1 files changed, 1326 insertions, 0 deletions

diff --git a/sound/pci/hda/hda_controller.c b/sound/pci/hda/hda_controller.c
new file mode 100644
index 000000000..083df287c
--- /dev/null
+++ b/sound/pci/hda/hda_controller.c
@@ -0,0 +1,1326 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ *
+ *  Implementation of primary alsa driver code base for Intel HD Audio.
+ *
+ *  Copyright(c) 2004 Intel Corporation. All rights reserved.
+ *
+ *  Copyright (c) 2004 Takashi Iwai <tiwai@suse.de>
+ *                     PeiSen Hou <pshou@realtek.com.tw>
+ */
+
+#include <linux/clocksource.h>
+#include <linux/delay.h>
+#include <linux/interrupt.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/pm_runtime.h>
+#include <linux/slab.h>
+
+#ifdef CONFIG_X86
+/* for art-tsc conversion */
+#include <asm/tsc.h>
+#endif
+
+#include <sound/core.h>
+#include <sound/initval.h>
+#include "hda_controller.h"
+#include "hda_local.h"
+
+#define CREATE_TRACE_POINTS
+#include "hda_controller_trace.h"
+
+/* DSP lock helpers */
+#define dsp_lock(dev)		snd_hdac_dsp_lock(azx_stream(dev))
+#define dsp_unlock(dev)		snd_hdac_dsp_unlock(azx_stream(dev))
+#define dsp_is_locked(dev)	snd_hdac_stream_is_locked(azx_stream(dev))
+
+/* assign a stream for the PCM */
+static inline struct azx_dev *
+azx_assign_device(struct azx *chip, struct snd_pcm_substream *substream)
+{
+	struct hdac_stream *s;
+
+	s = snd_hdac_stream_assign(azx_bus(chip), substream);
+	if (!s)
+		return NULL;
+	return stream_to_azx_dev(s);
+}
+
+/* release the assigned stream */
+static inline void azx_release_device(struct azx_dev *azx_dev)
+{
+	snd_hdac_stream_release(azx_stream(azx_dev));
+}
+
+static inline struct hda_pcm_stream *
+to_hda_pcm_stream(struct snd_pcm_substream *substream)
+{
+	struct azx_pcm *apcm = snd_pcm_substream_chip(substream);
+	return &apcm->info->stream[substream->stream];
+}
+
+static u64 azx_adjust_codec_delay(struct snd_pcm_substream *substream,
+				u64 nsec)
+{
+	struct azx_pcm *apcm = snd_pcm_substream_chip(substream);
+	struct hda_pcm_stream *hinfo = to_hda_pcm_stream(substream);
+	u64 codec_frames, codec_nsecs;
+
+	if (!hinfo->ops.get_delay)
+		return nsec;
+
+	codec_frames = hinfo->ops.get_delay(hinfo, apcm->codec, substream);
+	codec_nsecs = div_u64(codec_frames * 1000000000LL,
+			      substream->runtime->rate);
+
+	if (substream->stream == SNDRV_PCM_STREAM_CAPTURE)
+		return nsec + codec_nsecs;
+
+	return (nsec > codec_nsecs) ? nsec - codec_nsecs : 0;
+}
+
+/*
+ * PCM ops
+ */
+
+static int azx_pcm_close(struct snd_pcm_substream *substream)
+{
+	struct azx_pcm *apcm = snd_pcm_substream_chip(substream);
+	struct hda_pcm_stream *hinfo = to_hda_pcm_stream(substream);
+	struct azx *chip = apcm->chip;
+	struct azx_dev *azx_dev = get_azx_dev(substream);
+
+	trace_azx_pcm_close(chip, azx_dev);
+	mutex_lock(&chip->open_mutex);
+	azx_release_device(azx_dev);
+	if (hinfo->ops.close)
+		hinfo->ops.close(hinfo, apcm->codec, substream);
+	snd_hda_power_down(apcm->codec);
+	mutex_unlock(&chip->open_mutex);
+	snd_hda_codec_pcm_put(apcm->info);
+	return 0;
+}
+
+static int azx_pcm_hw_params(struct snd_pcm_substream *substream,
+			     struct snd_pcm_hw_params *hw_params)
+{
+	struct azx_pcm *apcm = snd_pcm_substream_chip(substream);
+	struct azx *chip = apcm->chip;
+	struct azx_dev *azx_dev = get_azx_dev(substream);
+	int ret = 0;
+
+	trace_azx_pcm_hw_params(chip, azx_dev);
+	dsp_lock(azx_dev);
+	if (dsp_is_locked(azx_dev)) {
+		ret = -EBUSY;
+		goto unlock;
+	}
+
+	azx_dev->core.bufsize = 0;
+	azx_dev->core.period_bytes = 0;
+	azx_dev->core.format_val = 0;
+
+unlock:
+	dsp_unlock(azx_dev);
+	return ret;
+}
+
+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 = to_hda_pcm_stream(substream);
+
+	/* reset BDL address */
+	dsp_lock(azx_dev);
+	if (!dsp_is_locked(azx_dev))
+		snd_hdac_stream_cleanup(azx_stream(azx_dev));
+
+	snd_hda_codec_cleanup(apcm->codec, hinfo, substream);
+
+	azx_stream(azx_dev)->prepared = 0;
+	dsp_unlock(azx_dev);
+	return 0;
+}
+
+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 = to_hda_pcm_stream(substream);
+	struct snd_pcm_runtime *runtime = substream->runtime;
+	unsigned int format_val, stream_tag;
+	int err;
+	struct hda_spdif_out *spdif =
+		snd_hda_spdif_out_of_nid(apcm->codec, hinfo->nid);
+	unsigned short ctls = spdif ? spdif->ctls : 0;
+
+	trace_azx_pcm_prepare(chip, azx_dev);
+	dsp_lock(azx_dev);
+	if (dsp_is_locked(azx_dev)) {
