text: /*
   * Copyright (C) STMicroelectronics SA 2015
   * Authors: Arnaud Pouliquen <arnaud.pouliquen@st.com>
   *          for STMicroelectronics.
   * License terms:  GNU General Public License (GPL), version 2
   */
  
  #include <linux/io.h>
  #include <linux/module.h>
  #include <linux/regmap.h>
  #include <linux/reset.h>
  #include <linux/mfd/syscon.h>
  
  #include <sound/soc.h>
  #include <sound/soc-dapm.h>
  
  /* DAC definitions */
  
  /* stih407 DAC registers */
  /* sysconf 5041: Audio-Gue-Control */
  #define STIH407_AUDIO_GLUE_CTRL 0x000000A4
  /* sysconf 5042: Audio-DAC-Control */
  #define STIH407_AUDIO_DAC_CTRL 0x000000A8
  
  /* DAC definitions */
  #define STIH407_DAC_SOFTMUTE		0x0
  #define STIH407_DAC_STANDBY_ANA		0x1
  #define STIH407_DAC_STANDBY		0x2
  
  #define STIH407_DAC_SOFTMUTE_MASK	BIT(STIH407_DAC_SOFTMUTE)
  #define STIH407_DAC_STANDBY_ANA_MASK    BIT(STIH407_DAC_STANDBY_ANA)
  #define STIH407_DAC_STANDBY_MASK        BIT(STIH407_DAC_STANDBY)
  
  /* SPDIF definitions */
  #define SPDIF_BIPHASE_ENABLE		0x6
  #define SPDIF_BIPHASE_IDLE		0x7
  
  #define SPDIF_BIPHASE_ENABLE_MASK	BIT(SPDIF_BIPHASE_ENABLE)
  #define SPDIF_BIPHASE_IDLE_MASK		BIT(SPDIF_BIPHASE_IDLE)
  
  enum {
  	STI_SAS_DAI_SPDIF_OUT,
  	STI_SAS_DAI_ANALOG_OUT,
  };
  
  static const struct reg_default stih407_sas_reg_defaults[] = {
  	{ STIH407_AUDIO_DAC_CTRL, 0x000000000 },
  	{ STIH407_AUDIO_GLUE_CTRL, 0x00000040 },
  };
  
  struct sti_dac_audio {
  	struct regmap *regmap;
  	struct regmap *virt_regmap;
  	struct regmap_field  **field;
  	struct reset_control *rst;
  	int mclk;
  };
  
  struct sti_spdif_audio {
  	struct regmap *regmap;
  	struct regmap_field  **field;
  	int mclk;
  };
  
  /* device data structure */
  struct sti_sas_dev_data {
  	const struct regmap_config *regmap;
  	const struct snd_soc_dai_ops *dac_ops;  /* DAC function callbacks */
  	const struct snd_soc_dapm_widget *dapm_widgets; /* dapms declaration */
  	const int num_dapm_widgets; /* dapms declaration */
  	const struct snd_soc_dapm_route *dapm_routes; /* route declaration */
  	const int num_dapm_routes; /* route declaration */
  };
  
  /* driver data structure */
  struct sti_sas_data {
  	struct device *dev;
  	const struct sti_sas_dev_data *dev_data;
  	struct sti_dac_audio dac;
  	struct sti_spdif_audio spdif;
  };
  
  /* Read a register from the sysconf reg bank */
  static int sti_sas_read_reg(void *context, unsigned int reg,
  			    unsigned int *value)
  {
  	struct sti_sas_data *drvdata = context;
  	int status;
  	u32 val;
  
  	status = regmap_read(drvdata->dac.regmap, reg, &val);
  	*value = (unsigned int)val;
  
  	return status;
  }
  
  /* Read a register from the sysconf reg bank */
  static int sti_sas_write_reg(void *context, unsigned int reg,
  			     unsigned int value)
  {
  	struct sti_sas_data *drvdata = context;
  	int status;
  
  	status = regmap_write(drvdata->dac.regmap, reg, value);
  
  	return status;
  }
  
  static int  sti_sas_init_sas_registers(struct snd_soc_codec *codec,
  				       struct sti_sas_data *data)
  {
  	int ret;
  	/*
  	 * DAC and SPDIF are activated by default
  	 * put them in IDLE to save power
  	 */
  
  	/* Initialise bi-phase formatter to disabled */
  	ret = snd_soc_update_bits(codec, STIH407_AUDIO_GLUE_CTRL,
  				  SPDIF_BIPHASE_ENABLE_MASK, 0);
  
  	if (!ret)
  		/* Initialise bi-phase formatter idle value to 0 */
  		ret = snd_soc_update_bits(codec, STIH407_AUDIO_GLUE_CTRL,
  					  SPDIF_BIPHASE_IDLE_MASK, 0);
  	if (ret < 0) {
  		dev_err(codec->dev, "Failed to update SPDIF registers\n");
  		return ret;
  	}
  
