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1/*
2 * of-thermal.c - Generic Thermal Management device tree support.
3 *
4 * Copyright (C) 2013 Texas Instruments
5 * Copyright (C) 2013 Eduardo Valentin <eduardo.valentin@ti.com>
6 *
7 *
8 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
9 *
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.
13 *
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.
18 *
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.
22 *
23 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
24 */
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>
34
35#include "thermal_core.h"
36
37/*** Private data structures to represent thermal device tree data ***/
38
39/**
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
46 */
47
48struct __thermal_bind_params {
49 struct device_node *cooling_device;
50 unsigned int trip_id;
51 unsigned int usage;
52 unsigned long min;
53 unsigned long max;
54};
55
56/**
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 * @slope: slope of the temperature adjustment curve
62 * @offset: offset of the temperature adjustment curve
63 * @ntrips: number of trip points
64 * @trips: an array of trip points (0..ntrips - 1)
65 * @num_tbps: number of thermal bind params
66 * @tbps: an array of thermal bind params (0..num_tbps - 1)
67 * @sensor_data: sensor private data used while reading temperature and trend
68 * @ops: set of callbacks to handle the thermal zone based on DT
69 */
70
71struct __thermal_zone {
72 enum thermal_device_mode mode;
73 int passive_delay;
74 int polling_delay;
75 int slope;
76 int offset;
77
78 /* trip data */
79 int ntrips;
80 struct thermal_trip *trips;
81
82 /* cooling binding data */
83 int num_tbps;
84 struct __thermal_bind_params *tbps;
85
86 /* sensor interface */
87 void *sensor_data;
88 const struct thermal_zone_of_device_ops *ops;
89};
90
91/*** DT thermal zone device callbacks ***/
92
93static int of_thermal_get_temp(struct thermal_zone_device *tz,
94 int *temp)
95{
96 struct __thermal_zone *data = tz->devdata;
97
98 if (!data->ops->get_temp)
99 return -EINVAL;
100
101 return data->ops->get_temp(data->sensor_data, temp);
102}
103
104/**
105 * of_thermal_get_ntrips - function to export number of available trip
106 * points.
107 * @tz: pointer to a thermal zone
108 *
109 * This function is a globally visible wrapper to get number of trip points
110 * stored in the local struct __thermal_zone
111 *
112 * Return: number of available trip points, -ENODEV when data not available
113 */
114int of_thermal_get_ntrips(struct thermal_zone_device *tz)
115{
116 struct __thermal_zone *data = tz->devdata;
117
118 if (!data || IS_ERR(data))
119 return -ENODEV;
120
121 return data->ntrips;
122}
123EXPORT_SYMBOL_GPL(of_thermal_get_ntrips);
124
125/**
126 * of_thermal_is_trip_valid - function to check if trip point is valid
127 *
128 * @tz: pointer to a thermal zone
129 * @trip: trip point to evaluate
130 *
131 * This function is responsible for checking if passed trip point is valid
132 *
133 * Return: true if trip point is valid, false otherwise
134 */
135bool of_thermal_is_trip_valid(struct thermal_zone_device *tz, int trip)
136{
137 struct __thermal_zone *data = tz->devdata;
138
139 if (!data || trip >= data->ntrips || trip < 0)
140 return false;
141
142 return true;
143}
144EXPORT_SYMBOL_GPL(of_thermal_is_trip_valid);
145
146/**
147 * of_thermal_get_trip_points - function to get access to a globally exported
148 * trip points
149 *
150 * @tz: pointer to a thermal zone
151 *
