hda_intel.c

		}
	}

	/* clear rirb int */
	status = azx_readb(chip, RIRBSTS);
	if (status & RIRB_INT_MASK) {
		if (!chip->single_cmd && (status & RIRB_INT_RESPONSE))
			azx_update_rirb(chip);
		azx_writeb(chip, RIRBSTS, RIRB_INT_MASK);
	}

#if 0
	/* clear state status int */
	if (azx_readb(chip, STATESTS) & 0x04)
		azx_writeb(chip, STATESTS, 0x04);
#endif
	spin_unlock(&chip->reg_lock);
	
	return IRQ_HANDLED;
}


/*
 * set up a BDL entry
 */
static int setup_bdle(struct snd_pcm_substream *substream,
		      struct azx_dev *azx_dev, u32 **bdlp,
		      int ofs, int size, int with_ioc)
{
	u32 *bdl = *bdlp;

	while (size > 0) {
		dma_addr_t addr;
		int chunk;

		if (azx_dev->frags >= AZX_MAX_BDL_ENTRIES)
			return -EINVAL;

		addr = snd_pcm_sgbuf_get_addr(substream, ofs);
		/* program the address field of the BDL entry */
		bdl[0] = cpu_to_le32((u32)addr);
		bdl[1] = cpu_to_le32(upper_32_bits(addr));
		/* program the size field of the BDL entry */
		chunk = snd_pcm_sgbuf_get_chunk_size(substream, ofs, size);
		bdl[2] = cpu_to_le32(chunk);
		/* program the IOC to enable interrupt
		 * only when the whole fragment is processed
		 */
		size -= chunk;
		bdl[3] = (size || !with_ioc) ? 0 : cpu_to_le32(0x01);
		bdl += 4;
		azx_dev->frags++;
		ofs += chunk;
	}
	*bdlp = bdl;
	return ofs;
}

/*
 * set up BDL entries
 */
static int azx_setup_periods(struct azx *chip,
			     struct snd_pcm_substream *substream,
			     struct azx_dev *azx_dev)
{
	u32 *bdl;
	int i, ofs, periods, period_bytes;
	int pos_adj;

	/* reset BDL address */
	azx_sd_writel(azx_dev, SD_BDLPL, 0);
	azx_sd_writel(azx_dev, SD_BDLPU, 0);

	period_bytes = snd_pcm_lib_period_bytes(substream);
	azx_dev->period_bytes = period_bytes;
	periods = azx_dev->bufsize / period_bytes;

	/* program the initial BDL entries */
	bdl = (u32 *)azx_dev->bdl.area;
	ofs = 0;
	azx_dev->frags = 0;
	azx_dev->irq_ignore = 0;
	pos_adj = bdl_pos_adj[chip->dev_index];
	if (pos_adj > 0) {
		struct snd_pcm_runtime *runtime = substream->runtime;
		int pos_align = pos_adj;
		pos_adj = (pos_adj * runtime->rate + 47999) / 48000;
		if (!pos_adj)
			pos_adj = pos_align;
		else
			pos_adj = ((pos_adj + pos_align - 1) / pos_align) *
				pos_align;
		pos_adj = frames_to_bytes(runtime, pos_adj);
		if (pos_adj >= period_bytes) {
			snd_printk(KERN_WARNING "Too big adjustment %d\n",
				   bdl_pos_adj[chip->dev_index]);
			pos_adj = 0;
		} else {
			ofs = setup_bdle(substream, azx_dev,
					 &bdl, ofs, pos_adj, 1);
			if (ofs < 0)
				goto error;
			azx_dev->irq_ignore = 1;
		}
	} else
		pos_adj = 0;
	for (i = 0; i < periods; i++) {
		if (i == periods - 1 && pos_adj)
			ofs = setup_bdle(substream, azx_dev, &bdl, ofs,
					 period_bytes - pos_adj, 0);
		else
			ofs = setup_bdle(substream, azx_dev, &bdl, ofs,
					 period_bytes, 1);
		if (ofs < 0)
			goto error;
	}
	return 0;

 error:
	snd_printk(KERN_ERR "Too many BDL entries: buffer=%d, period=%d\n",
		   azx_dev->bufsize, period_bytes);
	/* reset */
	azx_sd_writel(azx_dev, SD_BDLPL, 0);
	azx_sd_writel(azx_dev, SD_BDLPU, 0);
	return -EINVAL;
}

