// SPDX-License-Identifier: GPL-2.0+
// Copyright 2017-2021 NXP

#include <linux/dma-mapping.h>
#include <linux/slab.h>
#include <linux/module.h>
#include <linux/delay.h>
#include <linux/rpmsg.h>
#include <sound/core.h>
#include <sound/pcm.h>
#include <sound/pcm_params.h>
#include <sound/dmaengine_pcm.h>
#include <sound/soc.h>

#include "imx-pcm.h"
#include "fsl_rpmsg.h"
#include "imx-pcm-rpmsg.h"

static const struct snd_pcm_hardware imx_rpmsg_pcm_hardware = {
        .info = SNDRV_PCM_INFO_INTERLEAVED |
                SNDRV_PCM_INFO_BLOCK_TRANSFER |
                SNDRV_PCM_INFO_BATCH |
                SNDRV_PCM_INFO_MMAP |
                SNDRV_PCM_INFO_MMAP_VALID |
                SNDRV_PCM_INFO_NO_PERIOD_WAKEUP |
                SNDRV_PCM_INFO_PAUSE |
                SNDRV_PCM_INFO_RESUME,
        .buffer_bytes_max = IMX_DEFAULT_DMABUF_SIZE,
        .period_bytes_min = 512,
        .period_bytes_max = 65536,
        .periods_min = 2,
        .periods_max = 6000,
        .fifo_size = 0,
};

static int imx_rpmsg_pcm_send_message(struct rpmsg_msg *msg,
                                      struct rpmsg_info *info)
{
        struct rpmsg_device *rpdev = info->rpdev;
        int ret = 0;

        mutex_lock(&info->msg_lock);
        if (!rpdev) {
                dev_err(info->dev, "rpmsg channel not ready\n");
                mutex_unlock(&info->msg_lock);
                return -EINVAL;
        }

        dev_dbg(&rpdev->dev, "send cmd %d\n", msg->s_msg.header.cmd);

        if (!(msg->s_msg.header.type == MSG_TYPE_C))
                reinit_completion(&info->cmd_complete);

        ret = rpmsg_send(rpdev->ept, (void *)&msg->s_msg,
                         sizeof(struct rpmsg_s_msg));
        if (ret) {
                dev_err(&rpdev->dev, "rpmsg_send failed: %d\n", ret);
                mutex_unlock(&info->msg_lock);
                return ret;
        }

        /* No receive msg for TYPE_C command */
        if (msg->s_msg.header.type == MSG_TYPE_C) {
                mutex_unlock(&info->msg_lock);
                return 0;
        }

        /* wait response from rpmsg */
        ret = wait_for_completion_timeout(&info->cmd_complete,
                                          msecs_to_jiffies(RPMSG_TIMEOUT));
        if (!ret) {
                dev_err(&rpdev->dev, "rpmsg_send cmd %d timeout!\n",
                        msg->s_msg.header.cmd);
                mutex_unlock(&info->msg_lock);
                return -ETIMEDOUT;
        }

        memcpy(&msg->r_msg, &info->r_msg, sizeof(struct rpmsg_r_msg));
        memcpy(&info->msg[msg->r_msg.header.cmd].r_msg,
               &msg->r_msg, sizeof(struct rpmsg_r_msg));

        /*
         * Reset the buffer pointer to be zero, actully we have
         * set the buffer pointer to be zero in imx_rpmsg_terminate_all
         * But if there is timer task queued in queue, after it is
         * executed the buffer pointer will be changed, so need to
         * reset it again with TERMINATE command.
         */
        switch (msg->s_msg.header.cmd) {
        case TX_TERMINATE:
                info->msg[TX_POINTER].r_msg.param.buffer_offset = 0;
                break;
        case RX_TERMINATE:
                info->msg[RX_POINTER].r_msg.param.buffer_offset = 0;
                break;
        default:
                break;
        }

        dev_dbg(&rpdev->dev, "cmd:%d, resp %d\n", msg->s_msg.header.cmd,
                info->r_msg.param.resp);

        mutex_unlock(&info->msg_lock);

        return 0;
}

static int imx_rpmsg_insert_workqueue(struct snd_pcm_substream *substream,
                                      struct rpmsg_msg *msg,
                                      struct rpmsg_info *info)
{
        unsigned long flags;
        int ret = 0;

