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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-27 10:05:51 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-27 10:05:51 +0000
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treea94efe259b9009378be6d90eb30d2b019d95c194 /Documentation/devicetree/bindings/thermal/nvidia,tegra124-soctherm.txt
parentInitial commit. (diff)
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Adding upstream version 5.10.209.upstream/5.10.209upstream
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+Tegra124 SOCTHERM thermal management system
+
+The SOCTHERM IP block contains thermal sensors, support for polled
+or interrupt-based thermal monitoring, CPU and GPU throttling based
+on temperature trip points, and handling external overcurrent
+notifications. It is also used to manage emergency shutdown in an
+overheating situation.
+
+Required properties :
+- compatible : For Tegra124, must contain "nvidia,tegra124-soctherm".
+ For Tegra132, must contain "nvidia,tegra132-soctherm".
+ For Tegra210, must contain "nvidia,tegra210-soctherm".
+- reg : Should contain at least 2 entries for each entry in reg-names:
+ - SOCTHERM register set
+ - Tegra CAR register set: Required for Tegra124 and Tegra210.
+ - CCROC register set: Required for Tegra132.
+- reg-names : Should contain at least 2 entries:
+ - soctherm-reg
+ - car-reg
+ - ccroc-reg
+- interrupts : Defines the interrupt used by SOCTHERM
+- clocks : Must contain an entry for each entry in clock-names.
+ See ../clocks/clock-bindings.txt for details.
+- clock-names : Must include the following entries:
+ - tsensor
+ - soctherm
+- resets : Must contain an entry for each entry in reset-names.
+ See ../reset/reset.txt for details.
+- reset-names : Must include the following entries:
+ - soctherm
+- #thermal-sensor-cells : Should be 1. For a description of this property, see
+ Documentation/devicetree/bindings/thermal/thermal-sensor.yaml.
+ See <dt-bindings/thermal/tegra124-soctherm.h> for a list of valid values
+ when referring to thermal sensors.
+- throttle-cfgs: A sub-node which is a container of configuration for each
+ hardware throttle events. These events can be set as cooling devices.
+ * throttle events: Sub-nodes must be named as "light" or "heavy".
+ Properties:
+ - nvidia,priority: Each throttles has its own throttle settings, so the
+ SW need to set priorities for various throttle, the HW arbiter can select
+ the final throttle settings.
+ Bigger value indicates higher priority, In general, higher priority
+ translates to lower target frequency. SW needs to ensure that critical
+ thermal alarms are given higher priority, and ensure that there is
+ no race if priority of two vectors is set to the same value.
+ The range of this value is 1~100.
+ - nvidia,cpu-throt-percent: This property is for Tegra124 and Tegra210.
+ It is the throttling depth of pulse skippers, it's the percentage
+ throttling.
+ - nvidia,cpu-throt-level: This property is only for Tegra132, it is the
+ level of pulse skippers, which used to throttle clock frequencies. It
+ indicates cpu clock throttling depth, and the depth can be programmed.
+ Must set as following values:
+ TEGRA_SOCTHERM_THROT_LEVEL_LOW, TEGRA_SOCTHERM_THROT_LEVEL_MED
+ TEGRA_SOCTHERM_THROT_LEVEL_HIGH, TEGRA_SOCTHERM_THROT_LEVEL_NONE
+ - nvidia,gpu-throt-level: This property is for Tegra124 and Tegra210.
+ It is the level of pulse skippers, which used to throttle clock
+ frequencies. It indicates gpu clock throttling depth and can be
+ programmed to any of the following values which represent a throttling
+ percentage:
+ TEGRA_SOCTHERM_THROT_LEVEL_NONE (0%)
+ TEGRA_SOCTHERM_THROT_LEVEL_LOW (50%),
+ TEGRA_SOCTHERM_THROT_LEVEL_MED (75%),
+ TEGRA_SOCTHERM_THROT_LEVEL_HIGH (85%).
+ - #cooling-cells: Should be 1. This cooling device only support on/off state.
+ For a description of this property see:
+ Documentation/devicetree/bindings/thermal/thermal-cooling-devices.yaml
+
+ Optional properties: The following properties are T210 specific and
+ valid only for OCx throttle events.
+ - nvidia,count-threshold: Specifies the number of OC events that are
+ required for triggering an interrupt. Interrupts are not triggered if
+ the property is missing. A value of 0 will interrupt on every OC alarm.
+ - nvidia,polarity-active-low: Configures the polarity of the OC alaram
+ signal. If present, this means assert low, otherwise assert high.
+ - nvidia,alarm-filter: Number of clocks to filter event. When the filter
+ expires (which means the OC event has not occurred for a long time),
+ the counter is cleared and filter is rearmed. Default value is 0.
+ - nvidia,throttle-period-us: Specifies the number of uSec for which
+ throttling is engaged after the OC event is deasserted. Default value
+ is 0.
+
+Optional properties:
+- nvidia,thermtrips : When present, this property specifies the temperature at
+ which the soctherm hardware will assert the thermal trigger signal to the
+ Power Management IC, which can be configured to reset or shutdown the device.
+ It is an array of pairs where each pair represents a tsensor id followed by a
+ temperature in milli Celcius. In the absence of this property the critical
+ trip point will be used for thermtrip temperature.
