Let device tree set thermal zones in the thermal-sensors list of phandles and set up the thermal zone hierarchy based on the information present there.
Cc: Zhang Rui <[email protected]> Cc: Eduardo Valentin <[email protected]> Signed-off-by: Javi Merino <[email protected]> --- .../devicetree/bindings/thermal/thermal.txt | 154 ++++++++++++++++++++- drivers/thermal/of-thermal.c | 98 +++++++++++++ 2 files changed, 249 insertions(+), 3 deletions(-) diff --git a/Documentation/devicetree/bindings/thermal/thermal.txt b/Documentation/devicetree/bindings/thermal/thermal.txt index 41b817f7b670..52b7e9ae3b4d 100644 --- a/Documentation/devicetree/bindings/thermal/thermal.txt +++ b/Documentation/devicetree/bindings/thermal/thermal.txt @@ -145,9 +145,12 @@ Required properties: Size: one cell - thermal-sensors: A list of thermal sensor phandles and sensor specifier - Type: list of used while monitoring the thermal zone. - phandles + sensor - specifier + Type: list of used while monitoring the thermal zone. The phandles + phandles + sensor can point to thermal sensors or other thermal zone + specifier nodes. If it points to other thermal zone + nodes you should omit the sensor specifier + and set #thermal-sensor-cells to 0 for the + thermal zone. - trips: A sub-node which is a container of only trip point nodes Type: sub-node required to describe the thermal zone. @@ -603,3 +606,148 @@ thermal-zones { The above example is a mix of previous examples, a sensor IP with several internal sensors used to monitor different zones, one of them is composed by several sensors and with different cooling devices. + +(e) Board thermal with stacked thermal zones + +Instead of setting up one thermal zone combining multiple thermal +zones and multiple trip points for each cooling device, we can create +a hierarchy of thermal zones. + +#include <dt-bindings/thermal/thermal.h> + +&i2c1 { + ... + /* + * An IC with several temperature sensor. + */ + adc_dummy: sensor@0x50 { + ... + #thermal-sensor-cells = <1>; /* sensor internal ID */ + }; +}; + +thermal-zones { + + cpu_thermal: cpu_thermal { + polling-delay-passive = <1000>; /* milliseconds */ + polling-delay = <2500>; /* milliseconds */ + + sustainable-power = <2500>; + + thermal-sensors = <&adc_dummy 0> + + trips { + cpu_trip: cpu-trip { + temperature = <60000>; /* millicelsius */ + hysteresis = <2000>; /* millicelsius */ + type = "passive"; + }; + }; + + cooling-maps { + map0 { + trip = <&cpu_trip>; + cooling-device = <&cpu0 0 2>; + }; + }; + }; + + gpu_thermal: gpu_thermal { + polling-delay-passive = <1000>; /* milliseconds */ + polling-delay = <2500>; /* milliseconds */ + + sustainable-power = <2500>; + + thermal-sensors = <&adc_dummy 2> + + trips { + gpu_trip: gpu-trip { + temperature = <55000>; /* millicelsius */ + hysteresis = <2000>; /* millicelsius */ + type = "passive"; + } + }; + + cooling-maps { + map0 { + trip = <&gpu_trip>; + cooling-device = <&gpu0 0 2>; + }; + }; + }; + + lcd_thermal: lcd_thermal { + polling-delay-passive = <1000>; /* milliseconds */ + polling-delay = <2500>; /* milliseconds */ + + sustainable-power = <2500>; + + thermal-sensors = <&adc_dummy 1> + + trips { + lcd_trip: lcp-trip { + temperature = <53000>; /* millicelsius */ + hysteresis = <2000>; /* millicelsius */ + type = "passive"; + }; + }; + + cooling-maps { + map0 { + trip = <&lcd_trip>; + cooling-device = <&lcd0 5 10>; + }; + }; + }; + + board_thermal: board-thermal { + polling-delay-passive = <1000>; /* milliseconds */ + polling-delay = <2500>; /* milliseconds */ + + thermal-sensors = <&cpu_thermal &gpu_thermal &lcd_thermal> + + sustainable-power = <2500>; + + trips { + warm_trip: warm-trip { + temperature = <62000>; /* millicelsius */ + hysteresis = <2000>; /* millicelsius */ + type = "passive"; + }; + crit_trip: crit-trip { + temperature = <68000>; /* millicelsius */ + hysteresis = <2000>; /* millicelsius */ + type = "critical"; + }; + }; + + cooling-maps { + map0 { + trip = <&warm_trip>; + cooling-device = <&cpu0 2 2>; + contribution = <55>; + }; + map1 { + trip = <&warm_trip>; + cooling-device = <&gpu0 2 