text: /*
   * 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>       
   *
   *  This program is free software; you can redistribute  it and/or modify it
   *  under  the terms of  the GNU General  Public License as published by the
   *  Free Software Foundation;  either version 2 of the  License, or (at your
   *  option) any later version.
   *
   */
  
  #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/initval.h>
  
  #define DPCM_MAX_BE_USERS	8
  
  /**
   * 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)
  {
  	struct snd_pcm_runtime *runtime = substream->runtime;
  	runtime->hw.info = hw->info;
  	runtime->hw.formats = hw->formats;
  	runtime->hw.period_bytes_min = hw->period_bytes_min;
  	runtime->hw.period_bytes_max = hw->period_bytes_max;
  	runtime->hw.periods_min = hw->periods_min;
  	runtime->hw.periods_max = hw->periods_max;
  	runtime->hw.buffer_bytes_max = hw->buffer_bytes_max;
  	runtime->hw.fifo_size = hw->fifo_size;
  	return 0;
  }
  EXPORT_SYMBOL_GPL(snd_soc_set_runtime_hwparams);
  
  /* DPCM stream event, send event to FE and all active BEs. */
  static int dpcm_dapm_stream_event(struct snd_soc_pcm_runtime *fe, int dir,
  	int event)
  {
  	struct snd_soc_dpcm *dpcm;
  
  	list_for_each_entry(dpcm, &fe->dpcm[dir].be_clients, list_be) {
  
  		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);
  
  		snd_soc_dapm_stream_event(be, dir, event);
  	}
  
  	snd_soc_dapm_stream_event(fe, dir, event);
  
  	return 0;
  }
  
  static int soc_pcm_apply_symmetry(struct snd_pcm_substream *substream,
  					struct snd_soc_dai *soc_dai)
  {
  	struct snd_soc_pcm_runtime *rtd = substream->private_data;
  	int ret;
  
  	if (!soc_dai->driver->symmetric_rates &&
  	    !rtd->dai_link->symmetric_rates)
  		return 0;
  
  	/* This can happen if multiple streams are starting simultaneously -
  	 * the second can need to get its constraints before the first has
  	 * picked a rate.  Complain and allow the application to carry on.
  	 */
  	if (!soc_dai->rate) {
  		dev_warn(soc_dai->dev,
  			 "ASoC: Not enforcing symmetric_rates due to race\n");
  		return 0;
  	}
  
  	dev_dbg(soc_dai->dev, "ASoC: Symmetry forces %dHz rate\n", soc_dai->rate);
  
  	ret = snd_pcm_hw_constraint_minmax(substream->runtime,
  					   SNDRV_PCM_HW_PARAM_RATE,
  					   soc_dai->rate, soc_dai->rate);
  	if (ret < 0) {
  		dev_err(soc_dai->dev,
  			"ASoC: Unable to apply rate symmetry constraint: %d\n",
  			ret);
  		return ret;
  	}
  
  	return 0;
  }
  
  /*
   * List of sample sizes that might go over the bus for parameter
   * application.  There ought to be a wildcard sample size for things
   * like the DAC/ADC resolution to use but there isn't right now.
   */
  static int sample_sizes[] = {
  	24, 32,
  };
  
  static void soc_pcm_apply_msb(struct snd_pcm_substream *substream,
  			      struct snd_soc_dai *dai)
  {
  	int ret, i, bits;
  
  	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
  		bits = dai->driver->playback.sig_bits;
  	else
  		bits = dai->driver->capture.sig_bits;
  
  	if (!bits)
  		return;
  
  	for (i = 0; i < ARRAY_SIZE(sample_sizes); i++) {
  		if (bits >= sample_sizes[i])
  			continue;
  
  		ret = snd_pcm_hw_constraint_msbits(substream->runtime, 0,
  						   sample_sizes[i], bits);
  		if (ret != 0)
  			dev_warn(dai->dev,
  				 "ASoC: Failed to set MSB %d/%d: %d\n",
  				 bits, sample_sizes[i], ret);
  	}
  }
  
  static void soc_pcm_init_runtime_hw(struct snd_pcm_runtime *runtime,
  	struct snd_soc_pcm_stream *codec_stream,
  	struct snd_soc_pcm_stream *cpu_stream)
  {
  	struct snd_pcm_hardware *hw = &runtime->hw;
  
  	hw->channels_min = max(codec_stream->channels_min,
  		cpu_stream->channels_min);
  	hw->channels_max = min(codec_stream->channels_max,
  		cpu_stream->channels_max);
  	hw->formats = codec_stream->formats & cpu_stream->formats;
  	hw->rates = codec_stream->rates & cpu_stream->rates;
  	if (codec_stream->rates
  		& (SNDRV_PCM_RATE_KNOT | SNDRV_PCM_RATE_CONTINUOUS))
  		hw->rates |= cpu_stream->rates;
  	if (cpu_stream->rates
  		& (SNDRV_PCM_RATE_KNOT | SNDRV_PCM_RATE_CONTINUOUS))
  		hw->rates |= codec_stream->rates;
  
  	snd_pcm_limit_hw_rates(runtime);
  
  	hw->rate_min = max(hw->rate_min, cpu_stream->rate_min);
  	hw->rate_min = max(hw->rate_min, codec_stream->rate_min);
  	hw->rate_max = min_not_zero(hw->rate_max, cpu_stream->rate_max);
  	hw->rate_max = min_not_zero(hw->rate_max, codec_stream->rate_max);
  }
  
  /*
   * 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, platform, machine and codec DAI.
   */
  static int soc_pcm_open(struct snd_pcm_substream *substream)
  {
  	struct snd_soc_pcm_runtime *rtd = substream->private_data;
  	struct snd_pcm_runtime *runtime = substream->runtime;
  	struct snd_soc_platform *platform = rtd->platform;
  	struct snd_soc_dai *cpu_dai = rtd->cpu_dai;
  	struct snd_soc_dai *codec_dai = rtd->codec_dai;
  	struct snd_soc_dai_driver *cpu_dai_drv = cpu_dai->driver;
  	struct snd_soc_dai_driver *codec_dai_drv = codec_dai->driver;
  	int ret = 0;
  
  	pinctrl_pm_select_default_state(cpu_dai->dev);
  	pinctrl_pm_select_default_state(codec_dai->dev);
  	pm_runtime_get_sync(cpu_dai->dev);
  	pm_runtime_get_sync(codec_dai->dev);
  	pm_runtime_get_sync(platform->dev);
  
  	mutex_lock_nested(&rtd->pcm_mutex, rtd->pcm_subclass);
  
  	/* startup the audio subsystem */
  	if (cpu_dai->driver->ops && cpu_dai->driver->ops->startup) {
  		ret = cpu_dai->driver->ops->startup(substream, cpu_dai);
  		if (ret < 0) {
  			dev_err(cpu_dai->dev, "ASoC: can't open interface"
  				" %s: %d\n", cpu_dai->name, ret);
  			goto out;
  		}
  	}
  
  	if (platform->driver->ops && platform->driver->ops->open) {
  		ret = platform->driver->ops->open(substream);
  		if (ret < 0) {
  			dev_err(platform->dev, "ASoC: can't open platform"
  				" %s: %d\n", platform->name, ret);
  			goto platform_err;
  		}
  	}
  
  	if (codec_dai->driver->ops && codec_dai->driver->ops->startup) {
  		ret = codec_dai->driver->ops->startup(substream, codec_dai);
  		if (ret < 0) {
  			dev_err(codec_dai->dev, "ASoC: can't open codec"
  				" %s: %d\n", codec_dai->name, ret);
  			goto codec_dai_err;
  		}
  	}
  
  	if (rtd->dai_link->ops && rtd->dai_link->ops->startup) {
  		ret = rtd->dai_link->ops->startup(substream);
  		if (ret < 0) {
  			pr_err("ASoC: %s startup failed: %d\n",
  			       rtd->dai_link->name, ret);
  			goto machine_err;
  		}
  	}
  
