text: // SPDX-License-Identifier: GPL-2.0-only
  /*
   * omap-hdmi-audio.c -- OMAP4+ DSS HDMI audio support library
   *
   * Copyright (C) 2014 Texas Instruments Incorporated - http://www.ti.com
   *
   * Author: Jyri Sarha <jsarha@ti.com>
   */
  
  #include <linux/kernel.h>
  #include <linux/module.h>
  #include <linux/err.h>
  #include <linux/string.h>
  #include <linux/platform_device.h>
  #include <sound/soc.h>
  #include <sound/pcm_params.h>
  #include <sound/dmaengine_pcm.h>
  #include <uapi/sound/asound.h>
  #include <sound/asoundef.h>
  #include <sound/omap-hdmi-audio.h>
  
  #include "sdma-pcm.h"
  
  #define DRV_NAME "omap-hdmi-audio"
  
  struct hdmi_audio_data {
  	struct snd_soc_card *card;
  
  	const struct omap_hdmi_audio_ops *ops;
  	struct device *dssdev;
  	struct snd_dmaengine_dai_dma_data dma_data;
  	struct omap_dss_audio dss_audio;
  	struct snd_aes_iec958 iec;
  	struct snd_cea_861_aud_if cea;
  
  	struct mutex current_stream_lock;
  	struct snd_pcm_substream *current_stream;
  };
  
  static
  struct hdmi_audio_data *card_drvdata_substream(struct snd_pcm_substream *ss)
  {
  	struct snd_soc_pcm_runtime *rtd = ss->private_data;
  
  	return snd_soc_card_get_drvdata(rtd->card);
  }
  
  static void hdmi_dai_abort(struct device *dev)
  {
  	struct hdmi_audio_data *ad = dev_get_drvdata(dev);
  
  	mutex_lock(&ad->current_stream_lock);
  	if (ad->current_stream && ad->current_stream->runtime &&
  	    snd_pcm_running(ad->current_stream)) {
  		dev_err(dev, "HDMI display disabled, aborting playback\n");
  		snd_pcm_stream_lock_irq(ad->current_stream);
  		snd_pcm_stop(ad->current_stream, SNDRV_PCM_STATE_DISCONNECTED);
  		snd_pcm_stream_unlock_irq(ad->current_stream);
  	}
  	mutex_unlock(&ad->current_stream_lock);
  }
  
  static int hdmi_dai_startup(struct snd_pcm_substream *substream,
  			    struct snd_soc_dai *dai)
  {
  	struct hdmi_audio_data *ad = card_drvdata_substream(substream);
  	int ret;
  	/*
  	 * Make sure that the period bytes are multiple of the DMA packet size.
  	 * Largest packet size we use is 32 32-bit words = 128 bytes
  	 */
  	ret = snd_pcm_hw_constraint_step(substream->runtime, 0,
  					 SNDRV_PCM_HW_PARAM_PERIOD_BYTES, 128);
  	if (ret < 0) {
  		dev_err(dai->dev, "Could not apply period constraint: %d\n",
  			ret);
  		return ret;
  	}
  	ret = snd_pcm_hw_constraint_step(substream->runtime, 0,
  					 SNDRV_PCM_HW_PARAM_BUFFER_BYTES, 128);
  	if (ret < 0) {
  		dev_err(dai->dev, "Could not apply buffer constraint: %d\n",
  			ret);
  		return ret;
  	}
  
  	snd_soc_dai_set_dma_data(dai, substream, &ad->dma_data);
  
  	mutex_lock(&ad->current_stream_lock);
  	ad->current_stream = substream;
  	mutex_unlock(&ad->current_stream_lock);
  
  	ret = ad->ops->audio_startup(ad->dssdev, hdmi_dai_abort);
  
  	if (ret) {
  		mutex_lock(&ad->current_stream_lock);
  		ad->current_stream = NULL;
  		mutex_unlock(&ad->current_stream_lock);
  	}
  
  	return ret;
  }
  
  static int hdmi_dai_hw_params(struct snd_pcm_substream *substream,
  			      struct snd_pcm_hw_params *params,
  			      struct snd_soc_dai *dai)
  {
  	struct hdmi_audio_data *ad = card_drvdata_substream(substream);
  	struct snd_aes_iec958 *iec = &ad->iec;
  	struct snd_cea_861_aud_if *cea = &ad->cea;
  
