[PATCH RFC] dt-bindings: sound: Convert cirrus,cs35l36 to DT schema

[PATCH RFC] dt-bindings: sound: Convert cirrus,cs35l36 to DT schema

[David Heidelberg via B4 Relay]

From: David Heidelberg <david@ixit.cz>

Convert CS35L36 Speaker Amplifier.

Changes:
 - maintainers email to the generic Cirrus email
 - Both the codec and downstream worked just fine without
   VP-supply provided. Align with datasheet for similar models.
 - add dai-common.yaml to cover for '#sound-dai-cells',
   'sound-name-prefix'

Co-developed-by: Rob Herring (Arm) <robh@kernel.org>
Signed-off-by: Rob Herring (Arm) <robh@kernel.org>
Signed-off-by: David Heidelberg <david@ixit.cz>
---
Relevant for Pixel 3 / 3XL / 4.
---
 .../devicetree/bindings/sound/cirrus,cs35l36.yaml  | 224 +++++++++++++++++++++
 .../devicetree/bindings/sound/cs35l36.txt          | 168 ----------------
 2 files changed, 224 insertions(+), 168 deletions(-)

diff --git a/Documentation/devicetree/bindings/sound/cirrus,cs35l36.yaml b/Documentation/devicetree/bindings/sound/cirrus,cs35l36.yaml
new file mode 100644
index 0000000000000..af0acaaefb68e
--- /dev/null
+++ b/Documentation/devicetree/bindings/sound/cirrus,cs35l36.yaml
@@ -0,0 +1,224 @@
+# SPDX-License-Identifier: GPL-2.0-only
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/cirrus,cs35l36.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Cirrus Logic CS35L36 Speaker Amplifier
+
+maintainers:
+  - patches@opensource.cirrus.com
+  - Bjorn Helgaas <bhelgaas@google.com>
+
+description: |
+  CS35L36 is a boosted mono Class D amplifier
+
+allOf:
+  - $ref: /schemas/sound/dai-common.yaml#
+
+properties:
+  compatible:
+    enum:
+      - cirrus,cs35l36
+
+  reg:
+    maxItems: 1
+
+  interrupts:
+    maxItems: 1
+
+  VA-supply:
+    description: Voltage regulator of analog internal section
+
+  VP-supply:
+    description: Voltage regulator of boost converter
+
+  reset-gpios:
+    maxItems: 1
+
+  cirrus,boost-ctl-millivolt:
+    description: Boost converter output voltage in millivolts (step 50)
+    $ref: /schemas/types.yaml#/definitions/uint32
+    minimum: 2550
+    maximum: 12000
+
+  cirrus,boost-peak-milliamp:
+    description: Boost-converter peak current limit in mA (step 50)
+    $ref: /schemas/types.yaml#/definitions/uint32
+    default: 4500
+    minimum: 1600
+    maximum: 4500
+
+  cirrus,boost-ind-nanohenry:
+    description: Initial inductor estimation reference value in nanohenry (1000=1μH, 1200=1.2μH)
+    $ref: /schemas/types.yaml#/definitions/uint32
+    default: 1000
+
+  cirrus,multi-amp-mode:
+    description: Hi-Z ASP port when more than one amplifier in system.
+    type: boolean
+
+  cirrus,boost-ctl-select:
+    description: Boost converter control source selection
+    $ref: /schemas/types.yaml#/definitions/uint32
+    default: 0x01
+    enum:
+      - 0x00 # Control Port
+      - 0x01 # Class
+      - 0x10 # Sync
+
+  cirrus,amp-pcm-inv:
+    description: Invert incoming PCM data when true.
+    type: boolean
+
+  cirrus,imon-pol-inv:
+    description: Invert polarity of outbound IMON feedback when true.
+    type: boolean
+
+  cirrus,vmon-pol-inv:
+    description: Invert polarity of outbound VMON feedback when true.
+    type: boolean
+
+  cirrus,dcm-mode-enable:
+    description: Enable boost converter automatic Discontinuous Conduction Mode.
+    type: boolean
+
+  cirrus,weak-fet-disable:
+    description: Reduce output driver strength in Weak-FET Drive Mode when true.
