/*
   * BRIEF MODULE DESCRIPTION
   *  Driver for AMD Au1000 MIPS Processor, AC'97 Sound Port
   *
   * Copyright 2004 Cooper Street Innovations Inc.
   * Author: Charles Eidsness	<charles@cooper-street.com>
   *
   *  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  SOFTWARE  IS PROVIDED   ``AS  IS'' AND   ANY  EXPRESS OR IMPLIED
   *  WARRANTIES,   INCLUDING, BUT NOT  LIMITED  TO, THE IMPLIED WARRANTIES OF
   *  MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN
   *  NO  EVENT  SHALL   THE AUTHOR  BE    LIABLE FOR ANY   DIRECT, INDIRECT,
   *  INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
   *  NOT LIMITED   TO, PROCUREMENT OF  SUBSTITUTE GOODS  OR SERVICES; LOSS OF
   *  USE, DATA,  OR PROFITS; OR  BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
   *  ANY THEORY OF LIABILITY, WHETHER IN  CONTRACT, STRICT LIABILITY, OR TORT
   *  (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
   *  THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
   *
   *  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.,
   *  675 Mass Ave, Cambridge, MA 02139, USA.
   *
   * History:
   *
   * 2004-09-09 Charles Eidsness	-- Original verion -- based on
   * 				  sa11xx-uda1341.c ALSA driver and the
   *				  au1000.c OSS driver.
   * 2004-09-09 Matt Porter	-- Added support for ALSA 1.0.6
   *
   */
  
  #include <linux/ioport.h>
  #include <linux/interrupt.h>

  #include <linux/init.h>
  #include <linux/slab.h>

  #include <linux/module.h>

  #include <sound/core.h>
  #include <sound/initval.h>
  #include <sound/pcm.h>

  #include <sound/pcm_params.h>

  #include <sound/ac97_codec.h>
  #include <asm/mach-au1x00/au1000.h>
  #include <asm/mach-au1x00/au1000_dma.h>
  
  MODULE_AUTHOR("Charles Eidsness <charles@cooper-street.com>");
  MODULE_DESCRIPTION("Au1000 AC'97 ALSA Driver");
  MODULE_LICENSE("GPL");

  MODULE_SUPPORTED_DEVICE("{{AMD,Au1000 AC'97}}");

  #define PLAYBACK 0
  #define CAPTURE 1
  #define AC97_SLOT_3 0x01
  #define AC97_SLOT_4 0x02
  #define AC97_SLOT_6 0x08
  #define AC97_CMD_IRQ 31
  #define READ 0
  #define WRITE 1
  #define READ_WAIT 2
  #define RW_DONE 3

  struct au1000_period
  {
  	u32 start;
  	u32 relative_end;	/*realtive to start of buffer*/

  	struct au1000_period * next;

  };
  
  /*Au1000 AC97 Port Control Reisters*/

  struct au1000_ac97_reg {
  	u32 volatile config;
  	u32 volatile status;
  	u32 volatile data;
  	u32 volatile cmd;
  	u32 volatile cntrl;
  };

  struct audio_stream {

  	struct snd_pcm_substream *substream;

  	int dma;
  	spinlock_t dma_lock;

  	struct au1000_period * buffer;

  	unsigned int period_size;
  	unsigned int periods;

  };

  struct snd_au1000 {
  	struct snd_card *card;
  	struct au1000_ac97_reg volatile *ac97_ioport;

  
  	struct resource *ac97_res_port;
  	spinlock_t ac97_lock;

  	struct snd_ac97 *ac97;

  	struct snd_pcm *pcm;
  	struct audio_stream *stream[2];	/* playback & capture */
  };

  /*--------------------------- Local Functions --------------------------------*/
  static void

  au1000_set_ac97_xmit_slots(struct snd_au1000 *au1000, long xmit_slots)

  {
  	u32 volatile ac97_config;
  
  	spin_lock(&au1000->ac97_lock);
  	ac97_config = au1000->ac97_ioport->config;
  	ac97_config = ac97_config & ~AC97C_XMIT_SLOTS_MASK;
  	ac97_config |= (xmit_slots << AC97C_XMIT_SLOTS_BIT);
  	au1000->ac97_ioport->config = ac97_config;
  	spin_unlock(&au1000->ac97_lock);
  }
  
  static void

  au1000_set_ac97_recv_slots(struct snd_au1000 *au1000, long recv_slots)