152 * This function provides a pointer to trip points table
153 *
154 * Return: pointer to trip points table, NULL otherwise
155 */
156const struct thermal_trip *
157of_thermal_get_trip_points(struct thermal_zone_device *tz)
158{
159 struct __thermal_zone *data = tz->devdata;
160
161 if (!data)
162 return NULL;
163
164 return data->trips;
165}
166EXPORT_SYMBOL_GPL(of_thermal_get_trip_points);
167
168/**
169 * of_thermal_set_emul_temp - function to set emulated temperature
170 *
171 * @tz: pointer to a thermal zone
172 * @temp: temperature to set
173 *
174 * This function gives the ability to set emulated value of temperature,
175 * which is handy for debugging
176 *
177 * Return: zero on success, error code otherwise
178 */
179static int of_thermal_set_emul_temp(struct thermal_zone_device *tz,
180 int temp)
181{
182 struct __thermal_zone *data = tz->devdata;
183
184 if (!data->ops || !data->ops->set_emul_temp)
185 return -EINVAL;
186
187 return data->ops->set_emul_temp(data->sensor_data, temp);
188}
189
190static int of_thermal_get_trend(struct thermal_zone_device *tz, int trip,
191 enum thermal_trend *trend)
192{
193 struct __thermal_zone *data = tz->devdata;
194 long dev_trend;
195 int r;
196
197 if (!data->ops->get_trend)
198 return -EINVAL;
199
200 r = data->ops->get_trend(data->sensor_data, &dev_trend);
201 if (r)
202 return r;
203
204 /* TODO: These intervals might have some thresholds, but in core code */
205 if (dev_trend > 0)
206 *trend = THERMAL_TREND_RAISING;
207 else if (dev_trend < 0)
208 *trend = THERMAL_TREND_DROPPING;
209 else
210 *trend = THERMAL_TREND_STABLE;
211
212 return 0;
213}
214
215static int of_thermal_bind(struct thermal_zone_device *thermal,
216 struct thermal_cooling_device *cdev)
217{
218 struct __thermal_zone *data = thermal->devdata;
219 int i;
220
221 if (!data || IS_ERR(data))
222 return -ENODEV;
223
224 /* find where to bind */
225 for (i = 0; i < data->num_tbps; i++) {
226 struct __thermal_bind_params *tbp = data->tbps + i;
227
228 if (tbp->cooling_device == cdev->np) {
229 int ret;
230
231 ret = thermal_zone_bind_cooling_device(thermal,
232 tbp->trip_id, cdev,
233 tbp->max,
234 tbp->min,
235 tbp->usage);
236 if (ret)
237 return ret;
238 }
239 }
240
241 return 0;
242}
243
244static int of_thermal_unbind(struct thermal_zone_device *thermal,
245 struct thermal_cooling_device *cdev)
246{
247 struct __thermal_zone *data = thermal->devdata;
248 int i;
249
250 if (!data || IS_ERR(data))
251 return -ENODEV;
252
253 /* find where to unbind */
254 for (i = 0; i < data->num_tbps; i++) {
255 struct __thermal_bind_params *tbp = data->tbps + i;
256
257 if (tbp->cooling_device == cdev->np) {
258 int ret;
259
260 ret = thermal_zone_unbind_cooling_device(thermal,
261 tbp->trip_id, cdev);
262 if (ret)
263 return ret;
264 }
265 }
266
267 return 0;
268}
269
270static int of_thermal_get_mode(struct thermal_zone_device *tz,
271 enum thermal_device_mode *mode)
272{
273 struct __thermal_zone *data = tz->devdata;
274
275 *mode = data->mode;
276
277 return 0;
278}
279
280static int of_thermal_set_mode(struct thermal_zone_device *tz,
281 enum thermal_device_mode mode)
282{
283 struct __thermal_zone *data = tz->devdata;
284
285 mutex_lock(&tz->lock);
286
287 if (mode == THERMAL_DEVICE_ENABLED)
288 tz->polling_delay = data->polling_delay;
289 else
290 tz->polling_delay = 0;
291
292 mutex_unlock(&tz->lock);
293
294 data->mode = mode;
295 thermal_zone_device_update(tz);
296
297 return 0;
298}
299
300static int of_thermal_get_trip_type(struct thermal_zone_device *tz, int trip,