+		err = -EBUSY;
+		goto unlock;
+	}
+
+	snd_hdac_stream_reset(azx_stream(azx_dev));
+	format_val = snd_hdac_calc_stream_format(runtime->rate,
+						runtime->channels,
+						runtime->format,
+						hinfo->maxbps,
+						ctls);
+	if (!format_val) {
+		dev_err(chip->card->dev,
+			"invalid format_val, rate=%d, ch=%d, format=%d\n",
+			runtime->rate, runtime->channels, runtime->format);
+		err = -EINVAL;
+		goto unlock;
+	}
+
+	err = snd_hdac_stream_set_params(azx_stream(azx_dev), format_val);
+	if (err < 0)
+		goto unlock;
+
+	snd_hdac_stream_setup(azx_stream(azx_dev));
+
+	stream_tag = azx_dev->core.stream_tag;
+	/* CA-IBG chips need the playback stream starting from 1 */
+	if ((chip->driver_caps & AZX_DCAPS_CTX_WORKAROUND) &&
+	    stream_tag > chip->capture_streams)
+		stream_tag -= chip->capture_streams;
+	err = snd_hda_codec_prepare(apcm->codec, hinfo, stream_tag,
+				     azx_dev->core.format_val, substream);
+
+ unlock:
+	if (!err)
+		azx_stream(azx_dev)->prepared = 1;
+	dsp_unlock(azx_dev);
+	return err;
+}
+
+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 hdac_bus *bus = azx_bus(chip);
+	struct azx_dev *azx_dev;
+	struct snd_pcm_substream *s;
+	struct hdac_stream *hstr;
+	bool start;
+	int sbits = 0;
+	int sync_reg;
+
+	azx_dev = get_azx_dev(substream);
+	trace_azx_pcm_trigger(chip, azx_dev, cmd);
+
+	hstr = azx_stream(azx_dev);
+	if (chip->driver_caps & AZX_DCAPS_OLD_SSYNC)
+		sync_reg = AZX_REG_OLD_SSYNC;
+	else
+		sync_reg = AZX_REG_SSYNC;
+
+	if (dsp_is_locked(azx_dev) || !hstr->prepared)
+		return -EPIPE;
+
+	switch (cmd) {
+	case SNDRV_PCM_TRIGGER_START:
+	case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
+	case SNDRV_PCM_TRIGGER_RESUME:
+		start = true;
+		break;
+	case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
+	case SNDRV_PCM_TRIGGER_SUSPEND:
+	case SNDRV_PCM_TRIGGER_STOP:
+		start = false;
+		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->core.index;
+		snd_pcm_trigger_done(s, substream);
+	}
+
+	spin_lock(&bus->reg_lock);
+
+	/* first, set SYNC bits of corresponding streams */
+	snd_hdac_stream_sync_trigger(hstr, true, sbits, sync_reg);
+
+	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_dev->insufficient = 1;
+			snd_hdac_stream_start(azx_stream(azx_dev), true);
+		} else {
+			snd_hdac_stream_stop(azx_stream(azx_dev));
+		}
+	}
+	spin_unlock(&bus->reg_lock);
+
+	snd_hdac_stream_sync(hstr, start, sbits);
+
+	spin_lock(&bus->reg_lock);
+	/* reset SYNC bits */
+	snd_hdac_stream_sync_trigger(hstr, false, sbits, sync_reg);
+	if (start)
+		snd_hdac_stream_timecounter_init(hstr, sbits);
+	spin_unlock(&bus->reg_lock);
+	return 0;
+}
+
+unsigned int azx_get_pos_lpib(struct azx *chip, struct azx_dev *azx_dev)
+{
+	return snd_hdac_stream_get_pos_lpib(azx_stream(azx_dev));
+}
+EXPORT_SYMBOL_GPL(azx_get_pos_lpib);
+
+unsigned int azx_get_pos_posbuf(struct azx *chip, struct azx_dev *azx_dev)
+{
+	return snd_hdac_stream_get_pos_posbuf(azx_stream(azx_dev));
+}
+EXPORT_SYMBOL_GPL(azx_get_pos_posbuf);
+
+unsigned int azx_get_position(struct azx *chip,
+			      struct azx_dev *azx_dev)
+{
+	struct snd_pcm_substream *substream = azx_dev->core.substream;
+	unsigned int pos;
+	int stream = substream->stream;
+	int delay = 0;
+
+	if (chip->get_position[stream])
+		pos = chip->get_position[stream](chip, azx_dev);
+	else /* use the position buffer as default */
+		pos = azx_get_pos_posbuf(chip, azx_dev);
+
+	if (pos >= azx_dev->core.bufsize)
+		pos = 0;
+
+	if (substream->runtime) {
+		struct azx_pcm *apcm = snd_pcm_substream_chip(substream);
+		struct hda_pcm_stream *hinfo = to_hda_pcm_stream(substream);
+
+		if (chip->get_delay[stream])
+			delay += chip->get_delay[stream](chip, azx_dev, pos);
+		if (hinfo->ops.get_delay)
+			delay += hinfo->ops.get_delay(hinfo, apcm->codec,
+						      substream);
+		substream->runtime->delay = delay;
+	}
+
+	trace_azx_get_position(chip, azx_dev, pos, delay);
+	return pos;
+}
+EXPORT_SYMBOL_GPL(azx_get_position);
+
+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));
+}
+
+/*
+ * azx_scale64: Scale base by mult/div while not overflowing sanely
+ *
+ * Derived from scale64_check_overflow in kernel/time/timekeeping.c
+ *
+ * The tmestamps for a 48Khz stream can overflow after (2^64/10^9)/48K which
+ * is about 384307 ie ~4.5 days.
+ *
+ * This scales the calculation so that overflow will happen but after 2^64 /
+ * 48000 secs, which is pretty large!
