sound/soc/tegra/tegra20_spdif.c - arm/linux - Git at Google

 /*
  * tegra20_spdif.c - Tegra20 SPDIF driver
  *
  * Author: Stephen Warren <swarren@nvidia.com>
  * Copyright (C) 2011-2012 - NVIDIA, Inc.
  *
  * 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.
  *
  * This program is distributed in the hope that it will be useful, but
  * WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  * General Public License for more details.
  *
  * You should have received a copy of the GNU General Public License
  * along with this program; if not, write to the Free Software
  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
  * 02110-1301 USA
  *
  */

 #include <linux/clk.h>
 #include <linux/device.h>
 #include <linux/io.h>
 #include <linux/module.h>
 #include <linux/platform_device.h>
 #include <linux/pm_runtime.h>
 #include <linux/regmap.h>
 #include <linux/slab.h>
 #include <sound/core.h>
 #include <sound/pcm.h>
 #include <sound/pcm_params.h>
 #include <sound/soc.h>
 #include <sound/dmaengine_pcm.h>

 #include "tegra20_spdif.h"

 #define DRV_NAME "tegra20-spdif"

 static int tegra20_spdif_runtime_suspend(struct device *dev)
 {
 	struct tegra20_spdif *spdif = dev_get_drvdata(dev);

 	clk_disable_unprepare(spdif->clk_spdif_out);

 	return 0;
 }

 static int tegra20_spdif_runtime_resume(struct device *dev)
 {
 	struct tegra20_spdif *spdif = dev_get_drvdata(dev);
 	int ret;

 	ret = clk_prepare_enable(spdif->clk_spdif_out);
 	if (ret) {
 		dev_err(dev, "clk_enable failed: %d\n", ret);
 		return ret;
 	}

 	return 0;
 }

 static int tegra20_spdif_hw_params(struct snd_pcm_substream *substream,
 				struct snd_pcm_hw_params *params,
 				struct snd_soc_dai *dai)
 {
 	struct device *dev = dai->dev;
 	struct tegra20_spdif *spdif = snd_soc_dai_get_drvdata(dai);
 	unsigned int mask = 0, val = 0;
 	int ret, spdifclock;

 	mask |= TEGRA20_SPDIF_CTRL_PACK |
 		TEGRA20_SPDIF_CTRL_BIT_MODE_MASK;
 	switch (params_format(params)) {
 	case SNDRV_PCM_FORMAT_S16_LE:
 		val |= TEGRA20_SPDIF_CTRL_PACK |
 		       TEGRA20_SPDIF_CTRL_BIT_MODE_16BIT;
 		break;
 	default:
 		return -EINVAL;
 	}

 	regmap_update_bits(spdif->regmap, TEGRA20_SPDIF_CTRL, mask, val);

 	switch (params_rate(params)) {
 	case 32000:
 		spdifclock = 4096000;
 		break;
 	case 44100:
 		spdifclock = 5644800;
 		break;
 	case 48000:
 		spdifclock = 6144000;
 		break;
 	case 88200:
 		spdifclock = 11289600;
 		break;
 	case 96000:
 		spdifclock = 12288000;
 		break;
 	case 176400:
 		spdifclock = 22579200;
 		break;
 	case 192000:
 		spdifclock = 24576000;
 		break;
 	default:
 		return -EINVAL;
 	}

 	ret = clk_set_rate(spdif->clk_spdif_out, spdifclock);
 	if (ret) {
 		dev_err(dev, "Can't set SPDIF clock rate: %d\n", ret);
 		return ret;
 	}

 	return 0;
 }

 static void tegra20_spdif_start_playback(struct tegra20_spdif *spdif)
 {
 	regmap_update_bits(spdif->regmap, TEGRA20_SPDIF_CTRL,
 			   TEGRA20_SPDIF_CTRL_TX_EN,
 			   TEGRA20_SPDIF_CTRL_TX_EN);
 }

 static void tegra20_spdif_stop_playback(struct tegra20_spdif *spdif)
 {
 	regmap_update_bits(spdif->regmap, TEGRA20_SPDIF_CTRL,
 			   TEGRA20_SPDIF_CTRL_TX_EN, 0);
 }

 static int tegra20_spdif_trigger(struct snd_pcm_substream *substream, int cmd,
 				struct snd_soc_dai *dai)
 {
 	struct tegra20_spdif *spdif = snd_soc_dai_get_drvdata(dai);

