psc-i2s.c

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/*
 * Au12x0/Au1550 PSC ALSA ASoC audio support.
 *
 * (c) 2007-2008 MSC Vertriebsges.m.b.H.,
 *  Manuel Lauss <[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.
 *
 * Au1xxx-PSC I2S glue.
 *
 * NOTE: so far only PSC slave mode (bit- and frameclock) is supported.
 */

#include <linux/init.h>
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/suspend.h>
#include <sound/core.h>
#include <sound/pcm.h>
#include <sound/initval.h>
#include <sound/soc.h>
#include <asm/mach-au1x00/au1000.h>
#include <asm/mach-au1x00/au1xxx_psc.h>

#include "psc.h"

/* supported I2S DAI hardware formats */
#define AU1XPSC_I2S_DAIFMT \
    (SND_SOC_DAIFMT_I2S | SND_SOC_DAIFMT_LEFT_J |   \
     SND_SOC_DAIFMT_NB_NF)

/* supported I2S direction */
#define AU1XPSC_I2S_DIR \
    (SND_SOC_DAIDIR_PLAYBACK | SND_SOC_DAIDIR_CAPTURE)

#define AU1XPSC_I2S_RATES \
    SNDRV_PCM_RATE_8000_192000

#define AU1XPSC_I2S_FMTS \
    (SNDRV_PCM_FMTBIT_S16_LE | SNDRV_PCM_FMTBIT_S24_LE)

#define I2SSTAT_BUSY(stype) \
    ((stype) == SNDRV_PCM_STREAM_PLAYBACK ? PSC_I2SSTAT_TB : PSC_I2SSTAT_RB)
#define I2SPCR_START(stype) \
    ((stype) == SNDRV_PCM_STREAM_PLAYBACK ? PSC_I2SPCR_TS : PSC_I2SPCR_RS)
#define I2SPCR_STOP(stype)  \
    ((stype) == SNDRV_PCM_STREAM_PLAYBACK ? PSC_I2SPCR_TP : PSC_I2SPCR_RP)
#define I2SPCR_CLRFIFO(stype)   \
    ((stype) == SNDRV_PCM_STREAM_PLAYBACK ? PSC_I2SPCR_TC : PSC_I2SPCR_RC)


static int au1xpsc_i2s_set_fmt(struct snd_soc_dai *cpu_dai,
                   unsigned int fmt)
{
    struct au1xpsc_audio_data *pscdata = snd_soc_dai_get_drvdata(cpu_dai);
    unsigned long ct;
    int ret;

    ret = -EINVAL;

    ct = pscdata->cfg;

    ct &= ~(PSC_I2SCFG_XM | PSC_I2SCFG_MLJ);    /* left-justified */
    switch (fmt & SND_SOC_DAIFMT_FORMAT_MASK) {
    case SND_SOC_DAIFMT_I2S:
        ct |= PSC_I2SCFG_XM;    /* enable I2S mode */
        break;
    case SND_SOC_DAIFMT_MSB:
        break;
    case SND_SOC_DAIFMT_LSB:
        ct |= PSC_I2SCFG_MLJ;   /* LSB (right-) justified */
        break;
    default:
        goto out;
    }

    ct &= ~(PSC_I2SCFG_BI | PSC_I2SCFG_WI);     /* IB-IF */
    switch (fmt & SND_SOC_DAIFMT_INV_MASK) {
    case SND_SOC_DAIFMT_NB_NF:
        ct |= PSC_I2SCFG_BI | PSC_I2SCFG_WI;
        break;
    case SND_SOC_DAIFMT_NB_IF:
        ct |= PSC_I2SCFG_BI;
        break;
    case SND_SOC_DAIFMT_IB_NF:
        ct |= PSC_I2SCFG_WI;
        break;
    case SND_SOC_DAIFMT_IB_IF:
        break;
    default:
        goto out;
    }

