new file mode 100644
@@ -0,0 +1,498 @@
+* Thermal Framework Device Tree descriptor
+
+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, not 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:
+- sensors: used to describe the device source of temperature sensing;
+- cooling devices: used to describe devices source of power dissipation control;
+- trip points: used to describe points in temperature domain defined to
+make the system aware of hardware limits;
+- cooling attachments: used to describe links between trip points and
+cooling devices;
+- thermal zones: used to describe thermal data within the hardware;
+
+It follows a description of each type of these device tree nodes.
+
+* Sensor devices
+
+Sensor devices are nodes providing temperature sensing capabilities on thermal
+zones. Typical devices are I2C ADC converters and bandgaps. Theses are nodes
+providing temperature data to thermal zones. Temperature sensor devices may
+control one or more internal sensors.
+
+Required property:
+- #sensor-cells: Used to provide sensor device specific information
+ while referring to it. Must be at least 1, 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. 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 level of cooling.
+
+Required property:
+- cooling-min-level: A unsigned integer indicating the smallest
+ cooling level accepted. Typically 0.
+- cooling-max-level: An unsigned integer indicating the largest
+ cooling level accepted.
+- #cooling-cells: Used to provide cooling device specific information
+ while referring to it. Must be at least 2, in order
+ to specify minimum and maximum cooling level used
+ in the reference. See Cooling device attachments 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: the trip temperature level, in milliCelsius.
+- hysteresis: a (low) hysteresis value on 'temperature'. This is a
+ relative value, in milliCelsius.
+- type: the trip type. Here is the type mapping:
+ THERMAL_TRIP_ACTIVE 0: A trip point to enable active cooling
+ THERMAL_TRIP_PASSIVE 1: A trip point to enable passive cooling
+ THERMAL_TRIP_HOT 2: A trip point to notify emergency
+ THERMAL_TRIP_CRITICAL 3: Hardware not reliable.
+
+Refer to include/dt-bindings/thermal/thermal.h for definition of these consts.
+
+* Cooling device attachments
+
+The cooling device attachments 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 parameters,
+ referring to which cooling device is used in this
+ binding. The required parameters are: the minimum
+ cooling level and the maximum cooling level used
+ in this attach.
+- trip: A phandle of a trip point node within the same thermal
+ zone.
+
+Optional property:
+- contribution: The cooling contribution to the thermal zone of the
+ referred cooling device at the referred trip point.
+ The contribution is a value from 0 to 100. The sum
+ of all cooling contributions within a thermal zone
+ must never exceed 100.
+
+Note: Using the THERMAL_NO_LIMIT (-1L) constant in the cooling-device phandle
+limit parameters means:
+(i) - minimum level allowed for minimum cooling level used in the reference.
+(ii) - maximum level allowed for maximum cooling level used in the reference.
+Refer to include/dt-bindings/thermal/thermal.h for definition of this constant.
+
+* Thermal zones
+
+The thermal-zone node is the node containing all the required info
+for describing a thermal zone, including its cdev bindings. The thermal_zone
+node must contain, apart from its own properties, one node containing
+trip nodes and one node containing all the zone cooling attachments.
+
+Required properties:
+- passive-delay: The maximum number of milliseconds to wait between polls
+ when performing passive cooling.
+- polling-delay: The maximum number of milliseconds to wait between polls
+ when checking this thermal zone.
+- sensors: A list of sensor phandles and their parameters. The
+ required parameter is the sensor id, in order to
+ identify internal sensors when the sensor IC features
+ several sensing units.
+- trips: A sub-node containing several trip point nodes required
+ to describe the thermal zone.
+- cooling-attachments A sub-node containing several cooling device attaches
+ nodes, used to describe the relation between trips
+ and cooling devices.
+
+Optional property:
+- coefficients: An array of integers (one signed cell) containing
+ coefficients to compose a linear relation between
+ the sensors described in the sensors property.
+ 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 offsets.
+
+Note: The delay properties are bound to the maximum dT/dt (temperature
+derivative over time) in two situations for a thermal zone:
+(i) - when active cooling is activated (passive-delay); and
+(ii) - when the zone just needs to be monitored (polling-delay).
+The maximum dT/dt is highly bound to hardware power consumption and dissipation
+capability.
+
+* 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 {
+ cpu0: cpu@0 {
+ ...
+ cooling-min-level = <0>;
+ cooling-max-level = <3>;
+ #cooling-cells = <2>; /* min followed by max */
+ };
+ ...
+};
+
+&i2c1 {
+ ...
+ fan0: fan@0x48 {
+ ...
+ cooling-min-level = <0>;
+ cooling-max-level = <9>;
+ #cooling-cells = <2>; /* min followed by max */
+ };
+};
+
+bandgap0: bandgap@0x0000ED00 {
+ ...
