summaryrefslogtreecommitdiff
path: root/drivers/thermal/thermal_of.c
blob: 330690a3a2089f00ca8137ef752331d0b4b10099 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
// SPDX-License-Identifier: GPL-2.0
/*
 *  of-thermal.c - Generic Thermal Management device tree support.
 *
 *  Copyright (C) 2013 Texas Instruments
 *  Copyright (C) 2013 Eduardo Valentin <eduardo.valentin@ti.com>
 */

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#include <linux/err.h>
#include <linux/export.h>
#include <linux/of.h>
#include <linux/slab.h>
#include <linux/thermal.h>
#include <linux/types.h>
#include <linux/string.h>

#include "thermal_core.h"

/***   functions parsing device tree nodes   ***/

static int of_find_trip_id(struct device_node *np, struct device_node *trip)
{
	struct device_node *trips;
	struct device_node *t;
	int i = 0;

	trips = of_get_child_by_name(np, "trips");
	if (!trips) {
		pr_err("Failed to find 'trips' node\n");
		return -EINVAL;
	}

	/*
	 * Find the trip id point associated with the cooling device map
	 */
	for_each_child_of_node(trips, t) {

		if (t == trip)
			goto out;
		i++;
	}

	i = -ENXIO;
out:
	of_node_put(trips);

	return i;
}

/*
 * It maps 'enum thermal_trip_type' found in include/linux/thermal.h
 * into the device tree binding of 'trip', property type.
 */
static const char * const trip_types[] = {
	[THERMAL_TRIP_ACTIVE]	= "active",
	[THERMAL_TRIP_PASSIVE]	= "passive",
	[THERMAL_TRIP_HOT]	= "hot",
	[THERMAL_TRIP_CRITICAL]	= "critical",
};

/**
 * thermal_of_get_trip_type - Get phy mode for given device_node
 * @np:	Pointer to the given device_node
 * @type: Pointer to resulting trip type
 *
 * The function gets trip type string from property 'type',
 * and store its index in trip_types table in @type,
 *
 * Return: 0 on success, or errno in error case.
 */
static int thermal_of_get_trip_type(struct device_node *np,
				    enum thermal_trip_type *type)
{
	const char *t;
	int err, i;

	err = of_property_read_string(np, "type", &t);
	if (err < 0)
		return err;

	for (i = 0; i < ARRAY_SIZE(trip_types); i++)
		if (!strcasecmp(t, trip_types[i])) {
			*type = i;
			return 0;
		}

	return -ENODEV;
}

static int thermal_of_populate_trip(struct device_node *np,
				    struct thermal_trip *trip)
{
	int prop;
	int ret;

	ret = of_property_read_u32(np, "temperature", &prop);
	if (ret < 0) {
		pr_err("missing temperature property\n");
		return ret;
	}
	trip->temperature = prop;

	ret = of_property_read_u32(np, "hysteresis", &prop);
	if (ret < 0) {
		pr_err("missing hysteresis property\n");
		return ret;
	}
	trip->hysteresis = prop;

	ret = thermal_of_get_trip_type(np, &trip->type);
	if (ret < 0) {
		pr_err("wrong trip type property\n");
		return ret;
	}

	return 0;
}

static struct thermal_trip *thermal_of_trips_init(struct device_node *np, int *ntrips)
{
	struct thermal_trip *tt;
	struct device_node *trips, *trip;
	int ret, count;

	trips = of_get_child_by_name(np, "trips");
	if (!trips) {
		pr_err("Failed to find 'trips' node\n");
		return ERR_PTR(-EINVAL);
	}

	count = of_get_child_count(trips);
	if (!count) {
		pr_err("No trip point defined\n");
		ret = -EINVAL;
		goto out_of_node_put;
	}

	tt = kzalloc(sizeof(*tt) * count, GFP_KERNEL);
	if (!tt) {
		ret = -ENOMEM;
		goto out_of_node_put;
	}

	*ntrips = count;

	count = 0;
	for_each_child_of_node(trips, trip) {
		ret = thermal_of_populate_trip(trip, &tt[count++]);
		if (ret)
			goto out_kfree;
	}

	of_node_put(trips);

	return tt;

out_kfree:
	kfree(tt);
	*ntrips = 0;
out_of_node_put:
	of_node_put(trips);

	return ERR_PTR(ret);
}

static struct device_node *of_thermal_zone_find(struct device_node *sensor, int id)
{
	struct device_node *np, *tz;
	struct of_phandle_args sensor_specs;

	np = of_find_node_by_name(NULL, "thermal-zones");
	if (!np) {
		pr_debug("No thermal zones description\n");
		return ERR_PTR(-ENODEV);
	}