/*
 * set up the SD for streaming
 */
static int azx_setup_controller(struct azx *chip, struct azx_dev *azx_dev)
{
	unsigned char val;
	int timeout;

	/* make sure the run bit is zero for SD */
	azx_sd_writeb(azx_dev, SD_CTL, azx_sd_readb(azx_dev, SD_CTL) &
		      ~SD_CTL_DMA_START);
	/* reset stream */
	azx_sd_writeb(azx_dev, SD_CTL, azx_sd_readb(azx_dev, SD_CTL) |
		      SD_CTL_STREAM_RESET);
	udelay(3);
	timeout = 300;
	while (!((val = azx_sd_readb(azx_dev, SD_CTL)) & SD_CTL_STREAM_RESET) &&
	       --timeout)
		;
	val &= ~SD_CTL_STREAM_RESET;
	azx_sd_writeb(azx_dev, SD_CTL, val);
	udelay(3);

	timeout = 300;
	/* waiting for hardware to report that the stream is out of reset */
	while (((val = azx_sd_readb(azx_dev, SD_CTL)) & SD_CTL_STREAM_RESET) &&
	       --timeout)
		;

	/* program the stream_tag */
	azx_sd_writel(azx_dev, SD_CTL,
		      (azx_sd_readl(azx_dev, SD_CTL) & ~SD_CTL_STREAM_TAG_MASK)|
		      (azx_dev->stream_tag << SD_CTL_STREAM_TAG_SHIFT));

	/* program the length of samples in cyclic buffer */
	azx_sd_writel(azx_dev, SD_CBL, azx_dev->bufsize);

	/* program the stream format */
	/* this value needs to be the same as the one programmed */
	azx_sd_writew(azx_dev, SD_FORMAT, azx_dev->format_val);

	/* program the stream LVI (last valid index) of the BDL */
	azx_sd_writew(azx_dev, SD_LVI, azx_dev->frags - 1);

	/* program the BDL address */
	/* lower BDL address */
	azx_sd_writel(azx_dev, SD_BDLPL, (u32)azx_dev->bdl.addr);
	/* upper BDL address */
	azx_sd_writel(azx_dev, SD_BDLPU, upper_32_bits(azx_dev->bdl.addr));

	/* enable the position buffer */
	if (chip->position_fix == POS_FIX_POSBUF ||
	    chip->position_fix == POS_FIX_AUTO ||
	    chip->via_dmapos_patch) {
		if (!(azx_readl(chip, DPLBASE) & ICH6_DPLBASE_ENABLE))
			azx_writel(chip, DPLBASE,
				(u32)chip->posbuf.addr | ICH6_DPLBASE_ENABLE);
	}

	/* set the interrupt enable bits in the descriptor control register */
	azx_sd_writel(azx_dev, SD_CTL,
		      azx_sd_readl(azx_dev, SD_CTL) | SD_INT_MASK);

	return 0;
}

/*
 * Probe the given codec address
 */
static int probe_codec(struct azx *chip, int addr)
{
	unsigned int cmd = (addr << 28) | (AC_NODE_ROOT << 20) |
		(AC_VERB_PARAMETERS << 8) | AC_PAR_VENDOR_ID;
	unsigned int res;

	chip->probing = 1;
	azx_send_cmd(chip->bus, cmd);
	res = azx_get_response(chip->bus);
	chip->probing = 0;
	if (res == -1)
		return -EIO;
	snd_printdd("hda_intel: codec #%d probed OK\n", addr);
	return 0;
}

static int azx_attach_pcm_stream(struct hda_bus *bus, struct hda_codec *codec,
				 struct hda_pcm *cpcm);
static void azx_stop_chip(struct azx *chip);

/*
 * Codec initialization
 */

/* number of codec slots for each chipset: 0 = default slots (i.e. 4) */
static unsigned int azx_max_codecs[AZX_NUM_DRIVERS] __devinitdata = {
	[AZX_DRIVER_TERA] = 1,
};

static int __devinit azx_codec_create(struct azx *chip, const char *model,
				      unsigned int codec_probe_mask)
{
	struct hda_bus_template bus_temp;
	int c, codecs, err;
	int max_slots;