+ #sensor-cells = <1>;
+};
+
+cpu-thermal: cpu-thermal {
+ passive-delay = <250>; /* milliseconds */
+ polling-delay = <1000>; /* milliseconds */
+
+ /* sensor ID */
+ sensors = <&bandgap0 0>;
+
+ trips {
+ cpu-alert0: cpu-alert {
+ temperature = <90000>; /* milliCelsius */
+ hysteresis = <2000>; /* milliCelsius */
+ type = <THERMAL_TRIP_ACTIVE>;
+ };
+ cpu-alert1: cpu-alert {
+ temperature = <100000>; /* milliCelsius */
+ hysteresis = <2000>; /* milliCelsius */
+ type = <THERMAL_TRIP_PASSIVE>;
+ };
+ cpu-crit: cpu-crit {
+ temperature = <125000>; /* milliCelsius */
+ hysteresis = <2000>; /* milliCelsius */
+ type = <THERMAL_TRIP_CRITICAL>;
+ };
+ };
+
+ cooling-attachments {
+ attach0 {
+ trip = <&cpu-alert0>;
+ cooling-device = <&fan0 THERMAL_NO_LIMITS 4>;
+ };
+ attach1 {
+ trip = <&cpu-alert1>;
+ cooling-device = <&fan0 5 THERMAL_NO_LIMITS>;
+ };
+ attach2 {
+ trip = <&cpu-alert1>;
+ cooling-device =
+ <&cpu0 THERMAL_NO_LIMITS THERMAL_NO_LIMITS>;
+ };
+ };
+};
+
+In the example above, the ADC sensor at address 0x0000ED00 is used to monitor
+the zone 'cpu-thermal' using its the sensor 0. The fan0, a fan device controlled
+via I2C bus 1, at adress 0x48, is used to remove the heat out of the thermal
+zone 'cpu-thermal' using its cooling levels 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 level.
+The cpu@0 device is also linked to the same thermal zone, 'cpu-thermal', as a
+passive cooling device, using all its cooling levels at trip point 'cpu-alert1',
+which is a trip point at 100C.
+
+(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>
+
+bandgap0: bandgap@0x0000ED00 {
+ ...
+ #sensor-cells = <1>;
+};
+
+cpu-thermal: cpu-thermal {
+ passive-delay = <250>; /* milliseconds */
+ polling-delay = <1000>; /* milliseconds */
+
+ /* sensor ID */
+ 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 = <THERMAL_TRIP_PASSIVE>;
+ };
+ cpu-crit: cpu-crit {
+ temperature = <125000>; /* milliCelsius */
+ hysteresis = <2000>; /* milliCelsius */
+ type = <THERMAL_TRIP_CRITICAL>;
+ };
+ };
+
+ cooling-attachments {
+ /* each zone within the SoC may have its own cooling */
+ ...
+ };
+};
+
+gpu-thermal: gpu-thermal {
+ passive-delay = <120>; /* milliseconds */
+ polling-delay = <1000>; /* milliseconds */
+
+ /* sensor ID */
+ 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 = <THERMAL_TRIP_PASSIVE>;
+ };
+ gpu-crit: gpu-crit {
+ temperature = <105000>; /* milliCelsius */
+ hysteresis = <2000>; /* milliCelsius */
+ type = <THERMAL_TRIP_CRITICAL>;
+ };
+ };
+
+ cooling-attachments {
+ /* each zone within the SoC may have its own cooling */
+ ...
+ };
+};
+
+dsp-thermal: dsp-thermal {
+ passive-delay = <50>; /* milliseconds */
+ polling-delay = <1000>; /* milliseconds */
+
+ /* sensor ID */
+ 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 = <THERMAL_TRIP_PASSIVE>;
+ };
+ dsp-crit: gpu-crit {
+ temperature = <135000>; /* milliCelsius */
+ hysteresis = <2000>; /* milliCelsius */
+ type = <THERMAL_TRIP_CRITICAL>;
+ };
+ };
+
+ cooling-attachments {
+ /* 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
+#sensor-cells property and using the first parameter as sensor ID.
+In the example, then, bandgap.sensor0 is used to monitor CPU thermal zone,
+bandgap.sensor1 is used to monitor GPU thermal zone and bandgap.sensor2
+is used to monitor DSP thermal zone. Each zone may be uncorrelated,
+having its own dT/dt requirements, trips and cooling attachments.
+
+
+(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 {
+ ...
+ adc: sensor@0x49 {
+ ...
+ #sensor-cells = <1>;
+ };
+};
+
+bandgap0: bandgap@0x0000ED00 {
+ ...
