2 * of-thermal.c - Generic Thermal Management device tree support.
4 * Copyright (C) 2013 Texas Instruments
5 * Copyright (C) 2013 Eduardo Valentin <eduardo.valentin@ti.com>
8 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
10 * This program is free software; you can redistribute it and/or modify
11 * it under the terms of the GNU General Public License as published by
12 * the Free Software Foundation; version 2 of the License.
14 * This program is distributed in the hope that it will be useful, but
15 * WITHOUT ANY WARRANTY; without even the implied warranty of
16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
17 * General Public License for more details.
19 * You should have received a copy of the GNU General Public License along
20 * with this program; if not, write to the Free Software Foundation, Inc.,
21 * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
23 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
25 #include <linux/thermal.h>
26 #include <linux/slab.h>
27 #include <linux/types.h>
28 #include <linux/of_device.h>
29 #include <linux/of_platform.h>
30 #include <linux/err.h>
31 #include <linux/export.h>
32 #include <linux/string.h>
33 #include <linux/thermal.h>
35 #include "thermal_core.h"
37 /*** Private data structures to represent thermal device tree data ***/
40 * struct __thermal_bind_param - a match between trip and cooling device
41 * @cooling_device: a pointer to identify the referred cooling device
42 * @trip_id: the trip point index
43 * @usage: the percentage (from 0 to 100) of cooling contribution
44 * @min: minimum cooling state used at this trip point
45 * @max: maximum cooling state used at this trip point
48 struct __thermal_bind_params {
49 struct device_node *cooling_device;
57 * struct __thermal_zone - internal representation of a thermal zone
58 * @mode: current thermal zone device mode (enabled/disabled)
59 * @passive_delay: polling interval while passive cooling is activated
60 * @polling_delay: zone polling interval
61 * @ntrips: number of trip points
62 * @trips: an array of trip points (0..ntrips - 1)
63 * @num_tbps: number of thermal bind params
64 * @tbps: an array of thermal bind params (0..num_tbps - 1)
65 * @sensor_data: sensor private data used while reading temperature and trend
66 * @ops: set of callbacks to handle the thermal zone based on DT
69 struct __thermal_zone {
70 enum thermal_device_mode mode;
76 struct thermal_trip *trips;
78 /* cooling binding data */
80 struct __thermal_bind_params *tbps;
82 /* sensor interface */
84 const struct thermal_zone_of_device_ops *ops;
87 /*** DT thermal zone device callbacks ***/
89 static int of_thermal_get_temp(struct thermal_zone_device *tz,
92 struct __thermal_zone *data = tz->devdata;
94 if (!data->ops->get_temp)
97 return data->ops->get_temp(data->sensor_data, temp);
101 * of_thermal_get_ntrips - function to export number of available trip
103 * @tz: pointer to a thermal zone
105 * This function is a globally visible wrapper to get number of trip points
106 * stored in the local struct __thermal_zone
108 * Return: number of available trip points, -ENODEV when data not available
110 int of_thermal_get_ntrips(struct thermal_zone_device *tz)
112 struct __thermal_zone *data = tz->devdata;
114 if (!data || IS_ERR(data))
119 EXPORT_SYMBOL_GPL(of_thermal_get_ntrips);
122 * of_thermal_is_trip_valid - function to check if trip point is valid
124 * @tz: pointer to a thermal zone
125 * @trip: trip point to evaluate
127 * This function is responsible for checking if passed trip point is valid