        /*
         * Queue the work to workqueue.
         * If the queue is full, drop the message.
         */
        spin_lock_irqsave(&info->wq_lock, flags);
        if (info->work_write_index != info->work_read_index) {
                int index = info->work_write_index;

                memcpy(&info->work_list[index].msg, msg,
                       sizeof(struct rpmsg_s_msg));

                queue_work(info->rpmsg_wq, &info->work_list[index].work);
                info->work_write_index++;
                info->work_write_index %= WORK_MAX_NUM;
        } else {
                info->msg_drop_count[substream->stream]++;
                ret = -EPIPE;
        }
        spin_unlock_irqrestore(&info->wq_lock, flags);

        return ret;
}

static int imx_rpmsg_pcm_hw_params(struct snd_soc_component *component,
                                   struct snd_pcm_substream *substream,
                                   struct snd_pcm_hw_params *params)
{
        struct rpmsg_info *info = dev_get_drvdata(component->dev);
        struct rpmsg_msg *msg;

        if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
                msg = &info->msg[TX_HW_PARAM];
                msg->s_msg.header.cmd = TX_HW_PARAM;
        } else {
                msg = &info->msg[RX_HW_PARAM];
                msg->s_msg.header.cmd = RX_HW_PARAM;
        }

        msg->s_msg.param.rate = params_rate(params);

        switch (params_format(params)) {
        case SNDRV_PCM_FORMAT_S16_LE:
                msg->s_msg.param.format   = RPMSG_S16_LE;
                break;
        case SNDRV_PCM_FORMAT_S24_LE:
                msg->s_msg.param.format   = RPMSG_S24_LE;
                break;
        case SNDRV_PCM_FORMAT_DSD_U16_LE:
                msg->s_msg.param.format   = RPMSG_DSD_U16_LE;
                break;
        case SNDRV_PCM_FORMAT_DSD_U32_LE:
                msg->s_msg.param.format   = RPMSG_DSD_U32_LE;
                break;
        default:
                msg->s_msg.param.format   = RPMSG_S32_LE;
                break;
        }

        switch (params_channels(params)) {
        case 1:
                msg->s_msg.param.channels = RPMSG_CH_LEFT;
                break;
        case 2:
                msg->s_msg.param.channels = RPMSG_CH_STEREO;
                break;
        default:
                msg->s_msg.param.channels = params_channels(params);
                break;
        }

        info->send_message(msg, info);

        return 0;
}

static snd_pcm_uframes_t imx_rpmsg_pcm_pointer(struct snd_soc_component *component,
                                               struct snd_pcm_substream *substream)
{
        struct rpmsg_info *info = dev_get_drvdata(component->dev);
        struct rpmsg_msg *msg;
        unsigned int pos = 0;
        int buffer_tail = 0;

        if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
                msg = &info->msg[TX_PERIOD_DONE + MSG_TYPE_A_NUM];
        else
                msg = &info->msg[RX_PERIOD_DONE + MSG_TYPE_A_NUM];

        buffer_tail = msg->r_msg.param.buffer_tail;
        pos = buffer_tail * snd_pcm_lib_period_bytes(substream);

        return bytes_to_frames(substream->runtime, pos);
}

static void imx_rpmsg_timer_callback(struct timer_list *t)
{
        struct stream_timer  *stream_timer =
                        timer_container_of(stream_timer, t, timer);
        struct snd_pcm_substream *substream = stream_timer->substream;
        struct rpmsg_info *info = stream_timer->info;
        struct rpmsg_msg *msg;

        if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
                msg = &info->msg[TX_PERIOD_DONE + MSG_TYPE_A_NUM];
                msg->s_msg.header.cmd = TX_PERIOD_DONE;
        } else {
                msg = &info->msg[RX_PERIOD_DONE + MSG_TYPE_A_NUM];
                msg->s_msg.header.cmd = RX_PERIOD_DONE;
        }

