xref: /openbmc/linux/drivers/opp/of.c (revision 8dd3cdea)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Generic OPP OF helpers
4  *
5  * Copyright (C) 2009-2010 Texas Instruments Incorporated.
6  *	Nishanth Menon
7  *	Romit Dasgupta
8  *	Kevin Hilman
9  */
10 
11 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
12 
13 #include <linux/cpu.h>
14 #include <linux/errno.h>
15 #include <linux/device.h>
16 #include <linux/of_device.h>
17 #include <linux/pm_domain.h>
18 #include <linux/slab.h>
19 #include <linux/export.h>
20 #include <linux/energy_model.h>
21 
22 #include "opp.h"
23 
24 /*
25  * Returns opp descriptor node for a device node, caller must
26  * do of_node_put().
27  */
28 static struct device_node *_opp_of_get_opp_desc_node(struct device_node *np,
29 						     int index)
30 {
31 	/* "operating-points-v2" can be an array for power domain providers */
32 	return of_parse_phandle(np, "operating-points-v2", index);
33 }
34 
35 /* Returns opp descriptor node for a device, caller must do of_node_put() */
36 struct device_node *dev_pm_opp_of_get_opp_desc_node(struct device *dev)
37 {
38 	return _opp_of_get_opp_desc_node(dev->of_node, 0);
39 }
40 EXPORT_SYMBOL_GPL(dev_pm_opp_of_get_opp_desc_node);
41 
42 struct opp_table *_managed_opp(struct device *dev, int index)
43 {
44 	struct opp_table *opp_table, *managed_table = NULL;
45 	struct device_node *np;
46 
47 	np = _opp_of_get_opp_desc_node(dev->of_node, index);
48 	if (!np)
49 		return NULL;
50 
51 	list_for_each_entry(opp_table, &opp_tables, node) {
52 		if (opp_table->np == np) {
53 			/*
54 			 * Multiple devices can point to the same OPP table and
55 			 * so will have same node-pointer, np.
56 			 *
57 			 * But the OPPs will be considered as shared only if the
58 			 * OPP table contains a "opp-shared" property.
59 			 */
60 			if (opp_table->shared_opp == OPP_TABLE_ACCESS_SHARED) {
61 				_get_opp_table_kref(opp_table);
62 				managed_table = opp_table;
63 			}
64 
65 			break;
66 		}
67 	}
68 
69 	of_node_put(np);
70 
71 	return managed_table;
72 }
73 
74 /* The caller must call dev_pm_opp_put() after the OPP is used */
75 static struct dev_pm_opp *_find_opp_of_np(struct opp_table *opp_table,
76 					  struct device_node *opp_np)
77 {
78 	struct dev_pm_opp *opp;
79 
80 	mutex_lock(&opp_table->lock);
81 
82 	list_for_each_entry(opp, &opp_table->opp_list, node) {
83 		if (opp->np == opp_np) {
84 			dev_pm_opp_get(opp);
85 			mutex_unlock(&opp_table->lock);
86 			return opp;
87 		}
88 	}
89 
90 	mutex_unlock(&opp_table->lock);
91 
92 	return NULL;
93 }
94 
95 static struct device_node *of_parse_required_opp(struct device_node *np,
96 						 int index)
97 {
98 	return of_parse_phandle(np, "required-opps", index);
99 }
100 
101 /* The caller must call dev_pm_opp_put_opp_table() after the table is used */
102 static struct opp_table *_find_table_of_opp_np(struct device_node *opp_np)
103 {
104 	struct opp_table *opp_table;
105 	struct device_node *opp_table_np;
106 
107 	opp_table_np = of_get_parent(opp_np);
108 	if (!opp_table_np)
109 		goto err;
110 
111 	/* It is safe to put the node now as all we need now is its address */
112 	of_node_put(opp_table_np);
113 
114 	mutex_lock(&opp_table_lock);
115 	list_for_each_entry(opp_table, &opp_tables, node) {
116 		if (opp_table_np == opp_table->np) {
117 			_get_opp_table_kref(opp_table);
118 			mutex_unlock(&opp_table_lock);
119 			return opp_table;
120 		}
121 	}
122 	mutex_unlock(&opp_table_lock);
123 
124 err:
125 	return ERR_PTR(-ENODEV);
126 }
127 
128 /* Free resources previously acquired by _opp_table_alloc_required_tables() */
129 static void _opp_table_free_required_tables(struct opp_table *opp_table)
130 {
131 	struct opp_table **required_opp_tables = opp_table->required_opp_tables;
132 	int i;
133 
134 	if (!required_opp_tables)
135 		return;
136 
137 	for (i = 0; i < opp_table->required_opp_count; i++) {
138 		if (IS_ERR_OR_NULL(required_opp_tables[i]))
139 			continue;
140 
141 		dev_pm_opp_put_opp_table(required_opp_tables[i]);
142 	}
143 
144 	kfree(required_opp_tables);
145 
146 	opp_table->required_opp_count = 0;
147 	opp_table->required_opp_tables = NULL;
148 	list_del(&opp_table->lazy);
149 }
150 
151 /*
152  * Populate all devices and opp tables which are part of "required-opps" list.
153  * Checking only the first OPP node should be enough.
154  */
155 static void _opp_table_alloc_required_tables(struct opp_table *opp_table,
156 					     struct device *dev,
157 					     struct device_node *opp_np)
158 {
159 	struct opp_table **required_opp_tables;
160 	struct device_node *required_np, *np;
161 	bool lazy = false;
162 	int count, i;
163 
164 	/* Traversing the first OPP node is all we need */
165 	np = of_get_next_available_child(opp_np, NULL);
166 	if (!np) {
167 		dev_warn(dev, "Empty OPP table\n");
168 
169 		return;
170 	}
171 
172 	count = of_count_phandle_with_args(np, "required-opps", NULL);
173 	if (count <= 0)
174 		goto put_np;
175 
176 	required_opp_tables = kcalloc(count, sizeof(*required_opp_tables),
177 				      GFP_KERNEL);
178 	if (!required_opp_tables)
179 		goto put_np;
180 
181 	opp_table->required_opp_tables = required_opp_tables;
182 	opp_table->required_opp_count = count;
183 
184 	for (i = 0; i < count; i++) {
185 		required_np = of_parse_required_opp(np, i);
186 		if (!required_np)
187 			goto free_required_tables;
188 
189 		required_opp_tables[i] = _find_table_of_opp_np(required_np);
190 		of_node_put(required_np);
191 
192 		if (IS_ERR(required_opp_tables[i]))
193 			lazy = true;
194 	}
195 
196 	/* Let's do the linking later on */
197 	if (lazy)
198 		list_add(&opp_table->lazy, &lazy_opp_tables);
199 
200 	goto put_np;
201 
202 free_required_tables:
203 	_opp_table_free_required_tables(opp_table);
204 put_np:
205 	of_node_put(np);
206 }
207 
208 void _of_init_opp_table(struct opp_table *opp_table, struct device *dev,
209 			int index)
210 {
211 	struct device_node *np, *opp_np;
212 	u32 val;
213 
214 	/*
215 	 * Only required for backward compatibility with v1 bindings, but isn't
216 	 * harmful for other cases. And so we do it unconditionally.
