sound/soc/pxa/pxa2xx-i2s.c - kernel/msm-4.9 - Gitiles

 /*
  * pxa2xx-i2s.c  --  ALSA Soc Audio Layer
  *
  * Copyright 2005 Wolfson Microelectronics PLC.
  * Author: Liam Girdwood
  *         lrg@slimlogic.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/platform_device.h>
 #include <sound/core.h>
 #include <sound/pcm.h>
 #include <sound/initval.h>
 #include <sound/soc.h>
 #include <sound/pxa2xx-lib.h>

 #include <mach/hardware.h>
 #include <mach/pxa-regs.h>
 #include <mach/audio.h>

 #include "pxa2xx-pcm.h"
 #include "pxa2xx-i2s.h"

 /*
  * I2S Controller Register and Bit Definitions
  */
 #define SACR0		__REG(0x40400000)  /* Global Control Register */
 #define SACR1		__REG(0x40400004)  /* Serial Audio I 2 S/MSB-Justified Control Register */
 #define SASR0		__REG(0x4040000C)  /* Serial Audio I 2 S/MSB-Justified Interface and FIFO Status Register */
 #define SAIMR		__REG(0x40400014)  /* Serial Audio Interrupt Mask Register */
 #define SAICR		__REG(0x40400018)  /* Serial Audio Interrupt Clear Register */
 #define SADIV		__REG(0x40400060)  /* Audio Clock Divider Register. */
 #define SADR		__REG(0x40400080)  /* Serial Audio Data Register (TX and RX FIFO access Register). */

 #define SACR0_RFTH(x)	((x) << 12)	/* Rx FIFO Interrupt or DMA Trigger Threshold */
 #define SACR0_TFTH(x)	((x) << 8)	/* Tx FIFO Interrupt or DMA Trigger Threshold */
 #define SACR0_STRF	(1 << 5)	/* FIFO Select for EFWR Special Function */
 #define SACR0_EFWR	(1 << 4)	/* Enable EFWR Function  */
 #define SACR0_RST	(1 << 3)	/* FIFO, i2s Register Reset */
 #define SACR0_BCKD	(1 << 2) 	/* Bit Clock Direction */
 #define SACR0_ENB	(1 << 0)	/* Enable I2S Link */
 #define SACR1_ENLBF	(1 << 5)	/* Enable Loopback */
 #define SACR1_DRPL	(1 << 4) 	/* Disable Replaying Function */
 #define SACR1_DREC	(1 << 3)	/* Disable Recording Function */
 #define SACR1_AMSL	(1 << 0)	/* Specify Alternate Mode */

 #define SASR0_I2SOFF	(1 << 7)	/* Controller Status */
 #define SASR0_ROR	(1 << 6)	/* Rx FIFO Overrun */
 #define SASR0_TUR	(1 << 5)	/* Tx FIFO Underrun */
 #define SASR0_RFS	(1 << 4)	/* Rx FIFO Service Request */
 #define SASR0_TFS	(1 << 3)	/* Tx FIFO Service Request */
 #define SASR0_BSY	(1 << 2)	/* I2S Busy */
 #define SASR0_RNE	(1 << 1)	/* Rx FIFO Not Empty */
 #define SASR0_TNF	(1 << 0) 	/* Tx FIFO Not Empty */

 #define SAICR_ROR	(1 << 6)	/* Clear Rx FIFO Overrun Interrupt */
 #define SAICR_TUR	(1 << 5)	/* Clear Tx FIFO Underrun Interrupt */