        imx_rpmsg_insert_workqueue(substream, msg, info);
}

static int imx_rpmsg_pcm_open(struct snd_soc_component *component,
                              struct snd_pcm_substream *substream)
{
        struct rpmsg_info *info = dev_get_drvdata(component->dev);
        struct snd_soc_pcm_runtime *rtd = snd_soc_substream_to_rtd(substream);
        struct snd_soc_dai *cpu_dai = snd_soc_rtd_to_cpu(rtd, 0);
        struct fsl_rpmsg *rpmsg = dev_get_drvdata(cpu_dai->dev);
        struct snd_pcm_hardware pcm_hardware;
        struct rpmsg_msg *msg;
        int ret = 0;
        int cmd;

        if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
                msg = &info->msg[TX_OPEN];
                msg->s_msg.header.cmd = TX_OPEN;

                /* reinitialize buffer counter*/
                cmd = TX_PERIOD_DONE + MSG_TYPE_A_NUM;
                info->msg[cmd].s_msg.param.buffer_tail = 0;
                info->msg[cmd].r_msg.param.buffer_tail = 0;
                info->msg[TX_POINTER].r_msg.param.buffer_offset = 0;

        } else {
                msg = &info->msg[RX_OPEN];
                msg->s_msg.header.cmd = RX_OPEN;

                /* reinitialize buffer counter*/
                cmd = RX_PERIOD_DONE + MSG_TYPE_A_NUM;
                info->msg[cmd].s_msg.param.buffer_tail = 0;
                info->msg[cmd].r_msg.param.buffer_tail = 0;
                info->msg[RX_POINTER].r_msg.param.buffer_offset = 0;
        }

        info->send_message(msg, info);

        pcm_hardware = imx_rpmsg_pcm_hardware;
        pcm_hardware.buffer_bytes_max = rpmsg->buffer_size[substream->stream];
        pcm_hardware.period_bytes_max = pcm_hardware.buffer_bytes_max / 2;

        snd_soc_set_runtime_hwparams(substream, &pcm_hardware);

        ret = snd_pcm_hw_constraint_integer(substream->runtime,
                                            SNDRV_PCM_HW_PARAM_PERIODS);
        if (ret < 0)
                return ret;

        info->msg_drop_count[substream->stream] = 0;

        /* Create timer*/
        info->stream_timer[substream->stream].info = info;
        info->stream_timer[substream->stream].substream = substream;
        timer_setup(&info->stream_timer[substream->stream].timer,
                    imx_rpmsg_timer_callback, 0);
        return ret;
}

static int imx_rpmsg_pcm_close(struct snd_soc_component *component,
                               struct snd_pcm_substream *substream)
{
        struct snd_soc_pcm_runtime *rtd = snd_soc_substream_to_rtd(substream);
        struct rpmsg_info *info = dev_get_drvdata(component->dev);
        struct rpmsg_msg *msg;

        /* Flush work in workqueue to make TX_CLOSE is the last message */
        flush_workqueue(info->rpmsg_wq);

        if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
                msg = &info->msg[TX_CLOSE];
                msg->s_msg.header.cmd = TX_CLOSE;
        } else {
                msg = &info->msg[RX_CLOSE];
                msg->s_msg.header.cmd = RX_CLOSE;
        }

        info->send_message(msg, info);

        timer_delete(&info->stream_timer[substream->stream].timer);

        rtd->dai_link->ignore_suspend = 0;

        if (info->msg_drop_count[substream->stream])
                dev_warn(rtd->dev, "Msg is dropped!, number is %d\n",
                         info->msg_drop_count[substream->stream]);

        return 0;
}

static int imx_rpmsg_pcm_prepare(struct snd_soc_component *component,
                                 struct snd_pcm_substream *substream)
{
        struct snd_pcm_runtime *runtime = substream->runtime;
        struct snd_soc_pcm_runtime *rtd = snd_soc_substream_to_rtd(substream);
        struct snd_soc_dai *cpu_dai = snd_soc_rtd_to_cpu(rtd, 0);
        struct fsl_rpmsg *rpmsg = dev_get_drvdata(cpu_dai->dev);