  {
  	u32 volatile ac97_config;
  
  	spin_lock(&au1000->ac97_lock);
  	ac97_config = au1000->ac97_ioport->config;
  	ac97_config = ac97_config & ~AC97C_RECV_SLOTS_MASK;
  	ac97_config |= (recv_slots << AC97C_RECV_SLOTS_BIT);
  	au1000->ac97_ioport->config = ac97_config;
  	spin_unlock(&au1000->ac97_lock);
  }
  
  
  static void

  au1000_release_dma_link(struct audio_stream *stream)

  {

  	struct au1000_period * pointer;
  	struct au1000_period * pointer_next;

  	stream->period_size = 0;
  	stream->periods = 0;
  	pointer = stream->buffer;
  	if (! pointer)
  		return;
  	do {
  		pointer_next = pointer->next;
  		kfree(pointer);
  		pointer = pointer_next;
  	} while (pointer != stream->buffer);
  	stream->buffer = NULL;
  }
  
  static int

  au1000_setup_dma_link(struct audio_stream *stream, unsigned int period_bytes,

  		      unsigned int periods)
  {

  	struct snd_pcm_substream *substream = stream->substream;
  	struct snd_pcm_runtime *runtime = substream->runtime;

  	struct au1000_period *pointer;

  	unsigned long dma_start;
  	int i;
  
  	dma_start = virt_to_phys(runtime->dma_area);

  	if (stream->period_size == period_bytes &&
  	    stream->periods == periods)
  		return 0; /* not changed */

  	au1000_release_dma_link(stream);

  	stream->period_size = period_bytes;
  	stream->periods = periods;

  	stream->buffer = kmalloc(sizeof(struct au1000_period), GFP_KERNEL);

  	if (! stream->buffer)
  		return -ENOMEM;
  	pointer = stream->buffer;
  	for (i = 0; i < periods; i++) {
  		pointer->start = (u32)(dma_start + (i * period_bytes));
  		pointer->relative_end = (u32) (((i+1) * period_bytes) - 0x1);
  		if (i < periods - 1) {
  			pointer->next = kmalloc(sizeof(struct au1000_period), GFP_KERNEL);
  			if (! pointer->next) {
  				au1000_release_dma_link(stream);
  				return -ENOMEM;
  			}
  			pointer = pointer->next;
  		}

  	}

  	pointer->next = stream->buffer;
  	return 0;

  }
  
  static void

  au1000_dma_stop(struct audio_stream *stream)

  {

  	if (snd_BUG_ON(!stream->buffer))
  		return;

  	disable_dma(stream->dma);
  }

  static void

  au1000_dma_start(struct audio_stream *stream)

  {

  	if (snd_BUG_ON(!stream->buffer))
  		return;

  	init_dma(stream->dma);
  	if (get_dma_active_buffer(stream->dma) == 0) {
  		clear_dma_done0(stream->dma);
  		set_dma_addr0(stream->dma, stream->buffer->start);
  		set_dma_count0(stream->dma, stream->period_size >> 1);
  		set_dma_addr1(stream->dma, stream->buffer->next->start);
  		set_dma_count1(stream->dma, stream->period_size >> 1);
  	} else {
  		clear_dma_done1(stream->dma);
  		set_dma_addr1(stream->dma, stream->buffer->start);
  		set_dma_count1(stream->dma, stream->period_size >> 1);
  		set_dma_addr0(stream->dma, stream->buffer->next->start);
  		set_dma_count0(stream->dma, stream->period_size >> 1);

  	}

  	enable_dma_buffers(stream->dma);
  	start_dma(stream->dma);

  }
  
  static irqreturn_t

  au1000_dma_interrupt(int irq, void *dev_id)

  {

  	struct audio_stream *stream = (struct audio_stream *) dev_id;
  	struct snd_pcm_substream *substream = stream->substream;

  
  	spin_lock(&stream->dma_lock);
  	switch (get_dma_buffer_done(stream->dma)) {
  	case DMA_D0:
  		stream->buffer = stream->buffer->next;
  		clear_dma_done0(stream->dma);
  		set_dma_addr0(stream->dma, stream->buffer->next->start);
  		set_dma_count0(stream->dma, stream->period_size >> 1);
  		enable_dma_buffer0(stream->dma);
  		break;
  	case DMA_D1:
  		stream->buffer = stream->buffer->next;
  		clear_dma_done1(stream->dma);
  		set_dma_addr1(stream->dma, stream->buffer->next->start);
  		set_dma_count1(stream->dma, stream->period_size >> 1);
  		enable_dma_buffer1(stream->dma);
  		break;
  	case (DMA_D0 | DMA_D1):

  		printk(KERN_ERR "DMA %d missed interrupt.
  ",stream->dma);
  		au1000_dma_stop(stream);
  		au1000_dma_start(stream);

  		break;
  	case (~DMA_D0 & ~DMA_D1):
  		printk(KERN_ERR "DMA %d empty irq.
  ",stream->dma);
  	}
  	spin_unlock(&stream->dma_lock);
  	snd_pcm_period_elapsed(substream);
  	return IRQ_HANDLED;
  }
  
