO_INTERLEAVED |
     SNDRV_PCM_INFO_BLOCK_TRANSFER |
     SNDRV_PCM_INFO_MMAP_VALID | SNDRV_PCM_INFO_SYNC_START |
     SNDRV_PCM_INFO_PAUSE /* | SNDRV_PCM_INFO_RESUME */),
 .formats =  (SNDRV_PCM_FMTBIT_U8 | SNDRV_PCM_FMTBIT_S16_LE |
     SNDRV_PCM_FMTBIT_S8 | SNDRV_PCM_FMTBIT_U16_LE),
 .rates =  SNDRV_PCM_RATE_CONTINUOUS | SNDRV_PCM_RATE_8000_48000,
 .rate_min =  4000,
 .rate_max =  48000,
 .channels_min =  1,
 .channels_max =  2,
 .buffer_bytes_max = (256*1024),
 .period_bytes_min = 64,
 .period_bytes_max = (256*1024),
 .periods_min =  1,
 .periods_max =  1024,
 .fifo_size =  0,
};

/*
 *  Capture support device description
 */

static const struct snd_pcm_hardware snd_trident_capture =
{
 .info =   (SNDRV_PCM_INFO_MMAP | SNDRV_PCM_INFO_INTERLEAVED |
     SNDRV_PCM_INFO_BLOCK_TRANSFER |
     SNDRV_PCM_INFO_MMAP_VALID | SNDRV_PCM_INFO_SYNC_START |
     SNDRV_PCM_INFO_PAUSE /* | SNDRV_PCM_INFO_RESUME */),
 .formats =  (SNDRV_PCM_FMTBIT_U8 | SNDRV_PCM_FMTBIT_S16_LE |
     SNDRV_PCM_FMTBIT_S8 | SNDRV_PCM_FMTBIT_U16_LE),
 .rates =  SNDRV_PCM_RATE_CONTINUOUS | SNDRV_PCM_RATE_8000_48000,
 .rate_min =  4000,
 .rate_max =  48000,
 .channels_min =  1,
 .channels_max =  2,
 .buffer_bytes_max = (128*1024),
 .period_bytes_min = 64,
 .period_bytes_max = (128*1024),
 .periods_min =  1,
 .periods_max =  1024,
 .fifo_size =  0,
};

/*
 *  Foldback capture support device description
 */

static const struct snd_pcm_hardware snd_trident_foldback =
{
 .info =   (SNDRV_PCM_INFO_MMAP | SNDRV_PCM_INFO_INTERLEAVED |
     SNDRV_PCM_INFO_BLOCK_TRANSFER |
     SNDRV_PCM_INFO_MMAP_VALID | SNDRV_PCM_INFO_SYNC_START |
     SNDRV_PCM_INFO_PAUSE /* | SNDRV_PCM_INFO_RESUME */),
 .formats =  SNDRV_PCM_FMTBIT_S16_LE,
 .rates =  SNDRV_PCM_RATE_48000,
 .rate_min =  48000,
 .rate_max =  48000,
 .channels_min =  2,
 .channels_max =  2,
 .buffer_bytes_max = (128*1024),
 .period_bytes_min = 64,
 .period_bytes_max = (128*1024),
 .periods_min =  1,
 .periods_max =  1024,
 .fifo_size =  0,
};

/*
 *  SPDIF playback support device description
 */

static const struct snd_pcm_hardware snd_trident_spdif =
{
 .info =   (SNDRV_PCM_INFO_MMAP | SNDRV_PCM_INFO_INTERLEAVED |
     SNDRV_PCM_INFO_BLOCK_TRANSFER |
     SNDRV_PCM_INFO_MMAP_VALID | SNDRV_PCM_INFO_SYNC_START |
     SNDRV_PCM_INFO_PAUSE /* | SNDRV_PCM_INFO_RESUME */),
 .formats =  SNDRV_PCM_FMTBIT_S16_LE,
 .rates =  (SNDRV_PCM_RATE_32000 | SNDRV_PCM_RATE_44100 |
     SNDRV_PCM_RATE_48000),
 .rate_min =  32000,
 .rate_max =  48000,
 .channels_min =  2,
 .channels_max =  2,
 .buffer_bytes_max = (128*1024),
 .period_bytes_min = 64,
 .period_bytes_max = (128*1024),
 .periods_min =  1,
 .periods_max =  1024,
 .fifo_size =  0,
};

