txx9aclc.c

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/*
 * Generic TXx9 ACLC platform driver
 *
 * Copyright (C) 2009 Atsushi Nemoto
 *
 * Based on RBTX49xx patch from CELF patch archive.
 * (C) Copyright TOSHIBA CORPORATION 2004-2006
 *
 * 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.
 */

#include <linux/module.h>
#include <linux/init.h>
#include <linux/platform_device.h>
#include <linux/scatterlist.h>
#include <linux/slab.h>
#include <sound/core.h>
#include <sound/pcm.h>
#include <sound/pcm_params.h>
#include <sound/soc.h>
#include "txx9aclc.h"

static struct txx9aclc_soc_device {
    struct txx9aclc_dmadata dmadata[2];
} txx9aclc_soc_device;

/* REVISIT: How to find txx9aclc_drvdata from snd_ac97? */
static struct txx9aclc_plat_drvdata *txx9aclc_drvdata;

static int txx9aclc_dma_init(struct txx9aclc_soc_device *dev,
                 struct txx9aclc_dmadata *dmadata);

static const struct snd_pcm_hardware txx9aclc_pcm_hardware = {
    /*
     * REVISIT: SNDRV_PCM_INFO_MMAP | SNDRV_PCM_INFO_MMAP_VALID
     * needs more works for noncoherent MIPS.
     */
    .info         = SNDRV_PCM_INFO_INTERLEAVED |
                SNDRV_PCM_INFO_BATCH |
                SNDRV_PCM_INFO_PAUSE,
#ifdef __BIG_ENDIAN
    .formats      = SNDRV_PCM_FMTBIT_S16_BE,
#else
    .formats      = SNDRV_PCM_FMTBIT_S16_LE,
#endif
    .period_bytes_min = 1024,
    .period_bytes_max = 8 * 1024,
    .periods_min      = 2,
    .periods_max      = 4096,
    .buffer_bytes_max = 32 * 1024,
};

static int txx9aclc_pcm_hw_params(struct snd_pcm_substream *substream,
                  struct snd_pcm_hw_params *params)
{
    struct snd_soc_pcm_runtime *rtd = snd_pcm_substream_chip(substream);
    struct snd_pcm_runtime *runtime = substream->runtime;
    struct txx9aclc_dmadata *dmadata = runtime->private_data;
    int ret;

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

    dev_dbg(rtd->platform->dev,
        "runtime->dma_area = %#lx dma_addr = %#lx dma_bytes = %zd "
        "runtime->min_align %ld\n",
        (unsigned long)runtime->dma_area,
        (unsigned long)runtime->dma_addr, runtime->dma_bytes,
        runtime->min_align);
    dev_dbg(rtd->platform->dev,
        "periods %d period_bytes %d stream %d\n",
        params_periods(params), params_period_bytes(params),
        substream->stream);

    dmadata->substream = substream;
    dmadata->pos = 0;
    return 0;
}

static int txx9aclc_pcm_hw_free(struct snd_pcm_substream *substream)
{
    return snd_pcm_lib_free_pages(substream);
}

static int txx9aclc_pcm_prepare(struct snd_pcm_substream *substream)
{
    struct snd_pcm_runtime *runtime = substream->runtime;
    struct txx9aclc_dmadata *dmadata = runtime->private_data;

    dmadata->dma_addr = runtime->dma_addr;
    dmadata->buffer_bytes = snd_pcm_lib_buffer_bytes(substream);
    dmadata->period_bytes = snd_pcm_lib_period_bytes(substream);

    if (dmadata->buffer_bytes == dmadata->period_bytes) {
        dmadata->frag_bytes = dmadata->period_bytes >> 1;
        dmadata->frags = 2;
    } else {
        dmadata->frag_bytes = dmadata->period_bytes;
        dmadata->frags = dmadata->buffer_bytes / dmadata->period_bytes;
    }
    dmadata->frag_count = 0;
    dmadata->pos = 0;
    return 0;
}

static void txx9aclc_dma_complete(void *arg)
{
    struct txx9aclc_dmadata *dmadata = arg;
    unsigned long flags;

