/*
   *  linux/sound/arm/aaci.c - ARM PrimeCell AACI PL041 driver
   *
   *  Copyright (C) 2003 Deep Blue Solutions Ltd, All Rights Reserved.
   *
   * 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.
   *
   *  Documentation: ARM DDI 0173B
   */
  #include <linux/module.h>
  #include <linux/delay.h>
  #include <linux/init.h>
  #include <linux/ioport.h>
  #include <linux/device.h>
  #include <linux/spinlock.h>
  #include <linux/interrupt.h>
  #include <linux/err.h>

  #include <linux/amba/bus.h>

  #include <linux/io.h>

  #include <sound/core.h>
  #include <sound/initval.h>
  #include <sound/ac97_codec.h>
  #include <sound/pcm.h>
  #include <sound/pcm_params.h>
  
  #include "aaci.h"

  
  #define DRIVER_NAME	"aaci-pl041"

  #define FRAME_PERIOD_US	21

  /*
   * PM support is not complete.  Turn it off.
   */
  #undef CONFIG_PM

  static void aaci_ac97_select_codec(struct aaci *aaci, struct snd_ac97 *ac97)

  {
  	u32 v, maincr = aaci->maincr | MAINCR_SCRA(ac97->num);
  
  	/*
  	 * Ensure that the slot 1/2 RX registers are empty.
  	 */
  	v = readl(aaci->base + AACI_SLFR);
  	if (v & SLFR_2RXV)
  		readl(aaci->base + AACI_SL2RX);
  	if (v & SLFR_1RXV)
  		readl(aaci->base + AACI_SL1RX);

  	if (maincr != readl(aaci->base + AACI_MAINCR)) {
  		writel(maincr, aaci->base + AACI_MAINCR);
  		readl(aaci->base + AACI_MAINCR);
  		udelay(1);
  	}

  }
  
  /*
   * P29:
   *  The recommended use of programming the external codec through slot 1
   *  and slot 2 data is to use the channels during setup routines and the
   *  slot register at any other time.  The data written into slot 1, slot 2
   *  and slot 12 registers is transmitted only when their corresponding
   *  SI1TxEn, SI2TxEn and SI12TxEn bits are set in the AACI_MAINCR
   *  register.
   */

  static void aaci_ac97_write(struct snd_ac97 *ac97, unsigned short reg,
  			    unsigned short val)

  {
  	struct aaci *aaci = ac97->private_data;

  	int timeout;

  	u32 v;
  
  	if (ac97->num >= 4)
  		return;

  	mutex_lock(&aaci->ac97_sem);

  
  	aaci_ac97_select_codec(aaci, ac97);
  
  	/*
  	 * P54: You must ensure that AACI_SL2TX is always written
  	 * to, if required, before data is written to AACI_SL1TX.
  	 */
  	writel(val << 4, aaci->base + AACI_SL2TX);
  	writel(reg << 12, aaci->base + AACI_SL1TX);

  	/* Initially, wait one frame period */
  	udelay(FRAME_PERIOD_US);
  
  	/* And then wait an additional eight frame periods for it to be sent */
  	timeout = FRAME_PERIOD_US * 8;

  	do {

  		udelay(1);

  		v = readl(aaci->base + AACI_SLFR);

  	} while ((v & (SLFR_1TXB|SLFR_2TXB)) && --timeout);

  	if (v & (SLFR_1TXB|SLFR_2TXB))

  		dev_err(&aaci->dev->dev,
  			"timeout waiting for write to complete
  ");

  	mutex_unlock(&aaci->ac97_sem);

  }
  
  /*
   * Read an AC'97 register.
   */

  static unsigned short aaci_ac97_read(struct snd_ac97 *ac97, unsigned short reg)

  {
  	struct aaci *aaci = ac97->private_data;

  	int timeout, retries = 10;

  	u32 v;
  
  	if (ac97->num >= 4)
  		return ~0;

  	mutex_lock(&aaci->ac97_sem);

  
  	aaci_ac97_select_codec(aaci, ac97);
  
  	/*
  	 * Write the register address to slot 1.
  	 */
  	writel((reg << 12) | (1 << 19), aaci->base + AACI_SL1TX);

  	/* Initially, wait one frame period */
  	udelay(FRAME_PERIOD_US);
  
  	/* And then wait an additional eight frame periods for it to be sent */
  	timeout = FRAME_PERIOD_US * 8;

  	do {

  		udelay(1);

  		v = readl(aaci->base + AACI_SLFR);

  	} while ((v & SLFR_1TXB) && --timeout);

  	if (v & SLFR_1TXB) {

  		dev_err(&aaci->dev->dev, "timeout on slot 1 TX busy
  ");
  		v = ~0;
  		goto out;
  	}

  	/* Now wait for the response frame */
  	udelay(FRAME_PERIOD_US);

