sound/soc/davinci/davinci-i2s.c - kernel/msm-4.19 - Gitiles

 /*
  * ALSA SoC I2S (McBSP) Audio Layer for TI DAVINCI processor
  *
  * Author:      Vladimir Barinov, <vbarinov@embeddedalley.com>
  * Copyright:   (C) 2007 MontaVista Software, Inc., <source@mvista.com>
  *
  * 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.
  */

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

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

 #include <mach/asp.h>

 #include "davinci-pcm.h"


 /*
  * NOTE:  terminology here is confusing.
  *
  *  - This driver supports the "Audio Serial Port" (ASP),
  *    found on dm6446, dm355, and other DaVinci chips.
  *
  *  - But it labels it a "Multi-channel Buffered Serial Port"
  *    (McBSP) as on older chips like the dm642 ... which was
  *    backward-compatible, possibly explaining that confusion.
  *
  *  - OMAP chips have a controller called McBSP, which is
  *    incompatible with the DaVinci flavor of McBSP.
  *
  *  - Newer DaVinci chips have a controller called McASP,
  *    incompatible with ASP and with either McBSP.
  *
  * In short:  this uses ASP to implement I2S, not McBSP.
  * And it won't be the only DaVinci implemention of I2S.
  */
 #define DAVINCI_MCBSP_DRR_REG	0x00
 #define DAVINCI_MCBSP_DXR_REG	0x04
 #define DAVINCI_MCBSP_SPCR_REG	0x08
 #define DAVINCI_MCBSP_RCR_REG	0x0c
 #define DAVINCI_MCBSP_XCR_REG	0x10
 #define DAVINCI_MCBSP_SRGR_REG	0x14
 #define DAVINCI_MCBSP_PCR_REG	0x24

 #define DAVINCI_MCBSP_SPCR_RRST		(1 << 0)
 #define DAVINCI_MCBSP_SPCR_RINTM(v)	((v) << 4)
 #define DAVINCI_MCBSP_SPCR_XRST		(1 << 16)
 #define DAVINCI_MCBSP_SPCR_XINTM(v)	((v) << 20)
 #define DAVINCI_MCBSP_SPCR_GRST		(1 << 22)
 #define DAVINCI_MCBSP_SPCR_FRST		(1 << 23)
 #define DAVINCI_MCBSP_SPCR_FREE		(1 << 25)

 #define DAVINCI_MCBSP_RCR_RWDLEN1(v)	((v) << 5)
 #define DAVINCI_MCBSP_RCR_RFRLEN1(v)	((v) << 8)
 #define DAVINCI_MCBSP_RCR_RDATDLY(v)	((v) << 16)
 #define DAVINCI_MCBSP_RCR_RFIG		(1 << 18)
 #define DAVINCI_MCBSP_RCR_RWDLEN2(v)	((v) << 21)

 #define DAVINCI_MCBSP_XCR_XWDLEN1(v)	((v) << 5)
 #define DAVINCI_MCBSP_XCR_XFRLEN1(v)	((v) << 8)
 #define DAVINCI_MCBSP_XCR_XDATDLY(v)	((v) << 16)
 #define DAVINCI_MCBSP_XCR_XFIG		(1 << 18)
 #define DAVINCI_MCBSP_XCR_XWDLEN2(v)	((v) << 21)

 #define DAVINCI_MCBSP_SRGR_FWID(v)	((v) << 8)
 #define DAVINCI_MCBSP_SRGR_FPER(v)	((v) << 16)
 #define DAVINCI_MCBSP_SRGR_FSGM		(1 << 28)

 #define DAVINCI_MCBSP_PCR_CLKRP		(1 << 0)
 #define DAVINCI_MCBSP_PCR_CLKXP		(1 << 1)
 #define DAVINCI_MCBSP_PCR_FSRP		(1 << 2)
 #define DAVINCI_MCBSP_PCR_FSXP		(1 << 3)
 #define DAVINCI_MCBSP_PCR_SCLKME	(1 << 7)
 #define DAVINCI_MCBSP_PCR_CLKRM		(1 << 8)
 #define DAVINCI_MCBSP_PCR_CLKXM		(1 << 9)
 #define DAVINCI_MCBSP_PCR_FSRM		(1 << 10)
 #define DAVINCI_MCBSP_PCR_FSXM		(1 << 11)

 enum {
 	DAVINCI_MCBSP_WORD_8 = 0,
 	DAVINCI_MCBSP_WORD_12,
 	DAVINCI_MCBSP_WORD_16,
 	DAVINCI_MCBSP_WORD_20,
 	DAVINCI_MCBSP_WORD_24,
 	DAVINCI_MCBSP_WORD_32,
 };

 static struct davinci_pcm_dma_params davinci_i2s_pcm_out = {
 	.name = "I2S PCM Stereo out",
 };

 static struct davinci_pcm_dma_params davinci_i2s_pcm_in = {
 	.name = "I2S PCM Stereo in",
 };

 struct davinci_mcbsp_dev {
 	void __iomem			*base;
 #define MOD_DSP_A	0
 #define MOD_DSP_B	1
 	int				mode;
 	u32				pcr;
 	struct clk			*clk;
 	struct davinci_pcm_dma_params	*dma_params[2];
 };

 static inline void davinci_mcbsp_write_reg(struct davinci_mcbsp_dev *dev,
 					   int reg, u32 val)
 {
 	__raw_writel(val, dev->base + reg);
 }

 static inline u32 davinci_mcbsp_read_reg(struct davinci_mcbsp_dev *dev, int reg)
 {
 	return __raw_readl(dev->base + reg);
 }

 static void toggle_clock(struct davinci_mcbsp_dev *dev, int playback)
 {
 	u32 m = playback ? DAVINCI_MCBSP_PCR_CLKXP : DAVINCI_MCBSP_PCR_CLKRP;
 	/* The clock needs to toggle to complete reset.
 	 * So, fake it by toggling the clk polarity.
 	 */
 	davinci_mcbsp_write_reg(dev, DAVINCI_MCBSP_PCR_REG, dev->pcr ^ m);
 	davinci_mcbsp_write_reg(dev, DAVINCI_MCBSP_PCR_REG, dev->pcr);
 }

 static void davinci_mcbsp_start(struct davinci_mcbsp_dev *dev,
 		struct snd_pcm_substream *substream)
 {
 	struct snd_soc_pcm_runtime *rtd = substream->private_data;
 	struct snd_soc_device *socdev = rtd->socdev;
 	struct snd_soc_platform *platform = socdev->card->platform;
 	int playback = (substream->stream == SNDRV_PCM_STREAM_PLAYBACK);
 	u32 spcr;
 	u32 mask = playback ? DAVINCI_MCBSP_SPCR_XRST : DAVINCI_MCBSP_SPCR_RRST;
 	spcr = davinci_mcbsp_read_reg(dev, DAVINCI_MCBSP_SPCR_REG);
 	if (spcr & mask) {
 		/* start off disabled */
 		davinci_mcbsp_write_reg(dev, DAVINCI_MCBSP_SPCR_REG,
 				spcr & ~mask);
 		toggle_clock(dev, playback);
 	}
 	if (dev->pcr & (DAVINCI_MCBSP_PCR_FSXM | DAVINCI_MCBSP_PCR_FSRM |
 			DAVINCI_MCBSP_PCR_CLKXM | DAVINCI_MCBSP_PCR_CLKRM)) {
 		/* Start the sample generator */
 		spcr |= DAVINCI_MCBSP_SPCR_GRST;
 		davinci_mcbsp_write_reg(dev, DAVINCI_MCBSP_SPCR_REG, spcr);
 	}

