sound/soc/s3c24xx/s3c2412-i2s.c - maze/linux - Git at Google

 /* sound/soc/s3c24xx/s3c2412-i2s.c
  *
  * ALSA Soc Audio Layer - S3C2412 I2S driver
  *
  * Copyright (c) 2006 Wolfson Microelectronics PLC.
  *	Graeme Gregory graeme.gregory@wolfsonmicro.com
  *	linux@wolfsonmicro.com
  *
  * Copyright (c) 2007, 2004-2005 Simtec Electronics
  *	http://armlinux.simtec.co.uk/
  *	Ben Dooks <ben@simtec.co.uk>
  *
  * 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;  either version 2 of the  License, or (at your
  * option) any later version.
  */

 #include <linux/init.h>
 #include <linux/module.h>
 #include <linux/device.h>
 #include <linux/delay.h>
 #include <linux/clk.h>
 #include <linux/kernel.h>

 #include <sound/core.h>
 #include <sound/pcm.h>
 #include <sound/pcm_params.h>
 #include <sound/initval.h>
 #include <sound/soc.h>
 #include <mach/hardware.h>

 #include <linux/io.h>
 #include <asm/dma.h>

 #include <asm/plat-s3c24xx/regs-s3c2412-iis.h>

 #include <mach/regs-gpio.h>
 #include <mach/audio.h>
 #include <mach/dma.h>

 #include "s3c24xx-pcm.h"
 #include "s3c2412-i2s.h"

 #define S3C2412_I2S_DEBUG 0
 #define S3C2412_I2S_DEBUG_CON 0

 #if S3C2412_I2S_DEBUG
 #define DBG(x...) printk(KERN_INFO x)
 #else
 #define DBG(x...) do { } while (0)
 #endif

 static struct s3c2410_dma_client s3c2412_dma_client_out = {
 	.name		= "I2S PCM Stereo out"
 };

 static struct s3c2410_dma_client s3c2412_dma_client_in = {
 	.name		= "I2S PCM Stereo in"
 };

 static struct s3c24xx_pcm_dma_params s3c2412_i2s_pcm_stereo_out = {
 	.client		= &s3c2412_dma_client_out,
 	.channel	= DMACH_I2S_OUT,
 	.dma_addr	= S3C2410_PA_IIS + S3C2412_IISTXD,
 	.dma_size	= 4,
 };

 static struct s3c24xx_pcm_dma_params s3c2412_i2s_pcm_stereo_in = {
 	.client		= &s3c2412_dma_client_in,
 	.channel	= DMACH_I2S_IN,
 	.dma_addr	= S3C2410_PA_IIS + S3C2412_IISRXD,
 	.dma_size	= 4,
 };

 struct s3c2412_i2s_info {
 	struct device	*dev;
 	void __iomem	*regs;
 	struct clk	*iis_clk;
 	struct clk	*iis_pclk;
 	struct clk	*iis_cclk;

 	u32		 suspend_iismod;
 	u32		 suspend_iiscon;
 	u32		 suspend_iispsr;
 };

 static struct s3c2412_i2s_info s3c2412_i2s;

 #define bit_set(v, b) (((v) & (b)) ? 1 : 0)

 #if S3C2412_I2S_DEBUG_CON
 static void dbg_showcon(const char *fn, u32 con)
 {
 	printk(KERN_DEBUG "%s: LRI=%d, TXFEMPT=%d, RXFEMPT=%d, TXFFULL=%d, RXFFULL=%d\n", fn,
 	       bit_set(con, S3C2412_IISCON_LRINDEX),
 	       bit_set(con, S3C2412_IISCON_TXFIFO_EMPTY),
 	       bit_set(con, S3C2412_IISCON_RXFIFO_EMPTY),
 	       bit_set(con, S3C2412_IISCON_TXFIFO_FULL),
 	       bit_set(con, S3C2412_IISCON_RXFIFO_FULL));

 	printk(KERN_DEBUG "%s: PAUSE: TXDMA=%d, RXDMA=%d, TXCH=%d, RXCH=%d\n",
 	       fn,
 	       bit_set(con, S3C2412_IISCON_TXDMA_PAUSE),
 	       bit_set(con, S3C2412_IISCON_RXDMA_PAUSE),
 	       bit_set(con, S3C2412_IISCON_TXCH_PAUSE),
 	       bit_set(con, S3C2412_IISCON_RXCH_PAUSE));
 	printk(KERN_DEBUG "%s: ACTIVE: TXDMA=%d, RXDMA=%d, IIS=%d\n", fn,
 	       bit_set(con, S3C2412_IISCON_TXDMA_ACTIVE),
 	       bit_set(con, S3C2412_IISCON_RXDMA_ACTIVE),
 	       bit_set(con, S3C2412_IISCON_IIS_ACTIVE));
 }
 #else
 static inline void dbg_showcon(const char *fn, u32 con)
 {
 }
 #endif

 /* Turn on or off the transmission path. */
 static void s3c2412_snd_txctrl(int on)
 {
 	struct s3c2412_i2s_info *i2s = &s3c2412_i2s;
 	void __iomem *regs = i2s->regs;
 	u32 fic, con, mod;

 	DBG("%s(%d)\n", __func__, on);

 	fic = readl(regs + S3C2412_IISFIC);
 	con = readl(regs + S3C2412_IISCON);
 	mod = readl(regs + S3C2412_IISMOD);

 	DBG("%s: IIS: CON=%x MOD=%x FIC=%x\n", __func__, con, mod, fic);

 	if (on) {
 		con |= S3C2412_IISCON_TXDMA_ACTIVE | S3C2412_IISCON_IIS_ACTIVE;
 		con &= ~S3C2412_IISCON_TXDMA_PAUSE;
 		con &= ~S3C2412_IISCON_TXCH_PAUSE;

 		switch (mod & S3C2412_IISMOD_MODE_MASK) {
 		case S3C2412_IISMOD_MODE_TXONLY:
 		case S3C2412_IISMOD_MODE_TXRX:
 			/* do nothing, we are in the right mode */
 			break;

 		case S3C2412_IISMOD_MODE_RXONLY:
 			mod &= ~S3C2412_IISMOD_MODE_MASK;
 			mod |= S3C2412_IISMOD_MODE_TXRX;
 			break;

 		default:
 			dev_err(i2s->dev, "TXEN: Invalid MODE in IISMOD\n");
 		}

 		writel(con, regs + S3C2412_IISCON);
 		writel(mod, regs + S3C2412_IISMOD);
 	} else {
 		/* Note, we do not have any indication that the FIFO problems
 		 * tha the S3C2410/2440 had apply here, so we should be able
 		 * to disable the DMA and TX without resetting the FIFOS.
 		 */

 		con |=  S3C2412_IISCON_TXDMA_PAUSE;
 		con |=  S3C2412_IISCON_TXCH_PAUSE;
 		con &= ~S3C2412_IISCON_TXDMA_ACTIVE;

