xref: /linux/drivers/opp/of.c (revision c5d3cdad688ed75fb311a3a671eb30ba7106d7d3)
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 	lockdep_assert_held(&opp_table_lock);
116 
117 	opp_table_np = of_get_parent(opp_np);
118 	if (!opp_table_np)
119 		goto err;
120 
121 	/* It is safe to put the node now as all we need now is its address */
122 	of_node_put(opp_table_np);
123 
124 	list_for_each_entry(opp_table, &opp_tables, node) {
125 		if (opp_table_np == opp_table->np) {
126 			_get_opp_table_kref(opp_table);
127 			return opp_table;
128 		}
129 	}
130 
131 err:
132 	return ERR_PTR(-ENODEV);
133 }
134 
135 /* Free resources previously acquired by _opp_table_alloc_required_tables() */
136 static void _opp_table_free_required_tables(struct opp_table *opp_table)
137 {
138 	struct opp_table **required_opp_tables = opp_table->required_opp_tables;
139 	int i;
140 
141 	if (!required_opp_tables)
142 		return;
143 
144 	for (i = 0; i < opp_table->required_opp_count; i++) {
145 		if (IS_ERR_OR_NULL(required_opp_tables[i]))
146 			break;
147 
148 		dev_pm_opp_put_opp_table(required_opp_tables[i]);
149 	}
150 
151 	kfree(required_opp_tables);
152 
153 	opp_table->required_opp_count = 0;
154 	opp_table->required_opp_tables = NULL;
155 }
156 
157 /*
158  * Populate all devices and opp tables which are part of "required-opps" list.
159  * Checking only the first OPP node should be enough.
160  */
161 static void _opp_table_alloc_required_tables(struct opp_table *opp_table,
162 					     struct device *dev,
163 					     struct device_node *opp_np)
164 {
165 	struct opp_table **required_opp_tables;
166 	struct device_node *required_np, *np;
167 	int count, i;
168 
169 	/* Traversing the first OPP node is all we need */
170 	np = of_get_next_available_child(opp_np, NULL);
171 	if (!np) {
172 		dev_err(dev, "Empty OPP table\n");
173 		return;
174 	}
175 
176 	count = of_count_phandle_with_args(np, "required-opps", NULL);
177 	if (!count)
178 		goto put_np;
179 
180 	required_opp_tables = kcalloc(count, sizeof(*required_opp_tables),
181 				      GFP_KERNEL);
182 	if (!required_opp_tables)
183 		goto put_np;
184 
185 	opp_table->required_opp_tables = required_opp_tables;
186 	opp_table->required_opp_count = count;
187 
188 	for (i = 0; i < count; i++) {
189 		required_np = of_parse_required_opp(np, i);
190 		if (!required_np)
191 			goto free_required_tables;
192 
193 		required_opp_tables[i] = _find_table_of_opp_np(required_np);
194 		of_node_put(required_np);
195 
196 		if (IS_ERR(required_opp_tables[i]))
197 			goto free_required_tables;
198 
199 		/*
200 		 * We only support genpd's OPPs in the "required-opps" for now,
201 		 * as we don't know how much about other cases. Error out if the
202 		 * required OPP doesn't belong to a genpd.
203 		 */
204 		if (!required_opp_tables[i]->is_genpd) {
205 			dev_err(dev, "required-opp doesn't belong to genpd: %pOF\n",
206 				required_np);
207 			goto free_required_tables;
208 		}
209 	}
210 
211 	goto put_np;
212 
213 free_required_tables:
214 	_opp_table_free_required_tables(opp_table);
215 put_np:
216 	of_node_put(np);
217 }
218 
219 void _of_init_opp_table(struct opp_table *opp_table, struct device *dev,
220 			int index)
221 {
222 	struct device_node *np, *opp_np;
223 	u32 val;
224 
225 	/*
226 	 * Only required for backward compatibility with v1 bindings, but isn't
227 	 * harmful for other cases. And so we do it unconditionally.
228 	 */
229 	np = of_node_get(dev->of_node);
230 	if (!np)
231 		return;
232 
233 	if (!of_property_read_u32(np, "clock-latency", &val))
234 		opp_table->clock_latency_ns_max = val;
235 	of_property_read_u32(np, "voltage-tolerance",
236 			     &opp_table->voltage_tolerance_v1);
237 
238 	if (of_find_property(np, "#power-domain-cells", NULL))
239 		opp_table->is_genpd = true;
240 
241 	/* Get OPP table node */
242 	opp_np = _opp_of_get_opp_desc_node(np, index);
243 	of_node_put(np);
244 
245 	if (!opp_np)
246 		return;
247 
248 	if (of_property_read_bool(opp_np, "opp-shared"))
249 		opp_table->shared_opp = OPP_TABLE_ACCESS_SHARED;
250 	else
251 		opp_table->shared_opp = OPP_TABLE_ACCESS_EXCLUSIVE;
252 
253 	opp_table->np = opp_np;
254 
255 	_opp_table_alloc_required_tables(opp_table, dev, opp_np);
256 	of_node_put(opp_np);
257 }
258 
259 void _of_clear_opp_table(struct opp_table *opp_table)
260 {
261 	_opp_table_free_required_tables(opp_table);
262 }
263 
264 /*
265  * Release all resources previously acquired with a call to
266  * _of_opp_alloc_required_opps().
