[PATCH 0/2] watchdog: realtek-otto: add fallback compatible

[PATCH 0/2] watchdog: realtek-otto: add fallback compatible

[Sander Vanheule]

Like for the GPIO hardware of the Realtek Otto platform, add a fallback
compatible for the watchdog hardware.

For backward compatibility, the binding will still allow current
single-compatible devicetrees to work, but new devicetrees, including
new compatibles, should use a two-component compatible.

This series serves to address comments regarding the device compatibles
for the patches adding RTL9607C watchdog support [1].

[1] https://lore.kernel.org/lkml/20260509163101.722793-1-adilov@disroot.org/

Sander Vanheule (2):
  dt-bindings: watchdog: realtek,otto-wdt: Add fallback compatible
  watchdog: realtek-otto: add fallback compatible

 .../bindings/watchdog/realtek,otto-wdt.yaml   | 19 ++++++++++++++-----
 drivers/watchdog/realtek_otto_wdt.c           |  2 ++
 2 files changed, 16 insertions(+), 5 deletions(-)

-- 
2.54.0

[PATCH 1/2] dt-bindings: watchdog: realtek,otto-wdt: Add fallback compatible

[Sander Vanheule]

As all known hardware instantiations of this watchdog behave the same, a
fallback compatible can be added.

To remain compatible with existing single-compatible bindings, the
current compatibles are duplicated. New compatibles should only be added
to the list with fallback.

Signed-off-by: Sander Vanheule <sander@svanheule.net>
---
 .../bindings/watchdog/realtek,otto-wdt.yaml   | 19 ++++++++++++++-----
 1 file changed, 14 insertions(+), 5 deletions(-)

diff --git a/Documentation/devicetree/bindings/watchdog/realtek,otto-wdt.yaml b/Documentation/devicetree/bindings/watchdog/realtek,otto-wdt.yaml
index 1f5390a67cdb..dcaf29588bcd 100644
--- a/Documentation/devicetree/bindings/watchdog/realtek,otto-wdt.yaml
+++ b/Documentation/devicetree/bindings/watchdog/realtek,otto-wdt.yaml
@@ -25,11 +25,20 @@ allOf:
 
 properties:
   compatible:
-    enum:
-      - realtek,rtl8380-wdt
-      - realtek,rtl8390-wdt
-      - realtek,rtl9300-wdt
-      - realtek,rtl9310-wdt
+    oneOf:
+      - items:
+          - enum:
+            - realtek,rtl8380-wdt
+            - realtek,rtl8390-wdt
+            - realtek,rtl9300-wdt
+            - realtek,rtl9310-wdt
+          - const: realtek,otto-wdt
+      # Legacy without fallback, do not extend
+      - enum:
+          - realtek,rtl8380-wdt
+          - realtek,rtl8390-wdt
+          - realtek,rtl9300-wdt
+          - realtek,rtl9310-wdt
 
   reg:
     maxItems: 1
-- 
2.54.0

Re: [PATCH 1/2] dt-bindings: watchdog: realtek,otto-wdt: Add fallback compatible

[Rob Herring (Arm)]

On Tue, 12 May 2026 13:08:47 +0200, Sander Vanheule wrote:
> As all known hardware instantiations of this watchdog behave the same, a
> fallback compatible can be added.
> 
> To remain compatible with existing single-compatible bindings, the
> current compatibles are duplicated. New compatibles should only be added
> to the list with fallback.
> 
> Signed-off-by: Sander Vanheule <sander@svanheule.net>
> ---
>  .../bindings/watchdog/realtek,otto-wdt.yaml   | 19 ++++++++++++++-----
>  1 file changed, 14 insertions(+), 5 deletions(-)
> 

My bot found errors running 'make dt_binding_check' on your patch:

yamllint warnings/errors:
./Documentation/devicetree/bindings/watchdog/realtek,otto-wdt.yaml:31:13: [warning] wrong indentation: expected 14 but found 12 (indentation)

dtschema/dtc warnings/errors:

doc reference errors (make refcheckdocs):

See https://patchwork.kernel.org/project/devicetree/patch/20260512110848.106620-2-sander@svanheule.net

The base for the series is generally the latest rc1. A different dependency
should be noted in *this* patch.

