text: // SPDX-License-Identifier: GPL-2.0+
  //
  // soc-pcm.c  --  ALSA SoC PCM
  //
  // Copyright 2005 Wolfson Microelectronics PLC.
  // Copyright 2005 Openedhand Ltd.
  // Copyright (C) 2010 Slimlogic Ltd.
  // Copyright (C) 2010 Texas Instruments Inc.
  //
  // Authors: Liam Girdwood <lrg@ti.com>
  //          Mark Brown <broonie@opensource.wolfsonmicro.com>
  
  #include <linux/kernel.h>
  #include <linux/init.h>
  #include <linux/delay.h>
  #include <linux/pinctrl/consumer.h>
  #include <linux/pm_runtime.h>
  #include <linux/slab.h>
  #include <linux/workqueue.h>
  #include <linux/export.h>
  #include <linux/debugfs.h>
  #include <sound/core.h>
  #include <sound/pcm.h>
  #include <sound/pcm_params.h>
  #include <sound/soc.h>
  #include <sound/soc-dpcm.h>
  #include <sound/soc-link.h>
  #include <sound/initval.h>
  
  #define DPCM_MAX_BE_USERS	8
  
  static inline const char *soc_cpu_dai_name(struct snd_soc_pcm_runtime *rtd)
  {
  	return (rtd)->num_cpus == 1 ? asoc_rtd_to_cpu(rtd, 0)->name : "multicpu";
  }
  static inline const char *soc_codec_dai_name(struct snd_soc_pcm_runtime *rtd)
  {
  	return (rtd)->num_codecs == 1 ? asoc_rtd_to_codec(rtd, 0)->name : "multicodec";
  }
  
  #ifdef CONFIG_DEBUG_FS
  static const char *dpcm_state_string(enum snd_soc_dpcm_state state)
  {
  	switch (state) {
  	case SND_SOC_DPCM_STATE_NEW:
  		return "new";
  	case SND_SOC_DPCM_STATE_OPEN:
  		return "open";
  	case SND_SOC_DPCM_STATE_HW_PARAMS:
  		return "hw_params";
  	case SND_SOC_DPCM_STATE_PREPARE:
  		return "prepare";
  	case SND_SOC_DPCM_STATE_START:
  		return "start";
  	case SND_SOC_DPCM_STATE_STOP:
  		return "stop";
  	case SND_SOC_DPCM_STATE_SUSPEND:
  		return "suspend";
  	case SND_SOC_DPCM_STATE_PAUSED:
  		return "paused";
  	case SND_SOC_DPCM_STATE_HW_FREE:
  		return "hw_free";
  	case SND_SOC_DPCM_STATE_CLOSE:
  		return "close";
  	}
  
  	return "unknown";
  }
  
  static ssize_t dpcm_show_state(struct snd_soc_pcm_runtime *fe,
  			       int stream, char *buf, size_t size)
  {
  	struct snd_pcm_hw_params *params = &fe->dpcm[stream].hw_params;
  	struct snd_soc_dpcm *dpcm;
  	ssize_t offset = 0;
  	unsigned long flags;
  
  	/* FE state */
  	offset += scnprintf(buf + offset, size - offset,
  			   "[%s - %s]\n", fe->dai_link->name,
  			   stream ? "Capture" : "Playback");
  
  	offset += scnprintf(buf + offset, size - offset, "State: %s\n",
  			   dpcm_state_string(fe->dpcm[stream].state));
  
  	if ((fe->dpcm[stream].state >= SND_SOC_DPCM_STATE_HW_PARAMS) &&
  	    (fe->dpcm[stream].state <= SND_SOC_DPCM_STATE_STOP))
  		offset += scnprintf(buf + offset, size - offset,
  				   "Hardware Params: "
  				   "Format = %s, Channels = %d, Rate = %d\n",
  				   snd_pcm_format_name(params_format(params)),
  				   params_channels(params),
  				   params_rate(params));
  
  	/* BEs state */
  	offset += scnprintf(buf + offset, size - offset, "Backends:\n");
  
  	if (list_empty(&fe->dpcm[stream].be_clients)) {
  		offset += scnprintf(buf + offset, size - offset,
  				   " No active DSP links\n");
  		goto out;
  	}
  
  	spin_lock_irqsave(&fe->card->dpcm_lock, flags);
  	for_each_dpcm_be(fe, stream, dpcm) {
  		struct snd_soc_pcm_runtime *be = dpcm->be;
  		params = &dpcm->hw_params;
  
  		offset += scnprintf(buf + offset, size - offset,
  				   "- %s\n", be->dai_link->name);
  
  		offset += scnprintf(buf + offset, size - offset,
  				   "   State: %s\n",
  				   dpcm_state_string(be->dpcm[stream].state));
  
  		if ((be->dpcm[stream].state >= SND_SOC_DPCM_STATE_HW_PARAMS) &&
  		    (be->dpcm[stream].state <= SND_SOC_DPCM_STATE_STOP))
  			offset += scnprintf(buf + offset, size - offset,
  					   "   Hardware Params: "
  					   "Format = %s, Channels = %d, Rate = %d\n",
  					   snd_pcm_format_name(params_format(params)),
  					   params_channels(params),
  					   params_rate(params));
  	}
  	spin_unlock_irqrestore(&fe->card->dpcm_lock, flags);
  out:
  	return offset;
  }
  
  static ssize_t dpcm_state_read_file(struct file *file, char __user *user_buf,
  				    size_t count, loff_t *ppos)
  {
  	struct snd_soc_pcm_runtime *fe = file->private_data;
  	ssize_t out_count = PAGE_SIZE, offset = 0, ret = 0;
  	int stream;
  	char *buf;
  
  	if (fe->num_cpus > 1) {
  		dev_err(fe->dev,
  			"%s doesn't support Multi CPU yet\n", __func__);
  		return -EINVAL;
  	}
  
  	buf = kmalloc(out_count, GFP_KERNEL);
  	if (!buf)
  		return -ENOMEM;
  
  	for_each_pcm_streams(stream)
  		if (snd_soc_dai_stream_valid(asoc_rtd_to_cpu(fe, 0), stream))
  			offset += dpcm_show_state(fe, stream,
  						  buf + offset,
  						  out_count - offset);
  
  	ret = simple_read_from_buffer(user_buf, count, ppos, buf, offset);
  
  	kfree(buf);
  	return ret;
  }
  
  static const struct file_operations dpcm_state_fops = {
  	.open = simple_open,
  	.read = dpcm_state_read_file,
  	.llseek = default_llseek,
  };
  
  void soc_dpcm_debugfs_add(struct snd_soc_pcm_runtime *rtd)
  {
  	if (!rtd->dai_link->dynamic)
  		return;
  
  	if (!rtd->card->debugfs_card_root)
  		return;
  
  	rtd->debugfs_dpcm_root = debugfs_create_dir(rtd->dai_link->name,
  						    rtd->card->debugfs_card_root);
  
  	debugfs_create_file("state", 0444, rtd->debugfs_dpcm_root,
  			    rtd, &dpcm_state_fops);
  }
  
  static void dpcm_create_debugfs_state(struct snd_soc_dpcm *dpcm, int stream)
  {
  	char *name;
  
  	name = kasprintf(GFP_KERNEL, "%s:%s", dpcm->be->dai_link->name,
  			 stream ? "capture" : "playback");
  	if (name) {
  		dpcm->debugfs_state = debugfs_create_dir(
  			name, dpcm->fe->debugfs_dpcm_root);
  		debugfs_create_u32("state", 0644, dpcm->debugfs_state,
  				   &dpcm->state);
  		kfree(name);
  	}
  }
  
  static void dpcm_remove_debugfs_state(struct snd_soc_dpcm *dpcm)
  {
  	debugfs_remove_recursive(dpcm->debugfs_state);
  }
  
  #else
  static inline void dpcm_create_debugfs_state(struct snd_soc_dpcm *dpcm,
  					     int stream)
  {
  }
  
  static inline void dpcm_remove_debugfs_state(struct snd_soc_dpcm *dpcm)
  {
  }
  #endif
  
  /* Set FE's runtime_update state; the state is protected via PCM stream lock
   * for avoiding the race with trigger callback.
   * If the state is unset and a trigger is pending while the previous operation,
   * process the pending trigger action here.
   */
  static int dpcm_fe_dai_do_trigger(struct snd_pcm_substream *substream, int cmd);
  static void dpcm_set_fe_update_state(struct snd_soc_pcm_runtime *fe,
  				     int stream, enum snd_soc_dpcm_update state)
  {
  	struct snd_pcm_substream *substream =
  		snd_soc_dpcm_get_substream(fe, stream);
  
  	snd_pcm_stream_lock_irq(substream);
  	if (state == SND_SOC_DPCM_UPDATE_NO && fe->dpcm[stream].trigger_pending) {
  		dpcm_fe_dai_do_trigger(substream,
  				       fe->dpcm[stream].trigger_pending - 1);
  		fe->dpcm[stream].trigger_pending = 0;
  	}
  	fe->dpcm[stream].runtime_update = state;
  	snd_pcm_stream_unlock_irq(substream);
  }
  
  static void dpcm_set_be_update_state(struct snd_soc_pcm_runtime *be,
  				     int stream, enum snd_soc_dpcm_update state)
  {
  	be->dpcm[stream].runtime_update = state;
  }
  
  /**
   * snd_soc_runtime_action() - Increment/Decrement active count for
   * PCM runtime components
   * @rtd: ASoC PCM runtime that is activated
   * @stream: Direction of the PCM stream
   * @action: Activate stream if 1. Deactivate if -1.
   *
   * Increments/Decrements the active count for all the DAIs and components
   * attached to a PCM runtime.
   * Should typically be called when a stream is opened.
   *
   * Must be called with the rtd->card->pcm_mutex being held
   */
  void snd_soc_runtime_action(struct snd_soc_pcm_runtime *rtd,
  			    int stream, int action)
  {
  	struct snd_soc_dai *dai;
  	int i;
  
  	lockdep_assert_held(&rtd->card->pcm_mutex);
  
  	for_each_rtd_dais(rtd, i, dai)
  		snd_soc_dai_action(dai, stream, action);
  }
  EXPORT_SYMBOL_GPL(snd_soc_runtime_action);
  
  /**
   * snd_soc_runtime_ignore_pmdown_time() - Check whether to ignore the power down delay
   * @rtd: The ASoC PCM runtime that should be checked.
   *
   * This function checks whether the power down delay should be ignored for a
   * specific PCM runtime. Returns true if the delay is 0, if it the DAI link has
   * been configured to ignore the delay, or if none of the components benefits
   * from having the delay.
   */
  bool snd_soc_runtime_ignore_pmdown_time(struct snd_soc_pcm_runtime *rtd)
  {
  	struct snd_soc_component *component;
  	bool ignore = true;
  	int i;
  
  	if (!rtd->pmdown_time || rtd->dai_link->ignore_pmdown_time)
  		return true;
  
  	for_each_rtd_components(rtd, i, component)
  		ignore &= !component->driver->use_pmdown_time;
  
  	return ignore;
  }
  
  /**
   * snd_soc_set_runtime_hwparams - set the runtime hardware parameters
   * @substream: the pcm substream
   * @hw: the hardware parameters
   *
   * Sets the substream runtime hardware parameters.
   */
  int snd_soc_set_runtime_hwparams(struct snd_pcm_substream *substream,
  	const struct snd_pcm_hardware *hw)
  {
  	substream->runtime->hw = *hw;
  
  	return 0;
  }
  EXPORT_SYMBOL_GPL(snd_soc_set_runtime_hwparams);
  
  /* DPCM stream event, send event to FE and all active BEs. */
  int dpcm_dapm_stream_event(struct snd_soc_pcm_runtime *fe, int dir,
  	int event)
  {
  	struct snd_soc_dpcm *dpcm;
  
  	for_each_dpcm_be(fe, dir, dpcm) {
  
  		struct snd_soc_pcm_runtime *be = dpcm->be;
  
  		dev_dbg(be->dev, "ASoC: BE %s event %d dir %d\n",
  				be->dai_link->name, event, dir);
  
  		if ((event == SND_SOC_DAPM_STREAM_STOP) &&
  		    (be->dpcm[dir].users >= 1))
  			continue;
  
  		snd_soc_dapm_stream_event(be, dir, event);
  	}
  
  	snd_soc_dapm_stream_event(fe, dir, event);
  
  	return 0;
  }
  
  static void soc_pcm_set_dai_params(struct snd_soc_dai *dai,
  				   struct snd_pcm_hw_params *params)
  {
  	if (params) {
  		dai->rate	 = params_rate(params);
  		dai->channels	 = params_channels(params);
  		dai->sample_bits = snd_pcm_format_physical_width(params_format(params));
  	} else {
  		dai->rate	 = 0;
  		dai->channels	 = 0;
  		dai->sample_bits = 0;
  	}
  }
  
  static int soc_pcm_apply_symmetry(struct snd_pcm_substream *substream,
  					struct snd_soc_dai *soc_dai)
  {
  	struct snd_soc_pcm_runtime *rtd = asoc_substream_to_rtd(substream);
  	int ret;
  
  	if (!snd_soc_dai_active(soc_dai))
  		return 0;
  
  #define __soc_pcm_apply_symmetry(name, NAME)				\
  	if (soc_dai->name && (soc_dai->driver->symmetric_##name ||	\
  			      rtd->dai_link->symmetric_##name)) {	\
  		dev_dbg(soc_dai->dev, "ASoC: Symmetry forces %s to %d\n",\
  			#name, soc_dai->name);				\
  									\
  		ret = snd_pcm_hw_constraint_single(substream->runtime,	\
  						   SNDRV_PCM_HW_PARAM_##NAME,\
  						   soc_dai->name);	\
  		if (ret < 0) {						\
  			dev_err(soc_dai->dev,				\
  				"ASoC: Unable to apply %s constraint: %d\n",\
  				#name, ret);				\
  			return ret;					\
  		}							\
  	}
  