  	/* Init DAC configuration */
  	/* init configuration */
  	ret =  snd_soc_update_bits(codec, STIH407_AUDIO_DAC_CTRL,
  				   STIH407_DAC_STANDBY_MASK,
  				   STIH407_DAC_STANDBY_MASK);
  
  	if (!ret)
  		ret = snd_soc_update_bits(codec, STIH407_AUDIO_DAC_CTRL,
  					  STIH407_DAC_STANDBY_ANA_MASK,
  					  STIH407_DAC_STANDBY_ANA_MASK);
  	if (!ret)
  		ret = snd_soc_update_bits(codec, STIH407_AUDIO_DAC_CTRL,
  					  STIH407_DAC_SOFTMUTE_MASK,
  					  STIH407_DAC_SOFTMUTE_MASK);
  
  	if (ret < 0) {
  		dev_err(codec->dev, "Failed to update DAC registers\n");
  		return ret;
  	}
  
  	return ret;
  }
  
  /*
   * DAC
   */
  static int sti_sas_dac_set_fmt(struct snd_soc_dai *dai, unsigned int fmt)
  {
  	/* Sanity check only */
  	if ((fmt & SND_SOC_DAIFMT_MASTER_MASK) != SND_SOC_DAIFMT_CBS_CFS) {
  		dev_err(dai->codec->dev,
  			"%s: ERROR: Unsupporter master mask 0x%x\n",
  			__func__, fmt & SND_SOC_DAIFMT_MASTER_MASK);
  		return -EINVAL;
  	}
  
  	return 0;
  }
  
  static const struct snd_soc_dapm_widget stih407_sas_dapm_widgets[] = {
  	SND_SOC_DAPM_OUT_DRV("DAC standby ana", STIH407_AUDIO_DAC_CTRL,
  			     STIH407_DAC_STANDBY_ANA, 1, NULL, 0),
  	SND_SOC_DAPM_DAC("DAC standby",  "dac_p", STIH407_AUDIO_DAC_CTRL,
  			 STIH407_DAC_STANDBY, 1),
  	SND_SOC_DAPM_OUTPUT("DAC Output"),
  };
  
  static const struct snd_soc_dapm_route stih407_sas_route[] = {
  	{"DAC Output", NULL, "DAC standby ana"},
  	{"DAC standby ana", NULL, "DAC standby"},
  };
  
  
  static int stih407_sas_dac_mute(struct snd_soc_dai *dai, int mute, int stream)
  {
  	struct snd_soc_codec *codec = dai->codec;
  
  	if (mute) {
  		return snd_soc_update_bits(codec, STIH407_AUDIO_DAC_CTRL,
  					    STIH407_DAC_SOFTMUTE_MASK,
  					    STIH407_DAC_SOFTMUTE_MASK);
  	} else {
  		return snd_soc_update_bits(codec, STIH407_AUDIO_DAC_CTRL,
  					    STIH407_DAC_SOFTMUTE_MASK,
  					    0);
  	}
  }
  
  /*
   * SPDIF
   */
  static int sti_sas_spdif_set_fmt(struct snd_soc_dai *dai,
  				 unsigned int fmt)
  {
  	if ((fmt & SND_SOC_DAIFMT_MASTER_MASK) != SND_SOC_DAIFMT_CBS_CFS) {
  		dev_err(dai->codec->dev,
  			"%s: ERROR: Unsupporter master mask 0x%x\n",
  			__func__, fmt & SND_SOC_DAIFMT_MASTER_MASK);
  		return -EINVAL;
  	}
  
  	return 0;
  }
  
  /*
   * sti_sas_spdif_trigger:
   * Trigger function is used to ensure that BiPhase Formater is disabled
   * before CPU dai is stopped.
   * This is mandatory to avoid that BPF is stalled
   */
  static int sti_sas_spdif_trigger(struct snd_pcm_substream *substream, int cmd,
  				 struct snd_soc_dai *dai)
  {
  	struct snd_soc_codec *codec = dai->codec;
  
  	switch (cmd) {
  	case SNDRV_PCM_TRIGGER_START:
  	case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
  		return snd_soc_update_bits(codec, STIH407_AUDIO_GLUE_CTRL,
  					    SPDIF_BIPHASE_ENABLE_MASK,
  					    SPDIF_BIPHASE_ENABLE_MASK);
  	case SNDRV_PCM_TRIGGER_RESUME:
  	case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
  	case SNDRV_PCM_TRIGGER_STOP:
  	case SNDRV_PCM_TRIGGER_SUSPEND:
  		return snd_soc_update_bits(codec, STIH407_AUDIO_GLUE_CTRL,
  					    SPDIF_BIPHASE_ENABLE_MASK,
  					    0);
  	default:
  		return -EINVAL;
  	}
  }
  
