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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_device.h>
14#include <linux/of_platform.h>
15#include <linux/slab.h>
16#include <linux/thermal.h>
17#include <linux/types.h>
18#include <linux/string.h>
19
20#include "thermal_core.h"
21
22/*** Private data structures to represent thermal device tree data ***/
23
24/**
25 * struct __thermal_cooling_bind_param - a cooling device for a trip point
26 * @cooling_device: a pointer to identify the referred cooling device
27 * @min: minimum cooling state used at this trip point
28 * @max: maximum cooling state used at this trip point
29 */
30
31struct __thermal_cooling_bind_param {
32 struct device_node *cooling_device;
33 unsigned long min;
34 unsigned long max;
35};
36
37/**
38 * struct __thermal_bind_param - a match between trip and cooling device
39 * @tcbp: a pointer to an array of cooling devices
40 * @count: number of elements in array
41 * @trip_id: the trip point index
42 * @usage: the percentage (from 0 to 100) of cooling contribution
43 */
44
45struct __thermal_bind_params {
46 struct __thermal_cooling_bind_param *tcbp;
47 unsigned int count;
48 unsigned int trip_id;
49 unsigned int usage;
50};
51
52/**
53 * struct __thermal_zone - internal representation of a thermal zone
54 * @passive_delay: polling interval while passive cooling is activated
55 * @polling_delay: zone polling interval
56 * @slope: slope of the temperature adjustment curve
57 * @offset: offset of the temperature adjustment curve
58 * @ntrips: number of trip points
59 * @trips: an array of trip points (0..ntrips - 1)
60 * @num_tbps: number of thermal bind params
61 * @tbps: an array of thermal bind params (0..num_tbps - 1)
62 * @sensor_data: sensor private data used while reading temperature and trend
63 * @ops: set of callbacks to handle the thermal zone based on DT
64 */
65
66struct __thermal_zone {
67 int passive_delay;
68 int polling_delay;
69 int slope;
70 int offset;
71
72 /* trip data */
73 int ntrips;
74 struct thermal_trip *trips;
75
76 /* cooling binding data */
77 int num_tbps;
78 struct __thermal_bind_params *tbps;
79
80 /* sensor interface */
81 void *sensor_data;
82 const struct thermal_zone_of_device_ops *ops;
83};
84
85/*** DT thermal zone device callbacks ***/
86
87static int of_thermal_get_temp(struct thermal_zone_device *tz,
88 int *temp)
89{
90 struct __thermal_zone *data = tz->devdata;
91
92 if (!data->ops->get_temp)
93 return -EINVAL;
94
95 return data->ops->get_temp(data->sensor_data, temp);
96}
97
98static int of_thermal_set_trips(struct thermal_zone_device *tz,
99 int low, int high)
100{
101 struct __thermal_zone *data = tz->devdata;
102
103 if (!data->ops || !data->ops->set_trips)
104 return -EINVAL;
105
106 return data->ops->set_trips(data->sensor_data, low, high);
107}
108
109/**
110 * of_thermal_get_ntrips - function to export number of available trip
111 * points.
112 * @tz: pointer to a thermal zone
113 *
114 * This function is a globally visible wrapper to get number of trip points
115 * stored in the local struct __thermal_zone
116 *
117 * Return: number of available trip points, -ENODEV when data not available
118 */
119int of_thermal_get_ntrips(struct thermal_zone_device *tz)
120{
121 struct __thermal_zone *data = tz->devdata;
122
123 if (!data || IS_ERR(data))
124 return -ENODEV;
125
126 return data->ntrips;
127}
128EXPORT_SYMBOL_GPL(of_thermal_get_ntrips);
129
130/**
131 * of_thermal_is_trip_valid - function to check if trip point is valid
132 *
133 * @tz: pointer to a thermal zone
134 * @trip: trip point to evaluate
135 *
136 * This function is responsible for checking if passed trip point is valid
137 *
138 * Return: true if trip point is valid, false otherwise
139 */
140bool of_thermal_is_trip_valid(struct thermal_zone_device *tz, int trip)
141{
142 struct __thermal_zone *data = tz->devdata;
143
144 if (!data || trip >= data->ntrips || trip < 0)