 #define SAIMR_ROR	(1 << 6)	/* Enable Rx FIFO Overrun Condition Interrupt */
 #define SAIMR_TUR	(1 << 5)	/* Enable Tx FIFO Underrun Condition Interrupt */
 #define SAIMR_RFS	(1 << 4)	/* Enable Rx FIFO Service Interrupt */
 #define SAIMR_TFS	(1 << 3)	/* Enable Tx FIFO Service Interrupt */

 struct pxa_i2s_port {
 	u32 sadiv;
 	u32 sacr0;
 	u32 sacr1;
 	u32 saimr;
 	int master;
 	u32 fmt;
 };
 static struct pxa_i2s_port pxa_i2s;
 static struct clk *clk_i2s;

 static struct pxa2xx_pcm_dma_params pxa2xx_i2s_pcm_stereo_out = {
 	.name			= "I2S PCM Stereo out",
 	.dev_addr		= __PREG(SADR),
 	.drcmr			= &DRCMR(3),
 	.dcmd			= DCMD_INCSRCADDR | DCMD_FLOWTRG |
 				  DCMD_BURST32 | DCMD_WIDTH4,
 };

 static struct pxa2xx_pcm_dma_params pxa2xx_i2s_pcm_stereo_in = {
 	.name			= "I2S PCM Stereo in",
 	.dev_addr		= __PREG(SADR),
 	.drcmr			= &DRCMR(2),
 	.dcmd			= DCMD_INCTRGADDR | DCMD_FLOWSRC |
 				  DCMD_BURST32 | DCMD_WIDTH4,
 };

 static int pxa2xx_i2s_startup(struct snd_pcm_substream *substream,
 			      struct snd_soc_dai *dai)
 {
 	struct snd_soc_pcm_runtime *rtd = substream->private_data;
 	struct snd_soc_dai *cpu_dai = rtd->dai->cpu_dai;

 	if (IS_ERR(clk_i2s))
 		return PTR_ERR(clk_i2s);

 	if (!cpu_dai->active) {
 		SACR0 |= SACR0_RST;
 		SACR0 = 0;
 	}

 	return 0;
 }

 /* wait for I2S controller to be ready */
 static int pxa_i2s_wait(void)
 {
 	int i;

 	/* flush the Rx FIFO */
 	for(i = 0; i < 16; i++)
 		SADR;
 	return 0;
 }

 static int pxa2xx_i2s_set_dai_fmt(struct snd_soc_dai *cpu_dai,
 		unsigned int fmt)
 {
 	/* interface format */
 	switch (fmt & SND_SOC_DAIFMT_FORMAT_MASK) {
 	case SND_SOC_DAIFMT_I2S:
 		pxa_i2s.fmt = 0;
 		break;
 	case SND_SOC_DAIFMT_LEFT_J:
 		pxa_i2s.fmt = SACR1_AMSL;
 		break;
 	}

 	switch (fmt & SND_SOC_DAIFMT_MASTER_MASK) {
 	case SND_SOC_DAIFMT_CBS_CFS:
 		pxa_i2s.master = 1;
 		break;
 	case SND_SOC_DAIFMT_CBM_CFS:
 		pxa_i2s.master = 0;
 		break;
 	default:
 		break;
 	}
 	return 0;
 }

 static int pxa2xx_i2s_set_dai_sysclk(struct snd_soc_dai *cpu_dai,
 		int clk_id, unsigned int freq, int dir)
 {
 	if (clk_id != PXA2XX_I2S_SYSCLK)
 		return -ENODEV;

 	return 0;
 }

 static int pxa2xx_i2s_hw_params(struct snd_pcm_substream *substream,
 				struct snd_pcm_hw_params *params,
 				struct snd_soc_dai *dai)
 {
 	struct snd_soc_pcm_runtime *rtd = substream->private_data;
 	struct snd_soc_dai *cpu_dai = rtd->dai->cpu_dai;

 	BUG_ON(IS_ERR(clk_i2s));
 	clk_enable(clk_i2s);
 	pxa_i2s_wait();

 	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
 		cpu_dai->dma_data = &pxa2xx_i2s_pcm_stereo_out;
 	else
 		cpu_dai->dma_data = &pxa2xx_i2s_pcm_stereo_in;

 	/* is port used by another stream */
 	if (!(SACR0 & SACR0_ENB)) {

 		SACR0 = 0;
 		SACR1 = 0;
 		if (pxa_i2s.master)
 			SACR0 |= SACR0_BCKD;