  	/* And then wait an additional eight frame periods for data */
  	timeout = FRAME_PERIOD_US * 8;

  	do {

  		udelay(1);

  		cond_resched();
  		v = readl(aaci->base + AACI_SLFR) & (SLFR_1RXV|SLFR_2RXV);

  	} while ((v != (SLFR_1RXV|SLFR_2RXV)) && --timeout);

  	if (v != (SLFR_1RXV|SLFR_2RXV)) {

  		dev_err(&aaci->dev->dev, "timeout on RX valid
  ");

  		v = ~0;

  		goto out;

  	}

  	do {
  		v = readl(aaci->base + AACI_SL1RX) >> 12;
  		if (v == reg) {
  			v = readl(aaci->base + AACI_SL2RX) >> 4;
  			break;
  		} else if (--retries) {
  			dev_warn(&aaci->dev->dev,
  				 "ac97 read back fail.  retry
  ");
  			continue;
  		} else {
  			dev_warn(&aaci->dev->dev,
  				"wrong ac97 register read back (%x != %x)
  ",
  				v, reg);
  			v = ~0;
  		}
  	} while (retries);
   out:

  	mutex_unlock(&aaci->ac97_sem);

  	return v;
  }

  static inline void
  aaci_chan_wait_ready(struct aaci_runtime *aacirun, unsigned long mask)

  {
  	u32 val;
  	int timeout = 5000;
  
  	do {

  		udelay(1);

  		val = readl(aacirun->base + AACI_SR);

  	} while (val & mask && timeout--);

  }
  
  
  
  /*
   * Interrupt support.
   */

  static void aaci_fifo_irq(struct aaci *aaci, int channel, u32 mask)

  {

  	if (mask & ISR_ORINTR) {
  		dev_warn(&aaci->dev->dev, "RX overrun on chan %d
  ", channel);
  		writel(ICLR_RXOEC1 << channel, aaci->base + AACI_INTCLR);
  	}
  
  	if (mask & ISR_RXTOINTR) {
  		dev_warn(&aaci->dev->dev, "RX timeout on chan %d
  ", channel);
  		writel(ICLR_RXTOFEC1 << channel, aaci->base + AACI_INTCLR);
  	}
  
  	if (mask & ISR_RXINTR) {
  		struct aaci_runtime *aacirun = &aaci->capture;

  		bool period_elapsed = false;

  		void *ptr;
  
  		if (!aacirun->substream || !aacirun->start) {

  			dev_warn(&aaci->dev->dev, "RX interrupt???
  ");

  			writel(0, aacirun->base + AACI_IE);
  			return;
  		}

  		spin_lock(&aacirun->lock);
  
  		ptr = aacirun->ptr;

  		do {

  			unsigned int len = aacirun->fifo_bytes;

  			u32 val;
  
  			if (aacirun->bytes <= 0) {
  				aacirun->bytes += aacirun->period;

  				period_elapsed = true;

  			}
  			if (!(aacirun->cr & CR_EN))
  				break;
  
  			val = readl(aacirun->base + AACI_SR);
  			if (!(val & SR_RXHF))
  				break;
  			if (!(val & SR_RXFF))
  				len >>= 1;
  
  			aacirun->bytes -= len;
  
  			/* reading 16 bytes at a time */
  			for( ; len > 0; len -= 16) {
  				asm(
  					"ldmia	%1, {r0, r1, r2, r3}
  \t"
  					"stmia	%0!, {r0, r1, r2, r3}"
  					: "+r" (ptr)
  					: "r" (aacirun->fifo)
  					: "r0", "r1", "r2", "r3", "cc");
  
  				if (ptr >= aacirun->end)
  					ptr = aacirun->start;
  			}
  		} while(1);

  		aacirun->ptr = ptr;

  
  		spin_unlock(&aacirun->lock);

  
  		if (period_elapsed)
  			snd_pcm_period_elapsed(aacirun->substream);

  	}

  	if (mask & ISR_URINTR) {

  		dev_dbg(&aaci->dev->dev, "TX underrun on chan %d
  ", channel);
  		writel(ICLR_TXUEC1 << channel, aaci->base + AACI_INTCLR);

  	}
  
  	if (mask & ISR_TXINTR) {
  		struct aaci_runtime *aacirun = &aaci->playback;

  		bool period_elapsed = false;

  		void *ptr;
  
  		if (!aacirun->substream || !aacirun->start) {

  			dev_warn(&aaci->dev->dev, "TX interrupt???
  ");

  			writel(0, aacirun->base + AACI_IE);
  			return;
  		}

  		spin_lock(&aacirun->lock);

  		ptr = aacirun->ptr;
  		do {

  			unsigned int len = aacirun->fifo_bytes;

  			u32 val;
  
  			if (aacirun->bytes <= 0) {
  				aacirun->bytes += aacirun->period;

  				period_elapsed = true;

