[PATCH 0/2] Add SoundWire port constraints into SDCA stream

[PATCH 0/2] Add SoundWire port constraints into SDCA stream

[Charles Keepax]

SDCA adds constraints onto the DAI based on the DisCo properties for the
Input/Output Terminal. As the SoundWire port for a Terminal can be
selected it is possible for the SoundWire port to support fewer options
than the Terminal. These patches add the SoundWire port properties into
the constraints for the DAI startup to cover these situations.

Charles Keepax (2):
  ASoC: SDCA: Factor out helper for creating mask of Cluster channels
  ASoC: SDCA: Add port constraints into sdca_asoc_set_constraints()

 include/sound/sdca_asoc.h            |   4 +-
 sound/soc/sdca/sdca_asoc.c           | 176 ++++++++++++++++++++-------
 sound/soc/sdca/sdca_class_function.c |   3 +-
 3 files changed, 140 insertions(+), 43 deletions(-)

-- 
2.47.3

[PATCH 1/2] ASoC: SDCA: Factor out helper for creating mask of Cluster channels

[Charles Keepax]

Factor out the code that builds a mask of the allowed channels from the
Cluster information. This is slightly cleaner and prepares for
additional constraints to be added to sdca_asoc_set_constraints().

Signed-off-by: Charles Keepax <ckeepax@opensource.cirrus.com>
---
 sound/soc/sdca/sdca_asoc.c | 64 +++++++++++++++++++++++---------------
 1 file changed, 39 insertions(+), 25 deletions(-)

diff --git a/sound/soc/sdca/sdca_asoc.c b/sound/soc/sdca/sdca_asoc.c
index ccc579f878ff1..b801cb92cc3db 100644
--- a/sound/soc/sdca/sdca_asoc.c
+++ b/sound/soc/sdca/sdca_asoc.c
@@ -1434,6 +1434,37 @@ int sdca_asoc_populate_component(struct device *dev,
 }
 EXPORT_SYMBOL_NS(sdca_asoc_populate_component, "SND_SOC_SDCA");
 
+static int get_cluster_mask(struct device *dev, struct sdca_function_data *function,
+			    struct sdca_entity *entity, unsigned int *ch_mask)
+{
+	struct sdca_control_range *range;
+	struct sdca_control *control;
+	int i;
+
+	control = sdca_selector_find_control(dev, entity, SDCA_CTL_IT_CLUSTERINDEX);
+	if (!control)
+		return -EINVAL;
+
+	range = sdca_control_find_range(dev, entity, control, SDCA_CLUSTER_NCOLS, 0);
+	if (!range)
+		return -EINVAL;
+
+	*ch_mask = 0;
+
+	for (i = 0; i < range->rows; i++) {
+		int clusterid = sdca_range(range, SDCA_CLUSTER_CLUSTERID, i);
+		struct sdca_cluster *cluster;
+
+		cluster = sdca_id_find_cluster(dev, function, clusterid);
+		if (!cluster)
+			return -ENODEV;
+
+		*ch_mask |= (1 << (cluster->num_channels - 1));
+	}
+
+	return 0;
+}
+
 /**
  * sdca_asoc_set_constraints - constrain channels available on a DAI
  * @dev: Pointer to the device, used for error messages.
@@ -1457,38 +1488,21 @@ int sdca_asoc_set_constraints(struct device *dev, struct regmap *regmap,
 	};
 	struct sdca_entity *entity = &function->entities[dai->id];
 	struct snd_pcm_hw_constraint_list *constraint;
-	struct sdca_control_range *range;
-	struct sdca_control *control;
-	unsigned int channel_mask = 0;
-	int i, ret;
+	unsigned int cluster_ch_mask;
+	int ret;
 
 	static_assert(ARRAY_SIZE(channel_list) == SDCA_MAX_CHANNEL_COUNT);
-	static_assert(sizeof(channel_mask) * BITS_PER_BYTE >= SDCA_MAX_CHANNEL_COUNT);
+	static_assert(sizeof(cluster_ch_mask) * BITS_PER_BYTE >= SDCA_MAX_CHANNEL_COUNT);
 
 	if (entity->type != SDCA_ENTITY_TYPE_IT)
 		return 0;
 
