snd-go7007.c

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/*
 * Copyright (C) 2005-2006 Micronas USA Inc.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License (Version 2) as
 * published by the Free Software Foundation.
 *
 * 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, write to the Free Software Foundation,
 * Inc., 59 Temple Place - Suite 330, Boston MA 02111-1307, USA.
 */

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/init.h>
#include <linux/spinlock.h>
#include <linux/delay.h>
#include <linux/sched.h>
#include <linux/vmalloc.h>
#include <linux/time.h>
#include <linux/mm.h>
#include <linux/i2c.h>
#include <linux/mutex.h>
#include <linux/uaccess.h>
#include <linux/slab.h>
#include <sound/core.h>
#include <sound/pcm.h>
#include <sound/initval.h>

#include "go7007-priv.h"

static int index[SNDRV_CARDS] = SNDRV_DEFAULT_IDX;
static char *id[SNDRV_CARDS] = SNDRV_DEFAULT_STR;
static bool enable[SNDRV_CARDS] = SNDRV_DEFAULT_ENABLE_PNP;

module_param_array(index, int, NULL, 0444);
module_param_array(id, charp, NULL, 0444);
module_param_array(enable, bool, NULL, 0444);
MODULE_PARM_DESC(index, "Index value for the go7007 audio driver");
MODULE_PARM_DESC(id, "ID string for the go7007 audio driver");
MODULE_PARM_DESC(enable, "Enable for the go7007 audio driver");

struct go7007_snd {
    struct snd_card *card;
    struct snd_pcm *pcm;
    struct snd_pcm_substream *substream;
    spinlock_t lock;
    int w_idx;
    int hw_ptr;
    int avail;
    int capturing;
};

static struct snd_pcm_hardware go7007_snd_capture_hw = {
    .info           = (SNDRV_PCM_INFO_MMAP |
                    SNDRV_PCM_INFO_INTERLEAVED |
                    SNDRV_PCM_INFO_BLOCK_TRANSFER |
                    SNDRV_PCM_INFO_MMAP_VALID),
    .formats        = SNDRV_PCM_FMTBIT_S16_LE,
    .rates          = SNDRV_PCM_RATE_48000,
    .rate_min       = 48000,
    .rate_max       = 48000,
    .channels_min       = 2,
    .channels_max       = 2,
    .buffer_bytes_max   = (128*1024),
    .period_bytes_min   = 4096,
    .period_bytes_max   = (128*1024),
    .periods_min        = 1,
    .periods_max        = 32,
};

static void parse_audio_stream_data(struct go7007 *go, u8 *buf, int length)
{
    struct go7007_snd *gosnd = go->snd_context;
    struct snd_pcm_runtime *runtime = gosnd->substream->runtime;
    int frames = bytes_to_frames(runtime, length);

    spin_lock(&gosnd->lock);
    gosnd->hw_ptr += frames;
    if (gosnd->hw_ptr >= runtime->buffer_size)
        gosnd->hw_ptr -= runtime->buffer_size;
    gosnd->avail += frames;
    spin_unlock(&gosnd->lock);
    if (gosnd->w_idx + length > runtime->dma_bytes) {
        int cpy = runtime->dma_bytes - gosnd->w_idx;

        memcpy(runtime->dma_area + gosnd->w_idx, buf, cpy);
        length -= cpy;
        buf += cpy;
        gosnd->w_idx = 0;
    }
    memcpy(runtime->dma_area + gosnd->w_idx, buf, length);
    gosnd->w_idx += length;
    spin_lock(&gosnd->lock);
    if (gosnd->avail < runtime->period_size) {
        spin_unlock(&gosnd->lock);
        return;
    }
    gosnd->avail -= runtime->period_size;
    spin_unlock(&gosnd->lock);
    if (gosnd->capturing)
        snd_pcm_period_elapsed(gosnd->substream);
}

static int go7007_snd_hw_params(struct snd_pcm_substream *substream,
                struct snd_pcm_hw_params *hw_params)
{
    struct go7007 *go = snd_pcm_substream_chip(substream);
    unsigned int bytes;

    bytes = params_buffer_bytes(hw_params);
    if (substream->runtime->dma_bytes > 0)
        vfree(substream->runtime->dma_area);
    substream->runtime->dma_bytes = 0;
    substream->runtime->dma_area = vmalloc(bytes);
    if (substream->runtime->dma_area == NULL)
        return -ENOMEM;
    substream->runtime->dma_bytes = bytes;
    go->audio_deliver = parse_audio_stream_data;
    return 0;
}

static int go7007_snd_hw_free(struct snd_pcm_substream *substream)
{
    struct go7007 *go = snd_pcm_substream_chip(substream);

    go->audio_deliver = NULL;
    if (substream->runtime->dma_bytes > 0)
        vfree(substream->runtime->dma_area);
    substream->runtime->dma_bytes = 0;
    return 0;
}

static int go7007_snd_capture_open(struct snd_pcm_substream *substream)
{
    struct go7007 *go = snd_pcm_substream_chip(substream);
    struct go7007_snd *gosnd = go->snd_context;
    unsigned long flags;
    int r;

