ARM: dts: rockchip: Configure the GPU thermal zone for mickey

mickey crams a lot of hardware into a tiny package, which requires
more aggressive thermal throttling than for devices with a larger
footprint. Configure the GPU thermal zone to throttle the GPU
progressively at temperatures >= 60°C. Heat dissipated by the
CPUs also affects the GPU temperature, hence we cap the CPU
frequency to 1.4 GHz for temperatures above 65°C. Further throttling
of the CPUs may be performed by the CPU thermal zone.

The configuration matches that of the downstream Chrome OS 3.14
kernel, the 'official' kernel for mickey.

Signed-off-by: Matthias Kaehlcke <mka@chromium.org>
Reviewed-by: Douglas Anderson <dianders@chromium.org>
Signed-off-by: Heiko Stuebner <heiko@sntech.de>

diff --git a/arch/arm/boot/dts/rk3288-veyron-mickey.dts b/arch/arm/boot/dts/rk3288-veyron-mickey.dts
index 34797ab..945e808 100644 (file)
--- a/arch/arm/boot/dts/rk3288-veyron-mickey.dts
+++ b/arch/arm/boot/dts/rk3288-veyron-mickey.dts
@@ -136,6 +136,73 @@
        };
 };
 
+&gpu_thermal {
+       /delete-node/ trips;
+       /delete-node/ cooling-maps;
+
+       trips {
+               gpu_alert_warmish: gpu_alert_warmish {
+                       temperature = <60000>; /* millicelsius */
+                       hysteresis = <2000>; /* millicelsius */
+                       type = "passive";
+               };
+               gpu_alert_warm: gpu_alert_warm {
+                       temperature = <65000>; /* millicelsius */
+                       hysteresis = <2000>; /* millicelsius */
+                       type = "passive";
+               };
+               gpu_alert_hotter: gpu_alert_hotter {
+                       temperature = <84000>; /* millicelsius */
+                       hysteresis = <2000>; /* millicelsius */
+                       type = "passive";
+               };
+               gpu_alert_very_very_hot: gpu_alert_very_very_hot {
+                       temperature = <86000>; /* millicelsius */
+                       hysteresis = <2000>; /* millicelsius */
+                       type = "passive";
+               };
+               gpu_crit: gpu_crit {
+                       temperature = <90000>; /* millicelsius */
+                       hysteresis = <2000>; /* millicelsius */
+                       type = "critical";
+               };
+       };
+
+       cooling-maps {
+               /* After 1st level throttle the GPU down to as low as 400 MHz */
+               gpu_warmish_limit_gpu {
+                       trip = <&gpu_alert_warmish>;
+                       cooling-device = <&gpu THERMAL_NO_LIMIT 1>;
+               };
+
+               /*
+                * Slightly after we throttle the GPU, we'll also make sure that
+                * the CPU can't go faster than 1.4 GHz.  Note that we won't
+                * throttle the CPU lower than 1.4 GHz due to GPU heat--we'll
+                * let the CPU do the rest itself.
+                */
+               gpu_warm_limit_cpu {
+                       trip = <&gpu_alert_warm>;
+                       cooling-device = <&cpu0 4 4>,
+                                        <&cpu1 4 4>,
+                                        <&cpu2 4 4>,
+                                        <&cpu3 4 4>;
+               };
+
+               /* When hot, GPU goes down to 300 MHz */
+               gpu_hotter_limit_gpu {
+                       trip = <&gpu_alert_hotter>;
+                       cooling-device = <&gpu 2 2>;
+               };
+
+               /* When really hot, don't let GPU go _above_ 300 MHz */
+               gpu_very_very_hot_limit_gpu {
+                       trip = <&gpu_alert_very_very_hot>;
+                       cooling-device = <&gpu 2 THERMAL_NO_LIMIT>;
+               };
+       };
+};
+
 &i2c2 {
        status = "disabled";
 };