text: /*
   *  Copyright (c) by Jaroslav Kysela <perex@perex.cz>
   *                   Uros Bizjak <uros@kss-loka.si>
   *
   *  Routines for control of 8-bit SoundBlaster cards and clones
   *  Please note: I don't have access to old SB8 soundcards.
   *
   *
   *   This program is free software; you can redistribute it and/or modify
   *   it under the terms of the GNU General Public License as published by
   *   the Free Software Foundation; either version 2 of the License, or
   *   (at your option) any later version.
   *
   *   This program is distributed in the hope that it will be useful,
   *   but WITHOUT ANY WARRANTY; without even the implied warranty of
   *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   *   GNU General Public License for more details.
   *
   *   You should have received a copy of the GNU General Public License
   *   along with this program; if not, write to the Free Software
   *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
   *
   * --
   *
   * Thu Apr 29 20:36:17 BST 1999 George David Morrison <gdm@gedamo.demon.co.uk>
   *   DSP can't respond to commands whilst in "high speed" mode. Caused 
   *   glitching during playback. Fixed.
   *
   * Wed Jul 12 22:02:55 CEST 2000 Uros Bizjak <uros@kss-loka.si>
   *   Cleaned up and rewrote lowlevel routines.
   */
  
  #include <linux/io.h>
  #include <asm/dma.h>
  #include <linux/init.h>
  #include <linux/time.h>
  #include <linux/module.h>
  #include <sound/core.h>
  #include <sound/sb.h>
  
  MODULE_AUTHOR("Jaroslav Kysela <perex@perex.cz>, Uros Bizjak <uros@kss-loka.si>");
  MODULE_DESCRIPTION("Routines for control of 8-bit SoundBlaster cards and clones");
  MODULE_LICENSE("GPL");
  
  #define SB8_CLOCK	1000000
  #define SB8_DEN(v)	((SB8_CLOCK + (v) / 2) / (v))
  #define SB8_RATE(v)	(SB8_CLOCK / SB8_DEN(v))
  
  static const struct snd_ratnum clock = {
  	.num = SB8_CLOCK,
  	.den_min = 1,
  	.den_max = 256,
  	.den_step = 1,
  };
  
  static const struct snd_pcm_hw_constraint_ratnums hw_constraints_clock = {
  	.nrats = 1,
  	.rats = &clock,
  };
  
  static const struct snd_ratnum stereo_clocks[] = {
  	{
  		.num = SB8_CLOCK,
  		.den_min = SB8_DEN(22050),
  		.den_max = SB8_DEN(22050),
  		.den_step = 1,
  	},
  	{
  		.num = SB8_CLOCK,
  		.den_min = SB8_DEN(11025),
  		.den_max = SB8_DEN(11025),
  		.den_step = 1,
  	}
  };
  
  static int snd_sb8_hw_constraint_rate_channels(struct snd_pcm_hw_params *params,
  					       struct snd_pcm_hw_rule *rule)
  {
  	struct snd_interval *c = hw_param_interval(params, SNDRV_PCM_HW_PARAM_CHANNELS);
  	if (c->min > 1) {
  	  	unsigned int num = 0, den = 0;
  		int err = snd_interval_ratnum(hw_param_interval(params, SNDRV_PCM_HW_PARAM_RATE),
  					  2, stereo_clocks, &num, &den);
  		if (err >= 0 && den) {
  			params->rate_num = num;
  			params->rate_den = den;
  		}
  		return err;
  	}
  	return 0;
  }
  
  static int snd_sb8_hw_constraint_channels_rate(struct snd_pcm_hw_params *params,
  					       struct snd_pcm_hw_rule *rule)
  {
  	struct snd_interval *r = hw_param_interval(params, SNDRV_PCM_HW_PARAM_RATE);
  	if (r->min > SB8_RATE(22050) || r->max <= SB8_RATE(11025)) {
  		struct snd_interval t = { .min = 1, .max = 1 };
  		return snd_interval_refine(hw_param_interval(params, SNDRV_PCM_HW_PARAM_CHANNELS), &t);
  	}
  	return 0;
  }
  
