ASoC: hdmi-codec: Add hdmi-codec for external HDMI-encoders

The hdmi-codec is a platform device driver to be registered from
drivers of external HDMI encoders with I2S and/or spdif interface. The
driver in turn registers an ASoC codec for the HDMI encoder's audio
functionality.

The structures and definitions in the API header are mostly redundant
copies of similar structures in ASoC headers. This is on purpose to
avoid direct dependencies to ASoC structures in video side driver.
Signed-off-by: Jyri Sarha <jsarha@ti.com>
Acked-by: Arnaud Pouliquen <arnaud.pouliquen@st.com>
Acked-by: PC Liao <pc.liao@mediatek.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

include/sound/hdmi-codec.h

+/*
+ * hdmi-codec.h - HDMI Codec driver API
+ *
+ * Copyright (C) 2014 Texas Instruments Incorporated - http://www.ti.com
+ *
+ * Author: Jyri Sarha <jsarha@ti.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.
+ *
+ * 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.
+ */
+
+#ifndef __HDMI_CODEC_H__
+#define __HDMI_CODEC_H__
+
+#include <linux/hdmi.h>
+#include <drm/drm_edid.h>
+#include <sound/asoundef.h>
+#include <uapi/sound/asound.h>
+
+/*
+ * Protocol between ASoC cpu-dai and HDMI-encoder
+ */
+struct hdmi_codec_daifmt {
+	enum {
+		HDMI_I2S,
+		HDMI_RIGHT_J,
+		HDMI_LEFT_J,
+		HDMI_DSP_A,
+		HDMI_DSP_B,
+		HDMI_AC97,
+		HDMI_SPDIF,
+	} fmt;
+	int bit_clk_inv:1;
+	int frame_clk_inv:1;
+	int bit_clk_master:1;
+	int frame_clk_master:1;
+};
+
+/*
+ * HDMI audio parameters
+ */
+struct hdmi_codec_params {
+	struct hdmi_audio_infoframe cea;
+	struct snd_aes_iec958 iec;
+	int sample_rate;
+	int sample_width;
+	int channels;
+};
+
+struct hdmi_codec_ops {
+	/*
+	 * Called when ASoC starts an audio stream setup.
+	 * Optional
+	 */
+	int (*audio_startup)(struct device *dev);
+
+	/*
+	 * Configures HDMI-encoder for audio stream.
+	 * Mandatory
+	 */
+	int (*hw_params)(struct device *dev,
+			 struct hdmi_codec_daifmt *fmt,
+			 struct hdmi_codec_params *hparms);
+
+	/*
+	 * Shuts down the audio stream.
+	 * Mandatory
+	 */
+	void (*audio_shutdown)(struct device *dev);
+
+	/*
+	 * Mute/unmute HDMI audio stream.
+	 * Optional
+	 */
+	int (*digital_mute)(struct device *dev, bool enable);
+
+	/*
+	 * Provides EDID-Like-Data from connected HDMI device.
+	 * Optional
+	 */
+	int (*get_eld)(struct device *dev, uint8_t *buf, size_t len);
+};
+
+/* HDMI codec initalization data */
+struct hdmi_codec_pdata {
+	const struct hdmi_codec_ops *ops;
+	uint i2s:1;
+	uint spdif:1;
+	int max_i2s_channels;
+};
+
+#define HDMI_CODEC_DRV_NAME "hdmi-audio-codec"
+
+#endif /* __HDMI_CODEC_H__ */

sound/soc/codecs/Kconfig

@@ -88,6 +88,7 @@ config SND_SOC_ALL_CODECS
 	select SND_SOC_MC13783 if MFD_MC13XXX
 	select SND_SOC_ML26124 if I2C
 	select SND_SOC_NAU8825 if I2C
+	select SND_SOC_HDMI_CODEC
 	select SND_SOC_PCM1681 if I2C
 	select SND_SOC_PCM179X_I2C if I2C
 	select SND_SOC_PCM179X_SPI if SPI_MASTER
@@ -477,6 +478,11 @@ config SND_SOC_BT_SCO
 config SND_SOC_DMIC
 	tristate
 