static const struct snd_pcm_hardware snd_trident_spdif_7018 =
{
 .info =   (SNDRV_PCM_INFO_MMAP | SNDRV_PCM_INFO_INTERLEAVED |
     SNDRV_PCM_INFO_BLOCK_TRANSFER |
     SNDRV_PCM_INFO_MMAP_VALID | SNDRV_PCM_INFO_SYNC_START |
     SNDRV_PCM_INFO_PAUSE /* | SNDRV_PCM_INFO_RESUME */),
 .formats =  SNDRV_PCM_FMTBIT_S16_LE,
 .rates =  SNDRV_PCM_RATE_48000,
 .rate_min =  48000,
 .rate_max =  48000,
 .channels_min =  2,
 .channels_max =  2,
 .buffer_bytes_max = (128*1024),
 .period_bytes_min = 64,
 .period_bytes_max = (128*1024),
 .periods_min =  1,
 .periods_max =  1024,
 .fifo_size =  0,
};

static void snd_trident_pcm_free_substream(struct snd_pcm_runtime *runtime)
{
 struct snd_trident_voice *voice = runtime->private_data;
 struct snd_trident *trident;

 if (voice) {
  trident = voice->trident;
  snd_trident_free_voice(trident, voice);
 }
}

static int snd_trident_playback_open(struct snd_pcm_substream *substream)
{
 struct snd_trident *trident = snd_pcm_substream_chip(substream);
 struct snd_pcm_runtime *runtime = substream->runtime;
 struct snd_trident_voice *voice;

 voice = snd_trident_alloc_voice(trident, SNDRV_TRIDENT_VOICE_TYPE_PCM, 0, 0);
 if (voice == NULL)
  return -EAGAIN;
 snd_trident_pcm_mixer_build(trident, voice, substream);
 voice->substream = substream;
 runtime->private_data = voice;
 runtime->private_free = snd_trident_pcm_free_substream;
 runtime->hw = snd_trident_playback;
 snd_pcm_set_sync(substream);
 snd_pcm_hw_constraint_minmax(runtime, SNDRV_PCM_HW_PARAM_BUFFER_SIZE, 0, 64*1024);
 return 0;
}

/*---------------------------------------------------------------------------
   snd_trident_playback_close
  
   Description: This routine will close the 4DWave playback device. For now 
                we will simply free the dma transfer buffer.
                
   Parameters: substream  - PCM substream class

  ---------------------------------------------------------------------------*/
static int snd_trident_playback_close(struct snd_pcm_substream *substream)
{
 struct snd_trident *trident = snd_pcm_substream_chip(substream);
 struct snd_pcm_runtime *runtime = substream->runtime;
 struct snd_trident_voice *voice = runtime->private_data;

 snd_trident_pcm_mixer_free(trident, voice, substream);
 return 0;
}

/*---------------------------------------------------------------------------
   snd_trident_spdif_open
  
   Description: This routine will open the 4DWave SPDIF device.

   Parameters: substream  - PCM substream class

   Returns:     status  - success or failure flag
  
  ---------------------------------------------------------------------------*/

static int snd_trident_spdif_open(struct snd_pcm_substream *substream)
{
 struct snd_trident *trident = snd_pcm_substream_chip(substream);
 struct snd_trident_voice *voice;
 struct snd_pcm_runtime *runtime = substream->runtime;
 
 voice = snd_trident_alloc_voice(trident, SNDRV_TRIDENT_VOICE_TYPE_PCM, 0, 0);
 if (voice == NULL)
  return -EAGAIN;
 voice->spdif = 1;
 voice->substream = substream;
 spin_lock_irq(&trident->reg_lock);
 trident->spdif_pcm_bits = trident->spdif_bits;
 spin_unlock_irq(&trident->reg_lock);