  			}

  			if (!(aacirun->cr & CR_EN))

  				break;
  
  			val = readl(aacirun->base + AACI_SR);
  			if (!(val & SR_TXHE))
  				break;
  			if (!(val & SR_TXFE))
  				len >>= 1;
  
  			aacirun->bytes -= len;
  
  			/* writing 16 bytes at a time */
  			for ( ; len > 0; len -= 16) {
  				asm(
  					"ldmia	%0!, {r0, r1, r2, r3}
  \t"
  					"stmia	%1, {r0, r1, r2, r3}"
  					: "+r" (ptr)
  					: "r" (aacirun->fifo)
  					: "r0", "r1", "r2", "r3", "cc");
  
  				if (ptr >= aacirun->end)
  					ptr = aacirun->start;
  			}
  		} while (1);
  
  		aacirun->ptr = ptr;

  
  		spin_unlock(&aacirun->lock);

  
  		if (period_elapsed)
  			snd_pcm_period_elapsed(aacirun->substream);

  	}
  }

  static irqreturn_t aaci_irq(int irq, void *devid)

  {
  	struct aaci *aaci = devid;
  	u32 mask;
  	int i;

  	mask = readl(aaci->base + AACI_ALLINTS);
  	if (mask) {
  		u32 m = mask;
  		for (i = 0; i < 4; i++, m >>= 7) {
  			if (m & 0x7f) {

  				aaci_fifo_irq(aaci, i, m);

  			}
  		}
  	}

  
  	return mask ? IRQ_HANDLED : IRQ_NONE;
  }
  
  
  
  /*
   * ALSA support.
   */

  static struct snd_pcm_hardware aaci_hw_info = {

  	.info			= SNDRV_PCM_INFO_MMAP |
  				  SNDRV_PCM_INFO_MMAP_VALID |
  				  SNDRV_PCM_INFO_INTERLEAVED |
  				  SNDRV_PCM_INFO_BLOCK_TRANSFER |
  				  SNDRV_PCM_INFO_RESUME,
  
  	/*
  	 * ALSA doesn't support 18-bit or 20-bit packed into 32-bit
  	 * words.  It also doesn't support 12-bit at all.
  	 */
  	.formats		= SNDRV_PCM_FMTBIT_S16_LE,

  	/* rates are setup from the AC'97 codec */

  	.channels_min		= 2,

  	.channels_max		= 2,

  	.buffer_bytes_max	= 64 * 1024,
  	.period_bytes_min	= 256,
  	.period_bytes_max	= PAGE_SIZE,
  	.periods_min		= 4,
  	.periods_max		= PAGE_SIZE / 16,
  };

  /*
   * We can support two and four channel audio.  Unfortunately
   * six channel audio requires a non-standard channel ordering:
   *   2 -> FL(3), FR(4)
   *   4 -> FL(3), FR(4), SL(7), SR(8)
   *   6 -> FL(3), FR(4), SL(7), SR(8), C(6), LFE(9) (required)
   *        FL(3), FR(4), C(6), SL(7), SR(8), LFE(9) (actual)
   * This requires an ALSA configuration file to correct.
   */
  static int aaci_rule_channels(struct snd_pcm_hw_params *p,
  	struct snd_pcm_hw_rule *rule)
  {
  	static unsigned int channel_list[] = { 2, 4, 6 };
  	struct aaci *aaci = rule->private;
  	unsigned int mask = 1 << 0, slots;
  
  	/* pcms[0] is the our 5.1 PCM instance. */
  	slots = aaci->ac97_bus->pcms[0].r[0].slots;
  	if (slots & (1 << AC97_SLOT_PCM_SLEFT)) {
  		mask |= 1 << 1;
  		if (slots & (1 << AC97_SLOT_LFE))
  			mask |= 1 << 2;
  	}
  
  	return snd_interval_list(hw_param_interval(p, rule->var),
  				 ARRAY_SIZE(channel_list), channel_list, mask);
  }
  
  static int aaci_pcm_open(struct snd_pcm_substream *substream)

  {

  	struct snd_pcm_runtime *runtime = substream->runtime;

  	struct aaci *aaci = substream->private_data;
  	struct aaci_runtime *aacirun;

  	int ret = 0;

  	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
  		aacirun = &aaci->playback;
  	} else {
  		aacirun = &aaci->capture;
  	}

  	aacirun->substream = substream;
  	runtime->private_data = aacirun;
  	runtime->hw = aaci_hw_info;

  	runtime->hw.rates = aacirun->pcm->rates;
  	snd_pcm_limit_hw_rates(runtime);

  	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
  		runtime->hw.channels_max = 6;
  
  		/* Add rule describing channel dependency. */
  		ret = snd_pcm_hw_rule_add(substream->runtime, 0,
  					  SNDRV_PCM_HW_PARAM_CHANNELS,
  					  aaci_rule_channels, aaci,
  					  SNDRV_PCM_HW_PARAM_CHANNELS, -1);
  		if (ret)
  			return ret;
  
  		if (aacirun->pcm->r[1].slots)
  			snd_ac97_pcm_double_rate_rules(runtime);
  	}

  	/*

  	 * ALSA wants the byte-size of the FIFOs.  As we only support
  	 * 16-bit samples, this is twice the FIFO depth irrespective
  	 * of whether it's in compact mode or not.