-	control = sdca_selector_find_control(dev, entity, SDCA_CTL_IT_CLUSTERINDEX);
-	if (!control)
-		return -EINVAL;
-
-	range = sdca_control_find_range(dev, entity, control, SDCA_CLUSTER_NCOLS, 0);
-	if (!range)
-		return -EINVAL;
-
-	for (i = 0; i < range->rows; i++) {
-		int clusterid = sdca_range(range, SDCA_CLUSTER_CLUSTERID, i);
-		struct sdca_cluster *cluster;
-
-		cluster = sdca_id_find_cluster(dev, function, clusterid);
-		if (!cluster)
-			return -ENODEV;
-
-		channel_mask |= (1 << (cluster->num_channels - 1));
-	}
+	ret = get_cluster_mask(dev, function, entity, &cluster_ch_mask);
+	if (ret)
+		return ret;
 
 	dev_dbg(dev, "%s: set channel constraint mask: %#x\n",
-		entity->label, channel_mask);
+		entity->label, cluster_ch_mask);
 
 	constraint = kzalloc_obj(*constraint);
 	if (!constraint)
@@ -1496,7 +1510,7 @@ int sdca_asoc_set_constraints(struct device *dev, struct regmap *regmap,
 
 	constraint->count = ARRAY_SIZE(channel_list);
 	constraint->list = channel_list;
-	constraint->mask = channel_mask;
+	constraint->mask = cluster_ch_mask;
 
 	ret = snd_pcm_hw_constraint_list(substream->runtime, 0,
 					 SNDRV_PCM_HW_PARAM_CHANNELS,
-- 
2.47.3

[PATCH 2/2] ASoC: SDCA: Add port constraints into sdca_asoc_set_constraints()

[Charles Keepax]

Currently the SDCA code constrains the params based on the DisCo for
the SDCA Terminal used. However, it ignores the properties of the
SoundWire port, which in some cases may further constrain the allowed
params. Add additional constraints to apply these restrictions.

Some minor additional refactoring is required since port constraints
should be applied for both Input and Output Terminals, whereas
currently Cluster constraints are only handled for Input Terminals.

Signed-off-by: Charles Keepax <ckeepax@opensource.cirrus.com>
---
 include/sound/sdca_asoc.h            |   4 +-
 sound/soc/sdca/sdca_asoc.c           | 122 ++++++++++++++++++++++-----
 sound/soc/sdca/sdca_class_function.c |   3 +-
 3 files changed, 106 insertions(+), 23 deletions(-)

diff --git a/include/sound/sdca_asoc.h b/include/sound/sdca_asoc.h
index 599a72f335153..965ca5ce06a77 100644
--- a/include/sound/sdca_asoc.h
+++ b/include/sound/sdca_asoc.h
@@ -12,6 +12,7 @@
 
 struct device;
 struct regmap;
+struct sdw_slave;
 struct sdca_function_data;
 struct sdca_pde_delay;
 struct snd_ctl_elem_value;
@@ -89,7 +90,8 @@ int sdca_asoc_populate_rate_format(struct device *dev,
 				struct sdca_entity *entity,
 				struct snd_soc_pcm_stream *stream);
 
-int sdca_asoc_set_constraints(struct device *dev, struct regmap *regmap,
+int sdca_asoc_set_constraints(struct device *dev, struct sdw_slave *sdw,
+			      struct regmap *regmap,
 			      struct sdca_function_data *function,
 			      struct snd_pcm_substream *substream,
 			      struct snd_soc_dai *dai);
diff --git a/sound/soc/sdca/sdca_asoc.c b/sound/soc/sdca/sdca_asoc.c
index b801cb92cc3db..4a96ec5d11743 100644
--- a/sound/soc/sdca/sdca_asoc.c
+++ b/sound/soc/sdca/sdca_asoc.c
@@ -13,11 +13,13 @@
 #include <linux/delay.h>
 #include <linux/dev_printk.h>
 #include <linux/device.h>
+#include <linux/limits.h>
 #include <linux/minmax.h>
 #include <linux/module.h>
 #include <linux/overflow.h>
 #include <linux/pm_runtime.h>
 #include <linux/regmap.h>
+#include <linux/soundwire/sdw.h>
 #include <linux/soundwire/sdw_registers.h>
 #include <linux/string_helpers.h>
 #include <linux/types.h>
@@ -1465,9 +1467,56 @@ static int get_cluster_mask(struct device *dev, struct sdca_function_data *funct
 	return 0;
 }
 
