xref: /openbmc/linux/drivers/opp/core.c (revision 55fd7e02)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Generic OPP Interface
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/clk.h>
14 #include <linux/errno.h>
15 #include <linux/err.h>
16 #include <linux/slab.h>
17 #include <linux/device.h>
18 #include <linux/export.h>
19 #include <linux/pm_domain.h>
20 #include <linux/regulator/consumer.h>
21 
22 #include "opp.h"
23 
24 /*
25  * The root of the list of all opp-tables. All opp_table structures branch off
26  * from here, with each opp_table containing the list of opps it supports in
27  * various states of availability.
28  */
29 LIST_HEAD(opp_tables);
30 /* Lock to allow exclusive modification to the device and opp lists */
31 DEFINE_MUTEX(opp_table_lock);
32 
33 static struct opp_device *_find_opp_dev(const struct device *dev,
34 					struct opp_table *opp_table)
35 {
36 	struct opp_device *opp_dev;
37 
38 	list_for_each_entry(opp_dev, &opp_table->dev_list, node)
39 		if (opp_dev->dev == dev)
40 			return opp_dev;
41 
42 	return NULL;
43 }
44 
45 static struct opp_table *_find_opp_table_unlocked(struct device *dev)
46 {
47 	struct opp_table *opp_table;
48 	bool found;
49 
50 	list_for_each_entry(opp_table, &opp_tables, node) {
51 		mutex_lock(&opp_table->lock);
52 		found = !!_find_opp_dev(dev, opp_table);
53 		mutex_unlock(&opp_table->lock);
54 
55 		if (found) {
56 			_get_opp_table_kref(opp_table);
57 
58 			return opp_table;
59 		}
60 	}
61 
62 	return ERR_PTR(-ENODEV);
63 }
64 
65 /**
66  * _find_opp_table() - find opp_table struct using device pointer
67  * @dev:	device pointer used to lookup OPP table
68  *
69  * Search OPP table for one containing matching device.
70  *
71  * Return: pointer to 'struct opp_table' if found, otherwise -ENODEV or
72  * -EINVAL based on type of error.
73  *
74  * The callers must call dev_pm_opp_put_opp_table() after the table is used.
75  */
76 struct opp_table *_find_opp_table(struct device *dev)
77 {
78 	struct opp_table *opp_table;
79 
80 	if (IS_ERR_OR_NULL(dev)) {
81 		pr_err("%s: Invalid parameters\n", __func__);
82 		return ERR_PTR(-EINVAL);
83 	}
84 
85 	mutex_lock(&opp_table_lock);
86 	opp_table = _find_opp_table_unlocked(dev);
87 	mutex_unlock(&opp_table_lock);
88 
89 	return opp_table;
90 }
91 
92 /**
93  * dev_pm_opp_get_voltage() - Gets the voltage corresponding to an opp
94  * @opp:	opp for which voltage has to be returned for
95  *
96  * Return: voltage in micro volt corresponding to the opp, else
97  * return 0
98  *
99  * This is useful only for devices with single power supply.
100  */
101 unsigned long dev_pm_opp_get_voltage(struct dev_pm_opp *opp)
102 {
103 	if (IS_ERR_OR_NULL(opp)) {
104 		pr_err("%s: Invalid parameters\n", __func__);
105 		return 0;
106 	}
107 
108 	return opp->supplies[0].u_volt;
109 }
110 EXPORT_SYMBOL_GPL(dev_pm_opp_get_voltage);
111 
112 /**
113  * dev_pm_opp_get_freq() - Gets the frequency corresponding to an available opp
114  * @opp:	opp for which frequency has to be returned for
115  *
116  * Return: frequency in hertz corresponding to the opp, else
117  * return 0
118  */
119 unsigned long dev_pm_opp_get_freq(struct dev_pm_opp *opp)
120 {
121 	if (IS_ERR_OR_NULL(opp) || !opp->available) {
122 		pr_err("%s: Invalid parameters\n", __func__);
123 		return 0;
124 	}
125 
126 	return opp->rate;
127 }
128 EXPORT_SYMBOL_GPL(dev_pm_opp_get_freq);
129 
130 /**
131  * dev_pm_opp_get_level() - Gets the level corresponding to an available opp
132  * @opp:	opp for which level value has to be returned for
133  *
134  * Return: level read from device tree corresponding to the opp, else
135  * return 0.
136  */
137 unsigned int dev_pm_opp_get_level(struct dev_pm_opp *opp)
138 {
139 	if (IS_ERR_OR_NULL(opp) || !opp->available) {
140 		pr_err("%s: Invalid parameters\n", __func__);
141 		return 0;
142 	}
143 
144 	return opp->level;
145 }
146 EXPORT_SYMBOL_GPL(dev_pm_opp_get_level);
147 
148 /**
149  * dev_pm_opp_is_turbo() - Returns if opp is turbo OPP or not
150  * @opp: opp for which turbo mode is being verified
151  *
152  * Turbo OPPs are not for normal use, and can be enabled (under certain
153  * conditions) for short duration of times to finish high throughput work
154  * quickly. Running on them for longer times may overheat the chip.
155  *
156  * Return: true if opp is turbo opp, else false.
157  */
158 bool dev_pm_opp_is_turbo(struct dev_pm_opp *opp)
159 {
160 	if (IS_ERR_OR_NULL(opp) || !opp->available) {
161 		pr_err("%s: Invalid parameters\n", __func__);
162 		return false;
163 	}
164 
165 	return opp->turbo;
166 }
167 EXPORT_SYMBOL_GPL(dev_pm_opp_is_turbo);
168 
169 /**
170  * dev_pm_opp_get_max_clock_latency() - Get max clock latency in nanoseconds
171  * @dev:	device for which we do this operation
172  *
173  * Return: This function returns the max clock latency in nanoseconds.
174  */
175 unsigned long dev_pm_opp_get_max_clock_latency(struct device *dev)
176 {
177 	struct opp_table *opp_table;
178 	unsigned long clock_latency_ns;
179 
180 	opp_table = _find_opp_table(dev);
181 	if (IS_ERR(opp_table))
182 		return 0;
183 
184 	clock_latency_ns = opp_table->clock_latency_ns_max;
185 
186 	dev_pm_opp_put_opp_table(opp_table);
187 
188 	return clock_latency_ns;
189 }
190 EXPORT_SYMBOL_GPL(dev_pm_opp_get_max_clock_latency);
191 
192 /**
193  * dev_pm_opp_get_max_volt_latency() - Get max voltage latency in nanoseconds
194  * @dev: device for which we do this operation
195  *
196  * Return: This function returns the max voltage latency in nanoseconds.
197  */
198 unsigned long dev_pm_opp_get_max_volt_latency(struct device *dev)
199 {
200 	struct opp_table *opp_table;
201 	struct dev_pm_opp *opp;
202 	struct regulator *reg;
203 	unsigned long latency_ns = 0;
204 	int ret, i, count;
205 	struct {
206 		unsigned long min;
207 		unsigned long max;
208 	} *uV;
209 
210 	opp_table = _find_opp_table(dev);
211 	if (IS_ERR(opp_table))
212 		return 0;
213 
214 	/* Regulator may not be required for the device */
215 	if (!opp_table->regulators)
216 		goto put_opp_table;
217 
218 	count = opp_table->regulator_count;
219 
220 	uV = kmalloc_array(count, sizeof(*uV), GFP_KERNEL);
221 	if (!uV)
222 		goto put_opp_table;
223 
224 	mutex_lock(&opp_table->lock);
225 
226 	for (i = 0; i < count; i++) {
227 		uV[i].min = ~0;
228 		uV[i].max = 0;
229 
230 		list_for_each_entry(opp, &opp_table->opp_list, node) {
231 			if (!opp->available)
232 				continue;
233 
234 			if (opp->supplies[i].u_volt_min < uV[i].min)
235 				uV[i].min = opp->supplies[i].u_volt_min;
236 			if (opp->supplies[i].u_volt_max > uV[i].max)
237 				uV[i].max = opp->supplies[i].u_volt_max;
238 		}
239 	}
240 
241 	mutex_unlock(&opp_table->lock);
242 
243 	/*
244 	 * The caller needs to ensure that opp_table (and hence the regulator)
245 	 * isn't freed, while we are executing this routine.
