[PATCH 0/2] ASoC: cs35l56/57/62/63: Use the correct SoundWire DP for feedback

[PATCH 0/2] ASoC: cs35l56/57/62/63: Use the correct SoundWire DP for feedback

[Richard Fitzgerald]

The amp feedback path (AEC) was incorrectly using SoundWire DP3.
The firmware outputs SDCA OT25 feedback on DP4. DP3 is reserved for
SDCA companion amp.

This series adds a DAI for OT25 and switches the sdw machine driver
to use the new DAI for the feedback path.

Richard Fitzgerald (2):
  ASoC: cs35l56: Add DAI for SDCA OT25 stream
  ASoC: sdw_utils: Switch CS35L56/57/62/63 to use OT25 DAI

 include/sound/cs35l56.h             |  1 +
 sound/soc/codecs/cs35l56-sdw.c      |  9 +++--
 sound/soc/codecs/cs35l56.c          | 54 +++++++++++++++++++++++++++++
 sound/soc/sdw_utils/soc_sdw_utils.c |  8 ++---
 4 files changed, 66 insertions(+), 6 deletions(-)

-- 
2.47.3

[PATCH 1/2] ASoC: cs35l56: Add DAI for SDCA OT25 stream

[Richard Fitzgerald]

Add a DAI for the SDCA OT25 stream on SoundWire DP4.

The SDCA-defined OT25 stream is an amp reference feedback, typically used
for AEC. The firmware outputs this on DP4. The firmware owns all control
registers for this stream so there are no mixer controls or any other
configuration options.

Signed-off-by: Richard Fitzgerald <rf@opensource.cirrus.com>
---
 include/sound/cs35l56.h        |  1 +
 sound/soc/codecs/cs35l56-sdw.c |  9 ++++--
 sound/soc/codecs/cs35l56.c     | 54 ++++++++++++++++++++++++++++++++++
 3 files changed, 62 insertions(+), 2 deletions(-)

diff --git a/include/sound/cs35l56.h b/include/sound/cs35l56.h
index 45a5df574aa6d..747e10ec1a274 100644
--- a/include/sound/cs35l56.h
+++ b/include/sound/cs35l56.h
@@ -312,6 +312,7 @@ struct snd_ctl_elem_value;
 
 #define CS35L56_SDW1_PLAYBACK_PORT			1
 #define CS35L56_SDW1_CAPTURE_PORT			3
+#define CS35L56_OT25_CAPTURE_PORT			4
 
 #define CS35L56_NUM_BULK_SUPPLIES			3
 #define CS35L56_NUM_DSP_REGIONS				5
diff --git a/sound/soc/codecs/cs35l56-sdw.c b/sound/soc/codecs/cs35l56-sdw.c
index 98bb4542b9143..e10f04d677f4d 100644
--- a/sound/soc/codecs/cs35l56-sdw.c
+++ b/sound/soc/codecs/cs35l56-sdw.c
@@ -265,11 +265,11 @@ static int cs35l56_sdw_read_prop(struct sdw_slave *peripheral)
 	if (ret == 0)
 		prop->clk_stop_mode1 = !!clock_stop_1;
 
-	ports = devm_kcalloc(cs35l56->base.dev, 2, sizeof(*ports), GFP_KERNEL);
+	ports = devm_kcalloc(cs35l56->base.dev, 3, sizeof(*ports), GFP_KERNEL);
 	if (!ports)
 		return -ENOMEM;
 
-	prop->source_ports = BIT(CS35L56_SDW1_CAPTURE_PORT);
+	prop->source_ports = BIT(CS35L56_SDW1_CAPTURE_PORT) | BIT(CS35L56_OT25_CAPTURE_PORT);
 	prop->sink_ports = BIT(CS35L56_SDW1_PLAYBACK_PORT);
 	prop->paging_support = true;
 	prop->use_domain_irq = true;
@@ -286,6 +286,11 @@ static int cs35l56_sdw_read_prop(struct sdw_slave *peripheral)
 	ports[1].num = CS35L56_SDW1_CAPTURE_PORT;
 	ports[1].type = SDW_DPN_FULL;
 	ports[1].ch_prep_timeout = 10;
+
+	/* DP4 - capture */
+	ports[2].num = CS35L56_OT25_CAPTURE_PORT;
+	ports[2].type = SDW_DPN_FULL;
+	ports[2].ch_prep_timeout = 10;
 	prop->src_dpn_prop = &ports[1];
 