 		switch (mod & S3C2412_IISMOD_MODE_MASK) {
 		case S3C2412_IISMOD_MODE_TXRX:
 			mod &= ~S3C2412_IISMOD_MODE_MASK;
 			mod |= S3C2412_IISMOD_MODE_RXONLY;
 			break;

 		case S3C2412_IISMOD_MODE_TXONLY:
 			mod &= ~S3C2412_IISMOD_MODE_MASK;
 			con &= ~S3C2412_IISCON_IIS_ACTIVE;
 			break;

 		default:
 			dev_err(i2s->dev, "TXDIS: Invalid MODE in IISMOD\n");
 		}

 		writel(mod, regs + S3C2412_IISMOD);
 		writel(con, regs + S3C2412_IISCON);
 	}

 	fic = readl(regs + S3C2412_IISFIC);
 	dbg_showcon(__func__, con);
 	DBG("%s: IIS: CON=%x MOD=%x FIC=%x\n", __func__, con, mod, fic);
 }

 static void s3c2412_snd_rxctrl(int on)
 {
 	struct s3c2412_i2s_info *i2s = &s3c2412_i2s;
 	void __iomem *regs = i2s->regs;
 	u32 fic, con, mod;

 	DBG("%s(%d)\n", __func__, on);

 	fic = readl(regs + S3C2412_IISFIC);
 	con = readl(regs + S3C2412_IISCON);
 	mod = readl(regs + S3C2412_IISMOD);

 	DBG("%s: IIS: CON=%x MOD=%x FIC=%x\n", __func__, con, mod, fic);

 	if (on) {
 		con |= S3C2412_IISCON_RXDMA_ACTIVE | S3C2412_IISCON_IIS_ACTIVE;
 		con &= ~S3C2412_IISCON_RXDMA_PAUSE;
 		con &= ~S3C2412_IISCON_RXCH_PAUSE;

 		switch (mod & S3C2412_IISMOD_MODE_MASK) {
 		case S3C2412_IISMOD_MODE_TXRX:
 		case S3C2412_IISMOD_MODE_RXONLY:
 			/* do nothing, we are in the right mode */
 			break;

 		case S3C2412_IISMOD_MODE_TXONLY:
 			mod &= ~S3C2412_IISMOD_MODE_MASK;
 			mod |= S3C2412_IISMOD_MODE_TXRX;
 			break;

 		default:
 			dev_err(i2s->dev, "RXEN: Invalid MODE in IISMOD\n");
 		}

 		writel(mod, regs + S3C2412_IISMOD);
 		writel(con, regs + S3C2412_IISCON);
 	} else {
 		/* See txctrl notes on FIFOs. */

 		con &= ~S3C2412_IISCON_RXDMA_ACTIVE;
 		con |=  S3C2412_IISCON_RXDMA_PAUSE;
 		con |=  S3C2412_IISCON_RXCH_PAUSE;

 		switch (mod & S3C2412_IISMOD_MODE_MASK) {
 		case S3C2412_IISMOD_MODE_RXONLY:
 			con &= ~S3C2412_IISCON_IIS_ACTIVE;
 			mod &= ~S3C2412_IISMOD_MODE_MASK;
 			break;

 		case S3C2412_IISMOD_MODE_TXRX:
 			mod &= ~S3C2412_IISMOD_MODE_MASK;
 			mod |= S3C2412_IISMOD_MODE_TXONLY;
 			break;

 		default:
 			dev_err(i2s->dev, "RXEN: Invalid MODE in IISMOD\n");
 		}

 		writel(con, regs + S3C2412_IISCON);
 		writel(mod, regs + S3C2412_IISMOD);
 	}

 	fic = readl(regs + S3C2412_IISFIC);
 	DBG("%s: IIS: CON=%x MOD=%x FIC=%x\n", __func__, con, mod, fic);
 }


 /*
  * Wait for the LR signal to allow synchronisation to the L/R clock
  * from the codec. May only be needed for slave mode.
  */
 static int s3c2412_snd_lrsync(void)
 {
 	u32 iiscon;
 	unsigned long timeout = jiffies + msecs_to_jiffies(5);

 	DBG("Entered %s\n", __func__);

 	while (1) {
 		iiscon = readl(s3c2412_i2s.regs + S3C2412_IISCON);
 		if (iiscon & S3C2412_IISCON_LRINDEX)
 			break;

 		if (timeout < jiffies) {
 			printk(KERN_ERR "%s: timeout\n", __func__);
 			return -ETIMEDOUT;
 		}
 	}

 	return 0;
 }

 /*
  * Check whether CPU is the master or slave
  */
 static inline int s3c2412_snd_is_clkmaster(void)
 {
 	u32 iismod = readl(s3c2412_i2s.regs + S3C2412_IISMOD);

 	DBG("Entered %s\n", __func__);

 	iismod &= S3C2412_IISMOD_MASTER_MASK;
 	return !(iismod == S3C2412_IISMOD_SLAVE);
 }

 /*
  * Set S3C2412 I2S DAI format
  */
 static int s3c2412_i2s_set_fmt(struct snd_soc_dai *cpu_dai,
 			       unsigned int fmt)
 {
 	u32 iismod;


 	DBG("Entered %s\n", __func__);

 	iismod = readl(s3c2412_i2s.regs + S3C2412_IISMOD);
 	DBG("hw_params r: IISMOD: %x \n", iismod);

 	switch (fmt & SND_SOC_DAIFMT_MASTER_MASK) {
 	case SND_SOC_DAIFMT_CBM_CFM:
 		iismod &= ~S3C2412_IISMOD_MASTER_MASK;
 		iismod |= S3C2412_IISMOD_SLAVE;
 		break;
 	case SND_SOC_DAIFMT_CBS_CFS:
 		iismod &= ~S3C2412_IISMOD_MASTER_MASK;
 		iismod |= S3C2412_IISMOD_MASTER_INTERNAL;
 		break;
 	default:
 		DBG("unknwon master/slave format\n");
 		return -EINVAL;
 	}

 	iismod &= ~S3C2412_IISMOD_SDF_MASK;

 	switch (fmt & SND_SOC_DAIFMT_FORMAT_MASK) {
 	case SND_SOC_DAIFMT_RIGHT_J:
 		iismod |= S3C2412_IISMOD_SDF_MSB;
 		break;
 	case SND_SOC_DAIFMT_LEFT_J:
 		iismod |= S3C2412_IISMOD_SDF_LSB;
 		break;
 	case SND_SOC_DAIFMT_I2S:
 		iismod |= S3C2412_IISMOD_SDF_IIS;
 		break;
 	default:
 		DBG("Unknown data format\n");
 		return -EINVAL;
 	}

 	writel(iismod, s3c2412_i2s.regs + S3C2412_IISMOD);
 	DBG("hw_params w: IISMOD: %x \n", iismod);
 	return 0;
 }

 static int s3c2412_i2s_hw_params(struct snd_pcm_substream *substream,
 				 struct snd_pcm_hw_params *params)
 {
 	struct snd_soc_pcm_runtime *rtd = substream->private_data;
 	u32 iismod;

 	DBG("Entered %s\n", __func__);