+    type: boolean
+
+  cirrus,classh-wk-fet-delay:
+    description: Weak-FET entry delay in ms
+    $ref: /schemas/types.yaml#/definitions/uint32
+    default: 100
+    enum:
+      - 0 # 0
+      - 1 # 5
+      - 2 # 10
+      - 3 # 50
+      - 4 # 100
+      - 5 # 200
+      - 6 # 500
+      - 7 # 1000
+
+  cirrus,classh-weak-fet-thld-millivolt:
+    description: Weak-FET drive threshold in mV
+    $ref: /schemas/types.yaml#/definitions/uint32
+    enum: [50, 100, 150, 200, 250, 300, 350, 400, 450, 500, 550, 600, 650, 700]
+
+  cirrus,temp-warn-threshold:
+    description: Overtemperature warning threshold
+    $ref: /schemas/types.yaml#/definitions/uint32
+    default: 2
+    enum:
+      - 0 # 105°C
+      - 1 # 115°C
+      - 2 # 125°C
+      - 3 # 135°C
+
+  cirrus,irq-drive-select:
+    description: Interrupt output driver type
+    $ref: /schemas/types.yaml#/definitions/uint32
+    default: 1
+    enum:
+      - 0 # open-drain
+      - 1 # push-pull
+
+  cirrus,irq-gpio-select:
+    description: Programmable IRQ pin selection
+    $ref: /schemas/types.yaml#/definitions/uint32
+    enum:
+      - 0 # PDM_DATA/SWIRE_SD/INT
+      - 1 # GPIO
+
+  cirrus,vpbr-config:
+    description: Brownout prevention configuration sub-node
+    type: object
+    additionalProperties: false
+
+    properties:
+      cirrus,vpbr-en:
+        description: VBST brownout prevention enable
+        $ref: /schemas/types.yaml#/definitions/uint32
+        default: 0
+        enum:
+          - 0 # disabled
+          - 1 # enabled
+
+      cirrus,vpbr-thld:
+        description: Initial VPBR threshold voltage
+        $ref: /schemas/types.yaml#/definitions/uint32
+
+      cirrus,vpbr-atk-rate:
+        description: Attenuation attack step rate
+        $ref: /schemas/types.yaml#/definitions/uint32
+
+      cirrus,vpbr-atk-vol:
+        description: VP brownout prevention step size
+        $ref: /schemas/types.yaml#/definitions/uint32
+
+      cirrus,vpbr-max-attn:
+        description: Maximum attenuation during VP brownout prevention
+        $ref: /schemas/types.yaml#/definitions/uint32
+
+      cirrus,vpbr-wait:
+        description: Delay between brownout clearance and attenuation release
+        $ref: /schemas/types.yaml#/definitions/uint32
+
+      cirrus,vpbr-rel-rate:
+        description: Attenuation release step rate
+        $ref: /schemas/types.yaml#/definitions/uint32
+
+      cirrus,vpbr-mute-en:
+        description: Mute audio if maximum attenuation reached
+        $ref: /schemas/types.yaml#/definitions/uint32
+
+required:
+  - compatible
+  - reg
+  - interrupts
+  - VA-supply
+
+unevaluatedProperties: false
+
+examples:
+  - |
+    #include <dt-bindings/gpio/gpio.h>
+    #include <dt-bindings/interrupt-controller/irq.h>
+
+    i2c {
+        #address-cells = <1>;
+        #size-cells = <0>;
+
+        codec@40 {
+            compatible = "cirrus,cs35l36";
+            reg = <0x40>;
+            VA-supply = <&dummy_vreg>;
+            VP-supply = <&dummy_vreg>;
+            reset-gpios = <&gpio0 54 GPIO_ACTIVE_HIGH>;
+            interrupts = <3 IRQ_TYPE_LEVEL_LOW>;
+
+            cirrus,boost-ind-nanohenry = <1000>;
+            cirrus,boost-ctl-millivolt = <10000>;
+            cirrus,boost-peak-milliamp = <4500>;
+            cirrus,boost-ctl-select = <0x00>;
+            cirrus,weak-fet-delay = <4>;
+            cirrus,weak-fet-thld = <0x01>;