  /*-------------------------- PCM Audio Streams -------------------------------*/
  
  static unsigned int rates[] = {8000, 11025, 16000, 22050};

  static struct snd_pcm_hw_constraint_list hw_constraints_rates = {

  	.count	= ARRAY_SIZE(rates),

  	.list	= rates,
  	.mask	= 0,
  };

  static struct snd_pcm_hardware snd_au1000_hw =

  {
  	.info			= (SNDRV_PCM_INFO_INTERLEAVED | \
  				SNDRV_PCM_INFO_MMAP | SNDRV_PCM_INFO_MMAP_VALID),
  	.formats		= SNDRV_PCM_FMTBIT_S16_LE,
  	.rates			= (SNDRV_PCM_RATE_8000 | SNDRV_PCM_RATE_11025 |
  				SNDRV_PCM_RATE_16000 | SNDRV_PCM_RATE_22050),
  	.rate_min		= 8000,
  	.rate_max		= 22050,
  	.channels_min		= 1,
  	.channels_max		= 2,
  	.buffer_bytes_max	= 128*1024,
  	.period_bytes_min	= 32,
  	.period_bytes_max	= 16*1024,
  	.periods_min		= 8,
  	.periods_max		= 255,
  	.fifo_size		= 16,
  };
  
  static int

  snd_au1000_playback_open(struct snd_pcm_substream *substream)

  {

  	struct snd_au1000 *au1000 = substream->pcm->private_data;

  	au1000->stream[PLAYBACK]->substream = substream;
  	au1000->stream[PLAYBACK]->buffer = NULL;
  	substream->private_data = au1000->stream[PLAYBACK];

  	substream->runtime->hw = snd_au1000_hw;

  	return (snd_pcm_hw_constraint_list(substream->runtime, 0,
  		SNDRV_PCM_HW_PARAM_RATE, &hw_constraints_rates) < 0);
  }
  
  static int

  snd_au1000_capture_open(struct snd_pcm_substream *substream)

  {

  	struct snd_au1000 *au1000 = substream->pcm->private_data;

  	au1000->stream[CAPTURE]->substream = substream;
  	au1000->stream[CAPTURE]->buffer = NULL;
  	substream->private_data = au1000->stream[CAPTURE];

  	substream->runtime->hw = snd_au1000_hw;

  	return (snd_pcm_hw_constraint_list(substream->runtime, 0,
  		SNDRV_PCM_HW_PARAM_RATE, &hw_constraints_rates) < 0);

  }
  
  static int

  snd_au1000_playback_close(struct snd_pcm_substream *substream)

  {

  	struct snd_au1000 *au1000 = substream->pcm->private_data;

  	au1000->stream[PLAYBACK]->substream = NULL;
  	return 0;
  }
  
  static int

  snd_au1000_capture_close(struct snd_pcm_substream *substream)

  {

  	struct snd_au1000 *au1000 = substream->pcm->private_data;

  	au1000->stream[CAPTURE]->substream = NULL;
  	return 0;
  }
  
  static int

  snd_au1000_hw_params(struct snd_pcm_substream *substream,
  					struct snd_pcm_hw_params *hw_params)

  {

  	struct audio_stream *stream = substream->private_data;

  	int err;
  
  	err = snd_pcm_lib_malloc_pages(substream,
  				       params_buffer_bytes(hw_params));
  	if (err < 0)
  		return err;
  	return au1000_setup_dma_link(stream,
  				     params_period_bytes(hw_params),
  				     params_periods(hw_params));

  }
  
  static int

  snd_au1000_hw_free(struct snd_pcm_substream *substream)

  {

  	struct audio_stream *stream = substream->private_data;

  	au1000_release_dma_link(stream);

  	return snd_pcm_lib_free_pages(substream);
  }
  
  static int

  snd_au1000_playback_prepare(struct snd_pcm_substream *substream)