  	WARN_ON(ad->current_stream != substream);
  
  	switch (params_format(params)) {
  	case SNDRV_PCM_FORMAT_S16_LE:
  		ad->dma_data.maxburst = 16;
  		break;
  	case SNDRV_PCM_FORMAT_S24_LE:
  		ad->dma_data.maxburst = 32;
  		break;
  	default:
  		dev_err(dai->dev, "format not supported!\n");
  		return -EINVAL;
  	}
  
  	ad->dss_audio.iec = iec;
  	ad->dss_audio.cea = cea;
  	/*
  	 * fill the IEC-60958 channel status word
  	 */
  	/* initialize the word bytes */
  	memset(iec->status, 0, sizeof(iec->status));
  
  	/* specify IEC-60958-3 (commercial use) */
  	iec->status[0] &= ~IEC958_AES0_PROFESSIONAL;
  
  	/* specify that the audio is LPCM*/
  	iec->status[0] &= ~IEC958_AES0_NONAUDIO;
  
  	iec->status[0] |= IEC958_AES0_CON_NOT_COPYRIGHT;
  
  	iec->status[0] |= IEC958_AES0_CON_EMPHASIS_NONE;
  
  	iec->status[1] = IEC958_AES1_CON_GENERAL;
  
  	iec->status[2] |= IEC958_AES2_CON_SOURCE_UNSPEC;
  
  	iec->status[2] |= IEC958_AES2_CON_CHANNEL_UNSPEC;
  
  	switch (params_rate(params)) {
  	case 32000:
  		iec->status[3] |= IEC958_AES3_CON_FS_32000;
  		break;
  	case 44100:
  		iec->status[3] |= IEC958_AES3_CON_FS_44100;
  		break;
  	case 48000:
  		iec->status[3] |= IEC958_AES3_CON_FS_48000;
  		break;
  	case 88200:
  		iec->status[3] |= IEC958_AES3_CON_FS_88200;
  		break;
  	case 96000:
  		iec->status[3] |= IEC958_AES3_CON_FS_96000;
  		break;
  	case 176400:
  		iec->status[3] |= IEC958_AES3_CON_FS_176400;
  		break;
  	case 192000:
  		iec->status[3] |= IEC958_AES3_CON_FS_192000;
  		break;
  	default:
  		dev_err(dai->dev, "rate not supported!\n");
  		return -EINVAL;
  	}
  
  	/* specify the clock accuracy */
  	iec->status[3] |= IEC958_AES3_CON_CLOCK_1000PPM;
  
  	/*
  	 * specify the word length. The same word length value can mean
  	 * two different lengths. Hence, we need to specify the maximum
  	 * word length as well.
  	 */
  	switch (params_format(params)) {
  	case SNDRV_PCM_FORMAT_S16_LE:
  		iec->status[4] |= IEC958_AES4_CON_WORDLEN_20_16;
  		iec->status[4] &= ~IEC958_AES4_CON_MAX_WORDLEN_24;
  		break;
  	case SNDRV_PCM_FORMAT_S24_LE:
  		iec->status[4] |= IEC958_AES4_CON_WORDLEN_24_20;
  		iec->status[4] |= IEC958_AES4_CON_MAX_WORDLEN_24;
  		break;
  	default:
  		dev_err(dai->dev, "format not supported!\n");
  		return -EINVAL;
  	}
  