  	__soc_pcm_apply_symmetry(rate,		RATE);
  	__soc_pcm_apply_symmetry(channels,	CHANNELS);
  	__soc_pcm_apply_symmetry(sample_bits,	SAMPLE_BITS);
  
  	return 0;
  }
  
  static int soc_pcm_params_symmetry(struct snd_pcm_substream *substream,
  				struct snd_pcm_hw_params *params)
  {
  	struct snd_soc_pcm_runtime *rtd = asoc_substream_to_rtd(substream);
  	struct snd_soc_dai d;
  	struct snd_soc_dai *dai;
  	struct snd_soc_dai *cpu_dai;
  	unsigned int symmetry, i;
  
  	d.name = __func__;
  	soc_pcm_set_dai_params(&d, params);
  
  #define __soc_pcm_params_symmetry(xxx)					\
  	symmetry = rtd->dai_link->symmetric_##xxx;			\
  	for_each_rtd_dais(rtd, i, dai)					\
  		symmetry |= dai->driver->symmetric_##xxx;		\
  									\
  	if (symmetry)							\
  		for_each_rtd_cpu_dais(rtd, i, cpu_dai)			\
  			if (!snd_soc_dai_is_dummy(cpu_dai) &&		\
  			    cpu_dai->xxx && cpu_dai->xxx != d.xxx) {	\
  				dev_err(rtd->dev, "ASoC: unmatched %s symmetry: %s:%d - %s:%d\n", \
  					#xxx, cpu_dai->name, cpu_dai->xxx, d.name, d.xxx); \
  				return -EINVAL;				\
  			}
  
  	/* reject unmatched parameters when applying symmetry */
  	__soc_pcm_params_symmetry(rate);
  	__soc_pcm_params_symmetry(channels);
  	__soc_pcm_params_symmetry(sample_bits);
  
  	return 0;
  }
  
  static void soc_pcm_update_symmetry(struct snd_pcm_substream *substream)
  {
  	struct snd_soc_pcm_runtime *rtd = asoc_substream_to_rtd(substream);
  	struct snd_soc_dai_link *link = rtd->dai_link;
  	struct snd_soc_dai *dai;
  	unsigned int symmetry, i;
  
  	symmetry = link->symmetric_rate ||
  		link->symmetric_channels ||
  		link->symmetric_sample_bits;
  
  	for_each_rtd_dais(rtd, i, dai)
  		symmetry = symmetry ||
  			dai->driver->symmetric_rate ||
  			dai->driver->symmetric_channels ||
  			dai->driver->symmetric_sample_bits;
  
  	if (symmetry)
  		substream->runtime->hw.info |= SNDRV_PCM_INFO_JOINT_DUPLEX;
  }
  
  static void soc_pcm_set_msb(struct snd_pcm_substream *substream, int bits)
  {
  	struct snd_soc_pcm_runtime *rtd = asoc_substream_to_rtd(substream);
  	int ret;
  
  	if (!bits)
  		return;
  
  	ret = snd_pcm_hw_constraint_msbits(substream->runtime, 0, 0, bits);
  	if (ret != 0)
  		dev_warn(rtd->dev, "ASoC: Failed to set MSB %d: %d\n",
  				 bits, ret);
  }
  
  static void soc_pcm_apply_msb(struct snd_pcm_substream *substream)
  {
  	struct snd_soc_pcm_runtime *rtd = asoc_substream_to_rtd(substream);
  	struct snd_soc_dai *cpu_dai;
  	struct snd_soc_dai *codec_dai;
  	struct snd_soc_pcm_stream *pcm_codec, *pcm_cpu;
  	int stream = substream->stream;
  	int i;
  	unsigned int bits = 0, cpu_bits = 0;
  
  	for_each_rtd_codec_dais(rtd, i, codec_dai) {
  		pcm_codec = snd_soc_dai_get_pcm_stream(codec_dai, stream);
  
  		if (pcm_codec->sig_bits == 0) {
  			bits = 0;
  			break;
  		}
  		bits = max(pcm_codec->sig_bits, bits);
  	}
  
  	for_each_rtd_cpu_dais(rtd, i, cpu_dai) {
  		pcm_cpu = snd_soc_dai_get_pcm_stream(cpu_dai, stream);
  
  		if (pcm_cpu->sig_bits == 0) {
  			cpu_bits = 0;
  			break;
  		}
  		cpu_bits = max(pcm_cpu->sig_bits, cpu_bits);
  	}
  
  	soc_pcm_set_msb(substream, bits);
  	soc_pcm_set_msb(substream, cpu_bits);
  }
  
  static void soc_pcm_hw_init(struct snd_pcm_hardware *hw)
  {
  	hw->rates		= UINT_MAX;
  	hw->rate_min		= 0;
  	hw->rate_max		= UINT_MAX;
  	hw->channels_min	= 0;
  	hw->channels_max	= UINT_MAX;
  	hw->formats		= ULLONG_MAX;
  }
  
  static void soc_pcm_hw_update_rate(struct snd_pcm_hardware *hw,
  				   struct snd_soc_pcm_stream *p)
  {
  	hw->rates = snd_pcm_rate_mask_intersect(hw->rates, p->rates);
  
  	/* setup hw->rate_min/max via hw->rates first */
  	snd_pcm_hw_limit_rates(hw);
  
  	/* update hw->rate_min/max by snd_soc_pcm_stream */
  	hw->rate_min = max(hw->rate_min, p->rate_min);
  	hw->rate_max = min_not_zero(hw->rate_max, p->rate_max);
  }
  
  static void soc_pcm_hw_update_chan(struct snd_pcm_hardware *hw,
  				   struct snd_soc_pcm_stream *p)
  {
  	hw->channels_min = max(hw->channels_min, p->channels_min);
  	hw->channels_max = min(hw->channels_max, p->channels_max);
  }
  
  static void soc_pcm_hw_update_format(struct snd_pcm_hardware *hw,
  				     struct snd_soc_pcm_stream *p)
  {
  	hw->formats &= p->formats;
  }
  
  /**
   * snd_soc_runtime_calc_hw() - Calculate hw limits for a PCM stream
   * @rtd: ASoC PCM runtime
   * @hw: PCM hardware parameters (output)
   * @stream: Direction of the PCM stream
   *
   * Calculates the subset of stream parameters supported by all DAIs
   * associated with the PCM stream.
   */
  int snd_soc_runtime_calc_hw(struct snd_soc_pcm_runtime *rtd,
  			    struct snd_pcm_hardware *hw, int stream)
  {
  	struct snd_soc_dai *codec_dai;
  	struct snd_soc_dai *cpu_dai;
  	struct snd_soc_pcm_stream *codec_stream;
  	struct snd_soc_pcm_stream *cpu_stream;
  	unsigned int cpu_chan_min = 0, cpu_chan_max = UINT_MAX;
  	int i;
  
  	soc_pcm_hw_init(hw);
  
  	/* first calculate min/max only for CPUs in the DAI link */
  	for_each_rtd_cpu_dais(rtd, i, cpu_dai) {
  
  		/*
  		 * Skip CPUs which don't support the current stream type.
  		 * Otherwise, since the rate, channel, and format values will
  		 * zero in that case, we would have no usable settings left,
  		 * causing the resulting setup to fail.
  		 */
  		if (!snd_soc_dai_stream_valid(cpu_dai, stream))
  			continue;
  
  		cpu_stream = snd_soc_dai_get_pcm_stream(cpu_dai, stream);
  
  		soc_pcm_hw_update_chan(hw, cpu_stream);
  		soc_pcm_hw_update_rate(hw, cpu_stream);
  		soc_pcm_hw_update_format(hw, cpu_stream);
  	}
  	cpu_chan_min = hw->channels_min;
  	cpu_chan_max = hw->channels_max;
  
  	/* second calculate min/max only for CODECs in the DAI link */
  	for_each_rtd_codec_dais(rtd, i, codec_dai) {
  
  		/*
  		 * Skip CODECs which don't support the current stream type.
  		 * Otherwise, since the rate, channel, and format values will
  		 * zero in that case, we would have no usable settings left,
  		 * causing the resulting setup to fail.
  		 */
  		if (!snd_soc_dai_stream_valid(codec_dai, stream))
  			continue;
  
  		codec_stream = snd_soc_dai_get_pcm_stream(codec_dai, stream);
  
  		soc_pcm_hw_update_chan(hw, codec_stream);
  		soc_pcm_hw_update_rate(hw, codec_stream);
  		soc_pcm_hw_update_format(hw, codec_stream);
  	}
  
  	/* Verify both a valid CPU DAI and a valid CODEC DAI were found */
  	if (!hw->channels_min)
  		return -EINVAL;
  
  	/*
  	 * chan min/max cannot be enforced if there are multiple CODEC DAIs
  	 * connected to CPU DAI(s), use CPU DAI's directly and let
  	 * channel allocation be fixed up later
  	 */
  	if (rtd->num_codecs > 1) {
  		hw->channels_min = cpu_chan_min;
  		hw->channels_max = cpu_chan_max;
  	}
  
  	return 0;
  }
  EXPORT_SYMBOL_GPL(snd_soc_runtime_calc_hw);
  
  static void soc_pcm_init_runtime_hw(struct snd_pcm_substream *substream)
  {
  	struct snd_pcm_hardware *hw = &substream->runtime->hw;
  	struct snd_soc_pcm_runtime *rtd = asoc_substream_to_rtd(substream);
  	u64 formats = hw->formats;
  
  	/*
  	 * At least one CPU and one CODEC should match. Otherwise, we should
  	 * have bailed out on a higher level, since there would be no CPU or
  	 * CODEC to support the transfer direction in that case.
  	 */
  	snd_soc_runtime_calc_hw(rtd, hw, substream->stream);
  
  	if (formats)
  		hw->formats &= formats;
  }
  
  static int soc_pcm_components_open(struct snd_pcm_substream *substream)
  {
  	struct snd_soc_pcm_runtime *rtd = asoc_substream_to_rtd(substream);
  	struct snd_soc_component *component;
  	int i, ret = 0;
  
  	for_each_rtd_components(rtd, i, component) {
  		ret = snd_soc_component_module_get_when_open(component, substream);
  		if (ret < 0)
  			break;
  
  		ret = snd_soc_component_open(component, substream);
  		if (ret < 0)
  			break;
  	}
  
  	return ret;
  }
  
  static int soc_pcm_components_close(struct snd_pcm_substream *substream,
  				    int rollback)
  {
  	struct snd_soc_pcm_runtime *rtd = asoc_substream_to_rtd(substream);
  	struct snd_soc_component *component;
  	int i, r, ret = 0;
  
  	for_each_rtd_components(rtd, i, component) {
  		r = snd_soc_component_close(component, substream, rollback);
  		if (r < 0)
  			ret = r; /* use last ret */
  
  		snd_soc_component_module_put_when_close(component, substream, rollback);
  	}
  
  	return ret;
  }
  
  static int soc_pcm_clean(struct snd_pcm_substream *substream, int rollback)
  {
  	struct snd_soc_pcm_runtime *rtd = asoc_substream_to_rtd(substream);
  	struct snd_soc_component *component;
  	struct snd_soc_dai *dai;
  	int i;
  
  	mutex_lock_nested(&rtd->card->pcm_mutex, rtd->card->pcm_subclass);
  
  	if (!rollback)
  		snd_soc_runtime_deactivate(rtd, substream->stream);
  
  	for_each_rtd_dais(rtd, i, dai)
  		snd_soc_dai_shutdown(dai, substream, rollback);
  
  	snd_soc_link_shutdown(substream, rollback);
  
  	soc_pcm_components_close(substream, rollback);
  
  
  	mutex_unlock(&rtd->card->pcm_mutex);
  
  	snd_soc_pcm_component_pm_runtime_put(rtd, substream, rollback);
  
  	for_each_rtd_components(rtd, i, component)
  		if (!snd_soc_component_active(component))
  			pinctrl_pm_select_sleep_state(component->dev);
  
  	return 0;
  }
  
  /*
   * Called by ALSA when a PCM substream is closed. Private data can be
   * freed here. The cpu DAI, codec DAI, machine and components are also
   * shutdown.
   */
  static int soc_pcm_close(struct snd_pcm_substream *substream)
  {
  	return soc_pcm_clean(substream, 0);
  }
  
  static int soc_hw_sanity_check(struct snd_pcm_substream *substream)
  {
  	struct snd_soc_pcm_runtime *rtd = asoc_substream_to_rtd(substream);
  	struct snd_pcm_hardware *hw = &substream->runtime->hw;
  	const char *name_cpu = soc_cpu_dai_name(rtd);
  	const char *name_codec = soc_codec_dai_name(rtd);
  	const char *err_msg;
  	struct device *dev = rtd->dev;
  
  	err_msg = "rates";
  	if (!hw->rates)
  		goto config_err;
  
  	err_msg = "formats";
  	if (!hw->formats)
  		goto config_err;
  
  	err_msg = "channels";
  	if (!hw->channels_min || !hw->channels_max ||
  	     hw->channels_min  >  hw->channels_max)
  		goto config_err;
  
  	dev_dbg(dev, "ASoC: %s <-> %s info:\n",		name_codec,
  							name_cpu);
  	dev_dbg(dev, "ASoC: rate mask 0x%x\n",		hw->rates);
  	dev_dbg(dev, "ASoC: ch   min %d max %d\n",	hw->channels_min,
  							hw->channels_max);
  	dev_dbg(dev, "ASoC: rate min %d max %d\n",	hw->rate_min,
  							hw->rate_max);
  
  	return 0;
  
  config_err:
  	dev_err(dev, "ASoC: %s <-> %s No matching %s\n",
  		name_codec, name_cpu, err_msg);
  	return -EINVAL;
  }
  