  static int snd_sb8_playback_prepare(struct snd_pcm_substream *substream)
  {
  	unsigned long flags;
  	struct snd_sb *chip = snd_pcm_substream_chip(substream);
  	struct snd_pcm_runtime *runtime = substream->runtime;
  	unsigned int mixreg, rate, size, count;
  	unsigned char format;
  	unsigned char stereo = runtime->channels > 1;
  	int dma;
  
  	rate = runtime->rate;
  	switch (chip->hardware) {
  	case SB_HW_JAZZ16:
  		if (runtime->format == SNDRV_PCM_FORMAT_S16_LE) {
  			if (chip->mode & SB_MODE_CAPTURE_16)
  				return -EBUSY;
  			else
  				chip->mode |= SB_MODE_PLAYBACK_16;
  		}
  		chip->playback_format = SB_DSP_LO_OUTPUT_AUTO;
  		break;
  	case SB_HW_PRO:
  		if (runtime->channels > 1) {
  			if (snd_BUG_ON(rate != SB8_RATE(11025) &&
  				       rate != SB8_RATE(22050)))
  				return -EINVAL;
  			chip->playback_format = SB_DSP_HI_OUTPUT_AUTO;
  			break;
  		}
  		/* fallthru */
  	case SB_HW_201:
  		if (rate > 23000) {
  			chip->playback_format = SB_DSP_HI_OUTPUT_AUTO;
  			break;
  		}
  		/* fallthru */
  	case SB_HW_20:
  		chip->playback_format = SB_DSP_LO_OUTPUT_AUTO;
  		break;
  	case SB_HW_10:
  		chip->playback_format = SB_DSP_OUTPUT;
  		break;
  	default:
  		return -EINVAL;
  	}
  	if (chip->mode & SB_MODE_PLAYBACK_16) {
  		format = stereo ? SB_DSP_STEREO_16BIT : SB_DSP_MONO_16BIT;
  		dma = chip->dma16;
  	} else {
  		format = stereo ? SB_DSP_STEREO_8BIT : SB_DSP_MONO_8BIT;
  		chip->mode |= SB_MODE_PLAYBACK_8;
  		dma = chip->dma8;
  	}
  	size = chip->p_dma_size = snd_pcm_lib_buffer_bytes(substream);
  	count = chip->p_period_size = snd_pcm_lib_period_bytes(substream);
  	spin_lock_irqsave(&chip->reg_lock, flags);
  	snd_sbdsp_command(chip, SB_DSP_SPEAKER_ON);
  	if (chip->hardware == SB_HW_JAZZ16)
  		snd_sbdsp_command(chip, format);
  	else if (stereo) {
  		/* set playback stereo mode */
  		spin_lock(&chip->mixer_lock);
  		mixreg = snd_sbmixer_read(chip, SB_DSP_STEREO_SW);
  		snd_sbmixer_write(chip, SB_DSP_STEREO_SW, mixreg | 0x02);
  		spin_unlock(&chip->mixer_lock);
  