	/*
	 * Search for each thermal zone, a defined sensor
	 * corresponding to the one passed as parameter
	 */
	for_each_available_child_of_node(np, tz) {

		int count, i;

		count = of_count_phandle_with_args(tz, "thermal-sensors",
						   "#thermal-sensor-cells");
		if (count <= 0) {
			pr_err("%pOFn: missing thermal sensor\n", tz);
			tz = ERR_PTR(-EINVAL);
			goto out;
		}

		for (i = 0; i < count; i++) {

			int ret;

			ret = of_parse_phandle_with_args(tz, "thermal-sensors",
							 "#thermal-sensor-cells",
							 i, &sensor_specs);
			if (ret < 0) {
				pr_err("%pOFn: Failed to read thermal-sensors cells: %d\n", tz, ret);
				tz = ERR_PTR(ret);
				goto out;
			}

			if ((sensor == sensor_specs.np) && id == (sensor_specs.args_count ?
								  sensor_specs.args[0] : 0)) {
				pr_debug("sensor %pOFn id=%d belongs to %pOFn\n", sensor, id, tz);
				goto out;
			}
		}
	}
	tz = ERR_PTR(-ENODEV);
out:
	of_node_put(np);
	return tz;
}

static int thermal_of_monitor_init(struct device_node *np, int *delay, int *pdelay)
{
	int ret;

	ret = of_property_read_u32(np, "polling-delay-passive", pdelay);
	if (ret < 0) {
		pr_err("%pOFn: missing polling-delay-passive property\n", np);
		return ret;
	}

	ret = of_property_read_u32(np, "polling-delay", delay);
	if (ret < 0) {
		pr_err("%pOFn: missing polling-delay property\n", np);
		return ret;
	}

	return 0;
}

static void thermal_of_parameters_init(struct device_node *np,
				       struct thermal_zone_params *tzp)
{
	int coef[2];
	int ncoef = ARRAY_SIZE(coef);
	int prop, ret;

	tzp->no_hwmon = true;

	if (!of_property_read_u32(np, "sustainable-power", &prop))
		tzp->sustainable_power = prop;

	/*
	 * For now, the thermal framework supports only one sensor per
	 * thermal zone. Thus, we are considering only the first two
	 * values as slope and offset.
	 */
	ret = of_property_read_u32_array(np, "coefficients", coef, ncoef);
	if (ret) {
		coef[0] = 1;
		coef[1] = 0;
	}

	tzp->slope = coef[0];
	tzp->offset = coef[1];
}

static struct device_node *thermal_of_zone_get_by_name(struct thermal_zone_device *tz)
{
	struct device_node *np, *tz_np;

	np = of_find_node_by_name(NULL, "thermal-zones");
	if (!np)
		return ERR_PTR(-ENODEV);

	tz_np = of_get_child_by_name(np, tz->type);

	of_node_put(np);

	if (!tz_np)
		return ERR_PTR(-ENODEV);

	return tz_np;
}

static int __thermal_of_unbind(struct device_node *map_np, int index, int trip_id,
			       struct thermal_zone_device *tz, struct thermal_cooling_device *cdev)
{
	struct of_phandle_args cooling_spec;
	int ret;

	ret = of_parse_phandle_with_args(map_np, "cooling-device", "#cooling-cells",
					 index, &cooling_spec);

	of_node_put(cooling_spec.np);

	if (ret < 0) {
		pr_err("Invalid cooling-device entry\n");
		return ret;
	}

	if (cooling_spec.args_count < 2) {
		pr_err("wrong reference to cooling device, missing limits\n");
		return -EINVAL;
	}

	if (cooling_spec.np != cdev->np)
		return 0;

	ret = thermal_zone_unbind_cooling_device(tz, trip_id, cdev);
	if (ret)
		pr_err("Failed to unbind '%s' with '%s': %d\n", tz->type, cdev->type, ret);

	return ret;
}

static int __thermal_of_bind(struct device_node *map_np, int index, int trip_id,
			     struct thermal_zone_device *tz, struct thermal_cooling_device *cdev)
{
	struct of_phandle_args cooling_spec;
	int ret, weight = THERMAL_WEIGHT_DEFAULT;

	of_property_read_u32(map_np, "contribution", &weight);

	ret = of_parse_phandle_with_args(map_np, "cooling-device", "#cooling-cells",
					 index, &cooling_spec);

	of_node_put(cooling_spec.np);

	if (ret < 0) {
		pr_err("Invalid cooling-device entry\n");
		return ret;
	}

	if (cooling_spec.args_count < 2) {
		pr_err("wrong reference to cooling device, missing limits\n");
		return -EINVAL;
	}

