sound/soc/fsl/imx-ssi.c - kernel/msm-4.9 - Gitiles

 /*
  * imx-ssi.c  --  ALSA Soc Audio Layer
  *
  * Copyright 2009 Sascha Hauer <s.hauer@pengutronix.de>
  *
  * This code is based on code copyrighted by Freescale,
  * Liam Girdwood, Javier Martin and probably others.
  *
  *  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.
  *
  *
  * The i.MX SSI core has some nasty limitations in AC97 mode. While most
  * sane processor vendors have a FIFO per AC97 slot, the i.MX has only
  * one FIFO which combines all valid receive slots. We cannot even select
  * which slots we want to receive. The WM9712 with which this driver
  * was developed with always sends GPIO status data in slot 12 which
  * we receive in our (PCM-) data stream. The only chance we have is to
  * manually skip this data in the FIQ handler. With sampling rates different
  * from 48000Hz not every frame has valid receive data, so the ratio
  * between pcm data and GPIO status data changes. Our FIQ handler is not
  * able to handle this, hence this driver only works with 48000Hz sampling
  * rate.
  * Reading and writing AC97 registers is another challenge. The core
  * provides us status bits when the read register is updated with *another*
  * value. When we read the same register two times (and the register still
  * contains the same value) these status bits are not set. We work
  * around this by not polling these bits but only wait a fixed delay.
  *
  */

 #include <linux/clk.h>
 #include <linux/delay.h>
 #include <linux/device.h>
 #include <linux/dma-mapping.h>
 #include <linux/init.h>
 #include <linux/interrupt.h>
 #include <linux/module.h>
 #include <linux/platform_device.h>
 #include <linux/slab.h>

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

 #include <linux/platform_data/asoc-imx-ssi.h>

 #include "imx-ssi.h"
 #include "fsl_utils.h"

 #define SSI_SACNT_DEFAULT (SSI_SACNT_AC97EN | SSI_SACNT_FV)

 /*
  * SSI Network Mode or TDM slots configuration.
  * Should only be called when port is inactive (i.e. SSIEN = 0).
  */
 static int imx_ssi_set_dai_tdm_slot(struct snd_soc_dai *cpu_dai,
 	unsigned int tx_mask, unsigned int rx_mask, int slots, int slot_width)
 {
 	struct imx_ssi *ssi = snd_soc_dai_get_drvdata(cpu_dai);
 	u32 sccr;

 	sccr = readl(ssi->base + SSI_STCCR);
 	sccr &= ~SSI_STCCR_DC_MASK;
 	sccr |= SSI_STCCR_DC(slots - 1);
 	writel(sccr, ssi->base + SSI_STCCR);

 	sccr = readl(ssi->base + SSI_SRCCR);
 	sccr &= ~SSI_STCCR_DC_MASK;
 	sccr |= SSI_STCCR_DC(slots - 1);
 	writel(sccr, ssi->base + SSI_SRCCR);

 	writel(~tx_mask, ssi->base + SSI_STMSK);
 	writel(~rx_mask, ssi->base + SSI_SRMSK);

 	return 0;
 }

 /*
  * SSI DAI format configuration.
  * Should only be called when port is inactive (i.e. SSIEN = 0).
  */
 static int imx_ssi_set_dai_fmt(struct snd_soc_dai *cpu_dai, unsigned int fmt)
 {
 	struct imx_ssi *ssi = snd_soc_dai_get_drvdata(cpu_dai);
 	u32 strcr = 0, scr;

 	scr = readl(ssi->base + SSI_SCR) & ~(SSI_SCR_SYN | SSI_SCR_NET);

 	/* DAI mode */
 	switch (fmt & SND_SOC_DAIFMT_FORMAT_MASK) {
 	case SND_SOC_DAIFMT_I2S:
 		/* data on rising edge of bclk, frame low 1clk before data */
 		strcr |= SSI_STCR_TFSI | SSI_STCR_TEFS | SSI_STCR_TXBIT0;
 		scr |= SSI_SCR_NET;
 		if (ssi->flags & IMX_SSI_USE_I2S_SLAVE) {
 			scr &= ~SSI_I2S_MODE_MASK;
 			scr |= SSI_SCR_I2S_MODE_SLAVE;
 		}
 		break;
 	case SND_SOC_DAIFMT_LEFT_J:
 		/* data on rising edge of bclk, frame high with data */
 		strcr |= SSI_STCR_TXBIT0;
 		break;
 	case SND_SOC_DAIFMT_DSP_B:
 		/* data on rising edge of bclk, frame high with data */
 		strcr |= SSI_STCR_TFSL | SSI_STCR_TXBIT0;
 		break;
 	case SND_SOC_DAIFMT_DSP_A:
 		/* data on rising edge of bclk, frame high 1clk before data */
 		strcr |= SSI_STCR_TFSL | SSI_STCR_TXBIT0 | SSI_STCR_TEFS;
 		break;
 	}

 	/* DAI clock inversion */
 	switch (fmt & SND_SOC_DAIFMT_INV_MASK) {
 	case SND_SOC_DAIFMT_IB_IF:
 		strcr |= SSI_STCR_TFSI;
 		strcr &= ~SSI_STCR_TSCKP;
 		break;
 	case SND_SOC_DAIFMT_IB_NF:
 		strcr &= ~(SSI_STCR_TSCKP | SSI_STCR_TFSI);
 		break;
 	case SND_SOC_DAIFMT_NB_IF:
 		strcr |= SSI_STCR_TFSI | SSI_STCR_TSCKP;
 		break;
 	case SND_SOC_DAIFMT_NB_NF:
 		strcr &= ~SSI_STCR_TFSI;
 		strcr |= SSI_STCR_TSCKP;
 		break;
 	}