+ #sensor-cells = <1>;
+};
+
+cpu-thermal: cpu-thermal {
+ passive-delay = <250>; /* milliseconds */
+ polling-delay = <1000>; /* milliseconds */
+
+ /* sensor ID */
+ sensors = <&bandgap0 0>,
+ <&adc 0>;
+
+ /* hotspot = 100 * bandgap - 120 * adc + 484 */
+ coefficients = <100 -120 484>;
+
+ trips {
+ ...
+ };
+
+ cooling-attachments {
+ ...
+ };
+};
+
+In some cases, there is a need to use more than one sensor to extrapolate
+a thermal hotspot in the silicon. The above example illustrate this situation.
+For instance, it may be the case that a sensor external to CPU IP may be place
+close to CPU hotspot and together with internal CPU sensor, it is used
+to determine the hotspot. The hyppotetical extrapolation rule would be:
+ hotspot = 100 * bandgap - 120 * adc + 484
+
+The same idea can be used to add fixed offset:
+ passive-delay = <1000>; /* milliseconds */
+ polling-delay = <2500>; /* milliseconds */
+ hotspot = 1 * adc + 6000
+
+In the above equation, the hotspot is always 6C higher than what is read
+from the sensor ADC. The binding would be then:
+ /* sensor ID */
+ sensors = <&adc 0>;
+
+ /* 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 {
+ ...
+ adc-dummy: sensor@0x50 {
+ ...
+ #sensor-cells = <1>; /* sensor internal ID */
+ };
+};
+
+batt-thermal {
+ passive-delay = <500>; /* milliseconds */
+ polling-delay = <2500>; /* milliseconds */
+
+ /* sensor ID */
+ sensors = <&adc-dummy 4>;
+
+ trips {
+ ...
+ };
+
+ cooling-attachments {
+ ...
+ };
+};
+
+board-thermal: board-thermal {
+ passive-delay = <1000>; /* milliseconds */
+ polling-delay = <2500>; /* milliseconds */
+
+ /* sensor ID */
+ sensors = <&adc-dummy 0>,
+ <&adc-dummy 1>,
+ <&adc-dymmy 2>;
+ /*
+ * 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 = <THERMAL_TRIP_PASSIVE>;
+ };
+ gpu-trip: gpu-trip {
+ temperature = <55000>; /* milliCelsius */
+ hysteresis = <2000>; /* milliCelsius */
+ type = <THERMAL_TRIP_PASSIVE>;
+ }
+ lcd-trip: lcp-trip {
+ temperature = <53000>; /* milliCelsius */
+ hysteresis = <2000>; /* milliCelsius */
+ type = <THERMAL_TRIP_PASSIVE>;
+ };
+ crit-trip: crit-trip {
+ temperature = <68000>; /* milliCelsius */
+ hysteresis = <2000>; /* milliCelsius */
+ type = <THERMAL_TRIP_CRITICAL>;
+ };
+ };
+
+ cooling-attachments {
+ attach0 {
+ trip = <&cpu-trip>;
+ cooling-device = <&cpu0 0 2>;
+ contribution = <55>;
+ };
+ attach1 {
+ trip = <&gpu-trip>;
+ cooling-device = <&gpu0 0 2>;
+ contribution = <20>;
+ };
+ attach2 {
+ 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.
@@ -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
@@ -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
new file mode 100644
@@ -0,0 +1,757 @@
+/*
+ * 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 level used at this trip point
+ * @max: maximum cooling level 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 fw 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 fw 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;
+
+ /* For now, thermal framework supports only 1 sensor per zone */
+ ret = of_parse_phandle_with_args(child, "sensors",
+ "#sensor-cells",
+ 0, &sensor_specs);
+ if (ret)
+ continue;
+
+ if (sensor_specs.args_count < 1)
+ continue;
+
+ if (sensor_specs.np == sensor_np &&
+ sensor_specs.args[0] == 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 attachment data
+ * @np: DT node containing a cooling-attachment node
+ * @__tbp: data structure to be filled with cooling attachment info
+ * @trips: array of thermal zone trip points
+ * @ntrips: number of trip points inside trips.
+ *
+ * This function parses a cooling-attachment 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, "usage", &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;
+}
+
+/**
+ * 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 = of_property_read_u32(np, "type", &prop);
+ if (ret < 0) {
+ pr_err("missing type property\n");
+ return ret;
+ }
+ trip->type = prop;
+
+ /* Required for cooling attachment 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.