	memset(&bus_temp, 0, sizeof(bus_temp));
	bus_temp.private_data = chip;
	bus_temp.modelname = model;
	bus_temp.pci = chip->pci;
	bus_temp.ops.command = azx_send_cmd;
	bus_temp.ops.get_response = azx_get_response;
	bus_temp.ops.attach_pcm = azx_attach_pcm_stream;
#ifdef CONFIG_SND_HDA_POWER_SAVE
	bus_temp.power_save = &power_save;
	bus_temp.ops.pm_notify = azx_power_notify;
#endif

	err = snd_hda_bus_new(chip->card, &bus_temp, &chip->bus);
	if (err < 0)
		return err;

	if (chip->driver_type == AZX_DRIVER_NVIDIA)
		chip->bus->needs_damn_long_delay = 1;

	codecs = 0;
	max_slots = azx_max_codecs[chip->driver_type];
	if (!max_slots)
		max_slots = AZX_MAX_CODECS;

	/* First try to probe all given codec slots */
	for (c = 0; c < max_slots; c++) {
		if ((chip->codec_mask & (1 << c)) & codec_probe_mask) {
			if (probe_codec(chip, c) < 0) {
				/* Some BIOSen give you wrong codec addresses
				 * that don't exist
				 */
				snd_printk(KERN_WARNING
					   "hda_intel: Codec #%d probe error; "
					   "disabling it...\n", c);
				chip->codec_mask &= ~(1 << c);
				/* More badly, accessing to a non-existing
				 * codec often screws up the controller chip,
				 * and distrubs the further communications.
				 * Thus if an error occurs during probing,
				 * better to reset the controller chip to
				 * get back to the sanity state.
				 */
				azx_stop_chip(chip);
				azx_init_chip(chip);
			}
		}
	}

	/* Then create codec instances */
	for (c = 0; c < max_slots; c++) {
		if ((chip->codec_mask & (1 << c)) & codec_probe_mask) {
			struct hda_codec *codec;
			err = snd_hda_codec_new(chip->bus, c, &codec);
			if (err < 0)
				continue;
			codecs++;
		}
	}
	if (!codecs) {
		snd_printk(KERN_ERR SFX "no codecs initialized\n");
		return -ENXIO;
	}

	return 0;
}


/*
 * PCM support
 */

/* assign a stream for the PCM */
static inline struct azx_dev *azx_assign_device(struct azx *chip, int stream)
{
	int dev, i, nums;
	if (stream == SNDRV_PCM_STREAM_PLAYBACK) {
		dev = chip->playback_index_offset;
		nums = chip->playback_streams;
	} else {
		dev = chip->capture_index_offset;
		nums = chip->capture_streams;
	}
	for (i = 0; i < nums; i++, dev++)
		if (!chip->azx_dev[dev].opened) {
			chip->azx_dev[dev].opened = 1;
			return &chip->azx_dev[dev];
		}
	return NULL;
}

/* release the assigned stream */
static inline void azx_release_device(struct azx_dev *azx_dev)
{
	azx_dev->opened = 0;
}

static struct snd_pcm_hardware azx_pcm_hw = {
	.info =			(SNDRV_PCM_INFO_MMAP |
				 SNDRV_PCM_INFO_INTERLEAVED |
				 SNDRV_PCM_INFO_BLOCK_TRANSFER |
				 SNDRV_PCM_INFO_MMAP_VALID |
				 /* No full-resume yet implemented */
				 /* SNDRV_PCM_INFO_RESUME |*/
				 SNDRV_PCM_INFO_PAUSE |
				 SNDRV_PCM_INFO_SYNC_START),
	.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 =	AZX_MAX_BUF_SIZE,
	.period_bytes_min =	128,
	.period_bytes_max =	AZX_MAX_BUF_SIZE / 2,
	.periods_min =		2,
	.periods_max =		AZX_MAX_FRAG,
	.fifo_size =		0,
};

struct azx_pcm {
	struct azx *chip;
	struct hda_codec *codec;
	struct hda_pcm_stream *hinfo[2];
};

static int azx_pcm_open(struct snd_pcm_substream *substream)
{
	struct azx_pcm *apcm = snd_pcm_substream_chip(substream);
	struct hda_pcm_stream *hinfo = apcm->hinfo[substream->stream];
	struct azx *chip = apcm->chip;
	struct azx_dev *azx_dev;
	struct snd_pcm_runtime *runtime = substream->runtime;
	unsigned long flags;
	int err;

