/*
   * Copyright (c) 2009-2010 Nuvoton technology corporation.
   *
   * Wan ZongShun <mcuos.com@gmail.com>
   *
   * 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/init.h>
  #include <linux/module.h>
  #include <linux/slab.h>
  #include <linux/device.h>
  #include <linux/delay.h>
  #include <linux/mutex.h>
  #include <linux/suspend.h>
  #include <sound/core.h>
  #include <sound/pcm.h>
  #include <sound/initval.h>
  #include <sound/soc.h>

  #include <linux/clk.h>
  
  #include <mach/mfp.h>

  #include "nuc900-audio.h"

  
  static DEFINE_MUTEX(ac97_mutex);
  struct nuc900_audio *nuc900_ac97_data;
  
  static int nuc900_checkready(void)
  {
  	struct nuc900_audio *nuc900_audio = nuc900_ac97_data;
  
  	if (!(AUDIO_READ(nuc900_audio->mmio + ACTL_ACIS0) & CODEC_READY))
  		return -EPERM;
  
  	return 0;
  }
  
  /* AC97 controller reads codec register */
  static unsigned short nuc900_ac97_read(struct snd_ac97 *ac97,
  					unsigned short reg)
  {
  	struct nuc900_audio *nuc900_audio = nuc900_ac97_data;
  	unsigned long timeout = 0x10000, val;
  
  	mutex_lock(&ac97_mutex);
  
  	val = nuc900_checkready();

  	if (val) {

  		dev_err(nuc900_audio->dev, "AC97 codec is not ready
  ");
  		goto out;
  	}
  
  	/* set the R_WB bit and write register index */
  	AUDIO_WRITE(nuc900_audio->mmio + ACTL_ACOS1, R_WB | reg);
  
  	/* set the valid frame bit and valid slots */
  	val = AUDIO_READ(nuc900_audio->mmio + ACTL_ACOS0);
  	val |= (VALID_FRAME | SLOT1_VALID);
  	AUDIO_WRITE(nuc900_audio->mmio + ACTL_ACOS0, val);
  
  	udelay(100);
  
  	/* polling the AC_R_FINISH */

  	while (!(AUDIO_READ(nuc900_audio->mmio + ACTL_ACCON) & AC_R_FINISH)
  								&& timeout--)

  		mdelay(1);
  
  	if (!timeout) {
  		dev_err(nuc900_audio->dev, "AC97 read register time out !
  ");
  		val = -EPERM;
  		goto out;
  	}
  
  	val = AUDIO_READ(nuc900_audio->mmio + ACTL_ACOS0) ;
  	val &= ~SLOT1_VALID;
  	AUDIO_WRITE(nuc900_audio->mmio + ACTL_ACOS0, val);
  
  	if (AUDIO_READ(nuc900_audio->mmio + ACTL_ACIS1) >> 2 != reg) {
  		dev_err(nuc900_audio->dev,
  				"R_INDEX of REG_ACTL_ACIS1 not match!
  ");
  	}
  
  	udelay(100);
  	val = (AUDIO_READ(nuc900_audio->mmio + ACTL_ACIS2) & 0xFFFF);
  
  out:
  	mutex_unlock(&ac97_mutex);
  	return val;
  }
  
  /* AC97 controller writes to codec register */
  static void nuc900_ac97_write(struct snd_ac97 *ac97, unsigned short reg,
  				unsigned short val)
  {
  	struct nuc900_audio *nuc900_audio = nuc900_ac97_data;
  	unsigned long tmp, timeout = 0x10000;
  
  	mutex_lock(&ac97_mutex);
  
  	tmp = nuc900_checkready();

  	if (tmp)

  		dev_err(nuc900_audio->dev, "AC97 codec is not ready
  ");
  
  	/* clear the R_WB bit and write register index */
  	AUDIO_WRITE(nuc900_audio->mmio + ACTL_ACOS1, reg);
  
  	/* write register value */
  	AUDIO_WRITE(nuc900_audio->mmio + ACTL_ACOS2, val);
  