	if (cooling_spec.np != cdev->np)
		return 0;

	ret = thermal_zone_bind_cooling_device(tz, trip_id, cdev, cooling_spec.args[1],
					       cooling_spec.args[0],
					       weight);
	if (ret)
		pr_err("Failed to bind '%s' with '%s': %d\n", tz->type, cdev->type, ret);

	return ret;
}

static int thermal_of_for_each_cooling_device(struct device_node *tz_np, struct device_node *map_np,
					      struct thermal_zone_device *tz, struct thermal_cooling_device *cdev,
					      int (*action)(struct device_node *, int, int,
							    struct thermal_zone_device *, struct thermal_cooling_device *))
{
	struct device_node *tr_np;
	int count, i, trip_id;

	tr_np = of_parse_phandle(map_np, "trip", 0);
	if (!tr_np)
		return -ENODEV;

	trip_id = of_find_trip_id(tz_np, tr_np);
	if (trip_id < 0)
		return trip_id;

	count = of_count_phandle_with_args(map_np, "cooling-device", "#cooling-cells");
	if (count <= 0) {
		pr_err("Add a cooling_device property with at least one device\n");
		return -ENOENT;
	}

	/*
	 * At this point, we don't want to bail out when there is an
	 * error, we will try to bind/unbind as many as possible
	 * cooling devices
	 */
	for (i = 0; i < count; i++)
		action(map_np, i, trip_id, tz, cdev);

	return 0;
}

static int thermal_of_for_each_cooling_maps(struct thermal_zone_device *tz,
					    struct thermal_cooling_device *cdev,
					    int (*action)(struct device_node *, int, int,
							  struct thermal_zone_device *, struct thermal_cooling_device *))
{
	struct device_node *tz_np, *cm_np, *child;
	int ret = 0;

	tz_np = thermal_of_zone_get_by_name(tz);
	if (IS_ERR(tz_np)) {
		pr_err("Failed to get node tz by name\n");
		return PTR_ERR(tz_np);
	}

	cm_np = of_get_child_by_name(tz_np, "cooling-maps");
	if (!cm_np)
		goto out;

	for_each_child_of_node(cm_np, child) {
		ret = thermal_of_for_each_cooling_device(tz_np, child, tz, cdev, action);
		if (ret)
			break;
	}

	of_node_put(cm_np);
out:
	of_node_put(tz_np);

	return ret;
}

static int thermal_of_bind(struct thermal_zone_device *tz,
			   struct thermal_cooling_device *cdev)
{
	return thermal_of_for_each_cooling_maps(tz, cdev, __thermal_of_bind);
}

static int thermal_of_unbind(struct thermal_zone_device *tz,
			     struct thermal_cooling_device *cdev)
{
	return thermal_of_for_each_cooling_maps(tz, cdev, __thermal_of_unbind);
}

/**
 * thermal_of_zone_unregister - Cleanup the specific allocated ressources
 *
 * This function disables the thermal zone and frees the different
 * ressources allocated specific to the thermal OF.
 *
 * @tz: a pointer to the thermal zone structure
 */
static void thermal_of_zone_unregister(struct thermal_zone_device *tz)
{
	struct thermal_trip *trips = tz->trips;
	struct thermal_zone_device_ops *ops = tz->ops;

	thermal_zone_device_disable(tz);
	thermal_zone_device_unregister(tz);
	kfree(trips);
	kfree(ops);
}

/**
 * thermal_of_zone_register - Register a thermal zone with device node
 * sensor
 *
 * The thermal_of_zone_register() parses a device tree given a device
 * node sensor and identifier. It searches for the thermal zone
 * associated to the couple sensor/id and retrieves all the thermal
 * zone properties and registers new thermal zone with those
 * properties.
 *
 * @sensor: A device node pointer corresponding to the sensor in the device tree
 * @id: An integer as sensor identifier
 * @data: A private data to be stored in the thermal zone dedicated private area
 * @ops: A set of thermal sensor ops
 *
 * Return: a valid thermal zone structure pointer on success.
 * 	- EINVAL: if the device tree thermal description is malformed
 *	- ENOMEM: if one structure can not be allocated
 *	- Other negative errors are returned by the underlying called functions
 */
static struct thermal_zone_device *thermal_of_zone_register(struct device_node *sensor, int id, void *data,
							    const struct thermal_zone_device_ops *ops)
{
	struct thermal_zone_device *tz;
	struct thermal_trip *trips;
	struct thermal_zone_params tzp = {};
	struct thermal_zone_device_ops *of_ops;
	struct device_node *np;
	int delay, pdelay;
	int ntrips, mask;
	int ret;

