[PATCH v5 3/5] dt-bindings: watchdog: qcom-wdt: Document sram property

[Kathiravan Thirumoorthy]

Document the "sram" property for the watchdog device on Qualcomm
IPQ platforms. Use this property to extract the restart reason from
IMEM, which is updated by XBL. Populate the watchdog's bootstatus sysFS
entry with this information, when the system reboots due to a watchdog
timeout.

Describe this property for the IPQ5424 watchdog device and extend support
to other targets subsequently.

Signed-off-by: Kathiravan Thirumoorthy <kathiravan.thirumoorthy@xxxxxxxxxxxxxxxx>
---
Changes in v5:
	- Rename the property 'qcom,imem' to 'sram'
Changes in v4:
	- New patch
---
 .../devicetree/bindings/watchdog/qcom-wdt.yaml       | 20 ++++++++++++++++++++
 1 file changed, 20 insertions(+)

diff --git a/Documentation/devicetree/bindings/watchdog/qcom-wdt.yaml b/Documentation/devicetree/bindings/watchdog/qcom-wdt.yaml
index 49e2b807db0bc9d3edfc93ec41ad0df0b74ed032..74a09c391fd8e2befeac07f254ea16d0ca362248 100644
--- a/Documentation/devicetree/bindings/watchdog/qcom-wdt.yaml
+++ b/Documentation/devicetree/bindings/watchdog/qcom-wdt.yaml
@@ -81,6 +81,16 @@ properties:
     minItems: 1
     maxItems: 5
 
+  sram:
+    $ref: /schemas/types.yaml#/definitions/phandle-array
+    description:
+      phandle to the IMEM syscon node that exposes the system restart reason
+    items:
+      - items:
+          - description: phandle of IMEM syscon
+          - description: offset of restart reason region
+          - description: value indicate that the watchdog timeout has occurred
+
 required:
   - compatible
   - reg
@@ -117,6 +127,16 @@ allOf:
       required:
         - clock-frequency
 
+  - if:
+      properties:
+        compatible:
+          contains:
+            enum:
+              - qcom,apss-wdt-ipq5424
+    then:
+      required:
+        - sram
+
 unevaluatedProperties: false
 
 examples:

-- 
2.34.1