  	/* set the valid frame bit and valid slots */
  	tmp = AUDIO_READ(nuc900_audio->mmio + ACTL_ACOS0);
  	tmp |= SLOT1_VALID | SLOT2_VALID | VALID_FRAME;
  	AUDIO_WRITE(nuc900_audio->mmio + ACTL_ACOS0, tmp);
  
  	udelay(100);
  
  	/* polling the AC_W_FINISH */

  	while ((AUDIO_READ(nuc900_audio->mmio + ACTL_ACCON) & AC_W_FINISH)
  								&& timeout--)

  		mdelay(1);
  
  	if (!timeout)
  		dev_err(nuc900_audio->dev, "AC97 write register time out !
  ");
  
  	tmp = AUDIO_READ(nuc900_audio->mmio + ACTL_ACOS0);
  	tmp &= ~(SLOT1_VALID | SLOT2_VALID);
  	AUDIO_WRITE(nuc900_audio->mmio + ACTL_ACOS0, tmp);
  
  	mutex_unlock(&ac97_mutex);
  
  }
  
  static void nuc900_ac97_warm_reset(struct snd_ac97 *ac97)
  {
  	struct nuc900_audio *nuc900_audio = nuc900_ac97_data;
  	unsigned long val;
  
  	mutex_lock(&ac97_mutex);
  
  	/* warm reset AC 97 */
  	val = AUDIO_READ(nuc900_audio->mmio + ACTL_ACCON);
  	val |= AC_W_RES;
  	AUDIO_WRITE(nuc900_audio->mmio + ACTL_ACCON, val);

  	udelay(100);

  
  	val = nuc900_checkready();

  	if (val)

  		dev_err(nuc900_audio->dev, "AC97 codec is not ready
  ");
  
  	mutex_unlock(&ac97_mutex);
  }
  
  static void nuc900_ac97_cold_reset(struct snd_ac97 *ac97)
  {
  	struct nuc900_audio *nuc900_audio = nuc900_ac97_data;
  	unsigned long val;
  
  	mutex_lock(&ac97_mutex);
  
  	/* reset Audio Controller */
  	val = AUDIO_READ(nuc900_audio->mmio + ACTL_RESET);
  	val |= ACTL_RESET_BIT;
  	AUDIO_WRITE(nuc900_audio->mmio + ACTL_RESET, val);

  	val = AUDIO_READ(nuc900_audio->mmio + ACTL_RESET);
  	val &= (~ACTL_RESET_BIT);
  	AUDIO_WRITE(nuc900_audio->mmio + ACTL_RESET, val);

  	/* reset AC-link interface */
  
  	val = AUDIO_READ(nuc900_audio->mmio + ACTL_RESET);
  	val |= AC_RESET;
  	AUDIO_WRITE(nuc900_audio->mmio + ACTL_RESET, val);

  	val = AUDIO_READ(nuc900_audio->mmio + ACTL_RESET);
  	val &= ~AC_RESET;
  	AUDIO_WRITE(nuc900_audio->mmio + ACTL_RESET, val);

  	/* cold reset AC 97 */
  	val = AUDIO_READ(nuc900_audio->mmio + ACTL_ACCON);
  	val |= AC_C_RES;
  	AUDIO_WRITE(nuc900_audio->mmio + ACTL_ACCON, val);

  	val = AUDIO_READ(nuc900_audio->mmio + ACTL_ACCON);
  	val &= (~AC_C_RES);
  	AUDIO_WRITE(nuc900_audio->mmio + ACTL_ACCON, val);

  	udelay(100);

  
  	mutex_unlock(&ac97_mutex);
  
