xref: /openbmc/linux/drivers/opp/of.c (revision 8dda2eac)
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 	struct device_node *required_np;
99 
100 	required_np = of_parse_phandle(np, "required-opps", index);
101 	if (unlikely(!required_np)) {
102 		pr_err("%s: Unable to parse required-opps: %pOF, index: %d\n",
103 		       __func__, np, index);
104 	}
105 
106 	return required_np;
107 }
108 
109 /* The caller must call dev_pm_opp_put_opp_table() after the table is used */
110 static struct opp_table *_find_table_of_opp_np(struct device_node *opp_np)
111 {
112 	struct opp_table *opp_table;
113 	struct device_node *opp_table_np;
114 
115 	opp_table_np = of_get_parent(opp_np);
116 	if (!opp_table_np)
117 		goto err;
118 
119 	/* It is safe to put the node now as all we need now is its address */
120 	of_node_put(opp_table_np);
121 
122 	mutex_lock(&opp_table_lock);
123 	list_for_each_entry(opp_table, &opp_tables, node) {
124 		if (opp_table_np == opp_table->np) {
125 			_get_opp_table_kref(opp_table);
126 			mutex_unlock(&opp_table_lock);
127 			return opp_table;
128 		}
129 	}
130 	mutex_unlock(&opp_table_lock);
131 
132 err:
133 	return ERR_PTR(-ENODEV);
134 }
135 
136 /* Free resources previously acquired by _opp_table_alloc_required_tables() */
137 static void _opp_table_free_required_tables(struct opp_table *opp_table)
138 {
139 	struct opp_table **required_opp_tables = opp_table->required_opp_tables;
140 	int i;
141 
142 	if (!required_opp_tables)
143 		return;
144 
145 	for (i = 0; i < opp_table->required_opp_count; i++) {
146 		if (IS_ERR_OR_NULL(required_opp_tables[i]))
147 			continue;
148 
149 		dev_pm_opp_put_opp_table(required_opp_tables[i]);
150 	}
151 
152 	kfree(required_opp_tables);
153 
154 	opp_table->required_opp_count = 0;
155 	opp_table->required_opp_tables = NULL;
156 	list_del(&opp_table->lazy);
157 }
158 
159 /*
160  * Populate all devices and opp tables which are part of "required-opps" list.
161  * Checking only the first OPP node should be enough.
162  */
163 static void _opp_table_alloc_required_tables(struct opp_table *opp_table,
164 					     struct device *dev,
165 					     struct device_node *opp_np)
166 {
167 	struct opp_table **required_opp_tables;
168 	struct device_node *required_np, *np;
169 	bool lazy = false;
170 	int count, i;
171 
172 	/* Traversing the first OPP node is all we need */
173 	np = of_get_next_available_child(opp_np, NULL);
174 	if (!np) {
175 		dev_warn(dev, "Empty OPP table\n");
176 
177 		return;
178 	}
179 
180 	count = of_count_phandle_with_args(np, "required-opps", NULL);
181 	if (!count)
182 		goto put_np;
183 
184 	required_opp_tables = kcalloc(count, sizeof(*required_opp_tables),
185 				      GFP_KERNEL);
186 	if (!required_opp_tables)
187 		goto put_np;
188 
189 	opp_table->required_opp_tables = required_opp_tables;
190 	opp_table->required_opp_count = count;
191 
192 	for (i = 0; i < count; i++) {
193 		required_np = of_parse_required_opp(np, i);
194 		if (!required_np)
195 			goto free_required_tables;
196 
197 		required_opp_tables[i] = _find_table_of_opp_np(required_np);
198 		of_node_put(required_np);
199 
200 		if (IS_ERR(required_opp_tables[i]))
201 			lazy = true;
202 	}
203 
204 	/* Let's do the linking later on */
205 	if (lazy)
206 		list_add(&opp_table->lazy, &lazy_opp_tables);
207 
208 	goto put_np;
209 
210 free_required_tables:
211 	_opp_table_free_required_tables(opp_table);
212 put_np:
213 	of_node_put(np);
214 }
215 
216 void _of_init_opp_table(struct opp_table *opp_table, struct device *dev,
217 			int index)
218 {
219 	struct device_node *np, *opp_np;
220 	u32 val;
221 
222 	/*
223 	 * Only required for backward compatibility with v1 bindings, but isn't
224 	 * harmful for other cases. And so we do it unconditionally.
225 	 */
226 	np = of_node_get(dev->of_node);
227 	if (!np)
228 		return;
229 
230 	if (!of_property_read_u32(np, "clock-latency", &val))
231 		opp_table->clock_latency_ns_max = val;
232 	of_property_read_u32(np, "voltage-tolerance",
233 			     &opp_table->voltage_tolerance_v1);
234 
235 	if (of_find_property(np, "#power-domain-cells", NULL))
236 		opp_table->is_genpd = true;
237 
238 	/* Get OPP table node */
239 	opp_np = _opp_of_get_opp_desc_node(np, index);
240 	of_node_put(np);
241 
242 	if (!opp_np)
243 		return;
244 
245 	if (of_property_read_bool(opp_np, "opp-shared"))
246 		opp_table->shared_opp = OPP_TABLE_ACCESS_SHARED;
247 	else
248 		opp_table->shared_opp = OPP_TABLE_ACCESS_EXCLUSIVE;
249 
250 	opp_table->np = opp_np;
251 
252 	_opp_table_alloc_required_tables(opp_table, dev, opp_np);
253 	of_node_put(opp_np);
254 }
255 
256 void _of_clear_opp_table(struct opp_table *opp_table)
257 {
258 	_opp_table_free_required_tables(opp_table);
259 }
260 
261 /*
262  * Release all resources previously acquired with a call to
263  * _of_opp_alloc_required_opps().