129 * Return: true if trip point is valid, false otherwise
131 bool of_thermal_is_trip_valid(struct thermal_zone_device *tz, int trip)
133 struct __thermal_zone *data = tz->devdata;
135 if (!data || trip >= data->ntrips || trip < 0)
140 EXPORT_SYMBOL_GPL(of_thermal_is_trip_valid);
143 * of_thermal_get_trip_points - function to get access to a globally exported
146 * @tz: pointer to a thermal zone
148 * This function provides a pointer to trip points table
150 * Return: pointer to trip points table, NULL otherwise
152 const struct thermal_trip *
153 of_thermal_get_trip_points(struct thermal_zone_device *tz)
155 struct __thermal_zone *data = tz->devdata;
162 EXPORT_SYMBOL_GPL(of_thermal_get_trip_points);
165 * of_thermal_set_emul_temp - function to set emulated temperature
167 * @tz: pointer to a thermal zone
168 * @temp: temperature to set
170 * This function gives the ability to set emulated value of temperature,
171 * which is handy for debugging
173 * Return: zero on success, error code otherwise
175 static int of_thermal_set_emul_temp(struct thermal_zone_device *tz,
178 struct __thermal_zone *data = tz->devdata;
180 if (!data->ops || !data->ops->set_emul_temp)
183 return data->ops->set_emul_temp(data->sensor_data, temp);
186 static int of_thermal_get_trend(struct thermal_zone_device *tz, int trip,
187 enum thermal_trend *trend)
189 struct __thermal_zone *data = tz->devdata;
193 if (!data->ops->get_trend)
196 r = data->ops->get_trend(data->sensor_data, &dev_trend);
200 /* TODO: These intervals might have some thresholds, but in core code */
202 *trend = THERMAL_TREND_RAISING;
203 else if (dev_trend < 0)
204 *trend = THERMAL_TREND_DROPPING;
206 *trend = THERMAL_TREND_STABLE;
211 static int of_thermal_bind(struct thermal_zone_device *thermal,
212 struct thermal_cooling_device *cdev)
214 struct __thermal_zone *data = thermal->devdata;
217 if (!data || IS_ERR(data))
220 /* find where to bind */
221 for (i = 0; i < data->num_tbps; i++) {
222 struct __thermal_bind_params *tbp = data->tbps + i;
224 if (tbp->cooling_device == cdev->np) {
227 ret = thermal_zone_bind_cooling_device(thermal,
240 static int of_thermal_unbind(struct thermal_zone_device *thermal,
241 struct thermal_cooling_device *cdev)
243 struct __thermal_zone *data = thermal->devdata;
246 if (!data || IS_ERR(data))
249 /* find where to unbind */
250 for (i = 0; i < data->num_tbps; i++) {
251 struct __thermal_bind_params *tbp = data->tbps + i;
253 if (tbp->cooling_device == cdev->np) {
256 ret = thermal_zone_unbind_cooling_device(thermal,
266 static int of_thermal_get_mode(struct thermal_zone_device *tz,
267 enum thermal_device_mode *mode)
269 struct __thermal_zone *data = tz->devdata;
276 static int of_thermal_set_mode(struct thermal_zone_device *tz,
277 enum thermal_device_mode mode)
279 struct __thermal_zone *data = tz->devdata;
281 mutex_lock(&tz->lock);
283 if (mode == THERMAL_DEVICE_ENABLED)
284 tz->polling_delay = data->polling_delay;
286 tz->polling_delay = 0;
288 mutex_unlock(&tz->lock);
291 thermal_zone_device_update(tz);
296 static int of_thermal_get_trip_type(struct thermal_zone_device *tz, int trip,
297 enum thermal_trip_type *type)
299 struct __thermal_zone *data = tz->devdata;
301 if (trip >= data->ntrips || trip < 0)
304 *type = data->trips[trip].type;
309 static int of_thermal_get_trip_temp(struct thermal_zone_device *tz, int trip,
312 struct __thermal_zone *data = tz->devdata;
314 if (trip >= data->ntrips || trip < 0)
317 *temp = data->trips[trip].temperature;
322 static int of_thermal_set_trip_temp(struct thermal_zone_device *tz, int trip,
