[RFC PATCH 1/8] ASoC: SDCA: hw_params: program upstream Input Terminals for OT DAI

[Srinivas Kandagatla]

For a capture stream the DAI is the Output Terminal so
sdca_asoc_hw_params() only programs the OT itself: cluster, clock
and Usage.  The upstream Input Terminals that actually source the
audio never get their Usage, ClusterIndex or clock programmed, so
the power domain comes up but no samples are produced.

Walk the source graph from the OT and program every Input Terminal
reachable through it.

Assisted-by: Claude:claude-opus-4-7
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@xxxxxxxxxxxxxxxx>
---
 sound/soc/sdca/sdca_asoc.c | 51 ++++++++++++++++++++++++++++++++++++++
 1 file changed, 51 insertions(+)

diff --git a/sound/soc/sdca/sdca_asoc.c b/sound/soc/sdca/sdca_asoc.c
index b4dedba719dc..ac688cd62970 100644
--- a/sound/soc/sdca/sdca_asoc.c
+++ b/sound/soc/sdca/sdca_asoc.c
@@ -1726,6 +1726,51 @@ static int set_usage(struct device *dev, struct regmap *regmap,
 	return -EINVAL;
 }
 
+/*
+ * For a capture stream the ASoC DAI is the Output Terminal, so hw_params
+ * only programs the OT itself.  The upstream Input Terminal(s) that
+ * actually source the audio (e.g. a mic input behind a power-domain entity)
+ * never get their Usage / ClusterIndex / clock programmed and stay inactive,
+ * so the power domain comes up but no samples are produced.  Walk the source
+ * graph from the OT and program every Input Terminal we reach.
+ */
+static int set_input_terminal_sources(struct device *dev, struct regmap *regmap,
+				      struct sdca_function_data *function,
+				      struct sdca_entity *entity,
+				      int channels, int rate, int width)
+{
+	int i, ret;
+
+	for (i = 0; i < entity->num_sources; i++) {
+		struct sdca_entity *src = entity->sources[i];
+
+		if (src->type == SDCA_ENTITY_TYPE_IT) {
+			ret = set_cluster(dev, regmap, function, src, channels);
+			if (ret)
+				return ret;
+
+			if (src->iot.clock) {
+				ret = set_clock(dev, regmap, function,
+						src->iot.clock, rate);
+				if (ret)
+					return ret;
+			}
+
+			ret = set_usage(dev, regmap, function, src,
+					SDCA_CTL_IT_USAGE, rate, width);
+			if (ret)
+				return ret;
+		}
+
+		ret = set_input_terminal_sources(dev, regmap, function, src,
+						 channels, rate, width);
+		if (ret)
+			return ret;
+	}
+
+	return 0;
+}
+
 /**
  * sdca_asoc_hw_params - set SDCA channels, sample rate and bit depth
  * @dev: Pointer to the device, used for error messages.
@@ -1762,6 +1807,12 @@ int sdca_asoc_hw_params(struct device *dev, struct regmap *regmap,
 		break;
 	case SDCA_ENTITY_TYPE_OT:
 		usage_sel = SDCA_CTL_OT_USAGE;
+
+		/* Program the upstream Input Terminal(s) that source this OT. */
+		ret = set_input_terminal_sources(dev, regmap, function, entity,
+						 channels, rate, width);
+		if (ret)
+			return ret;
 		break;
 	default:
 		dev_err(dev, "%s: hw_params on non-terminal entity\n", entity->label);
-- 
2.53.0