264  */
265 void _of_opp_free_required_opps(struct opp_table *opp_table,
266 				struct dev_pm_opp *opp)
267 {
268 	struct dev_pm_opp **required_opps = opp->required_opps;
269 	int i;
270 
271 	if (!required_opps)
272 		return;
273 
274 	for (i = 0; i < opp_table->required_opp_count; i++) {
275 		if (!required_opps[i])
276 			continue;
277 
278 		/* Put the reference back */
279 		dev_pm_opp_put(required_opps[i]);
280 	}
281 
282 	opp->required_opps = NULL;
283 	kfree(required_opps);
284 }
285 
286 /* Populate all required OPPs which are part of "required-opps" list */
287 static int _of_opp_alloc_required_opps(struct opp_table *opp_table,
288 				       struct dev_pm_opp *opp)
289 {
290 	struct dev_pm_opp **required_opps;
291 	struct opp_table *required_table;
292 	struct device_node *np;
293 	int i, ret, count = opp_table->required_opp_count;
294 
295 	if (!count)
296 		return 0;
297 
298 	required_opps = kcalloc(count, sizeof(*required_opps), GFP_KERNEL);
299 	if (!required_opps)
300 		return -ENOMEM;
301 
302 	opp->required_opps = required_opps;
303 
304 	for (i = 0; i < count; i++) {
305 		required_table = opp_table->required_opp_tables[i];
306 
307 		/* Required table not added yet, we will link later */
308 		if (IS_ERR_OR_NULL(required_table))
309 			continue;
310 
311 		np = of_parse_required_opp(opp->np, i);
312 		if (unlikely(!np)) {
313 			ret = -ENODEV;
314 			goto free_required_opps;
315 		}
316 
317 		required_opps[i] = _find_opp_of_np(required_table, np);
318 		of_node_put(np);
319 
320 		if (!required_opps[i]) {
321 			pr_err("%s: Unable to find required OPP node: %pOF (%d)\n",
322 			       __func__, opp->np, i);
323 			ret = -ENODEV;
324 			goto free_required_opps;
325 		}
326 	}
327 
328 	return 0;
329 
330 free_required_opps:
331 	_of_opp_free_required_opps(opp_table, opp);
332 
333 	return ret;
334 }
335 
336 /* Link required OPPs for an individual OPP */
337 static int lazy_link_required_opps(struct opp_table *opp_table,
338 				   struct opp_table *new_table, int index)
339 {
340 	struct device_node *required_np;
341 	struct dev_pm_opp *opp;
342 
343 	list_for_each_entry(opp, &opp_table->opp_list, node) {
344 		required_np = of_parse_required_opp(opp->np, index);
345 		if (unlikely(!required_np))
346 			return -ENODEV;
347 
348 		opp->required_opps[index] = _find_opp_of_np(new_table, required_np);
349 		of_node_put(required_np);
350 
351 		if (!opp->required_opps[index]) {
352 			pr_err("%s: Unable to find required OPP node: %pOF (%d)\n",
353 			       __func__, opp->np, index);
354 			return -ENODEV;
355 		}
356 	}
357 
358 	return 0;
359 }
360 
361 /* Link required OPPs for all OPPs of the newly added OPP table */
362 static void lazy_link_required_opp_table(struct opp_table *new_table)
363 {
364 	struct opp_table *opp_table, *temp, **required_opp_tables;
365 	struct device_node *required_np, *opp_np, *required_table_np;
366 	struct dev_pm_opp *opp;
367 	int i, ret;
368 
369 	mutex_lock(&opp_table_lock);
370 
371 	list_for_each_entry_safe(opp_table, temp, &lazy_opp_tables, lazy) {
372 		bool lazy = false;
373 
374 		/* opp_np can't be invalid here */
375 		opp_np = of_get_next_available_child(opp_table->np, NULL);
376 
377 		for (i = 0; i < opp_table->required_opp_count; i++) {
378 			required_opp_tables = opp_table->required_opp_tables;
379 
380 			/* Required opp-table is already parsed */
381 			if (!IS_ERR(required_opp_tables[i]))
382 				continue;
383 
384 			/* required_np can't be invalid here */
385 			required_np = of_parse_required_opp(opp_np, i);
386 			required_table_np = of_get_parent(required_np);
387 
388 			of_node_put(required_table_np);
389 			of_node_put(required_np);
390 
391 			/*
392 			 * Newly added table isn't the required opp-table for
393 			 * opp_table.
394 			 */
395 			if (required_table_np != new_table->np) {
396 				lazy = true;
397 				continue;
398 			}
399 
400 			required_opp_tables[i] = new_table;
401 			_get_opp_table_kref(new_table);
402 
403 			/* Link OPPs now */
404 			ret = lazy_link_required_opps(opp_table, new_table, i);
405 			if (ret) {
406 				/* The OPPs will be marked unusable */
407 				lazy = false;
408 				break;
409 			}
410 		}
411 
412 		of_node_put(opp_np);
413 
414 		/* All required opp-tables found, remove from lazy list */
415 		if (!lazy) {
416 			list_del_init(&opp_table->lazy);
417 
418 			list_for_each_entry(opp, &opp_table->opp_list, node)
419 				_required_opps_available(opp, opp_table->required_opp_count);
420 		}
421 	}
422 
423 	mutex_unlock(&opp_table_lock);
424 }
425 
426 static int _bandwidth_supported(struct device *dev, struct opp_table *opp_table)
427 {
428 	struct device_node *np, *opp_np;
429 	struct property *prop;
430 
431 	if (!opp_table) {
432 		np = of_node_get(dev->of_node);
433 		if (!np)
434 			return -ENODEV;
435 
436 		opp_np = _opp_of_get_opp_desc_node(np, 0);
437 		of_node_put(np);
438 	} else {
439 		opp_np = of_node_get(opp_table->np);
440 	}
441 
442 	/* Lets not fail in case we are parsing opp-v1 bindings */
443 	if (!opp_np)
444 		return 0;
445 
446 	/* Checking only first OPP is sufficient */
447 	np = of_get_next_available_child(opp_np, NULL);
448 	if (!np) {
449 		dev_err(dev, "OPP table empty\n");
450 		return -EINVAL;
451 	}
452 	of_node_put(opp_np);
453 
454 	prop = of_find_property(np, "opp-peak-kBps", NULL);