267  */
268 void _of_opp_free_required_opps(struct opp_table *opp_table,
269 				struct dev_pm_opp *opp)
270 {
271 	struct dev_pm_opp **required_opps = opp->required_opps;
272 	int i;
273 
274 	if (!required_opps)
275 		return;
276 
277 	for (i = 0; i < opp_table->required_opp_count; i++) {
278 		if (!required_opps[i])
279 			break;
280 
281 		/* Put the reference back */
282 		dev_pm_opp_put(required_opps[i]);
283 	}
284 
285 	kfree(required_opps);
286 	opp->required_opps = NULL;
287 }
288 
289 /* Populate all required OPPs which are part of "required-opps" list */
290 static int _of_opp_alloc_required_opps(struct opp_table *opp_table,
291 				       struct dev_pm_opp *opp)
292 {
293 	struct dev_pm_opp **required_opps;
294 	struct opp_table *required_table;
295 	struct device_node *np;
296 	int i, ret, count = opp_table->required_opp_count;
297 
298 	if (!count)
299 		return 0;
300 
301 	required_opps = kcalloc(count, sizeof(*required_opps), GFP_KERNEL);
302 	if (!required_opps)
303 		return -ENOMEM;
304 
305 	opp->required_opps = required_opps;
306 
307 	for (i = 0; i < count; i++) {
308 		required_table = opp_table->required_opp_tables[i];
309 
310 		np = of_parse_required_opp(opp->np, i);
311 		if (unlikely(!np)) {
312 			ret = -ENODEV;
313 			goto free_required_opps;
314 		}
315 
316 		required_opps[i] = _find_opp_of_np(required_table, np);
317 		of_node_put(np);
318 
319 		if (!required_opps[i]) {
320 			pr_err("%s: Unable to find required OPP node: %pOF (%d)\n",
321 			       __func__, opp->np, i);
322 			ret = -ENODEV;
323 			goto free_required_opps;
324 		}
325 	}
326 
327 	return 0;
328 
329 free_required_opps:
330 	_of_opp_free_required_opps(opp_table, opp);
331 
332 	return ret;
333 }
334 
335 static bool _opp_is_supported(struct device *dev, struct opp_table *opp_table,
336 			      struct device_node *np)
337 {
338 	unsigned int count = opp_table->supported_hw_count;
339 	u32 version;
340 	int ret;
341 
342 	if (!opp_table->supported_hw) {
343 		/*
344 		 * In the case that no supported_hw has been set by the
345 		 * platform but there is an opp-supported-hw value set for
346 		 * an OPP then the OPP should not be enabled as there is
347 		 * no way to see if the hardware supports it.
348 		 */
349 		if (of_find_property(np, "opp-supported-hw", NULL))
350 			return false;
351 		else
352 			return true;
353 	}
354 
355 	while (count--) {
356 		ret = of_property_read_u32_index(np, "opp-supported-hw", count,
357 						 &version);
358 		if (ret) {
359 			dev_warn(dev, "%s: failed to read opp-supported-hw property at index %d: %d\n",
360 				 __func__, count, ret);
361 			return false;
362 		}
363 
364 		/* Both of these are bitwise masks of the versions */
365 		if (!(version & opp_table->supported_hw[count]))
366 			return false;
367 	}
368 
369 	return true;
370 }
371 
372 static int opp_parse_supplies(struct dev_pm_opp *opp, struct device *dev,
373 			      struct opp_table *opp_table)
374 {
375 	u32 *microvolt, *microamp = NULL;
376 	int supplies = opp_table->regulator_count, vcount, icount, ret, i, j;
377 	struct property *prop = NULL;
378 	char name[NAME_MAX];
379 
380 	/* Search for "opp-microvolt-<name>" */
381 	if (opp_table->prop_name) {
382 		snprintf(name, sizeof(name), "opp-microvolt-%s",
383 			 opp_table->prop_name);
384 		prop = of_find_property(opp->np, name, NULL);
385 	}
386 
387 	if (!prop) {
388 		/* Search for "opp-microvolt" */
389 		sprintf(name, "opp-microvolt");
390 		prop = of_find_property(opp->np, name, NULL);
391 
392 		/* Missing property isn't a problem, but an invalid entry is */
