/*
 * soc-pcm.c  --  ALSA SoC PCM
 *
 * Copyright 2005 Wolfson Microelectronics PLC.
 * Copyright 2005 Openedhand Ltd.
 * Copyright (C) 2010 Slimlogic Ltd.
 * Copyright (C) 2010 Texas Instruments Inc.
 *
 * Authors: Liam Girdwood <lrg@ti.com>
 *          Mark Brown <broonie@opensource.wolfsonmicro.com>       
 *
 *  This program is free software; you can redistribute  it and/or modify it
 *  under  the terms of  the GNU General  Public License as published by the
 *  Free Software Foundation;  either version 2 of the  License, or (at your
 *  option) any later version.
 *
 */

#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/delay.h>
#include <linux/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

/* DPCM stream event, send event to FE and all active BEs. */
static int dpcm_dapm_stream_event(struct snd_soc_pcm_runtime *fe, int dir,
        int event)
{
        struct snd_soc_dpcm *dpcm;

        list_for_each_entry(dpcm, &fe->dpcm[dir].be_clients, list_be) {

                struct snd_soc_pcm_runtime *be = dpcm->be;

                dev_dbg(be->dev, "pm: BE %s event %d dir %d\n",
                                be->dai_link->name, event, dir);

                snd_soc_dapm_stream_event(be, dir, event);
        }

        snd_soc_dapm_stream_event(fe, dir, event);

        return 0;
}

static int soc_pcm_apply_symmetry(struct snd_pcm_substream *substream,
                                        struct snd_soc_dai *soc_dai)
{
        struct snd_soc_pcm_runtime *rtd = substream->private_data;
        int ret;

        if (!soc_dai->driver->symmetric_rates &&
            !rtd->dai_link->symmetric_rates)
                return 0;

        /* This can happen if multiple streams are starting simultaneously -
         * the second can need to get its constraints before the first has
         * picked a rate.  Complain and allow the application to carry on.
         */
        if (!soc_dai->rate) {
                dev_warn(soc_dai->dev,
                         "Not enforcing symmetric_rates due to race\n");
                return 0;
        }

        dev_dbg(soc_dai->dev, "Symmetry forces %dHz rate\n", soc_dai->rate);

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

        return 0;
}

/*
 * List of sample sizes that might go over the bus for parameter
 * application.  There ought to be a wildcard sample size for things
 * like the DAC/ADC resolution to use but there isn't right now.
 */
static int sample_sizes[] = {
        24, 32,
};

static void soc_pcm_apply_msb(struct snd_pcm_substream *substream,
                              struct snd_soc_dai *dai)
{
        int ret, i, bits;

        if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
                bits = dai->driver->playback.sig_bits;
        else
                bits = dai->driver->capture.sig_bits;

        if (!bits)
                return;

        for (i = 0; i < ARRAY_SIZE(sample_sizes); i++) {
                if (bits >= sample_sizes[i])
                        continue;

                ret = snd_pcm_hw_constraint_msbits(substream->runtime, 0,
                                                   sample_sizes[i], bits);
                if (ret != 0)
                        dev_warn(dai->dev,
                                 "Failed to set MSB %d/%d: %d\n",
                                 bits, sample_sizes[i], 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, platform, machine and codec DAI.
 */
static int soc_pcm_open(struct snd_pcm_substream *substream)
{
        struct snd_soc_pcm_runtime *rtd = substream->private_data;
        struct snd_pcm_runtime *runtime = substream->runtime;
        struct snd_soc_platform *platform = rtd->platform;
        struct snd_soc_dai *cpu_dai = rtd->cpu_dai;
        struct snd_soc_dai *codec_dai = rtd->codec_dai;
        struct snd_soc_dai_driver *cpu_dai_drv = cpu_dai->driver;
        struct snd_soc_dai_driver *codec_dai_drv = codec_dai->driver;
        int ret = 0;

        pm_runtime_get_sync(cpu_dai->dev);
        pm_runtime_get_sync(codec_dai->dev);
        pm_runtime_get_sync(platform->dev);

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

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

        if (platform->driver->ops && platform->driver->ops->open) {
                ret = platform->driver->ops->open(substream);
                if (ret < 0) {
                        dev_err(platform->dev, "can't open platform %s: %d\n",
                                platform->name, ret);
                        goto platform_err;
                }
        }

        if (codec_dai->driver->ops->startup) {
                ret = codec_dai->driver->ops->startup(substream, codec_dai);
                if (ret < 0) {
                        dev_err(codec_dai->dev, "can't open codec %s: %d\n",
                                codec_dai->name, ret);
                        goto codec_dai_err;
                }
        }

        if (rtd->dai_link->ops && rtd->dai_link->ops->startup) {
                ret = rtd->dai_link->ops->startup(substream);
                if (ret < 0) {
                        pr_err("asoc: %s startup failed: %d\n",
                               rtd->dai_link->name, ret);
                        goto machine_err;
                }
        }

        /* Dynamic PCM DAI links compat checks use dynamic capabilities */
        if (rtd->dai_link->dynamic || rtd->dai_link->no_pcm)
                goto dynamic;

        /* Check that the codec and cpu DAIs are compatible */
        if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
                runtime->hw.rate_min =
                        max(codec_dai_drv->playback.rate_min,
                            cpu_dai_drv->playback.rate_min);
                runtime->hw.rate_max =
                        min(codec_dai_drv->playback.rate_max,
                            cpu_dai_drv->playback.rate_max);
                runtime->hw.channels_min =
                        max(codec_dai_drv->playback.channels_min,
                                cpu_dai_drv->playback.channels_min);
                runtime->hw.channels_max =
                        min(codec_dai_drv->playback.channels_max,
                                cpu_dai_drv->playback.channels_max);
                runtime->hw.formats =
                        codec_dai_drv->playback.formats & cpu_dai_drv->playback.formats;
                runtime->hw.rates =
                        codec_dai_drv->playback.rates & cpu_dai_drv->playback.rates;
                if (codec_dai_drv->playback.rates
                           & (SNDRV_PCM_RATE_KNOT | SNDRV_PCM_RATE_CONTINUOUS))
                        runtime->hw.rates |= cpu_dai_drv->playback.rates;
                if (cpu_dai_drv->playback.rates
                           & (SNDRV_PCM_RATE_KNOT | SNDRV_PCM_RATE_CONTINUOUS))
                        runtime->hw.rates |= codec_dai_drv->playback.rates;
        } else {
                runtime->hw.rate_min =
                        max(codec_dai_drv->capture.rate_min,
                            cpu_dai_drv->capture.rate_min);
                runtime->hw.rate_max =
                        min(codec_dai_drv->capture.rate_max,
                            cpu_dai_drv->capture.rate_max);
                runtime->hw.channels_min =
                        max(codec_dai_drv->capture.channels_min,
                                cpu_dai_drv->capture.channels_min);
                runtime->hw.channels_max =
                        min(codec_dai_drv->capture.channels_max,
                                cpu_dai_drv->capture.channels_max);
                runtime->hw.formats =
                        codec_dai_drv->capture.formats & cpu_dai_drv->capture.formats;
                runtime->hw.rates =
                        codec_dai_drv->capture.rates & cpu_dai_drv->capture.rates;
                if (codec_dai_drv->capture.rates
                           & (SNDRV_PCM_RATE_KNOT | SNDRV_PCM_RATE_CONTINUOUS))
                        runtime->hw.rates |= cpu_dai_drv->capture.rates;
                if (cpu_dai_drv->capture.rates
                           & (SNDRV_PCM_RATE_KNOT | SNDRV_PCM_RATE_CONTINUOUS))
                        runtime->hw.rates |= codec_dai_drv->capture.rates;
        }

        ret = -EINVAL;
        snd_pcm_limit_hw_rates(runtime);
        if (!runtime->hw.rates) {
                printk(KERN_ERR "asoc: %s <-> %s No matching rates\n",
                        codec_dai->name, cpu_dai->name);
                goto config_err;
        }
        if (!runtime->hw.formats) {
                printk(KERN_ERR "asoc: %s <-> %s No matching formats\n",
                        codec_dai->name, cpu_dai->name);
                goto config_err;
        }
        if (!runtime->hw.channels_min || !runtime->hw.channels_max ||
            runtime->hw.channels_min > runtime->hw.channels_max) {
                printk(KERN_ERR "asoc: %s <-> %s No matching channels\n",
                                codec_dai->name, cpu_dai->name);
                goto config_err;
        }

        soc_pcm_apply_msb(substream, codec_dai);
        soc_pcm_apply_msb(substream, cpu_dai);

        /* Symmetry only applies if we've already got an active stream. */
        if (cpu_dai->active) {
                ret = soc_pcm_apply_symmetry(substream, cpu_dai);
                if (ret != 0)
                        goto config_err;
        }

        if (codec_dai->active) {
                ret = soc_pcm_apply_symmetry(substream, codec_dai);
                if (ret != 0)
                        goto config_err;
        }

        pr_debug("asoc: %s <-> %s info:\n",
                        codec_dai->name, cpu_dai->name);
        pr_debug("asoc: rate mask 0x%x\n", runtime->hw.rates);
        pr_debug("asoc: min ch %d max ch %d\n", runtime->hw.channels_min,
                 runtime->hw.channels_max);
        pr_debug("asoc: min rate %d max rate %d\n", runtime->hw.rate_min,
                 runtime->hw.rate_max);

dynamic:
        if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
                cpu_dai->playback_active++;
                codec_dai->playback_active++;
        } else {
                cpu_dai->capture_active++;
                codec_dai->capture_active++;
        }
        cpu_dai->active++;
        codec_dai->active++;
        rtd->codec->active++;
        mutex_unlock(&rtd->pcm_mutex);
        return 0;