 	/* DAI clock master masks */
 	switch (fmt & SND_SOC_DAIFMT_MASTER_MASK) {
 	case SND_SOC_DAIFMT_CBM_CFM:
 		break;
 	default:
 		/* Master mode not implemented, needs handling of clocks. */
 		return -EINVAL;
 	}

 	strcr |= SSI_STCR_TFEN0;

 	if (ssi->flags & IMX_SSI_NET)
 		scr |= SSI_SCR_NET;
 	if (ssi->flags & IMX_SSI_SYN)
 		scr |= SSI_SCR_SYN;

 	writel(strcr, ssi->base + SSI_STCR);
 	writel(strcr, ssi->base + SSI_SRCR);
 	writel(scr, ssi->base + SSI_SCR);

 	return 0;
 }

 /*
  * SSI system clock configuration.
  * Should only be called when port is inactive (i.e. SSIEN = 0).
  */
 static int imx_ssi_set_dai_sysclk(struct snd_soc_dai *cpu_dai,
 				  int clk_id, unsigned int freq, int dir)
 {
 	struct imx_ssi *ssi = snd_soc_dai_get_drvdata(cpu_dai);
 	u32 scr;

 	scr = readl(ssi->base + SSI_SCR);

 	switch (clk_id) {
 	case IMX_SSP_SYS_CLK:
 		if (dir == SND_SOC_CLOCK_OUT)
 			scr |= SSI_SCR_SYS_CLK_EN;
 		else
 			scr &= ~SSI_SCR_SYS_CLK_EN;
 		break;
 	default:
 		return -EINVAL;
 	}

 	writel(scr, ssi->base + SSI_SCR);

 	return 0;
 }

 /*
  * SSI Clock dividers
  * Should only be called when port is inactive (i.e. SSIEN = 0).
  */
 static int imx_ssi_set_dai_clkdiv(struct snd_soc_dai *cpu_dai,
 				  int div_id, int div)
 {
 	struct imx_ssi *ssi = snd_soc_dai_get_drvdata(cpu_dai);
 	u32 stccr, srccr;

 	stccr = readl(ssi->base + SSI_STCCR);
 	srccr = readl(ssi->base + SSI_SRCCR);

 	switch (div_id) {
 	case IMX_SSI_TX_DIV_2:
 		stccr &= ~SSI_STCCR_DIV2;
 		stccr |= div;
 		break;
 	case IMX_SSI_TX_DIV_PSR:
 		stccr &= ~SSI_STCCR_PSR;
 		stccr |= div;
 		break;
 	case IMX_SSI_TX_DIV_PM:
 		stccr &= ~0xff;
 		stccr |= SSI_STCCR_PM(div);
 		break;
 	case IMX_SSI_RX_DIV_2:
 		stccr &= ~SSI_STCCR_DIV2;
 		stccr |= div;
 		break;
 	case IMX_SSI_RX_DIV_PSR:
 		stccr &= ~SSI_STCCR_PSR;
 		stccr |= div;
 		break;
 	case IMX_SSI_RX_DIV_PM:
 		stccr &= ~0xff;
 		stccr |= SSI_STCCR_PM(div);
 		break;
 	default:
 		return -EINVAL;
 	}

 	writel(stccr, ssi->base + SSI_STCCR);
 	writel(srccr, ssi->base + SSI_SRCCR);

 	return 0;
 }

 /*
  * Should only be called when port is inactive (i.e. SSIEN = 0),
  * although can be called multiple times by upper layers.
  */
 static int imx_ssi_hw_params(struct snd_pcm_substream *substream,
 			     struct snd_pcm_hw_params *params,
 			     struct snd_soc_dai *cpu_dai)
 {
 	struct imx_ssi *ssi = snd_soc_dai_get_drvdata(cpu_dai);
 	u32 reg, sccr;

 	/* Tx/Rx config */
 	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
 		reg = SSI_STCCR;
 	else
 		reg = SSI_SRCCR;

 	if (ssi->flags & IMX_SSI_SYN)
 		reg = SSI_STCCR;

 	sccr = readl(ssi->base + reg) & ~SSI_STCCR_WL_MASK;

 	/* DAI data (word) size */
 	switch (params_format(params)) {
 	case SNDRV_PCM_FORMAT_S16_LE:
 		sccr |= SSI_SRCCR_WL(16);
 		break;
 	case SNDRV_PCM_FORMAT_S20_3LE:
 		sccr |= SSI_SRCCR_WL(20);
 		break;
 	case SNDRV_PCM_FORMAT_S24_LE:
 		sccr |= SSI_SRCCR_WL(24);
 		break;
 	}

 	writel(sccr, ssi->base + reg);

 	return 0;
 }

 static int imx_ssi_trigger(struct snd_pcm_substream *substream, int cmd,
 		struct snd_soc_dai *dai)
 {
 	struct imx_ssi *ssi = snd_soc_dai_get_drvdata(dai);
 	unsigned int sier_bits, sier;
 	unsigned int scr;

 	scr = readl(ssi->base + SSI_SCR);
 	sier = readl(ssi->base + SSI_SIER);

 	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
 		if (ssi->flags & IMX_SSI_DMA)
 			sier_bits = SSI_SIER_TDMAE;
 		else
 			sier_bits = SSI_SIER_TIE | SSI_SIER_TFE0_EN;
 	} else {
 		if (ssi->flags & IMX_SSI_DMA)
 			sier_bits = SSI_SIER_RDMAE;
 		else
 			sier_bits = SSI_SIER_RIE | SSI_SIER_RFF0_EN;
 	}

 	switch (cmd) {
 	case SNDRV_PCM_TRIGGER_START:
 	case SNDRV_PCM_TRIGGER_RESUME:
 	case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
 		if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
 			scr |= SSI_SCR_TE;
 		else
 			scr |= SSI_SCR_RE;
 		sier |= sier_bits;

 		scr |= SSI_SCR_SSIEN;

 		break;

 	case SNDRV_PCM_TRIGGER_STOP:
 	case SNDRV_PCM_TRIGGER_SUSPEND:
 	case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
 		if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
 			scr &= ~SSI_SCR_TE;
 		else
 			scr &= ~SSI_SCR_RE;
 		sier &= ~sier_bits;

 		if (!(scr & (SSI_SCR_TE | SSI_SCR_RE)))
 			scr &= ~SSI_SCR_SSIEN;