  	 */

  	runtime->hw.fifo_size = aaci->fifo_depth * 2;

  	mutex_lock(&aaci->irq_lock);
  	if (!aaci->users++) {
  		ret = request_irq(aaci->dev->irq[0], aaci_irq,

  			   IRQF_SHARED, DRIVER_NAME, aaci);

  		if (ret != 0)
  			aaci->users--;
  	}
  	mutex_unlock(&aaci->irq_lock);

  	return ret;
  }
  
  
  /*
   * Common ALSA stuff
   */

  static int aaci_pcm_close(struct snd_pcm_substream *substream)

  {
  	struct aaci *aaci = substream->private_data;
  	struct aaci_runtime *aacirun = substream->runtime->private_data;

  	WARN_ON(aacirun->cr & CR_EN);

  
  	aacirun->substream = NULL;

  
  	mutex_lock(&aaci->irq_lock);
  	if (!--aaci->users)
  		free_irq(aaci->dev->irq[0], aaci);
  	mutex_unlock(&aaci->irq_lock);

  
  	return 0;
  }

  static int aaci_pcm_hw_free(struct snd_pcm_substream *substream)

  {
  	struct aaci_runtime *aacirun = substream->runtime->private_data;
  
  	/*
  	 * This must not be called with the device enabled.
  	 */

  	WARN_ON(aacirun->cr & CR_EN);

  
  	if (aacirun->pcm_open)
  		snd_ac97_pcm_close(aacirun->pcm);
  	aacirun->pcm_open = 0;
  
  	/*
  	 * Clear out the DMA and any allocated buffers.
  	 */

  	snd_pcm_lib_free_pages(substream);

  
  	return 0;
  }

  /* Channel to slot mask */
  static const u32 channels_to_slotmask[] = {
  	[2] = CR_SL3 | CR_SL4,
  	[4] = CR_SL3 | CR_SL4 | CR_SL7 | CR_SL8,
  	[6] = CR_SL3 | CR_SL4 | CR_SL7 | CR_SL8 | CR_SL6 | CR_SL9,
  };

  static int aaci_pcm_hw_params(struct snd_pcm_substream *substream,

  			      struct snd_pcm_hw_params *params)

  {

  	struct aaci_runtime *aacirun = substream->runtime->private_data;
  	unsigned int channels = params_channels(params);
  	unsigned int rate = params_rate(params);
  	int dbl = rate > 48000;

  	int err;
  
  	aaci_pcm_hw_free(substream);

  	if (aacirun->pcm_open) {
  		snd_ac97_pcm_close(aacirun->pcm);
  		aacirun->pcm_open = 0;
  	}

  	/* channels is already limited to 2, 4, or 6 by aaci_rule_channels */
  	if (dbl && channels != 2)
  		return -EINVAL;

  	err = snd_pcm_lib_malloc_pages(substream,
  				       params_buffer_bytes(params));

  	if (err >= 0) {

  		struct aaci *aaci = substream->private_data;

  		err = snd_ac97_pcm_open(aacirun->pcm, rate, channels,

  					aacirun->pcm->r[dbl].slots);

  		aacirun->pcm_open = err == 0;

  		aacirun->cr = CR_FEN | CR_COMPACT | CR_SZ16;

  		aacirun->cr |= channels_to_slotmask[channels + dbl * 2];

  		/*
  		 * fifo_bytes is the number of bytes we transfer to/from
  		 * the FIFO, including padding.  So that's x4.  As we're
  		 * in compact mode, the FIFO is half the size.
  		 */
  		aacirun->fifo_bytes = aaci->fifo_depth * 4 / 2;

  	}

  	return err;
  }

  static int aaci_pcm_prepare(struct snd_pcm_substream *substream)

  {

  	struct snd_pcm_runtime *runtime = substream->runtime;

  	struct aaci_runtime *aacirun = runtime->private_data;

  	aacirun->period	= snd_pcm_lib_period_bytes(substream);

  	aacirun->start	= runtime->dma_area;

  	aacirun->end	= aacirun->start + snd_pcm_lib_buffer_bytes(substream);

  	aacirun->ptr	= aacirun->start;

  	aacirun->bytes	= aacirun->period;

  
  	return 0;
  }

  static snd_pcm_uframes_t aaci_pcm_pointer(struct snd_pcm_substream *substream)

