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psc-i2s.c

/*
 * Au12x0/Au1550 PSC ALSA ASoC audio support.
 *
 * (c) 2007-2008 MSC Vertriebsges.m.b.H.,
 *    Manuel Lauss <manuel.lauss@gmail.com>
 *
 * 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: all of these drivers can only work with a SINGLE instance
 *     of a PSC. Multiple independent audio devices are impossible
 *     with ASoC v1.
 * NOTE: so far only PSC slave mode (bit- and frameclock) is supported.
 */

#include <linux/init.h>
#include <linux/module.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) == PCM_TX ? PSC_I2SSTAT_TB : PSC_I2SSTAT_RB)
#define I2SPCR_START(stype)   \
      ((stype) == PCM_TX ? PSC_I2SPCR_TS : PSC_I2SPCR_RS)
#define I2SPCR_STOP(stype)    \
      ((stype) == PCM_TX ? PSC_I2SPCR_TP : PSC_I2SPCR_RP)
#define I2SPCR_CLRFIFO(stype) \
      ((stype) == PCM_TX ? PSC_I2SPCR_TC : PSC_I2SPCR_RC)


/* instance data. There can be only one, MacLeod!!!! */
static struct au1xpsc_audio_data *au1xpsc_i2s_workdata;

static int au1xpsc_i2s_set_fmt(struct snd_soc_dai *cpu_dai,
                         unsigned int fmt)
{
      struct au1xpsc_audio_data *pscdata = au1xpsc_i2s_workdata;
      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 = au1xpsc_i2s_workdata;

      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 = au1xpsc_i2s_workdata;
      int ret, stype = SUBSTREAM_TYPE(substream);

      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_probe(struct platform_device *pdev,
                       struct snd_soc_dai *dai)
{
      return      au1xpsc_i2s_workdata ? 0 : -ENODEV;
}

static void au1xpsc_i2s_remove(struct platform_device *pdev,
                         struct snd_soc_dai *dai)
{
}

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

struct snd_soc_dai au1xpsc_i2s_dai = {
      .name             = "au1xpsc_i2s",
      .probe                  = au1xpsc_i2s_probe,
      .remove                 = au1xpsc_i2s_remove,
      .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,
};
EXPORT_SYMBOL(au1xpsc_i2s_dai);

static int __init au1xpsc_i2s_drvprobe(struct platform_device *pdev)
{
      struct resource *r;
      unsigned long sel;
      int ret;
      struct au1xpsc_audio_data *wd;

      if (au1xpsc_i2s_workdata)
            return -EBUSY;

      wd = kzalloc(sizeof(struct au1xpsc_audio_data), GFP_KERNEL);
      if (!wd)
            return -ENOMEM;

      r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
      if (!r) {
            ret = -ENODEV;
            goto out0;
      }

      ret = -EBUSY;
      wd->ioarea = request_mem_region(r->start, r->end - r->start + 1,
                              "au1xpsc_i2s");
      if (!wd->ioarea)
            goto out0;

      wd->mmio = ioremap(r->start, 0xffff);
      if (!wd->mmio)
            goto out1;

      /* 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.
       */

      ret = snd_soc_register_dai(&au1xpsc_i2s_dai);
      if (ret)
            goto out1;

      /* finally add the DMA device for this PSC */
      wd->dmapd = au1xpsc_pcm_add(pdev);
      if (wd->dmapd) {
            platform_set_drvdata(pdev, wd);
            au1xpsc_i2s_workdata = wd;
            return 0;
      }

      snd_soc_unregister_dai(&au1xpsc_i2s_dai);
out1:
      release_resource(wd->ioarea);
      kfree(wd->ioarea);
out0:
      kfree(wd);
      return ret;
}

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

      if (wd->dmapd)
            au1xpsc_pcm_destroy(wd->dmapd);

      snd_soc_unregister_dai(&au1xpsc_i2s_dai);

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

      iounmap(wd->mmio);
      release_resource(wd->ioarea);
      kfree(wd->ioarea);
      kfree(wd);

      au1xpsc_i2s_workdata = NULL;  /* MDEV */

      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),
};

static int __init au1xpsc_i2s_load(void)
{
      au1xpsc_i2s_workdata = NULL;
      return platform_driver_register(&au1xpsc_i2s_driver);
}

static void __exit au1xpsc_i2s_unload(void)
{
      platform_driver_unregister(&au1xpsc_i2s_driver);
}

module_init(au1xpsc_i2s_load);
module_exit(au1xpsc_i2s_unload);

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

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