  	/* 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 */
  	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
  		soc_pcm_init_runtime_hw(runtime, &codec_dai_drv->playback,
  			&cpu_dai_drv->playback);
  	} else {
  		soc_pcm_init_runtime_hw(runtime, &codec_dai_drv->capture,
  			&cpu_dai_drv->capture);
  	}
  
  	ret = -EINVAL;
  	if (!runtime->hw.rates) {
  		printk(KERN_ERR "ASoC: %s <-> %s No matching rates\n",
  			codec_dai->name, cpu_dai->name);
  		goto config_err;
  	}
  	if (!runtime->hw.formats) {
  		printk(KERN_ERR "ASoC: %s <-> %s No matching formats\n",
  			codec_dai->name, cpu_dai->name);
  		goto config_err;
  	}
  	if (!runtime->hw.channels_min || !runtime->hw.channels_max ||
  	    runtime->hw.channels_min > runtime->hw.channels_max) {
  		printk(KERN_ERR "ASoC: %s <-> %s No matching channels\n",
  				codec_dai->name, cpu_dai->name);
  		goto config_err;
  	}
  
  	soc_pcm_apply_msb(substream, codec_dai);
  	soc_pcm_apply_msb(substream, cpu_dai);
  
  	/* Symmetry only applies if we've already got an active stream. */
  	if (cpu_dai->active) {
  		ret = soc_pcm_apply_symmetry(substream, cpu_dai);
  		if (ret != 0)
  			goto config_err;
  	}
  
  	if (codec_dai->active) {
  		ret = soc_pcm_apply_symmetry(substream, codec_dai);
  		if (ret != 0)
  			goto config_err;
  	}
  
  	pr_debug("ASoC: %s <-> %s info:\n",
  			codec_dai->name, cpu_dai->name);
  	pr_debug("ASoC: rate mask 0x%x\n", runtime->hw.rates);
  	pr_debug("ASoC: min ch %d max ch %d\n", runtime->hw.channels_min,
  		 runtime->hw.channels_max);
  	pr_debug("ASoC: min rate %d max rate %d\n", runtime->hw.rate_min,
  		 runtime->hw.rate_max);
  
  dynamic:
  	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
  		cpu_dai->playback_active++;
  		codec_dai->playback_active++;
  	} else {
  		cpu_dai->capture_active++;
  		codec_dai->capture_active++;
  	}
  	cpu_dai->active++;
  	codec_dai->active++;
  	rtd->codec->active++;
  	mutex_unlock(&rtd->pcm_mutex);
  	return 0;
  
  config_err:
  	if (rtd->dai_link->ops && rtd->dai_link->ops->shutdown)
  		rtd->dai_link->ops->shutdown(substream);
  
  machine_err:
  	if (codec_dai->driver->ops->shutdown)
  		codec_dai->driver->ops->shutdown(substream, codec_dai);
  
  codec_dai_err:
  	if (platform->driver->ops && platform->driver->ops->close)
  		platform->driver->ops->close(substream);
  
  platform_err:
  	if (cpu_dai->driver->ops->shutdown)
  		cpu_dai->driver->ops->shutdown(substream, cpu_dai);
  out:
  	mutex_unlock(&rtd->pcm_mutex);
  
  	pm_runtime_put(platform->dev);
  	pm_runtime_put(codec_dai->dev);
  	pm_runtime_put(cpu_dai->dev);
  	if (!codec_dai->active)
  		pinctrl_pm_select_sleep_state(codec_dai->dev);
  	if (!cpu_dai->active)
  		pinctrl_pm_select_sleep_state(cpu_dai->dev);
  
  	return ret;
  }
  
  /*
   * Power down the audio subsystem pmdown_time msecs after close is called.
   * This is to ensure there are no pops or clicks in between any music tracks
   * due to DAPM power cycling.
   */
  static void close_delayed_work(struct work_struct *work)
  {
  	struct snd_soc_pcm_runtime *rtd =
  			container_of(work, struct snd_soc_pcm_runtime, delayed_work.work);
  	struct snd_soc_dai *codec_dai = rtd->codec_dai;
  
  	mutex_lock_nested(&rtd->pcm_mutex, rtd->pcm_subclass);
  
  	dev_dbg(rtd->dev, "ASoC: pop wq checking: %s status: %s waiting: %s\n",
  		 codec_dai->driver->playback.stream_name,
  		 codec_dai->playback_active ? "active" : "inactive",
  		 rtd->pop_wait ? "yes" : "no");
  
  	/* are we waiting on this codec DAI stream */
  	if (rtd->pop_wait == 1) {
  		rtd->pop_wait = 0;
  		snd_soc_dapm_stream_event(rtd, SNDRV_PCM_STREAM_PLAYBACK,
  					  SND_SOC_DAPM_STREAM_STOP);
  	}
  
  	mutex_unlock(&rtd->pcm_mutex);
  }
  
  /*
   * Called by ALSA when a PCM substream is closed. Private data can be
   * freed here. The cpu DAI, codec DAI, machine and platform are also
   * shutdown.
   */
  static int soc_pcm_close(struct snd_pcm_substream *substream)
  {
  	struct snd_soc_pcm_runtime *rtd = substream->private_data;
  	struct snd_soc_platform *platform = rtd->platform;
  	struct snd_soc_dai *cpu_dai = rtd->cpu_dai;
  	struct snd_soc_dai *codec_dai = rtd->codec_dai;
  	struct snd_soc_codec *codec = rtd->codec;
  
  	mutex_lock_nested(&rtd->pcm_mutex, rtd->pcm_subclass);
  
  	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
  		cpu_dai->playback_active--;
  		codec_dai->playback_active--;
  	} else {
  		cpu_dai->capture_active--;
  		codec_dai->capture_active--;
  	}
  
  	cpu_dai->active--;
  	codec_dai->active--;
  	codec->active--;
  
  	/* clear the corresponding DAIs rate when inactive */
  	if (!cpu_dai->active)
  		cpu_dai->rate = 0;
  
  	if (!codec_dai->active)
  		codec_dai->rate = 0;
  
  	/* Muting the DAC suppresses artifacts caused during digital
  	 * shutdown, for example from stopping clocks.
  	 */
  	snd_soc_dai_digital_mute(codec_dai, 1, substream->stream);
  
  	if (cpu_dai->driver->ops->shutdown)
  		cpu_dai->driver->ops->shutdown(substream, cpu_dai);
  
  	if (codec_dai->driver->ops->shutdown)
  		codec_dai->driver->ops->shutdown(substream, codec_dai);
  
  	if (rtd->dai_link->ops && rtd->dai_link->ops->shutdown)
  		rtd->dai_link->ops->shutdown(substream);
  
  	if (platform->driver->ops && platform->driver->ops->close)
  		platform->driver->ops->close(substream);
  	cpu_dai->runtime = NULL;
  
  	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
  		if (!rtd->pmdown_time || codec->ignore_pmdown_time ||
  		    rtd->dai_link->ignore_pmdown_time) {
  			/* powered down playback stream now */
  			snd_soc_dapm_stream_event(rtd,
  						  SNDRV_PCM_STREAM_PLAYBACK,
  						  SND_SOC_DAPM_STREAM_STOP);
  		} else {
  			/* start delayed pop wq here for playback streams */
  			rtd->pop_wait = 1;
  			queue_delayed_work(system_power_efficient_wq,
  					   &rtd->delayed_work,
  					   msecs_to_jiffies(rtd->pmdown_time));
  		}
  	} else {
  		/* capture streams can be powered down now */
  		snd_soc_dapm_stream_event(rtd, SNDRV_PCM_STREAM_CAPTURE,
  					  SND_SOC_DAPM_STREAM_STOP);
  	}
  
  	mutex_unlock(&rtd->pcm_mutex);
  
  	pm_runtime_put(platform->dev);
  	pm_runtime_put(codec_dai->dev);
  	pm_runtime_put(cpu_dai->dev);
  	if (!codec_dai->active)
  		pinctrl_pm_select_sleep_state(codec_dai->dev);
  	if (!cpu_dai->active)
  		pinctrl_pm_select_sleep_state(cpu_dai->dev);
  
  	return 0;
  }
  
  /*
   * 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 = substream->private_data;
  	struct snd_soc_platform *platform = rtd->platform;
  	struct snd_soc_dai *cpu_dai = rtd->cpu_dai;
  	struct snd_soc_dai *codec_dai = rtd->codec_dai;
  	int ret = 0;
  