+config SND_SOC_HDMI_CODEC
+       tristate
+       select SND_PCM_ELD
+       select SND_PCM_IEC958
+
 config SND_SOC_ES8328
 	tristate "Everest Semi ES8328 CODEC"
 

sound/soc/codecs/Makefile

@@ -81,6 +81,7 @@ snd-soc-max9850-objs := max9850.o
 snd-soc-mc13783-objs := mc13783.o
 snd-soc-ml26124-objs := ml26124.o
 snd-soc-nau8825-objs := nau8825.o
+snd-soc-hdmi-codec-objs := hdmi-codec.o
 snd-soc-pcm1681-objs := pcm1681.o
 snd-soc-pcm179x-codec-objs := pcm179x.o
 snd-soc-pcm179x-i2c-objs := pcm179x-i2c.o
@@ -290,6 +291,7 @@ obj-$(CONFIG_SND_SOC_MAX9850)	+= snd-soc-max9850.o
 obj-$(CONFIG_SND_SOC_MC13783)	+= snd-soc-mc13783.o
 obj-$(CONFIG_SND_SOC_ML26124)	+= snd-soc-ml26124.o
 obj-$(CONFIG_SND_SOC_NAU8825)   += snd-soc-nau8825.o
+obj-$(CONFIG_SND_SOC_HDMI_CODEC)	+= snd-soc-hdmi-codec.o
 obj-$(CONFIG_SND_SOC_PCM1681)	+= snd-soc-pcm1681.o
 obj-$(CONFIG_SND_SOC_PCM179X)	+= snd-soc-pcm179x-codec.o
 obj-$(CONFIG_SND_SOC_PCM179X_I2C)	+= snd-soc-pcm179x-i2c.o

