ARM: dts: exynos: Add CPU cooling on Arndale Octa

Arndale Octa board comes without fan so proper CPU cooling is necessary
to avoid critical shutdowns when CPUs are busy.  Although thermal zones
were present but CPU cooling was missing in DTS.

Adjust the trip points and add respective cooling nodes for each CPU
thermal zone.  The CPU throttling will start at 60 degrees of C,
intensify at 80 degrees of C and slow down CPUs as much as possible at
110 degrees of C.

With this configuration, when running four CPU intensive tasks, the
temperatures did not exceed 90 degrees of Celsius mostly oscillating
around 88 degrees in hottest thermal zone.  Test was however done with
only four CPUs online (big cluster, Cortex A15) because of errors when
booting secondary CPUs.

Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>

diff --git a/arch/arm/boot/dts/exynos5420-arndale-octa.dts b/arch/arm/boot/dts/exynos5420-arndale-octa.dts
index 308c74ebeacd7adeb92d520b4015bbeb2da97e94..889712481c95c8ddaa451ca045ee0cad3c9dacd3 100644 (file)
--- a/arch/arm/boot/dts/exynos5420-arndale-octa.dts
+++ b/arch/arm/boot/dts/exynos5420-arndale-octa.dts
@@ -59,6 +59,270 @@
        cpu-supply = <&buck6_reg>;
 };
 