    switch (fmt & SND_SOC_DAIFMT_MASTER_MASK) {
    case SND_SOC_DAIFMT_CBM_CFM:    /* CODEC master */
        ct |= PSC_I2SCFG_MS;    /* PSC I2S slave mode */
        break;
    case SND_SOC_DAIFMT_CBS_CFS:    /* CODEC slave */
        ct &= ~PSC_I2SCFG_MS;   /* PSC I2S Master mode */
        break;
    default:
        goto out;
    }

    pscdata->cfg = ct;
    ret = 0;
out:
    return ret;
}

static int au1xpsc_i2s_hw_params(struct snd_pcm_substream *substream,
                 struct snd_pcm_hw_params *params,
                 struct snd_soc_dai *dai)
{
    struct au1xpsc_audio_data *pscdata = snd_soc_dai_get_drvdata(dai);

    int cfgbits;
    unsigned long stat;

    /* check if the PSC is already streaming data */
    stat = au_readl(I2S_STAT(pscdata));
    if (stat & (PSC_I2SSTAT_TB | PSC_I2SSTAT_RB)) {
        /* reject parameters not currently set up in hardware */
        cfgbits = au_readl(I2S_CFG(pscdata));
        if ((PSC_I2SCFG_GET_LEN(cfgbits) != params->msbits) ||
            (params_rate(params) != pscdata->rate))
            return -EINVAL;
    } else {
        /* set sample bitdepth */
        pscdata->cfg &= ~(0x1f << 4);
        pscdata->cfg |= PSC_I2SCFG_SET_LEN(params->msbits);
        /* remember current rate for other stream */
        pscdata->rate = params_rate(params);
    }
    return 0;
}

/* Configure PSC late:  on my devel systems the codec  is I2S master and
 * supplies the i2sbitclock __AND__ i2sMclk (!) to the PSC unit.  ASoC
 * uses aggressive PM and  switches the codec off  when it is not in use
 * which also means the PSC unit doesn't get any clocks and is therefore
 * dead. That's why this chunk here gets called from the trigger callback
 * because I can be reasonably certain the codec is driving the clocks.
 */
static int au1xpsc_i2s_configure(struct au1xpsc_audio_data *pscdata)
{
    unsigned long tmo;

    /* bring PSC out of sleep, and configure I2S unit */
    au_writel(PSC_CTRL_ENABLE, PSC_CTRL(pscdata));
    au_sync();

    tmo = 1000000;
    while (!(au_readl(I2S_STAT(pscdata)) & PSC_I2SSTAT_SR) && tmo)
        tmo--;

    if (!tmo)
        goto psc_err;

    au_writel(0, I2S_CFG(pscdata));
    au_sync();
    au_writel(pscdata->cfg | PSC_I2SCFG_DE_ENABLE, I2S_CFG(pscdata));
    au_sync();

    /* wait for I2S controller to become ready */
    tmo = 1000000;
    while (!(au_readl(I2S_STAT(pscdata)) & PSC_I2SSTAT_DR) && tmo)
        tmo--;

    if (tmo)
        return 0;

psc_err:
    au_writel(0, I2S_CFG(pscdata));
    au_writel(PSC_CTRL_SUSPEND, PSC_CTRL(pscdata));
    au_sync();
    return -ETIMEDOUT;
}

static int au1xpsc_i2s_start(struct au1xpsc_audio_data *pscdata, int stype)
{
    unsigned long tmo, stat;
    int ret;

    ret = 0;

    /* if both TX and RX are idle, configure the PSC  */
    stat = au_readl(I2S_STAT(pscdata));
    if (!(stat & (PSC_I2SSTAT_TB | PSC_I2SSTAT_RB))) {
        ret = au1xpsc_i2s_configure(pscdata);
        if (ret)
            goto out;
    }

    au_writel(I2SPCR_CLRFIFO(stype), I2S_PCR(pscdata));
    au_sync();
    au_writel(I2SPCR_START(stype), I2S_PCR(pscdata));
    au_sync();