+ *
+ * In caln below:
+ *	base may overflow, but since there isn’t any additional division
+ *	performed on base it’s OK
+ *	rem can’t overflow because both are 32-bit values
+ */
+
+#ifdef CONFIG_X86
+static u64 azx_scale64(u64 base, u32 num, u32 den)
+{
+	u64 rem;
+
+	rem = do_div(base, den);
+
+	base *= num;
+	rem *= num;
+
+	do_div(rem, den);
+
+	return base + rem;
+}
+
+static int azx_get_sync_time(ktime_t *device,
+		struct system_counterval_t *system, void *ctx)
+{
+	struct snd_pcm_substream *substream = ctx;
+	struct azx_dev *azx_dev = get_azx_dev(substream);
+	struct azx_pcm *apcm = snd_pcm_substream_chip(substream);
+	struct azx *chip = apcm->chip;
+	struct snd_pcm_runtime *runtime;
+	u64 ll_counter, ll_counter_l, ll_counter_h;
+	u64 tsc_counter, tsc_counter_l, tsc_counter_h;
+	u32 wallclk_ctr, wallclk_cycles;
+	bool direction;
+	u32 dma_select;
+	u32 timeout;
+	u32 retry_count = 0;
+
+	runtime = substream->runtime;
+
+	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
+		direction = 1;
+	else
+		direction = 0;
+
+	/* 0th stream tag is not used, so DMA ch 0 is for 1st stream tag */
+	do {
+		timeout = 100;
+		dma_select = (direction << GTSCC_CDMAS_DMA_DIR_SHIFT) |
+					(azx_dev->core.stream_tag - 1);
+		snd_hdac_chip_writel(azx_bus(chip), GTSCC, dma_select);
+
+		/* Enable the capture */
+		snd_hdac_chip_updatel(azx_bus(chip), GTSCC, 0, GTSCC_TSCCI_MASK);
+
+		while (timeout) {
+			if (snd_hdac_chip_readl(azx_bus(chip), GTSCC) &
+						GTSCC_TSCCD_MASK)
+				break;
+
+			timeout--;
+		}
+
+		if (!timeout) {
+			dev_err(chip->card->dev, "GTSCC capture Timedout!\n");
+			return -EIO;
+		}
+
+		/* Read wall clock counter */
+		wallclk_ctr = snd_hdac_chip_readl(azx_bus(chip), WALFCC);
+
+		/* Read TSC counter */
+		tsc_counter_l = snd_hdac_chip_readl(azx_bus(chip), TSCCL);
+		tsc_counter_h = snd_hdac_chip_readl(azx_bus(chip), TSCCU);
+
+		/* Read Link counter */
+		ll_counter_l = snd_hdac_chip_readl(azx_bus(chip), LLPCL);
+		ll_counter_h = snd_hdac_chip_readl(azx_bus(chip), LLPCU);
+
+		/* Ack: registers read done */
+		snd_hdac_chip_writel(azx_bus(chip), GTSCC, GTSCC_TSCCD_SHIFT);
+
+		tsc_counter = (tsc_counter_h << TSCCU_CCU_SHIFT) |
+						tsc_counter_l;
+
+		ll_counter = (ll_counter_h << LLPC_CCU_SHIFT) |	ll_counter_l;
+		wallclk_cycles = wallclk_ctr & WALFCC_CIF_MASK;
+
+		/*
+		 * An error occurs near frame "rollover". The clocks in
+		 * frame value indicates whether this error may have
+		 * occurred. Here we use the value of 10 i.e.,
+		 * HDA_MAX_CYCLE_OFFSET
+		 */
+		if (wallclk_cycles < HDA_MAX_CYCLE_VALUE - HDA_MAX_CYCLE_OFFSET
+					&& wallclk_cycles > HDA_MAX_CYCLE_OFFSET)
+			break;
+
+		/*
+		 * Sleep before we read again, else we may again get
+		 * value near to MAX_CYCLE. Try to sleep for different
+		 * amount of time so we dont hit the same number again
+		 */
+		udelay(retry_count++);
+
+	} while (retry_count != HDA_MAX_CYCLE_READ_RETRY);
+
+	if (retry_count == HDA_MAX_CYCLE_READ_RETRY) {
+		dev_err_ratelimited(chip->card->dev,
+			"Error in WALFCC cycle count\n");
+		return -EIO;
+	}
+
+	*device = ns_to_ktime(azx_scale64(ll_counter,
+				NSEC_PER_SEC, runtime->rate));
+	*device = ktime_add_ns(*device, (wallclk_cycles * NSEC_PER_SEC) /
+			       ((HDA_MAX_CYCLE_VALUE + 1) * runtime->rate));
+
+	*system = convert_art_to_tsc(tsc_counter);
+
+	return 0;
+}
+
+#else
+static int azx_get_sync_time(ktime_t *device,
+		struct system_counterval_t *system, void *ctx)
+{
+	return -ENXIO;
+}
+#endif
+
+static int azx_get_crosststamp(struct snd_pcm_substream *substream,
+			      struct system_device_crosststamp *xtstamp)
+{
+	return get_device_system_crosststamp(azx_get_sync_time,
+					substream, NULL, xtstamp);
+}
+
+static inline bool is_link_time_supported(struct snd_pcm_runtime *runtime,
+				struct snd_pcm_audio_tstamp_config *ts)
+{
+	if (runtime->hw.info & SNDRV_PCM_INFO_HAS_LINK_SYNCHRONIZED_ATIME)
+		if (ts->type_requested == SNDRV_PCM_AUDIO_TSTAMP_TYPE_LINK_SYNCHRONIZED)
+			return true;
+
+	return false;
+}
+