  {

  	struct snd_pcm_runtime *runtime = substream->runtime;

  	struct aaci_runtime *aacirun = runtime->private_data;
  	ssize_t bytes = aacirun->ptr - aacirun->start;
  
  	return bytes_to_frames(runtime, bytes);
  }

  
  /*
   * Playback specific ALSA stuff
   */

  static void aaci_pcm_playback_stop(struct aaci_runtime *aacirun)
  {
  	u32 ie;
  
  	ie = readl(aacirun->base + AACI_IE);
  	ie &= ~(IE_URIE|IE_TXIE);
  	writel(ie, aacirun->base + AACI_IE);

  	aacirun->cr &= ~CR_EN;

  	aaci_chan_wait_ready(aacirun, SR_TXB);

  	writel(aacirun->cr, aacirun->base + AACI_TXCR);
  }
  
  static void aaci_pcm_playback_start(struct aaci_runtime *aacirun)
  {
  	u32 ie;

  	aaci_chan_wait_ready(aacirun, SR_TXB);

  	aacirun->cr |= CR_EN;

  
  	ie = readl(aacirun->base + AACI_IE);
  	ie |= IE_URIE | IE_TXIE;
  	writel(ie, aacirun->base + AACI_IE);
  	writel(aacirun->cr, aacirun->base + AACI_TXCR);
  }

  static int aaci_pcm_playback_trigger(struct snd_pcm_substream *substream, int cmd)

  {

  	struct aaci_runtime *aacirun = substream->runtime->private_data;
  	unsigned long flags;
  	int ret = 0;

  	spin_lock_irqsave(&aacirun->lock, flags);

  	switch (cmd) {
  	case SNDRV_PCM_TRIGGER_START:
  		aaci_pcm_playback_start(aacirun);
  		break;
  
  	case SNDRV_PCM_TRIGGER_RESUME:
  		aaci_pcm_playback_start(aacirun);
  		break;
  
  	case SNDRV_PCM_TRIGGER_STOP:
  		aaci_pcm_playback_stop(aacirun);
  		break;
  
  	case SNDRV_PCM_TRIGGER_SUSPEND:
  		aaci_pcm_playback_stop(aacirun);
  		break;
  
  	case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
  		break;
  
  	case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
  		break;
  
  	default:
  		ret = -EINVAL;
  	}

  
  	spin_unlock_irqrestore(&aacirun->lock, flags);

  
  	return ret;
  }

  static struct snd_pcm_ops aaci_playback_ops = {

  	.open		= aaci_pcm_open,

  	.close		= aaci_pcm_close,
  	.ioctl		= snd_pcm_lib_ioctl,

  	.hw_params	= aaci_pcm_hw_params,

  	.hw_free	= aaci_pcm_hw_free,
  	.prepare	= aaci_pcm_prepare,
  	.trigger	= aaci_pcm_playback_trigger,
  	.pointer	= aaci_pcm_pointer,

  };

  static void aaci_pcm_capture_stop(struct aaci_runtime *aacirun)
  {
  	u32 ie;

  	aaci_chan_wait_ready(aacirun, SR_RXB);

  
  	ie = readl(aacirun->base + AACI_IE);
  	ie &= ~(IE_ORIE | IE_RXIE);
  	writel(ie, aacirun->base+AACI_IE);
  
  	aacirun->cr &= ~CR_EN;

  	writel(aacirun->cr, aacirun->base + AACI_RXCR);
  }
  
  static void aaci_pcm_capture_start(struct aaci_runtime *aacirun)
  {
  	u32 ie;

  	aaci_chan_wait_ready(aacirun, SR_RXB);

  
  #ifdef DEBUG
  	/* RX Timeout value: bits 28:17 in RXCR */
  	aacirun->cr |= 0xf << 17;
  #endif
  
  	aacirun->cr |= CR_EN;
  	writel(aacirun->cr, aacirun->base + AACI_RXCR);
  
  	ie = readl(aacirun->base + AACI_IE);
  	ie |= IE_ORIE |IE_RXIE; // overrun and rx interrupt -- half full
  	writel(ie, aacirun->base + AACI_IE);
  }

  static int aaci_pcm_capture_trigger(struct snd_pcm_substream *substream, int cmd)
  {

  	struct aaci_runtime *aacirun = substream->runtime->private_data;
  	unsigned long flags;
  	int ret = 0;

  	spin_lock_irqsave(&aacirun->lock, flags);

  
  	switch (cmd) {
  	case SNDRV_PCM_TRIGGER_START:
  		aaci_pcm_capture_start(aacirun);
  		break;
  
  	case SNDRV_PCM_TRIGGER_RESUME:
  		aaci_pcm_capture_start(aacirun);
  		break;
  
  	case SNDRV_PCM_TRIGGER_STOP:
  		aaci_pcm_capture_stop(aacirun);
  		break;
  
  	case SNDRV_PCM_TRIGGER_SUSPEND:
  		aaci_pcm_capture_stop(aacirun);
  		break;
  
  	case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
  		break;
  
  	case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
  		break;
  
  	default:
  		ret = -EINVAL;
  	}

  	spin_unlock_irqrestore(&aacirun->lock, flags);

  
  	return ret;
  }

  static int aaci_pcm_capture_prepare(struct snd_pcm_substream *substream)

