nuc900-pcm.c

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/*
 * Copyright (c) 2010 Nuvoton technology corporation.
 *
 * Wan ZongShun <[email protected]>
 *
 * 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;version 2 of the License.
 *
 */

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

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

#include <mach/hardware.h>

#include "nuc900-audio.h"

static const struct snd_pcm_hardware nuc900_pcm_hardware = {
    .info           = SNDRV_PCM_INFO_INTERLEAVED |
                    SNDRV_PCM_INFO_BLOCK_TRANSFER |
                    SNDRV_PCM_INFO_MMAP |
                    SNDRV_PCM_INFO_MMAP_VALID |
                    SNDRV_PCM_INFO_PAUSE |
                    SNDRV_PCM_INFO_RESUME,
    .formats        = SNDRV_PCM_FMTBIT_S16_LE,
    .channels_min       = 1,
    .channels_max       = 2,
    .buffer_bytes_max   = 4*1024,
    .period_bytes_min   = 1*1024,
    .period_bytes_max   = 4*1024,
    .periods_min        = 1,
    .periods_max        = 1024,
};

static int nuc900_dma_hw_params(struct snd_pcm_substream *substream,
    struct snd_pcm_hw_params *params)
{
    struct snd_pcm_runtime *runtime = substream->runtime;
    struct nuc900_audio *nuc900_audio = runtime->private_data;
    unsigned long flags;
    int ret = 0;

    ret = snd_pcm_lib_malloc_pages(substream, params_buffer_bytes(params));
    if (ret < 0)
        return ret;

    spin_lock_irqsave(&nuc900_audio->lock, flags);

    nuc900_audio->substream = substream;
    nuc900_audio->dma_addr[substream->stream] = runtime->dma_addr;
    nuc900_audio->buffersize[substream->stream] =
                        params_buffer_bytes(params);

    spin_unlock_irqrestore(&nuc900_audio->lock, flags);

    return ret;
}

static void nuc900_update_dma_register(struct snd_pcm_substream *substream,
                dma_addr_t dma_addr, size_t count)
{
    struct snd_pcm_runtime *runtime = substream->runtime;
    struct nuc900_audio *nuc900_audio = runtime->private_data;
    void __iomem *mmio_addr, *mmio_len;

    if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
        mmio_addr = nuc900_audio->mmio + ACTL_PDSTB;
        mmio_len = nuc900_audio->mmio + ACTL_PDST_LENGTH;
    } else {
        mmio_addr = nuc900_audio->mmio + ACTL_RDSTB;
        mmio_len = nuc900_audio->mmio + ACTL_RDST_LENGTH;
    }

    AUDIO_WRITE(mmio_addr, dma_addr);
    AUDIO_WRITE(mmio_len, count);
}

static void nuc900_dma_start(struct snd_pcm_substream *substream)
{
    struct snd_pcm_runtime *runtime = substream->runtime;
    struct nuc900_audio *nuc900_audio = runtime->private_data;
    unsigned long val;

    val = AUDIO_READ(nuc900_audio->mmio + ACTL_CON);
    val |= (T_DMA_IRQ | R_DMA_IRQ);
    AUDIO_WRITE(nuc900_audio->mmio + ACTL_CON, val);
}

static void nuc900_dma_stop(struct snd_pcm_substream *substream)
{
    struct snd_pcm_runtime *runtime = substream->runtime;
    struct nuc900_audio *nuc900_audio = runtime->private_data;
    unsigned long val;

    val = AUDIO_READ(nuc900_audio->mmio + ACTL_CON);
    val &= ~(T_DMA_IRQ | R_DMA_IRQ);
    AUDIO_WRITE(nuc900_audio->mmio + ACTL_CON, val);
}

static irqreturn_t nuc900_dma_interrupt(int irq, void *dev_id)
{
    struct snd_pcm_substream *substream = dev_id;
    struct nuc900_audio *nuc900_audio = substream->runtime->private_data;
    unsigned long val;

    spin_lock(&nuc900_audio->lock);

    val = AUDIO_READ(nuc900_audio->mmio + ACTL_CON);

