[alsa-devel] [PATCH 4/9] ASoC: davinci-evm: HDMI audio support for TDA998x trough McASP I2S bus

[Jyri Sarha]

Add machine driver support for BeagleBone-Black HDMI audio. BBB has
NXP TDA998X HDMI transmitter connected to McASP port in I2S mode. The
44100 Hz sample-rate and it's multiples can not be accurately produced
on BBB. The only supported sample format is SNDRV_PCM_FORMAT_S32_LE.
The 8 least significant bits are ignored.

Signed-off-by: Jyri Sarha <jsarha at ti.com>
---
 .../bindings/sound/davinci-evm-audio.txt           |    4 +-
 sound/soc/davinci/davinci-evm.c                    |   82 +++++++++++++++++++-
 2 files changed, 83 insertions(+), 3 deletions(-)

diff --git a/Documentation/devicetree/bindings/sound/davinci-evm-audio.txt b/Documentation/devicetree/bindings/sound/davinci-evm-audio.txt
index 963e100..c137436 100644
--- a/Documentation/devicetree/bindings/sound/davinci-evm-audio.txt
+++ b/Documentation/devicetree/bindings/sound/davinci-evm-audio.txt
@@ -1,7 +1,9 @@
 * Texas Instruments SoC audio setups with TLV320AIC3X Codec
 
 Required properties:
-- compatible : "ti,da830-evm-audio" : forDM365/DA8xx/OMAPL1x/AM33xx
+- compatible : "ti,da830-evm-audio" : for DM365/DA8xx/OMAPL1x/AM33xx
+               "ti,am335x-beaglebone-black-audio" : for Beaglebone-black HDMI
+                                                    audio
 - ti,model : The user-visible name of this sound complex.
 - ti,audio-codec : The phandle of the TLV320AIC3x audio codec
 - ti,mcasp-controller : The phandle of the McASP controller
diff --git a/sound/soc/davinci/davinci-evm.c b/sound/soc/davinci/davinci-evm.c
index a50010e..9b98667 100644
--- a/sound/soc/davinci/davinci-evm.c
+++ b/sound/soc/davinci/davinci-evm.c
@@ -21,6 +21,7 @@
 #include <sound/core.h>
 #include <sound/pcm.h>
 #include <sound/soc.h>
+#include <sound/pcm_params.h>
 
 #include <asm/dma.h>
 #include <asm/mach-types.h>
@@ -83,12 +84,46 @@ static int evm_hw_params(struct snd_pcm_substream *substream,
 	return 0;
 }
 
+/* If changing sample format the tda998x configuration (REG_CTS_N) needs
+   to be changed. */
+#define TDA998X_SAMPLE_FORMAT SNDRV_PCM_FORMAT_S32_LE
+static int evm_tda998x_startup(struct snd_pcm_substream *substream)
+{
+	struct snd_pcm_runtime *runtime = substream->runtime;
+	struct snd_mask *fmt = constrs_mask(&runtime->hw_constraints,
+					    SNDRV_PCM_HW_PARAM_FORMAT);
+	snd_mask_none(fmt);
+	snd_mask_set(fmt, TDA998X_SAMPLE_FORMAT);
+
+	return evm_startup(substream);
+}
+
+static int evm_tda998x_hw_params(struct snd_pcm_substream *substream,
+				 struct snd_pcm_hw_params *params)
+{
+	struct snd_soc_pcm_runtime *rtd = substream->private_data;
+	struct snd_soc_dai *cpu_dai = rtd->cpu_dai;
+	struct snd_soc_card *soc_card = rtd->card;
+	struct snd_soc_card_drvdata_davinci *drvdata =
+		snd_soc_card_get_drvdata(soc_card);
+
+	return snd_soc_dai_set_sysclk(cpu_dai, 0, drvdata->sysclk,
+				      SND_SOC_CLOCK_IN);
+}
+
 static struct snd_soc_ops evm_ops = {
 	.startup = evm_startup,
 	.shutdown = evm_shutdown,
 	.hw_params = evm_hw_params,
 };
 
+
+static struct snd_soc_ops evm_tda998x_ops = {
+	.startup = evm_tda998x_startup,
+	.shutdown = evm_shutdown,
+	.hw_params = evm_tda998x_hw_params,
+};
+
 /* davinci-evm machine dapm widgets */
 static const struct snd_soc_dapm_widget aic3x_dapm_widgets[] = {
 	SND_SOC_DAPM_HP("Headphone Jack", NULL),
@@ -149,6 +184,35 @@ static int evm_aic3x_init(struct snd_soc_pcm_runtime *rtd)
 	return 0;
 }
 
+static const struct snd_soc_dapm_widget tda998x_dapm_widgets[] = {
+	SND_SOC_DAPM_OUTPUT("HDMI Out"),
+};
+
+static int evm_tda998x_init(struct snd_soc_pcm_runtime *rtd)
+{
+	struct snd_soc_dai *cpu_dai = rtd->cpu_dai;
+	struct snd_soc_dapm_context *dapm = &rtd->codec->dapm;
+	struct snd_soc_card *soc_card = rtd->card;
+	int ret;
+
+	ret = snd_soc_dai_set_clkdiv(cpu_dai, 0, 1);
+	if (ret < 0)
+		return ret;
+
+	snd_soc_dapm_new_controls(dapm, tda998x_dapm_widgets,
+				  ARRAY_SIZE(tda998x_dapm_widgets));
+
+	ret = snd_soc_of_parse_audio_routing(soc_card, "ti,audio-routing");
+
+	/* not connected */
+	snd_soc_dapm_disable_pin(dapm, "RX");
+
+	/* always connected */
+	snd_soc_dapm_enable_pin(dapm, "HDMI Out");
+
+	return 0;
+}
+
 /* davinci-evm digital audio interface glue - connects codec <--> CPU */
 static struct snd_soc_dai_link dm6446_evm_dai = {
 	.name = "TLV320AIC3X",
@@ -334,7 +398,7 @@ static struct snd_soc_card da850_snd_soc_card = {
 #if defined(CONFIG_OF)
 
 /*
- * The struct is used as place holder. It will be completely
+ * The structs are used as place holders. They will be completely
  * filled with data from dt node.
  */
 static struct snd_soc_dai_link evm_dai_tlv320aic3x = {
@@ -347,10 +411,24 @@ static struct snd_soc_dai_link evm_dai_tlv320aic3x = {
 		   SND_SOC_DAIFMT_IB_NF,
 };
 
+static struct snd_soc_dai_link evm_dai_tda998x_hdmi = {
+	.name		= "NXP TDA998x HDMI Chip",
+	.stream_name	= "HDMI",
+	.codec_dai_name	= "hdmi-hifi",
+	.ops		= &evm_tda998x_ops,
+	.init           = evm_tda998x_init,
+	.dai_fmt	= (SND_SOC_DAIFMT_CBS_CFS | SND_SOC_DAIFMT_I2S |
+			   SND_SOC_DAIFMT_IB_NF),
+};
+
 static const struct of_device_id davinci_evm_dt_ids[] = {
 	{
 		.compatible = "ti,da830-evm-audio",
-		.data = (void *) &evm_dai_tlv320aic3x,
+		.data = &evm_dai_tlv320aic3x,
+	},
+	{
+		.compatible = "ti,am335x-beaglebone-black-audio",
+		.data = &evm_dai_tda998x_hdmi,
 	},
 	{ /* sentinel */ }
 };
-- 
1.7.9.5