393 		if (!prop) {
394 			if (unlikely(supplies == -1)) {
395 				/* Initialize regulator_count */
396 				opp_table->regulator_count = 0;
397 				return 0;
398 			}
399 
400 			if (!supplies)
401 				return 0;
402 
403 			dev_err(dev, "%s: opp-microvolt missing although OPP managing regulators\n",
404 				__func__);
405 			return -EINVAL;
406 		}
407 	}
408 
409 	if (unlikely(supplies == -1)) {
410 		/* Initialize regulator_count */
411 		supplies = opp_table->regulator_count = 1;
412 	} else if (unlikely(!supplies)) {
413 		dev_err(dev, "%s: opp-microvolt wasn't expected\n", __func__);
414 		return -EINVAL;
415 	}
416 
417 	vcount = of_property_count_u32_elems(opp->np, name);
418 	if (vcount < 0) {
419 		dev_err(dev, "%s: Invalid %s property (%d)\n",
420 			__func__, name, vcount);
421 		return vcount;
422 	}
423 
424 	/* There can be one or three elements per supply */
425 	if (vcount != supplies && vcount != supplies * 3) {
426 		dev_err(dev, "%s: Invalid number of elements in %s property (%d) with supplies (%d)\n",
427 			__func__, name, vcount, supplies);
428 		return -EINVAL;
429 	}
430 
431 	microvolt = kmalloc_array(vcount, sizeof(*microvolt), GFP_KERNEL);
432 	if (!microvolt)
433 		return -ENOMEM;
434 
435 	ret = of_property_read_u32_array(opp->np, name, microvolt, vcount);
436 	if (ret) {
437 		dev_err(dev, "%s: error parsing %s: %d\n", __func__, name, ret);
438 		ret = -EINVAL;
439 		goto free_microvolt;
440 	}
441 
442 	/* Search for "opp-microamp-<name>" */
443 	prop = NULL;
444 	if (opp_table->prop_name) {
445 		snprintf(name, sizeof(name), "opp-microamp-%s",
446 			 opp_table->prop_name);
447 		prop = of_find_property(opp->np, name, NULL);
448 	}
449 
450 	if (!prop) {
451 		/* Search for "opp-microamp" */
452 		sprintf(name, "opp-microamp");
453 		prop = of_find_property(opp->np, name, NULL);
454 	}
455 
456 	if (prop) {
457 		icount = of_property_count_u32_elems(opp->np, name);
458 		if (icount < 0) {
459 			dev_err(dev, "%s: Invalid %s property (%d)\n", __func__,
460 				name, icount);
461 			ret = icount;
462 			goto free_microvolt;
463 		}
464 
465 		if (icount != supplies) {
466 			dev_err(dev, "%s: Invalid number of elements in %s property (%d) with supplies (%d)\n",
467 				__func__, name, icount, supplies);
468 			ret = -EINVAL;
469 			goto free_microvolt;
470 		}
471 
472 		microamp = kmalloc_array(icount, sizeof(*microamp), GFP_KERNEL);
473 		if (!microamp) {
474 			ret = -EINVAL;
475 			goto free_microvolt;
476 		}
477 
478 		ret = of_property_read_u32_array(opp->np, name, microamp,
479 						 icount);
480 		if (ret) {
481 			dev_err(dev, "%s: error parsing %s: %d\n", __func__,
482 				name, ret);
483 			ret = -EINVAL;
484 			goto free_microamp;
485 		}
486 	}
487 
488 	for (i = 0, j = 0; i < supplies; i++) {
489 		opp->supplies[i].u_volt = microvolt[j++];
490 
491 		if (vcount == supplies) {
492 			opp->supplies[i].u_volt_min = opp->supplies[i].u_volt;
493 			opp->supplies[i].u_volt_max = opp->supplies[i].u_volt;
494 		} else {
495 			opp->supplies[i].u_volt_min = microvolt[j++];
496 			opp->supplies[i].u_volt_max = microvolt[j++];
497 		}
498 
499 		if (microamp)
500 			opp->supplies[i].u_amp = microamp[i];
501 	}
502 
503 free_microamp:
504 	kfree(microamp);
505 free_microvolt:
506 	kfree(microvolt);
507 
508 	return ret;
509 }
510 
511 /**
512  * dev_pm_opp_of_remove_table() - Free OPP table entries created from static DT
513  *				  entries
514  * @dev:	device pointer used to lookup OPP table.
515  *
516  * Free OPPs created using static entries present in DT.
