From e22dfe2e094493c1f831fe35dc38f543519490f0 Mon Sep 17 00:00:00 2001
From: Sugar Zhang <sugar.zhang@rock-chips.com>
Date: Tue, 9 Jul 2024 17:29:15 +0800
Subject: [PATCH] ASoC: hdmi-codec: Add support for HDMI-TX DLP

Support for HDMI-TX Audio Digital Loopback.

e.g.

&hdmi {
	audio,digital-loopback;
};

Signed-off-by: Sugar Zhang <sugar.zhang@rock-chips.com>
Change-Id: Id5b4490b8bd96559b49fb8225cf93feac7c3d5c2
---
 sound/soc/codecs/hdmi-codec.c | 15 +++++++++++++++
 1 file changed, 15 insertions(+)

diff --git a/sound/soc/codecs/hdmi-codec.c b/sound/soc/codecs/hdmi-codec.c
index 5d44964caa4f..2849ea39efc8 100644
--- a/sound/soc/codecs/hdmi-codec.c
+++ b/sound/soc/codecs/hdmi-codec.c
@@ -272,6 +272,7 @@ struct hdmi_codec_priv {
 	struct mutex lock;
 	bool busy;
 	bool eld_bypass;
+	bool tx_dlp;
 	struct snd_soc_jack *jack;
 	unsigned int jack_status;
 	u8 iec_status[AES_IEC958_STATUS_SIZE];
@@ -460,6 +461,9 @@ static int hdmi_codec_startup(struct snd_pcm_substream *substream,
 	bool tx = substream->stream == SNDRV_PCM_STREAM_PLAYBACK;
 	int ret = 0;
 
+	if (hcp->tx_dlp && substream->stream != SNDRV_PCM_STREAM_PLAYBACK)
+		return 0;
+
 	mutex_lock(&hcp->lock);
 	if (hcp->busy) {
 		dev_err(dai->dev, "Only one simultaneous stream supported!\n");
@@ -500,6 +504,9 @@ static void hdmi_codec_shutdown(struct snd_pcm_substream *substream,
 {
 	struct hdmi_codec_priv *hcp = snd_soc_dai_get_drvdata(dai);
 
+	if (hcp->tx_dlp && substream->stream != SNDRV_PCM_STREAM_PLAYBACK)
+		return;
+
 	hcp->chmap_idx = HDMI_CODEC_CHMAP_IDX_UNKNOWN;
 	hcp->hcd.ops->audio_shutdown(dai->dev->parent, hcp->hcd.data);
 
@@ -561,6 +568,9 @@ static int hdmi_codec_hw_params(struct snd_pcm_substream *substream,
 	};
 	int ret;
 
+	if (hcp->tx_dlp && substream->stream != SNDRV_PCM_STREAM_PLAYBACK)
+		return 0;
+
 	if (!hcp->hcd.ops->hw_params)
 		return 0;
 
@@ -602,6 +612,9 @@ static int hdmi_codec_prepare(struct snd_pcm_substream *substream,
 	struct hdmi_codec_params hp;
 	int ret;
 
+	if (hcp->tx_dlp && substream->stream != SNDRV_PCM_STREAM_PLAYBACK)
+		return 0;
+
 	if (!hcp->hcd.ops->prepare)
 		return 0;
 
@@ -1083,6 +1096,8 @@ static int hdmi_codec_probe(struct platform_device *pdev)
 	hcp->hcd = *hcd;
 	mutex_init(&hcp->lock);
 
+	hcp->tx_dlp = device_property_read_bool(dev->parent, "audio,digital-loopback");
+
 	ret = snd_pcm_create_iec958_consumer_default(hcp->iec_status,
 						     sizeof(hcp->iec_status));
 	if (ret < 0)