[v2,1/3] dt-bindings: pwm: Add binding for Allwinner D1/T113-S3/R329 PWM controller

Allwinner's D1, T113-S3 and R329 SoCs have a new pwm
controller witch is different from the previous pwm-sun4i.

The D1 and T113 are identical in terms of peripherals,
they differ only in the architecture of the CPU core, and
even share the majority of their DT. Because of that,
using the same compatible makes sense.
The R329 is a different SoC though, and should have
a different compatible string added, especially as there
is a difference in the number of channels.

D1 and T113s SoCs have one PWM controller with 8 channels.
R329 SoC has two PWM controllers in both power domains, one of
them has 9 channels (CPUX one) and the other has 6 (CPUS one).

Add a device tree binding for them.

Signed-off-by: Aleksandr Shubin <privatesub2@gmail.com>
---
 .../bindings/pwm/allwinner,sun20i-pwm.yaml    | 83 +++++++++++++++++++
 1 file changed, 83 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/pwm/allwinner,sun20i-pwm.yaml

Hey Alexksandr,

On Fri, Jun 23, 2023 at 05:59:59PM +0300, Aleksandr Shubin wrote:
> Allwinner's D1, T113-S3 and R329 SoCs have a new pwm
> controller witch is different from the previous pwm-sun4i.
> 
> The D1 and T113 are identical in terms of peripherals,
> they differ only in the architecture of the CPU core, and
> even share the majority of their DT. Because of that,
> using the same compatible makes sense.
> The R329 is a different SoC though, and should have
> a different compatible string added, especially as there
> is a difference in the number of channels.
> 
> D1 and T113s SoCs have one PWM controller with 8 channels.
> R329 SoC has two PWM controllers in both power domains, one of
> them has 9 channels (CPUX one) and the other has 6 (CPUS one).
> 
> Add a device tree binding for them.
> 
> Signed-off-by: Aleksandr Shubin <privatesub2@gmail.com>
> ---
>  .../bindings/pwm/allwinner,sun20i-pwm.yaml    | 83 +++++++++++++++++++
>  1 file changed, 83 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/pwm/allwinner,sun20i-pwm.yaml
> 
> diff --git a/Documentation/devicetree/bindings/pwm/allwinner,sun20i-pwm.yaml b/Documentation/devicetree/bindings/pwm/allwinner,sun20i-pwm.yaml
> new file mode 100644
> index 000000000000..eec9d1dd67c2
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/pwm/allwinner,sun20i-pwm.yaml
> @@ -0,0 +1,83 @@
> +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/pwm/allwinner,sun20i-pwm.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: Allwinner D1, T113-S3 and R329 PWM
> +
> +maintainers:
> +  - Aleksandr Shubin <privatesub2@gmail.com>
> +
> +properties:
> +  compatible:
> +    oneOf:
> +      - const: allwinner,sun20i-d1-pwm
> +      - items:
> +          - const: allwinner,sun20i-r329-pwm
> +          - const: allwinner,sun20i-d1-pwm
> +
> +  reg:
> +    maxItems: 1
> +
> +  "#pwm-cells":
> +    const: 3
> +
> +  clocks:
> +    items:
> +      - description: 24 MHz oscillator
> +      - description: Bus Clock
> +
> +  clock-names:
> +    items:
> +      - const: hosc
> +      - const: bus
> +
> +  resets:
> +    maxItems: 1
> +    description: module reset
> +
> +allOf:
> +  - $ref: pwm.yaml#
> +
> +  - if:
> +      properties:
> +        compatible:
> +          contains:
> +            const: allwinner,sun20i-r329-pwm
> +
> +    then:
> +      properties:
> +        allwinner,pwm-channels:
> +          $ref: /schemas/types.yaml#/definitions/uint32
> +          description: The number of PWM channels configured for this instance
> +          enum: [6, 9]

Last time I acked something like this, Krzysztof complained about
defining properties inside conditionals. This diff avoids the
definition in the conditional, while also disallowing it on the D1.
Thoughts?

diff --git a/Documentation/devicetree/bindings/pwm/allwinner,sun20i-pwm.yaml b/Documentation/devicetree/bindings/pwm/allwinner,sun20i-pwm.yaml
index eec9d1dd67c2..6c04aaa5e9ab 100644
--- a/Documentation/devicetree/bindings/pwm/allwinner,sun20i-pwm.yaml
+++ b/Documentation/devicetree/bindings/pwm/allwinner,sun20i-pwm.yaml
@@ -37,6 +37,11 @@ properties:
     maxItems: 1
     description: module reset
 
+  allwinner,pwm-channels:
+    $ref: /schemas/types.yaml#/definitions/uint32
+    description: The number of PWM channels configured for this instance
+    enum: [6, 9]
+
 allOf:
   - $ref: pwm.yaml#
 
