sound/soc/samsung/s3c24xx-i2s.c - third_party/kernel - Git at Google

 // SPDX-License-Identifier: GPL-2.0+
 //
 // s3c24xx-i2s.c  --  ALSA Soc Audio Layer
 //
 // (c) 2006 Wolfson Microelectronics PLC.
 // Graeme Gregory graeme.gregory@wolfsonmicro.com or linux@wolfsonmicro.com
 //
 // Copyright 2004-2005 Simtec Electronics
 //	http://armlinux.simtec.co.uk/
 //	Ben Dooks <ben@simtec.co.uk>

 #include <linux/delay.h>
 #include <linux/clk.h>
 #include <linux/io.h>
 #include <linux/gpio.h>
 #include <linux/module.h>

 #include <sound/soc.h>
 #include <sound/pcm_params.h>

 #include "regs-iis.h"
 #include "dma.h"
 #include "s3c24xx-i2s.h"

 static struct snd_dmaengine_dai_dma_data s3c24xx_i2s_pcm_stereo_out = {
 	.chan_name	= "tx",
 	.addr_width	= 2,
 };

 static struct snd_dmaengine_dai_dma_data s3c24xx_i2s_pcm_stereo_in = {
 	.chan_name	= "rx",
 	.addr_width	= 2,
 };

 struct s3c24xx_i2s_info {
 	void __iomem	*regs;
 	struct clk	*iis_clk;
 	u32		iiscon;
 	u32		iismod;
 	u32		iisfcon;
 	u32		iispsr;
 };
 static struct s3c24xx_i2s_info s3c24xx_i2s;

 static void s3c24xx_snd_txctrl(int on)
 {
 	u32 iisfcon;
 	u32 iiscon;
 	u32 iismod;

 	iisfcon = readl(s3c24xx_i2s.regs + S3C2410_IISFCON);
 	iiscon  = readl(s3c24xx_i2s.regs + S3C2410_IISCON);
 	iismod  = readl(s3c24xx_i2s.regs + S3C2410_IISMOD);

 	pr_debug("r: IISCON: %x IISMOD: %x IISFCON: %x\n", iiscon, iismod, iisfcon);

 	if (on) {
 		iisfcon |= S3C2410_IISFCON_TXDMA | S3C2410_IISFCON_TXENABLE;
 		iiscon  |= S3C2410_IISCON_TXDMAEN | S3C2410_IISCON_IISEN;
 		iiscon  &= ~S3C2410_IISCON_TXIDLE;
 		iismod  |= S3C2410_IISMOD_TXMODE;

 		writel(iismod,  s3c24xx_i2s.regs + S3C2410_IISMOD);
 		writel(iisfcon, s3c24xx_i2s.regs + S3C2410_IISFCON);
 		writel(iiscon,  s3c24xx_i2s.regs + S3C2410_IISCON);
 	} else {
 		/* note, we have to disable the FIFOs otherwise bad things
 		 * seem to happen when the DMA stops. According to the
 		 * Samsung supplied kernel, this should allow the DMA
 		 * engine and FIFOs to reset. If this isn't allowed, the
 		 * DMA engine will simply freeze randomly.
 		 */

 		iisfcon &= ~S3C2410_IISFCON_TXENABLE;
 		iisfcon &= ~S3C2410_IISFCON_TXDMA;
 		iiscon  |=  S3C2410_IISCON_TXIDLE;
 		iiscon  &= ~S3C2410_IISCON_TXDMAEN;
 		iismod  &= ~S3C2410_IISMOD_TXMODE;

 		writel(iiscon,  s3c24xx_i2s.regs + S3C2410_IISCON);
 		writel(iisfcon, s3c24xx_i2s.regs + S3C2410_IISFCON);
 		writel(iismod,  s3c24xx_i2s.regs + S3C2410_IISMOD);
 	}

 	pr_debug("w: IISCON: %x IISMOD: %x IISFCON: %x\n", iiscon, iismod, iisfcon);
 }

 static void s3c24xx_snd_rxctrl(int on)
 {
 	u32 iisfcon;
 	u32 iiscon;
 	u32 iismod;

 	iisfcon = readl(s3c24xx_i2s.regs + S3C2410_IISFCON);
 	iiscon  = readl(s3c24xx_i2s.regs + S3C2410_IISCON);
 	iismod  = readl(s3c24xx_i2s.regs + S3C2410_IISMOD);

 	pr_debug("r: IISCON: %x IISMOD: %x IISFCON: %x\n", iiscon, iismod, iisfcon);