145 return false;
146
147 return true;
148}
149EXPORT_SYMBOL_GPL(of_thermal_is_trip_valid);
150
151/**
152 * of_thermal_get_trip_points - function to get access to a globally exported
153 * trip points
154 *
155 * @tz: pointer to a thermal zone
156 *
157 * This function provides a pointer to trip points table
158 *
159 * Return: pointer to trip points table, NULL otherwise
160 */
161const struct thermal_trip *
162of_thermal_get_trip_points(struct thermal_zone_device *tz)
163{
164 struct __thermal_zone *data = tz->devdata;
165
166 if (!data)
167 return NULL;
168
169 return data->trips;
170}
171EXPORT_SYMBOL_GPL(of_thermal_get_trip_points);
172
173/**
174 * of_thermal_set_emul_temp - function to set emulated temperature
175 *
176 * @tz: pointer to a thermal zone
177 * @temp: temperature to set
178 *
179 * This function gives the ability to set emulated value of temperature,
180 * which is handy for debugging
181 *
182 * Return: zero on success, error code otherwise
183 */
184static int of_thermal_set_emul_temp(struct thermal_zone_device *tz,
185 int temp)
186{
187 struct __thermal_zone *data = tz->devdata;
188
189 return data->ops->set_emul_temp(data->sensor_data, temp);
190}
191
192static int of_thermal_get_trend(struct thermal_zone_device *tz, int trip,
193 enum thermal_trend *trend)
194{
195 struct __thermal_zone *data = tz->devdata;
196
197 if (!data->ops->get_trend)
198 return -EINVAL;
199
200 return data->ops->get_trend(data->sensor_data, trip, trend);
201}
202
203static int of_thermal_bind(struct thermal_zone_device *thermal,
204 struct thermal_cooling_device *cdev)
205{
206 struct __thermal_zone *data = thermal->devdata;
207 struct __thermal_bind_params *tbp;
208 struct __thermal_cooling_bind_param *tcbp;
209 int i, j;
210
211 if (!data || IS_ERR(data))
212 return -ENODEV;
213
214 /* find where to bind */
215 for (i = 0; i < data->num_tbps; i++) {
216 tbp = data->tbps + i;
217
218 for (j = 0; j < tbp->count; j++) {
219 tcbp = tbp->tcbp + j;
220
221 if (tcbp->cooling_device == cdev->np) {
222 int ret;
223
224 ret = thermal_zone_bind_cooling_device(thermal,
225 tbp->trip_id, cdev,
226 tcbp->max,
227 tcbp->min,
228 tbp->usage);
229 if (ret)
230 return ret;
231 }
232 }
233 }
234
235 return 0;
236}
237
238static int of_thermal_unbind(struct thermal_zone_device *thermal,
239 struct thermal_cooling_device *cdev)
240{
241 struct __thermal_zone *data = thermal->devdata;
242 struct __thermal_bind_params *tbp;
243 struct __thermal_cooling_bind_param *tcbp;
244 int i, j;
245
246 if (!data || IS_ERR(data))
247 return -ENODEV;
248
249 /* find where to unbind */
250 for (i = 0; i < data->num_tbps; i++) {
251 tbp = data->tbps + i;
252
253 for (j = 0; j < tbp->count; j++) {
254 tcbp = tbp->tcbp + j;
255
256 if (tcbp->cooling_device == cdev->np) {
257 int ret;
258
259 ret = thermal_zone_unbind_cooling_device(thermal,
260 tbp->trip_id, cdev);
261 if (ret)
262 return ret;
263 }
264 }
265 }
266
267 return 0;
268}
269
270static int of_thermal_get_trip_type(struct thermal_zone_device *tz, int trip,
271 enum thermal_trip_type *type)
272{
273 struct __thermal_zone *data = tz->devdata;
274
275 if (trip >= data->ntrips || trip < 0)
276 return -EDOM;
277
278 *type = data->trips[trip].type;
279
280 return 0;
281}
282
283static int of_thermal_get_trip_temp(struct thermal_zone_device *tz, int trip,
284 int *temp)
285{
286 struct __thermal_zone *data = tz->devdata;
287
288 if (trip >= data->ntrips || trip < 0)
289 return -EDOM;
290
291 *temp = data->trips[trip].temperature;
292
293 return 0;
294}
295
296static int of_thermal_set_trip_temp(struct thermal_zone_device *tz, int trip,
297 int temp)
298{
299 struct __thermal_zone *data = tz->devdata;
300
301 if (trip >= data->ntrips || trip < 0)
302 return -EDOM;
303
304 if (data->ops->set_trip_temp) {
305 int ret;
306
307 ret = data->ops->set_trip_temp(data->sensor_data, trip, temp);
308 if (ret)
309 return ret;
310 }
311
