This enables passive cooling by down-regulating CPU voltage
and frequency.
For trip points, I used a slightly lowered values from the BSP
code. The critical temperature of 110°C from BSP code seemed
like a lot, so I rounded it off to 100°C.
The critical trip point value is 30°C above the maximum recommended
ambient temperature (70°C) for the SoC from the datasheet, so there's
some headroom even at such a high ambient temperature.
Signed-off-by: Ondrej Jirman <[email protected]>
---
arch/arm/boot/dts/sun8i-h3.dtsi | 25 +++++++++++++++++++++++++
1 file changed, 25 insertions(+)
v2:
- added more detail to the commit description
diff --git a/arch/arm/boot/dts/sun8i-h3.dtsi b/arch/arm/boot/dts/sun8i-h3.dtsi
index 20217e2ca4d3a..e83aa6866e7ea 100644
--- a/arch/arm/boot/dts/sun8i-h3.dtsi
+++ b/arch/arm/boot/dts/sun8i-h3.dtsi
@@ -41,6 +41,7 @@
*/
#include "sunxi-h3-h5.dtsi"
+#include <dt-bindings/thermal/thermal.h>
/ {
cpu0_opp_table: opp_table0 {
@@ -227,6 +228,30 @@ cpu_thermal: cpu-thermal {
polling-delay-passive = <0>;
polling-delay = <0>;
thermal-sensors = <&ths 0>;
+
+ trips {
+ cpu_hot_trip: cpu-hot {
+ temperature = <80000>;
+ hysteresis = <2000>;
+ type = "passive";
+ };
+
+ cpu_very_hot_trip: cpu-very-hot {
+ temperature = <100000>;
+ hysteresis = <0>;
+ type = "critical";
+ };
+ };
+
+ cooling-maps {
+ cpu-hot-limit {
+ trip = <&cpu_hot_trip>;
+ 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>;
+ };
+ };
};
};
};
--
2.25.1
On Mon, Feb 24, 2020 at 05:54:46PM +0100, Ondrej Jirman wrote:
> This enables passive cooling by down-regulating CPU voltage
> and frequency.
>
> For trip points, I used a slightly lowered values from the BSP
> code. The critical temperature of 110?C from BSP code seemed
> like a lot, so I rounded it off to 100?C.
>
> The critical trip point value is 30?C above the maximum recommended
> ambient temperature (70?C) for the SoC from the datasheet, so there's
> some headroom even at such a high ambient temperature.
>
> Signed-off-by: Ondrej Jirman <[email protected]>
Applied, thanks
Maxime