        /*
         * NON-MMAP mode, NONBLOCK, Version 2, enable lpa in dts
         * four conditions to determine the lpa is enabled.
         */
        if ((runtime->access == SNDRV_PCM_ACCESS_RW_INTERLEAVED ||
             runtime->access == SNDRV_PCM_ACCESS_RW_NONINTERLEAVED) &&
             rpmsg->enable_lpa) {
                /*
                 * Ignore suspend operation in low power mode
                 * M core will continue playback music on A core suspend.
                 */
                rtd->dai_link->ignore_suspend = 1;
                rpmsg->force_lpa = 1;
        } else {
                rpmsg->force_lpa = 0;
        }

        return 0;
}

static void imx_rpmsg_pcm_dma_complete(void *arg)
{
        struct snd_pcm_substream *substream = arg;

        snd_pcm_period_elapsed(substream);
}

static int imx_rpmsg_prepare_and_submit(struct snd_soc_component *component,
                                        struct snd_pcm_substream *substream)
{
        struct rpmsg_info *info = dev_get_drvdata(component->dev);
        struct rpmsg_msg *msg;

        if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
                msg = &info->msg[TX_BUFFER];
                msg->s_msg.header.cmd = TX_BUFFER;
        } else {
                msg = &info->msg[RX_BUFFER];
                msg->s_msg.header.cmd = RX_BUFFER;
        }

        /* Send buffer address and buffer size */
        msg->s_msg.param.buffer_addr = substream->runtime->dma_addr;
        msg->s_msg.param.buffer_size = snd_pcm_lib_buffer_bytes(substream);
        msg->s_msg.param.period_size = snd_pcm_lib_period_bytes(substream);
        msg->s_msg.param.buffer_tail = 0;

        info->num_period[substream->stream] = msg->s_msg.param.buffer_size /
                                              msg->s_msg.param.period_size;

        info->callback[substream->stream] = imx_rpmsg_pcm_dma_complete;
        info->callback_param[substream->stream] = substream;

        return imx_rpmsg_insert_workqueue(substream, msg, info);
}

static int imx_rpmsg_async_issue_pending(struct snd_soc_component *component,
                                         struct snd_pcm_substream *substream)
{
        struct rpmsg_info *info = dev_get_drvdata(component->dev);
        struct rpmsg_msg *msg;

        if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
                msg = &info->msg[TX_START];
                msg->s_msg.header.cmd = TX_START;
        } else {
                msg = &info->msg[RX_START];
                msg->s_msg.header.cmd = RX_START;
        }

        return imx_rpmsg_insert_workqueue(substream, msg, info);
}

static int imx_rpmsg_restart(struct snd_soc_component *component,
                             struct snd_pcm_substream *substream)
{
        struct rpmsg_info *info = dev_get_drvdata(component->dev);
        struct rpmsg_msg *msg;

        if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
                msg = &info->msg[TX_RESTART];
                msg->s_msg.header.cmd = TX_RESTART;
        } else {
                msg = &info->msg[RX_RESTART];
                msg->s_msg.header.cmd = RX_RESTART;
        }

        return imx_rpmsg_insert_workqueue(substream, msg, info);
}

static int imx_rpmsg_pause(struct snd_soc_component *component,
                           struct snd_pcm_substream *substream)
{
        struct rpmsg_info *info = dev_get_drvdata(component->dev);
        struct rpmsg_msg *msg;

        if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
                msg = &info->msg[TX_PAUSE];
                msg->s_msg.header.cmd = TX_PAUSE;
        } else {
                msg = &info->msg[RX_PAUSE];
                msg->s_msg.header.cmd = RX_PAUSE;
        }

        return imx_rpmsg_insert_workqueue(substream, msg, info);
}

static int imx_rpmsg_terminate_all(struct snd_soc_component *component,
                                   struct snd_pcm_substream *substream)
{
        struct rpmsg_info *info = dev_get_drvdata(component->dev);
        struct rpmsg_msg *msg;
        int cmd;

