diff options
| -rw-r--r-- | Documentation/devicetree/bindings/thermal/thermal.txt | 595 | ||||
| -rw-r--r-- | drivers/thermal/Kconfig | 13 | ||||
| -rw-r--r-- | drivers/thermal/Makefile | 1 | ||||
| -rw-r--r-- | drivers/thermal/of-thermal.c | 849 | ||||
| -rw-r--r-- | drivers/thermal/thermal_core.c | 9 | ||||
| -rw-r--r-- | drivers/thermal/thermal_core.h | 9 | ||||
| -rw-r--r-- | include/dt-bindings/thermal/thermal.h | 17 | ||||
| -rw-r--r-- | include/linux/thermal.h | 28 |
8 files changed, 1518 insertions, 3 deletions
diff --git a/Documentation/devicetree/bindings/thermal/thermal.txt b/Documentation/devicetree/bindings/thermal/thermal.txt new file mode 100644 index 000000000000..f5db6b72a36f --- /dev/null +++ b/Documentation/devicetree/bindings/thermal/thermal.txt @@ -0,0 +1,595 @@ +* Thermal Framework Device Tree descriptor + +This file describes a generic binding to provide a way of +defining hardware thermal structure using device tree. +A thermal structure includes thermal zones and their components, +such as trip points, polling intervals, sensors and cooling devices +binding descriptors. + +The target of device tree thermal descriptors is to describe only +the hardware thermal aspects. The thermal device tree bindings are +not about how the system must control or which algorithm or policy +must be taken in place. + +There are five types of nodes involved to describe thermal bindings: +- thermal sensors: devices which may be used to take temperature + measurements. +- cooling devices: devices which may be used to dissipate heat. +- trip points: describe key temperatures at which cooling is recommended. The + set of points should be chosen based on hardware limits. +- cooling maps: used to describe links between trip points and cooling devices; +- thermal zones: used to describe thermal data within the hardware; + +The following is a description of each of these node types. + +* Thermal sensor devices + +Thermal sensor devices are nodes providing temperature sensing capabilities on +thermal zones. Typical devices are I2C ADC converters and bandgaps. These are +nodes providing temperature data to thermal zones. Thermal sensor devices may +control one or more internal sensors. + +Required property: +- #thermal-sensor-cells: Used to provide sensor device specific information + Type: unsigned while referring to it. Typically 0 on thermal sensor + Size: one cell nodes with only one sensor, and at least 1 on nodes + with several internal sensors, in order + to identify uniquely the sensor instances within + the IC. See thermal zone binding for more details + on how consumers refer to sensor devices. + +* Cooling device nodes + +Cooling devices are nodes providing control on power dissipation. There +are essentially two ways to provide control on power dissipation. First +is by means of regulating device performance, which is known as passive +cooling. A typical passive cooling is a CPU that has dynamic voltage and +frequency scaling (DVFS), and uses lower frequencies as cooling states. +Second is by means of activating devices in order to remove +the dissipated heat, which is known as active cooling, e.g. regulating +fan speeds. In both cases, cooling devices shall have a way to determine +the state of cooling in which the device is. + +Any cooling device has a range of cooling states (i.e. different levels +of heat dissipation). For example a fan's cooling states correspond to +the different fan speeds possible. Cooling states are referred to by +single unsigned integers, where larger numbers mean greater heat +dissipation. The precise set of cooling states associated with a device +(as referred to be the cooling-min-state and cooling-max-state +properties) should be defined in a particular device's binding. +For more examples of cooling devices, refer to the example sections below. + +Required properties: +- cooling-min-state: An integer indicating the smallest + Type: unsigned cooling state accepted. Typically 0. + Size: one cell + +- cooling-max-state: An integer indicating the largest + Type: unsigned cooling state accepted. + Size: one cell + +- #cooling-cells: Used to provide cooling device specific information + Type: unsigned while referring to it. Must be at least 2, in order + Size: one cell to specify minimum and maximum cooling state used + in the reference. The first cell is the minimum + cooling state requested and the second cell is + the maximum cooling state requested in the reference. + See Cooling device maps section below for more details + on how consumers refer to cooling devices. + +* Trip points + +The trip node is a node to describe a point in the temperature domain +in which the system takes an action. This node describes just the point, +not the action. + +Required properties: +- temperature: An integer indicating the trip temperature level, + Type: signed in millicelsius. + Size: one cell + +- hysteresis: A low hysteresis value on temperature property (above). + Type: unsigned This is a relative value, in millicelsius. + Size: one cell + +- type: a string containing the trip type. Expected values are: + "active": A trip point to enable active cooling + "passive": A trip point to enable passive cooling + "hot": A trip point to notify emergency + "critical": Hardware not reliable. + Type: string + +* Cooling device maps + +The cooling device maps node is a node to describe how cooling devices +get assigned to trip points of the zone. The cooling devices are expected +to be loaded in the target system. + +Required properties: +- cooling-device: A phandle of a cooling device with its specifier, + Type: phandle + referring to which cooling device is used in this + cooling specifier binding. In the cooling specifier, the first cell + is the