 	switch (cmd) {
 	case SNDRV_PCM_TRIGGER_START:
 	case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
 	case SNDRV_PCM_TRIGGER_RESUME:
 		tegra20_spdif_start_playback(spdif);
 		break;
 	case SNDRV_PCM_TRIGGER_STOP:
 	case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
 	case SNDRV_PCM_TRIGGER_SUSPEND:
 		tegra20_spdif_stop_playback(spdif);
 		break;
 	default:
 		return -EINVAL;
 	}

 	return 0;
 }

 static int tegra20_spdif_probe(struct snd_soc_dai *dai)
 {
 	struct tegra20_spdif *spdif = snd_soc_dai_get_drvdata(dai);

 	dai->capture_dma_data = NULL;
 	dai->playback_dma_data = &spdif->playback_dma_data;

 	return 0;
 }

 static const struct snd_soc_dai_ops tegra20_spdif_dai_ops = {
 	.hw_params	= tegra20_spdif_hw_params,
 	.trigger	= tegra20_spdif_trigger,
 };

 static struct snd_soc_dai_driver tegra20_spdif_dai = {
 	.name = DRV_NAME,
 	.probe = tegra20_spdif_probe,
 	.playback = {
 		.stream_name = "Playback",
 		.channels_min = 2,
 		.channels_max = 2,
 		.rates = SNDRV_PCM_RATE_32000 | SNDRV_PCM_RATE_44100 |
 				SNDRV_PCM_RATE_48000,
 		.formats = SNDRV_PCM_FMTBIT_S16_LE,
 	},
 	.ops = &tegra20_spdif_dai_ops,
 };

 static const struct snd_soc_component_driver tegra20_spdif_component = {
 	.name		= DRV_NAME,
 };

 static bool tegra20_spdif_wr_rd_reg(struct device *dev, unsigned int reg)
 {
 	switch (reg) {
 	case TEGRA20_SPDIF_CTRL:
 	case TEGRA20_SPDIF_STATUS:
 	case TEGRA20_SPDIF_STROBE_CTRL:
 	case TEGRA20_SPDIF_DATA_FIFO_CSR:
 	case TEGRA20_SPDIF_DATA_OUT:
 	case TEGRA20_SPDIF_DATA_IN:
 	case TEGRA20_SPDIF_CH_STA_RX_A:
 	case TEGRA20_SPDIF_CH_STA_RX_B:
 	case TEGRA20_SPDIF_CH_STA_RX_C:
 	case TEGRA20_SPDIF_CH_STA_RX_D:
 	case TEGRA20_SPDIF_CH_STA_RX_E:
 	case TEGRA20_SPDIF_CH_STA_RX_F:
 	case TEGRA20_SPDIF_CH_STA_TX_A:
 	case TEGRA20_SPDIF_CH_STA_TX_B:
 	case TEGRA20_SPDIF_CH_STA_TX_C:
 	case TEGRA20_SPDIF_CH_STA_TX_D:
 	case TEGRA20_SPDIF_CH_STA_TX_E:
 	case TEGRA20_SPDIF_CH_STA_TX_F:
 	case TEGRA20_SPDIF_USR_STA_RX_A:
 	case TEGRA20_SPDIF_USR_DAT_TX_A:
 		return true;
 	default:
 		return false;
 	}
 }

 static bool tegra20_spdif_volatile_reg(struct device *dev, unsigned int reg)
 {
 	switch (reg) {
 	case TEGRA20_SPDIF_STATUS:
 	case TEGRA20_SPDIF_DATA_FIFO_CSR:
 	case TEGRA20_SPDIF_DATA_OUT:
 	case TEGRA20_SPDIF_DATA_IN:
 	case TEGRA20_SPDIF_CH_STA_RX_A:
 	case TEGRA20_SPDIF_CH_STA_RX_B:
 	case TEGRA20_SPDIF_CH_STA_RX_C:
 	case TEGRA20_SPDIF_CH_STA_RX_D:
 	case TEGRA20_SPDIF_CH_STA_RX_E:
 	case TEGRA20_SPDIF_CH_STA_RX_F:
 	case TEGRA20_SPDIF_USR_STA_RX_A:
 	case TEGRA20_SPDIF_USR_DAT_TX_A:
 		return true;
 	default:
 		return false;
 	}
 }

 static bool tegra20_spdif_precious_reg(struct device *dev, unsigned int reg)
 {
 	switch (reg) {
 	case TEGRA20_SPDIF_DATA_OUT:
 	case TEGRA20_SPDIF_DATA_IN:
 	case TEGRA20_SPDIF_USR_STA_RX_A:
 	case TEGRA20_SPDIF_USR_DAT_TX_A:
 		return true;
 	default:
 		return false;
 	}
 }

