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1// SPDX-License-Identifier: GPL-2.0
2/*
3 * of-thermal.c - Generic Thermal Management device tree support.
4 *
5 * Copyright (C) 2013 Texas Instruments
6 * Copyright (C) 2013 Eduardo Valentin <eduardo.valentin@ti.com>
7 */
8
9#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
10
11#include <linux/err.h>
12#include <linux/export.h>
13#include <linux/of.h>
14#include <linux/slab.h>
15#include <linux/thermal.h>
16#include <linux/types.h>
17#include <linux/string.h>
18
19#include "thermal_core.h"
20
21/*** functions parsing device tree nodes ***/
22
23static int of_find_trip_id(struct device_node *np, struct device_node *trip)
24{
25 struct device_node *trips;
26 struct device_node *t;
27 int i = 0;
28
29 trips = of_get_child_by_name(np, "trips");
30 if (!trips) {
31 pr_err("Failed to find 'trips' node\n");
32 return -EINVAL;
33 }
34
35 /*
36 * Find the trip id point associated with the cooling device map
37 */
38 for_each_child_of_node(trips, t) {
39
40 if (t == trip) {
41 of_node_put(t);
42 goto out;
43 }
44 i++;
45 }
46
47 i = -ENXIO;
48out:
49 of_node_put(trips);
50
51 return i;
52}
53
54/*
55 * It maps 'enum thermal_trip_type' found in include/linux/thermal.h
56 * into the device tree binding of 'trip', property type.
57 */
58static 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",
63};
64
65/**
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
69 *
70 * The function gets trip type string from property 'type',
71 * and store its index in trip_types table in @type,
72 *
73 * Return: 0 on success, or errno in error case.
74 */
75static int thermal_of_get_trip_type(struct device_node *np,
76 enum thermal_trip_type *type)
77{
78 const char *t;
79 int err, i;
80
81 err = of_property_read_string(np, "type", &t);
82 if (err < 0)
83 return err;
84
85 for (i = 0; i < ARRAY_SIZE(trip_types); i++)
86 if (!strcasecmp(t, trip_types[i])) {
87 *type = i;
88 return 0;
89 }
90
91 return -ENODEV;
92}
93
94static int thermal_of_populate_trip(struct device_node *np,
95 struct thermal_trip *trip)
96{
97 int prop;
98 int ret;
99
100 ret = of_property_read_u32(np, "temperature", &prop);
101 if (ret < 0) {
102 pr_err("missing temperature property\n");
103 return ret;
104 }
105 trip->temperature = prop;
106
107 ret = of_property_read_u32(np, "hysteresis", &prop);
108 if (ret < 0) {
109 pr_err("missing hysteresis property\n");
110 return ret;
111 }
112 trip->hysteresis = prop;
113
114 ret = thermal_of_get_trip_type(np, &trip->type);
115 if (ret < 0) {
116 pr_err("wrong trip type property\n");
117 return ret;
118 }
119
120 return 0;
121}
122
123static struct thermal_trip *thermal_of_trips_init(struct device_node *np, int *ntrips)
124{
125 struct thermal_trip *tt;
126 struct device_node *trips, *trip;
127 int ret, count;
128
129 trips = of_get_child_by_name(np, "trips");
130 if (!trips) {
