// 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/initval.h>

#define DPCM_MAX_BE_USERS       8

/**
 * snd_soc_runtime_activate() - Increment active count for PCM runtime components
 * @rtd: ASoC PCM runtime that is activated
 * @stream: Direction of the PCM stream
 *
 * Increments 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_activate(struct snd_soc_pcm_runtime *rtd, int stream)
{
        struct snd_soc_dai *cpu_dai = rtd->cpu_dai;
        struct snd_soc_dai *codec_dai;
        int i;

        lockdep_assert_held(&rtd->card->pcm_mutex);

        if (stream == SNDRV_PCM_STREAM_PLAYBACK) {
                cpu_dai->playback_active++;
                for_each_rtd_codec_dai(rtd, i, codec_dai)
                        codec_dai->playback_active++;
        } else {
                cpu_dai->capture_active++;
                for_each_rtd_codec_dai(rtd, i, codec_dai)
                        codec_dai->capture_active++;
        }

        cpu_dai->active++;
        cpu_dai->component->active++;
        for_each_rtd_codec_dai(rtd, i, codec_dai) {
                codec_dai->active++;
                codec_dai->component->active++;
        }
}

/**
 * snd_soc_runtime_deactivate() - Decrement active count for PCM runtime components
 * @rtd: ASoC PCM runtime that is deactivated
 * @stream: Direction of the PCM stream
 *
 * Decrements the active count for all the DAIs and components attached to a PCM
 * runtime. Should typically be called when a stream is closed.
 *
 * Must be called with the rtd->card->pcm_mutex being held
 */
void snd_soc_runtime_deactivate(struct snd_soc_pcm_runtime *rtd, int stream)
{
        struct snd_soc_dai *cpu_dai = rtd->cpu_dai;
        struct snd_soc_dai *codec_dai;
        int i;

        lockdep_assert_held(&rtd->card->pcm_mutex);

        if (stream == SNDRV_PCM_STREAM_PLAYBACK) {
                cpu_dai->playback_active--;
                for_each_rtd_codec_dai(rtd, i, codec_dai)
                        codec_dai->playback_active--;
        } else {
                cpu_dai->capture_active--;
                for_each_rtd_codec_dai(rtd, i, codec_dai)
                        codec_dai->capture_active--;
        }

        cpu_dai->active--;
        cpu_dai->component->active--;
        for_each_rtd_codec_dai(rtd, i, codec_dai) {
                codec_dai->component->active--;
                codec_dai->active--;
        }
}

/**
 * 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_rtdcom_list *rtdcom;
        struct snd_soc_component *component;
        bool ignore = true;

        if (!rtd->pmdown_time || rtd->dai_link->ignore_pmdown_time)
                return true;

        for_each_rtdcom(rtd, rtdcom) {
                component = rtdcom->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)
{
        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. */
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 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->rate && (soc_dai->driver->symmetric_rates ||
                                rtd->dai_link->symmetric_rates)) {
                dev_dbg(soc_dai->dev, "ASoC: Symmetry forces %dHz rate\n",
                                soc_dai->rate);

                ret = snd_pcm_hw_constraint_single(substream->runtime,
                                                SNDRV_PCM_HW_PARAM_RATE,
                                                soc_dai->rate);
                if (ret < 0) {
                        dev_err(soc_dai->dev,
                                "ASoC: Unable to apply rate constraint: %d\n",
                                ret);
                        return ret;
                }
        }

        if (soc_dai->channels && (soc_dai->driver->symmetric_channels ||
                                rtd->dai_link->symmetric_channels)) {
                dev_dbg(soc_dai->dev, "ASoC: Symmetry forces %d channel(s)\n",
                                soc_dai->channels);

                ret = snd_pcm_hw_constraint_single(substream->runtime,
                                                SNDRV_PCM_HW_PARAM_CHANNELS,
                                                soc_dai->channels);
                if (ret < 0) {
                        dev_err(soc_dai->dev,
                                "ASoC: Unable to apply channel symmetry constraint: %d\n",
                                ret);
                        return ret;
                }
        }

        if (soc_dai->sample_bits && (soc_dai->driver->symmetric_samplebits ||
                                rtd->dai_link->symmetric_samplebits)) {
                dev_dbg(soc_dai->dev, "ASoC: Symmetry forces %d sample bits\n",
                                soc_dai->sample_bits);

                ret = snd_pcm_hw_constraint_single(substream->runtime,
                                                SNDRV_PCM_HW_PARAM_SAMPLE_BITS,
                                                soc_dai->sample_bits);
                if (ret < 0) {
                        dev_err(soc_dai->dev,
                                "ASoC: Unable to apply sample bits symmetry constraint: %d\n",
                                ret);
                        return ret;
                }
        }

        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 = substream->private_data;
        struct snd_soc_dai *cpu_dai = rtd->cpu_dai;
        struct snd_soc_dai *codec_dai;
        unsigned int rate, channels, sample_bits, symmetry, i;

        rate = params_rate(params);
        channels = params_channels(params);
        sample_bits = snd_pcm_format_physical_width(params_format(params));