 		break;
 	default:
 		return -EINVAL;
 	}

 	if (!(ssi->flags & IMX_SSI_USE_AC97))
 		/* rx/tx are always enabled to access ac97 registers */
 		writel(scr, ssi->base + SSI_SCR);

 	writel(sier, ssi->base + SSI_SIER);

 	return 0;
 }

 static const struct snd_soc_dai_ops imx_ssi_pcm_dai_ops = {
 	.hw_params	= imx_ssi_hw_params,
 	.set_fmt	= imx_ssi_set_dai_fmt,
 	.set_clkdiv	= imx_ssi_set_dai_clkdiv,
 	.set_sysclk	= imx_ssi_set_dai_sysclk,
 	.set_tdm_slot	= imx_ssi_set_dai_tdm_slot,
 	.trigger	= imx_ssi_trigger,
 };

 static int imx_ssi_dai_probe(struct snd_soc_dai *dai)
 {
 	struct imx_ssi *ssi = dev_get_drvdata(dai->dev);
 	uint32_t val;

 	snd_soc_dai_set_drvdata(dai, ssi);

 	val = SSI_SFCSR_TFWM0(ssi->dma_params_tx.maxburst) |
 		SSI_SFCSR_RFWM0(ssi->dma_params_rx.maxburst);
 	writel(val, ssi->base + SSI_SFCSR);

 	/* Tx/Rx config */
 	dai->playback_dma_data = &ssi->dma_params_tx;
 	dai->capture_dma_data = &ssi->dma_params_rx;

 	return 0;
 }

 static struct snd_soc_dai_driver imx_ssi_dai = {
 	.probe = imx_ssi_dai_probe,
 	.playback = {
 		.channels_min = 1,
 		.channels_max = 2,
 		.rates = SNDRV_PCM_RATE_8000_96000,
 		.formats = SNDRV_PCM_FMTBIT_S16_LE,
 	},
 	.capture = {
 		.channels_min = 1,
 		.channels_max = 2,
 		.rates = SNDRV_PCM_RATE_8000_96000,
 		.formats = SNDRV_PCM_FMTBIT_S16_LE,
 	},
 	.ops = &imx_ssi_pcm_dai_ops,
 };

 static struct snd_soc_dai_driver imx_ac97_dai = {
 	.probe = imx_ssi_dai_probe,
 	.bus_control = true,
 	.playback = {
 		.stream_name = "AC97 Playback",
 		.channels_min = 2,
 		.channels_max = 2,
 		.rates = SNDRV_PCM_RATE_8000_48000,
 		.formats = SNDRV_PCM_FMTBIT_S16_LE,
 	},
 	.capture = {
 		.stream_name = "AC97 Capture",
 		.channels_min = 2,
 		.channels_max = 2,
 		.rates = SNDRV_PCM_RATE_48000,
 		.formats = SNDRV_PCM_FMTBIT_S16_LE,
 	},
 	.ops = &imx_ssi_pcm_dai_ops,
 };

 static const struct snd_soc_component_driver imx_component = {
 	.name		= DRV_NAME,
 };

 static void setup_channel_to_ac97(struct imx_ssi *imx_ssi)
 {
 	void __iomem *base = imx_ssi->base;

 	writel(0x0, base + SSI_SCR);
 	writel(0x0, base + SSI_STCR);
 	writel(0x0, base + SSI_SRCR);

 	writel(SSI_SCR_SYN | SSI_SCR_NET, base + SSI_SCR);

 	writel(SSI_SFCSR_RFWM0(8) |
 		SSI_SFCSR_TFWM0(8) |
 		SSI_SFCSR_RFWM1(8) |
 		SSI_SFCSR_TFWM1(8), base + SSI_SFCSR);

 	writel(SSI_STCCR_WL(16) | SSI_STCCR_DC(12), base + SSI_STCCR);
 	writel(SSI_STCCR_WL(16) | SSI_STCCR_DC(12), base + SSI_SRCCR);

 	writel(SSI_SCR_SYN | SSI_SCR_NET | SSI_SCR_SSIEN, base + SSI_SCR);
 	writel(SSI_SOR_WAIT(3), base + SSI_SOR);

 	writel(SSI_SCR_SYN | SSI_SCR_NET | SSI_SCR_SSIEN |
 			SSI_SCR_TE | SSI_SCR_RE,
 			base + SSI_SCR);

 	writel(SSI_SACNT_DEFAULT, base + SSI_SACNT);
 	writel(0xff, base + SSI_SACCDIS);
 	writel(0x300, base + SSI_SACCEN);
 }

 static struct imx_ssi *ac97_ssi;

 static void imx_ssi_ac97_write(struct snd_ac97 *ac97, unsigned short reg,
 		unsigned short val)
 {
 	struct imx_ssi *imx_ssi = ac97_ssi;
 	void __iomem *base = imx_ssi->base;
 	unsigned int lreg;
 	unsigned int lval;

 	if (reg > 0x7f)
 		return;

 	pr_debug("%s: 0x%02x 0x%04x\n", __func__, reg, val);

 	lreg = reg <<  12;
 	writel(lreg, base + SSI_SACADD);

 	lval = val << 4;
 	writel(lval , base + SSI_SACDAT);

 	writel(SSI_SACNT_DEFAULT | SSI_SACNT_WR, base + SSI_SACNT);
 	udelay(100);
 }

 static unsigned short imx_ssi_ac97_read(struct snd_ac97 *ac97,
 		unsigned short reg)
 {
 	struct imx_ssi *imx_ssi = ac97_ssi;
 	void __iomem *base = imx_ssi->base;

 	unsigned short val = -1;
 	unsigned int lreg;

 	lreg = (reg & 0x7f) <<  12 ;
 	writel(lreg, base + SSI_SACADD);
 	writel(SSI_SACNT_DEFAULT | SSI_SACNT_RD, base + SSI_SACNT);

 	udelay(100);

 	val = (readl(base + SSI_SACDAT) >> 4) & 0xffff;

 	pr_debug("%s: 0x%02x 0x%04x\n", __func__, reg, val);

 	return val;
 }

 static void imx_ssi_ac97_reset(struct snd_ac97 *ac97)
 {
 	struct imx_ssi *imx_ssi = ac97_ssi;

 	if (imx_ssi->ac97_reset)
 		imx_ssi->ac97_reset(ac97);
 	/* First read sometimes fails, do a dummy read */
 	imx_ssi_ac97_read(ac97, 0);
 }

 static void imx_ssi_ac97_warm_reset(struct snd_ac97 *ac97)
 {
 	struct imx_ssi *imx_ssi = ac97_ssi;

 	if (imx_ssi->ac97_warm_reset)
 		imx_ssi->ac97_warm_reset(ac97);