131 pr_err("Failed to find 'trips' node\n");
132 return ERR_PTR(-EINVAL);
133 }
134
135 count = of_get_child_count(trips);
136 if (!count) {
137 pr_err("No trip point defined\n");
138 ret = -EINVAL;
139 goto out_of_node_put;
140 }
141
142 tt = kzalloc(sizeof(*tt) * count, GFP_KERNEL);
143 if (!tt) {
144 ret = -ENOMEM;
145 goto out_of_node_put;
146 }
147
148 *ntrips = count;
149
150 count = 0;
151 for_each_child_of_node(trips, trip) {
152 ret = thermal_of_populate_trip(trip, &tt[count++]);
153 if (ret)
154 goto out_kfree;
155 }
156
157 of_node_put(trips);
158
159 return tt;
160
161out_kfree:
162 kfree(tt);
163 *ntrips = 0;
164out_of_node_put:
165 of_node_put(trips);
166
167 return ERR_PTR(ret);
168}
169
170static struct device_node *of_thermal_zone_find(struct device_node *sensor, int id)
171{
172 struct device_node *np, *tz;
173 struct of_phandle_args sensor_specs;
174
175 np = of_find_node_by_name(NULL, "thermal-zones");
176 if (!np) {
177 pr_debug("No thermal zones description\n");
178 return ERR_PTR(-ENODEV);
179 }
180
181 /*
182 * Search for each thermal zone, a defined sensor
183 * corresponding to the one passed as parameter
184 */
185 for_each_available_child_of_node(np, tz) {
186
187 int count, i;
188
189 count = of_count_phandle_with_args(tz, "thermal-sensors",
190 "#thermal-sensor-cells");
191 if (count <= 0) {
192 pr_err("%pOFn: missing thermal sensor\n", tz);
193 tz = ERR_PTR(-EINVAL);
194 goto out;
195 }
196
197 for (i = 0; i < count; i++) {
198
199 int ret;
200
201 ret = of_parse_phandle_with_args(tz, "thermal-sensors",
202 "#thermal-sensor-cells",
203 i, &sensor_specs);
204 if (ret < 0) {
205 pr_err("%pOFn: Failed to read thermal-sensors cells: %d\n", tz, ret);
206 tz = ERR_PTR(ret);
207 goto out;
208 }
209
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);
213 goto out;
214 }
215 }
216 }
217 tz = ERR_PTR(-ENODEV);
218out:
219 of_node_put(np);
220 return tz;
221}
222
223static int thermal_of_monitor_init(struct device_node *np, int *delay, int *pdelay)
224{
225 int ret;
226
227 ret = of_property_read_u32(np, "polling-delay-passive", pdelay);
228 if (ret < 0) {
229 pr_err("%pOFn: missing polling-delay-passive property\n", np);
230 return ret;
231 }
232
233 ret = of_property_read_u32(np, "polling-delay", delay);
234 if (ret < 0) {
235 pr_err("%pOFn: missing polling-delay property\n", np);
236 return ret;
237 }
238
239 return 0;
240}
241
242static void thermal_of_parameters_init(struct device_node *np,
243 struct thermal_zone_params *tzp)
244{
245 int coef[2];
246 int ncoef = ARRAY_SIZE(coef);
247 int prop, ret;
248
249 tzp->no_hwmon = true;
250
251 if (!of_property_read_u32(np, "sustainable-power", &prop))
252 tzp->sustainable_power = prop;
253
254 /*
255 * For now, the thermal framework supports only one sensor per
256 * thermal zone. Thus, we are considering only the first two
257 * values as slope and offset.