sound/soc/codecs/hdmi-codec.c

+/*
+ * ALSA SoC codec for HDMI encoder drivers
+ * Copyright (C) 2015 Texas Instruments Incorporated - http://www.ti.com/
+ * Author: Jyri Sarha <jsarha@ti.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.
+ *
+ * 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.
+ */
+#include <linux/module.h>
+#include <linux/string.h>
+#include <sound/core.h>
+#include <sound/pcm.h>
+#include <sound/pcm_params.h>
+#include <sound/soc.h>
+#include <sound/pcm_drm_eld.h>
+#include <sound/hdmi-codec.h>
+#include <sound/pcm_iec958.h>
+
+#include <drm/drm_crtc.h> /* This is only to get MAX_ELD_BYTES */
+
+struct hdmi_codec_priv {
+	struct hdmi_codec_pdata hcd;
+	struct snd_soc_dai_driver *daidrv;
+	struct hdmi_codec_daifmt daifmt[2];
+	struct mutex current_stream_lock;
+	struct snd_pcm_substream *current_stream;
+	struct snd_pcm_hw_constraint_list ratec;
+	uint8_t eld[MAX_ELD_BYTES];
+};
+
+static const struct snd_soc_dapm_widget hdmi_widgets[] = {
+	SND_SOC_DAPM_OUTPUT("TX"),
+};
+
+static const struct snd_soc_dapm_route hdmi_routes[] = {
+	{ "TX", NULL, "Playback" },
+};
+
+enum {
+	DAI_ID_I2S = 0,
+	DAI_ID_SPDIF,
+};
+
+static int hdmi_codec_new_stream(struct snd_pcm_substream *substream,
+				 struct snd_soc_dai *dai)
+{
+	struct hdmi_codec_priv *hcp = snd_soc_dai_get_drvdata(dai);
+	int ret = 0;
+
+	mutex_lock(&hcp->current_stream_lock);
+	if (!hcp->current_stream) {
+		hcp->current_stream = substream;
+	} else if (hcp->current_stream != substream) {
+		dev_err(dai->dev, "Only one simultaneous stream supported!\n");
+		ret = -EINVAL;
+	}
+	mutex_unlock(&hcp->current_stream_lock);
+
+	return ret;
+}
+
+static int hdmi_codec_startup(struct snd_pcm_substream *substream,
+			      struct snd_soc_dai *dai)
+{
+	struct hdmi_codec_priv *hcp = snd_soc_dai_get_drvdata(dai);
+	int ret = 0;
+
+	dev_dbg(dai->dev, "%s()\n", __func__);
+
+	ret = hdmi_codec_new_stream(substream, dai);
+	if (ret)
+		return ret;
+
+	if (hcp->hcd.ops->audio_startup) {
+		ret = hcp->hcd.ops->audio_startup(dai->dev->parent);
+		if (ret) {
+			mutex_lock(&hcp->current_stream_lock);
+			hcp->current_stream = NULL;
+			mutex_unlock(&hcp->current_stream_lock);
+			return ret;
+		}
+	}
+
+	if (hcp->hcd.ops->get_eld) {
+		ret = hcp->hcd.ops->get_eld(dai->dev->parent, hcp->eld,
+					    sizeof(hcp->eld));
+
+		if (!ret) {
+			ret = snd_pcm_hw_constraint_eld(substream->runtime,
+							hcp->eld);
+			if (ret)
+				return ret;
+		}
+	}
+	return 0;
+}
+
+static void hdmi_codec_shutdown(struct snd_pcm_substream *substream,
+				struct snd_soc_dai *dai)
+{
+	struct hdmi_codec_priv *hcp = snd_soc_dai_get_drvdata(dai);
+
+	dev_dbg(dai->dev, "%s()\n", __func__);
+
+	WARN_ON(hcp->current_stream != substream);
+
+	hcp->hcd.ops->audio_shutdown(dai->dev->parent);
+
+	mutex_lock(&hcp->current_stream_lock);
+	hcp->current_stream = NULL;
+	mutex_unlock(&hcp->current_stream_lock);
+}
+
+static int hdmi_codec_hw_params(struct snd_pcm_substream *substream,
+				struct snd_pcm_hw_params *params,
+				struct snd_soc_dai *dai)
+{
+	struct hdmi_codec_priv *hcp = snd_soc_dai_get_drvdata(dai);
+	struct hdmi_codec_params hp = {
+		.iec = {
+			.status = { 0 },
+			.subcode = { 0 },
+			.pad = 0,
+			.dig_subframe = { 0 },
+		}
+	};
+	int ret;
+
+	dev_dbg(dai->dev, "%s() width %d rate %d channels %d\n", __func__,