	mutex_lock(&chip->open_mutex);
	azx_dev = azx_assign_device(chip, substream->stream);
	if (azx_dev == NULL) {
		mutex_unlock(&chip->open_mutex);
		return -EBUSY;
	}
	runtime->hw = azx_pcm_hw;
	runtime->hw.channels_min = hinfo->channels_min;
	runtime->hw.channels_max = hinfo->channels_max;
	runtime->hw.formats = hinfo->formats;
	runtime->hw.rates = hinfo->rates;
	snd_pcm_limit_hw_rates(runtime);
	snd_pcm_hw_constraint_integer(runtime, SNDRV_PCM_HW_PARAM_PERIODS);
	snd_pcm_hw_constraint_step(runtime, 0, SNDRV_PCM_HW_PARAM_BUFFER_BYTES,
				   128);
	snd_pcm_hw_constraint_step(runtime, 0, SNDRV_PCM_HW_PARAM_PERIOD_BYTES,
				   128);
	snd_hda_power_up(apcm->codec);
	err = hinfo->ops.open(hinfo, apcm->codec, substream);
	if (err < 0) {
		azx_release_device(azx_dev);
		snd_hda_power_down(apcm->codec);
		mutex_unlock(&chip->open_mutex);
		return err;
	}
	spin_lock_irqsave(&chip->reg_lock, flags);
	azx_dev->substream = substream;
	azx_dev->running = 0;
	spin_unlock_irqrestore(&chip->reg_lock, flags);

	runtime->private_data = azx_dev;
	snd_pcm_set_sync(substream);
	mutex_unlock(&chip->open_mutex);
	return 0;
}

static int azx_pcm_close(struct snd_pcm_substream *substream)
{
	struct azx_pcm *apcm = snd_pcm_substream_chip(substream);
	struct hda_pcm_stream *hinfo = apcm->hinfo[substream->stream];
	struct azx *chip = apcm->chip;
	struct azx_dev *azx_dev = get_azx_dev(substream);
	unsigned long flags;

	mutex_lock(&chip->open_mutex);
	spin_lock_irqsave(&chip->reg_lock, flags);
	azx_dev->substream = NULL;
	azx_dev->running = 0;
	spin_unlock_irqrestore(&chip->reg_lock, flags);
	azx_release_device(azx_dev);
	hinfo->ops.close(hinfo, apcm->codec, substream);
	snd_hda_power_down(apcm->codec);
	mutex_unlock(&chip->open_mutex);
	return 0;
}

static int azx_pcm_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 azx_pcm_hw_free(struct snd_pcm_substream *substream)
{
	struct azx_pcm *apcm = snd_pcm_substream_chip(substream);
	struct azx_dev *azx_dev = get_azx_dev(substream);
	struct hda_pcm_stream *hinfo = apcm->hinfo[substream->stream];

	/* reset BDL address */
	azx_sd_writel(azx_dev, SD_BDLPL, 0);
	azx_sd_writel(azx_dev, SD_BDLPU, 0);
	azx_sd_writel(azx_dev, SD_CTL, 0);

	hinfo->ops.cleanup(hinfo, apcm->codec, substream);

	return snd_pcm_lib_free_pages(substream);
}

static int azx_pcm_prepare(struct snd_pcm_substream *substream)
{
	struct azx_pcm *apcm = snd_pcm_substream_chip(substream);
	struct azx *chip = apcm->chip;
	struct azx_dev *azx_dev = get_azx_dev(substream);
	struct hda_pcm_stream *hinfo = apcm->hinfo[substream->stream];
	struct snd_pcm_runtime *runtime = substream->runtime;

	azx_dev->bufsize = snd_pcm_lib_buffer_bytes(substream);
	azx_dev->format_val = snd_hda_calc_stream_format(runtime->rate,
							 runtime->channels,
							 runtime->format,
							 hinfo->maxbps);
	if (!azx_dev->format_val) {
		snd_printk(KERN_ERR SFX
			   "invalid format_val, rate=%d, ch=%d, format=%d\n",
			   runtime->rate, runtime->channels, runtime->format);
		return -EINVAL;
	}

	snd_printdd("azx_pcm_prepare: bufsize=0x%x, format=0x%x\n",
		    azx_dev->bufsize, azx_dev->format_val);
	if (azx_setup_periods(chip, substream, azx_dev) < 0)
		return -EINVAL;
	azx_setup_controller(chip, azx_dev);
	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
		azx_dev->fifo_size = azx_sd_readw(azx_dev, SD_FIFOSIZE) + 1;
	else
		azx_dev->fifo_size = 0;