  static bool sti_sas_volatile_register(struct device *dev, unsigned int reg)
  {
  	if (reg == STIH407_AUDIO_GLUE_CTRL)
  		return true;
  
  	return false;
  }
  
  /*
   * CODEC DAIS
   */
  
  /*
   * sti_sas_set_sysclk:
   * get MCLK input frequency to check that MCLK-FS ratio is coherent
   */
  static int sti_sas_set_sysclk(struct snd_soc_dai *dai, int clk_id,
  			      unsigned int freq, int dir)
  {
  	struct snd_soc_codec *codec = dai->codec;
  	struct sti_sas_data *drvdata = dev_get_drvdata(codec->dev);
  
  	if (dir == SND_SOC_CLOCK_OUT)
  		return 0;
  
  	if (clk_id != 0)
  		return -EINVAL;
  
  	switch (dai->id) {
  	case STI_SAS_DAI_SPDIF_OUT:
  		drvdata->spdif.mclk = freq;
  		break;
  
  	case STI_SAS_DAI_ANALOG_OUT:
  		drvdata->dac.mclk = freq;
  		break;
  	}
  
  	return 0;
  }
  
  static int sti_sas_prepare(struct snd_pcm_substream *substream,
  			   struct snd_soc_dai *dai)
  {
  	struct snd_soc_codec *codec = dai->codec;
  	struct sti_sas_data *drvdata = dev_get_drvdata(codec->dev);
  	struct snd_pcm_runtime *runtime = substream->runtime;
  
  	switch (dai->id) {
  	case STI_SAS_DAI_SPDIF_OUT:
  		if ((drvdata->spdif.mclk / runtime->rate) != 128) {
  			dev_err(codec->dev, "unexpected mclk-fs ratio\n");
  			return -EINVAL;
  		}
  		break;
  	case STI_SAS_DAI_ANALOG_OUT:
  		if ((drvdata->dac.mclk / runtime->rate) != 256) {
  			dev_err(codec->dev, "unexpected mclk-fs ratio\n");
  			return -EINVAL;
  		}
  		break;
  	}
  
  	return 0;
  }
  
  static const struct snd_soc_dai_ops stih407_dac_ops = {
  	.set_fmt = sti_sas_dac_set_fmt,
  	.mute_stream = stih407_sas_dac_mute,
  	.prepare = sti_sas_prepare,
  	.set_sysclk = sti_sas_set_sysclk,
  };
  
  static const struct regmap_config stih407_sas_regmap = {
  	.reg_bits = 32,
  	.val_bits = 32,
  	.fast_io = true,
  	.max_register = STIH407_AUDIO_DAC_CTRL,
  	.reg_defaults = stih407_sas_reg_defaults,
  	.num_reg_defaults = ARRAY_SIZE(stih407_sas_reg_defaults),
  	.volatile_reg = sti_sas_volatile_register,
  	.cache_type = REGCACHE_RBTREE,
  	.reg_read = sti_sas_read_reg,
  	.reg_write = sti_sas_write_reg,
  };
  
  static const struct sti_sas_dev_data stih407_data = {
  	.regmap = &stih407_sas_regmap,
  	.dac_ops = &stih407_dac_ops,
  	.dapm_widgets = stih407_sas_dapm_widgets,
  	.num_dapm_widgets = ARRAY_SIZE(stih407_sas_dapm_widgets),
  	.dapm_routes =	stih407_sas_route,
  	.num_dapm_routes = ARRAY_SIZE(stih407_sas_route),
  };
  
  static struct snd_soc_dai_driver sti_sas_dai[] = {
  	{
  		.name = "sas-dai-spdif-out",
  		.id = STI_SAS_DAI_SPDIF_OUT,
  		.playback = {
  			.stream_name = "spdif_p",
  			.channels_min = 2,
  			.channels_max = 2,
  			.rates = SNDRV_PCM_RATE_32000 | SNDRV_PCM_RATE_44100 |
  				 SNDRV_PCM_RATE_48000 | SNDRV_PCM_RATE_64000 |
  				 SNDRV_PCM_RATE_88200 | SNDRV_PCM_RATE_96000 |
  				 SNDRV_PCM_RATE_192000,
  			.formats = SNDRV_PCM_FMTBIT_S16_LE |
  				   SNDRV_PCM_FMTBIT_S32_LE,
  		},
  		.ops = (struct snd_soc_dai_ops[]) {
  			{
  				.set_fmt = sti_sas_spdif_set_fmt,
  				.trigger = sti_sas_spdif_trigger,
  				.set_sysclk = sti_sas_set_sysclk,
  				.prepare = sti_sas_prepare,
  			}
  		},
  	},
  	{
  		.name = "sas-dai-dac",
  		.id = STI_SAS_DAI_ANALOG_OUT,
  		.playback = {
  			.stream_name = "dac_p",
  			.channels_min = 2,
  			.channels_max = 2,
  			.rates = SNDRV_PCM_RATE_8000_48000,
  			.formats = SNDRV_PCM_FMTBIT_S16_LE |
  				   SNDRV_PCM_FMTBIT_S32_LE,
  		},
  	},
  };
  