312 /* thermal framework should take care of data->mask & (1 << trip) */
313 data->trips[trip].temperature = temp;
314
315 return 0;
316}
317
318static int of_thermal_get_trip_hyst(struct thermal_zone_device *tz, int trip,
319 int *hyst)
320{
321 struct __thermal_zone *data = tz->devdata;
322
323 if (trip >= data->ntrips || trip < 0)
324 return -EDOM;
325
326 *hyst = data->trips[trip].hysteresis;
327
328 return 0;
329}
330
331static int of_thermal_set_trip_hyst(struct thermal_zone_device *tz, int trip,
332 int hyst)
333{
334 struct __thermal_zone *data = tz->devdata;
335
336 if (trip >= data->ntrips || trip < 0)
337 return -EDOM;
338
339 /* thermal framework should take care of data->mask & (1 << trip) */
340 data->trips[trip].hysteresis = hyst;
341
342 return 0;
343}
344
345static int of_thermal_get_crit_temp(struct thermal_zone_device *tz,
346 int *temp)
347{
348 struct __thermal_zone *data = tz->devdata;
349 int i;
350
351 for (i = 0; i < data->ntrips; i++)
352 if (data->trips[i].type == THERMAL_TRIP_CRITICAL) {
353 *temp = data->trips[i].temperature;
354 return 0;
355 }
356
357 return -EINVAL;
358}
359
360static struct thermal_zone_device_ops of_thermal_ops = {
361 .get_trip_type = of_thermal_get_trip_type,
362 .get_trip_temp = of_thermal_get_trip_temp,
363 .set_trip_temp = of_thermal_set_trip_temp,
364 .get_trip_hyst = of_thermal_get_trip_hyst,
365 .set_trip_hyst = of_thermal_set_trip_hyst,
366 .get_crit_temp = of_thermal_get_crit_temp,
367
368 .bind = of_thermal_bind,
369 .unbind = of_thermal_unbind,
370};
371
372/*** sensor API ***/
373
374static struct thermal_zone_device *
375thermal_zone_of_add_sensor(struct device_node *zone,
376 struct device_node *sensor, void *data,
377 const struct thermal_zone_of_device_ops *ops)
378{
379 struct thermal_zone_device *tzd;
380 struct __thermal_zone *tz;
381
382 tzd = thermal_zone_get_zone_by_name(zone->name);
383 if (IS_ERR(tzd))
384 return ERR_PTR(-EPROBE_DEFER);
385
386 tz = tzd->devdata;
387
388 if (!ops)
389 return ERR_PTR(-EINVAL);
390
391 mutex_lock(&tzd->lock);
392 tz->ops = ops;
393 tz->sensor_data = data;
394
395 tzd->ops->get_temp = of_thermal_get_temp;
396 tzd->ops->get_trend = of_thermal_get_trend;
397
398 /*
399 * The thermal zone core will calculate the window if they have set the
400 * optional set_trips pointer.
401 */
402 if (ops->set_trips)
403 tzd->ops->set_trips = of_thermal_set_trips;
404
405 if (ops->set_emul_temp)
406 tzd->ops->set_emul_temp = of_thermal_set_emul_temp;
407
408 mutex_unlock(&tzd->lock);
409
410 return tzd;
411}
412
413/**
414 * thermal_zone_of_get_sensor_id - get sensor ID from a DT thermal zone
415 * @tz_np: a valid thermal zone device node.
416 * @sensor_np: a sensor node of a valid sensor device.
417 * @id: the sensor ID returned if success.
418 *
419 * This function will get sensor ID from a given thermal zone node and
420 * the sensor node must match the temperature provider @sensor_np.
421 *
422 * Return: 0 on success, proper error code otherwise.
423 */
424
425int thermal_zone_of_get_sensor_id(struct device_node *tz_np,
426 struct device_node *sensor_np,
427 u32 *id)
428{
429 struct of_phandle_args sensor_specs;
430 int ret;
431
432 ret = of_parse_phandle_with_args(tz_np,
433 "thermal-sensors",
434 "#thermal-sensor-cells",
435 0,
436 &sensor_specs);
437 if (ret)
438 return ret;
439
440 if (sensor_specs.np != sensor_np) {
441 of_node_put(sensor_specs.np);
442 return -ENODEV;
443 }
444
445 if (sensor_specs.args_count > 1)
446 pr_warn("%pOFn: too many cells in sensor specifier %d\n",
447 sensor_specs.np, sensor_specs.args_count);
448
449 *id = sensor_specs.args_count ? sensor_specs.args[0] : 0;
450
451 of_node_put(sensor_specs.np);
452
453 return 0;
454}
455EXPORT_SYMBOL_GPL(thermal_zone_of_get_sensor_id);
456
457/**
458 * thermal_zone_of_sensor_register - registers a sensor to a DT thermal zone
459 * @dev: a valid struct device pointer of a sensor device. Must contain
460 * a valid .of_node, for the sensor node.
