/* arch/arm/mach-msm/audio_evrc.c
 *
 * Copyright (c) 2008 QUALCOMM USA, INC.
 *
 * This code also borrows from audio_aac.c, which is
 * Copyright (C) 2008 Google, Inc.
 * Copyright (C) 2008 HTC Corporation
 *
 * This software is licensed under the terms of the GNU General Public
 * License version 2, as published by the Free Software Foundation, and
 * may be copied, distributed, and modified under those terms.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
 *
 * See the GNU General Public License for more details.
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, you can find it at http://www.fsf.org.
 */

#include <linux/module.h>
#include <linux/fs.h>
#include <linux/miscdevice.h>
#include <linux/uaccess.h>
#include <linux/kthread.h>
#include <linux/wait.h>
#include <linux/dma-mapping.h>
#include <linux/delay.h>

#include <asm/atomic.h>
#include <asm/ioctls.h>
#include <mach/msm_adsp.h>
#include <linux/msm_audio.h>
#include "audmgr.h"

#include <mach/qdsp5/qdsp5audppcmdi.h>
#include <mach/qdsp5/qdsp5audppmsg.h>
#include <mach/qdsp5/qdsp5audplaycmdi.h>
#include <mach/qdsp5/qdsp5audplaymsg.h>

#include "adsp.h"

#ifdef DEBUG
#define dprintk(format, arg...) \
        printk(KERN_DEBUG format, ## arg)
#else
#define dprintk(format, arg...) do {} while (0)
#endif

/* Hold 30 packets of 24 bytes each*/
#define BUFSZ                   720
#define DMASZ                   (BUFSZ * 2)

#define AUDDEC_DEC_EVRC         12

#define PCM_BUFSZ_MIN           1600    /* 100ms worth of data */
#define PCM_BUF_MAX_COUNT       5
/* DSP only accepts 5 buffers at most
 * but support 2 buffers currently
 */
#define EVRC_DECODED_FRSZ       320     /* EVRC 20ms 8KHz mono PCM size */

#define ROUTING_MODE_FTRT       1
#define ROUTING_MODE_RT         2
/* Decoder status received from AUDPPTASK */
#define  AUDPP_DEC_STATUS_SLEEP 0
#define  AUDPP_DEC_STATUS_INIT  1
#define  AUDPP_DEC_STATUS_CFG   2
#define  AUDPP_DEC_STATUS_PLAY  3

struct buffer {
        void *data;
        unsigned size;
        unsigned used;          /* Input usage actual DSP produced PCM size  */
        unsigned addr;
};

struct audio {
        struct buffer out[2];

        spinlock_t dsp_lock;

        uint8_t out_head;
        uint8_t out_tail;
        uint8_t out_needed;     /* number of buffers the dsp is waiting for */

        atomic_t out_bytes;

        struct mutex lock;
        struct mutex write_lock;
        wait_queue_head_t write_wait;

        /* Host PCM section */
        struct buffer in[PCM_BUF_MAX_COUNT];
        struct mutex read_lock;
        wait_queue_head_t read_wait;    /* Wait queue for read */
        char *read_data;        /* pointer to reader buffer */
        dma_addr_t read_phys;   /* physical address of reader buffer */
        uint8_t read_next;      /* index to input buffers to be read next */
        uint8_t fill_next;      /* index to buffer that DSP should be filling */
        uint8_t pcm_buf_count;  /* number of pcm buffer allocated */
        /* ---- End of Host PCM section */

        struct msm_adsp_module *audplay;
        struct audmgr audmgr;

        /* data allocated for various buffers */
        char *data;
        dma_addr_t phys;

        uint8_t opened:1;
        uint8_t enabled:1;
        uint8_t running:1;
        uint8_t stopped:1;      /* set when stopped, cleared on flush */
        uint8_t pcm_feedback:1;
        uint8_t buf_refresh:1;

        unsigned volume;
        uint16_t dec_id;
        uint32_t read_ptr_offset;
};
static struct audio the_evrc_audio;

static int auddec_dsp_config(struct audio *audio, int enable);
static void audpp_cmd_cfg_adec_params(struct audio *audio);
static void audpp_cmd_cfg_routing_mode(struct audio *audio);
static void audevrc_send_data(struct audio *audio, unsigned needed);
static void audevrc_dsp_event(void *private, unsigned id, uint16_t *msg);
static void audevrc_config_hostpcm(struct audio *audio);
static void audevrc_buffer_refresh(struct audio *audio);