        if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
                msg = &info->msg[TX_TERMINATE];
                msg->s_msg.header.cmd = TX_TERMINATE;
                /* Clear buffer count*/
                cmd = TX_PERIOD_DONE + MSG_TYPE_A_NUM;
                info->msg[cmd].s_msg.param.buffer_tail = 0;
                info->msg[cmd].r_msg.param.buffer_tail = 0;
                info->msg[TX_POINTER].r_msg.param.buffer_offset = 0;
        } else {
                msg = &info->msg[RX_TERMINATE];
                msg->s_msg.header.cmd = RX_TERMINATE;
                /* Clear buffer count*/
                cmd = RX_PERIOD_DONE + MSG_TYPE_A_NUM;
                info->msg[cmd].s_msg.param.buffer_tail = 0;
                info->msg[cmd].r_msg.param.buffer_tail = 0;
                info->msg[RX_POINTER].r_msg.param.buffer_offset = 0;
        }

        timer_delete(&info->stream_timer[substream->stream].timer);

        return imx_rpmsg_insert_workqueue(substream, msg, info);
}

static int imx_rpmsg_pcm_trigger(struct snd_soc_component *component,
                                 struct snd_pcm_substream *substream, int cmd)
{
        struct snd_pcm_runtime *runtime = substream->runtime;
        struct snd_soc_pcm_runtime *rtd = snd_soc_substream_to_rtd(substream);
        struct snd_soc_dai *cpu_dai = snd_soc_rtd_to_cpu(rtd, 0);
        struct fsl_rpmsg *rpmsg = dev_get_drvdata(cpu_dai->dev);
        int ret = 0;

        switch (cmd) {
        case SNDRV_PCM_TRIGGER_START:
                ret = imx_rpmsg_prepare_and_submit(component, substream);
                if (ret)
                        return ret;
                ret = imx_rpmsg_async_issue_pending(component, substream);
                break;
        case SNDRV_PCM_TRIGGER_RESUME:
                if (rpmsg->force_lpa)
                        break;
                fallthrough;
        case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
                ret = imx_rpmsg_restart(component, substream);
                break;
        case SNDRV_PCM_TRIGGER_SUSPEND:
                if (!rpmsg->force_lpa) {
                        if (runtime->info & SNDRV_PCM_INFO_PAUSE)
                                ret = imx_rpmsg_pause(component, substream);
                        else
                                ret = imx_rpmsg_terminate_all(component, substream);
                }
                break;
        case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
                ret = imx_rpmsg_pause(component, substream);
                break;
        case SNDRV_PCM_TRIGGER_STOP:
                ret = imx_rpmsg_terminate_all(component, substream);
                break;
        default:
                return -EINVAL;
        }

        if (ret)
                return ret;

        return 0;
}

/*
 * imx_rpmsg_pcm_ack
 *
 * Send the period index to M core through rpmsg, but not send
 * all the period index to M core, reduce some unnessesary msg
 * to reduce the pressure of rpmsg bandwidth.
 */
static int imx_rpmsg_pcm_ack(struct snd_soc_component *component,
                             struct snd_pcm_substream *substream)
{
        struct snd_pcm_runtime *runtime = substream->runtime;
        struct snd_soc_pcm_runtime *rtd = snd_soc_substream_to_rtd(substream);
        struct snd_soc_dai *cpu_dai = snd_soc_rtd_to_cpu(rtd, 0);
        struct fsl_rpmsg *rpmsg = dev_get_drvdata(cpu_dai->dev);
        struct rpmsg_info *info = dev_get_drvdata(component->dev);
        snd_pcm_uframes_t period_size = runtime->period_size;
        snd_pcm_sframes_t avail;
        struct timer_list *timer;
        struct rpmsg_msg *msg;
        unsigned long flags;
        int buffer_tail = 0;
        int written_num;

        if (!rpmsg->force_lpa)
                return 0;

        if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
                msg = &info->msg[TX_PERIOD_DONE + MSG_TYPE_A_NUM];
                msg->s_msg.header.cmd = TX_PERIOD_DONE;
        } else {
                msg = &info->msg[RX_PERIOD_DONE + MSG_TYPE_A_NUM];
                msg->s_msg.header.cmd = RX_PERIOD_DONE;
        }

        msg->s_msg.header.type = MSG_TYPE_C;

        buffer_tail = (frames_to_bytes(runtime, runtime->control->appl_ptr) %
                       snd_pcm_lib_buffer_bytes(substream));
        buffer_tail = buffer_tail / snd_pcm_lib_period_bytes(substream);