 static const struct regmap_config tegra20_spdif_regmap_config = {
 	.reg_bits = 32,
 	.reg_stride = 4,
 	.val_bits = 32,
 	.max_register = TEGRA20_SPDIF_USR_DAT_TX_A,
 	.writeable_reg = tegra20_spdif_wr_rd_reg,
 	.readable_reg = tegra20_spdif_wr_rd_reg,
 	.volatile_reg = tegra20_spdif_volatile_reg,
 	.precious_reg = tegra20_spdif_precious_reg,
 	.cache_type = REGCACHE_FLAT,
 };

 static int tegra20_spdif_platform_probe(struct platform_device *pdev)
 {
 	struct tegra20_spdif *spdif;
 	struct resource *mem, *dmareq;
 	void __iomem *regs;
 	int ret;

 	spdif = devm_kzalloc(&pdev->dev, sizeof(struct tegra20_spdif),
 			     GFP_KERNEL);
 	if (!spdif)
 		return -ENOMEM;

 	dev_set_drvdata(&pdev->dev, spdif);

 	spdif->clk_spdif_out = devm_clk_get(&pdev->dev, "spdif_out");
 	if (IS_ERR(spdif->clk_spdif_out)) {
 		pr_err("Can't retrieve spdif clock\n");
 		ret = PTR_ERR(spdif->clk_spdif_out);
 		return ret;
 	}

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

 	dmareq = platform_get_resource(pdev, IORESOURCE_DMA, 0);
 	if (!dmareq) {
 		dev_err(&pdev->dev, "No DMA resource\n");
 		return -ENODEV;
 	}

 	spdif->regmap = devm_regmap_init_mmio(&pdev->dev, regs,
 					    &tegra20_spdif_regmap_config);
 	if (IS_ERR(spdif->regmap)) {
 		dev_err(&pdev->dev, "regmap init failed\n");
 		ret = PTR_ERR(spdif->regmap);
 		return ret;
 	}

 	spdif->playback_dma_data.addr = mem->start + TEGRA20_SPDIF_DATA_OUT;
 	spdif->playback_dma_data.addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
 	spdif->playback_dma_data.maxburst = 4;
 	spdif->playback_dma_data.slave_id = dmareq->start;

 	pm_runtime_enable(&pdev->dev);
 	if (!pm_runtime_enabled(&pdev->dev)) {
 		ret = tegra20_spdif_runtime_resume(&pdev->dev);
 		if (ret)
 			goto err_pm_disable;
 	}

 	ret = snd_soc_register_component(&pdev->dev, &tegra20_spdif_component,
 					 &tegra20_spdif_dai, 1);
 	if (ret) {
 		dev_err(&pdev->dev, "Could not register DAI: %d\n", ret);
 		ret = -ENOMEM;
 		goto err_suspend;
 	}

 	ret = tegra_pcm_platform_register(&pdev->dev);
 	if (ret) {
 		dev_err(&pdev->dev, "Could not register PCM: %d\n", ret);
 		goto err_unregister_component;
 	}

 	return 0;

 err_unregister_component:
 	snd_soc_unregister_component(&pdev->dev);
 err_suspend:
 	if (!pm_runtime_status_suspended(&pdev->dev))
 		tegra20_spdif_runtime_suspend(&pdev->dev);
 err_pm_disable:
 	pm_runtime_disable(&pdev->dev);

 	return ret;
 }

 static int tegra20_spdif_platform_remove(struct platform_device *pdev)
 {
 	pm_runtime_disable(&pdev->dev);
 	if (!pm_runtime_status_suspended(&pdev->dev))
 		tegra20_spdif_runtime_suspend(&pdev->dev);

 	tegra_pcm_platform_unregister(&pdev->dev);
 	snd_soc_unregister_component(&pdev->dev);

 	return 0;
 }

 static const struct dev_pm_ops tegra20_spdif_pm_ops = {
 	SET_RUNTIME_PM_OPS(tegra20_spdif_runtime_suspend,
 			   tegra20_spdif_runtime_resume, NULL)
 };

 static struct platform_driver tegra20_spdif_driver = {
 	.driver = {
 		.name = DRV_NAME,
 		.pm = &tegra20_spdif_pm_ops,
 	},
 	.probe = tegra20_spdif_platform_probe,
 	.remove = tegra20_spdif_platform_remove,
 };

 module_platform_driver(tegra20_spdif_driver);