  		/* Soundblaster hardware programming reference guide, 3-23 */
  		snd_sbdsp_command(chip, SB_DSP_DMA8_EXIT);
  		runtime->dma_area[0] = 0x80;
  		snd_dma_program(dma, runtime->dma_addr, 1, DMA_MODE_WRITE);
  		/* force interrupt */
  		snd_sbdsp_command(chip, SB_DSP_OUTPUT);
  		snd_sbdsp_command(chip, 0);
  		snd_sbdsp_command(chip, 0);
  	}
  	snd_sbdsp_command(chip, SB_DSP_SAMPLE_RATE);
  	if (stereo) {
  		snd_sbdsp_command(chip, 256 - runtime->rate_den / 2);
  		spin_lock(&chip->mixer_lock);
  		/* save output filter status and turn it off */
  		mixreg = snd_sbmixer_read(chip, SB_DSP_PLAYBACK_FILT);
  		snd_sbmixer_write(chip, SB_DSP_PLAYBACK_FILT, mixreg | 0x20);
  		spin_unlock(&chip->mixer_lock);
  		/* just use force_mode16 for temporary storate... */
  		chip->force_mode16 = mixreg;
  	} else {
  		snd_sbdsp_command(chip, 256 - runtime->rate_den);
  	}
  	if (chip->playback_format != SB_DSP_OUTPUT) {
  		if (chip->mode & SB_MODE_PLAYBACK_16)
  			count /= 2;
  		count--;
  		snd_sbdsp_command(chip, SB_DSP_BLOCK_SIZE);
  		snd_sbdsp_command(chip, count & 0xff);
  		snd_sbdsp_command(chip, count >> 8);
  	}
  	spin_unlock_irqrestore(&chip->reg_lock, flags);
  	snd_dma_program(dma, runtime->dma_addr,
  			size, DMA_MODE_WRITE | DMA_AUTOINIT);
  	return 0;
  }
  
  static int snd_sb8_playback_trigger(struct snd_pcm_substream *substream,
  				    int cmd)
  {
  	unsigned long flags;
  	struct snd_sb *chip = snd_pcm_substream_chip(substream);
  	unsigned int count;
  
  	spin_lock_irqsave(&chip->reg_lock, flags);
  	switch (cmd) {
  	case SNDRV_PCM_TRIGGER_START:
  		snd_sbdsp_command(chip, chip->playback_format);
  		if (chip->playback_format == SB_DSP_OUTPUT) {
  			count = chip->p_period_size - 1;
  			snd_sbdsp_command(chip, count & 0xff);
  			snd_sbdsp_command(chip, count >> 8);
  		}
  		break;
  	case SNDRV_PCM_TRIGGER_STOP:
  		if (chip->playback_format == SB_DSP_HI_OUTPUT_AUTO) {
  			struct snd_pcm_runtime *runtime = substream->runtime;
  			snd_sbdsp_reset(chip);
  			if (runtime->channels > 1) {
  				spin_lock(&chip->mixer_lock);
  				/* restore output filter and set hardware to mono mode */ 
  				snd_sbmixer_write(chip, SB_DSP_STEREO_SW, chip->force_mode16 & ~0x02);
  				spin_unlock(&chip->mixer_lock);
  			}
  		} else {
  			snd_sbdsp_command(chip, SB_DSP_DMA8_OFF);
  		}
  		snd_sbdsp_command(chip, SB_DSP_SPEAKER_OFF);
  	}
  	spin_unlock_irqrestore(&chip->reg_lock, flags);
  	return 0;
  }
  
  static int snd_sb8_hw_params(struct snd_pcm_substream *substream,
  			     struct snd_pcm_hw_params *hw_params)
  {
  	return snd_pcm_lib_malloc_pages(substream, params_buffer_bytes(hw_params));
  }
  
  static int snd_sb8_hw_free(struct snd_pcm_substream *substream)
  {
  	snd_pcm_lib_free_pages(substream);
  	return 0;
  }
  
  static int snd_sb8_capture_prepare(struct snd_pcm_substream *substream)
  {
  	unsigned long flags;
  	struct snd_sb *chip = snd_pcm_substream_chip(substream);
  	struct snd_pcm_runtime *runtime = substream->runtime;
  	unsigned int mixreg, rate, size, count;
  	unsigned char format;
  	unsigned char stereo = runtime->channels > 1;
  	int dma;
  