  	/*
  	 * Fill the CEA-861 audio infoframe (see spec for details)
  	 */
  
  	cea->db1_ct_cc = (params_channels(params) - 1)
  		& CEA861_AUDIO_INFOFRAME_DB1CC;
  	cea->db1_ct_cc |= CEA861_AUDIO_INFOFRAME_DB1CT_FROM_STREAM;
  
  	cea->db2_sf_ss = CEA861_AUDIO_INFOFRAME_DB2SF_FROM_STREAM;
  	cea->db2_sf_ss |= CEA861_AUDIO_INFOFRAME_DB2SS_FROM_STREAM;
  
  	cea->db3 = 0; /* not used, all zeros */
  
  	if (params_channels(params) == 2)
  		cea->db4_ca = 0x0;
  	else if (params_channels(params) == 6)
  		cea->db4_ca = 0xb;
  	else
  		cea->db4_ca = 0x13;
  
  	if (cea->db4_ca == 0x00)
  		cea->db5_dminh_lsv = CEA861_AUDIO_INFOFRAME_DB5_DM_INH_PERMITTED;
  	else
  		cea->db5_dminh_lsv = CEA861_AUDIO_INFOFRAME_DB5_DM_INH_PROHIBITED;
  
  	/* the expression is trivial but makes clear what we are doing */
  	cea->db5_dminh_lsv |= (0 & CEA861_AUDIO_INFOFRAME_DB5_LSV);
  
  	return ad->ops->audio_config(ad->dssdev, &ad->dss_audio);
  }
  
  static int hdmi_dai_trigger(struct snd_pcm_substream *substream, int cmd,
  			    struct snd_soc_dai *dai)
  {
  	struct hdmi_audio_data *ad = card_drvdata_substream(substream);
  	int err = 0;
  
  	WARN_ON(ad->current_stream != substream);
  
  	switch (cmd) {
  	case SNDRV_PCM_TRIGGER_START:
  	case SNDRV_PCM_TRIGGER_RESUME:
  	case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
  		err = ad->ops->audio_start(ad->dssdev);
  		break;
  	case SNDRV_PCM_TRIGGER_STOP:
  	case SNDRV_PCM_TRIGGER_SUSPEND:
  	case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
  		ad->ops->audio_stop(ad->dssdev);
  		break;
  	default:
  		err = -EINVAL;
  	}
  	return err;
  }
  
  static void hdmi_dai_shutdown(struct snd_pcm_substream *substream,
  			      struct snd_soc_dai *dai)
  {
  	struct hdmi_audio_data *ad = card_drvdata_substream(substream);
  
  	WARN_ON(ad->current_stream != substream);
  
  	ad->ops->audio_shutdown(ad->dssdev);
  
  	mutex_lock(&ad->current_stream_lock);
  	ad->current_stream = NULL;
  	mutex_unlock(&ad->current_stream_lock);
  }
  
  static const struct snd_soc_dai_ops hdmi_dai_ops = {
  	.startup	= hdmi_dai_startup,
  	.hw_params	= hdmi_dai_hw_params,
  	.trigger	= hdmi_dai_trigger,
  	.shutdown	= hdmi_dai_shutdown,
  };
  
  static const struct snd_soc_component_driver omap_hdmi_component = {
  	.name = "omapdss_hdmi",
  };
  
  static struct snd_soc_dai_driver omap5_hdmi_dai = {
  	.name = "omap5-hdmi-dai",
  	.playback = {
  		.channels_min = 2,
  		.channels_max = 8,
  		.rates = (SNDRV_PCM_RATE_32000 | SNDRV_PCM_RATE_44100 |
  			  SNDRV_PCM_RATE_48000 | SNDRV_PCM_RATE_88200 |
  			  SNDRV_PCM_RATE_96000 | SNDRV_PCM_RATE_176400 |
  			  SNDRV_PCM_RATE_192000),
  		.formats = SNDRV_PCM_FMTBIT_S16_LE,
  	},
  	.ops = &hdmi_dai_ops,
  };
  
  static struct snd_soc_dai_driver omap4_hdmi_dai = {
  	.name = "omap4-hdmi-dai",
  	.playback = {
  		.channels_min = 2,
  		.channels_max = 8,
  		.rates = (SNDRV_PCM_RATE_32000 | SNDRV_PCM_RATE_44100 |
  			  SNDRV_PCM_RATE_48000 | SNDRV_PCM_RATE_88200 |
  			  SNDRV_PCM_RATE_96000 | SNDRV_PCM_RATE_176400 |
  			  SNDRV_PCM_RATE_192000),
  		.formats = SNDRV_PCM_FMTBIT_S16_LE | SNDRV_PCM_FMTBIT_S24_LE,
  	},
  	.ops = &hdmi_dai_ops,
  };
  