455 	of_node_put(np);
456 
457 	if (!prop || !prop->length)
458 		return 0;
459 
460 	return 1;
461 }
462 
463 int dev_pm_opp_of_find_icc_paths(struct device *dev,
464 				 struct opp_table *opp_table)
465 {
466 	struct device_node *np;
467 	int ret, i, count, num_paths;
468 	struct icc_path **paths;
469 
470 	ret = _bandwidth_supported(dev, opp_table);
471 	if (ret == -EINVAL)
472 		return 0; /* Empty OPP table is a valid corner-case, let's not fail */
473 	else if (ret <= 0)
474 		return ret;
475 
476 	ret = 0;
477 
478 	np = of_node_get(dev->of_node);
479 	if (!np)
480 		return 0;
481 
482 	count = of_count_phandle_with_args(np, "interconnects",
483 					   "#interconnect-cells");
484 	of_node_put(np);
485 	if (count < 0)
486 		return 0;
487 
488 	/* two phandles when #interconnect-cells = <1> */
489 	if (count % 2) {
490 		dev_err(dev, "%s: Invalid interconnects values\n", __func__);
491 		return -EINVAL;
492 	}
493 
494 	num_paths = count / 2;
495 	paths = kcalloc(num_paths, sizeof(*paths), GFP_KERNEL);
496 	if (!paths)
497 		return -ENOMEM;
498 
499 	for (i = 0; i < num_paths; i++) {
500 		paths[i] = of_icc_get_by_index(dev, i);
501 		if (IS_ERR(paths[i])) {
502 			ret = PTR_ERR(paths[i]);
503 			if (ret != -EPROBE_DEFER) {
504 				dev_err(dev, "%s: Unable to get path%d: %d\n",
505 					__func__, i, ret);
506 			}
507 			goto err;
508 		}
509 	}
510 
511 	if (opp_table) {
512 		opp_table->paths = paths;
513 		opp_table->path_count = num_paths;
514 		return 0;
515 	}
516 
517 err:
518 	while (i--)
519 		icc_put(paths[i]);
520 
521 	kfree(paths);
522 
523 	return ret;
524 }
525 EXPORT_SYMBOL_GPL(dev_pm_opp_of_find_icc_paths);
526 
527 static bool _opp_is_supported(struct device *dev, struct opp_table *opp_table,
528 			      struct device_node *np)
529 {
530 	unsigned int levels = opp_table->supported_hw_count;
531 	int count, versions, ret, i, j;
532 	u32 val;
533 
534 	if (!opp_table->supported_hw) {
535 		/*
536 		 * In the case that no supported_hw has been set by the
537 		 * platform but there is an opp-supported-hw value set for
538 		 * an OPP then the OPP should not be enabled as there is
539 		 * no way to see if the hardware supports it.
540 		 */
541 		if (of_find_property(np, "opp-supported-hw", NULL))
542 			return false;
543 		else
544 			return true;
545 	}
546 
547 	count = of_property_count_u32_elems(np, "opp-supported-hw");
548 	if (count <= 0 || count % levels) {
549 		dev_err(dev, "%s: Invalid opp-supported-hw property (%d)\n",
550 			__func__, count);
551 		return false;
552 	}
553 
554 	versions = count / levels;
555 
556 	/* All levels in at least one of the versions should match */
557 	for (i = 0; i < versions; i++) {
558 		bool supported = true;
559 
560 		for (j = 0; j < levels; j++) {
561 			ret = of_property_read_u32_index(np, "opp-supported-hw",
562 							 i * levels + j, &val);
563 			if (ret) {
564 				dev_warn(dev, "%s: failed to read opp-supported-hw property at index %d: %d\n",
565 					 __func__, i * levels + j, ret);
566 				return false;
567 			}
568 
569 			/* Check if the level is supported */
570 			if (!(val & opp_table->supported_hw[j])) {
571 				supported = false;
572 				break;
573 			}
574 		}
575 
576 		if (supported)
577 			return true;
578 	}
579 
580 	return false;
581 }
582 
583 static int opp_parse_supplies(struct dev_pm_opp *opp, struct device *dev,
584 			      struct opp_table *opp_table)
585 {
586 	u32 *microvolt, *microamp = NULL;
587 	int supplies = opp_table->regulator_count, vcount, icount, ret, i, j;
588 	struct property *prop = NULL;
589 	char name[NAME_MAX];
590 
591 	/* Search for "opp-microvolt-<name>" */
592 	if (opp_table->prop_name) {
593 		snprintf(name, sizeof(name), "opp-microvolt-%s",
594 			 opp_table->prop_name);
595 		prop = of_find_property(opp->np, name, NULL);
596 	}
597 
598 	if (!prop) {
599 		/* Search for "opp-microvolt" */
600 		sprintf(name, "opp-microvolt");
601 		prop = of_find_property(opp->np, name, NULL);
602 
603 		/* Missing property isn't a problem, but an invalid entry is */
604 		if (!prop) {
605 			if (unlikely(supplies == -1)) {
606 				/* Initialize regulator_count */
607 				opp_table->regulator_count = 0;
608 				return 0;
609 			}
610 
611 			if (!supplies)
612 				return 0;
613 
614 			dev_err(dev, "%s: opp-microvolt missing although OPP managing regulators\n",
615 				__func__);
616 			return -EINVAL;
617 		}
618 	}
619 
620 	if (unlikely(supplies == -1)) {
621 		/* Initialize regulator_count */
622 		supplies = opp_table->regulator_count = 1;
623 	} else if (unlikely(!supplies)) {
624 		dev_err(dev, "%s: opp-microvolt wasn't expected\n", __func__);
625 		return -EINVAL;
626 	}
627 
628 	vcount = of_property_count_u32_elems(opp->np, name);
629 	if (vcount < 0) {
630 		dev_err(dev, "%s: Invalid %s property (%d)\n",
631 			__func__, name, vcount);
632 		return vcount;
633 	}
634 
635 	/* There can be one or three elements per supply */
636 	if (vcount != supplies && vcount != supplies * 3) {
637 		dev_err(dev, "%s: Invalid number of elements in %s property (%d) with supplies (%d)\n",
638 			__func__, name, vcount, supplies);
639 		return -EINVAL;
640 	}
641 
642 	microvolt = kmalloc_array(vcount, sizeof(*microvolt), GFP_KERNEL);
643 	if (!microvolt)
644 		return -ENOMEM;
645 