        /* reject unmatched parameters when applying symmetry */
        symmetry = cpu_dai->driver->symmetric_rates ||
                rtd->dai_link->symmetric_rates;

        for_each_rtd_codec_dai(rtd, i, codec_dai)
                symmetry |= codec_dai->driver->symmetric_rates;

        if (symmetry && cpu_dai->rate && cpu_dai->rate != rate) {
                dev_err(rtd->dev, "ASoC: unmatched rate symmetry: %d - %d\n",
                                cpu_dai->rate, rate);
                return -EINVAL;
        }

        symmetry = cpu_dai->driver->symmetric_channels ||
                rtd->dai_link->symmetric_channels;

        for_each_rtd_codec_dai(rtd, i, codec_dai)
                symmetry |= codec_dai->driver->symmetric_channels;

        if (symmetry && cpu_dai->channels && cpu_dai->channels != channels) {
                dev_err(rtd->dev, "ASoC: unmatched channel symmetry: %d - %d\n",
                                cpu_dai->channels, channels);
                return -EINVAL;
        }

        symmetry = cpu_dai->driver->symmetric_samplebits ||
                rtd->dai_link->symmetric_samplebits;

        for_each_rtd_codec_dai(rtd, i, codec_dai)
                symmetry |= codec_dai->driver->symmetric_samplebits;

        if (symmetry && cpu_dai->sample_bits && cpu_dai->sample_bits != sample_bits) {
                dev_err(rtd->dev, "ASoC: unmatched sample bits symmetry: %d - %d\n",
                                cpu_dai->sample_bits, sample_bits);
                return -EINVAL;
        }

        return 0;
}

static bool soc_pcm_has_symmetry(struct snd_pcm_substream *substream)
{
        struct snd_soc_pcm_runtime *rtd = substream->private_data;
        struct snd_soc_dai_driver *cpu_driver = rtd->cpu_dai->driver;
        struct snd_soc_dai_link *link = rtd->dai_link;
        struct snd_soc_dai *codec_dai;
        unsigned int symmetry, i;

        symmetry = cpu_driver->symmetric_rates || link->symmetric_rates ||
                cpu_driver->symmetric_channels || link->symmetric_channels ||
                cpu_driver->symmetric_samplebits || link->symmetric_samplebits;

        for_each_rtd_codec_dai(rtd, i, codec_dai)
                symmetry = symmetry ||
                        codec_dai->driver->symmetric_rates ||
                        codec_dai->driver->symmetric_channels ||
                        codec_dai->driver->symmetric_samplebits;

        return symmetry;
}

static void soc_pcm_set_msb(struct snd_pcm_substream *substream, int bits)
{
        struct snd_soc_pcm_runtime *rtd = substream->private_data;
        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 = substream->private_data;
        struct snd_soc_dai *cpu_dai = rtd->cpu_dai;
        struct snd_soc_dai *codec_dai;
        int i;
        unsigned int bits = 0, cpu_bits;

        if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
                for_each_rtd_codec_dai(rtd, i, codec_dai) {
                        if (codec_dai->driver->playback.sig_bits == 0) {
                                bits = 0;
                                break;
                        }
                        bits = max(codec_dai->driver->playback.sig_bits, bits);
                }
                cpu_bits = cpu_dai->driver->playback.sig_bits;
        } else {
                for_each_rtd_codec_dai(rtd, i, codec_dai) {
                        if (codec_dai->driver->capture.sig_bits == 0) {
                                bits = 0;
                                break;
                        }
                        bits = max(codec_dai->driver->capture.sig_bits, bits);
                }
                cpu_bits = cpu_dai->driver->capture.sig_bits;
        }

        soc_pcm_set_msb(substream, bits);
        soc_pcm_set_msb(substream, cpu_bits);
}

static void soc_pcm_init_runtime_hw(struct snd_pcm_substream *substream)
{
        struct snd_pcm_runtime *runtime = substream->runtime;
        struct snd_pcm_hardware *hw = &runtime->hw;
        struct snd_soc_pcm_runtime *rtd = substream->private_data;
        struct snd_soc_dai *codec_dai;
        struct snd_soc_dai_driver *cpu_dai_drv = rtd->cpu_dai->driver;
        struct snd_soc_dai_driver *codec_dai_drv;
        struct snd_soc_pcm_stream *codec_stream;
        struct snd_soc_pcm_stream *cpu_stream;
        unsigned int chan_min = 0, chan_max = UINT_MAX;
        unsigned int rate_min = 0, rate_max = UINT_MAX;
        unsigned int rates = UINT_MAX;
        u64 formats = ULLONG_MAX;
        int i;

        if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
                cpu_stream = &cpu_dai_drv->playback;
        else
                cpu_stream = &cpu_dai_drv->capture;

        /* first calculate min/max only for CODECs in the DAI link */
        for_each_rtd_codec_dai(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.
                 * At least one CODEC should match, otherwise we should have
                 * bailed out on a higher level, since there would be no
                 * CODEC to support the transfer direction in that case.
                 */
                if (!snd_soc_dai_stream_valid(codec_dai,
                                              substream->stream))
                        continue;

                codec_dai_drv = codec_dai->driver;
                if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
                        codec_stream = &codec_dai_drv->playback;
                else
                        codec_stream = &codec_dai_drv->capture;
                chan_min = max(chan_min, codec_stream->channels_min);
                chan_max = min(chan_max, codec_stream->channels_max);
                rate_min = max(rate_min, codec_stream->rate_min);
                rate_max = min_not_zero(rate_max, codec_stream->rate_max);
                formats &= codec_stream->formats;
                rates = snd_pcm_rate_mask_intersect(codec_stream->rates, rates);
        }