 	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
 		rtd->dai->cpu_dai->dma_data = &s3c2412_i2s_pcm_stereo_out;
 	else
 		rtd->dai->cpu_dai->dma_data = &s3c2412_i2s_pcm_stereo_in;

 	/* Working copies of register */
 	iismod = readl(s3c2412_i2s.regs + S3C2412_IISMOD);
 	DBG("%s: r: IISMOD: %x\n", __func__, iismod);

 	switch (params_format(params)) {
 	case SNDRV_PCM_FORMAT_S8:
 		iismod |= S3C2412_IISMOD_8BIT;
 		break;
 	case SNDRV_PCM_FORMAT_S16_LE:
 		iismod &= ~S3C2412_IISMOD_8BIT;
 		break;
 	}

 	writel(iismod, s3c2412_i2s.regs + S3C2412_IISMOD);
 	DBG("%s: w: IISMOD: %x\n", __func__, iismod);
 	return 0;
 }

 static int s3c2412_i2s_trigger(struct snd_pcm_substream *substream, int cmd)
 {
 	int capture = (substream->stream == SNDRV_PCM_STREAM_CAPTURE);
 	unsigned long irqs;
 	int ret = 0;

 	DBG("Entered %s\n", __func__);

 	switch (cmd) {
 	case SNDRV_PCM_TRIGGER_START:
 		/* On start, ensure that the FIFOs are cleared and reset. */

 		writel(capture ? S3C2412_IISFIC_RXFLUSH : S3C2412_IISFIC_TXFLUSH,
 		       s3c2412_i2s.regs + S3C2412_IISFIC);

 		/* clear again, just in case */
 		writel(0x0, s3c2412_i2s.regs + S3C2412_IISFIC);

 	case SNDRV_PCM_TRIGGER_RESUME:
 	case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
 		if (!s3c2412_snd_is_clkmaster()) {
 			ret = s3c2412_snd_lrsync();
 			if (ret)
 				goto exit_err;
 		}

 		local_irq_save(irqs);

 		if (capture)
 			s3c2412_snd_rxctrl(1);
 		else
 			s3c2412_snd_txctrl(1);

 		local_irq_restore(irqs);
 		break;

 	case SNDRV_PCM_TRIGGER_STOP:
 	case SNDRV_PCM_TRIGGER_SUSPEND:
 	case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
 		local_irq_save(irqs);

 		if (capture)
 			s3c2412_snd_rxctrl(0);
 		else
 			s3c2412_snd_txctrl(0);

 		local_irq_restore(irqs);
 		break;
 	default:
 		ret = -EINVAL;
 		break;
 	}

 exit_err:
 	return ret;
 }

 /* default table of all avaialable root fs divisors */
 static unsigned int s3c2412_iis_fs[] = { 256, 512, 384, 768, 0 };

 int s3c2412_iis_calc_rate(struct s3c2412_rate_calc *info,
 			  unsigned int *fstab,
 			  unsigned int rate, struct clk *clk)
 {
 	unsigned long clkrate = clk_get_rate(clk);
 	unsigned int div;
 	unsigned int fsclk;
 	unsigned int actual;
 	unsigned int fs;
 	unsigned int fsdiv;
 	signed int deviation = 0;
 	unsigned int best_fs = 0;
 	unsigned int best_div = 0;
 	unsigned int best_rate = 0;
 	unsigned int best_deviation = INT_MAX;


 	if (fstab == NULL)
 		fstab = s3c2412_iis_fs;

 	for (fs = 0;; fs++) {
 		fsdiv = s3c2412_iis_fs[fs];

 		if (fsdiv == 0)
 			break;

 		fsclk = clkrate / fsdiv;
 		div = fsclk / rate;

 		if ((fsclk % rate) > (rate / 2))
 			div++;

 		if (div <= 1)
 			continue;

 		actual = clkrate / (fsdiv * div);
 		deviation = actual - rate;

 		printk(KERN_DEBUG "%dfs: div %d => result %d, deviation %d\n",
 		       fsdiv, div, actual, deviation);

 		deviation = abs(deviation);

 		if (deviation < best_deviation) {
 			best_fs = fsdiv;
 			best_div = div;
 			best_rate = actual;
 			best_deviation = deviation;
 		}

 		if (deviation == 0)
 			break;
 	}

 	printk(KERN_DEBUG "best: fs=%d, div=%d, rate=%d\n",
 	       best_fs, best_div, best_rate);

 	info->fs_div = best_fs;
 	info->clk_div = best_div;

 	return 0;
 }
 EXPORT_SYMBOL_GPL(s3c2412_iis_calc_rate);

 /*
  * Set S3C2412 Clock source
  */
 static int s3c2412_i2s_set_sysclk(struct snd_soc_dai *cpu_dai,
 				  int clk_id, unsigned int freq, int dir)
 {
 	u32 iismod = readl(s3c2412_i2s.regs + S3C2412_IISMOD);

 	DBG("%s(%p, %d, %u, %d)\n", __func__, cpu_dai, clk_id,
 	    freq, dir);

 	switch (clk_id) {
 	case S3C2412_CLKSRC_PCLK:
 		iismod &= ~S3C2412_IISMOD_MASTER_MASK;
 		iismod |= S3C2412_IISMOD_MASTER_INTERNAL;
 		break;
 	case S3C2412_CLKSRC_I2SCLK:
 		iismod &= ~S3C2412_IISMOD_MASTER_MASK;
 		iismod |= S3C2412_IISMOD_MASTER_EXTERNAL;
 		break;
 	default:
 		return -EINVAL;
 	}

 	writel(iismod, s3c2412_i2s.regs + S3C2412_IISMOD);
 	return 0;
 }

 /*
  * Set S3C2412 Clock dividers
  */
 static int s3c2412_i2s_set_clkdiv(struct snd_soc_dai *cpu_dai,
 				  int div_id, int div)
 {
 	struct s3c2412_i2s_info *i2s = &s3c2412_i2s;
 	u32 reg;

 	DBG("%s(%p, %d, %d)\n", __func__, cpu_dai, div_id, div);

 	switch (div_id) {
 	case S3C2412_DIV_BCLK:
 		reg = readl(i2s->regs + S3C2412_IISMOD);
 		reg &= ~S3C2412_IISMOD_BCLK_MASK;
 		writel(reg | div, i2s->regs + S3C2412_IISMOD);