If you already ran 'make dt_binding_check' and didn't see the above
error(s), then make sure 'yamllint' is installed and dt-schema is up to
date:

pip3 install dtschema --upgrade

Please check and re-submit after running the above command yourself. Note
that DT_SCHEMA_FILES can be set to your schema file to speed up checking
your schema. However, it must be unset to test all examples with your schema.

Re: [PATCH 1/2] dt-bindings: watchdog: realtek,otto-wdt: Add fallback compatible

[sashiko-bot]

Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:
- [Low] Improper YAML indentation for the new enum sequence will cause `make dt_binding_check` to fail.
--

commit a7861dc20069d6726a660807ddc12d7c2ba28a4c
Author: Sander Vanheule <sander@svanheule.net>

dt-bindings: watchdog: realtek,otto-wdt: Add fallback compatible

This commit adds a fallback compatible for the realtek,otto-wdt watchdog
binding. It duplicates the existing compatibles into a new list structure
to remain compatible with older device trees that use a single compatible
string.

> diff --git a/Documentation/devicetree/bindings/watchdog/realtek,otto-wdt.yaml b/Documentation/devicetree/bindings/watchdog/realtek,otto-wdt.yaml
> --- a/Documentation/devicetree/bindings/watchdog/realtek,otto-wdt.yaml
> +++ b/Documentation/devicetree/bindings/watchdog/realtek,otto-wdt.yaml
> @@ -25,11 +25,20 @@ allOf:
>  
>  properties:
>    compatible:
> -    enum:
> -      - realtek,rtl8380-wdt
> -      - realtek,rtl8390-wdt
> -      - realtek,rtl9300-wdt
> -      - realtek,rtl9310-wdt
> +    oneOf:
> +      - items:
> +          - enum:
> +            - realtek,rtl8380-wdt

This isn't a runtime bug, but could the YAML indentation for this sequence
cause make dt_binding_check to fail?

The kernel's yamllint configuration enforces indent-sequences. Because these
sequence items start at the exact same indentation level as their parent enum
mapping key, yamllint will flag this as an indentation error.

> +            - realtek,rtl8390-wdt
> +            - realtek,rtl9300-wdt
> +            - realtek,rtl9310-wdt
> +          - const: realtek,otto-wdt

[ ... ]

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/20260512110848.106620-1-sander@svanheule.net?part=1

[PATCH 2/2] watchdog: realtek-otto: add fallback compatible

[Sander Vanheule]

As the binding now supports a fallback compatible for (new) devicetrees,
let's add it to the list of supported compatibles. If new compatibles
are added to the binding, driver updates may no longer be required.

Signed-off-by: Sander Vanheule <sander@svanheule.net>
---
 drivers/watchdog/realtek_otto_wdt.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/watchdog/realtek_otto_wdt.c b/drivers/watchdog/realtek_otto_wdt.c
index 2c30ddd574c5..b4eb2f87f991 100644
--- a/drivers/watchdog/realtek_otto_wdt.c
+++ b/drivers/watchdog/realtek_otto_wdt.c
@@ -350,6 +350,8 @@ static int otto_wdt_probe(struct platform_device *pdev)
 }
 
 static const struct of_device_id otto_wdt_ids[] = {
+	{ .compatible = "realtek,otto-wdt" },
+	/* Legacy bindings without fallback compatible */
 	{ .compatible = "realtek,rtl8380-wdt" },
 	{ .compatible = "realtek,rtl8390-wdt" },
 	{ .compatible = "realtek,rtl9300-wdt" },
-- 
2.54.0