dt-bindings: watchdog: fsl-imx: document suspend in wait mode

Property "fsl,suspend-in-wait" suspends watchdog in "WAIT" mode which
corresponds to Linux's Suspend-to-Idle S0 mode. If this property is not
set and the device is put into Suspend-to-Idle mode, the watchdog
triggers a reset after 128 seconds.

Signed-off-by: Andrej Picej <andrej.picej@norik.com>
Reviewed-by: Fabio Estevam <festevam@gmail.com>
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Link: https://lore.kernel.org/r/20221104070358.426657-3-andrej.picej@norik.com
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wim Van Sebroeck <wim@linux-watchdog.org>

Documentation/devicetree/bindings/watchdog/fsl-imx-wdt.yaml

@@ -9,9 +9,6 @@ title: Freescale i.MX Watchdog Timer (WDT) Controller
 maintainers:
   - Anson Huang <Anson.Huang@nxp.com>
 
-allOf:
-  - $ref: "watchdog.yaml#"
-
 properties:
   compatible:
     oneOf:
@@ -55,11 +52,45 @@ properties:
       If present, the watchdog device is configured to assert its
       external reset (WDOG_B) instead of issuing a software reset.
 
+  fsl,suspend-in-wait:
+    $ref: /schemas/types.yaml#/definitions/flag
+    description: |
+      If present, the watchdog device is suspended in WAIT mode
+      (Suspend-to-Idle). Only supported on certain devices.
+
 required:
   - compatible
   - interrupts
   - reg
 
+allOf:
+  - $ref: watchdog.yaml#
+  - if:
+      not:
+        properties:
+          compatible:
+            contains:
+              enum:
+                - fsl,imx25-wdt
+                - fsl,imx35-wdt
+                - fsl,imx50-wdt
+                - fsl,imx51-wdt
+                - fsl,imx53-wdt
+                - fsl,imx6q-wdt
+                - fsl,imx6sl-wdt
+                - fsl,imx6sll-wdt
+                - fsl,imx6sx-wdt
+                - fsl,imx6ul-wdt
+                - fsl,imx7d-wdt
+                - fsl,imx8mm-wdt
+                - fsl,imx8mn-wdt
+                - fsl,imx8mp-wdt
+                - fsl,imx8mq-wdt
+                - fsl,vf610-wdt
+    then:
+      properties:
+        fsl,suspend-in-wait: false
+
 unevaluatedProperties: false
 
 examples: