ASoC: SOF: ipc4-topology: Allow the use of multiple formats for src output

The SRC module can only change the rate, it keeps the format and channels
intact, but this does not mean the the num_output_formats must be 0:
The SRC module can support different formats/channels, we just need to
check if the output format lists the correct combination of out rate and
the input format/channels.

Change the logic to prioritize the sink_rate of the module as target rate,
then the rate of the FE in case of capture or in case of playback check the
single rate specified in the output formats.

Signed-off-by: Peter Ujfalusi <peter.ujfalusi@linux.intel.com>

Author: ujfalusi

sound/soc/sof/ipc4-topology.c

@@ -2629,16 +2629,6 @@ static int sof_ipc4_prepare_src_module(struct snd_sof_widget *swidget,
 	if (input_fmt_index < 0)
 		return input_fmt_index;
 
-	/*
-	 * For playback, the SRC sink rate will be configured based on the requested output
-	 * format, which is restricted to only deal with DAI's with a single format for now.
-	 */
-	if (dir == SNDRV_PCM_STREAM_PLAYBACK && available_fmt->num_output_formats > 1) {
-		dev_err(sdev->dev, "Invalid number of output formats: %d for SRC %s\n",
-			available_fmt->num_output_formats, swidget->widget->name);
-		return -EINVAL;
-	}
-
 	/*
 	 * SRC does not perform format conversion, so the output channels and valid bit depth must
 	 * be the same as that of the input.
@@ -2648,12 +2638,36 @@ static int sof_ipc4_prepare_src_module(struct snd_sof_widget *swidget,
 	out_ref_valid_bits = SOF_IPC4_AUDIO_FORMAT_CFG_V_BIT_DEPTH(in_audio_fmt->fmt_cfg);
 	out_ref_type = sof_ipc4_fmt_cfg_to_type(in_audio_fmt->fmt_cfg);
 
-	/*
-	 * For capture, the SRC module should convert the rate to match the rate requested by the
-	 * PCM hw_params. Set the reference params based on the fe_params unconditionally as it
-	 * will be ignored for playback anyway.
-	 */
-	out_ref_rate = params_rate(fe_params);
+	if (src->data.sink_rate) {
+		/* Use the sink rate as reference */
+		out_ref_rate = src->data.sink_rate;
+	} else if (dir == SNDRV_PCM_STREAM_CAPTURE) {
+		/*
+		 * Use the fe rate as reference for capture if the sink rate is
+		 * not set since we need to convert to the rate the PCM device
+		 * is openned with
+		 */
+		out_ref_rate = params_rate(fe_params);
+	} else {
+		/*
+		 * Otherwise try to guess what the rate should be:
+		 * The output formats must have single rate specified if the
+		 * sink rate is not set for an SRC in playback path.
+		 */
+		int i;
+
+		out_audio_fmt = &available_fmt->output_pin_fmts[0].audio_fmt;
+		out_ref_rate = out_audio_fmt->sampling_frequency;
+		for (i = 1; i < available_fmt->num_output_formats; i++) {
+			out_audio_fmt = &available_fmt->output_pin_fmts[i].audio_fmt;
+			if (out_ref_rate != out_audio_fmt->sampling_frequency) {
+				dev_err(sdev->dev,
+					"Cannot determine the output rate for SRC: %s\n",
+					swidget->widget->name);
+				return -EINVAL;
+			}
+		}
+	}
 
 	output_fmt_index = sof_ipc4_init_output_audio_fmt(sdev, swidget,
 							  &src->data.base_config,