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

machine_err:
        if (codec_dai->driver->ops->shutdown)
                codec_dai->driver->ops->shutdown(substream, codec_dai);

codec_dai_err:
        if (platform->driver->ops && platform->driver->ops->close)
                platform->driver->ops->close(substream);

platform_err:
        if (cpu_dai->driver->ops->shutdown)
                cpu_dai->driver->ops->shutdown(substream, cpu_dai);
out:
        mutex_unlock(&rtd->pcm_mutex);

        pm_runtime_put(platform->dev);
        pm_runtime_put(codec_dai->dev);
        pm_runtime_put(cpu_dai->dev);

        return ret;
}

/*
 * Power down the audio subsystem pmdown_time msecs after close is called.
 * This is to ensure there are no pops or clicks in between any music tracks
 * due to DAPM power cycling.
 */
static void close_delayed_work(struct work_struct *work)
{
        struct snd_soc_pcm_runtime *rtd =
                        container_of(work, struct snd_soc_pcm_runtime, delayed_work.work);
        struct snd_soc_dai *codec_dai = rtd->codec_dai;

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

        pr_debug("pop wq checking: %s status: %s waiting: %s\n",
                 codec_dai->driver->playback.stream_name,
                 codec_dai->playback_active ? "active" : "inactive",
                 codec_dai->pop_wait ? "yes" : "no");

        /* are we waiting on this codec DAI stream */
        if (codec_dai->pop_wait == 1) {
                codec_dai->pop_wait = 0;
                snd_soc_dapm_stream_event(rtd, SNDRV_PCM_STREAM_PLAYBACK,
                                          SND_SOC_DAPM_STREAM_STOP);
        }

        mutex_unlock(&rtd->pcm_mutex);
}

/*
 * Called by ALSA when a PCM substream is closed. Private data can be
 * freed here. The cpu DAI, codec DAI, machine and platform are also
 * shutdown.
 */
static int soc_pcm_close(struct snd_pcm_substream *substream)
{
        struct snd_soc_pcm_runtime *rtd = substream->private_data;
        struct snd_soc_platform *platform = rtd->platform;
        struct snd_soc_dai *cpu_dai = rtd->cpu_dai;
        struct snd_soc_dai *codec_dai = rtd->codec_dai;
        struct snd_soc_codec *codec = rtd->codec;

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

        if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
                cpu_dai->playback_active--;
                codec_dai->playback_active--;
        } else {
                cpu_dai->capture_active--;
                codec_dai->capture_active--;
        }

        cpu_dai->active--;
        codec_dai->active--;
        codec->active--;

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

        if (!codec_dai->active)
                codec_dai->rate = 0;

        /* Muting the DAC suppresses artifacts caused during digital
         * shutdown, for example from stopping clocks.
         */
        if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
                snd_soc_dai_digital_mute(codec_dai, 1);

        if (cpu_dai->driver->ops->shutdown)
                cpu_dai->driver->ops->shutdown(substream, cpu_dai);

        if (codec_dai->driver->ops->shutdown)
                codec_dai->driver->ops->shutdown(substream, codec_dai);

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

        if (platform->driver->ops && platform->driver->ops->close)
                platform->driver->ops->close(substream);
        cpu_dai->runtime = NULL;

        if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
                if (!rtd->pmdown_time || codec->ignore_pmdown_time ||
                    rtd->dai_link->ignore_pmdown_time) {
                        /* powered down playback stream now */
                        snd_soc_dapm_stream_event(rtd,
                                                  SNDRV_PCM_STREAM_PLAYBACK,
                                                  SND_SOC_DAPM_STREAM_STOP);
                } else {
                        /* start delayed pop wq here for playback streams */
                        codec_dai->pop_wait = 1;
                        schedule_delayed_work(&rtd->delayed_work,
                                msecs_to_jiffies(rtd->pmdown_time));
                }
        } else {
                /* capture streams can be powered down now */
                snd_soc_dapm_stream_event(rtd, SNDRV_PCM_STREAM_CAPTURE,
                                          SND_SOC_DAPM_STREAM_STOP);
        }

        mutex_unlock(&rtd->pcm_mutex);

        pm_runtime_put(platform->dev);
        pm_runtime_put(codec_dai->dev);
        pm_runtime_put(cpu_dai->dev);

        return 0;
}

/*
 * Called by ALSA when the PCM substream is prepared, can set format, sample
 * rate, etc.  This function is non atomic and can be called multiple times,
 * it can refer to the runtime info.
 */
static int soc_pcm_prepare(struct snd_pcm_substream *substream)
{
        struct snd_soc_pcm_runtime *rtd = substream->private_data;
        struct snd_soc_platform *platform = rtd->platform;
        struct snd_soc_dai *cpu_dai = rtd->cpu_dai;
        struct snd_soc_dai *codec_dai = rtd->codec_dai;
        int ret = 0;

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

        if (rtd->dai_link->ops && rtd->dai_link->ops->prepare) {
                ret = rtd->dai_link->ops->prepare(substream);
                if (ret < 0) {
                        pr_err("asoc: machine prepare error: %d\n", ret);
                        goto out;
                }
        }

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

        if (codec_dai->driver->ops->prepare) {
                ret = codec_dai->driver->ops->prepare(substream, codec_dai);
                if (ret < 0) {
                        dev_err(codec_dai->dev, "DAI prepare error: %d\n",
                                ret);
                        goto out;
                }
        }

        if (cpu_dai->driver->ops->prepare) {
                ret = cpu_dai->driver->ops->prepare(substream, cpu_dai);
                if (ret < 0) {
                        dev_err(cpu_dai->dev, "DAI prepare error: %d\n",
                                ret);
                        goto out;
                }
        }

        /* cancel any delayed stream shutdown that is pending */
        if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK &&
            codec_dai->pop_wait) {
                codec_dai->pop_wait = 0;
                cancel_delayed_work(&rtd->delayed_work);
        }

        snd_soc_dapm_stream_event(rtd, substream->stream,
                        SND_SOC_DAPM_STREAM_START);

        snd_soc_dai_digital_mute(codec_dai, 0);

out:
        mutex_unlock(&rtd->pcm_mutex);
        return ret;
}

/*
 * Called by ALSA when the hardware params are set by application. This
 * function can also be called multiple times and can allocate buffers
 * (using snd_pcm_lib_* ). It's non-atomic.
 */
static int soc_pcm_hw_params(struct snd_pcm_substream *substream,
                                struct snd_pcm_hw_params *params)
{
        struct snd_soc_pcm_runtime *rtd = substream->private_data;
        struct snd_soc_platform *platform = rtd->platform;
        struct snd_soc_dai *cpu_dai = rtd->cpu_dai;
        struct snd_soc_dai *codec_dai = rtd->codec_dai;
        int ret = 0;

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

        if (rtd->dai_link->ops && rtd->dai_link->ops->hw_params) {
                ret = rtd->dai_link->ops->hw_params(substream, params);
                if (ret < 0) {
                        pr_err("asoc: machine hw_params failed: %d\n", ret);
                        goto out;
                }
        }

        if (codec_dai->driver->ops->hw_params) {
                ret = codec_dai->driver->ops->hw_params(substream, params, codec_dai);
                if (ret < 0) {
                        dev_err(codec_dai->dev, "can't set %s hw params: %d\n",
                                codec_dai->name, ret);
                        goto codec_err;
                }
        }

        if (cpu_dai->driver->ops->hw_params) {
                ret = cpu_dai->driver->ops->hw_params(substream, params, cpu_dai);
                if (ret < 0) {
                        dev_err(cpu_dai->dev, "%s hw params failed: %d\n",
                                cpu_dai->name, ret);
                        goto interface_err;
                }
        }

        if (platform->driver->ops && platform->driver->ops->hw_params) {
                ret = platform->driver->ops->hw_params(substream, params);
                if (ret < 0) {
                        dev_err(platform->dev, "%s hw params failed: %d\n",
                               platform->name, ret);
                        goto platform_err;
                }
        }

        /* store the rate for each DAIs */
        cpu_dai->rate = params_rate(params);
        codec_dai->rate = params_rate(params);

out:
        mutex_unlock(&rtd->pcm_mutex);
        return ret;

platform_err:
        if (cpu_dai->driver->ops->hw_free)
                cpu_dai->driver->ops->hw_free(substream, cpu_dai);

interface_err:
        if (codec_dai->driver->ops->hw_free)
                codec_dai->driver->ops->hw_free(substream, codec_dai);

codec_err:
        if (rtd->dai_link->ops && rtd->dai_link->ops->hw_free)
                rtd->dai_link->ops->hw_free(substream);

        mutex_unlock(&rtd->pcm_mutex);
        return ret;
}

/*
 * Frees resources allocated by hw_params, can be called multiple times
 */
static int soc_pcm_hw_free(struct snd_pcm_substream *substream)
{
        struct snd_soc_pcm_runtime *rtd = substream->private_data;
        struct snd_soc_platform *platform = rtd->platform;
        struct snd_soc_dai *cpu_dai = rtd->cpu_dai;
        struct snd_soc_dai *codec_dai = rtd->codec_dai;
        struct snd_soc_codec *codec = rtd->codec;