/* must be called with audio->lock held */
static int audevrc_enable(struct audio *audio)
{
        struct audmgr_config cfg;
        int rc;

        if (audio->enabled)
                return 0;

        audio->out_tail = 0;
        audio->out_needed = 0;

        cfg.tx_rate = RPC_AUD_DEF_SAMPLE_RATE_NONE;
        cfg.rx_rate = RPC_AUD_DEF_SAMPLE_RATE_48000;
        cfg.def_method = RPC_AUD_DEF_METHOD_PLAYBACK;
        cfg.codec = RPC_AUD_DEF_CODEC_EVRC;
        cfg.snd_method = RPC_SND_METHOD_MIDI;

        rc = audmgr_enable(&audio->audmgr, &cfg);
        if (rc < 0)
                return rc;

        if (msm_adsp_enable(audio->audplay)) {
                pr_err("audio: msm_adsp_enable(audplay) failed\n");
                audmgr_disable(&audio->audmgr);
                return -ENODEV;
        }

        if (audpp_enable(audio->dec_id, audevrc_dsp_event, audio)) {
                pr_err("audio: audpp_enable() failed\n");
                msm_adsp_disable(audio->audplay);
                audmgr_disable(&audio->audmgr);
                return -ENODEV;
        }
        audio->enabled = 1;
        return 0;
}

/* must be called with audio->lock held */
static int audevrc_disable(struct audio *audio)
{
        if (audio->enabled) {
                audio->enabled = 0;
                auddec_dsp_config(audio, 0);
                wake_up(&audio->write_wait);
                wake_up(&audio->read_wait);
                msm_adsp_disable(audio->audplay);
                audpp_disable(audio->dec_id, audio);
                audmgr_disable(&audio->audmgr);
                audio->out_needed = 0;
        }
        return 0;
}

/* ------------------- dsp --------------------- */

static void audevrc_update_pcm_buf_entry(struct audio *audio,
                                         uint32_t *payload)
{
        uint8_t index;
        unsigned long flags;

        spin_lock_irqsave(&audio->dsp_lock, flags);
        for (index = 0; index < payload[1]; index++) {
                if (audio->in[audio->fill_next].addr
                                == payload[2 + index * 2]) {
                        dprintk("audevrc_update_pcm_buf_entry: in[%d] ready\n",
                                audio->fill_next);
                        audio->in[audio->fill_next].used =
                                payload[3 + index * 2];
                        if ((++audio->fill_next) == audio->pcm_buf_count)
                                audio->fill_next = 0;

                } else {
                        pr_err
                        ("audevrc_update_pcm_buf_entry: expected=%x ret=%x\n",
                                audio->in[audio->fill_next].addr,
                                payload[1 + index * 2]);
                        break;
                }
        }
        if (audio->in[audio->fill_next].used == 0) {
                audevrc_buffer_refresh(audio);
        } else {
                dprintk("audevrc_update_pcm_buf_entry: read cannot keep up\n");
                audio->buf_refresh = 1;
        }

        spin_unlock_irqrestore(&audio->dsp_lock, flags);
        wake_up(&audio->read_wait);
}

static void audplay_dsp_event(void *data, unsigned id, size_t len,
                              void (*getevent) (void *ptr, size_t len))
{
        struct audio *audio = data;
        uint32_t msg[28];
        getevent(msg, sizeof(msg));

        dprintk("audplay_dsp_event: msg_id=%x\n", id);
        switch (id) {
        case AUDPLAY_MSG_DEC_NEEDS_DATA:
                audevrc_send_data(audio, 1);
                break;
        case AUDPLAY_MSG_BUFFER_UPDATE:
                dprintk("audevrc_update_pcm_buf_entry:======> \n");
                audevrc_update_pcm_buf_entry(audio, msg);
                break;
        default:
                pr_err("unexpected message from decoder \n");
        }
}

static void audevrc_dsp_event(void *private, unsigned id, uint16_t *msg)
{
        struct audio *audio = private;

        switch (id) {
        case AUDPP_MSG_STATUS_MSG:{
                        unsigned status = msg[1];