258 */
259 ret = of_property_read_u32_array(np, "coefficients", coef, ncoef);
260 if (ret) {
261 coef[0] = 1;
262 coef[1] = 0;
263 }
264
265 tzp->slope = coef[0];
266 tzp->offset = coef[1];
267}
268
269static struct device_node *thermal_of_zone_get_by_name(struct thermal_zone_device *tz)
270{
271 struct device_node *np, *tz_np;
272
273 np = of_find_node_by_name(NULL, "thermal-zones");
274 if (!np)
275 return ERR_PTR(-ENODEV);
276
277 tz_np = of_get_child_by_name(np, tz->type);
278
279 of_node_put(np);
280
281 if (!tz_np)
282 return ERR_PTR(-ENODEV);
283
284 return tz_np;
285}
286
287static int __thermal_of_unbind(struct device_node *map_np, int index, int trip_id,
288 struct thermal_zone_device *tz, struct thermal_cooling_device *cdev)
289{
290 struct of_phandle_args cooling_spec;
291 int ret;
292
293 ret = of_parse_phandle_with_args(map_np, "cooling-device", "#cooling-cells",
294 index, &cooling_spec);
295
296 if (ret < 0) {
297 pr_err("Invalid cooling-device entry\n");
298 return ret;
299 }
300
301 of_node_put(cooling_spec.np);
302
303 if (cooling_spec.args_count < 2) {
304 pr_err("wrong reference to cooling device, missing limits\n");
305 return -EINVAL;
306 }
307
308 if (cooling_spec.np != cdev->np)
309 return 0;
310
311 ret = thermal_zone_unbind_cooling_device(tz, trip_id, cdev);
312 if (ret)
313 pr_err("Failed to unbind '%s' with '%s': %d\n", tz->type, cdev->type, ret);
314
315 return ret;
316}
317
318static int __thermal_of_bind(struct device_node *map_np, int index, int trip_id,
319 struct thermal_zone_device *tz, struct thermal_cooling_device *cdev)
320{
321 struct of_phandle_args cooling_spec;
322 int ret, weight = THERMAL_WEIGHT_DEFAULT;
323
324 of_property_read_u32(map_np, "contribution", &weight);
325
326 ret = of_parse_phandle_with_args(map_np, "cooling-device", "#cooling-cells",
327 index, &cooling_spec);
328
329 if (ret < 0) {
330 pr_err("Invalid cooling-device entry\n");
331 return ret;
332 }
333
334 of_node_put(cooling_spec.np);
335
336 if (cooling_spec.args_count < 2) {
337 pr_err("wrong reference to cooling device, missing limits\n");
338 return -EINVAL;
339 }
340
341 if (cooling_spec.np != cdev->np)
342 return 0;
343
344 ret = thermal_zone_bind_cooling_device(tz, trip_id, cdev, cooling_spec.args[1],
345 cooling_spec.args[0],
346 weight);
347 if (ret)
348 pr_err("Failed to bind '%s' with '%s': %d\n", tz->type, cdev->type, ret);
349
350 return ret;
351}
352
353static int thermal_of_for_each_cooling_device(struct device_node *tz_np, struct device_node *map_np,
354 struct thermal_zone_device *tz, struct thermal_cooling_device *cdev,
355 int (*action)(struct device_node *, int, int,
356 struct thermal_zone_device *, struct thermal_cooling_device *))
357{
358 struct device_node *tr_np;
359 int count, i, trip_id;
360
361 tr_np = of_parse_phandle(map_np, "trip", 0);
362 if (!tr_np)
363 return -ENODEV;
364
365 trip_id = of_find_trip_id(tz_np, tr_np);
366 if (trip_id < 0)
367 return trip_id;
368
369 count = of_count_phandle_with_args(map_np, "cooling-device", "#cooling-cells");
370 if (count <= 0) {
371 pr_err("Add a cooling_device property with at least one device\n");
372 return -ENOENT;
373 }
374
375 /*
376 * At this point, we don't want to bail out when there is an
377 * error, we will try to bind/unbind as many as possible
378 * cooling devices
379 */
380 for (i = 0; i < count; i++)
381 action(map_np, i, trip_id, tz, cdev);
382
383 return 0;
384}
385
386static int thermal_of_for_each_cooling_maps(struct thermal_zone_device *tz,
387 struct thermal_cooling_device *cdev,
388 int (*action)(struct device_node *, int, int,
389 struct thermal_zone_device *, struct thermal_cooling_device *))
390{
391 struct device_node *tz_np, *cm_np, *child;
392 int ret = 0;
393
394 tz_np = thermal_of_zone_get_by_name(tz);
395 if (IS_ERR(tz_np)) {
396 pr_err("Failed to get node tz by name\n");
397 return PTR_ERR(tz_np);
398 }
399
400 cm_np = of_get_child_by_name(tz_np, "cooling-maps");
401 if (!cm_np)
402 goto out;
403
404 for_each_child_of_node(cm_np, child) {
405 ret = thermal_of_for_each_cooling_device(tz_np, child, tz, cdev, action);
406 if (ret) {
407 of_node_put(child);
408 break;
409 }
410 }
411
412 of_node_put(cm_np);
413out:
414 of_node_put(tz_np);
415
416 return ret;
417}
418
419static int thermal_of_bind(struct thermal_zone_device *tz,
420 struct thermal_cooling_device *cdev)
421{
422 return thermal_of_for_each_cooling_maps(tz, cdev, __thermal_of_bind);
423}
424
425static int thermal_of_unbind(struct thermal_zone_device *tz,
426 struct thermal_cooling_device *cdev)
427{
428 return thermal_of_for_each_cooling_maps(tz, cdev, __thermal_of_unbind);
429}
430
431/**
432 * thermal_of_zone_unregister - Cleanup the specific allocated ressources
433 *
434 * This function disables the thermal zone and frees the different
435 * ressources allocated specific to the thermal OF.
