[PATCH 0/3] ASoC: wcd938x: enable t14s audio headset

[PATCH 0/3] ASoC: wcd938x: enable t14s audio headset

[srinivas.kandagatla]

From: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>

On Lenovo ThinkPad T14s, the headset is connected via a HiFi Switch to
support CTIA and OMTP headsets. This switch is used to minimise pop and
click during headset type switching.

This patchset adds required bindings and changes to codec and dts to   
tnable the regulator required to power this switch along with wiring up
gpio that control the headset switching.

Without this patchset, there will be lots of noise on headset and mic
will not we functional.
   
Srinivas Kandagatla (3):
  ASoC: dt-bindings: wcd93xx: add bindings for audio switch controlling
    hp
  ASoC: codecs: wcd938x: add support power on hp audio switch
  arm64: dts: qcom: x1e78100-t14s: Enable audio headset support

 .../bindings/sound/qcom,wcd93xx-common.yaml    |  4 ++++
 .../dts/qcom/x1e78100-lenovo-thinkpad-t14s.dts | 18 +++++++++++++++++-
 sound/soc/codecs/wcd938x.c                     |  7 +++++++
 3 files changed, 28 insertions(+), 1 deletion(-)

-- 
2.39.5

[PATCH 1/3] ASoC: dt-bindings: wcd93xx: add bindings for audio switch controlling hp

[srinivas.kandagatla]

From: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>

On some platforms to minimise pop and click during switching between
CTIA and OMTP headset an additional HiFi Switch is used. Most common
case is that this switch is switched on by default, but on some
platforms this needs a regulator enable.

This patch adds required bindings to add such regulator.

Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
---
 .../devicetree/bindings/sound/qcom,wcd93xx-common.yaml        | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/Documentation/devicetree/bindings/sound/qcom,wcd93xx-common.yaml b/Documentation/devicetree/bindings/sound/qcom,wcd93xx-common.yaml
index f78ba148ad25..fa00570caf24 100644
--- a/Documentation/devicetree/bindings/sound/qcom,wcd93xx-common.yaml
+++ b/Documentation/devicetree/bindings/sound/qcom,wcd93xx-common.yaml
@@ -26,6 +26,10 @@ properties:
   vdd-mic-bias-supply:
     description: A reference to the 3.8V mic bias supply
 
+  vdd-hp-switch-supply:
+    description: A reference to the audio switch supply
+      for switching CTIA/OMTP Headset
+
   qcom,tx-device:
     $ref: /schemas/types.yaml#/definitions/phandle-array
     description: A reference to Soundwire tx device phandle
-- 
2.39.5

Re: [PATCH 1/3] ASoC: dt-bindings: wcd93xx: add bindings for audio switch controlling hp

[Dmitry Baryshkov]

On Wed, Mar 19, 2025 at 09:16:35AM +0000, srinivas.kandagatla@linaro.org wrote:
> From: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
> 
> On some platforms to minimise pop and click during switching between
> CTIA and OMTP headset an additional HiFi Switch is used. Most common
> case is that this switch is switched on by default, but on some
> platforms this needs a regulator enable.

Is this regulator supplying the codec or some external component? In the
latter case it's likely that it should not be a part of WCD bindings.

> This patch adds required bindings to add such regulator.
> 
> Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
> ---
>  .../devicetree/bindings/sound/qcom,wcd93xx-common.yaml        | 4 ++++
>  1 file changed, 4 insertions(+)
> 
> diff --git a/Documentation/devicetree/bindings/sound/qcom,wcd93xx-common.yaml b/Documentation/devicetree/bindings/sound/qcom,wcd93xx-common.yaml
> index f78ba148ad25..fa00570caf24 100644
> --- a/Documentation/devicetree/bindings/sound/qcom,wcd93xx-common.yaml
> +++ b/Documentation/devicetree/bindings/sound/qcom,wcd93xx-common.yaml
> @@ -26,6 +26,10 @@ properties:
>    vdd-mic-bias-supply:
>      description: A reference to the 3.8V mic bias supply
>  
> +  vdd-hp-switch-supply:
> +    description: A reference to the audio switch supply
> +      for switching CTIA/OMTP Headset
> +
>    qcom,tx-device:
>      $ref: /schemas/types.yaml#/definitions/phandle-array
>      description: A reference to Soundwire tx device phandle
> -- 
> 2.39.5
> 

