1 // SPDX-License-Identifier: GPL-2.0
3 * of-thermal.c - Generic Thermal Management device tree support.
5 * Copyright (C) 2013 Texas Instruments
6 * Copyright (C) 2013 Eduardo Valentin <eduardo.valentin@ti.com>
9 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
11 #include <linux/err.h>
12 #include <linux/export.h>
14 #include <linux/slab.h>
15 #include <linux/thermal.h>
16 #include <linux/types.h>
17 #include <linux/string.h>
19 #include "thermal_core.h"
21 /*** functions parsing device tree nodes ***/
23 static int of_find_trip_id(struct device_node *np, struct device_node *trip)
25 struct device_node *trips;
26 struct device_node *t;
29 trips = of_get_child_by_name(np, "trips");
31 pr_err("Failed to find 'trips' node\n");
36 * Find the trip id point associated with the cooling device map
38 for_each_child_of_node(trips, t) {
55 * It maps 'enum thermal_trip_type' found in include/linux/thermal.h
56 * into the device tree binding of 'trip', property type.
58 static const char * const trip_types[] = {
59 [THERMAL_TRIP_ACTIVE] = "active",
60 [THERMAL_TRIP_PASSIVE] = "passive",
61 [THERMAL_TRIP_HOT] = "hot",
62 [THERMAL_TRIP_CRITICAL] = "critical",
66 * thermal_of_get_trip_type - Get phy mode for given device_node
67 * @np: Pointer to the given device_node
68 * @type: Pointer to resulting trip type
70 * The function gets trip type string from property 'type',
71 * and store its index in trip_types table in @type,
73 * Return: 0 on success, or errno in error case.
75 static int thermal_of_get_trip_type(struct device_node *np,
76 enum thermal_trip_type *type)
81 err = of_property_read_string(np, "type", &t);
85 for (i = 0; i < ARRAY_SIZE(trip_types); i++)
86 if (!strcasecmp(t, trip_types[i])) {
94 static int thermal_of_populate_trip(struct device_node *np,
95 struct thermal_trip *trip)
100 ret = of_property_read_u32(np, "temperature", &prop);
102 pr_err("missing temperature property\n");
105 trip->temperature = prop;
107 ret = of_property_read_u32(np, "hysteresis", &prop);
109 pr_err("missing hysteresis property\n");
112 trip->hysteresis = prop;
114 ret = thermal_of_get_trip_type(np, &trip->type);
116 pr_err("wrong trip type property\n");
123 static struct thermal_trip *thermal_of_trips_init(struct device_node *np, int *ntrips)
125 struct thermal_trip *tt;
126 struct device_node *trips, *trip;
129 trips = of_get_child_by_name(np, "trips");
131 pr_err("Failed to find 'trips' node\n");
132 return ERR_PTR(-EINVAL);
135 count = of_get_child_count(trips);
137 pr_err("No trip point defined\n");
139 goto out_of_node_put;
142 tt = kzalloc(sizeof(*tt) * count, GFP_KERNEL);
145 goto out_of_node_put;
151 for_each_child_of_node(trips, trip) {
152 ret = thermal_of_populate_trip(trip, &tt[count++]);
170 static struct device_node *of_thermal_zone_find(struct device_node *sensor, int id)
172 struct device_node *np, *tz;
173 struct of_phandle_args sensor_specs;
175 np = of_find_node_by_name(NULL, "thermal-zones");
177 pr_debug("No thermal zones description\n");
178 return ERR_PTR(-ENODEV);
182 * Search for each thermal zone, a defined sensor
183 * corresponding to the one passed as parameter
185 for_each_available_child_of_node(np, tz) {
189 count = of_count_phandle_with_args(tz, "thermal-sensors",
190 "#thermal-sensor-cells");
192 pr_err("%pOFn: missing thermal sensor\n", tz);
193 tz = ERR_PTR(-EINVAL);
197 for (i = 0; i < count; i++) {
201 ret = of_parse_phandle_with_args(tz, "thermal-sensors",
202 "#thermal-sensor-cells",
205 pr_err("%pOFn: Failed to read thermal-sensors cells: %d\n", tz, ret);
210 if ((sensor == sensor_specs.np) && id == (sensor_specs.args_count ?
211 sensor_specs.args[0] : 0)) {
212 pr_debug("sensor %pOFn id=%d belongs to %pOFn\n", sensor, id, tz);
217 tz = ERR_PTR(-ENODEV);
223 static int thermal_of_monitor_init(struct device_node *np, int *delay, int *pdelay)
227 ret = of_property_read_u32(np, "polling-delay-passive", pdelay);
228 if (ret == -EINVAL) {
230 } else if (ret < 0) {
231 pr_err("%pOFn: Couldn't get polling-delay-passive: %d\n", np, ret);
235 ret = of_property_read_u32(np, "polling-delay", delay);
236 if (ret == -EINVAL) {
238 } else if (ret < 0) {
239 pr_err("%pOFn: Couldn't get polling-delay: %d\n", np, ret);
246 static void thermal_of_parameters_init(struct device_node *np,
247 struct thermal_zone_params *tzp)
250 int ncoef = ARRAY_SIZE(coef);
253 tzp->no_hwmon = true;
255 if (!of_property_read_u32(np, "sustainable-power", &prop))
256 tzp->sustainable_power = prop;
259 * For now, the thermal framework supports only one sensor per
260 * thermal zone. Thus, we are considering only the first two
261 * values as slope and offset.