  	mutex_lock_nested(&rtd->pcm_mutex, rtd->pcm_subclass);
  
  	if (rtd->dai_link->ops && rtd->dai_link->ops->prepare) {
  		ret = rtd->dai_link->ops->prepare(substream);
  		if (ret < 0) {
  			dev_err(rtd->card->dev, "ASoC: machine prepare error:"
  				" %d\n", ret);
  			goto out;
  		}
  	}
  
  	if (platform->driver->ops && platform->driver->ops->prepare) {
  		ret = platform->driver->ops->prepare(substream);
  		if (ret < 0) {
  			dev_err(platform->dev, "ASoC: platform prepare error:"
  				" %d\n", ret);
  			goto out;
  		}
  	}
  
  	if (codec_dai->driver->ops && codec_dai->driver->ops->prepare) {
  		ret = codec_dai->driver->ops->prepare(substream, codec_dai);
  		if (ret < 0) {
  			dev_err(codec_dai->dev, "ASoC: DAI prepare error: %d\n",
  				ret);
  			goto out;
  		}
  	}
  
  	if (cpu_dai->driver->ops && cpu_dai->driver->ops->prepare) {
  		ret = cpu_dai->driver->ops->prepare(substream, cpu_dai);
  		if (ret < 0) {
  			dev_err(cpu_dai->dev, "ASoC: DAI prepare error: %d\n",
  				ret);
  			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);
  
  	snd_soc_dai_digital_mute(codec_dai, 0, substream->stream);
  
  out:
  	mutex_unlock(&rtd->pcm_mutex);
  	return ret;
  }
  
  /*
   * 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 = substream->private_data;
  	struct snd_soc_platform *platform = rtd->platform;
  	struct snd_soc_dai *cpu_dai = rtd->cpu_dai;
  	struct snd_soc_dai *codec_dai = rtd->codec_dai;
  	int ret = 0;
  
  	mutex_lock_nested(&rtd->pcm_mutex, rtd->pcm_subclass);
  
  	if (rtd->dai_link->ops && rtd->dai_link->ops->hw_params) {
  		ret = rtd->dai_link->ops->hw_params(substream, params);
  		if (ret < 0) {
  			dev_err(rtd->card->dev, "ASoC: machine hw_params"
  				" failed: %d\n", ret);
  			goto out;
  		}
  	}
  
  	if (codec_dai->driver->ops && codec_dai->driver->ops->hw_params) {
  		ret = codec_dai->driver->ops->hw_params(substream, params, codec_dai);
  		if (ret < 0) {
  			dev_err(codec_dai->dev, "ASoC: can't set %s hw params:"
  				" %d\n", codec_dai->name, ret);
  			goto codec_err;
  		}
  	}
  
  	if (cpu_dai->driver->ops && cpu_dai->driver->ops->hw_params) {
  		ret = cpu_dai->driver->ops->hw_params(substream, params, cpu_dai);
  		if (ret < 0) {
  			dev_err(cpu_dai->dev, "ASoC: %s hw params failed: %d\n",
  				cpu_dai->name, ret);
  			goto interface_err;
  		}
  	}
  
  	if (platform->driver->ops && platform->driver->ops->hw_params) {
  		ret = platform->driver->ops->hw_params(substream, params);
  		if (ret < 0) {
  			dev_err(platform->dev, "ASoC: %s hw params failed: %d\n",
  			       platform->name, ret);
  			goto platform_err;
  		}
  	}
  
  	/* store the rate for each DAIs */
  	cpu_dai->rate = params_rate(params);
  	codec_dai->rate = params_rate(params);
  
  out:
  	mutex_unlock(&rtd->pcm_mutex);
  	return ret;
  
  platform_err:
  	if (cpu_dai->driver->ops && cpu_dai->driver->ops->hw_free)
  		cpu_dai->driver->ops->hw_free(substream, cpu_dai);
  
  interface_err:
  	if (codec_dai->driver->ops && codec_dai->driver->ops->hw_free)
  		codec_dai->driver->ops->hw_free(substream, codec_dai);
  
  codec_err:
  	if (rtd->dai_link->ops && rtd->dai_link->ops->hw_free)
  		rtd->dai_link->ops->hw_free(substream);
  
  	mutex_unlock(&rtd->pcm_mutex);
  	return ret;
  }
  
  /*
   * Frees resources allocated by hw_params, can be called multiple times
   */
  static int soc_pcm_hw_free(struct snd_pcm_substream *substream)
  {
  	struct snd_soc_pcm_runtime *rtd = substream->private_data;
  	struct snd_soc_platform *platform = rtd->platform;
  	struct snd_soc_dai *cpu_dai = rtd->cpu_dai;
  	struct snd_soc_dai *codec_dai = rtd->codec_dai;
  	bool playback = substream->stream == SNDRV_PCM_STREAM_PLAYBACK;
  
  	mutex_lock_nested(&rtd->pcm_mutex, rtd->pcm_subclass);
  
  	/* apply codec digital mute */
  	if ((playback && codec_dai->playback_active == 1) ||
  	    (!playback && codec_dai->capture_active == 1))
  		snd_soc_dai_digital_mute(codec_dai, 1, substream->stream);
  
  	/* free any machine hw params */
  	if (rtd->dai_link->ops && rtd->dai_link->ops->hw_free)
  		rtd->dai_link->ops->hw_free(substream);
  
  	/* free any DMA resources */
  	if (platform->driver->ops && platform->driver->ops->hw_free)
  		platform->driver->ops->hw_free(substream);
  
  	/* now free hw params for the DAIs  */
  	if (codec_dai->driver->ops && codec_dai->driver->ops->hw_free)
  		codec_dai->driver->ops->hw_free(substream, codec_dai);
  
  	if (cpu_dai->driver->ops && cpu_dai->driver->ops->hw_free)
  		cpu_dai->driver->ops->hw_free(substream, cpu_dai);
  
  	mutex_unlock(&rtd->pcm_mutex);
  	return 0;
  }
  
  static int soc_pcm_trigger(struct snd_pcm_substream *substream, int cmd)
  {
  	struct snd_soc_pcm_runtime *rtd = substream->private_data;
  	struct snd_soc_platform *platform = rtd->platform;
  	struct snd_soc_dai *cpu_dai = rtd->cpu_dai;
  	struct snd_soc_dai *codec_dai = rtd->codec_dai;
  	int ret;
  
  	if (codec_dai->driver->ops && codec_dai->driver->ops->trigger) {
  		ret = codec_dai->driver->ops->trigger(substream, cmd, codec_dai);
  		if (ret < 0)
  			return ret;
  	}
  
  	if (platform->driver->ops && platform->driver->ops->trigger) {
  		ret = platform->driver->ops->trigger(substream, cmd);
  		if (ret < 0)
  			return ret;
  	}
  
  	if (cpu_dai->driver->ops && cpu_dai->driver->ops->trigger) {
  		ret = cpu_dai->driver->ops->trigger(substream, cmd, cpu_dai);
  		if (ret < 0)
  			return ret;
  	}
  	return 0;
  }
  
  static int soc_pcm_bespoke_trigger(struct snd_pcm_substream *substream,
  				   int cmd)
  {
  	struct snd_soc_pcm_runtime *rtd = substream->private_data;
  	struct snd_soc_platform *platform = rtd->platform;
  	struct snd_soc_dai *cpu_dai = rtd->cpu_dai;
  	struct snd_soc_dai *codec_dai = rtd->codec_dai;
  	int ret;
  
  	if (codec_dai->driver->ops &&
  	    codec_dai->driver->ops->bespoke_trigger) {
  		ret = codec_dai->driver->ops->bespoke_trigger(substream, cmd, codec_dai);
  		if (ret < 0)
  			return ret;
  	}
  
  	if (platform->driver->ops && platform->driver->bespoke_trigger) {
  		ret = platform->driver->bespoke_trigger(substream, cmd);
  		if (ret < 0)
  			return ret;
  	}
  