-- 
With best wishes
Dmitry

Re: [PATCH 1/3] ASoC: dt-bindings: wcd93xx: add bindings for audio switch controlling hp

[Srinivas Kandagatla]

On 19/03/2025 10:01, Dmitry Baryshkov wrote:
> On Wed, Mar 19, 2025 at 09:16:35AM +0000, srinivas.kandagatla@linaro.org wrote:
>> From: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
>>
>> On some platforms to minimise pop and click during switching between
>> CTIA and OMTP headset an additional HiFi Switch is used. Most common
>> case is that this switch is switched on by default, but on some
>> platforms this needs a regulator enable.
> 
> Is this regulator supplying the codec or some external component? In the
> latter case it's likely that it should not be a part of WCD bindings.

This is regulator powering a mux that is driven by gpio which is part of 
codec binding. So I would assume this will fall into the codec.

Where would we fit this if not part of codec?

Unless we mark this regulator as always on.

--srini
> 
>> This patch adds required bindings to add such regulator.
>>
>> Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
>> ---
>>   .../devicetree/bindings/sound/qcom,wcd93xx-common.yaml        | 4 ++++
>>   1 file changed, 4 insertions(+)
>>
>> diff --git a/Documentation/devicetree/bindings/sound/qcom,wcd93xx-common.yaml b/Documentation/devicetree/bindings/sound/qcom,wcd93xx-common.yaml
>> index f78ba148ad25..fa00570caf24 100644
>> --- a/Documentation/devicetree/bindings/sound/qcom,wcd93xx-common.yaml
>> +++ b/Documentation/devicetree/bindings/sound/qcom,wcd93xx-common.yaml
>> @@ -26,6 +26,10 @@ properties:
>>     vdd-mic-bias-supply:
>>       description: A reference to the 3.8V mic bias supply
>>   
>> +  vdd-hp-switch-supply:
>> +    description: A reference to the audio switch supply
>> +      for switching CTIA/OMTP Headset
>> +
>>     qcom,tx-device:
>>       $ref: /schemas/types.yaml#/definitions/phandle-array
>>       description: A reference to Soundwire tx device phandle
>> -- 
>> 2.39.5
>>
> 

Re: [PATCH 1/3] ASoC: dt-bindings: wcd93xx: add bindings for audio switch controlling hp

[Mark Brown]

[-- Attachment #1: Type: text/plain, Size: 603 bytes --]

On Wed, Mar 19, 2025 at 03:59:23PM +0000, Srinivas Kandagatla wrote:
> On 19/03/2025 10:01, Dmitry Baryshkov wrote:

> > Is this regulator supplying the codec or some external component? In the
> > latter case it's likely that it should not be a part of WCD bindings.

> This is regulator powering a mux that is driven by gpio which is part of
> codec binding. So I would assume this will fall into the codec.

> Where would we fit this if not part of codec?

> Unless we mark this regulator as always on.

I would expect that the mux would appear in the DT and consume both the
GPIO and the regulator.

[-- Attachment #2: signature.asc --]
[-- Type: application/pgp-signature, Size: 488 bytes --]

Re: [PATCH 1/3] ASoC: dt-bindings: wcd93xx: add bindings for audio switch controlling hp

[Srinivas Kandagatla]

On 19/03/2025 16:03, Mark Brown wrote:
> On Wed, Mar 19, 2025 at 03:59:23PM +0000, Srinivas Kandagatla wrote:
>> On 19/03/2025 10:01, Dmitry Baryshkov wrote:
> 
>>> Is this regulator supplying the codec or some external component? In the
>>> latter case it's likely that it should not be a part of WCD bindings.
> 
>> This is regulator powering a mux that is driven by gpio which is part of
>> codec binding. So I would assume this will fall into the codec.
> 
>> Where would we fit this if not part of codec?
> 
>> Unless we mark this regulator as always on.
> 
> I would expect that the mux would appear in the DT and consume both the
> GPIO and the regulator.
Yes, its doable, so we would endup with a mux driver consuming regulator 
and gpio and move the gpio handling in codec to move to use mux control.

Let met try that and see how it looks like.