+static int azx_get_time_info(struct snd_pcm_substream *substream,
+			struct timespec64 *system_ts, struct timespec64 *audio_ts,
+			struct snd_pcm_audio_tstamp_config *audio_tstamp_config,
+			struct snd_pcm_audio_tstamp_report *audio_tstamp_report)
+{
+	struct azx_dev *azx_dev = get_azx_dev(substream);
+	struct snd_pcm_runtime *runtime = substream->runtime;
+	struct system_device_crosststamp xtstamp;
+	int ret;
+	u64 nsec;
+
+	if ((substream->runtime->hw.info & SNDRV_PCM_INFO_HAS_LINK_ATIME) &&
+		(audio_tstamp_config->type_requested == SNDRV_PCM_AUDIO_TSTAMP_TYPE_LINK)) {
+
+		snd_pcm_gettime(substream->runtime, system_ts);
+
+		nsec = timecounter_read(&azx_dev->core.tc);
+		if (audio_tstamp_config->report_delay)
+			nsec = azx_adjust_codec_delay(substream, nsec);
+
+		*audio_ts = ns_to_timespec64(nsec);
+
+		audio_tstamp_report->actual_type = SNDRV_PCM_AUDIO_TSTAMP_TYPE_LINK;
+		audio_tstamp_report->accuracy_report = 1; /* rest of structure is valid */
+		audio_tstamp_report->accuracy = 42; /* 24 MHz WallClock == 42ns resolution */
+
+	} else if (is_link_time_supported(runtime, audio_tstamp_config)) {
+
+		ret = azx_get_crosststamp(substream, &xtstamp);
+		if (ret)
+			return ret;
+
+		switch (runtime->tstamp_type) {
+		case SNDRV_PCM_TSTAMP_TYPE_MONOTONIC:
+			return -EINVAL;
+
+		case SNDRV_PCM_TSTAMP_TYPE_MONOTONIC_RAW:
+			*system_ts = ktime_to_timespec64(xtstamp.sys_monoraw);
+			break;
+
+		default:
+			*system_ts = ktime_to_timespec64(xtstamp.sys_realtime);
+			break;
+
+		}
+
+		*audio_ts = ktime_to_timespec64(xtstamp.device);
+
+		audio_tstamp_report->actual_type =
+			SNDRV_PCM_AUDIO_TSTAMP_TYPE_LINK_SYNCHRONIZED;
+		audio_tstamp_report->accuracy_report = 1;
+		/* 24 MHz WallClock == 42ns resolution */
+		audio_tstamp_report->accuracy = 42;
+
+	} else {
+		audio_tstamp_report->actual_type = SNDRV_PCM_AUDIO_TSTAMP_TYPE_DEFAULT;
+	}
+
+	return 0;
+}
+
+static const 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 |
+				 SNDRV_PCM_INFO_HAS_WALL_CLOCK | /* legacy */
+				 SNDRV_PCM_INFO_HAS_LINK_ATIME |
+				 SNDRV_PCM_INFO_NO_PERIOD_WAKEUP),
+	.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,
+};
+
+static int azx_pcm_open(struct snd_pcm_substream *substream)
+{
+	struct azx_pcm *apcm = snd_pcm_substream_chip(substream);
+	struct hda_pcm_stream *hinfo = to_hda_pcm_stream(substream);
+	struct azx *chip = apcm->chip;
+	struct azx_dev *azx_dev;
+	struct snd_pcm_runtime *runtime = substream->runtime;
+	int err;
+	int buff_step;
+
+	snd_hda_codec_pcm_get(apcm->info);
+	mutex_lock(&chip->open_mutex);
+	azx_dev = azx_assign_device(chip, substream);
+	trace_azx_pcm_open(chip, azx_dev);
+	if (azx_dev == NULL) {
+		err = -EBUSY;
+		goto unlock;
+	}
+	runtime->private_data = azx_dev;
+
+	runtime->hw = azx_pcm_hw;
+	if (chip->gts_present)
+		runtime->hw.info |= SNDRV_PCM_INFO_HAS_LINK_SYNCHRONIZED_ATIME;
+	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);
+
+	/* avoid wrap-around with wall-clock */
+	snd_pcm_hw_constraint_minmax(runtime, SNDRV_PCM_HW_PARAM_BUFFER_TIME,
+				     20,
+				     178000000);
+
+	if (chip->align_buffer_size)
+		/* constrain buffer sizes to be multiple of 128
+		   bytes. This is more efficient in terms of memory
+		   access but isn't required by the HDA spec and
+		   prevents users from specifying exact period/buffer
+		   sizes. For example for 44.1kHz, a period size set
+		   to 20ms will be rounded to 19.59ms. */
+		buff_step = 128;
+	else
+		/* Don't enforce steps on buffer sizes, still need to
+		   be multiple of 4 bytes (HDA spec). Tested on Intel
+		   HDA controllers, may not work on all devices where
+		   option needs to be disabled */
+		buff_step = 4;
+
+	snd_pcm_hw_constraint_step(runtime, 0, SNDRV_PCM_HW_PARAM_BUFFER_BYTES,
+				   buff_step);
+	snd_pcm_hw_constraint_step(runtime, 0, SNDRV_PCM_HW_PARAM_PERIOD_BYTES,
+				   buff_step);
+	snd_hda_power_up(apcm->codec);
+	if (hinfo->ops.open)
+		err = hinfo->ops.open(hinfo, apcm->codec, substream);
+	else
+		err = -ENODEV;
+	if (err < 0) {