 	/* First read sometimes fails, do a dummy read */
 	imx_ssi_ac97_read(ac97, 0);
 }

 static struct snd_ac97_bus_ops imx_ssi_ac97_ops = {
 	.read		= imx_ssi_ac97_read,
 	.write		= imx_ssi_ac97_write,
 	.reset		= imx_ssi_ac97_reset,
 	.warm_reset	= imx_ssi_ac97_warm_reset
 };

 static int imx_ssi_probe(struct platform_device *pdev)
 {
 	struct resource *res;
 	struct imx_ssi *ssi;
 	struct imx_ssi_platform_data *pdata = pdev->dev.platform_data;
 	int ret = 0;
 	struct snd_soc_dai_driver *dai;

 	ssi = devm_kzalloc(&pdev->dev, sizeof(*ssi), GFP_KERNEL);
 	if (!ssi)
 		return -ENOMEM;
 	dev_set_drvdata(&pdev->dev, ssi);

 	if (pdata) {
 		ssi->ac97_reset = pdata->ac97_reset;
 		ssi->ac97_warm_reset = pdata->ac97_warm_reset;
 		ssi->flags = pdata->flags;
 	}

 	ssi->irq = platform_get_irq(pdev, 0);

 	ssi->clk = devm_clk_get(&pdev->dev, NULL);
 	if (IS_ERR(ssi->clk)) {
 		ret = PTR_ERR(ssi->clk);
 		dev_err(&pdev->dev, "Cannot get the clock: %d\n",
 			ret);
 		goto failed_clk;
 	}
 	ret = clk_prepare_enable(ssi->clk);
 	if (ret)
 		goto failed_clk;

 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 	ssi->base = devm_ioremap_resource(&pdev->dev, res);
 	if (IS_ERR(ssi->base)) {
 		ret = PTR_ERR(ssi->base);
 		goto failed_register;
 	}

 	if (ssi->flags & IMX_SSI_USE_AC97) {
 		if (ac97_ssi) {
 			dev_err(&pdev->dev, "AC'97 SSI already registered\n");
 			ret = -EBUSY;
 			goto failed_register;
 		}
 		ac97_ssi = ssi;
 		setup_channel_to_ac97(ssi);
 		dai = &imx_ac97_dai;
 	} else
 		dai = &imx_ssi_dai;

 	writel(0x0, ssi->base + SSI_SIER);

 	ssi->dma_params_rx.addr = res->start + SSI_SRX0;
 	ssi->dma_params_tx.addr = res->start + SSI_STX0;

 	ssi->dma_params_tx.maxburst = 6;
 	ssi->dma_params_rx.maxburst = 4;

 	ssi->dma_params_tx.filter_data = &ssi->filter_data_tx;
 	ssi->dma_params_rx.filter_data = &ssi->filter_data_rx;

 	res = platform_get_resource_byname(pdev, IORESOURCE_DMA, "tx0");
 	if (res) {
 		imx_pcm_dma_params_init_data(&ssi->filter_data_tx, res->start,
 			IMX_DMATYPE_SSI);
 	}

 	res = platform_get_resource_byname(pdev, IORESOURCE_DMA, "rx0");
 	if (res) {
 		imx_pcm_dma_params_init_data(&ssi->filter_data_rx, res->start,
 			IMX_DMATYPE_SSI);
 	}

 	platform_set_drvdata(pdev, ssi);

 	ret = snd_soc_set_ac97_ops(&imx_ssi_ac97_ops);
 	if (ret != 0) {
 		dev_err(&pdev->dev, "Failed to set AC'97 ops: %d\n", ret);
 		goto failed_register;
 	}

 	ret = snd_soc_register_component(&pdev->dev, &imx_component,
 					 dai, 1);
 	if (ret) {
 		dev_err(&pdev->dev, "register DAI failed\n");
 		goto failed_register;
 	}

 	ssi->fiq_params.irq = ssi->irq;
 	ssi->fiq_params.base = ssi->base;
 	ssi->fiq_params.dma_params_rx = &ssi->dma_params_rx;
 	ssi->fiq_params.dma_params_tx = &ssi->dma_params_tx;

 	ssi->fiq_init = imx_pcm_fiq_init(pdev, &ssi->fiq_params);
 	ssi->dma_init = imx_pcm_dma_init(pdev, IMX_SSI_DMABUF_SIZE);

 	if (ssi->fiq_init && ssi->dma_init) {
 		ret = ssi->fiq_init;
 		goto failed_pcm;
 	}

 	return 0;

 failed_pcm:
 	snd_soc_unregister_component(&pdev->dev);
 failed_register:
 	clk_disable_unprepare(ssi->clk);
 failed_clk:
 	snd_soc_set_ac97_ops(NULL);

 	return ret;
 }

 static int imx_ssi_remove(struct platform_device *pdev)
 {
 	struct imx_ssi *ssi = platform_get_drvdata(pdev);

 	if (!ssi->fiq_init)
 		imx_pcm_fiq_exit(pdev);

 	snd_soc_unregister_component(&pdev->dev);

 	if (ssi->flags & IMX_SSI_USE_AC97)
 		ac97_ssi = NULL;

 	clk_disable_unprepare(ssi->clk);
 	snd_soc_set_ac97_ops(NULL);

 	return 0;
 }

 static struct platform_driver imx_ssi_driver = {
 	.probe = imx_ssi_probe,
 	.remove = imx_ssi_remove,