 	if (playback) {
 		/* Stop the DMA to avoid data loss */
 		/* while the transmitter is out of reset to handle XSYNCERR */
 		if (platform->pcm_ops->trigger) {
 			int ret = platform->pcm_ops->trigger(substream,
 				SNDRV_PCM_TRIGGER_STOP);
 			if (ret < 0)
 				printk(KERN_DEBUG "Playback DMA stop failed\n");
 		}

 		/* Enable the transmitter */
 		spcr = davinci_mcbsp_read_reg(dev, DAVINCI_MCBSP_SPCR_REG);
 		spcr |= DAVINCI_MCBSP_SPCR_XRST;
 		davinci_mcbsp_write_reg(dev, DAVINCI_MCBSP_SPCR_REG, spcr);

 		/* wait for any unexpected frame sync error to occur */
 		udelay(100);

 		/* Disable the transmitter to clear any outstanding XSYNCERR */
 		spcr = davinci_mcbsp_read_reg(dev, DAVINCI_MCBSP_SPCR_REG);
 		spcr &= ~DAVINCI_MCBSP_SPCR_XRST;
 		davinci_mcbsp_write_reg(dev, DAVINCI_MCBSP_SPCR_REG, spcr);
 		toggle_clock(dev, playback);

 		/* Restart the DMA */
 		if (platform->pcm_ops->trigger) {
 			int ret = platform->pcm_ops->trigger(substream,
 				SNDRV_PCM_TRIGGER_START);
 			if (ret < 0)
 				printk(KERN_DEBUG "Playback DMA start failed\n");
 		}
 	}

 	/* Enable transmitter or receiver */
 	spcr = davinci_mcbsp_read_reg(dev, DAVINCI_MCBSP_SPCR_REG);
 	spcr |= mask;

 	if (dev->pcr & (DAVINCI_MCBSP_PCR_FSXM | DAVINCI_MCBSP_PCR_FSRM)) {
 		/* Start frame sync */
 		spcr |= DAVINCI_MCBSP_SPCR_FRST;
 	}
 	davinci_mcbsp_write_reg(dev, DAVINCI_MCBSP_SPCR_REG, spcr);
 }

 static void davinci_mcbsp_stop(struct davinci_mcbsp_dev *dev, int playback)
 {
 	u32 spcr;

 	/* Reset transmitter/receiver and sample rate/frame sync generators */
 	spcr = davinci_mcbsp_read_reg(dev, DAVINCI_MCBSP_SPCR_REG);
 	spcr &= ~(DAVINCI_MCBSP_SPCR_GRST | DAVINCI_MCBSP_SPCR_FRST);
 	spcr &= playback ? ~DAVINCI_MCBSP_SPCR_XRST : ~DAVINCI_MCBSP_SPCR_RRST;
 	davinci_mcbsp_write_reg(dev, DAVINCI_MCBSP_SPCR_REG, spcr);
 	toggle_clock(dev, playback);
 }

 static int davinci_i2s_startup(struct snd_pcm_substream *substream,
 			       struct snd_soc_dai *cpu_dai)
 {
 	struct davinci_mcbsp_dev *dev = cpu_dai->private_data;
 	cpu_dai->dma_data = dev->dma_params[substream->stream];
 	return 0;
 }

 #define DEFAULT_BITPERSAMPLE	16

 static int davinci_i2s_set_dai_fmt(struct snd_soc_dai *cpu_dai,
 				   unsigned int fmt)
 {
 	struct davinci_mcbsp_dev *dev = cpu_dai->private_data;
 	unsigned int pcr;
 	unsigned int srgr;
 	srgr = DAVINCI_MCBSP_SRGR_FSGM |
 		DAVINCI_MCBSP_SRGR_FPER(DEFAULT_BITPERSAMPLE * 2 - 1) |
 		DAVINCI_MCBSP_SRGR_FWID(DEFAULT_BITPERSAMPLE - 1);

 	/* set master/slave audio interface */
 	switch (fmt & SND_SOC_DAIFMT_MASTER_MASK) {
 	case SND_SOC_DAIFMT_CBS_CFS:
 		/* cpu is master */
 		pcr = DAVINCI_MCBSP_PCR_FSXM |
 			DAVINCI_MCBSP_PCR_FSRM |
 			DAVINCI_MCBSP_PCR_CLKXM |
 			DAVINCI_MCBSP_PCR_CLKRM;
 		break;
 	case SND_SOC_DAIFMT_CBM_CFS:
 		/* McBSP CLKR pin is the input for the Sample Rate Generator.
 		 * McBSP FSR and FSX are driven by the Sample Rate Generator. */
 		pcr = DAVINCI_MCBSP_PCR_SCLKME |
 			DAVINCI_MCBSP_PCR_FSXM |
 			DAVINCI_MCBSP_PCR_FSRM;
 		break;
 	case SND_SOC_DAIFMT_CBM_CFM:
 		/* codec is master */
 		pcr = 0;
 		break;
 	default:
 		printk(KERN_ERR "%s:bad master\n", __func__);
 		return -EINVAL;
 	}

 	/* interface format */
 	switch (fmt & SND_SOC_DAIFMT_FORMAT_MASK) {
 	case SND_SOC_DAIFMT_I2S:
 		/* Davinci doesn't support TRUE I2S, but some codecs will have
 		 * the left and right channels contiguous. This allows
 		 * dsp_a mode to be used with an inverted normal frame clk.
 		 * If your codec is master and does not have contiguous
 		 * channels, then you will have sound on only one channel.
 		 * Try using a different mode, or codec as slave.
 		 *
 		 * The TLV320AIC33 is an example of a codec where this works.
 		 * It has a variable bit clock frequency allowing it to have
 		 * valid data on every bit clock.
 		 *
 		 * The TLV320AIC23 is an example of a codec where this does not
 		 * work. It has a fixed bit clock frequency with progressively
 		 * more empty bit clock slots between channels as the sample
 		 * rate is lowered.
 		 */
 		fmt ^= SND_SOC_DAIFMT_NB_IF;
 	case SND_SOC_DAIFMT_DSP_A:
 		dev->mode = MOD_DSP_A;
 		break;
 	case SND_SOC_DAIFMT_DSP_B:
 		dev->mode = MOD_DSP_B;
 		break;
 	default:
 		printk(KERN_ERR "%s:bad format\n", __func__);
 		return -EINVAL;
 	}

