[PATCH v4 6/8] ARM: sun8i: a33: add CPU thermal throttling

From: Quentin Schulz
Date: Wed Apr 05 2017 - 11:10:34 EST


This adds CPU thermal throttling for the Allwinner A33. It uses the
thermal sensor present in the SoC's GPADC.

Signed-off-by: Quentin Schulz <quentin.schulz@xxxxxxxxxxxxxxxxxx>
---

v3:
- switched to new phandle because of modified DT node name for the GPADC
(named THS),
- got rid of cooling-min-level and cooling-max-level as it's not used in any
code in the kernel,

v2:
- updated cooling-max-level to reflect newly added OPPs,

arch/arm/boot/dts/sun8i-a33.dtsi | 45 ++++++++++++++++++++++++++++++++++++++++
1 file changed, 45 insertions(+)

diff --git a/arch/arm/boot/dts/sun8i-a33.dtsi b/arch/arm/boot/dts/sun8i-a33.dtsi
index 9734e63..b88c107 100644
--- a/arch/arm/boot/dts/sun8i-a33.dtsi
+++ b/arch/arm/boot/dts/sun8i-a33.dtsi
@@ -43,6 +43,7 @@
*/

#include "sun8i-a23-a33.dtsi"
+#include <dt-bindings/thermal/thermal.h>

/ {
cpu0_opp_table: opp_table0 {
@@ -127,6 +128,7 @@
clocks = <&ccu CLK_CPUX>;
clock-names = "cpu";
operating-points-v2 = <&cpu0_opp_table>;
+ #cooling-cells = <2>;
};

cpu@1 {
@@ -170,6 +172,49 @@
};
};

+ thermal-zones {
+ cpu_thermal {
+ /* milliseconds */
+ polling-delay-passive = <250>;
+ polling-delay = <1000>;
+ thermal-sensors = <&ths>;
+
+ cooling-maps {
+ map0 {
+ trip = <&cpu_alert0>;
+ cooling-device = <&cpu0 THERMAL_NO_LIMIT THERMAL_NO_LIMIT>;
+ };
+ map1 {
+ trip = <&cpu_alert1>;
+ cooling-device = <&cpu0 THERMAL_NO_LIMIT THERMAL_NO_LIMIT>;
+ };
+ };
+
+ trips {
+ cpu_alert0: cpu_alert0 {
+ /* milliCelsius */
+ temperature = <75000>;
+ hysteresis = <2000>;
+ type = "passive";
+ };
+
+ cpu_alert1: cpu_alert1 {
+ /* milliCelsius */
+ temperature = <90000>;
+ hysteresis = <2000>;
+ type = "hot";
+ };
+
+ cpu_crit: cpu_crit {
+ /* milliCelsius */
+ temperature = <110000>;
+ hysteresis = <2000>;
+ type = "critical";
+ };
+ };
+ };
+ };
+
memory {
reg = <0x40000000 0x80000000>;
};
--
2.9.3