+		azx_release_device(azx_dev);
+		goto powerdown;
+	}
+	snd_pcm_limit_hw_rates(runtime);
+	/* sanity check */
+	if (snd_BUG_ON(!runtime->hw.channels_min) ||
+	    snd_BUG_ON(!runtime->hw.channels_max) ||
+	    snd_BUG_ON(!runtime->hw.formats) ||
+	    snd_BUG_ON(!runtime->hw.rates)) {
+		azx_release_device(azx_dev);
+		if (hinfo->ops.close)
+			hinfo->ops.close(hinfo, apcm->codec, substream);
+		err = -EINVAL;
+		goto powerdown;
+	}
+
+	/* disable LINK_ATIME timestamps for capture streams
+	   until we figure out how to handle digital inputs */
+	if (substream->stream == SNDRV_PCM_STREAM_CAPTURE) {
+		runtime->hw.info &= ~SNDRV_PCM_INFO_HAS_WALL_CLOCK; /* legacy */
+		runtime->hw.info &= ~SNDRV_PCM_INFO_HAS_LINK_ATIME;
+	}
+
+	snd_pcm_set_sync(substream);
+	mutex_unlock(&chip->open_mutex);
+	return 0;
+
+ powerdown:
+	snd_hda_power_down(apcm->codec);
+ unlock:
+	mutex_unlock(&chip->open_mutex);
+	snd_hda_codec_pcm_put(apcm->info);
+	return err;
+}
+
+static const struct snd_pcm_ops azx_pcm_ops = {
+	.open = azx_pcm_open,
+	.close = azx_pcm_close,
+	.hw_params = azx_pcm_hw_params,
+	.hw_free = azx_pcm_hw_free,
+	.prepare = azx_pcm_prepare,
+	.trigger = azx_pcm_trigger,
+	.pointer = azx_pcm_pointer,
+	.get_time_info =  azx_get_time_info,
+};
+
+static void azx_pcm_free(struct snd_pcm *pcm)
+{
+	struct azx_pcm *apcm = pcm->private_data;
+	if (apcm) {
+		list_del(&apcm->list);
+		apcm->info->pcm = NULL;
+		kfree(apcm);
+	}
+}
+
+#define MAX_PREALLOC_SIZE	(32 * 1024 * 1024)
+
+int snd_hda_attach_pcm_stream(struct hda_bus *_bus, struct hda_codec *codec,
+			      struct hda_pcm *cpcm)
+{
+	struct hdac_bus *bus = &_bus->core;
+	struct azx *chip = bus_to_azx(bus);
+	struct snd_pcm *pcm;
+	struct azx_pcm *apcm;
+	int pcm_dev = cpcm->device;
+	unsigned int size;
+	int s, err;
+	int type = SNDRV_DMA_TYPE_DEV_SG;
+
+	list_for_each_entry(apcm, &chip->pcm_list, list) {
+		if (apcm->pcm->device == pcm_dev) {
+			dev_err(chip->card->dev, "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;
+	strscpy(pcm->name, cpcm->name, sizeof(pcm->name));
+	apcm = kzalloc(sizeof(*apcm), GFP_KERNEL);
+	if (apcm == NULL) {
+		snd_device_free(chip->card, pcm);
+		return -ENOMEM;
+	}
+	apcm->chip = chip;
+	apcm->pcm = pcm;
+	apcm->codec = codec;
+	apcm->info = cpcm;
+	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;
+	list_add_tail(&apcm->list, &chip->pcm_list);
+	cpcm->pcm = pcm;
+	for (s = 0; s < 2; s++) {
+		if (cpcm->stream[s].substreams)
+			snd_pcm_set_ops(pcm, s, &azx_pcm_ops);
+	}
+	/* buffer pre-allocation */
+	size = CONFIG_SND_HDA_PREALLOC_SIZE * 1024;
+	if (size > MAX_PREALLOC_SIZE)
+		size = MAX_PREALLOC_SIZE;
+	if (chip->uc_buffer)
+		type = SNDRV_DMA_TYPE_DEV_WC_SG;
+	snd_pcm_set_managed_buffer_all(pcm, type, chip->card->dev,
+				       size, MAX_PREALLOC_SIZE);
+	return 0;
+}
+
+static unsigned int azx_command_addr(u32 cmd)
+{
+	unsigned int addr = cmd >> 28;
+
+	if (addr >= AZX_MAX_CODECS) {
+		snd_BUG();
+		addr = 0;
+	}
+
+	return addr;
+}
+
+/* receive a response */
+static int azx_rirb_get_response(struct hdac_bus *bus, unsigned int addr,
+				 unsigned int *res)
+{
+	struct azx *chip = bus_to_azx(bus);
+	struct hda_bus *hbus = &chip->bus;
+	int err;
+
+ again:
+	err = snd_hdac_bus_get_response(bus, addr, res);
+	if (!err)
+		return 0;
+
+	if (hbus->no_response_fallback)
+		return -EIO;
+
+	if (!bus->polling_mode) {
+		dev_warn(chip->card->dev,
+			 "azx_get_response timeout, switching to polling mode: last cmd=0x%08x\n",
+			 bus->last_cmd[addr]);
+		bus->polling_mode = 1;
+		goto again;
+	}
+
+	if (chip->msi) {
+		dev_warn(chip->card->dev,
+			 "No response from codec, disabling MSI: last cmd=0x%08x\n",
+			 bus->last_cmd[addr]);
+		if (chip->ops->disable_msi_reset_irq &&
+		    chip->ops->disable_msi_reset_irq(chip) < 0)
+			return -EIO;
+		goto again;
+	}
+
+	if (chip->probing) {
+		/* If this critical timeout happens during the codec probing
+		 * phase, this is likely an access to a non-existing codec
+		 * slot.  Better to return an error and reset the system.