--srini

Re: [PATCH 1/3] ASoC: dt-bindings: wcd93xx: add bindings for audio switch controlling hp

[Krzysztof Kozlowski]

On Wed, Mar 19, 2025 at 06:00:51PM +0000, Srinivas Kandagatla wrote:
> 
> 
> On 19/03/2025 16:03, Mark Brown wrote:
> > On Wed, Mar 19, 2025 at 03:59:23PM +0000, Srinivas Kandagatla wrote:
> > > On 19/03/2025 10:01, Dmitry Baryshkov wrote:
> > 
> > > > Is this regulator supplying the codec or some external component? In the
> > > > latter case it's likely that it should not be a part of WCD bindings.
> > 
> > > This is regulator powering a mux that is driven by gpio which is part of
> > > codec binding. So I would assume this will fall into the codec.
> > 
> > > Where would we fit this if not part of codec?
> > 
> > > Unless we mark this regulator as always on.
> > 
> > I would expect that the mux would appear in the DT and consume both the
> > GPIO and the regulator.
> Yes, its doable, so we would endup with a mux driver consuming regulator and
> gpio and move the gpio handling in codec to move to use mux control.
> 
> Let met try that and see how it looks like.

Looking at schematics this is clearly not a supply of a codec, but as
Dmitry said, separate switch. Actually two switches.

Best regards,
Krzysztof

Re: [PATCH 1/3] ASoC: dt-bindings: wcd93xx: add bindings for audio switch controlling hp

[Srinivas Kandagatla]

On 20/03/2025 09:31, Krzysztof Kozlowski wrote:
> On Wed, Mar 19, 2025 at 06:00:51PM +0000, Srinivas Kandagatla wrote:
>>
>>
>> On 19/03/2025 16:03, Mark Brown wrote:
>>> On Wed, Mar 19, 2025 at 03:59:23PM +0000, Srinivas Kandagatla wrote:
>>>> On 19/03/2025 10:01, Dmitry Baryshkov wrote:
>>>
>>>>> Is this regulator supplying the codec or some external component? In the
>>>>> latter case it's likely that it should not be a part of WCD bindings.
>>>
>>>> This is regulator powering a mux that is driven by gpio which is part of
>>>> codec binding. So I would assume this will fall into the codec.
>>>
>>>> Where would we fit this if not part of codec?
>>>
>>>> Unless we mark this regulator as always on.
>>>
>>> I would expect that the mux would appear in the DT and consume both the
>>> GPIO and the regulator.
>> Yes, its doable, so we would endup with a mux driver consuming regulator and
>> gpio and move the gpio handling in codec to move to use mux control.
>>
>> Let met try that and see how it looks like.
> 
> Looking at schematics this is clearly not a supply of a codec, but as
> Dmitry said, separate switch. Actually two switches.

AFAIU, Adding single mux for both seems to be the best option.
Eventhough physically they are two muxes but they can not be driven 
independently, and logically/functionally they are doing only one thing 
of handing us/euro headset.


But if we represent these two muxes as two different nodes then the 
driver is messed up, as all the resources (gpios. pinctrls, regultors) 
will be shared and we can not control them independently.



thanks,
Srini
> 
> Best regards,
> Krzysztof
> 

[PATCH 2/3] ASoC: codecs: wcd938x: add support power on hp audio switch

[srinivas.kandagatla]

From: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>

On some platforms to minimise pop and click during switching between
CTIA and OMTP headset an additional HiFi Switch is used. Most common
case is that this switch is switched on by default, but on some
platforms this needs a regulator enable. Enable this regulator if
platform is setup with regulator.

Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
---
 sound/soc/codecs/wcd938x.c | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/sound/soc/codecs/wcd938x.c b/sound/soc/codecs/wcd938x.c
index f2a4f3262bdb..a00845089e13 100644
--- a/sound/soc/codecs/wcd938x.c
+++ b/sound/soc/codecs/wcd938x.c
@@ -3267,6 +3267,13 @@ static int wcd938x_populate_dt_data(struct wcd938x_priv *wcd938x, struct device
 		return dev_err_probe(dev, PTR_ERR(wcd938x->us_euro_gpio),
 				     "us-euro swap Control GPIO not found\n");
 
+	ret = devm_regulator_get_enable_optional(dev, "vdd-hp-switch");
+	if (ret && ret != -ENODEV) {
+		if (ret != -EPROBE_DEFER)
+			dev_err(dev, "Couldn't retrieve/enable audio switch supply\n");
+		return ret;
+	}
+
 	cfg->swap_gnd_mic = wcd938x_swap_gnd_mic;
 
 	wcd938x->supplies[0].supply = "vdd-rxtx";
-- 
2.39.5

[PATCH 3/3] arm64: dts: qcom: x1e78100-t14s: Enable audio headset support

[srinivas.kandagatla]

From: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>

On Lenovo ThinkPad T14s, the headset is connected via a HiFi Switch to
support CTIA and OMTP headsets. This switch is used to minimise pop and
click during headset type switching.