325 struct __thermal_zone *data = tz->devdata;
327 if (trip >= data->ntrips || trip < 0)
330 /* thermal framework should take care of data->mask & (1 << trip) */
331 data->trips[trip].temperature = temp;
336 static int of_thermal_get_trip_hyst(struct thermal_zone_device *tz, int trip,
339 struct __thermal_zone *data = tz->devdata;
341 if (trip >= data->ntrips || trip < 0)
344 *hyst = data->trips[trip].hysteresis;
349 static int of_thermal_set_trip_hyst(struct thermal_zone_device *tz, int trip,
352 struct __thermal_zone *data = tz->devdata;
354 if (trip >= data->ntrips || trip < 0)
357 /* thermal framework should take care of data->mask & (1 << trip) */
358 data->trips[trip].hysteresis = hyst;
363 static int of_thermal_get_crit_temp(struct thermal_zone_device *tz,
366 struct __thermal_zone *data = tz->devdata;
369 for (i = 0; i < data->ntrips; i++)
370 if (data->trips[i].type == THERMAL_TRIP_CRITICAL) {
371 *temp = data->trips[i].temperature;
378 static struct thermal_zone_device_ops of_thermal_ops = {
379 .get_mode = of_thermal_get_mode,
380 .set_mode = of_thermal_set_mode,
382 .get_trip_type = of_thermal_get_trip_type,
383 .get_trip_temp = of_thermal_get_trip_temp,
384 .set_trip_temp = of_thermal_set_trip_temp,
385 .get_trip_hyst = of_thermal_get_trip_hyst,
386 .set_trip_hyst = of_thermal_set_trip_hyst,
387 .get_crit_temp = of_thermal_get_crit_temp,
389 .bind = of_thermal_bind,
390 .unbind = of_thermal_unbind,
395 static struct thermal_zone_device *
396 thermal_zone_of_add_sensor(struct device_node *zone,
397 struct device_node *sensor, void *data,
398 const struct thermal_zone_of_device_ops *ops)
400 struct thermal_zone_device *tzd;
401 struct __thermal_zone *tz;
403 tzd = thermal_zone_get_zone_by_name(zone->name);
405 return ERR_PTR(-EPROBE_DEFER);
410 return ERR_PTR(-EINVAL);
412 mutex_lock(&tzd->lock);
414 tz->sensor_data = data;
416 tzd->ops->get_temp = of_thermal_get_temp;
417 tzd->ops->get_trend = of_thermal_get_trend;
418 tzd->ops->set_emul_temp = of_thermal_set_emul_temp;
419 mutex_unlock(&tzd->lock);
425 * thermal_zone_of_sensor_register - registers a sensor to a DT thermal zone
426 * @dev: a valid struct device pointer of a sensor device. Must contain
427 * a valid .of_node, for the sensor node.
428 * @sensor_id: a sensor identifier, in case the sensor IP has more
430 * @data: a private pointer (owned by the caller) that will be passed
431 * back, when a temperature reading is needed.
432 * @ops: struct thermal_zone_of_device_ops *. Must contain at least .get_temp.
434 * This function will search the list of thermal zones described in device
435 * tree and look for the zone that refer to the sensor device pointed by
436 * @dev->of_node as temperature providers. For the zone pointing to the
437 * sensor node, the sensor will be added to the DT thermal zone device.
439 * The thermal zone temperature is provided by the @get_temp function
440 * pointer. When called, it will have the private pointer @data back.
442 * The thermal zone temperature trend is provided by the @get_trend function
443 * pointer. When called, it will have the private pointer @data back.
446 * 01 - This function must enqueue the new sensor instead of using
447 * it as the only source of temperature values.
449 * 02 - There must be a way to match the sensor with all thermal zones
452 * Return: On success returns a valid struct thermal_zone_device,
453 * otherwise, it returns a corresponding ERR_PTR(). Caller must
454 * check the return value with help of IS_ERR() helper.