  	if (cpu_dai->driver->ops && cpu_dai->driver->ops->bespoke_trigger) {
  		ret = cpu_dai->driver->ops->bespoke_trigger(substream, cmd, cpu_dai);
  		if (ret < 0)
  			return ret;
  	}
  	return 0;
  }
  /*
   * soc level wrapper for pointer callback
   * If cpu_dai, codec_dai, platform driver has the delay callback, than
   * 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 = substream->private_data;
  	struct snd_soc_platform *platform = rtd->platform;
  	struct snd_soc_dai *cpu_dai = rtd->cpu_dai;
  	struct snd_soc_dai *codec_dai = rtd->codec_dai;
  	struct snd_pcm_runtime *runtime = substream->runtime;
  	snd_pcm_uframes_t offset = 0;
  	snd_pcm_sframes_t delay = 0;
  
  	if (platform->driver->ops && platform->driver->ops->pointer)
  		offset = platform->driver->ops->pointer(substream);
  
  	if (cpu_dai->driver->ops && cpu_dai->driver->ops->delay)
  		delay += cpu_dai->driver->ops->delay(substream, cpu_dai);
  
  	if (codec_dai->driver->ops && codec_dai->driver->ops->delay)
  		delay += codec_dai->driver->ops->delay(substream, codec_dai);
  
  	if (platform->driver->delay)
  		delay += platform->driver->delay(substream, codec_dai);
  
  	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;
  
  	/* only add new dpcms */
  	list_for_each_entry(dpcm, &fe->dpcm[stream].be_clients, list_be) {
  		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;
  	list_add(&dpcm->list_be, &fe->dpcm[stream].be_clients);
  	list_add(&dpcm->list_fe, &be->dpcm[stream].fe_clients);
  
  	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);
  
  #ifdef CONFIG_DEBUG_FS
  	dpcm->debugfs_state = debugfs_create_u32(be->dai_link->name, 0644,
  			fe->debugfs_dpcm_root, &dpcm->state);
  #endif
  	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);
  
  	list_for_each_entry(dpcm, &be->dpcm[stream].fe_clients, list_fe) {
  		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 */
  static void dpcm_be_disconnect(struct snd_soc_pcm_runtime *fe, int stream)
  {
  	struct snd_soc_dpcm *dpcm, *d;
  
  	list_for_each_entry_safe(dpcm, d, &fe->dpcm[stream].be_clients, list_be) {
  		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);
  
  #ifdef CONFIG_DEBUG_FS
  		debugfs_remove(dpcm->debugfs_state);
  #endif
  		list_del(&dpcm->list_be);
  		list_del(&dpcm->list_fe);
  		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;
  	int i;
  
  	if (stream == SNDRV_PCM_STREAM_PLAYBACK) {
  		for (i = 0; i < card->num_links; i++) {
  			be = &card->rtd[i];
  
  			if (!be->dai_link->no_pcm)
  				continue;
  
  			if (be->cpu_dai->playback_widget == widget ||
  				be->codec_dai->playback_widget == widget)
  				return be;
  		}
  	} else {
  
  		for (i = 0; i < card->num_links; i++) {
  			be = &card->rtd[i];
  
  			if (!be->dai_link->no_pcm)
  				continue;
  
  			if (be->cpu_dai->capture_widget == widget ||
  				be->codec_dai->capture_widget == widget)
  				return be;
  		}
  	}
  
  	dev_err(card->dev, "ASoC: can't get %s BE for %s\n",
  		stream ? "capture" : "playback", widget->name);
  	return NULL;
  }
  
  static inline struct snd_soc_dapm_widget *
  	rtd_get_cpu_widget(struct snd_soc_pcm_runtime *rtd, int stream)
  {
  	if (stream == SNDRV_PCM_STREAM_PLAYBACK)
  		return rtd->cpu_dai->playback_widget;
  	else
  		return rtd->cpu_dai->capture_widget;
  }
  
  static inline struct snd_soc_dapm_widget *
  	rtd_get_codec_widget(struct snd_soc_pcm_runtime *rtd, int stream)
  {
  	if (stream == SNDRV_PCM_STREAM_PLAYBACK)
  		return rtd->codec_dai->playback_widget;
  	else
  		return rtd->codec_dai->capture_widget;
  }
  
  static int widget_in_list(struct snd_soc_dapm_widget_list *list,
  		struct snd_soc_dapm_widget *widget)
  {
  	int i;
  
  	for (i = 0; i < list->num_widgets; i++) {
  		if (widget == list->widgets[i])
  			return 1;
  	}
  
  	return 0;
  }
  
  static 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 = fe->cpu_dai;
  	struct snd_soc_dapm_widget_list *list;
  	int paths;
  
  	list = kzalloc(sizeof(struct snd_soc_dapm_widget_list) +
  			sizeof(struct snd_soc_dapm_widget *), GFP_KERNEL);
  	if (list == NULL)
  		return -ENOMEM;
  
  	/* get number of valid DAI paths and their widgets */
  	paths = snd_soc_dapm_dai_get_connected_widgets(cpu_dai, stream, &list);
  
  	dev_dbg(fe->dev, "ASoC: found %d audio %s paths\n", paths,
  			stream ? "capture" : "playback");
  
  	*list_ = list;
  	return paths;
  }
  
  static inline void dpcm_path_put(struct snd_soc_dapm_widget_list **list)
  {
  	kfree(*list);
  }
  
  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;
  	struct snd_soc_dapm_widget_list *list = *list_;
  	struct snd_soc_dapm_widget *widget;
  	int prune = 0;
  
  	/* Destroy any old FE <--> BE connections */
  	list_for_each_entry(dpcm, &fe->dpcm[stream].be_clients, list_be) {
  
  		/* is there a valid CPU DAI widget for this BE */
  		widget = rtd_get_cpu_widget(dpcm->be, stream);
  
  		/* prune the BE if it's no longer in our active list */
  		if (widget && widget_in_list(list, widget))
  			continue;
  
  		/* is there a valid CODEC DAI widget for this BE */
  		widget = rtd_get_codec_widget(dpcm->be, stream);
  
  		/* prune the BE if it's no longer in our active list */
  		if (widget && widget_in_list(list, widget))
  			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->be->dpcm[stream].runtime_update = 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;
  	int i, new = 0, err;
  
  	/* Create any new FE <--> BE connections */
  	for (i = 0; i < list->num_widgets; i++) {
  
  		switch (list->widgets[i]->id) {
  		case snd_soc_dapm_dai_in:
  		case snd_soc_dapm_dai_out:
  			break;
  		default:
  			continue;
  		}
  
  		/* is there a valid BE rtd for this widget */
  		be = dpcm_get_be(card, list->widgets[i], stream);
  		if (!be) {
  			dev_err(fe->dev, "ASoC: no BE found for %s\n",
  					list->widgets[i]->name);
  			continue;
  		}
  
  		/* make sure BE is a real BE */
  		if (!be->dai_link->no_pcm)
  			continue;
  
  		/* don't connect if FE is not running */
  		if (!fe->dpcm[stream].runtime)
  			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",
  				list->widgets[i]->name);
  			break;
  		} else if (err == 0) /* already connected */
  			continue;
  
  		/* new */
  		be->dpcm[stream].runtime_update = 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.
   */
  static 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);
  }
  
  static void dpcm_clear_pending_state(struct snd_soc_pcm_runtime *fe, int stream)
  {
  	struct snd_soc_dpcm *dpcm;
  
  	list_for_each_entry(dpcm, &fe->dpcm[stream].be_clients, list_be)
  		dpcm->be->dpcm[stream].runtime_update =
  						SND_SOC_DPCM_UPDATE_NO;
  }
  
  static void dpcm_be_dai_startup_unwind(struct snd_soc_pcm_runtime *fe,
  	int stream)
  {
  	struct snd_soc_dpcm *dpcm;
  
  	/* disable any enabled and non active backends */
  	list_for_each_entry(dpcm, &fe->dpcm[stream].be_clients, list_be) {
  
  		struct snd_soc_pcm_runtime *be = dpcm->be;
  		struct snd_pcm_substream *be_substream =
  			snd_soc_dpcm_get_substream(be, stream);
  