217 	 */
218 	np = of_node_get(dev->of_node);
219 	if (!np)
220 		return;
221 
222 	if (!of_property_read_u32(np, "clock-latency", &val))
223 		opp_table->clock_latency_ns_max = val;
224 	of_property_read_u32(np, "voltage-tolerance",
225 			     &opp_table->voltage_tolerance_v1);
226 
227 	if (of_find_property(np, "#power-domain-cells", NULL))
228 		opp_table->is_genpd = true;
229 
230 	/* Get OPP table node */
231 	opp_np = _opp_of_get_opp_desc_node(np, index);
232 	of_node_put(np);
233 
234 	if (!opp_np)
235 		return;
236 
237 	if (of_property_read_bool(opp_np, "opp-shared"))
238 		opp_table->shared_opp = OPP_TABLE_ACCESS_SHARED;
239 	else
240 		opp_table->shared_opp = OPP_TABLE_ACCESS_EXCLUSIVE;
241 
242 	opp_table->np = opp_np;
243 
244 	_opp_table_alloc_required_tables(opp_table, dev, opp_np);
245 	of_node_put(opp_np);
246 }
247 
248 void _of_clear_opp_table(struct opp_table *opp_table)
249 {
250 	_opp_table_free_required_tables(opp_table);
251 }
252 
253 /*
254  * Release all resources previously acquired with a call to
255  * _of_opp_alloc_required_opps().
256  */
257 void _of_opp_free_required_opps(struct opp_table *opp_table,
258 				struct dev_pm_opp *opp)
259 {
260 	struct dev_pm_opp **required_opps = opp->required_opps;
261 	int i;
262 
263 	if (!required_opps)
264 		return;
265 
266 	for (i = 0; i < opp_table->required_opp_count; i++) {
267 		if (!required_opps[i])
268 			continue;
269 
270 		/* Put the reference back */
271 		dev_pm_opp_put(required_opps[i]);
272 	}
273 
274 	opp->required_opps = NULL;
275 	kfree(required_opps);
276 }
277 
278 /* Populate all required OPPs which are part of "required-opps" list */
279 static int _of_opp_alloc_required_opps(struct opp_table *opp_table,
280 				       struct dev_pm_opp *opp)
281 {
282 	struct dev_pm_opp **required_opps;
283 	struct opp_table *required_table;
284 	struct device_node *np;
285 	int i, ret, count = opp_table->required_opp_count;
286 
287 	if (!count)
288 		return 0;
289 
290 	required_opps = kcalloc(count, sizeof(*required_opps), GFP_KERNEL);
291 	if (!required_opps)
292 		return -ENOMEM;
293 
294 	opp->required_opps = required_opps;
295 
296 	for (i = 0; i < count; i++) {
297 		required_table = opp_table->required_opp_tables[i];
298 
299 		/* Required table not added yet, we will link later */
300 		if (IS_ERR_OR_NULL(required_table))
301 			continue;
302 
303 		np = of_parse_required_opp(opp->np, i);
304 		if (unlikely(!np)) {
305 			ret = -ENODEV;
306 			goto free_required_opps;
307 		}
308 
309 		required_opps[i] = _find_opp_of_np(required_table, np);
310 		of_node_put(np);
311 
312 		if (!required_opps[i]) {
313 			pr_err("%s: Unable to find required OPP node: %pOF (%d)\n",
314 			       __func__, opp->np, i);
315 			ret = -ENODEV;
316 			goto free_required_opps;
317 		}
318 	}
319 
320 	return 0;
321 
322 free_required_opps:
323 	_of_opp_free_required_opps(opp_table, opp);
324 
325 	return ret;
326 }
327 
328 /* Link required OPPs for an individual OPP */
329 static int lazy_link_required_opps(struct opp_table *opp_table,
330 				   struct opp_table *new_table, int index)
331 {
332 	struct device_node *required_np;
333 	struct dev_pm_opp *opp;
334 
335 	list_for_each_entry(opp, &opp_table->opp_list, node) {
336 		required_np = of_parse_required_opp(opp->np, index);
337 		if (unlikely(!required_np))
338 			return -ENODEV;
339 
340 		opp->required_opps[index] = _find_opp_of_np(new_table, required_np);
341 		of_node_put(required_np);
342 
343 		if (!opp->required_opps[index]) {
344 			pr_err("%s: Unable to find required OPP node: %pOF (%d)\n",
345 			       __func__, opp->np, index);
346 			return -ENODEV;
347 		}
348 	}
349 
350 	return 0;
351 }
352 
353 /* Link required OPPs for all OPPs of the newly added OPP table */
354 static void lazy_link_required_opp_table(struct opp_table *new_table)
355 {
356 	struct opp_table *opp_table, *temp, **required_opp_tables;
357 	struct device_node *required_np, *opp_np, *required_table_np;
358 	struct dev_pm_opp *opp;
359 	int i, ret;
360 
361 	mutex_lock(&opp_table_lock);
362 
363 	list_for_each_entry_safe(opp_table, temp, &lazy_opp_tables, lazy) {
364 		bool lazy = false;
365 
366 		/* opp_np can't be invalid here */
367 		opp_np = of_get_next_available_child(opp_table->np, NULL);
368 
369 		for (i = 0; i < opp_table->required_opp_count; i++) {
370 			required_opp_tables = opp_table->required_opp_tables;
371 
372 			/* Required opp-table is already parsed */
373 			if (!IS_ERR(required_opp_tables[i]))
374 				continue;
375 
376 			/* required_np can't be invalid here */
377 			required_np = of_parse_required_opp(opp_np, i);
378 			required_table_np = of_get_parent(required_np);
379 
380 			of_node_put(required_table_np);
381 			of_node_put(required_np);
382 
383 			/*
384 			 * Newly added table isn't the required opp-table for
385 			 * opp_table.
