// 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/slab.h>
#include <linux/workqueue.h>
#include <linux/export.h>
#include <linux/debugfs.h>
#include <sound/core.h>
#include <sound/pcm.h>
#include <sound/pcm_params.h>
#include <sound/soc.h>
#include <sound/soc-dpcm.h>
#include <sound/soc-link.h>
#include <sound/initval.h>

#define soc_pcm_ret(rtd, ret) _soc_pcm_ret(rtd, __func__, ret)
static inline int _soc_pcm_ret(struct snd_soc_pcm_runtime *rtd,
                               const char *func, int ret)
{
        return snd_soc_ret(rtd->dev, ret,
                           "at %s() on %s\n", func, rtd->dai_link->name);
}

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

/* is the current PCM operation for this BE ? */
static int snd_soc_dpcm_can_be_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;
}

static int snd_soc_dpcm_check_state(struct snd_soc_pcm_runtime *fe,
                                    struct snd_soc_pcm_runtime *be,
                                    int stream,
                                    const enum snd_soc_dpcm_state *states,
                                    int num_states)
{
        struct snd_soc_dpcm *dpcm;
        int state;
        int ret = 1;
        int i;

        for_each_dpcm_fe(be, stream, dpcm) {

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

                state = dpcm->fe->dpcm[stream].state;
                for (i = 0; i < num_states; i++) {
                        if (state == states[i]) {
                                ret = 0;
                                break;
                        }
                }
        }

        /* it's safe to do this BE DAI */
        return ret;
}

/*
 * We can only hw_free, stop, pause or suspend a BE DAI if any of it's FE
 * are not running, paused or suspended for the specified stream direction.
 */
static int snd_soc_dpcm_can_be_free_stop(struct snd_soc_pcm_runtime *fe,
                                         struct snd_soc_pcm_runtime *be, int stream)
{
        const enum snd_soc_dpcm_state state[] = {
                SND_SOC_DPCM_STATE_START,
                SND_SOC_DPCM_STATE_PAUSED,
                SND_SOC_DPCM_STATE_SUSPEND,
        };

        return snd_soc_dpcm_check_state(fe, be, stream, state, ARRAY_SIZE(state));
}

/*
 * 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.
 */
static int snd_soc_dpcm_can_be_params(struct snd_soc_pcm_runtime *fe,
                                      struct snd_soc_pcm_runtime *be, int stream)
{
        const enum snd_soc_dpcm_state state[] = {
                SND_SOC_DPCM_STATE_START,
                SND_SOC_DPCM_STATE_PAUSED,
                SND_SOC_DPCM_STATE_SUSPEND,
                SND_SOC_DPCM_STATE_PREPARE,
        };

        return snd_soc_dpcm_check_state(fe, be, stream, state, ARRAY_SIZE(state));
}

/*
 * We can only prepare a BE DAI if any of it's FE are not prepared,
 * running or paused for the specified stream direction.
 */
static int snd_soc_dpcm_can_be_prepared(struct snd_soc_pcm_runtime *fe,
                                        struct snd_soc_pcm_runtime *be, int stream)
{
        const enum snd_soc_dpcm_state state[] = {
                SND_SOC_DPCM_STATE_START,
                SND_SOC_DPCM_STATE_PAUSED,
                SND_SOC_DPCM_STATE_PREPARE,
        };

        return snd_soc_dpcm_check_state(fe, be, stream, state, ARRAY_SIZE(state));
}

#define DPCM_MAX_BE_USERS       8

static inline const char *soc_cpu_dai_name(struct snd_soc_pcm_runtime *rtd)
{
        return (rtd)->dai_link->num_cpus == 1 ? snd_soc_rtd_to_cpu(rtd, 0)->name : "multicpu";
}
static inline const char *soc_codec_dai_name(struct snd_soc_pcm_runtime *rtd)
{
        return (rtd)->dai_link->num_codecs == 1 ? snd_soc_rtd_to_codec(rtd, 0)->name : "multicodec";
}

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

        return "unknown";
}

#ifdef CONFIG_DEBUG_FS
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 += scnprintf(buf + offset, size - offset,
                           "[%s - %s]\n", fe->dai_link->name,
                           stream ? "Capture" : "Playback");

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

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

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

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

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

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

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

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

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

        if (fe->dai_link->num_cpus > 1)
                return snd_soc_ret(fe->dev, -EINVAL,
                        "%s doesn't support Multi CPU yet\n", __func__);

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

        snd_soc_dpcm_mutex_lock(fe);
        for_each_pcm_streams(stream)
                if (snd_soc_dai_stream_valid(snd_soc_rtd_to_cpu(fe, 0), stream))
                        offset += dpcm_show_state(fe, stream,
                                                  buf + offset,
                                                  out_count - offset);
        snd_soc_dpcm_mutex_unlock(fe);

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

        kfree(buf);
        return ret;
}

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

void soc_dpcm_debugfs_add(struct snd_soc_pcm_runtime *rtd)
{
        if (!rtd->dai_link->dynamic)
                return;

        if (!rtd->card->debugfs_card_root)
                return;

        rtd->debugfs_dpcm_root = debugfs_create_dir(rtd->dai_link->name,
                                                    rtd->card->debugfs_card_root);

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

static void dpcm_create_debugfs_state(struct snd_soc_dpcm *dpcm, int stream)
{
        char *name;

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

static void dpcm_remove_debugfs_state(struct snd_soc_dpcm *dpcm)
{
        debugfs_remove_recursive(dpcm->debugfs_state);
}

#else
static inline void dpcm_create_debugfs_state(struct snd_soc_dpcm *dpcm,
                                             int stream)
{
}

static inline void dpcm_remove_debugfs_state(struct snd_soc_dpcm *dpcm)
{
}
#endif

/* Set FE's runtime_update state; the state is protected via PCM stream lock
 * for avoiding the race with trigger callback.
 * If the state is unset and a trigger is pending while the previous operation,
 * process the pending trigger action here.
 */
static int dpcm_fe_dai_do_trigger(struct snd_pcm_substream *substream, int cmd);
static void dpcm_set_fe_update_state(struct snd_soc_pcm_runtime *fe,
                                     int stream, enum snd_soc_dpcm_update state)
{
        struct snd_pcm_substream *substream =
                snd_soc_dpcm_get_substream(fe, stream);

        snd_pcm_stream_lock_irq(substream);
        if (state == SND_SOC_DPCM_UPDATE_NO && fe->dpcm[stream].trigger_pending) {
                dpcm_fe_dai_do_trigger(substream,
                                       fe->dpcm[stream].trigger_pending - 1);
                fe->dpcm[stream].trigger_pending = 0;
        }
        fe->dpcm[stream].runtime_update = state;
        snd_pcm_stream_unlock_irq(substream);
}

static void dpcm_set_be_update_state(struct snd_soc_pcm_runtime *be,
                                     int stream, enum snd_soc_dpcm_update state)
{
        be->dpcm[stream].runtime_update = state;
}

/**
 * snd_soc_runtime_action() - Increment/Decrement active count for
 * PCM runtime components
 * @rtd: ASoC PCM runtime that is activated
 * @stream: Direction of the PCM stream
 * @action: Activate stream if 1. Deactivate if -1.
 *
 * Increments/Decrements the active count for all the DAIs and components
 * attached to a PCM runtime.
 * Should typically be called when a stream is opened.
 *
 * Must be called with the rtd->card->pcm_mutex being held
 */
void snd_soc_runtime_action(struct snd_soc_pcm_runtime *rtd,
                            int stream, int action)
{
        struct snd_soc_component *component;
        struct snd_soc_dai *dai;
        int i;

        snd_soc_dpcm_mutex_assert_held(rtd);

        for_each_rtd_dais(rtd, i, dai)
                snd_soc_dai_action(dai, stream, action);

        /* Increments/Decrements the active count for components without DAIs */
        for_each_rtd_components(rtd, i, component) {
                if (component->num_dai)
                        continue;
                component->active += action;
        }
}
EXPORT_SYMBOL_GPL(snd_soc_runtime_action);

/**
 * snd_soc_runtime_ignore_pmdown_time() - Check whether to ignore the power down delay
 * @rtd: The ASoC PCM runtime that should be checked.
 *
 * This function checks whether the power down delay should be ignored for a
 * specific PCM runtime. Returns true if the delay is 0, if the DAI link has
 * been configured to ignore the delay, or if none of the components benefits
 * from having the delay.
 */
bool snd_soc_runtime_ignore_pmdown_time(struct snd_soc_pcm_runtime *rtd)
{
        struct snd_soc_component *component;
        int i;

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

        for_each_rtd_components(rtd, i, component)
                if (component->driver->use_pmdown_time)
                        /* No need to go through all components */
                        return false;

        return true;
}

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

        snd_soc_dpcm_mutex_assert_held(fe);

        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);
}

static void soc_pcm_set_dai_params(struct snd_soc_dai *dai,
                                   struct snd_pcm_hw_params *params)
{
        if (params) {
                dai->symmetric_rate        = params_rate(params);
                dai->symmetric_channels    = params_channels(params);
                dai->symmetric_sample_bits = snd_pcm_format_physical_width(params_format(params));
        } else {
                dai->symmetric_rate        = 0;
                dai->symmetric_channels    = 0;
                dai->symmetric_sample_bits = 0;
        }
}

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

        if (!snd_soc_dai_active(soc_dai))
                return 0;

#define __soc_pcm_apply_symmetry(name, NAME)                            \
        if (soc_dai->symmetric_##name &&                                \
            (soc_dai->driver->symmetric_##name || rtd->dai_link->symmetric_##name)) { \
                dev_dbg(soc_dai->dev, "ASoC: Symmetry forces %s to %d\n",\
                        #name, soc_dai->symmetric_##name);              \
                                                                        \
                ret = snd_pcm_hw_constraint_single(substream->runtime,  \
                                                   SNDRV_PCM_HW_PARAM_##NAME,\
                                                   soc_dai->symmetric_##name);  \
                if (ret < 0)                                                    \
                        return snd_soc_ret(soc_dai->dev, ret,                   \
                                "Unable to apply %s constraint\n", #name);      \
        }