  /*
   * Called by ALSA when a PCM substream is opened, the runtime->hw record is
   * then initialized and any private data can be allocated. This also calls
   * startup for the cpu DAI, component, machine and codec DAI.
   */
  static int soc_pcm_open(struct snd_pcm_substream *substream)
  {
  	struct snd_soc_pcm_runtime *rtd = asoc_substream_to_rtd(substream);
  	struct snd_soc_component *component;
  	struct snd_soc_dai *dai;
  	int i, ret = 0;
  
  	for_each_rtd_components(rtd, i, component)
  		pinctrl_pm_select_default_state(component->dev);
  
  	ret = snd_soc_pcm_component_pm_runtime_get(rtd, substream);
  	if (ret < 0)
  		goto pm_err;
  
  	mutex_lock_nested(&rtd->card->pcm_mutex, rtd->card->pcm_subclass);
  
  	ret = soc_pcm_components_open(substream);
  	if (ret < 0)
  		goto err;
  
  	ret = snd_soc_link_startup(substream);
  	if (ret < 0)
  		goto err;
  
  	/* startup the audio subsystem */
  	for_each_rtd_dais(rtd, i, dai) {
  		ret = snd_soc_dai_startup(dai, substream);
  		if (ret < 0)
  			goto err;
  
  		if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
  			dai->tx_mask = 0;
  		else
  			dai->rx_mask = 0;
  	}
  
  	/* Dynamic PCM DAI links compat checks use dynamic capabilities */
  	if (rtd->dai_link->dynamic || rtd->dai_link->no_pcm)
  		goto dynamic;
  
  	/* Check that the codec and cpu DAIs are compatible */
  	soc_pcm_init_runtime_hw(substream);
  
  	soc_pcm_update_symmetry(substream);
  
  	ret = soc_hw_sanity_check(substream);
  	if (ret < 0)
  		goto err;
  
  	soc_pcm_apply_msb(substream);
  
  	/* Symmetry only applies if we've already got an active stream. */
  	for_each_rtd_dais(rtd, i, dai) {
  		ret = soc_pcm_apply_symmetry(substream, dai);
  		if (ret != 0)
  			goto err;
  	}
  dynamic:
  	snd_soc_runtime_activate(rtd, substream->stream);
  	ret = 0;
  err:
  	mutex_unlock(&rtd->card->pcm_mutex);
  pm_err:
  	if (ret < 0) {
  		soc_pcm_clean(substream, 1);
  		dev_err(rtd->dev, "%s() failed (%d)", __func__, ret);
  	}
  
  	return ret;
  }
  
  static void codec2codec_close_delayed_work(struct snd_soc_pcm_runtime *rtd)
  {
  	/*
  	 * Currently nothing to do for c2c links
  	 * Since c2c links are internal nodes in the DAPM graph and
  	 * don't interface with the outside world or application layer
  	 * we don't have to do any special handling on close.
  	 */
  }
  
  /*
   * Called by ALSA when the PCM substream is prepared, can set format, sample
   * rate, etc.  This function is non atomic and can be called multiple times,
   * it can refer to the runtime info.
   */
  static int soc_pcm_prepare(struct snd_pcm_substream *substream)
  {
  	struct snd_soc_pcm_runtime *rtd = asoc_substream_to_rtd(substream);
  	struct snd_soc_dai *dai;
  	int i, ret = 0;
  
  	mutex_lock_nested(&rtd->card->pcm_mutex, rtd->card->pcm_subclass);
  
  	ret = snd_soc_link_prepare(substream);
  	if (ret < 0)
  		goto out;
  
  	ret = snd_soc_pcm_component_prepare(substream);
  	if (ret < 0)
  		goto out;
  
  	ret = snd_soc_pcm_dai_prepare(substream);
  	if (ret < 0)
  		goto out;
  
  	/* cancel any delayed stream shutdown that is pending */
  	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK &&
  	    rtd->pop_wait) {
  		rtd->pop_wait = 0;
  		cancel_delayed_work(&rtd->delayed_work);
  	}
  
  	snd_soc_dapm_stream_event(rtd, substream->stream,
  			SND_SOC_DAPM_STREAM_START);
  
  	for_each_rtd_dais(rtd, i, dai)
  		snd_soc_dai_digital_mute(dai, 0, substream->stream);
  
  out:
  	mutex_unlock(&rtd->card->pcm_mutex);
  
  	if (ret < 0)
  		dev_err(rtd->dev, "ASoC: %s() failed (%d)\n", __func__, ret);
  
  	return ret;
  }
  
  static void soc_pcm_codec_params_fixup(struct snd_pcm_hw_params *params,
  				       unsigned int mask)
  {
  	struct snd_interval *interval;
  	int channels = hweight_long(mask);
  
  	interval = hw_param_interval(params, SNDRV_PCM_HW_PARAM_CHANNELS);
  	interval->min = channels;
  	interval->max = channels;
  }
  
  static int soc_pcm_hw_clean(struct snd_pcm_substream *substream, int rollback)
  {
  	struct snd_soc_pcm_runtime *rtd = asoc_substream_to_rtd(substream);
  	struct snd_soc_dai *dai;
  	int i;
  
  	mutex_lock_nested(&rtd->card->pcm_mutex, rtd->card->pcm_subclass);
  
  	/* clear the corresponding DAIs parameters when going to be inactive */
  	for_each_rtd_dais(rtd, i, dai) {
  		int active = snd_soc_dai_stream_active(dai, substream->stream);
  
  		if (snd_soc_dai_active(dai) == 1)
  			soc_pcm_set_dai_params(dai, NULL);
  
  		if (active == 1)
  			snd_soc_dai_digital_mute(dai, 1, substream->stream);
  	}
  
  	/* run the stream event */
  	snd_soc_dapm_stream_stop(rtd, substream->stream);
  
  	/* free any machine hw params */
  	snd_soc_link_hw_free(substream, rollback);
  
  	/* free any component resources */
  	snd_soc_pcm_component_hw_free(substream, rollback);
  
  	/* now free hw params for the DAIs  */
  	for_each_rtd_dais(rtd, i, dai) {
  		if (!snd_soc_dai_stream_valid(dai, substream->stream))
  			continue;
  
  		snd_soc_dai_hw_free(dai, substream, rollback);
  	}
  
  	mutex_unlock(&rtd->card->pcm_mutex);
  	return 0;
  }
  
  /*
   * Frees resources allocated by hw_params, can be called multiple times
   */
  static int soc_pcm_hw_free(struct snd_pcm_substream *substream)
  {
  	return soc_pcm_hw_clean(substream, 0);
  }
  
  /*
   * Called by ALSA when the hardware params are set by application. This
   * function can also be called multiple times and can allocate buffers
   * (using snd_pcm_lib_* ). It's non-atomic.
   */
  static int soc_pcm_hw_params(struct snd_pcm_substream *substream,
  				struct snd_pcm_hw_params *params)
  {
  	struct snd_soc_pcm_runtime *rtd = asoc_substream_to_rtd(substream);
  	struct snd_soc_dai *cpu_dai;
  	struct snd_soc_dai *codec_dai;
  	int i, ret = 0;
  
  	mutex_lock_nested(&rtd->card->pcm_mutex, rtd->card->pcm_subclass);
  
  	ret = soc_pcm_params_symmetry(substream, params);
  	if (ret)
  		goto out;
  
  	ret = snd_soc_link_hw_params(substream, params);
  	if (ret < 0)
  		goto out;
  
  	for_each_rtd_codec_dais(rtd, i, codec_dai) {
  		struct snd_pcm_hw_params codec_params;
  
  		/*
  		 * Skip CODECs which don't support the current stream type,
  		 * the idea being that if a CODEC is not used for the currently
  		 * set up transfer direction, it should not need to be
  		 * configured, especially since the configuration used might
  		 * not even be supported by that CODEC. There may be cases
  		 * however where a CODEC needs to be set up although it is
  		 * actually not being used for the transfer, e.g. if a
  		 * capture-only CODEC is acting as an LRCLK and/or BCLK master
  		 * for the DAI link including a playback-only CODEC.
  		 * If this becomes necessary, we will have to augment the
  		 * machine driver setup with information on how to act, so
  		 * we can do the right thing here.
  		 */
  		if (!snd_soc_dai_stream_valid(codec_dai, substream->stream))
  			continue;
  
  		/* copy params for each codec */
  		codec_params = *params;
  
  		/* fixup params based on TDM slot masks */
  		if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK &&
  		    codec_dai->tx_mask)
  			soc_pcm_codec_params_fixup(&codec_params,
  						   codec_dai->tx_mask);
  
  		if (substream->stream == SNDRV_PCM_STREAM_CAPTURE &&
  		    codec_dai->rx_mask)
  			soc_pcm_codec_params_fixup(&codec_params,
  						   codec_dai->rx_mask);
  
  		ret = snd_soc_dai_hw_params(codec_dai, substream,
  					    &codec_params);
  		if(ret < 0)
  			goto out;
  
  		soc_pcm_set_dai_params(codec_dai, &codec_params);
  		snd_soc_dapm_update_dai(substream, &codec_params, codec_dai);
  	}
  
  	for_each_rtd_cpu_dais(rtd, i, cpu_dai) {
  		/*
  		 * Skip CPUs which don't support the current stream
  		 * type. See soc_pcm_init_runtime_hw() for more details
  		 */
  		if (!snd_soc_dai_stream_valid(cpu_dai, substream->stream))
  			continue;
  
  		ret = snd_soc_dai_hw_params(cpu_dai, substream, params);
  		if (ret < 0)
  			goto out;
  
  		/* store the parameters for each DAI */
  		soc_pcm_set_dai_params(cpu_dai, params);
  		snd_soc_dapm_update_dai(substream, params, cpu_dai);
  	}
  
  	ret = snd_soc_pcm_component_hw_params(substream, params);
  out:
  	mutex_unlock(&rtd->card->pcm_mutex);
  
  	if (ret < 0) {
  		soc_pcm_hw_clean(substream, 1);
  		dev_err(rtd->dev, "ASoC: %s() failed (%d)\n", __func__, ret);
  	}
  
  	return ret;
  }
  
  static int soc_pcm_trigger(struct snd_pcm_substream *substream, int cmd)
  {
  	struct snd_soc_pcm_runtime *rtd = asoc_substream_to_rtd(substream);
  	int ret = -EINVAL, _ret = 0;
  	int rollback = 0;
  
  	switch (cmd) {
  	case SNDRV_PCM_TRIGGER_START:
  	case SNDRV_PCM_TRIGGER_RESUME:
  	case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
  		ret = snd_soc_link_trigger(substream, cmd, 0);
  		if (ret < 0)
  			goto start_err;
  
  		ret = snd_soc_pcm_component_trigger(substream, cmd, 0);
  		if (ret < 0)
  			goto start_err;
  
  		ret = snd_soc_pcm_dai_trigger(substream, cmd, 0);
  start_err:
  		if (ret < 0)
  			rollback = 1;
  	}
  
  	if (rollback) {
  		_ret = ret;
  		switch (cmd) {
  		case SNDRV_PCM_TRIGGER_START:
  			cmd = SNDRV_PCM_TRIGGER_STOP;
  			break;
  		case SNDRV_PCM_TRIGGER_RESUME:
  			cmd = SNDRV_PCM_TRIGGER_SUSPEND;
  			break;
  		case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
  			cmd = SNDRV_PCM_TRIGGER_PAUSE_PUSH;
  			break;
  		}
  	}
  
  	switch (cmd) {
  	case SNDRV_PCM_TRIGGER_STOP:
  	case SNDRV_PCM_TRIGGER_SUSPEND:
  	case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
  		if (rtd->dai_link->stop_dma_first) {
  			ret = snd_soc_pcm_component_trigger(substream, cmd, rollback);
  			if (ret < 0)
  				break;
  
  			ret = snd_soc_pcm_dai_trigger(substream, cmd, rollback);
  			if (ret < 0)
  				break;
  		} else {
  			ret = snd_soc_pcm_dai_trigger(substream, cmd, rollback);
  			if (ret < 0)
  				break;
  
  			ret = snd_soc_pcm_component_trigger(substream, cmd, rollback);
  			if (ret < 0)
  				break;
  		}
  		ret = snd_soc_link_trigger(substream, cmd, rollback);
  		break;
  	}
  
  	if (_ret)
  		ret = _ret;
  
  	return ret;
  }
  
  /*
   * soc level wrapper for pointer callback
   * If cpu_dai, codec_dai, component driver has the delay callback, then
   * the runtime->delay will be updated accordingly.
   */
  static snd_pcm_uframes_t soc_pcm_pointer(struct snd_pcm_substream *substream)
  {
  	struct snd_soc_pcm_runtime *rtd = asoc_substream_to_rtd(substream);
  	struct snd_soc_dai *cpu_dai;
  	struct snd_soc_dai *codec_dai;
  	struct snd_pcm_runtime *runtime = substream->runtime;
  	snd_pcm_uframes_t offset = 0;
  	snd_pcm_sframes_t delay = 0;
  	snd_pcm_sframes_t codec_delay = 0;
  	snd_pcm_sframes_t cpu_delay = 0;
  	int i;
  
  	/* clearing the previous total delay */
  	runtime->delay = 0;
  
  	offset = snd_soc_pcm_component_pointer(substream);
  
  	/* base delay if assigned in pointer callback */
  	delay = runtime->delay;
  
  	for_each_rtd_cpu_dais(rtd, i, cpu_dai) {
  		cpu_delay = max(cpu_delay,
  				snd_soc_dai_delay(cpu_dai, substream));
  	}
  	delay += cpu_delay;
  
  	for_each_rtd_codec_dais(rtd, i, codec_dai) {
  		codec_delay = max(codec_delay,
  				  snd_soc_dai_delay(codec_dai, substream));
  	}
  	delay += codec_delay;
  
  	runtime->delay = delay;
  
  	return offset;
  }
  
  /* connect a FE and BE */
  static int dpcm_be_connect(struct snd_soc_pcm_runtime *fe,
  		struct snd_soc_pcm_runtime *be, int stream)
  {
  	struct snd_soc_dpcm *dpcm;
  	unsigned long flags;
  