 	switch (fmt & SND_SOC_DAIFMT_INV_MASK) {
 	case SND_SOC_DAIFMT_NB_NF:
 		/* CLKRP Receive clock polarity,
 		 *	1 - sampled on rising edge of CLKR
 		 *	valid on rising edge
 		 * CLKXP Transmit clock polarity,
 		 *	1 - clocked on falling edge of CLKX
 		 *	valid on rising edge
 		 * FSRP  Receive frame sync pol, 0 - active high
 		 * FSXP  Transmit frame sync pol, 0 - active high
 		 */
 		pcr |= (DAVINCI_MCBSP_PCR_CLKXP | DAVINCI_MCBSP_PCR_CLKRP);
 		break;
 	case SND_SOC_DAIFMT_IB_IF:
 		/* CLKRP Receive clock polarity,
 		 *	0 - sampled on falling edge of CLKR
 		 *	valid on falling edge
 		 * CLKXP Transmit clock polarity,
 		 *	0 - clocked on rising edge of CLKX
 		 *	valid on falling edge
 		 * FSRP  Receive frame sync pol, 1 - active low
 		 * FSXP  Transmit frame sync pol, 1 - active low
 		 */
 		pcr |= (DAVINCI_MCBSP_PCR_FSXP | DAVINCI_MCBSP_PCR_FSRP);
 		break;
 	case SND_SOC_DAIFMT_NB_IF:
 		/* CLKRP Receive clock polarity,
 		 *	1 - sampled on rising edge of CLKR
 		 *	valid on rising edge
 		 * CLKXP Transmit clock polarity,
 		 *	1 - clocked on falling edge of CLKX
 		 *	valid on rising edge
 		 * FSRP  Receive frame sync pol, 1 - active low
 		 * FSXP  Transmit frame sync pol, 1 - active low
 		 */
 		pcr |= (DAVINCI_MCBSP_PCR_CLKXP | DAVINCI_MCBSP_PCR_CLKRP |
 			DAVINCI_MCBSP_PCR_FSXP | DAVINCI_MCBSP_PCR_FSRP);
 		break;
 	case SND_SOC_DAIFMT_IB_NF:
 		/* CLKRP Receive clock polarity,
 		 *	0 - sampled on falling edge of CLKR
 		 *	valid on falling edge
 		 * CLKXP Transmit clock polarity,
 		 *	0 - clocked on rising edge of CLKX
 		 *	valid on falling edge
 		 * FSRP  Receive frame sync pol, 0 - active high
 		 * FSXP  Transmit frame sync pol, 0 - active high
 		 */
 		break;
 	default:
 		return -EINVAL;
 	}
 	davinci_mcbsp_write_reg(dev, DAVINCI_MCBSP_SRGR_REG, srgr);
 	dev->pcr = pcr;
 	davinci_mcbsp_write_reg(dev, DAVINCI_MCBSP_PCR_REG, pcr);
 	return 0;
 }

 static int davinci_i2s_hw_params(struct snd_pcm_substream *substream,
 				 struct snd_pcm_hw_params *params,
 				 struct snd_soc_dai *dai)
 {
 	struct davinci_pcm_dma_params *dma_params = dai->dma_data;
 	struct davinci_mcbsp_dev *dev = dai->private_data;
 	struct snd_interval *i = NULL;
 	int mcbsp_word_length;
 	unsigned int rcr, xcr, srgr;
 	u32 spcr;

 	/* general line settings */
 	spcr = davinci_mcbsp_read_reg(dev, DAVINCI_MCBSP_SPCR_REG);
 	if (substream->stream == SNDRV_PCM_STREAM_CAPTURE) {
 		spcr |= DAVINCI_MCBSP_SPCR_RINTM(3) | DAVINCI_MCBSP_SPCR_FREE;
 		davinci_mcbsp_write_reg(dev, DAVINCI_MCBSP_SPCR_REG, spcr);
 	} else {
 		spcr |= DAVINCI_MCBSP_SPCR_XINTM(3) | DAVINCI_MCBSP_SPCR_FREE;
 		davinci_mcbsp_write_reg(dev, DAVINCI_MCBSP_SPCR_REG, spcr);
 	}

 	i = hw_param_interval(params, SNDRV_PCM_HW_PARAM_SAMPLE_BITS);
 	srgr = DAVINCI_MCBSP_SRGR_FSGM;
 	srgr |= DAVINCI_MCBSP_SRGR_FWID(snd_interval_value(i) - 1);

 	i = hw_param_interval(params, SNDRV_PCM_HW_PARAM_FRAME_BITS);
 	srgr |= DAVINCI_MCBSP_SRGR_FPER(snd_interval_value(i) - 1);
 	davinci_mcbsp_write_reg(dev, DAVINCI_MCBSP_SRGR_REG, srgr);

 	rcr = DAVINCI_MCBSP_RCR_RFIG;
 	xcr = DAVINCI_MCBSP_XCR_XFIG;
 	if (dev->mode == MOD_DSP_B) {
 		rcr |= DAVINCI_MCBSP_RCR_RDATDLY(0);
 		xcr |= DAVINCI_MCBSP_XCR_XDATDLY(0);
 	} else {
 		rcr |= DAVINCI_MCBSP_RCR_RDATDLY(1);
 		xcr |= DAVINCI_MCBSP_XCR_XDATDLY(1);
 	}
 	/* Determine xfer data type */
 	switch (params_format(params)) {
 	case SNDRV_PCM_FORMAT_S8:
 		dma_params->data_type = 1;
 		mcbsp_word_length = DAVINCI_MCBSP_WORD_8;
 		break;
 	case SNDRV_PCM_FORMAT_S16_LE:
 		dma_params->data_type = 2;
 		mcbsp_word_length = DAVINCI_MCBSP_WORD_16;
 		break;
 	case SNDRV_PCM_FORMAT_S32_LE:
 		dma_params->data_type = 4;
 		mcbsp_word_length = DAVINCI_MCBSP_WORD_32;
 		break;
 	default:
 		printk(KERN_WARNING "davinci-i2s: unsupported PCM format\n");
 		return -EINVAL;
 	}

 	rcr |= DAVINCI_MCBSP_RCR_RFRLEN1(1);
 	xcr |= DAVINCI_MCBSP_XCR_XFRLEN1(1);

 	rcr |= DAVINCI_MCBSP_RCR_RWDLEN1(mcbsp_word_length) |
 		DAVINCI_MCBSP_RCR_RWDLEN2(mcbsp_word_length);
 	xcr |= DAVINCI_MCBSP_XCR_XWDLEN1(mcbsp_word_length) |
 		DAVINCI_MCBSP_XCR_XWDLEN2(mcbsp_word_length);