    /* dma completion handler cannot submit new operations */
    spin_lock_irqsave(&dmadata->dma_lock, flags);
    if (dmadata->frag_count >= 0) {
        dmadata->dmacount--;
        BUG_ON(dmadata->dmacount < 0);
        tasklet_schedule(&dmadata->tasklet);
    }
    spin_unlock_irqrestore(&dmadata->dma_lock, flags);
}

static struct dma_async_tx_descriptor *
txx9aclc_dma_submit(struct txx9aclc_dmadata *dmadata, dma_addr_t buf_dma_addr)
{
    struct dma_chan *chan = dmadata->dma_chan;
    struct dma_async_tx_descriptor *desc;
    struct scatterlist sg;

    sg_init_table(&sg, 1);
    sg_set_page(&sg, pfn_to_page(PFN_DOWN(buf_dma_addr)),
            dmadata->frag_bytes, buf_dma_addr & (PAGE_SIZE - 1));
    sg_dma_address(&sg) = buf_dma_addr;
    desc = dmaengine_prep_slave_sg(chan, &sg, 1,
        dmadata->substream->stream == SNDRV_PCM_STREAM_PLAYBACK ?
        DMA_MEM_TO_DEV : DMA_DEV_TO_MEM,
        DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
    if (!desc) {
        dev_err(&chan->dev->device, "cannot prepare slave dma\n");
        return NULL;
    }
    desc->callback = txx9aclc_dma_complete;
    desc->callback_param = dmadata;
    desc->tx_submit(desc);
    return desc;
}

#define NR_DMA_CHAIN        2

static void txx9aclc_dma_tasklet(unsigned long data)
{
    struct txx9aclc_dmadata *dmadata = (struct txx9aclc_dmadata *)data;
    struct dma_chan *chan = dmadata->dma_chan;
    struct dma_async_tx_descriptor *desc;
    struct snd_pcm_substream *substream = dmadata->substream;
    u32 ctlbit = substream->stream == SNDRV_PCM_STREAM_PLAYBACK ?
        ACCTL_AUDODMA : ACCTL_AUDIDMA;
    int i;
    unsigned long flags;

    spin_lock_irqsave(&dmadata->dma_lock, flags);
    if (dmadata->frag_count < 0) {
        struct txx9aclc_plat_drvdata *drvdata = txx9aclc_drvdata;
        void __iomem *base = drvdata->base;

        spin_unlock_irqrestore(&dmadata->dma_lock, flags);
        chan->device->device_control(chan, DMA_TERMINATE_ALL, 0);
        /* first time */
        for (i = 0; i < NR_DMA_CHAIN; i++) {
            desc = txx9aclc_dma_submit(dmadata,
                dmadata->dma_addr + i * dmadata->frag_bytes);
            if (!desc)
                return;
        }
        dmadata->dmacount = NR_DMA_CHAIN;
        chan->device->device_issue_pending(chan);
        spin_lock_irqsave(&dmadata->dma_lock, flags);
        __raw_writel(ctlbit, base + ACCTLEN);
        dmadata->frag_count = NR_DMA_CHAIN % dmadata->frags;
        spin_unlock_irqrestore(&dmadata->dma_lock, flags);
        return;
    }
    BUG_ON(dmadata->dmacount >= NR_DMA_CHAIN);
    while (dmadata->dmacount < NR_DMA_CHAIN) {
        dmadata->dmacount++;
        spin_unlock_irqrestore(&dmadata->dma_lock, flags);
        desc = txx9aclc_dma_submit(dmadata,
            dmadata->dma_addr +
            dmadata->frag_count * dmadata->frag_bytes);
        if (!desc)
            return;
        chan->device->device_issue_pending(chan);

        spin_lock_irqsave(&dmadata->dma_lock, flags);
        dmadata->frag_count++;
        dmadata->frag_count %= dmadata->frags;
        dmadata->pos += dmadata->frag_bytes;
        dmadata->pos %= dmadata->buffer_bytes;
        if ((dmadata->frag_count * dmadata->frag_bytes) %
            dmadata->period_bytes == 0)
            snd_pcm_period_elapsed(substream);
    }
    spin_unlock_irqrestore(&dmadata->dma_lock, flags);
}

static int txx9aclc_pcm_trigger(struct snd_pcm_substream *substream, int cmd)
{
    struct txx9aclc_dmadata *dmadata = substream->runtime->private_data;
    struct txx9aclc_plat_drvdata *drvdata =txx9aclc_drvdata;
    void __iomem *base = drvdata->base;
    unsigned long flags;
    int ret = 0;
    u32 ctlbit = substream->stream == SNDRV_PCM_STREAM_PLAYBACK ?
        ACCTL_AUDODMA : ACCTL_AUDIDMA;