517  */
518 void dev_pm_opp_of_remove_table(struct device *dev)
519 {
520 	_dev_pm_opp_find_and_remove_table(dev);
521 }
522 EXPORT_SYMBOL_GPL(dev_pm_opp_of_remove_table);
523 
524 /**
525  * _opp_add_static_v2() - Allocate static OPPs (As per 'v2' DT bindings)
526  * @opp_table:	OPP table
527  * @dev:	device for which we do this operation
528  * @np:		device node
529  *
530  * This function adds an opp definition to the opp table and returns status. The
531  * opp can be controlled using dev_pm_opp_enable/disable functions and may be
532  * removed by dev_pm_opp_remove.
533  *
534  * Return:
535  * Valid OPP pointer:
536  *		On success
537  * NULL:
538  *		Duplicate OPPs (both freq and volt are same) and opp->available
539  *		OR if the OPP is not supported by hardware.
540  * ERR_PTR(-EEXIST):
541  *		Freq are same and volt are different OR
542  *		Duplicate OPPs (both freq and volt are same) and !opp->available
543  * ERR_PTR(-ENOMEM):
544  *		Memory allocation failure
545  * ERR_PTR(-EINVAL):
546  *		Failed parsing the OPP node
547  */
548 static struct dev_pm_opp *_opp_add_static_v2(struct opp_table *opp_table,
549 		struct device *dev, struct device_node *np)
550 {
551 	struct dev_pm_opp *new_opp;
552 	u64 rate = 0;
553 	u32 val;
554 	int ret;
555 	bool rate_not_available = false;
556 
557 	new_opp = _opp_allocate(opp_table);
558 	if (!new_opp)
559 		return ERR_PTR(-ENOMEM);
560 
561 	ret = of_property_read_u64(np, "opp-hz", &rate);
562 	if (ret < 0) {
563 		/* "opp-hz" is optional for devices like power domains. */
564 		if (!opp_table->is_genpd) {
565 			dev_err(dev, "%s: opp-hz not found\n", __func__);
566 			goto free_opp;
567 		}
568 
569 		rate_not_available = true;
570 	} else {
571 		/*
572 		 * Rate is defined as an unsigned long in clk API, and so
573 		 * casting explicitly to its type. Must be fixed once rate is 64
574 		 * bit guaranteed in clk API.
575 		 */
576 		new_opp->rate = (unsigned long)rate;
577 	}
578 
579 	of_property_read_u32(np, "opp-level", &new_opp->level);
580 
581 	/* Check if the OPP supports hardware's hierarchy of versions or not */
582 	if (!_opp_is_supported(dev, opp_table, np)) {
583 		dev_dbg(dev, "OPP not supported by hardware: %llu\n", rate);
584 		goto free_opp;
585 	}
586 
587 	new_opp->turbo = of_property_read_bool(np, "turbo-mode");
588 
589 	new_opp->np = np;
590 	new_opp->dynamic = false;
591 	new_opp->available = true;
592 
593 	ret = _of_opp_alloc_required_opps(opp_table, new_opp);
594 	if (ret)
595 		goto free_opp;
596 
597 	if (!of_property_read_u32(np, "clock-latency-ns", &val))
598 		new_opp->clock_latency_ns = val;
599 
600 	ret = opp_parse_supplies(new_opp, dev, opp_table);
601 	if (ret)
602 		goto free_required_opps;
603 
604 	if (opp_table->is_genpd)
605 		new_opp->pstate = pm_genpd_opp_to_performance_state(dev, new_opp);
606 
607 	ret = _opp_add(dev, new_opp, opp_table, rate_not_available);
608 	if (ret) {
609 		/* Don't return error for duplicate OPPs */
610 		if (ret == -EBUSY)
611 			ret = 0;
612 		goto free_required_opps;
613 	}
614 
615 	/* OPP to select on device suspend */
616 	if (of_property_read_bool(np, "opp-suspend")) {
617 		if (opp_table->suspend_opp) {
618 			/* Pick the OPP with higher rate as suspend OPP */
619 			if (new_opp->rate > opp_table->suspend_opp->rate) {
620 				opp_table->suspend_opp->suspend = false;
621 				new_opp->suspend = true;
622 				opp_table->suspend_opp = new_opp;
623 			}
624 		} else {
625 			new_opp->suspend = true;
626 			opp_table->suspend_opp = new_opp;
627 		}
628 	}
629 
630 	if (new_opp->clock_latency_ns > opp_table->clock_latency_ns_max)
631 		opp_table->clock_latency_ns_max = new_opp->clock_latency_ns;
632 
633 	pr_debug("%s: turbo:%d rate:%lu uv:%lu uvmin:%lu uvmax:%lu latency:%lu\n",
634 		 __func__, new_opp->turbo, new_opp->rate,
635 		 new_opp->supplies[0].u_volt, new_opp->supplies[0].u_volt_min,
636 		 new_opp->supplies[0].u_volt_max, new_opp->clock_latency_ns);
637 
638 	/*
639 	 * Notify the changes in the availability of the operable
640 	 * frequency/voltage list.