 	if (on) {
 		iisfcon |= S3C2410_IISFCON_RXDMA | S3C2410_IISFCON_RXENABLE;
 		iiscon  |= S3C2410_IISCON_RXDMAEN | S3C2410_IISCON_IISEN;
 		iiscon  &= ~S3C2410_IISCON_RXIDLE;
 		iismod  |= S3C2410_IISMOD_RXMODE;

 		writel(iismod,  s3c24xx_i2s.regs + S3C2410_IISMOD);
 		writel(iisfcon, s3c24xx_i2s.regs + S3C2410_IISFCON);
 		writel(iiscon,  s3c24xx_i2s.regs + S3C2410_IISCON);
 	} else {
 		/* note, we have to disable the FIFOs otherwise bad things
 		 * seem to happen when the DMA stops. According to the
 		 * Samsung supplied kernel, this should allow the DMA
 		 * engine and FIFOs to reset. If this isn't allowed, the
 		 * DMA engine will simply freeze randomly.
 		 */

 		iisfcon &= ~S3C2410_IISFCON_RXENABLE;
 		iisfcon &= ~S3C2410_IISFCON_RXDMA;
 		iiscon  |= S3C2410_IISCON_RXIDLE;
 		iiscon  &= ~S3C2410_IISCON_RXDMAEN;
 		iismod  &= ~S3C2410_IISMOD_RXMODE;

 		writel(iisfcon, s3c24xx_i2s.regs + S3C2410_IISFCON);
 		writel(iiscon,  s3c24xx_i2s.regs + S3C2410_IISCON);
 		writel(iismod,  s3c24xx_i2s.regs + S3C2410_IISMOD);
 	}

 	pr_debug("w: IISCON: %x IISMOD: %x IISFCON: %x\n", iiscon, iismod, iisfcon);
 }

 /*
  * 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 s3c24xx_snd_lrsync(void)
 {
 	u32 iiscon;
 	int timeout = 50; /* 5ms */

 	while (1) {
 		iiscon = readl(s3c24xx_i2s.regs + S3C2410_IISCON);
 		if (iiscon & S3C2410_IISCON_LRINDEX)
 			break;

 		if (!timeout--)
 			return -ETIMEDOUT;
 		udelay(100);
 	}

 	return 0;
 }

 /*
  * Check whether CPU is the master or slave
  */
 static inline int s3c24xx_snd_is_clkmaster(void)
 {
 	return (readl(s3c24xx_i2s.regs + S3C2410_IISMOD) & S3C2410_IISMOD_SLAVE) ? 0:1;
 }

 /*
  * Set S3C24xx I2S DAI format
  */
 static int s3c24xx_i2s_set_fmt(struct snd_soc_dai *cpu_dai,
 		unsigned int fmt)
 {
 	u32 iismod;

 	iismod = readl(s3c24xx_i2s.regs + S3C2410_IISMOD);
 	pr_debug("hw_params r: IISMOD: %x \n", iismod);

 	switch (fmt & SND_SOC_DAIFMT_MASTER_MASK) {
 	case SND_SOC_DAIFMT_CBM_CFM:
 		iismod |= S3C2410_IISMOD_SLAVE;
 		break;
 	case SND_SOC_DAIFMT_CBS_CFS:
 		iismod &= ~S3C2410_IISMOD_SLAVE;
 		break;
 	default:
 		return -EINVAL;
 	}

 	switch (fmt & SND_SOC_DAIFMT_FORMAT_MASK) {
 	case SND_SOC_DAIFMT_LEFT_J:
 		iismod |= S3C2410_IISMOD_MSB;
 		break;
 	case SND_SOC_DAIFMT_I2S:
 		iismod &= ~S3C2410_IISMOD_MSB;
 		break;
 	default:
 		return -EINVAL;
 	}

 	writel(iismod, s3c24xx_i2s.regs + S3C2410_IISMOD);
 	pr_debug("hw_params w: IISMOD: %x \n", iismod);

 	return 0;
 }

 static int s3c24xx_i2s_hw_params(struct snd_pcm_substream *substream,
 				 struct snd_pcm_hw_params *params,
 				 struct snd_soc_dai *dai)
 {
 	struct snd_dmaengine_dai_dma_data *dma_data;
 	u32 iismod;

 	dma_data = snd_soc_dai_get_dma_data(dai, substream);