246 	 */
247 	for (i = 0; i < count; i++) {
248 		reg = opp_table->regulators[i];
249 		ret = regulator_set_voltage_time(reg, uV[i].min, uV[i].max);
250 		if (ret > 0)
251 			latency_ns += ret * 1000;
252 	}
253 
254 	kfree(uV);
255 put_opp_table:
256 	dev_pm_opp_put_opp_table(opp_table);
257 
258 	return latency_ns;
259 }
260 EXPORT_SYMBOL_GPL(dev_pm_opp_get_max_volt_latency);
261 
262 /**
263  * dev_pm_opp_get_max_transition_latency() - Get max transition latency in
264  *					     nanoseconds
265  * @dev: device for which we do this operation
266  *
267  * Return: This function returns the max transition latency, in nanoseconds, to
268  * switch from one OPP to other.
269  */
270 unsigned long dev_pm_opp_get_max_transition_latency(struct device *dev)
271 {
272 	return dev_pm_opp_get_max_volt_latency(dev) +
273 		dev_pm_opp_get_max_clock_latency(dev);
274 }
275 EXPORT_SYMBOL_GPL(dev_pm_opp_get_max_transition_latency);
276 
277 /**
278  * dev_pm_opp_get_suspend_opp_freq() - Get frequency of suspend opp in Hz
279  * @dev:	device for which we do this operation
280  *
281  * Return: This function returns the frequency of the OPP marked as suspend_opp
282  * if one is available, else returns 0;
283  */
284 unsigned long dev_pm_opp_get_suspend_opp_freq(struct device *dev)
285 {
286 	struct opp_table *opp_table;
287 	unsigned long freq = 0;
288 
289 	opp_table = _find_opp_table(dev);
290 	if (IS_ERR(opp_table))
291 		return 0;
292 
293 	if (opp_table->suspend_opp && opp_table->suspend_opp->available)
294 		freq = dev_pm_opp_get_freq(opp_table->suspend_opp);
295 
296 	dev_pm_opp_put_opp_table(opp_table);
297 
298 	return freq;
299 }
300 EXPORT_SYMBOL_GPL(dev_pm_opp_get_suspend_opp_freq);
301 
302 int _get_opp_count(struct opp_table *opp_table)
303 {
304 	struct dev_pm_opp *opp;
305 	int count = 0;
306 
307 	mutex_lock(&opp_table->lock);
308 
309 	list_for_each_entry(opp, &opp_table->opp_list, node) {
310 		if (opp->available)
311 			count++;
312 	}
313 
314 	mutex_unlock(&opp_table->lock);
315 
316 	return count;
317 }
318 
319 /**
320  * dev_pm_opp_get_opp_count() - Get number of opps available in the opp table
321  * @dev:	device for which we do this operation
322  *
323  * Return: This function returns the number of available opps if there are any,
324  * else returns 0 if none or the corresponding error value.
325  */
326 int dev_pm_opp_get_opp_count(struct device *dev)
327 {
328 	struct opp_table *opp_table;
329 	int count;
330 
331 	opp_table = _find_opp_table(dev);
332 	if (IS_ERR(opp_table)) {
333 		count = PTR_ERR(opp_table);
334 		dev_dbg(dev, "%s: OPP table not found (%d)\n",
335 			__func__, count);
336 		return count;
337 	}
338 
339 	count = _get_opp_count(opp_table);
340 	dev_pm_opp_put_opp_table(opp_table);
341 
342 	return count;
343 }
344 EXPORT_SYMBOL_GPL(dev_pm_opp_get_opp_count);
345 
346 /**
347  * dev_pm_opp_find_freq_exact() - search for an exact frequency
348  * @dev:		device for which we do this operation
349  * @freq:		frequency to search for
350  * @available:		true/false - match for available opp
351  *
352  * Return: Searches for exact match in the opp table and returns pointer to the
353  * matching opp if found, else returns ERR_PTR in case of error and should
354  * be handled using IS_ERR. Error return values can be:
355  * EINVAL:	for bad pointer
356  * ERANGE:	no match found for search
357  * ENODEV:	if device not found in list of registered devices
358  *
359  * Note: available is a modifier for the search. if available=true, then the
360  * match is for exact matching frequency and is available in the stored OPP
361  * table. if false, the match is for exact frequency which is not available.
362  *
363  * This provides a mechanism to enable an opp which is not available currently
364  * or the opposite as well.
365  *
366  * The callers are required to call dev_pm_opp_put() for the returned OPP after
367  * use.
368  */
369 struct dev_pm_opp *dev_pm_opp_find_freq_exact(struct device *dev,
370 					      unsigned long freq,
371 					      bool available)
372 {
373 	struct opp_table *opp_table;
374 	struct dev_pm_opp *temp_opp, *opp = ERR_PTR(-ERANGE);
375 
376 	opp_table = _find_opp_table(dev);
377 	if (IS_ERR(opp_table)) {
378 		int r = PTR_ERR(opp_table);
379 
380 		dev_err(dev, "%s: OPP table not found (%d)\n", __func__, r);
381 		return ERR_PTR(r);
382 	}
383 
384 	mutex_lock(&opp_table->lock);
385 
386 	list_for_each_entry(temp_opp, &opp_table->opp_list, node) {
387 		if (temp_opp->available == available &&
388 				temp_opp->rate == freq) {
389 			opp = temp_opp;
390 
391 			/* Increment the reference count of OPP */
392 			dev_pm_opp_get(opp);
393 			break;
394 		}
395 	}
396 
397 	mutex_unlock(&opp_table->lock);
398 	dev_pm_opp_put_opp_table(opp_table);
399 
400 	return opp;
401 }
402 EXPORT_SYMBOL_GPL(dev_pm_opp_find_freq_exact);
403 
404 /**
405  * dev_pm_opp_find_level_exact() - search for an exact level
406  * @dev:		device for which we do this operation
407  * @level:		level to search for
408  *
409  * Return: Searches for exact match in the opp table and returns pointer to the
410  * matching opp if found, else returns ERR_PTR in case of error and should
411  * be handled using IS_ERR. Error return values can be:
412  * EINVAL:	for bad pointer
413  * ERANGE:	no match found for search
414  * ENODEV:	if device not found in list of registered devices
415  *
416  * The callers are required to call dev_pm_opp_put() for the returned OPP after
417  * use.
418  */
419 struct dev_pm_opp *dev_pm_opp_find_level_exact(struct device *dev,
420 					       unsigned int level)
421 {
422 	struct opp_table *opp_table;
423 	struct dev_pm_opp *temp_opp, *opp = ERR_PTR(-ERANGE);
424 
425 	opp_table = _find_opp_table(dev);
426 	if (IS_ERR(opp_table)) {
427 		int r = PTR_ERR(opp_table);
428 
429 		dev_err(dev, "%s: OPP table not found (%d)\n", __func__, r);
430 		return ERR_PTR(r);
431 	}
432 
433 	mutex_lock(&opp_table->lock);
434 
435 	list_for_each_entry(temp_opp, &opp_table->opp_list, node) {
436 		if (temp_opp->level == level) {
437 			opp = temp_opp;
438 
439 			/* Increment the reference count of OPP */
440 			dev_pm_opp_get(opp);
441 			break;
442 		}
443 	}
444 
445 	mutex_unlock(&opp_table->lock);
446 	dev_pm_opp_put_opp_table(opp_table);
447 
448 	return opp;
449 }
450 EXPORT_SYMBOL_GPL(dev_pm_opp_find_level_exact);
451 
452 static noinline struct dev_pm_opp *_find_freq_ceil(struct opp_table *opp_table,
453 						   unsigned long *freq)
454 {
455 	struct dev_pm_opp *temp_opp, *opp = ERR_PTR(-ERANGE);
456 
457 	mutex_lock(&opp_table->lock);
458 
459 	list_for_each_entry(temp_opp, &opp_table->opp_list, node) {
460 		if (temp_opp->available && temp_opp->rate >= *freq) {
461 			opp = temp_opp;
462 			*freq = opp->rate;
463 
464 			/* Increment the reference count of OPP */
465 			dev_pm_opp_get(opp);
466 			break;
467 		}
468 	}
469 
470 	mutex_unlock(&opp_table->lock);
471 
472 	return opp;
473 }
474 
475 /**
476  * dev_pm_opp_find_freq_ceil() - Search for an rounded ceil freq
477  * @dev:	device for which we do this operation
478  * @freq:	Start frequency
479  *
480  * Search for the matching ceil *available* OPP from a starting freq
481  * for a device.