2>; + contribution = <20>; + }; + map2 { + trip = <&lcd_trip>; + cooling-device = <&lcd0 7 10>; + contribution = <15>; + }; + }; + }; +}; + +The above example is a different take at example (d). We create one +thermal zone per sensor: cpu_thermal, gpu_thermal and lcd_thermal. +Each of which has its own trip point for each own cooling device. We +then define a board_thermal thermal zone that is a combination of all +the other thermal zones. If the board hits its warm_trip, then all +cooling devices are throttled. + +This example illustrates how we can throttle each device individually +if its too hot and at the same time have some control over the whole +system. diff --git a/drivers/thermal/of-thermal.c b/drivers/thermal/of-thermal.c index 42b7d4253b94..d0431f6058bd 100644 --- a/drivers/thermal/of-thermal.c +++ b/drivers/thermal/of-thermal.c @@ -166,6 +166,26 @@ of_thermal_get_trip_points(struct thermal_zone_device *tz) EXPORT_SYMBOL_GPL(of_thermal_get_trip_points); /** + * of_thermal_is_thermal_zone() - check that a device node corresponds to a thermal zone + * @np: the device node + * + * Valid thermal zone device nodes must provide the + * polling-delay-passive and polling-delay properties. If this device + * node provides them return true, as it's a valid device node for a + * thermal zone. + */ +static bool of_thermal_is_thermal_zone(struct device_node *np) +{ + u32 out; + + if ((of_property_read_u32(np, "polling-delay-passive", &out)) || + (of_property_read_u32(np, "polling-delay", &out))) + return false; + + return true; +} + +/** * of_thermal_set_emul_temp - function to set emulated temperature * * @tz: pointer to a thermal zone @@ -858,6 +878,81 @@ static inline void of_thermal_free_zone(struct __thermal_zone *tz) } /** + * link_stacked_thermal_zones() - link thermal zones that are a superset of thermal zones + * @np: device node for the root of the thermal zones + * + * A thermal zone can specify other thermal zones as its input using + * the thermal-sensors property of device tree. This function parses + * all the thermal zones in dt and adds the thermal zones in their + * thermal-sensors as sub-thermalzones. + */ +static void link_stacked_thermal_zones(struct device_node *np) +{ + struct device_node *child; + + for_each_child_of_node(np, child) { + int i, num_sensors; + struct thermal_zone_device *tz; + + num_sensors = of_count_phandle_with_args(child, + "thermal-sensors", + "#thermal-sensor-cells"); + if (num_sensors <= 0) + continue; + + tz = thermal_zone_get_zone_by_name(child->name); + if (IS_ERR_OR_NULL(tz)) { + /* + * If the tz is available we should have added + * it in of_parse_thermal_zones() + */ + WARN(of_device_is_available(child), + "Couldn't find thermal zone for %s\n", + of_node_full_name(child)); + continue; + } + + for (i = 0; i < num_sensors; i++) { + struct of_phandle_args sensor_specs; + struct thermal_zone_device *subtz; + int ret; + + ret = of_parse_phandle_with_args(child, + "thermal-sensors", + "#thermal-sensor-cells", + i, &sensor_specs); + if (ret) { + pr_warn("Failed to parse thermal-sensors of %s: %d\n", + of_node_full_name(child), ret); + of_node_put(sensor_specs.np); + continue; + } + + if (!of_thermal_is_thermal_zone(sensor_specs.np)) { + of_node_put(sensor_specs.np); + continue; + } + + subtz = thermal_zone_get_zone_by_name( + sensor_specs.np->name); + if (IS_ERR_OR_NULL(subtz)) { + pr_warn("Couldn't find thermal zone for %s, is it disabled?\n", + of_node_full_name(sensor_specs.np)); + of_node_put(sensor_specs.np); + continue; + } + + ret = thermal_zone_add_subtz(tz, subtz); + if (ret) + pr_warn("Failed to add thermal zone %s to %s: %d\n", + subtz->type, tz->type, ret); + + of_node_put(sensor_specs.np); + } + } +} + +/** * of_parse_thermal_zones - parse device tree thermal data * * Initialization function that can be called by machine initialization @@ -936,6 +1031,9 @@ int __init of_parse_thermal_zones(void) /* attempting to build remaining zones still */ } } + + link_stacked_thermal_zones(np); + of_node_put(np); return 0; -- 1.9.1 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