                        switch (status) {
                        case AUDPP_DEC_STATUS_SLEEP:
                                dprintk("decoder status: sleep \n");
                                break;

                        case AUDPP_DEC_STATUS_INIT:
                                dprintk("decoder status: init \n");
                                audpp_cmd_cfg_routing_mode(audio);
                                break;

                        case AUDPP_DEC_STATUS_CFG:
                                dprintk("decoder status: cfg \n");
                                break;
                        case AUDPP_DEC_STATUS_PLAY:
                                dprintk("decoder status: play \n");
                                if (audio->pcm_feedback) {
                                        audevrc_config_hostpcm(audio);
                                        audevrc_buffer_refresh(audio);
                                }
                                break;
                        default:
                                pr_err("unknown decoder status \n");
                        }
                        break;
                }
        case AUDPP_MSG_CFG_MSG:
                if (msg[0] == AUDPP_MSG_ENA_ENA) {
                        dprintk("audevrc_dsp_event: CFG_MSG ENABLE\n");
                        auddec_dsp_config(audio, 1);
                        audio->out_needed = 0;
                        audio->running = 1;
                        audpp_set_volume_and_pan(audio->dec_id, audio->volume,
                                                 0);
                        audpp_avsync(audio->dec_id, 22050);
                } else if (msg[0] == AUDPP_MSG_ENA_DIS) {
                        dprintk("audevrc_dsp_event: CFG_MSG DISABLE\n");
                        audpp_avsync(audio->dec_id, 0);
                        audio->running = 0;
                } else {
                        pr_err("audevrc_dsp_event: CFG_MSG %d?\n", msg[0]);
                }
                break;
        case AUDPP_MSG_ROUTING_ACK:
                dprintk("audevrc_dsp_event: ROUTING_ACK\n");
                audpp_cmd_cfg_adec_params(audio);
                break;

        default:
                pr_err("audevrc_dsp_event: UNKNOWN (%d)\n", id);
        }

}

struct msm_adsp_ops audplay_adsp_ops_evrc = {
        .event = audplay_dsp_event,
};

#define audplay_send_queue0(audio, cmd, len) \
        msm_adsp_write(audio->audplay, QDSP_uPAudPlay0BitStreamCtrlQueue, \
                       cmd, len)

static int auddec_dsp_config(struct audio *audio, int enable)
{
        audpp_cmd_cfg_dec_type cmd;

        memset(&cmd, 0, sizeof(cmd));
        cmd.cmd_id = AUDPP_CMD_CFG_DEC_TYPE;
        if (enable)
                cmd.dec0_cfg = AUDPP_CMD_UPDATDE_CFG_DEC |
                    AUDPP_CMD_ENA_DEC_V | AUDDEC_DEC_EVRC;
        else
                cmd.dec0_cfg = AUDPP_CMD_UPDATDE_CFG_DEC | AUDPP_CMD_DIS_DEC_V;

        return audpp_send_queue1(&cmd, sizeof(cmd));
}

static void audpp_cmd_cfg_adec_params(struct audio *audio)
{
        struct audpp_cmd_cfg_adec_params_evrc cmd;

        memset(&cmd, 0, sizeof(cmd));
        cmd.common.cmd_id = AUDPP_CMD_CFG_ADEC_PARAMS;
        cmd.common.length = sizeof(cmd);
        cmd.common.dec_id = audio->dec_id;
        cmd.common.input_sampling_frequency = 8000;
        cmd.stereo_cfg = AUDPP_CMD_PCM_INTF_MONO_V;