 	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
 		davinci_mcbsp_write_reg(dev, DAVINCI_MCBSP_XCR_REG, xcr);
 	else
 		davinci_mcbsp_write_reg(dev, DAVINCI_MCBSP_RCR_REG, rcr);
 	return 0;
 }

 static int davinci_i2s_prepare(struct snd_pcm_substream *substream,
 		struct snd_soc_dai *dai)
 {
 	struct davinci_mcbsp_dev *dev = dai->private_data;
 	int playback = (substream->stream == SNDRV_PCM_STREAM_PLAYBACK);
 	davinci_mcbsp_stop(dev, playback);
 	if ((dev->pcr & DAVINCI_MCBSP_PCR_FSXM) == 0) {
 		/* codec is master */
 		davinci_mcbsp_start(dev, substream);
 	}
 	return 0;
 }

 static int davinci_i2s_trigger(struct snd_pcm_substream *substream, int cmd,
 			       struct snd_soc_dai *dai)
 {
 	struct davinci_mcbsp_dev *dev = dai->private_data;
 	int ret = 0;
 	int playback = (substream->stream == SNDRV_PCM_STREAM_PLAYBACK);
 	if ((dev->pcr & DAVINCI_MCBSP_PCR_FSXM) == 0)
 		return 0;	/* return if codec is master */

 	switch (cmd) {
 	case SNDRV_PCM_TRIGGER_START:
 	case SNDRV_PCM_TRIGGER_RESUME:
 	case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
 		davinci_mcbsp_start(dev, substream);
 		break;
 	case SNDRV_PCM_TRIGGER_STOP:
 	case SNDRV_PCM_TRIGGER_SUSPEND:
 	case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
 		davinci_mcbsp_stop(dev, playback);
 		break;
 	default:
 		ret = -EINVAL;
 	}
 	return ret;
 }

 static void davinci_i2s_shutdown(struct snd_pcm_substream *substream,
 		struct snd_soc_dai *dai)
 {
 	struct davinci_mcbsp_dev *dev = dai->private_data;
 	int playback = (substream->stream == SNDRV_PCM_STREAM_PLAYBACK);
 	davinci_mcbsp_stop(dev, playback);
 }

 #define DAVINCI_I2S_RATES	SNDRV_PCM_RATE_8000_96000

 static struct snd_soc_dai_ops davinci_i2s_dai_ops = {
 	.startup 	= davinci_i2s_startup,
 	.shutdown	= davinci_i2s_shutdown,
 	.prepare	= davinci_i2s_prepare,
 	.trigger	= davinci_i2s_trigger,
 	.hw_params	= davinci_i2s_hw_params,
 	.set_fmt	= davinci_i2s_set_dai_fmt,

 };

 struct snd_soc_dai davinci_i2s_dai = {
 	.name = "davinci-i2s",
 	.id = 0,
 	.playback = {
 		.channels_min = 2,
 		.channels_max = 2,
 		.rates = DAVINCI_I2S_RATES,
 		.formats = SNDRV_PCM_FMTBIT_S16_LE,},
 	.capture = {
 		.channels_min = 2,
 		.channels_max = 2,
 		.rates = DAVINCI_I2S_RATES,
 		.formats = SNDRV_PCM_FMTBIT_S16_LE,},
 	.ops = &davinci_i2s_dai_ops,

 };
 EXPORT_SYMBOL_GPL(davinci_i2s_dai);

 static int davinci_i2s_probe(struct platform_device *pdev)
 {
 	struct snd_platform_data *pdata = pdev->dev.platform_data;
 	struct davinci_mcbsp_dev *dev;
 	struct resource *mem, *ioarea, *res;
 	int ret;

 	mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 	if (!mem) {
 		dev_err(&pdev->dev, "no mem resource?\n");
 		return -ENODEV;
 	}

 	ioarea = request_mem_region(mem->start, (mem->end - mem->start) + 1,
 				    pdev->name);
 	if (!ioarea) {
 		dev_err(&pdev->dev, "McBSP region already claimed\n");
 		return -EBUSY;
 	}

 	dev = kzalloc(sizeof(struct davinci_mcbsp_dev), GFP_KERNEL);
 	if (!dev) {
 		ret = -ENOMEM;
 		goto err_release_region;
 	}

 	dev->clk = clk_get(&pdev->dev, NULL);
 	if (IS_ERR(dev->clk)) {
 		ret = -ENODEV;
 		goto err_free_mem;
 	}
 	clk_enable(dev->clk);

 	dev->base = (void __iomem *)IO_ADDRESS(mem->start);

 	dev->dma_params[SNDRV_PCM_STREAM_PLAYBACK] = &davinci_i2s_pcm_out;
 	dev->dma_params[SNDRV_PCM_STREAM_PLAYBACK]->dma_addr =
 	    (dma_addr_t)(io_v2p(dev->base) + DAVINCI_MCBSP_DXR_REG);

 	dev->dma_params[SNDRV_PCM_STREAM_CAPTURE] = &davinci_i2s_pcm_in;
 	dev->dma_params[SNDRV_PCM_STREAM_CAPTURE]->dma_addr =
 	    (dma_addr_t)(io_v2p(dev->base) + DAVINCI_MCBSP_DRR_REG);

 	/* first TX, then RX */
 	res = platform_get_resource(pdev, IORESOURCE_DMA, 0);
 	if (!res) {
 		dev_err(&pdev->dev, "no DMA resource\n");
 		ret = -ENXIO;
 		goto err_free_mem;
 	}
 	dev->dma_params[SNDRV_PCM_STREAM_PLAYBACK]->channel = res->start;

 	res = platform_get_resource(pdev, IORESOURCE_DMA, 1);
 	if (!res) {
 		dev_err(&pdev->dev, "no DMA resource\n");
 		ret = -ENXIO;
 		goto err_free_mem;
 	}
 	dev->dma_params[SNDRV_PCM_STREAM_CAPTURE]->channel = res->start;

 	davinci_i2s_dai.private_data = dev;
 	ret = snd_soc_register_dai(&davinci_i2s_dai);
 	if (ret != 0)
 		goto err_free_mem;

 	return 0;

 err_free_mem:
 	kfree(dev);
 err_release_region:
 	release_mem_region(mem->start, (mem->end - mem->start) + 1);

 	return ret;
 }

 static int davinci_i2s_remove(struct platform_device *pdev)
 {
 	struct davinci_mcbsp_dev *dev = davinci_i2s_dai.private_data;
 	struct resource *mem;

 	snd_soc_unregister_dai(&davinci_i2s_dai);
 	clk_disable(dev->clk);
 	clk_put(dev->clk);
 	dev->clk = NULL;
 	kfree(dev);
 	mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 	release_mem_region(mem->start, (mem->end - mem->start) + 1);

 	return 0;
 }

 static struct platform_driver davinci_mcbsp_driver = {
 	.probe		= davinci_i2s_probe,
 	.remove		= davinci_i2s_remove,
 	.driver		= {
 		.name	= "davinci-asp",
 		.owner	= THIS_MODULE,
 	},
 };

 static int __init davinci_i2s_init(void)
 {
 	return platform_driver_register(&davinci_mcbsp_driver);
 }
 module_init(davinci_i2s_init);

 static void __exit davinci_i2s_exit(void)
 {
 	platform_driver_unregister(&davinci_mcbsp_driver);
 }
 module_exit(davinci_i2s_exit);