minimum cooling state and the second cell + is the maximum cooling state used in this map. +- trip: A phandle of a trip point node within the same thermal + Type: phandle of zone. + trip point node + +Optional property: +- contribution: The cooling contribution to the thermal zone of the + Type: unsigned referred cooling device at the referred trip point. + Size: one cell The contribution is a ratio of the sum + of all cooling contributions within a thermal zone. + +Note: Using the THERMAL_NO_LIMIT (-1UL) constant in the cooling-device phandle +limit specifier means: +(i) - minimum state allowed for minimum cooling state used in the reference. +(ii) - maximum state allowed for maximum cooling state used in the reference. +Refer to include/dt-bindings/thermal/thermal.h for definition of this constant. + +* Thermal zone nodes + +The thermal zone node is the node containing all the required info +for describing a thermal zone, including its cooling device bindings. The +thermal zone node must contain, apart from its own properties, one sub-node +containing trip nodes and one sub-node containing all the zone cooling maps. + +Required properties: +- polling-delay: The maximum number of milliseconds to wait between polls + Type: unsigned when checking this thermal zone. + Size: one cell + +- polling-delay-passive: The maximum number of milliseconds to wait + Type: unsigned between polls when performing passive cooling. + 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 + +- trips: A sub-node which is a container of only trip point nodes + Type: sub-node required to describe the thermal zone. + +- cooling-maps: A sub-node which is a container of only cooling device + Type: sub-node map nodes, used to describe the relation between trips + and cooling devices. + +Optional property: +- coefficients: An array of integers (one signed cell) containing + Type: array coefficients to compose a linear relation between + Elem size: one cell the sensors listed in the thermal-sensors property. + Elem type: signed Coefficients defaults to 1, in case this property + is not specified. A simple linear polynomial is used: + Z = c0 * x0 + c1 + x1 + ... + c(n-1) * x(n-1) + cn. + + The coefficients are ordered and they match with sensors + by means of sensor ID. Additional coefficients are + interpreted as constant offset. + +Note: The delay properties are bound to the maximum dT/dt (temperature +derivative over time) in two situations for a thermal zone: +(i) - when passive cooling is activated (polling-delay-passive); and +(ii) - when the zone just needs to be monitored (polling-delay) or +when active cooling is activated. + +The maximum dT/dt is highly bound to hardware power consumption and dissipation +capability. The delays should be chosen to account for said max dT/dt, +such that a device does not cross several trip boundaries unexpectedly +between polls. Choosing the right polling delays shall avoid having the +device in temperature ranges that may damage the silicon structures and +reduce silicon lifetime. + +* The thermal-zones node + +The "thermal-zones" node is a container for all thermal zone nodes. It shall +contain only sub-nodes describing thermal zones as in the section +"Thermal zone nodes". The "thermal-zones" node appears under "/". + +* Examples + +Below are several examples on how to use thermal data descriptors +using device tree bindings: + +(a) - CPU thermal zone + +The CPU thermal zone example below describes how to setup one thermal zone +using one single sensor as temperature source and many cooling devices and +power dissipation control sources. + +#include <dt-bindings/thermal/thermal.h> + +cpus { + /* + * Here is an example of describing a cooling device for a DVFS + * capable CPU. The CPU node describes its four OPPs. + * The cooling states possible are 0..3, and they are + * used as OPP indexes. The minimum cooling state is 0, which means + * all four OPPs can be available to the system. The maximum + * cooling state is 3, which means only the lowest OPPs (198MHz@0.85V) + * can be available in the system. + */ + cpu0: cpu@0 { + ... + operating-points = < + /* kHz uV */ + 970000 1200000 + 792000 1100000 + 396000 950000 + 198000 850000 + >; + cooling-min-state = <0>; + cooling-max-state = <3>; + #cooling-cells = <2>; /* min followed by max */ + }; + ... +}; + +&i2c1 { + ... + /* + * A simple fan controller which supports 10 speeds of operation + * (represented as 0-9). + */ + fan0: fan@0x48 { + ... + cooling-min-state = <0>; + cooling-max-state = <9>; + #cooling-cells = <2>; /* min followed by max */ + }; +}; + +ocp { + ... + /* + * A simple IC with a single bandgap temperature sensor. + */ + bandgap0: bandgap@0x0000ED00 { + ... + #thermal-sensor-cells = <0>; + }; +}; + +thermal-zones { + cpu-thermal: cpu-thermal { + polling-delay-passive = <250>; /* milliseconds */ + polling-delay = <1000>; /* milliseconds */ + + thermal-sensors = <&bandgap0>; + + trips { + cpu-alert0: cpu-alert { + temperature = <90000>; /* millicelsius */ + hysteresis = <2000>; /* millicelsius */ + type = "active"; + }; + cpu-alert1: cpu-alert { + temperature = <100000>; /* millicelsius */ + hysteresis = <2000>; /* millicelsius */ + type = "passive"; + }; + cpu-crit: cpu-crit { + temperature = <125000>; /* millicelsius */ + hysteresis = <2000>; /* millicelsius */ + type = "critical"; + }; + }; + + cooling-maps { + map0 { + trip = <&cpu-alert0>; + cooling-device = <&fan0 THERMAL_NO_LIMITS 4>; + }; + map1 { + trip = <&cpu-alert1>; + cooling-device = <&fan0 5 THERMAL_NO_LIMITS>; + }; + map2 { + trip = <&cpu-alert1>; + cooling-device = + <&cpu0 THERMAL_NO_LIMITS THERMAL_NO_LIMITS>; + }; + }; + }; +}; + +In the example above, the ADC sensor (bandgap0) at address 0x0000ED00 is +used to monitor