 	dev_dbg(&peripheral->dev, "clock stop mode 1 supported: %s\n",
diff --git a/sound/soc/codecs/cs35l56.c b/sound/soc/codecs/cs35l56.c
index 74129fcc79dce..dd264c310e1eb 100644
--- a/sound/soc/codecs/cs35l56.c
+++ b/sound/soc/codecs/cs35l56.c
@@ -32,6 +32,7 @@
 #include <sound/cs-amp-lib.h>
 #include <sound/pcm.h>
 #include <sound/pcm_params.h>
+#include <sound/sdw.h>
 #include <sound/soc.h>
 #include <sound/soc-dapm.h>
 #include <sound/tlv.h>
@@ -324,6 +325,7 @@ static const struct snd_soc_dapm_widget cs35l56_dapm_widgets[] = {
 	SND_SOC_DAPM_SIGGEN("VDDBMON ADC"),
 	SND_SOC_DAPM_SIGGEN("VBSTMON ADC"),
 	SND_SOC_DAPM_SIGGEN("TEMPMON ADC"),
+	SND_SOC_DAPM_SIGGEN("OT25 Reference"),
 
 	SND_SOC_DAPM_INPUT("Calibrate"),
 };
@@ -388,6 +390,8 @@ static const struct snd_soc_dapm_route cs35l56_audio_map[] = {
 	{ "SDW1 Capture", NULL, "SDW1 TX2 Source" },
 	{ "SDW1 Capture", NULL, "SDW1 TX3 Source" },
 	{ "SDW1 Capture", NULL, "SDW1 TX4 Source" },
+
+	{ "OT25", NULL, "OT25 Reference" },
 };
 
 static int cs35l56_dsp_event(struct snd_soc_dapm_widget *w,
@@ -722,6 +726,37 @@ static int cs35l56_sdw_dai_set_stream(struct snd_soc_dai *dai,
 	return 0;
 }
 
+static int cs35l56_ot25_dai_hw_params(struct snd_pcm_substream *substream,
+				      struct snd_pcm_hw_params *params,
+				      struct snd_soc_dai *dai)
+{
+	struct cs35l56_private *cs35l56 = snd_soc_component_get_drvdata(dai->component);
+	struct sdw_stream_runtime *sdw_stream = snd_soc_dai_get_dma_data(dai, substream);
+	struct sdw_stream_config sconfig = { };
+	struct sdw_port_config pconfig = { };
+	int ret;
+
+	dev_dbg(cs35l56->base.dev, "%s: rate %d\n", __func__, params_rate(params));
+
+	if (!cs35l56->base.init_done)
+		return -ENODEV;
+
+	if (!sdw_stream)
+		return -EINVAL;
+
+	snd_sdw_params_to_config(substream, params, &sconfig, &pconfig);
+	pconfig.num = CS35L56_OT25_CAPTURE_PORT;
+
+	ret = sdw_stream_add_slave(cs35l56->sdw_peripheral, &sconfig, &pconfig,
+				   1, sdw_stream);
+	if (ret) {
+		dev_err(dai->dev, "Failed to add OT25 stream: %d\n", ret);
+		return ret;
+	}
+
+	return 0;
+}
+
 static const struct snd_soc_dai_ops cs35l56_sdw_dai_ops = {
 	.set_tdm_slot = cs35l56_sdw_dai_set_tdm_slot,
 	.shutdown = cs35l56_sdw_dai_shutdown,
@@ -730,6 +765,13 @@ static const struct snd_soc_dai_ops cs35l56_sdw_dai_ops = {
 	.set_stream = cs35l56_sdw_dai_set_stream,
 };
 
+static const struct snd_soc_dai_ops cs35l56_ot25_dai_ops = {
+	.shutdown = cs35l56_sdw_dai_shutdown,
+	.hw_params = cs35l56_ot25_dai_hw_params,
+	.hw_free = cs35l56_sdw_dai_hw_free,
+	.set_stream = cs35l56_sdw_dai_set_stream,
+};
+
 static struct snd_soc_dai_driver cs35l56_dai[] = {
 	{
 		.name = "cs35l56-asp1",
@@ -778,6 +820,18 @@ static struct snd_soc_dai_driver cs35l56_dai[] = {
 		.symmetric_rate = 1,
 		.ops = &cs35l56_sdw_dai_ops,
 	},
+	{
+		.name = "cs35l56-ot25",
+		.id = 3,
+		.capture = {
+			.stream_name = "OT25",
+			.channels_min = 1,
+			.channels_max = 2,
+			.rates = CS35L56_RATES,
+			.formats = CS35L56_TX_FORMATS,
+		},
+		.ops = &cs35l56_ot25_dai_ops,
+	},
 };
 
 static int cs35l56_write_cal(struct cs35l56_private *cs35l56)
-- 
2.47.3

[PATCH 2/2] ASoC: sdw_utils: Switch CS35L56/57/62/63 to use OT25 DAI

[Richard Fitzgerald]

Change the CS35L56/57/62/63 entries in codec_info_list[] to use
the OT25 DAI for amp feedback.