 MODULE_AUTHOR("Vladimir Barinov");
 MODULE_DESCRIPTION("TI DAVINCI I2S (McBSP) SoC Interface");
 MODULE_LICENSE("GPL");
	/*
	* ALSA SoC I2S (McBSP) Audio Layer for TI DAVINCI processor
	*
	* Author: Vladimir Barinov, <vbarinov@embeddedalley.com>
	* Copyright: (C) 2007 MontaVista Software, Inc., <source@mvista.com>
	*
	* 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.
	*/

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

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

	#include <mach/asp.h>

	#include "davinci-pcm.h"


	/*
	* NOTE: terminology here is confusing.
	*
	* - This driver supports the "Audio Serial Port" (ASP),
	* found on dm6446, dm355, and other DaVinci chips.
	*
	* - But it labels it a "Multi-channel Buffered Serial Port"
	* (McBSP) as on older chips like the dm642 ... which was
	* backward-compatible, possibly explaining that confusion.
	*
	* - OMAP chips have a controller called McBSP, which is
	* incompatible with the DaVinci flavor of McBSP.
	*
	* - Newer DaVinci chips have a controller called McASP,
	* incompatible with ASP and with either McBSP.
	*
	* In short: this uses ASP to implement I2S, not McBSP.
	* And it won't be the only DaVinci implemention of I2S.
	*/
	#define DAVINCI_MCBSP_DRR_REG 0x00
	#define DAVINCI_MCBSP_DXR_REG 0x04
	#define DAVINCI_MCBSP_SPCR_REG 0x08
	#define DAVINCI_MCBSP_RCR_REG 0x0c
	#define DAVINCI_MCBSP_XCR_REG 0x10
	#define DAVINCI_MCBSP_SRGR_REG 0x14
	#define DAVINCI_MCBSP_PCR_REG 0x24

	#define DAVINCI_MCBSP_SPCR_RRST (1 << 0)
	#define DAVINCI_MCBSP_SPCR_RINTM(v) ((v) << 4)
	#define DAVINCI_MCBSP_SPCR_XRST (1 << 16)
	#define DAVINCI_MCBSP_SPCR_XINTM(v) ((v) << 20)
	#define DAVINCI_MCBSP_SPCR_GRST (1 << 22)
	#define DAVINCI_MCBSP_SPCR_FRST (1 << 23)
	#define DAVINCI_MCBSP_SPCR_FREE (1 << 25)

	#define DAVINCI_MCBSP_RCR_RWDLEN1(v) ((v) << 5)
	#define DAVINCI_MCBSP_RCR_RFRLEN1(v) ((v) << 8)
	#define DAVINCI_MCBSP_RCR_RDATDLY(v) ((v) << 16)
	#define DAVINCI_MCBSP_RCR_RFIG (1 << 18)
	#define DAVINCI_MCBSP_RCR_RWDLEN2(v) ((v) << 21)

	#define DAVINCI_MCBSP_XCR_XWDLEN1(v) ((v) << 5)
	#define DAVINCI_MCBSP_XCR_XFRLEN1(v) ((v) << 8)
	#define DAVINCI_MCBSP_XCR_XDATDLY(v) ((v) << 16)
	#define DAVINCI_MCBSP_XCR_XFIG (1 << 18)
	#define DAVINCI_MCBSP_XCR_XWDLEN2(v) ((v) << 21)

	#define DAVINCI_MCBSP_SRGR_FWID(v) ((v) << 8)
	#define DAVINCI_MCBSP_SRGR_FPER(v) ((v) << 16)
	#define DAVINCI_MCBSP_SRGR_FSGM (1 << 28)

	#define DAVINCI_MCBSP_PCR_CLKRP (1 << 0)
	#define DAVINCI_MCBSP_PCR_CLKXP (1 << 1)
	#define DAVINCI_MCBSP_PCR_FSRP (1 << 2)
	#define DAVINCI_MCBSP_PCR_FSXP (1 << 3)
	#define DAVINCI_MCBSP_PCR_SCLKME (1 << 7)
	#define DAVINCI_MCBSP_PCR_CLKRM (1 << 8)
	#define DAVINCI_MCBSP_PCR_CLKXM (1 << 9)
	#define DAVINCI_MCBSP_PCR_FSRM (1 << 10)
	#define DAVINCI_MCBSP_PCR_FSXM (1 << 11)

	enum {
	DAVINCI_MCBSP_WORD_8 = 0,
	DAVINCI_MCBSP_WORD_12,
	DAVINCI_MCBSP_WORD_16,
	DAVINCI_MCBSP_WORD_20,
	DAVINCI_MCBSP_WORD_24,
	DAVINCI_MCBSP_WORD_32,
	};

	static struct davinci_pcm_dma_params davinci_i2s_pcm_out = {
	.name = "I2S PCM Stereo out",
	};

	static struct davinci_pcm_dma_params davinci_i2s_pcm_in = {
	.name = "I2S PCM Stereo in",
	};

	struct davinci_mcbsp_dev {
	void __iomem *base;
	#define MOD_DSP_A 0
	#define MOD_DSP_B 1
	int mode;
	u32 pcr;
	struct clk *clk;
	struct davinci_pcm_dma_params *dma_params[2];
	};

	static inline void davinci_mcbsp_write_reg(struct davinci_mcbsp_dev *dev,
	int reg, u32 val)
	{
	__raw_writel(val, dev->base + reg);
	}

	static inline u32 davinci_mcbsp_read_reg(struct davinci_mcbsp_dev *dev, int reg)
	{
	return __raw_readl(dev->base + reg);
	}

	static void toggle_clock(struct davinci_mcbsp_dev *dev, int playback)
	{
	u32 m = playback ? DAVINCI_MCBSP_PCR_CLKXP : DAVINCI_MCBSP_PCR_CLKRP;
	/* The clock needs to toggle to complete reset.
	* So, fake it by toggling the clk polarity.
	*/
	davinci_mcbsp_write_reg(dev, DAVINCI_MCBSP_PCR_REG, dev->pcr ^ m);
	davinci_mcbsp_write_reg(dev, DAVINCI_MCBSP_PCR_REG, dev->pcr);
	}