 	.driver = {
 		.name = "imx-ssi",
 	},
 };

 module_platform_driver(imx_ssi_driver);

 /* Module information */
 MODULE_AUTHOR("Sascha Hauer, <s.hauer@pengutronix.de>");
 MODULE_DESCRIPTION("i.MX I2S/ac97 SoC Interface");
 MODULE_LICENSE("GPL");
 MODULE_ALIAS("platform:imx-ssi");
	/*
	* imx-ssi.c -- ALSA Soc Audio Layer
	*
	* Copyright 2009 Sascha Hauer <s.hauer@pengutronix.de>
	*
	* This code is based on code copyrighted by Freescale,
	* Liam Girdwood, Javier Martin and probably others.
	*
	* 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.
	*
	*
	* The i.MX SSI core has some nasty limitations in AC97 mode. While most
	* sane processor vendors have a FIFO per AC97 slot, the i.MX has only
	* one FIFO which combines all valid receive slots. We cannot even select
	* which slots we want to receive. The WM9712 with which this driver
	* was developed with always sends GPIO status data in slot 12 which
	* we receive in our (PCM-) data stream. The only chance we have is to
	* manually skip this data in the FIQ handler. With sampling rates different
	* from 48000Hz not every frame has valid receive data, so the ratio
	* between pcm data and GPIO status data changes. Our FIQ handler is not
	* able to handle this, hence this driver only works with 48000Hz sampling
	* rate.
	* Reading and writing AC97 registers is another challenge. The core
	* provides us status bits when the read register is updated with another
	* value. When we read the same register two times (and the register still
	* contains the same value) these status bits are not set. We work
	* around this by not polling these bits but only wait a fixed delay.
	*
	*/

	#include <linux/clk.h>
	#include <linux/delay.h>
	#include <linux/device.h>
	#include <linux/dma-mapping.h>
	#include <linux/init.h>
	#include <linux/interrupt.h>
	#include <linux/module.h>
	#include <linux/platform_device.h>
	#include <linux/slab.h>

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

	#include <linux/platform_data/asoc-imx-ssi.h>

	#include "imx-ssi.h"
	#include "fsl_utils.h"

	#define SSI_SACNT_DEFAULT (SSI_SACNT_AC97EN \| SSI_SACNT_FV)

	/*
	* SSI Network Mode or TDM slots configuration.
	* Should only be called when port is inactive (i.e. SSIEN = 0).
	*/
	static int imx_ssi_set_dai_tdm_slot(struct snd_soc_dai *cpu_dai,
	unsigned int tx_mask, unsigned int rx_mask, int slots, int slot_width)
	{
	struct imx_ssi *ssi = snd_soc_dai_get_drvdata(cpu_dai);
	u32 sccr;

	sccr = readl(ssi->base + SSI_STCCR);
	sccr &= ~SSI_STCCR_DC_MASK;
	sccr \|= SSI_STCCR_DC(slots - 1);
	writel(sccr, ssi->base + SSI_STCCR);

	sccr = readl(ssi->base + SSI_SRCCR);
	sccr &= ~SSI_STCCR_DC_MASK;
	sccr \|= SSI_STCCR_DC(slots - 1);
	writel(sccr, ssi->base + SSI_SRCCR);

	writel(~tx_mask, ssi->base + SSI_STMSK);
	writel(~rx_mask, ssi->base + SSI_SRMSK);

	return 0;
	}

	/*
	* SSI DAI format configuration.
	* Should only be called when port is inactive (i.e. SSIEN = 0).
	*/
	static int imx_ssi_set_dai_fmt(struct snd_soc_dai *cpu_dai, unsigned int fmt)
	{
	struct imx_ssi *ssi = snd_soc_dai_get_drvdata(cpu_dai);
	u32 strcr = 0, scr;

	scr = readl(ssi->base + SSI_SCR) & ~(SSI_SCR_SYN \| SSI_SCR_NET);

	/* DAI mode */
	switch (fmt & SND_SOC_DAIFMT_FORMAT_MASK) {
	case SND_SOC_DAIFMT_I2S:
	/* data on rising edge of bclk, frame low 1clk before data */
	strcr \|= SSI_STCR_TFSI \| SSI_STCR_TEFS \| SSI_STCR_TXBIT0;
	scr \|= SSI_SCR_NET;
	if (ssi->flags & IMX_SSI_USE_I2S_SLAVE) {
	scr &= ~SSI_I2S_MODE_MASK;
	scr \|= SSI_SCR_I2S_MODE_SLAVE;
	}
	break;
	case SND_SOC_DAIFMT_LEFT_J:
	/* data on rising edge of bclk, frame high with data */
	strcr \|= SSI_STCR_TXBIT0;
	break;
	case SND_SOC_DAIFMT_DSP_B:
	/* data on rising edge of bclk, frame high with data */
	strcr \|= SSI_STCR_TFSL \| SSI_STCR_TXBIT0;
	break;
	case SND_SOC_DAIFMT_DSP_A:
	/* data on rising edge of bclk, frame high 1clk before data */
	strcr \|= SSI_STCR_TFSL \| SSI_STCR_TXBIT0 \| SSI_STCR_TEFS;
	break;
	}

	/* DAI clock inversion */
	switch (fmt & SND_SOC_DAIFMT_INV_MASK) {
	case SND_SOC_DAIFMT_IB_IF:
	strcr \|= SSI_STCR_TFSI;
	strcr &= ~SSI_STCR_TSCKP;
	break;
	case SND_SOC_DAIFMT_IB_NF:
	strcr &= ~(SSI_STCR_TSCKP \| SSI_STCR_TFSI);
	break;
	case SND_SOC_DAIFMT_NB_IF:
	strcr \|= SSI_STCR_TFSI \| SSI_STCR_TSCKP;
	break;
	case SND_SOC_DAIFMT_NB_NF:
	strcr &= ~SSI_STCR_TFSI;
	strcr \|= SSI_STCR_TSCKP;
	break;
	}