263 ret = of_property_read_u32_array(np, "coefficients", coef, ncoef);
269 tzp->slope = coef[0];
270 tzp->offset = coef[1];
273 static struct device_node *thermal_of_zone_get_by_name(struct thermal_zone_device *tz)
275 struct device_node *np, *tz_np;
277 np = of_find_node_by_name(NULL, "thermal-zones");
279 return ERR_PTR(-ENODEV);
281 tz_np = of_get_child_by_name(np, tz->type);
286 return ERR_PTR(-ENODEV);
291 static int __thermal_of_unbind(struct device_node *map_np, int index, int trip_id,
292 struct thermal_zone_device *tz, struct thermal_cooling_device *cdev)
294 struct of_phandle_args cooling_spec;
297 ret = of_parse_phandle_with_args(map_np, "cooling-device", "#cooling-cells",
298 index, &cooling_spec);
301 pr_err("Invalid cooling-device entry\n");
305 of_node_put(cooling_spec.np);
307 if (cooling_spec.args_count < 2) {
308 pr_err("wrong reference to cooling device, missing limits\n");
312 if (cooling_spec.np != cdev->np)
315 ret = thermal_zone_unbind_cooling_device(tz, trip_id, cdev);
317 pr_err("Failed to unbind '%s' with '%s': %d\n", tz->type, cdev->type, ret);
322 static int __thermal_of_bind(struct device_node *map_np, int index, int trip_id,
323 struct thermal_zone_device *tz, struct thermal_cooling_device *cdev)
325 struct of_phandle_args cooling_spec;
326 int ret, weight = THERMAL_WEIGHT_DEFAULT;
328 of_property_read_u32(map_np, "contribution", &weight);
330 ret = of_parse_phandle_with_args(map_np, "cooling-device", "#cooling-cells",
331 index, &cooling_spec);
334 pr_err("Invalid cooling-device entry\n");
338 of_node_put(cooling_spec.np);
340 if (cooling_spec.args_count < 2) {
341 pr_err("wrong reference to cooling device, missing limits\n");
345 if (cooling_spec.np != cdev->np)
348 ret = thermal_zone_bind_cooling_device(tz, trip_id, cdev, cooling_spec.args[1],
349 cooling_spec.args[0],
352 pr_err("Failed to bind '%s' with '%s': %d\n", tz->type, cdev->type, ret);
357 static int thermal_of_for_each_cooling_device(struct device_node *tz_np, struct device_node *map_np,
358 struct thermal_zone_device *tz, struct thermal_cooling_device *cdev,
359 int (*action)(struct device_node *, int, int,
360 struct thermal_zone_device *, struct thermal_cooling_device *))
362 struct device_node *tr_np;
363 int count, i, trip_id;
365 tr_np = of_parse_phandle(map_np, "trip", 0);
369 trip_id = of_find_trip_id(tz_np, tr_np);
373 count = of_count_phandle_with_args(map_np, "cooling-device", "#cooling-cells");
375 pr_err("Add a cooling_device property with at least one device\n");
380 * At this point, we don't want to bail out when there is an
381 * error, we will try to bind/unbind as many as possible
384 for (i = 0; i < count; i++)
385 action(map_np, i, trip_id, tz, cdev);
390 static int thermal_of_for_each_cooling_maps(struct thermal_zone_device *tz,
391 struct thermal_cooling_device *cdev,
392 int (*action)(struct device_node *, int, int,
393 struct thermal_zone_device *, struct thermal_cooling_device *))
395 struct device_node *tz_np, *cm_np, *child;
398 tz_np = thermal_of_zone_get_by_name(tz);
400 pr_err("Failed to get node tz by name\n");
401 return PTR_ERR(tz_np);
404 cm_np = of_get_child_by_name(tz_np, "cooling-maps");
408 for_each_child_of_node(cm_np, child) {
409 ret = thermal_of_for_each_cooling_device(tz_np, child, tz, cdev, action);
423 static int thermal_of_bind(struct thermal_zone_device *tz,
424 struct thermal_cooling_device *cdev)
426 return thermal_of_for_each_cooling_maps(tz, cdev, __thermal_of_bind);
429 static int thermal_of_unbind(struct thermal_zone_device *tz,
430 struct thermal_cooling_device *cdev)
432 return thermal_of_for_each_cooling_maps(tz, cdev, __thermal_of_unbind);
436 * thermal_of_zone_unregister - Cleanup the specific allocated ressources
438 * This function disables the thermal zone and frees the different
439 * ressources allocated specific to the thermal OF.