	return hinfo->ops.prepare(hinfo, apcm->codec, azx_dev->stream_tag,
				  azx_dev->format_val, substream);
}

static int azx_pcm_trigger(struct snd_pcm_substream *substream, int cmd)
{
	struct azx_pcm *apcm = snd_pcm_substream_chip(substream);
	struct azx *chip = apcm->chip;
	struct azx_dev *azx_dev;
	struct snd_pcm_substream *s;
	int start, nsync = 0, sbits = 0;
	int nwait, timeout;

	switch (cmd) {
	case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
	case SNDRV_PCM_TRIGGER_RESUME:
	case SNDRV_PCM_TRIGGER_START:
		start = 1;
		break;
	case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
	case SNDRV_PCM_TRIGGER_SUSPEND:
	case SNDRV_PCM_TRIGGER_STOP:
		start = 0;
		break;
	default:
		return -EINVAL;
	}

	snd_pcm_group_for_each_entry(s, substream) {
		if (s->pcm->card != substream->pcm->card)
			continue;
		azx_dev = get_azx_dev(s);
		sbits |= 1 << azx_dev->index;
		nsync++;
		snd_pcm_trigger_done(s, substream);
	}

	spin_lock(&chip->reg_lock);
	if (nsync > 1) {
		/* first, set SYNC bits of corresponding streams */
		azx_writel(chip, SYNC, azx_readl(chip, SYNC) | sbits);
	}
	snd_pcm_group_for_each_entry(s, substream) {
		if (s->pcm->card != substream->pcm->card)
			continue;
		azx_dev = get_azx_dev(s);
		if (start)
			azx_stream_start(chip, azx_dev);
		else
			azx_stream_stop(chip, azx_dev);
		azx_dev->running = start;
	}
	spin_unlock(&chip->reg_lock);
	if (start) {
		if (nsync == 1)
			return 0;
		/* wait until all FIFOs get ready */
		for (timeout = 5000; timeout; timeout--) {
			nwait = 0;
			snd_pcm_group_for_each_entry(s, substream) {
				if (s->pcm->card != substream->pcm->card)
					continue;
				azx_dev = get_azx_dev(s);
				if (!(azx_sd_readb(azx_dev, SD_STS) &
				      SD_STS_FIFO_READY))
					nwait++;
			}
			if (!nwait)
				break;
			cpu_relax();
		}
	} else {
		/* wait until all RUN bits are cleared */
		for (timeout = 5000; timeout; timeout--) {
			nwait = 0;
			snd_pcm_group_for_each_entry(s, substream) {
				if (s->pcm->card != substream->pcm->card)
					continue;
				azx_dev = get_azx_dev(s);
				if (azx_sd_readb(azx_dev, SD_CTL) &
				    SD_CTL_DMA_START)
					nwait++;
			}
			if (!nwait)
				break;
			cpu_relax();
		}
	}
	if (nsync > 1) {
		spin_lock(&chip->reg_lock);
		/* reset SYNC bits */
		azx_writel(chip, SYNC, azx_readl(chip, SYNC) & ~sbits);
		spin_unlock(&chip->reg_lock);
	}
	return 0;
}

/* get the current DMA position with correction on VIA chips */
static unsigned int azx_via_get_position(struct azx *chip,
					 struct azx_dev *azx_dev)
{
	unsigned int link_pos, mini_pos, bound_pos;
	unsigned int mod_link_pos, mod_dma_pos, mod_mini_pos;
	unsigned int fifo_size;

	link_pos = azx_sd_readl(azx_dev, SD_LPIB);
	if (azx_dev->index >= 4) {
		/* Playback, no problem using link position */
		return link_pos;
	}

	/* Capture */
	/* For new chipset,
	 * use mod to get the DMA position just like old chipset
	 */
	mod_dma_pos = le32_to_cpu(*azx_dev->posbuf);
	mod_dma_pos %= azx_dev->period_bytes;

	/* azx_dev->fifo_size can't get FIFO size of in stream.
	 * Get from base address + offset.
	 */
	fifo_size = readw(chip->remap_addr + VIA_IN_STREAM0_FIFO_SIZE_OFFSET);

	if (azx_dev->insufficient) {
		/* Link position never gather than FIFO size */
		if (link_pos <= fifo_size)
			return 0;

		azx_dev->insufficient = 0;
	}

	if (link_pos <= fifo_size)
		mini_pos = azx_dev->bufsize + link_pos - fifo_size;
	else
		mini_pos = link_pos - fifo_size;