  {

  	struct snd_au1000 *au1000 = substream->pcm->private_data;
  	struct snd_pcm_runtime *runtime = substream->runtime;

  	if (runtime->channels == 1)
  		au1000_set_ac97_xmit_slots(au1000, AC97_SLOT_4);

  	else

  		au1000_set_ac97_xmit_slots(au1000, AC97_SLOT_3 | AC97_SLOT_4);

  	snd_ac97_set_rate(au1000->ac97, AC97_PCM_FRONT_DAC_RATE, runtime->rate);
  	return 0;
  }
  
  static int

  snd_au1000_capture_prepare(struct snd_pcm_substream *substream)

  {

  	struct snd_au1000 *au1000 = substream->pcm->private_data;
  	struct snd_pcm_runtime *runtime = substream->runtime;

  	if (runtime->channels == 1)
  		au1000_set_ac97_recv_slots(au1000, AC97_SLOT_4);

  	else

  		au1000_set_ac97_recv_slots(au1000, AC97_SLOT_3 | AC97_SLOT_4);

  	snd_ac97_set_rate(au1000->ac97, AC97_PCM_LR_ADC_RATE, runtime->rate);
  	return 0;
  }
  
  static int

  snd_au1000_trigger(struct snd_pcm_substream *substream, int cmd)

  {

  	struct audio_stream *stream = substream->private_data;

  	int err = 0;

  	spin_lock(&stream->dma_lock);

  	switch (cmd) {
  	case SNDRV_PCM_TRIGGER_START:
  		au1000_dma_start(stream);
  		break;
  	case SNDRV_PCM_TRIGGER_STOP:
  		au1000_dma_stop(stream);
  		break;
  	default:
  		err = -EINVAL;
  		break;
  	}

  	spin_unlock(&stream->dma_lock);

  	return err;
  }
  
  static snd_pcm_uframes_t

  snd_au1000_pointer(struct snd_pcm_substream *substream)

  {

  	struct audio_stream *stream = substream->private_data;
  	struct snd_pcm_runtime *runtime = substream->runtime;

  	long location;

  	spin_lock(&stream->dma_lock);

  	location = get_dma_residue(stream->dma);

  	spin_unlock(&stream->dma_lock);

  	location = stream->buffer->relative_end - location;
  	if (location == -1)
  		location = 0;
  	return bytes_to_frames(runtime,location);
  }

  static struct snd_pcm_ops snd_card_au1000_playback_ops = {

  	.open			= snd_au1000_playback_open,
  	.close			= snd_au1000_playback_close,
  	.ioctl			= snd_pcm_lib_ioctl,
  	.hw_params	        = snd_au1000_hw_params,
  	.hw_free	        = snd_au1000_hw_free,
  	.prepare		= snd_au1000_playback_prepare,
  	.trigger		= snd_au1000_trigger,
  	.pointer		= snd_au1000_pointer,
  };

  static struct snd_pcm_ops snd_card_au1000_capture_ops = {

  	.open			= snd_au1000_capture_open,
  	.close			= snd_au1000_capture_close,
  	.ioctl			= snd_pcm_lib_ioctl,
  	.hw_params	        = snd_au1000_hw_params,
  	.hw_free	        = snd_au1000_hw_free,
  	.prepare		= snd_au1000_capture_prepare,
  	.trigger		= snd_au1000_trigger,
  	.pointer		= snd_au1000_pointer,
  };
  
  static int __devinit

  snd_au1000_pcm_new(struct snd_au1000 *au1000)

  {

  	struct snd_pcm *pcm;

  	int err;
  	unsigned long flags;
  
  	if ((err = snd_pcm_new(au1000->card, "AU1000 AC97 PCM", 0, 1, 1, &pcm)) < 0)
  		return err;
  
  	snd_pcm_lib_preallocate_pages_for_all(pcm, SNDRV_DMA_TYPE_CONTINUOUS,
  		snd_dma_continuous_data(GFP_KERNEL), 128*1024, 128*1024);
  
  	snd_pcm_set_ops(pcm, SNDRV_PCM_STREAM_PLAYBACK,
  		&snd_card_au1000_playback_ops);
  	snd_pcm_set_ops(pcm, SNDRV_PCM_STREAM_CAPTURE,
  		&snd_card_au1000_capture_ops);
  
  	pcm->private_data = au1000;
  	pcm->info_flags = 0;
  	strcpy(pcm->name, "Au1000 AC97 PCM");

  	spin_lock_init(&au1000->stream[PLAYBACK]->dma_lock);
  	spin_lock_init(&au1000->stream[CAPTURE]->dma_lock);

  	flags = claim_dma_lock();
  	if ((au1000->stream[PLAYBACK]->dma = request_au1000_dma(DMA_ID_AC97C_TX,