436 *
437 * @tz: a pointer to the thermal zone structure
438 */
439static void thermal_of_zone_unregister(struct thermal_zone_device *tz)
440{
441 struct thermal_trip *trips = tz->trips;
442 struct thermal_zone_device_ops *ops = tz->ops;
443
444 thermal_zone_device_disable(tz);
445 thermal_zone_device_unregister(tz);
446 kfree(trips);
447 kfree(ops);
448}
449
450/**
451 * thermal_of_zone_register - Register a thermal zone with device node
452 * sensor
453 *
454 * The thermal_of_zone_register() parses a device tree given a device
455 * node sensor and identifier. It searches for the thermal zone
456 * associated to the couple sensor/id and retrieves all the thermal
457 * zone properties and registers new thermal zone with those
458 * properties.
459 *
460 * @sensor: A device node pointer corresponding to the sensor in the device tree
461 * @id: An integer as sensor identifier
462 * @data: A private data to be stored in the thermal zone dedicated private area
463 * @ops: A set of thermal sensor ops
464 *
465 * Return: a valid thermal zone structure pointer on success.
466 * - EINVAL: if the device tree thermal description is malformed
467 * - ENOMEM: if one structure can not be allocated
468 * - Other negative errors are returned by the underlying called functions
469 */
470static struct thermal_zone_device *thermal_of_zone_register(struct device_node *sensor, int id, void *data,
471 const struct thermal_zone_device_ops *ops)
472{
473 struct thermal_zone_device *tz;
474 struct thermal_trip *trips;
475 struct thermal_zone_params tzp = {};
476 struct thermal_zone_device_ops *of_ops;
477 struct device_node *np;
478 const char *action;
479 int delay, pdelay;
480 int ntrips, mask;
481 int ret;
482
483 of_ops = kmemdup(ops, sizeof(*ops), GFP_KERNEL);
484 if (!of_ops)
485 return ERR_PTR(-ENOMEM);
486
487 np = of_thermal_zone_find(sensor, id);
488 if (IS_ERR(np)) {
489 if (PTR_ERR(np) != -ENODEV)
490 pr_err("Failed to find thermal zone for %pOFn id=%d\n", sensor, id);
491 ret = PTR_ERR(np);
492 goto out_kfree_of_ops;
493 }
494
495 trips = thermal_of_trips_init(np, &ntrips);
496 if (IS_ERR(trips)) {
497 pr_err("Failed to find trip points for %pOFn id=%d\n", sensor, id);
498 ret = PTR_ERR(trips);
499 goto out_kfree_of_ops;
500 }
501
502 ret = thermal_of_monitor_init(np, &delay, &pdelay);
503 if (ret) {
504 pr_err("Failed to initialize monitoring delays from %pOFn\n", np);
505 goto out_kfree_trips;
506 }
507
508 thermal_of_parameters_init(np, &tzp);
509
510 of_ops->bind = thermal_of_bind;
511 of_ops->unbind = thermal_of_unbind;
512
513 mask = GENMASK_ULL((ntrips) - 1, 0);
514
515 ret = of_property_read_string(np, "critical-action", &action);
516 if (!ret)
517 if (!of_ops->critical && !strcasecmp(action, "reboot"))
518 of_ops->critical = thermal_zone_device_critical_reboot;
519
520 tz = thermal_zone_device_register_with_trips(np->name, trips, ntrips,
521 mask, data, of_ops, &tzp,
