/*
   * 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: 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");