The AMP feedback was incorrectly using a DAI connected to DP3,
but that is reserved for SDCA companion amp. The correct amp
output is DP4, which is the SDCA OT25 feedback output.

Fixes: 898cd43bde307 ("ASoC: intel: sof_sdw: Add support for CS35L63 into machine driver")
Signed-off-by: Richard Fitzgerald <rf@opensource.cirrus.com>
---
 sound/soc/sdw_utils/soc_sdw_utils.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/sound/soc/sdw_utils/soc_sdw_utils.c b/sound/soc/sdw_utils/soc_sdw_utils.c
index 14aee10b40ba7..7a19de75f32b5 100644
--- a/sound/soc/sdw_utils/soc_sdw_utils.c
+++ b/sound/soc/sdw_utils/soc_sdw_utils.c
@@ -1035,7 +1035,7 @@ struct asoc_sdw_codec_info codec_info_list[] = {
 			},
 			{
 				.direction = {false, true},
-				.dai_name = "cs35l56-sdw1c",
+				.dai_name = "cs35l56-ot25",
 				.dai_type = SOC_SDW_DAI_TYPE_AMP,
 				.dailink = {SOC_SDW_UNUSED_DAI_ID, SOC_SDW_AMP_IN_DAI_ID},
 			},
@@ -1063,7 +1063,7 @@ struct asoc_sdw_codec_info codec_info_list[] = {
 			},
 			{
 				.direction = {false, true},
-				.dai_name = "cs35l56-sdw1c",
+				.dai_name = "cs35l56-ot25",
 				.dai_type = SOC_SDW_DAI_TYPE_AMP,
 				.dailink = {SOC_SDW_UNUSED_DAI_ID, SOC_SDW_AMP_IN_DAI_ID},
 			},
@@ -1091,7 +1091,7 @@ struct asoc_sdw_codec_info codec_info_list[] = {
 			},
 			{
 				.direction = {false, true},
-				.dai_name = "cs35l56-sdw1c",
+				.dai_name = "cs35l56-ot25",
 				.dai_type = SOC_SDW_DAI_TYPE_AMP,
 				.dailink = {SOC_SDW_UNUSED_DAI_ID, SOC_SDW_AMP_IN_DAI_ID},
 			},
@@ -1119,7 +1119,7 @@ struct asoc_sdw_codec_info codec_info_list[] = {
 			},
 			{
 				.direction = {false, true},
-				.dai_name = "cs35l56-sdw1c",
+				.dai_name = "cs35l56-ot25",
 				.dai_type = SOC_SDW_DAI_TYPE_AMP,
 				.dailink = {SOC_SDW_UNUSED_DAI_ID, SOC_SDW_AMP_IN_DAI_ID},
 			},
-- 
2.47.3

Re: [PATCH 0/2] ASoC: cs35l56/57/62/63: Use the correct SoundWire DP for feedback

[Pierre-Louis Bossart]

On 10/5/26 17:52, Richard Fitzgerald wrote:
> The amp feedback path (AEC) was incorrectly using SoundWire DP3.
> The firmware outputs SDCA OT25 feedback on DP4. DP3 is reserved for
> SDCA companion amp.
> 
> This series adds a DAI for OT25 and switches the sdw machine driver
> to use the new DAI for the feedback path.

Is there any merit in keeping this DP3 exposed as a capture DAI, if
indeed it's intended to be a side connection for a companion chip?

I never quite understood how those companion chips would be managed,
IIRC we don't have support for device-to-device transfers, do we? the
entire stream definition and bandwidth calculation are based on a host
port as source or target.

> Richard Fitzgerald (2):
>   ASoC: cs35l56: Add DAI for SDCA OT25 stream
>   ASoC: sdw_utils: Switch CS35L56/57/62/63 to use OT25 DAI
> 
>  include/sound/cs35l56.h             |  1 +
>  sound/soc/codecs/cs35l56-sdw.c      |  9 +++--
>  sound/soc/codecs/cs35l56.c          | 54 +++++++++++++++++++++++++++++
>  sound/soc/sdw_utils/soc_sdw_utils.c |  8 ++---
>  4 files changed, 66 insertions(+), 6 deletions(-)
> 

Re: [PATCH 0/2] ASoC: cs35l56/57/62/63: Use the correct SoundWire DP for feedback

[Richard Fitzgerald]

On 05/10/2026 7:33 pm, Pierre-Louis Bossart wrote:
> On 10/5/26 17:52, Richard Fitzgerald wrote:
>> The amp feedback path (AEC) was incorrectly using SoundWire DP3.
>> The firmware outputs SDCA OT25 feedback on DP4. DP3 is reserved for
>> SDCA companion amp.
>>
>> This series adds a DAI for OT25 and switches the sdw machine driver
>> to use the new DAI for the feedback path.
> 
> Is there any merit in keeping this DP3 exposed as a capture DAI, if
> indeed it's intended to be a side connection for a companion chip?