461 * @sensor_id: a sensor identifier, in case the sensor IP has more
462 * than one sensors
463 * @data: a private pointer (owned by the caller) that will be passed
464 * back, when a temperature reading is needed.
465 * @ops: struct thermal_zone_of_device_ops *. Must contain at least .get_temp.
466 *
467 * This function will search the list of thermal zones described in device
468 * tree and look for the zone that refer to the sensor device pointed by
469 * @dev->of_node as temperature providers. For the zone pointing to the
470 * sensor node, the sensor will be added to the DT thermal zone device.
471 *
472 * The thermal zone temperature is provided by the @get_temp function
473 * pointer. When called, it will have the private pointer @data back.
474 *
475 * The thermal zone temperature trend is provided by the @get_trend function
476 * pointer. When called, it will have the private pointer @data back.
477 *
478 * TODO:
479 * 01 - This function must enqueue the new sensor instead of using
480 * it as the only source of temperature values.
481 *
482 * 02 - There must be a way to match the sensor with all thermal zones
483 * that refer to it.
484 *
485 * Return: On success returns a valid struct thermal_zone_device,
486 * otherwise, it returns a corresponding ERR_PTR(). Caller must
487 * check the return value with help of IS_ERR() helper.
488 */
489struct thermal_zone_device *
490thermal_zone_of_sensor_register(struct device *dev, int sensor_id, void *data,
491 const struct thermal_zone_of_device_ops *ops)
492{
493 struct device_node *np, *child, *sensor_np;
494 struct thermal_zone_device *tzd = ERR_PTR(-ENODEV);
495
496 np = of_find_node_by_name(NULL, "thermal-zones");
497 if (!np)
498 return ERR_PTR(-ENODEV);
499
500 if (!dev || !dev->of_node) {
501 of_node_put(np);
502 return ERR_PTR(-ENODEV);
503 }
504
505 sensor_np = of_node_get(dev->of_node);
506
507 for_each_available_child_of_node(np, child) {
508 int ret, id;
509
510 /* For now, thermal framework supports only 1 sensor per zone */
511 ret = thermal_zone_of_get_sensor_id(child, sensor_np, &id);
512 if (ret)
513 continue;
514
515 if (id == sensor_id) {
516 tzd = thermal_zone_of_add_sensor(child, sensor_np,
517 data, ops);
518 if (!IS_ERR(tzd))
519 thermal_zone_device_enable(tzd);
520
521 of_node_put(child);
522 goto exit;
523 }
524 }
525exit:
526 of_node_put(sensor_np);
527 of_node_put(np);
528
529 return tzd;
530}
531EXPORT_SYMBOL_GPL(thermal_zone_of_sensor_register);
532
533/**
534 * thermal_zone_of_sensor_unregister - unregisters a sensor from a DT thermal zone
535 * @dev: a valid struct device pointer of a sensor device. Must contain
536 * a valid .of_node, for the sensor node.
537 * @tzd: a pointer to struct thermal_zone_device where the sensor is registered.
538 *
539 * This function removes the sensor callbacks and private data from the
540 * thermal zone device registered with thermal_zone_of_sensor_register()
541 * API. It will also silent the zone by remove the .get_temp() and .get_trend()
542 * thermal zone device callbacks.
543 *
544 * TODO: When the support to several sensors per zone is added, this
545 * function must search the sensor list based on @dev parameter.
546 *
547 */
548void thermal_zone_of_sensor_unregister(struct device *dev,
549 struct thermal_zone_device *tzd)
550{
551 struct __thermal_zone *tz;
552
553 if (!dev || !tzd || !tzd->devdata)
554 return;
555
556 tz = tzd->devdata;
557
558 /* no __thermal_zone, nothing to be done */
559 if (!tz)
560 return;
561
562 /* stop temperature polling */
563 thermal_zone_device_disable(tzd);
564
565 mutex_lock(&tzd->lock);
566 tzd->ops->get_temp = NULL;
567 tzd->ops->get_trend = NULL;
568 tzd->ops->set_emul_temp = NULL;
569
570 tz->ops = NULL;
571 tz->sensor_data = NULL;
572 mutex_unlock(&tzd->lock);
573}
574EXPORT_SYMBOL_GPL(thermal_zone_of_sensor_unregister);
575
576static void devm_thermal_zone_of_sensor_release(struct device *dev, void *res)
577{
578 thermal_zone_of_sensor_unregister(dev,
579 *(struct thermal_zone_device **)res);
580}
581
582static int devm_thermal_zone_of_sensor_match(struct device *dev, void *res,
583 void *data)
584{
585 struct thermal_zone_device **r = res;
586
587 if (WARN_ON(!r || !*r))
588 return 0;
589
590 return *r == data;
591}
592
593/**
594 * devm_thermal_zone_of_sensor_register - Resource managed version of
595 * thermal_zone_of_sensor_register()
596 * @dev: a valid struct device pointer of a sensor device. Must contain
597 * a valid .of_node, for the sensor node.