  	/* only add new dpcms */
  	for_each_dpcm_be(fe, stream, dpcm) {
  		if (dpcm->be == be && dpcm->fe == fe)
  			return 0;
  	}
  
  	dpcm = kzalloc(sizeof(struct snd_soc_dpcm), GFP_KERNEL);
  	if (!dpcm)
  		return -ENOMEM;
  
  	dpcm->be = be;
  	dpcm->fe = fe;
  	be->dpcm[stream].runtime = fe->dpcm[stream].runtime;
  	dpcm->state = SND_SOC_DPCM_LINK_STATE_NEW;
  	spin_lock_irqsave(&fe->card->dpcm_lock, flags);
  	list_add(&dpcm->list_be, &fe->dpcm[stream].be_clients);
  	list_add(&dpcm->list_fe, &be->dpcm[stream].fe_clients);
  	spin_unlock_irqrestore(&fe->card->dpcm_lock, flags);
  
  	dev_dbg(fe->dev, "connected new DPCM %s path %s %s %s\n",
  			stream ? "capture" : "playback",  fe->dai_link->name,
  			stream ? "<-" : "->", be->dai_link->name);
  
  	dpcm_create_debugfs_state(dpcm, stream);
  
  	return 1;
  }
  
  /* reparent a BE onto another FE */
  static void dpcm_be_reparent(struct snd_soc_pcm_runtime *fe,
  			struct snd_soc_pcm_runtime *be, int stream)
  {
  	struct snd_soc_dpcm *dpcm;
  	struct snd_pcm_substream *fe_substream, *be_substream;
  
  	/* reparent if BE is connected to other FEs */
  	if (!be->dpcm[stream].users)
  		return;
  
  	be_substream = snd_soc_dpcm_get_substream(be, stream);
  
  	for_each_dpcm_fe(be, stream, dpcm) {
  		if (dpcm->fe == fe)
  			continue;
  
  		dev_dbg(fe->dev, "reparent %s path %s %s %s\n",
  			stream ? "capture" : "playback",
  			dpcm->fe->dai_link->name,
  			stream ? "<-" : "->", dpcm->be->dai_link->name);
  
  		fe_substream = snd_soc_dpcm_get_substream(dpcm->fe, stream);
  		be_substream->runtime = fe_substream->runtime;
  		break;
  	}
  }
  
  /* disconnect a BE and FE */
  void dpcm_be_disconnect(struct snd_soc_pcm_runtime *fe, int stream)
  {
  	struct snd_soc_dpcm *dpcm, *d;
  	unsigned long flags;
  
  	for_each_dpcm_be_safe(fe, stream, dpcm, d) {
  		dev_dbg(fe->dev, "ASoC: BE %s disconnect check for %s\n",
  				stream ? "capture" : "playback",
  				dpcm->be->dai_link->name);
  
  		if (dpcm->state != SND_SOC_DPCM_LINK_STATE_FREE)
  			continue;
  
  		dev_dbg(fe->dev, "freed DSP %s path %s %s %s\n",
  			stream ? "capture" : "playback", fe->dai_link->name,
  			stream ? "<-" : "->", dpcm->be->dai_link->name);
  
  		/* BEs still alive need new FE */
  		dpcm_be_reparent(fe, dpcm->be, stream);
  
  		dpcm_remove_debugfs_state(dpcm);
  
  		spin_lock_irqsave(&fe->card->dpcm_lock, flags);
  		list_del(&dpcm->list_be);
  		list_del(&dpcm->list_fe);
  		spin_unlock_irqrestore(&fe->card->dpcm_lock, flags);
  		kfree(dpcm);
  	}
  }
  
  /* get BE for DAI widget and stream */
  static struct snd_soc_pcm_runtime *dpcm_get_be(struct snd_soc_card *card,
  		struct snd_soc_dapm_widget *widget, int stream)
  {
  	struct snd_soc_pcm_runtime *be;
  	struct snd_soc_dapm_widget *w;
  	struct snd_soc_dai *dai;
  	int i;
  
  	dev_dbg(card->dev, "ASoC: find BE for widget %s\n", widget->name);
  
  	for_each_card_rtds(card, be) {
  
  		if (!be->dai_link->no_pcm)
  			continue;
  
  		for_each_rtd_dais(be, i, dai) {
  			w = snd_soc_dai_get_widget(dai, stream);
  
  			dev_dbg(card->dev, "ASoC: try BE : %s\n",
  				w ? w->name : "(not set)");
  
  			if (w == widget)
  				return be;
  		}
  	}
  
  	/* Widget provided is not a BE */
  	return NULL;
  }
  
  static int widget_in_list(struct snd_soc_dapm_widget_list *list,
  		struct snd_soc_dapm_widget *widget)
  {
  	struct snd_soc_dapm_widget *w;
  	int i;
  
  	for_each_dapm_widgets(list, i, w)
  		if (widget == w)
  			return 1;
  
  	return 0;
  }
  
  static bool dpcm_end_walk_at_be(struct snd_soc_dapm_widget *widget,
  		enum snd_soc_dapm_direction dir)
  {
  	struct snd_soc_card *card = widget->dapm->card;
  	struct snd_soc_pcm_runtime *rtd;
  	int stream;
  
  	/* adjust dir to stream */
  	if (dir == SND_SOC_DAPM_DIR_OUT)
  		stream = SNDRV_PCM_STREAM_PLAYBACK;
  	else
  		stream = SNDRV_PCM_STREAM_CAPTURE;
  
  	rtd = dpcm_get_be(card, widget, stream);
  	if (rtd)
  		return true;
  
  	return false;
  }
  
  int dpcm_path_get(struct snd_soc_pcm_runtime *fe,
  	int stream, struct snd_soc_dapm_widget_list **list)
  {
  	struct snd_soc_dai *cpu_dai = asoc_rtd_to_cpu(fe, 0);
  	int paths;
  
  	if (fe->num_cpus > 1) {
  		dev_err(fe->dev,
  			"%s doesn't support Multi CPU yet\n", __func__);
  		return -EINVAL;
  	}
  
  	/* get number of valid DAI paths and their widgets */
  	paths = snd_soc_dapm_dai_get_connected_widgets(cpu_dai, stream, list,
  			fe->card->component_chaining ?
  				NULL : dpcm_end_walk_at_be);
  
  	if (paths > 0)
  		dev_dbg(fe->dev, "ASoC: found %d audio %s paths\n", paths,
  			stream ? "capture" : "playback");
  	else if (paths == 0)
  		dev_dbg(fe->dev, "ASoC: %s no valid %s path\n", fe->dai_link->name,
  			 stream ? "capture" : "playback");
  
  	return paths;
  }
  
  void dpcm_path_put(struct snd_soc_dapm_widget_list **list)
  {
  	snd_soc_dapm_dai_free_widgets(list);
  }
  
  static bool dpcm_be_is_active(struct snd_soc_dpcm *dpcm, int stream,
  			      struct snd_soc_dapm_widget_list *list)
  {
  	struct snd_soc_dapm_widget *widget;
  	struct snd_soc_dai *dai;
  	unsigned int i;
  
  	/* is there a valid DAI widget for this BE */
  	for_each_rtd_dais(dpcm->be, i, dai) {
  		widget = snd_soc_dai_get_widget(dai, stream);
  
  		/*
  		 * The BE is pruned only if none of the dai
  		 * widgets are in the active list.
  		 */
  		if (widget && widget_in_list(list, widget))
  			return true;
  	}
  
  	return false;
  }
  
  static int dpcm_prune_paths(struct snd_soc_pcm_runtime *fe, int stream,
  			    struct snd_soc_dapm_widget_list **list_)
  {
  	struct snd_soc_dpcm *dpcm;
  	int prune = 0;
  
  	/* Destroy any old FE <--> BE connections */
  	for_each_dpcm_be(fe, stream, dpcm) {
  		if (dpcm_be_is_active(dpcm, stream, *list_))
  			continue;
  
  		dev_dbg(fe->dev, "ASoC: pruning %s BE %s for %s\n",
  			stream ? "capture" : "playback",
  			dpcm->be->dai_link->name, fe->dai_link->name);
  		dpcm->state = SND_SOC_DPCM_LINK_STATE_FREE;
  		dpcm_set_be_update_state(dpcm->be, stream, SND_SOC_DPCM_UPDATE_BE);
  		prune++;
  	}
  
  	dev_dbg(fe->dev, "ASoC: found %d old BE paths for pruning\n", prune);
  	return prune;
  }
  
  static int dpcm_add_paths(struct snd_soc_pcm_runtime *fe, int stream,
  	struct snd_soc_dapm_widget_list **list_)
  {
  	struct snd_soc_card *card = fe->card;
  	struct snd_soc_dapm_widget_list *list = *list_;
  	struct snd_soc_pcm_runtime *be;
  	struct snd_soc_dapm_widget *widget;
  	int i, new = 0, err;
  
  	/* Create any new FE <--> BE connections */
  	for_each_dapm_widgets(list, i, widget) {
  
  		switch (widget->id) {
  		case snd_soc_dapm_dai_in:
  			if (stream != SNDRV_PCM_STREAM_PLAYBACK)
  				continue;
  			break;
  		case snd_soc_dapm_dai_out:
  			if (stream != SNDRV_PCM_STREAM_CAPTURE)
  				continue;
  			break;
  		default:
  			continue;
  		}
  
  		/* is there a valid BE rtd for this widget */
  		be = dpcm_get_be(card, widget, stream);
  		if (!be) {
  			dev_dbg(fe->dev, "ASoC: no BE found for %s\n",
  				widget->name);
  			continue;
  		}
  
  		/* don't connect if FE is not running */
  		if (!fe->dpcm[stream].runtime && !fe->fe_compr)
  			continue;
  
  		/* newly connected FE and BE */
  		err = dpcm_be_connect(fe, be, stream);
  		if (err < 0) {
  			dev_err(fe->dev, "ASoC: can't connect %s\n",
  				widget->name);
  			break;
  		} else if (err == 0) /* already connected */
  			continue;
  
  		/* new */
  		dpcm_set_be_update_state(be, stream, SND_SOC_DPCM_UPDATE_BE);
  		new++;
  	}
  
  	dev_dbg(fe->dev, "ASoC: found %d new BE paths\n", new);
  	return new;
  }
  
  /*
   * Find the corresponding BE DAIs that source or sink audio to this
   * FE substream.
   */
  int dpcm_process_paths(struct snd_soc_pcm_runtime *fe,
  	int stream, struct snd_soc_dapm_widget_list **list, int new)
  {
  	if (new)
  		return dpcm_add_paths(fe, stream, list);
  	else
  		return dpcm_prune_paths(fe, stream, list);
  }
  
  void dpcm_clear_pending_state(struct snd_soc_pcm_runtime *fe, int stream)
  {
  	struct snd_soc_dpcm *dpcm;
  	unsigned long flags;
  
  	spin_lock_irqsave(&fe->card->dpcm_lock, flags);
  	for_each_dpcm_be(fe, stream, dpcm)
  		dpcm_set_be_update_state(dpcm->be, stream, SND_SOC_DPCM_UPDATE_NO);
  	spin_unlock_irqrestore(&fe->card->dpcm_lock, flags);
  }
  
  void dpcm_be_dai_stop(struct snd_soc_pcm_runtime *fe, int stream,
  		      int do_hw_free, struct snd_soc_dpcm *last)
  {
  	struct snd_soc_dpcm *dpcm;
  
  	/* disable any enabled and non active backends */
  	for_each_dpcm_be(fe, stream, dpcm) {
  		struct snd_soc_pcm_runtime *be = dpcm->be;
  		struct snd_pcm_substream *be_substream =
  			snd_soc_dpcm_get_substream(be, stream);
  
  		if (dpcm == last)
  			return;
  
  		/* is this op for this BE ? */
  		if (!snd_soc_dpcm_be_can_update(fe, be, stream))
  			continue;
  
  		if (be->dpcm[stream].users == 0) {
  			dev_err(be->dev, "ASoC: no users %s at close - state %d\n",
  				stream ? "capture" : "playback",
  				be->dpcm[stream].state);
  			continue;
  		}
  
  		if (--be->dpcm[stream].users != 0)
  			continue;
  
  		if (be->dpcm[stream].state != SND_SOC_DPCM_STATE_OPEN) {
  			if (!do_hw_free)
  				continue;
  
  			if (be->dpcm[stream].state != SND_SOC_DPCM_STATE_HW_FREE) {
  				soc_pcm_hw_free(be_substream);
  				be->dpcm[stream].state = SND_SOC_DPCM_STATE_HW_FREE;
  			}
  		}
  
  		soc_pcm_close(be_substream);
  		be_substream->runtime = NULL;
  		be->dpcm[stream].state = SND_SOC_DPCM_STATE_CLOSE;
  	}
  }
  
  int dpcm_be_dai_startup(struct snd_soc_pcm_runtime *fe, int stream)
  {
  	struct snd_soc_pcm_runtime *be;
  	struct snd_soc_dpcm *dpcm;
  	int err, count = 0;
  
  	/* only startup BE DAIs that are either sinks or sources to this FE DAI */
  	for_each_dpcm_be(fe, stream, dpcm) {
  		struct snd_pcm_substream *be_substream;
  
  		be = dpcm->be;
  		be_substream = snd_soc_dpcm_get_substream(be, stream);
  
  		if (!be_substream) {
  			dev_err(be->dev, "ASoC: no backend %s stream\n",
  				stream ? "capture" : "playback");
  			continue;
  		}
  