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

        /* apply codec digital mute */
        if (!codec->active)
                snd_soc_dai_digital_mute(codec_dai, 1);

        /* free any machine hw params */
        if (rtd->dai_link->ops && rtd->dai_link->ops->hw_free)
                rtd->dai_link->ops->hw_free(substream);

        /* free any DMA resources */
        if (platform->driver->ops && platform->driver->ops->hw_free)
                platform->driver->ops->hw_free(substream);

        /* now free hw params for the DAIs  */
        if (codec_dai->driver->ops->hw_free)
                codec_dai->driver->ops->hw_free(substream, codec_dai);

        if (cpu_dai->driver->ops->hw_free)
                cpu_dai->driver->ops->hw_free(substream, cpu_dai);

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

static int soc_pcm_trigger(struct snd_pcm_substream *substream, int cmd)
{
        struct snd_soc_pcm_runtime *rtd = substream->private_data;
        struct snd_soc_platform *platform = rtd->platform;
        struct snd_soc_dai *cpu_dai = rtd->cpu_dai;
        struct snd_soc_dai *codec_dai = rtd->codec_dai;
        int ret;

        if (codec_dai->driver->ops->trigger) {
                ret = codec_dai->driver->ops->trigger(substream, cmd, codec_dai);
                if (ret < 0)
                        return ret;
        }

        if (platform->driver->ops && platform->driver->ops->trigger) {
                ret = platform->driver->ops->trigger(substream, cmd);
                if (ret < 0)
                        return ret;
        }

        if (cpu_dai->driver->ops->trigger) {
                ret = cpu_dai->driver->ops->trigger(substream, cmd, cpu_dai);
                if (ret < 0)
                        return ret;
        }
        return 0;
}

static int soc_pcm_bespoke_trigger(struct snd_pcm_substream *substream,
                                   int cmd)
{
        struct snd_soc_pcm_runtime *rtd = substream->private_data;
        struct snd_soc_platform *platform = rtd->platform;
        struct snd_soc_dai *cpu_dai = rtd->cpu_dai;
        struct snd_soc_dai *codec_dai = rtd->codec_dai;
        int ret;

        if (codec_dai->driver->ops->bespoke_trigger) {
                ret = codec_dai->driver->ops->bespoke_trigger(substream, cmd, codec_dai);
                if (ret < 0)
                        return ret;
        }

        if (platform->driver->bespoke_trigger) {
                ret = platform->driver->bespoke_trigger(substream, cmd);
                if (ret < 0)
                        return ret;
        }

        if (cpu_dai->driver->ops->bespoke_trigger) {
                ret = cpu_dai->driver->ops->bespoke_trigger(substream, cmd, cpu_dai);
                if (ret < 0)
                        return ret;
        }
        return 0;
}
/*
 * soc level wrapper for pointer callback
 * If cpu_dai, codec_dai, platform driver has the delay callback, than
 * the runtime->delay will be updated accordingly.
 */
static snd_pcm_uframes_t soc_pcm_pointer(struct snd_pcm_substream *substream)
{
        struct snd_soc_pcm_runtime *rtd = substream->private_data;
        struct snd_soc_platform *platform = rtd->platform;
        struct snd_soc_dai *cpu_dai = rtd->cpu_dai;
        struct snd_soc_dai *codec_dai = rtd->codec_dai;
        struct snd_pcm_runtime *runtime = substream->runtime;
        snd_pcm_uframes_t offset = 0;
        snd_pcm_sframes_t delay = 0;

        if (platform->driver->ops && platform->driver->ops->pointer)
                offset = platform->driver->ops->pointer(substream);

        if (cpu_dai->driver->ops->delay)
                delay += cpu_dai->driver->ops->delay(substream, cpu_dai);

        if (codec_dai->driver->ops->delay)
                delay += codec_dai->driver->ops->delay(substream, codec_dai);

        if (platform->driver->delay)
                delay += platform->driver->delay(substream, codec_dai);

        runtime->delay = delay;

        return offset;
}

/* connect a FE and BE */
static int dpcm_be_connect(struct snd_soc_pcm_runtime *fe,
                struct snd_soc_pcm_runtime *be, int stream)
{
        struct snd_soc_dpcm *dpcm;

        /* only add new dpcms */
        list_for_each_entry(dpcm, &fe->dpcm[stream].be_clients, list_be) {
                if (dpcm->be == be && dpcm->fe == fe)
                        return 0;
        }

        dpcm = kzalloc(sizeof(struct snd_soc_dpcm), GFP_KERNEL);
        if (!dpcm)
                return -ENOMEM;

        dpcm->be = be;
        dpcm->fe = fe;
        be->dpcm[stream].runtime = fe->dpcm[stream].runtime;
        dpcm->state = SND_SOC_DPCM_LINK_STATE_NEW;
        list_add(&dpcm->list_be, &fe->dpcm[stream].be_clients);
        list_add(&dpcm->list_fe, &be->dpcm[stream].fe_clients);

        dev_dbg(fe->dev, "  connected new DPCM %s path %s %s %s\n",
                        stream ? "capture" : "playback",  fe->dai_link->name,
                        stream ? "<-" : "->", be->dai_link->name);

#ifdef CONFIG_DEBUG_FS
        dpcm->debugfs_state = debugfs_create_u32(be->dai_link->name, 0644,
                        fe->debugfs_dpcm_root, &dpcm->state);
#endif
        return 1;
}

/* reparent a BE onto another FE */
static void dpcm_be_reparent(struct snd_soc_pcm_runtime *fe,
                        struct snd_soc_pcm_runtime *be, int stream)
{
        struct snd_soc_dpcm *dpcm;
        struct snd_pcm_substream *fe_substream, *be_substream;

        /* reparent if BE is connected to other FEs */
        if (!be->dpcm[stream].users)
                return;

        be_substream = snd_soc_dpcm_get_substream(be, stream);

        list_for_each_entry(dpcm, &be->dpcm[stream].fe_clients, list_fe) {
                if (dpcm->fe == fe)
                        continue;

                dev_dbg(fe->dev, "  reparent %s path %s %s %s\n",
                        stream ? "capture" : "playback",
                        dpcm->fe->dai_link->name,
                        stream ? "<-" : "->", dpcm->be->dai_link->name);

                fe_substream = snd_soc_dpcm_get_substream(dpcm->fe, stream);
                be_substream->runtime = fe_substream->runtime;
                break;
        }
}

/* disconnect a BE and FE */
static void dpcm_be_disconnect(struct snd_soc_pcm_runtime *fe, int stream)
{
        struct snd_soc_dpcm *dpcm, *d;

        list_for_each_entry_safe(dpcm, d, &fe->dpcm[stream].be_clients, list_be) {
                dev_dbg(fe->dev, "BE %s disconnect check for %s\n",
                                stream ? "capture" : "playback",
                                dpcm->be->dai_link->name);

                if (dpcm->state != SND_SOC_DPCM_LINK_STATE_FREE)
                        continue;

                dev_dbg(fe->dev, "  freed DSP %s path %s %s %s\n",
                        stream ? "capture" : "playback", fe->dai_link->name,
                        stream ? "<-" : "->", dpcm->be->dai_link->name);

                /* BEs still alive need new FE */
                dpcm_be_reparent(fe, dpcm->be, stream);

#ifdef CONFIG_DEBUG_FS
                debugfs_remove(dpcm->debugfs_state);
#endif
                list_del(&dpcm->list_be);
                list_del(&dpcm->list_fe);
                kfree(dpcm);
        }
}

/* get BE for DAI widget and stream */
static struct snd_soc_pcm_runtime *dpcm_get_be(struct snd_soc_card *card,
                struct snd_soc_dapm_widget *widget, int stream)
{
        struct snd_soc_pcm_runtime *be;
        int i;

        if (stream == SNDRV_PCM_STREAM_PLAYBACK) {
                for (i = 0; i < card->num_links; i++) {
                        be = &card->rtd[i];

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

                        if (be->cpu_dai->playback_widget == widget ||
                                be->codec_dai->playback_widget == widget)
                                return be;
                }
        } else {

                for (i = 0; i < card->num_links; i++) {
                        be = &card->rtd[i];

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

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

        dev_err(card->dev, "can't get %s BE for %s\n",
                stream ? "capture" : "playback", widget->name);
        return NULL;
}

static inline struct snd_soc_dapm_widget *
        rtd_get_cpu_widget(struct snd_soc_pcm_runtime *rtd, int stream)
{
        if (stream == SNDRV_PCM_STREAM_PLAYBACK)
                return rtd->cpu_dai->playback_widget;
        else
                return rtd->cpu_dai->capture_widget;
}

static inline struct snd_soc_dapm_widget *
        rtd_get_codec_widget(struct snd_soc_pcm_runtime *rtd, int stream)
{
        if (stream == SNDRV_PCM_STREAM_PLAYBACK)
                return rtd->codec_dai->playback_widget;
        else
                return rtd->codec_dai->capture_widget;
}

static int widget_in_list(struct snd_soc_dapm_widget_list *list,
                struct snd_soc_dapm_widget *widget)
{
        int i;

        for (i = 0; i < list->num_widgets; i++) {
                if (widget == list->widgets[i])
                        return 1;
        }

        return 0;
}

static int dpcm_path_get(struct snd_soc_pcm_runtime *fe,
        int stream, struct snd_soc_dapm_widget_list **list_)
{
        struct snd_soc_dai *cpu_dai = fe->cpu_dai;
        struct snd_soc_dapm_widget_list *list;
        int paths;

        list = kzalloc(sizeof(struct snd_soc_dapm_widget_list) +
                        sizeof(struct snd_soc_dapm_widget *), GFP_KERNEL);
        if (list == NULL)
                return -ENOMEM;