386 			 */
387 			if (required_table_np != new_table->np) {
388 				lazy = true;
389 				continue;
390 			}
391 
392 			required_opp_tables[i] = new_table;
393 			_get_opp_table_kref(new_table);
394 
395 			/* Link OPPs now */
396 			ret = lazy_link_required_opps(opp_table, new_table, i);
397 			if (ret) {
398 				/* The OPPs will be marked unusable */
399 				lazy = false;
400 				break;
401 			}
402 		}
403 
404 		of_node_put(opp_np);
405 
406 		/* All required opp-tables found, remove from lazy list */
407 		if (!lazy) {
408 			list_del_init(&opp_table->lazy);
409 
410 			list_for_each_entry(opp, &opp_table->opp_list, node)
411 				_required_opps_available(opp, opp_table->required_opp_count);
412 		}
413 	}
414 
415 	mutex_unlock(&opp_table_lock);
416 }
417 
418 static int _bandwidth_supported(struct device *dev, struct opp_table *opp_table)
419 {
420 	struct device_node *np, *opp_np;
421 	struct property *prop;
422 
423 	if (!opp_table) {
424 		np = of_node_get(dev->of_node);
425 		if (!np)
426 			return -ENODEV;
427 
428 		opp_np = _opp_of_get_opp_desc_node(np, 0);
429 		of_node_put(np);
430 	} else {
431 		opp_np = of_node_get(opp_table->np);
432 	}
433 
434 	/* Lets not fail in case we are parsing opp-v1 bindings */
435 	if (!opp_np)
436 		return 0;
437 
438 	/* Checking only first OPP is sufficient */
439 	np = of_get_next_available_child(opp_np, NULL);
440 	if (!np) {
441 		dev_err(dev, "OPP table empty\n");
442 		return -EINVAL;
443 	}
444 	of_node_put(opp_np);
445 
446 	prop = of_find_property(np, "opp-peak-kBps", NULL);
447 	of_node_put(np);
448 
449 	if (!prop || !prop->length)
450 		return 0;
451 
452 	return 1;
453 }
454 
455 int dev_pm_opp_of_find_icc_paths(struct device *dev,
456 				 struct opp_table *opp_table)
457 {
458 	struct device_node *np;
459 	int ret, i, count, num_paths;
460 	struct icc_path **paths;
461 
462 	ret = _bandwidth_supported(dev, opp_table);
463 	if (ret == -EINVAL)
464 		return 0; /* Empty OPP table is a valid corner-case, let's not fail */
465 	else if (ret <= 0)
466 		return ret;
467 
468 	ret = 0;
469 
470 	np = of_node_get(dev->of_node);
471 	if (!np)
472 		return 0;
473 
474 	count = of_count_phandle_with_args(np, "interconnects",
475 					   "#interconnect-cells");
476 	of_node_put(np);
477 	if (count < 0)
478 		return 0;
479 
480 	/* two phandles when #interconnect-cells = <1> */
481 	if (count % 2) {
482 		dev_err(dev, "%s: Invalid interconnects values\n", __func__);
483 		return -EINVAL;
484 	}
485 
486 	num_paths = count / 2;
487 	paths = kcalloc(num_paths, sizeof(*paths), GFP_KERNEL);
488 	if (!paths)
489 		return -ENOMEM;
490 
491 	for (i = 0; i < num_paths; i++) {
492 		paths[i] = of_icc_get_by_index(dev, i);
493 		if (IS_ERR(paths[i])) {
494 			ret = PTR_ERR(paths[i]);
495 			if (ret != -EPROBE_DEFER) {
496 				dev_err(dev, "%s: Unable to get path%d: %d\n",
497 					__func__, i, ret);
498 			}
499 			goto err;
500 		}
501 	}
502 
503 	if (opp_table) {
504 		opp_table->paths = paths;
505 		opp_table->path_count = num_paths;
506 		return 0;
507 	}
508 
509 err:
510 	while (i--)
511 		icc_put(paths[i]);
512 
513 	kfree(paths);
514 
515 	return ret;
516 }
517 EXPORT_SYMBOL_GPL(dev_pm_opp_of_find_icc_paths);
518 
519 static bool _opp_is_supported(struct device *dev, struct opp_table *opp_table,
520 			      struct device_node *np)
521 {
522 	unsigned int levels = opp_table->supported_hw_count;
523 	int count, versions, ret, i, j;
524 	u32 val;
525 
526 	if (!opp_table->supported_hw) {
527 		/*
528 		 * In the case that no supported_hw has been set by the
529 		 * platform but there is an opp-supported-hw value set for
530 		 * an OPP then the OPP should not be enabled as there is
531 		 * no way to see if the hardware supports it.
532 		 */
533 		if (of_find_property(np, "opp-supported-hw", NULL))
534 			return false;
535 		else
536 			return true;
537 	}
538 
539 	count = of_property_count_u32_elems(np, "opp-supported-hw");
540 	if (count <= 0 || count % levels) {
541 		dev_err(dev, "%s: Invalid opp-supported-hw property (%d)\n",
542 			__func__, count);
543 		return false;
544 	}
545 
546 	versions = count / levels;
547 
548 	/* All levels in at least one of the versions should match */
549 	for (i = 0; i < versions; i++) {
550 		bool supported = true;
551 
552 		for (j = 0; j < levels; j++) {
553 			ret = of_property_read_u32_index(np, "opp-supported-hw",
554 							 i * levels + j, &val);
555 			if (ret) {
556 				dev_warn(dev, "%s: failed to read opp-supported-hw property at index %d: %d\n",
557 					 __func__, i * levels + j, ret);
558 				return false;
559 			}
560 
561 			/* Check if the level is supported */
562 			if (!(val & opp_table->supported_hw[j])) {
563 				supported = false;
564 				break;
565 			}
566 		}
567 
568 		if (supported)
569 			return true;
570 	}
571 
572 	return false;
573 }
574 
575 static int opp_parse_supplies(struct dev_pm_opp *opp, struct device *dev,
576 			      struct opp_table *opp_table)
577 {
578 	u32 *microvolt, *microamp = NULL, *microwatt = NULL;
579 	int supplies = opp_table->regulator_count;
580 	int vcount, icount, pcount, ret, i, j;
581 	struct property *prop = NULL;
582 	char name[NAME_MAX];
583 
584 	/* Search for "opp-microvolt-<name>" */
585 	if (opp_table->prop_name) {
586 		snprintf(name, sizeof(name), "opp-microvolt-%s",
587 			 opp_table->prop_name);
588 		prop = of_find_property(opp->np, name, NULL);
589 	}
590 
591 	if (!prop) {
592 		/* Search for "opp-microvolt" */
593 		sprintf(name, "opp-microvolt");
594 		prop = of_find_property(opp->np, name, NULL);
595 
596 		/* Missing property isn't a problem, but an invalid entry is */
597 		if (!prop) {
598 			if (unlikely(supplies == -1)) {
599 				/* Initialize regulator_count */
600 				opp_table->regulator_count = 0;
601 				return 0;
602 			}
603 
604 			if (!supplies)
605 				return 0;
606 
607 			dev_err(dev, "%s: opp-microvolt missing although OPP managing regulators\n",
608 				__func__);
609 			return -EINVAL;
610 		}
611 	}
612 
613 	if (unlikely(supplies == -1)) {
614 		/* Initialize regulator_count */
615 		supplies = opp_table->regulator_count = 1;
616 	} else if (unlikely(!supplies)) {
617 		dev_err(dev, "%s: opp-microvolt wasn't expected\n", __func__);
618 		return -EINVAL;
619 	}
620 
621 	vcount = of_property_count_u32_elems(opp->np, name);
622 	if (vcount < 0) {
623 		dev_err(dev, "%s: Invalid %s property (%d)\n",
624 			__func__, name, vcount);
625 		return vcount;
626 	}
627 
628 	/* There can be one or three elements per supply */
629 	if (vcount != supplies && vcount != supplies * 3) {
630 		dev_err(dev, "%s: Invalid number of elements in %s property (%d) with supplies (%d)\n",