 		SACR0 |= SACR0_RFTH(14) | SACR0_TFTH(1);
 		SACR1 |= pxa_i2s.fmt;
 	}
 	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
 		SAIMR |= SAIMR_TFS;
 	else
 		SAIMR |= SAIMR_RFS;

 	switch (params_rate(params)) {
 	case 8000:
 		SADIV = 0x48;
 		break;
 	case 11025:
 		SADIV = 0x34;
 		break;
 	case 16000:
 		SADIV = 0x24;
 		break;
 	case 22050:
 		SADIV = 0x1a;
 		break;
 	case 44100:
 		SADIV = 0xd;
 		break;
 	case 48000:
 		SADIV = 0xc;
 		break;
 	case 96000: /* not in manual and possibly slightly inaccurate */
 		SADIV = 0x6;
 		break;
 	}

 	return 0;
 }

 static int pxa2xx_i2s_trigger(struct snd_pcm_substream *substream, int cmd,
 			      struct snd_soc_dai *dai)
 {
 	int ret = 0;

 	switch (cmd) {
 	case SNDRV_PCM_TRIGGER_START:
 		SACR0 |= SACR0_ENB;
 		break;
 	case SNDRV_PCM_TRIGGER_RESUME:
 	case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
 	case SNDRV_PCM_TRIGGER_STOP:
 	case SNDRV_PCM_TRIGGER_SUSPEND:
 	case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
 		break;
 	default:
 		ret = -EINVAL;
 	}

 	return ret;
 }

 static void pxa2xx_i2s_shutdown(struct snd_pcm_substream *substream,
 				struct snd_soc_dai *dai)
 {
 	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
 		SACR1 |= SACR1_DRPL;
 		SAIMR &= ~SAIMR_TFS;
 	} else {
 		SACR1 |= SACR1_DREC;
 		SAIMR &= ~SAIMR_RFS;
 	}

 	if (SACR1 & (SACR1_DREC | SACR1_DRPL)) {
 		SACR0 &= ~SACR0_ENB;
 		pxa_i2s_wait();
 		clk_disable(clk_i2s);
 	}

 	clk_put(clk_i2s);
 }

 #ifdef CONFIG_PM
 static int pxa2xx_i2s_suspend(struct snd_soc_dai *dai)
 {
 	if (!dai->active)
 		return 0;

 	/* store registers */
 	pxa_i2s.sacr0 = SACR0;
 	pxa_i2s.sacr1 = SACR1;
 	pxa_i2s.saimr = SAIMR;
 	pxa_i2s.sadiv = SADIV;

 	/* deactivate link */
 	SACR0 &= ~SACR0_ENB;
 	pxa_i2s_wait();
 	return 0;
 }

 static int pxa2xx_i2s_resume(struct snd_soc_dai *dai)
 {
 	if (!dai->active)
 		return 0;

 	pxa_i2s_wait();

 	SACR0 = pxa_i2s.sacr0 &= ~SACR0_ENB;
 	SACR1 = pxa_i2s.sacr1;
 	SAIMR = pxa_i2s.saimr;
 	SADIV = pxa_i2s.sadiv;
 	SACR0 |= SACR0_ENB;

 	return 0;
 }

 #else
 #define pxa2xx_i2s_suspend	NULL
 #define pxa2xx_i2s_resume	NULL
 #endif

 #define PXA2XX_I2S_RATES (SNDRV_PCM_RATE_8000 | SNDRV_PCM_RATE_11025 |\
 		SNDRV_PCM_RATE_16000 | SNDRV_PCM_RATE_22050 | SNDRV_PCM_RATE_44100 | \
 		SNDRV_PCM_RATE_48000 | SNDRV_PCM_RATE_96000)

 struct snd_soc_dai pxa_i2s_dai = {
 	.name = "pxa2xx-i2s",
 	.id = 0,
 	.suspend = pxa2xx_i2s_suspend,
 	.resume = pxa2xx_i2s_resume,
 	.playback = {
 		.channels_min = 2,
 		.channels_max = 2,
 		.rates = PXA2XX_I2S_RATES,
 		.formats = SNDRV_PCM_FMTBIT_S16_LE,},
 	.capture = {
 		.channels_min = 2,
 		.channels_max = 2,
 		.rates = PXA2XX_I2S_RATES,
 		.formats = SNDRV_PCM_FMTBIT_S16_LE,},
 	.ops = {
 		.startup = pxa2xx_i2s_startup,
 		.shutdown = pxa2xx_i2s_shutdown,
 		.trigger = pxa2xx_i2s_trigger,
 		.hw_params = pxa2xx_i2s_hw_params,
 		.set_fmt = pxa2xx_i2s_set_dai_fmt,
 		.set_sysclk = pxa2xx_i2s_set_dai_sysclk,
 	},
 };