 	/* Working copies of register */
 	iismod = readl(s3c24xx_i2s.regs + S3C2410_IISMOD);
 	pr_debug("hw_params r: IISMOD: %x\n", iismod);

 	switch (params_width(params)) {
 	case 8:
 		iismod &= ~S3C2410_IISMOD_16BIT;
 		dma_data->addr_width = 1;
 		break;
 	case 16:
 		iismod |= S3C2410_IISMOD_16BIT;
 		dma_data->addr_width = 2;
 		break;
 	default:
 		return -EINVAL;
 	}

 	writel(iismod, s3c24xx_i2s.regs + S3C2410_IISMOD);
 	pr_debug("hw_params w: IISMOD: %x\n", iismod);

 	return 0;
 }

 static int s3c24xx_i2s_trigger(struct snd_pcm_substream *substream, int cmd,
 			       struct snd_soc_dai *dai)
 {
 	int ret = 0;

 	switch (cmd) {
 	case SNDRV_PCM_TRIGGER_START:
 	case SNDRV_PCM_TRIGGER_RESUME:
 	case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
 		if (!s3c24xx_snd_is_clkmaster()) {
 			ret = s3c24xx_snd_lrsync();
 			if (ret)
 				goto exit_err;
 		}

 		if (substream->stream == SNDRV_PCM_STREAM_CAPTURE)
 			s3c24xx_snd_rxctrl(1);
 		else
 			s3c24xx_snd_txctrl(1);

 		break;
 	case SNDRV_PCM_TRIGGER_STOP:
 	case SNDRV_PCM_TRIGGER_SUSPEND:
 	case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
 		if (substream->stream == SNDRV_PCM_STREAM_CAPTURE)
 			s3c24xx_snd_rxctrl(0);
 		else
 			s3c24xx_snd_txctrl(0);
 		break;
 	default:
 		ret = -EINVAL;
 		break;
 	}

 exit_err:
 	return ret;
 }

 /*
  * Set S3C24xx Clock source
  */
 static int s3c24xx_i2s_set_sysclk(struct snd_soc_dai *cpu_dai,
 	int clk_id, unsigned int freq, int dir)
 {
 	u32 iismod = readl(s3c24xx_i2s.regs + S3C2410_IISMOD);

 	iismod &= ~S3C2440_IISMOD_MPLL;

 	switch (clk_id) {
 	case S3C24XX_CLKSRC_PCLK:
 		break;
 	case S3C24XX_CLKSRC_MPLL:
 		iismod |= S3C2440_IISMOD_MPLL;
 		break;
 	default:
 		return -EINVAL;
 	}

 	writel(iismod, s3c24xx_i2s.regs + S3C2410_IISMOD);
 	return 0;
 }

 /*
  * Set S3C24xx Clock dividers
  */
 static int s3c24xx_i2s_set_clkdiv(struct snd_soc_dai *cpu_dai,
 	int div_id, int div)
 {
 	u32 reg;

 	switch (div_id) {
 	case S3C24XX_DIV_BCLK:
 		reg = readl(s3c24xx_i2s.regs + S3C2410_IISMOD) & ~S3C2410_IISMOD_FS_MASK;
 		writel(reg | div, s3c24xx_i2s.regs + S3C2410_IISMOD);
 		break;
 	case S3C24XX_DIV_MCLK:
 		reg = readl(s3c24xx_i2s.regs + S3C2410_IISMOD) & ~(S3C2410_IISMOD_384FS);
 		writel(reg | div, s3c24xx_i2s.regs + S3C2410_IISMOD);
 		break;
 	case S3C24XX_DIV_PRESCALER:
 		writel(div, s3c24xx_i2s.regs + S3C2410_IISPSR);
 		reg = readl(s3c24xx_i2s.regs + S3C2410_IISCON);
 		writel(reg | S3C2410_IISCON_PSCEN, s3c24xx_i2s.regs + S3C2410_IISCON);
 		break;
 	default:
 		return -EINVAL;
 	}

 	return 0;
 }

 /*
  * To avoid duplicating clock code, allow machine driver to
  * get the clockrate from here.
  */
 u32 s3c24xx_i2s_get_clockrate(void)
 {
 	return clk_get_rate(s3c24xx_i2s.iis_clk);
 }
 EXPORT_SYMBOL_GPL(s3c24xx_i2s_get_clockrate);

 static int s3c24xx_i2s_probe(struct snd_soc_dai *dai)
 {
 	int ret;
 	snd_soc_dai_init_dma_data(dai, &s3c24xx_i2s_pcm_stereo_out,
 					&s3c24xx_i2s_pcm_stereo_in);

 	s3c24xx_i2s.iis_clk = devm_clk_get(dai->dev, "iis");
 	if (IS_ERR(s3c24xx_i2s.iis_clk)) {
 		pr_err("failed to get iis_clock\n");
 		return PTR_ERR(s3c24xx_i2s.iis_clk);
 	}
 	ret = clk_prepare_enable(s3c24xx_i2s.iis_clk);
 	if (ret)
 		return ret;