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

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

        *list_ = list;
        return paths;
}

static inline void dpcm_path_put(struct snd_soc_dapm_widget_list **list)
{
        kfree(*list);
}

static int dpcm_prune_paths(struct snd_soc_pcm_runtime *fe, int stream,
        struct snd_soc_dapm_widget_list **list_)
{
        struct snd_soc_dpcm *dpcm;
        struct snd_soc_dapm_widget_list *list = *list_;
        struct snd_soc_dapm_widget *widget;
        int prune = 0;

        /* Destroy any old FE <--> BE connections */
        list_for_each_entry(dpcm, &fe->dpcm[stream].be_clients, list_be) {

                /* is there a valid CPU DAI widget for this BE */
                widget = rtd_get_cpu_widget(dpcm->be, stream);

                /* prune the BE if it's no longer in our active list */
                if (widget && widget_in_list(list, widget))
                        continue;

                /* is there a valid CODEC DAI widget for this BE */
                widget = rtd_get_codec_widget(dpcm->be, stream);

                /* prune the BE if it's no longer in our active list */
                if (widget && widget_in_list(list, widget))
                        continue;

                dev_dbg(fe->dev, "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, "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++) {

                if (list->widgets[i]->id != snd_soc_dapm_dai)
                        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, "no BE found for %s\n",
                                        list->widgets[i]->name);
                        continue;
                }

                /* make sure BE is a real BE */
                if (!be->dai_link->no_pcm)
                        continue;

                /* don't connect if FE is not running */
                if (!fe->dpcm[stream].runtime)
                        continue;

                /* newly connected FE and BE */
                err = dpcm_be_connect(fe, be, stream);
                if (err < 0) {
                        dev_err(fe->dev, "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, "found %d new BE paths\n", new);
        return new;
}

/*
 * Find the corresponding BE DAIs that source or sink audio to this
 * FE substream.
 */
static int dpcm_process_paths(struct snd_soc_pcm_runtime *fe,
        int stream, struct snd_soc_dapm_widget_list **list, int new)
{
        if (new)
                return dpcm_add_paths(fe, stream, list);
        else
                return dpcm_prune_paths(fe, stream, list);
}

static void dpcm_clear_pending_state(struct snd_soc_pcm_runtime *fe, int stream)
{
        struct snd_soc_dpcm *dpcm;

        list_for_each_entry(dpcm, &fe->dpcm[stream].be_clients, list_be)
                dpcm->be->dpcm[stream].runtime_update =
                                                SND_SOC_DPCM_UPDATE_NO;
}

static void dpcm_be_dai_startup_unwind(struct snd_soc_pcm_runtime *fe,
        int stream)
{
        struct snd_soc_dpcm *dpcm;

        /* disable any enabled and non active backends */
        list_for_each_entry(dpcm, &fe->dpcm[stream].be_clients, list_be) {

                struct snd_soc_pcm_runtime *be = dpcm->be;
                struct snd_pcm_substream *be_substream =
                        snd_soc_dpcm_get_substream(be, stream);

                if (be->dpcm[stream].users == 0)

                        dev_err(be->dev, "no users %s at close - state %d\n",
                                stream ? "capture" : "playback",
                                be->dpcm[stream].state);

                if (--be->dpcm[stream].users != 0)
                        continue;

                if (be->dpcm[stream].state != SND_SOC_DPCM_STATE_OPEN)
                        continue;

                soc_pcm_close(be_substream);
                be_substream->runtime = NULL;
                be->dpcm[stream].state = SND_SOC_DPCM_STATE_CLOSE;
        }
}

static int dpcm_be_dai_startup(struct snd_soc_pcm_runtime *fe, int stream)
{
        struct snd_soc_dpcm *dpcm;
        int err, count = 0;

        /* only startup BE DAIs that are either sinks or sources to this FE DAI */
        list_for_each_entry(dpcm, &fe->dpcm[stream].be_clients, list_be) {

                struct snd_soc_pcm_runtime *be = dpcm->be;
                struct snd_pcm_substream *be_substream =
                        snd_soc_dpcm_get_substream(be, stream);

                /* 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, "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, "dpcm: open BE %s\n", be->dai_link->name);

                be_substream->runtime = be->dpcm[stream].runtime;
                err = soc_pcm_open(be_substream);
                if (err < 0) {
                        dev_err(be->dev, "BE open failed %d\n", err);
                        be->dpcm[stream].users--;
                        if (be->dpcm[stream].users < 0)
                                dev_err(be->dev, "no users %s at unwind %d\n",
                                        stream ? "capture" : "playback",
                                        be->dpcm[stream].state);

                        be->dpcm[stream].state = SND_SOC_DPCM_STATE_CLOSE;
                        goto unwind;
                }

                be->dpcm[stream].state = SND_SOC_DPCM_STATE_OPEN;
                count++;
        }

        return count;

unwind:
        /* disable any enabled and non active backends */
        list_for_each_entry_continue_reverse(dpcm, &fe->dpcm[stream].be_clients, list_be) {
                struct snd_soc_pcm_runtime *be = dpcm->be;
                struct snd_pcm_substream *be_substream =
                        snd_soc_dpcm_get_substream(be, stream);

                if (!snd_soc_dpcm_be_can_update(fe, be, stream))
                        continue;

                if (be->dpcm[stream].users == 0)
                        dev_err(be->dev, "no users %s at close %d\n",
                                stream ? "capture" : "playback",
                                be->dpcm[stream].state);

                if (--be->dpcm[stream].users != 0)
                        continue;

                if (be->dpcm[stream].state != SND_SOC_DPCM_STATE_OPEN)
                        continue;

                soc_pcm_close(be_substream);
                be_substream->runtime = NULL;
                be->dpcm[stream].state = SND_SOC_DPCM_STATE_CLOSE;
        }

        return err;
}

static void dpcm_set_fe_runtime(struct snd_pcm_substream *substream)
{
        struct snd_pcm_runtime *runtime = substream->runtime;
        struct snd_soc_pcm_runtime *rtd = substream->private_data;
        struct snd_soc_dai *cpu_dai = rtd->cpu_dai;
        struct snd_soc_dai_driver *cpu_dai_drv = cpu_dai->driver;

        if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
                runtime->hw.rate_min = cpu_dai_drv->playback.rate_min;
                runtime->hw.rate_max = cpu_dai_drv->playback.rate_max;
                runtime->hw.channels_min = cpu_dai_drv->playback.channels_min;
                runtime->hw.channels_max = cpu_dai_drv->playback.channels_max;
                runtime->hw.formats &= cpu_dai_drv->playback.formats;
                runtime->hw.rates = cpu_dai_drv->playback.rates;
        } else {
                runtime->hw.rate_min = cpu_dai_drv->capture.rate_min;
                runtime->hw.rate_max = cpu_dai_drv->capture.rate_max;
                runtime->hw.channels_min = cpu_dai_drv->capture.channels_min;
                runtime->hw.channels_max = cpu_dai_drv->capture.channels_max;
                runtime->hw.formats &= cpu_dai_drv->capture.formats;
                runtime->hw.rates = cpu_dai_drv->capture.rates;
        }
}

static int dpcm_fe_dai_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;

        fe->dpcm[stream].runtime_update = SND_SOC_DPCM_UPDATE_FE;

        ret = dpcm_be_dai_startup(fe, fe_substream->stream);
        if (ret < 0) {
                dev_err(fe->dev,"dpcm: failed to start some BEs %d\n", ret);
                goto be_err;
        }

        dev_dbg(fe->dev, "dpcm: 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,"dpcm: 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);

        fe->dpcm[stream].runtime_update = SND_SOC_DPCM_UPDATE_NO;
        return 0;

unwind:
        dpcm_be_dai_startup_unwind(fe, fe_substream->stream);
be_err:
        fe->dpcm[stream].runtime_update = SND_SOC_DPCM_UPDATE_NO;
        return ret;
}

static int dpcm_be_dai_shutdown(struct snd_soc_pcm_runtime *fe, int stream)
{
        struct snd_soc_dpcm *dpcm;

        /* only shutdown BEs that are either sinks or sources to this FE DAI */
        list_for_each_entry(dpcm, &fe->dpcm[stream].be_clients, list_be) {

                struct snd_soc_pcm_runtime *be = dpcm->be;
                struct snd_pcm_substream *be_substream =
                        snd_soc_dpcm_get_substream(be, stream);

