omap-pcm.c

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/*
 * omap-pcm.c  --  ALSA PCM interface for the OMAP SoC
 *
 * Copyright (C) 2008 Nokia Corporation
 *
 * Contact: Jarkko Nikula <[email protected]>
 *          Peter Ujfalusi <[email protected]>
 *
 * 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., 51 Franklin St, Fifth Floor, Boston, MA
 * 02110-1301 USA
 *
 */

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

#include <plat/cpu.h>
#include "omap-pcm.h"

static const struct snd_pcm_hardware omap_pcm_hardware = {
    .info           = SNDRV_PCM_INFO_MMAP |
                  SNDRV_PCM_INFO_MMAP_VALID |
                  SNDRV_PCM_INFO_INTERLEAVED |
                  SNDRV_PCM_INFO_PAUSE |
                  SNDRV_PCM_INFO_RESUME |
                  SNDRV_PCM_INFO_NO_PERIOD_WAKEUP,
    .formats        = SNDRV_PCM_FMTBIT_S16_LE |
                  SNDRV_PCM_FMTBIT_S32_LE,
    .period_bytes_min   = 32,
    .period_bytes_max   = 64 * 1024,
    .periods_min        = 2,
    .periods_max        = 255,
    .buffer_bytes_max   = 128 * 1024,
};

static int omap_pcm_get_dma_buswidth(int num_bits)
{
    int buswidth;

    switch (num_bits) {
    case 16:
        buswidth = DMA_SLAVE_BUSWIDTH_2_BYTES;
        break;
    case 32:
        buswidth = DMA_SLAVE_BUSWIDTH_4_BYTES;
        break;
    default:
        buswidth = -EINVAL;
        break;
    }
    return buswidth;
}


/* this may get called several times by oss emulation */
static int omap_pcm_hw_params(struct snd_pcm_substream *substream,
                  struct snd_pcm_hw_params *params)
{
    struct snd_pcm_runtime *runtime = substream->runtime;
    struct snd_soc_pcm_runtime *rtd = substream->private_data;
    struct omap_pcm_dma_data *dma_data;
    struct dma_slave_config config;
    struct dma_chan *chan;
    int err = 0;

    dma_data = snd_soc_dai_get_dma_data(rtd->cpu_dai, substream);

    /* return if this is a bufferless transfer e.g.
     * codec <--> BT codec or GSM modem -- lg FIXME */
    if (!dma_data)
        return 0;

    snd_pcm_set_runtime_buffer(substream, &substream->dma_buffer);
    runtime->dma_bytes = params_buffer_bytes(params);

    chan = snd_dmaengine_pcm_get_chan(substream);
    if (!chan)
        return -EINVAL;

    /* fills in addr_width and direction */
    err = snd_hwparams_to_dma_slave_config(substream, params, &config);
    if (err)
        return err;

    /* Override the *_dma addr_width if requested by the DAI driver */
    if (dma_data->data_type) {
        int buswidth = omap_pcm_get_dma_buswidth(dma_data->data_type);

        if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
            config.dst_addr_width = buswidth;
        else
            config.src_addr_width = buswidth;
    }

    config.src_addr = dma_data->port_addr;
    config.dst_addr = dma_data->port_addr;
    config.src_maxburst = dma_data->packet_size;
    config.dst_maxburst = dma_data->packet_size;

    return dmaengine_slave_config(chan, &config);
}

static int omap_pcm_hw_free(struct snd_pcm_substream *substream)
{
    snd_pcm_set_runtime_buffer(substream, NULL);
    return 0;
}

static int omap_pcm_trigger(struct snd_pcm_substream *substream, int cmd)
{
    struct snd_soc_pcm_runtime *rtd = substream->private_data;
    struct omap_pcm_dma_data *dma_data;
    int ret = 0;

    dma_data = snd_soc_dai_get_dma_data(rtd->cpu_dai, substream);

    switch (cmd) {
    case SNDRV_PCM_TRIGGER_START:
    case SNDRV_PCM_TRIGGER_RESUME:
    case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
        /* Configure McBSP internal buffer usage */
        if (dma_data->set_threshold)
            dma_data->set_threshold(substream);
        break;

    case SNDRV_PCM_TRIGGER_STOP:
    case SNDRV_PCM_TRIGGER_SUSPEND:
    case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
        break;
    default:
        ret = -EINVAL;
    }

    if (ret == 0)
        ret = snd_dmaengine_pcm_trigger(substream, cmd);

    return ret;
}

static snd_pcm_uframes_t omap_pcm_pointer(struct snd_pcm_substream *substream)
{
    snd_pcm_uframes_t offset;

    if (cpu_is_omap1510())
        offset = snd_dmaengine_pcm_pointer_no_residue(substream);
    else
        offset = snd_dmaengine_pcm_pointer(substream);

    return offset;
}

static int omap_pcm_open(struct snd_pcm_substream *substream)
{
    struct snd_pcm_runtime *runtime = substream->runtime;
    struct snd_soc_pcm_runtime *rtd = substream->private_data;
    struct omap_pcm_dma_data *dma_data;
    int ret;

    snd_soc_set_runtime_hwparams(substream, &omap_pcm_hardware);