641 	 */
642 	blocking_notifier_call_chain(&opp_table->head, OPP_EVENT_ADD, new_opp);
643 	return new_opp;
644 
645 free_required_opps:
646 	_of_opp_free_required_opps(opp_table, new_opp);
647 free_opp:
648 	_opp_free(new_opp);
649 
650 	return ERR_PTR(ret);
651 }
652 
653 /* Initializes OPP tables based on new bindings */
654 static int _of_add_opp_table_v2(struct device *dev, struct opp_table *opp_table)
655 {
656 	struct device_node *np;
657 	int ret, count = 0, pstate_count = 0;
658 	struct dev_pm_opp *opp;
659 
660 	/* OPP table is already initialized for the device */
661 	mutex_lock(&opp_table->lock);
662 	if (opp_table->parsed_static_opps) {
663 		opp_table->parsed_static_opps++;
664 		mutex_unlock(&opp_table->lock);
665 		return 0;
666 	}
667 
668 	opp_table->parsed_static_opps = 1;
669 	mutex_unlock(&opp_table->lock);
670 
671 	/* We have opp-table node now, iterate over it and add OPPs */
672 	for_each_available_child_of_node(opp_table->np, np) {
673 		opp = _opp_add_static_v2(opp_table, dev, np);
674 		if (IS_ERR(opp)) {
675 			ret = PTR_ERR(opp);
676 			dev_err(dev, "%s: Failed to add OPP, %d\n", __func__,
677 				ret);
678 			of_node_put(np);
679 			goto remove_static_opp;
680 		} else if (opp) {
681 			count++;
682 		}
683 	}
684 
685 	/* There should be one of more OPP defined */
686 	if (WARN_ON(!count)) {
687 		ret = -ENOENT;
688 		goto remove_static_opp;
689 	}
690 
691 	list_for_each_entry(opp, &opp_table->opp_list, node)
692 		pstate_count += !!opp->pstate;
693 
694 	/* Either all or none of the nodes shall have performance state set */
695 	if (pstate_count && pstate_count != count) {
696 		dev_err(dev, "Not all nodes have performance state set (%d: %d)\n",
697 			count, pstate_count);
698 		ret = -ENOENT;
699 		goto remove_static_opp;
700 	}
701 
702 	if (pstate_count)
703 		opp_table->genpd_performance_state = true;
704 
705 	return 0;
706 
707 remove_static_opp:
708 	_opp_remove_all_static(opp_table);
709 
710 	return ret;
711 }
712 
713 /* Initializes OPP tables based on old-deprecated bindings */
714 static int _of_add_opp_table_v1(struct device *dev, struct opp_table *opp_table)
715 {
716 	const struct property *prop;
717 	const __be32 *val;
718 	int nr, ret = 0;
719 
720 	prop = of_find_property(dev->of_node, "operating-points", NULL);
721 	if (!prop)
722 		return -ENODEV;
723 	if (!prop->value)
724 		return -ENODATA;
725 
726 	/*
727 	 * Each OPP is a set of tuples consisting of frequency and
728 	 * voltage like <freq-kHz vol-uV>.
729 	 */
730 	nr = prop->length / sizeof(u32);
731 	if (nr % 2) {
732 		dev_err(dev, "%s: Invalid OPP table\n", __func__);
733 		return -EINVAL;
734 	}
735 
736 	val = prop->value;
737 	while (nr) {
738 		unsigned long freq = be32_to_cpup(val++) * 1000;
739 		unsigned long volt = be32_to_cpup(val++);
740 
741 		ret = _opp_add_v1(opp_table, dev, freq, volt, false);
742 		if (ret) {
743 			dev_err(dev, "%s: Failed to add OPP %ld (%d)\n",
744 				__func__, freq, ret);
745 			_opp_remove_all_static(opp_table);
746 			return ret;
747 		}
748 		nr -= 2;
749 	}
750 
751 	return ret;
752 }
753 
754 /**
755  * dev_pm_opp_of_add_table() - Initialize opp table from device tree
756  * @dev:	device pointer used to lookup OPP table.
757  *
758  * Register the initial OPP table with the OPP library for given device.
759  *
760  * Return:
761  * 0		On success OR
762  *		Duplicate OPPs (both freq and volt are same) and opp->available
763  * -EEXIST	Freq are same and volt are different OR
764  *		Duplicate OPPs (both freq and volt are same) and !opp->available
765  * -ENOMEM	Memory allocation failure
766  * -ENODEV	when 'operating-points' property is not found or is invalid data
767  *		in device node.
