dt-bindings: watchdog: Add ARM smc wdt for mt8173 watchdog

This watchdog can be used on ARM systems with a Secure
Monitor firmware to forward watchdog operations to
firmware via a Secure Monitor Call.

Signed-off-by: Evan Benn <evanbenn@chromium.org>
Reviewed-by: Rob Herring <robh@kernel.org>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Link: https://lore.kernel.org/r/20200505131242.v6.1.Id96574f1f52479d7a2f3b866b8a0552ab8c03d7f@changeid
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wim Van Sebroeck <wim@linux-watchdog.org>

diff --git a/Documentation/devicetree/bindings/watchdog/arm-smc-wdt.yaml b/Documentation/devicetree/bindings/watchdog/arm-smc-wdt.yaml
new file mode 100644 (file)
index 0000000..bec6515
--- /dev/null
+++ b/Documentation/devicetree/bindings/watchdog/arm-smc-wdt.yaml
@@ -0,0 +1,37 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/watchdog/arm-smc-wdt.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: ARM Secure Monitor Call based watchdog
+
+allOf:
+  - $ref: "watchdog.yaml#"
+
+maintainers:
+  - Julius Werner <jwerner@chromium.org>
+
+properties:
+  compatible:
+    enum:
+      - arm,smc-wdt
+  arm,smc-id:
+    allOf:
+      - $ref: /schemas/types.yaml#/definitions/uint32
+    description: |
+      The ATF smc function id used by the firmware.
+      Defaults to 0x82003D06 if unset.
+
+required:
+  - compatible
+
+examples:
+  - |
+    watchdog {
+      compatible = "arm,smc-wdt";
+      arm,smc-id = <0x82003D06>;
+      timeout-sec = <15>;
+    };
+
+...

diff --git a/MAINTAINERS b/MAINTAINERS
index 50659d76976b712dffa0e14e287f2e142235116a..7c062ef0ebb243110bdd327c6282e20001ea8904 100644 (file)
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -1456,6 +1456,12 @@ S:       Maintained
 F:     Documentation/devicetree/bindings/interrupt-controller/arm,vic.txt
 F:     drivers/irqchip/irq-vic.c
 
+ARM SMC WATCHDOG DRIVER
+M:     Julius Werner <jwerner@chromium.org>
+R:     Evan Benn <evanbenn@chromium.org>
+S:     Maintained
+F:     devicetree/bindings/watchdog/arm-smc-wdt.yaml
+
 ARM SMMU DRIVERS
 M:     Will Deacon <will@kernel.org>
 R:     Robin Murphy <robin.murphy@arm.com>