631 			__func__, name, vcount, supplies);
632 		return -EINVAL;
633 	}
634 
635 	microvolt = kmalloc_array(vcount, sizeof(*microvolt), GFP_KERNEL);
636 	if (!microvolt)
637 		return -ENOMEM;
638 
639 	ret = of_property_read_u32_array(opp->np, name, microvolt, vcount);
640 	if (ret) {
641 		dev_err(dev, "%s: error parsing %s: %d\n", __func__, name, ret);
642 		ret = -EINVAL;
643 		goto free_microvolt;
644 	}
645 
646 	/* Search for "opp-microamp-<name>" */
647 	prop = NULL;
648 	if (opp_table->prop_name) {
649 		snprintf(name, sizeof(name), "opp-microamp-%s",
650 			 opp_table->prop_name);
651 		prop = of_find_property(opp->np, name, NULL);
652 	}
653 
654 	if (!prop) {
655 		/* Search for "opp-microamp" */
656 		sprintf(name, "opp-microamp");
657 		prop = of_find_property(opp->np, name, NULL);
658 	}
659 
660 	if (prop) {
661 		icount = of_property_count_u32_elems(opp->np, name);
662 		if (icount < 0) {
663 			dev_err(dev, "%s: Invalid %s property (%d)\n", __func__,
664 				name, icount);
665 			ret = icount;
666 			goto free_microvolt;
667 		}
668 
669 		if (icount != supplies) {
670 			dev_err(dev, "%s: Invalid number of elements in %s property (%d) with supplies (%d)\n",
671 				__func__, name, icount, supplies);
672 			ret = -EINVAL;
673 			goto free_microvolt;
674 		}
675 
676 		microamp = kmalloc_array(icount, sizeof(*microamp), GFP_KERNEL);
677 		if (!microamp) {
678 			ret = -EINVAL;
679 			goto free_microvolt;
680 		}
681 
682 		ret = of_property_read_u32_array(opp->np, name, microamp,
683 						 icount);
684 		if (ret) {
685 			dev_err(dev, "%s: error parsing %s: %d\n", __func__,
686 				name, ret);
687 			ret = -EINVAL;
688 			goto free_microamp;
689 		}
690 	}
691 
692 	/* Search for "opp-microwatt" */
693 	sprintf(name, "opp-microwatt");
694 	prop = of_find_property(opp->np, name, NULL);
695 
696 	if (prop) {
697 		pcount = of_property_count_u32_elems(opp->np, name);
698 		if (pcount < 0) {
699 			dev_err(dev, "%s: Invalid %s property (%d)\n", __func__,
700 				name, pcount);
701 			ret = pcount;
702 			goto free_microamp;
703 		}
704 
705 		if (pcount != supplies) {
706 			dev_err(dev, "%s: Invalid number of elements in %s property (%d) with supplies (%d)\n",
707 				__func__, name, pcount, supplies);
708 			ret = -EINVAL;
709 			goto free_microamp;
710 		}
711 
712 		microwatt = kmalloc_array(pcount, sizeof(*microwatt),
713 					  GFP_KERNEL);
714 		if (!microwatt) {
715 			ret = -EINVAL;
716 			goto free_microamp;
717 		}
718 
719 		ret = of_property_read_u32_array(opp->np, name, microwatt,
720 						 pcount);
721 		if (ret) {
722 			dev_err(dev, "%s: error parsing %s: %d\n", __func__,
723 				name, ret);
724 			ret = -EINVAL;
725 			goto free_microwatt;
726 		}
727 	}
728 
729 	for (i = 0, j = 0; i < supplies; i++) {
730 		opp->supplies[i].u_volt = microvolt[j++];
731 
732 		if (vcount == supplies) {
733 			opp->supplies[i].u_volt_min = opp->supplies[i].u_volt;
734 			opp->supplies[i].u_volt_max = opp->supplies[i].u_volt;
735 		} else {
736 			opp->supplies[i].u_volt_min = microvolt[j++];
737 			opp->supplies[i].u_volt_max = microvolt[j++];
738 		}
739 
740 		if (microamp)
741 			opp->supplies[i].u_amp = microamp[i];
742 
743 		if (microwatt)
744 			opp->supplies[i].u_watt = microwatt[i];
745 	}
746 
747 free_microwatt:
748 	kfree(microwatt);
749 free_microamp:
750 	kfree(microamp);
751 free_microvolt:
752 	kfree(microvolt);
753 
754 	return ret;
755 }
756 
757 /**
758  * dev_pm_opp_of_remove_table() - Free OPP table entries created from static DT
759  *				  entries
760  * @dev:	device pointer used to lookup OPP table.
761  *
762  * Free OPPs created using static entries present in DT.
763  */
764 void dev_pm_opp_of_remove_table(struct device *dev)
765 {
766 	dev_pm_opp_remove_table(dev);
767 }
768 EXPORT_SYMBOL_GPL(dev_pm_opp_of_remove_table);
769 
770 static int _read_bw(struct dev_pm_opp *new_opp, struct opp_table *table,
771 		    struct device_node *np, bool peak)
772 {
773 	const char *name = peak ? "opp-peak-kBps" : "opp-avg-kBps";
774 	struct property *prop;
775 	int i, count, ret;
776 	u32 *bw;
777 
778 	prop = of_find_property(np, name, NULL);
779 	if (!prop)
780 		return -ENODEV;
781 
782 	count = prop->length / sizeof(u32);
783 	if (table->path_count != count) {
784 		pr_err("%s: Mismatch between %s and paths (%d %d)\n",
785 				__func__, name, count, table->path_count);
786 		return -EINVAL;
787 	}
788 
789 	bw = kmalloc_array(count, sizeof(*bw), GFP_KERNEL);
790 	if (!bw)
791 		return -ENOMEM;
792 
793 	ret = of_property_read_u32_array(np, name, bw, count);
794 	if (ret) {
795 		pr_err("%s: Error parsing %s: %d\n", __func__, name, ret);
796 		goto out;
797 	}
798 
799 	for (i = 0; i < count; i++) {
800 		if (peak)
801 			new_opp->bandwidth[i].peak = kBps_to_icc(bw[i]);
802 		else
803 			new_opp->bandwidth[i].avg = kBps_to_icc(bw[i]);
804 	}
805 
806 out:
807 	kfree(bw);
808 	return ret;
809 }
810 
811 static int _read_opp_key(struct dev_pm_opp *new_opp, struct opp_table *table,
812 			 struct device_node *np, bool *rate_not_available)
813 {
814 	bool found = false;
815 	u64 rate;
816 	int ret;
817 
818 	ret = of_property_read_u64(np, "opp-hz", &rate);
819 	if (!ret) {
820 		/*
821 		 * Rate is defined as an unsigned long in clk API, and so
822 		 * casting explicitly to its type. Must be fixed once rate is 64
823 		 * bit guaranteed in clk API.
824 		 */
825 		new_opp->rate = (unsigned long)rate;
826 		found = true;
827 	}
828 	*rate_not_available = !!ret;
829 
830 	/*
831 	 * Bandwidth consists of peak and average (optional) values:
832 	 * opp-peak-kBps = <path1_value path2_value>;
833 	 * opp-avg-kBps = <path1_value path2_value>;
834 	 */
835 	ret = _read_bw(new_opp, table, np, true);
836 	if (!ret) {
837 		found = true;
838 		ret = _read_bw(new_opp, table, np, false);
839 	}
840 
841 	/* The properties were found but we failed to parse them */
842 	if (ret && ret != -ENODEV)
843 		return ret;
844 
845 	if (!of_property_read_u32(np, "opp-level", &new_opp->level))
846 		found = true;
847 
848 	if (found)
849 		return 0;
850 
851 	return ret;
852 }
853 
854 /**
855  * _opp_add_static_v2() - Allocate static OPPs (As per 'v2' DT bindings)
856  * @opp_table:	OPP table
857  * @dev:	device for which we do this operation
858  * @np:		device node
859  *
860  * This function adds an opp definition to the opp table and returns status. The
861  * opp can be controlled using dev_pm_opp_enable/disable functions and may be
862  * removed by dev_pm_opp_remove.
863  *
864  * Return:
865  * Valid OPP pointer:
866  *		On success
867  * NULL:
868  *		Duplicate OPPs (both freq and volt are same) and opp->available
869  *		OR if the OPP is not supported by hardware.