	/* Find nearest previous boudary */
	mod_mini_pos = mini_pos % azx_dev->period_bytes;
	mod_link_pos = link_pos % azx_dev->period_bytes;
	if (mod_link_pos >= fifo_size)
		bound_pos = link_pos - mod_link_pos;
	else if (mod_dma_pos >= mod_mini_pos)
		bound_pos = mini_pos - mod_mini_pos;
	else {
		bound_pos = mini_pos - mod_mini_pos + azx_dev->period_bytes;
		if (bound_pos >= azx_dev->bufsize)
			bound_pos = 0;
	}

	/* Calculate real DMA position we want */
	return bound_pos + mod_dma_pos;
}

static unsigned int azx_get_position(struct azx *chip,
				     struct azx_dev *azx_dev)
{
	unsigned int pos;

	if (chip->via_dmapos_patch)
		pos = azx_via_get_position(chip, azx_dev);
	else if (chip->position_fix == POS_FIX_POSBUF ||
		 chip->position_fix == POS_FIX_AUTO) {
		/* use the position buffer */
		pos = le32_to_cpu(*azx_dev->posbuf);
	} else {
		/* read LPIB */
		pos = azx_sd_readl(azx_dev, SD_LPIB);
	}
	if (pos >= azx_dev->bufsize)
		pos = 0;
	return pos;
}

static snd_pcm_uframes_t azx_pcm_pointer(struct snd_pcm_substream *substream)
{
	struct azx_pcm *apcm = snd_pcm_substream_chip(substream);
	struct azx *chip = apcm->chip;
	struct azx_dev *azx_dev = get_azx_dev(substream);
	return bytes_to_frames(substream->runtime,
			       azx_get_position(chip, azx_dev));
}

/*
 * Check whether the current DMA position is acceptable for updating
 * periods.  Returns non-zero if it's OK.
 *
 * Many HD-audio controllers appear pretty inaccurate about
 * the update-IRQ timing.  The IRQ is issued before actually the
 * data is processed.  So, we need to process it afterwords in a
 * workqueue.
 */
static int azx_position_ok(struct azx *chip, struct azx_dev *azx_dev)
{
	unsigned int pos;

	pos = azx_get_position(chip, azx_dev);
	if (chip->position_fix == POS_FIX_AUTO) {
		if (!pos) {
			printk(KERN_WARNING
			       "hda-intel: Invalid position buffer, "
			       "using LPIB read method instead.\n");
			chip->position_fix = POS_FIX_LPIB;
			pos = azx_get_position(chip, azx_dev);
		} else
			chip->position_fix = POS_FIX_POSBUF;
	}

	if (!bdl_pos_adj[chip->dev_index])
		return 1; /* no delayed ack */
	if (pos % azx_dev->period_bytes > azx_dev->period_bytes / 2)
		return 0; /* NG - it's below the period boundary */
	return 1; /* OK, it's fine */
}

/*
 * The work for pending PCM period updates.
 */
static void azx_irq_pending_work(struct work_struct *work)
{
	struct azx *chip = container_of(work, struct azx, irq_pending_work);
	int i, pending;

	if (!chip->irq_pending_warned) {
		printk(KERN_WARNING
		       "hda-intel: IRQ timing workaround is activated "
		       "for card #%d. Suggest a bigger bdl_pos_adj.\n",
		       chip->card->number);
		chip->irq_pending_warned = 1;
	}

	for (;;) {
		pending = 0;
		spin_lock_irq(&chip->reg_lock);
		for (i = 0; i < chip->num_streams; i++) {
			struct azx_dev *azx_dev = &chip->azx_dev[i];
			if (!azx_dev->irq_pending ||
			    !azx_dev->substream ||
			    !azx_dev->running)
				continue;
			if (azx_position_ok(chip, azx_dev)) {
				azx_dev->irq_pending = 0;
				spin_unlock(&chip->reg_lock);
				snd_pcm_period_elapsed(azx_dev->substream);
				spin_lock(&chip->reg_lock);
			} else
				pending++;
		}
		spin_unlock_irq(&chip->reg_lock);
		if (!pending)
			return;
		cond_resched();
	}
}