456 struct thermal_zone_device *
457 thermal_zone_of_sensor_register(struct device *dev, int sensor_id, void *data,
458 const struct thermal_zone_of_device_ops *ops)
460 struct device_node *np, *child, *sensor_np;
461 struct thermal_zone_device *tzd = ERR_PTR(-ENODEV);
463 np = of_find_node_by_name(NULL, "thermal-zones");
465 return ERR_PTR(-ENODEV);
467 if (!dev || !dev->of_node) {
469 return ERR_PTR(-EINVAL);
472 sensor_np = of_node_get(dev->of_node);
474 for_each_child_of_node(np, child) {
475 struct of_phandle_args sensor_specs;
478 /* Check whether child is enabled or not */
479 if (!of_device_is_available(child))
482 /* For now, thermal framework supports only 1 sensor per zone */
483 ret = of_parse_phandle_with_args(child, "thermal-sensors",
484 "#thermal-sensor-cells",
489 if (sensor_specs.args_count >= 1) {
490 id = sensor_specs.args[0];
491 WARN(sensor_specs.args_count > 1,
492 "%s: too many cells in sensor specifier %d\n",
493 sensor_specs.np->name, sensor_specs.args_count);
498 if (sensor_specs.np == sensor_np && id == sensor_id) {
499 tzd = thermal_zone_of_add_sensor(child, sensor_np,
502 tzd->ops->set_mode(tzd, THERMAL_DEVICE_ENABLED);
504 of_node_put(sensor_specs.np);
508 of_node_put(sensor_specs.np);
511 of_node_put(sensor_np);
516 EXPORT_SYMBOL_GPL(thermal_zone_of_sensor_register);
519 * thermal_zone_of_sensor_unregister - unregisters a sensor from a DT thermal zone
520 * @dev: a valid struct device pointer of a sensor device. Must contain
521 * a valid .of_node, for the sensor node.
522 * @tzd: a pointer to struct thermal_zone_device where the sensor is registered.
524 * This function removes the sensor callbacks and private data from the
525 * thermal zone device registered with thermal_zone_of_sensor_register()
526 * API. It will also silent the zone by remove the .get_temp() and .get_trend()
527 * thermal zone device callbacks.
529 * TODO: When the support to several sensors per zone is added, this
530 * function must search the sensor list based on @dev parameter.
533 void thermal_zone_of_sensor_unregister(struct device *dev,
534 struct thermal_zone_device *tzd)
536 struct __thermal_zone *tz;
538 if (!dev || !tzd || !tzd->devdata)
543 /* no __thermal_zone, nothing to be done */
547 mutex_lock(&tzd->lock);
548 tzd->ops->get_temp = NULL;
549 tzd->ops->get_trend = NULL;
550 tzd->ops->set_emul_temp = NULL;
553 tz->sensor_data = NULL;
554 mutex_unlock(&tzd->lock);
556 EXPORT_SYMBOL_GPL(thermal_zone_of_sensor_unregister);
558 /*** functions parsing device tree nodes ***/
561 * thermal_of_populate_bind_params - parse and fill cooling map data
562 * @np: DT node containing a cooling-map node
563 * @__tbp: data structure to be filled with cooling map info
564 * @trips: array of thermal zone trip points
565 * @ntrips: number of trip points inside trips.
567 * This function parses a cooling-map type of node represented by
568 * @np parameter and fills the read data into @__tbp data structure.
569 * It needs the already parsed array of trip points of the thermal zone
572 * Return: 0 on success, proper error code otherwise
574 static int thermal_of_populate_bind_params(struct device_node *np,
575 struct __thermal_bind_params *__tbp,
576 struct thermal_trip *trips,
579 struct of_phandle_args cooling_spec;
580 struct device_node *trip;
584 /* Default weight. Usage is optional */
585 __tbp->usage = THERMAL_WEIGHT_DEFAULT;
586 ret = of_property_read_u32(np, "contribution", &prop);
590 trip = of_parse_phandle(np, "trip", 0);
592 pr_err("missing trip property\n");
596 /* match using device_node */
597 for (i = 0; i < ntrips; i++)
598 if (trip == trips[i].np) {
608 ret = of_parse_phandle_with_args(np, "cooling-device", "#cooling-cells",
611 pr_err("missing cooling_device property\n");
614 __tbp->cooling_device = cooling_spec.np;
615 if (cooling_spec.args_count >= 2) { /* at least min and max */
616 __tbp->min = cooling_spec.args[0];
617 __tbp->max = cooling_spec.args[1];
619 pr_err("wrong reference to cooling device, missing limits\n");
629 * It maps 'enum thermal_trip_type' found in include/linux/thermal.h
630 * into the device tree binding of 'trip', property type.