646 	ret = of_property_read_u32_array(opp->np, name, microvolt, vcount);
647 	if (ret) {
648 		dev_err(dev, "%s: error parsing %s: %d\n", __func__, name, ret);
649 		ret = -EINVAL;
650 		goto free_microvolt;
651 	}
652 
653 	/* Search for "opp-microamp-<name>" */
654 	prop = NULL;
655 	if (opp_table->prop_name) {
656 		snprintf(name, sizeof(name), "opp-microamp-%s",
657 			 opp_table->prop_name);
658 		prop = of_find_property(opp->np, name, NULL);
659 	}
660 
661 	if (!prop) {
662 		/* Search for "opp-microamp" */
663 		sprintf(name, "opp-microamp");
664 		prop = of_find_property(opp->np, name, NULL);
665 	}
666 
667 	if (prop) {
668 		icount = of_property_count_u32_elems(opp->np, name);
669 		if (icount < 0) {
670 			dev_err(dev, "%s: Invalid %s property (%d)\n", __func__,
671 				name, icount);
672 			ret = icount;
673 			goto free_microvolt;
674 		}
675 
676 		if (icount != supplies) {
677 			dev_err(dev, "%s: Invalid number of elements in %s property (%d) with supplies (%d)\n",
678 				__func__, name, icount, supplies);
679 			ret = -EINVAL;
680 			goto free_microvolt;
681 		}
682 
683 		microamp = kmalloc_array(icount, sizeof(*microamp), GFP_KERNEL);
684 		if (!microamp) {
685 			ret = -EINVAL;
686 			goto free_microvolt;
687 		}
688 
689 		ret = of_property_read_u32_array(opp->np, name, microamp,
690 						 icount);
691 		if (ret) {
692 			dev_err(dev, "%s: error parsing %s: %d\n", __func__,
693 				name, ret);
694 			ret = -EINVAL;
695 			goto free_microamp;
696 		}
697 	}
698 
699 	for (i = 0, j = 0; i < supplies; i++) {
700 		opp->supplies[i].u_volt = microvolt[j++];
701 
702 		if (vcount == supplies) {
703 			opp->supplies[i].u_volt_min = opp->supplies[i].u_volt;
704 			opp->supplies[i].u_volt_max = opp->supplies[i].u_volt;
705 		} else {
706 			opp->supplies[i].u_volt_min = microvolt[j++];
707 			opp->supplies[i].u_volt_max = microvolt[j++];
708 		}
709 
710 		if (microamp)
711 			opp->supplies[i].u_amp = microamp[i];
712 	}
713 
714 free_microamp:
715 	kfree(microamp);
716 free_microvolt:
717 	kfree(microvolt);
718 
719 	return ret;
720 }
721 
722 /**
723  * dev_pm_opp_of_remove_table() - Free OPP table entries created from static DT
724  *				  entries
725  * @dev:	device pointer used to lookup OPP table.
726  *
727  * Free OPPs created using static entries present in DT.
728  */
729 void dev_pm_opp_of_remove_table(struct device *dev)
730 {
731 	dev_pm_opp_remove_table(dev);
732 }
733 EXPORT_SYMBOL_GPL(dev_pm_opp_of_remove_table);
734 
735 static int _read_bw(struct dev_pm_opp *new_opp, struct opp_table *table,
736 		    struct device_node *np, bool peak)
737 {
738 	const char *name = peak ? "opp-peak-kBps" : "opp-avg-kBps";
739 	struct property *prop;
740 	int i, count, ret;
741 	u32 *bw;
742 
743 	prop = of_find_property(np, name, NULL);
744 	if (!prop)
745 		return -ENODEV;
746 
747 	count = prop->length / sizeof(u32);
748 	if (table->path_count != count) {
749 		pr_err("%s: Mismatch between %s and paths (%d %d)\n",
750 				__func__, name, count, table->path_count);
751 		return -EINVAL;
752 	}
753 
754 	bw = kmalloc_array(count, sizeof(*bw), GFP_KERNEL);
755 	if (!bw)
756 		return -ENOMEM;
757 
758 	ret = of_property_read_u32_array(np, name, bw, count);
759 	if (ret) {
760 		pr_err("%s: Error parsing %s: %d\n", __func__, name, ret);
761 		goto out;
762 	}
763 
764 	for (i = 0; i < count; i++) {
765 		if (peak)
766 			new_opp->bandwidth[i].peak = kBps_to_icc(bw[i]);
767 		else
768 			new_opp->bandwidth[i].avg = kBps_to_icc(bw[i]);
769 	}
770 
771 out:
772 	kfree(bw);
773 	return ret;
774 }
775 
776 static int _read_opp_key(struct dev_pm_opp *new_opp, struct opp_table *table,
777 			 struct device_node *np, bool *rate_not_available)
778 {
779 	bool found = false;
780 	u64 rate;
781 	int ret;
782 
783 	ret = of_property_read_u64(np, "opp-hz", &rate);
784 	if (!ret) {
785 		/*
786 		 * Rate is defined as an unsigned long in clk API, and so
787 		 * casting explicitly to its type. Must be fixed once rate is 64
788 		 * bit guaranteed in clk API.
789 		 */
790 		new_opp->rate = (unsigned long)rate;
791 		found = true;
792 	}
793 	*rate_not_available = !!ret;
794 
795 	/*
796 	 * Bandwidth consists of peak and average (optional) values:
797 	 * opp-peak-kBps = <path1_value path2_value>;
798 	 * opp-avg-kBps = <path1_value path2_value>;
799 	 */
800 	ret = _read_bw(new_opp, table, np, true);
801 	if (!ret) {
802 		found = true;
803 		ret = _read_bw(new_opp, table, np, false);
804 	}
805 
806 	/* The properties were found but we failed to parse them */
807 	if (ret && ret != -ENODEV)
808 		return ret;
809 
810 	if (!of_property_read_u32(np, "opp-level", &new_opp->level))
811 		found = true;
812 
813 	if (found)
814 		return 0;
815 
816 	return ret;
817 }
818 
819 /**
820  * _opp_add_static_v2() - Allocate static OPPs (As per 'v2' DT bindings)
821  * @opp_table:	OPP table
822  * @dev:	device for which we do this operation
823  * @np:		device node
824  *
825  * This function adds an opp definition to the opp table and returns status. The
826  * opp can be controlled using dev_pm_opp_enable/disable functions and may be
827  * removed by dev_pm_opp_remove.
828  *
829  * Return:
830  * Valid OPP pointer:
831  *		On success
832  * NULL:
833  *		Duplicate OPPs (both freq and volt are same) and opp->available
834  *		OR if the OPP is not supported by hardware.