 EXPORT_SYMBOL_GPL(pxa_i2s_dai);

 static int pxa2xx_i2s_probe(struct platform_device *dev)
 {
 	int ret;

 	clk_i2s = clk_get(&dev->dev, "I2SCLK");
 	if (IS_ERR(clk_i2s))
 		return PTR_ERR(clk_i2s);

 	pxa_i2s_dai.dev = &dev->dev;
 	ret = snd_soc_register_dai(&pxa_i2s_dai);
 	if (ret != 0)
 		clk_put(clk_i2s);

 	return ret;
 }

 static int __devexit pxa2xx_i2s_remove(struct platform_device *dev)
 {
 	snd_soc_unregister_dai(&pxa_i2s_dai);
 	clk_put(clk_i2s);
 	clk_i2s = ERR_PTR(-ENOENT);
 	return 0;
 }

 static struct platform_driver pxa2xx_i2s_driver = {
 	.probe = pxa2xx_i2s_probe,
 	.remove = __devexit_p(pxa2xx_i2s_remove),

 	.driver = {
 		.name = "pxa2xx-i2s",
 		.owner = THIS_MODULE,
 	},
 };

 static int __init pxa2xx_i2s_init(void)
 {
 	clk_i2s = ERR_PTR(-ENOENT);
 	return platform_driver_register(&pxa2xx_i2s_driver);
 }

 static void __exit pxa2xx_i2s_exit(void)
 {
 	platform_driver_unregister(&pxa2xx_i2s_driver);
 }

 module_init(pxa2xx_i2s_init);
 module_exit(pxa2xx_i2s_exit);

 /* Module information */
 MODULE_AUTHOR("Liam Girdwood, lrg@slimlogic.co.uk");
 MODULE_DESCRIPTION("pxa2xx I2S SoC Interface");
 MODULE_LICENSE("GPL");
	/*
	* pxa2xx-i2s.c -- ALSA Soc Audio Layer
	*
	* Copyright 2005 Wolfson Microelectronics PLC.
	* Author: Liam Girdwood
	* lrg@slimlogic.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/platform_device.h>
	#include <sound/core.h>
	#include <sound/pcm.h>
	#include <sound/initval.h>
	#include <sound/soc.h>
	#include <sound/pxa2xx-lib.h>

	#include <mach/hardware.h>
	#include <mach/pxa-regs.h>
	#include <mach/audio.h>

	#include "pxa2xx-pcm.h"
	#include "pxa2xx-i2s.h"

	/*
	* I2S Controller Register and Bit Definitions
	*/
	#define SACR0 __REG(0x40400000) /* Global Control Register */
	#define SACR1 __REG(0x40400004) /* Serial Audio I 2 S/MSB-Justified Control Register */
	#define SASR0 __REG(0x4040000C) /* Serial Audio I 2 S/MSB-Justified Interface and FIFO Status Register */
	#define SAIMR __REG(0x40400014) /* Serial Audio Interrupt Mask Register */
	#define SAICR __REG(0x40400018) /* Serial Audio Interrupt Clear Register */
	#define SADIV __REG(0x40400060) /* Audio Clock Divider Register. */
	#define SADR __REG(0x40400080) /* Serial Audio Data Register (TX and RX FIFO access Register). */