Enable the regulator required to power this switch along with wiring up
gpio that control the headset switching.

Without this, headset audio will be very noisy and might see headset
detection errors.

Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
---
 .../dts/qcom/x1e78100-lenovo-thinkpad-t14s.dts | 18 +++++++++++++++++-
 1 file changed, 17 insertions(+), 1 deletion(-)

diff --git a/arch/arm64/boot/dts/qcom/x1e78100-lenovo-thinkpad-t14s.dts b/arch/arm64/boot/dts/qcom/x1e78100-lenovo-thinkpad-t14s.dts
index b2c2347f54fa..f39c51c809e8 100644
--- a/arch/arm64/boot/dts/qcom/x1e78100-lenovo-thinkpad-t14s.dts
+++ b/arch/arm64/boot/dts/qcom/x1e78100-lenovo-thinkpad-t14s.dts
@@ -22,7 +22,7 @@ / {
 	wcd938x: audio-codec {
 		compatible = "qcom,wcd9385-codec";
 
-		pinctrl-0 = <&wcd_default>;
+		pinctrl-0 = <&wcd_default>, <&us_euro_hs_sel>;
 		pinctrl-names = "default";
 
 		qcom,micbias1-microvolt = <1800000>;
@@ -36,11 +36,13 @@ wcd938x: audio-codec {
 		qcom,tx-device = <&wcd_tx>;
 
 		reset-gpios = <&tlmm 191 GPIO_ACTIVE_LOW>;
+		us-euro-gpios = <&tlmm 68 GPIO_ACTIVE_HIGH>;
 
 		vdd-buck-supply = <&vreg_l15b_1p8>;
 		vdd-rxtx-supply = <&vreg_l15b_1p8>;
 		vdd-io-supply = <&vreg_l15b_1p8>;
 		vdd-mic-bias-supply = <&vreg_bob1>;
+		vdd-hp-switch-supply = <&vreg_l16b_2p5>;
 
 		#sound-dai-cells = <1>;
 	};
@@ -367,6 +369,13 @@ vreg_l15b_1p8: ldo15 {
 			regulator-initial-mode = <RPMH_REGULATOR_MODE_HPM>;
 		};
 
+		vreg_l16b_2p5: ldo16 {
+			regulator-name = "vreg_l6b_2p5";
+			regulator-min-microvolt = <2504000>;
+			regulator-max-microvolt = <2504000>;
+			regulator-initial-mode = <RPMH_REGULATOR_MODE_HPM>;
+		};
+
 		vreg_l17b_2p5: ldo17 {
 			regulator-name = "vreg_l17b_2p5";
 			regulator-min-microvolt = <2504000>;
@@ -942,6 +951,13 @@ int-n-pins {
 		};
 	};
 
+	us_euro_hs_sel: us-euro-hs-sel-state {
+		pins = "gpio68";
+		function = "gpio";
+		bias-pull-down;
+		drive-strength = <2>;
+	};
+
 	kybd_default: kybd-default-state {
 		pins = "gpio67";
 		function = "gpio";
-- 
2.39.5

Re: [PATCH 3/3] arm64: dts: qcom: x1e78100-t14s: Enable audio headset support

[Krzysztof Kozlowski]

On Wed, Mar 19, 2025 at 09:16:37AM +0000, srinivas.kandagatla@linaro.org wrote:
>  		vdd-buck-supply = <&vreg_l15b_1p8>;
>  		vdd-rxtx-supply = <&vreg_l15b_1p8>;
>  		vdd-io-supply = <&vreg_l15b_1p8>;
>  		vdd-mic-bias-supply = <&vreg_bob1>;
> +		vdd-hp-switch-supply = <&vreg_l16b_2p5>;
>  
>  		#sound-dai-cells = <1>;
>  	};
> @@ -367,6 +369,13 @@ vreg_l15b_1p8: ldo15 {
>  			regulator-initial-mode = <RPMH_REGULATOR_MODE_HPM>;
>  		};
>  
> +		vreg_l16b_2p5: ldo16 {
> +			regulator-name = "vreg_l6b_2p5";

Typo: l16b

Best regards,
Krzysztof