 MODULE_AUTHOR("Stephen Warren <swarren@nvidia.com>");
 MODULE_DESCRIPTION("Tegra20 SPDIF ASoC driver");
 MODULE_LICENSE("GPL");
 MODULE_ALIAS("platform:" DRV_NAME);
	/*
	* tegra20_spdif.c - Tegra20 SPDIF driver
	*
	* Author: Stephen Warren <swarren@nvidia.com>
	* Copyright (C) 2011-2012 - NVIDIA, Inc.
	*
	* 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.
	*
	* This program is distributed in the hope that it will be useful, but
	* WITHOUT ANY WARRANTY; without even the implied warranty of
	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
	* General Public License for more details.
	*
	* You should have received a copy of the GNU General Public License
	* along with this program; if not, write to the Free Software
	* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
	* 02110-1301 USA
	*
	*/

	#include <linux/clk.h>
	#include <linux/device.h>
	#include <linux/io.h>
	#include <linux/module.h>
	#include <linux/platform_device.h>
	#include <linux/pm_runtime.h>
	#include <linux/regmap.h>
	#include <linux/slab.h>
	#include <sound/core.h>
	#include <sound/pcm.h>
	#include <sound/pcm_params.h>
	#include <sound/soc.h>
	#include <sound/dmaengine_pcm.h>

	#include "tegra20_spdif.h"

	#define DRV_NAME "tegra20-spdif"

	static int tegra20_spdif_runtime_suspend(struct device *dev)
	{
	struct tegra20_spdif *spdif = dev_get_drvdata(dev);

	clk_disable_unprepare(spdif->clk_spdif_out);

	return 0;
	}

	static int tegra20_spdif_runtime_resume(struct device *dev)
	{
	struct tegra20_spdif *spdif = dev_get_drvdata(dev);
	int ret;

	ret = clk_prepare_enable(spdif->clk_spdif_out);
	if (ret) {
	dev_err(dev, "clk_enable failed: %d\n", ret);
	return ret;
	}

	return 0;
	}

	static int tegra20_spdif_hw_params(struct snd_pcm_substream *substream,
	struct snd_pcm_hw_params *params,
	struct snd_soc_dai *dai)
	{
	struct device *dev = dai->dev;
	struct tegra20_spdif *spdif = snd_soc_dai_get_drvdata(dai);
	unsigned int mask = 0, val = 0;
	int ret, spdifclock;

	mask \|= TEGRA20_SPDIF_CTRL_PACK \|
	TEGRA20_SPDIF_CTRL_BIT_MODE_MASK;
	switch (params_format(params)) {
	case SNDRV_PCM_FORMAT_S16_LE:
	val \|= TEGRA20_SPDIF_CTRL_PACK \|
	TEGRA20_SPDIF_CTRL_BIT_MODE_16BIT;
	break;
	default:
	return -EINVAL;
	}

	regmap_update_bits(spdif->regmap, TEGRA20_SPDIF_CTRL, mask, val);

	switch (params_rate(params)) {
	case 32000:
	spdifclock = 4096000;
	break;
	case 44100:
	spdifclock = 5644800;
	break;
	case 48000:
	spdifclock = 6144000;
	break;
	case 88200:
	spdifclock = 11289600;
	break;
	case 96000:
	spdifclock = 12288000;
	break;
	case 176400:
	spdifclock = 22579200;
	break;
	case 192000:
	spdifclock = 24576000;
	break;
	default:
	return -EINVAL;
	}

	ret = clk_set_rate(spdif->clk_spdif_out, spdifclock);
	if (ret) {
	dev_err(dev, "Can't set SPDIF clock rate: %d\n", ret);
	return ret;
	}

	return 0;
	}

	static void tegra20_spdif_start_playback(struct tegra20_spdif *spdif)
	{
	regmap_update_bits(spdif->regmap, TEGRA20_SPDIF_CTRL,
	TEGRA20_SPDIF_CTRL_TX_EN,
	TEGRA20_SPDIF_CTRL_TX_EN);
	}

	static void tegra20_spdif_stop_playback(struct tegra20_spdif *spdif)
	{
	regmap_update_bits(spdif->regmap, TEGRA20_SPDIF_CTRL,
	TEGRA20_SPDIF_CTRL_TX_EN, 0);
	}

	static int tegra20_spdif_trigger(struct snd_pcm_substream *substream, int cmd,
	struct snd_soc_dai *dai)
	{
	struct tegra20_spdif *spdif = snd_soc_dai_get_drvdata(dai);