/* clear irq_pending flags and assure no on-going workq */
static void azx_clear_irq_pending(struct azx *chip)
{
	int i;

	spin_lock_irq(&chip->reg_lock);
	for (i = 0; i < chip->num_streams; i++)
		chip->azx_dev[i].irq_pending = 0;
	spin_unlock_irq(&chip->reg_lock);
	flush_scheduled_work();
}

static struct snd_pcm_ops azx_pcm_ops = {
	.open = azx_pcm_open,
	.close = azx_pcm_close,
	.ioctl = snd_pcm_lib_ioctl,
	.hw_params = azx_pcm_hw_params,
	.hw_free = azx_pcm_hw_free,
	.prepare = azx_pcm_prepare,
	.trigger = azx_pcm_trigger,
	.pointer = azx_pcm_pointer,
	.page = snd_pcm_sgbuf_ops_page,
};

static void azx_pcm_free(struct snd_pcm *pcm)
{
	struct azx_pcm *apcm = pcm->private_data;
	if (apcm) {
		apcm->chip->pcm[pcm->device] = NULL;
		kfree(apcm);
	}
}

static int
azx_attach_pcm_stream(struct hda_bus *bus, struct hda_codec *codec,
		      struct hda_pcm *cpcm)
{
	struct azx *chip = bus->private_data;
	struct snd_pcm *pcm;
	struct azx_pcm *apcm;
	int pcm_dev = cpcm->device;
	int s, err;

	if (pcm_dev >= AZX_MAX_PCMS) {
		snd_printk(KERN_ERR SFX "Invalid PCM device number %d\n",
			   pcm_dev);
		return -EINVAL;
	}
	if (chip->pcm[pcm_dev]) {
		snd_printk(KERN_ERR SFX "PCM %d already exists\n", pcm_dev);
		return -EBUSY;
	}
	err = snd_pcm_new(chip->card, cpcm->name, pcm_dev,
			  cpcm->stream[SNDRV_PCM_STREAM_PLAYBACK].substreams,
			  cpcm->stream[SNDRV_PCM_STREAM_CAPTURE].substreams,
			  &pcm);
	if (err < 0)
		return err;
	strcpy(pcm->name, cpcm->name);
	apcm = kzalloc(sizeof(*apcm), GFP_KERNEL);
	if (apcm == NULL)
		return -ENOMEM;
	apcm->chip = chip;
	apcm->codec = codec;
	pcm->private_data = apcm;
	pcm->private_free = azx_pcm_free;
	if (cpcm->pcm_type == HDA_PCM_TYPE_MODEM)
		pcm->dev_class = SNDRV_PCM_CLASS_MODEM;
	chip->pcm[pcm_dev] = pcm;
	cpcm->pcm = pcm;
	for (s = 0; s < 2; s++) {
		apcm->hinfo[s] = &cpcm->stream[s];
		if (cpcm->stream[s].substreams)
			snd_pcm_set_ops(pcm, s, &azx_pcm_ops);
	}
	/* buffer pre-allocation */
	snd_pcm_lib_preallocate_pages_for_all(pcm, SNDRV_DMA_TYPE_DEV_SG,
					      snd_dma_pci_data(chip->pci),
					      1024 * 64, 32 * 1024 * 1024);
	return 0;
}

/*
 * mixer creation - all stuff is implemented in hda module
 */
static int __devinit azx_mixer_create(struct azx *chip)
{
	return snd_hda_build_controls(chip->bus);
}


/*
 * initialize SD streams
 */
static int __devinit azx_init_stream(struct azx *chip)
{
	int i;

	/* initialize each stream (aka device)
	 * assign the starting bdl address to each stream (device)
	 * and initialize
	 */
	for (i = 0; i < chip->num_streams; i++) {
		struct azx_dev *azx_dev = &chip->azx_dev[i];
		azx_dev->posbuf = (u32 __iomem *)(chip->posbuf.area + i * 8);
		/* offset: SDI0=0x80, SDI1=0xa0, ... SDO3=0x160 */
		azx_dev->sd_addr = chip->remap_addr + (0x20 * i + 0x80);
		/* int mask: SDI0=0x01, SDI1=0x02, ... SDO3=0x80 */
		azx_dev->sd_int_sta_mask = 1 << i;
		/* stream tag: must be non-zero and unique */
		azx_dev->index = i;
		azx_dev->stream_tag = i + 1;
	}

	return 0;
}

static int azx_acquire_irq(struct azx *chip, int do_disconnect)
{
	if (request_irq(chip->pci->irq, azx_interrupt,
			chip->msi ? 0 : IRQF_SHARED,
			"HDA Intel", chip)) {
		printk(KERN_ERR "hda-intel: unable to grab IRQ %d, "
		       "disabling device\n", chip->pci->irq);
		if (do_disconnect)
			snd_card_disconnect(chip->card);
		return -1;
	}
	chip->irq = chip->pci->irq;
	pci_intx(chip->pci, !chip->msi);
	return 0;
}


static void azx_stop_chip(struct azx *chip)
{
	if (!chip->initialized)
		return;