the zone 'cpu-thermal' using its sole sensor. A fan +device (fan0) is controlled via I2C bus 1, at address 0x48, and has ten +different cooling states 0-9. It is used to remove the heat out of +the thermal zone 'cpu-thermal' using its cooling states +from its minimum to 4, when it reaches trip point 'cpu-alert0' +at 90C, as an example of active cooling. The same cooling device is used at +'cpu-alert1', but from 5 to its maximum state. The cpu@0 device is also +linked to the same thermal zone, 'cpu-thermal', as a passive cooling device, +using all its cooling states at trip point 'cpu-alert1', +which is a trip point at 100C. On the thermal zone 'cpu-thermal', at the +temperature of 125C, represented by the trip point 'cpu-crit', the silicon +is not reliable anymore. + +(b) - IC with several internal sensors + +The example below describes how to deploy several thermal zones based off a +single sensor IC, assuming it has several internal sensors. This is a common +case on SoC designs with several internal IPs that may need different thermal +requirements, and thus may have their own sensor to monitor or detect internal +hotspots in their silicon. + +#include <dt-bindings/thermal/thermal.h> + +ocp { + ... + /* + * A simple IC with several bandgap temperature sensors. + */ + bandgap0: bandgap@0x0000ED00 { + ... + #thermal-sensor-cells = <1>; + }; +}; + +thermal-zones { + cpu-thermal: cpu-thermal { + polling-delay-passive = <250>; /* milliseconds */ + polling-delay = <1000>; /* milliseconds */ + + /* sensor ID */ + thermal-sensors = <&bandgap0 0>; + + trips { + /* each zone within the SoC may have its own trips */ + cpu-alert: cpu-alert { + temperature = <100000>; /* millicelsius */ + hysteresis = <2000>; /* millicelsius */ + type = "passive"; + }; + cpu-crit: cpu-crit { + temperature = <125000>; /* millicelsius */ + hysteresis = <2000>; /* millicelsius */ + type = "critical"; + }; + }; + + cooling-maps { + /* each zone within the SoC may have its own cooling */ + ... + }; + }; + + gpu-thermal: gpu-thermal { + polling-delay-passive = <120>; /* milliseconds */ + polling-delay = <1000>; /* milliseconds */ + + /* sensor ID */ + thermal-sensors = <&bandgap0 1>; + + trips { + /* each zone within the SoC may have its own trips */ + gpu-alert: gpu-alert { + temperature = <90000>; /* millicelsius */ + hysteresis = <2000>; /* millicelsius */ + type = "passive"; + }; + gpu-crit: gpu-crit { + temperature = <105000>; /* millicelsius */ + hysteresis = <2000>; /* millicelsius */ + type = "critical"; + }; + }; + + cooling-maps { + /* each zone within the SoC may have its own cooling */ + ... + }; + }; + + dsp-thermal: dsp-thermal { + polling-delay-passive = <50>; /* milliseconds */ + polling-delay = <1000>; /* milliseconds */ + + /* sensor ID */ + thermal-sensors = <&bandgap0 2>; + + trips { + /* each zone within the SoC may have its own trips */ + dsp-alert: gpu-alert { + temperature = <90000>; /* millicelsius */ + hysteresis = <2000>; /* millicelsius */ + type = "passive"; + }; + dsp-crit: gpu-crit { + temperature = <135000>; /* millicelsius */ + hysteresis = <2000>; /* millicelsius */ + type = "critical"; + }; + }; + + cooling-maps { + /* each zone within the SoC may have its own cooling */ + ... + }; + }; +}; + +In the example above, there is one bandgap IC which has the capability to +monitor three sensors. The hardware has been designed so that sensors are +placed on different places in the DIE to monitor different temperature +hotspots: one for CPU thermal zone, one for GPU thermal zone and the +other to monitor a DSP thermal zone. + +Thus, there is a need to assign each sensor provided by the bandgap IC +to different thermal zones. This is achieved by means of using the +#thermal-sensor-cells property and using the first cell of the sensor +specifier as sensor ID. In the example, then, <bandgap 0> is used to +monitor CPU thermal zone, <bandgap 1> is used to monitor GPU thermal +zone and <bandgap 2> is used to monitor DSP thermal zone. Each zone +may be uncorrelated, having its own dT/dt requirements, trips +and cooling maps. + + +(c) - Several sensors within one single thermal zone + +The example below illustrates how to use more than one sensor within +one thermal zone. + +#include <dt-bindings/thermal/thermal.h> + +&i2c1 { + ... + /* + * A simple IC with a single temperature sensor. + */ + adc: sensor@0x49 { + ... + #thermal-sensor-cells = <0>; + }; +}; + +ocp { + ... + /* + * A simple IC with a single bandgap temperature sensor. + */ + bandgap0: bandgap@0x0000ED00 { + ... + #thermal-sensor-cells = <0>; + }; +}; + +thermal-zones { + cpu-thermal: cpu-thermal { + polling-delay-passive = <250>; /* milliseconds */ + polling-delay = <1000>; /* milliseconds */ + + thermal-sensors = <&bandgap0>, /* cpu */ + <&adc>; /* pcb north */ + + /* hotspot = 100 * bandgap - 120 * adc + 484 */ + coefficients = <100 -120 484>; + + trips { + ... + }; + + cooling-maps { + ... + }; + }; +}; + +In some cases, there is a need to use more than one sensor to extrapolate +a thermal hotspot in the silicon. The above example illustrates this situation. +For instance, it may be the case that a sensor external to CPU IP may be placed +close to CPU hotspot and together with internal CPU sensor, it is used +to determine the hotspot. Assuming this is the case for the above example, +the hypothetical extrapolation rule would be: + hotspot = 100 * bandgap - 120 * adc + 484 + +In other context, the same idea can be used to add fixed offset. For instance, +consider the hotspot extrapolation rule below: + hotspot = 1 * adc + 6000 + +In the above equation, the hotspot is always 6C higher than what is read +from the ADC sensor. The binding would be then: + thermal-sensors = <&adc>; + + /* hotspot = 1 * adc + 6000 */ + coefficients = <1 6000>; + +(d) - Board thermal + +The board thermal example below illustrates how to setup one thermal zone +with many sensors and many cooling devices. + +#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 { + batt-thermal { + polling-delay-passive = <500>; /* milliseconds */ + polling-delay = <2500>; /* milliseconds */ + + /* sensor ID */ + thermal-sensors = <&adc-dummy 4>; + + trips { + ... + }; + + cooling-maps { + ... + }; + }; + + board-thermal: board-thermal { + polling-delay-passive = <1000>; /* milliseconds */ + polling-delay = <2500>; /* milliseconds */ + + /* sensor ID */ + thermal-sensors = <&adc-dummy 0>, /* pcb top edge */ + <&adc-dummy 1>, /* lcd */ + <&adc-dymmy 2>; /* back cover */ + /* + * An array of coefficients describing the sensor + * linear relation. E.g.: + * z = c1*x1 + c2*x2 + c3*x3 + */ + coefficients = <1200 -345 890>; + + trips { + /* Trips are based on resulting linear equation */ + cpu-trip: cpu-trip { + temperature = <60000>; /* millicelsius */ + hysteresis = <2000>; /* millicelsius */ + type = "passive"; + }; + gpu-trip: gpu-trip { + temperature = <55000>; /* millicelsius */ + hysteresis = <2000>; /* millicelsius */ + type = "passive"; + } + lcd-trip: lcp-trip { + temperature = <53000>; /* millicelsius */ + hysteresis = <2000>; /* millicelsius */ + type = "passive"; + }; + crit-trip: crit-trip { + temperature = <68000>; /* millicelsius */ + hysteresis = <2000>; /* millicelsius */ + type = "critical"; + }; + }; + + cooling-maps { + map0 { + trip = <&cpu-trip>; + cooling-device = <&cpu0 0 2>; + contribution = <55>; + }; + map1 { + trip = <&gpu-trip>; + cooling-device = <&gpu0 0 2>; + contribution = <20>; + }; + map2 { + trip = <&lcd-trip>; + cooling-device = <&lcd0 5 10>; + contribution = <15>; + }; + }; + }; +}; + +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. diff --git a/drivers/thermal/Kconfig b/drivers/thermal/Kconfig index d8448bf2de94..3630c074f461 100644 --- a/drivers/thermal/Kconfig +++ b/drivers/thermal/Kconfig @@ -29,6 +29,19 @@ config THERMAL_HWMON Say 'Y' here if you want all thermal sensors to have hwmon sysfs interface too. +config THERMAL_OF + bool + prompt "APIs to parse thermal data out of device tree" + depends on OF + default y + help + This options provides helpers to add the support to + read and parse thermal data definitions out of the + device tree blob. + + Say 'Y' here if you need to build thermal infrastructure + based on device tree. + choice prompt "Default Thermal governor" default THERMAL_DEFAULT_GOV_STEP_WISE diff --git a/drivers/thermal/Makefile b/drivers/thermal/Makefile index db989e9afbfd..71f8eef49c1c 100644 --- a/drivers/thermal/Makefile +++ b/drivers/thermal/Makefile @@ -7,6 +7,7 @@ thermal_sys-y += thermal_core.o # interface to/from other layers providing sensors thermal_sys-$(CONFIG_THERMAL_HWMON) += thermal_hwmon.o +thermal_sys-$(CONFIG_THERMAL_OF) += of-thermal.o # governors thermal_sys-$(CONFIG_THERMAL_GOV_FAIR_SHARE) += fair_share.o diff --git a/drivers/thermal/of-thermal.c b/drivers/thermal/of-thermal.c new file mode 100644 index 000000000000..04b1be7fa018 --- /dev/null +++ b/drivers/thermal/of-thermal.c @@ -0,0 +1,849 @@ +/* + * of-thermal.c - Generic Thermal Management device tree support. + * + * Copyright (C) 2013 Texas Instruments + * Copyright (C) 2013 Eduardo Valentin <eduardo.valentin@ti.com> + * + * + * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; version 2 of the License. + * + * This program is distributed in the hope that it will be useful, but + * WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * General Public License for more details. + * + * You should have received a copy of the GNU General Public License along + * with this program; if not, write to the Free Software Foundation, Inc., + * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA. + * + * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + */ +#include <linux/thermal.h> +#include <linux/slab.h> +#include <linux/types.h> +#include <linux/of_device.h> +#include <linux/of_platform.h> +#include <linux/err.h> +#include <linux/export.h> +#include <linux/string.h> + +#include "thermal_core.h" + +/*** Private data structures to represent thermal device tree data ***/ + +/** + * struct __thermal_trip - representation of a point in temperature domain + * @np: pointer to struct device_node that this trip point was created from + * @temperature: temperature value in miliCelsius + * @hysteresis: relative hysteresis in miliCelsius + * @type: trip point type + */ + +struct __thermal_trip { + struct device_node *np; + unsigned long int temperature; + unsigned long int hysteresis; + enum thermal_trip_type type; +}; + +/** + * struct __thermal_bind_param - a match between trip and cooling device + * @cooling_device: a pointer to identify the referred cooling device + * @trip_id: the trip point index + * @usage: the percentage (from 0 to 100) of cooling contribution + * @min: minimum cooling state used at this trip point + * @max: maximum cooling state used at this trip point + */ + +struct __thermal_bind_params { + struct device_node *cooling_device; + unsigned int trip_id; + unsigned int usage; + unsigned long min; + unsigned long max; +}; + +/** + * struct __thermal_zone - internal representation of a thermal zone + * @mode: current thermal zone device mode (enabled/disabled) + * @passive_delay: polling interval while passive cooling is activated + * @polling_delay: zone polling interval + * @ntrips: number of trip points + * @trips: an array of trip points (0..ntrips - 1) + * @num_tbps: number of thermal bind params + * @tbps: an array of thermal bind params (0..num_tbps - 1) + * @sensor_data: sensor private data used while reading temperature and trend + * @get_temp: sensor