                /* is this op for this BE ? */
                if (!snd_soc_dpcm_be_can_update(fe, be, stream))
                        continue;

                if (be->dpcm[stream].users == 0)
                        dev_err(be->dev, "no users %s at close - state %d\n",
                                stream ? "capture" : "playback",
                                be->dpcm[stream].state);

                if (--be->dpcm[stream].users != 0)
                        continue;

                if ((be->dpcm[stream].state != SND_SOC_DPCM_STATE_HW_FREE) &&
                    (be->dpcm[stream].state != SND_SOC_DPCM_STATE_OPEN))
                        continue;

                dev_dbg(be->dev, "dpcm: close BE %s\n",
                        dpcm->fe->dai_link->name);

                soc_pcm_close(be_substream);
                be_substream->runtime = NULL;

                be->dpcm[stream].state = SND_SOC_DPCM_STATE_CLOSE;
        }
        return 0;
}

static int dpcm_fe_dai_shutdown(struct snd_pcm_substream *substream)
{
        struct snd_soc_pcm_runtime *fe = substream->private_data;
        int stream = substream->stream;

        fe->dpcm[stream].runtime_update = SND_SOC_DPCM_UPDATE_FE;

        /* shutdown the BEs */
        dpcm_be_dai_shutdown(fe, substream->stream);

        dev_dbg(fe->dev, "dpcm: 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;
        fe->dpcm[stream].runtime_update = SND_SOC_DPCM_UPDATE_NO;
        return 0;
}

static int dpcm_be_dai_hw_free(struct snd_soc_pcm_runtime *fe, int stream)
{
        struct snd_soc_dpcm *dpcm;

        /* only hw_params backends that are either sinks or sources
         * to this frontend DAI */
        list_for_each_entry(dpcm, &fe->dpcm[stream].be_clients, list_be) {

                struct snd_soc_pcm_runtime *be = dpcm->be;
                struct snd_pcm_substream *be_substream =
                        snd_soc_dpcm_get_substream(be, stream);

                /* is this op for this BE ? */
                if (!snd_soc_dpcm_be_can_update(fe, be, stream))
                        continue;

                /* only free hw when no longer used - check all FEs */
                if (!snd_soc_dpcm_can_be_free_stop(fe, be, stream))
                                continue;

                if ((be->dpcm[stream].state != SND_SOC_DPCM_STATE_HW_PARAMS) &&
                    (be->dpcm[stream].state != SND_SOC_DPCM_STATE_PREPARE) &&
                    (be->dpcm[stream].state != SND_SOC_DPCM_STATE_HW_FREE) &&
                    (be->dpcm[stream].state != SND_SOC_DPCM_STATE_PAUSED) &&
                    (be->dpcm[stream].state != SND_SOC_DPCM_STATE_STOP))
                        continue;

                dev_dbg(be->dev, "dpcm: hw_free BE %s\n",
                        dpcm->fe->dai_link->name);

                soc_pcm_hw_free(be_substream);

                be->dpcm[stream].state = SND_SOC_DPCM_STATE_HW_FREE;
        }

        return 0;
}

static int dpcm_fe_dai_hw_free(struct snd_pcm_substream *substream)
{
        struct snd_soc_pcm_runtime *fe = substream->private_data;
        int err, stream = substream->stream;

        mutex_lock_nested(&fe->card->mutex, SND_SOC_CARD_CLASS_RUNTIME);
        fe->dpcm[stream].runtime_update = SND_SOC_DPCM_UPDATE_FE;

        dev_dbg(fe->dev, "dpcm: 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,"dpcm: 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;
        fe->dpcm[stream].runtime_update = SND_SOC_DPCM_UPDATE_NO;

        mutex_unlock(&fe->card->mutex);
        return 0;
}

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

        list_for_each_entry(dpcm, &fe->dpcm[stream].be_clients, list_be) {

                struct snd_soc_pcm_runtime *be = dpcm->be;
                struct snd_pcm_substream *be_substream =
                        snd_soc_dpcm_get_substream(be, stream);

                /* is this op for this BE ? */
                if (!snd_soc_dpcm_be_can_update(fe, be, stream))
                        continue;

                /* only allow hw_params() if no connected FEs are running */
                if (!snd_soc_dpcm_can_be_params(fe, be, stream))
                        continue;

                if ((be->dpcm[stream].state != SND_SOC_DPCM_STATE_OPEN) &&
                    (be->dpcm[stream].state != SND_SOC_DPCM_STATE_HW_PARAMS) &&
                    (be->dpcm[stream].state != SND_SOC_DPCM_STATE_HW_FREE))
                        continue;

                dev_dbg(be->dev, "dpcm: hw_params BE %s\n",
                        dpcm->fe->dai_link->name);

                /* copy params for each dpcm */
                memcpy(&dpcm->hw_params, &fe->dpcm[stream].hw_params,
                                sizeof(struct snd_pcm_hw_params));

                /* perform any hw_params fixups */
                if (be->dai_link->be_hw_params_fixup) {
                        ret = be->dai_link->be_hw_params_fixup(be,
                                        &dpcm->hw_params);
                        if (ret < 0) {
                                dev_err(be->dev,
                                        "dpcm: hw_params BE fixup failed %d\n",
                                        ret);
                                goto unwind;
                        }
                }

                ret = soc_pcm_hw_params(be_substream, &dpcm->hw_params);
                if (ret < 0) {
                        dev_err(dpcm->be->dev,
                                "dpcm: hw_params BE failed %d\n", ret);
                        goto unwind;
                }

                be->dpcm[stream].state = SND_SOC_DPCM_STATE_HW_PARAMS;
        }
        return 0;

unwind:
        /* disable any enabled and non active backends */
        list_for_each_entry_continue_reverse(dpcm, &fe->dpcm[stream].be_clients, list_be) {
                struct snd_soc_pcm_runtime *be = dpcm->be;
                struct snd_pcm_substream *be_substream =
                        snd_soc_dpcm_get_substream(be, stream);

                if (!snd_soc_dpcm_be_can_update(fe, be, stream))
                        continue;

                /* only allow hw_free() if no connected FEs are running */
                if (!snd_soc_dpcm_can_be_free_stop(fe, be, stream))
                        continue;

                if ((be->dpcm[stream].state != SND_SOC_DPCM_STATE_OPEN) &&
                   (be->dpcm[stream].state != SND_SOC_DPCM_STATE_HW_PARAMS) &&
                   (be->dpcm[stream].state != SND_SOC_DPCM_STATE_HW_FREE) &&
                   (be->dpcm[stream].state != SND_SOC_DPCM_STATE_STOP))
                        continue;

                soc_pcm_hw_free(be_substream);
        }

        return ret;
}

static int dpcm_fe_dai_hw_params(struct snd_pcm_substream *substream,
                                 struct snd_pcm_hw_params *params)
{
        struct snd_soc_pcm_runtime *fe = substream->private_data;
        int ret, stream = substream->stream;

        mutex_lock_nested(&fe->card->mutex, SND_SOC_CARD_CLASS_RUNTIME);
        fe->dpcm[stream].runtime_update = 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,"dpcm: hw_params BE failed %d\n", ret);
                goto out;
        }

        dev_dbg(fe->dev, "dpcm: 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,"dpcm: 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:
        fe->dpcm[stream].runtime_update = 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, "dpcm: trigger BE %s cmd %d\n",
                        dpcm->fe->dai_link->name, cmd);

        ret = soc_pcm_trigger(substream, cmd);
        if (ret < 0)
                dev_err(dpcm->be->dev,"dpcm: trigger BE failed %d\n", ret);

        return ret;
}

static int dpcm_be_dai_trigger(struct snd_soc_pcm_runtime *fe, int stream,
                               int cmd)
{
        struct snd_soc_dpcm *dpcm;
        int ret = 0;

        list_for_each_entry(dpcm, &fe->dpcm[stream].be_clients, list_be) {

                struct snd_soc_pcm_runtime *be = dpcm->be;
                struct snd_pcm_substream *be_substream =
                        snd_soc_dpcm_get_substream(be, stream);

                /* is this op for this BE ? */
                if (!snd_soc_dpcm_be_can_update(fe, be, stream))
                        continue;

                switch (cmd) {
                case SNDRV_PCM_TRIGGER_START:
                        if ((be->dpcm[stream].state != SND_SOC_DPCM_STATE_PREPARE) &&
                            (be->dpcm[stream].state != SND_SOC_DPCM_STATE_STOP))
                                continue;

                        ret = dpcm_do_trigger(dpcm, be_substream, cmd);
                        if (ret)
                                return ret;

                        be->dpcm[stream].state = SND_SOC_DPCM_STATE_START;
                        break;
                case SNDRV_PCM_TRIGGER_RESUME:
                        if ((be->dpcm[stream].state != SND_SOC_DPCM_STATE_SUSPEND))
                                continue;

                        ret = dpcm_do_trigger(dpcm, be_substream, cmd);
                        if (ret)
                                return ret;

                        be->dpcm[stream].state = SND_SOC_DPCM_STATE_START;
                        break;
                case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
                        if ((be->dpcm[stream].state != SND_SOC_DPCM_STATE_PAUSED))
                                continue;

                        ret = dpcm_do_trigger(dpcm, be_substream, cmd);
                        if (ret)
                                return ret;

                        be->dpcm[stream].state = SND_SOC_DPCM_STATE_START;
                        break;
                case SNDRV_PCM_TRIGGER_STOP:
                        if (be->dpcm[stream].state != SND_SOC_DPCM_STATE_START)
                                continue;