I kept this patch to a minimum because it is a Fixes: so it must apply
to older kernels.

However, you are correct. DP3 isn't used now. Not even on companion amp. 
DP3 is a companion output from the amp (SDCA OT127), but Cirrus
companion amp goes codec->amp so uses DP1 on the amp.

When the driver was being written the SDCA spec and firmware behavior
were not fully defined so pairing of the symmetrical DP1+DP3
(for play+capture) was carried forward from previous amps. But SDCA
doesn't provide any sort of UCM capability - widgets on the device have
defined, fixed functionality that has to be preconfigured by the
firmware to match what SDCA needs. Ultimately DP4 was more suitable for
OT25. DP4 also works for loopback testing.

Removing DP3 would also solve some other problems that the driver and
firmware are both "owning" the registers. We originally attempted to
sync this up, then gave up on that complexity and overwrite the register
settings the firmware made.

Re: [PATCH 0/2] ASoC: cs35l56/57/62/63: Use the correct SoundWire DP for feedback

[Pierre-Louis Bossart]

On 10/6/26 11:53, Richard Fitzgerald wrote:
> On 05/10/2026 7:33 pm, Pierre-Louis Bossart wrote:
>> On 10/5/26 17:52, Richard Fitzgerald wrote:
>>> The amp feedback path (AEC) was incorrectly using SoundWire DP3.
>>> The firmware outputs SDCA OT25 feedback on DP4. DP3 is reserved for
>>> SDCA companion amp.
>>>
>>> This series adds a DAI for OT25 and switches the sdw machine driver
>>> to use the new DAI for the feedback path.
>>
>> Is there any merit in keeping this DP3 exposed as a capture DAI, if
>> indeed it's intended to be a side connection for a companion chip?
> 
> I kept this patch to a minimum because it is a Fixes: so it must apply
> to older kernels.
> 
> However, you are correct. DP3 isn't used now. Not even on companion amp.
> DP3 is a companion output from the amp (SDCA OT127), but Cirrus
> companion amp goes codec->amp so uses DP1 on the amp.
> 
> When the driver was being written the SDCA spec and firmware behavior
> were not fully defined so pairing of the symmetrical DP1+DP3
> (for play+capture) was carried forward from previous amps. But SDCA
> doesn't provide any sort of UCM capability - widgets on the device have
> defined, fixed functionality that has to be preconfigured by the
> firmware to match what SDCA needs. Ultimately DP4 was more suitable for
> OT25. DP4 also works for loopback testing.
> 
> Removing DP3 would also solve some other problems that the driver and
> firmware are both "owning" the registers. We originally attempted to
> sync this up, then gave up on that complexity and overwrite the register
> settings the firmware made.

thanks for the explanations, I guess we'll see a follow-up patch to
remove DP3 altogether at some point.

Re: [PATCH 0/2] ASoC: cs35l56/57/62/63: Use the correct SoundWire DP for feedback

[Pierre-Louis Bossart]

On 10/5/26 17:52, Richard Fitzgerald wrote:
> The amp feedback path (AEC) was incorrectly using SoundWire DP3.
> The firmware outputs SDCA OT25 feedback on DP4. DP3 is reserved for
> SDCA companion amp.
> 
> This series adds a DAI for OT25 and switches the sdw machine driver
> to use the new DAI for the feedback path.
> 
> Richard Fitzgerald (2):
>   ASoC: cs35l56: Add DAI for SDCA OT25 stream
>   ASoC: sdw_utils: Switch CS35L56/57/62/63 to use OT25 DAI

Reviewed-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.dev>

> 
>  include/sound/cs35l56.h             |  1 +
>  sound/soc/codecs/cs35l56-sdw.c      |  9 +++--
>  sound/soc/codecs/cs35l56.c          | 54 +++++++++++++++++++++++++++++
>  sound/soc/sdw_utils/soc_sdw_utils.c |  8 ++---
>  4 files changed, 66 insertions(+), 6 deletions(-)
>