  {
  	struct snd_pcm_runtime *runtime = substream->runtime;
  	struct aaci *aaci = substream->private_data;
  
  	aaci_pcm_prepare(substream);
  
  	/* allow changing of sample rate */
  	aaci_ac97_write(aaci->ac97, AC97_EXTENDED_STATUS, 0x0001); /* VRA */
  	aaci_ac97_write(aaci->ac97, AC97_PCM_LR_ADC_RATE, runtime->rate);
  	aaci_ac97_write(aaci->ac97, AC97_PCM_MIC_ADC_RATE, runtime->rate);
  
  	/* Record select: Mic: 0, Aux: 3, Line: 4 */
  	aaci_ac97_write(aaci->ac97, AC97_REC_SEL, 0x0404);
  
  	return 0;
  }

  static struct snd_pcm_ops aaci_capture_ops = {

  	.open		= aaci_pcm_open,
  	.close		= aaci_pcm_close,
  	.ioctl		= snd_pcm_lib_ioctl,

  	.hw_params	= aaci_pcm_hw_params,

  	.hw_free	= aaci_pcm_hw_free,
  	.prepare	= aaci_pcm_capture_prepare,
  	.trigger	= aaci_pcm_capture_trigger,
  	.pointer	= aaci_pcm_pointer,

  };

  
  /*
   * Power Management.
   */
  #ifdef CONFIG_PM

  static int aaci_do_suspend(struct snd_card *card, unsigned int state)

  {
  	struct aaci *aaci = card->private_data;

  	snd_power_change_state(card, SNDRV_CTL_POWER_D3cold);
  	snd_pcm_suspend_all(aaci->pcm);

  	return 0;
  }

  static int aaci_do_resume(struct snd_card *card, unsigned int state)

  {

  	snd_power_change_state(card, SNDRV_CTL_POWER_D0);

  	return 0;
  }

  static int aaci_suspend(struct amba_device *dev, pm_message_t state)

  {

  	struct snd_card *card = amba_get_drvdata(dev);

  	return card ? aaci_do_suspend(card) : 0;
  }
  
  static int aaci_resume(struct amba_device *dev)
  {

  	struct snd_card *card = amba_get_drvdata(dev);

  	return card ? aaci_do_resume(card) : 0;
  }
  #else
  #define aaci_do_suspend		NULL
  #define aaci_do_resume		NULL
  #define aaci_suspend		NULL
  #define aaci_resume		NULL
  #endif
  
  
  static struct ac97_pcm ac97_defs[] __devinitdata = {

  	[0] = {	/* Front PCM */

  		.exclusive = 1,
  		.r = {
  			[0] = {
  				.slots	= (1 << AC97_SLOT_PCM_LEFT) |
  					  (1 << AC97_SLOT_PCM_RIGHT) |
  					  (1 << AC97_SLOT_PCM_CENTER) |
  					  (1 << AC97_SLOT_PCM_SLEFT) |
  					  (1 << AC97_SLOT_PCM_SRIGHT) |
  					  (1 << AC97_SLOT_LFE),
  			},

  			[1] = {
  				.slots	= (1 << AC97_SLOT_PCM_LEFT) |
  					  (1 << AC97_SLOT_PCM_RIGHT) |
  					  (1 << AC97_SLOT_PCM_LEFT_0) |
  					  (1 << AC97_SLOT_PCM_RIGHT_0),
  			},

  		},
  	},
  	[1] = {	/* PCM in */
  		.stream = 1,
  		.exclusive = 1,
  		.r = {
  			[0] = {
  				.slots	= (1 << AC97_SLOT_PCM_LEFT) |
  					  (1 << AC97_SLOT_PCM_RIGHT),
  			},
  		},
  	},
  	[2] = {	/* Mic in */
  		.stream = 1,
  		.exclusive = 1,
  		.r = {
  			[0] = {
  				.slots	= (1 << AC97_SLOT_MIC),
  			},
  		},
  	}
  };

  static struct snd_ac97_bus_ops aaci_bus_ops = {

  	.write	= aaci_ac97_write,
  	.read	= aaci_ac97_read,
  };
  
  static int __devinit aaci_probe_ac97(struct aaci *aaci)
  {

  	struct snd_ac97_template ac97_template;
  	struct snd_ac97_bus *ac97_bus;
  	struct snd_ac97 *ac97;

  	int ret;
  
  	/*
  	 * Assert AACIRESET for 2us
  	 */
  	writel(0, aaci->base + AACI_RESET);
  	udelay(2);
  	writel(RESET_NRST, aaci->base + AACI_RESET);
  