  		/* is this op for this BE ? */
  		if (!snd_soc_dpcm_be_can_update(fe, be, stream))
  			continue;
  
  		/* first time the dpcm is open ? */
  		if (be->dpcm[stream].users == DPCM_MAX_BE_USERS) {
  			dev_err(be->dev, "ASoC: too many users %s at open %d\n",
  				stream ? "capture" : "playback",
  				be->dpcm[stream].state);
  			continue;
  		}
  
  		if (be->dpcm[stream].users++ != 0)
  			continue;
  
  		if ((be->dpcm[stream].state != SND_SOC_DPCM_STATE_NEW) &&
  		    (be->dpcm[stream].state != SND_SOC_DPCM_STATE_CLOSE))
  			continue;
  
  		dev_dbg(be->dev, "ASoC: open %s BE %s\n",
  			stream ? "capture" : "playback", be->dai_link->name);
  
  		be_substream->runtime = be->dpcm[stream].runtime;
  		err = soc_pcm_open(be_substream);
  		if (err < 0) {
  			be->dpcm[stream].users--;
  			if (be->dpcm[stream].users < 0)
  				dev_err(be->dev, "ASoC: no users %s at unwind %d\n",
  					stream ? "capture" : "playback",
  					be->dpcm[stream].state);
  
  			be->dpcm[stream].state = SND_SOC_DPCM_STATE_CLOSE;
  			goto unwind;
  		}
  
  		be->dpcm[stream].state = SND_SOC_DPCM_STATE_OPEN;
  		count++;
  	}
  
  	return count;
  
  unwind:
  	dpcm_be_dai_startup_rollback(fe, stream, dpcm);
  
  	dev_err(fe->dev, "ASoC: %s() failed at %s (%d)\n",
  		__func__, be->dai_link->name, err);
  
  	return err;
  }
  
  static void dpcm_runtime_setup_fe(struct snd_pcm_substream *substream)
  {
  	struct snd_soc_pcm_runtime *fe = asoc_substream_to_rtd(substream);
  	struct snd_pcm_runtime *runtime = substream->runtime;
  	struct snd_pcm_hardware *hw = &runtime->hw;
  	struct snd_soc_dai *dai;
  	int stream = substream->stream;
  	int i;
  
  	soc_pcm_hw_init(hw);
  
  	for_each_rtd_cpu_dais(fe, i, dai) {
  		struct snd_soc_pcm_stream *cpu_stream;
  
  		/*
  		 * Skip CPUs which don't support the current stream
  		 * type. See soc_pcm_init_runtime_hw() for more details
  		 */
  		if (!snd_soc_dai_stream_valid(dai, stream))
  			continue;
  
  		cpu_stream = snd_soc_dai_get_pcm_stream(dai, stream);
  
  		soc_pcm_hw_update_rate(hw, cpu_stream);
  		soc_pcm_hw_update_chan(hw, cpu_stream);
  		soc_pcm_hw_update_format(hw, cpu_stream);
  	}
  
  }
  
  static void dpcm_runtime_setup_be_format(struct snd_pcm_substream *substream)
  {
  	struct snd_soc_pcm_runtime *fe = asoc_substream_to_rtd(substream);
  	struct snd_pcm_runtime *runtime = substream->runtime;
  	struct snd_pcm_hardware *hw = &runtime->hw;
  	struct snd_soc_dpcm *dpcm;
  	struct snd_soc_dai *dai;
  	int stream = substream->stream;
  
  	if (!fe->dai_link->dpcm_merged_format)
  		return;
  
  	/*
  	 * It returns merged BE codec format
  	 * if FE want to use it (= dpcm_merged_format)
  	 */
  
  	for_each_dpcm_be(fe, stream, dpcm) {
  		struct snd_soc_pcm_runtime *be = dpcm->be;
  		struct snd_soc_pcm_stream *codec_stream;
  		int i;
  
  		for_each_rtd_codec_dais(be, i, dai) {
  			/*
  			 * Skip CODECs which don't support the current stream
  			 * type. See soc_pcm_init_runtime_hw() for more details
  			 */
  			if (!snd_soc_dai_stream_valid(dai, stream))
  				continue;
  
  			codec_stream = snd_soc_dai_get_pcm_stream(dai, stream);
  
  			soc_pcm_hw_update_format(hw, codec_stream);
  		}
  	}
  }
  
  static void dpcm_runtime_setup_be_chan(struct snd_pcm_substream *substream)
  {
  	struct snd_soc_pcm_runtime *fe = asoc_substream_to_rtd(substream);
  	struct snd_pcm_runtime *runtime = substream->runtime;
  	struct snd_pcm_hardware *hw = &runtime->hw;
  	struct snd_soc_dpcm *dpcm;
  	int stream = substream->stream;
  
  	if (!fe->dai_link->dpcm_merged_chan)
  		return;
  
  	/*
  	 * It returns merged BE codec channel;
  	 * if FE want to use it (= dpcm_merged_chan)
  	 */
  
  	for_each_dpcm_be(fe, stream, dpcm) {
  		struct snd_soc_pcm_runtime *be = dpcm->be;
  		struct snd_soc_pcm_stream *codec_stream;
  		struct snd_soc_pcm_stream *cpu_stream;
  		struct snd_soc_dai *dai;
  		int i;
  
  		for_each_rtd_cpu_dais(be, i, dai) {
  			/*
  			 * Skip CPUs which don't support the current stream
  			 * type. See soc_pcm_init_runtime_hw() for more details
  			 */
  			if (!snd_soc_dai_stream_valid(dai, stream))
  				continue;
  
  			cpu_stream = snd_soc_dai_get_pcm_stream(dai, stream);
  
  			soc_pcm_hw_update_chan(hw, cpu_stream);
  		}
  
  		/*
  		 * chan min/max cannot be enforced if there are multiple CODEC
  		 * DAIs connected to a single CPU DAI, use CPU DAI's directly
  		 */
  		if (be->num_codecs == 1) {
  			codec_stream = snd_soc_dai_get_pcm_stream(asoc_rtd_to_codec(be, 0), stream);
  
  			soc_pcm_hw_update_chan(hw, codec_stream);
  		}
  	}
  }
  
  static void dpcm_runtime_setup_be_rate(struct snd_pcm_substream *substream)
  {
  	struct snd_soc_pcm_runtime *fe = asoc_substream_to_rtd(substream);
  	struct snd_pcm_runtime *runtime = substream->runtime;
  	struct snd_pcm_hardware *hw = &runtime->hw;
  	struct snd_soc_dpcm *dpcm;
  	int stream = substream->stream;
  
  	if (!fe->dai_link->dpcm_merged_rate)
  		return;
  
  	/*
  	 * It returns merged BE codec channel;
  	 * if FE want to use it (= dpcm_merged_chan)
  	 */
  
  	for_each_dpcm_be(fe, stream, dpcm) {
  		struct snd_soc_pcm_runtime *be = dpcm->be;
  		struct snd_soc_pcm_stream *pcm;
  		struct snd_soc_dai *dai;
  		int i;
  
  		for_each_rtd_dais(be, i, dai) {
  			/*
  			 * Skip DAIs which don't support the current stream
  			 * type. See soc_pcm_init_runtime_hw() for more details
  			 */
  			if (!snd_soc_dai_stream_valid(dai, stream))
  				continue;
  
  			pcm = snd_soc_dai_get_pcm_stream(dai, stream);
  
  			soc_pcm_hw_update_rate(hw, pcm);
  		}
  	}
  }
  
  static int dpcm_apply_symmetry(struct snd_pcm_substream *fe_substream,
  			       int stream)
  {
  	struct snd_soc_dpcm *dpcm;
  	struct snd_soc_pcm_runtime *fe = asoc_substream_to_rtd(fe_substream);
  	struct snd_soc_dai *fe_cpu_dai;
  	int err = 0;
  	int i;
  
  	/* apply symmetry for FE */
  	soc_pcm_update_symmetry(fe_substream);
  
  	for_each_rtd_cpu_dais (fe, i, fe_cpu_dai) {
  		/* Symmetry only applies if we've got an active stream. */
  		err = soc_pcm_apply_symmetry(fe_substream, fe_cpu_dai);
  		if (err < 0)
  			goto error;
  	}
  
  	/* apply symmetry for BE */
  	for_each_dpcm_be(fe, stream, dpcm) {
  		struct snd_soc_pcm_runtime *be = dpcm->be;
  		struct snd_pcm_substream *be_substream =
  			snd_soc_dpcm_get_substream(be, stream);
  		struct snd_soc_pcm_runtime *rtd;
  		struct snd_soc_dai *dai;
  
  		/* A backend may not have the requested substream */
  		if (!be_substream)
  			continue;
  
  		rtd = asoc_substream_to_rtd(be_substream);
  		if (rtd->dai_link->be_hw_params_fixup)
  			continue;
  
  		soc_pcm_update_symmetry(be_substream);
  
  		/* Symmetry only applies if we've got an active stream. */
  		for_each_rtd_dais(rtd, i, dai) {
  			err = soc_pcm_apply_symmetry(fe_substream, dai);
  			if (err < 0)
  				goto error;
  		}
  	}
  error:
  	if (err < 0)
  		dev_err(fe->dev, "ASoC: %s failed (%d)\n", __func__, err);
  
  	return err;
  }
  
  static int dpcm_fe_dai_startup(struct snd_pcm_substream *fe_substream)
  {
  	struct snd_soc_pcm_runtime *fe = asoc_substream_to_rtd(fe_substream);
  	int stream = fe_substream->stream, ret = 0;
  
  	dpcm_set_fe_update_state(fe, stream, SND_SOC_DPCM_UPDATE_FE);
  
  	ret = dpcm_be_dai_startup(fe, stream);
  	if (ret < 0)
  		goto be_err;
  
  	dev_dbg(fe->dev, "ASoC: open FE %s\n", fe->dai_link->name);
  
  	/* start the DAI frontend */
  	ret = soc_pcm_open(fe_substream);
  	if (ret < 0)
  		goto unwind;
  
  	fe->dpcm[stream].state = SND_SOC_DPCM_STATE_OPEN;
  
  	dpcm_runtime_setup_fe(fe_substream);
  
  	dpcm_runtime_setup_be_format(fe_substream);
  	dpcm_runtime_setup_be_chan(fe_substream);
  	dpcm_runtime_setup_be_rate(fe_substream);
  
  	ret = dpcm_apply_symmetry(fe_substream, stream);
  
  unwind:
  	if (ret < 0)
  		dpcm_be_dai_startup_unwind(fe, stream);
  be_err:
  	dpcm_set_fe_update_state(fe, stream, SND_SOC_DPCM_UPDATE_NO);
  
  	if (ret < 0)
  		dev_err(fe->dev, "%s() failed (%d)\n", __func__, ret);
  
  	return ret;
  }
  
  static int dpcm_fe_dai_shutdown(struct snd_pcm_substream *substream)
  {
  	struct snd_soc_pcm_runtime *fe = asoc_substream_to_rtd(substream);
  	int stream = substream->stream;
  
  	dpcm_set_fe_update_state(fe, stream, SND_SOC_DPCM_UPDATE_FE);
  
  	/* shutdown the BEs */
  	dpcm_be_dai_shutdown(fe, stream);
  
  	dev_dbg(fe->dev, "ASoC: close FE %s\n", fe->dai_link->name);
  
  	/* now shutdown the frontend */
  	soc_pcm_close(substream);
  
  	/* run the stream stop event */
  	dpcm_dapm_stream_event(fe, stream, SND_SOC_DAPM_STREAM_STOP);
  
  	fe->dpcm[stream].state = SND_SOC_DPCM_STATE_CLOSE;
  	dpcm_set_fe_update_state(fe, stream, SND_SOC_DPCM_UPDATE_NO);
  	return 0;
  }
  
  void dpcm_be_dai_hw_free(struct snd_soc_pcm_runtime *fe, int stream)
  {
  	struct snd_soc_dpcm *dpcm;
  
  	/* only hw_params backends that are either sinks or sources
  	 * to this frontend DAI */
  	for_each_dpcm_be(fe, stream, dpcm) {
  
  		struct snd_soc_pcm_runtime *be = dpcm->be;
  		struct snd_pcm_substream *be_substream =
  			snd_soc_dpcm_get_substream(be, stream);
  
  		/* is this op for this BE ? */
  		if (!snd_soc_dpcm_be_can_update(fe, be, stream))
  			continue;
  
  		/* only free hw when no longer used - check all FEs */
  		if (!snd_soc_dpcm_can_be_free_stop(fe, be, stream))
  				continue;
  
  		/* do not free hw if this BE is used by other FE */
  		if (be->dpcm[stream].users > 1)
  			continue;
  
  		if ((be->dpcm[stream].state != SND_SOC_DPCM_STATE_HW_PARAMS) &&
  		    (be->dpcm[stream].state != SND_SOC_DPCM_STATE_PREPARE) &&
  		    (be->dpcm[stream].state != SND_SOC_DPCM_STATE_HW_FREE) &&
  		    (be->dpcm[stream].state != SND_SOC_DPCM_STATE_PAUSED) &&
  		    (be->dpcm[stream].state != SND_SOC_DPCM_STATE_STOP) &&
  		    (be->dpcm[stream].state != SND_SOC_DPCM_STATE_SUSPEND))
  			continue;
  
  		dev_dbg(be->dev, "ASoC: hw_free BE %s\n",
  			be->dai_link->name);
  
  		soc_pcm_hw_free(be_substream);
  
  		be->dpcm[stream].state = SND_SOC_DPCM_STATE_HW_FREE;
  	}
  }
  
  static int dpcm_fe_dai_hw_free(struct snd_pcm_substream *substream)
  {
  	struct snd_soc_pcm_runtime *fe = asoc_substream_to_rtd(substream);
  	int stream = substream->stream;
  
  	mutex_lock_nested(&fe->card->mutex, SND_SOC_CARD_CLASS_RUNTIME);
  	dpcm_set_fe_update_state(fe, stream, SND_SOC_DPCM_UPDATE_FE);
  
  	dev_dbg(fe->dev, "ASoC: hw_free FE %s\n", fe->dai_link->name);
  