482  *
483  * Return: matching *opp and refreshes *freq accordingly, else returns
484  * ERR_PTR in case of error and should be handled using IS_ERR. Error return
485  * values can be:
486  * EINVAL:	for bad pointer
487  * ERANGE:	no match found for search
488  * ENODEV:	if device not found in list of registered devices
489  *
490  * The callers are required to call dev_pm_opp_put() for the returned OPP after
491  * use.
492  */
493 struct dev_pm_opp *dev_pm_opp_find_freq_ceil(struct device *dev,
494 					     unsigned long *freq)
495 {
496 	struct opp_table *opp_table;
497 	struct dev_pm_opp *opp;
498 
499 	if (!dev || !freq) {
500 		dev_err(dev, "%s: Invalid argument freq=%p\n", __func__, freq);
501 		return ERR_PTR(-EINVAL);
502 	}
503 
504 	opp_table = _find_opp_table(dev);
505 	if (IS_ERR(opp_table))
506 		return ERR_CAST(opp_table);
507 
508 	opp = _find_freq_ceil(opp_table, freq);
509 
510 	dev_pm_opp_put_opp_table(opp_table);
511 
512 	return opp;
513 }
514 EXPORT_SYMBOL_GPL(dev_pm_opp_find_freq_ceil);
515 
516 /**
517  * dev_pm_opp_find_freq_floor() - Search for a rounded floor freq
518  * @dev:	device for which we do this operation
519  * @freq:	Start frequency
520  *
521  * Search for the matching floor *available* OPP from a starting freq
522  * for a device.
523  *
524  * Return: matching *opp and refreshes *freq accordingly, else returns
525  * ERR_PTR in case of error and should be handled using IS_ERR. Error return
526  * values can be:
527  * EINVAL:	for bad pointer
528  * ERANGE:	no match found for search
529  * ENODEV:	if device not found in list of registered devices
530  *
531  * The callers are required to call dev_pm_opp_put() for the returned OPP after
532  * use.
533  */
534 struct dev_pm_opp *dev_pm_opp_find_freq_floor(struct device *dev,
535 					      unsigned long *freq)
536 {
537 	struct opp_table *opp_table;
538 	struct dev_pm_opp *temp_opp, *opp = ERR_PTR(-ERANGE);
539 
540 	if (!dev || !freq) {
541 		dev_err(dev, "%s: Invalid argument freq=%p\n", __func__, freq);
542 		return ERR_PTR(-EINVAL);
543 	}
544 
545 	opp_table = _find_opp_table(dev);
546 	if (IS_ERR(opp_table))
547 		return ERR_CAST(opp_table);
548 
549 	mutex_lock(&opp_table->lock);
550 
551 	list_for_each_entry(temp_opp, &opp_table->opp_list, node) {
552 		if (temp_opp->available) {
553 			/* go to the next node, before choosing prev */
554 			if (temp_opp->rate > *freq)
555 				break;
556 			else
557 				opp = temp_opp;
558 		}
559 	}
560 
561 	/* Increment the reference count of OPP */
562 	if (!IS_ERR(opp))
563 		dev_pm_opp_get(opp);
564 	mutex_unlock(&opp_table->lock);
565 	dev_pm_opp_put_opp_table(opp_table);
566 
567 	if (!IS_ERR(opp))
568 		*freq = opp->rate;
569 
570 	return opp;
571 }
572 EXPORT_SYMBOL_GPL(dev_pm_opp_find_freq_floor);
573 
574 /**
575  * dev_pm_opp_find_freq_ceil_by_volt() - Find OPP with highest frequency for
576  *					 target voltage.
577  * @dev:	Device for which we do this operation.
578  * @u_volt:	Target voltage.
579  *
580  * Search for OPP with highest (ceil) frequency and has voltage <= u_volt.
581  *
582  * Return: matching *opp, else returns ERR_PTR in case of error which should be
583  * handled using IS_ERR.
584  *
585  * Error return values can be:
586  * EINVAL:	bad parameters
587  *
588  * The callers are required to call dev_pm_opp_put() for the returned OPP after
589  * use.
590  */
591 struct dev_pm_opp *dev_pm_opp_find_freq_ceil_by_volt(struct device *dev,
592 						     unsigned long u_volt)
593 {
594 	struct opp_table *opp_table;
595 	struct dev_pm_opp *temp_opp, *opp = ERR_PTR(-ERANGE);
596 
597 	if (!dev || !u_volt) {
598 		dev_err(dev, "%s: Invalid argument volt=%lu\n", __func__,
599 			u_volt);
600 		return ERR_PTR(-EINVAL);
601 	}
602 
603 	opp_table = _find_opp_table(dev);
604 	if (IS_ERR(opp_table))
605 		return ERR_CAST(opp_table);
606 
607 	mutex_lock(&opp_table->lock);
608 
609 	list_for_each_entry(temp_opp, &opp_table->opp_list, node) {
610 		if (temp_opp->available) {
611 			if (temp_opp->supplies[0].u_volt > u_volt)
612 				break;
613 			opp = temp_opp;
614 		}
615 	}
616 
617 	/* Increment the reference count of OPP */
618 	if (!IS_ERR(opp))
619 		dev_pm_opp_get(opp);
620 
621 	mutex_unlock(&opp_table->lock);
622 	dev_pm_opp_put_opp_table(opp_table);
623 
624 	return opp;
625 }
626 EXPORT_SYMBOL_GPL(dev_pm_opp_find_freq_ceil_by_volt);
627 
628 static int _set_opp_voltage(struct device *dev, struct regulator *reg,
629 			    struct dev_pm_opp_supply *supply)
630 {
631 	int ret;
632 
633 	/* Regulator not available for device */
634 	if (IS_ERR(reg)) {
635 		dev_dbg(dev, "%s: regulator not available: %ld\n", __func__,
636 			PTR_ERR(reg));
637 		return 0;
638 	}
639 
640 	dev_dbg(dev, "%s: voltages (mV): %lu %lu %lu\n", __func__,
641 		supply->u_volt_min, supply->u_volt, supply->u_volt_max);
642 
643 	ret = regulator_set_voltage_triplet(reg, supply->u_volt_min,
644 					    supply->u_volt, supply->u_volt_max);
645 	if (ret)
646 		dev_err(dev, "%s: failed to set voltage (%lu %lu %lu mV): %d\n",
647 			__func__, supply->u_volt_min, supply->u_volt,
648 			supply->u_volt_max, ret);
649 
650 	return ret;
651 }
652 
653 static inline int _generic_set_opp_clk_only(struct device *dev, struct clk *clk,
654 					    unsigned long freq)
655 {
656 	int ret;
657 
658 	ret = clk_set_rate(clk, freq);
659 	if (ret) {
660 		dev_err(dev, "%s: failed to set clock rate: %d\n", __func__,
661 			ret);
662 	}
663 
664 	return ret;
665 }
666 
667 static int _generic_set_opp_regulator(struct opp_table *opp_table,
668 				      struct device *dev,
669 				      unsigned long old_freq,
670 				      unsigned long freq,
671 				      struct dev_pm_opp_supply *old_supply,
672 				      struct dev_pm_opp_supply *new_supply)
673 {
674 	struct regulator *reg = opp_table->regulators[0];
675 	int ret;
676 
677 	/* This function only supports single regulator per device */
678 	if (WARN_ON(opp_table->regulator_count > 1)) {
679 		dev_err(dev, "multiple regulators are not supported\n");
680 		return -EINVAL;
681 	}
682 
683 	/* Scaling up? Scale voltage before frequency */
684 	if (freq >= old_freq) {
685 		ret = _set_opp_voltage(dev, reg, new_supply);
686 		if (ret)
687 			goto restore_voltage;
688 	}
689 
690 	/* Change frequency */
691 	ret = _generic_set_opp_clk_only(dev, opp_table->clk, freq);
692 	if (ret)
693 		goto restore_voltage;
694 
695 	/* Scaling down? Scale voltage after frequency */
696 	if (freq < old_freq) {
697 		ret = _set_opp_voltage(dev, reg, new_supply);
698 		if (ret)
699 			goto restore_freq;
700 	}
701 
702 	/*
703 	 * Enable the regulator after setting its voltages, otherwise it breaks
704 	 * some boot-enabled regulators.
