dt-bindings: watchdog: qcom-wdt: Document sram property

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.

Reviewed-by: Rob Herring (Arm) <robh@kernel.org>
Signed-off-by: Kathiravan Thirumoorthy <kathiravan.thirumoorthy@oss.qualcomm.com>
Link: https://lore.kernel.org/r/20260408-wdt_reset_reason-v10-1-caf66786329f@oss.qualcomm.com
Signed-off-by: Guenter Roeck <linux@roeck-us.net>

diff --git a/Documentation/devicetree/bindings/watchdog/qcom-wdt.yaml b/Documentation/devicetree/bindings/watchdog/qcom-wdt.yaml
index 9f861045b71e8316ae88f8078a86043a6d04def8..3ead00da3cd6ffa0f6102179565723d4ab6c2929 100644 (file)
--- a/Documentation/devicetree/bindings/watchdog/qcom-wdt.yaml
+++ b/Documentation/devicetree/bindings/watchdog/qcom-wdt.yaml
@@ -84,6 +84,12 @@ properties:
     minItems: 1
     maxItems: 5
 
+  sram:
+    maxItems: 1
+    description:
+      A reference to an region residing in IMEM(on-chip SRAM), which contains
+      the system restart reason value populated by the bootloader.
+
 required:
   - compatible
   - reg