  	/* call hw_free on the frontend */
  	soc_pcm_hw_free(substream);
  
  	/* only hw_params backends that are either sinks or sources
  	 * to this frontend DAI */
  	dpcm_be_dai_hw_free(fe, stream);
  
  	fe->dpcm[stream].state = SND_SOC_DPCM_STATE_HW_FREE;
  	dpcm_set_fe_update_state(fe, stream, SND_SOC_DPCM_UPDATE_NO);
  
  	mutex_unlock(&fe->card->mutex);
  	return 0;
  }
  
  int dpcm_be_dai_hw_params(struct snd_soc_pcm_runtime *fe, int stream)
  {
  	struct snd_soc_pcm_runtime *be;
  	struct snd_pcm_substream *be_substream;
  	struct snd_soc_dpcm *dpcm;
  	int ret;
  
  	for_each_dpcm_be(fe, stream, dpcm) {
  		be = dpcm->be;
  		be_substream = snd_soc_dpcm_get_substream(be, stream);
  
  		/* is this op for this BE ? */
  		if (!snd_soc_dpcm_be_can_update(fe, be, stream))
  			continue;
  
  		/* copy params for each dpcm */
  		memcpy(&dpcm->hw_params, &fe->dpcm[stream].hw_params,
  				sizeof(struct snd_pcm_hw_params));
  
  		/* perform any hw_params fixups */
  		ret = snd_soc_link_be_hw_params_fixup(be, &dpcm->hw_params);
  		if (ret < 0)
  			goto unwind;
  
  		/* copy the fixed-up hw params for BE dai */
  		memcpy(&be->dpcm[stream].hw_params, &dpcm->hw_params,
  		       sizeof(struct snd_pcm_hw_params));
  
  		/* only allow hw_params() if no connected FEs are running */
  		if (!snd_soc_dpcm_can_be_params(fe, be, stream))
  			continue;
  
  		if ((be->dpcm[stream].state != SND_SOC_DPCM_STATE_OPEN) &&
  		    (be->dpcm[stream].state != SND_SOC_DPCM_STATE_HW_PARAMS) &&
  		    (be->dpcm[stream].state != SND_SOC_DPCM_STATE_HW_FREE))
  			continue;
  
  		dev_dbg(be->dev, "ASoC: hw_params BE %s\n",
  			be->dai_link->name);
  
  		ret = soc_pcm_hw_params(be_substream, &dpcm->hw_params);
  		if (ret < 0)
  			goto unwind;
  
  		be->dpcm[stream].state = SND_SOC_DPCM_STATE_HW_PARAMS;
  	}
  	return 0;
  
  unwind:
  	dev_dbg(fe->dev, "ASoC: %s() failed at %s (%d)\n",
  		__func__, be->dai_link->name, ret);
  
  	/* disable any enabled and non active backends */
  	for_each_dpcm_be_rollback(fe, stream, dpcm) {
  		be = dpcm->be;
  		be_substream = snd_soc_dpcm_get_substream(be, stream);
  
  		if (!snd_soc_dpcm_be_can_update(fe, be, stream))
  			continue;
  
  		/* only allow hw_free() if no connected FEs are running */
  		if (!snd_soc_dpcm_can_be_free_stop(fe, be, stream))
  			continue;
  
  		if ((be->dpcm[stream].state != SND_SOC_DPCM_STATE_OPEN) &&
  		   (be->dpcm[stream].state != SND_SOC_DPCM_STATE_HW_PARAMS) &&
  		   (be->dpcm[stream].state != SND_SOC_DPCM_STATE_HW_FREE) &&
  		   (be->dpcm[stream].state != SND_SOC_DPCM_STATE_STOP))
  			continue;
  
  		soc_pcm_hw_free(be_substream);
  	}
  
  	return ret;
  }
  
  static int dpcm_fe_dai_hw_params(struct snd_pcm_substream *substream,
  				 struct snd_pcm_hw_params *params)
  {
  	struct snd_soc_pcm_runtime *fe = asoc_substream_to_rtd(substream);
  	int ret, stream = substream->stream;
  
  	mutex_lock_nested(&fe->card->mutex, SND_SOC_CARD_CLASS_RUNTIME);
  	dpcm_set_fe_update_state(fe, stream, SND_SOC_DPCM_UPDATE_FE);
  
  	memcpy(&fe->dpcm[stream].hw_params, params,
  			sizeof(struct snd_pcm_hw_params));
  	ret = dpcm_be_dai_hw_params(fe, stream);
  	if (ret < 0)
  		goto out;
  
  	dev_dbg(fe->dev, "ASoC: hw_params FE %s rate %d chan %x fmt %d\n",
  			fe->dai_link->name, params_rate(params),
  			params_channels(params), params_format(params));
  
  	/* call hw_params on the frontend */
  	ret = soc_pcm_hw_params(substream, params);
  	if (ret < 0)
  		dpcm_be_dai_hw_free(fe, stream);
  	else
  		fe->dpcm[stream].state = SND_SOC_DPCM_STATE_HW_PARAMS;
  
  out:
  	dpcm_set_fe_update_state(fe, stream, SND_SOC_DPCM_UPDATE_NO);
  	mutex_unlock(&fe->card->mutex);
  
  	if (ret < 0)
  		dev_err(fe->dev, "ASoC: %s failed (%d)\n", __func__, ret);
  
  	return ret;
  }
  
  int dpcm_be_dai_trigger(struct snd_soc_pcm_runtime *fe, int stream,
  			       int cmd)
  {
  	struct snd_soc_pcm_runtime *be;
  	struct snd_soc_dpcm *dpcm;
  	int ret = 0;
  
  	for_each_dpcm_be(fe, stream, dpcm) {
  		struct snd_pcm_substream *be_substream;
  
  		be = dpcm->be;
  		be_substream = snd_soc_dpcm_get_substream(be, stream);
  
  		/* is this op for this BE ? */
  		if (!snd_soc_dpcm_be_can_update(fe, be, stream))
  			continue;
  
  		dev_dbg(be->dev, "ASoC: trigger BE %s cmd %d\n",
  			be->dai_link->name, cmd);
  
  		switch (cmd) {
  		case SNDRV_PCM_TRIGGER_START:
  			if ((be->dpcm[stream].state != SND_SOC_DPCM_STATE_PREPARE) &&
  			    (be->dpcm[stream].state != SND_SOC_DPCM_STATE_STOP) &&
  			    (be->dpcm[stream].state != SND_SOC_DPCM_STATE_PAUSED))
  				continue;
  
  			ret = soc_pcm_trigger(be_substream, cmd);
  			if (ret)
  				goto end;
  
  			be->dpcm[stream].state = SND_SOC_DPCM_STATE_START;
  			break;
  		case SNDRV_PCM_TRIGGER_RESUME:
  			if ((be->dpcm[stream].state != SND_SOC_DPCM_STATE_SUSPEND))
  				continue;
  
  			ret = soc_pcm_trigger(be_substream, cmd);
  			if (ret)
  				goto end;
  
  			be->dpcm[stream].state = SND_SOC_DPCM_STATE_START;
  			break;
  		case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
  			if ((be->dpcm[stream].state != SND_SOC_DPCM_STATE_PAUSED))
  				continue;
  
  			ret = soc_pcm_trigger(be_substream, cmd);
  			if (ret)
  				goto end;
  
  			be->dpcm[stream].state = SND_SOC_DPCM_STATE_START;
  			break;
  		case SNDRV_PCM_TRIGGER_STOP:
  			if ((be->dpcm[stream].state != SND_SOC_DPCM_STATE_START) &&
  			    (be->dpcm[stream].state != SND_SOC_DPCM_STATE_PAUSED))
  				continue;
  
  			if (!snd_soc_dpcm_can_be_free_stop(fe, be, stream))
  				continue;
  
  			ret = soc_pcm_trigger(be_substream, cmd);
  			if (ret)
  				goto end;
  
  			be->dpcm[stream].state = SND_SOC_DPCM_STATE_STOP;
  			break;
  		case SNDRV_PCM_TRIGGER_SUSPEND:
  			if (be->dpcm[stream].state != SND_SOC_DPCM_STATE_START)
  				continue;
  
  			if (!snd_soc_dpcm_can_be_free_stop(fe, be, stream))
  				continue;
  
  			ret = soc_pcm_trigger(be_substream, cmd);
  			if (ret)
  				goto end;
  
  			be->dpcm[stream].state = SND_SOC_DPCM_STATE_SUSPEND;
  			break;
  		case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
  			if (be->dpcm[stream].state != SND_SOC_DPCM_STATE_START)
  				continue;
  
  			if (!snd_soc_dpcm_can_be_free_stop(fe, be, stream))
  				continue;
  
  			ret = soc_pcm_trigger(be_substream, cmd);
  			if (ret)
  				goto end;
  
  			be->dpcm[stream].state = SND_SOC_DPCM_STATE_PAUSED;
  			break;
  		}
  	}
  end:
  	if (ret < 0)
  		dev_err(fe->dev, "ASoC: %s() failed at %s (%d)\n",
  			__func__, be->dai_link->name, ret);
  	return ret;
  }
  EXPORT_SYMBOL_GPL(dpcm_be_dai_trigger);
  
  static int dpcm_dai_trigger_fe_be(struct snd_pcm_substream *substream,
  				  int cmd, bool fe_first)
  {
  	struct snd_soc_pcm_runtime *fe = asoc_substream_to_rtd(substream);
  	int ret;
  
  	/* call trigger on the frontend before the backend. */
  	if (fe_first) {
  		dev_dbg(fe->dev, "ASoC: pre trigger FE %s cmd %d\n",
  			fe->dai_link->name, cmd);
  
  		ret = soc_pcm_trigger(substream, cmd);
  		if (ret < 0)
  			return ret;
  
  		ret = dpcm_be_dai_trigger(fe, substream->stream, cmd);
  		return ret;
  	}
  
  	/* call trigger on the frontend after the backend. */
  	ret = dpcm_be_dai_trigger(fe, substream->stream, cmd);
  	if (ret < 0)
  		return ret;
  
  	dev_dbg(fe->dev, "ASoC: post trigger FE %s cmd %d\n",
  		fe->dai_link->name, cmd);
  
  	ret = soc_pcm_trigger(substream, cmd);
  
  	return ret;
  }
  
  static int dpcm_fe_dai_do_trigger(struct snd_pcm_substream *substream, int cmd)
  {
  	struct snd_soc_pcm_runtime *fe = asoc_substream_to_rtd(substream);
  	int stream = substream->stream;
  	int ret = 0;
  	enum snd_soc_dpcm_trigger trigger = fe->dai_link->trigger[stream];
  
  	fe->dpcm[stream].runtime_update = SND_SOC_DPCM_UPDATE_FE;
  
  	switch (trigger) {
  	case SND_SOC_DPCM_TRIGGER_PRE:
  		switch (cmd) {
  		case SNDRV_PCM_TRIGGER_START:
  		case SNDRV_PCM_TRIGGER_RESUME:
  		case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
  		case SNDRV_PCM_TRIGGER_DRAIN:
  			ret = dpcm_dai_trigger_fe_be(substream, cmd, true);
  			break;
  		case SNDRV_PCM_TRIGGER_STOP:
  		case SNDRV_PCM_TRIGGER_SUSPEND:
  		case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
  			ret = dpcm_dai_trigger_fe_be(substream, cmd, false);
  			break;
  		default:
  			ret = -EINVAL;
  			break;
  		}
  		break;
  	case SND_SOC_DPCM_TRIGGER_POST:
  		switch (cmd) {
  		case SNDRV_PCM_TRIGGER_START:
  		case SNDRV_PCM_TRIGGER_RESUME:
  		case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
  		case SNDRV_PCM_TRIGGER_DRAIN:
  			ret = dpcm_dai_trigger_fe_be(substream, cmd, false);
  			break;
  		case SNDRV_PCM_TRIGGER_STOP:
  		case SNDRV_PCM_TRIGGER_SUSPEND:
  		case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
  			ret = dpcm_dai_trigger_fe_be(substream, cmd, true);
  			break;
  		default:
  			ret = -EINVAL;
  			break;
  		}
  		break;
  	case SND_SOC_DPCM_TRIGGER_BESPOKE:
  		/* bespoke trigger() - handles both FE and BEs */
  
  		dev_dbg(fe->dev, "ASoC: bespoke trigger FE %s cmd %d\n",
  				fe->dai_link->name, cmd);
  
  		ret = snd_soc_pcm_dai_bespoke_trigger(substream, cmd);
  		break;
  	default:
  		dev_err(fe->dev, "ASoC: invalid trigger cmd %d for %s\n", cmd,
  				fe->dai_link->name);
  		ret = -EINVAL;
  		goto out;
  	}
  
  	if (ret < 0) {
  		dev_err(fe->dev, "ASoC: trigger FE cmd: %d failed: %d\n",
  			cmd, ret);
  		goto out;
  	}
  
  	switch (cmd) {
  	case SNDRV_PCM_TRIGGER_START:
  	case SNDRV_PCM_TRIGGER_RESUME:
  	case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
  		fe->dpcm[stream].state = SND_SOC_DPCM_STATE_START;
  		break;
  	case SNDRV_PCM_TRIGGER_STOP:
  	case SNDRV_PCM_TRIGGER_SUSPEND:
  		fe->dpcm[stream].state = SND_SOC_DPCM_STATE_STOP;
  		break;
  	case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
  		fe->dpcm[stream].state = SND_SOC_DPCM_STATE_PAUSED;
  		break;
  	}
  
  out:
  	fe->dpcm[stream].runtime_update = SND_SOC_DPCM_UPDATE_NO;
  	return ret;
  }
  
  static int dpcm_fe_dai_trigger(struct snd_pcm_substream *substream, int cmd)
  {
  	struct snd_soc_pcm_runtime *fe = asoc_substream_to_rtd(substream);
  	int stream = substream->stream;
  