  	rate = runtime->rate;
  	switch (chip->hardware) {
  	case SB_HW_JAZZ16:
  		if (runtime->format == SNDRV_PCM_FORMAT_S16_LE) {
  			if (chip->mode & SB_MODE_PLAYBACK_16)
  				return -EBUSY;
  			else
  				chip->mode |= SB_MODE_CAPTURE_16;
  		}
  		chip->capture_format = SB_DSP_LO_INPUT_AUTO;
  		break;
  	case SB_HW_PRO:
  		if (runtime->channels > 1) {
  			if (snd_BUG_ON(rate != SB8_RATE(11025) &&
  				       rate != SB8_RATE(22050)))
  				return -EINVAL;
  			chip->capture_format = SB_DSP_HI_INPUT_AUTO;
  			break;
  		}
  		chip->capture_format = (rate > 23000) ? SB_DSP_HI_INPUT_AUTO : SB_DSP_LO_INPUT_AUTO;
  		break;
  	case SB_HW_201:
  		if (rate > 13000) {
  			chip->capture_format = SB_DSP_HI_INPUT_AUTO;
  			break;
  		}
  		/* fallthru */
  	case SB_HW_20:
  		chip->capture_format = SB_DSP_LO_INPUT_AUTO;
  		break;
  	case SB_HW_10:
  		chip->capture_format = SB_DSP_INPUT;
  		break;
  	default:
  		return -EINVAL;
  	}
  	if (chip->mode & SB_MODE_CAPTURE_16) {
  		format = stereo ? SB_DSP_STEREO_16BIT : SB_DSP_MONO_16BIT;
  		dma = chip->dma16;
  	} else {
  		format = stereo ? SB_DSP_STEREO_8BIT : SB_DSP_MONO_8BIT;
  		chip->mode |= SB_MODE_CAPTURE_8;
  		dma = chip->dma8;
  	}
  	size = chip->c_dma_size = snd_pcm_lib_buffer_bytes(substream);
  	count = chip->c_period_size = snd_pcm_lib_period_bytes(substream);
  	spin_lock_irqsave(&chip->reg_lock, flags);
  	snd_sbdsp_command(chip, SB_DSP_SPEAKER_OFF);
  	if (chip->hardware == SB_HW_JAZZ16)
  		snd_sbdsp_command(chip, format);
  	else if (stereo)
  		snd_sbdsp_command(chip, SB_DSP_STEREO_8BIT);
  	snd_sbdsp_command(chip, SB_DSP_SAMPLE_RATE);
  	if (stereo) {
  		snd_sbdsp_command(chip, 256 - runtime->rate_den / 2);
  		spin_lock(&chip->mixer_lock);
  		/* save input filter status and turn it off */
  		mixreg = snd_sbmixer_read(chip, SB_DSP_CAPTURE_FILT);
  		snd_sbmixer_write(chip, SB_DSP_CAPTURE_FILT, mixreg | 0x20);
  		spin_unlock(&chip->mixer_lock);
  		/* just use force_mode16 for temporary storate... */
  		chip->force_mode16 = mixreg;
  	} else {
  		snd_sbdsp_command(chip, 256 - runtime->rate_den);
  	}
  	if (chip->capture_format != SB_DSP_INPUT) {
  		if (chip->mode & SB_MODE_PLAYBACK_16)
  			count /= 2;
  		count--;
  		snd_sbdsp_command(chip, SB_DSP_BLOCK_SIZE);
  		snd_sbdsp_command(chip, count & 0xff);
  		snd_sbdsp_command(chip, count >> 8);
  	}
  	spin_unlock_irqrestore(&chip->reg_lock, flags);
  	snd_dma_program(dma, runtime->dma_addr,
  			size, DMA_MODE_READ | DMA_AUTOINIT);
  	return 0;
  }
  
  static int snd_sb8_capture_trigger(struct snd_pcm_substream *substream,
  				   int cmd)
  {
  	unsigned long flags;
  	struct snd_sb *chip = snd_pcm_substream_chip(substream);
  	unsigned int count;
  