	switch (cmd) {
	case SNDRV_PCM_TRIGGER_START:
	case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
	case SNDRV_PCM_TRIGGER_RESUME:
	tegra20_spdif_start_playback(spdif);
	break;
	case SNDRV_PCM_TRIGGER_STOP:
	case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
	case SNDRV_PCM_TRIGGER_SUSPEND:
	tegra20_spdif_stop_playback(spdif);
	break;
	default:
	return -EINVAL;
	}

	return 0;
	}

	static int tegra20_spdif_probe(struct snd_soc_dai *dai)
	{
	struct tegra20_spdif *spdif = snd_soc_dai_get_drvdata(dai);

	dai->capture_dma_data = NULL;
	dai->playback_dma_data = &spdif->playback_dma_data;

	return 0;
	}

	static const struct snd_soc_dai_ops tegra20_spdif_dai_ops = {
	.hw_params = tegra20_spdif_hw_params,
	.trigger = tegra20_spdif_trigger,
	};

	static struct snd_soc_dai_driver tegra20_spdif_dai = {
	.name = DRV_NAME,
	.probe = tegra20_spdif_probe,
	.playback = {
	.stream_name = "Playback",
	.channels_min = 2,
	.channels_max = 2,
	.rates = SNDRV_PCM_RATE_32000 \| SNDRV_PCM_RATE_44100 \|
	SNDRV_PCM_RATE_48000,
	.formats = SNDRV_PCM_FMTBIT_S16_LE,
	},
	.ops = &tegra20_spdif_dai_ops,
	};

	static const struct snd_soc_component_driver tegra20_spdif_component = {
	.name = DRV_NAME,
	};

	static bool tegra20_spdif_wr_rd_reg(struct device *dev, unsigned int reg)
	{
	switch (reg) {
	case TEGRA20_SPDIF_CTRL:
	case TEGRA20_SPDIF_STATUS:
	case TEGRA20_SPDIF_STROBE_CTRL:
	case TEGRA20_SPDIF_DATA_FIFO_CSR:
	case TEGRA20_SPDIF_DATA_OUT:
	case TEGRA20_SPDIF_DATA_IN:
	case TEGRA20_SPDIF_CH_STA_RX_A:
	case TEGRA20_SPDIF_CH_STA_RX_B:
	case TEGRA20_SPDIF_CH_STA_RX_C:
	case TEGRA20_SPDIF_CH_STA_RX_D:
	case TEGRA20_SPDIF_CH_STA_RX_E:
	case TEGRA20_SPDIF_CH_STA_RX_F:
	case TEGRA20_SPDIF_CH_STA_TX_A:
	case TEGRA20_SPDIF_CH_STA_TX_B:
	case TEGRA20_SPDIF_CH_STA_TX_C:
	case TEGRA20_SPDIF_CH_STA_TX_D:
	case TEGRA20_SPDIF_CH_STA_TX_E:
	case TEGRA20_SPDIF_CH_STA_TX_F:
	case TEGRA20_SPDIF_USR_STA_RX_A:
	case TEGRA20_SPDIF_USR_DAT_TX_A:
	return true;
	default:
	return false;
	}
	}

	static bool tegra20_spdif_volatile_reg(struct device *dev, unsigned int reg)
	{
	switch (reg) {
	case TEGRA20_SPDIF_STATUS:
	case TEGRA20_SPDIF_DATA_FIFO_CSR:
	case TEGRA20_SPDIF_DATA_OUT:
	case TEGRA20_SPDIF_DATA_IN:
	case TEGRA20_SPDIF_CH_STA_RX_A:
	case TEGRA20_SPDIF_CH_STA_RX_B:
	case TEGRA20_SPDIF_CH_STA_RX_C:
	case TEGRA20_SPDIF_CH_STA_RX_D:
	case TEGRA20_SPDIF_CH_STA_RX_E:
	case TEGRA20_SPDIF_CH_STA_RX_F:
	case TEGRA20_SPDIF_USR_STA_RX_A:
	case TEGRA20_SPDIF_USR_DAT_TX_A:
	return true;
	default:
	return false;
	}
	}

	static bool tegra20_spdif_precious_reg(struct device *dev, unsigned int reg)
	{
	switch (reg) {
	case TEGRA20_SPDIF_DATA_OUT:
	case TEGRA20_SPDIF_DATA_IN:
	case TEGRA20_SPDIF_USR_STA_RX_A:
	case TEGRA20_SPDIF_USR_DAT_TX_A:
	return true;
	default:
	return false;
	}
	}