 	writel(S3C2410_IISCON_IISEN, s3c24xx_i2s.regs + S3C2410_IISCON);

 	s3c24xx_snd_txctrl(0);
 	s3c24xx_snd_rxctrl(0);

 	return 0;
 }

 #ifdef CONFIG_PM
 static int s3c24xx_i2s_suspend(struct snd_soc_component *component)
 {
 	s3c24xx_i2s.iiscon = readl(s3c24xx_i2s.regs + S3C2410_IISCON);
 	s3c24xx_i2s.iismod = readl(s3c24xx_i2s.regs + S3C2410_IISMOD);
 	s3c24xx_i2s.iisfcon = readl(s3c24xx_i2s.regs + S3C2410_IISFCON);
 	s3c24xx_i2s.iispsr = readl(s3c24xx_i2s.regs + S3C2410_IISPSR);

 	clk_disable_unprepare(s3c24xx_i2s.iis_clk);

 	return 0;
 }

 static int s3c24xx_i2s_resume(struct snd_soc_component *component)
 {
 	int ret;

 	ret = clk_prepare_enable(s3c24xx_i2s.iis_clk);
 	if (ret)
 		return ret;

 	writel(s3c24xx_i2s.iiscon, s3c24xx_i2s.regs + S3C2410_IISCON);
 	writel(s3c24xx_i2s.iismod, s3c24xx_i2s.regs + S3C2410_IISMOD);
 	writel(s3c24xx_i2s.iisfcon, s3c24xx_i2s.regs + S3C2410_IISFCON);
 	writel(s3c24xx_i2s.iispsr, s3c24xx_i2s.regs + S3C2410_IISPSR);

 	return 0;
 }
 #else
 #define s3c24xx_i2s_suspend NULL
 #define s3c24xx_i2s_resume NULL
 #endif

 #define S3C24XX_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)

 static const struct snd_soc_dai_ops s3c24xx_i2s_dai_ops = {
 	.trigger	= s3c24xx_i2s_trigger,
 	.hw_params	= s3c24xx_i2s_hw_params,
 	.set_fmt	= s3c24xx_i2s_set_fmt,
 	.set_clkdiv	= s3c24xx_i2s_set_clkdiv,
 	.set_sysclk	= s3c24xx_i2s_set_sysclk,
 };

 static struct snd_soc_dai_driver s3c24xx_i2s_dai = {
 	.probe = s3c24xx_i2s_probe,
 	.playback = {
 		.channels_min = 2,
 		.channels_max = 2,
 		.rates = S3C24XX_I2S_RATES,
 		.formats = SNDRV_PCM_FMTBIT_S8 | SNDRV_PCM_FMTBIT_S16_LE,},
 	.capture = {
 		.channels_min = 2,
 		.channels_max = 2,
 		.rates = S3C24XX_I2S_RATES,
 		.formats = SNDRV_PCM_FMTBIT_S8 | SNDRV_PCM_FMTBIT_S16_LE,},
 	.ops = &s3c24xx_i2s_dai_ops,
 };

 static const struct snd_soc_component_driver s3c24xx_i2s_component = {
 	.name		= "s3c24xx-i2s",
 	.suspend	= s3c24xx_i2s_suspend,
 	.resume		= s3c24xx_i2s_resume,
 };

 static int s3c24xx_iis_dev_probe(struct platform_device *pdev)
 {
 	struct resource *res;
 	int ret;

 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 	s3c24xx_i2s.regs = devm_ioremap_resource(&pdev->dev, res);
 	if (IS_ERR(s3c24xx_i2s.regs))
 		return PTR_ERR(s3c24xx_i2s.regs);

 	s3c24xx_i2s_pcm_stereo_out.addr = res->start + S3C2410_IISFIFO;
 	s3c24xx_i2s_pcm_stereo_in.addr = res->start + S3C2410_IISFIFO;

 	ret = samsung_asoc_dma_platform_register(&pdev->dev, NULL,
 						 "tx", "rx", NULL);
 	if (ret) {
 		dev_err(&pdev->dev, "Failed to register the DMA: %d\n", ret);
 		return ret;
 	}

 	ret = devm_snd_soc_register_component(&pdev->dev,
 			&s3c24xx_i2s_component, &s3c24xx_i2s_dai, 1);
 	if (ret)
 		dev_err(&pdev->dev, "Failed to register the DAI\n");

 	return ret;
 }

 static struct platform_driver s3c24xx_iis_driver = {
 	.probe  = s3c24xx_iis_dev_probe,
 	.driver = {
 		.name = "s3c24xx-iis",
 	},
 };

 module_platform_driver(s3c24xx_iis_driver);