	/* DAI clock master masks */
	switch (fmt & SND_SOC_DAIFMT_MASTER_MASK) {
	case SND_SOC_DAIFMT_CBM_CFM:
	break;
	default:
	/* Master mode not implemented, needs handling of clocks. */
	return -EINVAL;
	}

	strcr \|= SSI_STCR_TFEN0;

	if (ssi->flags & IMX_SSI_NET)
	scr \|= SSI_SCR_NET;
	if (ssi->flags & IMX_SSI_SYN)
	scr \|= SSI_SCR_SYN;

	writel(strcr, ssi->base + SSI_STCR);
	writel(strcr, ssi->base + SSI_SRCR);
	writel(scr, ssi->base + SSI_SCR);

	return 0;
	}

	/*
	* SSI system clock configuration.
	* Should only be called when port is inactive (i.e. SSIEN = 0).
	*/
	static int imx_ssi_set_dai_sysclk(struct snd_soc_dai *cpu_dai,
	int clk_id, unsigned int freq, int dir)
	{
	struct imx_ssi *ssi = snd_soc_dai_get_drvdata(cpu_dai);
	u32 scr;

	scr = readl(ssi->base + SSI_SCR);

	switch (clk_id) {
	case IMX_SSP_SYS_CLK:
	if (dir == SND_SOC_CLOCK_OUT)
	scr \|= SSI_SCR_SYS_CLK_EN;
	else
	scr &= ~SSI_SCR_SYS_CLK_EN;
	break;
	default:
	return -EINVAL;
	}

	writel(scr, ssi->base + SSI_SCR);

	return 0;
	}

	/*
	* SSI Clock dividers
	* Should only be called when port is inactive (i.e. SSIEN = 0).
	*/
	static int imx_ssi_set_dai_clkdiv(struct snd_soc_dai *cpu_dai,
	int div_id, int div)
	{
	struct imx_ssi *ssi = snd_soc_dai_get_drvdata(cpu_dai);
	u32 stccr, srccr;

	stccr = readl(ssi->base + SSI_STCCR);
	srccr = readl(ssi->base + SSI_SRCCR);

	switch (div_id) {
	case IMX_SSI_TX_DIV_2:
	stccr &= ~SSI_STCCR_DIV2;
	stccr \|= div;
	break;
	case IMX_SSI_TX_DIV_PSR:
	stccr &= ~SSI_STCCR_PSR;
	stccr \|= div;
	break;
	case IMX_SSI_TX_DIV_PM:
	stccr &= ~0xff;
	stccr \|= SSI_STCCR_PM(div);
	break;
	case IMX_SSI_RX_DIV_2:
	stccr &= ~SSI_STCCR_DIV2;
	stccr \|= div;
	break;
	case IMX_SSI_RX_DIV_PSR:
	stccr &= ~SSI_STCCR_PSR;
	stccr \|= div;
	break;
	case IMX_SSI_RX_DIV_PM:
	stccr &= ~0xff;
	stccr \|= SSI_STCCR_PM(div);
	break;
	default:
	return -EINVAL;
	}

	writel(stccr, ssi->base + SSI_STCCR);
	writel(srccr, ssi->base + SSI_SRCCR);

	return 0;
	}

	/*
	* Should only be called when port is inactive (i.e. SSIEN = 0),
	* although can be called multiple times by upper layers.
	*/
	static int imx_ssi_hw_params(struct snd_pcm_substream *substream,
	struct snd_pcm_hw_params *params,
	struct snd_soc_dai *cpu_dai)
	{
	struct imx_ssi *ssi = snd_soc_dai_get_drvdata(cpu_dai);
	u32 reg, sccr;

	/* Tx/Rx config */
	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
	reg = SSI_STCCR;
	else
	reg = SSI_SRCCR;

	if (ssi->flags & IMX_SSI_SYN)
	reg = SSI_STCCR;

	sccr = readl(ssi->base + reg) & ~SSI_STCCR_WL_MASK;

	/* DAI data (word) size */
	switch (params_format(params)) {
	case SNDRV_PCM_FORMAT_S16_LE:
	sccr \|= SSI_SRCCR_WL(16);
	break;
	case SNDRV_PCM_FORMAT_S20_3LE:
	sccr \|= SSI_SRCCR_WL(20);
	break;
	case SNDRV_PCM_FORMAT_S24_LE:
	sccr \|= SSI_SRCCR_WL(24);
	break;
	}

	writel(sccr, ssi->base + reg);

	return 0;
	}

	static int imx_ssi_trigger(struct snd_pcm_substream *substream, int cmd,
	struct snd_soc_dai *dai)
	{
	struct imx_ssi *ssi = snd_soc_dai_get_drvdata(dai);
	unsigned int sier_bits, sier;
	unsigned int scr;

	scr = readl(ssi->base + SSI_SCR);
	sier = readl(ssi->base + SSI_SIER);

	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
	if (ssi->flags & IMX_SSI_DMA)
	sier_bits = SSI_SIER_TDMAE;
	else
	sier_bits = SSI_SIER_TIE \| SSI_SIER_TFE0_EN;
	} else {
	if (ssi->flags & IMX_SSI_DMA)
	sier_bits = SSI_SIER_RDMAE;
	else
	sier_bits = SSI_SIER_RIE \| SSI_SIER_RFF0_EN;
	}

	switch (cmd) {
	case SNDRV_PCM_TRIGGER_START:
	case SNDRV_PCM_TRIGGER_RESUME:
	case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
	scr \|= SSI_SCR_TE;
	else
	scr \|= SSI_SCR_RE;
	sier \|= sier_bits;

	scr \|= SSI_SCR_SSIEN;

	break;

	case SNDRV_PCM_TRIGGER_STOP:
	case SNDRV_PCM_TRIGGER_SUSPEND:
	case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
	scr &= ~SSI_SCR_TE;
	else
	scr &= ~SSI_SCR_RE;
	sier &= ~sier_bits;

	if (!(scr & (SSI_SCR_TE \| SSI_SCR_RE)))
	scr &= ~SSI_SCR_SSIEN;