598 * @sensor_id: a sensor identifier, in case the sensor IP has more
599 * than one sensors
600 * @data: a private pointer (owned by the caller) that will be passed
601 * back, when a temperature reading is needed.
602 * @ops: struct thermal_zone_of_device_ops *. Must contain at least .get_temp.
603 *
604 * Refer thermal_zone_of_sensor_register() for more details.
605 *
606 * Return: On success returns a valid struct thermal_zone_device,
607 * otherwise, it returns a corresponding ERR_PTR(). Caller must
608 * check the return value with help of IS_ERR() helper.
609 * Registered thermal_zone_device device will automatically be
610 * released when device is unbounded.
611 */
612struct thermal_zone_device *devm_thermal_zone_of_sensor_register(
613 struct device *dev, int sensor_id,
614 void *data, const struct thermal_zone_of_device_ops *ops)
615{
616 struct thermal_zone_device **ptr, *tzd;
617
618 ptr = devres_alloc(devm_thermal_zone_of_sensor_release, sizeof(*ptr),
619 GFP_KERNEL);
620 if (!ptr)
621 return ERR_PTR(-ENOMEM);
622
623 tzd = thermal_zone_of_sensor_register(dev, sensor_id, data, ops);
624 if (IS_ERR(tzd)) {
625 devres_free(ptr);
626 return tzd;
627 }
628
629 *ptr = tzd;
630 devres_add(dev, ptr);
631
632 return tzd;
633}
634EXPORT_SYMBOL_GPL(devm_thermal_zone_of_sensor_register);
635
636/**
637 * devm_thermal_zone_of_sensor_unregister - Resource managed version of
638 * thermal_zone_of_sensor_unregister().
639 * @dev: Device for which which resource was allocated.
640 * @tzd: a pointer to struct thermal_zone_device where the sensor is registered.
641 *
642 * This function removes the sensor callbacks and private data from the
643 * thermal zone device registered with devm_thermal_zone_of_sensor_register()
644 * API. It will also silent the zone by remove the .get_temp() and .get_trend()
645 * thermal zone device callbacks.
646 * Normally this function will not need to be called and the resource
647 * management code will ensure that the resource is freed.
648 */
649void devm_thermal_zone_of_sensor_unregister(struct device *dev,
650 struct thermal_zone_device *tzd)
651{
652 WARN_ON(devres_release(dev, devm_thermal_zone_of_sensor_release,
653 devm_thermal_zone_of_sensor_match, tzd));
654}
655EXPORT_SYMBOL_GPL(devm_thermal_zone_of_sensor_unregister);
656
657/*** functions parsing device tree nodes ***/
658
659/**
660 * thermal_of_populate_bind_params - parse and fill cooling map data
661 * @np: DT node containing a cooling-map node
662 * @__tbp: data structure to be filled with cooling map info
663 * @trips: array of thermal zone trip points
664 * @ntrips: number of trip points inside trips.
665 *
666 * This function parses a cooling-map type of node represented by
667 * @np parameter and fills the read data into @__tbp data structure.
668 * It needs the already parsed array of trip points of the thermal zone
669 * in consideration.