301 enum thermal_trip_type *type)
302{
303 struct __thermal_zone *data = tz->devdata;
304
305 if (trip >= data->ntrips || trip < 0)
306 return -EDOM;
307
308 *type = data->trips[trip].type;
309
310 return 0;
311}
312
313static int of_thermal_get_trip_temp(struct thermal_zone_device *tz, int trip,
314 int *temp)
315{
316 struct __thermal_zone *data = tz->devdata;
317
318 if (trip >= data->ntrips || trip < 0)
319 return -EDOM;
320
321 *temp = data->trips[trip].temperature;
322
323 return 0;
324}
325
326static int of_thermal_set_trip_temp(struct thermal_zone_device *tz, int trip,
327 int temp)
328{
329 struct __thermal_zone *data = tz->devdata;
330
331 if (trip >= data->ntrips || trip < 0)
332 return -EDOM;
333
334 /* thermal framework should take care of data->mask & (1 << trip) */
335 data->trips[trip].temperature = temp;
336
337 return 0;
338}
339
340static int of_thermal_get_trip_hyst(struct thermal_zone_device *tz, int trip,
341 int *hyst)
342{
343 struct __thermal_zone *data = tz->devdata;
344
345 if (trip >= data->ntrips || trip < 0)
346 return -EDOM;
347
348 *hyst = data->trips[trip].hysteresis;
349
350 return 0;
351}
352
353static int of_thermal_set_trip_hyst(struct thermal_zone_device *tz, int trip,
354 int hyst)
355{
356 struct __thermal_zone *data = tz->devdata;
357
358 if (trip >= data->ntrips || trip < 0)
359 return -EDOM;
360
361 /* thermal framework should take care of data->mask & (1 << trip) */
362 data->trips[trip].hysteresis = hyst;
363
364 return 0;
365}
366
367static int of_thermal_get_crit_temp(struct thermal_zone_device *tz,
368 int *temp)
369{
370 struct __thermal_zone *data = tz->devdata;
371 int i;
372
373 for (i = 0; i < data->ntrips; i++)
374 if (data->trips[i].type == THERMAL_TRIP_CRITICAL) {
375 *temp = data->trips[i].temperature;
376 return 0;
377 }
378
379 return -EINVAL;
380}
381
382static struct thermal_zone_device_ops of_thermal_ops = {
383 .get_mode = of_thermal_get_mode,
384 .set_mode = of_thermal_set_mode,
385
386 .get_trip_type = of_thermal_get_trip_type,
387 .get_trip_temp = of_thermal_get_trip_temp,
388 .set_trip_temp = of_thermal_set_trip_temp,
389 .get_trip_hyst = of_thermal_get_trip_hyst,
390 .set_trip_hyst = of_thermal_set_trip_hyst,
391 .get_crit_temp = of_thermal_get_crit_temp,
392
393 .bind = of_thermal_bind,
394 .unbind = of_thermal_unbind,
395};
396
397/*** sensor API ***/
398
399static struct thermal_zone_device *
400thermal_zone_of_add_sensor(struct device_node *zone,
401 struct device_node *sensor, void *data,
402 const struct thermal_zone_of_device_ops *ops)
403{
404 struct thermal_zone_device *tzd;
405 struct __thermal_zone *tz;
406
407 tzd = thermal_zone_get_zone_by_name(zone->name);
408 if (IS_ERR(tzd))
409 return ERR_PTR(-EPROBE_DEFER);
410
411 tz = tzd->devdata;
412
413 if (!ops)
414 return ERR_PTR(-EINVAL);
415
416 mutex_lock(&tzd->lock);
417 tz->ops = ops;
418 tz->sensor_data = data;
419
420 tzd->ops->get_temp = of_thermal_get_temp;
421 tzd->ops->get_trend = of_thermal_get_trend;
422 tzd->ops->set_emul_temp = of_thermal_set_emul_temp;
423 mutex_unlock(&tzd->lock);
424
425 return tzd;
426}
427
428/**
429 * thermal_zone_of_sensor_register - registers a sensor to a DT thermal zone
430 * @dev: a valid struct device pointer of a sensor device. Must contain
431 * a valid .of_node, for the sensor node.
432 * @sensor_id: a sensor identifier, in case the sensor IP has more
433 * than one sensors
434 * @data: a private pointer (owned by the caller) that will be passed
435 * back, when a temperature reading is needed.