  	spin_lock_irqsave(&chip->reg_lock, flags);
  	switch (cmd) {
  	case SNDRV_PCM_TRIGGER_START:
  		snd_sbdsp_command(chip, chip->capture_format);
  		if (chip->capture_format == SB_DSP_INPUT) {
  			count = chip->c_period_size - 1;
  			snd_sbdsp_command(chip, count & 0xff);
  			snd_sbdsp_command(chip, count >> 8);
  		}
  		break;
  	case SNDRV_PCM_TRIGGER_STOP:
  		if (chip->capture_format == SB_DSP_HI_INPUT_AUTO) {
  			struct snd_pcm_runtime *runtime = substream->runtime;
  			snd_sbdsp_reset(chip);
  			if (runtime->channels > 1) {
  				/* restore input filter status */
  				spin_lock(&chip->mixer_lock);
  				snd_sbmixer_write(chip, SB_DSP_CAPTURE_FILT, chip->force_mode16);
  				spin_unlock(&chip->mixer_lock);
  				/* set hardware to mono mode */
  				snd_sbdsp_command(chip, SB_DSP_MONO_8BIT);
  			}
  		} else {
  			snd_sbdsp_command(chip, SB_DSP_DMA8_OFF);
  		}
  		snd_sbdsp_command(chip, SB_DSP_SPEAKER_OFF);
  	}
  	spin_unlock_irqrestore(&chip->reg_lock, flags);
  	return 0;
  }
  
  irqreturn_t snd_sb8dsp_interrupt(struct snd_sb *chip)
  {
  	struct snd_pcm_substream *substream;
  	struct snd_pcm_runtime *runtime;
  
  	snd_sb_ack_8bit(chip);
  	switch (chip->mode) {
  	case SB_MODE_PLAYBACK_16:	/* ok.. playback is active */
  		if (chip->hardware != SB_HW_JAZZ16)
  			break;
  		/* fallthru */
  	case SB_MODE_PLAYBACK_8:
  		substream = chip->playback_substream;
  		runtime = substream->runtime;
  		if (chip->playback_format == SB_DSP_OUTPUT)
  		    	snd_sb8_playback_trigger(substream, SNDRV_PCM_TRIGGER_START);
  		snd_pcm_period_elapsed(substream);
  		break;
  	case SB_MODE_CAPTURE_16:
  		if (chip->hardware != SB_HW_JAZZ16)
  			break;
  		/* fallthru */
  	case SB_MODE_CAPTURE_8:
  		substream = chip->capture_substream;
  		runtime = substream->runtime;
  		if (chip->capture_format == SB_DSP_INPUT)
  		    	snd_sb8_capture_trigger(substream, SNDRV_PCM_TRIGGER_START);
  		snd_pcm_period_elapsed(substream);
  		break;
  	}
  	return IRQ_HANDLED;
  }
  
  static snd_pcm_uframes_t snd_sb8_playback_pointer(struct snd_pcm_substream *substream)
  {
  	struct snd_sb *chip = snd_pcm_substream_chip(substream);
  	size_t ptr;
  	int dma;
  
  	if (chip->mode & SB_MODE_PLAYBACK_8)
  		dma = chip->dma8;
  	else if (chip->mode & SB_MODE_PLAYBACK_16)
  		dma = chip->dma16;
  	else
  		return 0;
  	ptr = snd_dma_pointer(dma, chip->p_dma_size);
  	return bytes_to_frames(substream->runtime, ptr);
  }
  
  static snd_pcm_uframes_t snd_sb8_capture_pointer(struct snd_pcm_substream *substream)
  {
  	struct snd_sb *chip = snd_pcm_substream_chip(substream);
  	size_t ptr;
  	int dma;
  
  	if (chip->mode & SB_MODE_CAPTURE_8)
  		dma = chip->dma8;
  	else if (chip->mode & SB_MODE_CAPTURE_16)
  		dma = chip->dma16;
  	else
  		return 0;
  	ptr = snd_dma_pointer(dma, chip->c_dma_size);
  	return bytes_to_frames(substream->runtime, ptr);
  }
  