        __soc_pcm_apply_symmetry(rate,          RATE);
        __soc_pcm_apply_symmetry(channels,      CHANNELS);
        __soc_pcm_apply_symmetry(sample_bits,   SAMPLE_BITS);

        return 0;
}

static int soc_pcm_params_symmetry(struct snd_pcm_substream *substream,
                                struct snd_pcm_hw_params *params)
{
        struct snd_soc_pcm_runtime *rtd = snd_soc_substream_to_rtd(substream);
        struct snd_soc_dai d;
        struct snd_soc_dai *dai;
        struct snd_soc_dai *cpu_dai;
        unsigned int symmetry, i;

        d.name = __func__;
        soc_pcm_set_dai_params(&d, params);

#define __soc_pcm_params_symmetry(xxx)                                  \
        symmetry = rtd->dai_link->symmetric_##xxx;                      \
        for_each_rtd_dais(rtd, i, dai)                                  \
                symmetry |= dai->driver->symmetric_##xxx;               \
                                                                        \
        if (symmetry)                                                   \
                for_each_rtd_cpu_dais(rtd, i, cpu_dai)                  \
                        if (!snd_soc_dai_is_dummy(cpu_dai) &&           \
                            cpu_dai->symmetric_##xxx &&                 \
                            cpu_dai->symmetric_##xxx != d.symmetric_##xxx) \
                                return snd_soc_ret(rtd->dev, -EINVAL,   \
                                                   "unmatched %s symmetry: %s:%d - %s:%d\n", \
                                                   #xxx, cpu_dai->name, cpu_dai->symmetric_##xxx, \
                                                   d.name, d.symmetric_##xxx);

        /* reject unmatched parameters when applying symmetry */
        __soc_pcm_params_symmetry(rate);
        __soc_pcm_params_symmetry(channels);
        __soc_pcm_params_symmetry(sample_bits);

        return 0;
}

static void soc_pcm_update_symmetry(struct snd_pcm_substream *substream)
{
        struct snd_soc_pcm_runtime *rtd = snd_soc_substream_to_rtd(substream);
        struct snd_soc_dai_link *link = rtd->dai_link;
        struct snd_soc_dai *dai;
        unsigned int symmetry, i;

        symmetry = link->symmetric_rate ||
                link->symmetric_channels ||
                link->symmetric_sample_bits;

        for_each_rtd_dais(rtd, i, dai)
                symmetry = symmetry ||
                        dai->driver->symmetric_rate ||
                        dai->driver->symmetric_channels ||
                        dai->driver->symmetric_sample_bits;

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

static void soc_pcm_set_msb(struct snd_pcm_substream *substream, int bits)
{
        struct snd_soc_pcm_runtime *rtd = snd_soc_substream_to_rtd(substream);
        int ret;

        if (!bits)
                return;

        ret = snd_pcm_hw_constraint_msbits(substream->runtime, 0, 0, bits);
        if (ret != 0)
                dev_warn(rtd->dev, "ASoC: Failed to set MSB %d: %d\n",
                                 bits, ret);
}

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

        for_each_rtd_codec_dais(rtd, i, codec_dai) {
                const struct snd_soc_pcm_stream *pcm_codec = snd_soc_dai_get_pcm_stream(codec_dai, stream);

                if (pcm_codec->sig_bits == 0) {
                        bits = 0;
                        break;
                }
                bits = max(pcm_codec->sig_bits, bits);
        }

        for_each_rtd_cpu_dais(rtd, i, cpu_dai) {
                const struct snd_soc_pcm_stream *pcm_cpu = snd_soc_dai_get_pcm_stream(cpu_dai, stream);

                if (pcm_cpu->sig_bits == 0) {
                        cpu_bits = 0;
                        break;
                }
                cpu_bits = max(pcm_cpu->sig_bits, cpu_bits);
        }

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

static void soc_pcm_hw_init(struct snd_pcm_hardware *hw)
{
        hw->rates               = UINT_MAX;
        hw->rate_min            = 0;
        hw->rate_max            = UINT_MAX;
        hw->channels_min        = 0;
        hw->channels_max        = UINT_MAX;
        hw->formats             = ULLONG_MAX;
}

static void soc_pcm_hw_update_rate(struct snd_pcm_hardware *hw,
                                   const struct snd_soc_pcm_stream *p)
{
        hw->rates = snd_pcm_rate_mask_intersect(hw->rates, p->rates);

        /* setup hw->rate_min/max via hw->rates first */
        snd_pcm_hw_limit_rates(hw);

        /* update hw->rate_min/max by snd_soc_pcm_stream */
        hw->rate_min = max(hw->rate_min, p->rate_min);
        hw->rate_max = min_not_zero(hw->rate_max, p->rate_max);
}

static void soc_pcm_hw_update_chan(struct snd_pcm_hardware *hw,
                                   const struct snd_soc_pcm_stream *p)
{
        hw->channels_min = max(hw->channels_min, p->channels_min);
        hw->channels_max = min(hw->channels_max, p->channels_max);
}

static void soc_pcm_hw_update_format(struct snd_pcm_hardware *hw,
                                     const struct snd_soc_pcm_stream *p)
{
        hw->formats     &= p->formats;
        hw->subformats  &= p->subformats;
}

/**
 * snd_soc_runtime_calc_hw() - Calculate hw limits for a PCM stream
 * @rtd: ASoC PCM runtime
 * @hw: PCM hardware parameters (output)
 * @stream: Direction of the PCM stream
 *
 * Calculates the subset of stream parameters supported by all DAIs
 * associated with the PCM stream.
 */
int snd_soc_runtime_calc_hw(struct snd_soc_pcm_runtime *rtd,
                            struct snd_pcm_hardware *hw, int stream)
{
        struct snd_soc_dai *codec_dai;
        struct snd_soc_dai *cpu_dai;
        const struct snd_soc_pcm_stream *codec_stream;
        const struct snd_soc_pcm_stream *cpu_stream;
        unsigned int cpu_chan_min = 0, cpu_chan_max = UINT_MAX;
        int i;

        soc_pcm_hw_init(hw);

        /* first calculate min/max only for CPUs in the DAI link */
        for_each_rtd_cpu_dais(rtd, i, cpu_dai) {

                /*
                 * Skip CPUs which don't support the current stream type.
                 * Otherwise, since the rate, channel, and format values will
                 * zero in that case, we would have no usable settings left,
                 * causing the resulting setup to fail.
                 */
                if (!snd_soc_dai_stream_valid(cpu_dai, stream))
                        continue;

                cpu_stream = snd_soc_dai_get_pcm_stream(cpu_dai, stream);

                soc_pcm_hw_update_chan(hw, cpu_stream);
                soc_pcm_hw_update_rate(hw, cpu_stream);
                soc_pcm_hw_update_format(hw, cpu_stream);
        }
        cpu_chan_min = hw->channels_min;
        cpu_chan_max = hw->channels_max;

        /* second calculate min/max only for CODECs in the DAI link */
        for_each_rtd_codec_dais(rtd, i, codec_dai) {

                /*
                 * Skip CODECs which don't support the current stream type.
                 * Otherwise, since the rate, channel, and format values will
                 * zero in that case, we would have no usable settings left,
                 * causing the resulting setup to fail.
                 */
                if (!snd_soc_dai_stream_valid(codec_dai, stream))
                        continue;

                codec_stream = snd_soc_dai_get_pcm_stream(codec_dai, stream);

                soc_pcm_hw_update_chan(hw, codec_stream);
                soc_pcm_hw_update_rate(hw, codec_stream);
                soc_pcm_hw_update_format(hw, codec_stream);
        }

        /* Verify both a valid CPU DAI and a valid CODEC DAI were found */
        if (!hw->channels_min)
                return -EINVAL;

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

        return 0;
}
EXPORT_SYMBOL_GPL(snd_soc_runtime_calc_hw);

static void soc_pcm_init_runtime_hw(struct snd_pcm_substream *substream)
{
        struct snd_pcm_hardware *hw = &substream->runtime->hw;
        struct snd_soc_pcm_runtime *rtd = snd_soc_substream_to_rtd(substream);
        u64 formats = hw->formats;

        /*
         * At least one CPU and one CODEC should match. Otherwise, we should
         * have bailed out on a higher level, since there would be no CPU or
         * CODEC to support the transfer direction in that case.
         */
        snd_soc_runtime_calc_hw(rtd, hw, substream->stream);

        if (formats)
                hw->formats &= formats;
}

static int soc_pcm_components_open(struct snd_pcm_substream *substream)
{
        struct snd_soc_pcm_runtime *rtd = snd_soc_substream_to_rtd(substream);
        struct snd_soc_component *component;
        int i, ret = 0;

        for_each_rtd_components(rtd, i, component) {
                ret = snd_soc_component_module_get_when_open(component, substream);
                if (ret < 0)
                        break;

                ret = snd_soc_component_open(component, substream);
                if (ret < 0)
                        break;
        }

        return ret;
}

static int soc_pcm_components_close(struct snd_pcm_substream *substream,
                                    int rollback)
{
        struct snd_soc_pcm_runtime *rtd = snd_soc_substream_to_rtd(substream);
        struct snd_soc_component *component;
        int i, ret = 0;

        for_each_rtd_components(rtd, i, component) {
                int r = snd_soc_component_close(component, substream, rollback);
                if (r < 0)
                        ret = r; /* use last ret */

                snd_soc_component_module_put_when_close(component, substream, rollback);
        }

        return ret;
}

static int soc_pcm_clean(struct snd_soc_pcm_runtime *rtd,
                         struct snd_pcm_substream *substream, int rollback)
{
        struct snd_soc_component *component;
        struct snd_soc_dai *dai;
        int i;

        snd_soc_dpcm_mutex_assert_held(rtd);

        if (!rollback) {
                snd_soc_runtime_deactivate(rtd, substream->stream);