                        if (!snd_soc_dpcm_can_be_free_stop(fe, be, stream))
                                continue;

                        ret = dpcm_do_trigger(dpcm, be_substream, cmd);
                        if (ret)
                                return ret;

                        be->dpcm[stream].state = SND_SOC_DPCM_STATE_STOP;
                        break;
                case SNDRV_PCM_TRIGGER_SUSPEND:
                        if (be->dpcm[stream].state != SND_SOC_DPCM_STATE_STOP)
                                continue;

                        if (!snd_soc_dpcm_can_be_free_stop(fe, be, stream))
                                continue;

                        ret = dpcm_do_trigger(dpcm, be_substream, cmd);
                        if (ret)
                                return ret;

                        be->dpcm[stream].state = SND_SOC_DPCM_STATE_SUSPEND;
                        break;
                case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
                        if (be->dpcm[stream].state != SND_SOC_DPCM_STATE_START)
                                continue;

                        if (!snd_soc_dpcm_can_be_free_stop(fe, be, stream))
                                continue;

                        ret = dpcm_do_trigger(dpcm, be_substream, cmd);
                        if (ret)
                                return ret;

                        be->dpcm[stream].state = SND_SOC_DPCM_STATE_PAUSED;
                        break;
                }
        }

        return ret;
}
EXPORT_SYMBOL_GPL(dpcm_be_dai_trigger);

static int dpcm_fe_dai_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, "dpcm: 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,"dpcm: 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,"dpcm: trigger FE failed %d\n", ret);
                        goto out;
                }

                dev_dbg(fe->dev, "dpcm: 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, "dpcm: 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,"dpcm: trigger FE failed %d\n", ret);
                        goto out;
                }
                break;
        default:
                dev_err(fe->dev, "dpcm: invalid trigger cmd %d for %s\n", cmd,
                                fe->dai_link->name);
                ret = -EINVAL;
                goto out;
        }

        switch (cmd) {
        case SNDRV_PCM_TRIGGER_START:
        case SNDRV_PCM_TRIGGER_RESUME:
        case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
                fe->dpcm[stream].state = SND_SOC_DPCM_STATE_START;
                break;
        case SNDRV_PCM_TRIGGER_STOP:
        case SNDRV_PCM_TRIGGER_SUSPEND:
        case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
                fe->dpcm[stream].state = SND_SOC_DPCM_STATE_STOP;
                break;
        }

out:
        fe->dpcm[stream].runtime_update = SND_SOC_DPCM_UPDATE_NO;
        return ret;
}

static int dpcm_be_dai_prepare(struct snd_soc_pcm_runtime *fe, int stream)
{
        struct snd_soc_dpcm *dpcm;
        int ret = 0;

        list_for_each_entry(dpcm, &fe->dpcm[stream].be_clients, list_be) {

                struct snd_soc_pcm_runtime *be = dpcm->be;
                struct snd_pcm_substream *be_substream =
                        snd_soc_dpcm_get_substream(be, stream);

                /* is this op for this BE ? */
                if (!snd_soc_dpcm_be_can_update(fe, be, stream))
                        continue;

                if ((be->dpcm[stream].state != SND_SOC_DPCM_STATE_HW_PARAMS) &&
                    (be->dpcm[stream].state != SND_SOC_DPCM_STATE_STOP))
                        continue;

                dev_dbg(be->dev, "dpcm: prepare BE %s\n",
                        dpcm->fe->dai_link->name);

                ret = soc_pcm_prepare(be_substream);
                if (ret < 0) {
                        dev_err(be->dev, "dpcm: 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, "dpcm: prepare FE %s\n", fe->dai_link->name);

        fe->dpcm[stream].runtime_update = 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, "dpcm: 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,"dpcm: 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:
        fe->dpcm[stream].runtime_update = SND_SOC_DPCM_UPDATE_NO;
        mutex_unlock(&fe->card->mutex);

        return ret;
}

static int soc_pcm_ioctl(struct snd_pcm_substream *substream,
                     unsigned int cmd, void *arg)
{
        struct snd_soc_pcm_runtime *rtd = substream->private_data;
        struct snd_soc_platform *platform = rtd->platform;

        if (platform->driver->ops->ioctl)
                return platform->driver->ops->ioctl(substream, cmd, arg);
        return snd_pcm_lib_ioctl(substream, cmd, arg);
}

static int dpcm_run_update_shutdown(struct snd_soc_pcm_runtime *fe, int stream)
{
        struct snd_pcm_substream *substream =
                snd_soc_dpcm_get_substream(fe, stream);
        enum snd_soc_dpcm_trigger trigger = fe->dai_link->trigger[stream];
        int err;

        dev_dbg(fe->dev, "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, "dpcm: 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,"dpcm: trigger FE failed %d\n", err);
        } else {
                dev_dbg(fe->dev, "dpcm: 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,"dpcm: trigger FE failed %d\n", err);
        }

        err = dpcm_be_dai_hw_free(fe, stream);
        if (err < 0)
                dev_err(fe->dev,"dpcm: hw_free FE failed %d\n", err);

        err = dpcm_be_dai_shutdown(fe, stream);
        if (err < 0)
                dev_err(fe->dev,"dpcm: shutdown FE failed %d\n", err);

        /* run the stream event for each BE */
        dpcm_dapm_stream_event(fe, stream, SND_SOC_DAPM_STREAM_NOP);

        return 0;
}

static int dpcm_run_update_startup(struct snd_soc_pcm_runtime *fe, int stream)
{
        struct snd_pcm_substream *substream =
                snd_soc_dpcm_get_substream(fe, stream);
        struct snd_soc_dpcm *dpcm;
        enum snd_soc_dpcm_trigger trigger = fe->dai_link->trigger[stream];
        int ret;

        dev_dbg(fe->dev, "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;
                return ret;
        }

        /* 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;
                return ret;
        }

        /* 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;
                return ret;
        }

        /* 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, "dpcm: 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,"dpcm: bespoke trigger FE failed %d\n", ret);
                        goto hw_free;
                }
        } else {
                dev_dbg(fe->dev, "dpcm: 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,"dpcm: trigger FE failed %d\n", ret);
                        goto hw_free;
                }
        }

        return 0;

hw_free:
        dpcm_be_dai_hw_free(fe, stream);
close:
        dpcm_be_dai_shutdown(fe, stream);
disconnect:
        /* disconnect any non started BEs */
        list_for_each_entry(dpcm, &fe->dpcm[stream].be_clients, list_be) {
                struct snd_soc_pcm_runtime *be = dpcm->be;
                if (be->dpcm[stream].state != SND_SOC_DPCM_STATE_START)
                                dpcm->state = SND_SOC_DPCM_LINK_STATE_FREE;
        }

        return ret;
}

static int dpcm_run_new_update(struct snd_soc_pcm_runtime *fe, int stream)
{
        int ret;

        fe->dpcm[stream].runtime_update = SND_SOC_DPCM_UPDATE_BE;
        ret = dpcm_run_update_startup(fe, stream);
        if (ret < 0)
                dev_err(fe->dev, "failed to startup some BEs\n");
        fe->dpcm[stream].runtime_update = SND_SOC_DPCM_UPDATE_NO;

        return ret;
}

static int dpcm_run_old_update(struct snd_soc_pcm_runtime *fe, int stream)
{
        int ret;

        fe->dpcm[stream].runtime_update = SND_SOC_DPCM_UPDATE_BE;
        ret = dpcm_run_update_shutdown(fe, stream);
        if (ret < 0)
                dev_err(fe->dev, "failed to shutdown some BEs\n");
        fe->dpcm[stream].runtime_update = SND_SOC_DPCM_UPDATE_NO;

        return ret;
}

/* Called by DAPM mixer/mux changes to update audio routing between PCMs and
 * any DAI links.
 */
int soc_dpcm_runtime_update(struct snd_soc_dapm_widget *widget)
{
        struct snd_soc_card *card;
        int i, old, new, paths;

        if (widget->codec)
                card = widget->codec->card;
        else if (widget->platform)
                card = widget->platform->card;
        else
                return -EINVAL;

        mutex_lock_nested(&card->mutex, SND_SOC_CARD_CLASS_RUNTIME);
        for (i = 0; i < card->num_rtd; i++) {
                struct snd_soc_dapm_widget_list *list;
                struct snd_soc_pcm_runtime *fe = &card->rtd[i];

                /* make sure link is FE */
                if (!fe->dai_link->dynamic)
                        continue;

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

                /* DAPM sync will call this to update DSP paths */
                dev_dbg(fe->dev, "DPCM runtime update for FE %s\n",
                        fe->dai_link->name);

                /* skip if FE doesn't have playback capability */
                if (!fe->cpu_dai->driver->playback.channels_min)
                        goto capture;

                paths = dpcm_path_get(fe, SNDRV_PCM_STREAM_PLAYBACK, &list);
                if (paths < 0) {
                        dev_warn(fe->dev, "%s no valid %s path\n",
                                        fe->dai_link->name,  "playback");
                        mutex_unlock(&card->mutex);
                        return paths;
                }