  }
  
  /* AC97 controller operations */
  struct snd_ac97_bus_ops soc_ac97_ops = {
  	.read		= nuc900_ac97_read,
  	.write		= nuc900_ac97_write,
  	.reset		= nuc900_ac97_cold_reset,
  	.warm_reset	= nuc900_ac97_warm_reset,
  }
  EXPORT_SYMBOL_GPL(soc_ac97_ops);
  
  static int nuc900_ac97_trigger(struct snd_pcm_substream *substream,
  				int cmd, struct snd_soc_dai *dai)
  {
  	struct nuc900_audio *nuc900_audio = nuc900_ac97_data;

  	int ret;

  	unsigned long val, tmp;
  
  	ret = 0;
  
  	switch (cmd) {
  	case SNDRV_PCM_TRIGGER_START:
  	case SNDRV_PCM_TRIGGER_RESUME:
  		val = AUDIO_READ(nuc900_audio->mmio + ACTL_RESET);

  		if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {

  			tmp = AUDIO_READ(nuc900_audio->mmio + ACTL_ACOS0);
  			tmp |= (SLOT3_VALID | SLOT4_VALID | VALID_FRAME);
  			AUDIO_WRITE(nuc900_audio->mmio + ACTL_ACOS0, tmp);
  
  			tmp = AUDIO_READ(nuc900_audio->mmio + ACTL_PSR);
  			tmp |= (P_DMA_END_IRQ | P_DMA_MIDDLE_IRQ);
  			AUDIO_WRITE(nuc900_audio->mmio + ACTL_PSR, tmp);
  			val |= AC_PLAY;
  		} else {
  			tmp = AUDIO_READ(nuc900_audio->mmio + ACTL_RSR);
  			tmp |= (R_DMA_END_IRQ | R_DMA_MIDDLE_IRQ);
  
  			AUDIO_WRITE(nuc900_audio->mmio + ACTL_RSR, tmp);
  			val |= AC_RECORD;
  		}
  
  		AUDIO_WRITE(nuc900_audio->mmio + ACTL_RESET, val);
  
  		break;
  	case SNDRV_PCM_TRIGGER_STOP:
  	case SNDRV_PCM_TRIGGER_SUSPEND:
  		val = AUDIO_READ(nuc900_audio->mmio + ACTL_RESET);

  		if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {

  			tmp = AUDIO_READ(nuc900_audio->mmio + ACTL_ACOS0);
  			tmp &= ~(SLOT3_VALID | SLOT4_VALID);
  			AUDIO_WRITE(nuc900_audio->mmio + ACTL_ACOS0, tmp);
  
  			AUDIO_WRITE(nuc900_audio->mmio + ACTL_PSR, RESET_PRSR);
  			val &= ~AC_PLAY;
  		} else {
  			AUDIO_WRITE(nuc900_audio->mmio + ACTL_RSR, RESET_PRSR);
  			val &= ~AC_RECORD;
  		}
  
  		AUDIO_WRITE(nuc900_audio->mmio + ACTL_RESET, val);
  
  		break;
  	default:
  		ret = -EINVAL;
  	}
  
  	return ret;
  }

  static int nuc900_ac97_probe(struct snd_soc_dai *dai)

  {
  	struct nuc900_audio *nuc900_audio = nuc900_ac97_data;
  	unsigned long val;
  
  	mutex_lock(&ac97_mutex);
  
  	/* enable unit clock */
  	clk_enable(nuc900_audio->clk);
  
  	/* enable audio controller and AC-link interface */
  	val = AUDIO_READ(nuc900_audio->mmio + ACTL_CON);
  	val |= (IIS_AC_PIN_SEL | ACLINK_EN);
  	AUDIO_WRITE(nuc900_audio->mmio + ACTL_CON, val);
  
  	mutex_unlock(&ac97_mutex);
  
  	return 0;
  }

  static int nuc900_ac97_remove(struct snd_soc_dai *dai)

  {
  	struct nuc900_audio *nuc900_audio = nuc900_ac97_data;
  
  	clk_disable(nuc900_audio->clk);

  	return 0;