  			"AC97 TX", au1000_dma_interrupt, 0,

  			au1000->stream[PLAYBACK])) < 0) {
  		release_dma_lock(flags);
  		return -EBUSY;
  	}
  	if ((au1000->stream[CAPTURE]->dma = request_au1000_dma(DMA_ID_AC97C_RX,

  			"AC97 RX", au1000_dma_interrupt, 0,

  			au1000->stream[CAPTURE])) < 0){
  		release_dma_lock(flags);
  		return -EBUSY;
  	}
  	/* enable DMA coherency in read/write DMA channels */
  	set_dma_mode(au1000->stream[PLAYBACK]->dma,
  		     get_dma_mode(au1000->stream[PLAYBACK]->dma) & ~DMA_NC);
  	set_dma_mode(au1000->stream[CAPTURE]->dma,
  		     get_dma_mode(au1000->stream[CAPTURE]->dma) & ~DMA_NC);
  	release_dma_lock(flags);

  	au1000->pcm = pcm;
  	return 0;
  }
  
  
  /*-------------------------- AC97 CODEC Control ------------------------------*/
  
  static unsigned short

  snd_au1000_ac97_read(struct snd_ac97 *ac97, unsigned short reg)

  {

  	struct snd_au1000 *au1000 = ac97->private_data;

  	u32 volatile cmd;
  	u16 volatile data;
  	int             i;

  	spin_lock(&au1000->ac97_lock);

  /* would rather use the interrupt than this polling but it works and I can't
  get the interrupt driven case to work efficiently */

  	for (i = 0; i < 0x5000; i++)
  		if (!(au1000->ac97_ioport->status & AC97C_CP))
  			break;
  	if (i == 0x5000)
  		printk(KERN_ERR "au1000 AC97: AC97 command read timeout
  ");
  
  	cmd = (u32) reg & AC97C_INDEX_MASK;
  	cmd |= AC97C_READ;
  	au1000->ac97_ioport->cmd = cmd;
  
  	/* now wait for the data */
  	for (i = 0; i < 0x5000; i++)
  		if (!(au1000->ac97_ioport->status & AC97C_CP))
  			break;
  	if (i == 0x5000) {
  		printk(KERN_ERR "au1000 AC97: AC97 command read timeout
  ");

  		spin_unlock(&au1000->ac97_lock);

  		return 0;
  	}
  
  	data = au1000->ac97_ioport->cmd & 0xffff;

  	spin_unlock(&au1000->ac97_lock);

  
  	return data;
  
  }
  
  
  static void

  snd_au1000_ac97_write(struct snd_ac97 *ac97, unsigned short reg, unsigned short val)

  {

  	struct snd_au1000 *au1000 = ac97->private_data;

  	u32 cmd;
  	int i;

  	spin_lock(&au1000->ac97_lock);

  /* would rather use the interrupt than this polling but it works and I can't
  get the interrupt driven case to work efficiently */

  	for (i = 0; i < 0x5000; i++)
  		if (!(au1000->ac97_ioport->status & AC97C_CP))
  			break;
  	if (i == 0x5000)
  		printk(KERN_ERR "au1000 AC97: AC97 command write timeout
  ");
  
  	cmd = (u32) reg & AC97C_INDEX_MASK;
  	cmd &= ~AC97C_READ;
  	cmd |= ((u32) val << AC97C_WD_BIT);
  	au1000->ac97_ioport->cmd = cmd;

  	spin_unlock(&au1000->ac97_lock);

  }

  
  static int __devinit

  snd_au1000_ac97_new(struct snd_au1000 *au1000)

  {
  	int err;

  	struct snd_ac97_bus *pbus;
  	struct snd_ac97_template ac97;
   	static struct snd_ac97_bus_ops ops = {
  		.write = snd_au1000_ac97_write,
  		.read = snd_au1000_ac97_read,
  	};

  	if ((au1000->ac97_res_port = request_mem_region(CPHYSADDR(AC97C_CONFIG),
  	       		0x100000, "Au1x00 AC97")) == NULL) {

  		snd_printk(KERN_ERR "ALSA AC97: can't grap AC97 port
  ");
  		return -EBUSY;
  	}

  	au1000->ac97_ioport = (struct au1000_ac97_reg *)
  		KSEG1ADDR(au1000->ac97_res_port->start);

  
  	spin_lock_init(&au1000->ac97_lock);