	of_ops = kmemdup(ops, sizeof(*ops), GFP_KERNEL);
	if (!of_ops)
		return ERR_PTR(-ENOMEM);

	np = of_thermal_zone_find(sensor, id);
	if (IS_ERR(np)) {
		if (PTR_ERR(np) != -ENODEV)
			pr_err("Failed to find thermal zone for %pOFn id=%d\n", sensor, id);
		ret = PTR_ERR(np);
		goto out_kfree_of_ops;
	}

	trips = thermal_of_trips_init(np, &ntrips);
	if (IS_ERR(trips)) {
		pr_err("Failed to find trip points for %pOFn id=%d\n", sensor, id);
		ret = PTR_ERR(trips);
		goto out_kfree_of_ops;
	}

	ret = thermal_of_monitor_init(np, &delay, &pdelay);
	if (ret) {
		pr_err("Failed to initialize monitoring delays from %pOFn\n", np);
		goto out_kfree_trips;
	}

	thermal_of_parameters_init(np, &tzp);

	of_ops->bind = thermal_of_bind;
	of_ops->unbind = thermal_of_unbind;

	mask = GENMASK_ULL((ntrips) - 1, 0);

	tz = thermal_zone_device_register_with_trips(np->name, trips, ntrips,
						     mask, data, of_ops, &tzp,
						     pdelay, delay);
	if (IS_ERR(tz)) {
		ret = PTR_ERR(tz);
		pr_err("Failed to register thermal zone %pOFn: %d\n", np, ret);
		goto out_kfree_trips;
	}

	ret = thermal_zone_device_enable(tz);
	if (ret) {
		pr_err("Failed to enabled thermal zone '%s', id=%d: %d\n",
		       tz->type, tz->id, ret);
		thermal_of_zone_unregister(tz);
		return ERR_PTR(ret);
	}

	return tz;

out_kfree_trips:
	kfree(trips);
out_kfree_of_ops:
	kfree(of_ops);

	return ERR_PTR(ret);
}

static void devm_thermal_of_zone_release(struct device *dev, void *res)
{
	thermal_of_zone_unregister(*(struct thermal_zone_device **)res);
}

static int devm_thermal_of_zone_match(struct device *dev, void *res,
				      void *data)
{
	struct thermal_zone_device **r = res;

	if (WARN_ON(!r || !*r))
		return 0;

	return *r == data;
}

/**
 * devm_thermal_of_zone_register - register a thermal tied with the sensor life cycle
 *
 * This function is the device version of the thermal_of_zone_register() function.
 *
 * @dev: a device structure pointer to sensor to be tied with the thermal zone OF life cycle
 * @sensor_id: the sensor identifier
 * @data: a pointer to a private data to be stored in the thermal zone 'devdata' field
 * @ops: a pointer to the ops structure associated with the sensor
 */
struct thermal_zone_device *devm_thermal_of_zone_register(struct device *dev, int sensor_id, void *data,
							  const struct thermal_zone_device_ops *ops)
{
	struct thermal_zone_device **ptr, *tzd;

	ptr = devres_alloc(devm_thermal_of_zone_release, sizeof(*ptr),
			   GFP_KERNEL);
	if (!ptr)
		return ERR_PTR(-ENOMEM);

	tzd = thermal_of_zone_register(dev->of_node, sensor_id, data, ops);
	if (IS_ERR(tzd)) {
		devres_free(ptr);
		return tzd;
	}

	*ptr = tzd;
	devres_add(dev, ptr);

	return tzd;
}
EXPORT_SYMBOL_GPL(devm_thermal_of_zone_register);

/**
 * devm_thermal_of_zone_unregister - Resource managed version of
 *				thermal_of_zone_unregister().
 * @dev: Device for which which resource was allocated.
 * @tz: a pointer to struct thermal_zone where the sensor is registered.
 *
 * This function removes the sensor callbacks and private data from the
 * thermal zone device registered with devm_thermal_zone_of_sensor_register()
 * API. It will also silent the zone by remove the .get_temp() and .get_trend()
 * thermal zone device callbacks.
 * Normally this function will not need to be called and the resource
 * management code will ensure that the resource is freed.
 */
void devm_thermal_of_zone_unregister(struct device *dev, struct thermal_zone_device *tz)
{
	WARN_ON(devres_release(dev, devm_thermal_of_zone_release,
			       devm_thermal_of_zone_match, tz));
}
EXPORT_SYMBOL_GPL(devm_thermal_of_zone_unregister);