 /* Module information */
 MODULE_AUTHOR("Ben Dooks, <ben@simtec.co.uk>");
 MODULE_DESCRIPTION("s3c24xx I2S SoC Interface");
 MODULE_LICENSE("GPL");
 MODULE_ALIAS("platform:s3c24xx-iis");
	// SPDX-License-Identifier: GPL-2.0+
	//
	// s3c24xx-i2s.c -- ALSA Soc Audio Layer
	//
	// (c) 2006 Wolfson Microelectronics PLC.
	// Graeme Gregory graeme.gregory@wolfsonmicro.com or linux@wolfsonmicro.com
	//
	// Copyright 2004-2005 Simtec Electronics
	// http://armlinux.simtec.co.uk/
	// Ben Dooks <ben@simtec.co.uk>

	#include <linux/delay.h>
	#include <linux/clk.h>
	#include <linux/io.h>
	#include <linux/gpio.h>
	#include <linux/module.h>

	#include <sound/soc.h>
	#include <sound/pcm_params.h>

	#include "regs-iis.h"
	#include "dma.h"
	#include "s3c24xx-i2s.h"

	static struct snd_dmaengine_dai_dma_data s3c24xx_i2s_pcm_stereo_out = {
	.chan_name = "tx",
	.addr_width = 2,
	};

	static struct snd_dmaengine_dai_dma_data s3c24xx_i2s_pcm_stereo_in = {
	.chan_name = "rx",
	.addr_width = 2,
	};

	struct s3c24xx_i2s_info {
	void __iomem *regs;
	struct clk *iis_clk;
	u32 iiscon;
	u32 iismod;
	u32 iisfcon;
	u32 iispsr;
	};
	static struct s3c24xx_i2s_info s3c24xx_i2s;

	static void s3c24xx_snd_txctrl(int on)
	{
	u32 iisfcon;
	u32 iiscon;
	u32 iismod;

	iisfcon = readl(s3c24xx_i2s.regs + S3C2410_IISFCON);
	iiscon = readl(s3c24xx_i2s.regs + S3C2410_IISCON);
	iismod = readl(s3c24xx_i2s.regs + S3C2410_IISMOD);

	pr_debug("r: IISCON: %x IISMOD: %x IISFCON: %x\n", iiscon, iismod, iisfcon);

	if (on) {
	iisfcon \|= S3C2410_IISFCON_TXDMA \| S3C2410_IISFCON_TXENABLE;
	iiscon \|= S3C2410_IISCON_TXDMAEN \| S3C2410_IISCON_IISEN;
	iiscon &= ~S3C2410_IISCON_TXIDLE;
	iismod \|= S3C2410_IISMOD_TXMODE;

	writel(iismod, s3c24xx_i2s.regs + S3C2410_IISMOD);
	writel(iisfcon, s3c24xx_i2s.regs + S3C2410_IISFCON);
	writel(iiscon, s3c24xx_i2s.regs + S3C2410_IISCON);
	} else {
	/* note, we have to disable the FIFOs otherwise bad things
	* seem to happen when the DMA stops. According to the
	* Samsung supplied kernel, this should allow the DMA
	* engine and FIFOs to reset. If this isn't allowed, the
	* DMA engine will simply freeze randomly.
	*/

	iisfcon &= ~S3C2410_IISFCON_TXENABLE;
	iisfcon &= ~S3C2410_IISFCON_TXDMA;
	iiscon \|= S3C2410_IISCON_TXIDLE;
	iiscon &= ~S3C2410_IISCON_TXDMAEN;
	iismod &= ~S3C2410_IISMOD_TXMODE;

	writel(iiscon, s3c24xx_i2s.regs + S3C2410_IISCON);
	writel(iisfcon, s3c24xx_i2s.regs + S3C2410_IISFCON);
	writel(iismod, s3c24xx_i2s.regs + S3C2410_IISMOD);
	}

	pr_debug("w: IISCON: %x IISMOD: %x IISFCON: %x\n", iiscon, iismod, iisfcon);
	}

	static void s3c24xx_snd_rxctrl(int on)
	{
	u32 iisfcon;
	u32 iiscon;
	u32 iismod;

	iisfcon = readl(s3c24xx_i2s.regs + S3C2410_IISFCON);
	iiscon = readl(s3c24xx_i2s.regs + S3C2410_IISCON);
	iismod = readl(s3c24xx_i2s.regs + S3C2410_IISMOD);