436 * @ops: struct thermal_zone_of_device_ops *. Must contain at least .get_temp.
437 *
438 * This function will search the list of thermal zones described in device
439 * tree and look for the zone that refer to the sensor device pointed by
440 * @dev->of_node as temperature providers. For the zone pointing to the
441 * sensor node, the sensor will be added to the DT thermal zone device.
442 *
443 * The thermal zone temperature is provided by the @get_temp function
444 * pointer. When called, it will have the private pointer @data back.
445 *
446 * The thermal zone temperature trend is provided by the @get_trend function
447 * pointer. When called, it will have the private pointer @data back.
448 *
449 * TODO:
450 * 01 - This function must enqueue the new sensor instead of using
451 * it as the only source of temperature values.
452 *
453 * 02 - There must be a way to match the sensor with all thermal zones
454 * that refer to it.
455 *
456 * Return: On success returns a valid struct thermal_zone_device,
457 * otherwise, it returns a corresponding ERR_PTR(). Caller must
458 * check the return value with help of IS_ERR() helper.
459 */
460struct thermal_zone_device *
461thermal_zone_of_sensor_register(struct device *dev, int sensor_id, void *data,
462 const struct thermal_zone_of_device_ops *ops)
463{
464 struct device_node *np, *child, *sensor_np;
465 struct thermal_zone_device *tzd = ERR_PTR(-ENODEV);
466
467 np = of_find_node_by_name(NULL, "thermal-zones");
468 if (!np)
469 return ERR_PTR(-ENODEV);
470
471 if (!dev || !dev->of_node) {
472 of_node_put(np);
473 return ERR_PTR(-EINVAL);
474 }
475
476 sensor_np = of_node_get(dev->of_node);
477
478 for_each_available_child_of_node(np, child) {
479 struct of_phandle_args sensor_specs;
480 int ret, id;
481
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",
485 0, &sensor_specs);
486 if (ret)
487 continue;
488
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);
494 } else {
495 id = 0;
496 }
497
498 if (sensor_specs.np == sensor_np && id == sensor_id) {
499 tzd = thermal_zone_of_add_sensor(child, sensor_np,
500 data, ops);
501 if (!IS_ERR(tzd))
502 tzd->ops->set_mode(tzd, THERMAL_DEVICE_ENABLED);
503
504 of_node_put(sensor_specs.np);
505 of_node_put(child);
506 goto exit;
507 }
508 of_node_put(sensor_specs.np);
509 }
510exit:
511 of_node_put(sensor_np);
512 of_node_put(np);
513
514 return tzd;
515}
516EXPORT_SYMBOL_GPL(thermal_zone_of_sensor_register);
517
518/**
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.
523 *
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.
528 *
529 * TODO: When the support to several sensors per zone is added, this
530 * function must search the sensor list based on @dev parameter.
531 *
532 */
533void thermal_zone_of_sensor_unregister(struct device *dev,
534 struct thermal_zone_device *tzd)
535{
536 struct __thermal_zone *tz;
537
538 if (!dev || !tzd || !tzd->devdata)
539 return;
540
541 tz = tzd->devdata;
542
543 /* no __thermal_zone, nothing to be done */
544 if (!tz)
545 return;
546
547 mutex_lock(&tzd->lock);
548 tzd->ops->get_temp = NULL;
549 tzd->ops->get_trend = NULL;
550 tzd->ops->set_emul_temp = NULL;
551
552 tz->ops = NULL;
553 tz->sensor_data = NULL;
554 mutex_unlock(&tzd->lock);
555}
556EXPORT_SYMBOL_GPL(thermal_zone_of_sensor_unregister);
557
558static void devm_thermal_zone_of_sensor_release(struct device *dev, void *res)
559{
560 thermal_zone_of_sensor_unregister(dev,
561 *(struct thermal_zone_device **)res);
562}
563
564static int devm_thermal_zone_of_sensor_match(struct device *dev, void *res,
565 void *data)
566{
567 struct thermal_zone_device **r = res;
568
569 if (WARN_ON(!r || !*r))
570 return 0;
571
572 return *r == data;
573}
574
575/**
576 * devm_thermal_zone_of_sensor_register - Resource managed version of
577 * thermal_zone_of_sensor_register()
578 * @dev: a valid struct device pointer of a sensor device. Must contain
579 * a valid .of_node, for the sensor node.