+		params_width(params), params_rate(params),
+		params_channels(params));
+
+	if (params_width(params) > 24)
+		params->msbits = 24;
+
+	ret = snd_pcm_create_iec958_consumer_hw_params(params, hp.iec.status,
+						       sizeof(hp.iec.status));
+	if (ret < 0) {
+		dev_err(dai->dev, "Creating IEC958 channel status failed %d\n",
+			ret);
+		return ret;
+	}
+
+	ret = hdmi_codec_new_stream(substream, dai);
+	if (ret)
+		return ret;
+
+	hdmi_audio_infoframe_init(&hp.cea);
+	hp.cea.channels = params_channels(params);
+	hp.cea.coding_type = HDMI_AUDIO_CODING_TYPE_STREAM;
+	hp.cea.sample_size = HDMI_AUDIO_SAMPLE_SIZE_STREAM;
+	hp.cea.sample_frequency = HDMI_AUDIO_SAMPLE_FREQUENCY_STREAM;
+
+	hp.sample_width = params_width(params);
+	hp.sample_rate = params_rate(params);
+	hp.channels = params_channels(params);
+
+	return hcp->hcd.ops->hw_params(dai->dev->parent, &hcp->daifmt[dai->id],
+				       &hp);
+}
+
+static int hdmi_codec_set_fmt(struct snd_soc_dai *dai,
+			      unsigned int fmt)
+{
+	struct hdmi_codec_priv *hcp = snd_soc_dai_get_drvdata(dai);
+	struct hdmi_codec_daifmt cf = { 0 };
+	int ret = 0;
+
+	dev_dbg(dai->dev, "%s()\n", __func__);
+
+	if (dai->id == DAI_ID_SPDIF) {
+		cf.fmt = HDMI_SPDIF;
+	} else {
+		switch (fmt & SND_SOC_DAIFMT_MASTER_MASK) {
+		case SND_SOC_DAIFMT_CBM_CFM:
+			cf.bit_clk_master = 1;
+			cf.frame_clk_master = 1;
+			break;
+		case SND_SOC_DAIFMT_CBS_CFM:
+			cf.frame_clk_master = 1;
+			break;
+		case SND_SOC_DAIFMT_CBM_CFS:
+			cf.bit_clk_master = 1;
+			break;
+		case SND_SOC_DAIFMT_CBS_CFS:
+			break;
+		default:
+			return -EINVAL;
+		}
+
+		switch (fmt & SND_SOC_DAIFMT_INV_MASK) {
+		case SND_SOC_DAIFMT_NB_NF:
+			break;
+		case SND_SOC_DAIFMT_NB_IF:
+			cf.frame_clk_inv = 1;
+			break;
+		case SND_SOC_DAIFMT_IB_NF:
+			cf.bit_clk_inv = 1;
+			break;
+		case SND_SOC_DAIFMT_IB_IF:
+			cf.frame_clk_inv = 1;
+			cf.bit_clk_inv = 1;
+			break;
+		}
+
+		switch (fmt & SND_SOC_DAIFMT_FORMAT_MASK) {
+		case SND_SOC_DAIFMT_I2S:
+			cf.fmt = HDMI_I2S;
+			break;
+		case SND_SOC_DAIFMT_DSP_A:
+			cf.fmt = HDMI_DSP_A;
+			break;
+		case SND_SOC_DAIFMT_DSP_B:
+			cf.fmt = HDMI_DSP_B;
+			break;
+		case SND_SOC_DAIFMT_RIGHT_J:
+			cf.fmt = HDMI_RIGHT_J;
+			break;
+		case SND_SOC_DAIFMT_LEFT_J:
+			cf.fmt = HDMI_LEFT_J;
+			break;
+		case SND_SOC_DAIFMT_AC97:
+			cf.fmt = HDMI_AC97;
+			break;
+		default:
+			dev_err(dai->dev, "Invalid DAI interface format\n");
+			return -EINVAL;
+		}
+	}
+
+	hcp->daifmt[dai->id] = cf;
+
+	return ret;
+}
+
+static int hdmi_codec_digital_mute(struct snd_soc_dai *dai, int mute)
+{
+	struct hdmi_codec_priv *hcp = snd_soc_dai_get_drvdata(dai);
+
+	dev_dbg(dai->dev, "%s()\n", __func__);
+
+	if (hcp->hcd.ops->digital_mute)
+		return hcp->hcd.ops->digital_mute(dai->dev->parent, mute);
+
+	return 0;
+}
+
+static const struct snd_soc_dai_ops hdmi_dai_ops = {
+	.startup	= hdmi_codec_startup,
+	.shutdown	= hdmi_codec_shutdown,
+	.hw_params	= hdmi_codec_hw_params,
+	.set_fmt	= hdmi_codec_set_fmt,
+	.digital_mute	= hdmi_codec_digital_mute,
+};
+
+
+#define HDMI_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)
+
+#define SPDIF_FORMATS	(SNDRV_PCM_FMTBIT_S16_LE | SNDRV_PCM_FMTBIT_S16_BE |\
+			 SNDRV_PCM_FMTBIT_S20_3LE | SNDRV_PCM_FMTBIT_S20_3BE |\
+			 SNDRV_PCM_FMTBIT_S24_3LE | SNDRV_PCM_FMTBIT_S24_3BE |\