    if (val & R_DMA_IRQ) {
        AUDIO_WRITE(nuc900_audio->mmio + ACTL_CON, val | R_DMA_IRQ);

        val = AUDIO_READ(nuc900_audio->mmio + ACTL_RSR);

        if (val & R_DMA_MIDDLE_IRQ) {
            val |= R_DMA_MIDDLE_IRQ;
            AUDIO_WRITE(nuc900_audio->mmio + ACTL_RSR, val);
        }

        if (val & R_DMA_END_IRQ) {
            val |= R_DMA_END_IRQ;
            AUDIO_WRITE(nuc900_audio->mmio + ACTL_RSR, val);
        }
    } else if (val & T_DMA_IRQ) {
        AUDIO_WRITE(nuc900_audio->mmio + ACTL_CON, val | T_DMA_IRQ);

        val = AUDIO_READ(nuc900_audio->mmio + ACTL_PSR);

        if (val & P_DMA_MIDDLE_IRQ) {
            val |= P_DMA_MIDDLE_IRQ;
            AUDIO_WRITE(nuc900_audio->mmio + ACTL_PSR, val);
        }

        if (val & P_DMA_END_IRQ) {
            val |= P_DMA_END_IRQ;
            AUDIO_WRITE(nuc900_audio->mmio + ACTL_PSR, val);
        }
    } else {
        dev_err(nuc900_audio->dev, "Wrong DMA interrupt status!\n");
        spin_unlock(&nuc900_audio->lock);
        return IRQ_HANDLED;
    }

    spin_unlock(&nuc900_audio->lock);

    snd_pcm_period_elapsed(substream);

    return IRQ_HANDLED;
}

static int nuc900_dma_hw_free(struct snd_pcm_substream *substream)
{
    snd_pcm_lib_free_pages(substream);
    return 0;
}

static int nuc900_dma_prepare(struct snd_pcm_substream *substream)
{
    struct snd_pcm_runtime *runtime = substream->runtime;
    struct nuc900_audio *nuc900_audio = runtime->private_data;
    unsigned long flags, val;
    int ret = 0;

    spin_lock_irqsave(&nuc900_audio->lock, flags);

    nuc900_update_dma_register(substream,
                nuc900_audio->dma_addr[substream->stream],
                nuc900_audio->buffersize[substream->stream]);

    val = AUDIO_READ(nuc900_audio->mmio + ACTL_RESET);

    switch (runtime->channels) {
    case 1:
        if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
            val &= ~(PLAY_LEFT_CHNNEL | PLAY_RIGHT_CHNNEL);
            val |= PLAY_RIGHT_CHNNEL;
        } else {
            val &= ~(RECORD_LEFT_CHNNEL | RECORD_RIGHT_CHNNEL);
            val |= RECORD_RIGHT_CHNNEL;
        }
        AUDIO_WRITE(nuc900_audio->mmio + ACTL_RESET, val);
        break;
    case 2:
        if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
            val |= (PLAY_LEFT_CHNNEL | PLAY_RIGHT_CHNNEL);
        else
            val |= (RECORD_LEFT_CHNNEL | RECORD_RIGHT_CHNNEL);
        AUDIO_WRITE(nuc900_audio->mmio + ACTL_RESET, val);
        break;
    default:
        ret = -EINVAL;
    }
    spin_unlock_irqrestore(&nuc900_audio->lock, flags);
    return ret;
}

static int nuc900_dma_trigger(struct snd_pcm_substream *substream, int cmd)
{
    int ret = 0;

    switch (cmd) {
    case SNDRV_PCM_TRIGGER_START:
    case SNDRV_PCM_TRIGGER_RESUME:
        nuc900_dma_start(substream);
        break;

    case SNDRV_PCM_TRIGGER_STOP:
    case SNDRV_PCM_TRIGGER_SUSPEND:
        nuc900_dma_stop(substream);
        break;

    default:
        ret = -EINVAL;
        break;
    }

    return ret;
}

static int nuc900_dma_getposition(struct snd_pcm_substream *substream,
                    dma_addr_t *src, dma_addr_t *dst)
{
    struct snd_pcm_runtime *runtime = substream->runtime;
    struct nuc900_audio *nuc900_audio = runtime->private_data;

