Re: [PATCH 1/2] drm/i2c: tda998x: adjust CTS_N audio pre-divider calculation
From: Sven Van Asbroeck
Date: Fri Feb 22 2019 - 16:18:57 EST
Russell, thank you so much for your patience, help and explanation, I really
appreciate it !
On Fri, Feb 22, 2019 at 3:16 PM Russell King - ARM Linux admin <linux@xxxxxxxxxxxxxxx> wrote:
>
> A possible solution to that would be for hdmi-codec to default that to
> zero unless it's been definitively provided by the ASoC "card", which
> would allow the old behaviour of selecting the CTS_N M/K values
> depending on the sample width, which we know works for some people.
>
Yes, that would keep the current users in business without them having to
change anything.
Of course, poor souls like myself would have to patch, say, simple-card so we
could provide a bclk ratio in the devicetree. Which would then propagate down
to the tda998x via hdmi-codec. Which is fine by me.
Combining your two previous suggestions, I get the following. Now sample_width
can be removed from tda998x_audio_params, as it's no longer used.
Would this be a good start?
diff --git a/drivers/gpu/drm/i2c/tda998x_drv.c b/drivers/gpu/drm/i2c/tda998x_drv.c
index a7c39f39793f..a306994ecc79 100644
--- a/drivers/gpu/drm/i2c/tda998x_drv.c
+++ b/drivers/gpu/drm/i2c/tda998x_drv.c
@@ -893,19 +893,25 @@ tda998x_configure_audio(struct tda998x_priv *priv,
reg_write(priv, REG_MUX_AP, MUX_AP_SELECT_I2S);
clksel_aip = AIP_CLKSEL_AIP_I2S;
clksel_fs = AIP_CLKSEL_FS_ACLK;
- switch (params->sample_width) {
+ switch (params->bclk_ratio) {
case 16:
+ cts_n = CTS_N_M(3) | CTS_N_K(0);
+ break;
+ case 32:
cts_n = CTS_N_M(3) | CTS_N_K(1);
break;
- case 18:
- case 20:
- case 24:
+ case 48:
cts_n = CTS_N_M(3) | CTS_N_K(2);
break;
- default:
- case 32:
+ case 64:
cts_n = CTS_N_M(3) | CTS_N_K(3);
break;
+ case 128:
+ cts_n = CTS_N_M(0) | CTS_N_K(0);
+ break;
+ default:
+ dev_err(&priv->hdmi->dev, "unsupported I2S bclk ratio\n");
+ return -EINVAL;
}
break;
@@ -982,7 +988,7 @@ static int tda998x_audio_hw_params(struct device *dev, void *data,
struct tda998x_priv *priv = dev_get_drvdata(dev);
int i, ret;
struct tda998x_audio_params audio = {
- .sample_width = params->sample_width,
+ .bclk_ratio = daifmt->bclk_ratio,
.sample_rate = params->sample_rate,
.cea = params->cea,
};
@@ -1004,6 +1010,23 @@ static int tda998x_audio_hw_params(struct device *dev, void *data,
if (priv->audio_port[i].format == AFMT_I2S)
audio.config = priv->audio_port[i].config;
audio.format = AFMT_I2S;
+ if (!audio.bclk_ratio) {
+ /* compatibility */
+ switch (params->sample_width) {
+ case 16:
+ audio.bclk_ratio = 32;
+ break;
+ case 18:
+ case 20:
+ case 24:
+ audio.bclk_ratio = 48;
+ break;
+ default:
+ case 32:
+ audio.bclk_ratio = 64;
+ break;
+ }
+ }
break;
case HDMI_SPDIF:
for (i = 0; i < ARRAY_SIZE(priv->audio_port); i++)
diff --git a/include/drm/i2c/tda998x.h b/include/drm/i2c/tda998x.h
index 3cb25ccbe5e6..039e1d9af2e0 100644
--- a/include/drm/i2c/tda998x.h
+++ b/include/drm/i2c/tda998x.h
@@ -14,7 +14,7 @@ enum {
struct tda998x_audio_params {
u8 config;
u8 format;
- unsigned sample_width;
+ u8 bclk_ratio;
unsigned sample_rate;
struct hdmi_audio_infoframe cea;
u8 status[5];
diff --git a/include/sound/hdmi-codec.h b/include/sound/hdmi-codec.h
index 9483c55f871b..0fca69880dc3 100644
--- a/include/sound/hdmi-codec.h
+++ b/include/sound/hdmi-codec.h
@@ -42,6 +42,7 @@ struct hdmi_codec_daifmt {
unsigned int frame_clk_inv:1;
unsigned int bit_clk_master:1;
unsigned int frame_clk_master:1;
+ unsigned int bclk_ratio;
};
/*
diff --git a/sound/soc/codecs/hdmi-codec.c b/sound/soc/codecs/hdmi-codec.c
index d00734d31e04..d82f26854c90 100644
--- a/sound/soc/codecs/hdmi-codec.c
+++ b/sound/soc/codecs/hdmi-codec.c
@@ -524,6 +524,17 @@ static int hdmi_codec_hw_params(struct snd_pcm_substream *substream,
&hcp->daifmt[dai->id], &hp);
}
+static int hdmi_codec_set_bclk_ratio(struct snd_soc_dai *dai,
+ unsigned int ratio)
+{
+ struct hdmi_codec_priv *hcp = snd_soc_dai_get_drvdata(dai);
+
+ /* FIXME: some validation here would be good? */
+ hcp->daifmt[dai->id].bclk_ratio = ratio;
+
+ return 0;
+}
+
static int hdmi_codec_set_fmt(struct snd_soc_dai *dai,
unsigned int fmt)
{
@@ -593,7 +604,11 @@ static int hdmi_codec_set_fmt(struct snd_soc_dai *dai,
}
}
- hcp->daifmt[dai->id] = cf;
+ hcp->daifmt[dai->id].fmt = cf.fmt;
+ hcp->daifmt[dai->id].bit_clk_inv = cf.bit_clk_inv;
+ hcp->daifmt[dai->id].frame_clk_inv = cf.frame_clk_inv;
+ hcp->daifmt[dai->id].bit_clk_master = cf.bit_clk_master;
+ hcp->daifmt[dai->id].frame_clk_master = cf.frame_clk_master;
return ret;
}
@@ -615,6 +630,7 @@ 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_bclk_ratio = hdmi_codec_set_bclk_ratio,
.set_fmt = hdmi_codec_set_fmt,
.digital_mute = hdmi_codec_digital_mute,
};
--
2.17.1