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

#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/delay.h>
#include <linux/slab.h>
#include <linux/workqueue.h>
#include <sound/core.h>
#include <sound/pcm.h>
#include <sound/pcm_params.h>
#include <sound/soc.h>
#include <sound/initval.h>

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

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

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

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

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

        return 0;
}

/*
 * Called by ALSA when a PCM substream is opened, the runtime->hw record is
 * then initialized and any private data can be allocated. This also calls
 * startup for the cpu DAI, platform, machine and codec DAI.
 */
static int soc_pcm_open(struct snd_pcm_substream *substream)
{
        struct snd_soc_pcm_runtime *rtd = substream->private_data;
        struct snd_pcm_runtime *runtime = substream->runtime;
        struct snd_soc_platform *platform = rtd->platform;
        struct snd_soc_dai *cpu_dai = rtd->cpu_dai;
        struct snd_soc_dai *codec_dai = rtd->codec_dai;
        struct snd_soc_dai_driver *cpu_dai_drv = cpu_dai->driver;
        struct snd_soc_dai_driver *codec_dai_drv = codec_dai->driver;
        int ret = 0;

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

        mutex_unlock(&rtd->pcm_mutex);
}

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

        if (platform->driver->ops && platform->driver->ops->prepare) {
                ret = platform->driver->ops->prepare(substream);
                if (ret < 0) {
                        printk(KERN_ERR "asoc: platform prepare error\n");
                        goto out;
                }
        }

        if (codec_dai->driver->ops->prepare) {
                ret = codec_dai->driver->ops->prepare(substream, codec_dai);
                if (ret < 0) {
                        printk(KERN_ERR "asoc: codec DAI prepare error\n");
                        goto out;
                }
        }

        if (cpu_dai->driver->ops->prepare) {
                ret = cpu_dai->driver->ops->prepare(substream, cpu_dai);
                if (ret < 0) {
                        printk(KERN_ERR "asoc: cpu DAI prepare error\n");
                        goto out;
                }
        }

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

        if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
                snd_soc_dapm_stream_event(rtd,
                                          codec_dai->driver->playback.stream_name,
                                          SND_SOC_DAPM_STREAM_START);
        else
                snd_soc_dapm_stream_event(rtd,
                                          codec_dai->driver->capture.stream_name,
                                          SND_SOC_DAPM_STREAM_START);

        snd_soc_dai_digital_mute(codec_dai, 0);

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

        runtime->delay = delay;

        return offset;
}

/* ASoC PCM operations */
static struct snd_pcm_ops soc_pcm_ops = {
        .open           = soc_pcm_open,
        .close          = soc_pcm_close,
        .hw_params      = soc_pcm_hw_params,
        .hw_free        = soc_pcm_hw_free,
        .prepare        = soc_pcm_prepare,
        .trigger        = soc_pcm_trigger,
        .pointer        = soc_pcm_pointer,
};

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

        /* check client and interface hw capabilities */
        snprintf(new_name, sizeof(new_name), "%s %s-%d",
                        rtd->dai_link->stream_name, codec_dai->name, num);

        if (codec_dai->driver->playback.channels_min)
                playback = 1;
        if (codec_dai->driver->capture.channels_min)
                capture = 1;

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

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

        rtd->pcm = pcm;
        pcm->private_data = rtd;
        if (platform->driver->ops) {
                soc_pcm_ops.mmap = platform->driver->ops->mmap;
                soc_pcm_ops.pointer = platform->driver->ops->pointer;
                soc_pcm_ops.ioctl = platform->driver->ops->ioctl;
                soc_pcm_ops.copy = platform->driver->ops->copy;
                soc_pcm_ops.silence = platform->driver->ops->silence;
                soc_pcm_ops.ack = platform->driver->ops->ack;
                soc_pcm_ops.page = platform->driver->ops->page;
        }

        if (playback)
                snd_pcm_set_ops(pcm, SNDRV_PCM_STREAM_PLAYBACK, &soc_pcm_ops);

        if (capture)
                snd_pcm_set_ops(pcm, SNDRV_PCM_STREAM_CAPTURE, &soc_pcm_ops);

        if (platform->driver->pcm_new) {
                ret = platform->driver->pcm_new(rtd);
                if (ret < 0) {
                        pr_err("asoc: platform pcm constructor failed\n");
                        return ret;
                }
        }

        pcm->private_free = platform->driver->pcm_free;
        printk(KERN_INFO "asoc: %s <-> %s mapping ok\n", codec_dai->name,
                cpu_dai->name);
        return ret;
}