	pr_debug("r: IISCON: %x IISMOD: %x IISFCON: %x\n", iiscon, iismod, iisfcon);

	if (on) {
	iisfcon \|= S3C2410_IISFCON_RXDMA \| S3C2410_IISFCON_RXENABLE;
	iiscon \|= S3C2410_IISCON_RXDMAEN \| S3C2410_IISCON_IISEN;
	iiscon &= ~S3C2410_IISCON_RXIDLE;
	iismod \|= S3C2410_IISMOD_RXMODE;

	writel(iismod, s3c24xx_i2s.regs + S3C2410_IISMOD);
	writel(iisfcon, s3c24xx_i2s.regs + S3C2410_IISFCON);
	writel(iiscon, s3c24xx_i2s.regs + S3C2410_IISCON);
	} else {
	/* note, we have to disable the FIFOs otherwise bad things
	* seem to happen when the DMA stops. According to the
	* Samsung supplied kernel, this should allow the DMA
	* engine and FIFOs to reset. If this isn't allowed, the
	* DMA engine will simply freeze randomly.
	*/

	iisfcon &= ~S3C2410_IISFCON_RXENABLE;
	iisfcon &= ~S3C2410_IISFCON_RXDMA;
	iiscon \|= S3C2410_IISCON_RXIDLE;
	iiscon &= ~S3C2410_IISCON_RXDMAEN;
	iismod &= ~S3C2410_IISMOD_RXMODE;

	writel(iisfcon, s3c24xx_i2s.regs + S3C2410_IISFCON);
	writel(iiscon, s3c24xx_i2s.regs + S3C2410_IISCON);
	writel(iismod, s3c24xx_i2s.regs + S3C2410_IISMOD);
	}

	pr_debug("w: IISCON: %x IISMOD: %x IISFCON: %x\n", iiscon, iismod, iisfcon);
	}

	/*
	* 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 s3c24xx_snd_lrsync(void)
	{
	u32 iiscon;
	int timeout = 50; /* 5ms */

	while (1) {
	iiscon = readl(s3c24xx_i2s.regs + S3C2410_IISCON);
	if (iiscon & S3C2410_IISCON_LRINDEX)
	break;

	if (!timeout--)
	return -ETIMEDOUT;
	udelay(100);
	}

	return 0;
	}

	/*
	* Check whether CPU is the master or slave
	*/
	static inline int s3c24xx_snd_is_clkmaster(void)
	{
	return (readl(s3c24xx_i2s.regs + S3C2410_IISMOD) & S3C2410_IISMOD_SLAVE) ? 0:1;
	}

	/*
	* Set S3C24xx I2S DAI format
	*/
	static int s3c24xx_i2s_set_fmt(struct snd_soc_dai *cpu_dai,
	unsigned int fmt)
	{
	u32 iismod;

	iismod = readl(s3c24xx_i2s.regs + S3C2410_IISMOD);
	pr_debug("hw_params r: IISMOD: %x \n", iismod);

	switch (fmt & SND_SOC_DAIFMT_MASTER_MASK) {
	case SND_SOC_DAIFMT_CBM_CFM:
	iismod \|= S3C2410_IISMOD_SLAVE;
	break;
	case SND_SOC_DAIFMT_CBS_CFS:
	iismod &= ~S3C2410_IISMOD_SLAVE;
	break;
	default:
	return -EINVAL;
	}

	switch (fmt & SND_SOC_DAIFMT_FORMAT_MASK) {
	case SND_SOC_DAIFMT_LEFT_J:
	iismod \|= S3C2410_IISMOD_MSB;
	break;
	case SND_SOC_DAIFMT_I2S:
	iismod &= ~S3C2410_IISMOD_MSB;
	break;
	default:
	return -EINVAL;
	}

	writel(iismod, s3c24xx_i2s.regs + S3C2410_IISMOD);
	pr_debug("hw_params w: IISMOD: %x \n", iismod);

	return 0;
	}

	static int s3c24xx_i2s_hw_params(struct snd_pcm_substream *substream,
	struct snd_pcm_hw_params *params,
	struct snd_soc_dai *dai)
	{
	struct snd_dmaengine_dai_dma_data *dma_data;
	u32 iismod;

	dma_data = snd_soc_dai_get_dma_data(dai, substream);