        /*
         * chan min/max cannot be enforced if there are multiple CODEC DAIs
         * connected to a single CPU DAI, use CPU DAI's directly and let
         * channel allocation be fixed up later
         */
        if (rtd->num_codecs > 1) {
                chan_min = cpu_stream->channels_min;
                chan_max = cpu_stream->channels_max;
        }

        hw->channels_min = max(chan_min, cpu_stream->channels_min);
        hw->channels_max = min(chan_max, cpu_stream->channels_max);
        if (hw->formats)
                hw->formats &= formats & cpu_stream->formats;
        else
                hw->formats = formats & cpu_stream->formats;
        hw->rates = snd_pcm_rate_mask_intersect(rates, cpu_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, rate_min);
        hw->rate_max = min_not_zero(hw->rate_max, cpu_stream->rate_max);
        hw->rate_max = min_not_zero(hw->rate_max, rate_max);
}

static int soc_pcm_components_open(struct snd_pcm_substream *substream,
                                   struct snd_soc_component **last)
{
        struct snd_soc_pcm_runtime *rtd = substream->private_data;
        struct snd_soc_rtdcom_list *rtdcom;
        struct snd_soc_component *component;
        int ret = 0;

        for_each_rtdcom(rtd, rtdcom) {
                component = rtdcom->component;
                *last = component;

                ret = snd_soc_component_module_get_when_open(component);
                if (ret < 0) {
                        dev_err(component->dev,
                                "ASoC: can't get module %s\n",
                                component->name);
                        return ret;
                }

                ret = snd_soc_component_open(component, substream);
                if (ret < 0) {
                        dev_err(component->dev,
                                "ASoC: can't open component %s: %d\n",
                                component->name, ret);
                        return ret;
                }
        }
        *last = NULL;
        return 0;
}

static int soc_pcm_components_close(struct snd_pcm_substream *substream,
                                    struct snd_soc_component *last)
{
        struct snd_soc_pcm_runtime *rtd = substream->private_data;
        struct snd_soc_rtdcom_list *rtdcom;
        struct snd_soc_component *component;
        int ret = 0;

        for_each_rtdcom(rtd, rtdcom) {
                component = rtdcom->component;

                if (component == last)
                        break;

                ret |= snd_soc_component_close(component, substream);
                snd_soc_component_module_put_when_close(component);
        }

        return ret;
}

/*
 * 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 = substream->private_data;
        struct snd_pcm_runtime *runtime = substream->runtime;
        struct snd_soc_component *component;
        struct snd_soc_rtdcom_list *rtdcom;
        struct snd_soc_dai *cpu_dai = rtd->cpu_dai;
        struct snd_soc_dai *codec_dai;
        const char *codec_dai_name = "multicodec";
        int i, ret = 0;

        pinctrl_pm_select_default_state(cpu_dai->dev);
        for_each_rtd_codec_dai(rtd, i, codec_dai)
                pinctrl_pm_select_default_state(codec_dai->dev);

        for_each_rtdcom(rtd, rtdcom) {
                component = rtdcom->component;

                pm_runtime_get_sync(component->dev);
        }

        mutex_lock_nested(&rtd->card->pcm_mutex, rtd->card->pcm_subclass);

        /* startup the audio subsystem */
        ret = snd_soc_dai_startup(cpu_dai, substream);
        if (ret < 0) {
                dev_err(cpu_dai->dev, "ASoC: can't open interface %s: %d\n",
                        cpu_dai->name, ret);
                goto out;
        }

        ret = soc_pcm_components_open(substream, &component);
        if (ret < 0)
                goto component_err;

        for_each_rtd_codec_dai(rtd, i, codec_dai) {
                ret = snd_soc_dai_startup(codec_dai, substream);
                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 (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
                        codec_dai->tx_mask = 0;
                else
                        codec_dai->rx_mask = 0;
        }

        if (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 */
        soc_pcm_init_runtime_hw(substream);

        if (rtd->num_codecs == 1)
                codec_dai_name = rtd->codec_dai->name;

        if (soc_pcm_has_symmetry(substream))
                runtime->hw.info |= SNDRV_PCM_INFO_JOINT_DUPLEX;

        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);

        /* 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;
        }

        for_each_rtd_codec_dai(rtd, i, codec_dai) {
                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:

        snd_soc_runtime_activate(rtd, substream->stream);

        mutex_unlock(&rtd->card->pcm_mutex);
        return 0;

config_err:
        if (rtd->dai_link->ops->shutdown)
                rtd->dai_link->ops->shutdown(substream);

machine_err:
        i = rtd->num_codecs;

codec_dai_err:
        for_each_rtd_codec_dai_rollback(rtd, i, codec_dai)
                snd_soc_dai_shutdown(codec_dai, substream);

component_err:
        soc_pcm_components_close(substream, component);

        snd_soc_dai_shutdown(cpu_dai, substream);
out:
        mutex_unlock(&rtd->card->pcm_mutex);

        for_each_rtdcom(rtd, rtdcom) {
                component = rtdcom->component;

                pm_runtime_mark_last_busy(component->dev);
                pm_runtime_put_autosuspend(component->dev);
        }

        for_each_rtd_codec_dai(rtd, i, codec_dai) {
                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_dais[0];

        mutex_lock_nested(&rtd->card->pcm_mutex, rtd->card->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->card->pcm_mutex);
}

static void codec2codec_close_delayed_work(struct work_struct *work)
{
        /*
         * 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 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)
{
        struct snd_soc_pcm_runtime *rtd = substream->private_data;
        struct snd_soc_component *component;
        struct snd_soc_rtdcom_list *rtdcom;
        struct snd_soc_dai *cpu_dai = rtd->cpu_dai;
        struct snd_soc_dai *codec_dai;
        int i;

        mutex_lock_nested(&rtd->card->pcm_mutex, rtd->card->pcm_subclass);

        snd_soc_runtime_deactivate(rtd, substream->stream);