835  * ERR_PTR(-EEXIST):
836  *		Freq are same and volt are different OR
837  *		Duplicate OPPs (both freq and volt are same) and !opp->available
838  * ERR_PTR(-ENOMEM):
839  *		Memory allocation failure
840  * ERR_PTR(-EINVAL):
841  *		Failed parsing the OPP node
842  */
843 static struct dev_pm_opp *_opp_add_static_v2(struct opp_table *opp_table,
844 		struct device *dev, struct device_node *np)
845 {
846 	struct dev_pm_opp *new_opp;
847 	u32 val;
848 	int ret;
849 	bool rate_not_available = false;
850 
851 	new_opp = _opp_allocate(opp_table);
852 	if (!new_opp)
853 		return ERR_PTR(-ENOMEM);
854 
855 	ret = _read_opp_key(new_opp, opp_table, np, &rate_not_available);
856 	if (ret < 0) {
857 		dev_err(dev, "%s: opp key field not found\n", __func__);
858 		goto free_opp;
859 	}
860 
861 	/* Check if the OPP supports hardware's hierarchy of versions or not */
862 	if (!_opp_is_supported(dev, opp_table, np)) {
863 		dev_dbg(dev, "OPP not supported by hardware: %lu\n",
864 			new_opp->rate);
865 		goto free_opp;
866 	}
867 
868 	new_opp->turbo = of_property_read_bool(np, "turbo-mode");
869 
870 	new_opp->np = np;
871 	new_opp->dynamic = false;
872 	new_opp->available = true;
873 
874 	ret = _of_opp_alloc_required_opps(opp_table, new_opp);
875 	if (ret)
876 		goto free_opp;
877 
878 	if (!of_property_read_u32(np, "clock-latency-ns", &val))
879 		new_opp->clock_latency_ns = val;
880 
881 	ret = opp_parse_supplies(new_opp, dev, opp_table);
882 	if (ret)
883 		goto free_required_opps;
884 
885 	if (opp_table->is_genpd)
886 		new_opp->pstate = pm_genpd_opp_to_performance_state(dev, new_opp);
887 
888 	ret = _opp_add(dev, new_opp, opp_table, rate_not_available);
889 	if (ret) {
890 		/* Don't return error for duplicate OPPs */
891 		if (ret == -EBUSY)
892 			ret = 0;
893 		goto free_required_opps;
894 	}
895 
896 	/* OPP to select on device suspend */
897 	if (of_property_read_bool(np, "opp-suspend")) {
898 		if (opp_table->suspend_opp) {
899 			/* Pick the OPP with higher rate as suspend OPP */
900 			if (new_opp->rate > opp_table->suspend_opp->rate) {
901 				opp_table->suspend_opp->suspend = false;
902 				new_opp->suspend = true;
903 				opp_table->suspend_opp = new_opp;
904 			}
905 		} else {
906 			new_opp->suspend = true;
907 			opp_table->suspend_opp = new_opp;
908 		}
909 	}
910 
911 	if (new_opp->clock_latency_ns > opp_table->clock_latency_ns_max)
912 		opp_table->clock_latency_ns_max = new_opp->clock_latency_ns;
913 
914 	pr_debug("%s: turbo:%d rate:%lu uv:%lu uvmin:%lu uvmax:%lu latency:%lu level:%u\n",
915 		 __func__, new_opp->turbo, new_opp->rate,
916 		 new_opp->supplies[0].u_volt, new_opp->supplies[0].u_volt_min,
917 		 new_opp->supplies[0].u_volt_max, new_opp->clock_latency_ns,
918 		 new_opp->level);
919 
920 	/*
921 	 * Notify the changes in the availability of the operable
922 	 * frequency/voltage list.
923 	 */
924 	blocking_notifier_call_chain(&opp_table->head, OPP_EVENT_ADD, new_opp);
925 	return new_opp;
926 
927 free_required_opps:
928 	_of_opp_free_required_opps(opp_table, new_opp);
929 free_opp:
930 	_opp_free(new_opp);
931 
932 	return ERR_PTR(ret);
933 }
934 
935 /* Initializes OPP tables based on new bindings */
936 static int _of_add_opp_table_v2(struct device *dev, struct opp_table *opp_table)
937 {
938 	struct device_node *np;
939 	int ret, count = 0;
940 	struct dev_pm_opp *opp;
941 
942 	/* OPP table is already initialized for the device */
943 	mutex_lock(&opp_table->lock);
944 	if (opp_table->parsed_static_opps) {
945 		opp_table->parsed_static_opps++;
946 		mutex_unlock(&opp_table->lock);
947 		return 0;
948 	}
949 
950 	opp_table->parsed_static_opps = 1;
951 	mutex_unlock(&opp_table->lock);
952 
953 	/* We have opp-table node now, iterate over it and add OPPs */
954 	for_each_available_child_of_node(opp_table->np, np) {
955 		opp = _opp_add_static_v2(opp_table, dev, np);
956 		if (IS_ERR(opp)) {
957 			ret = PTR_ERR(opp);
958 			dev_err(dev, "%s: Failed to add OPP, %d\n", __func__,
959 				ret);
960 			of_node_put(np);
961 			goto remove_static_opp;
962 		} else if (opp) {
963 			count++;
964 		}
965 	}
966 
967 	/* There should be one of more OPP defined */
968 	if (WARN_ON(!count)) {
969 		ret = -ENOENT;
970 		goto remove_static_opp;
971 	}
972 
973 	list_for_each_entry(opp, &opp_table->opp_list, node) {
974 		/* Any non-zero performance state would enable the feature */
975 		if (opp->pstate) {
976 			opp_table->genpd_performance_state = true;
977 			break;
978 		}
979 	}
980 
981 	lazy_link_required_opp_table(opp_table);
982 
983 	return 0;
984 
985 remove_static_opp:
986 	_opp_remove_all_static(opp_table);
987 
988 	return ret;
989 }
990 
991 /* Initializes OPP tables based on old-deprecated bindings */
992 static int _of_add_opp_table_v1(struct device *dev, struct opp_table *opp_table)
993 {
994 	const struct property *prop;
995 	const __be32 *val;
996 	int nr, ret = 0;
997 
998 	mutex_lock(&opp_table->lock);
999 	if (opp_table->parsed_static_opps) {
1000 		opp_table->parsed_static_opps++;
1001 		mutex_unlock(&opp_table->lock);
1002 		return 0;
1003 	}
1004 
1005 	opp_table->parsed_static_opps = 1;
1006 	mutex_unlock(&opp_table->lock);
1007 
1008 	prop = of_find_property(dev->of_node, "operating-points", NULL);
1009 	if (!prop) {
1010 		ret = -ENODEV;
1011 		goto remove_static_opp;
1012 	}
1013 	if (!prop->value) {
1014 		ret = -ENODATA;
1015 		goto remove_static_opp;
1016 	}
1017 
1018 	/*
1019 	 * Each OPP is a set of tuples consisting of frequency and
1020 	 * voltage like <freq-kHz vol-uV>.