+            cirrus,temp-warn-threshold = <1>;
+            cirrus,multi-amp-mode;
+            cirrus,irq-drive-select = <1>;
+            cirrus,irq-gpio-select = <0x01>;
+
+            cirrus,vpbr-config {
+                cirrus,vpbr-en = <0>;
+                cirrus,vpbr-thld = <0x05>;
+                cirrus,vpbr-atk-rate = <0x02>;
+                cirrus,vpbr-atk-vol = <0x01>;
+                cirrus,vpbr-max-attn = <0x09>;
+                cirrus,vpbr-wait = <0x01>;
+                cirrus,vpbr-rel-rate = <0x05>;
+                cirrus,vpbr-mute-en = <0x00>;
+            };
+        };
+    };
+...
diff --git a/Documentation/devicetree/bindings/sound/cs35l36.txt b/Documentation/devicetree/bindings/sound/cs35l36.txt
deleted file mode 100644
index d34117b8558e5..0000000000000
--- a/Documentation/devicetree/bindings/sound/cs35l36.txt
+++ /dev/null
@@ -1,168 +0,0 @@
-CS35L36 Speaker Amplifier
-
-Required properties:
-
-  - compatible : "cirrus,cs35l36"
-
-  - reg : the I2C address of the device for I2C
-
-  - VA-supply, VP-supply : power supplies for the device,
-  as covered in
-  Documentation/devicetree/bindings/regulator/regulator.txt.
-
-  - cirrus,boost-ctl-millivolt : Boost Voltage Value.  Configures the boost
-  converter's output voltage in mV. The range is from 2550mV to 12000mV with
-  increments of 50mV.
-  (Default) VP
-
-  - cirrus,boost-peak-milliamp : Boost-converter peak current limit in mA.
-  Configures the peak current by monitoring the current through the boost FET.
-  Range starts at 1600mA and goes to a maximum of 4500mA with increments of
-  50mA.
-  (Default) 4.50 Amps
-
-  - cirrus,boost-ind-nanohenry : Inductor estimation LBST reference value.
-  Seeds the digital boost converter's inductor estimation block with the initial
-  inductance value to reference.
-
-  1000 = 1uH (Default)
-  1200 = 1.2uH
-
-Optional properties:
-  - cirrus,multi-amp-mode : Boolean to determine if there are more than
-  one amplifier in the system. If more than one it is best to Hi-Z the ASP
-  port to prevent bus contention on the output signal
-
-  - cirrus,boost-ctl-select : Boost converter control source selection.
-  Selects the source of the BST_CTL target VBST voltage for the boost
-  converter to generate.
-  0x00 - Control Port Value
-  0x01 - Class H Tracking (Default)
-  0x10 - MultiDevice Sync Value
-
-  - cirrus,amp-pcm-inv : Boolean to determine Amplifier will invert incoming
-  PCM data
-
-  - cirrus,imon-pol-inv : Boolean to determine Amplifier will invert the
-  polarity of outbound IMON feedback data
-
-  - cirrus,vmon-pol-inv : Boolean to determine Amplifier will invert the
-  polarity of outbound VMON feedback data
-
-  - cirrus,dcm-mode-enable : Boost converter automatic DCM Mode enable.
-  This enables the digital boost converter to operate in a low power
-  (Discontinuous Conduction) mode during low loading conditions.
-
-  - cirrus,weak-fet-disable : Boolean : The strength of the output drivers is
-  reduced when operating in a Weak-FET Drive Mode and must not be used to drive
-  a large load.
-
-  - cirrus,classh-wk-fet-delay :  Weak-FET entry delay. Controls the delay
-  (in ms) before the Class H algorithm switches to the weak-FET voltage
-  (after the audio falls and remains below the value specified in WKFET_AMP_THLD).
-
-  0 = 0ms
-  1 = 5ms
-  2 = 10ms
-  3 = 50ms
-  4 = 100ms (Default)
-  5 = 200ms
-  6 = 500ms
-  7 = 1000ms
-