    if (src != NULL)
        *src = AUDIO_READ(nuc900_audio->mmio + ACTL_PDSTC);

    if (dst != NULL)
        *dst = AUDIO_READ(nuc900_audio->mmio + ACTL_RDSTC);

    return 0;
}

static snd_pcm_uframes_t nuc900_dma_pointer(struct snd_pcm_substream *substream)
{
    struct snd_pcm_runtime *runtime = substream->runtime;
    dma_addr_t src, dst;
    unsigned long res;

    nuc900_dma_getposition(substream, &src, &dst);

    if (substream->stream == SNDRV_PCM_STREAM_CAPTURE)
        res = dst - runtime->dma_addr;
    else
        res = src - runtime->dma_addr;

    return bytes_to_frames(substream->runtime, res);
}

static int nuc900_dma_open(struct snd_pcm_substream *substream)
{
    struct snd_pcm_runtime *runtime = substream->runtime;
    struct nuc900_audio *nuc900_audio;

    snd_soc_set_runtime_hwparams(substream, &nuc900_pcm_hardware);

    nuc900_audio = nuc900_ac97_data;

    if (request_irq(nuc900_audio->irq_num, nuc900_dma_interrupt,
            0, "nuc900-dma", substream))
        return -EBUSY;

    runtime->private_data = nuc900_audio;

    return 0;
}

static int nuc900_dma_close(struct snd_pcm_substream *substream)
{
    struct snd_pcm_runtime *runtime = substream->runtime;
    struct nuc900_audio *nuc900_audio = runtime->private_data;

    free_irq(nuc900_audio->irq_num, substream);

    return 0;
}

static int nuc900_dma_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 nuc900_dma_ops = {
    .open       = nuc900_dma_open,
    .close      = nuc900_dma_close,
    .ioctl      = snd_pcm_lib_ioctl,
    .hw_params  = nuc900_dma_hw_params,
    .hw_free    = nuc900_dma_hw_free,
    .prepare    = nuc900_dma_prepare,
    .trigger    = nuc900_dma_trigger,
    .pointer    = nuc900_dma_pointer,
    .mmap       = nuc900_dma_mmap,
};

static void nuc900_dma_free_dma_buffers(struct snd_pcm *pcm)
{
    snd_pcm_lib_preallocate_free_for_all(pcm);
}

static u64 nuc900_pcm_dmamask = DMA_BIT_MASK(32);
static int nuc900_dma_new(struct snd_soc_pcm_runtime *rtd)
{
    struct snd_card *card = rtd->card->snd_card;
    struct snd_pcm *pcm = rtd->pcm;

    if (!card->dev->dma_mask)
        card->dev->dma_mask = &nuc900_pcm_dmamask;
    if (!card->dev->coherent_dma_mask)
        card->dev->coherent_dma_mask = DMA_BIT_MASK(32);

    snd_pcm_lib_preallocate_pages_for_all(pcm, SNDRV_DMA_TYPE_DEV,
        card->dev, 4 * 1024, (4 * 1024) - 1);

    return 0;
}

static struct snd_soc_platform_driver nuc900_soc_platform = {
    .ops        = &nuc900_dma_ops,
    .pcm_new    = nuc900_dma_new,
    .pcm_free   = nuc900_dma_free_dma_buffers,
};

static int __devinit nuc900_soc_platform_probe(struct platform_device *pdev)
{
    return snd_soc_register_platform(&pdev->dev, &nuc900_soc_platform);
}

static int __devexit nuc900_soc_platform_remove(struct platform_device *pdev)
{
    snd_soc_unregister_platform(&pdev->dev);
    return 0;
}

static struct platform_driver nuc900_pcm_driver = {
    .driver = {
            .name = "nuc900-pcm-audio",
            .owner = THIS_MODULE,
    },

    .probe = nuc900_soc_platform_probe,
    .remove = __devexit_p(nuc900_soc_platform_remove),
};

module_platform_driver(nuc900_pcm_driver);

MODULE_AUTHOR("Wan ZongShun, <[email protected]>");
MODULE_DESCRIPTION("nuc900 Audio DMA module");
MODULE_LICENSE("GPL");