	static void davinci_mcbsp_start(struct davinci_mcbsp_dev *dev,
	struct snd_pcm_substream *substream)
	{
	struct snd_soc_pcm_runtime *rtd = substream->private_data;
	struct snd_soc_device *socdev = rtd->socdev;
	struct snd_soc_platform *platform = socdev->card->platform;
	int playback = (substream->stream == SNDRV_PCM_STREAM_PLAYBACK);
	u32 spcr;
	u32 mask = playback ? DAVINCI_MCBSP_SPCR_XRST : DAVINCI_MCBSP_SPCR_RRST;
	spcr = davinci_mcbsp_read_reg(dev, DAVINCI_MCBSP_SPCR_REG);
	if (spcr & mask) {
	/* start off disabled */
	davinci_mcbsp_write_reg(dev, DAVINCI_MCBSP_SPCR_REG,
	spcr & ~mask);
	toggle_clock(dev, playback);
	}
	if (dev->pcr & (DAVINCI_MCBSP_PCR_FSXM \| DAVINCI_MCBSP_PCR_FSRM \|
	DAVINCI_MCBSP_PCR_CLKXM \| DAVINCI_MCBSP_PCR_CLKRM)) {
	/* Start the sample generator */
	spcr \|= DAVINCI_MCBSP_SPCR_GRST;
	davinci_mcbsp_write_reg(dev, DAVINCI_MCBSP_SPCR_REG, spcr);
	}

	if (playback) {
	/* Stop the DMA to avoid data loss */
	/* while the transmitter is out of reset to handle XSYNCERR */
	if (platform->pcm_ops->trigger) {
	int ret = platform->pcm_ops->trigger(substream,
	SNDRV_PCM_TRIGGER_STOP);
	if (ret < 0)
	printk(KERN_DEBUG "Playback DMA stop failed\n");
	}

	/* Enable the transmitter */
	spcr = davinci_mcbsp_read_reg(dev, DAVINCI_MCBSP_SPCR_REG);
	spcr \|= DAVINCI_MCBSP_SPCR_XRST;
	davinci_mcbsp_write_reg(dev, DAVINCI_MCBSP_SPCR_REG, spcr);

	/* wait for any unexpected frame sync error to occur */
	udelay(100);

	/* Disable the transmitter to clear any outstanding XSYNCERR */
	spcr = davinci_mcbsp_read_reg(dev, DAVINCI_MCBSP_SPCR_REG);
	spcr &= ~DAVINCI_MCBSP_SPCR_XRST;
	davinci_mcbsp_write_reg(dev, DAVINCI_MCBSP_SPCR_REG, spcr);
	toggle_clock(dev, playback);

	/* Restart the DMA */
	if (platform->pcm_ops->trigger) {
	int ret = platform->pcm_ops->trigger(substream,
	SNDRV_PCM_TRIGGER_START);
	if (ret < 0)
	printk(KERN_DEBUG "Playback DMA start failed\n");
	}
	}

	/* Enable transmitter or receiver */
	spcr = davinci_mcbsp_read_reg(dev, DAVINCI_MCBSP_SPCR_REG);
	spcr \|= mask;

	if (dev->pcr & (DAVINCI_MCBSP_PCR_FSXM \| DAVINCI_MCBSP_PCR_FSRM)) {
	/* Start frame sync */
	spcr \|= DAVINCI_MCBSP_SPCR_FRST;
	}
	davinci_mcbsp_write_reg(dev, DAVINCI_MCBSP_SPCR_REG, spcr);
	}

	static void davinci_mcbsp_stop(struct davinci_mcbsp_dev *dev, int playback)
	{
	u32 spcr;

	/* Reset transmitter/receiver and sample rate/frame sync generators */
	spcr = davinci_mcbsp_read_reg(dev, DAVINCI_MCBSP_SPCR_REG);
	spcr &= ~(DAVINCI_MCBSP_SPCR_GRST \| DAVINCI_MCBSP_SPCR_FRST);
	spcr &= playback ? ~DAVINCI_MCBSP_SPCR_XRST : ~DAVINCI_MCBSP_SPCR_RRST;
	davinci_mcbsp_write_reg(dev, DAVINCI_MCBSP_SPCR_REG, spcr);
	toggle_clock(dev, playback);
	}

	static int davinci_i2s_startup(struct snd_pcm_substream *substream,
	struct snd_soc_dai *cpu_dai)
	{
	struct davinci_mcbsp_dev *dev = cpu_dai->private_data;
	cpu_dai->dma_data = dev->dma_params[substream->stream];
	return 0;
	}

	#define DEFAULT_BITPERSAMPLE 16

	static int davinci_i2s_set_dai_fmt(struct snd_soc_dai *cpu_dai,
	unsigned int fmt)
	{
	struct davinci_mcbsp_dev *dev = cpu_dai->private_data;
	unsigned int pcr;
	unsigned int srgr;
	srgr = DAVINCI_MCBSP_SRGR_FSGM \|
	DAVINCI_MCBSP_SRGR_FPER(DEFAULT_BITPERSAMPLE * 2 - 1) \|
	DAVINCI_MCBSP_SRGR_FWID(DEFAULT_BITPERSAMPLE - 1);

	/* set master/slave audio interface */
	switch (fmt & SND_SOC_DAIFMT_MASTER_MASK) {
	case SND_SOC_DAIFMT_CBS_CFS:
	/* cpu is master */
	pcr = DAVINCI_MCBSP_PCR_FSXM \|
	DAVINCI_MCBSP_PCR_FSRM \|
	DAVINCI_MCBSP_PCR_CLKXM \|
	DAVINCI_MCBSP_PCR_CLKRM;
	break;
	case SND_SOC_DAIFMT_CBM_CFS:
	/* McBSP CLKR pin is the input for the Sample Rate Generator.
	* McBSP FSR and FSX are driven by the Sample Rate Generator. */
	pcr = DAVINCI_MCBSP_PCR_SCLKME \|
	DAVINCI_MCBSP_PCR_FSXM \|
	DAVINCI_MCBSP_PCR_FSRM;
	break;
	case SND_SOC_DAIFMT_CBM_CFM:
	/* codec is master */
	pcr = 0;
	break;
	default:
	printk(KERN_ERR "%s:bad master\n", __func__);
	return -EINVAL;
	}