+		 */
+		return -EIO;
+	}
+
+	/* no fallback mechanism? */
+	if (!chip->fallback_to_single_cmd)
+		return -EIO;
+
+	/* a fatal communication error; need either to reset or to fallback
+	 * to the single_cmd mode
+	 */
+	if (hbus->allow_bus_reset && !hbus->response_reset && !hbus->in_reset) {
+		hbus->response_reset = 1;
+		dev_err(chip->card->dev,
+			"No response from codec, resetting bus: last cmd=0x%08x\n",
+			bus->last_cmd[addr]);
+		return -EAGAIN; /* give a chance to retry */
+	}
+
+	dev_err(chip->card->dev,
+		"azx_get_response timeout, switching to single_cmd mode: last cmd=0x%08x\n",
+		bus->last_cmd[addr]);
+	chip->single_cmd = 1;
+	hbus->response_reset = 0;
+	snd_hdac_bus_stop_cmd_io(bus);
+	return -EIO;
+}
+
+/*
+ * Use the single immediate command instead of CORB/RIRB for simplicity
+ *
+ * Note: according to Intel, this is not preferred use.  The command was
+ *       intended for the BIOS only, and may get confused with unsolicited
+ *       responses.  So, we shouldn't use it for normal operation from the
+ *       driver.
+ *       I left the codes, however, for debugging/testing purposes.
+ */
+
+/* receive a response */
+static int azx_single_wait_for_response(struct azx *chip, unsigned int addr)
+{
+	int timeout = 50;
+
+	while (timeout--) {
+		/* check IRV busy bit */
+		if (azx_readw(chip, IRS) & AZX_IRS_VALID) {
+			/* reuse rirb.res as the response return value */
+			azx_bus(chip)->rirb.res[addr] = azx_readl(chip, IR);
+			return 0;
+		}
+		udelay(1);
+	}
+	if (printk_ratelimit())
+		dev_dbg(chip->card->dev, "get_response timeout: IRS=0x%x\n",
+			azx_readw(chip, IRS));
+	azx_bus(chip)->rirb.res[addr] = -1;
+	return -EIO;
+}
+
+/* send a command */
+static int azx_single_send_cmd(struct hdac_bus *bus, u32 val)
+{
+	struct azx *chip = bus_to_azx(bus);
+	unsigned int addr = azx_command_addr(val);
+	int timeout = 50;
+
+	bus->last_cmd[azx_command_addr(val)] = val;
+	while (timeout--) {
+		/* check ICB busy bit */
+		if (!((azx_readw(chip, IRS) & AZX_IRS_BUSY))) {
+			/* Clear IRV valid bit */
+			azx_writew(chip, IRS, azx_readw(chip, IRS) |
+				   AZX_IRS_VALID);
+			azx_writel(chip, IC, val);
+			azx_writew(chip, IRS, azx_readw(chip, IRS) |
+				   AZX_IRS_BUSY);
+			return azx_single_wait_for_response(chip, addr);
+		}
+		udelay(1);
+	}
+	if (printk_ratelimit())
+		dev_dbg(chip->card->dev,
+			"send_cmd timeout: IRS=0x%x, val=0x%x\n",
+			azx_readw(chip, IRS), val);
+	return -EIO;
+}
+
+/* receive a response */
+static int azx_single_get_response(struct hdac_bus *bus, unsigned int addr,
+				   unsigned int *res)
+{
+	if (res)
+		*res = bus->rirb.res[addr];
+	return 0;
+}
+
+/*
+ * The below are the main callbacks from hda_codec.
+ *
+ * They are just the skeleton to call sub-callbacks according to the
+ * current setting of chip->single_cmd.
+ */
+
+/* send a command */
+static int azx_send_cmd(struct hdac_bus *bus, unsigned int val)
+{
+	struct azx *chip = bus_to_azx(bus);
+
+	if (chip->disabled)
+		return 0;
+	if (chip->single_cmd)
+		return azx_single_send_cmd(bus, val);
+	else
+		return snd_hdac_bus_send_cmd(bus, val);
+}
+
+/* get a response */
+static int azx_get_response(struct hdac_bus *bus, unsigned int addr,
+			    unsigned int *res)
+{
+	struct azx *chip = bus_to_azx(bus);
+
+	if (chip->disabled)
+		return 0;
+	if (chip->single_cmd)
+		return azx_single_get_response(bus, addr, res);
+	else
+		return azx_rirb_get_response(bus, addr, res);
+}
+
+static const struct hdac_bus_ops bus_core_ops = {
+	.command = azx_send_cmd,
+	.get_response = azx_get_response,
+};
+
+#ifdef CONFIG_SND_HDA_DSP_LOADER
+/*
+ * DSP loading code (e.g. for CA0132)
+ */
+
+/* use the first stream for loading DSP */
+static struct azx_dev *
+azx_get_dsp_loader_dev(struct azx *chip)
+{
+	struct hdac_bus *bus = azx_bus(chip);
+	struct hdac_stream *s;
+
+	list_for_each_entry(s, &bus->stream_list, list)
+		if (s->index == chip->playback_index_offset)
+			return stream_to_azx_dev(s);
+
+	return NULL;