  	/*
  	 * Give the AC'97 codec more than enough time
  	 * to wake up. (42us = ~2 frames at 48kHz.)
  	 */

  	udelay(FRAME_PERIOD_US * 2);

  
  	ret = snd_ac97_bus(aaci->card, 0, &aaci_bus_ops, aaci, &ac97_bus);
  	if (ret)
  		goto out;
  
  	ac97_bus->clock = 48000;
  	aaci->ac97_bus = ac97_bus;

  	memset(&ac97_template, 0, sizeof(struct snd_ac97_template));

  	ac97_template.private_data = aaci;
  	ac97_template.num = 0;
  	ac97_template.scaps = AC97_SCAP_SKIP_MODEM;
  
  	ret = snd_ac97_mixer(ac97_bus, &ac97_template, &ac97);
  	if (ret)
  		goto out;

  	aaci->ac97 = ac97;

  
  	/*
  	 * Disable AC97 PC Beep input on audio codecs.
  	 */
  	if (ac97_is_audio(ac97))
  		snd_ac97_write_cache(ac97, AC97_PC_BEEP, 0x801e);
  
  	ret = snd_ac97_pcm_assign(ac97_bus, ARRAY_SIZE(ac97_defs), ac97_defs);
  	if (ret)
  		goto out;
  
  	aaci->playback.pcm = &ac97_bus->pcms[0];

  	aaci->capture.pcm  = &ac97_bus->pcms[1];

  
   out:
  	return ret;
  }

  static void aaci_free_card(struct snd_card *card)

  {
  	struct aaci *aaci = card->private_data;
  	if (aaci->base)
  		iounmap(aaci->base);
  }
  
  static struct aaci * __devinit aaci_init_card(struct amba_device *dev)
  {
  	struct aaci *aaci;

  	struct snd_card *card;

  	int err;

  	err = snd_card_create(SNDRV_DEFAULT_IDX1, SNDRV_DEFAULT_STR1,
  			      THIS_MODULE, sizeof(struct aaci), &card);
  	if (err < 0)

  		return NULL;

  
  	card->private_free = aaci_free_card;

  
  	strlcpy(card->driver, DRIVER_NAME, sizeof(card->driver));
  	strlcpy(card->shortname, "ARM AC'97 Interface", sizeof(card->shortname));
  	snprintf(card->longname, sizeof(card->longname),

  		 "%s PL%03x rev%u at 0x%08llx, irq %d",
  		 card->shortname, amba_part(dev), amba_rev(dev),
  		 (unsigned long long)dev->res.start, dev->irq[0]);

  
  	aaci = card->private_data;

  	mutex_init(&aaci->ac97_sem);

  	mutex_init(&aaci->irq_lock);

  	aaci->card = card;
  	aaci->dev = dev;
  
  	/* Set MAINCR to allow slot 1 and 2 data IO */
  	aaci->maincr = MAINCR_IE | MAINCR_SL1RXEN | MAINCR_SL1TXEN |
  		       MAINCR_SL2RXEN | MAINCR_SL2TXEN;
  
  	return aaci;
  }
  
  static int __devinit aaci_init_pcm(struct aaci *aaci)
  {

  	struct snd_pcm *pcm;

  	int ret;

  	ret = snd_pcm_new(aaci->card, "AACI AC'97", 0, 1, 1, &pcm);

  	if (ret == 0) {
  		aaci->pcm = pcm;
  		pcm->private_data = aaci;
  		pcm->info_flags = 0;
  
  		strlcpy(pcm->name, DRIVER_NAME, sizeof(pcm->name));
  
  		snd_pcm_set_ops(pcm, SNDRV_PCM_STREAM_PLAYBACK, &aaci_playback_ops);

  		snd_pcm_set_ops(pcm, SNDRV_PCM_STREAM_CAPTURE, &aaci_capture_ops);

  		snd_pcm_lib_preallocate_pages_for_all(pcm, SNDRV_DMA_TYPE_DEV,

  						      NULL, 0, 64 * 1024);

  	}
  
  	return ret;
  }
  
  static unsigned int __devinit aaci_size_fifo(struct aaci *aaci)
  {

  	struct aaci_runtime *aacirun = &aaci->playback;

  	int i;

  	/*
  	 * Enable the channel, but don't assign it to any slots, so
  	 * it won't empty onto the AC'97 link.
  	 */

  	writel(CR_FEN | CR_SZ16 | CR_EN, aacirun->base + AACI_TXCR);

  	for (i = 0; !(readl(aacirun->base + AACI_SR) & SR_TXFF) && i < 4096; i++)
  		writel(0, aacirun->fifo);

  	writel(0, aacirun->base + AACI_TXCR);