705 	 */
706 	if (unlikely(!opp_table->regulator_enabled)) {
707 		ret = regulator_enable(reg);
708 		if (ret < 0)
709 			dev_warn(dev, "Failed to enable regulator: %d", ret);
710 		else
711 			opp_table->regulator_enabled = true;
712 	}
713 
714 	return 0;
715 
716 restore_freq:
717 	if (_generic_set_opp_clk_only(dev, opp_table->clk, old_freq))
718 		dev_err(dev, "%s: failed to restore old-freq (%lu Hz)\n",
719 			__func__, old_freq);
720 restore_voltage:
721 	/* This shouldn't harm even if the voltages weren't updated earlier */
722 	if (old_supply)
723 		_set_opp_voltage(dev, reg, old_supply);
724 
725 	return ret;
726 }
727 
728 static int _set_opp_bw(const struct opp_table *opp_table,
729 		       struct dev_pm_opp *opp, struct device *dev, bool remove)
730 {
731 	u32 avg, peak;
732 	int i, ret;
733 
734 	if (!opp_table->paths)
735 		return 0;
736 
737 	for (i = 0; i < opp_table->path_count; i++) {
738 		if (remove) {
739 			avg = 0;
740 			peak = 0;
741 		} else {
742 			avg = opp->bandwidth[i].avg;
743 			peak = opp->bandwidth[i].peak;
744 		}
745 		ret = icc_set_bw(opp_table->paths[i], avg, peak);
746 		if (ret) {
747 			dev_err(dev, "Failed to %s bandwidth[%d]: %d\n",
748 				remove ? "remove" : "set", i, ret);
749 			return ret;
750 		}
751 	}
752 
753 	return 0;
754 }
755 
756 static int _set_opp_custom(const struct opp_table *opp_table,
757 			   struct device *dev, unsigned long old_freq,
758 			   unsigned long freq,
759 			   struct dev_pm_opp_supply *old_supply,
760 			   struct dev_pm_opp_supply *new_supply)
761 {
762 	struct dev_pm_set_opp_data *data;
763 	int size;
764 
765 	data = opp_table->set_opp_data;
766 	data->regulators = opp_table->regulators;
767 	data->regulator_count = opp_table->regulator_count;
768 	data->clk = opp_table->clk;
769 	data->dev = dev;
770 
771 	data->old_opp.rate = old_freq;
772 	size = sizeof(*old_supply) * opp_table->regulator_count;
773 	if (!old_supply)
774 		memset(data->old_opp.supplies, 0, size);
775 	else
776 		memcpy(data->old_opp.supplies, old_supply, size);
777 
778 	data->new_opp.rate = freq;
779 	memcpy(data->new_opp.supplies, new_supply, size);
780 
781 	return opp_table->set_opp(data);
782 }
783 
784 /* This is only called for PM domain for now */
785 static int _set_required_opps(struct device *dev,
786 			      struct opp_table *opp_table,
787 			      struct dev_pm_opp *opp)
788 {
789 	struct opp_table **required_opp_tables = opp_table->required_opp_tables;
790 	struct device **genpd_virt_devs = opp_table->genpd_virt_devs;
791 	unsigned int pstate;
792 	int i, ret = 0;
793 
794 	if (!required_opp_tables)
795 		return 0;
796 
797 	/* Single genpd case */
798 	if (!genpd_virt_devs) {
799 		pstate = likely(opp) ? opp->required_opps[0]->pstate : 0;
800 		ret = dev_pm_genpd_set_performance_state(dev, pstate);
801 		if (ret) {
802 			dev_err(dev, "Failed to set performance state of %s: %d (%d)\n",
803 				dev_name(dev), pstate, ret);
804 		}
805 		return ret;
806 	}
807 
808 	/* Multiple genpd case */
809 
810 	/*
811 	 * Acquire genpd_virt_dev_lock to make sure we don't use a genpd_dev
812 	 * after it is freed from another thread.
813 	 */
814 	mutex_lock(&opp_table->genpd_virt_dev_lock);
815 
816 	for (i = 0; i < opp_table->required_opp_count; i++) {
817 		pstate = likely(opp) ? opp->required_opps[i]->pstate : 0;
818 
819 		if (!genpd_virt_devs[i])
820 			continue;
821 
822 		ret = dev_pm_genpd_set_performance_state(genpd_virt_devs[i], pstate);
823 		if (ret) {
824 			dev_err(dev, "Failed to set performance rate of %s: %d (%d)\n",
825 				dev_name(genpd_virt_devs[i]), pstate, ret);
826 			break;
827 		}
828 	}
829 	mutex_unlock(&opp_table->genpd_virt_dev_lock);
830 
831 	return ret;
832 }
833 
834 /**
835  * dev_pm_opp_set_rate() - Configure new OPP based on frequency
836  * @dev:	 device for which we do this operation
837  * @target_freq: frequency to achieve
838  *
839  * This configures the power-supplies to the levels specified by the OPP
840  * corresponding to the target_freq, and programs the clock to a value <=
841  * target_freq, as rounded by clk_round_rate(). Device wanting to run at fmax
842  * provided by the opp, should have already rounded to the target OPP's
843  * frequency.
844  */
845 int dev_pm_opp_set_rate(struct device *dev, unsigned long target_freq)
846 {
847 	struct opp_table *opp_table;
848 	unsigned long freq, old_freq, temp_freq;
849 	struct dev_pm_opp *old_opp, *opp;
850 	struct clk *clk;
851 	int ret;
852 
853 	opp_table = _find_opp_table(dev);
854 	if (IS_ERR(opp_table)) {
855 		dev_err(dev, "%s: device opp doesn't exist\n", __func__);
856 		return PTR_ERR(opp_table);
857 	}
858 
859 	if (unlikely(!target_freq)) {
860 		/*
861 		 * Some drivers need to support cases where some platforms may
862 		 * have OPP table for the device, while others don't and
863 		 * opp_set_rate() just needs to behave like clk_set_rate().
864 		 */
865 		if (!_get_opp_count(opp_table))
866 			return 0;
867 
868 		if (!opp_table->required_opp_tables && !opp_table->regulators &&
869 		    !opp_table->paths) {
870 			dev_err(dev, "target frequency can't be 0\n");
871 			ret = -EINVAL;
872 			goto put_opp_table;
873 		}
874 
875 		ret = _set_opp_bw(opp_table, NULL, dev, true);
876 		if (ret)
877 			return ret;
878 
879 		if (opp_table->regulator_enabled) {
880 			regulator_disable(opp_table->regulators[0]);
881 			opp_table->regulator_enabled = false;
882 		}
883 
884 		ret = _set_required_opps(dev, opp_table, NULL);
885 		goto put_opp_table;
886 	}
887 
888 	clk = opp_table->clk;
889 	if (IS_ERR(clk)) {
890 		dev_err(dev, "%s: No clock available for the device\n",
891 			__func__);
892 		ret = PTR_ERR(clk);
893 		goto put_opp_table;
894 	}
895 
896 	freq = clk_round_rate(clk, target_freq);
897 	if ((long)freq <= 0)
898 		freq = target_freq;
899 
900 	old_freq = clk_get_rate(clk);
901 
902 	/* Return early if nothing to do */
903 	if (old_freq == freq) {
904 		dev_dbg(dev, "%s: old/new frequencies (%lu Hz) are same, nothing to do\n",
905 			__func__, freq);
906 		ret = 0;
907 		goto put_opp_table;
908 	}
909 
910 	/*
911 	 * For IO devices which require an OPP on some platforms/SoCs
912 	 * while just needing to scale the clock on some others
913 	 * we look for empty OPP tables with just a clock handle and
914 	 * scale only the clk. This makes dev_pm_opp_set_rate()
915 	 * equivalent to a clk_set_rate()
916 	 */
917 	if (!_get_opp_count(opp_table)) {
918 		ret = _generic_set_opp_clk_only(dev, clk, freq);