    spin_lock_irqsave(&gosnd->lock, flags);
    if (gosnd->substream == NULL) {
        gosnd->substream = substream;
        substream->runtime->hw = go7007_snd_capture_hw;
        r = 0;
    } else
        r = -EBUSY;
    spin_unlock_irqrestore(&gosnd->lock, flags);
    return r;
}

static int go7007_snd_capture_close(struct snd_pcm_substream *substream)
{
    struct go7007 *go = snd_pcm_substream_chip(substream);
    struct go7007_snd *gosnd = go->snd_context;

    gosnd->substream = NULL;
    return 0;
}

static int go7007_snd_pcm_prepare(struct snd_pcm_substream *substream)
{
    return 0;
}

static int go7007_snd_pcm_trigger(struct snd_pcm_substream *substream, int cmd)
{
    struct go7007 *go = snd_pcm_substream_chip(substream);
    struct go7007_snd *gosnd = go->snd_context;

    switch (cmd) {
    case SNDRV_PCM_TRIGGER_START:
        /* Just set a flag to indicate we should signal ALSA when
         * sound comes in */
        gosnd->capturing = 1;
        return 0;
    case SNDRV_PCM_TRIGGER_STOP:
        gosnd->hw_ptr = gosnd->w_idx = gosnd->avail = 0;
        gosnd->capturing = 0;
        return 0;
    default:
        return -EINVAL;
    }
}

static snd_pcm_uframes_t go7007_snd_pcm_pointer(struct snd_pcm_substream *substream)
{
    struct go7007 *go = snd_pcm_substream_chip(substream);
    struct go7007_snd *gosnd = go->snd_context;

    return gosnd->hw_ptr;
}

static struct page *go7007_snd_pcm_page(struct snd_pcm_substream *substream,
                    unsigned long offset)
{
    return vmalloc_to_page(substream->runtime->dma_area + offset);
}

static struct snd_pcm_ops go7007_snd_capture_ops = {
    .open       = go7007_snd_capture_open,
    .close      = go7007_snd_capture_close,
    .ioctl      = snd_pcm_lib_ioctl,
    .hw_params  = go7007_snd_hw_params,
    .hw_free    = go7007_snd_hw_free,
    .prepare    = go7007_snd_pcm_prepare,
    .trigger    = go7007_snd_pcm_trigger,
    .pointer    = go7007_snd_pcm_pointer,
    .page       = go7007_snd_pcm_page,
};

static int go7007_snd_free(struct snd_device *device)
{
    struct go7007 *go = device->device_data;

    kfree(go->snd_context);
    go->snd_context = NULL;
    if (--go->ref_count == 0)
        kfree(go);
    return 0;
}

static struct snd_device_ops go7007_snd_device_ops = {
    .dev_free   = go7007_snd_free,
};

int go7007_snd_init(struct go7007 *go)
{
    static int dev;
    struct go7007_snd *gosnd;
    int ret = 0;

    if (dev >= SNDRV_CARDS)
        return -ENODEV;
    if (!enable[dev]) {
        dev++;
        return -ENOENT;
    }
    gosnd = kmalloc(sizeof(struct go7007_snd), GFP_KERNEL);
    if (gosnd == NULL)
        return -ENOMEM;
    spin_lock_init(&gosnd->lock);
    gosnd->hw_ptr = gosnd->w_idx = gosnd->avail = 0;
    gosnd->capturing = 0;
    ret = snd_card_create(index[dev], id[dev], THIS_MODULE, 0,
                  &gosnd->card);
    if (ret < 0) {
        kfree(gosnd);
        return ret;
    }
    ret = snd_device_new(gosnd->card, SNDRV_DEV_LOWLEVEL, go,
            &go7007_snd_device_ops);
    if (ret < 0) {
        kfree(gosnd);
        return ret;
    }
    snd_card_set_dev(gosnd->card, go->dev);
    ret = snd_pcm_new(gosnd->card, "go7007", 0, 0, 1, &gosnd->pcm);
    if (ret < 0) {
        snd_card_free(gosnd->card);
        kfree(gosnd);
        return ret;
    }
    strncpy(gosnd->card->driver, "go7007", sizeof(gosnd->card->driver));
    strncpy(gosnd->card->shortname, go->name, sizeof(gosnd->card->driver));
    strncpy(gosnd->card->longname, gosnd->card->shortname,
            sizeof(gosnd->card->longname));

    gosnd->pcm->private_data = go;
    snd_pcm_set_ops(gosnd->pcm, SNDRV_PCM_STREAM_CAPTURE,
            &go7007_snd_capture_ops);

    ret = snd_card_register(gosnd->card);
    if (ret < 0) {
        snd_card_free(gosnd->card);
        kfree(gosnd);
        return ret;
    }

    gosnd->substream = NULL;
    go->snd_context = gosnd;
    ++dev;
    ++go->ref_count;

    return 0;
}
EXPORT_SYMBOL(go7007_snd_init);

int go7007_snd_remove(struct go7007 *go)
{
    struct go7007_snd *gosnd = go->snd_context;

    snd_card_disconnect(gosnd->card);
    snd_card_free_when_closed(gosnd->card);
    return 0;
}
EXPORT_SYMBOL(go7007_snd_remove);

MODULE_LICENSE("GPL v2");