                /* Make sure DAI parameters cleared if the DAI becomes inactive */
                for_each_rtd_dais(rtd, i, dai) {
                        if (snd_soc_dai_active(dai) == 0)
                                soc_pcm_set_dai_params(dai, NULL);
                }
        }

        for_each_rtd_dais_reverse(rtd, i, dai)
                snd_soc_dai_shutdown(dai, substream, rollback);

        snd_soc_link_shutdown(substream, rollback);

        soc_pcm_components_close(substream, rollback);

        snd_soc_pcm_component_pm_runtime_put(rtd, substream, rollback);

        for_each_rtd_components(rtd, i, component)
                if (!snd_soc_component_active(component))
                        pinctrl_pm_select_sleep_state(component->dev);

        return 0;
}

/*
 * Called by ALSA when a PCM substream is closed. Private data can be
 * freed here. The cpu DAI, codec DAI, machine and components are also
 * shutdown.
 */
static int __soc_pcm_close(struct snd_soc_pcm_runtime *rtd,
                           struct snd_pcm_substream *substream)
{
        return soc_pcm_clean(rtd, substream, 0);
}

/* PCM close ops for non-DPCM streams */
static int soc_pcm_close(struct snd_pcm_substream *substream)
{
        struct snd_soc_pcm_runtime *rtd = snd_soc_substream_to_rtd(substream);

        snd_soc_dpcm_mutex_lock(rtd);
        __soc_pcm_close(rtd, substream);
        snd_soc_dpcm_mutex_unlock(rtd);
        return 0;
}

static int soc_hw_sanity_check(struct snd_pcm_substream *substream)
{
        struct snd_soc_pcm_runtime *rtd = snd_soc_substream_to_rtd(substream);
        struct snd_pcm_hardware *hw = &substream->runtime->hw;
        const char *name_cpu = soc_cpu_dai_name(rtd);
        const char *name_codec = soc_codec_dai_name(rtd);
        const char *err_msg;
        struct device *dev = rtd->dev;

        err_msg = "rates";
        if (!hw->rates)
                goto config_err;

        err_msg = "formats";
        if (!hw->formats)
                goto config_err;

        err_msg = "channels";
        if (!hw->channels_min || !hw->channels_max ||
             hw->channels_min  >  hw->channels_max)
                goto config_err;

        dev_dbg(dev, "ASoC: %s <-> %s info:\n",         name_codec,
                                                        name_cpu);
        dev_dbg(dev, "ASoC: rate mask 0x%x\n",          hw->rates);
        dev_dbg(dev, "ASoC: ch   min %d max %d\n",      hw->channels_min,
                                                        hw->channels_max);
        dev_dbg(dev, "ASoC: rate min %d max %d\n",      hw->rate_min,
                                                        hw->rate_max);

        return 0;

config_err:
        return snd_soc_ret(dev, -EINVAL,
                        "%s <-> %s No matching %s\n", name_codec, name_cpu, err_msg);
}

/*
 * 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_soc_pcm_runtime *rtd,
                          struct snd_pcm_substream *substream)
{
        struct snd_soc_component *component;
        struct snd_soc_dai *dai;
        int i, ret = 0;

        snd_soc_dpcm_mutex_assert_held(rtd);

        for_each_rtd_components(rtd, i, component)
                pinctrl_pm_select_default_state(component->dev);

        ret = snd_soc_pcm_component_pm_runtime_get(rtd, substream);
        if (ret < 0)
                goto err;

        ret = soc_pcm_components_open(substream);
        if (ret < 0)
                goto err;

        ret = snd_soc_link_startup(substream);
        if (ret < 0)
                goto err;

        /* startup the audio subsystem */
        for_each_rtd_dais(rtd, i, dai) {
                ret = snd_soc_dai_startup(dai, substream);
                if (ret < 0)
                        goto err;
        }

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

        /* Check that the codec and cpu DAIs are compatible */
        soc_pcm_init_runtime_hw(substream);

        soc_pcm_update_symmetry(substream);

        ret = soc_hw_sanity_check(substream);
        if (ret < 0)
                goto err;

        soc_pcm_apply_msb(substream);

        /* Symmetry only applies if we've already got an active stream. */
        for_each_rtd_dais(rtd, i, dai) {
                ret = soc_pcm_apply_symmetry(substream, dai);
                if (ret != 0)
                        goto err;
        }
dynamic:
        snd_soc_runtime_activate(rtd, substream->stream);
        ret = 0;
err:
        if (ret < 0)
                soc_pcm_clean(rtd, substream, 1);

        return soc_pcm_ret(rtd, ret);
}

/* PCM open ops for non-DPCM streams */
static int soc_pcm_open(struct snd_pcm_substream *substream)
{
        struct snd_soc_pcm_runtime *rtd = snd_soc_substream_to_rtd(substream);
        int ret;

        snd_soc_dpcm_mutex_lock(rtd);
        ret = __soc_pcm_open(rtd, substream);
        snd_soc_dpcm_mutex_unlock(rtd);
        return ret;
}

/*
 * 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_soc_pcm_runtime *rtd,
                             struct snd_pcm_substream *substream)
{
        struct snd_soc_dai *dai;
        int i, ret = 0;

        snd_soc_dpcm_mutex_assert_held(rtd);

        ret = snd_soc_link_prepare(substream);
        if (ret < 0)
                goto out;

        ret = snd_soc_pcm_component_prepare(substream);
        if (ret < 0)
                goto out;

        ret = snd_soc_pcm_dai_prepare(substream);
        if (ret < 0)
                goto out;

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

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

        for_each_rtd_dais(rtd, i, dai) {
                if (!snd_soc_dai_mute_is_ctrled_at_trigger(dai))
                        snd_soc_dai_digital_mute(dai, 0, substream->stream);
        }

out:
        /*
         * Don't use soc_pcm_ret() on .prepare callback to lower error log severity
         *
         * We don't want to log an error since we do not want to give userspace a way to do a
         * denial-of-service attack on the syslog / diskspace.
         */
        return ret;
}

/* PCM prepare ops for non-DPCM streams */
static int soc_pcm_prepare(struct snd_pcm_substream *substream)
{
        struct snd_soc_pcm_runtime *rtd = snd_soc_substream_to_rtd(substream);
        int ret;

        snd_soc_dpcm_mutex_lock(rtd);
        ret = __soc_pcm_prepare(rtd, substream);
        snd_soc_dpcm_mutex_unlock(rtd);

        /*
         * Don't use soc_pcm_ret() on .prepare callback to lower error log severity
         *
         * We don't want to log an error since we do not want to give userspace a way to do a
         * denial-of-service attack on the syslog / diskspace.
         */
        return ret;
}

static void soc_pcm_codec_params_fixup(struct snd_pcm_hw_params *params,
                                       unsigned int mask)
{
        struct snd_interval *interval;
        int channels = hweight_long(mask);

        interval = hw_param_interval(params, SNDRV_PCM_HW_PARAM_CHANNELS);
        interval->min = channels;
        interval->max = channels;
}

static int soc_pcm_hw_clean(struct snd_soc_pcm_runtime *rtd,
                            struct snd_pcm_substream *substream, int rollback)
{
        struct snd_soc_dai *dai;
        int i;

        snd_soc_dpcm_mutex_assert_held(rtd);

        /* clear the corresponding DAIs parameters when going to be inactive */
        for_each_rtd_dais(rtd, i, dai) {
                if (snd_soc_dai_active(dai) == 1)
                        soc_pcm_set_dai_params(dai, NULL);

                if (snd_soc_dai_stream_active(dai, substream->stream) == 1) {
                        if (!snd_soc_dai_mute_is_ctrled_at_trigger(dai))
                                snd_soc_dai_digital_mute(dai, 1, substream->stream);
                }
        }

        /* run the stream event */
        snd_soc_dapm_stream_stop(rtd, substream->stream);

        /* free any machine hw params */
        snd_soc_link_hw_free(substream, rollback);

        /* free any component resources */
        snd_soc_pcm_component_hw_free(substream, rollback);

        /* now free hw params for the DAIs  */
        for_each_rtd_dais(rtd, i, dai)
                if (snd_soc_dai_stream_valid(dai, substream->stream))
                        snd_soc_dai_hw_free(dai, substream, rollback);

        return 0;
}

/*
 * Frees resources allocated by hw_params, can be called multiple times
 */
static int __soc_pcm_hw_free(struct snd_soc_pcm_runtime *rtd,
                             struct snd_pcm_substream *substream)
{
        return soc_pcm_hw_clean(rtd, substream, 0);
}

/* hw_free PCM ops for non-DPCM streams */
static int soc_pcm_hw_free(struct snd_pcm_substream *substream)
{
        struct snd_soc_pcm_runtime *rtd = snd_soc_substream_to_rtd(substream);
        int ret;

        snd_soc_dpcm_mutex_lock(rtd);
        ret = __soc_pcm_hw_free(rtd, substream);
        snd_soc_dpcm_mutex_unlock(rtd);
        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 = snd_soc_substream_to_rtd(substream);
        struct snd_soc_dai *cpu_dai;
        struct snd_soc_dai *codec_dai;
        struct snd_pcm_hw_params tmp_params;
        int i, ret = 0;

        snd_soc_dpcm_mutex_assert_held(rtd);

        ret = soc_pcm_params_symmetry(substream, params);
        if (ret)
                goto out;

        ret = snd_soc_link_hw_params(substream, params);
        if (ret < 0)
                goto out;

        for_each_rtd_codec_dais(rtd, i, codec_dai) {
                unsigned int tdm_mask = snd_soc_dai_tdm_mask_get(codec_dai, substream->stream);

                /*
                 * 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 */
                tmp_params = *params;

                /* fixup params based on TDM slot masks */
                if (tdm_mask)
                        soc_pcm_codec_params_fixup(&tmp_params, tdm_mask);

                ret = snd_soc_dai_hw_params(codec_dai, substream,
                                            &tmp_params);
                if(ret < 0)
                        goto out;

                soc_pcm_set_dai_params(codec_dai, &tmp_params);
                snd_soc_dapm_update_dai(substream, &tmp_params, codec_dai);
        }

        for_each_rtd_cpu_dais(rtd, i, cpu_dai) {
                struct snd_soc_dai_link_ch_map *ch_maps;
                unsigned int ch_mask = 0;
                int j;

                /*
                 * Skip CPUs which don't support the current stream
                 * type. See soc_pcm_init_runtime_hw() for more details
                 */
                if (!snd_soc_dai_stream_valid(cpu_dai, substream->stream))
                        continue;