632 static const char * const trip_types[] = {
633 [THERMAL_TRIP_ACTIVE] = "active",
634 [THERMAL_TRIP_PASSIVE] = "passive",
635 [THERMAL_TRIP_HOT] = "hot",
636 [THERMAL_TRIP_CRITICAL] = "critical",
640 * thermal_of_get_trip_type - Get phy mode for given device_node
641 * @np: Pointer to the given device_node
642 * @type: Pointer to resulting trip type
644 * The function gets trip type string from property 'type',
645 * and store its index in trip_types table in @type,
647 * Return: 0 on success, or errno in error case.
649 static int thermal_of_get_trip_type(struct device_node *np,
650 enum thermal_trip_type *type)
655 err = of_property_read_string(np, "type", &t);
659 for (i = 0; i < ARRAY_SIZE(trip_types); i++)
660 if (!strcasecmp(t, trip_types[i])) {
669 * thermal_of_populate_trip - parse and fill one trip point data
670 * @np: DT node containing a trip point node
671 * @trip: trip point data structure to be filled up
673 * This function parses a trip point type of node represented by
674 * @np parameter and fills the read data into @trip data structure.
676 * Return: 0 on success, proper error code otherwise
678 static int thermal_of_populate_trip(struct device_node *np,
679 struct thermal_trip *trip)
684 ret = of_property_read_u32(np, "temperature", &prop);
686 pr_err("missing temperature property\n");
689 trip->temperature = prop;
691 ret = of_property_read_u32(np, "hysteresis", &prop);
693 pr_err("missing hysteresis property\n");
696 trip->hysteresis = prop;
698 ret = thermal_of_get_trip_type(np, &trip->type);
700 pr_err("wrong trip type property\n");
704 /* Required for cooling map matching */
712 * thermal_of_build_thermal_zone - parse and fill one thermal zone data
713 * @np: DT node containing a thermal zone node
715 * This function parses a thermal zone type of node represented by
716 * @np parameter and fills the read data into a __thermal_zone data structure
717 * and return this pointer.
719 * TODO: Missing properties to parse: thermal-sensor-names and coefficients
721 * Return: On success returns a valid struct __thermal_zone,
722 * otherwise, it returns a corresponding ERR_PTR(). Caller must
723 * check the return value with help of IS_ERR() helper.