670 *
671 * Return: 0 on success, proper error code otherwise
672 */
673static int thermal_of_populate_bind_params(struct device_node *np,
674 struct __thermal_bind_params *__tbp,
675 struct thermal_trip *trips,
676 int ntrips)
677{
678 struct of_phandle_args cooling_spec;
679 struct __thermal_cooling_bind_param *__tcbp;
680 struct device_node *trip;
681 int ret, i, count;
682 u32 prop;
683
684 /* Default weight. Usage is optional */
685 __tbp->usage = THERMAL_WEIGHT_DEFAULT;
686 ret = of_property_read_u32(np, "contribution", &prop);
687 if (ret == 0)
688 __tbp->usage = prop;
689
690 trip = of_parse_phandle(np, "trip", 0);
691 if (!trip) {
692 pr_err("missing trip property\n");
693 return -ENODEV;
694 }
695
696 /* match using device_node */
697 for (i = 0; i < ntrips; i++)
698 if (trip == trips[i].np) {
699 __tbp->trip_id = i;
700 break;
701 }
702
703 if (i == ntrips) {
704 ret = -ENODEV;
705 goto end;
706 }
707
708 count = of_count_phandle_with_args(np, "cooling-device",
709 "#cooling-cells");
710 if (count <= 0) {
711 pr_err("Add a cooling_device property with at least one device\n");
712 ret = -ENOENT;
713 goto end;
714 }
715
716 __tcbp = kcalloc(count, sizeof(*__tcbp), GFP_KERNEL);
717 if (!__tcbp) {
718 ret = -ENOMEM;
719 goto end;
720 }
721
722 for (i = 0; i < count; i++) {
723 ret = of_parse_phandle_with_args(np, "cooling-device",
724 "#cooling-cells", i, &cooling_spec);
725 if (ret < 0) {
726 pr_err("Invalid cooling-device entry\n");
727 goto free_tcbp;
728 }
729
730 __tcbp[i].cooling_device = cooling_spec.np;
731
732 if (cooling_spec.args_count >= 2) { /* at least min and max */
733 __tcbp[i].min = cooling_spec.args[0];
734 __tcbp[i].max = cooling_spec.args[1];
735 } else {
736 pr_err("wrong reference to cooling device, missing limits\n");
737 }
738 }
739
740 __tbp->tcbp = __tcbp;
741 __tbp->count = count;
742
743 goto end;
744
745free_tcbp:
746 for (i = i - 1; i >= 0; i--)
747 of_node_put(__tcbp[i].cooling_device);
748 kfree(__tcbp);
749end:
750 of_node_put(trip);
751
752 return ret;
753}
754
755/*
756 * It maps 'enum thermal_trip_type' found in include/linux/thermal.h
757 * into the device tree binding of 'trip', property type.
758 */
759static const char * const trip_types[] = {
760 [THERMAL_TRIP_ACTIVE] = "active",
761 [THERMAL_TRIP_PASSIVE] = "passive",
762 [THERMAL_TRIP_HOT] = "hot",
763 [THERMAL_TRIP_CRITICAL] = "critical",
764};
765
766/**
767 * thermal_of_get_trip_type - Get phy mode for given device_node
768 * @np: Pointer to the given device_node
769 * @type: Pointer to resulting trip type
770 *
771 * The function gets trip type string from property 'type',
772 * and store its index in trip_types table in @type,
773 *
774 * Return: 0 on success, or errno in error case.
775 */
776static int thermal_of_get_trip_type(struct device_node *np,
777 enum thermal_trip_type *type)
778{
779 const char *t;
780 int err, i;
781
782 err = of_property_read_string(np, "type", &t);
783 if (err < 0)
784 return err;
785
786 for (i = 0; i < ARRAY_SIZE(trip_types); i++)
787 if (!strcasecmp(t, trip_types[i])) {
788 *type = i;
789 return 0;
790 }
791
792 return -ENODEV;
793}
794
795/**
796 * thermal_of_populate_trip - parse and fill one trip point data
797 * @np: DT node containing a trip point node
798 * @trip: trip point data structure to be filled up
799 *
800 * This function parses a trip point type of node represented by
801 * @np parameter and fills the read data into @trip data structure.
802 *
803 * Return: 0 on success, proper error code otherwise
804 */
805static int thermal_of_populate_trip(struct device_node *np,
806 struct thermal_trip *trip)
807{
808 int prop;
809 int ret;
810
811 ret = of_property_read_u32(np, "temperature", &prop);
812 if (ret < 0) {
813 pr_err("missing temperature property\n");
814 return ret;
815 }
816 trip->temperature = prop;
817
818 ret = of_property_read_u32(np, "hysteresis", &prop);
819 if (ret < 0) {
820 pr_err("missing hysteresis property\n");
821 return ret;
822 }
823 trip->hysteresis = prop;
824
825 ret = thermal_of_get_trip_type(np, &trip->type);
826 if (ret < 0) {
827 pr_err("wrong trip type property\n");
828 return ret;
829 }
830
831 /* Required for cooling map matching */
832 trip->np = np;
833 of_node_get(np);
834
835 return 0;
836}
837
838/**
839 * thermal_of_build_thermal_zone - parse and fill one thermal zone data
840 * @np: DT node containing a thermal zone node
841 *
842 * This function parses a thermal zone type of node represented by
843 * @np parameter and fills the read data into a __thermal_zone data structure
844 * and return this pointer.