        audpp_send_queue2(&cmd, sizeof(cmd));
}

static void audpp_cmd_cfg_routing_mode(struct audio *audio)
{
        struct audpp_cmd_routing_mode cmd;
        dprintk("audpp_cmd_cfg_routing_mode()\n");
        memset(&cmd, 0, sizeof(cmd));
        cmd.cmd_id = AUDPP_CMD_ROUTING_MODE;
        cmd.object_number = audio->dec_id;
        if (audio->pcm_feedback)
                cmd.routing_mode = ROUTING_MODE_FTRT;
        else
                cmd.routing_mode = ROUTING_MODE_RT;

        audpp_send_queue1(&cmd, sizeof(cmd));
}

static int audplay_dsp_send_data_avail(struct audio *audio,
                                       unsigned idx, unsigned len)
{
        audplay_cmd_bitstream_data_avail cmd;

        cmd.cmd_id = AUDPLAY_CMD_BITSTREAM_DATA_AVAIL;
        cmd.decoder_id = audio->dec_id;
        cmd.buf_ptr = audio->out[idx].addr;
        cmd.buf_size = len / 2;
        cmd.partition_number = 0;
        return audplay_send_queue0(audio, &cmd, sizeof(cmd));
}

static void audevrc_buffer_refresh(struct audio *audio)
{
        struct audplay_cmd_buffer_refresh refresh_cmd;

        refresh_cmd.cmd_id = AUDPLAY_CMD_BUFFER_REFRESH;
        refresh_cmd.num_buffers = 1;
        refresh_cmd.buf0_address = audio->in[audio->fill_next].addr;
        refresh_cmd.buf0_length = audio->in[audio->fill_next].size;

        refresh_cmd.buf_read_count = 0;
        dprintk("audplay_buffer_fresh: buf0_addr=%x buf0_len=%d\n",
                refresh_cmd.buf0_address, refresh_cmd.buf0_length);
        audplay_send_queue0(audio, &refresh_cmd, sizeof(refresh_cmd));
}

static void audevrc_config_hostpcm(struct audio *audio)
{
        struct audplay_cmd_hpcm_buf_cfg cfg_cmd;

        dprintk("audevrc_config_hostpcm()\n");
        cfg_cmd.cmd_id = AUDPLAY_CMD_HPCM_BUF_CFG;
        cfg_cmd.max_buffers = 1;
        cfg_cmd.byte_swap = 0;
        cfg_cmd.hostpcm_config = (0x8000) | (0x4000);
        cfg_cmd.feedback_frequency = 1;
        cfg_cmd.partition_number = 0;
        audplay_send_queue0(audio, &cfg_cmd, sizeof(cfg_cmd));

}

static void audevrc_send_data(struct audio *audio, unsigned needed)
{
        struct buffer *frame;
        unsigned long flags;

        spin_lock_irqsave(&audio->dsp_lock, flags);
        if (!audio->running)
                goto done;

        if (needed) {
                /* We were called from the callback because the DSP
                 * requested more data.  Note that the DSP does want
                 * more data, and if a buffer was in-flight, mark it
                 * as available (since the DSP must now be done with
                 * it).
                 */
                audio->out_needed = 1;
                frame = audio->out + audio->out_tail;
                if (frame->used == 0xffffffff) {
                        dprintk("frame %d free\n", audio->out_tail);
                        frame->used = 0;
                        audio->out_tail ^= 1;
                        wake_up(&audio->write_wait);
                }
        }

        if (audio->out_needed) {
                /* If the DSP currently wants data and we have a
                 * buffer available, we will send it and reset
                 * the needed flag.  We'll mark the buffer as in-flight
                 * so that it won't be recycled until the next buffer
                 * is requested
                 */

                frame = audio->out + audio->out_tail;
                if (frame->used) {
                        BUG_ON(frame->used == 0xffffffff);
                        dprintk("frame %d busy\n", audio->out_tail);
                        audplay_dsp_send_data_avail(audio, audio->out_tail,
                                                    frame->used);
                        frame->used = 0xffffffff;
                        audio->out_needed = 0;
                }
        }
done:
        spin_unlock_irqrestore(&audio->dsp_lock, flags);
}