 runtime->private_data = voice;
 runtime->private_free = snd_trident_pcm_free_substream;
 if (trident->device == TRIDENT_DEVICE_ID_SI7018) {
  runtime->hw = snd_trident_spdif;
 } else {
  runtime->hw = snd_trident_spdif_7018;
 }

 trident->spdif_pcm_ctl->vd[0].access &= ~SNDRV_CTL_ELEM_ACCESS_INACTIVE;
 snd_ctl_notify(trident->card, SNDRV_CTL_EVENT_MASK_VALUE |
         SNDRV_CTL_EVENT_MASK_INFO, &trident->spdif_pcm_ctl->id);

 snd_pcm_hw_constraint_minmax(runtime, SNDRV_PCM_HW_PARAM_BUFFER_SIZE, 0, 64*1024);
 return 0;
}


/*---------------------------------------------------------------------------
   snd_trident_spdif_close
  
   Description: This routine will close the 4DWave SPDIF device.
                
   Parameters: substream  - PCM substream class

  ---------------------------------------------------------------------------*/

static int snd_trident_spdif_close(struct snd_pcm_substream *substream)
{
 struct snd_trident *trident = snd_pcm_substream_chip(substream);
 unsigned int temp;

 spin_lock_irq(&trident->reg_lock);
 // restore default SPDIF setting
 if (trident->device != TRIDENT_DEVICE_ID_SI7018) {
  outb(trident->spdif_ctrl, TRID_REG(trident, NX_SPCTRL_SPCSO + 3));
  outl(trident->spdif_bits, TRID_REG(trident, NX_SPCSTATUS));
 } else {
  outl(trident->spdif_bits, TRID_REG(trident, SI_SPDIF_CS));
  temp = inl(TRID_REG(trident, SI_SERIAL_INTF_CTRL));
  if (trident->spdif_ctrl) {
   temp |= SPDIF_EN;
  } else {
   temp &= ~SPDIF_EN;
  }
  outl(temp, TRID_REG(trident, SI_SERIAL_INTF_CTRL));
 }
 spin_unlock_irq(&trident->reg_lock);
 trident->spdif_pcm_ctl->vd[0].access |= SNDRV_CTL_ELEM_ACCESS_INACTIVE;
 snd_ctl_notify(trident->card, SNDRV_CTL_EVENT_MASK_VALUE |
         SNDRV_CTL_EVENT_MASK_INFO, &trident->spdif_pcm_ctl->id);
 return 0;
}

/*---------------------------------------------------------------------------
   snd_trident_capture_open
  
   Description: This routine will open the 4DWave capture device.

   Parameters: substream  - PCM substream class

   Returns:     status  - success or failure flag

  ---------------------------------------------------------------------------*/

static int snd_trident_capture_open(struct snd_pcm_substream *substream)
{
 struct snd_trident *trident = snd_pcm_substream_chip(substream);
 struct snd_trident_voice *voice;
 struct snd_pcm_runtime *runtime = substream->runtime;

 voice = snd_trident_alloc_voice(trident, SNDRV_TRIDENT_VOICE_TYPE_PCM, 0, 0);
 if (voice == NULL)
  return -EAGAIN;
 voice->capture = 1;
 voice->substream = substream;
 runtime->private_data = voice;
 runtime->private_free = snd_trident_pcm_free_substream;
 runtime->hw = snd_trident_capture;
 snd_pcm_set_sync(substream);
 snd_pcm_hw_constraint_minmax(runtime, SNDRV_PCM_HW_PARAM_BUFFER_SIZE, 0, 64*1024);
 return 0;
}

/*---------------------------------------------------------------------------
   snd_trident_capture_close
  
   Description: This routine will close the 4DWave capture device. For now 
                we will simply free the dma transfer buffer.
                