 		DBG("%s: MOD=%08x\n", __func__, readl(i2s->regs + S3C2412_IISMOD));
 		break;

 	case S3C2412_DIV_RCLK:
 		if (div > 3) {
 			/* convert value to bit field */

 			switch (div) {
 			case 256:
 				div = S3C2412_IISMOD_RCLK_256FS;
 				break;

 			case 384:
 				div = S3C2412_IISMOD_RCLK_384FS;
 				break;

 			case 512:
 				div = S3C2412_IISMOD_RCLK_512FS;
 				break;

 			case 768:
 				div = S3C2412_IISMOD_RCLK_768FS;
 				break;

 			default:
 				return -EINVAL;
 			}
 		}

 		reg = readl(s3c2412_i2s.regs + S3C2412_IISMOD);
 		reg &= ~S3C2412_IISMOD_RCLK_MASK;
 		writel(reg | div, i2s->regs + S3C2412_IISMOD);
 		DBG("%s: MOD=%08x\n", __func__, readl(i2s->regs + S3C2412_IISMOD));
 		break;

 	case S3C2412_DIV_PRESCALER:
 		if (div >= 0) {
 			writel((div << 8) | S3C2412_IISPSR_PSREN,
 			       i2s->regs + S3C2412_IISPSR);
 		} else {
 			writel(0x0, i2s->regs + S3C2412_IISPSR);
 		}
 		DBG("%s: PSR=%08x\n", __func__, readl(i2s->regs + S3C2412_IISPSR));
 		break;

 	default:
 		return -EINVAL;
 	}

 	return 0;
 }

 struct clk *s3c2412_get_iisclk(void)
 {
 	return s3c2412_i2s.iis_clk;
 }
 EXPORT_SYMBOL_GPL(s3c2412_get_iisclk);


 static int s3c2412_i2s_probe(struct platform_device *pdev,
 			     struct snd_soc_dai *dai)
 {
 	DBG("Entered %s\n", __func__);

 	s3c2412_i2s.dev = &pdev->dev;

 	s3c2412_i2s.regs = ioremap(S3C2410_PA_IIS, 0x100);
 	if (s3c2412_i2s.regs == NULL)
 		return -ENXIO;

 	s3c2412_i2s.iis_pclk = clk_get(&pdev->dev, "iis");
 	if (s3c2412_i2s.iis_pclk == NULL) {
 		DBG("failed to get iis_clock\n");
 		iounmap(s3c2412_i2s.regs);
 		return -ENODEV;
 	}

 	s3c2412_i2s.iis_cclk = clk_get(&pdev->dev, "i2sclk");
 	if (s3c2412_i2s.iis_cclk == NULL) {
 		DBG("failed to get i2sclk clock\n");
 		iounmap(s3c2412_i2s.regs);
 		return -ENODEV;
 	}

 	clk_set_parent(s3c2412_i2s.iis_cclk, clk_get(NULL, "mpll"));

 	clk_enable(s3c2412_i2s.iis_pclk);
 	clk_enable(s3c2412_i2s.iis_cclk);

 	s3c2412_i2s.iis_clk = s3c2412_i2s.iis_pclk;

 	/* Configure the I2S pins in correct mode */
 	s3c2410_gpio_cfgpin(S3C2410_GPE0, S3C2410_GPE0_I2SLRCK);
 	s3c2410_gpio_cfgpin(S3C2410_GPE1, S3C2410_GPE1_I2SSCLK);
 	s3c2410_gpio_cfgpin(S3C2410_GPE2, S3C2410_GPE2_CDCLK);
 	s3c2410_gpio_cfgpin(S3C2410_GPE3, S3C2410_GPE3_I2SSDI);
 	s3c2410_gpio_cfgpin(S3C2410_GPE4, S3C2410_GPE4_I2SSDO);

 	s3c2412_snd_txctrl(0);
 	s3c2412_snd_rxctrl(0);

 	return 0;
 }

 #ifdef CONFIG_PM
 static int s3c2412_i2s_suspend(struct platform_device *dev,
 			      struct snd_soc_dai *dai)
 {
 	struct s3c2412_i2s_info *i2s = &s3c2412_i2s;
 	u32 iismod;

 	if (dai->active) {
 		i2s->suspend_iismod = readl(i2s->regs + S3C2412_IISMOD);
 		i2s->suspend_iiscon = readl(i2s->regs + S3C2412_IISCON);
 		i2s->suspend_iispsr = readl(i2s->regs + S3C2412_IISPSR);

 		/* some basic suspend checks */

 		iismod = readl(i2s->regs + S3C2412_IISMOD);

 		if (iismod & S3C2412_IISCON_RXDMA_ACTIVE)
 			dev_warn(&dev->dev, "%s: RXDMA active?\n", __func__);

 		if (iismod & S3C2412_IISCON_TXDMA_ACTIVE)
 			dev_warn(&dev->dev, "%s: TXDMA active?\n", __func__);

 		if (iismod & S3C2412_IISCON_IIS_ACTIVE)
 			dev_warn(&dev->dev, "%s: IIS active\n", __func__);
 	}

 	return 0;
 }

 static int s3c2412_i2s_resume(struct platform_device *pdev,
 			      struct snd_soc_dai *dai)
 {
 	struct s3c2412_i2s_info *i2s = &s3c2412_i2s;

 	dev_info(&pdev->dev, "dai_active %d, IISMOD %08x, IISCON %08x\n",
 		 dai->active, i2s->suspend_iismod, i2s->suspend_iiscon);

 	if (dai->active) {
 		writel(i2s->suspend_iiscon, i2s->regs + S3C2412_IISCON);
 		writel(i2s->suspend_iismod, i2s->regs + S3C2412_IISMOD);
 		writel(i2s->suspend_iispsr, i2s->regs + S3C2412_IISPSR);

 		writel(S3C2412_IISFIC_RXFLUSH | S3C2412_IISFIC_TXFLUSH,
 		       i2s->regs + S3C2412_IISFIC);

 		ndelay(250);
 		writel(0x0, i2s->regs + S3C2412_IISFIC);

 	}

 	return 0;
 }
 #else
 #define s3c2412_i2s_suspend NULL
 #define s3c2412_i2s_resume  NULL
 #endif /* CONFIG_PM */

 #define S3C2412_I2S_RATES \
 	(SNDRV_PCM_RATE_8000 | SNDRV_PCM_RATE_11025 | SNDRV_PCM_RATE_16000 | \
 	SNDRV_PCM_RATE_22050 | SNDRV_PCM_RATE_32000 | SNDRV_PCM_RATE_44100 | \
 	SNDRV_PCM_RATE_48000 | SNDRV_PCM_RATE_88200 | SNDRV_PCM_RATE_96000)

 struct snd_soc_dai s3c2412_i2s_dai = {
 	.name	= "s3c2412-i2s",
 	.id	= 0,
 	.type	= SND_SOC_DAI_I2S,
 	.probe	= s3c2412_i2s_probe,
 	.suspend = s3c2412_i2s_suspend,
 	.resume = s3c2412_i2s_resume,
 	.playback = {
 		.channels_min	= 2,
 		.channels_max	= 2,
 		.rates		= S3C2412_I2S_RATES,
 		.formats	= SNDRV_PCM_FMTBIT_S8 | SNDRV_PCM_FMTBIT_S16_LE,
 	},
 	.capture = {
 		.channels_min	= 2,
 		.channels_max	= 2,
 		.rates		= S3C2412_I2S_RATES,
 		.formats	= SNDRV_PCM_FMTBIT_S8 | SNDRV_PCM_FMTBIT_S16_LE,
 	},
 	.ops = {
 		.trigger	= s3c2412_i2s_trigger,
 		.hw_params	= s3c2412_i2s_hw_params,
 	},
 	.dai_ops = {
 		.set_fmt	= s3c2412_i2s_set_fmt,
 		.set_clkdiv	= s3c2412_i2s_set_clkdiv,
 		.set_sysclk	= s3c2412_i2s_set_sysclk,
 	},
 };
 EXPORT_SYMBOL_GPL(s3c2412_i2s_dai);