580 * @sensor_id: a sensor identifier, in case the sensor IP has more
581 * than one sensors
582 * @data: a private pointer (owned by the caller) that will be passed
583 * back, when a temperature reading is needed.
584 * @ops: struct thermal_zone_of_device_ops *. Must contain at least .get_temp.
585 *
586 * Refer thermal_zone_of_sensor_register() for more details.
587 *
588 * Return: On success returns a valid struct thermal_zone_device,
589 * otherwise, it returns a corresponding ERR_PTR(). Caller must
590 * check the return value with help of IS_ERR() helper.
591 * Registered hermal_zone_device device will automatically be
592 * released when device is unbounded.
593 */
594struct thermal_zone_device *devm_thermal_zone_of_sensor_register(
595 struct device *dev, int sensor_id,
596 void *data, const struct thermal_zone_of_device_ops *ops)
597{
598 struct thermal_zone_device **ptr, *tzd;
599
600 ptr = devres_alloc(devm_thermal_zone_of_sensor_release, sizeof(*ptr),
601 GFP_KERNEL);
602 if (!ptr)
603 return ERR_PTR(-ENOMEM);
604
605 tzd = thermal_zone_of_sensor_register(dev, sensor_id, data, ops);
606 if (IS_ERR(tzd)) {
607 devres_free(ptr);
608 return tzd;
609 }
610
611 *ptr = tzd;
612 devres_add(dev, ptr);
613
614 return tzd;
615}
616EXPORT_SYMBOL_GPL(devm_thermal_zone_of_sensor_register);
617
618/**
619 * devm_thermal_zone_of_sensor_unregister - Resource managed version of
620 * thermal_zone_of_sensor_unregister().
621 * @dev: Device for which which resource was allocated.
622 * @tzd: a pointer to struct thermal_zone_device where the sensor is registered.
623 *
624 * This function removes the sensor callbacks and private data from the
625 * thermal zone device registered with devm_thermal_zone_of_sensor_register()
626 * API. It will also silent the zone by remove the .get_temp() and .get_trend()
627 * thermal zone device callbacks.
628 * Normally this function will not need to be called and the resource
629 * management code will ensure that the resource is freed.
630 */
631void devm_thermal_zone_of_sensor_unregister(struct device *dev,
632 struct thermal_zone_device *tzd)
633{
634 WARN_ON(devres_release(dev, devm_thermal_zone_of_sensor_release,
635 devm_thermal_zone_of_sensor_match, tzd));
636}
637EXPORT_SYMBOL_GPL(devm_thermal_zone_of_sensor_unregister);
638
639/*** functions parsing device tree nodes ***/
640
641/**
642 * thermal_of_populate_bind_params - parse and fill cooling map data
643 * @np: DT node containing a cooling-map node
644 * @__tbp: data structure to be filled with cooling map info
645 * @trips: array of thermal zone trip points
646 * @ntrips: number of trip points inside trips.
647 *
648 * This function parses a cooling-map type of node represented by
649 * @np parameter and fills the read data into @__tbp data structure.
650 * It needs the already parsed array of trip points of the thermal zone
651 * in consideration.