-  - cirrus,classh-weak-fet-thld-millivolt : Weak-FET amplifier drive threshold.
-  Configures the signal threshold at which the PWM output stage enters
-  weak-FET operation. The range is 50mV to 700mV in 50mV increments.
-
-  - cirrus,temp-warn-threshold :  Amplifier overtemperature warning threshold.
-  Configures the threshold at which the overtemperature warning condition occurs.
-  When the threshold is met, the overtemperature warning attenuation is applied
-  and the TEMP_WARN_EINT interrupt status bit is set.
-  If TEMP_WARN_MASK = 0, INTb is asserted.
-
-  0 = 105C
-  1 = 115C
-  2 = 125C (Default)
-  3 = 135C
-
-  - cirrus,irq-drive-select : Selects the driver type of the selected interrupt
-  output.
-
-  0 = Open-drain
-  1 = Push-pull (Default)
-
-  - cirrus,irq-gpio-select : Selects the pin to serve as the programmable
-  interrupt output.
-
-  0 = PDM_DATA / SWIRE_SD / INT (Default)
-  1 = GPIO
-
-Optional properties for the "cirrus,vpbr-config" Sub-node
-
-  - cirrus,vpbr-en : VBST brownout prevention enable. Configures whether the
-  VBST brownout prevention algorithm is enabled or disabled.
-
-  0 = VBST brownout prevention disabled (default)
-  1 = VBST brownout prevention enabled
-
-  See Section 7.31.1 VPBR Config for configuration options & further details
-
-  - cirrus,vpbr-thld : Initial VPBR threshold. Configures the VP brownout
-  threshold voltage
-
-  - cirrus,cirrus,vpbr-atk-rate : Attenuation attack step rate. Configures the
-  amount delay between consecutive volume attenuation steps when a brownout
-  condition is present and the VP brownout condition is in an attacking state.
-
-  - cirrus,vpbr-atk-vol : VP brownout prevention step size. Configures the VP
-  brownout prevention attacking attenuation step size when operating in either
-  digital volume or analog gain modes.
-
-  - cirrus,vpbr-max-attn : Maximum attenuation that the VP brownout prevention
-  can apply to the audio signal.
-
-  - cirrus,vpbr-wait : Configures the delay time between a brownout condition
-  no longer being present and the VP brownout prevention entering an attenuation
-  release state.
-
-  - cirrus,vpbr-rel-rate : Attenuation release step rate. Configures the delay
-  between consecutive volume attenuation release steps when a brownout condition
-  is not longer present and the VP brownout is in an attenuation release state.
-
-  - cirrus,vpbr-mute-en : During the attack state, if the vpbr-max-attn value
-  is reached, the error condition still remains, and this bit is set, the audio
-  is muted.
-
-Example:
-
-cs35l36: cs35l36@40 {
-	compatible = "cirrus,cs35l36";
-	reg = <0x40>;
-	VA-supply = <&dummy_vreg>;
-	VP-supply = <&dummy_vreg>;
-	reset-gpios = <&gpio0 54 0>;
-	interrupt-parent = <&gpio8>;
-	interrupts = <3 IRQ_TYPE_LEVEL_LOW>;
-
-	cirrus,boost-ind-nanohenry = <1000>;
-	cirrus,boost-ctl-millivolt = <10000>;
-	cirrus,boost-peak-milliamp = <4500>;
-	cirrus,boost-ctl-select = <0x00>;
-	cirrus,weak-fet-delay = <0x04>;
-	cirrus,weak-fet-thld = <0x01>;
-	cirrus,temp-warn-threshold = <0x01>;
-	cirrus,multi-amp-mode;
-	cirrus,irq-drive-select = <0x01>;
-	cirrus,irq-gpio-select = <0x01>;
-
-	cirrus,vpbr-config {
-		cirrus,vpbr-en = <0x00>;
-		cirrus,vpbr-thld = <0x05>;
-		cirrus,vpbr-atk-rate = <0x02>;
-		cirrus,vpbr-atk-vol = <0x01>;
-		cirrus,vpbr-max-attn = <0x09>;
-		cirrus,vpbr-wait = <0x01>;
-		cirrus,vpbr-rel-rate = <0x05>;
-		cirrus,vpbr-mute-en = <0x00>;
-	};
-};