870  * ERR_PTR(-EEXIST):
871  *		Freq are same and volt are different OR
872  *		Duplicate OPPs (both freq and volt are same) and !opp->available
873  * ERR_PTR(-ENOMEM):
874  *		Memory allocation failure
875  * ERR_PTR(-EINVAL):
876  *		Failed parsing the OPP node
877  */
878 static struct dev_pm_opp *_opp_add_static_v2(struct opp_table *opp_table,
879 		struct device *dev, struct device_node *np)
880 {
881 	struct dev_pm_opp *new_opp;
882 	u32 val;
883 	int ret;
884 	bool rate_not_available = false;
885 
886 	new_opp = _opp_allocate(opp_table);
887 	if (!new_opp)
888 		return ERR_PTR(-ENOMEM);
889 
890 	ret = _read_opp_key(new_opp, opp_table, np, &rate_not_available);
891 	if (ret < 0) {
892 		dev_err(dev, "%s: opp key field not found\n", __func__);
893 		goto free_opp;
894 	}
895 
896 	/* Check if the OPP supports hardware's hierarchy of versions or not */
897 	if (!_opp_is_supported(dev, opp_table, np)) {
898 		dev_dbg(dev, "OPP not supported by hardware: %lu\n",
899 			new_opp->rate);
900 		goto free_opp;
901 	}
902 
903 	new_opp->turbo = of_property_read_bool(np, "turbo-mode");
904 
905 	new_opp->np = np;
906 	new_opp->dynamic = false;
907 	new_opp->available = true;
908 
909 	ret = _of_opp_alloc_required_opps(opp_table, new_opp);
910 	if (ret)
911 		goto free_opp;
912 
913 	if (!of_property_read_u32(np, "clock-latency-ns", &val))
914 		new_opp->clock_latency_ns = val;
915 
916 	ret = opp_parse_supplies(new_opp, dev, opp_table);
917 	if (ret)
918 		goto free_required_opps;
919 
920 	if (opp_table->is_genpd)
921 		new_opp->pstate = pm_genpd_opp_to_performance_state(dev, new_opp);
922 
923 	ret = _opp_add(dev, new_opp, opp_table, rate_not_available);
924 	if (ret) {
925 		/* Don't return error for duplicate OPPs */
926 		if (ret == -EBUSY)
927 			ret = 0;
928 		goto free_required_opps;
929 	}
930 
931 	/* OPP to select on device suspend */
932 	if (of_property_read_bool(np, "opp-suspend")) {
933 		if (opp_table->suspend_opp) {
934 			/* Pick the OPP with higher rate as suspend OPP */
935 			if (new_opp->rate > opp_table->suspend_opp->rate) {
936 				opp_table->suspend_opp->suspend = false;
937 				new_opp->suspend = true;
938 				opp_table->suspend_opp = new_opp;
939 			}
940 		} else {
941 			new_opp->suspend = true;
942 			opp_table->suspend_opp = new_opp;
943 		}
944 	}
945 
946 	if (new_opp->clock_latency_ns > opp_table->clock_latency_ns_max)
947 		opp_table->clock_latency_ns_max = new_opp->clock_latency_ns;
948 
949 	pr_debug("%s: turbo:%d rate:%lu uv:%lu uvmin:%lu uvmax:%lu latency:%lu level:%u\n",
950 		 __func__, new_opp->turbo, new_opp->rate,
951 		 new_opp->supplies[0].u_volt, new_opp->supplies[0].u_volt_min,
952 		 new_opp->supplies[0].u_volt_max, new_opp->clock_latency_ns,
953 		 new_opp->level);
954 
955 	/*
956 	 * Notify the changes in the availability of the operable
957 	 * frequency/voltage list.
958 	 */
959 	blocking_notifier_call_chain(&opp_table->head, OPP_EVENT_ADD, new_opp);
960 	return new_opp;
961 
962 free_required_opps:
963 	_of_opp_free_required_opps(opp_table, new_opp);
964 free_opp:
965 	_opp_free(new_opp);
966 
967 	return ret ? ERR_PTR(ret) : NULL;
968 }
969 
970 /* Initializes OPP tables based on new bindings */
971 static int _of_add_opp_table_v2(struct device *dev, struct opp_table *opp_table)
972 {
973 	struct device_node *np;
974 	int ret, count = 0;
975 	struct dev_pm_opp *opp;
976 
977 	/* OPP table is already initialized for the device */
978 	mutex_lock(&opp_table->lock);
979 	if (opp_table->parsed_static_opps) {
980 		opp_table->parsed_static_opps++;
981 		mutex_unlock(&opp_table->lock);
982 		return 0;
983 	}
984 
985 	opp_table->parsed_static_opps = 1;
986 	mutex_unlock(&opp_table->lock);
987 
988 	/* We have opp-table node now, iterate over it and add OPPs */
989 	for_each_available_child_of_node(opp_table->np, np) {
990 		opp = _opp_add_static_v2(opp_table, dev, np);
991 		if (IS_ERR(opp)) {
992 			ret = PTR_ERR(opp);
993 			dev_err(dev, "%s: Failed to add OPP, %d\n", __func__,
994 				ret);
995 			of_node_put(np);
996 			goto remove_static_opp;
997 		} else if (opp) {
998 			count++;
999 		}
1000 	}
1001 
1002 	/* There should be one or more OPPs defined */
1003 	if (!count) {
1004 		dev_err(dev, "%s: no supported OPPs", __func__);
1005 		ret = -ENOENT;
1006 		goto remove_static_opp;
1007 	}
1008 
1009 	list_for_each_entry(opp, &opp_table->opp_list, node) {
1010 		/* Any non-zero performance state would enable the feature */
1011 		if (opp->pstate) {
1012 			opp_table->genpd_performance_state = true;
1013 			break;
1014 		}
1015 	}
1016 
1017 	lazy_link_required_opp_table(opp_table);
1018 
1019 	return 0;
1020 
1021 remove_static_opp:
1022 	_opp_remove_all_static(opp_table);
1023 
1024 	return ret;
1025 }
1026 
1027 /* Initializes OPP tables based on old-deprecated bindings */
1028 static int _of_add_opp_table_v1(struct device *dev, struct opp_table *opp_table)
1029 {
1030 	const struct property *prop;
1031 	const __be32 *val;
1032 	int nr, ret = 0;
1033 
1034 	mutex_lock(&opp_table->lock);
1035 	if (opp_table->parsed_static_opps) {
1036 		opp_table->parsed_static_opps++;
1037 		mutex_unlock(&opp_table->lock);
1038 		return 0;
1039 	}
1040 
1041 	opp_table->parsed_static_opps = 1;
1042 	mutex_unlock(&opp_table->lock);
1043 
1044 	prop = of_find_property(dev->of_node, "operating-points", NULL);
1045 	if (!prop) {
1046 		ret = -ENODEV;
1047 		goto remove_static_opp;
1048 	}
1049 	if (!prop->value) {
1050 		ret = -ENODATA;
1051 		goto remove_static_opp;
1052 	}
1053 
1054 	/*
1055 	 * Each OPP is a set of tuples consisting of frequency and
1056 	 * voltage like <freq-kHz vol-uV>.