522 pdelay, delay);
523 if (IS_ERR(tz)) {
524 ret = PTR_ERR(tz);
525 pr_err("Failed to register thermal zone %pOFn: %d\n", np, ret);
526 goto out_kfree_trips;
527 }
528
529 ret = thermal_zone_device_enable(tz);
530 if (ret) {
531 pr_err("Failed to enabled thermal zone '%s', id=%d: %d\n",
532 tz->type, tz->id, ret);
533 thermal_of_zone_unregister(tz);
534 return ERR_PTR(ret);
535 }
536
537 return tz;
538
539out_kfree_trips:
540 kfree(trips);
541out_kfree_of_ops:
542 kfree(of_ops);
543
544 return ERR_PTR(ret);
545}
546
547static void devm_thermal_of_zone_release(struct device *dev, void *res)
548{
549 thermal_of_zone_unregister(*(struct thermal_zone_device **)res);
550}
551
552static int devm_thermal_of_zone_match(struct device *dev, void *res,
553 void *data)
554{
555 struct thermal_zone_device **r = res;
556
557 if (WARN_ON(!r || !*r))
558 return 0;
559
560 return *r == data;
561}
562
563/**
564 * devm_thermal_of_zone_register - register a thermal tied with the sensor life cycle
565 *
566 * This function is the device version of the thermal_of_zone_register() function.
567 *
568 * @dev: a device structure pointer to sensor to be tied with the thermal zone OF life cycle
569 * @sensor_id: the sensor identifier
570 * @data: a pointer to a private data to be stored in the thermal zone 'devdata' field
571 * @ops: a pointer to the ops structure associated with the sensor
572 */
573struct thermal_zone_device *devm_thermal_of_zone_register(struct device *dev, int sensor_id, void *data,
574 const struct thermal_zone_device_ops *ops)
575{
576 struct thermal_zone_device **ptr, *tzd;
577
578 ptr = devres_alloc(devm_thermal_of_zone_release, sizeof(*ptr),
579 GFP_KERNEL);
580 if (!ptr)
581 return ERR_PTR(-ENOMEM);
582
583 tzd = thermal_of_zone_register(dev->of_node, sensor_id, data, ops);
584 if (IS_ERR(tzd)) {
585 devres_free(ptr);
586 return tzd;
587 }
588
589 *ptr = tzd;
590 devres_add(dev, ptr);
591
592 return tzd;
593}
594EXPORT_SYMBOL_GPL(devm_thermal_of_zone_register);
595
596/**
597 * devm_thermal_of_zone_unregister - Resource managed version of
598 * thermal_of_zone_unregister().
599 * @dev: Device for which which resource was allocated.
600 * @tz: a pointer to struct thermal_zone where the sensor is registered.
601 *
602 * This function removes the sensor callbacks and private data from the
603 * thermal zone device registered with devm_thermal_zone_of_sensor_register()
604 * API. It will also silent the zone by remove the .get_temp() and .get_trend()
605 * thermal zone device callbacks.
606 * Normally this function will not need to be called and the resource
607 * management code will ensure that the resource is freed.
608 */
609void devm_thermal_of_zone_unregister(struct device *dev, struct thermal_zone_device *tz)
610{
611 WARN_ON(devres_release(dev, devm_thermal_of_zone_release,
612 devm_thermal_of_zone_match, tz));
613}
614EXPORT_SYMBOL_GPL(devm_thermal_of_zone_unregister);