[PATCH 1/3] arm64: dts: ti: k3-am62a: Enable CPU freq throttling on thermal alert

From: Daniel Schultz
Date: Fri May 02 2025 - 10:28:23 EST


Enable throttling down the CPU frequency when an alert temperature
threshold (lower than the critical threshold) is reached.

Signed-off-by: Daniel Schultz <d.schultz@xxxxxxxxx>
---
arch/arm64/boot/dts/ti/k3-am62a-thermal.dtsi | 57 ++++++++++++++++++--
arch/arm64/boot/dts/ti/k3-am62a7.dtsi | 4 ++
2 files changed, 58 insertions(+), 3 deletions(-)

diff --git a/arch/arm64/boot/dts/ti/k3-am62a-thermal.dtsi b/arch/arm64/boot/dts/ti/k3-am62a-thermal.dtsi
index c7486fb2a5b4..39ff9118b6c4 100644
--- a/arch/arm64/boot/dts/ti/k3-am62a-thermal.dtsi
+++ b/arch/arm64/boot/dts/ti/k3-am62a-thermal.dtsi
@@ -12,12 +12,29 @@ main0_thermal: main0-thermal {
thermal-sensors = <&wkup_vtm0 0>;

trips {
+ main0_alert: main0-alert {
+ temperature = <95000>;
+ hysteresis = <2000>;
+ type = "passive";
+ };
+
main0_crit: main0-crit {
temperature = <125000>; /* milliCelsius */
hysteresis = <2000>; /* milliCelsius */
type = "critical";
};
};
+
+ cooling-maps {
+ map0 {
+ trip = <&main0_alert>;
+ cooling-device =
+ <&cpu0 THERMAL_NO_LIMIT THERMAL_NO_LIMIT>,
+ <&cpu1 THERMAL_NO_LIMIT THERMAL_NO_LIMIT>,
+ <&cpu2 THERMAL_NO_LIMIT THERMAL_NO_LIMIT>,
+ <&cpu3 THERMAL_NO_LIMIT THERMAL_NO_LIMIT>;
+ };
+ };
};

main1_thermal: main1-thermal {
@@ -26,25 +43,59 @@ main1_thermal: main1-thermal {
thermal-sensors = <&wkup_vtm0 1>;

trips {
+ main1_alert: main1-alert {
+ temperature = <95000>;
+ hysteresis = <2000>;
+ type = "passive";
+ };
+
main1_crit: main1-crit {
temperature = <125000>; /* milliCelsius */
hysteresis = <2000>; /* milliCelsius */
type = "critical";
};
};
+
+ cooling-maps {
+ map0 {
+ trip = <&main1_alert>;
+ cooling-device =
+ <&cpu0 THERMAL_NO_LIMIT THERMAL_NO_LIMIT>,
+ <&cpu1 THERMAL_NO_LIMIT THERMAL_NO_LIMIT>,
+ <&cpu2 THERMAL_NO_LIMIT THERMAL_NO_LIMIT>,
+ <&cpu3 THERMAL_NO_LIMIT THERMAL_NO_LIMIT>;
+ };
+ };
};

main2_thermal: main2-thermal {
- polling-delay-passive = <250>; /* milliSeconds */
- polling-delay = <500>; /* milliSeconds */
- thermal-sensors = <&wkup_vtm0 2>;
+ polling-delay-passive = <250>; /* milliSeconds */
+ polling-delay = <500>; /* milliSeconds */
+ thermal-sensors = <&wkup_vtm0 2>;

trips {
+ main2_alert: main2-alert {
+ temperature = <95000>;
+ hysteresis = <2000>;
+ type = "passive";
+ };
+
main2_crit: main2-crit {
temperature = <125000>; /* milliCelsius */
hysteresis = <2000>; /* milliCelsius */
type = "critical";
};
};
+
+ cooling-maps {
+ map0 {
+ trip = <&main2_alert>;
+ cooling-device =
+ <&cpu0 THERMAL_NO_LIMIT THERMAL_NO_LIMIT>,
+ <&cpu1 THERMAL_NO_LIMIT THERMAL_NO_LIMIT>,
+ <&cpu2 THERMAL_NO_LIMIT THERMAL_NO_LIMIT>,
+ <&cpu3 THERMAL_NO_LIMIT THERMAL_NO_LIMIT>;
+ };
+ };
};
};
diff --git a/arch/arm64/boot/dts/ti/k3-am62a7.dtsi b/arch/arm64/boot/dts/ti/k3-am62a7.dtsi
index 6c99221beb6b..b6e5eee99370 100644
--- a/arch/arm64/boot/dts/ti/k3-am62a7.dtsi
+++ b/arch/arm64/boot/dts/ti/k3-am62a7.dtsi
@@ -50,6 +50,7 @@ cpu0: cpu@0 {
next-level-cache = <&L2_0>;
operating-points-v2 = <&a53_opp_table>;
clocks = <&k3_clks 135 0>;
+ #cooling-cells = <2>;
};

cpu1: cpu@1 {
@@ -66,6 +67,7 @@ cpu1: cpu@1 {
next-level-cache = <&L2_0>;
operating-points-v2 = <&a53_opp_table>;
clocks = <&k3_clks 136 0>;
+ #cooling-cells = <2>;
};

cpu2: cpu@2 {
@@ -82,6 +84,7 @@ cpu2: cpu@2 {
next-level-cache = <&L2_0>;
operating-points-v2 = <&a53_opp_table>;
clocks = <&k3_clks 137 0>;
+ #cooling-cells = <2>;
};

cpu3: cpu@3 {
@@ -98,6 +101,7 @@ cpu3: cpu@3 {
next-level-cache = <&L2_0>;
operating-points-v2 = <&a53_opp_table>;
clocks = <&k3_clks 138 0>;
+ #cooling-cells = <2>;
};
};

--
2.25.1