1057 	 */
1058 	nr = prop->length / sizeof(u32);
1059 	if (nr % 2) {
1060 		dev_err(dev, "%s: Invalid OPP table\n", __func__);
1061 		ret = -EINVAL;
1062 		goto remove_static_opp;
1063 	}
1064 
1065 	val = prop->value;
1066 	while (nr) {
1067 		unsigned long freq = be32_to_cpup(val++) * 1000;
1068 		unsigned long volt = be32_to_cpup(val++);
1069 
1070 		ret = _opp_add_v1(opp_table, dev, freq, volt, false);
1071 		if (ret) {
1072 			dev_err(dev, "%s: Failed to add OPP %ld (%d)\n",
1073 				__func__, freq, ret);
1074 			goto remove_static_opp;
1075 		}
1076 		nr -= 2;
1077 	}
1078 
1079 	return 0;
1080 
1081 remove_static_opp:
1082 	_opp_remove_all_static(opp_table);
1083 
1084 	return ret;
1085 }
1086 
1087 static int _of_add_table_indexed(struct device *dev, int index, bool getclk)
1088 {
1089 	struct opp_table *opp_table;
1090 	int ret, count;
1091 
1092 	if (index) {
1093 		/*
1094 		 * If only one phandle is present, then the same OPP table
1095 		 * applies for all index requests.
1096 		 */
1097 		count = of_count_phandle_with_args(dev->of_node,
1098 						   "operating-points-v2", NULL);
1099 		if (count == 1)
1100 			index = 0;
1101 	}
1102 
1103 	opp_table = _add_opp_table_indexed(dev, index, getclk);
1104 	if (IS_ERR(opp_table))
1105 		return PTR_ERR(opp_table);
1106 
1107 	/*
1108 	 * OPPs have two version of bindings now. Also try the old (v1)
1109 	 * bindings for backward compatibility with older dtbs.
1110 	 */
1111 	if (opp_table->np)
1112 		ret = _of_add_opp_table_v2(dev, opp_table);
1113 	else
1114 		ret = _of_add_opp_table_v1(dev, opp_table);
1115 
1116 	if (ret)
1117 		dev_pm_opp_put_opp_table(opp_table);
1118 
1119 	return ret;
1120 }
1121 
1122 static void devm_pm_opp_of_table_release(void *data)
1123 {
1124 	dev_pm_opp_of_remove_table(data);
1125 }
1126 
1127 static int _devm_of_add_table_indexed(struct device *dev, int index, bool getclk)
1128 {
1129 	int ret;
1130 
1131 	ret = _of_add_table_indexed(dev, index, getclk);
1132 	if (ret)
1133 		return ret;
1134 
1135 	return devm_add_action_or_reset(dev, devm_pm_opp_of_table_release, dev);
1136 }
1137 
1138 /**
1139  * devm_pm_opp_of_add_table() - Initialize opp table from device tree
1140  * @dev:	device pointer used to lookup OPP table.
1141  *
1142  * Register the initial OPP table with the OPP library for given device.
1143  *
1144  * The opp_table structure will be freed after the device is destroyed.
1145  *
1146  * Return:
1147  * 0		On success OR
1148  *		Duplicate OPPs (both freq and volt are same) and opp->available
1149  * -EEXIST	Freq are same and volt are different OR
1150  *		Duplicate OPPs (both freq and volt are same) and !opp->available
1151  * -ENOMEM	Memory allocation failure
1152  * -ENODEV	when 'operating-points' property is not found or is invalid data
1153  *		in device node.
1154  * -ENODATA	when empty 'operating-points' property is found
1155  * -EINVAL	when invalid entries are found in opp-v2 table
1156  */
1157 int devm_pm_opp_of_add_table(struct device *dev)
1158 {
1159 	return _devm_of_add_table_indexed(dev, 0, true);
1160 }
1161 EXPORT_SYMBOL_GPL(devm_pm_opp_of_add_table);
1162 
1163 /**
1164  * dev_pm_opp_of_add_table() - Initialize opp table from device tree
1165  * @dev:	device pointer used to lookup OPP table.
1166  *
1167  * Register the initial OPP table with the OPP library for given device.
1168  *
1169  * Return:
1170  * 0		On success OR
1171  *		Duplicate OPPs (both freq and volt are same) and opp->available
1172  * -EEXIST	Freq are same and volt are different OR
1173  *		Duplicate OPPs (both freq and volt are same) and !opp->available
1174  * -ENOMEM	Memory allocation failure
1175  * -ENODEV	when 'operating-points' property is not found or is invalid data
1176  *		in device node.
1177  * -ENODATA	when empty 'operating-points' property is found
1178  * -EINVAL	when invalid entries are found in opp-v2 table
1179  */
1180 int dev_pm_opp_of_add_table(struct device *dev)
1181 {
1182 	return _of_add_table_indexed(dev, 0, true);
1183 }
1184 EXPORT_SYMBOL_GPL(dev_pm_opp_of_add_table);
1185 
1186 /**
1187  * dev_pm_opp_of_add_table_indexed() - Initialize indexed opp table from device tree
1188  * @dev:	device pointer used to lookup OPP table.
1189  * @index:	Index number.
1190  *
1191  * Register the initial OPP table with the OPP library for given device only
1192  * using the "operating-points-v2" property.
1193  *
1194  * Return: Refer to dev_pm_opp_of_add_table() for return values.
1195  */
1196 int dev_pm_opp_of_add_table_indexed(struct device *dev, int index)
1197 {
1198 	return _of_add_table_indexed(dev, index, true);
1199 }
1200 EXPORT_SYMBOL_GPL(dev_pm_opp_of_add_table_indexed);
1201 
1202 /**
1203  * devm_pm_opp_of_add_table_indexed() - Initialize indexed opp table from device tree
1204  * @dev:	device pointer used to lookup OPP table.
1205  * @index:	Index number.
1206  *
1207  * This is a resource-managed variant of dev_pm_opp_of_add_table_indexed().
1208  */
1209 int devm_pm_opp_of_add_table_indexed(struct device *dev, int index)
1210 {
1211 	return _devm_of_add_table_indexed(dev, index, true);
1212 }
1213 EXPORT_SYMBOL_GPL(devm_pm_opp_of_add_table_indexed);
1214 
1215 /**
1216  * dev_pm_opp_of_add_table_noclk() - Initialize indexed opp table from device
1217  *		tree without getting clk for device.
1218  * @dev:	device pointer used to lookup OPP table.
1219  * @index:	Index number.
1220  *
1221  * Register the initial OPP table with the OPP library for given device only
1222  * using the "operating-points-v2" property. Do not try to get the clk for the
1223  * device.
1224  *
1225  * Return: Refer to dev_pm_opp_of_add_table() for return values.
1226  */
1227 int dev_pm_opp_of_add_table_noclk(struct device *dev, int index)
1228 {
1229 	return _of_add_table_indexed(dev, index, false);
1230 }
1231 EXPORT_SYMBOL_GPL(dev_pm_opp_of_add_table_noclk);
1232 
1233 /**
1234  * devm_pm_opp_of_add_table_noclk() - Initialize indexed opp table from device
1235  *		tree without getting clk for device.
1236  * @dev:	device pointer used to lookup OPP table.
1237  * @index:	Index number.
1238  *
1239  * This is a resource-managed variant of dev_pm_opp_of_add_table_noclk().