   Parameters: substream  - PCM substream class

  ---------------------------------------------------------------------------*/
static int snd_trident_capture_close(struct snd_pcm_substream *substream)
{
 return 0;
}

/*---------------------------------------------------------------------------
   snd_trident_foldback_open
  
   Description: This routine will open the 4DWave foldback capture device.

   Parameters: substream  - PCM substream class

   Returns:     status  - success or failure flag

  ---------------------------------------------------------------------------*/

static int snd_trident_foldback_open(struct snd_pcm_substream *substream)
{
 struct snd_trident *trident = snd_pcm_substream_chip(substream);
 struct snd_trident_voice *voice;
 struct snd_pcm_runtime *runtime = substream->runtime;

 voice = snd_trident_alloc_voice(trident, SNDRV_TRIDENT_VOICE_TYPE_PCM, 0, 0);
 if (voice == NULL)
  return -EAGAIN;
 voice->foldback_chan = substream->number;
 voice->substream = substream;
 runtime->private_data = voice;
 runtime->private_free = snd_trident_pcm_free_substream;
 runtime->hw = snd_trident_foldback;
 snd_pcm_hw_constraint_minmax(runtime, SNDRV_PCM_HW_PARAM_BUFFER_SIZE, 0, 64*1024);
 return 0;
}

/*---------------------------------------------------------------------------
   snd_trident_foldback_close
  
   Description: This routine will close the 4DWave foldback capture device. 
For now we will simply free the dma transfer buffer.
                
   Parameters: substream  - PCM substream class

  ---------------------------------------------------------------------------*/
static int snd_trident_foldback_close(struct snd_pcm_substream *substream)
{
 struct snd_trident *trident = snd_pcm_substream_chip(substream);
 struct snd_trident_voice *voice;
 struct snd_pcm_runtime *runtime = substream->runtime;
 voice = runtime->private_data;
 
 /* stop capture channel */
 spin_lock_irq(&trident->reg_lock);
 outb(0x00, TRID_REG(trident, T4D_RCI + voice->foldback_chan));
 spin_unlock_irq(&trident->reg_lock);
 return 0;
}

/*---------------------------------------------------------------------------
   PCM operations
  ---------------------------------------------------------------------------*/

static const struct snd_pcm_ops snd_trident_playback_ops = {
 .open =  snd_trident_playback_open,
 .close = snd_trident_playback_close,
 .hw_params = snd_trident_hw_params,
 .hw_free = snd_trident_hw_free,
 .prepare = snd_trident_playback_prepare,
 .trigger = snd_trident_trigger,
 .pointer = snd_trident_playback_pointer,
};

static const struct snd_pcm_ops snd_trident_nx_playback_ops = {
 .open =  snd_trident_playback_open,
 .close = snd_trident_playback_close,
 .hw_params = snd_trident_hw_params,
 .hw_free = snd_trident_hw_free,
 .prepare = snd_trident_playback_prepare,
 .trigger = snd_trident_trigger,
 .pointer = snd_trident_playback_pointer,
};

static const struct snd_pcm_ops snd_trident_capture_ops = {
 .open =  snd_trident_capture_open,
 .close = snd_trident_capture_close,
 .hw_params = snd_trident_capture_hw_params,
 .hw_free = snd_trident_hw_free,
 .prepare = snd_trident_capture_prepare,
 .trigger = snd_trident_trigger,
 .pointer = snd_trident_capture_pointer,
};

static const struct snd_pcm_ops snd_trident_si7018_capture_ops = {
 .open =  snd_trident_capture_open,
 .close = snd_trident_capture_close,
 .hw_params = snd_trident_si7018_capture_hw_params,
 .hw_free = snd_trident_si7018_capture_hw_free,
 .prepare = snd_trident_si7018_capture_prepare,
 .trigger = snd_trident_trigger,
 .pointer = snd_trident_playback_pointer,
};

static const struct snd_pcm_ops snd_trident_foldback_ops = {
 .open =  snd_trident_foldback_open,
 .close = snd_trident_foldback_close,
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