bf5xx-tdm-pcm.c

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/*
 * File:         sound/soc/blackfin/bf5xx-tdm-pcm.c
 * Author:       Barry Song <[email protected]>
 *
 * Created:      Tue June 06 2009
 * Description:  DMA driver for tdm codec
 *
 * Modified:
 *               Copyright 2009 Analog Devices Inc.
 *
 * Bugs:         Enter bugs at http://blackfin.uclinux.org/
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * 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, see the file COPYING, or write
 * to the Free Software Foundation, Inc.,
 * 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
 */

#include <linux/module.h>
#include <linux/init.h>
#include <linux/platform_device.h>
#include <linux/dma-mapping.h>
#include <linux/gfp.h>

#include <sound/core.h>
#include <sound/pcm.h>
#include <sound/pcm_params.h>
#include <sound/soc.h>

#include <asm/dma.h>

#include "bf5xx-tdm-pcm.h"
#include "bf5xx-tdm.h"
#include "bf5xx-sport.h"

#define PCM_BUFFER_MAX  0x8000
#define FRAGMENT_SIZE_MIN  (4*1024)
#define FRAGMENTS_MIN  2
#define FRAGMENTS_MAX  32

static void bf5xx_dma_irq(void *data)
{
    struct snd_pcm_substream *pcm = data;
    snd_pcm_period_elapsed(pcm);
}

static const struct snd_pcm_hardware bf5xx_pcm_hardware = {
    .info = (SNDRV_PCM_INFO_INTERLEAVED | SNDRV_PCM_INFO_BLOCK_TRANSFER |
        SNDRV_PCM_INFO_RESUME),
    .formats =          SNDRV_PCM_FMTBIT_S32_LE,
    .rates =            SNDRV_PCM_RATE_48000,
    .channels_min =     2,
    .channels_max =     8,
    .buffer_bytes_max = PCM_BUFFER_MAX,
    .period_bytes_min = FRAGMENT_SIZE_MIN,
    .period_bytes_max = PCM_BUFFER_MAX/2,
    .periods_min =      FRAGMENTS_MIN,
    .periods_max =      FRAGMENTS_MAX,
};

static int bf5xx_pcm_hw_params(struct snd_pcm_substream *substream,
    struct snd_pcm_hw_params *params)
{
    size_t size = bf5xx_pcm_hardware.buffer_bytes_max;
    snd_pcm_lib_malloc_pages(substream, size * 4);

    return 0;
}

static int bf5xx_pcm_hw_free(struct snd_pcm_substream *substream)
{
    snd_pcm_lib_free_pages(substream);

    return 0;
}

static int bf5xx_pcm_prepare(struct snd_pcm_substream *substream)
{
    struct snd_pcm_runtime *runtime = substream->runtime;
    struct sport_device *sport = runtime->private_data;
    int fragsize_bytes = frames_to_bytes(runtime, runtime->period_size);

    fragsize_bytes /= runtime->channels;
    /* inflate the fragsize to match the dma width of SPORT */
    fragsize_bytes *= 8;

    if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
        sport_set_tx_callback(sport, bf5xx_dma_irq, substream);
        sport_config_tx_dma(sport, runtime->dma_area,
            runtime->periods, fragsize_bytes);
    } else {
        sport_set_rx_callback(sport, bf5xx_dma_irq, substream);
        sport_config_rx_dma(sport, runtime->dma_area,
            runtime->periods, fragsize_bytes);
    }

    return 0;
}

static int bf5xx_pcm_trigger(struct snd_pcm_substream *substream, int cmd)
{
    struct snd_pcm_runtime *runtime = substream->runtime;
    struct sport_device *sport = runtime->private_data;
    int ret = 0;

    switch (cmd) {
    case SNDRV_PCM_TRIGGER_START:
        if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
            sport_tx_start(sport);
        else
            sport_rx_start(sport);
        break;
    case SNDRV_PCM_TRIGGER_STOP:
    case SNDRV_PCM_TRIGGER_SUSPEND:
    case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
        if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
            sport_tx_stop(sport);
        else
            sport_rx_stop(sport);
        break;
    default:
        ret = -EINVAL;
    }

    return ret;
}

static snd_pcm_uframes_t bf5xx_pcm_pointer(struct snd_pcm_substream *substream)
{
    struct snd_pcm_runtime *runtime = substream->runtime;
    struct sport_device *sport = runtime->private_data;
    unsigned int diff;
    snd_pcm_uframes_t frames;

    if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
        diff = sport_curr_offset_tx(sport);
        frames = diff / (8*4); /* 32 bytes per frame */
    } else {
        diff = sport_curr_offset_rx(sport);
        frames = diff / (8*4);
    }
    return frames;
}

static int bf5xx_pcm_open(struct snd_pcm_substream *substream)
{
    struct snd_soc_pcm_runtime *rtd = substream->private_data;
    struct snd_soc_dai *cpu_dai = rtd->cpu_dai;
    struct sport_device *sport_handle = snd_soc_dai_get_drvdata(cpu_dai);
    struct snd_pcm_runtime *runtime = substream->runtime;
    struct snd_dma_buffer *buf = &substream->dma_buffer;