  		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);
  
  		if (--be->dpcm[stream].users != 0)
  			continue;
  
  		if (be->dpcm[stream].state != SND_SOC_DPCM_STATE_OPEN)
  			continue;
  
  		soc_pcm_close(be_substream);
  		be_substream->runtime = NULL;
  		be->dpcm[stream].state = SND_SOC_DPCM_STATE_CLOSE;
  	}
  }
  
  static int dpcm_be_dai_startup(struct snd_soc_pcm_runtime *fe, int stream)
  {
  	struct snd_soc_dpcm *dpcm;
  	int err, count = 0;
  
  	/* only startup BE DAIs that are either sinks or sources to this FE DAI */
  	list_for_each_entry(dpcm, &fe->dpcm[stream].be_clients, list_be) {
  
  		struct snd_soc_pcm_runtime *be = dpcm->be;
  		struct snd_pcm_substream *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);
  
  		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) {
  			dev_err(be->dev, "ASoC: BE open failed %d\n", err);
  			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:
  	/* disable any enabled and non active backends */
  	list_for_each_entry_continue_reverse(dpcm, &fe->dpcm[stream].be_clients, list_be) {
  		struct snd_soc_pcm_runtime *be = dpcm->be;
  		struct snd_pcm_substream *be_substream =
  			snd_soc_dpcm_get_substream(be, stream);
  
  		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 %d\n",
  				stream ? "capture" : "playback",
  				be->dpcm[stream].state);
  
  		if (--be->dpcm[stream].users != 0)
  			continue;
  
  		if (be->dpcm[stream].state != SND_SOC_DPCM_STATE_OPEN)
  			continue;
  
  		soc_pcm_close(be_substream);
  		be_substream->runtime = NULL;
  		be->dpcm[stream].state = SND_SOC_DPCM_STATE_CLOSE;
  	}
  
  	return err;
  }
  
  static void dpcm_set_fe_runtime(struct snd_pcm_substream *substream)
  {
  	struct snd_pcm_runtime *runtime = substream->runtime;
  	struct snd_soc_pcm_runtime *rtd = substream->private_data;
  	struct snd_soc_dai *cpu_dai = rtd->cpu_dai;
  	struct snd_soc_dai_driver *cpu_dai_drv = cpu_dai->driver;
  
  	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
  		runtime->hw.rate_min = cpu_dai_drv->playback.rate_min;
  		runtime->hw.rate_max = cpu_dai_drv->playback.rate_max;
  		runtime->hw.channels_min = cpu_dai_drv->playback.channels_min;
  		runtime->hw.channels_max = cpu_dai_drv->playback.channels_max;
  		runtime->hw.formats &= cpu_dai_drv->playback.formats;
  		runtime->hw.rates = cpu_dai_drv->playback.rates;
  	} else {
  		runtime->hw.rate_min = cpu_dai_drv->capture.rate_min;
  		runtime->hw.rate_max = cpu_dai_drv->capture.rate_max;
  		runtime->hw.channels_min = cpu_dai_drv->capture.channels_min;
  		runtime->hw.channels_max = cpu_dai_drv->capture.channels_max;
  		runtime->hw.formats &= cpu_dai_drv->capture.formats;
  		runtime->hw.rates = cpu_dai_drv->capture.rates;
  	}
  }
  
  static int dpcm_fe_dai_do_trigger(struct snd_pcm_substream *substream, int cmd);
  
  /* 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 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 int dpcm_fe_dai_startup(struct snd_pcm_substream *fe_substream)
  {
  	struct snd_soc_pcm_runtime *fe = fe_substream->private_data;
  	struct snd_pcm_runtime *runtime = fe_substream->runtime;
  	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, fe_substream->stream);
  	if (ret < 0) {
  		dev_err(fe->dev,"ASoC: failed to start some BEs %d\n", ret);
  		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) {
  		dev_err(fe->dev,"ASoC: failed to start FE %d\n", ret);
  		goto unwind;
  	}
  
  	fe->dpcm[stream].state = SND_SOC_DPCM_STATE_OPEN;
  
  	dpcm_set_fe_runtime(fe_substream);
  	snd_pcm_limit_hw_rates(runtime);
  
  	dpcm_set_fe_update_state(fe, stream, SND_SOC_DPCM_UPDATE_NO);
  	return 0;
  
  unwind:
  	dpcm_be_dai_startup_unwind(fe, fe_substream->stream);
  be_err:
  	dpcm_set_fe_update_state(fe, stream, SND_SOC_DPCM_UPDATE_NO);
  	return ret;
  }
  
  static int dpcm_be_dai_shutdown(struct snd_soc_pcm_runtime *fe, int stream)
  {
  	struct snd_soc_dpcm *dpcm;
  
  	/* only shutdown BEs that are either sinks or sources to this FE DAI */
  	list_for_each_entry(dpcm, &fe->dpcm[stream].be_clients, list_be) {
  
  		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].users == 0)
  			dev_err(be->dev, "ASoC: no users %s at close - state %d\n",
  				stream ? "capture" : "playback",
  				be->dpcm[stream].state);
  
  		if (--be->dpcm[stream].users != 0)
  			continue;
  
  		if ((be->dpcm[stream].state != SND_SOC_DPCM_STATE_HW_FREE) &&
  		    (be->dpcm[stream].state != SND_SOC_DPCM_STATE_OPEN))
  			continue;
  
  		dev_dbg(be->dev, "ASoC: close BE %s\n",
  			dpcm->fe->dai_link->name);
  
  		soc_pcm_close(be_substream);
  		be_substream->runtime = NULL;
  
  		be->dpcm[stream].state = SND_SOC_DPCM_STATE_CLOSE;
  	}
  	return 0;
  }
  
  static int dpcm_fe_dai_shutdown(struct snd_pcm_substream *substream)
  {
  	struct snd_soc_pcm_runtime *fe = substream->private_data;
  	int stream = substream->stream;
  
  	dpcm_set_fe_update_state(fe, stream, SND_SOC_DPCM_UPDATE_FE);
  
  	/* shutdown the BEs */
  	dpcm_be_dai_shutdown(fe, substream->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 event for each BE */
  	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;
  }
  
  static int 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 */
  	list_for_each_entry(dpcm, &fe->dpcm[stream].be_clients, list_be) {
  
  		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;
  
  		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))
  			continue;
  
  		dev_dbg(be->dev, "ASoC: hw_free BE %s\n",
  			dpcm->fe->dai_link->name);
  
  		soc_pcm_hw_free(be_substream);
  
  		be->dpcm[stream].state = SND_SOC_DPCM_STATE_HW_FREE;
  	}
  
  	return 0;
  }
  
  static int dpcm_fe_dai_hw_free(struct snd_pcm_substream *substream)
  {
  	struct snd_soc_pcm_runtime *fe = substream->private_data;
  	int err, 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 */
  	err = soc_pcm_hw_free(substream);
  	if (err < 0)
  		dev_err(fe->dev,"ASoC: hw_free FE %s failed\n",
  			fe->dai_link->name);
  
  	/* only hw_params backends that are either sinks or sources
  	 * to this frontend DAI */
  	err = 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;
  }
  
  static int dpcm_be_dai_hw_params(struct snd_soc_pcm_runtime *fe, int stream)
  {
  	struct snd_soc_dpcm *dpcm;
  	int ret;
  
  	list_for_each_entry(dpcm, &fe->dpcm[stream].be_clients, list_be) {
  
  		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 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",
  			dpcm->fe->dai_link->name);
  