        /* clear the corresponding DAIs rate when inactive */
        if (!cpu_dai->active)
                cpu_dai->rate = 0;

        for_each_rtd_codec_dai(rtd, i, codec_dai) {
                if (!codec_dai->active)
                        codec_dai->rate = 0;
        }

        snd_soc_dai_digital_mute(cpu_dai, 1, substream->stream);

        snd_soc_dai_shutdown(cpu_dai, substream);

        for_each_rtd_codec_dai(rtd, i, codec_dai)
                snd_soc_dai_shutdown(codec_dai, substream);

        if (rtd->dai_link->ops->shutdown)
                rtd->dai_link->ops->shutdown(substream);

        soc_pcm_components_close(substream, NULL);

        if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
                if (snd_soc_runtime_ignore_pmdown_time(rtd)) {
                        /* 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->card->pcm_mutex);

        for_each_rtdcom(rtd, rtdcom) {
                component = rtdcom->component;

                pm_runtime_mark_last_busy(component->dev);
                pm_runtime_put_autosuspend(component->dev);
        }

        for_each_rtd_codec_dai(rtd, i, codec_dai) {
                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_component *component;
        struct snd_soc_rtdcom_list *rtdcom;
        struct snd_soc_dai *cpu_dai = rtd->cpu_dai;
        struct snd_soc_dai *codec_dai;
        int i, ret = 0;

        mutex_lock_nested(&rtd->card->pcm_mutex, rtd->card->pcm_subclass);

        if (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;
                }
        }

        for_each_rtdcom(rtd, rtdcom) {
                component = rtdcom->component;

                ret = snd_soc_component_prepare(component, substream);
                if (ret < 0) {
                        dev_err(component->dev,
                                "ASoC: platform prepare error: %d\n", ret);
                        goto out;
                }
        }

        for_each_rtd_codec_dai(rtd, i, codec_dai) {
                ret = snd_soc_dai_prepare(codec_dai, substream);
                if (ret < 0) {
                        dev_err(codec_dai->dev,
                                "ASoC: codec DAI prepare error: %d\n",
                                ret);
                        goto out;
                }
        }

        ret = snd_soc_dai_prepare(cpu_dai, substream);
        if (ret < 0) {
                dev_err(cpu_dai->dev,
                        "ASoC: cpu 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);

        for_each_rtd_codec_dai(rtd, i, codec_dai)
                snd_soc_dai_digital_mute(codec_dai, 0,
                                         substream->stream);
        snd_soc_dai_digital_mute(cpu_dai, 0, substream->stream);

out:
        mutex_unlock(&rtd->card->pcm_mutex);
        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_components_hw_free(struct snd_pcm_substream *substream,
                                      struct snd_soc_component *last)
{
        struct snd_soc_pcm_runtime *rtd = substream->private_data;
        struct snd_soc_rtdcom_list *rtdcom;
        struct snd_soc_component *component;
        int ret = 0;

        for_each_rtdcom(rtd, rtdcom) {
                component = rtdcom->component;

                if (component == last)
                        break;

                ret |= snd_soc_component_hw_free(component, substream);
        }

        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_component *component;
        struct snd_soc_rtdcom_list *rtdcom;
        struct snd_soc_dai *cpu_dai = rtd->cpu_dai;
        struct snd_soc_dai *codec_dai;
        int i, ret = 0;

        mutex_lock_nested(&rtd->card->pcm_mutex, rtd->card->pcm_subclass);
        if (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;
                }
        }

        for_each_rtd_codec_dai(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 codec_err;

                codec_dai->rate = params_rate(&codec_params);
                codec_dai->channels = params_channels(&codec_params);
                codec_dai->sample_bits = snd_pcm_format_physical_width(
                                                params_format(&codec_params));

                snd_soc_dapm_update_dai(substream, &codec_params, codec_dai);
        }

        ret = snd_soc_dai_hw_params(cpu_dai, substream, params);
        if (ret < 0)
                goto interface_err;

        /* store the parameters for each DAIs */
        cpu_dai->rate = params_rate(params);
        cpu_dai->channels = params_channels(params);
        cpu_dai->sample_bits =
                snd_pcm_format_physical_width(params_format(params));

        snd_soc_dapm_update_dai(substream, params, cpu_dai);

        for_each_rtdcom(rtd, rtdcom) {
                component = rtdcom->component;

                ret = snd_soc_component_hw_params(component, substream, params);
                if (ret < 0) {
                        dev_err(component->dev,
                                "ASoC: %s hw params failed: %d\n",
                                component->name, ret);
                        goto component_err;
                }
        }
        component = NULL;

        ret = soc_pcm_params_symmetry(substream, params);
        if (ret)
                goto component_err;
out:
        mutex_unlock(&rtd->card->pcm_mutex);
        return ret;

component_err:
        soc_pcm_components_hw_free(substream, component);

        snd_soc_dai_hw_free(cpu_dai, substream);
        cpu_dai->rate = 0;

interface_err:
        i = rtd->num_codecs;

codec_err:
        for_each_rtd_codec_dai_rollback(rtd, i, codec_dai) {
                if (!snd_soc_dai_stream_valid(codec_dai, substream->stream))
                        continue;

                snd_soc_dai_hw_free(codec_dai, substream);
                codec_dai->rate = 0;
        }

        if (rtd->dai_link->ops->hw_free)
                rtd->dai_link->ops->hw_free(substream);

        mutex_unlock(&rtd->card->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_dai *cpu_dai = rtd->cpu_dai;
        struct snd_soc_dai *codec_dai;

        bool playback = substream->stream == SNDRV_PCM_STREAM_PLAYBACK;
        int i;

        mutex_lock_nested(&rtd->card->pcm_mutex, rtd->card->pcm_subclass);