  
  	/*
  	 * Re-initialise the AACI after the FIFO depth test, to
  	 * ensure that the FIFOs are empty.  Unfortunately, merely
  	 * disabling the channel doesn't clear the FIFO.
  	 */
  	writel(aaci->maincr & ~MAINCR_IE, aaci->base + AACI_MAINCR);

  	readl(aaci->base + AACI_MAINCR);
  	udelay(1);

  	writel(aaci->maincr, aaci->base + AACI_MAINCR);
  
  	/*

  	 * If we hit 4096 entries, we failed.  Go back to the specified

  	 * fifo depth.
  	 */
  	if (i == 4096)
  		i = 8;
  
  	return i;
  }

  static int __devinit aaci_probe(struct amba_device *dev,
  	const struct amba_id *id)

  {
  	struct aaci *aaci;
  	int ret, i;
  
  	ret = amba_request_regions(dev, NULL);
  	if (ret)
  		return ret;
  
  	aaci = aaci_init_card(dev);

  	if (!aaci) {
  		ret = -ENOMEM;

  		goto out;
  	}

  	aaci->base = ioremap(dev->res.start, resource_size(&dev->res));

  	if (!aaci->base) {
  		ret = -ENOMEM;
  		goto out;
  	}
  
  	/*
  	 * Playback uses AACI channel 0
  	 */

  	spin_lock_init(&aaci->playback.lock);

  	aaci->playback.base = aaci->base + AACI_CSCH1;
  	aaci->playback.fifo = aaci->base + AACI_DR1;

  	/*
  	 * Capture uses AACI channel 0
  	 */

  	spin_lock_init(&aaci->capture.lock);

  	aaci->capture.base = aaci->base + AACI_CSCH1;
  	aaci->capture.fifo = aaci->base + AACI_DR1;

  	for (i = 0; i < 4; i++) {

  		void __iomem *base = aaci->base + i * 0x14;

  
  		writel(0, base + AACI_IE);
  		writel(0, base + AACI_TXCR);
  		writel(0, base + AACI_RXCR);
  	}
  
  	writel(0x1fff, aaci->base + AACI_INTCLR);
  	writel(aaci->maincr, aaci->base + AACI_MAINCR);

  	/*
  	 * Fix: ac97 read back fail errors by reading
  	 * from any arbitrary aaci register.
  	 */
  	readl(aaci->base + AACI_CSCH1);

  	ret = aaci_probe_ac97(aaci);
  	if (ret)
  		goto out;

  	/*

  	 * Size the FIFOs (must be multiple of 16).

  	 * This is the number of entries in the FIFO.

  	 */

  	aaci->fifo_depth = aaci_size_fifo(aaci);
  	if (aaci->fifo_depth & 15) {
  		printk(KERN_WARNING "AACI: FIFO depth %d not supported
  ",
  		       aaci->fifo_depth);

  		ret = -ENODEV;

  		goto out;

  	}

  
  	ret = aaci_init_pcm(aaci);
  	if (ret)
  		goto out;

  	snd_card_set_dev(aaci->card, &dev->dev);

  	ret = snd_card_register(aaci->card);
  	if (ret == 0) {

  		dev_info(&dev->dev, "%s
  ", aaci->card->longname);
  		dev_info(&dev->dev, "FIFO %u entries
  ", aaci->fifo_depth);

  		amba_set_drvdata(dev, aaci->card);
  		return ret;
  	}
  
   out:
  	if (aaci)
  		snd_card_free(aaci->card);
  	amba_release_regions(dev);
  	return ret;
  }
  
  static int __devexit aaci_remove(struct amba_device *dev)
  {

  	struct snd_card *card = amba_get_drvdata(dev);

  
  	amba_set_drvdata(dev, NULL);
  
  	if (card) {
  		struct aaci *aaci = card->private_data;
  		writel(0, aaci->base + AACI_MAINCR);
  
  		snd_card_free(card);
  		amba_release_regions(dev);
  	}
  
  	return 0;
  }
  
  static struct amba_id aaci_ids[] = {
  	{
  		.id	= 0x00041041,
  		.mask	= 0x000fffff,
  	},
  	{ 0, 0 },
  };

  MODULE_DEVICE_TABLE(amba, aaci_ids);

  static struct amba_driver aaci_driver = {
  	.drv		= {
  		.name	= DRIVER_NAME,
  	},
  	.probe		= aaci_probe,
  	.remove		= __devexit_p(aaci_remove),
  	.suspend	= aaci_suspend,
  	.resume		= aaci_resume,
  	.id_table	= aaci_ids,
  };
  
  static int __init aaci_init(void)
  {
  	return amba_driver_register(&aaci_driver);
  }
  
  static void __exit aaci_exit(void)
  {
  	amba_driver_unregister(&aaci_driver);
  }
  
  module_init(aaci_init);
  module_exit(aaci_exit);
  
  MODULE_LICENSE("GPL");
  MODULE_DESCRIPTION("ARM PrimeCell PL041 Advanced Audio CODEC Interface driver");