 /* Module information */
 MODULE_AUTHOR("Ben Dooks, <ben@simtec.co.uk>");
 MODULE_DESCRIPTION("S3C2412 I2S SoC Interface");
 MODULE_LICENSE("GPL");
	/* sound/soc/s3c24xx/s3c2412-i2s.c
	*
	* ALSA Soc Audio Layer - S3C2412 I2S driver
	*
	* Copyright (c) 2006 Wolfson Microelectronics PLC.
	* Graeme Gregory graeme.gregory@wolfsonmicro.com
	* linux@wolfsonmicro.com
	*
	* Copyright (c) 2007, 2004-2005 Simtec Electronics
	* http://armlinux.simtec.co.uk/
	* Ben Dooks <ben@simtec.co.uk>
	*
	* 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; either version 2 of the License, or (at your
	* option) any later version.
	*/

	#include <linux/init.h>
	#include <linux/module.h>
	#include <linux/device.h>
	#include <linux/delay.h>
	#include <linux/clk.h>
	#include <linux/kernel.h>

	#include <sound/core.h>
	#include <sound/pcm.h>
	#include <sound/pcm_params.h>
	#include <sound/initval.h>
	#include <sound/soc.h>
	#include <mach/hardware.h>

	#include <linux/io.h>
	#include <asm/dma.h>

	#include <asm/plat-s3c24xx/regs-s3c2412-iis.h>

	#include <mach/regs-gpio.h>
	#include <mach/audio.h>
	#include <mach/dma.h>

	#include "s3c24xx-pcm.h"
	#include "s3c2412-i2s.h"

	#define S3C2412_I2S_DEBUG 0
	#define S3C2412_I2S_DEBUG_CON 0

	#if S3C2412_I2S_DEBUG
	#define DBG(x...) printk(KERN_INFO x)
	#else
	#define DBG(x...) do { } while (0)
	#endif

	static struct s3c2410_dma_client s3c2412_dma_client_out = {
	.name = "I2S PCM Stereo out"
	};

	static struct s3c2410_dma_client s3c2412_dma_client_in = {
	.name = "I2S PCM Stereo in"
	};

	static struct s3c24xx_pcm_dma_params s3c2412_i2s_pcm_stereo_out = {
	.client = &s3c2412_dma_client_out,
	.channel = DMACH_I2S_OUT,
	.dma_addr = S3C2410_PA_IIS + S3C2412_IISTXD,
	.dma_size = 4,
	};

	static struct s3c24xx_pcm_dma_params s3c2412_i2s_pcm_stereo_in = {
	.client = &s3c2412_dma_client_in,
	.channel = DMACH_I2S_IN,
	.dma_addr = S3C2410_PA_IIS + S3C2412_IISRXD,
	.dma_size = 4,
	};

	struct s3c2412_i2s_info {
	struct device *dev;
	void __iomem *regs;
	struct clk *iis_clk;
	struct clk *iis_pclk;
	struct clk *iis_cclk;

	u32 suspend_iismod;
	u32 suspend_iiscon;
	u32 suspend_iispsr;
	};

	static struct s3c2412_i2s_info s3c2412_i2s;

	#define bit_set(v, b) (((v) & (b)) ? 1 : 0)

	#if S3C2412_I2S_DEBUG_CON
	static void dbg_showcon(const char *fn, u32 con)
	{
	printk(KERN_DEBUG "%s: LRI=%d, TXFEMPT=%d, RXFEMPT=%d, TXFFULL=%d, RXFFULL=%d\n", fn,
	bit_set(con, S3C2412_IISCON_LRINDEX),
	bit_set(con, S3C2412_IISCON_TXFIFO_EMPTY),
	bit_set(con, S3C2412_IISCON_RXFIFO_EMPTY),
	bit_set(con, S3C2412_IISCON_TXFIFO_FULL),
	bit_set(con, S3C2412_IISCON_RXFIFO_FULL));

	printk(KERN_DEBUG "%s: PAUSE: TXDMA=%d, RXDMA=%d, TXCH=%d, RXCH=%d\n",
	fn,
	bit_set(con, S3C2412_IISCON_TXDMA_PAUSE),
	bit_set(con, S3C2412_IISCON_RXDMA_PAUSE),
	bit_set(con, S3C2412_IISCON_TXCH_PAUSE),
	bit_set(con, S3C2412_IISCON_RXCH_PAUSE));
	printk(KERN_DEBUG "%s: ACTIVE: TXDMA=%d, RXDMA=%d, IIS=%d\n", fn,
	bit_set(con, S3C2412_IISCON_TXDMA_ACTIVE),
	bit_set(con, S3C2412_IISCON_RXDMA_ACTIVE),
	bit_set(con, S3C2412_IISCON_IIS_ACTIVE));
	}
	#else
	static inline void dbg_showcon(const char *fn, u32 con)
	{
	}
	#endif

	/* Turn on or off the transmission path. */
	static void s3c2412_snd_txctrl(int on)
	{
	struct s3c2412_i2s_info *i2s = &s3c2412_i2s;
	void __iomem *regs = i2s->regs;
	u32 fic, con, mod;

	DBG("%s(%d)\n", __func__, on);

	fic = readl(regs + S3C2412_IISFIC);
	con = readl(regs + S3C2412_IISCON);
	mod = readl(regs + S3C2412_IISMOD);

	DBG("%s: IIS: CON=%x MOD=%x FIC=%x\n", __func__, con, mod, fic);

	if (on) {
	con \|= S3C2412_IISCON_TXDMA_ACTIVE \| S3C2412_IISCON_IIS_ACTIVE;
	con &= ~S3C2412_IISCON_TXDMA_PAUSE;
	con &= ~S3C2412_IISCON_TXCH_PAUSE;

	switch (mod & S3C2412_IISMOD_MODE_MASK) {
	case S3C2412_IISMOD_MODE_TXONLY:
	case S3C2412_IISMOD_MODE_TXRX:
	/* do nothing, we are in the right mode */
	break;

	case S3C2412_IISMOD_MODE_RXONLY:
	mod &= ~S3C2412_IISMOD_MODE_MASK;
	mod \|= S3C2412_IISMOD_MODE_TXRX;
	break;

	default:
	dev_err(i2s->dev, "TXEN: Invalid MODE in IISMOD\n");
	}

	writel(con, regs + S3C2412_IISCON);
	writel(mod, regs + S3C2412_IISMOD);
	} else {
	/* Note, we do not have any indication that the FIFO problems
	* tha the S3C2410/2440 had apply here, so we should be able
	* to disable the DMA and TX without resetting the FIFOS.
	*/