  		/* 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 */
  		if (be->dai_link->be_hw_params_fixup) {
  			ret = be->dai_link->be_hw_params_fixup(be,
  					&dpcm->hw_params);
  			if (ret < 0) {
  				dev_err(be->dev,
  					"ASoC: hw_params BE fixup failed %d\n",
  					ret);
  				goto unwind;
  			}
  		}
  
  		ret = soc_pcm_hw_params(be_substream, &dpcm->hw_params);
  		if (ret < 0) {
  			dev_err(dpcm->be->dev,
  				"ASoC: hw_params BE failed %d\n", ret);
  			goto unwind;
  		}
  
  		be->dpcm[stream].state = SND_SOC_DPCM_STATE_HW_PARAMS;
  	}
  	return 0;
  
  unwind:
  	/* disable any enabled and non active backends */
  	list_for_each_entry_continue_reverse(dpcm, &fe->dpcm[stream].be_clients, list_be) {
  		struct snd_soc_pcm_runtime *be = dpcm->be;
  		struct snd_pcm_substream *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 = substream->private_data;
  	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[substream->stream].hw_params, params,
  			sizeof(struct snd_pcm_hw_params));
  	ret = dpcm_be_dai_hw_params(fe, substream->stream);
  	if (ret < 0) {
  		dev_err(fe->dev,"ASoC: hw_params BE failed %d\n", ret);
  		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) {
  		dev_err(fe->dev,"ASoC: hw_params FE failed %d\n", ret);
  		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);
  	return ret;
  }
  
  static int dpcm_do_trigger(struct snd_soc_dpcm *dpcm,
  		struct snd_pcm_substream *substream, int cmd)
  {
  	int ret;
  
  	dev_dbg(dpcm->be->dev, "ASoC: trigger BE %s cmd %d\n",
  			dpcm->fe->dai_link->name, cmd);
  
  	ret = soc_pcm_trigger(substream, cmd);
  	if (ret < 0)
  		dev_err(dpcm->be->dev,"ASoC: trigger BE failed %d\n", ret);
  
  	return ret;
  }
  
  static int dpcm_be_dai_trigger(struct snd_soc_pcm_runtime *fe, int stream,
  			       int cmd)
  {
  	struct snd_soc_dpcm *dpcm;
  	int ret = 0;
  
  	list_for_each_entry(dpcm, &fe->dpcm[stream].be_clients, list_be) {
  
  		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;
  
  		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))
  				continue;
  
  			ret = dpcm_do_trigger(dpcm, be_substream, cmd);
  			if (ret)
  				return ret;
  
  			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 = dpcm_do_trigger(dpcm, be_substream, cmd);
  			if (ret)
  				return ret;
  
  			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 = dpcm_do_trigger(dpcm, be_substream, cmd);
  			if (ret)
  				return ret;
  
  			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)
  				continue;
  
  			if (!snd_soc_dpcm_can_be_free_stop(fe, be, stream))
  				continue;
  
  			ret = dpcm_do_trigger(dpcm, be_substream, cmd);
  			if (ret)
  				return ret;
  
  			be->dpcm[stream].state = SND_SOC_DPCM_STATE_STOP;
  			break;
  		case SNDRV_PCM_TRIGGER_SUSPEND:
  			if (be->dpcm[stream].state != SND_SOC_DPCM_STATE_STOP)
  				continue;
  
  			if (!snd_soc_dpcm_can_be_free_stop(fe, be, stream))
  				continue;
  
  			ret = dpcm_do_trigger(dpcm, be_substream, cmd);
  			if (ret)
  				return ret;
  
  			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 = dpcm_do_trigger(dpcm, be_substream, cmd);
  			if (ret)
  				return ret;
  
  			be->dpcm[stream].state = SND_SOC_DPCM_STATE_PAUSED;
  			break;
  		}
  	}
  
  	return ret;
  }
  EXPORT_SYMBOL_GPL(dpcm_be_dai_trigger);
  
  static int dpcm_fe_dai_do_trigger(struct snd_pcm_substream *substream, int cmd)
  {
  	struct snd_soc_pcm_runtime *fe = substream->private_data;
  	int stream = substream->stream, ret;
  	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:
  		/* call trigger on the frontend before the backend. */
  
  		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) {
  			dev_err(fe->dev,"ASoC: trigger FE failed %d\n", ret);
  			goto out;
  		}
  
  		ret = dpcm_be_dai_trigger(fe, substream->stream, cmd);
  		break;
  	case SND_SOC_DPCM_TRIGGER_POST:
  		/* call trigger on the frontend after the backend. */
  
  		ret = dpcm_be_dai_trigger(fe, substream->stream, cmd);
  		if (ret < 0) {
  			dev_err(fe->dev,"ASoC: trigger FE failed %d\n", ret);
  			goto out;
  		}
  
  		dev_dbg(fe->dev, "ASoC: post trigger FE %s cmd %d\n",
  				fe->dai_link->name, cmd);
  
  		ret = soc_pcm_trigger(substream, cmd);
  		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 = soc_pcm_bespoke_trigger(substream, cmd);
  		if (ret < 0) {
  			dev_err(fe->dev,"ASoC: trigger FE failed %d\n", ret);
  			goto out;
  		}
  		break;
  	default:
  		dev_err(fe->dev, "ASoC: invalid trigger cmd %d for %s\n", cmd,
  				fe->dai_link->name);
  		ret = -EINVAL;
  		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:
  	case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
  		fe->dpcm[stream].state = SND_SOC_DPCM_STATE_STOP;
  		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 = substream->private_data;
  	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);
  }
  
  static int dpcm_be_dai_prepare(struct snd_soc_pcm_runtime *fe, int stream)
  {
  	struct snd_soc_dpcm *dpcm;
  	int ret = 0;
  
  	list_for_each_entry(dpcm, &fe->dpcm[stream].be_clients, list_be) {
  
  		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))
  			continue;
  
  		dev_dbg(be->dev, "ASoC: prepare BE %s\n",
  			dpcm->fe->dai_link->name);
  
  		ret = soc_pcm_prepare(be_substream);
  		if (ret < 0) {
  			dev_err(be->dev, "ASoC: backend prepare failed %d\n",
  				ret);
  			break;
  		}
  
  		be->dpcm[stream].state = SND_SOC_DPCM_STATE_PREPARE;
  	}
  	return ret;
  }
  
  static int dpcm_fe_dai_prepare(struct snd_pcm_substream *substream)
  {
  	struct snd_soc_pcm_runtime *fe = substream->private_data;
  	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, substream->stream);
  	if (ret < 0)
  		goto out;
  
  	/* call prepare on the frontend */
  	ret = soc_pcm_prepare(substream);
  	if (ret < 0) {
  		dev_err(fe->dev,"ASoC: prepare FE %s failed\n",
  			fe->dai_link->name);
  		goto out;
  	}
  
  	/* run the stream event for each BE */
  	dpcm_dapm_stream_event(fe, stream, SND_SOC_DAPM_STREAM_START);
  	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);
  
  	return ret;
  }
  
  static int soc_pcm_ioctl(struct snd_pcm_substream *substream,
  		     unsigned int cmd, void *arg)
  {
  	struct snd_soc_pcm_runtime *rtd = substream->private_data;
  	struct snd_soc_platform *platform = rtd->platform;
  
  	if (platform->driver->ops && platform->driver->ops->ioctl)
  		return platform->driver->ops->ioctl(substream, cmd, arg);
  	return snd_pcm_lib_ioctl(substream, cmd, arg);
  }
  
  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 = soc_pcm_bespoke_trigger(substream, SNDRV_PCM_TRIGGER_STOP);
  		if (err < 0)
  			dev_err(fe->dev,"ASoC: trigger FE failed %d\n", err);
  	} 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);
  		if (err < 0)
  			dev_err(fe->dev,"ASoC: trigger FE failed %d\n", err);
  	}
  
  	err = dpcm_be_dai_hw_free(fe, stream);
  	if (err < 0)
  		dev_err(fe->dev,"ASoC: hw_free FE failed %d\n", err);
  
  	err = dpcm_be_dai_shutdown(fe, stream);
  	if (err < 0)
  		dev_err(fe->dev,"ASoC: shutdown FE failed %d\n", err);
  
  	/* run the stream event for each BE */
  	dpcm_dapm_stream_event(fe, stream, SND_SOC_DAPM_STREAM_NOP);
  
  	return 0;
  }
  
  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;
  
  	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)
  		return -EINVAL;
  