1240  */
1241 int devm_pm_opp_of_add_table_noclk(struct device *dev, int index)
1242 {
1243 	return _devm_of_add_table_indexed(dev, index, false);
1244 }
1245 EXPORT_SYMBOL_GPL(devm_pm_opp_of_add_table_noclk);
1246 
1247 /* CPU device specific helpers */
1248 
1249 /**
1250  * dev_pm_opp_of_cpumask_remove_table() - Removes OPP table for @cpumask
1251  * @cpumask:	cpumask for which OPP table needs to be removed
1252  *
1253  * This removes the OPP tables for CPUs present in the @cpumask.
1254  * This should be used only to remove static entries created from DT.
1255  */
1256 void dev_pm_opp_of_cpumask_remove_table(const struct cpumask *cpumask)
1257 {
1258 	_dev_pm_opp_cpumask_remove_table(cpumask, -1);
1259 }
1260 EXPORT_SYMBOL_GPL(dev_pm_opp_of_cpumask_remove_table);
1261 
1262 /**
1263  * dev_pm_opp_of_cpumask_add_table() - Adds OPP table for @cpumask
1264  * @cpumask:	cpumask for which OPP table needs to be added.
1265  *
1266  * This adds the OPP tables for CPUs present in the @cpumask.
1267  */
1268 int dev_pm_opp_of_cpumask_add_table(const struct cpumask *cpumask)
1269 {
1270 	struct device *cpu_dev;
1271 	int cpu, ret;
1272 
1273 	if (WARN_ON(cpumask_empty(cpumask)))
1274 		return -ENODEV;
1275 
1276 	for_each_cpu(cpu, cpumask) {
1277 		cpu_dev = get_cpu_device(cpu);
1278 		if (!cpu_dev) {
1279 			pr_err("%s: failed to get cpu%d device\n", __func__,
1280 			       cpu);
1281 			ret = -ENODEV;
1282 			goto remove_table;
1283 		}
1284 
1285 		ret = dev_pm_opp_of_add_table(cpu_dev);
1286 		if (ret) {
1287 			/*
1288 			 * OPP may get registered dynamically, don't print error
1289 			 * message here.
1290 			 */
1291 			pr_debug("%s: couldn't find opp table for cpu:%d, %d\n",
1292 				 __func__, cpu, ret);
1293 
1294 			goto remove_table;
1295 		}
1296 	}
1297 
1298 	return 0;
1299 
1300 remove_table:
1301 	/* Free all other OPPs */
1302 	_dev_pm_opp_cpumask_remove_table(cpumask, cpu);
1303 
1304 	return ret;
1305 }
1306 EXPORT_SYMBOL_GPL(dev_pm_opp_of_cpumask_add_table);
1307 
1308 /*
1309  * Works only for OPP v2 bindings.
1310  *
1311  * Returns -ENOENT if operating-points-v2 bindings aren't supported.
1312  */
1313 /**
1314  * dev_pm_opp_of_get_sharing_cpus() - Get cpumask of CPUs sharing OPPs with
1315  *				      @cpu_dev using operating-points-v2
1316  *				      bindings.
1317  *
1318  * @cpu_dev:	CPU device for which we do this operation
1319  * @cpumask:	cpumask to update with information of sharing CPUs
1320  *
1321  * This updates the @cpumask with CPUs that are sharing OPPs with @cpu_dev.
1322  *
1323  * Returns -ENOENT if operating-points-v2 isn't present for @cpu_dev.
1324  */
1325 int dev_pm_opp_of_get_sharing_cpus(struct device *cpu_dev,
1326 				   struct cpumask *cpumask)
1327 {
1328 	struct device_node *np, *tmp_np, *cpu_np;
1329 	int cpu, ret = 0;
1330 
1331 	/* Get OPP descriptor node */
1332 	np = dev_pm_opp_of_get_opp_desc_node(cpu_dev);
1333 	if (!np) {
1334 		dev_dbg(cpu_dev, "%s: Couldn't find opp node.\n", __func__);
1335 		return -ENOENT;
1336 	}
1337 
1338 	cpumask_set_cpu(cpu_dev->id, cpumask);
1339 
1340 	/* OPPs are shared ? */
1341 	if (!of_property_read_bool(np, "opp-shared"))
1342 		goto put_cpu_node;
1343 
1344 	for_each_possible_cpu(cpu) {
1345 		if (cpu == cpu_dev->id)
1346 			continue;
1347 
1348 		cpu_np = of_cpu_device_node_get(cpu);
1349 		if (!cpu_np) {
1350 			dev_err(cpu_dev, "%s: failed to get cpu%d node\n",
1351 				__func__, cpu);
1352 			ret = -ENOENT;
1353 			goto put_cpu_node;
1354 		}
1355 
1356 		/* Get OPP descriptor node */
1357 		tmp_np = _opp_of_get_opp_desc_node(cpu_np, 0);
1358 		of_node_put(cpu_np);
1359 		if (!tmp_np) {
1360 			pr_err("%pOF: Couldn't find opp node\n", cpu_np);
1361 			ret = -ENOENT;
1362 			goto put_cpu_node;
1363 		}
1364 
1365 		/* CPUs are sharing opp node */
1366 		if (np == tmp_np)
1367 			cpumask_set_cpu(cpu, cpumask);
1368 
1369 		of_node_put(tmp_np);
1370 	}
1371 
1372 put_cpu_node:
1373 	of_node_put(np);
1374 	return ret;
1375 }
1376 EXPORT_SYMBOL_GPL(dev_pm_opp_of_get_sharing_cpus);
1377 
1378 /**
1379  * of_get_required_opp_performance_state() - Search for required OPP and return its performance state.
1380  * @np: Node that contains the "required-opps" property.
1381  * @index: Index of the phandle to parse.
1382  *
1383  * Returns the performance state of the OPP pointed out by the "required-opps"
1384  * property at @index in @np.
1385  *
1386  * Return: Zero or positive performance state on success, otherwise negative
1387  * value on errors.
1388  */
1389 int of_get_required_opp_performance_state(struct device_node *np, int index)
1390 {
1391 	struct dev_pm_opp *opp;
1392 	struct device_node *required_np;
1393 	struct opp_table *opp_table;
1394 	int pstate = -EINVAL;
1395 
1396 	required_np = of_parse_required_opp(np, index);
1397 	if (!required_np)
1398 		return -ENODEV;
1399 
1400 	opp_table = _find_table_of_opp_np(required_np);
1401 	if (IS_ERR(opp_table)) {
1402 		pr_err("%s: Failed to find required OPP table %pOF: %ld\n",
1403 		       __func__, np, PTR_ERR(opp_table));
1404 		goto put_required_np;
1405 	}
1406 
1407 	opp = _find_opp_of_np(opp_table, required_np);
1408 	if (opp) {
1409 		pstate = opp->pstate;
1410 		dev_pm_opp_put(opp);
1411 	}
1412 
1413 	dev_pm_opp_put_opp_table(opp_table);
1414 
1415 put_required_np:
1416 	of_node_put(required_np);
1417 
1418 	return pstate;
1419 }
1420 EXPORT_SYMBOL_GPL(of_get_required_opp_performance_state);
1421 
1422 /**
1423  * dev_pm_opp_get_of_node() - Gets the DT node corresponding to an opp
1424  * @opp:	opp for which DT node has to be returned for
1425  *
1426  * Return: DT node corresponding to the opp, else 0 on success.