  	/* configure pins for AC'97
  	TODO: move to board_setup.c */
  	au_writel(au_readl(SYS_PINFUNC) & ~0x02, SYS_PINFUNC);
  
  	/* Initialise Au1000's AC'97 Control Block */
  	au1000->ac97_ioport->cntrl = AC97C_RS | AC97C_CE;
  	udelay(10);
  	au1000->ac97_ioport->cntrl = AC97C_CE;
  	udelay(10);
  
  	/* Initialise External CODEC -- cold reset */
  	au1000->ac97_ioport->config = AC97C_RESET;
  	udelay(10);
  	au1000->ac97_ioport->config = 0x0;
  	mdelay(5);

  	/* Initialise AC97 middle-layer */

  	if ((err = snd_ac97_bus(au1000->card, 0, &ops, au1000, &pbus)) < 0)
   		return err;

  	memset(&ac97, 0, sizeof(ac97));
  	ac97.private_data = au1000;

  	if ((err = snd_ac97_mixer(pbus, &ac97, &au1000->ac97)) < 0)
  		return err;

  	return 0;

  }
  
  /*------------------------------ Setup / Destroy ----------------------------*/
  
  void

  snd_au1000_free(struct snd_card *card)

  {

  	struct snd_au1000 *au1000 = card->private_data;

  
  	if (au1000->ac97_res_port) {
  		/* put internal AC97 block into reset */
  		au1000->ac97_ioport->cntrl = AC97C_RS;
  		au1000->ac97_ioport = NULL;

  		release_and_free_resource(au1000->ac97_res_port);

  	}

  	if (au1000->stream[PLAYBACK]) {
  	  	if (au1000->stream[PLAYBACK]->dma >= 0)
  			free_au1000_dma(au1000->stream[PLAYBACK]->dma);
  		kfree(au1000->stream[PLAYBACK]);
  	}

  	if (au1000->stream[CAPTURE]) {
  		if (au1000->stream[CAPTURE]->dma >= 0)
  			free_au1000_dma(au1000->stream[CAPTURE]->dma);
  		kfree(au1000->stream[CAPTURE]);
  	}

  }

  static struct snd_card *au1000_card;

  static int __init
  au1000_init(void)
  {
  	int err;

  	struct snd_card *card;
  	struct snd_au1000 *au1000;

  	err = snd_card_create(-1, "AC97", THIS_MODULE,
  			      sizeof(struct snd_au1000), &card);
  	if (err < 0)
  		return err;

  
  	card->private_free = snd_au1000_free;
  	au1000 = card->private_data;

  	au1000->card = card;

  	au1000->stream[PLAYBACK] = kmalloc(sizeof(struct audio_stream), GFP_KERNEL);

  	au1000->stream[CAPTURE ] = kmalloc(sizeof(struct audio_stream), GFP_KERNEL);
  	/* so that snd_au1000_free will work as intended */
   	au1000->ac97_res_port = NULL;
  	if (au1000->stream[PLAYBACK])
  		au1000->stream[PLAYBACK]->dma = -1;
  	if (au1000->stream[CAPTURE ])
  		au1000->stream[CAPTURE ]->dma = -1;

  	if (au1000->stream[PLAYBACK] == NULL ||

  	    au1000->stream[CAPTURE ] == NULL) {

  		snd_card_free(card);

  		return -ENOMEM;
  	}

  	if ((err = snd_au1000_ac97_new(au1000)) < 0 ) {
  		snd_card_free(card);

  		return err;
  	}

  	if ((err = snd_au1000_pcm_new(au1000)) < 0) {
  		snd_card_free(card);

  		return err;
  	}

  	strcpy(card->driver, "Au1000-AC97");
  	strcpy(card->shortname, "AMD Au1000-AC97");
  	sprintf(card->longname, "AMD Au1000--AC97 ALSA Driver");

  	if ((err = snd_card_register(card)) < 0) {
  		snd_card_free(card);

  		return err;
  	}

  	printk(KERN_INFO "ALSA AC97: Driver Initialized
  ");

  	au1000_card = card;

  	return 0;
  }
  
  static void __exit au1000_exit(void)
  {

  	snd_card_free(au1000_card);

  }
  
  module_init(au1000_init);
  module_exit(au1000_exit);