	/* Working copies of register */
	iismod = readl(s3c24xx_i2s.regs + S3C2410_IISMOD);
	pr_debug("hw_params r: IISMOD: %x\n", iismod);

	switch (params_width(params)) {
	case 8:
	iismod &= ~S3C2410_IISMOD_16BIT;
	dma_data->addr_width = 1;
	break;
	case 16:
	iismod \|= S3C2410_IISMOD_16BIT;
	dma_data->addr_width = 2;
	break;
	default:
	return -EINVAL;
	}

	writel(iismod, s3c24xx_i2s.regs + S3C2410_IISMOD);
	pr_debug("hw_params w: IISMOD: %x\n", iismod);

	return 0;
	}

	static int s3c24xx_i2s_trigger(struct snd_pcm_substream *substream, int cmd,
	struct snd_soc_dai *dai)
	{
	int ret = 0;

	switch (cmd) {
	case SNDRV_PCM_TRIGGER_START:
	case SNDRV_PCM_TRIGGER_RESUME:
	case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
	if (!s3c24xx_snd_is_clkmaster()) {
	ret = s3c24xx_snd_lrsync();
	if (ret)
	goto exit_err;
	}

	if (substream->stream == SNDRV_PCM_STREAM_CAPTURE)
	s3c24xx_snd_rxctrl(1);
	else
	s3c24xx_snd_txctrl(1);

	break;
	case SNDRV_PCM_TRIGGER_STOP:
	case SNDRV_PCM_TRIGGER_SUSPEND:
	case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
	if (substream->stream == SNDRV_PCM_STREAM_CAPTURE)
	s3c24xx_snd_rxctrl(0);
	else
	s3c24xx_snd_txctrl(0);
	break;
	default:
	ret = -EINVAL;
	break;
	}

	exit_err:
	return ret;
	}

	/*
	* Set S3C24xx Clock source
	*/
	static int s3c24xx_i2s_set_sysclk(struct snd_soc_dai *cpu_dai,
	int clk_id, unsigned int freq, int dir)
	{
	u32 iismod = readl(s3c24xx_i2s.regs + S3C2410_IISMOD);

	iismod &= ~S3C2440_IISMOD_MPLL;

	switch (clk_id) {
	case S3C24XX_CLKSRC_PCLK:
	break;
	case S3C24XX_CLKSRC_MPLL:
	iismod \|= S3C2440_IISMOD_MPLL;
	break;
	default:
	return -EINVAL;
	}

	writel(iismod, s3c24xx_i2s.regs + S3C2410_IISMOD);
	return 0;
	}

	/*
	* Set S3C24xx Clock dividers
	*/
	static int s3c24xx_i2s_set_clkdiv(struct snd_soc_dai *cpu_dai,
	int div_id, int div)
	{
	u32 reg;

	switch (div_id) {
	case S3C24XX_DIV_BCLK:
	reg = readl(s3c24xx_i2s.regs + S3C2410_IISMOD) & ~S3C2410_IISMOD_FS_MASK;
	writel(reg \| div, s3c24xx_i2s.regs + S3C2410_IISMOD);
	break;
	case S3C24XX_DIV_MCLK:
	reg = readl(s3c24xx_i2s.regs + S3C2410_IISMOD) & ~(S3C2410_IISMOD_384FS);
	writel(reg \| div, s3c24xx_i2s.regs + S3C2410_IISMOD);
	break;
	case S3C24XX_DIV_PRESCALER:
	writel(div, s3c24xx_i2s.regs + S3C2410_IISPSR);
	reg = readl(s3c24xx_i2s.regs + S3C2410_IISCON);
	writel(reg \| S3C2410_IISCON_PSCEN, s3c24xx_i2s.regs + S3C2410_IISCON);
	break;
	default:
	return -EINVAL;
	}

	return 0;
	}

	/*
	* To avoid duplicating clock code, allow machine driver to
	* get the clockrate from here.
	*/
	u32 s3c24xx_i2s_get_clockrate(void)
	{
	return clk_get_rate(s3c24xx_i2s.iis_clk);
	}
	EXPORT_SYMBOL_GPL(s3c24xx_i2s_get_clockrate);

	static int s3c24xx_i2s_probe(struct snd_soc_dai *dai)
	{
	int ret;
	snd_soc_dai_init_dma_data(dai, &s3c24xx_i2s_pcm_stereo_out,
	&s3c24xx_i2s_pcm_stereo_in);

	s3c24xx_i2s.iis_clk = devm_clk_get(dai->dev, "iis");
	if (IS_ERR(s3c24xx_i2s.iis_clk)) {
	pr_err("failed to get iis_clock\n");
	return PTR_ERR(s3c24xx_i2s.iis_clk);
	}
	ret = clk_prepare_enable(s3c24xx_i2s.iis_clk);
	if (ret)
	return ret;

	writel(S3C2410_IISCON_IISEN, s3c24xx_i2s.regs + S3C2410_IISCON);