  /*
  
   */
  
  static struct snd_pcm_hardware snd_sb8_playback =
  {
  	.info =			(SNDRV_PCM_INFO_MMAP | SNDRV_PCM_INFO_INTERLEAVED |
  				 SNDRV_PCM_INFO_MMAP_VALID),
  	.formats =		 SNDRV_PCM_FMTBIT_U8,
  	.rates =		(SNDRV_PCM_RATE_CONTINUOUS | SNDRV_PCM_RATE_8000 |
  				 SNDRV_PCM_RATE_11025 | SNDRV_PCM_RATE_22050),
  	.rate_min =		4000,
  	.rate_max =		23000,
  	.channels_min =		1,
  	.channels_max =		1,
  	.buffer_bytes_max =	65536,
  	.period_bytes_min =	64,
  	.period_bytes_max =	65536,
  	.periods_min =		1,
  	.periods_max =		1024,
  	.fifo_size =		0,
  };
  
  static struct snd_pcm_hardware snd_sb8_capture =
  {
  	.info =			(SNDRV_PCM_INFO_MMAP | SNDRV_PCM_INFO_INTERLEAVED |
  				 SNDRV_PCM_INFO_MMAP_VALID),
  	.formats =		SNDRV_PCM_FMTBIT_U8,
  	.rates =		(SNDRV_PCM_RATE_CONTINUOUS | SNDRV_PCM_RATE_8000 |
  				 SNDRV_PCM_RATE_11025),
  	.rate_min =		4000,
  	.rate_max =		13000,
  	.channels_min =		1,
  	.channels_max =		1,
  	.buffer_bytes_max =	65536,
  	.period_bytes_min =	64,
  	.period_bytes_max =	65536,
  	.periods_min =		1,
  	.periods_max =		1024,
  	.fifo_size =		0,
  };
  
  /*
   *
   */
   
  static int snd_sb8_open(struct snd_pcm_substream *substream)
  {
  	struct snd_sb *chip = snd_pcm_substream_chip(substream);
  	struct snd_pcm_runtime *runtime = substream->runtime;
  	unsigned long flags;
  
  	spin_lock_irqsave(&chip->open_lock, flags);
  	if (chip->open) {
  		spin_unlock_irqrestore(&chip->open_lock, flags);
  		return -EAGAIN;
  	}
  	chip->open |= SB_OPEN_PCM;
  	spin_unlock_irqrestore(&chip->open_lock, flags);
  	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
  		chip->playback_substream = substream;
  		runtime->hw = snd_sb8_playback;
  	} else {
  		chip->capture_substream = substream;
  		runtime->hw = snd_sb8_capture;
  	}
  	switch (chip->hardware) {
  	case SB_HW_JAZZ16:
  		if (chip->dma16 == 5 || chip->dma16 == 7)
  			runtime->hw.formats |= SNDRV_PCM_FMTBIT_S16_LE;
  		runtime->hw.rates |= SNDRV_PCM_RATE_8000_48000;
  		runtime->hw.rate_min = 4000;
  		runtime->hw.rate_max = 50000;
  		runtime->hw.channels_max = 2;
  		break;
  	case SB_HW_PRO:
  		runtime->hw.rate_max = 44100;
  		runtime->hw.channels_max = 2;
  		snd_pcm_hw_rule_add(runtime, 0, SNDRV_PCM_HW_PARAM_RATE,
  				    snd_sb8_hw_constraint_rate_channels, NULL,
  				    SNDRV_PCM_HW_PARAM_CHANNELS,
  				    SNDRV_PCM_HW_PARAM_RATE, -1);
  		snd_pcm_hw_rule_add(runtime, 0, SNDRV_PCM_HW_PARAM_CHANNELS,
  				     snd_sb8_hw_constraint_channels_rate, NULL,
  				     SNDRV_PCM_HW_PARAM_RATE, -1);
  		break;
  	case SB_HW_201:
  		if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
  			runtime->hw.rate_max = 44100;
  		} else {
  			runtime->hw.rate_max = 15000;
  		}
  	default:
  		break;
  	}
  	snd_pcm_hw_constraint_ratnums(runtime, 0, SNDRV_PCM_HW_PARAM_RATE,
  				      &hw_constraints_clock);
  	if (chip->dma8 > 3 || chip->dma16 >= 0) {
  		snd_pcm_hw_constraint_step(runtime, 0,
  					   SNDRV_PCM_HW_PARAM_BUFFER_BYTES, 2);
  		snd_pcm_hw_constraint_step(runtime, 0,
  					   SNDRV_PCM_HW_PARAM_PERIOD_BYTES, 2);
  		runtime->hw.buffer_bytes_max = 128 * 1024 * 1024;
  		runtime->hw.period_bytes_max = 128 * 1024 * 1024;
  	}
  	return 0;	
  }
  