845 *
846 * TODO: Missing properties to parse: thermal-sensor-names
847 *
848 * Return: On success returns a valid struct __thermal_zone,
849 * otherwise, it returns a corresponding ERR_PTR(). Caller must
850 * check the return value with help of IS_ERR() helper.
851 */
852static struct __thermal_zone
853__init *thermal_of_build_thermal_zone(struct device_node *np)
854{
855 struct device_node *child = NULL, *gchild;
856 struct __thermal_zone *tz;
857 int ret, i;
858 u32 prop, coef[2];
859
860 if (!np) {
861 pr_err("no thermal zone np\n");
862 return ERR_PTR(-EINVAL);
863 }
864
865 tz = kzalloc(sizeof(*tz), GFP_KERNEL);
866 if (!tz)
867 return ERR_PTR(-ENOMEM);
868
869 ret = of_property_read_u32(np, "polling-delay-passive", &prop);
870 if (ret < 0) {
871 pr_err("%pOFn: missing polling-delay-passive property\n", np);
872 goto free_tz;
873 }
874 tz->passive_delay = prop;
875
876 ret = of_property_read_u32(np, "polling-delay", &prop);
877 if (ret < 0) {
878 pr_err("%pOFn: missing polling-delay property\n", np);
879 goto free_tz;
880 }
881 tz->polling_delay = prop;
882
883 /*
884 * REVIST: for now, the thermal framework supports only
885 * one sensor per thermal zone. Thus, we are considering
886 * only the first two values as slope and offset.
887 */
888 ret = of_property_read_u32_array(np, "coefficients", coef, 2);
889 if (ret == 0) {
890 tz->slope = coef[0];
891 tz->offset = coef[1];
892 } else {
893 tz->slope = 1;
894 tz->offset = 0;
895 }
896
897 /* trips */
898 child = of_get_child_by_name(np, "trips");
899
900 /* No trips provided */
901 if (!child)
902 goto finish;
903
904 tz->ntrips = of_get_child_count(child);
905 if (tz->ntrips == 0) /* must have at least one child */
906 goto finish;
907
908 tz->trips = kcalloc(tz->ntrips, sizeof(*tz->trips), GFP_KERNEL);
909 if (!tz->trips) {
910 ret = -ENOMEM;
911 goto free_tz;
912 }
913
914 i = 0;
915 for_each_child_of_node(child, gchild) {
916 ret = thermal_of_populate_trip(gchild, &tz->trips[i++]);
917 if (ret)
918 goto free_trips;
919 }
920
921 of_node_put(child);
922
923 /* cooling-maps */
924 child = of_get_child_by_name(np, "cooling-maps");
925
926 /* cooling-maps not provided */
927 if (!child)
928 goto finish;
929
930 tz->num_tbps = of_get_child_count(child);
931 if (tz->num_tbps == 0)
932 goto finish;
933
934 tz->tbps = kcalloc(tz->num_tbps, sizeof(*tz->tbps), GFP_KERNEL);
935 if (!tz->tbps) {
936 ret = -ENOMEM;
937 goto free_trips;
938 }
939
940 i = 0;
941 for_each_child_of_node(child, gchild) {
942 ret = thermal_of_populate_bind_params(gchild, &tz->tbps[i++],
943 tz->trips, tz->ntrips);
944 if (ret)
945 goto free_tbps;
946 }
947
948finish:
949 of_node_put(child);
950
951 return tz;
952
953free_tbps:
954 for (i = i - 1; i >= 0; i--) {
955 struct __thermal_bind_params *tbp = tz->tbps + i;
956 int j;
957
958 for (j = 0; j < tbp->count; j++)
959 of_node_put(tbp->tcbp[j].cooling_device);
960
961 kfree(tbp->tcbp);
962 }
963
964 kfree(tz->tbps);
965free_trips:
966 for (i = 0; i < tz->ntrips; i++)
967 of_node_put(tz->trips[i].np);
968 kfree(tz->trips);
969 of_node_put(gchild);
970free_tz:
971 kfree(tz);
972 of_node_put(child);
973
974 return ERR_PTR(ret);
975}
976
977static __init void of_thermal_free_zone(struct __thermal_zone *tz)
978{
979 struct __thermal_bind_params *tbp;
980 int i, j;
981
982 for (i = 0; i < tz->num_tbps; i++) {
983 tbp = tz->tbps + i;
984
985 for (j = 0; j < tbp->count; j++)
986 of_node_put(tbp->tcbp[j].cooling_device);
987
988 kfree(tbp->tcbp);
989 }
990
991 kfree(tz->tbps);
992 for (i = 0; i < tz->ntrips; i++)
993 of_node_put(tz->trips[i].np);
994 kfree(tz->trips);
995 kfree(tz);
996}
997
998/**
999 * of_thermal_destroy_zones - remove all zones parsed and allocated resources
1000 *
1001 * Finds all zones parsed and added to the thermal framework and remove them
1002 * from the system, together with their resources.
