ASoC: hdmi-codec: Add a prepare hook

The IEC958 status bit is usually set by the userspace after hw_params
has been called, so in order to use whatever is set by the userspace, we
need to implement the prepare hook. Let's add it to the hdmi_codec_ops,
and mandate that either prepare or hw_params is implemented.

Signed-off-by: Maxime Ripard <[e-mail]>
Acked-by: Mark Brown <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]

include/sound/hdmi-codec.h

···
 
 	/*
 	 * Configures HDMI-encoder for audio stream.
-	 * Mandatory
+	 * Having either prepare or hw_params is mandatory.
 	 */
 	int (*hw_params)(struct device *dev, void *data,
 			 struct hdmi_codec_daifmt *fmt,
 			 struct hdmi_codec_params *hparms);
+
+	/*
+	 * Configures HDMI-encoder for audio stream. Can be called
+	 * multiple times for each setup.
+	 *
+	 * Having either prepare or hw_params is mandatory.
+	 */
+	int (*prepare)(struct device *dev, void *data,
+		       struct hdmi_codec_daifmt *fmt,
+		       struct hdmi_codec_params *hparms);
 
 	/*
 	 * Shuts down the audio stream.

sound/soc/codecs/hdmi-codec.c

···
 	mutex_unlock(&hcp->lock);
 }
 
+static int hdmi_codec_fill_codec_params(struct snd_soc_dai *dai,
+					unsigned int sample_width,
+					unsigned int sample_rate,
+					unsigned int channels,
+					struct hdmi_codec_params *hp)
+{
+	struct hdmi_codec_priv *hcp = snd_soc_dai_get_drvdata(dai);
+	int idx;
+
+	/* Select a channel allocation that matches with ELD and pcm channels */
+	idx = hdmi_codec_get_ch_alloc_table_idx(hcp, channels);
+	if (idx < 0) {
+		dev_err(dai->dev, "Not able to map channels to speakers (%d)\n",
+			idx);
+		hcp->chmap_idx = HDMI_CODEC_CHMAP_IDX_UNKNOWN;
+		return idx;
+	}
+
+	memset(hp, 0, sizeof(*hp));
+
+	hdmi_audio_infoframe_init(&hp->cea);
+	hp->cea.channels = channels;
+	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->cea.channel_allocation = hdmi_codec_channel_alloc[idx].ca_id;
+
+	hp->sample_width = sample_width;
+	hp->sample_rate = sample_rate;
+	hp->channels = channels;
+
+	hcp->chmap_idx = hdmi_codec_channel_alloc[idx].ca_id;
+
+	return 0;
+}
+
 static int hdmi_codec_hw_params(struct snd_pcm_substream *substream,
 				struct snd_pcm_hw_params *params,
 				struct snd_soc_dai *dai)
···
 			.dig_subframe = { 0 },
 		}
 	};
-	int ret, idx;
+	int ret;
+
+	if (!hcp->hcd.ops->hw_params)
+		return 0;
 
 	dev_dbg(dai->dev, "%s() width %d rate %d channels %d\n", __func__,
 		params_width(params), params_rate(params),
 		params_channels(params));
+
+	ret = hdmi_codec_fill_codec_params(dai,
+					   params_width(params),
+					   params_rate(params),
+					   params_channels(params),
+					   &hp);
+	if (ret < 0)
+		return ret;
 
 	memcpy(hp.iec.status, hcp->iec_status, sizeof(hp.iec.status));
 	ret = snd_pcm_fill_iec958_consumer_hw_params(params, hp.iec.status,
···
 		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;
-
-	/* Select a channel allocation that matches with ELD and pcm channels */
-	idx = hdmi_codec_get_ch_alloc_table_idx(hcp, hp.cea.channels);
-	if (idx < 0) {
-		dev_err(dai->dev, "Not able to map channels to speakers (%d)\n",
-			idx);
-		hcp->chmap_idx = HDMI_CODEC_CHMAP_IDX_UNKNOWN;
-		return idx;
-	}
-	hp.cea.channel_allocation = hdmi_codec_channel_alloc[idx].ca_id;
-	hcp->chmap_idx = hdmi_codec_channel_alloc[idx].ca_id;
-
-	hp.sample_width = params_width(params);
-	hp.sample_rate = params_rate(params);
-	hp.channels = params_channels(params);
-
 	cf->bit_fmt = params_format(params);
 	return hcp->hcd.ops->hw_params(dai->dev->parent, hcp->hcd.data,
 				       cf, &hp);
+}
+
+static int hdmi_codec_prepare(struct snd_pcm_substream *substream,
+			      struct snd_soc_dai *dai)
+{
+	struct hdmi_codec_priv *hcp = snd_soc_dai_get_drvdata(dai);
+	struct hdmi_codec_daifmt *cf = dai->playback_dma_data;
+	struct snd_pcm_runtime *runtime = substream->runtime;
+	unsigned int channels = runtime->channels;
+	unsigned int width = snd_pcm_format_width(runtime->format);
+	unsigned int rate = runtime->rate;
+	struct hdmi_codec_params hp;
+	int ret;
+
+	if (!hcp->hcd.ops->prepare)
+		return 0;
+
+	dev_dbg(dai->dev, "%s() width %d rate %d channels %d\n", __func__,
+		width, rate, channels);
+
+	ret = hdmi_codec_fill_codec_params(dai, width, rate, channels, &hp);
+	if (ret < 0)
+		return ret;
+
+	memcpy(hp.iec.status, hcp->iec_status, sizeof(hp.iec.status));
+	ret = snd_pcm_fill_iec958_consumer(runtime, hp.iec.status,
+					   sizeof(hp.iec.status));
+	if (ret < 0) {
+		dev_err(dai->dev, "Creating IEC958 channel status failed %d\n",
+			ret);
+		return ret;
+	}
+
+	cf->bit_fmt = runtime->format;
+	return hcp->hcd.ops->prepare(dai->dev->parent, hcp->hcd.data,
+				     cf, &hp);
 }
 
 static int hdmi_codec_i2s_set_fmt(struct snd_soc_dai *dai,
···
 	.startup	= hdmi_codec_startup,
 	.shutdown	= hdmi_codec_shutdown,
 	.hw_params	= hdmi_codec_hw_params,
+	.prepare	= hdmi_codec_prepare,
 	.set_fmt	= hdmi_codec_i2s_set_fmt,
 	.mute_stream	= hdmi_codec_mute,
 };
···
 	}
 
 	dai_count = hcd->i2s + hcd->spdif;
-	if (dai_count < 1 || !hcd->ops || !hcd->ops->hw_params ||
+	if (dai_count < 1 || !hcd->ops ||
+	    (!hcd->ops->hw_params && !hcd->ops->prepare) ||
 	    !hcd->ops->audio_shutdown) {
 		dev_err(dev, "%s: Invalid parameters\n", __func__);
 		return -EINVAL;