    /* wait for start confirmation */
    tmo = 1000000;
    while (!(au_readl(I2S_STAT(pscdata)) & I2SSTAT_BUSY(stype)) && tmo)
        tmo--;

    if (!tmo) {
        au_writel(I2SPCR_STOP(stype), I2S_PCR(pscdata));
        au_sync();
        ret = -ETIMEDOUT;
    }
out:
    return ret;
}

static int au1xpsc_i2s_stop(struct au1xpsc_audio_data *pscdata, int stype)
{
    unsigned long tmo, stat;

    au_writel(I2SPCR_STOP(stype), I2S_PCR(pscdata));
    au_sync();

    /* wait for stop confirmation */
    tmo = 1000000;
    while ((au_readl(I2S_STAT(pscdata)) & I2SSTAT_BUSY(stype)) && tmo)
        tmo--;

    /* if both TX and RX are idle, disable PSC */
    stat = au_readl(I2S_STAT(pscdata));
    if (!(stat & (PSC_I2SSTAT_TB | PSC_I2SSTAT_RB))) {
        au_writel(0, I2S_CFG(pscdata));
        au_sync();
        au_writel(PSC_CTRL_SUSPEND, PSC_CTRL(pscdata));
        au_sync();
    }
    return 0;
}

static int au1xpsc_i2s_trigger(struct snd_pcm_substream *substream, int cmd,
                   struct snd_soc_dai *dai)
{
    struct au1xpsc_audio_data *pscdata = snd_soc_dai_get_drvdata(dai);
    int ret, stype = substream->stream;

    switch (cmd) {
    case SNDRV_PCM_TRIGGER_START:
    case SNDRV_PCM_TRIGGER_RESUME:
        ret = au1xpsc_i2s_start(pscdata, stype);
        break;
    case SNDRV_PCM_TRIGGER_STOP:
    case SNDRV_PCM_TRIGGER_SUSPEND:
        ret = au1xpsc_i2s_stop(pscdata, stype);
        break;
    default:
        ret = -EINVAL;
    }
    return ret;
}

static int au1xpsc_i2s_startup(struct snd_pcm_substream *substream,
                   struct snd_soc_dai *dai)
{
    struct au1xpsc_audio_data *pscdata = snd_soc_dai_get_drvdata(dai);
    snd_soc_dai_set_dma_data(dai, substream, &pscdata->dmaids[0]);
    return 0;
}

static const struct snd_soc_dai_ops au1xpsc_i2s_dai_ops = {
    .startup    = au1xpsc_i2s_startup,
    .trigger    = au1xpsc_i2s_trigger,
    .hw_params  = au1xpsc_i2s_hw_params,
    .set_fmt    = au1xpsc_i2s_set_fmt,
};

static const struct snd_soc_dai_driver au1xpsc_i2s_dai_template = {
    .playback = {
        .rates      = AU1XPSC_I2S_RATES,
        .formats    = AU1XPSC_I2S_FMTS,
        .channels_min   = 2,
        .channels_max   = 8,    /* 2 without external help */
    },
    .capture = {
        .rates      = AU1XPSC_I2S_RATES,
        .formats    = AU1XPSC_I2S_FMTS,
        .channels_min   = 2,
        .channels_max   = 8,    /* 2 without external help */
    },
    .ops = &au1xpsc_i2s_dai_ops,
};

static int __devinit au1xpsc_i2s_drvprobe(struct platform_device *pdev)
{
    struct resource *iores, *dmares;
    unsigned long sel;
    int ret;
    struct au1xpsc_audio_data *wd;

    wd = devm_kzalloc(&pdev->dev, sizeof(struct au1xpsc_audio_data),
              GFP_KERNEL);
    if (!wd)
        return -ENOMEM;

    iores = platform_get_resource(pdev, IORESOURCE_MEM, 0);
    if (!iores)
        return -ENODEV;

    ret = -EBUSY;
    if (!devm_request_mem_region(&pdev->dev, iores->start,
                     resource_size(iores),
                     pdev->name))
        return -EBUSY;

    wd->mmio = devm_ioremap(&pdev->dev, iores->start,
                resource_size(iores));
    if (!wd->mmio)
        return -EBUSY;

    dmares = platform_get_resource(pdev, IORESOURCE_DMA, 0);
    if (!dmares)
        return -EBUSY;
    wd->dmaids[SNDRV_PCM_STREAM_PLAYBACK] = dmares->start;

    dmares = platform_get_resource(pdev, IORESOURCE_DMA, 1);
    if (!dmares)
        return -EBUSY;
    wd->dmaids[SNDRV_PCM_STREAM_CAPTURE] = dmares->start;