                /* update any new playback paths */
                new = dpcm_process_paths(fe, SNDRV_PCM_STREAM_PLAYBACK, &list, 1);
                if (new) {
                        dpcm_run_new_update(fe, SNDRV_PCM_STREAM_PLAYBACK);
                        dpcm_clear_pending_state(fe, SNDRV_PCM_STREAM_PLAYBACK);
                        dpcm_be_disconnect(fe, SNDRV_PCM_STREAM_PLAYBACK);
                }

                /* update any old playback paths */
                old = dpcm_process_paths(fe, SNDRV_PCM_STREAM_PLAYBACK, &list, 0);
                if (old) {
                        dpcm_run_old_update(fe, SNDRV_PCM_STREAM_PLAYBACK);
                        dpcm_clear_pending_state(fe, SNDRV_PCM_STREAM_PLAYBACK);
                        dpcm_be_disconnect(fe, SNDRV_PCM_STREAM_PLAYBACK);
                }

capture:
                /* skip if FE doesn't have capture capability */
                if (!fe->cpu_dai->driver->capture.channels_min)
                        continue;

                paths = dpcm_path_get(fe, SNDRV_PCM_STREAM_CAPTURE, &list);
                if (paths < 0) {
                        dev_warn(fe->dev, "%s no valid %s path\n",
                                        fe->dai_link->name,  "capture");
                        mutex_unlock(&card->mutex);
                        return paths;
                }

                /* update any new capture paths */
                new = dpcm_process_paths(fe, SNDRV_PCM_STREAM_CAPTURE, &list, 1);
                if (new) {
                        dpcm_run_new_update(fe, SNDRV_PCM_STREAM_CAPTURE);
                        dpcm_clear_pending_state(fe, SNDRV_PCM_STREAM_CAPTURE);
                        dpcm_be_disconnect(fe, SNDRV_PCM_STREAM_CAPTURE);
                }

                /* update any old capture paths */
                old = dpcm_process_paths(fe, SNDRV_PCM_STREAM_CAPTURE, &list, 0);
                if (old) {
                        dpcm_run_old_update(fe, SNDRV_PCM_STREAM_CAPTURE);
                        dpcm_clear_pending_state(fe, SNDRV_PCM_STREAM_CAPTURE);
                        dpcm_be_disconnect(fe, SNDRV_PCM_STREAM_CAPTURE);
                }

                dpcm_path_put(&list);
        }

        mutex_unlock(&card->mutex);
        return 0;
}
int soc_dpcm_be_digital_mute(struct snd_soc_pcm_runtime *fe, int mute)
{
        struct snd_soc_dpcm *dpcm;
        struct list_head *clients =
                &fe->dpcm[SNDRV_PCM_STREAM_PLAYBACK].be_clients;

        list_for_each_entry(dpcm, clients, list_be) {

                struct snd_soc_pcm_runtime *be = dpcm->be;
                struct snd_soc_dai *dai = be->codec_dai;
                struct snd_soc_dai_driver *drv = dai->driver;

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

                dev_dbg(be->dev, "BE digital mute %s\n", be->dai_link->name);

                if (drv->ops->digital_mute && dai->playback_active)
                                drv->ops->digital_mute(dai, mute);
        }

        return 0;
}

static int dpcm_fe_dai_open(struct snd_pcm_substream *fe_substream)
{
        struct snd_soc_pcm_runtime *fe = fe_substream->private_data;
        struct snd_soc_dpcm *dpcm;
        struct snd_soc_dapm_widget_list *list;
        int ret;
        int stream = fe_substream->stream;

        mutex_lock_nested(&fe->card->mutex, SND_SOC_CARD_CLASS_RUNTIME);
        fe->dpcm[stream].runtime = fe_substream->runtime;

        if (dpcm_path_get(fe, stream, &list) <= 0) {
                dev_dbg(fe->dev, "asoc: %s no valid %s route\n",
                        fe->dai_link->name, stream ? "capture" : "playback");
        }

        /* calculate valid and active FE <-> BE dpcms */
        dpcm_process_paths(fe, stream, &list, 1);

        ret = dpcm_fe_dai_startup(fe_substream);
        if (ret < 0) {
                /* clean up all links */
                list_for_each_entry(dpcm, &fe->dpcm[stream].be_clients, list_be)
                        dpcm->state = SND_SOC_DPCM_LINK_STATE_FREE;

                dpcm_be_disconnect(fe, stream);
                fe->dpcm[stream].runtime = NULL;
        }

        dpcm_clear_pending_state(fe, stream);
        dpcm_path_put(&list);
        mutex_unlock(&fe->card->mutex);
        return ret;
}

static int dpcm_fe_dai_close(struct snd_pcm_substream *fe_substream)
{
        struct snd_soc_pcm_runtime *fe = fe_substream->private_data;
        struct snd_soc_dpcm *dpcm;
        int stream = fe_substream->stream, ret;

        mutex_lock_nested(&fe->card->mutex, SND_SOC_CARD_CLASS_RUNTIME);
        ret = dpcm_fe_dai_shutdown(fe_substream);

        /* mark FE's links ready to prune */
        list_for_each_entry(dpcm, &fe->dpcm[stream].be_clients, list_be)
                dpcm->state = SND_SOC_DPCM_LINK_STATE_FREE;

        dpcm_be_disconnect(fe, stream);

        fe->dpcm[stream].runtime = NULL;
        mutex_unlock(&fe->card->mutex);
        return ret;
}

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

        if (rtd->dai_link->dynamic || rtd->dai_link->no_pcm) {
                if (cpu_dai->driver->playback.channels_min)
                        playback = 1;
                if (cpu_dai->driver->capture.channels_min)
                        capture = 1;
        } else {
                if (codec_dai->driver->playback.channels_min)
                        playback = 1;
                if (codec_dai->driver->capture.channels_min)
                        capture = 1;
        }

        /* create the PCM */
        if (rtd->dai_link->no_pcm) {
                snprintf(new_name, sizeof(new_name), "(%s)",
                        rtd->dai_link->stream_name);

                ret = snd_pcm_new_internal(rtd->card->snd_card, new_name, num,
                                playback, capture, &pcm);
        } else {
                if (rtd->dai_link->dynamic)
                        snprintf(new_name, sizeof(new_name), "%s (*)",
                                rtd->dai_link->stream_name);
                else
                        snprintf(new_name, sizeof(new_name), "%s %s-%d",
                                rtd->dai_link->stream_name, codec_dai->name, num);

                ret = snd_pcm_new(rtd->card->snd_card, new_name, num, playback,
                        capture, &pcm);
        }
        if (ret < 0) {
                dev_err(rtd->card->dev, "can't create pcm for %s\n",
                        rtd->dai_link->name);
                return ret;
        }
        dev_dbg(rtd->card->dev, "registered pcm #%d %s\n",num, new_name);

        /* DAPM dai link stream work */
        INIT_DELAYED_WORK(&rtd->delayed_work, close_delayed_work);

        rtd->pcm = pcm;
        pcm->private_data = rtd;

        if (rtd->dai_link->no_pcm) {
                if (playback)
                        pcm->streams[SNDRV_PCM_STREAM_PLAYBACK].substream->private_data = rtd;
                if (capture)
                        pcm->streams[SNDRV_PCM_STREAM_CAPTURE].substream->private_data = rtd;
                goto out;
        }

        /* ASoC PCM operations */
        if (rtd->dai_link->dynamic) {
                rtd->ops.open           = dpcm_fe_dai_open;
                rtd->ops.hw_params      = dpcm_fe_dai_hw_params;
                rtd->ops.prepare        = dpcm_fe_dai_prepare;
                rtd->ops.trigger        = dpcm_fe_dai_trigger;
                rtd->ops.hw_free        = dpcm_fe_dai_hw_free;
                rtd->ops.close          = dpcm_fe_dai_close;
                rtd->ops.pointer        = soc_pcm_pointer;
                rtd->ops.ioctl          = soc_pcm_ioctl;
        } else {
                rtd->ops.open           = soc_pcm_open;
                rtd->ops.hw_params      = soc_pcm_hw_params;
                rtd->ops.prepare        = soc_pcm_prepare;
                rtd->ops.trigger        = soc_pcm_trigger;
                rtd->ops.hw_free        = soc_pcm_hw_free;
                rtd->ops.close          = soc_pcm_close;
                rtd->ops.pointer        = soc_pcm_pointer;
                rtd->ops.ioctl          = soc_pcm_ioctl;
        }

        if (platform->driver->ops) {
                rtd->ops.ack            = platform->driver->ops->ack;
                rtd->ops.copy           = platform->driver->ops->copy;
                rtd->ops.silence        = platform->driver->ops->silence;
                rtd->ops.page           = platform->driver->ops->page;
                rtd->ops.mmap           = platform->driver->ops->mmap;
        }

        if (playback)
                snd_pcm_set_ops(pcm, SNDRV_PCM_STREAM_PLAYBACK, &rtd->ops);

        if (capture)
                snd_pcm_set_ops(pcm, SNDRV_PCM_STREAM_CAPTURE, &rtd->ops);

        if (platform->driver->pcm_new) {
                ret = platform->driver->pcm_new(rtd);
                if (ret < 0) {
                        dev_err(platform->dev, "pcm constructor failed\n");
                        return ret;
                }
        }

        pcm->private_free = platform->driver->pcm_free;
out:
        dev_info(rtd->card->dev, " %s <-> %s mapping ok\n", codec_dai->name,
                cpu_dai->name);
        return ret;
}