                /* copy params for each cpu */
                tmp_params = *params;

                /*
                 * construct cpu channel mask by combining ch_mask of each
                 * codec which maps to the cpu.
                 * see
                 *      soc.h :: [dai_link->ch_maps Image sample]
                 */
                for_each_rtd_ch_maps(rtd, j, ch_maps)
                        if (ch_maps->cpu == i)
                                ch_mask |= ch_maps->ch_mask;

                /* fixup cpu channel number */
                if (ch_mask)
                        soc_pcm_codec_params_fixup(&tmp_params, ch_mask);

                ret = snd_soc_dai_hw_params(cpu_dai, substream, &tmp_params);
                if (ret < 0)
                        goto out;

                /* store the parameters for each DAI */
                soc_pcm_set_dai_params(cpu_dai, &tmp_params);
                snd_soc_dapm_update_dai(substream, &tmp_params, cpu_dai);
        }

        ret = snd_soc_pcm_component_hw_params(substream, params);
out:
        if (ret < 0)
                soc_pcm_hw_clean(rtd, substream, 1);

        return soc_pcm_ret(rtd, ret);
}

/* hw_params PCM ops for non-DPCM streams */
static int soc_pcm_hw_params(struct snd_pcm_substream *substream,
                             struct snd_pcm_hw_params *params)
{
        struct snd_soc_pcm_runtime *rtd = snd_soc_substream_to_rtd(substream);
        int ret;

        snd_soc_dpcm_mutex_lock(rtd);
        ret = __soc_pcm_hw_params(substream, params);
        snd_soc_dpcm_mutex_unlock(rtd);
        return ret;
}

#define TRIGGER_MAX 3
static int (* const trigger[][TRIGGER_MAX])(struct snd_pcm_substream *substream, int cmd, int rollback) = {
        [SND_SOC_TRIGGER_ORDER_DEFAULT] = {
                snd_soc_link_trigger,
                snd_soc_pcm_component_trigger,
                snd_soc_pcm_dai_trigger,
        },
        [SND_SOC_TRIGGER_ORDER_LDC] = {
                snd_soc_link_trigger,
                snd_soc_pcm_dai_trigger,
                snd_soc_pcm_component_trigger,
        },
};

static int soc_pcm_trigger(struct snd_pcm_substream *substream, int cmd)
{
        struct snd_soc_pcm_runtime *rtd = snd_soc_substream_to_rtd(substream);
        struct snd_soc_component *component;
        int ret = 0, r = 0, i;
        int rollback = 0;
        int start = 0, stop = 0;

        /*
         * select START/STOP sequence
         */
        for_each_rtd_components(rtd, i, component) {
                if (component->driver->trigger_start)
                        start = component->driver->trigger_start;
                if (component->driver->trigger_stop)
                        stop = component->driver->trigger_stop;
        }
        if (rtd->dai_link->trigger_start)
                start = rtd->dai_link->trigger_start;
        if (rtd->dai_link->trigger_stop)
                stop  = rtd->dai_link->trigger_stop;

        if (start < 0 || start >= SND_SOC_TRIGGER_ORDER_MAX ||
            stop  < 0 || stop  >= SND_SOC_TRIGGER_ORDER_MAX)
                return -EINVAL;

        /*
         * START
         */
        switch (cmd) {
        case SNDRV_PCM_TRIGGER_START:
        case SNDRV_PCM_TRIGGER_RESUME:
        case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
                for (i = 0; i < TRIGGER_MAX; i++) {
                        r = trigger[start][i](substream, cmd, 0);
                        if (r < 0)
                                break;
                }
        }

        /*
         * Rollback if START failed
         * find correspond STOP command
         */
        if (r < 0) {
                rollback = 1;
                ret = r;
                switch (cmd) {
                case SNDRV_PCM_TRIGGER_START:
                        cmd = SNDRV_PCM_TRIGGER_STOP;
                        break;
                case SNDRV_PCM_TRIGGER_RESUME:
                        cmd = SNDRV_PCM_TRIGGER_SUSPEND;
                        break;
                case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
                        cmd = SNDRV_PCM_TRIGGER_PAUSE_PUSH;
                        break;
                }
        }

        /*
         * STOP
         */
        switch (cmd) {
        case SNDRV_PCM_TRIGGER_STOP:
        case SNDRV_PCM_TRIGGER_SUSPEND:
        case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
                for (i = TRIGGER_MAX; i > 0; i--) {
                        r = trigger[stop][i - 1](substream, cmd, rollback);
                        if (r < 0)
                                ret = r;
                }
        }

        return ret;
}

/*
 * soc level wrapper for pointer callback
 * If cpu_dai, codec_dai, component driver has the delay callback, then
 * the runtime->delay will be updated via snd_soc_pcm_component/dai_delay().
 */
static snd_pcm_uframes_t soc_pcm_pointer(struct snd_pcm_substream *substream)
{
        struct snd_pcm_runtime *runtime = substream->runtime;
        snd_pcm_uframes_t offset = 0;
        snd_pcm_sframes_t codec_delay = 0;
        snd_pcm_sframes_t cpu_delay = 0;

        offset = snd_soc_pcm_component_pointer(substream);

        /* should be called *after* snd_soc_pcm_component_pointer() */
        snd_soc_pcm_dai_delay(substream, &cpu_delay, &codec_delay);
        snd_soc_pcm_component_delay(substream, &cpu_delay, &codec_delay);

        runtime->delay = cpu_delay + codec_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_pcm_substream *fe_substream;
        struct snd_pcm_substream *be_substream;
        struct snd_soc_dpcm *dpcm;

        snd_soc_dpcm_mutex_assert_held(fe);

        /* only add new dpcms */
        for_each_dpcm_be(fe, stream, dpcm)
                if (dpcm->be == be)
                        return 0;

        fe_substream = snd_soc_dpcm_get_substream(fe, stream);
        be_substream = snd_soc_dpcm_get_substream(be, stream);

        if (!fe_substream->pcm->nonatomic && be_substream->pcm->nonatomic)
                return snd_soc_ret(be->dev, -EINVAL,
                        "%s: %s is atomic but %s is nonatomic, invalid configuration\n",
                                   __func__, fe->dai_link->name, be->dai_link->name);

        if (fe_substream->pcm->nonatomic && !be_substream->pcm->nonatomic) {
                dev_dbg(be->dev, "FE is nonatomic but BE is not, forcing BE as nonatomic\n");
                be_substream->pcm->nonatomic = 1;
        }

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

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

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

        dpcm_create_debugfs_state(dpcm, stream);

        return 1;
}

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

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

        be_substream = snd_soc_dpcm_get_substream(be, stream);
        if (!be_substream)
                return;

        for_each_dpcm_fe(be, stream, dpcm) {
                if (dpcm->fe == fe)
                        continue;

                dev_dbg(fe->dev, "reparent %s path %s %s %s\n",
                        snd_pcm_direction_name(stream),
                        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;
        struct snd_pcm_substream *substream = snd_soc_dpcm_get_substream(fe, stream);
        LIST_HEAD(deleted_dpcms);

        snd_soc_dpcm_mutex_assert_held(fe);

        snd_pcm_stream_lock_irq(substream);
        for_each_dpcm_be_safe(fe, stream, dpcm, d) {
                dev_dbg(fe->dev, "ASoC: BE %s disconnect check for %s\n",
                                snd_pcm_direction_name(stream),
                                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",
                        snd_pcm_direction_name(stream), fe->dai_link->name,
                        stream ? "<-" : "->", dpcm->be->dai_link->name);

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

                list_del(&dpcm->list_be);
                list_move(&dpcm->list_fe, &deleted_dpcms);
        }
        snd_pcm_stream_unlock_irq(substream);

        while (!list_empty(&deleted_dpcms)) {
                dpcm = list_first_entry(&deleted_dpcms, struct snd_soc_dpcm,
                                        list_fe);
                list_del(&dpcm->list_fe);
                dpcm_remove_debugfs_state(dpcm);
                kfree(dpcm);
        }
}

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

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

        for_each_card_rtds(card, be) {

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

                if (!snd_soc_dpcm_get_substream(be, stream))
                        continue;

                for_each_rtd_dais(be, i, dai) {
                        w = snd_soc_dai_get_widget(dai, stream);

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

                        if (w == widget)
                                return be;
                }
        }

        /* Widget provided is not a BE */
        return NULL;
}

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

        for_each_dapm_widgets(list, i, w)
                if (widget == w)
                        return 1;

        return 0;
}
EXPORT_SYMBOL_GPL(widget_in_list);

bool dpcm_end_walk_at_be(struct snd_soc_dapm_widget *widget, enum snd_soc_dapm_direction dir)
{
        struct snd_soc_card *card = widget->dapm->card;
        struct snd_soc_pcm_runtime *rtd;
        int stream;

        /* adjust dir to stream */
        if (dir == SND_SOC_DAPM_DIR_OUT)
                stream = SNDRV_PCM_STREAM_PLAYBACK;
        else
                stream = SNDRV_PCM_STREAM_CAPTURE;

        rtd = dpcm_get_be(card, widget, stream);
        if (rtd)
                return true;

        return false;
}
EXPORT_SYMBOL_GPL(dpcm_end_walk_at_be);

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 = snd_soc_rtd_to_cpu(fe, 0);
        int paths;

        if (fe->dai_link->num_cpus > 1)
                return snd_soc_ret(fe->dev, -EINVAL,
                        "%s doesn't support Multi CPU yet\n", __func__);

        /* get number of valid DAI paths and their widgets */
        paths = snd_soc_dapm_dai_get_connected_widgets(cpu_dai, stream, list,
                        fe->card->component_chaining ?
                                NULL : dpcm_end_walk_at_be);

        if (paths > 0)
                dev_dbg(fe->dev, "ASoC: found %d audio %s paths\n", paths,
                        snd_pcm_direction_name(stream));
        else if (paths == 0)
                dev_dbg(fe->dev, "ASoC: %s no valid %s path\n", fe->dai_link->name,
                        snd_pcm_direction_name(stream));

        return paths;
}

void dpcm_path_put(struct snd_soc_dapm_widget_list **list)
{
        snd_soc_dapm_dai_free_widgets(list);
}

static bool dpcm_be_is_active(struct snd_soc_dpcm *dpcm, int stream,
                              struct snd_soc_dapm_widget_list *list)
{
        struct snd_soc_dai *dai;
        unsigned int i;