1021 	 */
1022 	nr = prop->length / sizeof(u32);
1023 	if (nr % 2) {
1024 		dev_err(dev, "%s: Invalid OPP table\n", __func__);
1025 		ret = -EINVAL;
1026 		goto remove_static_opp;
1027 	}
1028 
1029 	val = prop->value;
1030 	while (nr) {
1031 		unsigned long freq = be32_to_cpup(val++) * 1000;
1032 		unsigned long volt = be32_to_cpup(val++);
1033 
1034 		ret = _opp_add_v1(opp_table, dev, freq, volt, false);
1035 		if (ret) {
1036 			dev_err(dev, "%s: Failed to add OPP %ld (%d)\n",
1037 				__func__, freq, ret);
1038 			goto remove_static_opp;
1039 		}
1040 		nr -= 2;
1041 	}
1042 
1043 	return 0;
1044 
1045 remove_static_opp:
1046 	_opp_remove_all_static(opp_table);
1047 
1048 	return ret;
1049 }
1050 
1051 static int _of_add_table_indexed(struct device *dev, int index, bool getclk)
1052 {
1053 	struct opp_table *opp_table;
1054 	int ret, count;
1055 
1056 	if (index) {
1057 		/*
1058 		 * If only one phandle is present, then the same OPP table
1059 		 * applies for all index requests.
1060 		 */
1061 		count = of_count_phandle_with_args(dev->of_node,
1062 						   "operating-points-v2", NULL);
1063 		if (count == 1)
1064 			index = 0;
1065 	}
1066 
1067 	opp_table = _add_opp_table_indexed(dev, index, getclk);
1068 	if (IS_ERR(opp_table))
1069 		return PTR_ERR(opp_table);
1070 
1071 	/*
1072 	 * OPPs have two version of bindings now. Also try the old (v1)
1073 	 * bindings for backward compatibility with older dtbs.
1074 	 */
1075 	if (opp_table->np)
1076 		ret = _of_add_opp_table_v2(dev, opp_table);
1077 	else
1078 		ret = _of_add_opp_table_v1(dev, opp_table);
1079 
1080 	if (ret)
1081 		dev_pm_opp_put_opp_table(opp_table);
1082 
1083 	return ret;
1084 }
1085 
1086 static void devm_pm_opp_of_table_release(void *data)
1087 {
1088 	dev_pm_opp_of_remove_table(data);
1089 }
1090 
1091 /**
1092  * devm_pm_opp_of_add_table() - Initialize opp table from device tree
1093  * @dev:	device pointer used to lookup OPP table.
1094  *
1095  * Register the initial OPP table with the OPP library for given device.
1096  *
1097  * The opp_table structure will be freed after the device is destroyed.
1098  *
1099  * Return:
1100  * 0		On success OR
1101  *		Duplicate OPPs (both freq and volt are same) and opp->available
1102  * -EEXIST	Freq are same and volt are different OR
1103  *		Duplicate OPPs (both freq and volt are same) and !opp->available
1104  * -ENOMEM	Memory allocation failure
1105  * -ENODEV	when 'operating-points' property is not found or is invalid data
1106  *		in device node.
1107  * -ENODATA	when empty 'operating-points' property is found
1108  * -EINVAL	when invalid entries are found in opp-v2 table
1109  */
1110 int devm_pm_opp_of_add_table(struct device *dev)
1111 {
1112 	int ret;
1113 
1114 	ret = dev_pm_opp_of_add_table(dev);
1115 	if (ret)
1116 		return ret;
1117 
1118 	return devm_add_action_or_reset(dev, devm_pm_opp_of_table_release, dev);
1119 }
1120 EXPORT_SYMBOL_GPL(devm_pm_opp_of_add_table);
1121 
1122 /**
1123  * dev_pm_opp_of_add_table() - Initialize opp table from device tree
1124  * @dev:	device pointer used to lookup OPP table.
1125  *
1126  * Register the initial OPP table with the OPP library for given device.
1127  *
1128  * Return:
1129  * 0		On success OR
1130  *		Duplicate OPPs (both freq and volt are same) and opp->available
1131  * -EEXIST	Freq are same and volt are different OR
1132  *		Duplicate OPPs (both freq and volt are same) and !opp->available
1133  * -ENOMEM	Memory allocation failure
1134  * -ENODEV	when 'operating-points' property is not found or is invalid data
1135  *		in device node.
1136  * -ENODATA	when empty 'operating-points' property is found
1137  * -EINVAL	when invalid entries are found in opp-v2 table
1138  */
1139 int dev_pm_opp_of_add_table(struct device *dev)
1140 {
1141 	return _of_add_table_indexed(dev, 0, true);
1142 }
1143 EXPORT_SYMBOL_GPL(dev_pm_opp_of_add_table);
1144 
1145 /**
1146  * dev_pm_opp_of_add_table_indexed() - Initialize indexed opp table from device tree
1147  * @dev:	device pointer used to lookup OPP table.
1148  * @index:	Index number.
1149  *
1150  * Register the initial OPP table with the OPP library for given device only
1151  * using the "operating-points-v2" property.
1152  *
1153  * Return: Refer to dev_pm_opp_of_add_table() for return values.
1154  */
1155 int dev_pm_opp_of_add_table_indexed(struct device *dev, int index)
1156 {
1157 	return _of_add_table_indexed(dev, index, true);
1158 }
1159 EXPORT_SYMBOL_GPL(dev_pm_opp_of_add_table_indexed);
1160 
1161 /**
1162  * dev_pm_opp_of_add_table_noclk() - Initialize indexed opp table from device
1163  *		tree without getting clk for device.
1164  * @dev:	device pointer used to lookup OPP table.
1165  * @index:	Index number.
1166  *
1167  * Register the initial OPP table with the OPP library for given device only
1168  * using the "operating-points-v2" property. Do not try to get the clk for the
1169  * device.