725 static struct __thermal_zone *
726 thermal_of_build_thermal_zone(struct device_node *np)
728 struct device_node *child = NULL, *gchild;
729 struct __thermal_zone *tz;
734 pr_err("no thermal zone np\n");
735 return ERR_PTR(-EINVAL);
738 tz = kzalloc(sizeof(*tz), GFP_KERNEL);
740 return ERR_PTR(-ENOMEM);
742 ret = of_property_read_u32(np, "polling-delay-passive", &prop);
744 pr_err("missing polling-delay-passive property\n");
747 tz->passive_delay = prop;
749 ret = of_property_read_u32(np, "polling-delay", &prop);
751 pr_err("missing polling-delay property\n");
754 tz->polling_delay = prop;
757 child = of_get_child_by_name(np, "trips");
759 /* No trips provided */
763 tz->ntrips = of_get_child_count(child);
764 if (tz->ntrips == 0) /* must have at least one child */
767 tz->trips = kzalloc(tz->ntrips * sizeof(*tz->trips), GFP_KERNEL);
774 for_each_child_of_node(child, gchild) {
775 ret = thermal_of_populate_trip(gchild, &tz->trips[i++]);
783 child = of_get_child_by_name(np, "cooling-maps");
785 /* cooling-maps not provided */
789 tz->num_tbps = of_get_child_count(child);
790 if (tz->num_tbps == 0)
793 tz->tbps = kzalloc(tz->num_tbps * sizeof(*tz->tbps), GFP_KERNEL);
800 for_each_child_of_node(child, gchild) {
801 ret = thermal_of_populate_bind_params(gchild, &tz->tbps[i++],
802 tz->trips, tz->ntrips);
809 tz->mode = THERMAL_DEVICE_DISABLED;
814 for (i = 0; i < tz->num_tbps; i++)
815 of_node_put(tz->tbps[i].cooling_device);
818 for (i = 0; i < tz->ntrips; i++)
819 of_node_put(tz->trips[i].np);
829 static inline void of_thermal_free_zone(struct __thermal_zone *tz)
833 for (i = 0; i < tz->num_tbps; i++)
834 of_node_put(tz->tbps[i].cooling_device);
836 for (i = 0; i < tz->ntrips; i++)
837 of_node_put(tz->trips[i].np);
843 * of_parse_thermal_zones - parse device tree thermal data
845 * Initialization function that can be called by machine initialization
846 * code to parse thermal data and populate the thermal framework
847 * with hardware thermal zones info. This function only parses thermal zones.
848 * Cooling devices and sensor devices nodes are supposed to be parsed
849 * by their respective drivers.
851 * Return: 0 on success, proper error code otherwise
854 int __init of_parse_thermal_zones(void)
856 struct device_node *np, *child;
857 struct __thermal_zone *tz;
858 struct thermal_zone_device_ops *ops;
860 np = of_find_node_by_name(NULL, "thermal-zones");
862 pr_debug("unable to find thermal zones\n");
863 return 0; /* Run successfully on systems without thermal DT */
866 for_each_child_of_node(np, child) {
867 struct thermal_zone_device *zone;
868 struct thermal_zone_params *tzp;
871 /* Check whether child is enabled or not */
872 if (!of_device_is_available(child))
875 tz = thermal_of_build_thermal_zone(child);
877 pr_err("failed to build thermal zone %s: %ld\n",
883 ops = kmemdup(&of_thermal_ops, sizeof(*ops), GFP_KERNEL);
887 tzp = kzalloc(sizeof(*tzp), GFP_KERNEL);
893 /* No hwmon because there might be hwmon drivers registering */
894 tzp->no_hwmon = true;
896 if (!of_property_read_u32(child, "sustainable-power", &prop))
897 tzp->sustainable_power = prop;
899 zone = thermal_zone_device_register(child->name, tz->ntrips,
905 pr_err("Failed to build %s zone %ld\n", child->name,
909 of_thermal_free_zone(tz);
910 /* attempting to build remaining zones still */
920 of_thermal_free_zone(tz);
922 /* no memory available, so free what we have built */
923 of_thermal_destroy_zones();
929 * of_thermal_destroy_zones - remove all zones parsed and allocated resources
931 * Finds all zones parsed and added to the thermal framework and remove them
932 * from the system, together with their resources.
935 void of_thermal_destroy_zones(void)
937 struct device_node *np, *child;
939 np = of_find_node_by_name(NULL, "thermal-zones");
941 pr_err("unable to find thermal zones\n");
945 for_each_child_of_node(np, child) {
946 struct thermal_zone_device *zone;
948 /* Check whether child is enabled or not */
949 if (!of_device_is_available(child))
952 zone = thermal_zone_get_zone_by_name(child->name);
956 thermal_zone_device_unregister(zone);
959 of_thermal_free_zone(zone->devdata);