441 * @tz: a pointer to the thermal zone structure
443 static void thermal_of_zone_unregister(struct thermal_zone_device *tz)
445 struct thermal_trip *trips = tz->trips;
446 struct thermal_zone_device_ops *ops = tz->ops;
448 thermal_zone_device_disable(tz);
449 thermal_zone_device_unregister(tz);
455 * thermal_of_zone_register - Register a thermal zone with device node
458 * The thermal_of_zone_register() parses a device tree given a device
459 * node sensor and identifier. It searches for the thermal zone
460 * associated to the couple sensor/id and retrieves all the thermal
461 * zone properties and registers new thermal zone with those
464 * @sensor: A device node pointer corresponding to the sensor in the device tree
465 * @id: An integer as sensor identifier
466 * @data: A private data to be stored in the thermal zone dedicated private area
467 * @ops: A set of thermal sensor ops
469 * Return: a valid thermal zone structure pointer on success.
470 * - EINVAL: if the device tree thermal description is malformed
471 * - ENOMEM: if one structure can not be allocated
472 * - Other negative errors are returned by the underlying called functions
474 static struct thermal_zone_device *thermal_of_zone_register(struct device_node *sensor, int id, void *data,
475 const struct thermal_zone_device_ops *ops)
477 struct thermal_zone_device *tz;
478 struct thermal_trip *trips;
479 struct thermal_zone_params tzp = {};
480 struct thermal_zone_device_ops *of_ops;
481 struct device_node *np;
487 of_ops = kmemdup(ops, sizeof(*ops), GFP_KERNEL);
489 return ERR_PTR(-ENOMEM);
491 np = of_thermal_zone_find(sensor, id);
493 if (PTR_ERR(np) != -ENODEV)
494 pr_err("Failed to find thermal zone for %pOFn id=%d\n", sensor, id);
496 goto out_kfree_of_ops;
499 trips = thermal_of_trips_init(np, &ntrips);
501 pr_err("Failed to find trip points for %pOFn id=%d\n", sensor, id);
502 ret = PTR_ERR(trips);
503 goto out_kfree_of_ops;
506 ret = thermal_of_monitor_init(np, &delay, &pdelay);
508 pr_err("Failed to initialize monitoring delays from %pOFn\n", np);
509 goto out_kfree_trips;
512 thermal_of_parameters_init(np, &tzp);
514 of_ops->bind = thermal_of_bind;
515 of_ops->unbind = thermal_of_unbind;
517 mask = GENMASK_ULL((ntrips) - 1, 0);
519 ret = of_property_read_string(np, "critical-action", &action);
521 if (!of_ops->critical && !strcasecmp(action, "reboot"))
522 of_ops->critical = thermal_zone_device_critical_reboot;
524 tz = thermal_zone_device_register_with_trips(np->name, trips, ntrips,
525 mask, data, of_ops, &tzp,
529 pr_err("Failed to register thermal zone %pOFn: %d\n", np, ret);
530 goto out_kfree_trips;
533 ret = thermal_zone_device_enable(tz);
535 pr_err("Failed to enabled thermal zone '%s', id=%d: %d\n",
536 tz->type, tz->id, ret);
537 thermal_of_zone_unregister(tz);
551 static void devm_thermal_of_zone_release(struct device *dev, void *res)
553 thermal_of_zone_unregister(*(struct thermal_zone_device **)res);
556 static int devm_thermal_of_zone_match(struct device *dev, void *res,
559 struct thermal_zone_device **r = res;
561 if (WARN_ON(!r || !*r))
568 * devm_thermal_of_zone_register - register a thermal tied with the sensor life cycle
570 * This function is the device version of the thermal_of_zone_register() function.
572 * @dev: a device structure pointer to sensor to be tied with the thermal zone OF life cycle
573 * @sensor_id: the sensor identifier
574 * @data: a pointer to a private data to be stored in the thermal zone 'devdata' field
575 * @ops: a pointer to the ops structure associated with the sensor
577 struct thermal_zone_device *devm_thermal_of_zone_register(struct device *dev, int sensor_id, void *data,
578 const struct thermal_zone_device_ops *ops)
580 struct thermal_zone_device **ptr, *tzd;
582 ptr = devres_alloc(devm_thermal_of_zone_release, sizeof(*ptr),
585 return ERR_PTR(-ENOMEM);
587 tzd = thermal_of_zone_register(dev->of_node, sensor_id, data, ops);
594 devres_add(dev, ptr);
598 EXPORT_SYMBOL_GPL(devm_thermal_of_zone_register);
601 * devm_thermal_of_zone_unregister - Resource managed version of
602 * thermal_of_zone_unregister().
603 * @dev: Device for which which resource was allocated.
604 * @tz: a pointer to struct thermal_zone where the sensor is registered.
606 * This function removes the sensor callbacks and private data from the
607 * thermal zone device registered with devm_thermal_zone_of_sensor_register()
608 * API. It will also silent the zone by remove the .get_temp() and .get_trend()
609 * thermal zone device callbacks.
610 * Normally this function will not need to be called and the resource
611 * management code will ensure that the resource is freed.
613 void devm_thermal_of_zone_unregister(struct device *dev, struct thermal_zone_device *tz)
615 WARN_ON(devres_release(dev, devm_thermal_of_zone_release,
616 devm_thermal_of_zone_match, tz));
618 EXPORT_SYMBOL_GPL(devm_thermal_of_zone_unregister);