tegra_pcm.c

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/*
 * tegra_pcm.c - Tegra PCM driver
 *
 * Author: Stephen Warren <[email protected]>
 * Copyright (C) 2010,2012 - NVIDIA, Inc.
 *
 * Based on code copyright/by:
 *
 * Copyright (c) 2009-2010, NVIDIA Corporation.
 * Scott Peterson <[email protected]>
 * Vijay Mali <[email protected]>
 *
 * Copyright (C) 2010 Google, Inc.
 * Iliyan Malchev <[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/module.h>
#include <linux/slab.h>
#include <sound/core.h>
#include <sound/pcm.h>
#include <sound/pcm_params.h>
#include <sound/soc.h>
#include <sound/dmaengine_pcm.h>

#include "tegra_pcm.h"

static const struct snd_pcm_hardware tegra_pcm_hardware = {
    .info           = SNDRV_PCM_INFO_MMAP |
                  SNDRV_PCM_INFO_MMAP_VALID |
                  SNDRV_PCM_INFO_PAUSE |
                  SNDRV_PCM_INFO_RESUME |
                  SNDRV_PCM_INFO_INTERLEAVED,
    .formats        = SNDRV_PCM_FMTBIT_S16_LE,
    .channels_min       = 2,
    .channels_max       = 2,
    .period_bytes_min   = 1024,
    .period_bytes_max   = PAGE_SIZE,
    .periods_min        = 2,
    .periods_max        = 8,
    .buffer_bytes_max   = PAGE_SIZE * 8,
    .fifo_size      = 4,
};

static int tegra_pcm_open(struct snd_pcm_substream *substream)
{
    struct snd_soc_pcm_runtime *rtd = substream->private_data;
    struct device *dev = rtd->platform->dev;
    int ret;

    /* Set HW params now that initialization is complete */
    snd_soc_set_runtime_hwparams(substream, &tegra_pcm_hardware);

    ret = snd_dmaengine_pcm_open(substream, NULL, NULL);
    if (ret) {
        dev_err(dev, "dmaengine pcm open failed with err %d\n", ret);
        return ret;
    }

    return 0;
}

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

static int tegra_pcm_hw_params(struct snd_pcm_substream *substream,
                struct snd_pcm_hw_params *params)
{
    struct snd_soc_pcm_runtime *rtd = substream->private_data;
    struct device *dev = rtd->platform->dev;
    struct dma_chan *chan = snd_dmaengine_pcm_get_chan(substream);
    struct tegra_pcm_dma_params *dmap;
    struct dma_slave_config slave_config;
    int ret;

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

    ret = snd_hwparams_to_dma_slave_config(substream, params,
                        &slave_config);
    if (ret) {
        dev_err(dev, "hw params config failed with err %d\n", ret);
        return ret;
    }

    if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
        slave_config.dst_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
        slave_config.dst_addr = dmap->addr;
        slave_config.dst_maxburst = 4;
    } else {
        slave_config.src_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
        slave_config.src_addr = dmap->addr;
        slave_config.src_maxburst = 4;
    }
    slave_config.slave_id = dmap->req_sel;

    ret = dmaengine_slave_config(chan, &slave_config);
    if (ret < 0) {
        dev_err(dev, "dma slave config failed with err %d\n", ret);
        return ret;
    }

    snd_pcm_set_runtime_buffer(substream, &substream->dma_buffer);
    return 0;
}

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

static int tegra_pcm_trigger(struct snd_pcm_substream *substream, int cmd)
{
    switch (cmd) {
    case SNDRV_PCM_TRIGGER_START:
    case SNDRV_PCM_TRIGGER_RESUME:
    case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
        return snd_dmaengine_pcm_trigger(substream,
                    SNDRV_PCM_TRIGGER_START);

    case SNDRV_PCM_TRIGGER_STOP:
    case SNDRV_PCM_TRIGGER_SUSPEND:
    case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
        return snd_dmaengine_pcm_trigger(substream,
                    SNDRV_PCM_TRIGGER_STOP);
    default:
        return -EINVAL;
    }
    return 0;
}

static int tegra_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 tegra_pcm_ops = {
    .open       = tegra_pcm_open,
    .close      = tegra_pcm_close,
    .ioctl      = snd_pcm_lib_ioctl,
    .hw_params  = tegra_pcm_hw_params,
    .hw_free    = tegra_pcm_hw_free,
    .trigger    = tegra_pcm_trigger,
    .pointer    = snd_dmaengine_pcm_pointer,
    .mmap       = tegra_pcm_mmap,
};

static int tegra_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 = tegra_pcm_hardware.buffer_bytes_max;

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

    buf->dev.type = SNDRV_DMA_TYPE_DEV;
    buf->dev.dev = pcm->card->dev;
    buf->private_data = NULL;
    buf->bytes = size;

    return 0;
}

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

    substream = pcm->streams[stream].substream;
    if (!substream)
        return;

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

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

static u64 tegra_dma_mask = DMA_BIT_MASK(32);

static int tegra_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 = &tegra_dma_mask;
    if (!card->dev->coherent_dma_mask)
        card->dev->coherent_dma_mask = DMA_BIT_MASK(32);

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

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

    return 0;

err_free_play:
    tegra_pcm_deallocate_dma_buffer(pcm, SNDRV_PCM_STREAM_PLAYBACK);
err:
    return ret;
}

static void tegra_pcm_free(struct snd_pcm *pcm)
{
    tegra_pcm_deallocate_dma_buffer(pcm, SNDRV_PCM_STREAM_CAPTURE);
    tegra_pcm_deallocate_dma_buffer(pcm, SNDRV_PCM_STREAM_PLAYBACK);
}

static struct snd_soc_platform_driver tegra_pcm_platform = {
    .ops        = &tegra_pcm_ops,
    .pcm_new    = tegra_pcm_new,
    .pcm_free   = tegra_pcm_free,
};

int __devinit tegra_pcm_platform_register(struct device *dev)
{
    return snd_soc_register_platform(dev, &tegra_pcm_platform);
}
EXPORT_SYMBOL_GPL(tegra_pcm_platform_register);

void __devexit tegra_pcm_platform_unregister(struct device *dev)
{
    snd_soc_unregister_platform(dev);
}
EXPORT_SYMBOL_GPL(tegra_pcm_platform_unregister);

MODULE_AUTHOR("Stephen Warren <[email protected]>");
MODULE_DESCRIPTION("Tegra PCM ASoC driver");
MODULE_LICENSE("GPL");