	#define SACR0_RFTH(x) ((x) << 12) /* Rx FIFO Interrupt or DMA Trigger Threshold */
	#define SACR0_TFTH(x) ((x) << 8) /* Tx FIFO Interrupt or DMA Trigger Threshold */
	#define SACR0_STRF (1 << 5) /* FIFO Select for EFWR Special Function */
	#define SACR0_EFWR (1 << 4) /* Enable EFWR Function */
	#define SACR0_RST (1 << 3) /* FIFO, i2s Register Reset */
	#define SACR0_BCKD (1 << 2) /* Bit Clock Direction */
	#define SACR0_ENB (1 << 0) /* Enable I2S Link */
	#define SACR1_ENLBF (1 << 5) /* Enable Loopback */
	#define SACR1_DRPL (1 << 4) /* Disable Replaying Function */
	#define SACR1_DREC (1 << 3) /* Disable Recording Function */
	#define SACR1_AMSL (1 << 0) /* Specify Alternate Mode */

	#define SASR0_I2SOFF (1 << 7) /* Controller Status */
	#define SASR0_ROR (1 << 6) /* Rx FIFO Overrun */
	#define SASR0_TUR (1 << 5) /* Tx FIFO Underrun */
	#define SASR0_RFS (1 << 4) /* Rx FIFO Service Request */
	#define SASR0_TFS (1 << 3) /* Tx FIFO Service Request */
	#define SASR0_BSY (1 << 2) /* I2S Busy */
	#define SASR0_RNE (1 << 1) /* Rx FIFO Not Empty */
	#define SASR0_TNF (1 << 0) /* Tx FIFO Not Empty */

	#define SAICR_ROR (1 << 6) /* Clear Rx FIFO Overrun Interrupt */
	#define SAICR_TUR (1 << 5) /* Clear Tx FIFO Underrun Interrupt */

	#define SAIMR_ROR (1 << 6) /* Enable Rx FIFO Overrun Condition Interrupt */
	#define SAIMR_TUR (1 << 5) /* Enable Tx FIFO Underrun Condition Interrupt */
	#define SAIMR_RFS (1 << 4) /* Enable Rx FIFO Service Interrupt */
	#define SAIMR_TFS (1 << 3) /* Enable Tx FIFO Service Interrupt */

	struct pxa_i2s_port {
	u32 sadiv;
	u32 sacr0;
	u32 sacr1;
	u32 saimr;
	int master;
	u32 fmt;
	};
	static struct pxa_i2s_port pxa_i2s;
	static struct clk *clk_i2s;

	static struct pxa2xx_pcm_dma_params pxa2xx_i2s_pcm_stereo_out = {
	.name = "I2S PCM Stereo out",
	.dev_addr = __PREG(SADR),
	.drcmr = &DRCMR(3),
	.dcmd = DCMD_INCSRCADDR \| DCMD_FLOWTRG \|
	DCMD_BURST32 \| DCMD_WIDTH4,
	};

	static struct pxa2xx_pcm_dma_params pxa2xx_i2s_pcm_stereo_in = {
	.name = "I2S PCM Stereo in",
	.dev_addr = __PREG(SADR),
	.drcmr = &DRCMR(2),
	.dcmd = DCMD_INCTRGADDR \| DCMD_FLOWSRC \|
	DCMD_BURST32 \| DCMD_WIDTH4,
	};

	static int pxa2xx_i2s_startup(struct snd_pcm_substream *substream,
	struct snd_soc_dai *dai)
	{
	struct snd_soc_pcm_runtime *rtd = substream->private_data;
	struct snd_soc_dai *cpu_dai = rtd->dai->cpu_dai;

	if (IS_ERR(clk_i2s))
	return PTR_ERR(clk_i2s);

	if (!cpu_dai->active) {
	SACR0 \|= SACR0_RST;
	SACR0 = 0;
	}

	return 0;
	}

	/* wait for I2S controller to be ready */
	static int pxa_i2s_wait(void)
	{
	int i;