/* ------------------- device --------------------- */

static void audevrc_flush(struct audio *audio)
{
        audio->out[0].used = 0;
        audio->out[1].used = 0;
        audio->out_head = 0;
        audio->out_tail = 0;
        audio->stopped = 0;
        atomic_set(&audio->out_bytes, 0);
}

static void audevrc_flush_pcm_buf(struct audio *audio)
{
        uint8_t index;

        for (index = 0; index < PCM_BUF_MAX_COUNT; index++)
                audio->in[index].used = 0;

        audio->read_next = 0;
        audio->fill_next = 0;
}

static long audevrc_ioctl(struct file *file, unsigned int cmd,
                          unsigned long arg)
{
        struct audio *audio = file->private_data;
        int rc = 0;

        dprintk("audevrc_ioctl() cmd = %d\n", cmd);

        if (cmd == AUDIO_GET_STATS) {
                struct msm_audio_stats stats;
                stats.byte_count = audpp_avsync_byte_count(audio->dec_id);
                stats.sample_count = audpp_avsync_sample_count(audio->dec_id);
                if (copy_to_user((void *)arg, &stats, sizeof(stats)))
                        return -EFAULT;
                return 0;
        }
        if (cmd == AUDIO_SET_VOLUME) {
                unsigned long flags;
                spin_lock_irqsave(&audio->dsp_lock, flags);
                audio->volume = arg;
                if (audio->running)
                        audpp_set_volume_and_pan(audio->dec_id, arg, 0);
                spin_unlock_irqrestore(&audio->dsp_lock, flags);
                return 0;
        }
        mutex_lock(&audio->lock);
        switch (cmd) {
        case AUDIO_START:
                rc = audevrc_enable(audio);
                break;
        case AUDIO_STOP:
                rc = audevrc_disable(audio);
                audio->stopped = 1;
                break;
        case AUDIO_SET_CONFIG:{
                        dprintk("AUDIO_SET_CONFIG not applicable \n");
                        break;
                }
        case AUDIO_GET_CONFIG:{
                        struct msm_audio_config config;
                        config.buffer_size = BUFSZ;
                        config.buffer_count = 2;
                        config.sample_rate = 8000;
                        config.channel_count = 1;
                        config.unused[0] = 0;
                        config.unused[1] = 0;
                        config.unused[2] = 0;
                        config.unused[3] = 0;
                        if (copy_to_user((void *)arg, &config, sizeof(config)))
                                rc = -EFAULT;
                        else
                                rc = 0;
                        break;
                }
        case AUDIO_GET_PCM_CONFIG:{
                        struct msm_audio_pcm_config config;
                        config.pcm_feedback = 0;
                        config.buffer_count = PCM_BUF_MAX_COUNT;
                        config.buffer_size = PCM_BUFSZ_MIN;
                        if (copy_to_user((void *)arg, &config, sizeof(config)))
                                rc = -EFAULT;
                        else
                                rc = 0;
                        break;
                }
        case AUDIO_SET_PCM_CONFIG:{
                        struct msm_audio_pcm_config config;
                        if (copy_from_user
                            (&config, (void *)arg, sizeof(config))) {
                                rc = -EFAULT;
                                break;
                        }
                        if ((config.buffer_count > PCM_BUF_MAX_COUNT) ||
                            (config.buffer_count == 1))
                                config.buffer_count = PCM_BUF_MAX_COUNT;

                        if (config.buffer_size < PCM_BUFSZ_MIN)
                                config.buffer_size = PCM_BUFSZ_MIN;

                        /* Check if pcm feedback is required */
                        if ((config.pcm_feedback) && (!audio->read_data)) {
                                dprintk("audevrc_ioctl: allocate PCM buf %d\n",
                                        config.buffer_count *
                                        config.buffer_size);
                                audio->read_data =
                                    dma_alloc_coherent(NULL,
                                                       config.buffer_size *
                                                       config.buffer_count,
                                                       &audio->read_phys,
                                                       GFP_KERNEL);
                                if (!audio->read_data) {
                                        pr_err
                                        ("audevrc_ioctl: no mem for pcm buf\n");
                                        rc = -1;
                                } else {
                                        uint8_t index;
                                        uint32_t offset = 0;
                                        audio->pcm_feedback = 1;
                                        audio->buf_refresh = 0;
                                        audio->pcm_buf_count =
                                            config.buffer_count;
                                        audio->read_next = 0;
                                        audio->fill_next = 0;