+}
+
+int snd_hda_codec_load_dsp_prepare(struct hda_codec *codec, unsigned int format,
+				   unsigned int byte_size,
+				   struct snd_dma_buffer *bufp)
+{
+	struct hdac_bus *bus = &codec->bus->core;
+	struct azx *chip = bus_to_azx(bus);
+	struct azx_dev *azx_dev;
+	struct hdac_stream *hstr;
+	bool saved = false;
+	int err;
+
+	azx_dev = azx_get_dsp_loader_dev(chip);
+	hstr = azx_stream(azx_dev);
+	spin_lock_irq(&bus->reg_lock);
+	if (hstr->opened) {
+		chip->saved_azx_dev = *azx_dev;
+		saved = true;
+	}
+	spin_unlock_irq(&bus->reg_lock);
+
+	err = snd_hdac_dsp_prepare(hstr, format, byte_size, bufp);
+	if (err < 0) {
+		spin_lock_irq(&bus->reg_lock);
+		if (saved)
+			*azx_dev = chip->saved_azx_dev;
+		spin_unlock_irq(&bus->reg_lock);
+		return err;
+	}
+
+	hstr->prepared = 0;
+	return err;
+}
+EXPORT_SYMBOL_GPL(snd_hda_codec_load_dsp_prepare);
+
+void snd_hda_codec_load_dsp_trigger(struct hda_codec *codec, bool start)
+{
+	struct hdac_bus *bus = &codec->bus->core;
+	struct azx *chip = bus_to_azx(bus);
+	struct azx_dev *azx_dev = azx_get_dsp_loader_dev(chip);
+
+	snd_hdac_dsp_trigger(azx_stream(azx_dev), start);
+}
+EXPORT_SYMBOL_GPL(snd_hda_codec_load_dsp_trigger);
+
+void snd_hda_codec_load_dsp_cleanup(struct hda_codec *codec,
+				    struct snd_dma_buffer *dmab)
+{
+	struct hdac_bus *bus = &codec->bus->core;
+	struct azx *chip = bus_to_azx(bus);
+	struct azx_dev *azx_dev = azx_get_dsp_loader_dev(chip);
+	struct hdac_stream *hstr = azx_stream(azx_dev);
+
+	if (!dmab->area || !hstr->locked)
+		return;
+
+	snd_hdac_dsp_cleanup(hstr, dmab);
+	spin_lock_irq(&bus->reg_lock);
+	if (hstr->opened)
+		*azx_dev = chip->saved_azx_dev;
+	hstr->locked = false;
+	spin_unlock_irq(&bus->reg_lock);
+}
+EXPORT_SYMBOL_GPL(snd_hda_codec_load_dsp_cleanup);
+#endif /* CONFIG_SND_HDA_DSP_LOADER */
+
+/*
+ * reset and start the controller registers
+ */
+void azx_init_chip(struct azx *chip, bool full_reset)
+{
+	if (snd_hdac_bus_init_chip(azx_bus(chip), full_reset)) {
+		/* correct RINTCNT for CXT */
+		if (chip->driver_caps & AZX_DCAPS_CTX_WORKAROUND)
+			azx_writew(chip, RINTCNT, 0xc0);
+	}
+}
+EXPORT_SYMBOL_GPL(azx_init_chip);
+
+void azx_stop_all_streams(struct azx *chip)
+{
+	struct hdac_bus *bus = azx_bus(chip);
+
+	snd_hdac_stop_streams(bus);
+}
+EXPORT_SYMBOL_GPL(azx_stop_all_streams);
+
+void azx_stop_chip(struct azx *chip)
+{
+	snd_hdac_bus_stop_chip(azx_bus(chip));
+}
+EXPORT_SYMBOL_GPL(azx_stop_chip);
+
+/*
+ * interrupt handler
+ */
+static void stream_update(struct hdac_bus *bus, struct hdac_stream *s)
+{
+	struct azx *chip = bus_to_azx(bus);
+	struct azx_dev *azx_dev = stream_to_azx_dev(s);
+
+	/* check whether this IRQ is really acceptable */
+	if (!chip->ops->position_check ||
+	    chip->ops->position_check(chip, azx_dev)) {
+		spin_unlock(&bus->reg_lock);
+		snd_pcm_period_elapsed(azx_stream(azx_dev)->substream);
+		spin_lock(&bus->reg_lock);
+	}
+}
+
+irqreturn_t azx_interrupt(int irq, void *dev_id)
+{
+	struct azx *chip = dev_id;
+	struct hdac_bus *bus = azx_bus(chip);
+	u32 status;
+	bool active, handled = false;
+	int repeat = 0; /* count for avoiding endless loop */
+
+#ifdef CONFIG_PM
+	if (azx_has_pm_runtime(chip))
+		if (!pm_runtime_active(chip->card->dev))
+			return IRQ_NONE;
+#endif
+
+	spin_lock(&bus->reg_lock);
+
+	if (chip->disabled)
+		goto unlock;
+
+	do {
+		status = azx_readl(chip, INTSTS);
+		if (status == 0 || status == 0xffffffff)
+			break;
+
+		handled = true;
+		active = false;
+		if (snd_hdac_bus_handle_stream_irq(bus, status, stream_update))
+			active = true;
+
+		status = azx_readb(chip, RIRBSTS);
+		if (status & RIRB_INT_MASK) {
+			/*
+			 * Clearing the interrupt status here ensures that no
+			 * interrupt gets masked after the RIRB wp is read in
+			 * snd_hdac_bus_update_rirb. This avoids a possible
+			 * race condition where codec response in RIRB may
+			 * remain unserviced by IRQ, eventually falling back
+			 * to polling mode in azx_rirb_get_response.