919 		goto put_opp_table;
920 	}
921 
922 	temp_freq = old_freq;
923 	old_opp = _find_freq_ceil(opp_table, &temp_freq);
924 	if (IS_ERR(old_opp)) {
925 		dev_err(dev, "%s: failed to find current OPP for freq %lu (%ld)\n",
926 			__func__, old_freq, PTR_ERR(old_opp));
927 	}
928 
929 	temp_freq = freq;
930 	opp = _find_freq_ceil(opp_table, &temp_freq);
931 	if (IS_ERR(opp)) {
932 		ret = PTR_ERR(opp);
933 		dev_err(dev, "%s: failed to find OPP for freq %lu (%d)\n",
934 			__func__, freq, ret);
935 		goto put_old_opp;
936 	}
937 
938 	dev_dbg(dev, "%s: switching OPP: %lu Hz --> %lu Hz\n", __func__,
939 		old_freq, freq);
940 
941 	/* Scaling up? Configure required OPPs before frequency */
942 	if (freq >= old_freq) {
943 		ret = _set_required_opps(dev, opp_table, opp);
944 		if (ret)
945 			goto put_opp;
946 	}
947 
948 	if (opp_table->set_opp) {
949 		ret = _set_opp_custom(opp_table, dev, old_freq, freq,
950 				      IS_ERR(old_opp) ? NULL : old_opp->supplies,
951 				      opp->supplies);
952 	} else if (opp_table->regulators) {
953 		ret = _generic_set_opp_regulator(opp_table, dev, old_freq, freq,
954 						 IS_ERR(old_opp) ? NULL : old_opp->supplies,
955 						 opp->supplies);
956 	} else {
957 		/* Only frequency scaling */
958 		ret = _generic_set_opp_clk_only(dev, clk, freq);
959 	}
960 
961 	/* Scaling down? Configure required OPPs after frequency */
962 	if (!ret && freq < old_freq) {
963 		ret = _set_required_opps(dev, opp_table, opp);
964 		if (ret)
965 			dev_err(dev, "Failed to set required opps: %d\n", ret);
966 	}
967 
968 	if (!ret)
969 		ret = _set_opp_bw(opp_table, opp, dev, false);
970 
971 put_opp:
972 	dev_pm_opp_put(opp);
973 put_old_opp:
974 	if (!IS_ERR(old_opp))
975 		dev_pm_opp_put(old_opp);
976 put_opp_table:
977 	dev_pm_opp_put_opp_table(opp_table);
978 	return ret;
979 }
980 EXPORT_SYMBOL_GPL(dev_pm_opp_set_rate);
981 
982 /* OPP-dev Helpers */
983 static void _remove_opp_dev(struct opp_device *opp_dev,
984 			    struct opp_table *opp_table)
985 {
986 	opp_debug_unregister(opp_dev, opp_table);
987 	list_del(&opp_dev->node);
988 	kfree(opp_dev);
989 }
990 
991 static struct opp_device *_add_opp_dev_unlocked(const struct device *dev,
992 						struct opp_table *opp_table)
993 {
994 	struct opp_device *opp_dev;
995 
996 	opp_dev = kzalloc(sizeof(*opp_dev), GFP_KERNEL);
997 	if (!opp_dev)
998 		return NULL;
999 
1000 	/* Initialize opp-dev */
1001 	opp_dev->dev = dev;
1002 
1003 	list_add(&opp_dev->node, &opp_table->dev_list);
1004 
1005 	/* Create debugfs entries for the opp_table */
1006 	opp_debug_register(opp_dev, opp_table);
1007 
1008 	return opp_dev;
1009 }
1010 
1011 struct opp_device *_add_opp_dev(const struct device *dev,
1012 				struct opp_table *opp_table)
1013 {
1014 	struct opp_device *opp_dev;
1015 
1016 	mutex_lock(&opp_table->lock);
1017 	opp_dev = _add_opp_dev_unlocked(dev, opp_table);
1018 	mutex_unlock(&opp_table->lock);
1019 
1020 	return opp_dev;
1021 }
1022 
1023 static struct opp_table *_allocate_opp_table(struct device *dev, int index)
1024 {
1025 	struct opp_table *opp_table;
1026 	struct opp_device *opp_dev;
1027 	int ret;
1028 
1029 	/*
1030 	 * Allocate a new OPP table. In the infrequent case where a new
1031 	 * device is needed to be added, we pay this penalty.
1032 	 */
1033 	opp_table = kzalloc(sizeof(*opp_table), GFP_KERNEL);
1034 	if (!opp_table)
1035 		return NULL;
1036 
1037 	mutex_init(&opp_table->lock);
1038 	mutex_init(&opp_table->genpd_virt_dev_lock);
1039 	INIT_LIST_HEAD(&opp_table->dev_list);
1040 
1041 	/* Mark regulator count uninitialized */
1042 	opp_table->regulator_count = -1;
1043 
1044 	opp_dev = _add_opp_dev(dev, opp_table);
1045 	if (!opp_dev) {
1046 		kfree(opp_table);
1047 		return NULL;
1048 	}
1049 
1050 	_of_init_opp_table(opp_table, dev, index);
1051 
1052 	/* Find clk for the device */
1053 	opp_table->clk = clk_get(dev, NULL);
1054 	if (IS_ERR(opp_table->clk)) {
1055 		ret = PTR_ERR(opp_table->clk);
1056 		if (ret != -EPROBE_DEFER)
1057 			dev_dbg(dev, "%s: Couldn't find clock: %d\n", __func__,
1058 				ret);
1059 	}
1060 
1061 	/* Find interconnect path(s) for the device */
1062 	ret = dev_pm_opp_of_find_icc_paths(dev, opp_table);
1063 	if (ret)
1064 		dev_warn(dev, "%s: Error finding interconnect paths: %d\n",
1065 			 __func__, ret);
1066 
1067 	BLOCKING_INIT_NOTIFIER_HEAD(&opp_table->head);
1068 	INIT_LIST_HEAD(&opp_table->opp_list);
1069 	kref_init(&opp_table->kref);
1070 
1071 	/* Secure the device table modification */
1072 	list_add(&opp_table->node, &opp_tables);
1073 	return opp_table;
1074 }
1075 
1076 void _get_opp_table_kref(struct opp_table *opp_table)
1077 {
1078 	kref_get(&opp_table->kref);
1079 }
1080 
1081 static struct opp_table *_opp_get_opp_table(struct device *dev, int index)
1082 {
1083 	struct opp_table *opp_table;
1084 
1085 	/* Hold our table modification lock here */
1086 	mutex_lock(&opp_table_lock);
1087 
1088 	opp_table = _find_opp_table_unlocked(dev);
1089 	if (!IS_ERR(opp_table))
1090 		goto unlock;
1091 
1092 	opp_table = _managed_opp(dev, index);
1093 	if (opp_table) {
1094 		if (!_add_opp_dev_unlocked(dev, opp_table)) {
1095 			dev_pm_opp_put_opp_table(opp_table);
1096 			opp_table = NULL;
1097 		}
1098 		goto unlock;
1099 	}
1100 
1101 	opp_table = _allocate_opp_table(dev, index);
1102 
1103 unlock:
1104 	mutex_unlock(&opp_table_lock);
1105 
1106 	return opp_table;
1107 }
1108 
1109 struct opp_table *dev_pm_opp_get_opp_table(struct device *dev)
1110 {
1111 	return _opp_get_opp_table(dev, 0);
1112 }
1113 EXPORT_SYMBOL_GPL(dev_pm_opp_get_opp_table);
1114 
1115 struct opp_table *dev_pm_opp_get_opp_table_indexed(struct device *dev,
1116 						   int index)
1117 {
1118 	return _opp_get_opp_table(dev, index);
1119 }
1120 
1121 static void _opp_table_kref_release(struct kref *kref)
1122 {
1123 	struct opp_table *opp_table = container_of(kref, struct opp_table, kref);
1124 	struct opp_device *opp_dev, *temp;
1125 	int i;
1126 
1127 	_of_clear_opp_table(opp_table);
1128 
1129 	/* Release clk */
1130 	if (!IS_ERR(opp_table->clk))
1131 		clk_put(opp_table->clk);
1132 
1133 	if (opp_table->paths) {
1134 		for (i = 0; i < opp_table->path_count; i++)
1135 			icc_put(opp_table->paths[i]);
1136 		kfree(opp_table->paths);
1137 	}
1138 
1139 	WARN_ON(!list_empty(&opp_table->opp_list));
1140 
1141 	list_for_each_entry_safe(opp_dev, temp, &opp_table->dev_list, node) {
1142 		/*
1143 		 * The OPP table is getting removed, drop the performance state
1144 		 * constraints.