1170  *
1171  * Return: Refer to dev_pm_opp_of_add_table() for return values.
1172  */
1173 int dev_pm_opp_of_add_table_noclk(struct device *dev, int index)
1174 {
1175 	return _of_add_table_indexed(dev, index, false);
1176 }
1177 EXPORT_SYMBOL_GPL(dev_pm_opp_of_add_table_noclk);
1178 
1179 /* CPU device specific helpers */
1180 
1181 /**
1182  * dev_pm_opp_of_cpumask_remove_table() - Removes OPP table for @cpumask
1183  * @cpumask:	cpumask for which OPP table needs to be removed
1184  *
1185  * This removes the OPP tables for CPUs present in the @cpumask.
1186  * This should be used only to remove static entries created from DT.
1187  */
1188 void dev_pm_opp_of_cpumask_remove_table(const struct cpumask *cpumask)
1189 {
1190 	_dev_pm_opp_cpumask_remove_table(cpumask, -1);
1191 }
1192 EXPORT_SYMBOL_GPL(dev_pm_opp_of_cpumask_remove_table);
1193 
1194 /**
1195  * dev_pm_opp_of_cpumask_add_table() - Adds OPP table for @cpumask
1196  * @cpumask:	cpumask for which OPP table needs to be added.
1197  *
1198  * This adds the OPP tables for CPUs present in the @cpumask.
1199  */
1200 int dev_pm_opp_of_cpumask_add_table(const struct cpumask *cpumask)
1201 {
1202 	struct device *cpu_dev;
1203 	int cpu, ret;
1204 
1205 	if (WARN_ON(cpumask_empty(cpumask)))
1206 		return -ENODEV;
1207 
1208 	for_each_cpu(cpu, cpumask) {
1209 		cpu_dev = get_cpu_device(cpu);
1210 		if (!cpu_dev) {
1211 			pr_err("%s: failed to get cpu%d device\n", __func__,
1212 			       cpu);
1213 			ret = -ENODEV;
1214 			goto remove_table;
1215 		}
1216 
1217 		ret = dev_pm_opp_of_add_table(cpu_dev);
1218 		if (ret) {
1219 			/*
1220 			 * OPP may get registered dynamically, don't print error
1221 			 * message here.
1222 			 */
1223 			pr_debug("%s: couldn't find opp table for cpu:%d, %d\n",
1224 				 __func__, cpu, ret);
1225 
1226 			goto remove_table;
1227 		}
1228 	}
1229 
1230 	return 0;
1231 
1232 remove_table:
1233 	/* Free all other OPPs */
1234 	_dev_pm_opp_cpumask_remove_table(cpumask, cpu);
1235 
1236 	return ret;
1237 }
1238 EXPORT_SYMBOL_GPL(dev_pm_opp_of_cpumask_add_table);
1239 
1240 /*
1241  * Works only for OPP v2 bindings.
1242  *
1243  * Returns -ENOENT if operating-points-v2 bindings aren't supported.
1244  */
1245 /**
1246  * dev_pm_opp_of_get_sharing_cpus() - Get cpumask of CPUs sharing OPPs with
1247  *				      @cpu_dev using operating-points-v2
1248  *				      bindings.
1249  *
1250  * @cpu_dev:	CPU device for which we do this operation
1251  * @cpumask:	cpumask to update with information of sharing CPUs
1252  *
1253  * This updates the @cpumask with CPUs that are sharing OPPs with @cpu_dev.
1254  *
1255  * Returns -ENOENT if operating-points-v2 isn't present for @cpu_dev.
1256  */
1257 int dev_pm_opp_of_get_sharing_cpus(struct device *cpu_dev,
1258 				   struct cpumask *cpumask)
1259 {
1260 	struct device_node *np, *tmp_np, *cpu_np;
1261 	int cpu, ret = 0;
1262 
1263 	/* Get OPP descriptor node */
1264 	np = dev_pm_opp_of_get_opp_desc_node(cpu_dev);
1265 	if (!np) {
1266 		dev_dbg(cpu_dev, "%s: Couldn't find opp node.\n", __func__);
1267 		return -ENOENT;
1268 	}
1269 
1270 	cpumask_set_cpu(cpu_dev->id, cpumask);
1271 
1272 	/* OPPs are shared ? */
1273 	if (!of_property_read_bool(np, "opp-shared"))
1274 		goto put_cpu_node;
1275 
1276 	for_each_possible_cpu(cpu) {
1277 		if (cpu == cpu_dev->id)
1278 			continue;
1279 
1280 		cpu_np = of_cpu_device_node_get(cpu);
1281 		if (!cpu_np) {
1282 			dev_err(cpu_dev, "%s: failed to get cpu%d node\n",
1283 				__func__, cpu);
1284 			ret = -ENOENT;
1285 			goto put_cpu_node;
1286 		}
1287 
1288 		/* Get OPP descriptor node */
1289 		tmp_np = _opp_of_get_opp_desc_node(cpu_np, 0);
1290 		of_node_put(cpu_np);
1291 		if (!tmp_np) {
1292 			pr_err("%pOF: Couldn't find opp node\n", cpu_np);
1293 			ret = -ENOENT;
1294 			goto put_cpu_node;
1295 		}
1296 
1297 		/* CPUs are sharing opp node */
1298 		if (np == tmp_np)
1299 			cpumask_set_cpu(cpu, cpumask);
1300 
1301 		of_node_put(tmp_np);
1302 	}
1303 
1304 put_cpu_node:
1305 	of_node_put(np);
1306 	return ret;
1307 }
1308 EXPORT_SYMBOL_GPL(dev_pm_opp_of_get_sharing_cpus);
1309 
1310 /**
1311  * of_get_required_opp_performance_state() - Search for required OPP and return its performance state.
1312  * @np: Node that contains the "required-opps" property.
1313  * @index: Index of the phandle to parse.
1314  *
1315  * Returns the performance state of the OPP pointed out by the "required-opps"
1316  * property at @index in @np.
1317  *
1318  * Return: Zero or positive performance state on success, otherwise negative
1319  * value on errors.