  static int snd_sb8_close(struct snd_pcm_substream *substream)
  {
  	unsigned long flags;
  	struct snd_sb *chip = snd_pcm_substream_chip(substream);
  
  	chip->playback_substream = NULL;
  	chip->capture_substream = NULL;
  	spin_lock_irqsave(&chip->open_lock, flags);
  	chip->open &= ~SB_OPEN_PCM;
  	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
  		chip->mode &= ~SB_MODE_PLAYBACK;
  	else
  		chip->mode &= ~SB_MODE_CAPTURE;
  	spin_unlock_irqrestore(&chip->open_lock, flags);
  	return 0;
  }
  
  /*
   *  Initialization part
   */
   
  static struct snd_pcm_ops snd_sb8_playback_ops = {
  	.open =			snd_sb8_open,
  	.close =		snd_sb8_close,
  	.ioctl =		snd_pcm_lib_ioctl,
  	.hw_params =		snd_sb8_hw_params,
  	.hw_free =		snd_sb8_hw_free,
  	.prepare =		snd_sb8_playback_prepare,
  	.trigger =		snd_sb8_playback_trigger,
  	.pointer =		snd_sb8_playback_pointer,
  };
  
  static struct snd_pcm_ops snd_sb8_capture_ops = {
  	.open =			snd_sb8_open,
  	.close =		snd_sb8_close,
  	.ioctl =		snd_pcm_lib_ioctl,
  	.hw_params =		snd_sb8_hw_params,
  	.hw_free =		snd_sb8_hw_free,
  	.prepare =		snd_sb8_capture_prepare,
  	.trigger =		snd_sb8_capture_trigger,
  	.pointer =		snd_sb8_capture_pointer,
  };
  
  int snd_sb8dsp_pcm(struct snd_sb *chip, int device)
  {
  	struct snd_card *card = chip->card;
  	struct snd_pcm *pcm;
  	int err;
  	size_t max_prealloc = 64 * 1024;
  
  	if ((err = snd_pcm_new(card, "SB8 DSP", device, 1, 1, &pcm)) < 0)
  		return err;
  	sprintf(pcm->name, "DSP v%i.%i", chip->version >> 8, chip->version & 0xff);
  	pcm->info_flags = SNDRV_PCM_INFO_HALF_DUPLEX;
  	pcm->private_data = chip;
  
  	snd_pcm_set_ops(pcm, SNDRV_PCM_STREAM_PLAYBACK, &snd_sb8_playback_ops);
  	snd_pcm_set_ops(pcm, SNDRV_PCM_STREAM_CAPTURE, &snd_sb8_capture_ops);
  
  	if (chip->dma8 > 3 || chip->dma16 >= 0)
  		max_prealloc = 128 * 1024;
  	snd_pcm_lib_preallocate_pages_for_all(pcm, SNDRV_DMA_TYPE_DEV,
  					      snd_dma_isa_data(),
  					      64*1024, max_prealloc);
  
  	return 0;
  }
  
  EXPORT_SYMBOL(snd_sb8dsp_pcm);
  EXPORT_SYMBOL(snd_sb8dsp_interrupt);
    /* sb8_midi.c */
  EXPORT_SYMBOL(snd_sb8dsp_midi_interrupt);
  EXPORT_SYMBOL(snd_sb8dsp_midi);
  
  /*
   *  INIT part
   */
  
  static int __init alsa_sb8_init(void)
  {
  	return 0;
  }
  
  static void __exit alsa_sb8_exit(void)
  {
  }
  
  module_init(alsa_sb8_init)
  module_exit(alsa_sb8_exit)
  