	/* disable interrupts */
	azx_int_disable(chip);
	azx_int_clear(chip);

	/* disable CORB/RIRB */
	azx_free_cmd_io(chip);

	/* disable position buffer */
	azx_writel(chip, DPLBASE, 0);
	azx_writel(chip, DPUBASE, 0);

	chip->initialized = 0;
}

#ifdef CONFIG_SND_HDA_POWER_SAVE
/* power-up/down the controller */
static void azx_power_notify(struct hda_bus *bus)
{
	struct azx *chip = bus->private_data;
	struct hda_codec *c;
	int power_on = 0;

	list_for_each_entry(c, &bus->codec_list, list) {
		if (c->power_on) {
			power_on = 1;
			break;
		}
	}
	if (power_on)
		azx_init_chip(chip);
	else if (chip->running && power_save_controller)
		azx_stop_chip(chip);
}

static int snd_hda_codecs_inuse(struct hda_bus *bus)
{
	struct hda_codec *codec;

	list_for_each_entry(codec, &bus->codec_list, list) {
		if (snd_hda_codec_needs_resume(codec))
			return 1;
	}
	return 0;
}
#else /* !CONFIG_SND_HDA_POWER_SAVE */
#define snd_hda_codecs_inuse(bus) 1
#endif /* CONFIG_SND_HDA_POWER_SAVE */

#ifdef CONFIG_PM
/*
 * power management
 */
static int azx_suspend(struct pci_dev *pci, pm_message_t state)
{
	struct snd_card *card = pci_get_drvdata(pci);
	struct azx *chip = card->private_data;
	int i;

	snd_power_change_state(card, SNDRV_CTL_POWER_D3hot);
	azx_clear_irq_pending(chip);
	for (i = 0; i < AZX_MAX_PCMS; i++)
		snd_pcm_suspend_all(chip->pcm[i]);
	if (chip->initialized)
		snd_hda_suspend(chip->bus, state);
	azx_stop_chip(chip);
	if (chip->irq >= 0) {
		free_irq(chip->irq, chip);
		chip->irq = -1;
	}
	if (chip->msi)
		pci_disable_msi(chip->pci);
	pci_disable_device(pci);
	pci_save_state(pci);
	pci_set_power_state(pci, pci_choose_state(pci, state));
	return 0;
}

static int azx_resume(struct pci_dev *pci)
{
	struct snd_card *card = pci_get_drvdata(pci);
	struct azx *chip = card->private_data;

	pci_set_power_state(pci, PCI_D0);
	pci_restore_state(pci);
	if (pci_enable_device(pci) < 0) {
		printk(KERN_ERR "hda-intel: pci_enable_device failed, "
		       "disabling device\n");
		snd_card_disconnect(card);
		return -EIO;
	}
	pci_set_master(pci);
	if (chip->msi)
		if (pci_enable_msi(pci) < 0)
			chip->msi = 0;
	if (azx_acquire_irq(chip, 1) < 0)
		return -EIO;
	azx_init_pci(chip);

	if (snd_hda_codecs_inuse(chip->bus))
		azx_init_chip(chip);

	snd_hda_resume(chip->bus);
	snd_power_change_state(card, SNDRV_CTL_POWER_D0);
	return 0;
}
#endif /* CONFIG_PM */


/*
 * reboot notifier for hang-up problem at power-down
 */
static int azx_halt(struct notifier_block *nb, unsigned long event, void *buf)
{
	struct azx *chip = container_of(nb, struct azx, reboot_notifier);
	azx_stop_chip(chip);
	return NOTIFY_OK;
}

static void azx_notifier_register(struct azx *chip)
{
	chip->reboot_notifier.notifier_call = azx_halt;
	register_reboot_notifier(&chip->reboot_notifier);
}

static void azx_notifier_unregister(struct azx *chip)
{
	if (chip->reboot_notifier.notifier_call)
		unregister_reboot_notifier(&chip->reboot_notifier);
}

/*