1145 		 */
1146 		if (opp_table->genpd_performance_state)
1147 			dev_pm_genpd_set_performance_state((struct device *)(opp_dev->dev), 0);
1148 
1149 		_remove_opp_dev(opp_dev, opp_table);
1150 	}
1151 
1152 	mutex_destroy(&opp_table->genpd_virt_dev_lock);
1153 	mutex_destroy(&opp_table->lock);
1154 	list_del(&opp_table->node);
1155 	kfree(opp_table);
1156 
1157 	mutex_unlock(&opp_table_lock);
1158 }
1159 
1160 void dev_pm_opp_put_opp_table(struct opp_table *opp_table)
1161 {
1162 	kref_put_mutex(&opp_table->kref, _opp_table_kref_release,
1163 		       &opp_table_lock);
1164 }
1165 EXPORT_SYMBOL_GPL(dev_pm_opp_put_opp_table);
1166 
1167 void _opp_free(struct dev_pm_opp *opp)
1168 {
1169 	kfree(opp);
1170 }
1171 
1172 static void _opp_kref_release(struct dev_pm_opp *opp,
1173 			      struct opp_table *opp_table)
1174 {
1175 	/*
1176 	 * Notify the changes in the availability of the operable
1177 	 * frequency/voltage list.
1178 	 */
1179 	blocking_notifier_call_chain(&opp_table->head, OPP_EVENT_REMOVE, opp);
1180 	_of_opp_free_required_opps(opp_table, opp);
1181 	opp_debug_remove_one(opp);
1182 	list_del(&opp->node);
1183 	kfree(opp);
1184 }
1185 
1186 static void _opp_kref_release_unlocked(struct kref *kref)
1187 {
1188 	struct dev_pm_opp *opp = container_of(kref, struct dev_pm_opp, kref);
1189 	struct opp_table *opp_table = opp->opp_table;
1190 
1191 	_opp_kref_release(opp, opp_table);
1192 }
1193 
1194 static void _opp_kref_release_locked(struct kref *kref)
1195 {
1196 	struct dev_pm_opp *opp = container_of(kref, struct dev_pm_opp, kref);
1197 	struct opp_table *opp_table = opp->opp_table;
1198 
1199 	_opp_kref_release(opp, opp_table);
1200 	mutex_unlock(&opp_table->lock);
1201 }
1202 
1203 void dev_pm_opp_get(struct dev_pm_opp *opp)
1204 {
1205 	kref_get(&opp->kref);
1206 }
1207 
1208 void dev_pm_opp_put(struct dev_pm_opp *opp)
1209 {
1210 	kref_put_mutex(&opp->kref, _opp_kref_release_locked,
1211 		       &opp->opp_table->lock);
1212 }
1213 EXPORT_SYMBOL_GPL(dev_pm_opp_put);
1214 
1215 static void dev_pm_opp_put_unlocked(struct dev_pm_opp *opp)
1216 {
1217 	kref_put(&opp->kref, _opp_kref_release_unlocked);
1218 }
1219 
1220 /**
1221  * dev_pm_opp_remove()  - Remove an OPP from OPP table
1222  * @dev:	device for which we do this operation
1223  * @freq:	OPP to remove with matching 'freq'
1224  *
1225  * This function removes an opp from the opp table.
1226  */
1227 void dev_pm_opp_remove(struct device *dev, unsigned long freq)
1228 {
1229 	struct dev_pm_opp *opp;
1230 	struct opp_table *opp_table;
1231 	bool found = false;
1232 
1233 	opp_table = _find_opp_table(dev);
1234 	if (IS_ERR(opp_table))
1235 		return;
1236 
1237 	mutex_lock(&opp_table->lock);
1238 
1239 	list_for_each_entry(opp, &opp_table->opp_list, node) {
1240 		if (opp->rate == freq) {
1241 			found = true;
1242 			break;
1243 		}
1244 	}
1245 
1246 	mutex_unlock(&opp_table->lock);
1247 
1248 	if (found) {
1249 		dev_pm_opp_put(opp);
1250 
1251 		/* Drop the reference taken by dev_pm_opp_add() */
1252 		dev_pm_opp_put_opp_table(opp_table);
1253 	} else {
1254 		dev_warn(dev, "%s: Couldn't find OPP with freq: %lu\n",
1255 			 __func__, freq);
1256 	}
1257 
1258 	/* Drop the reference taken by _find_opp_table() */
1259 	dev_pm_opp_put_opp_table(opp_table);
1260 }
1261 EXPORT_SYMBOL_GPL(dev_pm_opp_remove);
1262 
1263 void _opp_remove_all_static(struct opp_table *opp_table)
1264 {
1265 	struct dev_pm_opp *opp, *tmp;
1266 
1267 	mutex_lock(&opp_table->lock);
1268 
1269 	if (!opp_table->parsed_static_opps || --opp_table->parsed_static_opps)
1270 		goto unlock;
1271 
1272 	list_for_each_entry_safe(opp, tmp, &opp_table->opp_list, node) {
1273 		if (!opp->dynamic)
1274 			dev_pm_opp_put_unlocked(opp);
1275 	}
1276 
1277 unlock:
1278 	mutex_unlock(&opp_table->lock);
1279 }
1280 
1281 /**
1282  * dev_pm_opp_remove_all_dynamic() - Remove all dynamically created OPPs
1283  * @dev:	device for which we do this operation
1284  *
1285  * This function removes all dynamically created OPPs from the opp table.
1286  */
1287 void dev_pm_opp_remove_all_dynamic(struct device *dev)
1288 {
1289 	struct opp_table *opp_table;
1290 	struct dev_pm_opp *opp, *temp;
1291 	int count = 0;
1292 
1293 	opp_table = _find_opp_table(dev);
1294 	if (IS_ERR(opp_table))
1295 		return;
1296 
1297 	mutex_lock(&opp_table->lock);
1298 	list_for_each_entry_safe(opp, temp, &opp_table->opp_list, node) {
1299 		if (opp->dynamic) {
1300 			dev_pm_opp_put_unlocked(opp);
1301 			count++;
1302 		}
1303 	}
1304 	mutex_unlock(&opp_table->lock);
1305 
1306 	/* Drop the references taken by dev_pm_opp_add() */
1307 	while (count--)
1308 		dev_pm_opp_put_opp_table(opp_table);
1309 
1310 	/* Drop the reference taken by _find_opp_table() */
1311 	dev_pm_opp_put_opp_table(opp_table);
1312 }
1313 EXPORT_SYMBOL_GPL(dev_pm_opp_remove_all_dynamic);
1314 
1315 struct dev_pm_opp *_opp_allocate(struct opp_table *table)
1316 {
1317 	struct dev_pm_opp *opp;
1318 	int supply_count, supply_size, icc_size;
1319 
1320 	/* Allocate space for at least one supply */
1321 	supply_count = table->regulator_count > 0 ? table->regulator_count : 1;
1322 	supply_size = sizeof(*opp->supplies) * supply_count;
1323 	icc_size = sizeof(*opp->bandwidth) * table->path_count;
1324 
1325 	/* allocate new OPP node and supplies structures */
1326 	opp = kzalloc(sizeof(*opp) + supply_size + icc_size, GFP_KERNEL);
1327 
1328 	if (!opp)
1329 		return NULL;
1330 
1331 	/* Put the supplies at the end of the OPP structure as an empty array */
1332 	opp->supplies = (struct dev_pm_opp_supply *)(opp + 1);
1333 	if (icc_size)
1334 		opp->bandwidth = (struct dev_pm_opp_icc_bw *)(opp->supplies + supply_count);
1335 	INIT_LIST_HEAD(&opp->node);
1336 
1337 	return opp;
1338 }
1339 
1340 static bool _opp_supported_by_regulators(struct dev_pm_opp *opp,
1341 					 struct opp_table *opp_table)
1342 {
1343 	struct regulator *reg;
1344 	int i;
1345 
1346 	if (!opp_table->regulators)
1347 		return true;
1348 
1349 	for (i = 0; i < opp_table->regulator_count; i++) {
1350 		reg = opp_table->regulators[i];
1351 
1352 		if (!regulator_is_supported_voltage(reg,
1353 					opp->supplies[i].u_volt_min,
1354 					opp->supplies[i].u_volt_max)) {
1355 			pr_warn("%s: OPP minuV: %lu maxuV: %lu, not supported by regulator\n",
1356 				__func__, opp->supplies[i].u_volt_min,
1357 				opp->supplies[i].u_volt_max);
1358 			return false;
1359 		}
1360 	}
1361 
1362 	return true;
1363 }
1364 
1365 int _opp_compare_key(struct dev_pm_opp *opp1, struct dev_pm_opp *opp2)
1366 {
1367 	if (opp1->rate != opp2->rate)
1368 		return opp1->rate < opp2->rate ? -1 : 1;
1369 	if (opp1->bandwidth && opp2->bandwidth &&
1370 	    opp1->bandwidth[0].peak != opp2->bandwidth[0].peak)
1371 		return opp1->bandwidth[0].peak < opp2->bandwidth[0].peak ? -1 : 1;
1372 	if (opp1->level != opp2->level)
1373 		return opp1->level < opp2->level ? -1 : 1;
1374 	return 0;
1375 }
1376 
1377 static int _opp_is_duplicate(struct device *dev, struct dev_pm_opp *new_opp,
1378 			     struct opp_table *opp_table,
1379 			     struct list_head **head)
1380 {
1381 	struct dev_pm_opp *opp;
1382 	int opp_cmp;
1383 
1384 	/*
1385 	 * Insert new OPP in order of increasing frequency and discard if
1386 	 * already present.