	break;
	default:
	return -EINVAL;
	}

	if (!(ssi->flags & IMX_SSI_USE_AC97))
	/* rx/tx are always enabled to access ac97 registers */
	writel(scr, ssi->base + SSI_SCR);

	writel(sier, ssi->base + SSI_SIER);

	return 0;
	}

	static const struct snd_soc_dai_ops imx_ssi_pcm_dai_ops = {
	.hw_params = imx_ssi_hw_params,
	.set_fmt = imx_ssi_set_dai_fmt,
	.set_clkdiv = imx_ssi_set_dai_clkdiv,
	.set_sysclk = imx_ssi_set_dai_sysclk,
	.set_tdm_slot = imx_ssi_set_dai_tdm_slot,
	.trigger = imx_ssi_trigger,
	};

	static int imx_ssi_dai_probe(struct snd_soc_dai *dai)
	{
	struct imx_ssi *ssi = dev_get_drvdata(dai->dev);
	uint32_t val;

	snd_soc_dai_set_drvdata(dai, ssi);

	val = SSI_SFCSR_TFWM0(ssi->dma_params_tx.maxburst) \|
	SSI_SFCSR_RFWM0(ssi->dma_params_rx.maxburst);
	writel(val, ssi->base + SSI_SFCSR);

	/* Tx/Rx config */
	dai->playback_dma_data = &ssi->dma_params_tx;
	dai->capture_dma_data = &ssi->dma_params_rx;

	return 0;
	}

	static struct snd_soc_dai_driver imx_ssi_dai = {
	.probe = imx_ssi_dai_probe,
	.playback = {
	.channels_min = 1,
	.channels_max = 2,
	.rates = SNDRV_PCM_RATE_8000_96000,
	.formats = SNDRV_PCM_FMTBIT_S16_LE,
	},
	.capture = {
	.channels_min = 1,
	.channels_max = 2,
	.rates = SNDRV_PCM_RATE_8000_96000,
	.formats = SNDRV_PCM_FMTBIT_S16_LE,
	},
	.ops = &imx_ssi_pcm_dai_ops,
	};

	static struct snd_soc_dai_driver imx_ac97_dai = {
	.probe = imx_ssi_dai_probe,
	.bus_control = true,
	.playback = {
	.stream_name = "AC97 Playback",
	.channels_min = 2,
	.channels_max = 2,
	.rates = SNDRV_PCM_RATE_8000_48000,
	.formats = SNDRV_PCM_FMTBIT_S16_LE,
	},
	.capture = {
	.stream_name = "AC97 Capture",
	.channels_min = 2,
	.channels_max = 2,
	.rates = SNDRV_PCM_RATE_48000,
	.formats = SNDRV_PCM_FMTBIT_S16_LE,
	},
	.ops = &imx_ssi_pcm_dai_ops,
	};

	static const struct snd_soc_component_driver imx_component = {
	.name = DRV_NAME,
	};

	static void setup_channel_to_ac97(struct imx_ssi *imx_ssi)
	{
	void __iomem *base = imx_ssi->base;

	writel(0x0, base + SSI_SCR);
	writel(0x0, base + SSI_STCR);
	writel(0x0, base + SSI_SRCR);

	writel(SSI_SCR_SYN \| SSI_SCR_NET, base + SSI_SCR);

	writel(SSI_SFCSR_RFWM0(8) \|
	SSI_SFCSR_TFWM0(8) \|
	SSI_SFCSR_RFWM1(8) \|
	SSI_SFCSR_TFWM1(8), base + SSI_SFCSR);

	writel(SSI_STCCR_WL(16) \| SSI_STCCR_DC(12), base + SSI_STCCR);
	writel(SSI_STCCR_WL(16) \| SSI_STCCR_DC(12), base + SSI_SRCCR);

	writel(SSI_SCR_SYN \| SSI_SCR_NET \| SSI_SCR_SSIEN, base + SSI_SCR);
	writel(SSI_SOR_WAIT(3), base + SSI_SOR);

	writel(SSI_SCR_SYN \| SSI_SCR_NET \| SSI_SCR_SSIEN \|
	SSI_SCR_TE \| SSI_SCR_RE,
	base + SSI_SCR);

	writel(SSI_SACNT_DEFAULT, base + SSI_SACNT);
	writel(0xff, base + SSI_SACCDIS);
	writel(0x300, base + SSI_SACCEN);
	}

	static struct imx_ssi *ac97_ssi;

	static void imx_ssi_ac97_write(struct snd_ac97 *ac97, unsigned short reg,
	unsigned short val)
	{
	struct imx_ssi *imx_ssi = ac97_ssi;
	void __iomem *base = imx_ssi->base;
	unsigned int lreg;
	unsigned int lval;

	if (reg > 0x7f)
	return;

	pr_debug("%s: 0x%02x 0x%04x\n", __func__, reg, val);

	lreg = reg << 12;
	writel(lreg, base + SSI_SACADD);

	lval = val << 4;
	writel(lval , base + SSI_SACDAT);

	writel(SSI_SACNT_DEFAULT \| SSI_SACNT_WR, base + SSI_SACNT);
	udelay(100);
	}

	static unsigned short imx_ssi_ac97_read(struct snd_ac97 *ac97,
	unsigned short reg)
	{
	struct imx_ssi *imx_ssi = ac97_ssi;
	void __iomem *base = imx_ssi->base;

	unsigned short val = -1;
	unsigned int lreg;

	lreg = (reg & 0x7f) << 12 ;
	writel(lreg, base + SSI_SACADD);
	writel(SSI_SACNT_DEFAULT \| SSI_SACNT_RD, base + SSI_SACNT);

	udelay(100);

	val = (readl(base + SSI_SACDAT) >> 4) & 0xffff;

	pr_debug("%s: 0x%02x 0x%04x\n", __func__, reg, val);

	return val;
	}

	static void imx_ssi_ac97_reset(struct snd_ac97 *ac97)
	{
	struct imx_ssi *imx_ssi = ac97_ssi;

	if (imx_ssi->ac97_reset)
	imx_ssi->ac97_reset(ac97);
	/* First read sometimes fails, do a dummy read */
	imx_ssi_ac97_read(ac97, 0);
	}

	static void imx_ssi_ac97_warm_reset(struct snd_ac97 *ac97)
	{
	struct imx_ssi *imx_ssi = ac97_ssi;

	if (imx_ssi->ac97_warm_reset)
	imx_ssi->ac97_warm_reset(ac97);