	/* interface format */
	switch (fmt & SND_SOC_DAIFMT_FORMAT_MASK) {
	case SND_SOC_DAIFMT_I2S:
	/* Davinci doesn't support TRUE I2S, but some codecs will have
	* the left and right channels contiguous. This allows
	* dsp_a mode to be used with an inverted normal frame clk.
	* If your codec is master and does not have contiguous
	* channels, then you will have sound on only one channel.
	* Try using a different mode, or codec as slave.
	*
	* The TLV320AIC33 is an example of a codec where this works.
	* It has a variable bit clock frequency allowing it to have
	* valid data on every bit clock.
	*
	* The TLV320AIC23 is an example of a codec where this does not
	* work. It has a fixed bit clock frequency with progressively
	* more empty bit clock slots between channels as the sample
	* rate is lowered.
	*/
	fmt ^= SND_SOC_DAIFMT_NB_IF;
	case SND_SOC_DAIFMT_DSP_A:
	dev->mode = MOD_DSP_A;
	break;
	case SND_SOC_DAIFMT_DSP_B:
	dev->mode = MOD_DSP_B;
	break;
	default:
	printk(KERN_ERR "%s:bad format\n", __func__);
	return -EINVAL;
	}

	switch (fmt & SND_SOC_DAIFMT_INV_MASK) {
	case SND_SOC_DAIFMT_NB_NF:
	/* CLKRP Receive clock polarity,
	* 1 - sampled on rising edge of CLKR
	* valid on rising edge
	* CLKXP Transmit clock polarity,
	* 1 - clocked on falling edge of CLKX
	* valid on rising edge
	* FSRP Receive frame sync pol, 0 - active high
	* FSXP Transmit frame sync pol, 0 - active high
	*/
	pcr \|= (DAVINCI_MCBSP_PCR_CLKXP \| DAVINCI_MCBSP_PCR_CLKRP);
	break;
	case SND_SOC_DAIFMT_IB_IF:
	/* CLKRP Receive clock polarity,
	* 0 - sampled on falling edge of CLKR
	* valid on falling edge
	* CLKXP Transmit clock polarity,
	* 0 - clocked on rising edge of CLKX
	* valid on falling edge
	* FSRP Receive frame sync pol, 1 - active low
	* FSXP Transmit frame sync pol, 1 - active low
	*/
	pcr \|= (DAVINCI_MCBSP_PCR_FSXP \| DAVINCI_MCBSP_PCR_FSRP);
	break;
	case SND_SOC_DAIFMT_NB_IF:
	/* CLKRP Receive clock polarity,
	* 1 - sampled on rising edge of CLKR
	* valid on rising edge
	* CLKXP Transmit clock polarity,
	* 1 - clocked on falling edge of CLKX
	* valid on rising edge
	* FSRP Receive frame sync pol, 1 - active low
	* FSXP Transmit frame sync pol, 1 - active low
	*/
	pcr \|= (DAVINCI_MCBSP_PCR_CLKXP \| DAVINCI_MCBSP_PCR_CLKRP \|
	DAVINCI_MCBSP_PCR_FSXP \| DAVINCI_MCBSP_PCR_FSRP);
	break;
	case SND_SOC_DAIFMT_IB_NF:
	/* CLKRP Receive clock polarity,
	* 0 - sampled on falling edge of CLKR
	* valid on falling edge
	* CLKXP Transmit clock polarity,
	* 0 - clocked on rising edge of CLKX
	* valid on falling edge
	* FSRP Receive frame sync pol, 0 - active high
	* FSXP Transmit frame sync pol, 0 - active high
	*/
	break;
	default:
	return -EINVAL;
	}
	davinci_mcbsp_write_reg(dev, DAVINCI_MCBSP_SRGR_REG, srgr);
	dev->pcr = pcr;
	davinci_mcbsp_write_reg(dev, DAVINCI_MCBSP_PCR_REG, pcr);
	return 0;
	}

	static int davinci_i2s_hw_params(struct snd_pcm_substream *substream,
	struct snd_pcm_hw_params *params,
	struct snd_soc_dai *dai)
	{
	struct davinci_pcm_dma_params *dma_params = dai->dma_data;
	struct davinci_mcbsp_dev *dev = dai->private_data;
	struct snd_interval *i = NULL;
	int mcbsp_word_length;
	unsigned int rcr, xcr, srgr;
	u32 spcr;

	/* general line settings */
	spcr = davinci_mcbsp_read_reg(dev, DAVINCI_MCBSP_SPCR_REG);
	if (substream->stream == SNDRV_PCM_STREAM_CAPTURE) {
	spcr \|= DAVINCI_MCBSP_SPCR_RINTM(3) \| DAVINCI_MCBSP_SPCR_FREE;
	davinci_mcbsp_write_reg(dev, DAVINCI_MCBSP_SPCR_REG, spcr);
	} else {
	spcr \|= DAVINCI_MCBSP_SPCR_XINTM(3) \| DAVINCI_MCBSP_SPCR_FREE;
	davinci_mcbsp_write_reg(dev, DAVINCI_MCBSP_SPCR_REG, spcr);
	}

	i = hw_param_interval(params, SNDRV_PCM_HW_PARAM_SAMPLE_BITS);
	srgr = DAVINCI_MCBSP_SRGR_FSGM;
	srgr \|= DAVINCI_MCBSP_SRGR_FWID(snd_interval_value(i) - 1);

	i = hw_param_interval(params, SNDRV_PCM_HW_PARAM_FRAME_BITS);
	srgr \|= DAVINCI_MCBSP_SRGR_FPER(snd_interval_value(i) - 1);
	davinci_mcbsp_write_reg(dev, DAVINCI_MCBSP_SRGR_REG, srgr);

	rcr = DAVINCI_MCBSP_RCR_RFIG;
	xcr = DAVINCI_MCBSP_XCR_XFIG;
	if (dev->mode == MOD_DSP_B) {
	rcr \|= DAVINCI_MCBSP_RCR_RDATDLY(0);
	xcr \|= DAVINCI_MCBSP_XCR_XDATDLY(0);
	} else {
	rcr \|= DAVINCI_MCBSP_RCR_RDATDLY(1);
	xcr \|= DAVINCI_MCBSP_XCR_XDATDLY(1);
	}
	/* Determine xfer data type */
	switch (params_format(params)) {
	case SNDRV_PCM_FORMAT_S8:
	dma_params->data_type = 1;
	mcbsp_word_length = DAVINCI_MCBSP_WORD_8;
	break;
	case SNDRV_PCM_FORMAT_S16_LE:
	dma_params->data_type = 2;
	mcbsp_word_length = DAVINCI_MCBSP_WORD_16;
	break;
	case SNDRV_PCM_FORMAT_S32_LE:
	dma_params->data_type = 4;
	mcbsp_word_length = DAVINCI_MCBSP_WORD_32;
	break;
	default:
	printk(KERN_WARNING "davinci-i2s: unsupported PCM format\n");
	return -EINVAL;
	}

	rcr \|= DAVINCI_MCBSP_RCR_RFRLEN1(1);
	xcr \|= DAVINCI_MCBSP_XCR_XFRLEN1(1);

	rcr \|= DAVINCI_MCBSP_RCR_RWDLEN1(mcbsp_word_length) \|
	DAVINCI_MCBSP_RCR_RWDLEN2(mcbsp_word_length);
	xcr \|= DAVINCI_MCBSP_XCR_XWDLEN1(mcbsp_word_length) \|
	DAVINCI_MCBSP_XCR_XWDLEN2(mcbsp_word_length);