  static int omap_hdmi_audio_probe(struct platform_device *pdev)
  {
  	struct omap_hdmi_audio_pdata *ha = pdev->dev.platform_data;
  	struct device *dev = &pdev->dev;
  	struct hdmi_audio_data *ad;
  	struct snd_soc_dai_driver *dai_drv;
  	struct snd_soc_card *card;
  	int ret;
  
  	if (!ha) {
  		dev_err(dev, "No platform data\n");
  		return -EINVAL;
  	}
  
  	ad = devm_kzalloc(dev, sizeof(*ad), GFP_KERNEL);
  	if (!ad)
  		return -ENOMEM;
  	ad->dssdev = ha->dev;
  	ad->ops = ha->ops;
  	ad->dma_data.addr = ha->audio_dma_addr;
  	ad->dma_data.filter_data = "audio_tx";
  	ad->dma_data.addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
  	mutex_init(&ad->current_stream_lock);
  
  	switch (ha->version) {
  	case 4:
  		dai_drv = &omap4_hdmi_dai;
  		break;
  	case 5:
  		dai_drv = &omap5_hdmi_dai;
  		break;
  	default:
  		return -EINVAL;
  	}
  	ret = devm_snd_soc_register_component(ad->dssdev, &omap_hdmi_component,
  					 dai_drv, 1);
  	if (ret)
  		return ret;
  
  	ret = sdma_pcm_platform_register(ad->dssdev, "audio_tx", NULL);
  	if (ret)
  		return ret;
  
  	card = devm_kzalloc(dev, sizeof(*card), GFP_KERNEL);
  	if (!card)
  		return -ENOMEM;
  
  	card->name = devm_kasprintf(dev, GFP_KERNEL,
  				    "HDMI %s", dev_name(ad->dssdev));
  	if (!card->name)
  		return -ENOMEM;
  
  	card->owner = THIS_MODULE;
  	card->dai_link =
  		devm_kzalloc(dev, sizeof(*(card->dai_link)), GFP_KERNEL);
  	if (!card->dai_link)
  		return -ENOMEM;
  	card->dai_link->name = card->name;
  	card->dai_link->stream_name = card->name;
  	card->dai_link->cpu_dai_name = dev_name(ad->dssdev);
  	card->dai_link->platform_name = dev_name(ad->dssdev);
  	card->dai_link->codec_name = "snd-soc-dummy";
  	card->dai_link->codec_dai_name = "snd-soc-dummy-dai";
  	card->num_links = 1;
  	card->dev = dev;
  
  	ret = snd_soc_register_card(card);
  	if (ret) {
  		dev_err(dev, "snd_soc_register_card failed (%d)\n", ret);
  		return ret;
  	}
  
  	ad->card = card;
  	snd_soc_card_set_drvdata(card, ad);
  
  	dev_set_drvdata(dev, ad);
  
  	return 0;
  }
  
  static int omap_hdmi_audio_remove(struct platform_device *pdev)
  {
  	struct hdmi_audio_data *ad = platform_get_drvdata(pdev);
  
  	snd_soc_unregister_card(ad->card);
  	return 0;
  }
  
  static struct platform_driver hdmi_audio_driver = {
  	.driver = {
  		.name = DRV_NAME,
  	},
  	.probe = omap_hdmi_audio_probe,
  	.remove = omap_hdmi_audio_remove,
  };
  
  module_platform_driver(hdmi_audio_driver);
  
  MODULE_AUTHOR("Jyri Sarha <jsarha@ti.com>");
  MODULE_DESCRIPTION("OMAP HDMI Audio Driver");
  MODULE_LICENSE("GPL");
  MODULE_ALIAS("platform:" DRV_NAME);
  