ASoC: SOF: ipc4-topology: Add support for process modules with no input pins

A tone generator module can be a type of processing module with no input
pins. Adjust the logic to set the reference params for selecting output
format and the basecfg format based on the output format.

Signed-off-by: Ranjani Sridharan <ranjani.sridharan@linux.intel.com>
Reviewed-by: Péter Ujfalusi <peter.ujfalusi@linux.intel.com>
Reviewed-by: Bard Liao <yung-chuan.liao@linux.intel.com>
Signed-off-by: Peter Ujfalusi <peter.ujfalusi@linux.intel.com>
Link: https://patch.msgid.link/20260204081833.16630-7-peter.ujfalusi@linux.intel.com
Signed-off-by: Mark Brown <broonie@kernel.org>

Author: ranj063

sound/soc/sof/ipc4-topology.c

@@ -2753,12 +2753,14 @@ static int sof_ipc4_prepare_process_module(struct snd_sof_widget *swidget,
 	int input_fmt_index = 0;
 	int ret;
 
-	input_fmt_index = sof_ipc4_init_input_audio_fmt(sdev, swidget,
-							&process->base_config,
-							pipeline_params,
-							available_fmt);
-	if (input_fmt_index < 0)
-		return input_fmt_index;
+	if (available_fmt->num_input_formats) {
+		input_fmt_index = sof_ipc4_init_input_audio_fmt(sdev, swidget,
+								&process->base_config,
+								pipeline_params,
+								available_fmt);
+		if (input_fmt_index < 0)
+			return input_fmt_index;
+	}
 
 	/* Configure output audio format only if the module supports output */
 	if (available_fmt->num_output_formats) {
@@ -2767,12 +2769,28 @@ static int sof_ipc4_prepare_process_module(struct snd_sof_widget *swidget,
 		u32 out_ref_rate, out_ref_channels;
 		int out_ref_valid_bits, out_ref_type;
 
-		in_fmt = &available_fmt->input_pin_fmts[input_fmt_index].audio_fmt;
+		if (available_fmt->num_input_formats) {
+			in_fmt = &available_fmt->input_pin_fmts[input_fmt_index].audio_fmt;
 
-		out_ref_rate = in_fmt->sampling_frequency;
-		out_ref_channels = SOF_IPC4_AUDIO_FORMAT_CFG_CHANNELS_COUNT(in_fmt->fmt_cfg);
-		out_ref_valid_bits = SOF_IPC4_AUDIO_FORMAT_CFG_V_BIT_DEPTH(in_fmt->fmt_cfg);
-		out_ref_type = sof_ipc4_fmt_cfg_to_type(in_fmt->fmt_cfg);
+			out_ref_rate = in_fmt->sampling_frequency;
+			out_ref_channels =
+				SOF_IPC4_AUDIO_FORMAT_CFG_CHANNELS_COUNT(in_fmt->fmt_cfg);
+			out_ref_valid_bits =
+				SOF_IPC4_AUDIO_FORMAT_CFG_V_BIT_DEPTH(in_fmt->fmt_cfg);
+			out_ref_type = sof_ipc4_fmt_cfg_to_type(in_fmt->fmt_cfg);
+		} else {
+			/* for modules without input formats, use FE params as reference */
+			out_ref_rate = params_rate(fe_params);
+			out_ref_channels = params_channels(fe_params);
+			ret = sof_ipc4_get_sample_type(sdev, fe_params);
+			if (ret < 0)
+				return ret;
+			out_ref_type = (u32)ret;
+
+			out_ref_valid_bits = sof_ipc4_get_valid_bits(sdev, fe_params);
+			if (out_ref_valid_bits < 0)
+				return out_ref_valid_bits;
+		}
 
 		output_fmt_index = sof_ipc4_init_output_audio_fmt(sdev, swidget,
 								  &process->base_config,
@@ -2800,6 +2818,16 @@ static int sof_ipc4_prepare_process_module(struct snd_sof_widget *swidget,
 			if (ret)
 				return ret;
 		}
+
+		/* set base cfg to match the first output format if there are no input formats */
+		if (!available_fmt->num_input_formats) {
+			struct sof_ipc4_audio_format *out_fmt;
+
+			out_fmt = &available_fmt->output_pin_fmts[0].audio_fmt;
+
+			/* copy output format */
+			memcpy(&process->base_config.audio_fmt, out_fmt, sizeof(*out_fmt));
+		}
 	}
 
 	sof_ipc4_dbg_module_audio_format(sdev->dev, swidget, available_fmt,