652 *
653 * Return: 0 on success, proper error code otherwise
654 */
655static int thermal_of_populate_bind_params(struct device_node *np,
656 struct __thermal_bind_params *__tbp,
657 struct thermal_trip *trips,
658 int ntrips)
659{
660 struct of_phandle_args cooling_spec;
661 struct device_node *trip;
662 int ret, i;
663 u32 prop;
664
665 /* Default weight. Usage is optional */
666 __tbp->usage = THERMAL_WEIGHT_DEFAULT;
667 ret = of_property_read_u32(np, "contribution", &prop);
668 if (ret == 0)
669 __tbp->usage = prop;
670
671 trip = of_parse_phandle(np, "trip", 0);
672 if (!trip) {
673 pr_err("missing trip property\n");
674 return -ENODEV;
675 }
676
677 /* match using device_node */
678 for (i = 0; i < ntrips; i++)
679 if (trip == trips[i].np) {
680 __tbp->trip_id = i;
681 break;
682 }
683
684 if (i == ntrips) {
685 ret = -ENODEV;
686 goto end;
687 }
688
689 ret = of_parse_phandle_with_args(np, "cooling-device", "#cooling-cells",
690 0, &cooling_spec);
691 if (ret < 0) {
692 pr_err("missing cooling_device property\n");
693 goto end;
694 }
695 __tbp->cooling_device = cooling_spec.np;
696 if (cooling_spec.args_count >= 2) { /* at least min and max */
697 __tbp->min = cooling_spec.args[0];
698 __tbp->max = cooling_spec.args[1];
699 } else {
700 pr_err("wrong reference to cooling device, missing limits\n");
701 }
702
703end:
704 of_node_put(trip);
705
706 return ret;
707}
708
709/**
710 * It maps 'enum thermal_trip_type' found in include/linux/thermal.h
711 * into the device tree binding of 'trip', property type.
712 */
713static const char * const trip_types[] = {
714 [THERMAL_TRIP_ACTIVE] = "active",
715 [THERMAL_TRIP_PASSIVE] = "passive",
716 [THERMAL_TRIP_HOT] = "hot",
717 [THERMAL_TRIP_CRITICAL] = "critical",
718};
719
720/**
721 * thermal_of_get_trip_type - Get phy mode for given device_node
722 * @np: Pointer to the given device_node
723 * @type: Pointer to resulting trip type
724 *
725 * The function gets trip type string from property 'type',
726 * and store its index in trip_types table in @type,
727 *
728 * Return: 0 on success, or errno in error case.
729 */
730static int thermal_of_get_trip_type(struct device_node *np,
731 enum thermal_trip_type *type)
732{
733 const char *t;
734 int err, i;
735
736 err = of_property_read_string(np, "type", &t);
737 if (err < 0)
738 return err;
739
740 for (i = 0; i < ARRAY_SIZE(trip_types); i++)
741 if (!strcasecmp(t, trip_types[i])) {
742 *type = i;
743 return 0;
744 }
745
746 return -ENODEV;
747}
748
749/**
750 * thermal_of_populate_trip - parse and fill one trip point data
751 * @np: DT node containing a trip point node
752 * @trip: trip point data structure to be filled up
753 *
754 * This function parses a trip point type of node represented by
755 * @np parameter and fills the read data into @trip data structure.
756 *
757 * Return: 0 on success, proper error code otherwise
758 */
759static int thermal_of_populate_trip(struct device_node *np,
760 struct thermal_trip *trip)
761{
762 int prop;
763 int ret;
764
765 ret = of_property_read_u32(np, "temperature", &prop);
766 if (ret < 0) {
767 pr_err("missing temperature property\n");
768 return ret;
769 }
770 trip->temperature = prop;
771
772 ret = of_property_read_u32(np, "hysteresis", &prop);
773 if (ret < 0) {
774 pr_err("missing hysteresis property\n");
775 return ret;
776 }
777 trip->hysteresis = prop;
778
779 ret = thermal_of_get_trip_type(np, &trip->type);
780 if (ret < 0) {
781 pr_err("wrong trip type property\n");
782 return ret;
783 }
784
785 /* Required for cooling map matching */
786 trip->np = np;
787 of_node_get(np);
788
789 return 0;
790}
791
792/**
793 * thermal_of_build_thermal_zone - parse and fill one thermal zone data
794 * @np: DT node containing a thermal zone node
795 *
796 * This function parses a thermal zone type of node represented by
797 * @np parameter and fills the read data into a __thermal_zone data structure
798 * and return this pointer.
799 *
800 * TODO: Missing properties to parse: thermal-sensor-names
801 *
802 * Return: On success returns a valid struct __thermal_zone,
803 * otherwise, it returns a corresponding ERR_PTR(). Caller must
804 * check the return value with help of IS_ERR() helper.