+ *
+ * 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, *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, "passive-delay", &prop);
+ if (ret < 0) {
+ pr_err("missing passive_delay property\n");
+ return ERR_PTR(ret);
+ }
+ tz->passive_delay = prop;
+
+ ret = of_property_read_u32(np, "polling-delay", &prop);
+ if (ret < 0) {
+ pr_err("missing polling_delay property\n");
+ return ERR_PTR(ret);
+ }
+ 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);
+ tz->trips = kzalloc(tz->ntrips * sizeof(*tz->trips), GFP_KERNEL);
+ if (!tz->trips)
+ return ERR_PTR(-ENOMEM);
+ i = 0;
+ for_each_child_of_node(child, gchild)
+ thermal_of_populate_trip(gchild, &tz->trips[i++]);
+
+ of_node_put(child);
+
+ /* cooling-attachments */
+ child = of_get_child_by_name(np, "cooling-attachments");
+
+ /* cooling-attachments provided */
+ if (!child)
+ goto finish;
+
+ tz->num_tbps = of_get_child_count(child);
+ tz->tbps = kzalloc(tz->num_tbps * sizeof(*tz->tbps), GFP_KERNEL);
+ if (!tz->tbps)
+ return ERR_PTR(-ENOMEM);
+ i = 0;
+ for_each_child_of_node(child, gchild)
+ thermal_of_populate_bind_params(gchild, &tz->tbps[i++],
+ tz->trips, tz->ntrips);
+
+finish:
+ tz->mode = THERMAL_DEVICE_DISABLED;
+
+ return 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)
+ return -ENOMEM;
+
+ tzp = kzalloc(sizeof(*tzp), GFP_KERNEL);
+ if (!tzp)
+ return -ENOMEM;
+
+ /* 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));
+ }
+
+ return 0;
+}
+
+/**
+ * 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 __exit of_thermal_destroy_zones(void)
+{
+ struct device_node *np, *child;
+ struct __thermal_zone *tz;
+
+ 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);
+ tz = zone->devdata;
+ kfree(tz->tbps);
+ kfree(tz->trips);
+ kfree(tz);
+ }
+}
@@ -1371,7 +1371,7 @@ 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)
{
@@ -1751,8 +1751,14 @@ 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:
@@ -1768,6 +1774,7 @@ error:
static void __exit thermal_exit(void)
{
+ of_thermal_destroy_zones();
genetlink_exit();
class_unregister(&thermal_class);
thermal_unregister_governors();
@@ -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__ */
new file mode 100644
@@ -0,0 +1,27 @@
+/*
+ * 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
+
+/*
+ * Here are the thermal trip types. This must
+ * match with enum thermal_trip_type at
+ * include/linux/thermal.h
+ */
+#define THERMAL_TRIP_ACTIVE 0
+#define THERMAL_TRIP_PASSIVE 1
+#define THERMAL_TRIP_HOT 2
+#define THERMAL_TRIP_CRITICAL 3
+
+/* On cooling devices upper and lower limits */
+#define THERMAL_NO_LIMIT (-1UL)
+
+#endif
+
@@ -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;
@@ -242,8 +243,31 @@ 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 *);
This patch introduces a device tree bindings for describing the hardware thermal behavior and limits. Also a parser to read and interpret the data and feed it in the thermal framework is presented. This patch introduces a thermal data parser for device tree. The parsed data is used to build thermal zones and thermal binding parameters. The output data can then be used to deploy thermal policies. This patch adds also documentation regarding this API and how to define tree nodes to use this infrastructure. Note that, in order to be able to have control on the sensor registration on the DT thermal zone, it was required to allow changing the thermal zone .get_temp callback. For this reason, this patch also removes the 'const' modifier from the .ops field of thermal zone devices. Cc: Zhang Rui <rui.zhang@intel.com> Cc: linux-pm@vger.kernel.org Cc: linux-kernel@vger.kernel.org Signed-off-by: Eduardo Valentin <eduardo.valentin@ti.com> --- .../devicetree/bindings/thermal/thermal.txt | 498 ++++++++++++++ drivers/thermal/Kconfig | 13 + drivers/thermal/Makefile | 1 + drivers/thermal/of-thermal.c | 757 +++++++++++++++++++++ drivers/thermal/thermal_core.c | 9 +- drivers/thermal/thermal_core.h | 9 + include/dt-bindings/thermal/thermal.h | 27 + include/linux/thermal.h | 28 +- 8 files changed, 1339 insertions(+), 3 deletions(-) create mode 100644 Documentation/devicetree/bindings/thermal/thermal.txt create mode 100644 drivers/thermal/of-thermal.c create mode 100644 include/dt-bindings/thermal/thermal.h --- Hello guys, I've got couple of review suggestions by Joe P., so I am resending v5, as they were minor changes. I've replaced kzalloc/memcpy by kmemdup and improved the error code reporting in the init function of the parser. Thanks Joe! Eduardo