    spin_lock_irqsave(&dmadata->dma_lock, flags);
    switch (cmd) {
    case SNDRV_PCM_TRIGGER_START:
        dmadata->frag_count = -1;
        tasklet_schedule(&dmadata->tasklet);
        break;
    case SNDRV_PCM_TRIGGER_STOP:
    case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
    case SNDRV_PCM_TRIGGER_SUSPEND:
        __raw_writel(ctlbit, base + ACCTLDIS);
        break;
    case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
    case SNDRV_PCM_TRIGGER_RESUME:
        __raw_writel(ctlbit, base + ACCTLEN);
        break;
    default:
        ret = -EINVAL;
    }
    spin_unlock_irqrestore(&dmadata->dma_lock, flags);
    return ret;
}

static snd_pcm_uframes_t
txx9aclc_pcm_pointer(struct snd_pcm_substream *substream)
{
    struct txx9aclc_dmadata *dmadata = substream->runtime->private_data;

    return bytes_to_frames(substream->runtime, dmadata->pos);
}

static int txx9aclc_pcm_open(struct snd_pcm_substream *substream)
{
    struct txx9aclc_soc_device *dev = &txx9aclc_soc_device;
    struct txx9aclc_dmadata *dmadata = &dev->dmadata[substream->stream];
    int ret;

    ret = snd_soc_set_runtime_hwparams(substream, &txx9aclc_pcm_hardware);
    if (ret)
        return ret;
    /* ensure that buffer size is a multiple of period size */
    ret = snd_pcm_hw_constraint_integer(substream->runtime,
                        SNDRV_PCM_HW_PARAM_PERIODS);
    if (ret < 0)
        return ret;
    substream->runtime->private_data = dmadata;
    return 0;
}

static int txx9aclc_pcm_close(struct snd_pcm_substream *substream)
{
    struct txx9aclc_dmadata *dmadata = substream->runtime->private_data;
    struct dma_chan *chan = dmadata->dma_chan;

    dmadata->frag_count = -1;
    chan->device->device_control(chan, DMA_TERMINATE_ALL, 0);
    return 0;
}

static struct snd_pcm_ops txx9aclc_pcm_ops = {
    .open       = txx9aclc_pcm_open,
    .close      = txx9aclc_pcm_close,
    .ioctl      = snd_pcm_lib_ioctl,
    .hw_params  = txx9aclc_pcm_hw_params,
    .hw_free    = txx9aclc_pcm_hw_free,
    .prepare    = txx9aclc_pcm_prepare,
    .trigger    = txx9aclc_pcm_trigger,
    .pointer    = txx9aclc_pcm_pointer,
};

static void txx9aclc_pcm_free_dma_buffers(struct snd_pcm *pcm)
{
    snd_pcm_lib_preallocate_free_for_all(pcm);
}

static int txx9aclc_pcm_new(struct snd_soc_pcm_runtime *rtd)
{
    struct snd_card *card = rtd->card->snd_card;
    struct snd_soc_dai *dai = rtd->cpu_dai;
    struct snd_pcm *pcm = rtd->pcm;
    struct platform_device *pdev = to_platform_device(dai->platform->dev);
    struct txx9aclc_soc_device *dev;
    struct resource *r;
    int i;
    int ret;

    /* at this point onwards the AC97 component has probed and this will be valid */
    dev = snd_soc_dai_get_drvdata(dai);

    dev->dmadata[0].stream = SNDRV_PCM_STREAM_PLAYBACK;
    dev->dmadata[1].stream = SNDRV_PCM_STREAM_CAPTURE;
    for (i = 0; i < 2; i++) {
        r = platform_get_resource(pdev, IORESOURCE_DMA, i);
        if (!r) {
            ret = -EBUSY;
            goto exit;
        }
        dev->dmadata[i].dma_res = r;
        ret = txx9aclc_dma_init(dev, &dev->dmadata[i]);
        if (ret)
            goto exit;
    }
    return snd_pcm_lib_preallocate_pages_for_all(pcm, SNDRV_DMA_TYPE_DEV,
        card->dev, 64 * 1024, 4 * 1024 * 1024);

exit:
    for (i = 0; i < 2; i++) {
        if (dev->dmadata[i].dma_chan)
            dma_release_channel(dev->dmadata[i].dma_chan);
        dev->dmadata[i].dma_chan = NULL;
    }
    return ret;
}