+			 SNDRV_PCM_FMTBIT_S24_LE | SNDRV_PCM_FMTBIT_S24_BE)
+
+/*
+ * This list is only for formats allowed on the I2S bus. So there is
+ * some formats listed that are not supported by HDMI interface. For
+ * instance allowing the 32-bit formats enables 24-precision with CPU
+ * DAIs that do not support 24-bit formats. If the extra formats cause
+ * problems, we should add the video side driver an option to disable
+ * them.
+ */
+#define I2S_FORMATS	(SNDRV_PCM_FMTBIT_S16_LE | SNDRV_PCM_FMTBIT_S16_BE |\
+			 SNDRV_PCM_FMTBIT_S20_3LE | SNDRV_PCM_FMTBIT_S20_3BE |\
+			 SNDRV_PCM_FMTBIT_S24_3LE | SNDRV_PCM_FMTBIT_S24_3BE |\
+			 SNDRV_PCM_FMTBIT_S24_LE | SNDRV_PCM_FMTBIT_S24_BE |\
+			 SNDRV_PCM_FMTBIT_S32_LE | SNDRV_PCM_FMTBIT_S32_BE)
+
+static struct snd_soc_dai_driver hdmi_i2s_dai = {
+	.name = "i2s-hifi",
+	.id = DAI_ID_I2S,
+	.playback = {
+		.stream_name = "Playback",
+		.channels_min = 2,
+		.channels_max = 8,
+		.rates = HDMI_RATES,
+		.formats = I2S_FORMATS,
+		.sig_bits = 24,
+	},
+	.ops = &hdmi_dai_ops,
+};
+
+static const struct snd_soc_dai_driver hdmi_spdif_dai = {
+	.name = "spdif-hifi",
+	.id = DAI_ID_SPDIF,
+	.playback = {
+		.stream_name = "Playback",
+		.channels_min = 2,
+		.channels_max = 2,
+		.rates = HDMI_RATES,
+		.formats = SPDIF_FORMATS,
+	},
+	.ops = &hdmi_dai_ops,
+};
+
+static struct snd_soc_codec_driver hdmi_codec = {
+	.dapm_widgets = hdmi_widgets,
+	.num_dapm_widgets = ARRAY_SIZE(hdmi_widgets),
+	.dapm_routes = hdmi_routes,
+	.num_dapm_routes = ARRAY_SIZE(hdmi_routes),
+};
+
+static int hdmi_codec_probe(struct platform_device *pdev)
+{
+	struct hdmi_codec_pdata *hcd = pdev->dev.platform_data;
+	struct device *dev = &pdev->dev;
+	struct hdmi_codec_priv *hcp;
+	int dai_count, i = 0;
+	int ret;
+
+	dev_dbg(dev, "%s()\n", __func__);
+
+	if (!hcd) {
+		dev_err(dev, "%s: No plalform data\n", __func__);
+		return -EINVAL;
+	}
+
+	dai_count = hcd->i2s + hcd->spdif;
+	if (dai_count < 1 || !hcd->ops || !hcd->ops->hw_params ||
+	    !hcd->ops->audio_shutdown) {
+		dev_err(dev, "%s: Invalid parameters\n", __func__);
+		return -EINVAL;
+	}
+
+	hcp = devm_kzalloc(dev, sizeof(*hcp), GFP_KERNEL);
+	if (!hcp)
+		return -ENOMEM;
+
+	hcp->hcd = *hcd;
+	mutex_init(&hcp->current_stream_lock);
+
+	hcp->daidrv = devm_kzalloc(dev, dai_count * sizeof(*hcp->daidrv),
+				   GFP_KERNEL);
+	if (!hcp->daidrv)
+		return -ENOMEM;
+
+	if (hcd->i2s) {
+		hcp->daidrv[i] = hdmi_i2s_dai;
+		hcp->daidrv[i].playback.channels_max =
+			hcd->max_i2s_channels;
+		i++;
+	}
+
+	if (hcd->spdif)
+		hcp->daidrv[i] = hdmi_spdif_dai;
+
+	ret = snd_soc_register_codec(dev, &hdmi_codec, hcp->daidrv,
+				     dai_count);
+	if (ret) {
+		dev_err(dev, "%s: snd_soc_register_codec() failed (%d)\n",
+			__func__, ret);
+		return ret;
+	}
+
+	dev_set_drvdata(dev, hcp);
+	return 0;
+}
+
+static int hdmi_codec_remove(struct platform_device *pdev)
+{
+	snd_soc_unregister_codec(&pdev->dev);
+	return 0;
+}
+
+static struct platform_driver hdmi_codec_driver = {
+	.driver = {
+		.name = HDMI_CODEC_DRV_NAME,
+	},
+	.probe = hdmi_codec_probe,
+	.remove = hdmi_codec_remove,
+};
+
+module_platform_driver(hdmi_codec_driver);
+
+MODULE_AUTHOR("Jyri Sarha <jsarha@ti.com>");
+MODULE_DESCRIPTION("HDMI Audio Codec Driver");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("platform:" HDMI_CODEC_DRV_NAME);