  	/* if FE's runtime_update is already set, we're in race;
  	 * process this trigger later at exit
  	 */
  	if (fe->dpcm[stream].runtime_update != SND_SOC_DPCM_UPDATE_NO) {
  		fe->dpcm[stream].trigger_pending = cmd + 1;
  		return 0; /* delayed, assuming it's successful */
  	}
  
  	/* we're alone, let's trigger */
  	return dpcm_fe_dai_do_trigger(substream, cmd);
  }
  
  int dpcm_be_dai_prepare(struct snd_soc_pcm_runtime *fe, int stream)
  {
  	struct snd_soc_dpcm *dpcm;
  	int ret = 0;
  
  	for_each_dpcm_be(fe, stream, dpcm) {
  
  		struct snd_soc_pcm_runtime *be = dpcm->be;
  		struct snd_pcm_substream *be_substream =
  			snd_soc_dpcm_get_substream(be, stream);
  
  		/* is this op for this BE ? */
  		if (!snd_soc_dpcm_be_can_update(fe, be, stream))
  			continue;
  
  		if ((be->dpcm[stream].state != SND_SOC_DPCM_STATE_HW_PARAMS) &&
  		    (be->dpcm[stream].state != SND_SOC_DPCM_STATE_STOP) &&
  		    (be->dpcm[stream].state != SND_SOC_DPCM_STATE_SUSPEND) &&
  		    (be->dpcm[stream].state != SND_SOC_DPCM_STATE_PAUSED))
  			continue;
  
  		dev_dbg(be->dev, "ASoC: prepare BE %s\n",
  			be->dai_link->name);
  
  		ret = soc_pcm_prepare(be_substream);
  		if (ret < 0)
  			break;
  
  		be->dpcm[stream].state = SND_SOC_DPCM_STATE_PREPARE;
  	}
  
  	if (ret < 0)
  		dev_err(fe->dev, "ASoC: %s() failed (%d)\n", __func__, ret);
  
  	return ret;
  }
  
  static int dpcm_fe_dai_prepare(struct snd_pcm_substream *substream)
  {
  	struct snd_soc_pcm_runtime *fe = asoc_substream_to_rtd(substream);
  	int stream = substream->stream, ret = 0;
  
  	mutex_lock_nested(&fe->card->mutex, SND_SOC_CARD_CLASS_RUNTIME);
  
  	dev_dbg(fe->dev, "ASoC: prepare FE %s\n", fe->dai_link->name);
  
  	dpcm_set_fe_update_state(fe, stream, SND_SOC_DPCM_UPDATE_FE);
  
  	/* there is no point preparing this FE if there are no BEs */
  	if (list_empty(&fe->dpcm[stream].be_clients)) {
  		dev_err(fe->dev, "ASoC: no backend DAIs enabled for %s\n",
  				fe->dai_link->name);
  		ret = -EINVAL;
  		goto out;
  	}
  
  	ret = dpcm_be_dai_prepare(fe, stream);
  	if (ret < 0)
  		goto out;
  
  	/* call prepare on the frontend */
  	ret = soc_pcm_prepare(substream);
  	if (ret < 0)
  		goto out;
  
  	fe->dpcm[stream].state = SND_SOC_DPCM_STATE_PREPARE;
  
  out:
  	dpcm_set_fe_update_state(fe, stream, SND_SOC_DPCM_UPDATE_NO);
  	mutex_unlock(&fe->card->mutex);
  
  	if (ret < 0)
  		dev_err(fe->dev, "ASoC: %s() failed (%d)\n", __func__, ret);
  
  	return ret;
  }
  
  static int dpcm_run_update_shutdown(struct snd_soc_pcm_runtime *fe, int stream)
  {
  	struct snd_pcm_substream *substream =
  		snd_soc_dpcm_get_substream(fe, stream);
  	enum snd_soc_dpcm_trigger trigger = fe->dai_link->trigger[stream];
  	int err;
  
  	dev_dbg(fe->dev, "ASoC: runtime %s close on FE %s\n",
  			stream ? "capture" : "playback", fe->dai_link->name);
  
  	if (trigger == SND_SOC_DPCM_TRIGGER_BESPOKE) {
  		/* call bespoke trigger - FE takes care of all BE triggers */
  		dev_dbg(fe->dev, "ASoC: bespoke trigger FE %s cmd stop\n",
  				fe->dai_link->name);
  
  		err = snd_soc_pcm_dai_bespoke_trigger(substream, SNDRV_PCM_TRIGGER_STOP);
  	} else {
  		dev_dbg(fe->dev, "ASoC: trigger FE %s cmd stop\n",
  			fe->dai_link->name);
  
  		err = dpcm_be_dai_trigger(fe, stream, SNDRV_PCM_TRIGGER_STOP);
  	}
  
  	dpcm_be_dai_hw_free(fe, stream);
  
  	dpcm_be_dai_shutdown(fe, stream);
  
  	/* run the stream event for each BE */
  	dpcm_dapm_stream_event(fe, stream, SND_SOC_DAPM_STREAM_NOP);
  
  	if (err < 0)
  		dev_err(fe->dev, "ASoC: %s() failed (%d)\n", __func__, err);
  
  	return err;
  }
  
  static int dpcm_run_update_startup(struct snd_soc_pcm_runtime *fe, int stream)
  {
  	struct snd_pcm_substream *substream =
  		snd_soc_dpcm_get_substream(fe, stream);
  	struct snd_soc_dpcm *dpcm;
  	enum snd_soc_dpcm_trigger trigger = fe->dai_link->trigger[stream];
  	int ret = 0;
  	unsigned long flags;
  
  	dev_dbg(fe->dev, "ASoC: runtime %s open on FE %s\n",
  			stream ? "capture" : "playback", fe->dai_link->name);
  
  	/* Only start the BE if the FE is ready */
  	if (fe->dpcm[stream].state == SND_SOC_DPCM_STATE_HW_FREE ||
  		fe->dpcm[stream].state == SND_SOC_DPCM_STATE_CLOSE) {
  		dev_err(fe->dev, "ASoC: FE %s is not ready %d\n",
  			fe->dai_link->name, fe->dpcm[stream].state);
  		ret = -EINVAL;
  		goto disconnect;
  	}
  
  	/* startup must always be called for new BEs */
  	ret = dpcm_be_dai_startup(fe, stream);
  	if (ret < 0)
  		goto disconnect;
  
  	/* keep going if FE state is > open */
  	if (fe->dpcm[stream].state == SND_SOC_DPCM_STATE_OPEN)
  		return 0;
  
  	ret = dpcm_be_dai_hw_params(fe, stream);
  	if (ret < 0)
  		goto close;
  
  	/* keep going if FE state is > hw_params */
  	if (fe->dpcm[stream].state == SND_SOC_DPCM_STATE_HW_PARAMS)
  		return 0;
  
  	ret = dpcm_be_dai_prepare(fe, stream);
  	if (ret < 0)
  		goto hw_free;
  
  	/* run the stream event for each BE */
  	dpcm_dapm_stream_event(fe, stream, SND_SOC_DAPM_STREAM_NOP);
  
  	/* keep going if FE state is > prepare */
  	if (fe->dpcm[stream].state == SND_SOC_DPCM_STATE_PREPARE ||
  		fe->dpcm[stream].state == SND_SOC_DPCM_STATE_STOP)
  		return 0;
  
  	if (trigger == SND_SOC_DPCM_TRIGGER_BESPOKE) {
  		/* call trigger on the frontend - FE takes care of all BE triggers */
  		dev_dbg(fe->dev, "ASoC: bespoke trigger FE %s cmd start\n",
  				fe->dai_link->name);
  
  		ret = snd_soc_pcm_dai_bespoke_trigger(substream, SNDRV_PCM_TRIGGER_START);
  		if (ret < 0)
  			goto hw_free;
  	} else {
  		dev_dbg(fe->dev, "ASoC: trigger FE %s cmd start\n",
  			fe->dai_link->name);
  
  		ret = dpcm_be_dai_trigger(fe, stream,
  					SNDRV_PCM_TRIGGER_START);
  		if (ret < 0)
  			goto hw_free;
  	}
  
  	return 0;
  
  hw_free:
  	dpcm_be_dai_hw_free(fe, stream);
  close:
  	dpcm_be_dai_shutdown(fe, stream);
  disconnect:
  	/* disconnect any pending BEs */
  	spin_lock_irqsave(&fe->card->dpcm_lock, flags);
  	for_each_dpcm_be(fe, stream, dpcm) {
  		struct snd_soc_pcm_runtime *be = dpcm->be;
  
  		/* is this op for this BE ? */
  		if (!snd_soc_dpcm_be_can_update(fe, be, stream))
  			continue;
  
  		if (be->dpcm[stream].state == SND_SOC_DPCM_STATE_CLOSE ||
  			be->dpcm[stream].state == SND_SOC_DPCM_STATE_NEW)
  				dpcm->state = SND_SOC_DPCM_LINK_STATE_FREE;
  	}
  	spin_unlock_irqrestore(&fe->card->dpcm_lock, flags);
  
  	if (ret < 0)
  		dev_err(fe->dev, "ASoC: %s() failed (%d)\n", __func__, ret);
  
  	return ret;
  }
  
  static int soc_dpcm_fe_runtime_update(struct snd_soc_pcm_runtime *fe, int new)
  {
  	struct snd_soc_dapm_widget_list *list;
  	int stream;
  	int count, paths;
  
  	if (!fe->dai_link->dynamic)
  		return 0;
  
  	if (fe->num_cpus > 1) {
  		dev_err(fe->dev,
  			"%s doesn't support Multi CPU yet\n", __func__);
  		return -EINVAL;
  	}
  
  	/* only check active links */
  	if (!snd_soc_dai_active(asoc_rtd_to_cpu(fe, 0)))
  		return 0;
  
  	/* DAPM sync will call this to update DSP paths */
  	dev_dbg(fe->dev, "ASoC: DPCM %s runtime update for FE %s\n",
  		new ? "new" : "old", fe->dai_link->name);
  
  	for_each_pcm_streams(stream) {
  
  		/* skip if FE doesn't have playback/capture capability */
  		if (!snd_soc_dai_stream_valid(asoc_rtd_to_cpu(fe, 0),   stream) ||
  		    !snd_soc_dai_stream_valid(asoc_rtd_to_codec(fe, 0), stream))
  			continue;
  
  		/* skip if FE isn't currently playing/capturing */
  		if (!snd_soc_dai_stream_active(asoc_rtd_to_cpu(fe, 0), stream) ||
  		    !snd_soc_dai_stream_active(asoc_rtd_to_codec(fe, 0), stream))
  			continue;
  
  		paths = dpcm_path_get(fe, stream, &list);
  		if (paths < 0)
  			return paths;
  
  		/* update any playback/capture paths */
  		count = dpcm_process_paths(fe, stream, &list, new);
  		if (count) {
  			dpcm_set_fe_update_state(fe, stream, SND_SOC_DPCM_UPDATE_BE);
  			if (new)
  				dpcm_run_update_startup(fe, stream);
  			else
  				dpcm_run_update_shutdown(fe, stream);
  			dpcm_set_fe_update_state(fe, stream, SND_SOC_DPCM_UPDATE_NO);
  
  			dpcm_clear_pending_state(fe, stream);
  			dpcm_be_disconnect(fe, stream);
  		}
  
  		dpcm_path_put(&list);
  	}
  
  	return 0;
  }
  
  /* Called by DAPM mixer/mux changes to update audio routing between PCMs and
   * any DAI links.
   */
  int snd_soc_dpcm_runtime_update(struct snd_soc_card *card)
  {
  	struct snd_soc_pcm_runtime *fe;
  	int ret = 0;
  
  	mutex_lock_nested(&card->mutex, SND_SOC_CARD_CLASS_RUNTIME);
  	/* shutdown all old paths first */
  	for_each_card_rtds(card, fe) {
  		ret = soc_dpcm_fe_runtime_update(fe, 0);
  		if (ret)
  			goto out;
  	}
  
  	/* bring new paths up */
  	for_each_card_rtds(card, fe) {
  		ret = soc_dpcm_fe_runtime_update(fe, 1);
  		if (ret)
  			goto out;
  	}
  
  out:
  	mutex_unlock(&card->mutex);
  	return ret;
  }
  EXPORT_SYMBOL_GPL(snd_soc_dpcm_runtime_update);
  
  static void dpcm_fe_dai_cleanup(struct snd_pcm_substream *fe_substream)
  {
  	struct snd_soc_pcm_runtime *fe = asoc_substream_to_rtd(fe_substream);
  	struct snd_soc_dpcm *dpcm;
  	int stream = fe_substream->stream;
  
  	/* mark FE's links ready to prune */
  	for_each_dpcm_be(fe, stream, dpcm)
  		dpcm->state = SND_SOC_DPCM_LINK_STATE_FREE;
  
  	dpcm_be_disconnect(fe, stream);
  
  	fe->dpcm[stream].runtime = NULL;
  }
  
  static int dpcm_fe_dai_close(struct snd_pcm_substream *fe_substream)
  {
  	struct snd_soc_pcm_runtime *fe = asoc_substream_to_rtd(fe_substream);
  	int ret;
  
  	mutex_lock_nested(&fe->card->mutex, SND_SOC_CARD_CLASS_RUNTIME);
  	ret = dpcm_fe_dai_shutdown(fe_substream);
  
  	dpcm_fe_dai_cleanup(fe_substream);
  
  	mutex_unlock(&fe->card->mutex);
  	return ret;
  }
  
  static int dpcm_fe_dai_open(struct snd_pcm_substream *fe_substream)
  {
  	struct snd_soc_pcm_runtime *fe = asoc_substream_to_rtd(fe_substream);
  	struct snd_soc_dapm_widget_list *list;
  	int ret;
  	int stream = fe_substream->stream;
  
  	mutex_lock_nested(&fe->card->mutex, SND_SOC_CARD_CLASS_RUNTIME);
  	fe->dpcm[stream].runtime = fe_substream->runtime;
  
  	ret = dpcm_path_get(fe, stream, &list);
  	if (ret < 0)
  		goto open_end;
  