callback to read temperature + * @get_trend: sensor callback to read temperature trend + */ + +struct __thermal_zone { + enum thermal_device_mode mode; + int passive_delay; + int polling_delay; + + /* trip data */ + int ntrips; + struct __thermal_trip *trips; + + /* cooling binding data */ + int num_tbps; + struct __thermal_bind_params *tbps; + + /* sensor interface */ + void *sensor_data; + int (*get_temp)(void *, long *); + int (*get_trend)(void *, long *); +}; + +/*** DT thermal zone device callbacks ***/ + +static int of_thermal_get_temp(struct thermal_zone_device *tz, + unsigned long *temp) +{ + struct __thermal_zone *data = tz->devdata; + + if (!data->get_temp) + return -EINVAL; + + return data->get_temp(data->sensor_data, temp); +} + +static int of_thermal_get_trend(struct thermal_zone_device *tz, int trip, + enum thermal_trend *trend) +{ + struct __thermal_zone *data = tz->devdata; + long dev_trend; + int r; + + if (!data->get_trend) + return -EINVAL; + + r = data->get_trend(data->sensor_data, &dev_trend); + if (r) + return r; + + /* TODO: These intervals might have some thresholds, but in core code */ + if (dev_trend > 0) + *trend = THERMAL_TREND_RAISING; + else if (dev_trend < 0) + *trend = THERMAL_TREND_DROPPING; + else + *trend = THERMAL_TREND_STABLE; + + return 0; +} + +static int of_thermal_bind(struct thermal_zone_device *thermal, + struct thermal_cooling_device *cdev) +{ + struct __thermal_zone *data = thermal->devdata; + int i; + + if (!data || IS_ERR(data)) + return -ENODEV; + + /* find where to bind */ + for (i = 0; i < data->num_tbps; i++) { + struct __thermal_bind_params *tbp = data->tbps + i; + + if (tbp->cooling_device == cdev->np) { + int ret; + + ret = thermal_zone_bind_cooling_device(thermal, + tbp->trip_id, cdev, + tbp->min, + tbp->max); + if (ret) + return ret; + } + } + + return 0; +} + +static int of_thermal_unbind(struct thermal_zone_device *thermal, + struct thermal_cooling_device *cdev) +{ + struct __thermal_zone *data = thermal->devdata; + int i; + + if (!data || IS_ERR(data)) + return -ENODEV; + + /* find where to unbind */ + for (i = 0; i < data->num_tbps; i++) { + struct __thermal_bind_params *tbp = data->tbps + i; + + if (tbp->cooling_device == cdev->np) { + int ret; + + ret = thermal_zone_unbind_cooling_device(thermal, + tbp->trip_id, cdev); + if (ret) + return ret; + } + } + + return 0; +} + +static int of_thermal_get_mode(struct thermal_zone_device *tz, + enum thermal_device_mode *mode) +{ + struct __thermal_zone *data = tz->devdata; + + *mode = data->mode; + + return 0; +} + +static int of_thermal_set_mode(struct thermal_zone_device *tz, + enum thermal_device_mode mode) +{ + struct __thermal_zone *data = tz->devdata; + + mutex_lock(&tz->lock); + + if (mode == THERMAL_DEVICE_ENABLED) + tz->polling_delay = data->polling_delay; + else + tz->polling_delay = 0; + + mutex_unlock(&tz->lock); + + data->mode = mode; + thermal_zone_device_update(tz); + + return 0; +} + +static int of_thermal_get_trip_type(struct thermal_zone_device *tz, int trip, + enum thermal_trip_type *type) +{ + struct __thermal_zone *data = tz->devdata; + + if (trip >= data->ntrips || trip < 0) + return -EDOM; + + *type = data->trips[trip].type; + + return 0; +} + +static int of_thermal_get_trip_temp(struct thermal_zone_device *tz, int trip, + unsigned long *temp) +{ + struct __thermal_zone *data = tz->devdata; + + if (trip >= data->ntrips || trip < 0) + return -EDOM; + + *temp = data->trips[trip].temperature; + + return 0; +} + +static int of_thermal_set_trip_temp(struct thermal_zone_device *tz, int trip, + unsigned long temp) +{ + struct __thermal_zone *data = tz->devdata; + + if (trip >= data->ntrips || trip < 0) + return -EDOM; + + /* thermal framework should take care of data->mask & (1 << trip) */ + data->trips[trip].temperature = temp; + + return 0; +} + +static int of_thermal_get_trip_hyst(struct thermal_zone_device *tz, int trip, + unsigned long *hyst) +{ + struct __thermal_zone *data = tz->devdata; + + if (trip >= data->ntrips || trip < 0) + return -EDOM; + + *hyst = data->trips[trip].hysteresis; + + return 0; +} + +static int of_thermal_set_trip_hyst(struct thermal_zone_device *tz, int trip, + unsigned long hyst) +{ + struct __thermal_zone *data = tz->devdata; + + if (trip >= data->ntrips || trip < 0) + return -EDOM; + + /* thermal framework should take care of data->mask & (1 << trip) */ + data->trips[trip].hysteresis = hyst; + + return 0; +} + +static int of_thermal_get_crit_temp(struct thermal_zone_device *tz, + unsigned long *temp) +{ + struct __thermal_zone *data = tz->devdata; + int i; + + for (i = 0; i < data->ntrips; i++) + if (data->trips[i].type == THERMAL_TRIP_CRITICAL) { + *temp = data->trips[i].temperature; + return 0; + } + + return -EINVAL; +} + +static struct thermal_zone_device_ops of_thermal_ops = { + .get_mode = of_thermal_get_mode, + .set_mode = of_thermal_set_mode, + + .get_trip_type = of_thermal_get_trip_type, + .get_trip_temp = of_thermal_get_trip_temp, + .set_trip_temp = of_thermal_set_trip_temp, + .get_trip_hyst = of_thermal_get_trip_hyst, + .set_trip_hyst = of_thermal_set_trip_hyst, + .get_crit_temp = of_thermal_get_crit_temp, + + .bind = of_thermal_bind, + .unbind = of_thermal_unbind, +}; + +/*** sensor API ***/ + +static struct thermal_zone_device * +thermal_zone_of_add_sensor(struct device_node *zone, + struct device_node *sensor, void *data, + int (*get_temp)(void *, long *), + int (*get_trend)(void *, long *)) +{ + struct thermal_zone_device *tzd; + struct __thermal_zone *tz; + + tzd = thermal_zone_get_zone_by_name(zone->name); + if (IS_ERR(tzd)) + return ERR_PTR(-EPROBE_DEFER); + + tz = tzd->devdata; + + mutex_lock(&tzd->lock); + tz->get_temp = get_temp; + tz->get_trend = get_trend; + tz->sensor_data = data; + + tzd->ops->get_temp = of_thermal_get_temp; + tzd->ops->get_trend = of_thermal_get_trend; + mutex_unlock(&tzd->lock); + + return tzd; +} + +/** + * thermal_zone_of_sensor_register - registers a sensor to a DT thermal zone + * @dev: a valid struct device pointer of a sensor device. Must contain + * a valid .of_node, for the sensor node. + * @sensor_id: a sensor identifier, in case the sensor IP has more + * than one sensors + * @data: a private pointer (owned by the caller) that will be passed + * back, when a temperature reading is needed. + * @get_temp: a pointer to a function that reads the sensor temperature. + * @get_trend: a pointer to a function that reads the sensor temperature trend. + * + * This function will search the list of thermal zones described in device + * tree and look for the zone that refer to the sensor device pointed by + * @dev->of_node as temperature providers. For the zone pointing to the + * sensor node, the sensor will be added to the DT thermal zone device. + * + * The thermal zone temperature is provided by the @get_temp function + * pointer. When called, it will have the private pointer @data back. + * + * The thermal zone temperature trend is provided by the @get_trend function + * pointer. When called, it will have the private pointer @data back. + * + * TODO: + * 01 - This function must enqueue the new sensor instead of using + * it as the only source of temperature values. + * + * 02 - There must be a way to match the sensor with all thermal zones + * that refer to it. + * + * Return: On success returns a valid struct thermal_zone_device, + * otherwise, it returns a corresponding ERR_PTR(). Caller must + * check the return value with help of IS_ERR() helper. + */ +struct thermal_zone_device * +thermal_zone_of_sensor_register(struct device *dev, int sensor_id, + void *data, int (*get_temp)(void *, long *), + int (*get_trend)(void *, long *)) +{ + struct device_node *np, *child, *sensor_np; + + np = of_find_node_by_name(NULL, "thermal-zones"); + if (!np) + return ERR_PTR(-ENODEV); + + if (!dev || !dev->of_node) + return ERR_PTR(-EINVAL); + + sensor_np = dev->of_node; + + for_each_child_of_node(np, child) { + struct of_phandle_args sensor_specs; + int ret, id; + + /* For now, thermal framework supports only 1 sensor per zone */ + ret = of_parse_phandle_with_args(child, "thermal-sensors", + "#thermal-sensor-cells", + 0, &sensor_specs); + if (ret) + continue; + + if (sensor_specs.args_count >= 1) { + id = sensor_specs.args[0]; + WARN(sensor_specs.args_count > 1, + "%s: too many cells in sensor specifier %d\n", + sensor_specs.np->name, sensor_specs.args_count); + } else { + id = 0; + } + + if (sensor_specs.np == sensor_np && id == sensor_id) { + of_node_put(np); + return thermal_zone_of_add_sensor(child, sensor_np, + data, + get_temp, + get_trend); + } + } + of_node_put(np); + + return ERR_PTR(-ENODEV); +} +EXPORT_SYMBOL_GPL(thermal_zone_of_sensor_register); + +/** + * thermal_zone_of_sensor_unregister - unregisters a sensor from a DT thermal zone + * @dev: a valid struct device pointer of a sensor device. Must contain + * a valid .of_node, for the sensor node. + * @tzd: a pointer to struct thermal_zone_device where the sensor is registered. + * + * This function removes the sensor callbacks and private data from the + * thermal zone device registered with thermal_zone_of_sensor_register() + * API. It will also silent the zone by remove the .get_temp() and .get_trend() + * thermal zone device callbacks. + * + * TODO: When the support to several sensors per zone is added, this + * function must search the sensor list based on @dev parameter. + * + */ +void thermal_zone_of_sensor_unregister(struct device *dev, + struct thermal_zone_device *tzd) +{ + struct __thermal_zone *tz; + + if (!dev || !tzd || !tzd->devdata) + return; + + tz = tzd->devdata; + + /* no __thermal_zone, nothing to be done */ + if (!tz) + return; + + mutex_lock(&tzd->lock); + tzd->ops->get_temp = NULL; + tzd->ops->get_trend = NULL; + + tz->get_temp = NULL; + tz->get_trend = NULL; + tz->sensor_data = NULL; + mutex_unlock(&tzd->lock); +} +EXPORT_SYMBOL_GPL(thermal_zone_of_sensor_unregister); + +/*** functions parsing device tree nodes ***/ + +/** + * thermal_of_populate_bind_params - parse and fill cooling map data + * @np: DT node containing a cooling-map node + * @__tbp: data structure to be filled with cooling map info + * @trips: array of thermal zone trip points + * @ntrips: number of trip points inside trips. + * + * This function parses a cooling-map type of node represented by + * @np parameter and fills the read data into @__tbp data structure. + * It needs the already parsed array of trip points of the thermal zone + * in consideration. + * + * Return: 0 on success, proper error code otherwise + */ +static int thermal_of_populate_bind_params(struct device_node *np, + struct __thermal_bind_params *__tbp, + struct __thermal_trip *trips, + int ntrips) +{ + struct of_phandle_args cooling_spec; + struct device_node *trip; + int ret, i; + u32 prop; + + /* Default weight. Usage is optional */ + __tbp->usage = 0; + ret = of_property_read_u32(np, "contribution", &prop); + if (ret == 0) + __tbp->usage = prop; + + trip = of_parse_phandle(np, "trip", 0); + if (!trip) { + pr_err("missing trip property\n"); + return -ENODEV; + } + + /* match using device_node */ + for (i = 0; i < ntrips; i++) + if (trip == trips[i].np) { + __tbp->trip_id = i; + break; + } + + if (i == ntrips) { + ret = -ENODEV; + goto end; + } + + ret = of_parse_phandle_with_args(np, "cooling-device", "#cooling-cells", + 0, &cooling_spec); + if (ret < 0) { + pr_err("missing cooling_device property\n"); + goto end; + } + __tbp->cooling_device = cooling_spec.np; + if (cooling_spec.args_count >= 2) { /* at least min