    /* preserve PSC clock source set up by platform (dev.platform_data
     * is already occupied by soc layer)
     */
    sel = au_readl(PSC_SEL(wd)) & PSC_SEL_CLK_MASK;
    au_writel(PSC_CTRL_DISABLE, PSC_CTRL(wd));
    au_sync();
    au_writel(PSC_SEL_PS_I2SMODE | sel, PSC_SEL(wd));
    au_writel(0, I2S_CFG(wd));
    au_sync();

    /* preconfigure: set max rx/tx fifo depths */
    wd->cfg |= PSC_I2SCFG_RT_FIFO8 | PSC_I2SCFG_TT_FIFO8;

    /* don't wait for I2S core to become ready now; clocks may not
     * be running yet; depending on clock input for PSC a wait might
     * time out.
     */

    /* name the DAI like this device instance ("au1xpsc-i2s.PSCINDEX") */
    memcpy(&wd->dai_drv, &au1xpsc_i2s_dai_template,
           sizeof(struct snd_soc_dai_driver));
    wd->dai_drv.name = dev_name(&pdev->dev);

    platform_set_drvdata(pdev, wd);

    return snd_soc_register_dai(&pdev->dev, &wd->dai_drv);
}

static int __devexit au1xpsc_i2s_drvremove(struct platform_device *pdev)
{
    struct au1xpsc_audio_data *wd = platform_get_drvdata(pdev);

    snd_soc_unregister_dai(&pdev->dev);

    au_writel(0, I2S_CFG(wd));
    au_sync();
    au_writel(PSC_CTRL_DISABLE, PSC_CTRL(wd));
    au_sync();

    return 0;
}

#ifdef CONFIG_PM
static int au1xpsc_i2s_drvsuspend(struct device *dev)
{
    struct au1xpsc_audio_data *wd = dev_get_drvdata(dev);

    /* save interesting register and disable PSC */
    wd->pm[0] = au_readl(PSC_SEL(wd));

    au_writel(0, I2S_CFG(wd));
    au_sync();
    au_writel(PSC_CTRL_DISABLE, PSC_CTRL(wd));
    au_sync();

    return 0;
}

static int au1xpsc_i2s_drvresume(struct device *dev)
{
    struct au1xpsc_audio_data *wd = dev_get_drvdata(dev);

    /* select I2S mode and PSC clock */
    au_writel(PSC_CTRL_DISABLE, PSC_CTRL(wd));
    au_sync();
    au_writel(0, PSC_SEL(wd));
    au_sync();
    au_writel(wd->pm[0], PSC_SEL(wd));
    au_sync();

    return 0;
}

static struct dev_pm_ops au1xpsci2s_pmops = {
    .suspend    = au1xpsc_i2s_drvsuspend,
    .resume     = au1xpsc_i2s_drvresume,
};

#define AU1XPSCI2S_PMOPS &au1xpsci2s_pmops

#else

#define AU1XPSCI2S_PMOPS NULL

#endif

static struct platform_driver au1xpsc_i2s_driver = {
    .driver     = {
        .name   = "au1xpsc_i2s",
        .owner  = THIS_MODULE,
        .pm = AU1XPSCI2S_PMOPS,
    },
    .probe      = au1xpsc_i2s_drvprobe,
    .remove     = __devexit_p(au1xpsc_i2s_drvremove),
};

module_platform_driver(au1xpsc_i2s_driver);

MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("Au12x0/Au1550 PSC I2S ALSA ASoC audio driver");
MODULE_AUTHOR("Manuel Lauss");