@@ -47,15 +52,14 @@ allOf:
             const: allwinner,sun20i-r329-pwm
 
     then:
-      properties:
-        allwinner,pwm-channels:
-          $ref: /schemas/types.yaml#/definitions/uint32
-          description: The number of PWM channels configured for this instance
-          enum: [6, 9]
-
       required:
         - allwinner,pwm-channels
 
+    else:
+      not:
+        required:
+          - allwinner,pwm-channels
+
 required:
   - compatible
   - reg


> +
> +      required:
> +        - allwinner,pwm-channels
> +
> +required:
> +  - compatible
> +  - reg
> +  - "#pwm-cells"
> +  - clocks
> +  - clock-names
> +  - resets
> +
> +additionalProperties: false
> +
> +examples:
> +  - |
> +    #include <dt-bindings/clock/sun20i-d1-ccu.h>
> +    #include <dt-bindings/reset/sun20i-d1-ccu.h>
> +
> +    pwm: pwm@2000c00 {
> +      compatible = "allwinner,sun20i-d1-pwm";
> +      reg = <0x02000c00 0x400>;
> +      clocks = <&dcxo>, <&ccu CLK_BUS_PWM>;
> +      clock-names = "hosc", "bus";
> +      resets = <&ccu RST_BUS_PWM>;
> +      #pwm-cells = <0x3>;
> +    };
> +
> +...
> -- 
> 2.25.1
>

On Fri, Jun 23, 2023 at 05:59:59PM +0300, Aleksandr Shubin wrote:
> +  resets:
> +    maxItems: 1
> +    description: module reset

Also, this description doesn't really add any value, resetting the
peripheral is the default meaning pretty much, and should be dropped.

On 23/06/2023 16:59, Aleksandr Shubin wrote:
> Allwinner's D1, T113-S3 and R329 SoCs have a new pwm
> controller witch is different from the previous pwm-sun4i.
> 
> The D1 and T113 are identical in terms of peripherals,
> they differ only in the architecture of the CPU core, and
> even share the majority of their DT. Because of that,
> using the same compatible makes sense.
> The R329 is a different SoC though, and should have
> a different compatible string added, especially as there
> is a difference in the number of channels.
> 
> D1 and T113s SoCs have one PWM controller with 8 channels.
> R329 SoC has two PWM controllers in both power domains, one of
> them has 9 channels (CPUX one) and the other has 6 (CPUS one).
> 
> Add a device tree binding for them.
> 
> Signed-off-by: Aleksandr Shubin <privatesub2@gmail.com>
> ---
>  .../bindings/pwm/allwinner,sun20i-pwm.yaml    | 83 +++++++++++++++++++
>  1 file changed, 83 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/pwm/allwinner,sun20i-pwm.yaml
> 
> diff --git a/Documentation/devicetree/bindings/pwm/allwinner,sun20i-pwm.yaml b/Documentation/devicetree/bindings/pwm/allwinner,sun20i-pwm.yaml
> new file mode 100644
> index 000000000000..eec9d1dd67c2
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/pwm/allwinner,sun20i-pwm.yaml
> @@ -0,0 +1,83 @@
> +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/pwm/allwinner,sun20i-pwm.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: Allwinner D1, T113-S3 and R329 PWM
> +
> +maintainers:
> +  - Aleksandr Shubin <privatesub2@gmail.com>
> +
> +properties:
> +  compatible:
> +    oneOf:
> +      - const: allwinner,sun20i-d1-pwm
> +      - items:
> +          - const: allwinner,sun20i-r329-pwm
> +          - const: allwinner,sun20i-d1-pwm
> +
> +  reg:
> +    maxItems: 1
> +
> +  "#pwm-cells":
> +    const: 3
> +
> +  clocks:
> +    items:
> +      - description: 24 MHz oscillator
> +      - description: Bus Clock
> +
> +  clock-names:
> +    items:
> +      - const: hosc
> +      - const: bus
> +
> +  resets:
> +    maxItems: 1
> +    description: module reset
> +
> +allOf:
> +  - $ref: pwm.yaml#
> +
> +  - if:
> +      properties:
> +        compatible:
> +          contains:
> +            const: allwinner,sun20i-r329-pwm
> +
> +    then:
> +      properties:
> +        allwinner,pwm-channels:
> +          $ref: /schemas/types.yaml#/definitions/uint32
> +          description: The number of PWM channels configured for this instance
> +          enum: [6, 9]
> +

Your DTS says this is 8, so you did not test it. Why do you need it in
the first place? r329 can have both 6 and 9?

Anyway, this won't work with additionalProperties, which you would see
with testing. Don't define properties in allOf. Also switch to
unevaluatedProperties: false.

Best regards,
Krzysztof