	static const struct regmap_config tegra20_spdif_regmap_config = {
	.reg_bits = 32,
	.reg_stride = 4,
	.val_bits = 32,
	.max_register = TEGRA20_SPDIF_USR_DAT_TX_A,
	.writeable_reg = tegra20_spdif_wr_rd_reg,
	.readable_reg = tegra20_spdif_wr_rd_reg,
	.volatile_reg = tegra20_spdif_volatile_reg,
	.precious_reg = tegra20_spdif_precious_reg,
	.cache_type = REGCACHE_FLAT,
	};

	static int tegra20_spdif_platform_probe(struct platform_device *pdev)
	{
	struct tegra20_spdif *spdif;
	struct resource mem, dmareq;
	void __iomem *regs;
	int ret;

	spdif = devm_kzalloc(&pdev->dev, sizeof(struct tegra20_spdif),
	GFP_KERNEL);
	if (!spdif)
	return -ENOMEM;

	dev_set_drvdata(&pdev->dev, spdif);

	spdif->clk_spdif_out = devm_clk_get(&pdev->dev, "spdif_out");
	if (IS_ERR(spdif->clk_spdif_out)) {
	pr_err("Can't retrieve spdif clock\n");
	ret = PTR_ERR(spdif->clk_spdif_out);
	return ret;
	}

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

	dmareq = platform_get_resource(pdev, IORESOURCE_DMA, 0);
	if (!dmareq) {
	dev_err(&pdev->dev, "No DMA resource\n");
	return -ENODEV;
	}

	spdif->regmap = devm_regmap_init_mmio(&pdev->dev, regs,
	&tegra20_spdif_regmap_config);
	if (IS_ERR(spdif->regmap)) {
	dev_err(&pdev->dev, "regmap init failed\n");
	ret = PTR_ERR(spdif->regmap);
	return ret;
	}

	spdif->playback_dma_data.addr = mem->start + TEGRA20_SPDIF_DATA_OUT;
	spdif->playback_dma_data.addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
	spdif->playback_dma_data.maxburst = 4;
	spdif->playback_dma_data.slave_id = dmareq->start;

	pm_runtime_enable(&pdev->dev);
	if (!pm_runtime_enabled(&pdev->dev)) {
	ret = tegra20_spdif_runtime_resume(&pdev->dev);
	if (ret)
	goto err_pm_disable;
	}

	ret = snd_soc_register_component(&pdev->dev, &tegra20_spdif_component,
	&tegra20_spdif_dai, 1);
	if (ret) {
	dev_err(&pdev->dev, "Could not register DAI: %d\n", ret);
	ret = -ENOMEM;
	goto err_suspend;
	}

	ret = tegra_pcm_platform_register(&pdev->dev);
	if (ret) {
	dev_err(&pdev->dev, "Could not register PCM: %d\n", ret);
	goto err_unregister_component;
	}

	return 0;

	err_unregister_component:
	snd_soc_unregister_component(&pdev->dev);
	err_suspend:
	if (!pm_runtime_status_suspended(&pdev->dev))
	tegra20_spdif_runtime_suspend(&pdev->dev);
	err_pm_disable:
	pm_runtime_disable(&pdev->dev);

	return ret;
	}

	static int tegra20_spdif_platform_remove(struct platform_device *pdev)
	{
	pm_runtime_disable(&pdev->dev);
	if (!pm_runtime_status_suspended(&pdev->dev))
	tegra20_spdif_runtime_suspend(&pdev->dev);

	tegra_pcm_platform_unregister(&pdev->dev);
	snd_soc_unregister_component(&pdev->dev);

	return 0;
	}

	static const struct dev_pm_ops tegra20_spdif_pm_ops = {
	SET_RUNTIME_PM_OPS(tegra20_spdif_runtime_suspend,
	tegra20_spdif_runtime_resume, NULL)
	};

	static struct platform_driver tegra20_spdif_driver = {
	.driver = {
	.name = DRV_NAME,
	.pm = &tegra20_spdif_pm_ops,
	},
	.probe = tegra20_spdif_platform_probe,
	.remove = tegra20_spdif_platform_remove,
	};

	module_platform_driver(tegra20_spdif_driver);

	MODULE_AUTHOR("Stephen Warren <swarren@nvidia.com>");
	MODULE_DESCRIPTION("Tegra20 SPDIF ASoC driver");
	MODULE_LICENSE("GPL");
	MODULE_ALIAS("platform:" DRV_NAME);