805 */
806static struct __thermal_zone
807__init *thermal_of_build_thermal_zone(struct device_node *np)
808{
809 struct device_node *child = NULL, *gchild;
810 struct __thermal_zone *tz;
811 int ret, i;
812 u32 prop, coef[2];
813
814 if (!np) {
815 pr_err("no thermal zone np\n");
816 return ERR_PTR(-EINVAL);
817 }
818
819 tz = kzalloc(sizeof(*tz), GFP_KERNEL);
820 if (!tz)
821 return ERR_PTR(-ENOMEM);
822
823 ret = of_property_read_u32(np, "polling-delay-passive", &prop);
824 if (ret < 0) {
825 pr_err("missing polling-delay-passive property\n");
826 goto free_tz;
827 }
828 tz->passive_delay = prop;
829
830 ret = of_property_read_u32(np, "polling-delay", &prop);
831 if (ret < 0) {
832 pr_err("missing polling-delay property\n");
833 goto free_tz;
834 }
835 tz->polling_delay = prop;
836
837 /*
838 * REVIST: for now, the thermal framework supports only
839 * one sensor per thermal zone. Thus, we are considering
840 * only the first two values as slope and offset.
841 */
842 ret = of_property_read_u32_array(np, "coefficients", coef, 2);
843 if (ret == 0) {
844 tz->slope = coef[0];
845 tz->offset = coef[1];
846 } else {
847 tz->slope = 1;
848 tz->offset = 0;
849 }
850
851 /* trips */
852 child = of_get_child_by_name(np, "trips");
853
854 /* No trips provided */
855 if (!child)
856 goto finish;
857
858 tz->ntrips = of_get_child_count(child);
859 if (tz->ntrips == 0) /* must have at least one child */
860 goto finish;
861
862 tz->trips = kzalloc(tz->ntrips * sizeof(*tz->trips), GFP_KERNEL);
863 if (!tz->trips) {
864 ret = -ENOMEM;
865 goto free_tz;
866 }
867
868 i = 0;
869 for_each_child_of_node(child, gchild) {
870 ret = thermal_of_populate_trip(gchild, &tz->trips[i++]);
871 if (ret)
872 goto free_trips;
873 }
874
875 of_node_put(child);
876
877 /* cooling-maps */
878 child = of_get_child_by_name(np, "cooling-maps");
879
880 /* cooling-maps not provided */
881 if (!child)
882 goto finish;
883
884 tz->num_tbps = of_get_child_count(child);
885 if (tz->num_tbps == 0)
886 goto finish;
887
888 tz->tbps = kzalloc(tz->num_tbps * sizeof(*tz->tbps), GFP_KERNEL);
889 if (!tz->tbps) {
890 ret = -ENOMEM;
891 goto free_trips;
892 }
893
894 i = 0;
895 for_each_child_of_node(child, gchild) {
896 ret = thermal_of_populate_bind_params(gchild, &tz->tbps[i++],
897 tz->trips, tz->ntrips);
898 if (ret)
899 goto free_tbps;
900 }
901
902finish:
903 of_node_put(child);
904 tz->mode = THERMAL_DEVICE_DISABLED;
905
906 return tz;
907
908free_tbps:
909 for (i = 0; i < tz->num_tbps; i++)
910 of_node_put(tz->tbps[i].cooling_device);
911 kfree(tz->tbps);
912free_trips:
913 for (i = 0; i < tz->ntrips; i++)
914 of_node_put(tz->trips[i].np);
915 kfree(tz->trips);
916 of_node_put(gchild);
917free_tz:
918 kfree(tz);
919 of_node_put(child);
920
921 return ERR_PTR(ret);
922}
923
924static inline void of_thermal_free_zone(struct __thermal_zone *tz)
925{
926 int i;
927
928 for (i = 0; i < tz->num_tbps; i++)
929 of_node_put(tz->tbps[i].cooling_device);
930 kfree(tz->tbps);
931 for (i = 0; i < tz->ntrips; i++)
932 of_node_put(tz->trips[i].np);
933 kfree(tz->trips);
934 kfree(tz);
935}
936
937/**
938 * of_parse_thermal_zones - parse device tree thermal data
939 *
940 * Initialization function that can be called by machine initialization
941 * code to parse thermal data and populate the thermal framework
942 * with hardware thermal zones info. This function only parses thermal zones.
