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>
---

Changes in v3:
- Remove /delete-node/ and create a new node for SMC watchdog.

Changes in v2:
- Move the modifications to mt8173-elm.dtsi and add some comments.

 arch/arm64/boot/dts/mediatek/mt8173-elm.dtsi | 13 +++++++++++++
 1 file changed, 13 insertions(+)

diff --git a/arch/arm64/boot/dts/mediatek/mt8173-elm.dtsi b/arch/arm64/boot/dts/mediatek/mt8173-elm.dtsi
index e21feb85d822..fc8203297bac 100644
--- a/arch/arm64/boot/dts/mediatek/mt8173-elm.dtsi
+++ b/arch/arm64/boot/dts/mediatek/mt8173-elm.dtsi
@@ -161,6 +161,19 @@ hdmi_connector_in: endpoint {
 			};
 		};
 	};
+
+
+	smc_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 {
-- 
2.37.1.359.gd136c6c3e2-goog

On 28/07/2022 17:39, Pin-yen Lin wrote:
> 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>
> ---
> 
> Changes in v3:
> - Remove /delete-node/ and create a new node for SMC watchdog.
> 
> Changes in v2:
> - Move the modifications to mt8173-elm.dtsi and add some comments.
> 
>  arch/arm64/boot/dts/mediatek/mt8173-elm.dtsi | 13 +++++++++++++
>  1 file changed, 13 insertions(+)
> 
> diff --git a/arch/arm64/boot/dts/mediatek/mt8173-elm.dtsi b/arch/arm64/boot/dts/mediatek/mt8173-elm.dtsi
> index e21feb85d822..fc8203297bac 100644
> --- a/arch/arm64/boot/dts/mediatek/mt8173-elm.dtsi
> +++ b/arch/arm64/boot/dts/mediatek/mt8173-elm.dtsi
> @@ -161,6 +161,19 @@ hdmi_connector_in: endpoint {
>  			};
>  		};
>  	};
> +
> +

Why?

> +	smc_watchdog {

No, you need to read the comment you receive one more time. So to be
clear: "watchdog"



Best regards,
Krzysztof

On Fri, Jul 29, 2022 at 1:54 AM Krzysztof Kozlowski
<krzysztof.kozlowski@linaro.org> wrote:
>
> On 28/07/2022 17:39, Pin-yen Lin wrote:
> > 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>
> > ---
> >
> > Changes in v3:
> > - Remove /delete-node/ and create a new node for SMC watchdog.
> >
> > Changes in v2:
> > - Move the modifications to mt8173-elm.dtsi and add some comments.
> >
> >  arch/arm64/boot/dts/mediatek/mt8173-elm.dtsi | 13 +++++++++++++
> >  1 file changed, 13 insertions(+)
> >
> > diff --git a/arch/arm64/boot/dts/mediatek/mt8173-elm.dtsi b/arch/arm64/boot/dts/mediatek/mt8173-elm.dtsi
> > index e21feb85d822..fc8203297bac 100644
> > --- a/arch/arm64/boot/dts/mediatek/mt8173-elm.dtsi
> > +++ b/arch/arm64/boot/dts/mediatek/mt8173-elm.dtsi
> > @@ -161,6 +161,19 @@ hdmi_connector_in: endpoint {
> >                       };
> >               };
> >       };
> > +
> > +
>
> Why?
>
> > +     smc_watchdog {
>
> No, you need to read the comment you receive one more time. So to be
> clear: "watchdog"
>
Ah I see. I'll fix this in v4.
>
>
> Best regards,
> Krzysztof