        /* is there a valid DAI widget for this BE */
        for_each_rtd_dais(dpcm->be, i, dai) {
                struct snd_soc_dapm_widget *widget = snd_soc_dai_get_widget(dai, stream);

                /*
                 * The BE is pruned only if none of the dai
                 * widgets are in the active list.
                 */
                if (widget && widget_in_list(list, widget))
                        return true;
        }

        return false;
}

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

        /* Destroy any old FE <--> BE connections */
        for_each_dpcm_be(fe, stream, dpcm) {
                if (dpcm_be_is_active(dpcm, stream, *list_))
                        continue;

                dev_dbg(fe->dev, "ASoC: pruning %s BE %s for %s\n",
                        snd_pcm_direction_name(stream),
                        dpcm->be->dai_link->name, fe->dai_link->name);
                dpcm->state = SND_SOC_DPCM_LINK_STATE_FREE;
                dpcm_set_be_update_state(dpcm->be, stream, SND_SOC_DPCM_UPDATE_BE);
                prune++;
        }

        dev_dbg(fe->dev, "ASoC: found %d old BE paths for pruning\n", prune);
        return prune;
}

int dpcm_add_paths(struct snd_soc_pcm_runtime *fe, int stream,
                   struct snd_soc_dapm_widget_list **list_)
{
        struct snd_soc_card *card = fe->card;
        struct snd_soc_dapm_widget_list *list = *list_;
        struct snd_soc_pcm_runtime *be;
        struct snd_soc_dapm_widget *widget;
        struct snd_pcm_substream *fe_substream = snd_soc_dpcm_get_substream(fe, stream);
        int i, new = 0, err;

        /* don't connect if FE is not running */
        if (!fe_substream->runtime && !fe->fe_compr)
                return new;

        /* Create any new FE <--> BE connections */
        for_each_dapm_widgets(list, i, widget) {

                switch (widget->id) {
                case snd_soc_dapm_dai_in:
                        if (stream != SNDRV_PCM_STREAM_PLAYBACK)
                                continue;
                        break;
                case snd_soc_dapm_dai_out:
                        if (stream != SNDRV_PCM_STREAM_CAPTURE)
                                continue;
                        break;
                default:
                        continue;
                }

                /* is there a valid BE rtd for this widget */
                be = dpcm_get_be(card, widget, stream);
                if (!be) {
                        dev_dbg(fe->dev, "ASoC: no BE found for %s\n",
                                widget->name);
                        continue;
                }

                /*
                 * Filter for systems with 'component_chaining' enabled.
                 * This helps to avoid unnecessary re-configuration of an
                 * already active BE on such systems and ensures the BE DAI
                 * widget is powered ON after hw_params() BE DAI callback.
                 */
                if (fe->card->component_chaining &&
                    (be->dpcm[stream].state != SND_SOC_DPCM_STATE_NEW) &&
                    (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_CLOSE))
                        continue;

                /* newly connected FE and BE */
                err = dpcm_be_connect(fe, be, stream);
                if (err < 0) {
                        dev_err(fe->dev, "ASoC: can't connect %s\n",
                                widget->name);
                        break;
                } else if (err == 0) /* already connected */
                        continue;

                /* new */
                dpcm_set_be_update_state(be, stream, SND_SOC_DPCM_UPDATE_BE);
                new++;
        }

        dev_dbg(fe->dev, "ASoC: found %d new BE paths\n", new);
        return new;
}

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

        for_each_dpcm_be(fe, stream, dpcm)
                dpcm_set_be_update_state(dpcm->be, stream, SND_SOC_DPCM_UPDATE_NO);
}

void dpcm_be_dai_stop(struct snd_soc_pcm_runtime *fe, int stream,
                      int do_hw_free, struct snd_soc_dpcm *last)
{
        struct snd_soc_dpcm *dpcm;

        /* disable any enabled and non active backends */
        for_each_dpcm_be(fe, stream, dpcm) {
                struct snd_soc_pcm_runtime *be = dpcm->be;
                struct snd_pcm_substream *be_substream =
                        snd_soc_dpcm_get_substream(be, stream);

                if (dpcm == last)
                        return;

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

                if (be->dpcm[stream].users == 0) {
                        dev_err(be->dev, "ASoC: no users %s at close - state %s\n",
                                snd_pcm_direction_name(stream),
                                dpcm_state_string(be->dpcm[stream].state));
                        continue;
                }

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

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

                        if (be->dpcm[stream].state != SND_SOC_DPCM_STATE_HW_FREE) {
                                __soc_pcm_hw_free(be, be_substream);
                                be->dpcm[stream].state = SND_SOC_DPCM_STATE_HW_FREE;
                        }
                }

                __soc_pcm_close(be, 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_pcm_substream *fe_substream = snd_soc_dpcm_get_substream(fe, stream);
        struct snd_soc_pcm_runtime *be;
        struct snd_soc_dpcm *dpcm;
        int err, count = 0;

        /* only startup BE DAIs that are either sinks or sources to this FE DAI */
        for_each_dpcm_be(fe, stream, dpcm) {
                struct snd_pcm_substream *be_substream;

                be = dpcm->be;
                be_substream = snd_soc_dpcm_get_substream(be, stream);

                if (!be_substream) {
                        dev_err(be->dev, "ASoC: no backend %s stream\n",
                                snd_pcm_direction_name(stream));
                        continue;
                }

                /* is this op for this BE ? */
                if (!snd_soc_dpcm_can_be_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 %s\n",
                                snd_pcm_direction_name(stream),
                                dpcm_state_string(be->dpcm[stream].state));
                        continue;
                }

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

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

                dev_dbg(be->dev, "ASoC: open %s BE %s\n",
                        snd_pcm_direction_name(stream), be->dai_link->name);

                be_substream->runtime = fe_substream->runtime;
                err = __soc_pcm_open(be, be_substream);
                if (err < 0) {
                        be->dpcm[stream].users--;
                        if (be->dpcm[stream].users < 0)
                                dev_err(be->dev, "ASoC: no users %s at unwind %s\n",
                                        snd_pcm_direction_name(stream),
                                        dpcm_state_string(be->dpcm[stream].state));

                        be->dpcm[stream].state = SND_SOC_DPCM_STATE_CLOSE;
                        goto unwind;
                }
                be->dpcm[stream].be_start = 0;
                be->dpcm[stream].state = SND_SOC_DPCM_STATE_OPEN;
                count++;
        }

        return count;

unwind:
        dpcm_be_dai_startup_rollback(fe, stream, dpcm);

        return soc_pcm_ret(fe, err);
}

static void dpcm_runtime_setup_fe(struct snd_pcm_substream *substream)
{
        struct snd_soc_pcm_runtime *fe = snd_soc_substream_to_rtd(substream);
        struct snd_pcm_runtime *runtime = substream->runtime;
        struct snd_pcm_hardware *hw = &runtime->hw;
        struct snd_soc_dai *dai;
        int stream = substream->stream;
        u64 formats = hw->formats;
        int i;

        soc_pcm_hw_init(hw);

        if (formats)
                hw->formats &= formats;

        for_each_rtd_cpu_dais(fe, i, dai) {
                const struct snd_soc_pcm_stream *cpu_stream;

                /*
                 * Skip CPUs which don't support the current stream
                 * type. See soc_pcm_init_runtime_hw() for more details
                 */
                if (!snd_soc_dai_stream_valid(dai, stream))
                        continue;

                cpu_stream = snd_soc_dai_get_pcm_stream(dai, stream);

                soc_pcm_hw_update_rate(hw, cpu_stream);
                soc_pcm_hw_update_chan(hw, cpu_stream);
                soc_pcm_hw_update_format(hw, cpu_stream);
        }

}

static void dpcm_runtime_setup_be_format(struct snd_pcm_substream *substream)
{
        struct snd_soc_pcm_runtime *fe = snd_soc_substream_to_rtd(substream);
        struct snd_pcm_runtime *runtime = substream->runtime;
        struct snd_pcm_hardware *hw = &runtime->hw;
        struct snd_soc_dpcm *dpcm;
        struct snd_soc_dai *dai;
        int stream = substream->stream;

        if (!fe->dai_link->dpcm_merged_format)
                return;

        /*
         * It returns merged BE codec format
         * if FE want to use it (= dpcm_merged_format)
         */

        for_each_dpcm_be(fe, stream, dpcm) {
                struct snd_soc_pcm_runtime *be = dpcm->be;
                const struct snd_soc_pcm_stream *codec_stream;
                int i;

                for_each_rtd_codec_dais(be, i, dai) {
                        /*
                         * Skip CODECs which don't support the current stream
                         * type. See soc_pcm_init_runtime_hw() for more details
                         */
                        if (!snd_soc_dai_stream_valid(dai, stream))
                                continue;

                        codec_stream = snd_soc_dai_get_pcm_stream(dai, stream);

                        soc_pcm_hw_update_format(hw, codec_stream);
                }
        }
}

static void dpcm_runtime_setup_be_chan(struct snd_pcm_substream *substream)
{
        struct snd_soc_pcm_runtime *fe = snd_soc_substream_to_rtd(substream);
        struct snd_pcm_runtime *runtime = substream->runtime;
        struct snd_pcm_hardware *hw = &runtime->hw;
        struct snd_soc_dpcm *dpcm;
        int stream = substream->stream;

        if (!fe->dai_link->dpcm_merged_chan)
                return;

        /*
         * It returns merged BE codec channel;
         * if FE want to use it (= dpcm_merged_chan)
         */

        for_each_dpcm_be(fe, stream, dpcm) {
                struct snd_soc_pcm_runtime *be = dpcm->be;
                const struct snd_soc_pcm_stream *cpu_stream;
                struct snd_soc_dai *dai;
                int i;

                for_each_rtd_cpu_dais(be, i, dai) {
                        /*
                         * Skip CPUs which don't support the current stream
                         * type. See soc_pcm_init_runtime_hw() for more details
                         */
                        if (!snd_soc_dai_stream_valid(dai, stream))
                                continue;