        /* There is update for period index */
        if (buffer_tail != msg->s_msg.param.buffer_tail) {
                written_num = buffer_tail - msg->s_msg.param.buffer_tail;
                if (written_num < 0)
                        written_num += runtime->periods;

                msg->s_msg.param.buffer_tail = buffer_tail;

                /* The notification message is updated to latest */
                spin_lock_irqsave(&info->lock[substream->stream], flags);
                memcpy(&info->notify[substream->stream], msg,
                       sizeof(struct rpmsg_s_msg));
                info->notify_updated[substream->stream] = true;
                spin_unlock_irqrestore(&info->lock[substream->stream], flags);

                if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
                        avail = snd_pcm_playback_hw_avail(runtime);
                else
                        avail = snd_pcm_capture_hw_avail(runtime);

                timer = &info->stream_timer[substream->stream].timer;
                /*
                 * If the data in the buffer is less than one period before
                 * this fill, which means the data may not enough on M
                 * core side, we need to send message immediately to let
                 * M core know the pointer is updated.
                 * if there is more than one period data in the buffer before
                 * this fill, which means the data is enough on M core side,
                 * we can delay one period (using timer) to send the message
                 * for reduce the message number in workqueue, because the
                 * pointer may be updated by ack function later, we can
                 * send latest pointer to M core side.
                 */
                if ((avail - written_num * period_size) <= period_size) {
                        imx_rpmsg_insert_workqueue(substream, msg, info);
                } else if (rpmsg->force_lpa && !timer_pending(timer)) {
                        int time_msec;

                        time_msec = (int)(runtime->period_size * 1000 / runtime->rate);
                        mod_timer(timer, jiffies + msecs_to_jiffies(time_msec));
                }
        }

        return 0;
}

static int imx_rpmsg_pcm_new(struct snd_soc_component *component,
                             struct snd_soc_pcm_runtime *rtd)
{
        struct snd_card *card = rtd->card->snd_card;
        struct snd_pcm *pcm = rtd->pcm;
        struct snd_soc_dai *cpu_dai = snd_soc_rtd_to_cpu(rtd, 0);
        struct fsl_rpmsg *rpmsg = dev_get_drvdata(cpu_dai->dev);
        struct snd_pcm_substream *substream;
        int ret;

        ret = dma_coerce_mask_and_coherent(card->dev, DMA_BIT_MASK(32));
        if (ret)
                return ret;

        substream = pcm->streams[SNDRV_PCM_STREAM_PLAYBACK].substream;
        if (substream) {
                ret = snd_pcm_set_fixed_buffer(substream, SNDRV_DMA_TYPE_DEV_WC, pcm->card->dev,
                                               rpmsg->buffer_size[SNDRV_PCM_STREAM_PLAYBACK]);
                if (ret < 0)
                        return ret;
        }
        substream = pcm->streams[SNDRV_PCM_STREAM_CAPTURE].substream;
        if (substream) {
                ret = snd_pcm_set_fixed_buffer(substream, SNDRV_DMA_TYPE_DEV_WC, pcm->card->dev,
                                               rpmsg->buffer_size[SNDRV_PCM_STREAM_CAPTURE]);
                if (ret < 0)
                        return ret;
        }

        return ret;
}

static const struct snd_soc_component_driver imx_rpmsg_soc_component = {
        .name           = IMX_PCM_DRV_NAME,
        .pcm_construct  = imx_rpmsg_pcm_new,
        .open           = imx_rpmsg_pcm_open,
        .close          = imx_rpmsg_pcm_close,
        .hw_params      = imx_rpmsg_pcm_hw_params,
        .trigger        = imx_rpmsg_pcm_trigger,
        .pointer        = imx_rpmsg_pcm_pointer,
        .ack            = imx_rpmsg_pcm_ack,
        .prepare        = imx_rpmsg_pcm_prepare,
};

static void imx_rpmsg_pcm_work(struct work_struct *work)
{
        struct work_of_rpmsg *work_of_rpmsg;
        bool is_notification = false;
        struct rpmsg_info *info;
        struct rpmsg_msg msg;
        unsigned long flags;

        work_of_rpmsg = container_of(work, struct work_of_rpmsg, work);
        info = work_of_rpmsg->info;