  }

  static const struct snd_soc_dai_ops nuc900_ac97_dai_ops = {

  	.trigger	= nuc900_ac97_trigger,
  };

  static struct snd_soc_dai_driver nuc900_ac97_dai = {

  	.probe			= nuc900_ac97_probe,
  	.remove			= nuc900_ac97_remove,
  	.ac97_control		= 1,
  	.playback = {
  		.rates		= SNDRV_PCM_RATE_8000_48000,
  		.formats	= SNDRV_PCM_FMTBIT_S16_LE,
  		.channels_min	= 1,
  		.channels_max	= 2,
  	},
  	.capture = {
  		.rates		= SNDRV_PCM_RATE_8000_48000,
  		.formats	= SNDRV_PCM_FMTBIT_S16_LE,
  		.channels_min	= 1,
  		.channels_max	= 2,
  	},
  	.ops = &nuc900_ac97_dai_ops,

  };

  
  static int __devinit nuc900_ac97_drvprobe(struct platform_device *pdev)
  {
  	struct nuc900_audio *nuc900_audio;
  	int ret;
  
  	if (nuc900_ac97_data)
  		return -EBUSY;
  
  	nuc900_audio = kzalloc(sizeof(struct nuc900_audio), GFP_KERNEL);
  	if (!nuc900_audio)
  		return -ENOMEM;
  
  	spin_lock_init(&nuc900_audio->lock);
  
  	nuc900_audio->res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
  	if (!nuc900_audio->res) {
  		ret = -ENODEV;
  		goto out0;
  	}
  
  	if (!request_mem_region(nuc900_audio->res->start,
  			resource_size(nuc900_audio->res), pdev->name)) {
  		ret = -EBUSY;
  		goto out0;
  	}
  
  	nuc900_audio->mmio = ioremap(nuc900_audio->res->start,
  					resource_size(nuc900_audio->res));
  	if (!nuc900_audio->mmio) {
  		ret = -ENOMEM;
  		goto out1;
  	}
  
  	nuc900_audio->clk = clk_get(&pdev->dev, NULL);
  	if (IS_ERR(nuc900_audio->clk)) {
  		ret = PTR_ERR(nuc900_audio->clk);
  		goto out2;
  	}
  
  	nuc900_audio->irq_num = platform_get_irq(pdev, 0);
  	if (!nuc900_audio->irq_num) {
  		ret = -EBUSY;

  		goto out3;

  	}
  
  	nuc900_ac97_data = nuc900_audio;

  	ret = snd_soc_register_dai(&pdev->dev, &nuc900_ac97_dai);

  	if (ret)
  		goto out3;

  	/* enbale ac97 multifunction pin */

  	mfp_set_groupg(nuc900_audio->dev, NULL);

  
  	return 0;
  
  out3:
  	clk_put(nuc900_audio->clk);
  out2:
  	iounmap(nuc900_audio->mmio);
  out1:
  	release_mem_region(nuc900_audio->res->start,
  					resource_size(nuc900_audio->res));
  out0:
  	kfree(nuc900_audio);
  	return ret;
  }
  
  static int __devexit nuc900_ac97_drvremove(struct platform_device *pdev)
  {

  	snd_soc_unregister_dai(&pdev->dev);

  
  	clk_put(nuc900_ac97_data->clk);
  	iounmap(nuc900_ac97_data->mmio);
  	release_mem_region(nuc900_ac97_data->res->start,
  				resource_size(nuc900_ac97_data->res));

  	kfree(nuc900_ac97_data);

  	nuc900_ac97_data = NULL;
  
  	return 0;
  }
  
  static struct platform_driver nuc900_ac97_driver = {
  	.driver	= {

  		.name	= "nuc900-ac97",

  		.owner	= THIS_MODULE,
  	},
  	.probe		= nuc900_ac97_drvprobe,
  	.remove		= __devexit_p(nuc900_ac97_drvremove),
  };

  module_platform_driver(nuc900_ac97_driver);

  
  MODULE_AUTHOR("Wan ZongShun <mcuos.com@gmail.com>");
  MODULE_DESCRIPTION("NUC900 AC97 SoC driver!");
  MODULE_LICENSE("GPL");
  MODULE_ALIAS("platform:nuc900-ac97");