                        cpu_stream = snd_soc_dai_get_pcm_stream(dai, stream);

                        soc_pcm_hw_update_chan(hw, cpu_stream);
                }

                /*
                 * chan min/max cannot be enforced if there are multiple CODEC
                 * DAIs connected to a single CPU DAI, use CPU DAI's directly
                 */
                if (be->dai_link->num_codecs == 1) {
                        const struct snd_soc_pcm_stream *codec_stream = snd_soc_dai_get_pcm_stream(
                                snd_soc_rtd_to_codec(be, 0), stream);

                        soc_pcm_hw_update_chan(hw, codec_stream);
                }
        }
}

static void dpcm_runtime_setup_be_rate(struct snd_pcm_substream *substream)
{
        struct snd_soc_pcm_runtime *fe = snd_soc_substream_to_rtd(substream);
        struct snd_pcm_runtime *runtime = substream->runtime;
        struct snd_pcm_hardware *hw = &runtime->hw;
        struct snd_soc_dpcm *dpcm;
        int stream = substream->stream;

        if (!fe->dai_link->dpcm_merged_rate)
                return;

        /*
         * It returns merged BE codec channel;
         * if FE want to use it (= dpcm_merged_chan)
         */

        for_each_dpcm_be(fe, stream, dpcm) {
                struct snd_soc_pcm_runtime *be = dpcm->be;
                const struct snd_soc_pcm_stream *pcm;
                struct snd_soc_dai *dai;
                int i;

                for_each_rtd_dais(be, i, dai) {
                        /*
                         * Skip DAIs which don't support the current stream
                         * type. See soc_pcm_init_runtime_hw() for more details
                         */
                        if (!snd_soc_dai_stream_valid(dai, stream))
                                continue;

                        pcm = snd_soc_dai_get_pcm_stream(dai, stream);

                        soc_pcm_hw_update_rate(hw, pcm);
                }
        }
}

static int dpcm_apply_symmetry(struct snd_pcm_substream *fe_substream,
                               int stream)
{
        struct snd_soc_dpcm *dpcm;
        struct snd_soc_pcm_runtime *fe = snd_soc_substream_to_rtd(fe_substream);
        struct snd_soc_dai *fe_cpu_dai;
        int err = 0;
        int i;

        /* apply symmetry for FE */
        soc_pcm_update_symmetry(fe_substream);

        for_each_rtd_cpu_dais (fe, i, fe_cpu_dai) {
                /* Symmetry only applies if we've got an active stream. */
                err = soc_pcm_apply_symmetry(fe_substream, fe_cpu_dai);
                if (err < 0)
                        goto error;
        }

        /* apply symmetry for BE */
        for_each_dpcm_be(fe, stream, dpcm) {
                struct snd_soc_pcm_runtime *be = dpcm->be;
                struct snd_pcm_substream *be_substream =
                        snd_soc_dpcm_get_substream(be, stream);
                struct snd_soc_pcm_runtime *rtd;
                struct snd_soc_dai *dai;

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

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

                soc_pcm_update_symmetry(be_substream);

                /* Symmetry only applies if we've got an active stream. */
                for_each_rtd_dais(rtd, i, dai) {
                        err = soc_pcm_apply_symmetry(fe_substream, dai);
                        if (err < 0)
                                goto error;
                }
        }
error:
        return soc_pcm_ret(fe, err);
}

static int dpcm_fe_dai_startup(struct snd_pcm_substream *fe_substream)
{
        struct snd_soc_pcm_runtime *fe = snd_soc_substream_to_rtd(fe_substream);
        int stream = fe_substream->stream, ret = 0;

        dpcm_set_fe_update_state(fe, stream, SND_SOC_DPCM_UPDATE_FE);

        ret = dpcm_be_dai_startup(fe, stream);
        if (ret < 0)
                goto be_err;

        dev_dbg(fe->dev, "ASoC: open FE %s\n", fe->dai_link->name);

        /* start the DAI frontend */
        ret = __soc_pcm_open(fe, fe_substream);
        if (ret < 0)
                goto unwind;

        fe->dpcm[stream].state = SND_SOC_DPCM_STATE_OPEN;

        dpcm_runtime_setup_fe(fe_substream);

        dpcm_runtime_setup_be_format(fe_substream);
        dpcm_runtime_setup_be_chan(fe_substream);
        dpcm_runtime_setup_be_rate(fe_substream);

        ret = dpcm_apply_symmetry(fe_substream, stream);

unwind:
        if (ret < 0)
                dpcm_be_dai_startup_unwind(fe, stream);
be_err:
        dpcm_set_fe_update_state(fe, stream, SND_SOC_DPCM_UPDATE_NO);

        return soc_pcm_ret(fe, ret);
}

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

        snd_soc_dpcm_mutex_assert_held(fe);

        dpcm_set_fe_update_state(fe, stream, SND_SOC_DPCM_UPDATE_FE);

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

        dev_dbg(fe->dev, "ASoC: close FE %s\n", fe->dai_link->name);

        /* now shutdown the frontend */
        __soc_pcm_close(fe, substream);

        /* run the stream stop event */
        dpcm_dapm_stream_event(fe, stream, SND_SOC_DAPM_STREAM_STOP);

        fe->dpcm[stream].state = SND_SOC_DPCM_STATE_CLOSE;
        dpcm_set_fe_update_state(fe, stream, SND_SOC_DPCM_UPDATE_NO);
        return 0;
}

void dpcm_be_dai_hw_free(struct snd_soc_pcm_runtime *fe, int stream)

{
        struct snd_soc_dpcm *dpcm;

        /* only hw_params backends that are either sinks or sources
         * to this frontend DAI */
        for_each_dpcm_be(fe, stream, dpcm) {

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

                /* is this op for this BE ? */
                if (!snd_soc_dpcm_can_be_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, be_substream);

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

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

        snd_soc_dpcm_mutex_lock(fe);
        dpcm_set_fe_update_state(fe, stream, SND_SOC_DPCM_UPDATE_FE);

        dev_dbg(fe->dev, "ASoC: hw_free FE %s\n", fe->dai_link->name);

        /* call hw_free on the frontend */
        soc_pcm_hw_clean(fe, substream, 0);

        /* only hw_params backends that are either sinks or sources
         * to this frontend DAI */
        dpcm_be_dai_hw_free(fe, stream);

        fe->dpcm[stream].state = SND_SOC_DPCM_STATE_HW_FREE;
        dpcm_set_fe_update_state(fe, stream, SND_SOC_DPCM_UPDATE_NO);

        snd_soc_dpcm_mutex_unlock(fe);
        return 0;
}

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

        for_each_dpcm_be(fe, stream, dpcm) {
                struct snd_pcm_hw_params hw_params;

                be = dpcm->be;
                be_substream = snd_soc_dpcm_get_substream(be, stream);

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

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

                /* perform any hw_params fixups */
                ret = snd_soc_link_be_hw_params_fixup(be, &hw_params);
                if (ret < 0)
                        goto unwind;

                /* copy the fixed-up hw params for BE dai */
                memcpy(&be->dpcm[stream].hw_params, &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, &hw_params);
                if (ret < 0)
                        goto unwind;

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

unwind:
        dev_dbg(fe->dev, "ASoC: %s() failed at %s (%d)\n",
                __func__, be->dai_link->name, ret);

        /* disable any enabled and non active backends */
        for_each_dpcm_be_rollback(fe, stream, dpcm) {
                be = dpcm->be;
                be_substream = snd_soc_dpcm_get_substream(be, stream);

                if (!snd_soc_dpcm_can_be_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, 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 = snd_soc_substream_to_rtd(substream);
        int ret, stream = substream->stream;

        snd_soc_dpcm_mutex_lock(fe);
        dpcm_set_fe_update_state(fe, stream, SND_SOC_DPCM_UPDATE_FE);

        memcpy(&fe->dpcm[stream].hw_params, params,
                        sizeof(struct snd_pcm_hw_params));
        ret = dpcm_be_dai_hw_params(fe, stream);
        if (ret < 0)
                goto out;

        dev_dbg(fe->dev, "ASoC: hw_params FE %s rate %d chan %x fmt %d\n",
                        fe->dai_link->name, params_rate(params),
                        params_channels(params), params_format(params));

        /* call hw_params on the frontend */
        ret = __soc_pcm_hw_params(substream, params);
        if (ret < 0)
                dpcm_be_dai_hw_free(fe, stream);
        else
                fe->dpcm[stream].state = SND_SOC_DPCM_STATE_HW_PARAMS;

out:
        dpcm_set_fe_update_state(fe, stream, SND_SOC_DPCM_UPDATE_NO);
        snd_soc_dpcm_mutex_unlock(fe);

        return soc_pcm_ret(fe, ret);
}

int dpcm_be_dai_trigger(struct snd_soc_pcm_runtime *fe, int stream,
                               int cmd)
{
        struct snd_soc_pcm_runtime *be;
        bool pause_stop_transition;
        struct snd_soc_dpcm *dpcm;
        unsigned long flags;
        int ret = 0;

        for_each_dpcm_be(fe, stream, dpcm) {
                struct snd_pcm_substream *be_substream;

                be = dpcm->be;
                be_substream = snd_soc_dpcm_get_substream(be, stream);

                snd_pcm_stream_lock_irqsave_nested(be_substream, flags);

                /* is this op for this BE ? */
                if (!snd_soc_dpcm_can_be_update(fe, be, stream))
                        goto next;

                dev_dbg(be->dev, "ASoC: trigger BE %s cmd %d\n",
                        be->dai_link->name, cmd);

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

                        be->dpcm[stream].be_start++;
                        if (be->dpcm[stream].be_start != 1)
                                goto next;

                        if (be->dpcm[stream].state == SND_SOC_DPCM_STATE_PAUSED)
                                ret = soc_pcm_trigger(be_substream,
                                                      SNDRV_PCM_TRIGGER_PAUSE_RELEASE);
                        else
                                ret = soc_pcm_trigger(be_substream,
                                                      SNDRV_PCM_TRIGGER_START);
                        if (ret) {
                                be->dpcm[stream].be_start--;
                                goto next;
                        }

                        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))
                                goto next;