        /*
         * Every work in the work queue, first we check if there
         * is update for period is filled, because there may be not
         * enough data in M core side, need to let M core know
         * data is updated immediately.
         */
        spin_lock_irqsave(&info->lock[TX], flags);
        if (info->notify_updated[TX]) {
                memcpy(&msg, &info->notify[TX], sizeof(struct rpmsg_s_msg));
                info->notify_updated[TX] = false;
                spin_unlock_irqrestore(&info->lock[TX], flags);
                info->send_message(&msg, info);
        } else {
                spin_unlock_irqrestore(&info->lock[TX], flags);
        }

        spin_lock_irqsave(&info->lock[RX], flags);
        if (info->notify_updated[RX]) {
                memcpy(&msg, &info->notify[RX], sizeof(struct rpmsg_s_msg));
                info->notify_updated[RX] = false;
                spin_unlock_irqrestore(&info->lock[RX], flags);
                info->send_message(&msg, info);
        } else {
                spin_unlock_irqrestore(&info->lock[RX], flags);
        }

        /* Skip the notification message for it has been processed above */
        if (work_of_rpmsg->msg.s_msg.header.type == MSG_TYPE_C &&
            (work_of_rpmsg->msg.s_msg.header.cmd == TX_PERIOD_DONE ||
             work_of_rpmsg->msg.s_msg.header.cmd == RX_PERIOD_DONE))
                is_notification = true;

        if (!is_notification)
                info->send_message(&work_of_rpmsg->msg, info);

        /* update read index */
        spin_lock_irqsave(&info->wq_lock, flags);
        info->work_read_index++;
        info->work_read_index %= WORK_MAX_NUM;
        spin_unlock_irqrestore(&info->wq_lock, flags);
}

static int imx_rpmsg_pcm_probe(struct platform_device *pdev)
{
        struct snd_soc_component *component;
        struct rpmsg_info *info;
        int ret, i;

        info = devm_kzalloc(&pdev->dev, sizeof(*info), GFP_KERNEL);
        if (!info)
                return -ENOMEM;

        platform_set_drvdata(pdev, info);

        info->rpdev = container_of(pdev->dev.parent, struct rpmsg_device, dev);
        info->dev = &pdev->dev;
        /* Setup work queue */
        info->rpmsg_wq = alloc_ordered_workqueue(info->rpdev->id.name,
                                                 WQ_HIGHPRI |
                                                 WQ_UNBOUND |
                                                 WQ_FREEZABLE);
        if (!info->rpmsg_wq) {
                dev_err(&pdev->dev, "workqueue create failed\n");
                return -ENOMEM;
        }

        /* Write index initialize 1, make it differ with the read index */
        info->work_write_index = 1;
        info->send_message = imx_rpmsg_pcm_send_message;

        for (i = 0; i < WORK_MAX_NUM; i++) {
                INIT_WORK(&info->work_list[i].work, imx_rpmsg_pcm_work);
                info->work_list[i].info = info;
        }

        /* Initialize msg */
        for (i = 0; i < MSG_MAX_NUM; i++) {
                info->msg[i].s_msg.header.cate  = IMX_RPMSG_AUDIO;
                info->msg[i].s_msg.header.major = IMX_RMPSG_MAJOR;
                info->msg[i].s_msg.header.minor = IMX_RMPSG_MINOR;
                info->msg[i].s_msg.header.type  = MSG_TYPE_A;
                info->msg[i].s_msg.param.audioindex = 0;
        }

        init_completion(&info->cmd_complete);
        mutex_init(&info->msg_lock);
        spin_lock_init(&info->lock[TX]);
        spin_lock_init(&info->lock[RX]);
        spin_lock_init(&info->wq_lock);

        ret = devm_snd_soc_register_component(&pdev->dev,
                                              &imx_rpmsg_soc_component,
                                              NULL, 0);
        if (ret)
                goto fail;

        component = snd_soc_lookup_component(&pdev->dev, NULL);
        if (!component) {
                ret = -EINVAL;
                goto fail;
        }