                                        for (index = 0;
                                             index < config.buffer_count;
                                             index++) {
                                                audio->in[index].data =
                                                    audio->read_data + offset;
                                                audio->in[index].addr =
                                                    audio->read_phys + offset;
                                                audio->in[index].size =
                                                    config.buffer_size;
                                                audio->in[index].used = 0;
                                                offset += config.buffer_size;
                                        }
                                        rc = 0;
                                }
                        } else {
                                rc = 0;
                        }
                        break;
                }
        case AUDIO_PAUSE:
                dprintk("%s: AUDIO_PAUSE %ld\n", __func__, arg);
                rc = audpp_pause(audio->dec_id, (int) arg);
                break;
        default:
                rc = -EINVAL;
        }
        mutex_unlock(&audio->lock);
        return rc;
}

static ssize_t audevrc_read(struct file *file, char __user *buf, size_t count,
                            loff_t *pos)
{
        struct audio *audio = file->private_data;
        const char __user *start = buf;
        int rc = 0;
        if (!audio->pcm_feedback) {
                return 0;
                /* PCM feedback is not enabled. Nothing to read */
        }
        mutex_lock(&audio->read_lock);
        dprintk("audevrc_read() \n");
        while (count > 0) {
                rc = wait_event_interruptible(audio->read_wait,
                                              (audio->in[audio->read_next].
                                               used > 0) || (audio->stopped));
                dprintk("audevrc_read() wait terminated \n");
                if (rc < 0)
                        break;
                if (audio->stopped) {
                        rc = -EBUSY;
                        break;
                }
                if (count < audio->in[audio->read_next].used) {
                        /* Read must happen in frame boundary. Since driver does
                         * not know frame size, read count must be greater or
                         * equal to size of PCM samples
                         */
                        dprintk("audevrc_read:read stop - partial frame\n");
                        break;
                } else {
                        dprintk("audevrc_read: read from in[%d]\n",
                                audio->read_next);
                        if (copy_to_user
                            (buf, audio->in[audio->read_next].data,
                             audio->in[audio->read_next].used)) {
                                pr_err("audevrc_read: invalid addr %x \n",
                                       (unsigned int)buf);
                                rc = -EFAULT;
                                break;
                        }
                        count -= audio->in[audio->read_next].used;
                        buf += audio->in[audio->read_next].used;
                        audio->in[audio->read_next].used = 0;
                        if ((++audio->read_next) == audio->pcm_buf_count)
                                audio->read_next = 0;
                        if (audio->in[audio->read_next].used == 0)
                                break;  /* No data ready at this moment
                                         * Exit while loop to prevent
                                         * output thread sleep too long
                                         */

                }
        }
        if (audio->buf_refresh) {
                audio->buf_refresh = 0;
                dprintk("audevrc_read: kick start pcm feedback again\n");
                audevrc_buffer_refresh(audio);
        }
        mutex_unlock(&audio->read_lock);
        if (buf > start)
                rc = buf - start;
        dprintk("audevrc_read: read %d bytes\n", rc);
        return rc;
}

static ssize_t audevrc_write(struct file *file, const char __user *buf,
                             size_t count, loff_t *pos)
{
        struct audio *audio = file->private_data;
        const char __user *start = buf;
        struct buffer *frame;
        size_t xfer;
        int rc = 0;

        if (count & 1)
                return -EINVAL;
        mutex_lock(&audio->write_lock);
        dprintk("audevrc_write() \n");
        while (count > 0) {
                frame = audio->out + audio->out_head;
                rc = wait_event_interruptible(audio->write_wait,
                                              (frame->used == 0)
                                              || (audio->stopped));
                if (rc < 0)
                        break;
                if (audio->stopped) {
                        rc = -EBUSY;
                        break;
                }
                xfer = (count > frame->size) ? frame->size : count;
                if (copy_from_user(frame->data, buf, xfer)) {
                        rc = -EFAULT;
                        break;
                }

                frame->used = xfer;
                audio->out_head ^= 1;
                count -= xfer;
                buf += xfer;

                audevrc_send_data(audio, 0);