	con \|= S3C2412_IISCON_TXDMA_PAUSE;
	con \|= S3C2412_IISCON_TXCH_PAUSE;
	con &= ~S3C2412_IISCON_TXDMA_ACTIVE;

	switch (mod & S3C2412_IISMOD_MODE_MASK) {
	case S3C2412_IISMOD_MODE_TXRX:
	mod &= ~S3C2412_IISMOD_MODE_MASK;
	mod \|= S3C2412_IISMOD_MODE_RXONLY;
	break;

	case S3C2412_IISMOD_MODE_TXONLY:
	mod &= ~S3C2412_IISMOD_MODE_MASK;
	con &= ~S3C2412_IISCON_IIS_ACTIVE;
	break;

	default:
	dev_err(i2s->dev, "TXDIS: Invalid MODE in IISMOD\n");
	}

	writel(mod, regs + S3C2412_IISMOD);
	writel(con, regs + S3C2412_IISCON);
	}

	fic = readl(regs + S3C2412_IISFIC);
	dbg_showcon(__func__, con);
	DBG("%s: IIS: CON=%x MOD=%x FIC=%x\n", __func__, con, mod, fic);
	}

	static void s3c2412_snd_rxctrl(int on)
	{
	struct s3c2412_i2s_info *i2s = &s3c2412_i2s;
	void __iomem *regs = i2s->regs;
	u32 fic, con, mod;

	DBG("%s(%d)\n", __func__, on);

	fic = readl(regs + S3C2412_IISFIC);
	con = readl(regs + S3C2412_IISCON);
	mod = readl(regs + S3C2412_IISMOD);

	DBG("%s: IIS: CON=%x MOD=%x FIC=%x\n", __func__, con, mod, fic);

	if (on) {
	con \|= S3C2412_IISCON_RXDMA_ACTIVE \| S3C2412_IISCON_IIS_ACTIVE;
	con &= ~S3C2412_IISCON_RXDMA_PAUSE;
	con &= ~S3C2412_IISCON_RXCH_PAUSE;

	switch (mod & S3C2412_IISMOD_MODE_MASK) {
	case S3C2412_IISMOD_MODE_TXRX:
	case S3C2412_IISMOD_MODE_RXONLY:
	/* do nothing, we are in the right mode */
	break;

	case S3C2412_IISMOD_MODE_TXONLY:
	mod &= ~S3C2412_IISMOD_MODE_MASK;
	mod \|= S3C2412_IISMOD_MODE_TXRX;
	break;

	default:
	dev_err(i2s->dev, "RXEN: Invalid MODE in IISMOD\n");
	}

	writel(mod, regs + S3C2412_IISMOD);
	writel(con, regs + S3C2412_IISCON);
	} else {
	/* See txctrl notes on FIFOs. */

	con &= ~S3C2412_IISCON_RXDMA_ACTIVE;
	con \|= S3C2412_IISCON_RXDMA_PAUSE;
	con \|= S3C2412_IISCON_RXCH_PAUSE;

	switch (mod & S3C2412_IISMOD_MODE_MASK) {
	case S3C2412_IISMOD_MODE_RXONLY:
	con &= ~S3C2412_IISCON_IIS_ACTIVE;
	mod &= ~S3C2412_IISMOD_MODE_MASK;
	break;

	case S3C2412_IISMOD_MODE_TXRX:
	mod &= ~S3C2412_IISMOD_MODE_MASK;
	mod \|= S3C2412_IISMOD_MODE_TXONLY;
	break;

	default:
	dev_err(i2s->dev, "RXEN: Invalid MODE in IISMOD\n");
	}

	writel(con, regs + S3C2412_IISCON);
	writel(mod, regs + S3C2412_IISMOD);
	}

	fic = readl(regs + S3C2412_IISFIC);
	DBG("%s: IIS: CON=%x MOD=%x FIC=%x\n", __func__, con, mod, fic);
	}


	/*
	* Wait for the LR signal to allow synchronisation to the L/R clock
	* from the codec. May only be needed for slave mode.
	*/
	static int s3c2412_snd_lrsync(void)
	{
	u32 iiscon;
	unsigned long timeout = jiffies + msecs_to_jiffies(5);

	DBG("Entered %s\n", __func__);

	while (1) {
	iiscon = readl(s3c2412_i2s.regs + S3C2412_IISCON);
	if (iiscon & S3C2412_IISCON_LRINDEX)
	break;

	if (timeout < jiffies) {
	printk(KERN_ERR "%s: timeout\n", __func__);
	return -ETIMEDOUT;
	}
	}

	return 0;
	}

	/*
	* Check whether CPU is the master or slave
	*/
	static inline int s3c2412_snd_is_clkmaster(void)
	{
	u32 iismod = readl(s3c2412_i2s.regs + S3C2412_IISMOD);

	DBG("Entered %s\n", __func__);

	iismod &= S3C2412_IISMOD_MASTER_MASK;
	return !(iismod == S3C2412_IISMOD_SLAVE);
	}

	/*
	* Set S3C2412 I2S DAI format
	*/
	static int s3c2412_i2s_set_fmt(struct snd_soc_dai *cpu_dai,
	unsigned int fmt)
	{
	u32 iismod;


	DBG("Entered %s\n", __func__);

	iismod = readl(s3c2412_i2s.regs + S3C2412_IISMOD);
	DBG("hw_params r: IISMOD: %x \n", iismod);

	switch (fmt & SND_SOC_DAIFMT_MASTER_MASK) {
	case SND_SOC_DAIFMT_CBM_CFM:
	iismod &= ~S3C2412_IISMOD_MASTER_MASK;
	iismod \|= S3C2412_IISMOD_SLAVE;
	break;
	case SND_SOC_DAIFMT_CBS_CFS:
	iismod &= ~S3C2412_IISMOD_MASTER_MASK;
	iismod \|= S3C2412_IISMOD_MASTER_INTERNAL;
	break;
	default:
	DBG("unknwon master/slave format\n");
	return -EINVAL;
	}

	iismod &= ~S3C2412_IISMOD_SDF_MASK;

	switch (fmt & SND_SOC_DAIFMT_FORMAT_MASK) {
	case SND_SOC_DAIFMT_RIGHT_J:
	iismod \|= S3C2412_IISMOD_SDF_MSB;
	break;
	case SND_SOC_DAIFMT_LEFT_J:
	iismod \|= S3C2412_IISMOD_SDF_LSB;
	break;
	case SND_SOC_DAIFMT_I2S:
	iismod \|= S3C2412_IISMOD_SDF_IIS;
	break;
	default:
	DBG("Unknown data format\n");
	return -EINVAL;
	}

	writel(iismod, s3c2412_i2s.regs + S3C2412_IISMOD);
	DBG("hw_params w: IISMOD: %x \n", iismod);
	return 0;
	}

	static int s3c2412_i2s_hw_params(struct snd_pcm_substream *substream,
	struct snd_pcm_hw_params *params)
	{
	struct snd_soc_pcm_runtime *rtd = substream->private_data;
	u32 iismod;