	/* flush the Rx FIFO */
	for(i = 0; i < 16; i++)
	SADR;
	return 0;
	}

	static int pxa2xx_i2s_set_dai_fmt(struct snd_soc_dai *cpu_dai,
	unsigned int fmt)
	{
	/* interface format */
	switch (fmt & SND_SOC_DAIFMT_FORMAT_MASK) {
	case SND_SOC_DAIFMT_I2S:
	pxa_i2s.fmt = 0;
	break;
	case SND_SOC_DAIFMT_LEFT_J:
	pxa_i2s.fmt = SACR1_AMSL;
	break;
	}

	switch (fmt & SND_SOC_DAIFMT_MASTER_MASK) {
	case SND_SOC_DAIFMT_CBS_CFS:
	pxa_i2s.master = 1;
	break;
	case SND_SOC_DAIFMT_CBM_CFS:
	pxa_i2s.master = 0;
	break;
	default:
	break;
	}
	return 0;
	}

	static int pxa2xx_i2s_set_dai_sysclk(struct snd_soc_dai *cpu_dai,
	int clk_id, unsigned int freq, int dir)
	{
	if (clk_id != PXA2XX_I2S_SYSCLK)
	return -ENODEV;

	return 0;
	}

	static int pxa2xx_i2s_hw_params(struct snd_pcm_substream *substream,
	struct snd_pcm_hw_params *params,
	struct snd_soc_dai *dai)
	{
	struct snd_soc_pcm_runtime *rtd = substream->private_data;
	struct snd_soc_dai *cpu_dai = rtd->dai->cpu_dai;

	BUG_ON(IS_ERR(clk_i2s));
	clk_enable(clk_i2s);
	pxa_i2s_wait();

	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
	cpu_dai->dma_data = &pxa2xx_i2s_pcm_stereo_out;
	else
	cpu_dai->dma_data = &pxa2xx_i2s_pcm_stereo_in;

	/* is port used by another stream */
	if (!(SACR0 & SACR0_ENB)) {

	SACR0 = 0;
	SACR1 = 0;
	if (pxa_i2s.master)
	SACR0 \|= SACR0_BCKD;

	SACR0 \|= SACR0_RFTH(14) \| SACR0_TFTH(1);
	SACR1 \|= pxa_i2s.fmt;
	}
	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
	SAIMR \|= SAIMR_TFS;
	else
	SAIMR \|= SAIMR_RFS;

	switch (params_rate(params)) {
	case 8000:
	SADIV = 0x48;
	break;
	case 11025:
	SADIV = 0x34;
	break;
	case 16000:
	SADIV = 0x24;
	break;
	case 22050:
	SADIV = 0x1a;
	break;
	case 44100:
	SADIV = 0xd;
	break;
	case 48000:
	SADIV = 0xc;
	break;
	case 96000: /* not in manual and possibly slightly inaccurate */
	SADIV = 0x6;
	break;
	}

	return 0;
	}

	static int pxa2xx_i2s_trigger(struct snd_pcm_substream *substream, int cmd,
	struct snd_soc_dai *dai)
	{
	int ret = 0;

	switch (cmd) {
	case SNDRV_PCM_TRIGGER_START:
	SACR0 \|= SACR0_ENB;
	break;
	case SNDRV_PCM_TRIGGER_RESUME:
	case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
	case SNDRV_PCM_TRIGGER_STOP:
	case SNDRV_PCM_TRIGGER_SUSPEND:
	case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
	break;
	default:
	ret = -EINVAL;
	}

	return ret;
	}

	static void pxa2xx_i2s_shutdown(struct snd_pcm_substream *substream,
	struct snd_soc_dai *dai)
	{
	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
	SACR1 \|= SACR1_DRPL;
	SAIMR &= ~SAIMR_TFS;
	} else {
	SACR1 \|= SACR1_DREC;
	SAIMR &= ~SAIMR_RFS;
	}

	if (SACR1 & (SACR1_DREC \| SACR1_DRPL)) {
	SACR0 &= ~SACR0_ENB;
	pxa_i2s_wait();
	clk_disable(clk_i2s);
	}

	clk_put(clk_i2s);
	}

	#ifdef CONFIG_PM
	static int pxa2xx_i2s_suspend(struct snd_soc_dai *dai)
	{
	if (!dai->active)
	return 0;