---
base-commit: 8cd9520d35a6c38db6567e97dd93b1f11f185dc6
change-id: 20260618-dt-cirrus-cs35l36-99c466fb13fd

Best regards,
-- 
David Heidelberg <david@ixit.cz>

Re: [PATCH RFC] dt-bindings: sound: Convert cirrus,cs35l36 to DT schema

[sashiko-bot]

Thank you for your contribution! Sashiko AI review found 4 potential issue(s) to consider:
- [Low] The `$id` field in the YAML schema omits the `sound/` subdirectory component, which breaks the schema cross-reference system.
- [Low] The `dt_binding_check` validation will fail because the example uses properties that are not defined in the schema.
- [Low] The default value for `cirrus,classh-wk-fet-delay` is set to `100`, which violates the property's own enum constraints.
- [Low] An incorrect and completely unrelated maintainer (Bjorn Helgaas) is listed for this Cirrus Logic audio codec binding.
--

commit 6ae17828fc1b1804817814b5209c4fcb2dc8b463
Author: David Heidelberg <david@ixit.cz>

dt-bindings: sound: Convert cirrus,cs35l36 to DT schema

Converts the CS35L36 Speaker Amplifier from a text binding to a DT schema.
It updates the maintainer to the generic Cirrus email, makes VP-supply
optional based on datasheet behavior, and incorporates dai-common.yaml.

> diff --git a/Documentation/devicetree/bindings/sound/cirrus,cs35l36.yaml b/Documentation/devicetree/bindings/sound/cirrus,cs35l36.yaml
> new file mode 100644
> index 0000000000000..af0acaaefb68e
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/sound/cirrus,cs35l36.yaml
> @@ -0,0 +1,224 @@
> +# SPDX-License-Identifier: GPL-2.0-only
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/cirrus,cs35l36.yaml#

[Severity: Low]
Does this `$id` path need to include the `sound/` subdirectory? Without it,
the schema cross-reference system might break.

> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: Cirrus Logic CS35L36 Speaker Amplifier
> +
> +maintainers:
> +  - patches@opensource.cirrus.com
> +  - Bjorn Helgaas <bhelgaas@google.com>

[Severity: Low]
Is Bjorn Helgaas the correct maintainer to list here for this Cirrus Logic
audio codec? Since he typically maintains PCI, listing him here might
misdirect queries and patches.

[ ... ]

> +  cirrus,classh-wk-fet-delay:
> +    description: Weak-FET entry delay in ms
> +    $ref: /schemas/types.yaml#/definitions/uint32
> +    default: 100

[Severity: Low]
Will this default value of 100 cause schema validation to fail? The enum
below only allows values from 0 to 7, where 4 seems to map to 100ms.

> +    enum:
> +      - 0 # 0
> +      - 1 # 5
> +      - 2 # 10
> +      - 3 # 50
> +      - 4 # 100
> +      - 5 # 200
> +      - 6 # 500
> +      - 7 # 1000

[ ... ]

> +            cirrus,boost-ind-nanohenry = <1000>;
> +            cirrus,boost-ctl-millivolt = <10000>;
> +            cirrus,boost-peak-milliamp = <4500>;
> +            cirrus,boost-ctl-select = <0x00>;
> +            cirrus,weak-fet-delay = <4>;
> +            cirrus,weak-fet-thld = <0x01>;

[Severity: Low]
Could this example cause `dt_binding_check` to fail? It uses
`cirrus,weak-fet-delay` and `cirrus,weak-fet-thld`, but the schema actually
defines these properties as `cirrus,classh-wk-fet-delay` and
`cirrus,classh-weak-fet-thld-millivolt` respectively. With
`unevaluatedProperties: false` set, undocumented properties will trigger a
fatal schema error.

> +            cirrus,temp-warn-threshold = <1>;
> +            cirrus,multi-amp-mode;
> +            cirrus,irq-drive-select = <1>;
> +            cirrus,irq-gpio-select = <0x01>;

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/20260618-dt-cirrus-cs35l36-v1-1-1a43515666ad@ixit.cz?part=1

Re: [PATCH RFC] dt-bindings: sound: Convert cirrus,cs35l36 to DT schema

[Mark Brown]

[-- Attachment #1: Type: text/plain, Size: 501 bytes --]

On Thu, Jun 18, 2026 at 04:33:28PM +0200, David Heidelberg via B4 Relay wrote:
> From: David Heidelberg <david@ixit.cz>
> 
> Convert CS35L36 Speaker Amplifier.

Please submit patches using subject lines reflecting the style for the
subsystem, this makes it easier for people to identify relevant patches.
Look at what existing commits in the area you're changing are doing and
make sure your subject lines visually resemble what they're doing.
There's no need to resubmit to fix this alone.

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