        /* clear the corresponding DAIs parameters when going to be inactive */
        if (cpu_dai->active == 1) {
                cpu_dai->rate = 0;
                cpu_dai->channels = 0;
                cpu_dai->sample_bits = 0;
        }

        for_each_rtd_codec_dai(rtd, i, codec_dai) {
                if (codec_dai->active == 1) {
                        codec_dai->rate = 0;
                        codec_dai->channels = 0;
                        codec_dai->sample_bits = 0;
                }
        }

        /* apply codec digital mute */
        for_each_rtd_codec_dai(rtd, i, codec_dai) {
                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->hw_free)
                rtd->dai_link->ops->hw_free(substream);

        /* free any component resources */
        soc_pcm_components_hw_free(substream, NULL);

        /* now free hw params for the DAIs  */
        for_each_rtd_codec_dai(rtd, i, codec_dai) {
                if (!snd_soc_dai_stream_valid(codec_dai, substream->stream))
                        continue;

                snd_soc_dai_hw_free(codec_dai, substream);
        }

        snd_soc_dai_hw_free(cpu_dai, substream);

        mutex_unlock(&rtd->card->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_component *component;
        struct snd_soc_rtdcom_list *rtdcom;
        struct snd_soc_dai *cpu_dai = rtd->cpu_dai;
        struct snd_soc_dai *codec_dai;
        int i, ret;

        for_each_rtd_codec_dai(rtd, i, codec_dai) {
                ret = snd_soc_dai_trigger(codec_dai, substream, cmd);
                if (ret < 0)
                        return ret;
        }

        for_each_rtdcom(rtd, rtdcom) {
                component = rtdcom->component;

                ret = snd_soc_component_trigger(component, substream, cmd);
                if (ret < 0)
                        return ret;
        }

        ret = snd_soc_dai_trigger(cpu_dai, substream, cmd);
        if (ret < 0)
                return ret;

        if (rtd->dai_link->ops->trigger) {
                ret = rtd->dai_link->ops->trigger(substream, cmd);
                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_dai *cpu_dai = rtd->cpu_dai;
        struct snd_soc_dai *codec_dai;
        int i, ret;

        for_each_rtd_codec_dai(rtd, i, codec_dai) {
                ret = snd_soc_dai_bespoke_trigger(codec_dai, substream, cmd);
                if (ret < 0)
                        return ret;
        }

        ret = snd_soc_dai_bespoke_trigger(cpu_dai, substream, cmd);
        if (ret < 0)
                return ret;

        return 0;
}
/*
 * 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 = substream->private_data;
        struct snd_soc_dai *cpu_dai = rtd->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;
        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;

        delay += snd_soc_dai_delay(cpu_dai, substream);

        for_each_rtd_codec_dai(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;
        char *name;

        /* 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);

#ifdef CONFIG_DEBUG_FS
        name = kasprintf(GFP_KERNEL, "%s:%s", be->dai_link->name,
                         stream ? "capture" : "playback");
        if (name) {
                dpcm->debugfs_state = debugfs_create_dir(name,
                                                         fe->debugfs_dpcm_root);
                debugfs_create_u32("state", 0644, dpcm->debugfs_state,
                                   &dpcm->state);
                kfree(name);
        }
#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);

        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);

#ifdef CONFIG_DEBUG_FS
                debugfs_remove_recursive(dpcm->debugfs_state);
#endif
                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_dai *dai;
        int i;

        dev_dbg(card->dev, "ASoC: find BE for widget %s\n", widget->name);

        if (stream == SNDRV_PCM_STREAM_PLAYBACK) {
                for_each_card_rtds(card, be) {

                        if (!be->dai_link->no_pcm)
                                continue;

                        dev_dbg(card->dev, "ASoC: try BE : %s\n",
                                be->cpu_dai->playback_widget ?
                                be->cpu_dai->playback_widget->name : "(not set)");

                        if (be->cpu_dai->playback_widget == widget)
                                return be;

                        for_each_rtd_codec_dai(be, i, dai) {
                                if (dai->playback_widget == widget)
                                        return be;
                        }
                }
        } else {

                for_each_card_rtds(card, be) {

                        if (!be->dai_link->no_pcm)
                                continue;

                        dev_dbg(card->dev, "ASoC: try BE %s\n",
                                be->cpu_dai->capture_widget ?
                                be->cpu_dai->capture_widget->name : "(not set)");

                        if (be->cpu_dai->capture_widget == widget)
                                return be;

                        for_each_rtd_codec_dai(be, i, dai) {
                                if (dai->capture_widget == widget)
                                        return be;
                        }
                }
        }