768  * -ENODATA	when empty 'operating-points' property is found
769  * -EINVAL	when invalid entries are found in opp-v2 table
770  */
771 int dev_pm_opp_of_add_table(struct device *dev)
772 {
773 	struct opp_table *opp_table;
774 	int ret;
775 
776 	opp_table = dev_pm_opp_get_opp_table_indexed(dev, 0);
777 	if (!opp_table)
778 		return -ENOMEM;
779 
780 	/*
781 	 * OPPs have two version of bindings now. Also try the old (v1)
782 	 * bindings for backward compatibility with older dtbs.
783 	 */
784 	if (opp_table->np)
785 		ret = _of_add_opp_table_v2(dev, opp_table);
786 	else
787 		ret = _of_add_opp_table_v1(dev, opp_table);
788 
789 	if (ret)
790 		dev_pm_opp_put_opp_table(opp_table);
791 
792 	return ret;
793 }
794 EXPORT_SYMBOL_GPL(dev_pm_opp_of_add_table);
795 
796 /**
797  * dev_pm_opp_of_add_table_indexed() - Initialize indexed opp table from device tree
798  * @dev:	device pointer used to lookup OPP table.
799  * @index:	Index number.
800  *
801  * Register the initial OPP table with the OPP library for given device only
802  * using the "operating-points-v2" property.
803  *
804  * Return:
805  * 0		On success OR
806  *		Duplicate OPPs (both freq and volt are same) and opp->available
807  * -EEXIST	Freq are same and volt are different OR
808  *		Duplicate OPPs (both freq and volt are same) and !opp->available
809  * -ENOMEM	Memory allocation failure
810  * -ENODEV	when 'operating-points' property is not found or is invalid data
811  *		in device node.
812  * -ENODATA	when empty 'operating-points' property is found
813  * -EINVAL	when invalid entries are found in opp-v2 table
814  */
815 int dev_pm_opp_of_add_table_indexed(struct device *dev, int index)
816 {
817 	struct opp_table *opp_table;
818 	int ret, count;
819 
820 	if (index) {
821 		/*
822 		 * If only one phandle is present, then the same OPP table
823 		 * applies for all index requests.
824 		 */
825 		count = of_count_phandle_with_args(dev->of_node,
826 						   "operating-points-v2", NULL);
827 		if (count == 1)
828 			index = 0;
829 	}
830 
831 	opp_table = dev_pm_opp_get_opp_table_indexed(dev, index);
832 	if (!opp_table)
833 		return -ENOMEM;
834 
835 	ret = _of_add_opp_table_v2(dev, opp_table);
836 	if (ret)
837 		dev_pm_opp_put_opp_table(opp_table);
838 
839 	return ret;
840 }
841 EXPORT_SYMBOL_GPL(dev_pm_opp_of_add_table_indexed);
842 
843 /* CPU device specific helpers */
844 
845 /**
846  * dev_pm_opp_of_cpumask_remove_table() - Removes OPP table for @cpumask
847  * @cpumask:	cpumask for which OPP table needs to be removed
848  *
849  * This removes the OPP tables for CPUs present in the @cpumask.
850  * This should be used only to remove static entries created from DT.
851  */
852 void dev_pm_opp_of_cpumask_remove_table(const struct cpumask *cpumask)
853 {
854 	_dev_pm_opp_cpumask_remove_table(cpumask, -1);
855 }
856 EXPORT_SYMBOL_GPL(dev_pm_opp_of_cpumask_remove_table);
857 
858 /**
859  * dev_pm_opp_of_cpumask_add_table() - Adds OPP table for @cpumask
860  * @cpumask:	cpumask for which OPP table needs to be added.
861  *
862  * This adds the OPP tables for CPUs present in the @cpumask.
863  */
864 int dev_pm_opp_of_cpumask_add_table(const struct cpumask *cpumask)
865 {
866 	struct device *cpu_dev;
867 	int cpu, ret;
868 
869 	if (WARN_ON(cpumask_empty(cpumask)))
870 		return -ENODEV;
871 
872 	for_each_cpu(cpu, cpumask) {
873 		cpu_dev = get_cpu_device(cpu);
874 		if (!cpu_dev) {
875 			pr_err("%s: failed to get cpu%d device\n", __func__,
876 			       cpu);
877 			ret = -ENODEV;
878 			goto remove_table;
879 		}
880 
881 		ret = dev_pm_opp_of_add_table(cpu_dev);
882 		if (ret) {
883 			/*
884 			 * OPP may get registered dynamically, don't print error
885 			 * message here.