1387 	 *
1388 	 * Need to use &opp_table->opp_list in the condition part of the 'for'
1389 	 * loop, don't replace it with head otherwise it will become an infinite
1390 	 * loop.
1391 	 */
1392 	list_for_each_entry(opp, &opp_table->opp_list, node) {
1393 		opp_cmp = _opp_compare_key(new_opp, opp);
1394 		if (opp_cmp > 0) {
1395 			*head = &opp->node;
1396 			continue;
1397 		}
1398 
1399 		if (opp_cmp < 0)
1400 			return 0;
1401 
1402 		/* Duplicate OPPs */
1403 		dev_warn(dev, "%s: duplicate OPPs detected. Existing: freq: %lu, volt: %lu, enabled: %d. New: freq: %lu, volt: %lu, enabled: %d\n",
1404 			 __func__, opp->rate, opp->supplies[0].u_volt,
1405 			 opp->available, new_opp->rate,
1406 			 new_opp->supplies[0].u_volt, new_opp->available);
1407 
1408 		/* Should we compare voltages for all regulators here ? */
1409 		return opp->available &&
1410 		       new_opp->supplies[0].u_volt == opp->supplies[0].u_volt ? -EBUSY : -EEXIST;
1411 	}
1412 
1413 	return 0;
1414 }
1415 
1416 /*
1417  * Returns:
1418  * 0: On success. And appropriate error message for duplicate OPPs.
1419  * -EBUSY: For OPP with same freq/volt and is available. The callers of
1420  *  _opp_add() must return 0 if they receive -EBUSY from it. This is to make
1421  *  sure we don't print error messages unnecessarily if different parts of
1422  *  kernel try to initialize the OPP table.
1423  * -EEXIST: For OPP with same freq but different volt or is unavailable. This
1424  *  should be considered an error by the callers of _opp_add().
1425  */
1426 int _opp_add(struct device *dev, struct dev_pm_opp *new_opp,
1427 	     struct opp_table *opp_table, bool rate_not_available)
1428 {
1429 	struct list_head *head;
1430 	int ret;
1431 
1432 	mutex_lock(&opp_table->lock);
1433 	head = &opp_table->opp_list;
1434 
1435 	if (likely(!rate_not_available)) {
1436 		ret = _opp_is_duplicate(dev, new_opp, opp_table, &head);
1437 		if (ret) {
1438 			mutex_unlock(&opp_table->lock);
1439 			return ret;
1440 		}
1441 	}
1442 
1443 	list_add(&new_opp->node, head);
1444 	mutex_unlock(&opp_table->lock);
1445 
1446 	new_opp->opp_table = opp_table;
1447 	kref_init(&new_opp->kref);
1448 
1449 	opp_debug_create_one(new_opp, opp_table);
1450 
1451 	if (!_opp_supported_by_regulators(new_opp, opp_table)) {
1452 		new_opp->available = false;
1453 		dev_warn(dev, "%s: OPP not supported by regulators (%lu)\n",
1454 			 __func__, new_opp->rate);
1455 	}
1456 
1457 	return 0;
1458 }
1459 
1460 /**
1461  * _opp_add_v1() - Allocate a OPP based on v1 bindings.
1462  * @opp_table:	OPP table
1463  * @dev:	device for which we do this operation
1464  * @freq:	Frequency in Hz for this OPP
1465  * @u_volt:	Voltage in uVolts for this OPP
1466  * @dynamic:	Dynamically added OPPs.
1467  *
1468  * This function adds an opp definition to the opp table and returns status.
1469  * The opp is made available by default and it can be controlled using
1470  * dev_pm_opp_enable/disable functions and may be removed by dev_pm_opp_remove.
1471  *
1472  * NOTE: "dynamic" parameter impacts OPPs added by the dev_pm_opp_of_add_table
1473  * and freed by dev_pm_opp_of_remove_table.
1474  *
1475  * Return:
1476  * 0		On success OR
1477  *		Duplicate OPPs (both freq and volt are same) and opp->available
1478  * -EEXIST	Freq are same and volt are different OR
1479  *		Duplicate OPPs (both freq and volt are same) and !opp->available
1480  * -ENOMEM	Memory allocation failure
1481  */
1482 int _opp_add_v1(struct opp_table *opp_table, struct device *dev,
1483 		unsigned long freq, long u_volt, bool dynamic)
1484 {
1485 	struct dev_pm_opp *new_opp;
1486 	unsigned long tol;
1487 	int ret;
1488 
1489 	new_opp = _opp_allocate(opp_table);
1490 	if (!new_opp)
1491 		return -ENOMEM;
1492 
1493 	/* populate the opp table */
1494 	new_opp->rate = freq;
1495 	tol = u_volt * opp_table->voltage_tolerance_v1 / 100;
1496 	new_opp->supplies[0].u_volt = u_volt;
1497 	new_opp->supplies[0].u_volt_min = u_volt - tol;
1498 	new_opp->supplies[0].u_volt_max = u_volt + tol;
1499 	new_opp->available = true;
1500 	new_opp->dynamic = dynamic;
1501 
1502 	ret = _opp_add(dev, new_opp, opp_table, false);
1503 	if (ret) {
1504 		/* Don't return error for duplicate OPPs */
1505 		if (ret == -EBUSY)
1506 			ret = 0;
1507 		goto free_opp;
1508 	}
1509 
1510 	/*
1511 	 * Notify the changes in the availability of the operable
1512 	 * frequency/voltage list.
1513 	 */
1514 	blocking_notifier_call_chain(&opp_table->head, OPP_EVENT_ADD, new_opp);
1515 	return 0;
1516 
1517 free_opp:
1518 	_opp_free(new_opp);
1519 
1520 	return ret;
1521 }
1522 
1523 /**
1524  * dev_pm_opp_set_supported_hw() - Set supported platforms
1525  * @dev: Device for which supported-hw has to be set.
1526  * @versions: Array of hierarchy of versions to match.
1527  * @count: Number of elements in the array.
1528  *
1529  * This is required only for the V2 bindings, and it enables a platform to
1530  * specify the hierarchy of versions it supports. OPP layer will then enable
1531  * OPPs, which are available for those versions, based on its 'opp-supported-hw'
1532  * property.
1533  */
1534 struct opp_table *dev_pm_opp_set_supported_hw(struct device *dev,
1535 			const u32 *versions, unsigned int count)
1536 {
1537 	struct opp_table *opp_table;
1538 
1539 	opp_table = dev_pm_opp_get_opp_table(dev);
1540 	if (!opp_table)
1541 		return ERR_PTR(-ENOMEM);
1542 
1543 	/* Make sure there are no concurrent readers while updating opp_table */
1544 	WARN_ON(!list_empty(&opp_table->opp_list));
1545 
1546 	/* Another CPU that shares the OPP table has set the property ? */
1547 	if (opp_table->supported_hw)
1548 		return opp_table;
1549 
1550 	opp_table->supported_hw = kmemdup(versions, count * sizeof(*versions),
1551 					GFP_KERNEL);
1552 	if (!opp_table->supported_hw) {
1553 		dev_pm_opp_put_opp_table(opp_table);
1554 		return ERR_PTR(-ENOMEM);
1555 	}
1556 
1557 	opp_table->supported_hw_count = count;
1558 
1559 	return opp_table;
1560 }
1561 EXPORT_SYMBOL_GPL(dev_pm_opp_set_supported_hw);
1562 
1563 /**
1564  * dev_pm_opp_put_supported_hw() - Releases resources blocked for supported hw
1565  * @opp_table: OPP table returned by dev_pm_opp_set_supported_hw().