        /* dai link name and stream name set correctly ? */
        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 *
        dai_get_widget(struct snd_soc_dai *dai, int stream)
{
        if (stream == SNDRV_PCM_STREAM_PLAYBACK)
                return dai->playback_widget;
        else
                return 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 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;
        struct snd_soc_dai *dai;
        int i;

        if (dir == SND_SOC_DAPM_DIR_OUT) {
                for_each_card_rtds(card, rtd) {
                        if (!rtd->dai_link->no_pcm)
                                continue;

                        if (rtd->cpu_dai->playback_widget == widget)
                                return true;

                        for_each_rtd_codec_dai(rtd, i, dai) {
                                if (dai->playback_widget == widget)
                                        return true;
                        }
                }
        } else { /* SND_SOC_DAPM_DIR_IN */
                for_each_card_rtds(card, rtd) {
                        if (!rtd->dai_link->no_pcm)
                                continue;

                        if (rtd->cpu_dai->capture_widget == widget)
                                return true;

                        for_each_rtd_codec_dai(rtd, i, dai) {
                                if (dai->capture_widget == widget)
                                        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 = fe->cpu_dai;
        int paths;

        /* get number of valid DAI paths and their widgets */
        paths = snd_soc_dapm_dai_get_connected_widgets(cpu_dai, stream, list,
                        dpcm_end_walk_at_be);

        dev_dbg(fe->dev, "ASoC: found %d audio %s paths\n", paths,
                        stream ? "capture" : "playback");

        return paths;
}

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;
        struct snd_soc_dai *dai;
        int prune = 0;

        /* Destroy any old FE <--> BE connections */
        for_each_dpcm_be(fe, stream, dpcm) {
                unsigned int i;

                /* is there a valid CPU DAI widget for this BE */
                widget = dai_get_widget(dpcm->be->cpu_dai, 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 */
                for_each_rtd_codec_dai(dpcm->be, i, dai) {
                        widget = dai_get_widget(dai, 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:
                        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, 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 && !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",
                                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.
 */
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->be->dpcm[stream].runtime_update =
                                                SND_SOC_DPCM_UPDATE_NO;
        spin_unlock_irqrestore(&fe->card->dpcm_lock, flags);
}

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 */
        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 (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;
        }
}

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 */
        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 (!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 */
        for_each_dpcm_be_rollback(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 (!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_init_runtime_hw(struct snd_pcm_runtime *runtime,
                                 struct snd_soc_pcm_stream *stream)
{
        runtime->hw.rate_min = stream->rate_min;
        runtime->hw.rate_max = min_not_zero(stream->rate_max, UINT_MAX);
        runtime->hw.channels_min = stream->channels_min;
        runtime->hw.channels_max = stream->channels_max;
        if (runtime->hw.formats)
                runtime->hw.formats &= stream->formats;
        else
                runtime->hw.formats = stream->formats;
        runtime->hw.rates = stream->rates;
}

static void dpcm_runtime_merge_format(struct snd_pcm_substream *substream,
                                      u64 *formats)
{
        struct snd_soc_pcm_runtime *fe = substream->private_data;
        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_dai_driver *codec_dai_drv;
                struct snd_soc_pcm_stream *codec_stream;
                int i;

                for_each_rtd_codec_dai(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_dai_drv = dai->driver;
                        if (stream == SNDRV_PCM_STREAM_PLAYBACK)
                                codec_stream = &codec_dai_drv->playback;
                        else
                                codec_stream = &codec_dai_drv->capture;

                        *formats &= codec_stream->formats;
                }
        }
}

static void dpcm_runtime_merge_chan(struct snd_pcm_substream *substream,
                                    unsigned int *channels_min,
                                    unsigned int *channels_max)
{
        struct snd_soc_pcm_runtime *fe = substream->private_data;
        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_dai_driver *cpu_dai_drv =  be->cpu_dai->driver;
                struct snd_soc_dai_driver *codec_dai_drv;
                struct snd_soc_pcm_stream *codec_stream;
                struct snd_soc_pcm_stream *cpu_stream;

                if (stream == SNDRV_PCM_STREAM_PLAYBACK)
                        cpu_stream = &cpu_dai_drv->playback;
                else
                        cpu_stream = &cpu_dai_drv->capture;

                *channels_min = max(*channels_min, cpu_stream->channels_min);
                *channels_max = min(*channels_max, cpu_stream->channels_max);

                /*
                 * 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_dai_drv = be->codec_dais[0]->driver;

                        if (stream == SNDRV_PCM_STREAM_PLAYBACK)
                                codec_stream = &codec_dai_drv->playback;
                        else
                                codec_stream = &codec_dai_drv->capture;

                        *channels_min = max(*channels_min,
                                            codec_stream->channels_min);
                        *channels_max = min(*channels_max,
                                            codec_stream->channels_max);
                }
        }
}

static void dpcm_runtime_merge_rate(struct snd_pcm_substream *substream,
                                    unsigned int *rates,
                                    unsigned int *rate_min,
                                    unsigned int *rate_max)
{
        struct snd_soc_pcm_runtime *fe = substream->private_data;
        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_dai_driver *cpu_dai_drv =  be->cpu_dai->driver;
                struct snd_soc_dai_driver *codec_dai_drv;
                struct snd_soc_pcm_stream *codec_stream;
                struct snd_soc_pcm_stream *cpu_stream;
                struct snd_soc_dai *dai;
                int i;

                if (stream == SNDRV_PCM_STREAM_PLAYBACK)
                        cpu_stream = &cpu_dai_drv->playback;
                else
                        cpu_stream = &cpu_dai_drv->capture;

