mali: Scale for temperature in juno static power model

Signed-off-by: Jon Medhurst <tixy@linaro.org>

1 files changed, 40 insertions, 8 deletions

diff --git a/drivers/gpu/arm/midgard/platform/juno_soc/mali_kbase_config_vexpress.c b/drivers/gpu/arm/midgard/platform/juno_soc/mali_kbase_config_vexpress.c
index a19199b8f7d4..9c776eb7ef6c 100644
--- a/drivers/gpu/arm/midgard/platform/juno_soc/mali_kbase_config_vexpress.c
+++ b/drivers/gpu/arm/midgard/platform/juno_soc/mali_kbase_config_vexpress.c
@@ -9,6 +9,7 @@
 
 #include <linux/ioport.h>
 #include <linux/devfreq_cooling.h>
+#include <linux/thermal.h>
 #include <mali_kbase.h>
 #include <mali_kbase_defs.h>
 #include <mali_kbase_config.h>
@@ -56,16 +57,47 @@ static struct kbase_pm_callback_conf pm_callbacks = {
 	.power_resume_callback = NULL
 };
 
+#define FALLBACK_STATIC_TEMPERATURE 55000
+
 static unsigned long juno_model_static_power(unsigned long voltage)
 {
-	/* Calculate power, corrected for voltage.
-	 * Shifts are done to avoid overflow. */
-	const unsigned long coefficient =
-		(410UL << 20) / (729000000UL >> 10);
-	const unsigned long voltage_cubed =
-		(voltage * voltage * voltage) >> 10;
-
-	return (((coefficient * voltage_cubed) >> 20));
+	struct thermal_zone_device *tz;
+	unsigned long temperature, temp;
+	unsigned long temp_squared, temp_cubed, temp_scaling_factor;
+	const unsigned long coefficient = (410UL << 20) / (729000000UL >> 10);
+	const unsigned long voltage_cubed = (voltage * voltage * voltage) >> 10;
+
+	tz = thermal_zone_get_zone_by_name("gpu");
+	if (IS_ERR(tz)) {
+		pr_warn_ratelimited("Error getting gpu thermal zone (%ld), not yet ready?\n",
+				PTR_ERR(tz));
+		temperature = FALLBACK_STATIC_TEMPERATURE;
+	} else {
+		int ret;
+
+		ret = tz->ops->get_temp(tz, &temperature);
+		if (ret) {
+			pr_warn_ratelimited("Error reading temperature for gpu thermal zone: %d\n",
+					ret);
+			temperature = FALLBACK_STATIC_TEMPERATURE;
+		}
+	}
+
+	/* Calculate the temperature scaling factor. To be applied to the
+	 * voltage scaled power.
+	 */
+	temp = temperature / 1000;
+	temp_squared = temp * temp;
+	temp_cubed = temp_squared * temp;
+	temp_scaling_factor =
+			(2 * temp_cubed)
+			- (80 * temp_squared)
+			+ (4700 * temp)
+			+ 32000;
+
+	return (((coefficient * voltage_cubed) >> 20)
+			* temp_scaling_factor)
+				/ 1000000;
 }
 
 static unsigned long juno_model_dynamic_power(unsigned long freq,