1427  *
1428  * The caller needs to put the node with of_node_put() after using it.
1429  */
1430 struct device_node *dev_pm_opp_get_of_node(struct dev_pm_opp *opp)
1431 {
1432 	if (IS_ERR_OR_NULL(opp)) {
1433 		pr_err("%s: Invalid parameters\n", __func__);
1434 		return NULL;
1435 	}
1436 
1437 	return of_node_get(opp->np);
1438 }
1439 EXPORT_SYMBOL_GPL(dev_pm_opp_get_of_node);
1440 
1441 /*
1442  * Callback function provided to the Energy Model framework upon registration.
1443  * It provides the power used by @dev at @kHz if it is the frequency of an
1444  * existing OPP, or at the frequency of the first OPP above @kHz otherwise
1445  * (see dev_pm_opp_find_freq_ceil()). This function updates @kHz to the ceiled
1446  * frequency and @mW to the associated power.
1447  *
1448  * Returns 0 on success or a proper -EINVAL value in case of error.
1449  */
1450 static int __maybe_unused
1451 _get_dt_power(unsigned long *mW, unsigned long *kHz, struct device *dev)
1452 {
1453 	struct dev_pm_opp *opp;
1454 	unsigned long opp_freq, opp_power;
1455 
1456 	/* Find the right frequency and related OPP */
1457 	opp_freq = *kHz * 1000;
1458 	opp = dev_pm_opp_find_freq_ceil(dev, &opp_freq);
1459 	if (IS_ERR(opp))
1460 		return -EINVAL;
1461 
1462 	opp_power = dev_pm_opp_get_power(opp);
1463 	dev_pm_opp_put(opp);
1464 	if (!opp_power)
1465 		return -EINVAL;
1466 
1467 	*kHz = opp_freq / 1000;
1468 	*mW = opp_power / 1000;
1469 
1470 	return 0;
1471 }
1472 
1473 /*
1474  * Callback function provided to the Energy Model framework upon registration.
1475  * This computes the power estimated by @dev at @kHz if it is the frequency
1476  * of an existing OPP, or at the frequency of the first OPP above @kHz otherwise
1477  * (see dev_pm_opp_find_freq_ceil()). This function updates @kHz to the ceiled
1478  * frequency and @mW to the associated power. The power is estimated as
1479  * P = C * V^2 * f with C being the device's capacitance and V and f
1480  * respectively the voltage and frequency of the OPP.
1481  *
1482  * Returns -EINVAL if the power calculation failed because of missing
1483  * parameters, 0 otherwise.
1484  */
1485 static int __maybe_unused _get_power(unsigned long *mW, unsigned long *kHz,
1486 				     struct device *dev)
1487 {
1488 	struct dev_pm_opp *opp;
1489 	struct device_node *np;
1490 	unsigned long mV, Hz;
1491 	u32 cap;
1492 	u64 tmp;
1493 	int ret;
1494 
1495 	np = of_node_get(dev->of_node);
1496 	if (!np)
1497 		return -EINVAL;
1498 
1499 	ret = of_property_read_u32(np, "dynamic-power-coefficient", &cap);
1500 	of_node_put(np);
1501 	if (ret)
1502 		return -EINVAL;
1503 
1504 	Hz = *kHz * 1000;
1505 	opp = dev_pm_opp_find_freq_ceil(dev, &Hz);
1506 	if (IS_ERR(opp))
1507 		return -EINVAL;
1508 
1509 	mV = dev_pm_opp_get_voltage(opp) / 1000;
1510 	dev_pm_opp_put(opp);
1511 	if (!mV)
1512 		return -EINVAL;
1513 
1514 	tmp = (u64)cap * mV * mV * (Hz / 1000000);
1515 	do_div(tmp, 1000000000);
1516 
1517 	*mW = (unsigned long)tmp;
1518 	*kHz = Hz / 1000;
1519 
1520 	return 0;
1521 }
1522 
1523 static bool _of_has_opp_microwatt_property(struct device *dev)
1524 {
1525 	unsigned long power, freq = 0;
1526 	struct dev_pm_opp *opp;
1527 
1528 	/* Check if at least one OPP has needed property */
1529 	opp = dev_pm_opp_find_freq_ceil(dev, &freq);
1530 	if (IS_ERR(opp))
1531 		return false;
1532 
1533 	power = dev_pm_opp_get_power(opp);
1534 	dev_pm_opp_put(opp);
1535 	if (!power)
1536 		return false;
1537 
1538 	return true;
1539 }
1540 
1541 /**
1542  * dev_pm_opp_of_register_em() - Attempt to register an Energy Model
1543  * @dev		: Device for which an Energy Model has to be registered
1544  * @cpus	: CPUs for which an Energy Model has to be registered. For
1545  *		other type of devices it should be set to NULL.
1546  *
1547  * This checks whether the "dynamic-power-coefficient" devicetree property has
1548  * been specified, and tries to register an Energy Model with it if it has.
1549  * Having this property means the voltages are known for OPPs and the EM
1550  * might be calculated.
1551  */
1552 int dev_pm_opp_of_register_em(struct device *dev, struct cpumask *cpus)
1553 {
1554 	struct em_data_callback em_cb;
1555 	struct device_node *np;
1556 	int ret, nr_opp;
1557 	u32 cap;
1558 
1559 	if (IS_ERR_OR_NULL(dev)) {
1560 		ret = -EINVAL;
1561 		goto failed;
1562 	}
1563 
1564 	nr_opp = dev_pm_opp_get_opp_count(dev);
1565 	if (nr_opp <= 0) {
1566 		ret = -EINVAL;
1567 		goto failed;
1568 	}
1569 
1570 	/* First, try to find more precised Energy Model in DT */
1571 	if (_of_has_opp_microwatt_property(dev)) {
1572 		EM_SET_ACTIVE_POWER_CB(em_cb, _get_dt_power);
1573 		goto register_em;
1574 	}
1575 
1576 	np = of_node_get(dev->of_node);
1577 	if (!np) {
1578 		ret = -EINVAL;
1579 		goto failed;
1580 	}
1581 
1582 	/*
1583 	 * Register an EM only if the 'dynamic-power-coefficient' property is
1584 	 * set in devicetree. It is assumed the voltage values are known if that
1585 	 * property is set since it is useless otherwise. If voltages are not
1586 	 * known, just let the EM registration fail with an error to alert the
1587 	 * user about the inconsistent configuration.
1588 	 */
1589 	ret = of_property_read_u32(np, "dynamic-power-coefficient", &cap);
1590 	of_node_put(np);
1591 	if (ret || !cap) {
1592 		dev_dbg(dev, "Couldn't find proper 'dynamic-power-coefficient' in DT\n");
1593 		ret = -EINVAL;
1594 		goto failed;
1595 	}
1596 
1597 	EM_SET_ACTIVE_POWER_CB(em_cb, _get_power);
1598 
1599 register_em:
1600 	ret = em_dev_register_perf_domain(dev, nr_opp, &em_cb, cpus, true);
1601 	if (ret)
1602 		goto failed;
1603 
1604 	return 0;
1605 
1606 failed:
1607 	dev_dbg(dev, "Couldn't register Energy Model %d\n", ret);
1608 	return ret;
1609 }
1610 EXPORT_SYMBOL_GPL(dev_pm_opp_of_register_em);
1611