and max */ + __tbp->min = cooling_spec.args[0]; + __tbp->max = cooling_spec.args[1]; + } else { + pr_err("wrong reference to cooling device, missing limits\n"); + } + +end: + of_node_put(trip); + + return ret; +} + +/** + * It maps 'enum thermal_trip_type' found in include/linux/thermal.h + * into the device tree binding of 'trip', property type. + */ +static const char * const trip_types[] = { + [THERMAL_TRIP_ACTIVE] = "active", + [THERMAL_TRIP_PASSIVE] = "passive", + [THERMAL_TRIP_HOT] = "hot", + [THERMAL_TRIP_CRITICAL] = "critical", +}; + +/** + * thermal_of_get_trip_type - Get phy mode for given device_node + * @np: Pointer to the given device_node + * @type: Pointer to resulting trip type + * + * The function gets trip type string from property 'type', + * and store its index in trip_types table in @type, + * + * Return: 0 on success, or errno in error case. + */ +static int thermal_of_get_trip_type(struct device_node *np, + enum thermal_trip_type *type) +{ + const char *t; + int err, i; + + err = of_property_read_string(np, "type", &t); + if (err < 0) + return err; + + for (i = 0; i < ARRAY_SIZE(trip_types); i++) + if (!strcasecmp(t, trip_types[i])) { + *type = i; + return 0; + } + + return -ENODEV; +} + +/** + * thermal_of_populate_trip - parse and fill one trip point data + * @np: DT node containing a trip point node + * @trip: trip point data structure to be filled up + * + * This function parses a trip point type of node represented by + * @np parameter and fills the read data into @trip data structure. + * + * Return: 0 on success, proper error code otherwise + */ +static int thermal_of_populate_trip(struct device_node *np, + struct __thermal_trip *trip) +{ + int prop; + int ret; + + ret = of_property_read_u32(np, "temperature", &prop); + if (ret < 0) { + pr_err("missing temperature property\n"); + return ret; + } + trip->temperature = prop; + + ret = of_property_read_u32(np, "hysteresis", &prop); + if (ret < 0) { + pr_err("missing hysteresis property\n"); + return ret; + } + trip->hysteresis = prop; + + ret = thermal_of_get_trip_type(np, &trip->type); + if (ret < 0) { + pr_err("wrong trip type property\n"); + return ret; + } + + /* Required for cooling map matching */ + trip->np = np; + + return 0; +} + +/** + * thermal_of_build_thermal_zone - parse and fill one thermal zone data + * @np: DT node containing a thermal zone node + * + * This function parses a thermal zone type of node represented by + * @np parameter and fills the read data into a __thermal_zone data structure + * and return this pointer. + * + * TODO: Missing properties to parse: thermal-sensor-names and coefficients + * + * Return: On success returns a valid struct __thermal_zone, + * otherwise, it returns a corresponding ERR_PTR(). Caller must + * check the return value with help of IS_ERR() helper. + */ +static struct __thermal_zone * +thermal_of_build_thermal_zone(struct device_node *np) +{ + struct device_node *child = NULL, *gchild; + struct __thermal_zone *tz; + int ret, i; + u32 prop; + + if (!np) { + pr_err("no thermal zone np\n"); + return ERR_PTR(-EINVAL); + } + + tz = kzalloc(sizeof(*tz), GFP_KERNEL); + if (!tz) + return ERR_PTR(-ENOMEM); + + ret = of_property_read_u32(np, "polling-delay-passive", &prop); + if (ret < 0) { + pr_err("missing polling-delay-passive property\n"); + goto free_tz; + } + tz->passive_delay = prop; + + ret = of_property_read_u32(np, "polling-delay", &prop); + if (ret < 0) { + pr_err("missing polling-delay property\n"); + goto free_tz; + } + tz->polling_delay = prop; + + /* trips */ + child = of_get_child_by_name(np, "trips"); + + /* No trips provided */ + if (!child) + goto finish; + + tz->ntrips = of_get_child_count(child); + if (tz->ntrips == 0) /* must have at least one child */ + goto finish; + + tz->trips = kzalloc(tz->ntrips * sizeof(*tz->trips), GFP_KERNEL); + if (!tz->trips) { + ret = -ENOMEM; + goto free_tz; + } + + i = 0; + for_each_child_of_node(child, gchild) { + ret = thermal_of_populate_trip(gchild, &tz->trips[i++]); + if (ret) + goto free_trips; + } + + of_node_put(child); + + /* cooling-maps */ + child = of_get_child_by_name(np, "cooling-maps"); + + /* cooling-maps not provided */ + if (!child) + goto finish; + + tz->num_tbps = of_get_child_count(child); + if (tz->num_tbps == 0) + goto finish; + + tz->tbps = kzalloc(tz->num_tbps * sizeof(*tz->tbps), GFP_KERNEL); + if (!tz->tbps) { + ret = -ENOMEM; + goto free_trips; + } + + i = 0; + for_each_child_of_node(child, gchild) + ret = thermal_of_populate_bind_params(gchild, &tz->tbps[i++], + tz->trips, tz->ntrips); + if (ret) + goto free_tbps; + +finish: + of_node_put(child); + tz->mode = THERMAL_DEVICE_DISABLED; + + return tz; + +free_tbps: + kfree(tz->tbps); +free_trips: + kfree(tz->trips); +free_tz: + kfree(tz); + of_node_put(child); + + return ERR_PTR(ret); +} + +static inline void of_thermal_free_zone(struct __thermal_zone *tz) +{ + kfree(tz->tbps); + kfree(tz->trips); + kfree(tz); +} + +/** + * of_parse_thermal_zones - parse device tree thermal data + * + * Initialization function that can be called by machine initialization + * code to parse thermal data and populate the thermal framework + * with hardware thermal zones info. This function only parses thermal zones. + * Cooling devices and sensor devices nodes are supposed to be parsed + * by their respective drivers. + * + * Return: 0 on success, proper error code otherwise + * + */ +int __init of_parse_thermal_zones(void) +{ + struct device_node *np, *child; + struct __thermal_zone *tz; + struct thermal_zone_device_ops *ops; + + np = of_find_node_by_name(NULL, "thermal-zones"); + if (!np) { + pr_debug("unable to find thermal zones\n"); + return 0; /* Run successfully on systems without thermal DT */ + } + + for_each_child_of_node(np, child) { + struct