  	/* 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 = soc_pcm_bespoke_trigger(substream, SNDRV_PCM_TRIGGER_START);
  		if (ret < 0) {
  			dev_err(fe->dev,"ASoC: bespoke trigger FE failed %d\n", ret);
  			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) {
  			dev_err(fe->dev,"ASoC: trigger FE failed %d\n", ret);
  			goto hw_free;
  		}
  	}
  
  	return 0;
  
  hw_free:
  	dpcm_be_dai_hw_free(fe, stream);
  close:
  	dpcm_be_dai_shutdown(fe, stream);
  disconnect:
  	/* disconnect any non started BEs */
  	list_for_each_entry(dpcm, &fe->dpcm[stream].be_clients, list_be) {
  		struct snd_soc_pcm_runtime *be = dpcm->be;
  		if (be->dpcm[stream].state != SND_SOC_DPCM_STATE_START)
  				dpcm->state = SND_SOC_DPCM_LINK_STATE_FREE;
  	}
  
  	return ret;
  }
  
  static int dpcm_run_new_update(struct snd_soc_pcm_runtime *fe, int stream)
  {
  	int ret;
  
  	dpcm_set_fe_update_state(fe, stream, SND_SOC_DPCM_UPDATE_BE);
  	ret = dpcm_run_update_startup(fe, stream);
  	if (ret < 0)
  		dev_err(fe->dev, "ASoC: failed to startup some BEs\n");
  	dpcm_set_fe_update_state(fe, stream, SND_SOC_DPCM_UPDATE_NO);
  
  	return ret;
  }
  
  static int dpcm_run_old_update(struct snd_soc_pcm_runtime *fe, int stream)
  {
  	int ret;
  
  	dpcm_set_fe_update_state(fe, stream, SND_SOC_DPCM_UPDATE_BE);
  	ret = dpcm_run_update_shutdown(fe, stream);
  	if (ret < 0)
  		dev_err(fe->dev, "ASoC: failed to shutdown some BEs\n");
  	dpcm_set_fe_update_state(fe, stream, SND_SOC_DPCM_UPDATE_NO);
  
  	return ret;
  }
  
  /* Called by DAPM mixer/mux changes to update audio routing between PCMs and
   * any DAI links.
   */
  int soc_dpcm_runtime_update(struct snd_soc_card *card)
  {
  	int i, old, new, paths;
  
  	mutex_lock_nested(&card->mutex, SND_SOC_CARD_CLASS_RUNTIME);
  	for (i = 0; i < card->num_rtd; i++) {
  		struct snd_soc_dapm_widget_list *list;
  		struct snd_soc_pcm_runtime *fe = &card->rtd[i];
  
  		/* make sure link is FE */
  		if (!fe->dai_link->dynamic)
  			continue;
  
  		/* only check active links */
  		if (!fe->cpu_dai->active)
  			continue;
  
  		/* DAPM sync will call this to update DSP paths */
  		dev_dbg(fe->dev, "ASoC: DPCM runtime update for FE %s\n",
  			fe->dai_link->name);
  
  		/* skip if FE doesn't have playback capability */
  		if (!fe->cpu_dai->driver->playback.channels_min)
  			goto capture;
  
  		paths = dpcm_path_get(fe, SNDRV_PCM_STREAM_PLAYBACK, &list);
  		if (paths < 0) {
  			dev_warn(fe->dev, "ASoC: %s no valid %s path\n",
  					fe->dai_link->name,  "playback");
  			mutex_unlock(&card->mutex);
  			return paths;
  		}
  
  		/* update any new playback paths */
  		new = dpcm_process_paths(fe, SNDRV_PCM_STREAM_PLAYBACK, &list, 1);
  		if (new) {
  			dpcm_run_new_update(fe, SNDRV_PCM_STREAM_PLAYBACK);
  			dpcm_clear_pending_state(fe, SNDRV_PCM_STREAM_PLAYBACK);
  			dpcm_be_disconnect(fe, SNDRV_PCM_STREAM_PLAYBACK);
  		}
  
  		/* update any old playback paths */
  		old = dpcm_process_paths(fe, SNDRV_PCM_STREAM_PLAYBACK, &list, 0);
  		if (old) {
  			dpcm_run_old_update(fe, SNDRV_PCM_STREAM_PLAYBACK);
  			dpcm_clear_pending_state(fe, SNDRV_PCM_STREAM_PLAYBACK);
  			dpcm_be_disconnect(fe, SNDRV_PCM_STREAM_PLAYBACK);
  		}
  
  		dpcm_path_put(&list);
  capture:
  		/* skip if FE doesn't have capture capability */
  		if (!fe->cpu_dai->driver->capture.channels_min)
  			continue;
  
  		paths = dpcm_path_get(fe, SNDRV_PCM_STREAM_CAPTURE, &list);
  		if (paths < 0) {
  			dev_warn(fe->dev, "ASoC: %s no valid %s path\n",
  					fe->dai_link->name,  "capture");
  			mutex_unlock(&card->mutex);
  			return paths;
  		}
  
  		/* update any new capture paths */
  		new = dpcm_process_paths(fe, SNDRV_PCM_STREAM_CAPTURE, &list, 1);
  		if (new) {
  			dpcm_run_new_update(fe, SNDRV_PCM_STREAM_CAPTURE);
  			dpcm_clear_pending_state(fe, SNDRV_PCM_STREAM_CAPTURE);
  			dpcm_be_disconnect(fe, SNDRV_PCM_STREAM_CAPTURE);
  		}
  
  		/* update any old capture paths */
  		old = dpcm_process_paths(fe, SNDRV_PCM_STREAM_CAPTURE, &list, 0);
  		if (old) {
  			dpcm_run_old_update(fe, SNDRV_PCM_STREAM_CAPTURE);
  			dpcm_clear_pending_state(fe, SNDRV_PCM_STREAM_CAPTURE);
  			dpcm_be_disconnect(fe, SNDRV_PCM_STREAM_CAPTURE);
  		}
  
  		dpcm_path_put(&list);
  	}
  
  	mutex_unlock(&card->mutex);
  	return 0;
  }
  int soc_dpcm_be_digital_mute(struct snd_soc_pcm_runtime *fe, int mute)
  {
  	struct snd_soc_dpcm *dpcm;
  	struct list_head *clients =
  		&fe->dpcm[SNDRV_PCM_STREAM_PLAYBACK].be_clients;
  
  	list_for_each_entry(dpcm, clients, list_be) {
  
  		struct snd_soc_pcm_runtime *be = dpcm->be;
  		struct snd_soc_dai *dai = be->codec_dai;
  		struct snd_soc_dai_driver *drv = dai->driver;
  
  		if (be->dai_link->ignore_suspend)
  			continue;
  
  		dev_dbg(be->dev, "ASoC: BE digital mute %s\n", be->dai_link->name);
  
  		if (drv->ops && drv->ops->digital_mute && dai->playback_active)
  			drv->ops->digital_mute(dai, mute);
  	}
  
  	return 0;
  }
  
  static int dpcm_fe_dai_open(struct snd_pcm_substream *fe_substream)
  {
  	struct snd_soc_pcm_runtime *fe = fe_substream->private_data;
  	struct snd_soc_dpcm *dpcm;
  	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;
  
  	if (dpcm_path_get(fe, stream, &list) <= 0) {
  		dev_dbg(fe->dev, "ASoC: %s no valid %s route\n",
  			fe->dai_link->name, stream ? "capture" : "playback");
  	}
  
  	/* calculate valid and active FE <-> BE dpcms */
  	dpcm_process_paths(fe, stream, &list, 1);
  
  	ret = dpcm_fe_dai_startup(fe_substream);
  	if (ret < 0) {
  		/* clean up all links */
  		list_for_each_entry(dpcm, &fe->dpcm[stream].be_clients, list_be)
  			dpcm->state = SND_SOC_DPCM_LINK_STATE_FREE;
  
  		dpcm_be_disconnect(fe, stream);
  		fe->dpcm[stream].runtime = NULL;
  	}
  
  	dpcm_clear_pending_state(fe, stream);
  	dpcm_path_put(&list);
  	mutex_unlock(&fe->card->mutex);
  	return ret;
  }
  
  static int dpcm_fe_dai_close(struct snd_pcm_substream *fe_substream)
  {
  	struct snd_soc_pcm_runtime *fe = fe_substream->private_data;
  	struct snd_soc_dpcm *dpcm;
  	int stream = fe_substream->stream, ret;
  
  	mutex_lock_nested(&fe->card->mutex, SND_SOC_CARD_CLASS_RUNTIME);
  	ret = dpcm_fe_dai_shutdown(fe_substream);
  