886 			 */
887 			pr_debug("%s: couldn't find opp table for cpu:%d, %d\n",
888 				 __func__, cpu, ret);
889 
890 			goto remove_table;
891 		}
892 	}
893 
894 	return 0;
895 
896 remove_table:
897 	/* Free all other OPPs */
898 	_dev_pm_opp_cpumask_remove_table(cpumask, cpu);
899 
900 	return ret;
901 }
902 EXPORT_SYMBOL_GPL(dev_pm_opp_of_cpumask_add_table);
903 
904 /*
905  * Works only for OPP v2 bindings.
906  *
907  * Returns -ENOENT if operating-points-v2 bindings aren't supported.
908  */
909 /**
910  * dev_pm_opp_of_get_sharing_cpus() - Get cpumask of CPUs sharing OPPs with
911  *				      @cpu_dev using operating-points-v2
912  *				      bindings.
913  *
914  * @cpu_dev:	CPU device for which we do this operation
915  * @cpumask:	cpumask to update with information of sharing CPUs
916  *
917  * This updates the @cpumask with CPUs that are sharing OPPs with @cpu_dev.
918  *
919  * Returns -ENOENT if operating-points-v2 isn't present for @cpu_dev.
920  */
921 int dev_pm_opp_of_get_sharing_cpus(struct device *cpu_dev,
922 				   struct cpumask *cpumask)
923 {
924 	struct device_node *np, *tmp_np, *cpu_np;
925 	int cpu, ret = 0;
926 
927 	/* Get OPP descriptor node */
928 	np = dev_pm_opp_of_get_opp_desc_node(cpu_dev);
929 	if (!np) {
930 		dev_dbg(cpu_dev, "%s: Couldn't find opp node.\n", __func__);
931 		return -ENOENT;
932 	}
933 
934 	cpumask_set_cpu(cpu_dev->id, cpumask);
935 
936 	/* OPPs are shared ? */
937 	if (!of_property_read_bool(np, "opp-shared"))
938 		goto put_cpu_node;
939 
940 	for_each_possible_cpu(cpu) {
941 		if (cpu == cpu_dev->id)
942 			continue;
943 
944 		cpu_np = of_cpu_device_node_get(cpu);
945 		if (!cpu_np) {
946 			dev_err(cpu_dev, "%s: failed to get cpu%d node\n",
947 				__func__, cpu);
948 			ret = -ENOENT;
949 			goto put_cpu_node;
950 		}
951 
952 		/* Get OPP descriptor node */
953 		tmp_np = _opp_of_get_opp_desc_node(cpu_np, 0);
954 		of_node_put(cpu_np);
955 		if (!tmp_np) {
956 			pr_err("%pOF: Couldn't find opp node\n", cpu_np);
957 			ret = -ENOENT;
958 			goto put_cpu_node;
959 		}
960 
961 		/* CPUs are sharing opp node */
962 		if (np == tmp_np)
963 			cpumask_set_cpu(cpu, cpumask);
964 
965 		of_node_put(tmp_np);
966 	}
967 
968 put_cpu_node:
969 	of_node_put(np);
970 	return ret;
971 }
972 EXPORT_SYMBOL_GPL(dev_pm_opp_of_get_sharing_cpus);
973 
974 /**
975  * of_get_required_opp_performance_state() - Search for required OPP and return its performance state.
976  * @np: Node that contains the "required-opps" property.
977  * @index: Index of the phandle to parse.
978  *
979  * Returns the performance state of the OPP pointed out by the "required-opps"
980  * property at @index in @np.
981  *
982  * Return: Zero or positive performance state on success, otherwise negative
983  * value on errors.
984  */
985 int of_get_required_opp_performance_state(struct device_node *np, int index)
986 {
987 	struct dev_pm_opp *opp;
988 	struct device_node *required_np;
989 	struct opp_table *opp_table;
990 	int pstate = -EINVAL;
991 
992 	required_np = of_parse_required_opp(np, index);
993 	if (!required_np)
994 		return -EINVAL;
995 
996 	opp_table = _find_table_of_opp_np(required_np);
997 	if (IS_ERR(opp_table)) {
998 		pr_err("%s: Failed to find required OPP table %pOF: %ld\n",
999 		       __func__, np, PTR_ERR(opp_table));
1000 		goto put_required_np;
1001 	}
1002 
1003 	opp = _find_opp_of_np(opp_table, required_np);
1004 	if (opp) {
1005 		pstate = opp->pstate;
1006 		dev_pm_opp_put(opp);
1007 	}
1008 
1009 	dev_pm_opp_put_opp_table(opp_table);
1010 
1011 put_required_np:
1012 	of_node_put(required_np);
1013 
1014 	return pstate;
1015 }
1016 EXPORT_SYMBOL_GPL(of_get_required_opp_performance_state);
1017 
1018 /**
1019  * dev_pm_opp_get_of_node() - Gets the DT node corresponding to an opp
1020  * @opp:	opp for which DT node has to be returned for
1021  *
1022  * Return: DT node corresponding to the opp, else 0 on success.