/* is the current PCM operation for this FE ? */
int snd_soc_dpcm_fe_can_update(struct snd_soc_pcm_runtime *fe, int stream)
{
        if (fe->dpcm[stream].runtime_update == SND_SOC_DPCM_UPDATE_FE)
                return 1;
        return 0;
}
EXPORT_SYMBOL_GPL(snd_soc_dpcm_fe_can_update);

/* is the current PCM operation for this BE ? */
int snd_soc_dpcm_be_can_update(struct snd_soc_pcm_runtime *fe,
                struct snd_soc_pcm_runtime *be, int stream)
{
        if ((fe->dpcm[stream].runtime_update == SND_SOC_DPCM_UPDATE_FE) ||
           ((fe->dpcm[stream].runtime_update == SND_SOC_DPCM_UPDATE_BE) &&
                  be->dpcm[stream].runtime_update))
                return 1;
        return 0;
}
EXPORT_SYMBOL_GPL(snd_soc_dpcm_be_can_update);

/* get the substream for this BE */
struct snd_pcm_substream *
        snd_soc_dpcm_get_substream(struct snd_soc_pcm_runtime *be, int stream)
{
        return be->pcm->streams[stream].substream;
}
EXPORT_SYMBOL_GPL(snd_soc_dpcm_get_substream);

/* get the BE runtime state */
enum snd_soc_dpcm_state
        snd_soc_dpcm_be_get_state(struct snd_soc_pcm_runtime *be, int stream)
{
        return be->dpcm[stream].state;
}
EXPORT_SYMBOL_GPL(snd_soc_dpcm_be_get_state);

/* set the BE runtime state */
void snd_soc_dpcm_be_set_state(struct snd_soc_pcm_runtime *be,
                int stream, enum snd_soc_dpcm_state state)
{
        be->dpcm[stream].state = state;
}
EXPORT_SYMBOL_GPL(snd_soc_dpcm_be_set_state);

/*
 * We can only hw_free, stop, pause or suspend a BE DAI if any of it's FE
 * are not running, paused or suspended for the specified stream direction.
 */
int snd_soc_dpcm_can_be_free_stop(struct snd_soc_pcm_runtime *fe,
                struct snd_soc_pcm_runtime *be, int stream)
{
        struct snd_soc_dpcm *dpcm;
        int state;

        list_for_each_entry(dpcm, &be->dpcm[stream].fe_clients, list_fe) {

                if (dpcm->fe == fe)
                        continue;

                state = dpcm->fe->dpcm[stream].state;
                if (state == SND_SOC_DPCM_STATE_START ||
                        state == SND_SOC_DPCM_STATE_PAUSED ||
                        state == SND_SOC_DPCM_STATE_SUSPEND)
                        return 0;
        }

        /* it's safe to free/stop this BE DAI */
        return 1;
}
EXPORT_SYMBOL_GPL(snd_soc_dpcm_can_be_free_stop);

/*
 * We can only change hw params a BE DAI if any of it's FE are not prepared,
 * running, paused or suspended for the specified stream direction.
 */
int snd_soc_dpcm_can_be_params(struct snd_soc_pcm_runtime *fe,
                struct snd_soc_pcm_runtime *be, int stream)
{
        struct snd_soc_dpcm *dpcm;
        int state;

        list_for_each_entry(dpcm, &be->dpcm[stream].fe_clients, list_fe) {

                if (dpcm->fe == fe)
                        continue;

                state = dpcm->fe->dpcm[stream].state;
                if (state == SND_SOC_DPCM_STATE_START ||
                        state == SND_SOC_DPCM_STATE_PAUSED ||
                        state == SND_SOC_DPCM_STATE_SUSPEND ||
                        state == SND_SOC_DPCM_STATE_PREPARE)
                        return 0;
        }

        /* it's safe to change hw_params */
        return 1;
}
EXPORT_SYMBOL_GPL(snd_soc_dpcm_can_be_params);

int snd_soc_platform_trigger(struct snd_pcm_substream *substream,
                int cmd, struct snd_soc_platform *platform)
{
        if (platform->driver->ops->trigger)
                return platform->driver->ops->trigger(substream, cmd);
        return 0;
}
EXPORT_SYMBOL_GPL(snd_soc_platform_trigger);

#ifdef CONFIG_DEBUG_FS
static char *dpcm_state_string(enum snd_soc_dpcm_state state)
{
        switch (state) {
        case SND_SOC_DPCM_STATE_NEW:
                return "new";
        case SND_SOC_DPCM_STATE_OPEN:
                return "open";
        case SND_SOC_DPCM_STATE_HW_PARAMS:
                return "hw_params";
        case SND_SOC_DPCM_STATE_PREPARE:
                return "prepare";
        case SND_SOC_DPCM_STATE_START:
                return "start";
        case SND_SOC_DPCM_STATE_STOP:
                return "stop";
        case SND_SOC_DPCM_STATE_SUSPEND:
                return "suspend";
        case SND_SOC_DPCM_STATE_PAUSED:
                return "paused";
        case SND_SOC_DPCM_STATE_HW_FREE:
                return "hw_free";
        case SND_SOC_DPCM_STATE_CLOSE:
                return "close";
        }

        return "unknown";
}

static ssize_t dpcm_show_state(struct snd_soc_pcm_runtime *fe,
                                int stream, char *buf, size_t size)
{
        struct snd_pcm_hw_params *params = &fe->dpcm[stream].hw_params;
        struct snd_soc_dpcm *dpcm;
        ssize_t offset = 0;

        /* FE state */
        offset += snprintf(buf + offset, size - offset,
                        "[%s - %s]\n", fe->dai_link->name,
                        stream ? "Capture" : "Playback");

        offset += snprintf(buf + offset, size - offset, "State: %s\n",
                        dpcm_state_string(fe->dpcm[stream].state));

        if ((fe->dpcm[stream].state >= SND_SOC_DPCM_STATE_HW_PARAMS) &&
            (fe->dpcm[stream].state <= SND_SOC_DPCM_STATE_STOP))
                offset += snprintf(buf + offset, size - offset,
                                "Hardware Params: "
                                "Format = %s, Channels = %d, Rate = %d\n",
                                snd_pcm_format_name(params_format(params)),
                                params_channels(params),
                                params_rate(params));

        /* BEs state */
        offset += snprintf(buf + offset, size - offset, "Backends:\n");

        if (list_empty(&fe->dpcm[stream].be_clients)) {
                offset += snprintf(buf + offset, size - offset,
                                " No active DSP links\n");
                goto out;
        }

        list_for_each_entry(dpcm, &fe->dpcm[stream].be_clients, list_be) {
                struct snd_soc_pcm_runtime *be = dpcm->be;
                params = &dpcm->hw_params;

                offset += snprintf(buf + offset, size - offset,
                                "- %s\n", be->dai_link->name);

                offset += snprintf(buf + offset, size - offset,
                                "   State: %s\n",
                                dpcm_state_string(be->dpcm[stream].state));

                if ((be->dpcm[stream].state >= SND_SOC_DPCM_STATE_HW_PARAMS) &&
                    (be->dpcm[stream].state <= SND_SOC_DPCM_STATE_STOP))
                        offset += snprintf(buf + offset, size - offset,
                                "   Hardware Params: "
                                "Format = %s, Channels = %d, Rate = %d\n",
                                snd_pcm_format_name(params_format(params)),
                                params_channels(params),
                                params_rate(params));
        }

out:
        return offset;
}

static ssize_t dpcm_state_read_file(struct file *file, char __user *user_buf,
                                size_t count, loff_t *ppos)
{
        struct snd_soc_pcm_runtime *fe = file->private_data;
        ssize_t out_count = PAGE_SIZE, offset = 0, ret = 0;
        char *buf;

        buf = kmalloc(out_count, GFP_KERNEL);
        if (!buf)
                return -ENOMEM;

        if (fe->cpu_dai->driver->playback.channels_min)
                offset += dpcm_show_state(fe, SNDRV_PCM_STREAM_PLAYBACK,
                                        buf + offset, out_count - offset);

        if (fe->cpu_dai->driver->capture.channels_min)
                offset += dpcm_show_state(fe, SNDRV_PCM_STREAM_CAPTURE,
                                        buf + offset, out_count - offset);

        ret = simple_read_from_buffer(user_buf, count, ppos, buf, offset);

        kfree(buf);
        return ret;
}

static const struct file_operations dpcm_state_fops = {
        .open = simple_open,
        .read = dpcm_state_read_file,
        .llseek = default_llseek,
};

int soc_dpcm_debugfs_add(struct snd_soc_pcm_runtime *rtd)
{
        if (!rtd->dai_link)
                return 0;

        rtd->debugfs_dpcm_root = debugfs_create_dir(rtd->dai_link->name,
                        rtd->card->debugfs_card_root);
        if (!rtd->debugfs_dpcm_root) {
                dev_dbg(rtd->dev,
                         "ASoC: Failed to create dpcm debugfs directory %s\n",
                         rtd->dai_link->name);
                return -EINVAL;
        }

        rtd->debugfs_dpcm_state = debugfs_create_file("state", 0444,
                                                rtd->debugfs_dpcm_root,
                                                rtd, &dpcm_state_fops);

        return 0;
}
#endif