    /* Ensure that buffer size is a multiple of period size */
    ret = snd_pcm_hw_constraint_integer(runtime,
                        SNDRV_PCM_HW_PARAM_PERIODS);
    if (ret < 0)
        return ret;

    dma_data = snd_soc_dai_get_dma_data(rtd->cpu_dai, substream);
    ret = snd_dmaengine_pcm_open(substream, omap_dma_filter_fn,
                     &dma_data->dma_req);
    return ret;
}

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

static int omap_pcm_mmap(struct snd_pcm_substream *substream,
    struct vm_area_struct *vma)
{
    struct snd_pcm_runtime *runtime = substream->runtime;

    return dma_mmap_writecombine(substream->pcm->card->dev, vma,
                     runtime->dma_area,
                     runtime->dma_addr,
                     runtime->dma_bytes);
}

static struct snd_pcm_ops omap_pcm_ops = {
    .open       = omap_pcm_open,
    .close      = omap_pcm_close,
    .ioctl      = snd_pcm_lib_ioctl,
    .hw_params  = omap_pcm_hw_params,
    .hw_free    = omap_pcm_hw_free,
    .trigger    = omap_pcm_trigger,
    .pointer    = omap_pcm_pointer,
    .mmap       = omap_pcm_mmap,
};

static u64 omap_pcm_dmamask = DMA_BIT_MASK(64);

static int omap_pcm_preallocate_dma_buffer(struct snd_pcm *pcm,
    int stream)
{
    struct snd_pcm_substream *substream = pcm->streams[stream].substream;
    struct snd_dma_buffer *buf = &substream->dma_buffer;
    size_t size = omap_pcm_hardware.buffer_bytes_max;

    buf->dev.type = SNDRV_DMA_TYPE_DEV;
    buf->dev.dev = pcm->card->dev;
    buf->private_data = NULL;
    buf->area = dma_alloc_writecombine(pcm->card->dev, size,
                       &buf->addr, GFP_KERNEL);
    if (!buf->area)
        return -ENOMEM;

    buf->bytes = size;
    return 0;
}

static void omap_pcm_free_dma_buffers(struct snd_pcm *pcm)
{
    struct snd_pcm_substream *substream;
    struct snd_dma_buffer *buf;
    int stream;

    for (stream = 0; stream < 2; stream++) {
        substream = pcm->streams[stream].substream;
        if (!substream)
            continue;

        buf = &substream->dma_buffer;
        if (!buf->area)
            continue;

        dma_free_writecombine(pcm->card->dev, buf->bytes,
                      buf->area, buf->addr);
        buf->area = NULL;
    }
}

static int omap_pcm_new(struct snd_soc_pcm_runtime *rtd)
{
    struct snd_card *card = rtd->card->snd_card;
    struct snd_pcm *pcm = rtd->pcm;
    int ret = 0;

    if (!card->dev->dma_mask)
        card->dev->dma_mask = &omap_pcm_dmamask;
    if (!card->dev->coherent_dma_mask)
        card->dev->coherent_dma_mask = DMA_BIT_MASK(64);

    if (pcm->streams[SNDRV_PCM_STREAM_PLAYBACK].substream) {
        ret = omap_pcm_preallocate_dma_buffer(pcm,
            SNDRV_PCM_STREAM_PLAYBACK);
        if (ret)
            goto out;
    }

    if (pcm->streams[SNDRV_PCM_STREAM_CAPTURE].substream) {
        ret = omap_pcm_preallocate_dma_buffer(pcm,
            SNDRV_PCM_STREAM_CAPTURE);
        if (ret)
            goto out;
    }

out:
    /* free preallocated buffers in case of error */
    if (ret)
        omap_pcm_free_dma_buffers(pcm);

    return ret;
}

static struct snd_soc_platform_driver omap_soc_platform = {
    .ops        = &omap_pcm_ops,
    .pcm_new    = omap_pcm_new,
    .pcm_free   = omap_pcm_free_dma_buffers,
};

static __devinit int omap_pcm_probe(struct platform_device *pdev)
{
    return snd_soc_register_platform(&pdev->dev,
            &omap_soc_platform);
}

static int __devexit omap_pcm_remove(struct platform_device *pdev)
{
    snd_soc_unregister_platform(&pdev->dev);
    return 0;
}

static struct platform_driver omap_pcm_driver = {
    .driver = {
            .name = "omap-pcm-audio",
            .owner = THIS_MODULE,
    },

    .probe = omap_pcm_probe,
    .remove = __devexit_p(omap_pcm_remove),
};

module_platform_driver(omap_pcm_driver);

MODULE_AUTHOR("Jarkko Nikula <[email protected]>");
MODULE_DESCRIPTION("OMAP PCM DMA module");
MODULE_LICENSE("GPL");
MODULE_ALIAS("platform:omap-pcm-audio");