arm64: dts: mt8173-elm: Switch to SMC watchdog

Switch to SMC watchdog because we need direct control of HW watchdog
registers from kernel. The corresponding firmware was uploaded in
https://review.trustedfirmware.org/c/TF-A/trusted-firmware-a/+/3405.

Signed-off-by: Pin-yen Lin <treapking@chromium.org>
Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Link: https://lore.kernel.org/r/20220729053254.220585-1-treapking@chromium.org
Signed-off-by: Matthias Brugger <matthias.bgg@gmail.com>

diff --git a/arch/arm64/boot/dts/mediatek/mt8173-elm.dtsi b/arch/arm64/boot/dts/mediatek/mt8173-elm.dtsi
index 5e24c34..d452cab 100644 (file)
--- a/arch/arm64/boot/dts/mediatek/mt8173-elm.dtsi
+++ b/arch/arm64/boot/dts/mediatek/mt8173-elm.dtsi
@@ -149,6 +149,18 @@
                        };
                };
        };
+
+       watchdog {
+               compatible = "arm,smc-wdt";
+       };
+};
+
+/*
+ * Disable the original MMIO watch dog and switch to the SMC watchdog, which
+ * operates on the same MMIO.
+ */
+&watchdog {
+       status = "disabled";
 };
 
 &mfg_async {