1003 *
1004 */
1005static __init void of_thermal_destroy_zones(void)
1006{
1007 struct device_node *np, *child;
1008
1009 np = of_find_node_by_name(NULL, "thermal-zones");
1010 if (!np) {
1011 pr_debug("unable to find thermal zones\n");
1012 return;
1013 }
1014
1015 for_each_available_child_of_node(np, child) {
1016 struct thermal_zone_device *zone;
1017
1018 zone = thermal_zone_get_zone_by_name(child->name);
1019 if (IS_ERR(zone))
1020 continue;
1021
1022 thermal_zone_device_unregister(zone);
1023 kfree(zone->tzp);
1024 kfree(zone->ops);
1025 of_thermal_free_zone(zone->devdata);
1026 }
1027 of_node_put(np);
1028}
1029
1030/**
1031 * of_parse_thermal_zones - parse device tree thermal data
1032 *
1033 * Initialization function that can be called by machine initialization
1034 * code to parse thermal data and populate the thermal framework
1035 * with hardware thermal zones info. This function only parses thermal zones.
1036 * Cooling devices and sensor devices nodes are supposed to be parsed
1037 * by their respective drivers.
1038 *
1039 * Return: 0 on success, proper error code otherwise
1040 *
1041 */
1042int __init of_parse_thermal_zones(void)
1043{
1044 struct device_node *np, *child;
1045 struct __thermal_zone *tz;
1046 struct thermal_zone_device_ops *ops;
1047
1048 np = of_find_node_by_name(NULL, "thermal-zones");
1049 if (!np) {
1050 pr_debug("unable to find thermal zones\n");
1051 return 0; /* Run successfully on systems without thermal DT */
1052 }
1053
1054 for_each_available_child_of_node(np, child) {
1055 struct thermal_zone_device *zone;
1056 struct thermal_zone_params *tzp;
1057 int i, mask = 0;
1058 u32 prop;
1059
1060 tz = thermal_of_build_thermal_zone(child);
1061 if (IS_ERR(tz)) {
1062 pr_err("failed to build thermal zone %pOFn: %ld\n",
1063 child,
1064 PTR_ERR(tz));
1065 continue;
1066 }
1067
1068 ops = kmemdup(&of_thermal_ops, sizeof(*ops), GFP_KERNEL);
1069 if (!ops)
1070 goto exit_free;
1071
1072 tzp = kzalloc(sizeof(*tzp), GFP_KERNEL);
1073 if (!tzp) {
1074 kfree(ops);
1075 goto exit_free;
1076 }
1077
1078 /* No hwmon because there might be hwmon drivers registering */
1079 tzp->no_hwmon = true;
1080
1081 if (!of_property_read_u32(child, "sustainable-power", &prop))
1082 tzp->sustainable_power = prop;
1083
1084 for (i = 0; i < tz->ntrips; i++)
1085 mask |= 1 << i;
1086
1087 /* these two are left for temperature drivers to use */
1088 tzp->slope = tz->slope;
1089 tzp->offset = tz->offset;
1090
1091 zone = thermal_zone_device_register(child->name, tz->ntrips,
1092 mask, tz,
1093 ops, tzp,
1094 tz->passive_delay,
1095 tz->polling_delay);
1096 if (IS_ERR(zone)) {
1097 pr_err("Failed to build %pOFn zone %ld\n", child,
1098 PTR_ERR(zone));
1099 kfree(tzp);
1100 kfree(ops);
1101 of_thermal_free_zone(tz);
1102 /* attempting to build remaining zones still */
1103 }
1104 }
1105 of_node_put(np);
1106
1107 return 0;
1108
1109exit_free:
1110 of_node_put(child);
1111 of_node_put(np);
1112 of_thermal_free_zone(tz);
1113
1114 /* no memory available, so free what we have built */
1115 of_thermal_destroy_zones();
1116
1117 return -ENOMEM;
1118}