                        be->dpcm[stream].be_start++;
                        if (be->dpcm[stream].be_start != 1)
                                goto next;

                        ret = soc_pcm_trigger(be_substream, cmd);
                        if (ret) {
                                be->dpcm[stream].be_start--;
                                goto next;
                        }

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

                        fe->dpcm[stream].fe_pause = false;
                        be->dpcm[stream].be_pause--;

                        be->dpcm[stream].be_start++;
                        if (be->dpcm[stream].be_start != 1)
                                goto next;

                        ret = soc_pcm_trigger(be_substream, cmd);
                        if (ret) {
                                be->dpcm[stream].be_start--;
                                goto next;
                        }

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

                        if (be->dpcm[stream].state == SND_SOC_DPCM_STATE_START)
                                be->dpcm[stream].be_start--;

                        if (be->dpcm[stream].be_start != 0)
                                goto next;

                        pause_stop_transition = false;
                        if (fe->dpcm[stream].fe_pause) {
                                pause_stop_transition = true;
                                fe->dpcm[stream].fe_pause = false;
                                be->dpcm[stream].be_pause--;
                        }

                        if (be->dpcm[stream].be_pause != 0)
                                ret = soc_pcm_trigger(be_substream, SNDRV_PCM_TRIGGER_PAUSE_PUSH);
                        else
                                ret = soc_pcm_trigger(be_substream, SNDRV_PCM_TRIGGER_STOP);

                        if (ret) {
                                if (be->dpcm[stream].state == SND_SOC_DPCM_STATE_START)
                                        be->dpcm[stream].be_start++;
                                if (pause_stop_transition) {
                                        fe->dpcm[stream].fe_pause = true;
                                        be->dpcm[stream].be_pause++;
                                }
                                goto next;
                        }

                        if (be->dpcm[stream].be_pause != 0)
                                be->dpcm[stream].state = SND_SOC_DPCM_STATE_PAUSED;
                        else
                                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)
                                goto next;

                        be->dpcm[stream].be_start--;
                        if (be->dpcm[stream].be_start != 0)
                                goto next;

                        ret = soc_pcm_trigger(be_substream, cmd);
                        if (ret) {
                                be->dpcm[stream].be_start++;
                                goto next;
                        }

                        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)
                                goto next;

                        fe->dpcm[stream].fe_pause = true;
                        be->dpcm[stream].be_pause++;

                        be->dpcm[stream].be_start--;
                        if (be->dpcm[stream].be_start != 0)
                                goto next;

                        ret = soc_pcm_trigger(be_substream, cmd);
                        if (ret) {
                                be->dpcm[stream].be_start++;
                                goto next;
                        }

                        be->dpcm[stream].state = SND_SOC_DPCM_STATE_PAUSED;
                        break;
                }
next:
                snd_pcm_stream_unlock_irqrestore(be_substream, flags);
                if (ret)
                        break;
        }
        return soc_pcm_ret(fe, ret);
}
EXPORT_SYMBOL_GPL(dpcm_be_dai_trigger);

static int dpcm_dai_trigger_fe_be(struct snd_pcm_substream *substream,
                                  int cmd, bool fe_first)
{
        struct snd_soc_pcm_runtime *fe = snd_soc_substream_to_rtd(substream);
        int ret;

        /* call trigger on the frontend before the backend. */
        if (fe_first) {
                dev_dbg(fe->dev, "ASoC: pre trigger FE %s cmd %d\n",
                        fe->dai_link->name, cmd);

                ret = soc_pcm_trigger(substream, cmd);
                if (ret < 0)
                        goto end;

                ret = dpcm_be_dai_trigger(fe, substream->stream, cmd);
        }
        /* call trigger on the frontend after the backend. */
        else {
                ret = dpcm_be_dai_trigger(fe, substream->stream, cmd);
                if (ret < 0)
                        goto end;

                dev_dbg(fe->dev, "ASoC: post trigger FE %s cmd %d\n",
                        fe->dai_link->name, cmd);

                ret = soc_pcm_trigger(substream, cmd);
        }
end:
        return snd_soc_ret(fe->dev, ret, "trigger FE cmd: %d failed\n", cmd);
}

static int dpcm_fe_dai_do_trigger(struct snd_pcm_substream *substream, int cmd)
{
        struct snd_soc_pcm_runtime *fe = snd_soc_substream_to_rtd(substream);
        int stream = substream->stream;
        int ret = 0;
        int fe_first;
        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:
                fe_first = true;
                break;
        case SND_SOC_DPCM_TRIGGER_POST:
                fe_first = false;
                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:
        case SNDRV_PCM_TRIGGER_DRAIN:
                ret = dpcm_dai_trigger_fe_be(substream, cmd, fe_first);
                break;
        case SNDRV_PCM_TRIGGER_STOP:
        case SNDRV_PCM_TRIGGER_SUSPEND:
        case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
                ret = dpcm_dai_trigger_fe_be(substream, cmd, !fe_first);
                break;
        default:
                ret = -EINVAL;
                break;
        }

        if (ret < 0)
                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 = snd_soc_substream_to_rtd(substream);
        int stream = substream->stream;

        /* if FE's runtime_update is already set, we're in race;
         * process this trigger later at exit
         */
        if (fe->dpcm[stream].runtime_update != SND_SOC_DPCM_UPDATE_NO) {
                fe->dpcm[stream].trigger_pending = cmd + 1;
                return 0; /* delayed, assuming it's successful */
        }

        /* we're alone, let's trigger */
        return dpcm_fe_dai_do_trigger(substream, cmd);
}

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

        for_each_dpcm_be(fe, stream, dpcm) {

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

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

                if (!snd_soc_dpcm_can_be_prepared(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, be_substream);
                if (ret < 0)
                        break;

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

        /*
         * Don't use soc_pcm_ret() on .prepare callback to lower error log severity
         *
         * We don't want to log an error since we do not want to give userspace a way to do a
         * denial-of-service attack on the syslog / diskspace.
         */
        return ret;
}

static int dpcm_fe_dai_prepare(struct snd_pcm_substream *substream)
{
        struct snd_soc_pcm_runtime *fe = snd_soc_substream_to_rtd(substream);
        int stream = substream->stream, ret = 0;

        snd_soc_dpcm_mutex_lock(fe);

        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);

        ret = dpcm_be_dai_prepare(fe, stream);
        if (ret < 0)
                goto out;

        /* call prepare on the frontend */
        ret = __soc_pcm_prepare(fe, substream);
        if (ret < 0)
                goto out;

        fe->dpcm[stream].state = SND_SOC_DPCM_STATE_PREPARE;

out:
        dpcm_set_fe_update_state(fe, stream, SND_SOC_DPCM_UPDATE_NO);
        snd_soc_dpcm_mutex_unlock(fe);

        /*
         * Don't use soc_pcm_ret() on .prepare callback to lower error log severity
         *
         * We don't want to log an error since we do not want to give userspace a way to do a
         * denial-of-service attack on the syslog / diskspace.
         */
        return ret;
}

static int dpcm_run_update_shutdown(struct snd_soc_pcm_runtime *fe, int stream)
{
        int err;

        dev_dbg(fe->dev, "ASoC: runtime %s close on FE %s\n",
                snd_pcm_direction_name(stream), fe->dai_link->name);

        err = dpcm_be_dai_trigger(fe, stream, SNDRV_PCM_TRIGGER_STOP);

        dpcm_be_dai_hw_free(fe, stream);

        dpcm_be_dai_shutdown(fe, stream);

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

        return soc_pcm_ret(fe, err);
}

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

        dev_dbg(fe->dev, "ASoC: runtime %s open on FE %s\n",
                snd_pcm_direction_name(stream), fe->dai_link->name);

        /* Only start the BE if the FE is ready */
        if (fe->dpcm[stream].state == SND_SOC_DPCM_STATE_HW_FREE ||
                fe->dpcm[stream].state == SND_SOC_DPCM_STATE_CLOSE) {
                dev_err(fe->dev, "ASoC: FE %s is not ready %s\n",
                        fe->dai_link->name, dpcm_state_string(fe->dpcm[stream].state));
                ret = -EINVAL;
                goto disconnect;
        }

        /* startup must always be called for new BEs */
        ret = dpcm_be_dai_startup(fe, stream);
        if (ret < 0)
                goto disconnect;

        /* keep going if FE state is > open */
        if (fe->dpcm[stream].state == SND_SOC_DPCM_STATE_OPEN)
                return 0;

        ret = dpcm_be_dai_hw_params(fe, stream);
        if (ret < 0)
                goto close;

        /* keep going if FE state is > hw_params */
        if (fe->dpcm[stream].state == SND_SOC_DPCM_STATE_HW_PARAMS)
                return 0;

        ret = dpcm_be_dai_prepare(fe, stream);
        if (ret < 0)
                goto hw_free;

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

        /* keep going if FE state is > prepare */
        if (fe->dpcm[stream].state == SND_SOC_DPCM_STATE_PREPARE ||
                fe->dpcm[stream].state == SND_SOC_DPCM_STATE_STOP)
                return 0;

        ret = dpcm_be_dai_trigger(fe, stream, SNDRV_PCM_TRIGGER_START);
        if (ret < 0)
                goto hw_free;

        return 0;

hw_free:
        dpcm_be_dai_hw_free(fe, stream);
close:
        dpcm_be_dai_shutdown(fe, stream);
disconnect:
        /* disconnect any pending BEs */
        for_each_dpcm_be(fe, stream, dpcm) {
                struct snd_soc_pcm_runtime *be = dpcm->be;

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

                if (be->dpcm[stream].state == SND_SOC_DPCM_STATE_CLOSE ||
                        be->dpcm[stream].state == SND_SOC_DPCM_STATE_NEW)
                                dpcm->state = SND_SOC_DPCM_LINK_STATE_FREE;
        }

        return soc_pcm_ret(fe, ret);
}

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

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

        if (fe->dai_link->num_cpus > 1)
                return snd_soc_ret(fe->dev, -EINVAL,
                        "%s doesn't support Multi CPU yet\n", __func__);

        /* only check active links */
        if (!snd_soc_dai_active(snd_soc_rtd_to_cpu(fe, 0)))
                return 0;