	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
	davinci_mcbsp_write_reg(dev, DAVINCI_MCBSP_XCR_REG, xcr);
	else
	davinci_mcbsp_write_reg(dev, DAVINCI_MCBSP_RCR_REG, rcr);
	return 0;
	}

	static int davinci_i2s_prepare(struct snd_pcm_substream *substream,
	struct snd_soc_dai *dai)
	{
	struct davinci_mcbsp_dev *dev = dai->private_data;
	int playback = (substream->stream == SNDRV_PCM_STREAM_PLAYBACK);
	davinci_mcbsp_stop(dev, playback);
	if ((dev->pcr & DAVINCI_MCBSP_PCR_FSXM) == 0) {
	/* codec is master */
	davinci_mcbsp_start(dev, substream);
	}
	return 0;
	}

	static int davinci_i2s_trigger(struct snd_pcm_substream *substream, int cmd,
	struct snd_soc_dai *dai)
	{
	struct davinci_mcbsp_dev *dev = dai->private_data;
	int ret = 0;
	int playback = (substream->stream == SNDRV_PCM_STREAM_PLAYBACK);
	if ((dev->pcr & DAVINCI_MCBSP_PCR_FSXM) == 0)
	return 0; /* return if codec is master */

	switch (cmd) {
	case SNDRV_PCM_TRIGGER_START:
	case SNDRV_PCM_TRIGGER_RESUME:
	case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
	davinci_mcbsp_start(dev, substream);
	break;
	case SNDRV_PCM_TRIGGER_STOP:
	case SNDRV_PCM_TRIGGER_SUSPEND:
	case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
	davinci_mcbsp_stop(dev, playback);
	break;
	default:
	ret = -EINVAL;
	}
	return ret;
	}

	static void davinci_i2s_shutdown(struct snd_pcm_substream *substream,
	struct snd_soc_dai *dai)
	{
	struct davinci_mcbsp_dev *dev = dai->private_data;
	int playback = (substream->stream == SNDRV_PCM_STREAM_PLAYBACK);
	davinci_mcbsp_stop(dev, playback);
	}

	#define DAVINCI_I2S_RATES SNDRV_PCM_RATE_8000_96000

	static struct snd_soc_dai_ops davinci_i2s_dai_ops = {
	.startup = davinci_i2s_startup,
	.shutdown = davinci_i2s_shutdown,
	.prepare = davinci_i2s_prepare,
	.trigger = davinci_i2s_trigger,
	.hw_params = davinci_i2s_hw_params,
	.set_fmt = davinci_i2s_set_dai_fmt,

	};

	struct snd_soc_dai davinci_i2s_dai = {
	.name = "davinci-i2s",
	.id = 0,
	.playback = {
	.channels_min = 2,
	.channels_max = 2,
	.rates = DAVINCI_I2S_RATES,
	.formats = SNDRV_PCM_FMTBIT_S16_LE,},
	.capture = {
	.channels_min = 2,
	.channels_max = 2,
	.rates = DAVINCI_I2S_RATES,
	.formats = SNDRV_PCM_FMTBIT_S16_LE,},
	.ops = &davinci_i2s_dai_ops,

	};
	EXPORT_SYMBOL_GPL(davinci_i2s_dai);

	static int davinci_i2s_probe(struct platform_device *pdev)
	{
	struct snd_platform_data *pdata = pdev->dev.platform_data;
	struct davinci_mcbsp_dev *dev;
	struct resource mem, ioarea, *res;
	int ret;

	mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	if (!mem) {
	dev_err(&pdev->dev, "no mem resource?\n");
	return -ENODEV;
	}

	ioarea = request_mem_region(mem->start, (mem->end - mem->start) + 1,
	pdev->name);
	if (!ioarea) {
	dev_err(&pdev->dev, "McBSP region already claimed\n");
	return -EBUSY;
	}

	dev = kzalloc(sizeof(struct davinci_mcbsp_dev), GFP_KERNEL);
	if (!dev) {
	ret = -ENOMEM;
	goto err_release_region;
	}

	dev->clk = clk_get(&pdev->dev, NULL);
	if (IS_ERR(dev->clk)) {
	ret = -ENODEV;
	goto err_free_mem;
	}
	clk_enable(dev->clk);

	dev->base = (void __iomem *)IO_ADDRESS(mem->start);

	dev->dma_params[SNDRV_PCM_STREAM_PLAYBACK] = &davinci_i2s_pcm_out;
	dev->dma_params[SNDRV_PCM_STREAM_PLAYBACK]->dma_addr =
	(dma_addr_t)(io_v2p(dev->base) + DAVINCI_MCBSP_DXR_REG);

	dev->dma_params[SNDRV_PCM_STREAM_CAPTURE] = &davinci_i2s_pcm_in;
	dev->dma_params[SNDRV_PCM_STREAM_CAPTURE]->dma_addr =
	(dma_addr_t)(io_v2p(dev->base) + DAVINCI_MCBSP_DRR_REG);

	/* first TX, then RX */
	res = platform_get_resource(pdev, IORESOURCE_DMA, 0);
	if (!res) {
	dev_err(&pdev->dev, "no DMA resource\n");
	ret = -ENXIO;
	goto err_free_mem;
	}
	dev->dma_params[SNDRV_PCM_STREAM_PLAYBACK]->channel = res->start;

	res = platform_get_resource(pdev, IORESOURCE_DMA, 1);
	if (!res) {
	dev_err(&pdev->dev, "no DMA resource\n");
	ret = -ENXIO;
	goto err_free_mem;
	}
	dev->dma_params[SNDRV_PCM_STREAM_CAPTURE]->channel = res->start;

	davinci_i2s_dai.private_data = dev;
	ret = snd_soc_register_dai(&davinci_i2s_dai);
	if (ret != 0)
	goto err_free_mem;

	return 0;

	err_free_mem:
	kfree(dev);
	err_release_region:
	release_mem_region(mem->start, (mem->end - mem->start) + 1);

	return ret;
	}

	static int davinci_i2s_remove(struct platform_device *pdev)
	{
	struct davinci_mcbsp_dev *dev = davinci_i2s_dai.private_data;
	struct resource *mem;

	snd_soc_unregister_dai(&davinci_i2s_dai);
	clk_disable(dev->clk);
	clk_put(dev->clk);
	dev->clk = NULL;
	kfree(dev);
	mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	release_mem_region(mem->start, (mem->end - mem->start) + 1);

	return 0;
	}

	static struct platform_driver davinci_mcbsp_driver = {
	.probe = davinci_i2s_probe,
	.remove = davinci_i2s_remove,
	.driver = {
	.name = "davinci-asp",
	.owner = THIS_MODULE,
	},
	};

	static int __init davinci_i2s_init(void)
	{
	return platform_driver_register(&davinci_mcbsp_driver);
	}
	module_init(davinci_i2s_init);

	static void __exit davinci_i2s_exit(void)
	{
	platform_driver_unregister(&davinci_mcbsp_driver);
	}
	module_exit(davinci_i2s_exit);

	MODULE_AUTHOR("Vladimir Barinov");
	MODULE_DESCRIPTION("TI DAVINCI I2S (McBSP) SoC Interface");
	MODULE_LICENSE("GPL");