1023  *
1024  * The caller needs to put the node with of_node_put() after using it.
1025  */
1026 struct device_node *dev_pm_opp_get_of_node(struct dev_pm_opp *opp)
1027 {
1028 	if (IS_ERR_OR_NULL(opp)) {
1029 		pr_err("%s: Invalid parameters\n", __func__);
1030 		return NULL;
1031 	}
1032 
1033 	return of_node_get(opp->np);
1034 }
1035 EXPORT_SYMBOL_GPL(dev_pm_opp_get_of_node);
1036 
1037 /*
1038  * Callback function provided to the Energy Model framework upon registration.
1039  * This computes the power estimated by @CPU at @kHz if it is the frequency
1040  * of an existing OPP, or at the frequency of the first OPP above @kHz otherwise
1041  * (see dev_pm_opp_find_freq_ceil()). This function updates @kHz to the ceiled
1042  * frequency and @mW to the associated power. The power is estimated as
1043  * P = C * V^2 * f with C being the CPU's capacitance and V and f respectively
1044  * the voltage and frequency of the OPP.
1045  *
1046  * Returns -ENODEV if the CPU device cannot be found, -EINVAL if the power
1047  * calculation failed because of missing parameters, 0 otherwise.
1048  */
1049 static int __maybe_unused _get_cpu_power(unsigned long *mW, unsigned long *kHz,
1050 					 int cpu)
1051 {
1052 	struct device *cpu_dev;
1053 	struct dev_pm_opp *opp;
1054 	struct device_node *np;
1055 	unsigned long mV, Hz;
1056 	u32 cap;
1057 	u64 tmp;
1058 	int ret;
1059 
1060 	cpu_dev = get_cpu_device(cpu);
1061 	if (!cpu_dev)
1062 		return -ENODEV;
1063 
1064 	np = of_node_get(cpu_dev->of_node);
1065 	if (!np)
1066 		return -EINVAL;
1067 
1068 	ret = of_property_read_u32(np, "dynamic-power-coefficient", &cap);
1069 	of_node_put(np);
1070 	if (ret)
1071 		return -EINVAL;
1072 
1073 	Hz = *kHz * 1000;
1074 	opp = dev_pm_opp_find_freq_ceil(cpu_dev, &Hz);
1075 	if (IS_ERR(opp))
1076 		return -EINVAL;
1077 
1078 	mV = dev_pm_opp_get_voltage(opp) / 1000;
1079 	dev_pm_opp_put(opp);
1080 	if (!mV)
1081 		return -EINVAL;
1082 
1083 	tmp = (u64)cap * mV * mV * (Hz / 1000000);
1084 	do_div(tmp, 1000000000);
1085 
1086 	*mW = (unsigned long)tmp;
1087 	*kHz = Hz / 1000;
1088 
1089 	return 0;
1090 }
1091 
1092 /**
1093  * dev_pm_opp_of_register_em() - Attempt to register an Energy Model
1094  * @cpus	: CPUs for which an Energy Model has to be registered
1095  *
1096  * This checks whether the "dynamic-power-coefficient" devicetree property has
1097  * been specified, and tries to register an Energy Model with it if it has.
1098  */
1099 void dev_pm_opp_of_register_em(struct cpumask *cpus)
1100 {
1101 	struct em_data_callback em_cb = EM_DATA_CB(_get_cpu_power);
1102 	int ret, nr_opp, cpu = cpumask_first(cpus);
1103 	struct device *cpu_dev;
1104 	struct device_node *np;
1105 	u32 cap;
1106 
1107 	cpu_dev = get_cpu_device(cpu);
1108 	if (!cpu_dev)
1109 		return;
1110 
1111 	nr_opp = dev_pm_opp_get_opp_count(cpu_dev);
1112 	if (nr_opp <= 0)
1113 		return;
1114 
1115 	np = of_node_get(cpu_dev->of_node);
1116 	if (!np)
1117 		return;
1118 
1119 	/*
1120 	 * Register an EM only if the 'dynamic-power-coefficient' property is
1121 	 * set in devicetree. It is assumed the voltage values are known if that
1122 	 * property is set since it is useless otherwise. If voltages are not
1123 	 * known, just let the EM registration fail with an error to alert the
1124 	 * user about the inconsistent configuration.
1125 	 */
1126 	ret = of_property_read_u32(np, "dynamic-power-coefficient", &cap);
1127 	of_node_put(np);
1128 	if (ret || !cap)
1129 		return;
1130 
1131 	em_register_perf_domain(cpus, nr_opp, &em_cb);
1132 }
1133 EXPORT_SYMBOL_GPL(dev_pm_opp_of_register_em);
1134