From e02e7813df718e01d51de6e6cc8a760e786457bd Mon Sep 17 00:00:00 2001
From: Russell King <rmk+kernel@armlinux.org.uk>
Date: Fri, 1 Mar 2019 11:07:19 +0000
Subject: drm/i2c: tda998x: support for bclk_ratio via hdmi-codec hw_params

Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
---
 drivers/gpu/drm/i2c/tda998x_drv.c | 57 ++++++++++++++++++++++++++++-----------
 1 file changed, 42 insertions(+), 15 deletions(-)

diff --git a/drivers/gpu/drm/i2c/tda998x_drv.c b/drivers/gpu/drm/i2c/tda998x_drv.c
index 9517f522dcb9..77787daab6d5 100644
--- a/drivers/gpu/drm/i2c/tda998x_drv.c
+++ b/drivers/gpu/drm/i2c/tda998x_drv.c
@@ -62,6 +62,7 @@ struct tda998x_priv {
 	u8 vip_cntrl_0;
 	u8 vip_cntrl_1;
 	u8 vip_cntrl_2;
+	u8 i2s_cts_n;
 	unsigned long tmds_clock;
 	struct tda998x_audio_settings audio;
 
@@ -961,25 +962,24 @@ static u8 tda998x_get_adiv(struct tda998x_priv *priv, unsigned int fs)
  *
  * Note: S/PDIF always uses a bclk_ratio of 64.
  */
-static int tda998x_derive_cts_n(struct tda998x_priv *priv,
-				struct tda998x_audio_settings *settings,
+static int tda998x_derive_cts_n(struct tda998x_priv *priv, u8 *cts_n,
 				unsigned int ratio)
 {
 	switch (ratio) {
 	case 16:
-		settings->cts_n = CTS_N_M(3) | CTS_N_K(0);
+		*cts_n = CTS_N_M(3) | CTS_N_K(0);
 		break;
 	case 32:
-		settings->cts_n = CTS_N_M(3) | CTS_N_K(1);
+		*cts_n = CTS_N_M(3) | CTS_N_K(1);
 		break;
 	case 48:
-		settings->cts_n = CTS_N_M(3) | CTS_N_K(2);
+		*cts_n = CTS_N_M(3) | CTS_N_K(2);
 		break;
 	case 64:
-		settings->cts_n = CTS_N_M(3) | CTS_N_K(3);
+		*cts_n = CTS_N_M(3) | CTS_N_K(3);
 		break;
 	case 128:
-		settings->cts_n = CTS_N_M(0) | CTS_N_K(0);
+		*cts_n = CTS_N_M(0) | CTS_N_K(0);
 		break;
 	default:
 		dev_err(&priv->hdmi->dev, "unsupported bclk ratio %ufs\n",
@@ -1059,12 +1059,28 @@ static void tda998x_configure_audio(struct tda998x_priv *priv)
 	tda998x_write_aif(priv, &settings->cea);
 }
 
+static int tda998x_audio_startup(struct device *dev, void *data)
+{
+	struct tda998x_priv *priv = dev_get_drvdata(dev);
+
+	priv->i2s_cts_n = 0xff;
+
+	return 0;
+}
+
+static int tda998x_audio_bclk_ratio(struct device *dev, void *data,
+				    unsigned int ratio)
+{
+	struct tda998x_priv *priv = dev_get_drvdata(dev);
+
+	return tda998x_derive_cts_n(priv, &priv->i2s_cts_n, ratio);
+}
+
 static int tda998x_audio_hw_params(struct device *dev, void *data,
 				   struct hdmi_codec_daifmt *daifmt,
 				   struct hdmi_codec_params *params)
 {
 	struct tda998x_priv *priv = dev_get_drvdata(dev);
-	unsigned int bclk_ratio;
 	bool spdif = daifmt->fmt == HDMI_SPDIF;
 	int ret;
 	struct tda998x_audio_settings audio = {
@@ -1107,10 +1123,19 @@ static int tda998x_audio_hw_params(struct device *dev, void *data,
 	if (ret < 0)
 		return ret;
 
-	bclk_ratio = spdif ? 64 : params->sample_width * 2;
-	ret = tda998x_derive_cts_n(priv, &audio, bclk_ratio);
-	if (ret < 0)
-		return ret;
+	if (spdif) {
+		tda998x_derive_cts_n(priv, &audio.cts_n, 64);
+	} else if (priv->i2s_cts_n != 0xff) {
+		audio.cts_n = priv->i2s_cts_n;
+	} else {
+		dev_warn_once(&priv->hdmi->dev,
+			      "I2S bit clock ratio not set, defaulting to 2x sample_width.\n"
+			      "Please call snd_soc_dai_set_bclk_ratio() for this codec.\n");
+		ret = tda998x_derive_cts_n(priv, &audio.cts_n,
+					   params->sample_width * 2);
+		if (ret < 0)
+			return ret;
+	}
 
 	mutex_lock(&priv->audio_mutex);
 	priv->audio = audio;
@@ -1160,6 +1185,8 @@ static int tda998x_audio_get_eld(struct device *dev, void *data,
 }
 
 static const struct hdmi_codec_ops audio_codec_ops = {
+	.audio_startup = tda998x_audio_startup,
+	.set_bclk_ratio = tda998x_audio_bclk_ratio,
 	.hw_params = tda998x_audio_hw_params,
 	.audio_shutdown = tda998x_audio_shutdown,
 	.digital_mute = tda998x_audio_digital_mute,
@@ -1757,7 +1784,7 @@ static int tda998x_set_config(struct tda998x_priv *priv,
 			    (p->mirr_f ? VIP_CNTRL_2_MIRR_F : 0);
 
 	if (p->audio_params.format != AFMT_UNUSED) {
-		unsigned int ratio, route;
+		unsigned int route;
 		bool spdif = p->audio_params.format == AFMT_SPDIF;
 
 		route = AUDIO_ROUTE_I2S + spdif;
@@ -1771,8 +1798,8 @@ static int tda998x_set_config(struct tda998x_priv *priv,
 		priv->audio.ena_ap = p->audio_params.config;
 		priv->audio.i2s_format = I2S_FORMAT_PHILIPS;
 
-		ratio = spdif ? 64 : p->audio_params.sample_width * 2;
-		return tda998x_derive_cts_n(priv, &priv->audio, ratio);
+		return tda998x_derive_cts_n(priv, &priv->audio.cts_n,
+					    p->audio_params.sample_width * 2);
 	}
 
 	return 0;
-- 
cgit