+static int get_port_masks(struct sdw_slave *sdw, unsigned int port,
+			  struct snd_pcm_substream *substream,
+			  unsigned int *word_mask, unsigned int *ch_mask)
+{
+	struct sdw_dpn_prop *prop;
+	unsigned int nprop;
+	int i, j;
+
+	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
+		prop = sdw->prop.sink_dpn_prop;
+		nprop = hweight32(sdw->prop.sink_ports);
+	} else {
+		prop = sdw->prop.src_dpn_prop;
+		nprop = hweight32(sdw->prop.source_ports);
+	}
+
+	*word_mask = 0;
+	*ch_mask = 0;
+
+	for (i = 0; i < nprop; i++) {
+		if (prop[i].num != port)
+			continue;
+
+		if (prop->min_word && prop->max_word) {
+			*word_mask = GENMASK(prop->min_word - 1, prop->max_word - 1);
+		} else {
+			for (j = 0; j < prop->num_words; j++)
+				*word_mask |= (1 << (prop->words[j] - 1));
+		}
+
+		/* Only handle the number of channels for constraints. */
+		if (prop->num_ch_combinations) {
+			for (j = 0; j < prop->num_ch_combinations; j++)
+				*ch_mask |= (1 << (hweight32(prop->ch_combinations[j]) - 1));
+		} else if (prop->min_ch && prop->max_ch) {
+			*ch_mask = GENMASK(prop->min_ch - 1, prop->max_ch - 1);
+		} else {
+			*ch_mask = GENMASK(0, prop->num_channels - 1);
+		}
+
+		return 0;
+	}
+
+	return -ENODEV;
+}
+
 /**
  * sdca_asoc_set_constraints - constrain channels available on a DAI
  * @dev: Pointer to the device, used for error messages.
+ * @sdw: Pointer to the SoundWire peripheral device.
  * @regmap: Pointer to the Function register map.
  * @function: Pointer to the Function information.
  * @substream: Pointer to the PCM substream.
@@ -1477,51 +1526,82 @@ static int get_cluster_mask(struct device *dev, struct sdca_function_data *funct
  *
  * Return: Returns zero on success, and a negative error code on failure.
  */
-int sdca_asoc_set_constraints(struct device *dev, struct regmap *regmap,
+int sdca_asoc_set_constraints(struct device *dev, struct sdw_slave *sdw,
+			      struct regmap *regmap,
 			      struct sdca_function_data *function,
 			      struct snd_pcm_substream *substream,
 			      struct snd_soc_dai *dai)
 {
-	static const unsigned int channel_list[] = {
+	static const unsigned int constraint_list[] = {
 		 1,  2,  3,  4,  5,  6,  7,  8,  9, 10, 11, 12, 13, 14, 15, 16,
 		17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32,
 	};
 	struct sdca_entity *entity = &function->entities[dai->id];
-	struct snd_pcm_hw_constraint_list *constraint;
+	struct snd_pcm_hw_constraint_list *constraints;
+	unsigned int port_ch_mask, port_width_mask;
 	unsigned int cluster_ch_mask;
+	int port;
 	int ret;
 
-	static_assert(ARRAY_SIZE(channel_list) == SDCA_MAX_CHANNEL_COUNT);
+	static_assert(ARRAY_SIZE(constraint_list) == SDCA_MAX_CHANNEL_COUNT);
 	static_assert(sizeof(cluster_ch_mask) * BITS_PER_BYTE >= SDCA_MAX_CHANNEL_COUNT);
 
-	if (entity->type != SDCA_ENTITY_TYPE_IT)
-		return 0;
+	/* FIXME: Currently only a single unshared port is supported */
+	port = sdca_asoc_get_port(dev, regmap, function, dai);
+	if (port < 0)
+		return port;
 
-	ret = get_cluster_mask(dev, function, entity, &cluster_ch_mask);
-	if (ret)
+	ret = get_port_masks(sdw, port, substream, &port_width_mask, &port_ch_mask);
+	if (ret < 0) {
+		dev_err(dev, "%s: no properties for port %d\n", entity->label, port);
 		return ret;
+	}
 
-	dev_dbg(dev, "%s: set channel constraint mask: %#x\n",
-		entity->label, cluster_ch_mask);
+	/* FIXME: OTs should inherit cluster information */
+	if (entity->type == SDCA_ENTITY_TYPE_IT) {
+		ret = get_cluster_mask(dev, function, entity, &cluster_ch_mask);
+		if (ret)
+			return ret;
+	} else {
+		cluster_ch_mask = UINT_MAX;
+	}
 