  	/* calculate valid and active FE <-> BE dpcms */
  	dpcm_process_paths(fe, stream, &list, 1);
  
  	ret = dpcm_fe_dai_startup(fe_substream);
  	if (ret < 0)
  		dpcm_fe_dai_cleanup(fe_substream);
  
  	dpcm_clear_pending_state(fe, stream);
  	dpcm_path_put(&list);
  open_end:
  	mutex_unlock(&fe->card->mutex);
  	return ret;
  }
  
  static int soc_get_playback_capture(struct snd_soc_pcm_runtime *rtd,
  				    int *playback, int *capture)
  {
  	struct snd_soc_dai *codec_dai;
  	struct snd_soc_dai *cpu_dai;
  	int stream;
  	int i;
  
  	if (rtd->dai_link->dynamic && rtd->num_cpus > 1) {
  		dev_err(rtd->dev,
  			"DPCM doesn't support Multi CPU for Front-Ends yet\n");
  		return -EINVAL;
  	}
  
  	if (rtd->dai_link->dynamic || rtd->dai_link->no_pcm) {
  		if (rtd->dai_link->dpcm_playback) {
  			stream = SNDRV_PCM_STREAM_PLAYBACK;
  
  			for_each_rtd_cpu_dais(rtd, i, cpu_dai) {
  				if (snd_soc_dai_stream_valid(cpu_dai, stream)) {
  					*playback = 1;
  					break;
  				}
  			}
  			if (!*playback) {
  				dev_err(rtd->card->dev,
  					"No CPU DAIs support playback for stream %s\n",
  					rtd->dai_link->stream_name);
  				return -EINVAL;
  			}
  		}
  		if (rtd->dai_link->dpcm_capture) {
  			stream = SNDRV_PCM_STREAM_CAPTURE;
  
  			for_each_rtd_cpu_dais(rtd, i, cpu_dai) {
  				if (snd_soc_dai_stream_valid(cpu_dai, stream)) {
  					*capture = 1;
  					break;
  				}
  			}
  
  			if (!*capture) {
  				dev_err(rtd->card->dev,
  					"No CPU DAIs support capture for stream %s\n",
  					rtd->dai_link->stream_name);
  				return -EINVAL;
  			}
  		}
  	} else {
  		/* Adapt stream for codec2codec links */
  		int cpu_capture = rtd->dai_link->params ?
  			SNDRV_PCM_STREAM_PLAYBACK : SNDRV_PCM_STREAM_CAPTURE;
  		int cpu_playback = rtd->dai_link->params ?
  			SNDRV_PCM_STREAM_CAPTURE : SNDRV_PCM_STREAM_PLAYBACK;
  
  		for_each_rtd_codec_dais(rtd, i, codec_dai) {
  			if (rtd->num_cpus == 1) {
  				cpu_dai = asoc_rtd_to_cpu(rtd, 0);
  			} else if (rtd->num_cpus == rtd->num_codecs) {
  				cpu_dai = asoc_rtd_to_cpu(rtd, i);
  			} else {
  				dev_err(rtd->card->dev,
  					"N cpus to M codecs link is not supported yet\n");
  				return -EINVAL;
  			}
  
  			if (snd_soc_dai_stream_valid(codec_dai, SNDRV_PCM_STREAM_PLAYBACK) &&
  			    snd_soc_dai_stream_valid(cpu_dai,   cpu_playback))
  				*playback = 1;
  			if (snd_soc_dai_stream_valid(codec_dai, SNDRV_PCM_STREAM_CAPTURE) &&
  			    snd_soc_dai_stream_valid(cpu_dai,   cpu_capture))
  				*capture = 1;
  		}
  	}
  
  	if (rtd->dai_link->playback_only) {
  		*playback = 1;
  		*capture = 0;
  	}
  
  	if (rtd->dai_link->capture_only) {
  		*playback = 0;
  		*capture = 1;
  	}
  
  	return 0;
  }
  
  static int soc_create_pcm(struct snd_pcm **pcm,
  			  struct snd_soc_pcm_runtime *rtd,
  			  int playback, int capture, int num)
  {
  	char new_name[64];
  	int ret;
  
  	/* create the PCM */
  	if (rtd->dai_link->params) {
  		snprintf(new_name, sizeof(new_name), "codec2codec(%s)",
  			 rtd->dai_link->stream_name);
  
  		ret = snd_pcm_new_internal(rtd->card->snd_card, new_name, num,
  					   playback, capture, pcm);
  	} else if (rtd->dai_link->no_pcm) {
  		snprintf(new_name, sizeof(new_name), "(%s)",
  			rtd->dai_link->stream_name);
  
  		ret = snd_pcm_new_internal(rtd->card->snd_card, new_name, num,
  				playback, capture, pcm);
  	} else {
  		if (rtd->dai_link->dynamic)
  			snprintf(new_name, sizeof(new_name), "%s (*)",
  				rtd->dai_link->stream_name);
  		else
  			snprintf(new_name, sizeof(new_name), "%s %s-%d",
  				rtd->dai_link->stream_name,
  				soc_codec_dai_name(rtd), num);
  
  		ret = snd_pcm_new(rtd->card->snd_card, new_name, num, playback,
  			capture, pcm);
  	}
  	if (ret < 0) {
  		dev_err(rtd->card->dev, "ASoC: can't create pcm %s for dailink %s: %d\n",
  			new_name, rtd->dai_link->name, ret);
  		return ret;
  	}
  	dev_dbg(rtd->card->dev, "ASoC: registered pcm #%d %s\n",num, new_name);
  
  	return 0;
  }
  
  /* create a new pcm */
  int soc_new_pcm(struct snd_soc_pcm_runtime *rtd, int num)
  {
  	struct snd_soc_component *component;
  	struct snd_pcm *pcm;
  	int ret = 0, playback = 0, capture = 0;
  	int i;
  
  	ret = soc_get_playback_capture(rtd, &playback, &capture);
  	if (ret < 0)
  		return ret;
  
  	ret = soc_create_pcm(&pcm, rtd, playback, capture, num);
  	if (ret < 0)
  		return ret;
  
  	/* DAPM dai link stream work */
  	if (rtd->dai_link->params)
  		rtd->close_delayed_work_func = codec2codec_close_delayed_work;
  	else
  		rtd->close_delayed_work_func = snd_soc_close_delayed_work;
  
  	rtd->pcm = pcm;
  	pcm->nonatomic = rtd->dai_link->nonatomic;
  	pcm->private_data = rtd;
  
  	if (rtd->dai_link->no_pcm || rtd->dai_link->params) {
  		if (playback)
  			pcm->streams[SNDRV_PCM_STREAM_PLAYBACK].substream->private_data = rtd;
  		if (capture)
  			pcm->streams[SNDRV_PCM_STREAM_CAPTURE].substream->private_data = rtd;
  		goto out;
  	}
  
  	/* ASoC PCM operations */
  	if (rtd->dai_link->dynamic) {
  		rtd->ops.open		= dpcm_fe_dai_open;
  		rtd->ops.hw_params	= dpcm_fe_dai_hw_params;
  		rtd->ops.prepare	= dpcm_fe_dai_prepare;
  		rtd->ops.trigger	= dpcm_fe_dai_trigger;
  		rtd->ops.hw_free	= dpcm_fe_dai_hw_free;
  		rtd->ops.close		= dpcm_fe_dai_close;
  		rtd->ops.pointer	= soc_pcm_pointer;
  	} else {
  		rtd->ops.open		= soc_pcm_open;
  		rtd->ops.hw_params	= soc_pcm_hw_params;
  		rtd->ops.prepare	= soc_pcm_prepare;
  		rtd->ops.trigger	= soc_pcm_trigger;
  		rtd->ops.hw_free	= soc_pcm_hw_free;
  		rtd->ops.close		= soc_pcm_close;
  		rtd->ops.pointer	= soc_pcm_pointer;
  	}
  
  	for_each_rtd_components(rtd, i, component) {
  		const struct snd_soc_component_driver *drv = component->driver;
  
  		if (drv->ioctl)
  			rtd->ops.ioctl		= snd_soc_pcm_component_ioctl;
  		if (drv->sync_stop)
  			rtd->ops.sync_stop	= snd_soc_pcm_component_sync_stop;
  		if (drv->copy_user)
  			rtd->ops.copy_user	= snd_soc_pcm_component_copy_user;
  		if (drv->page)
  			rtd->ops.page		= snd_soc_pcm_component_page;
  		if (drv->mmap)
  			rtd->ops.mmap		= snd_soc_pcm_component_mmap;
  		if (drv->ack)
  			rtd->ops.ack            = snd_soc_pcm_component_ack;
  	}
  
  	if (playback)
  		snd_pcm_set_ops(pcm, SNDRV_PCM_STREAM_PLAYBACK, &rtd->ops);
  
  	if (capture)
  		snd_pcm_set_ops(pcm, SNDRV_PCM_STREAM_CAPTURE, &rtd->ops);
  
  	ret = snd_soc_pcm_component_new(rtd);
  	if (ret < 0)
  		return ret;
  
  	pcm->no_device_suspend = true;
  out:
  	dev_dbg(rtd->card->dev, "%s <-> %s mapping ok\n",
  		soc_codec_dai_name(rtd), soc_cpu_dai_name(rtd));
  	return ret;
  }
  
  /* is the current PCM operation for this FE ? */
  int snd_soc_dpcm_fe_can_update(struct snd_soc_pcm_runtime *fe, int stream)
  {
  	if (fe->dpcm[stream].runtime_update == SND_SOC_DPCM_UPDATE_FE)
  		return 1;
  	return 0;
  }
  EXPORT_SYMBOL_GPL(snd_soc_dpcm_fe_can_update);
  
  /* is the current PCM operation for this BE ? */
  int snd_soc_dpcm_be_can_update(struct snd_soc_pcm_runtime *fe,
  		struct snd_soc_pcm_runtime *be, int stream)
  {
  	if ((fe->dpcm[stream].runtime_update == SND_SOC_DPCM_UPDATE_FE) ||
  	   ((fe->dpcm[stream].runtime_update == SND_SOC_DPCM_UPDATE_BE) &&
  		  be->dpcm[stream].runtime_update))
  		return 1;
  	return 0;
  }
  EXPORT_SYMBOL_GPL(snd_soc_dpcm_be_can_update);
  
  /* get the substream for this BE */
  struct snd_pcm_substream *
  	snd_soc_dpcm_get_substream(struct snd_soc_pcm_runtime *be, int stream)
  {
  	return be->pcm->streams[stream].substream;
  }
  EXPORT_SYMBOL_GPL(snd_soc_dpcm_get_substream);
  
  static int snd_soc_dpcm_check_state(struct snd_soc_pcm_runtime *fe,
  				    struct snd_soc_pcm_runtime *be,
  				    int stream,
  				    const enum snd_soc_dpcm_state *states,
  				    int num_states)
  {
  	struct snd_soc_dpcm *dpcm;
  	int state;
  	int ret = 1;
  	unsigned long flags;
  	int i;
  
  	spin_lock_irqsave(&fe->card->dpcm_lock, flags);
  	for_each_dpcm_fe(be, stream, dpcm) {
  
  		if (dpcm->fe == fe)
  			continue;
  
  		state = dpcm->fe->dpcm[stream].state;
  		for (i = 0; i < num_states; i++) {
  			if (state == states[i]) {
  				ret = 0;
  				break;
  			}
  		}
  	}
  	spin_unlock_irqrestore(&fe->card->dpcm_lock, flags);
  
  	/* it's safe to do this BE DAI */
  	return ret;
  }
  
  /*
   * We can only hw_free, stop, pause or suspend a BE DAI if any of it's FE
   * are not running, paused or suspended for the specified stream direction.
   */
  int snd_soc_dpcm_can_be_free_stop(struct snd_soc_pcm_runtime *fe,
  		struct snd_soc_pcm_runtime *be, int stream)
  {
  	const enum snd_soc_dpcm_state state[] = {
  		SND_SOC_DPCM_STATE_START,
  		SND_SOC_DPCM_STATE_PAUSED,
  		SND_SOC_DPCM_STATE_SUSPEND,
  	};
  
  	return snd_soc_dpcm_check_state(fe, be, stream, state, ARRAY_SIZE(state));
  }
  EXPORT_SYMBOL_GPL(snd_soc_dpcm_can_be_free_stop);
  
  /*
   * We can only change hw params a BE DAI if any of it's FE are not prepared,
   * running, paused or suspended for the specified stream direction.
   */
  int snd_soc_dpcm_can_be_params(struct snd_soc_pcm_runtime *fe,
  		struct snd_soc_pcm_runtime *be, int stream)
  {
  	const enum snd_soc_dpcm_state state[] = {
  		SND_SOC_DPCM_STATE_START,
  		SND_SOC_DPCM_STATE_PAUSED,
  		SND_SOC_DPCM_STATE_SUSPEND,
  		SND_SOC_DPCM_STATE_PREPARE,
  	};
  
  	return snd_soc_dpcm_check_state(fe, be, stream, state, ARRAY_SIZE(state));
  }
  EXPORT_SYMBOL_GPL(snd_soc_dpcm_can_be_params);
  