    int ret = 0;

    snd_soc_set_runtime_hwparams(substream, &bf5xx_pcm_hardware);

    ret = snd_pcm_hw_constraint_integer(runtime,
        SNDRV_PCM_HW_PARAM_PERIODS);
    if (ret < 0)
        goto out;

    if (sport_handle != NULL) {
        if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
            sport_handle->tx_buf = buf->area;
        else
            sport_handle->rx_buf = buf->area;

        runtime->private_data = sport_handle;
    } else {
        pr_err("sport_handle is NULL\n");
        ret = -ENODEV;
    }
out:
    return ret;
}

static int bf5xx_pcm_copy(struct snd_pcm_substream *substream, int channel,
    snd_pcm_uframes_t pos, void *buf, snd_pcm_uframes_t count)
{
    struct snd_pcm_runtime *runtime = substream->runtime;
    struct sport_device *sport = runtime->private_data;
    struct bf5xx_tdm_port *tdm_port = sport->private_data;
    unsigned int *src;
    unsigned int *dst;
    int i;

    if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
        src = buf;
        dst = (unsigned int *)substream->runtime->dma_area;

        dst += pos * 8;
        while (count--) {
            for (i = 0; i < substream->runtime->channels; i++)
                *(dst + tdm_port->tx_map[i]) = *src++;
            dst += 8;
        }
    } else {
        src = (unsigned int *)substream->runtime->dma_area;
        dst = buf;

        src += pos * 8;
        while (count--) {
            for (i = 0; i < substream->runtime->channels; i++)
                *dst++ = *(src + tdm_port->rx_map[i]);
            src += 8;
        }
    }

    return 0;
}

static int bf5xx_pcm_silence(struct snd_pcm_substream *substream,
    int channel, snd_pcm_uframes_t pos, snd_pcm_uframes_t count)
{
    unsigned char *buf = substream->runtime->dma_area;
    buf += pos * 8 * 4;
    memset(buf, '\0', count * 8 * 4);

    return 0;
}


struct snd_pcm_ops bf5xx_pcm_tdm_ops = {
    .open           = bf5xx_pcm_open,
    .ioctl          = snd_pcm_lib_ioctl,
    .hw_params      = bf5xx_pcm_hw_params,
    .hw_free        = bf5xx_pcm_hw_free,
    .prepare        = bf5xx_pcm_prepare,
    .trigger        = bf5xx_pcm_trigger,
    .pointer        = bf5xx_pcm_pointer,
    .copy           = bf5xx_pcm_copy,
    .silence        = bf5xx_pcm_silence,
};

static int bf5xx_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 = bf5xx_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_coherent(pcm->card->dev, size * 4,
        &buf->addr, GFP_KERNEL);
    if (!buf->area) {
        pr_err("Failed to allocate dma memory - Please increase uncached DMA memory region\n");
        return -ENOMEM;
    }
    buf->bytes = size;

    return 0;
}

static void bf5xx_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_coherent(NULL, buf->bytes, buf->area, 0);
        buf->area = NULL;
    }
}

static u64 bf5xx_pcm_dmamask = DMA_BIT_MASK(32);

static int bf5xx_pcm_tdm_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 = &bf5xx_pcm_dmamask;
    if (!card->dev->coherent_dma_mask)
        card->dev->coherent_dma_mask = DMA_BIT_MASK(32);

    if (pcm->streams[SNDRV_PCM_STREAM_PLAYBACK].substream) {
        ret = bf5xx_pcm_preallocate_dma_buffer(pcm,
            SNDRV_PCM_STREAM_PLAYBACK);
        if (ret)
            goto out;
    }

    if (pcm->streams[SNDRV_PCM_STREAM_CAPTURE].substream) {
        ret = bf5xx_pcm_preallocate_dma_buffer(pcm,
            SNDRV_PCM_STREAM_CAPTURE);
        if (ret)
            goto out;
    }
out:
    return ret;
}

static struct snd_soc_platform_driver bf5xx_tdm_soc_platform = {
    .ops        = &bf5xx_pcm_tdm_ops,
    .pcm_new        = bf5xx_pcm_tdm_new,
    .pcm_free       = bf5xx_pcm_free_dma_buffers,
};

static int __devinit bf5xx_soc_platform_probe(struct platform_device *pdev)
{
    return snd_soc_register_platform(&pdev->dev, &bf5xx_tdm_soc_platform);
}

static int __devexit bf5xx_soc_platform_remove(struct platform_device *pdev)
{
    snd_soc_unregister_platform(&pdev->dev);
    return 0;
}

static struct platform_driver bfin_tdm_driver = {
    .driver = {
            .name = "bfin-tdm-pcm-audio",
            .owner = THIS_MODULE,
    },

    .probe = bf5xx_soc_platform_probe,
    .remove = __devexit_p(bf5xx_soc_platform_remove),
};

module_platform_driver(bfin_tdm_driver);

MODULE_AUTHOR("Barry Song");
MODULE_DESCRIPTION("ADI Blackfin TDM PCM DMA module");
MODULE_LICENSE("GPL");