static bool filter(struct dma_chan *chan, void *param)
{
    struct txx9aclc_dmadata *dmadata = param;
    char *devname;
    bool found = false;

    devname = kasprintf(GFP_KERNEL, "%s.%d", dmadata->dma_res->name,
        (int)dmadata->dma_res->start);
    if (strcmp(dev_name(chan->device->dev), devname) == 0) {
        chan->private = &dmadata->dma_slave;
        found = true;
    }
    kfree(devname);
    return found;
}

static int txx9aclc_dma_init(struct txx9aclc_soc_device *dev,
                 struct txx9aclc_dmadata *dmadata)
{
    struct txx9aclc_plat_drvdata *drvdata =txx9aclc_drvdata;
    struct txx9dmac_slave *ds = &dmadata->dma_slave;
    dma_cap_mask_t mask;

    spin_lock_init(&dmadata->dma_lock);

    ds->reg_width = sizeof(u32);
    if (dmadata->stream == SNDRV_PCM_STREAM_PLAYBACK) {
        ds->tx_reg = drvdata->physbase + ACAUDODAT;
        ds->rx_reg = 0;
    } else {
        ds->tx_reg = 0;
        ds->rx_reg = drvdata->physbase + ACAUDIDAT;
    }

    /* Try to grab a DMA channel */
    dma_cap_zero(mask);
    dma_cap_set(DMA_SLAVE, mask);
    dmadata->dma_chan = dma_request_channel(mask, filter, dmadata);
    if (!dmadata->dma_chan) {
        printk(KERN_ERR
            "DMA channel for %s is not available\n",
            dmadata->stream == SNDRV_PCM_STREAM_PLAYBACK ?
            "playback" : "capture");
        return -EBUSY;
    }
    tasklet_init(&dmadata->tasklet, txx9aclc_dma_tasklet,
             (unsigned long)dmadata);
    return 0;
}

static int txx9aclc_pcm_probe(struct snd_soc_platform *platform)
{
    snd_soc_platform_set_drvdata(platform, &txx9aclc_soc_device);
    return 0;
}

static int txx9aclc_pcm_remove(struct snd_soc_platform *platform)
{
    struct txx9aclc_soc_device *dev = snd_soc_platform_get_drvdata(platform);
    struct txx9aclc_plat_drvdata *drvdata = txx9aclc_drvdata;
    void __iomem *base = drvdata->base;
    int i;

    /* disable all FIFO DMAs */
    __raw_writel(ACCTL_AUDODMA | ACCTL_AUDIDMA, base + ACCTLDIS);
    /* dummy R/W to clear pending DMAREQ if any */
    __raw_writel(__raw_readl(base + ACAUDIDAT), base + ACAUDODAT);

    for (i = 0; i < 2; i++) {
        struct txx9aclc_dmadata *dmadata = &dev->dmadata[i];
        struct dma_chan *chan = dmadata->dma_chan;
        if (chan) {
            dmadata->frag_count = -1;
            chan->device->device_control(chan,
                             DMA_TERMINATE_ALL, 0);
            dma_release_channel(chan);
        }
        dev->dmadata[i].dma_chan = NULL;
    }
    return 0;
}

static struct snd_soc_platform_driver txx9aclc_soc_platform = {
    .probe      = txx9aclc_pcm_probe,
    .remove     = txx9aclc_pcm_remove,
    .ops        = &txx9aclc_pcm_ops,
    .pcm_new    = txx9aclc_pcm_new,
    .pcm_free   = txx9aclc_pcm_free_dma_buffers,
};

static int __devinit txx9aclc_soc_platform_probe(struct platform_device *pdev)
{
    return snd_soc_register_platform(&pdev->dev, &txx9aclc_soc_platform);
}

static int __devexit txx9aclc_soc_platform_remove(struct platform_device *pdev)
{
    snd_soc_unregister_platform(&pdev->dev);
    return 0;
}

static struct platform_driver txx9aclc_pcm_driver = {
    .driver = {
            .name = "txx9aclc-pcm-audio",
            .owner = THIS_MODULE,
    },

    .probe = txx9aclc_soc_platform_probe,
    .remove = __devexit_p(txx9aclc_soc_platform_remove),
};

module_platform_driver(txx9aclc_pcm_driver);

MODULE_AUTHOR("Atsushi Nemoto <[email protected]>");
MODULE_DESCRIPTION("TXx9 ACLC Audio DMA driver");
MODULE_LICENSE("GPL");