+
+Note:
+- the "critical" type trip points will be used to set the temperature at which
+the SOC_THERM hardware will assert a thermal trigger if the "nvidia,thermtrips"
+property is missing. When the thermtrips property is present, the breach of a
+critical trip point is reported back to the thermal framework to implement
+software shutdown.
+
+- the "hot" type trip points will be set to SOC_THERM hardware as the throttle
+temperature. Once the the temperature of this thermal zone is higher
+than it, it will trigger the HW throttle event.
+
+Example :
+
+ soctherm@700e2000 {
+ compatible = "nvidia,tegra124-soctherm";
+ reg = <0x0 0x700e2000 0x0 0x600 /* SOC_THERM reg_base */
+ 0x0 0x60006000 0x0 0x400 /* CAR reg_base */
+ reg-names = "soctherm-reg", "car-reg";
+ interrupts = <GIC_SPI 48 IRQ_TYPE_LEVEL_HIGH>;
+ clocks = <&tegra_car TEGRA124_CLK_TSENSOR>,
+ <&tegra_car TEGRA124_CLK_SOC_THERM>;
+ clock-names = "tsensor", "soctherm";
+ resets = <&tegra_car 78>;
+ reset-names = "soctherm";
+
+ #thermal-sensor-cells = <1>;
+
+ nvidia,thermtrips = <TEGRA124_SOCTHERM_SENSOR_CPU 102500
+ TEGRA124_SOCTHERM_SENSOR_GPU 103000>;
+
+ throttle-cfgs {
+ /*
+ * When the "heavy" cooling device triggered,
+ * the HW will skip cpu clock's pulse in 85% depth,
+ * skip gpu clock's pulse in 85% level
+ */
+ throttle_heavy: heavy {
+ nvidia,priority = <100>;
+ nvidia,cpu-throt-percent = <85>;
+ nvidia,gpu-throt-level = <TEGRA_SOCTHERM_THROT_LEVEL_HIGH>;
+
+ #cooling-cells = <1>;
+ };
+
+ /*
+ * When the "light" cooling device triggered,
+ * the HW will skip cpu clock's pulse in 50% depth,
+ * skip gpu clock's pulse in 50% level
+ */
+ throttle_light: light {
+ nvidia,priority = <80>;
+ nvidia,cpu-throt-percent = <50>;
+ nvidia,gpu-throt-level = <TEGRA_SOCTHERM_THROT_LEVEL_LOW>;
+
+ #cooling-cells = <1>;
+ };
+
+ /*
+ * If these two devices are triggered in same time, the HW throttle
+ * arbiter will select the highest priority as the final throttle
+ * settings to skip cpu pulse.
+ */
+
+ throttle_oc1: oc1 {
+ nvidia,priority = <50>;
+ nvidia,polarity-active-low;
+ nvidia,count-threshold = <100>;
+ nvidia,alarm-filter = <5100000>;
+ nvidia,throttle-period-us = <0>;
+ nvidia,cpu-throt-percent = <75>;
+ nvidia,gpu-throt-level =
+ <TEGRA_SOCTHERM_THROT_LEVEL_MED>;
+ };
+ };
+ };
+
+Example: referring to Tegra132's "reg", "reg-names" and "throttle-cfgs" :
+
+ soctherm@700e2000 {
+ compatible = "nvidia,tegra132-soctherm";
+ reg = <0x0 0x700e2000 0x0 0x600 /* SOC_THERM reg_base */
+ 0x0 0x70040000 0x0 0x200>; /* CCROC reg_base */;
+ reg-names = "soctherm-reg", "ccroc-reg";
+
+ throttle-cfgs {
+ /*
+ * When the "heavy" cooling device triggered,
+ * the HW will skip cpu clock's pulse in HIGH level
+ */
+ throttle_heavy: heavy {
+ nvidia,priority = <100>;
+ nvidia,cpu-throt-level = <TEGRA_SOCTHERM_THROT_LEVEL_HIGH>;
+
+ #cooling-cells = <1>;
+ };
+
+ /*
+ * When the "light" cooling device triggered,
+ * the HW will skip cpu clock's pulse in MED level
+ */
+ throttle_light: light {
+ nvidia,priority = <80>;
+ nvidia,cpu-throt-level = <TEGRA_SOCTHERM_THROT_LEVEL_MED>;
+
+ #cooling-cells = <1>;
+ };
+
+ /*
+ * If these two devices are triggered in same time, the HW throttle
+ * arbiter will select the highest priority as the final throttle
+ * settings to skip cpu pulse.
+ */
+
+ };
+ };
+
+Example: referring to thermal sensors :
+
+ thermal-zones {
+ cpu {
+ polling-delay-passive = <1000>;
+ polling-delay = <1000>;
+
+ thermal-sensors =
+ <&soctherm TEGRA124_SOCTHERM_SENSOR_CPU>;
+
+ trips {
+ cpu_shutdown_trip: shutdown-trip {
+ temperature = <102500>;
+ hysteresis = <1000>;
+ type = "critical";
+ };
+
+ cpu_throttle_trip: throttle-trip {
+ temperature = <100000>;
+ hysteresis = <1000>;
+ type = "hot";
+ };
+ };
+
+ cooling-maps {
+ map0 {
+ trip = <&cpu_throttle_trip>;
+ cooling-device = <&throttle_heavy 1 1>;
+ };
+ };
+ };
+ };