thermal_zone_device *zone; + struct thermal_zone_params *tzp; + + tz = thermal_of_build_thermal_zone(child); + if (IS_ERR(tz)) { + pr_err("failed to build thermal zone %s: %ld\n", + child->name, + PTR_ERR(tz)); + continue; + } + + ops = kmemdup(&of_thermal_ops, sizeof(*ops), GFP_KERNEL); + if (!ops) + goto exit_free; + + tzp = kzalloc(sizeof(*tzp), GFP_KERNEL); + if (!tzp) { + kfree(ops); + goto exit_free; + } + + /* No hwmon because there might be hwmon drivers registering */ + tzp->no_hwmon = true; + + zone = thermal_zone_device_register(child->name, tz->ntrips, + 0, tz, + ops, tzp, + tz->passive_delay, + tz->polling_delay); + if (IS_ERR(zone)) { + pr_err("Failed to build %s zone %ld\n", child->name, + PTR_ERR(zone)); + kfree(tzp); + kfree(ops); + of_thermal_free_zone(tz); + /* attempting to build remaining zones still */ + } + } + + return 0; + +exit_free: + of_thermal_free_zone(tz); + + /* no memory available, so free what we have built */ + of_thermal_destroy_zones(); + + return -ENOMEM; +} + +/** + * of_thermal_destroy_zones - remove all zones parsed and allocated resources + * + * Finds all zones parsed and added to the thermal framework and remove them + * from the system, together with their resources. + * + */ +void of_thermal_destroy_zones(void) +{ + struct device_node *np, *child; + + np = of_find_node_by_name(NULL, "thermal-zones"); + if (!np) { + pr_err("unable to find thermal zones\n"); + return; + } + + for_each_child_of_node(np, child) { + struct thermal_zone_device *zone; + + zone = thermal_zone_get_zone_by_name(child->name); + if (IS_ERR(zone)) + continue; + + thermal_zone_device_unregister(zone); + kfree(zone->tzp); + kfree(zone->ops); + of_thermal_free_zone(zone->devdata); + } +} diff --git a/drivers/thermal/thermal_core.c b/drivers/thermal/thermal_core.c index 4f4b78889847..ed5f7657eb8c 100644 --- a/drivers/thermal/thermal_core.c +++ b/drivers/thermal/thermal_core.c @@ -1355,7 +1355,7 @@ static void remove_trip_attrs(struct thermal_zone_device *tz) */ struct thermal_zone_device *thermal_zone_device_register(const char *type, int trips, int mask, void *devdata, - const struct thermal_zone_device_ops *ops, + struct thermal_zone_device_ops *ops, const struct thermal_zone_params *tzp, int passive_delay, int polling_delay) { @@ -1735,8 +1735,14 @@ static int __init thermal_init(void) if (result) goto unregister_class; + result = of_parse_thermal_zones(); + if (result) + goto exit_netlink; + return 0; +exit_netlink: + genetlink_exit(); unregister_governors: thermal_unregister_governors(); unregister_class: @@ -1752,6 +1758,7 @@ error: static void __exit thermal_exit(void) { + of_thermal_destroy_zones(); genetlink_exit(); class_unregister(&thermal_class); thermal_unregister_governors(); diff --git a/drivers/thermal/thermal_core.h b/drivers/thermal/thermal_core.h index 7cf2f6626251..3db339fb636f 100644 --- a/drivers/thermal/thermal_core.h +++ b/drivers/thermal/thermal_core.h @@ -77,4 +77,13 @@ static inline int thermal_gov_user_space_register(void) { return 0; } static inline void thermal_gov_user_space_unregister(void) {} #endif /* CONFIG_THERMAL_GOV_USER_SPACE */ +/* device tree support */ +#ifdef CONFIG_THERMAL_OF +int of_parse_thermal_zones(void); +void of_thermal_destroy_zones(void); +#else +static inline int of_parse_thermal_zones(void) { return 0; } +static inline void of_thermal_destroy_zones(void) { } +#endif + #endif /* __THERMAL_CORE_H__ */ diff --git a/include/dt-bindings/thermal/thermal.h b/include/dt-bindings/thermal/thermal.h new file mode 100644 index 000000000000..59822a995858 --- /dev/null +++ b/include/dt-bindings/thermal/thermal.h @@ -0,0 +1,17 @@ +/* + * This header provides constants for most thermal bindings. + * + * Copyright (C) 2013 Texas Instruments + * Eduardo Valentin <eduardo.valentin@ti.com> + * + * GPLv2 only + */ + +#ifndef _DT_BINDINGS_THERMAL_THERMAL_H +#define _DT_BINDINGS_THERMAL_THERMAL_H + +/* On cooling devices upper and lower limits */ +#define THERMAL_NO_LIMIT (-1UL) + +#endif + diff --git a/include/linux/thermal.h b/include/linux/thermal.h index b4a975f25be0..bd2533bd16c2 100644 --- a/include/linux/thermal.h +++ b/include/linux/thermal.h @@ -143,6 +143,7 @@ struct thermal_cooling_device { int id; char type[THERMAL_NAME_LENGTH]; struct device device; + struct device_node *np; void *devdata; const struct thermal_cooling_device_ops *ops; bool updated; /* true if the cooling device does not need update */ @@ -172,7 +173,7 @@ struct thermal_zone_device { int emul_temperature; int passive; unsigned int forced_passive; - const struct thermal_zone_device_ops *ops; + struct thermal_zone_device_ops *ops; const struct thermal_zone_params *tzp; struct thermal_governor *governor; struct list_head thermal_instances; @@ -232,8 +233,31 @@ struct thermal_genl_event { }; /* Function declarations */ +#ifdef CONFIG_THERMAL_OF +struct thermal_zone_device * +thermal_zone_of_sensor_register(struct device *dev, int id, + void *data, int (*get_temp)(void *, long *), + int (*get_trend)(void *, long *)); +void thermal_zone_of_sensor_unregister(struct device *dev, + struct thermal_zone_device *tz); +#else +static inline struct thermal_zone_device * +thermal_zone_of_sensor_register(struct device *dev, int id, + void *data, int (*get_temp)(void *, long *), + int (*get_trend)(void *, long *)) +{ + return NULL; +} + +static inline +void thermal_zone_of_sensor_unregister(struct device *dev, + struct thermal_zone_device *tz) +{ +} + +#endif struct thermal_zone_device *thermal_zone_device_register(const char *, int, int, - void *, const struct thermal_zone_device_ops *, + void *, struct thermal_zone_device_ops *, const struct thermal_zone_params *, int, int); void thermal_zone_device_unregister(struct thermal_zone_device *); |