+&cpu0_thermal {
+       trips {
+               cpu0_alert0: cpu-alert-0 {
+                       temperature = <60000>; /* millicelsius */
+                       hysteresis = <5000>; /* millicelsius */
+                       type = "passive";
+               };
+               cpu0_alert1: cpu-alert-1 {
+                       temperature = <80000>; /* millicelsius */
+                       hysteresis = <10000>; /* millicelsius */
+                       type = "passive";
+               };
+               cpu0_alert2: cpu-alert-2 {
+                       temperature = <110000>; /* millicelsius */
+                       hysteresis = <10000>; /* millicelsius */
+                       type = "passive";
+               };
+               cpu0_crit0: cpu-crit-0 {
+                       temperature = <120000>; /* millicelsius */
+                       hysteresis = <0>; /* millicelsius */
+                       type = "critical";
+               };
+       };
+
+       cooling-maps {
+               /*
+                * Reduce the CPU speed by 2 steps, down to: 1600 MHz
+                * and 1100 MHz.
+                */
+               map0 {
+                       trip = <&cpu0_alert0>;
+                       cooling-device = <&cpu0 0 2>,
+                                        <&cpu1 0 2>,
+                                        <&cpu2 0 2>,
+                                        <&cpu3 0 2>,
+                                        <&cpu4 0 2>,
+                                        <&cpu5 0 2>,
+                                        <&cpu6 0 2>,
+                                        <&cpu7 0 2>;
+               };
+
+               /*
+                * Reduce the CPU speed down to 1200 MHz big (6 steps)
+                * and 800 MHz LITTLE (5 steps).
+                */
+               map1 {
+                       trip = <&cpu0_alert1>;
+                       cooling-device = <&cpu0 3 6>,
+                                        <&cpu1 3 6>,
+                                        <&cpu2 3 6>,
+                                        <&cpu3 3 6>,
+                                        <&cpu4 3 5>,
+                                        <&cpu5 3 5>,
+                                        <&cpu6 3 5>,
+                                        <&cpu7 3 5>;
+               };
+
+               /*
+                * Reduce the CPU speed as much as possible, down to 700 MHz
+                * big (11 steps) and 600 MHz LITTLE (7 steps).
+                */
+               map2 {
+                       trip = <&cpu0_alert2>;
+                       cooling-device = <&cpu0 6 11>,
+                                        <&cpu1 6 11>,
+                                        <&cpu2 6 11>,
+                                        <&cpu3 6 11>,
+                                        <&cpu4 5 7>,
+                                        <&cpu5 5 7>,
+                                        <&cpu6 5 7>,
+                                        <&cpu7 5 7>;
+               };
+       };
+};
+
+&cpu1_thermal {
+       trips {
+               cpu1_alert0: cpu-alert-0 {
+                       temperature = <60000>; /* millicelsius */
+                       hysteresis = <5000>; /* millicelsius */
+                       type = "passive";
+               };
+               cpu1_alert1: cpu-alert-1 {
+                       temperature = <80000>; /* millicelsius */
+                       hysteresis = <10000>; /* millicelsius */
+                       type = "passive";
+               };
+               cpu1_alert2: cpu-alert-2 {
+                       temperature = <110000>; /* millicelsius */
+                       hysteresis = <10000>; /* millicelsius */
+                       type = "passive";
+               };
+               cpu1_crit0: cpu-crit-0 {
+                       temperature = <120000>; /* millicelsius */
+                       hysteresis = <0>; /* millicelsius */
+                       type = "critical";
+               };
+       };
+
+       cooling-maps {
+               map0 {
+                       trip = <&cpu1_alert0>;
+                       cooling-device = <&cpu0 0 2>,
+                                        <&cpu1 0 2>,
+                                        <&cpu2 0 2>,
+                                        <&cpu3 0 2>,
+                                        <&cpu4 0 2>,
+                                        <&cpu5 0 2>,
+                                        <&cpu6 0 2>,
+                                        <&cpu7 0 2>;
+               };
+
+               map1 {
+                       trip = <&cpu1_alert1>;
+                       cooling-device = <&cpu0 3 6>,
+                                        <&cpu1 3 6>,
+                                        <&cpu2 3 6>,
+                                        <&cpu3 3 6>,
+                                        <&cpu4 3 5>,
+                                        <&cpu5 3 5>,
+                                        <&cpu6 3 5>,
+                                        <&cpu7 3 5>;
+               };
+
+               map2 {
+                       trip = <&cpu1_alert2>;
+                       cooling-device = <&cpu0 6 11>,
+                                        <&cpu1 6 11>,
+                                        <&cpu2 6 11>,
+                                        <&cpu3 6 11>,
+                                        <&cpu4 5 7>,
+                                        <&cpu5 5 7>,
+                                        <&cpu6 5 7>,
+                                        <&cpu7 5 7>;
+               };
+       };
+};
+
+&cpu2_thermal {
+       trips {
+               cpu2_alert0: cpu-alert-0 {
+                       temperature = <60000>; /* millicelsius */
+                       hysteresis = <5000>; /* millicelsius */
+                       type = "passive";
+               };
+               cpu2_alert1: cpu-alert-1 {
+                       temperature = <80000>; /* millicelsius */
+                       hysteresis = <10000>; /* millicelsius */
+                       type = "passive";
+               };
+               cpu2_alert2: cpu-alert-2 {
+                       temperature = <110000>; /* millicelsius */
+                       hysteresis = <10000>; /* millicelsius */
+                       type = "passive";
+               };
+               cpu2_crit0: cpu-crit-0 {
+                       temperature = <120000>; /* millicelsius */
+                       hysteresis = <0>; /* millicelsius */
+                       type = "critical";
+               };
+       };
+
+       cooling-maps {
+               map0 {
+                       trip = <&cpu2_alert0>;
+                       cooling-device = <&cpu0 0 2>,
+                                        <&cpu1 0 2>,
+                                        <&cpu2 0 2>,
+                                        <&cpu3 0 2>,
+                                        <&cpu4 0 2>,
+                                        <&cpu5 0 2>,
+                                        <&cpu6 0 2>,
+                                        <&cpu7 0 2>;
+               };
+
+               map1 {
+                       trip = <&cpu2_alert1>;
+                       cooling-device = <&cpu0 3 6>,
+                                        <&cpu1 3 6>,
+                                        <&cpu2 3 6>,
+                                        <&cpu3 3 6>,
+                                        <&cpu4 3 5>,
+                                        <&cpu5 3 5>,
+                                        <&cpu6 3 5>,
+                                        <&cpu7 3 5>;
+               };
+
+               map2 {
+                       trip = <&cpu2_alert2>;
+                       cooling-device = <&cpu0 6 11>,
+                                        <&cpu1 6 11>,
+                                        <&cpu2 6 11>,
+                                        <&cpu3 6 11>,
+                                        <&cpu4 6 7>,
+                                        <&cpu5 6 7>,
+                                        <&cpu6 6 7>,
+                                        <&cpu7 6 7>;
+               };
+       };
+};
+
+&cpu3_thermal {
+       trips {
+               cpu3_alert0: cpu-alert-0 {
+                       temperature = <60000>; /* millicelsius */
+                       hysteresis = <5000>; /* millicelsius */
+                       type = "passive";
+               };
+               cpu3_alert1: cpu-alert-1 {
+                       temperature = <80000>; /* millicelsius */
+                       hysteresis = <10000>; /* millicelsius */
+                       type = "passive";
+               };
+               cpu3_alert2: cpu-alert-2 {
+                       temperature = <110000>; /* millicelsius */
+                       hysteresis = <10000>; /* millicelsius */
+                       type = "passive";
+               };
+               cpu3_crit0: cpu-crit-0 {
+                       temperature = <120000>; /* millicelsius */
+                       hysteresis = <0>; /* millicelsius */
+                       type = "critical";
+               };
+       };
+
+       cooling-maps {
+               map0 {
+                       trip = <&cpu3_alert0>;
+                       cooling-device = <&cpu0 0 2>,
+                                        <&cpu1 0 2>,
+                                        <&cpu2 0 2>,
+                                        <&cpu3 0 2>,
+                                        <&cpu4 0 2>,
+                                        <&cpu5 0 2>,
+                                        <&cpu6 0 2>,
+                                        <&cpu7 0 2>;
+               };
+
+               map1 {
+                       trip = <&cpu3_alert1>;
+                       cooling-device = <&cpu0 3 6>,
+                                        <&cpu1 3 6>,
+                                        <&cpu2 3 6>,
+                                        <&cpu3 3 6>,
+                                        <&cpu4 3 5>,
+                                        <&cpu5 3 5>,
+                                        <&cpu6 3 5>,
+                                        <&cpu7 3 5>;
+               };
+
+               map2 {
+                       trip = <&cpu3_alert2>;
+                       cooling-device = <&cpu0 6 11>,
+                                        <&cpu1 6 11>,
+                                        <&cpu2 6 11>,
+                                        <&cpu3 6 11>,
+                                        <&cpu4 5 7>,
+                                        <&cpu5 5 7>,
+                                        <&cpu6 5 7>,
+                                        <&cpu7 5 7>;
+               };
+       };
+};
+
 &usbdrd_dwc3_1 {
        dr_mode = "host";
 };