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

        for_each_pcm_streams(stream) {

                /* skip if FE doesn't have playback/capture capability */
                if (!snd_soc_dai_stream_valid(snd_soc_rtd_to_cpu(fe, 0),   stream) ||
                    !snd_soc_dai_stream_valid(snd_soc_rtd_to_codec(fe, 0), stream))
                        continue;

                /* skip if FE isn't currently playing/capturing */
                if (!snd_soc_dai_stream_active(snd_soc_rtd_to_cpu(fe, 0), stream) ||
                    !snd_soc_dai_stream_active(snd_soc_rtd_to_codec(fe, 0), stream))
                        continue;

                paths = dpcm_path_get(fe, stream, &list);
                if (paths < 0)
                        return paths;

                /* update any playback/capture paths */
                /*
                 * Find the corresponding BE DAIs that source or sink audio to this
                 * FE substream.
                 */
                if (new)
                        count = dpcm_add_paths(fe, stream, &list);
                else
                        count = dpcm_prune_paths(fe, stream, &list);
                if (count) {
                        dpcm_set_fe_update_state(fe, stream, SND_SOC_DPCM_UPDATE_BE);
                        if (new)
                                dpcm_run_update_startup(fe, stream);
                        else
                                dpcm_run_update_shutdown(fe, stream);
                        dpcm_set_fe_update_state(fe, stream, SND_SOC_DPCM_UPDATE_NO);

                        dpcm_clear_pending_state(fe, stream);
                        dpcm_be_disconnect(fe, stream);
                }

                dpcm_path_put(&list);
        }

        return 0;
}

/* Called by DAPM mixer/mux changes to update audio routing between PCMs and
 * any DAI links.
 */
int snd_soc_dpcm_runtime_update(struct snd_soc_card *card)
{
        struct snd_soc_pcm_runtime *fe;
        int ret = 0;

        snd_soc_dpcm_mutex_lock(card);
        /* 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:
        snd_soc_dpcm_mutex_unlock(card);

        return snd_soc_ret(card->dev, ret, "%s() failed\n", __func__);
}
EXPORT_SYMBOL_GPL(snd_soc_dpcm_runtime_update);

static void dpcm_fe_dai_cleanup(struct snd_pcm_substream *fe_substream)
{
        struct snd_soc_pcm_runtime *fe = snd_soc_substream_to_rtd(fe_substream);
        struct snd_soc_dpcm *dpcm;
        int stream = fe_substream->stream;

        snd_soc_dpcm_mutex_assert_held(fe);

        /* 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);
}

static int dpcm_fe_dai_close(struct snd_pcm_substream *fe_substream)
{
        struct snd_soc_pcm_runtime *fe = snd_soc_substream_to_rtd(fe_substream);
        int ret;

        snd_soc_dpcm_mutex_lock(fe);
        ret = dpcm_fe_dai_shutdown(fe_substream);

        dpcm_fe_dai_cleanup(fe_substream);

        snd_soc_dpcm_mutex_unlock(fe);
        return ret;
}

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

        snd_soc_dpcm_mutex_lock(fe);

        ret = dpcm_path_get(fe, stream, &list);
        if (ret < 0)
                goto open_end;

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

        /* There is no point starting up this FE if there are no BEs. */
        if (list_empty(&fe->dpcm[stream].be_clients)) {
                /* dev_err_once() for visibility, dev_dbg() for debugging UCM profiles. */
                dev_err_once(fe->dev, "ASoC: no backend DAIs enabled for %s, possibly missing ALSA mixer-based routing or UCM profile\n",
                             fe->dai_link->name);
                dev_dbg(fe->dev, "ASoC: no backend DAIs enabled for %s\n", fe->dai_link->name);

                ret = -EINVAL;
                goto put_path;
        }

        ret = dpcm_fe_dai_startup(fe_substream);
        if (ret < 0)
                dpcm_fe_dai_cleanup(fe_substream);

        dpcm_clear_pending_state(fe, stream);
put_path:
        dpcm_path_put(&list);
open_end:
        snd_soc_dpcm_mutex_unlock(fe);
        return ret;
}

static int soc_get_playback_capture(struct snd_soc_pcm_runtime *rtd,
                                    int *playback, int *capture)
{
        struct snd_soc_dai_link *dai_link = rtd->dai_link;
        struct snd_soc_dai *cpu_dai;
        struct snd_soc_dai *codec_dai;
        struct snd_soc_dai_link_ch_map *ch_maps;
        struct snd_soc_dai *dummy_dai = snd_soc_find_dai(&snd_soc_dummy_dlc);
        int cpu_capture;
        int cpu_playback;
        int has_playback = 0;
        int has_capture  = 0;
        int i;

        if (dai_link->dynamic && dai_link->num_cpus > 1)
                return snd_soc_ret(rtd->dev, -EINVAL,
                                "DPCM doesn't support Multi CPU for Front-Ends yet\n");

        /* Adapt stream for codec2codec links */
        cpu_capture  = snd_soc_get_stream_cpu(dai_link, SNDRV_PCM_STREAM_CAPTURE);
        cpu_playback = snd_soc_get_stream_cpu(dai_link, SNDRV_PCM_STREAM_PLAYBACK);

        /*
         * see
         *      soc.h :: [dai_link->ch_maps Image sample]
         */
        for_each_rtd_ch_maps(rtd, i, ch_maps) {
                cpu_dai   = snd_soc_rtd_to_cpu(rtd,   ch_maps->cpu);
                codec_dai = snd_soc_rtd_to_codec(rtd, ch_maps->codec);

                /*
                 * FIXME
                 *
                 * DPCM Codec has been no checked before.
                 * It should be checked, but it breaks compatibility.
                 *
                 * For example there is a case that CPU have loopback capabilities which is used
                 * for tests on boards where the Codec has no capture capabilities. In this case,
                 * Codec capture validation check will be fail, but system should allow capture
                 * capabilities. We have no solution for it today.
                 */
                if (dai_link->dynamic || dai_link->no_pcm)
                        codec_dai = dummy_dai;

                if (snd_soc_dai_stream_valid(codec_dai, SNDRV_PCM_STREAM_PLAYBACK) &&
                    snd_soc_dai_stream_valid(cpu_dai,   cpu_playback))
                        has_playback = 1;
                if (snd_soc_dai_stream_valid(codec_dai, SNDRV_PCM_STREAM_CAPTURE) &&
                    snd_soc_dai_stream_valid(cpu_dai,   cpu_capture))
                        has_capture = 1;
        }

        if (dai_link->playback_only)
                has_capture = 0;

        if (dai_link->capture_only)
                has_playback = 0;

        if (!has_playback && !has_capture)
                return snd_soc_ret(rtd->dev, -EINVAL,
                        "substream %s has no playback, no capture\n", dai_link->stream_name);

        *playback = has_playback;
        *capture  = has_capture;

        return 0;
}

static int soc_create_pcm(struct snd_pcm **pcm,
                          struct snd_soc_pcm_runtime *rtd,
                          int playback, int capture)
{
        char new_name[64];
        int ret;

        /* create the PCM */
        if (rtd->dai_link->c2c_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, rtd->id,
                                           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, rtd->id,
                                playback, capture, pcm);
        } else {
                if (rtd->dai_link->dynamic)
                        snprintf(new_name, sizeof(new_name), "%s (*)",
                                rtd->dai_link->stream_name);
                else
                        snprintf(new_name, sizeof(new_name), "%s %s-%d",
                                rtd->dai_link->stream_name,
                                soc_codec_dai_name(rtd), rtd->id);

                ret = snd_pcm_new(rtd->card->snd_card, new_name, rtd->id, playback,
                        capture, pcm);
        }
        if (ret < 0)
                return snd_soc_ret(rtd->dev, ret,
                        "can't create pcm %s for dailink %s\n", new_name, rtd->dai_link->name);

        dev_dbg(rtd->card->dev, "ASoC: registered pcm #%d %s\n", rtd->id, new_name);

        return 0;
}

/* create a new pcm */
int soc_new_pcm(struct snd_soc_pcm_runtime *rtd)
{
        struct snd_soc_component *component;
        struct snd_pcm *pcm;
        int ret = 0, playback = 0, capture = 0;
        int i;

        ret = soc_get_playback_capture(rtd, &playback, &capture);
        if (ret < 0)
                return ret;

        ret = soc_create_pcm(&pcm, rtd, playback, capture);
        if (ret < 0)
                return ret;

        /* DAPM dai link stream 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.
         */
        if (!rtd->dai_link->c2c_params)
                rtd->close_delayed_work_func = snd_soc_close_delayed_work;

        rtd->pcm = pcm;
        pcm->nonatomic = rtd->dai_link->nonatomic;
        pcm->private_data = rtd;
        pcm->no_device_suspend = true;

        if (rtd->dai_link->no_pcm || rtd->dai_link->c2c_params) {
                if (playback)
                        pcm->streams[SNDRV_PCM_STREAM_PLAYBACK].substream->private_data = rtd;
                if (capture)
                        pcm->streams[SNDRV_PCM_STREAM_CAPTURE].substream->private_data = rtd;
                goto out;
        }

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

        for_each_rtd_components(rtd, i, component) {
                const struct snd_soc_component_driver *drv = component->driver;

                if (drv->ioctl)
                        rtd->ops.ioctl          = snd_soc_pcm_component_ioctl;
                if (drv->sync_stop)
                        rtd->ops.sync_stop      = snd_soc_pcm_component_sync_stop;
                if (drv->copy)
                        rtd->ops.copy           = snd_soc_pcm_component_copy;
                if (drv->page)
                        rtd->ops.page           = snd_soc_pcm_component_page;
                if (drv->mmap)
                        rtd->ops.mmap           = snd_soc_pcm_component_mmap;
                if (drv->ack)
                        rtd->ops.ack            = snd_soc_pcm_component_ack;
        }

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

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

        ret = snd_soc_pcm_component_new(rtd);
        if (ret < 0)
                return ret;
out:
        dev_dbg(rtd->card->dev, "%s <-> %s mapping ok\n",
                soc_codec_dai_name(rtd), soc_cpu_dai_name(rtd));
        return ret;
}

/* 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);