  #ifdef CONFIG_PM_SLEEP
  static int sti_sas_resume(struct snd_soc_codec *codec)
  {
  	struct sti_sas_data *drvdata = dev_get_drvdata(codec->dev);
  
  	return sti_sas_init_sas_registers(codec, drvdata);
  }
  #else
  #define sti_sas_resume NULL
  #endif
  
  static int sti_sas_codec_probe(struct snd_soc_codec *codec)
  {
  	struct sti_sas_data *drvdata = dev_get_drvdata(codec->dev);
  	int ret;
  
  	ret = sti_sas_init_sas_registers(codec, drvdata);
  
  	return ret;
  }
  
  static struct snd_soc_codec_driver sti_sas_driver = {
  	.probe = sti_sas_codec_probe,
  	.resume = sti_sas_resume,
  };
  
  static const struct of_device_id sti_sas_dev_match[] = {
  	{
  		.compatible = "st,stih407-sas-codec",
  		.data = &stih407_data,
  	},
  	{},
  };
  
  static int sti_sas_driver_probe(struct platform_device *pdev)
  {
  	struct device_node *pnode = pdev->dev.of_node;
  	struct sti_sas_data *drvdata;
  	const struct of_device_id *of_id;
  
  	/* Allocate device structure */
  	drvdata = devm_kzalloc(&pdev->dev, sizeof(struct sti_sas_data),
  			       GFP_KERNEL);
  	if (!drvdata)
  		return -ENOMEM;
  
  	/* Populate data structure depending on compatibility */
  	of_id = of_match_node(sti_sas_dev_match, pnode);
  	if (!of_id->data) {
  		dev_err(&pdev->dev, "data associated to device is missing\n");
  		return -EINVAL;
  	}
  
  	drvdata->dev_data = (struct sti_sas_dev_data *)of_id->data;
  
  	/* Initialise device structure */
  	drvdata->dev = &pdev->dev;
  
  	/* Request the DAC & SPDIF registers memory region */
  	drvdata->dac.virt_regmap = devm_regmap_init(&pdev->dev, NULL, drvdata,
  						    drvdata->dev_data->regmap);
  	if (IS_ERR(drvdata->dac.virt_regmap)) {
  		dev_err(&pdev->dev, "audio registers not enabled\n");
  		return PTR_ERR(drvdata->dac.virt_regmap);
  	}
  
  	/* Request the syscon region */
  	drvdata->dac.regmap =
  		syscon_regmap_lookup_by_phandle(pnode, "st,syscfg");
  	if (IS_ERR(drvdata->dac.regmap)) {
  		dev_err(&pdev->dev, "syscon registers not available\n");
  		return PTR_ERR(drvdata->dac.regmap);
  	}
  	drvdata->spdif.regmap = drvdata->dac.regmap;
  
  	sti_sas_dai[STI_SAS_DAI_ANALOG_OUT].ops = drvdata->dev_data->dac_ops;
  
  	/* Set dapms*/
  	sti_sas_driver.component_driver.dapm_widgets = drvdata->dev_data->dapm_widgets;
  	sti_sas_driver.component_driver.num_dapm_widgets = drvdata->dev_data->num_dapm_widgets;
  
  	sti_sas_driver.component_driver.dapm_routes = drvdata->dev_data->dapm_routes;
  	sti_sas_driver.component_driver.num_dapm_routes = drvdata->dev_data->num_dapm_routes;
  
  	/* Store context */
  	dev_set_drvdata(&pdev->dev, drvdata);
  
  	return snd_soc_register_codec(&pdev->dev, &sti_sas_driver,
  					sti_sas_dai,
  					ARRAY_SIZE(sti_sas_dai));
  }
  
  static int sti_sas_driver_remove(struct platform_device *pdev)
  {
  	snd_soc_unregister_codec(&pdev->dev);
  
  	return 0;
  }
  
  static struct platform_driver sti_sas_platform_driver = {
  	.driver = {
  		.name = "sti-sas-codec",
  		.of_match_table = sti_sas_dev_match,
  	},
  	.probe = sti_sas_driver_probe,
  	.remove = sti_sas_driver_remove,
  };
  
  module_platform_driver(sti_sas_platform_driver);
  
  MODULE_DESCRIPTION("audio codec for STMicroelectronics sti platforms");
  MODULE_AUTHOR("Arnaud.pouliquen@st.com");
  MODULE_LICENSE("GPL v2");
  