  	/* mark FE's links ready to prune */
  	list_for_each_entry(dpcm, &fe->dpcm[stream].be_clients, list_be)
  		dpcm->state = SND_SOC_DPCM_LINK_STATE_FREE;
  
  	dpcm_be_disconnect(fe, stream);
  
  	fe->dpcm[stream].runtime = NULL;
  	mutex_unlock(&fe->card->mutex);
  	return ret;
  }
  
  /* create a new pcm */
  int soc_new_pcm(struct snd_soc_pcm_runtime *rtd, int num)
  {
  	struct snd_soc_platform *platform = rtd->platform;
  	struct snd_soc_dai *codec_dai = rtd->codec_dai;
  	struct snd_soc_dai *cpu_dai = rtd->cpu_dai;
  	struct snd_pcm *pcm;
  	char new_name[64];
  	int ret = 0, playback = 0, capture = 0;
  
  	if (rtd->dai_link->dynamic || rtd->dai_link->no_pcm) {
  		if (cpu_dai->driver->playback.channels_min)
  			playback = 1;
  		if (cpu_dai->driver->capture.channels_min)
  			capture = 1;
  	} else {
  		if (codec_dai->driver->playback.channels_min &&
  		    cpu_dai->driver->playback.channels_min)
  			playback = 1;
  		if (codec_dai->driver->capture.channels_min &&
  		    cpu_dai->driver->capture.channels_min)
  			capture = 1;
  	}
  
  	if (rtd->dai_link->playback_only) {
  		playback = 1;
  		capture = 0;
  	}
  
  	if (rtd->dai_link->capture_only) {
  		playback = 0;
  		capture = 1;
  	}
  
  	/* create the PCM */
  	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, codec_dai->name, 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 for %s\n",
  			rtd->dai_link->name);
  		return ret;
  	}
  	dev_dbg(rtd->card->dev, "ASoC: registered pcm #%d %s\n",num, new_name);
  
  	/* DAPM dai link stream work */
  	INIT_DELAYED_WORK(&rtd->delayed_work, close_delayed_work);
  
  	rtd->pcm = pcm;
  	pcm->private_data = rtd;
  
  	if (rtd->dai_link->no_pcm) {
  		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;
  		rtd->ops.ioctl		= soc_pcm_ioctl;
  	} 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;
  		rtd->ops.ioctl		= soc_pcm_ioctl;
  	}
  
  	if (platform->driver->ops) {
  		rtd->ops.ack		= platform->driver->ops->ack;
  		rtd->ops.copy		= platform->driver->ops->copy;
  		rtd->ops.silence	= platform->driver->ops->silence;
  		rtd->ops.page		= platform->driver->ops->page;
  		rtd->ops.mmap		= platform->driver->ops->mmap;
  	}
  
  	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);
  
  	if (platform->driver->pcm_new) {
  		ret = platform->driver->pcm_new(rtd);
  		if (ret < 0) {
  			dev_err(platform->dev,
  				"ASoC: pcm constructor failed: %d\n",
  				ret);
  			return ret;
  		}
  	}
  
  	pcm->private_free = platform->driver->pcm_free;
  out:
  	dev_info(rtd->card->dev, "%s <-> %s mapping ok\n", codec_dai->name,
  		cpu_dai->name);
  	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);
  
  /* get the BE runtime state */
  enum snd_soc_dpcm_state
  	snd_soc_dpcm_be_get_state(struct snd_soc_pcm_runtime *be, int stream)
  {
  	return be->dpcm[stream].state;
  }
  EXPORT_SYMBOL_GPL(snd_soc_dpcm_be_get_state);
  
  /* set the BE runtime state */
  void snd_soc_dpcm_be_set_state(struct snd_soc_pcm_runtime *be,
  		int stream, enum snd_soc_dpcm_state state)
  {
  	be->dpcm[stream].state = state;
  }
  EXPORT_SYMBOL_GPL(snd_soc_dpcm_be_set_state);
  
  /*
   * 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)
  {
  	struct snd_soc_dpcm *dpcm;
  	int state;
  
  	list_for_each_entry(dpcm, &be->dpcm[stream].fe_clients, list_fe) {
  
  		if (dpcm->fe == fe)
  			continue;
  
  		state = dpcm->fe->dpcm[stream].state;
  		if (state == SND_SOC_DPCM_STATE_START ||
  			state == SND_SOC_DPCM_STATE_PAUSED ||
  			state == SND_SOC_DPCM_STATE_SUSPEND)
  			return 0;
  	}
  
  	/* it's safe to free/stop this BE DAI */
  	return 1;
  }
  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)
  {
  	struct snd_soc_dpcm *dpcm;
  	int state;
  
  	list_for_each_entry(dpcm, &be->dpcm[stream].fe_clients, list_fe) {
  
  		if (dpcm->fe == fe)
  			continue;
  
  		state = dpcm->fe->dpcm[stream].state;
  		if (state == SND_SOC_DPCM_STATE_START ||
  			state == SND_SOC_DPCM_STATE_PAUSED ||
  			state == SND_SOC_DPCM_STATE_SUSPEND ||
  			state == SND_SOC_DPCM_STATE_PREPARE)
  			return 0;
  	}
  
  	/* it's safe to change hw_params */
  	return 1;
  }
  EXPORT_SYMBOL_GPL(snd_soc_dpcm_can_be_params);
  
  int snd_soc_platform_trigger(struct snd_pcm_substream *substream,
  		int cmd, struct snd_soc_platform *platform)
  {
  	if (platform->driver->ops && platform->driver->ops->trigger)
  		return platform->driver->ops->trigger(substream, cmd);
  	return 0;
  }
  EXPORT_SYMBOL_GPL(snd_soc_platform_trigger);
  
  #ifdef CONFIG_DEBUG_FS
  static 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;
  
  	/* FE state */
  	offset += snprintf(buf + offset, size - offset,
  			"[%s - %s]\n", fe->dai_link->name,
  			stream ? "Capture" : "Playback");
  
  	offset += snprintf(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 += snprintf(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 += snprintf(buf + offset, size - offset, "Backends:\n");
  
  	if (list_empty(&fe->dpcm[stream].be_clients)) {
  		offset += snprintf(buf + offset, size - offset,
  				" No active DSP links\n");
  		goto out;
  	}
  
  	list_for_each_entry(dpcm, &fe->dpcm[stream].be_clients, list_be) {
  		struct snd_soc_pcm_runtime *be = dpcm->be;
  		params = &dpcm->hw_params;
  
  		offset += snprintf(buf + offset, size - offset,
  				"- %s\n", be->dai_link->name);
  
  		offset += snprintf(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 += snprintf(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));
  	}
  
  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;
  	char *buf;
  
  	buf = kmalloc(out_count, GFP_KERNEL);
  	if (!buf)
  		return -ENOMEM;
  
  	if (fe->cpu_dai->driver->playback.channels_min)
  		offset += dpcm_show_state(fe, SNDRV_PCM_STREAM_PLAYBACK,
  					buf + offset, out_count - offset);
  
  	if (fe->cpu_dai->driver->capture.channels_min)
  		offset += dpcm_show_state(fe, SNDRV_PCM_STREAM_CAPTURE,
  					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,
  };
  
  int soc_dpcm_debugfs_add(struct snd_soc_pcm_runtime *rtd)
  {
  	if (!rtd->dai_link)
  		return 0;
  
  	rtd->debugfs_dpcm_root = debugfs_create_dir(rtd->dai_link->name,
  			rtd->card->debugfs_card_root);
  	if (!rtd->debugfs_dpcm_root) {
  		dev_dbg(rtd->dev,
  			 "ASoC: Failed to create dpcm debugfs directory %s\n",
  			 rtd->dai_link->name);
  		return -EINVAL;
  	}
  
  	rtd->debugfs_dpcm_state = debugfs_create_file("state", 0444,
  						rtd->debugfs_dpcm_root,
  						rtd, &dpcm_state_fops);
  
  	return 0;
  }
  #endif
  