+			 */
+			azx_writeb(chip, RIRBSTS, RIRB_INT_MASK);
+			active = true;
+			if (status & RIRB_INT_RESPONSE) {
+				if (chip->driver_caps & AZX_DCAPS_CTX_WORKAROUND)
+					udelay(80);
+				snd_hdac_bus_update_rirb(bus);
+			}
+		}
+	} while (active && ++repeat < 10);
+
+ unlock:
+	spin_unlock(&bus->reg_lock);
+
+	return IRQ_RETVAL(handled);
+}
+EXPORT_SYMBOL_GPL(azx_interrupt);
+
+/*
+ * Codec initerface
+ */
+
+/*
+ * 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;
+	struct hdac_bus *bus = azx_bus(chip);
+	int err;
+	unsigned int res = -1;
+
+	mutex_lock(&bus->cmd_mutex);
+	chip->probing = 1;
+	azx_send_cmd(bus, cmd);
+	err = azx_get_response(bus, addr, &res);
+	chip->probing = 0;
+	mutex_unlock(&bus->cmd_mutex);
+	if (err < 0 || res == -1)
+		return -EIO;
+	dev_dbg(chip->card->dev, "codec #%d probed OK\n", addr);
+	return 0;
+}
+
+void snd_hda_bus_reset(struct hda_bus *bus)
+{
+	struct azx *chip = bus_to_azx(&bus->core);
+
+	bus->in_reset = 1;
+	azx_stop_chip(chip);
+	azx_init_chip(chip, true);
+	if (bus->core.chip_init)
+		snd_hda_bus_reset_codecs(bus);
+	bus->in_reset = 0;
+}
+
+/* HD-audio bus initialization */
+int azx_bus_init(struct azx *chip, const char *model)
+{
+	struct hda_bus *bus = &chip->bus;
+	int err;
+
+	err = snd_hdac_bus_init(&bus->core, chip->card->dev, &bus_core_ops);
+	if (err < 0)
+		return err;
+
+	bus->card = chip->card;
+	mutex_init(&bus->prepare_mutex);
+	bus->pci = chip->pci;
+	bus->modelname = model;
+	bus->mixer_assigned = -1;
+	bus->core.snoop = azx_snoop(chip);
+	if (chip->get_position[0] != azx_get_pos_lpib ||
+	    chip->get_position[1] != azx_get_pos_lpib)
+		bus->core.use_posbuf = true;
+	bus->core.bdl_pos_adj = chip->bdl_pos_adj;
+	if (chip->driver_caps & AZX_DCAPS_CORBRP_SELF_CLEAR)
+		bus->core.corbrp_self_clear = true;
+
+	if (chip->driver_caps & AZX_DCAPS_4K_BDLE_BOUNDARY)
+		bus->core.align_bdle_4k = true;
+
+	/* enable sync_write flag for stable communication as default */
+	bus->core.sync_write = 1;
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(azx_bus_init);
+
+/* Probe codecs */
+int azx_probe_codecs(struct azx *chip, unsigned int max_slots)
+{
+	struct hdac_bus *bus = azx_bus(chip);
+	int c, codecs, err;
+
+	codecs = 0;
+	if (!max_slots)
+		max_slots = AZX_DEFAULT_CODECS;
+
+	/* First try to probe all given codec slots */
+	for (c = 0; c < max_slots; c++) {
+		if ((bus->codec_mask & (1 << c)) & chip->codec_probe_mask) {
+			if (probe_codec(chip, c) < 0) {
+				/* Some BIOSen give you wrong codec addresses
+				 * that don't exist
+				 */
+				dev_warn(chip->card->dev,
+					 "Codec #%d probe error; disabling it...\n", c);
+				bus->codec_mask &= ~(1 << c);
+				/* More badly, accessing to a non-existing
+				 * codec often screws up the controller chip,
+				 * and disturbs 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, true);
+			}
+		}
+	}
+
+	/* Then create codec instances */
+	for (c = 0; c < max_slots; c++) {
+		if ((bus->codec_mask & (1 << c)) & chip->codec_probe_mask) {
+			struct hda_codec *codec;
+			err = snd_hda_codec_new(&chip->bus, chip->card, c, &codec);
+			if (err < 0)
+				continue;
+			codec->jackpoll_interval = chip->jackpoll_interval;
+			codec->beep_mode = chip->beep_mode;
+			codec->ctl_dev_id = chip->ctl_dev_id;
+			codecs++;
+		}
+	}
+	if (!codecs) {
+		dev_err(chip->card->dev, "no codecs initialized\n");
+		return -ENXIO;
+	}
+	return 0;
+}
+EXPORT_SYMBOL_GPL(azx_probe_codecs);
+
+/* configure each codec instance */
+int azx_codec_configure(struct azx *chip)
+{
+	struct hda_codec *codec, *next;
+	int success = 0;
+
+	list_for_each_codec(codec, &chip->bus) {
+		if (!snd_hda_codec_configure(codec))
+			success++;
+	}
+
+	if (success) {
+		/* unregister failed codecs if any codec has been probed */
+		list_for_each_codec_safe(codec, next, &chip->bus) {
+			if (!codec->configured) {
+				codec_err(codec, "Unable to configure, disabling\n");
+				snd_hdac_device_unregister(&codec->core);
+			}
+		}
+	}
+
+	return success ? 0 : -ENODEV;
+}
+EXPORT_SYMBOL_GPL(azx_codec_configure);
+
+static int stream_direction(struct azx *chip, unsigned char index)
+{
+	if (index >= chip->capture_index_offset &&
+	    index < chip->capture_index_offset + chip->capture_streams)
+		return SNDRV_PCM_STREAM_CAPTURE;
+	return SNDRV_PCM_STREAM_PLAYBACK;
+}
+
+/* initialize SD streams */
+int azx_init_streams(struct azx *chip)
+{
+	int i;
+	int stream_tags[2] = { 0, 0 };
+
+	/* 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 = kzalloc(sizeof(*azx_dev), GFP_KERNEL);
+		int dir, tag;
+
+		if (!azx_dev)
+			return -ENOMEM;
+
+		dir = stream_direction(chip, i);
+		/* stream tag must be unique throughout
+		 * the stream direction group,
+		 * valid values 1...15
+		 * use separate stream tag if the flag
+		 * AZX_DCAPS_SEPARATE_STREAM_TAG is used
+		 */
+		if (chip->driver_caps & AZX_DCAPS_SEPARATE_STREAM_TAG)
+			tag = ++stream_tags[dir];
+		else
+			tag = i + 1;
+		snd_hdac_stream_init(azx_bus(chip), azx_stream(azx_dev),
+				     i, dir, tag);
+	}
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(azx_init_streams);
+
+void azx_free_streams(struct azx *chip)
+{
+	struct hdac_bus *bus = azx_bus(chip);
+	struct hdac_stream *s;
+
+	while (!list_empty(&bus->stream_list)) {
+		s = list_first_entry(&bus->stream_list, struct hdac_stream, list);
+		list_del(&s->list);
+		kfree(stream_to_azx_dev(s));
+	}
+}
+EXPORT_SYMBOL_GPL(azx_free_streams);