	/* First read sometimes fails, do a dummy read */
	imx_ssi_ac97_read(ac97, 0);
	}

	static struct snd_ac97_bus_ops imx_ssi_ac97_ops = {
	.read = imx_ssi_ac97_read,
	.write = imx_ssi_ac97_write,
	.reset = imx_ssi_ac97_reset,
	.warm_reset = imx_ssi_ac97_warm_reset
	};

	static int imx_ssi_probe(struct platform_device *pdev)
	{
	struct resource *res;
	struct imx_ssi *ssi;
	struct imx_ssi_platform_data *pdata = pdev->dev.platform_data;
	int ret = 0;
	struct snd_soc_dai_driver *dai;

	ssi = devm_kzalloc(&pdev->dev, sizeof(*ssi), GFP_KERNEL);
	if (!ssi)
	return -ENOMEM;
	dev_set_drvdata(&pdev->dev, ssi);

	if (pdata) {
	ssi->ac97_reset = pdata->ac97_reset;
	ssi->ac97_warm_reset = pdata->ac97_warm_reset;
	ssi->flags = pdata->flags;
	}

	ssi->irq = platform_get_irq(pdev, 0);

	ssi->clk = devm_clk_get(&pdev->dev, NULL);
	if (IS_ERR(ssi->clk)) {
	ret = PTR_ERR(ssi->clk);
	dev_err(&pdev->dev, "Cannot get the clock: %d\n",
	ret);
	goto failed_clk;
	}
	ret = clk_prepare_enable(ssi->clk);
	if (ret)
	goto failed_clk;

	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	ssi->base = devm_ioremap_resource(&pdev->dev, res);
	if (IS_ERR(ssi->base)) {
	ret = PTR_ERR(ssi->base);
	goto failed_register;
	}

	if (ssi->flags & IMX_SSI_USE_AC97) {
	if (ac97_ssi) {
	dev_err(&pdev->dev, "AC'97 SSI already registered\n");
	ret = -EBUSY;
	goto failed_register;
	}
	ac97_ssi = ssi;
	setup_channel_to_ac97(ssi);
	dai = &imx_ac97_dai;
	} else
	dai = &imx_ssi_dai;

	writel(0x0, ssi->base + SSI_SIER);

	ssi->dma_params_rx.addr = res->start + SSI_SRX0;
	ssi->dma_params_tx.addr = res->start + SSI_STX0;

	ssi->dma_params_tx.maxburst = 6;
	ssi->dma_params_rx.maxburst = 4;

	ssi->dma_params_tx.filter_data = &ssi->filter_data_tx;
	ssi->dma_params_rx.filter_data = &ssi->filter_data_rx;

	res = platform_get_resource_byname(pdev, IORESOURCE_DMA, "tx0");
	if (res) {
	imx_pcm_dma_params_init_data(&ssi->filter_data_tx, res->start,
	IMX_DMATYPE_SSI);
	}

	res = platform_get_resource_byname(pdev, IORESOURCE_DMA, "rx0");
	if (res) {
	imx_pcm_dma_params_init_data(&ssi->filter_data_rx, res->start,
	IMX_DMATYPE_SSI);
	}

	platform_set_drvdata(pdev, ssi);

	ret = snd_soc_set_ac97_ops(&imx_ssi_ac97_ops);
	if (ret != 0) {
	dev_err(&pdev->dev, "Failed to set AC'97 ops: %d\n", ret);
	goto failed_register;
	}

	ret = snd_soc_register_component(&pdev->dev, &imx_component,
	dai, 1);
	if (ret) {
	dev_err(&pdev->dev, "register DAI failed\n");
	goto failed_register;
	}

	ssi->fiq_params.irq = ssi->irq;
	ssi->fiq_params.base = ssi->base;
	ssi->fiq_params.dma_params_rx = &ssi->dma_params_rx;
	ssi->fiq_params.dma_params_tx = &ssi->dma_params_tx;

	ssi->fiq_init = imx_pcm_fiq_init(pdev, &ssi->fiq_params);
	ssi->dma_init = imx_pcm_dma_init(pdev, IMX_SSI_DMABUF_SIZE);

	if (ssi->fiq_init && ssi->dma_init) {
	ret = ssi->fiq_init;
	goto failed_pcm;
	}

	return 0;

	failed_pcm:
	snd_soc_unregister_component(&pdev->dev);
	failed_register:
	clk_disable_unprepare(ssi->clk);
	failed_clk:
	snd_soc_set_ac97_ops(NULL);

	return ret;
	}

	static int imx_ssi_remove(struct platform_device *pdev)
	{
	struct imx_ssi *ssi = platform_get_drvdata(pdev);

	if (!ssi->fiq_init)
	imx_pcm_fiq_exit(pdev);

	snd_soc_unregister_component(&pdev->dev);

	if (ssi->flags & IMX_SSI_USE_AC97)
	ac97_ssi = NULL;

	clk_disable_unprepare(ssi->clk);
	snd_soc_set_ac97_ops(NULL);

	return 0;
	}

	static struct platform_driver imx_ssi_driver = {
	.probe = imx_ssi_probe,
	.remove = imx_ssi_remove,

	.driver = {
	.name = "imx-ssi",
	},
	};

	module_platform_driver(imx_ssi_driver);

	/* Module information */
	MODULE_AUTHOR("Sascha Hauer, <s.hauer@pengutronix.de>");
	MODULE_DESCRIPTION("i.MX I2S/ac97 SoC Interface");
	MODULE_LICENSE("GPL");
	MODULE_ALIAS("platform:imx-ssi");