1320  */
1321 int of_get_required_opp_performance_state(struct device_node *np, int index)
1322 {
1323 	struct dev_pm_opp *opp;
1324 	struct device_node *required_np;
1325 	struct opp_table *opp_table;
1326 	int pstate = -EINVAL;
1327 
1328 	required_np = of_parse_required_opp(np, index);
1329 	if (!required_np)
1330 		return -EINVAL;
1331 
1332 	opp_table = _find_table_of_opp_np(required_np);
1333 	if (IS_ERR(opp_table)) {
1334 		pr_err("%s: Failed to find required OPP table %pOF: %ld\n",
1335 		       __func__, np, PTR_ERR(opp_table));
1336 		goto put_required_np;
1337 	}
1338 
1339 	opp = _find_opp_of_np(opp_table, required_np);
1340 	if (opp) {
1341 		pstate = opp->pstate;
1342 		dev_pm_opp_put(opp);
1343 	}
1344 
1345 	dev_pm_opp_put_opp_table(opp_table);
1346 
1347 put_required_np:
1348 	of_node_put(required_np);
1349 
1350 	return pstate;
1351 }
1352 EXPORT_SYMBOL_GPL(of_get_required_opp_performance_state);
1353 
1354 /**
1355  * dev_pm_opp_get_of_node() - Gets the DT node corresponding to an opp
1356  * @opp:	opp for which DT node has to be returned for
1357  *
1358  * Return: DT node corresponding to the opp, else 0 on success.
1359  *
1360  * The caller needs to put the node with of_node_put() after using it.
1361  */
1362 struct device_node *dev_pm_opp_get_of_node(struct dev_pm_opp *opp)
1363 {
1364 	if (IS_ERR_OR_NULL(opp)) {
1365 		pr_err("%s: Invalid parameters\n", __func__);
1366 		return NULL;
1367 	}
1368 
1369 	return of_node_get(opp->np);
1370 }
1371 EXPORT_SYMBOL_GPL(dev_pm_opp_get_of_node);
1372 
1373 /*
1374  * Callback function provided to the Energy Model framework upon registration.
1375  * This computes the power estimated by @dev at @kHz if it is the frequency
1376  * of an existing OPP, or at the frequency of the first OPP above @kHz otherwise
1377  * (see dev_pm_opp_find_freq_ceil()). This function updates @kHz to the ceiled
1378  * frequency and @mW to the associated power. The power is estimated as
1379  * P = C * V^2 * f with C being the device's capacitance and V and f
1380  * respectively the voltage and frequency of the OPP.
1381  *
1382  * Returns -EINVAL if the power calculation failed because of missing
1383  * parameters, 0 otherwise.
1384  */
1385 static int __maybe_unused _get_power(unsigned long *mW, unsigned long *kHz,
1386 				     struct device *dev)
1387 {
1388 	struct dev_pm_opp *opp;
1389 	struct device_node *np;
1390 	unsigned long mV, Hz;
1391 	u32 cap;
1392 	u64 tmp;
1393 	int ret;
1394 
1395 	np = of_node_get(dev->of_node);
1396 	if (!np)
1397 		return -EINVAL;
1398 
1399 	ret = of_property_read_u32(np, "dynamic-power-coefficient", &cap);
1400 	of_node_put(np);
1401 	if (ret)
1402 		return -EINVAL;
1403 
1404 	Hz = *kHz * 1000;
1405 	opp = dev_pm_opp_find_freq_ceil(dev, &Hz);
1406 	if (IS_ERR(opp))
1407 		return -EINVAL;
1408 
1409 	mV = dev_pm_opp_get_voltage(opp) / 1000;
1410 	dev_pm_opp_put(opp);
1411 	if (!mV)
1412 		return -EINVAL;
1413 
1414 	tmp = (u64)cap * mV * mV * (Hz / 1000000);
1415 	do_div(tmp, 1000000000);
1416 
1417 	*mW = (unsigned long)tmp;
1418 	*kHz = Hz / 1000;
1419 
1420 	return 0;
1421 }
1422 
1423 /**
1424  * dev_pm_opp_of_register_em() - Attempt to register an Energy Model
1425  * @dev		: Device for which an Energy Model has to be registered
1426  * @cpus	: CPUs for which an Energy Model has to be registered. For
1427  *		other type of devices it should be set to NULL.
1428  *
1429  * This checks whether the "dynamic-power-coefficient" devicetree property has
1430  * been specified, and tries to register an Energy Model with it if it has.
1431  * Having this property means the voltages are known for OPPs and the EM
1432  * might be calculated.
1433  */
1434 int dev_pm_opp_of_register_em(struct device *dev, struct cpumask *cpus)
1435 {
1436 	struct em_data_callback em_cb = EM_DATA_CB(_get_power);
1437 	struct device_node *np;
1438 	int ret, nr_opp;
1439 	u32 cap;
1440 
1441 	if (IS_ERR_OR_NULL(dev)) {
1442 		ret = -EINVAL;
1443 		goto failed;
1444 	}
1445 
1446 	nr_opp = dev_pm_opp_get_opp_count(dev);
1447 	if (nr_opp <= 0) {
1448 		ret = -EINVAL;
1449 		goto failed;
1450 	}
1451 
1452 	np = of_node_get(dev->of_node);
1453 	if (!np) {
1454 		ret = -EINVAL;
1455 		goto failed;
1456 	}
1457 
1458 	/*
1459 	 * Register an EM only if the 'dynamic-power-coefficient' property is
1460 	 * set in devicetree. It is assumed the voltage values are known if that
1461 	 * property is set since it is useless otherwise. If voltages are not
1462 	 * known, just let the EM registration fail with an error to alert the
1463 	 * user about the inconsistent configuration.
1464 	 */
1465 	ret = of_property_read_u32(np, "dynamic-power-coefficient", &cap);
1466 	of_node_put(np);
1467 	if (ret || !cap) {
1468 		dev_dbg(dev, "Couldn't find proper 'dynamic-power-coefficient' in DT\n");
1469 		ret = -EINVAL;
1470 		goto failed;
1471 	}
1472 
1473 	ret = em_dev_register_perf_domain(dev, nr_opp, &em_cb, cpus, true);
1474 	if (ret)
1475 		goto failed;
1476 
1477 	return 0;
1478 
1479 failed:
1480 	dev_dbg(dev, "Couldn't register Energy Model %d\n", ret);
1481 	return ret;
1482 }
1483 EXPORT_SYMBOL_GPL(dev_pm_opp_of_register_em);
1484