	/* store registers */
	pxa_i2s.sacr0 = SACR0;
	pxa_i2s.sacr1 = SACR1;
	pxa_i2s.saimr = SAIMR;
	pxa_i2s.sadiv = SADIV;

	/* deactivate link */
	SACR0 &= ~SACR0_ENB;
	pxa_i2s_wait();
	return 0;
	}

	static int pxa2xx_i2s_resume(struct snd_soc_dai *dai)
	{
	if (!dai->active)
	return 0;

	pxa_i2s_wait();

	SACR0 = pxa_i2s.sacr0 &= ~SACR0_ENB;
	SACR1 = pxa_i2s.sacr1;
	SAIMR = pxa_i2s.saimr;
	SADIV = pxa_i2s.sadiv;
	SACR0 \|= SACR0_ENB;

	return 0;
	}

	#else
	#define pxa2xx_i2s_suspend NULL
	#define pxa2xx_i2s_resume NULL
	#endif

	#define PXA2XX_I2S_RATES (SNDRV_PCM_RATE_8000 \| SNDRV_PCM_RATE_11025 \|\
	SNDRV_PCM_RATE_16000 \| SNDRV_PCM_RATE_22050 \| SNDRV_PCM_RATE_44100 \| \
	SNDRV_PCM_RATE_48000 \| SNDRV_PCM_RATE_96000)

	struct snd_soc_dai pxa_i2s_dai = {
	.name = "pxa2xx-i2s",
	.id = 0,
	.suspend = pxa2xx_i2s_suspend,
	.resume = pxa2xx_i2s_resume,
	.playback = {
	.channels_min = 2,
	.channels_max = 2,
	.rates = PXA2XX_I2S_RATES,
	.formats = SNDRV_PCM_FMTBIT_S16_LE,},
	.capture = {
	.channels_min = 2,
	.channels_max = 2,
	.rates = PXA2XX_I2S_RATES,
	.formats = SNDRV_PCM_FMTBIT_S16_LE,},
	.ops = {
	.startup = pxa2xx_i2s_startup,
	.shutdown = pxa2xx_i2s_shutdown,
	.trigger = pxa2xx_i2s_trigger,
	.hw_params = pxa2xx_i2s_hw_params,
	.set_fmt = pxa2xx_i2s_set_dai_fmt,
	.set_sysclk = pxa2xx_i2s_set_dai_sysclk,
	},
	};

	EXPORT_SYMBOL_GPL(pxa_i2s_dai);

	static int pxa2xx_i2s_probe(struct platform_device *dev)
	{
	int ret;

	clk_i2s = clk_get(&dev->dev, "I2SCLK");
	if (IS_ERR(clk_i2s))
	return PTR_ERR(clk_i2s);

	pxa_i2s_dai.dev = &dev->dev;
	ret = snd_soc_register_dai(&pxa_i2s_dai);
	if (ret != 0)
	clk_put(clk_i2s);

	return ret;
	}

	static int __devexit pxa2xx_i2s_remove(struct platform_device *dev)
	{
	snd_soc_unregister_dai(&pxa_i2s_dai);
	clk_put(clk_i2s);
	clk_i2s = ERR_PTR(-ENOENT);
	return 0;
	}

	static struct platform_driver pxa2xx_i2s_driver = {
	.probe = pxa2xx_i2s_probe,
	.remove = __devexit_p(pxa2xx_i2s_remove),

	.driver = {
	.name = "pxa2xx-i2s",
	.owner = THIS_MODULE,
	},
	};

	static int __init pxa2xx_i2s_init(void)
	{
	clk_i2s = ERR_PTR(-ENOENT);
	return platform_driver_register(&pxa2xx_i2s_driver);
	}

	static void __exit pxa2xx_i2s_exit(void)
	{
	platform_driver_unregister(&pxa2xx_i2s_driver);
	}

	module_init(pxa2xx_i2s_init);
	module_exit(pxa2xx_i2s_exit);

	/* Module information */
	MODULE_AUTHOR("Liam Girdwood, lrg@slimlogic.co.uk");
	MODULE_DESCRIPTION("pxa2xx I2S SoC Interface");
	MODULE_LICENSE("GPL");