        }
        mutex_unlock(&audio->write_lock);
        if (buf > start)
                return buf - start;
        return rc;
}

static int audevrc_release(struct inode *inode, struct file *file)
{
        struct audio *audio = file->private_data;

        dprintk("audevrc_release()\n");

        mutex_lock(&audio->lock);
        audevrc_disable(audio);
        audevrc_flush(audio);
        audevrc_flush_pcm_buf(audio);
        msm_adsp_put(audio->audplay);
        audio->audplay = NULL;
        audio->opened = 0;
        dma_free_coherent(NULL, DMASZ, audio->data, audio->phys);
        audio->data = NULL;
        if (audio->read_data != NULL) {
                dma_free_coherent(NULL,
                                  audio->in[0].size * audio->pcm_buf_count,
                                  audio->read_data, audio->read_phys);
                audio->read_data = NULL;
        }
        audio->pcm_feedback = 0;
        mutex_unlock(&audio->lock);
        return 0;
}

static struct audio the_evrc_audio;

static int audevrc_open(struct inode *inode, struct file *file)
{
        struct audio *audio = &the_evrc_audio;
        int rc;

        if (audio->opened) {
                pr_err("audio: busy\n");
                return -EBUSY;
        }

        /* Acquire Lock */
        mutex_lock(&audio->lock);

        if (!audio->data) {
                audio->data = dma_alloc_coherent(NULL, DMASZ,
                                                 &audio->phys, GFP_KERNEL);
                if (!audio->data) {
                        pr_err("audio: could not allocate DMA buffers\n");
                        rc = -ENOMEM;
                        goto dma_fail;
                }
        }

        rc = audmgr_open(&audio->audmgr);
        if (rc)
                goto audmgr_fail;

        rc = msm_adsp_get("AUDPLAY0TASK", &audio->audplay,
                          &audplay_adsp_ops_evrc, audio);
        if (rc) {
                pr_err("audio: failed to get audplay0 dsp module\n");
                goto adsp_fail;
        }

        audio->dec_id = 0;

        audio->out[0].data = audio->data + 0;
        audio->out[0].addr = audio->phys + 0;
        audio->out[0].size = BUFSZ;

        audio->out[1].data = audio->data + BUFSZ;
        audio->out[1].addr = audio->phys + BUFSZ;
        audio->out[1].size = BUFSZ;

        audio->volume = 0x3FFF;

        audevrc_flush(audio);

        audio->opened = 1;
        file->private_data = audio;

        mutex_unlock(&audio->lock);
        return rc;

adsp_fail:
        audmgr_close(&audio->audmgr);
audmgr_fail:
        dma_free_coherent(NULL, DMASZ, audio->data, audio->phys);
dma_fail:
        mutex_unlock(&audio->lock);
        return rc;
}

static struct file_operations audio_evrc_fops = {
        .owner = THIS_MODULE,
        .open = audevrc_open,
        .release = audevrc_release,
        .read = audevrc_read,
        .write = audevrc_write,
        .unlocked_ioctl = audevrc_ioctl,
};

struct miscdevice audio_evrc_misc = {
        .minor = MISC_DYNAMIC_MINOR,
        .name = "msm_evrc",
        .fops = &audio_evrc_fops,
};

static int __init audevrc_init(void)
{
        mutex_init(&the_evrc_audio.lock);
        mutex_init(&the_evrc_audio.write_lock);
        mutex_init(&the_evrc_audio.read_lock);
        spin_lock_init(&the_evrc_audio.dsp_lock);
        init_waitqueue_head(&the_evrc_audio.write_wait);
        init_waitqueue_head(&the_evrc_audio.read_wait);
        the_evrc_audio.read_data = NULL;
        return misc_register(&audio_evrc_misc);
}

static void __exit audevrc_exit(void)
{
        misc_deregister(&audio_evrc_misc);
}

module_init(audevrc_init);
module_exit(audevrc_exit);

MODULE_DESCRIPTION("MSM EVRC driver");
MODULE_LICENSE("GPL v2");
MODULE_AUTHOR("QUALCOMM Inc");