-	constraint = kzalloc_obj(*constraint);
-	if (!constraint)
+	constraints = kzalloc_objs(*constraints, 2);
+	if (!constraints)
 		return -ENOMEM;
 
-	constraint->count = ARRAY_SIZE(channel_list);
-	constraint->list = channel_list;
-	constraint->mask = cluster_ch_mask;
+	constraints[0].count = ARRAY_SIZE(constraint_list);
+	constraints[0].list = constraint_list;
+	constraints[0].mask = cluster_ch_mask & port_ch_mask;
+
+	constraints[1].count = ARRAY_SIZE(constraint_list);
+	constraints[1].list = constraint_list;
+	constraints[1].mask = port_width_mask;
+
+	dev_dbg(dev, "%s: set constraint masks, channel: %#x, width: %#x\n",
+		entity->label, constraints[0].mask, constraints[1].mask);
 
 	ret = snd_pcm_hw_constraint_list(substream->runtime, 0,
 					 SNDRV_PCM_HW_PARAM_CHANNELS,
-					 constraint);
+					 &constraints[0]);
 	if (ret) {
-		dev_err(dev, "%s: failed to add constraint: %d\n", entity->label, ret);
-		kfree(constraint);
+		dev_err(dev, "%s: failed to add channel constraint: %d\n",
+			entity->label, ret);
+		kfree(constraints);
+		return ret;
+	}
+
+	ret = snd_pcm_hw_constraint_list(substream->runtime, 0,
+					 SNDRV_PCM_HW_PARAM_SAMPLE_BITS,
+					 &constraints[1]);
+	if (ret) {
+		dev_err(dev, "%s: failed to add word constraint: %d\n",
+			entity->label, ret);
+		kfree(constraints);
 		return ret;
 	}
 
-	snd_soc_dai_set_priv(dai, constraint);
+	snd_soc_dai_set_priv(dai, constraints);
 
 	return 0;
 }
@@ -1537,9 +1617,9 @@ EXPORT_SYMBOL_NS(sdca_asoc_set_constraints, "SND_SOC_SDCA");
 void sdca_asoc_free_constraints(struct snd_pcm_substream *substream,
 				struct snd_soc_dai *dai)
 {
-	struct snd_pcm_hw_constraint_list *constraint = snd_soc_dai_to_priv(dai);
+	struct snd_pcm_hw_constraint_list *constraints = snd_soc_dai_to_priv(dai);
 
-	kfree(constraint);
+	kfree(constraints);
 }
 EXPORT_SYMBOL_NS(sdca_asoc_free_constraints, "SND_SOC_SDCA");
 
diff --git a/sound/soc/sdca/sdca_class_function.c b/sound/soc/sdca/sdca_class_function.c
index 13b70f0f0dbf7..d7fba834601e6 100644
--- a/sound/soc/sdca/sdca_class_function.c
+++ b/sound/soc/sdca/sdca_class_function.c
@@ -121,8 +121,9 @@ static int class_function_startup(struct snd_pcm_substream *substream,
 				  struct snd_soc_dai *dai)
 {
 	struct class_function_drv *drv = snd_soc_component_get_drvdata(dai->component);
+	struct sdw_slave *sdw = dev_to_sdw_dev(drv->dev->parent);
 
-	return sdca_asoc_set_constraints(drv->dev, drv->regmap, drv->function,
+	return sdca_asoc_set_constraints(drv->dev, sdw, drv->regmap, drv->function,
 					 substream, dai);
 }
 
-- 
2.47.3

Re: [PATCH 2/2] ASoC: SDCA: Add port constraints into sdca_asoc_set_constraints()

[Charles Keepax]

On Thu, Nov 05, 2026 at 01:49:52PM +0000, Charles Keepax wrote:
> Currently the SDCA code constrains the params based on the DisCo for
> the SDCA Terminal used. However, it ignores the properties of the
> SoundWire port, which in some cases may further constrain the allowed
> params. Add additional constraints to apply these restrictions.
> 
> Some minor additional refactoring is required since port constraints
> should be applied for both Input and Output Terminals, whereas
> currently Cluster constraints are only handled for Input Terminals.
> 
> Signed-off-by: Charles Keepax <ckeepax@opensource.cirrus.com>
> ---

Some Sashiko comments to fix up on this one too.

Thanks,
Charles