	DBG("Entered %s\n", __func__);

	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
	rtd->dai->cpu_dai->dma_data = &s3c2412_i2s_pcm_stereo_out;
	else
	rtd->dai->cpu_dai->dma_data = &s3c2412_i2s_pcm_stereo_in;

	/* Working copies of register */
	iismod = readl(s3c2412_i2s.regs + S3C2412_IISMOD);
	DBG("%s: r: IISMOD: %x\n", __func__, iismod);

	switch (params_format(params)) {
	case SNDRV_PCM_FORMAT_S8:
	iismod \|= S3C2412_IISMOD_8BIT;
	break;
	case SNDRV_PCM_FORMAT_S16_LE:
	iismod &= ~S3C2412_IISMOD_8BIT;
	break;
	}

	writel(iismod, s3c2412_i2s.regs + S3C2412_IISMOD);
	DBG("%s: w: IISMOD: %x\n", __func__, iismod);
	return 0;
	}

	static int s3c2412_i2s_trigger(struct snd_pcm_substream *substream, int cmd)
	{
	int capture = (substream->stream == SNDRV_PCM_STREAM_CAPTURE);
	unsigned long irqs;
	int ret = 0;

	DBG("Entered %s\n", __func__);

	switch (cmd) {
	case SNDRV_PCM_TRIGGER_START:
	/* On start, ensure that the FIFOs are cleared and reset. */

	writel(capture ? S3C2412_IISFIC_RXFLUSH : S3C2412_IISFIC_TXFLUSH,
	s3c2412_i2s.regs + S3C2412_IISFIC);

	/* clear again, just in case */
	writel(0x0, s3c2412_i2s.regs + S3C2412_IISFIC);

	case SNDRV_PCM_TRIGGER_RESUME:
	case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
	if (!s3c2412_snd_is_clkmaster()) {
	ret = s3c2412_snd_lrsync();
	if (ret)
	goto exit_err;
	}

	local_irq_save(irqs);

	if (capture)
	s3c2412_snd_rxctrl(1);
	else
	s3c2412_snd_txctrl(1);

	local_irq_restore(irqs);
	break;

	case SNDRV_PCM_TRIGGER_STOP:
	case SNDRV_PCM_TRIGGER_SUSPEND:
	case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
	local_irq_save(irqs);

	if (capture)
	s3c2412_snd_rxctrl(0);
	else
	s3c2412_snd_txctrl(0);

	local_irq_restore(irqs);
	break;
	default:
	ret = -EINVAL;
	break;
	}

	exit_err:
	return ret;
	}

	/* default table of all avaialable root fs divisors */
	static unsigned int s3c2412_iis_fs[] = { 256, 512, 384, 768, 0 };

	int s3c2412_iis_calc_rate(struct s3c2412_rate_calc *info,
	unsigned int *fstab,
	unsigned int rate, struct clk *clk)
	{
	unsigned long clkrate = clk_get_rate(clk);
	unsigned int div;
	unsigned int fsclk;
	unsigned int actual;
	unsigned int fs;
	unsigned int fsdiv;
	signed int deviation = 0;
	unsigned int best_fs = 0;
	unsigned int best_div = 0;
	unsigned int best_rate = 0;
	unsigned int best_deviation = INT_MAX;


	if (fstab == NULL)
	fstab = s3c2412_iis_fs;

	for (fs = 0;; fs++) {
	fsdiv = s3c2412_iis_fs[fs];

	if (fsdiv == 0)
	break;

	fsclk = clkrate / fsdiv;
	div = fsclk / rate;

	if ((fsclk % rate) > (rate / 2))
	div++;

	if (div <= 1)
	continue;

	actual = clkrate / (fsdiv * div);
	deviation = actual - rate;

	printk(KERN_DEBUG "%dfs: div %d => result %d, deviation %d\n",
	fsdiv, div, actual, deviation);

	deviation = abs(deviation);

	if (deviation < best_deviation) {
	best_fs = fsdiv;
	best_div = div;
	best_rate = actual;
	best_deviation = deviation;
	}

	if (deviation == 0)
	break;
	}

	printk(KERN_DEBUG "best: fs=%d, div=%d, rate=%d\n",
	best_fs, best_div, best_rate);

	info->fs_div = best_fs;
	info->clk_div = best_div;

	return 0;
	}
	EXPORT_SYMBOL_GPL(s3c2412_iis_calc_rate);

	/*
	* Set S3C2412 Clock source
	*/
	static int s3c2412_i2s_set_sysclk(struct snd_soc_dai *cpu_dai,
	int clk_id, unsigned int freq, int dir)
	{
	u32 iismod = readl(s3c2412_i2s.regs + S3C2412_IISMOD);

	DBG("%s(%p, %d, %u, %d)\n", __func__, cpu_dai, clk_id,
	freq, dir);

	switch (clk_id) {
	case S3C2412_CLKSRC_PCLK:
	iismod &= ~S3C2412_IISMOD_MASTER_MASK;
	iismod \|= S3C2412_IISMOD_MASTER_INTERNAL;
	break;
	case S3C2412_CLKSRC_I2SCLK:
	iismod &= ~S3C2412_IISMOD_MASTER_MASK;
	iismod \|= S3C2412_IISMOD_MASTER_EXTERNAL;
	break;
	default:
	return -EINVAL;
	}

	writel(iismod, s3c2412_i2s.regs + S3C2412_IISMOD);
	return 0;
	}

	/*
	* Set S3C2412 Clock dividers
	*/
	static int s3c2412_i2s_set_clkdiv(struct snd_soc_dai *cpu_dai,
	int div_id, int div)
	{
	struct s3c2412_i2s_info *i2s = &s3c2412_i2s;
	u32 reg;

	DBG("%s(%p, %d, %d)\n", __func__, cpu_dai, div_id, div);

	switch (div_id) {
	case S3C2412_DIV_BCLK:
	reg = readl(i2s->regs + S3C2412_IISMOD);
	reg &= ~S3C2412_IISMOD_BCLK_MASK;
	writel(reg \| div, i2s->regs + S3C2412_IISMOD);