#ifdef CONFIG_DEBUG_FS
        component->debugfs_prefix = "rpmsg";
#endif

        return 0;

fail:
        if (info->rpmsg_wq)
                destroy_workqueue(info->rpmsg_wq);

        return ret;
}

static void imx_rpmsg_pcm_remove(struct platform_device *pdev)
{
        struct rpmsg_info *info = platform_get_drvdata(pdev);

        if (info->rpmsg_wq)
                destroy_workqueue(info->rpmsg_wq);
}

static int imx_rpmsg_pcm_runtime_resume(struct device *dev)
{
        struct rpmsg_info *info = dev_get_drvdata(dev);

        cpu_latency_qos_add_request(&info->pm_qos_req, 0);

        return 0;
}

static int imx_rpmsg_pcm_runtime_suspend(struct device *dev)
{
        struct rpmsg_info *info = dev_get_drvdata(dev);

        cpu_latency_qos_remove_request(&info->pm_qos_req);

        return 0;
}

static int imx_rpmsg_pcm_suspend(struct device *dev)
{
        struct rpmsg_info *info = dev_get_drvdata(dev);
        struct rpmsg_msg *rpmsg_tx;
        struct rpmsg_msg *rpmsg_rx;

        rpmsg_tx = &info->msg[TX_SUSPEND];
        rpmsg_rx = &info->msg[RX_SUSPEND];

        rpmsg_tx->s_msg.header.cmd = TX_SUSPEND;
        info->send_message(rpmsg_tx, info);

        rpmsg_rx->s_msg.header.cmd = RX_SUSPEND;
        info->send_message(rpmsg_rx, info);

        return 0;
}

static int imx_rpmsg_pcm_resume(struct device *dev)
{
        struct rpmsg_info *info = dev_get_drvdata(dev);
        struct rpmsg_msg *rpmsg_tx;
        struct rpmsg_msg *rpmsg_rx;

        rpmsg_tx = &info->msg[TX_RESUME];
        rpmsg_rx = &info->msg[RX_RESUME];

        rpmsg_tx->s_msg.header.cmd = TX_RESUME;
        info->send_message(rpmsg_tx, info);

        rpmsg_rx->s_msg.header.cmd = RX_RESUME;
        info->send_message(rpmsg_rx, info);

        return 0;
}

static const struct dev_pm_ops imx_rpmsg_pcm_pm_ops = {
        RUNTIME_PM_OPS(imx_rpmsg_pcm_runtime_suspend,
                       imx_rpmsg_pcm_runtime_resume, NULL)
        SYSTEM_SLEEP_PM_OPS(imx_rpmsg_pcm_suspend, imx_rpmsg_pcm_resume)
};

static const struct platform_device_id imx_rpmsg_pcm_id_table[] = {
        { .name = "rpmsg-audio-channel" },
        { .name = "rpmsg-micfil-channel" },
        { },
};
MODULE_DEVICE_TABLE(platform, imx_rpmsg_pcm_id_table);

static struct platform_driver imx_pcm_rpmsg_driver = {
        .probe  = imx_rpmsg_pcm_probe,
        .remove = imx_rpmsg_pcm_remove,
        .id_table = imx_rpmsg_pcm_id_table,
        .driver = {
                .name = IMX_PCM_DRV_NAME,
                .pm = pm_ptr(&imx_rpmsg_pcm_pm_ops),
        },
};
module_platform_driver(imx_pcm_rpmsg_driver);

MODULE_DESCRIPTION("Freescale SoC Audio RPMSG PCM interface");
MODULE_AUTHOR("Shengjiu Wang <shengjiu.wang@nxp.com>");
MODULE_ALIAS("platform:" IMX_PCM_DRV_NAME);
MODULE_LICENSE("GPL v2");