                *rate_min = max(*rate_min, cpu_stream->rate_min);
                *rate_max = min_not_zero(*rate_max, cpu_stream->rate_max);
                *rates = snd_pcm_rate_mask_intersect(*rates, cpu_stream->rates);

                for_each_rtd_codec_dai(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_dai_drv = dai->driver;
                        if (stream == SNDRV_PCM_STREAM_PLAYBACK)
                                codec_stream = &codec_dai_drv->playback;
                        else
                                codec_stream = &codec_dai_drv->capture;

                        *rate_min = max(*rate_min, codec_stream->rate_min);
                        *rate_max = min_not_zero(*rate_max,
                                                 codec_stream->rate_max);
                        *rates = snd_pcm_rate_mask_intersect(*rates,
                                                codec_stream->rates);
                }
        }
}

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)
                dpcm_init_runtime_hw(runtime, &cpu_dai_drv->playback);
        else
                dpcm_init_runtime_hw(runtime, &cpu_dai_drv->capture);

        dpcm_runtime_merge_format(substream, &runtime->hw.formats);
        dpcm_runtime_merge_chan(substream, &runtime->hw.channels_min,
                                &runtime->hw.channels_max);
        dpcm_runtime_merge_rate(substream, &runtime->hw.rates,
                                &runtime->hw.rate_min, &runtime->hw.rate_max);
}

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_apply_symmetry(struct snd_pcm_substream *fe_substream,
                               int stream)
{
        struct snd_soc_dpcm *dpcm;
        struct snd_soc_pcm_runtime *fe = fe_substream->private_data;
        struct snd_soc_dai *fe_cpu_dai = fe->cpu_dai;
        int err;

        /* apply symmetry for FE */
        if (soc_pcm_has_symmetry(fe_substream))
                fe_substream->runtime->hw.info |= SNDRV_PCM_INFO_JOINT_DUPLEX;

        /* Symmetry only applies if we've got an active stream. */
        if (fe_cpu_dai->active) {
                err = soc_pcm_apply_symmetry(fe_substream, fe_cpu_dai);
                if (err < 0)
                        return err;
        }

        /* 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 *codec_dai;
                int i;

                /* A backend may not have the requested substream */
                if (!be_substream)
                        continue;

                rtd = be_substream->private_data;
                if (rtd->dai_link->be_hw_params_fixup)
                        continue;

                if (soc_pcm_has_symmetry(be_substream))
                        be_substream->runtime->hw.info |= SNDRV_PCM_INFO_JOINT_DUPLEX;

                /* Symmetry only applies if we've got an active stream. */
                if (rtd->cpu_dai->active) {
                        err = soc_pcm_apply_symmetry(fe_substream,
                                                     rtd->cpu_dai);
                        if (err < 0)
                                return err;
                }

                for_each_rtd_codec_dai(rtd, i, codec_dai) {
                        if (codec_dai->active) {
                                err = soc_pcm_apply_symmetry(fe_substream,
                                                             codec_dai);
                                if (err < 0)
                                        return err;
                        }
                }
        }

        return 0;
}

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);

        ret = dpcm_apply_symmetry(fe_substream, stream);
        if (ret < 0) {
                dev_err(fe->dev, "ASoC: failed to apply dpcm symmetry %d\n",
                        ret);
                goto unwind;
        }

        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;
}

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 */
        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].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)) {
                        soc_pcm_hw_free(be_substream);
                        be->dpcm[stream].state = SND_SOC_DPCM_STATE_HW_FREE;
                }

                dev_dbg(be->dev, "ASoC: close BE %s\n",
                        be->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;
}

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 */
        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;
        }

        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;
}

int dpcm_be_dai_hw_params(struct snd_soc_pcm_runtime *fe, int stream)
{
        struct snd_soc_dpcm *dpcm;
        int ret;

        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;

                /* 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;
                        }
                }

                /* 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) {
                        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 */
        for_each_dpcm_be_rollback(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 (!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->be->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;
}

int dpcm_be_dai_trigger(struct snd_soc_pcm_runtime *fe, int stream,
                               int cmd)
{
        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;

                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_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_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:
                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 = 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);
}

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) {
                        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 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;
        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)
                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 */
        spin_lock_irqsave(&fe->card->dpcm_lock, flags);
        for_each_dpcm_be(fe, stream, dpcm) {
                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;
        }
        spin_unlock_irqrestore(&fe->card->dpcm_lock, flags);

        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;
}

static int soc_dpcm_fe_runtime_update(struct snd_soc_pcm_runtime *fe, int new)
{
        struct snd_soc_dapm_widget_list *list;
        int count, paths;

        if (!fe->dai_link->dynamic)
                return 0;

        /* only check active links */
        if (!fe->cpu_dai->active)
                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);

        /* skip if FE doesn't have playback capability */
        if (!snd_soc_dai_stream_valid(fe->cpu_dai,   SNDRV_PCM_STREAM_PLAYBACK) ||
            !snd_soc_dai_stream_valid(fe->codec_dai, SNDRV_PCM_STREAM_PLAYBACK))
                goto capture;

        /* skip if FE isn't currently playing */
        if (!fe->cpu_dai->playback_active || !fe->codec_dai->playback_active)
                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");
                return paths;
        }