	DBG("%s: MOD=%08x\n", __func__, readl(i2s->regs + S3C2412_IISMOD));
	break;

	case S3C2412_DIV_RCLK:
	if (div > 3) {
	/* convert value to bit field */

	switch (div) {
	case 256:
	div = S3C2412_IISMOD_RCLK_256FS;
	break;

	case 384:
	div = S3C2412_IISMOD_RCLK_384FS;
	break;

	case 512:
	div = S3C2412_IISMOD_RCLK_512FS;
	break;

	case 768:
	div = S3C2412_IISMOD_RCLK_768FS;
	break;

	default:
	return -EINVAL;
	}
	}

	reg = readl(s3c2412_i2s.regs + S3C2412_IISMOD);
	reg &= ~S3C2412_IISMOD_RCLK_MASK;
	writel(reg \| div, i2s->regs + S3C2412_IISMOD);
	DBG("%s: MOD=%08x\n", __func__, readl(i2s->regs + S3C2412_IISMOD));
	break;

	case S3C2412_DIV_PRESCALER:
	if (div >= 0) {
	writel((div << 8) \| S3C2412_IISPSR_PSREN,
	i2s->regs + S3C2412_IISPSR);
	} else {
	writel(0x0, i2s->regs + S3C2412_IISPSR);
	}
	DBG("%s: PSR=%08x\n", __func__, readl(i2s->regs + S3C2412_IISPSR));
	break;

	default:
	return -EINVAL;
	}

	return 0;
	}

	struct clk *s3c2412_get_iisclk(void)
	{
	return s3c2412_i2s.iis_clk;
	}
	EXPORT_SYMBOL_GPL(s3c2412_get_iisclk);


	static int s3c2412_i2s_probe(struct platform_device *pdev,
	struct snd_soc_dai *dai)
	{
	DBG("Entered %s\n", __func__);

	s3c2412_i2s.dev = &pdev->dev;

	s3c2412_i2s.regs = ioremap(S3C2410_PA_IIS, 0x100);
	if (s3c2412_i2s.regs == NULL)
	return -ENXIO;

	s3c2412_i2s.iis_pclk = clk_get(&pdev->dev, "iis");
	if (s3c2412_i2s.iis_pclk == NULL) {
	DBG("failed to get iis_clock\n");
	iounmap(s3c2412_i2s.regs);
	return -ENODEV;
	}

	s3c2412_i2s.iis_cclk = clk_get(&pdev->dev, "i2sclk");
	if (s3c2412_i2s.iis_cclk == NULL) {
	DBG("failed to get i2sclk clock\n");
	iounmap(s3c2412_i2s.regs);
	return -ENODEV;
	}

	clk_set_parent(s3c2412_i2s.iis_cclk, clk_get(NULL, "mpll"));

	clk_enable(s3c2412_i2s.iis_pclk);
	clk_enable(s3c2412_i2s.iis_cclk);

	s3c2412_i2s.iis_clk = s3c2412_i2s.iis_pclk;

	/* Configure the I2S pins in correct mode */
	s3c2410_gpio_cfgpin(S3C2410_GPE0, S3C2410_GPE0_I2SLRCK);
	s3c2410_gpio_cfgpin(S3C2410_GPE1, S3C2410_GPE1_I2SSCLK);
	s3c2410_gpio_cfgpin(S3C2410_GPE2, S3C2410_GPE2_CDCLK);
	s3c2410_gpio_cfgpin(S3C2410_GPE3, S3C2410_GPE3_I2SSDI);
	s3c2410_gpio_cfgpin(S3C2410_GPE4, S3C2410_GPE4_I2SSDO);

	s3c2412_snd_txctrl(0);
	s3c2412_snd_rxctrl(0);

	return 0;
	}

	#ifdef CONFIG_PM
	static int s3c2412_i2s_suspend(struct platform_device *dev,
	struct snd_soc_dai *dai)
	{
	struct s3c2412_i2s_info *i2s = &s3c2412_i2s;
	u32 iismod;

	if (dai->active) {
	i2s->suspend_iismod = readl(i2s->regs + S3C2412_IISMOD);
	i2s->suspend_iiscon = readl(i2s->regs + S3C2412_IISCON);
	i2s->suspend_iispsr = readl(i2s->regs + S3C2412_IISPSR);

	/* some basic suspend checks */

	iismod = readl(i2s->regs + S3C2412_IISMOD);

	if (iismod & S3C2412_IISCON_RXDMA_ACTIVE)
	dev_warn(&dev->dev, "%s: RXDMA active?\n", __func__);

	if (iismod & S3C2412_IISCON_TXDMA_ACTIVE)
	dev_warn(&dev->dev, "%s: TXDMA active?\n", __func__);

	if (iismod & S3C2412_IISCON_IIS_ACTIVE)
	dev_warn(&dev->dev, "%s: IIS active\n", __func__);
	}

	return 0;
	}

	static int s3c2412_i2s_resume(struct platform_device *pdev,
	struct snd_soc_dai *dai)
	{
	struct s3c2412_i2s_info *i2s = &s3c2412_i2s;

	dev_info(&pdev->dev, "dai_active %d, IISMOD %08x, IISCON %08x\n",
	dai->active, i2s->suspend_iismod, i2s->suspend_iiscon);

	if (dai->active) {
	writel(i2s->suspend_iiscon, i2s->regs + S3C2412_IISCON);
	writel(i2s->suspend_iismod, i2s->regs + S3C2412_IISMOD);
	writel(i2s->suspend_iispsr, i2s->regs + S3C2412_IISPSR);

	writel(S3C2412_IISFIC_RXFLUSH \| S3C2412_IISFIC_TXFLUSH,
	i2s->regs + S3C2412_IISFIC);

	ndelay(250);
	writel(0x0, i2s->regs + S3C2412_IISFIC);

	}

	return 0;
	}
	#else
	#define s3c2412_i2s_suspend NULL
	#define s3c2412_i2s_resume NULL
	#endif /* CONFIG_PM */

	#define S3C2412_I2S_RATES \
	(SNDRV_PCM_RATE_8000 \| SNDRV_PCM_RATE_11025 \| SNDRV_PCM_RATE_16000 \| \
	SNDRV_PCM_RATE_22050 \| SNDRV_PCM_RATE_32000 \| SNDRV_PCM_RATE_44100 \| \
	SNDRV_PCM_RATE_48000 \| SNDRV_PCM_RATE_88200 \| SNDRV_PCM_RATE_96000)

	struct snd_soc_dai s3c2412_i2s_dai = {
	.name = "s3c2412-i2s",
	.id = 0,
	.type = SND_SOC_DAI_I2S,
	.probe = s3c2412_i2s_probe,
	.suspend = s3c2412_i2s_suspend,
	.resume = s3c2412_i2s_resume,
	.playback = {
	.channels_min = 2,
	.channels_max = 2,
	.rates = S3C2412_I2S_RATES,
	.formats = SNDRV_PCM_FMTBIT_S8 \| SNDRV_PCM_FMTBIT_S16_LE,
	},
	.capture = {
	.channels_min = 2,
	.channels_max = 2,
	.rates = S3C2412_I2S_RATES,
	.formats = SNDRV_PCM_FMTBIT_S8 \| SNDRV_PCM_FMTBIT_S16_LE,
	},
	.ops = {
	.trigger = s3c2412_i2s_trigger,
	.hw_params = s3c2412_i2s_hw_params,
	},
	.dai_ops = {
	.set_fmt = s3c2412_i2s_set_fmt,
	.set_clkdiv = s3c2412_i2s_set_clkdiv,
	.set_sysclk = s3c2412_i2s_set_sysclk,
	},
	};
	EXPORT_SYMBOL_GPL(s3c2412_i2s_dai);

	/* Module information */
	MODULE_AUTHOR("Ben Dooks, <ben@simtec.co.uk>");
	MODULE_DESCRIPTION("S3C2412 I2S SoC Interface");
	MODULE_LICENSE("GPL");