	s3c24xx_snd_txctrl(0);
	s3c24xx_snd_rxctrl(0);

	return 0;
	}

	#ifdef CONFIG_PM
	static int s3c24xx_i2s_suspend(struct snd_soc_component *component)
	{
	s3c24xx_i2s.iiscon = readl(s3c24xx_i2s.regs + S3C2410_IISCON);
	s3c24xx_i2s.iismod = readl(s3c24xx_i2s.regs + S3C2410_IISMOD);
	s3c24xx_i2s.iisfcon = readl(s3c24xx_i2s.regs + S3C2410_IISFCON);
	s3c24xx_i2s.iispsr = readl(s3c24xx_i2s.regs + S3C2410_IISPSR);

	clk_disable_unprepare(s3c24xx_i2s.iis_clk);

	return 0;
	}

	static int s3c24xx_i2s_resume(struct snd_soc_component *component)
	{
	int ret;

	ret = clk_prepare_enable(s3c24xx_i2s.iis_clk);
	if (ret)
	return ret;

	writel(s3c24xx_i2s.iiscon, s3c24xx_i2s.regs + S3C2410_IISCON);
	writel(s3c24xx_i2s.iismod, s3c24xx_i2s.regs + S3C2410_IISMOD);
	writel(s3c24xx_i2s.iisfcon, s3c24xx_i2s.regs + S3C2410_IISFCON);
	writel(s3c24xx_i2s.iispsr, s3c24xx_i2s.regs + S3C2410_IISPSR);

	return 0;
	}
	#else
	#define s3c24xx_i2s_suspend NULL
	#define s3c24xx_i2s_resume NULL
	#endif

	#define S3C24XX_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)

	static const struct snd_soc_dai_ops s3c24xx_i2s_dai_ops = {
	.trigger = s3c24xx_i2s_trigger,
	.hw_params = s3c24xx_i2s_hw_params,
	.set_fmt = s3c24xx_i2s_set_fmt,
	.set_clkdiv = s3c24xx_i2s_set_clkdiv,
	.set_sysclk = s3c24xx_i2s_set_sysclk,
	};

	static struct snd_soc_dai_driver s3c24xx_i2s_dai = {
	.probe = s3c24xx_i2s_probe,
	.playback = {
	.channels_min = 2,
	.channels_max = 2,
	.rates = S3C24XX_I2S_RATES,
	.formats = SNDRV_PCM_FMTBIT_S8 \| SNDRV_PCM_FMTBIT_S16_LE,},
	.capture = {
	.channels_min = 2,
	.channels_max = 2,
	.rates = S3C24XX_I2S_RATES,
	.formats = SNDRV_PCM_FMTBIT_S8 \| SNDRV_PCM_FMTBIT_S16_LE,},
	.ops = &s3c24xx_i2s_dai_ops,
	};

	static const struct snd_soc_component_driver s3c24xx_i2s_component = {
	.name = "s3c24xx-i2s",
	.suspend = s3c24xx_i2s_suspend,
	.resume = s3c24xx_i2s_resume,
	};

	static int s3c24xx_iis_dev_probe(struct platform_device *pdev)
	{
	struct resource *res;
	int ret;

	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	s3c24xx_i2s.regs = devm_ioremap_resource(&pdev->dev, res);
	if (IS_ERR(s3c24xx_i2s.regs))
	return PTR_ERR(s3c24xx_i2s.regs);

	s3c24xx_i2s_pcm_stereo_out.addr = res->start + S3C2410_IISFIFO;
	s3c24xx_i2s_pcm_stereo_in.addr = res->start + S3C2410_IISFIFO;

	ret = samsung_asoc_dma_platform_register(&pdev->dev, NULL,
	"tx", "rx", NULL);
	if (ret) {
	dev_err(&pdev->dev, "Failed to register the DMA: %d\n", ret);
	return ret;
	}

	ret = devm_snd_soc_register_component(&pdev->dev,
	&s3c24xx_i2s_component, &s3c24xx_i2s_dai, 1);
	if (ret)
	dev_err(&pdev->dev, "Failed to register the DAI\n");

	return ret;
	}

	static struct platform_driver s3c24xx_iis_driver = {
	.probe = s3c24xx_iis_dev_probe,
	.driver = {
	.name = "s3c24xx-iis",
	},
	};

	module_platform_driver(s3c24xx_iis_driver);

	/* Module information */
	MODULE_AUTHOR("Ben Dooks, <ben@simtec.co.uk>");
	MODULE_DESCRIPTION("s3c24xx I2S SoC Interface");
	MODULE_LICENSE("GPL");
	MODULE_ALIAS("platform:s3c24xx-iis");