        /* update any playback paths */
        count = dpcm_process_paths(fe, SNDRV_PCM_STREAM_PLAYBACK, &list, new);
        if (count) {
                if (new)
                        dpcm_run_new_update(fe, SNDRV_PCM_STREAM_PLAYBACK);
                else
                        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 (!snd_soc_dai_stream_valid(fe->cpu_dai,   SNDRV_PCM_STREAM_CAPTURE) ||
            !snd_soc_dai_stream_valid(fe->codec_dai, SNDRV_PCM_STREAM_CAPTURE))
                return 0;

        /* skip if FE isn't currently capturing */
        if (!fe->cpu_dai->capture_active || !fe->codec_dai->capture_active)
                return 0;

        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");
                return paths;
        }

        /* update any old capture paths */
        count = dpcm_process_paths(fe, SNDRV_PCM_STREAM_CAPTURE, &list, new);
        if (count) {
                if (new)
                        dpcm_run_new_update(fe, SNDRV_PCM_STREAM_CAPTURE);
                else
                        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);

        return 0;
}

/* 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)
{
        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;
}
int soc_dpcm_be_digital_mute(struct snd_soc_pcm_runtime *fe, int mute)
{
        struct snd_soc_dpcm *dpcm;
        struct snd_soc_dai *dai;

        for_each_dpcm_be(fe, SNDRV_PCM_STREAM_PLAYBACK, dpcm) {

                struct snd_soc_pcm_runtime *be = dpcm->be;
                int i;

                if (be->dai_link->ignore_suspend)
                        continue;

                for_each_rtd_codec_dai(be, i, dai) {
                        struct snd_soc_dai_driver *drv = dai->driver;

                        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;

        ret = dpcm_path_get(fe, stream, &list);
        if (ret < 0) {
                mutex_unlock(&fe->card->mutex);
                return ret;
        } else if (ret == 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 */
                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;
        }

        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 */
        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;
        mutex_unlock(&fe->card->mutex);
        return ret;
}

static void soc_pcm_private_free(struct snd_pcm *pcm)
{
        struct snd_soc_pcm_runtime *rtd = pcm->private_data;

        /* need to sync the delayed work before releasing resources */
        flush_delayed_work(&rtd->delayed_work);
        snd_soc_pcm_component_free(pcm);
}

/* create a new pcm */
int soc_new_pcm(struct snd_soc_pcm_runtime *rtd, int num)
{
        struct snd_soc_dai *codec_dai;
        struct snd_soc_dai *cpu_dai = rtd->cpu_dai;
        struct snd_soc_rtdcom_list *rtdcom;
        struct snd_pcm *pcm;
        char new_name[64];
        int ret = 0, playback = 0, capture = 0;
        int i;

        if (rtd->dai_link->dynamic || rtd->dai_link->no_pcm) {
                playback = rtd->dai_link->dpcm_playback;
                capture = rtd->dai_link->dpcm_capture;
        } else {
                /* Adapt stream for codec2codec links */
                struct snd_soc_pcm_stream *cpu_capture = rtd->dai_link->params ?
                        &cpu_dai->driver->playback : &cpu_dai->driver->capture;
                struct snd_soc_pcm_stream *cpu_playback = rtd->dai_link->params ?
                        &cpu_dai->driver->capture : &cpu_dai->driver->playback;

                for_each_rtd_codec_dai(rtd, i, codec_dai) {
                        if (snd_soc_dai_stream_valid(codec_dai, SNDRV_PCM_STREAM_PLAYBACK) &&
                            snd_soc_dai_stream_valid(cpu_dai,   SNDRV_PCM_STREAM_PLAYBACK))
                                playback = 1;
                        if (snd_soc_dai_stream_valid(codec_dai, SNDRV_PCM_STREAM_CAPTURE) &&
                            snd_soc_dai_stream_valid(cpu_dai,   SNDRV_PCM_STREAM_CAPTURE))
                                capture = 1;
                }

                capture = capture && cpu_capture->channels_min;
                playback = playback && cpu_playback->channels_min;
        }

        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->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,
                                (rtd->num_codecs > 1) ?
                                "multicodec" : rtd->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 */
        if (rtd->dai_link->params)
                INIT_DELAYED_WORK(&rtd->delayed_work,
                                  codec2codec_close_delayed_work);
        else
                INIT_DELAYED_WORK(&rtd->delayed_work, close_delayed_work);

        pcm->nonatomic = rtd->dai_link->nonatomic;
        rtd->pcm = pcm;
        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;
                rtd->ops.ioctl          = snd_soc_pcm_component_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          = snd_soc_pcm_component_ioctl;
        }

        for_each_rtdcom(rtd, rtdcom) {
                const struct snd_pcm_ops *ops = rtdcom->component->driver->ops;

                if (!ops)
                        continue;

                if (ops->copy_user)
                        rtd->ops.copy_user      = snd_soc_pcm_component_copy_user;
                if (ops->page)
                        rtd->ops.page           = snd_soc_pcm_component_page;
                if (ops->mmap)
                        rtd->ops.mmap           = snd_soc_pcm_component_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);

        ret = snd_soc_pcm_component_new(pcm);
        if (ret < 0) {
                dev_err(rtd->dev, "ASoC: pcm constructor failed: %d\n", ret);
                return ret;
        }

        pcm->private_free = soc_pcm_private_free;
        pcm->no_device_suspend = true;
out:
        dev_info(rtd->card->dev, "%s <-> %s mapping ok\n",
                 (rtd->num_codecs > 1) ? "multicodec" : rtd->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);