943 * Cooling devices and sensor devices nodes are supposed to be parsed
944 * by their respective drivers.
945 *
946 * Return: 0 on success, proper error code otherwise
947 *
948 */
949int __init of_parse_thermal_zones(void)
950{
951 struct device_node *np, *child;
952 struct __thermal_zone *tz;
953 struct thermal_zone_device_ops *ops;
954
955 np = of_find_node_by_name(NULL, "thermal-zones");
956 if (!np) {
957 pr_debug("unable to find thermal zones\n");
958 return 0; /* Run successfully on systems without thermal DT */
959 }
960
961 for_each_available_child_of_node(np, child) {
962 struct thermal_zone_device *zone;
963 struct thermal_zone_params *tzp;
964 int i, mask = 0;
965 u32 prop;
966
967 tz = thermal_of_build_thermal_zone(child);
968 if (IS_ERR(tz)) {
969 pr_err("failed to build thermal zone %s: %ld\n",
970 child->name,
971 PTR_ERR(tz));
972 continue;
973 }
974
975 ops = kmemdup(&of_thermal_ops, sizeof(*ops), GFP_KERNEL);
976 if (!ops)
977 goto exit_free;
978
979 tzp = kzalloc(sizeof(*tzp), GFP_KERNEL);
980 if (!tzp) {
981 kfree(ops);
982 goto exit_free;
983 }
984
985 /* No hwmon because there might be hwmon drivers registering */
986 tzp->no_hwmon = true;
987
988 if (!of_property_read_u32(child, "sustainable-power", &prop))
989 tzp->sustainable_power = prop;
990
991 for (i = 0; i < tz->ntrips; i++)
992 mask |= 1 << i;
993
994 /* these two are left for temperature drivers to use */
995 tzp->slope = tz->slope;
996 tzp->offset = tz->offset;
997
998 zone = thermal_zone_device_register(child->name, tz->ntrips,
999 mask, tz,
1000 ops, tzp,
1001 tz->passive_delay,
1002 tz->polling_delay);
1003 if (IS_ERR(zone)) {
1004 pr_err("Failed to build %s zone %ld\n", child->name,
1005 PTR_ERR(zone));
1006 kfree(tzp);
1007 kfree(ops);
1008 of_thermal_free_zone(tz);
1009 /* attempting to build remaining zones still */
1010 }
1011 }
1012 of_node_put(np);
1013
1014 return 0;
1015
1016exit_free:
1017 of_node_put(child);
1018 of_node_put(np);
1019 of_thermal_free_zone(tz);
1020
1021 /* no memory available, so free what we have built */
1022 of_thermal_destroy_zones();
1023
1024 return -ENOMEM;
1025}
1026
1027/**
1028 * of_thermal_destroy_zones - remove all zones parsed and allocated resources
1029 *
1030 * Finds all zones parsed and added to the thermal framework and remove them
1031 * from the system, together with their resources.
1032 *
1033 */
1034void of_thermal_destroy_zones(void)
1035{
1036 struct device_node *np, *child;
1037
1038 np = of_find_node_by_name(NULL, "thermal-zones");
1039 if (!np) {
1040 pr_debug("unable to find thermal zones\n");
1041 return;
1042 }
1043
1044 for_each_available_child_of_node(np, child) {
1045 struct thermal_zone_device *zone;
1046
1047 zone = thermal_zone_get_zone_by_name(child->name);
1048 if (IS_ERR(zone))
1049 continue;
1050
1051 thermal_zone_device_unregister(zone);
1052 kfree(zone->tzp);
1053 kfree(zone->ops);
1054 of_thermal_free_zone(zone->devdata);
1055 }
1056 of_node_put(np);
1057}