1566  *
1567  * This is required only for the V2 bindings, and is called for a matching
1568  * dev_pm_opp_set_supported_hw(). Until this is called, the opp_table structure
1569  * will not be freed.
1570  */
1571 void dev_pm_opp_put_supported_hw(struct opp_table *opp_table)
1572 {
1573 	/* Make sure there are no concurrent readers while updating opp_table */
1574 	WARN_ON(!list_empty(&opp_table->opp_list));
1575 
1576 	kfree(opp_table->supported_hw);
1577 	opp_table->supported_hw = NULL;
1578 	opp_table->supported_hw_count = 0;
1579 
1580 	dev_pm_opp_put_opp_table(opp_table);
1581 }
1582 EXPORT_SYMBOL_GPL(dev_pm_opp_put_supported_hw);
1583 
1584 /**
1585  * dev_pm_opp_set_prop_name() - Set prop-extn name
1586  * @dev: Device for which the prop-name has to be set.
1587  * @name: name to postfix to properties.
1588  *
1589  * This is required only for the V2 bindings, and it enables a platform to
1590  * specify the extn to be used for certain property names. The properties to
1591  * which the extension will apply are opp-microvolt and opp-microamp. OPP core
1592  * should postfix the property name with -<name> while looking for them.
1593  */
1594 struct opp_table *dev_pm_opp_set_prop_name(struct device *dev, const char *name)
1595 {
1596 	struct opp_table *opp_table;
1597 
1598 	opp_table = dev_pm_opp_get_opp_table(dev);
1599 	if (!opp_table)
1600 		return ERR_PTR(-ENOMEM);
1601 
1602 	/* Make sure there are no concurrent readers while updating opp_table */
1603 	WARN_ON(!list_empty(&opp_table->opp_list));
1604 
1605 	/* Another CPU that shares the OPP table has set the property ? */
1606 	if (opp_table->prop_name)
1607 		return opp_table;
1608 
1609 	opp_table->prop_name = kstrdup(name, GFP_KERNEL);
1610 	if (!opp_table->prop_name) {
1611 		dev_pm_opp_put_opp_table(opp_table);
1612 		return ERR_PTR(-ENOMEM);
1613 	}
1614 
1615 	return opp_table;
1616 }
1617 EXPORT_SYMBOL_GPL(dev_pm_opp_set_prop_name);
1618 
1619 /**
1620  * dev_pm_opp_put_prop_name() - Releases resources blocked for prop-name
1621  * @opp_table: OPP table returned by dev_pm_opp_set_prop_name().
1622  *
1623  * This is required only for the V2 bindings, and is called for a matching
1624  * dev_pm_opp_set_prop_name(). Until this is called, the opp_table structure
1625  * will not be freed.
1626  */
1627 void dev_pm_opp_put_prop_name(struct opp_table *opp_table)
1628 {
1629 	/* Make sure there are no concurrent readers while updating opp_table */
1630 	WARN_ON(!list_empty(&opp_table->opp_list));
1631 
1632 	kfree(opp_table->prop_name);
1633 	opp_table->prop_name = NULL;
1634 
1635 	dev_pm_opp_put_opp_table(opp_table);
1636 }
1637 EXPORT_SYMBOL_GPL(dev_pm_opp_put_prop_name);
1638 
1639 static int _allocate_set_opp_data(struct opp_table *opp_table)
1640 {
1641 	struct dev_pm_set_opp_data *data;
1642 	int len, count = opp_table->regulator_count;
1643 
1644 	if (WARN_ON(!opp_table->regulators))
1645 		return -EINVAL;
1646 
1647 	/* space for set_opp_data */
1648 	len = sizeof(*data);
1649 
1650 	/* space for old_opp.supplies and new_opp.supplies */
1651 	len += 2 * sizeof(struct dev_pm_opp_supply) * count;
1652 
1653 	data = kzalloc(len, GFP_KERNEL);
1654 	if (!data)
1655 		return -ENOMEM;
1656 
1657 	data->old_opp.supplies = (void *)(data + 1);
1658 	data->new_opp.supplies = data->old_opp.supplies + count;
1659 
1660 	opp_table->set_opp_data = data;
1661 
1662 	return 0;
1663 }
1664 
1665 static void _free_set_opp_data(struct opp_table *opp_table)
1666 {
1667 	kfree(opp_table->set_opp_data);
1668 	opp_table->set_opp_data = NULL;
1669 }
1670 
1671 /**
1672  * dev_pm_opp_set_regulators() - Set regulator names for the device
1673  * @dev: Device for which regulator name is being set.
1674  * @names: Array of pointers to the names of the regulator.
1675  * @count: Number of regulators.
1676  *
1677  * In order to support OPP switching, OPP layer needs to know the name of the
1678  * device's regulators, as the core would be required to switch voltages as
1679  * well.
1680  *
1681  * This must be called before any OPPs are initialized for the device.
1682  */
1683 struct opp_table *dev_pm_opp_set_regulators(struct device *dev,
1684 					    const char * const names[],
1685 					    unsigned int count)
1686 {
1687 	struct opp_table *opp_table;
1688 	struct regulator *reg;
1689 	int ret, i;
1690 
1691 	opp_table = dev_pm_opp_get_opp_table(dev);
1692 	if (!opp_table)
1693 		return ERR_PTR(-ENOMEM);
1694 
1695 	/* This should be called before OPPs are initialized */
1696 	if (WARN_ON(!list_empty(&opp_table->opp_list))) {
1697 		ret = -EBUSY;
1698 		goto err;
1699 	}
1700 
1701 	/* Another CPU that shares the OPP table has set the regulators ? */
1702 	if (opp_table->regulators)
1703 		return opp_table;
1704 
1705 	opp_table->regulators = kmalloc_array(count,
1706 					      sizeof(*opp_table->regulators),
1707 					      GFP_KERNEL);
1708 	if (!opp_table->regulators) {
1709 		ret = -ENOMEM;
1710 		goto err;
1711 	}
1712 
1713 	for (i = 0; i < count; i++) {
1714 		reg = regulator_get_optional(dev, names[i]);
1715 		if (IS_ERR(reg)) {
1716 			ret = PTR_ERR(reg);
1717 			if (ret != -EPROBE_DEFER)
1718 				dev_err(dev, "%s: no regulator (%s) found: %d\n",
1719 					__func__, names[i], ret);
1720 			goto free_regulators;
1721 		}
1722 
1723 		opp_table->regulators[i] = reg;
1724 	}
1725 
1726 	opp_table->regulator_count = count;
1727 
1728 	/* Allocate block only once to pass to set_opp() routines */
1729 	ret = _allocate_set_opp_data(opp_table);
1730 	if (ret)
1731 		goto free_regulators;
1732 
1733 	return opp_table;
1734 
1735 free_regulators:
1736 	while (i != 0)
1737 		regulator_put(opp_table->regulators[--i]);
1738 
1739 	kfree(opp_table->regulators);
1740 	opp_table->regulators = NULL;
1741 	opp_table->regulator_count = -1;
1742 err:
1743 	dev_pm_opp_put_opp_table(opp_table);
1744 
1745 	return ERR_PTR(ret);
1746 }
1747 EXPORT_SYMBOL_GPL(dev_pm_opp_set_regulators);
1748 
1749 /**
1750  * dev_pm_opp_put_regulators() - Releases resources blocked for regulator
1751  * @opp_table: OPP table returned from dev_pm_opp_set_regulators().
1752  */
1753 void dev_pm_opp_put_regulators(struct opp_table *opp_table)
1754 {
1755 	int i;
1756 
1757 	if (!opp_table->regulators)
1758 		goto put_opp_table;
1759 
1760 	/* Make sure there are no concurrent readers while updating opp_table */
1761 	WARN_ON(!list_empty(&opp_table->opp_list));
1762 
1763 	if (opp_table->regulator_enabled) {
1764 		for (i = opp_table->regulator_count - 1; i >= 0; i--)
1765 			regulator_disable(opp_table->regulators[i]);
1766 
1767 		opp_table->regulator_enabled = false;
1768 	}
1769 
1770 	for (i = opp_table->regulator_count - 1; i >= 0; i--)
1771 		regulator_put(opp_table->regulators[i]);
1772 
1773 	_free_set_opp_data(opp_table);
1774 
1775 	kfree(opp_table->regulators);
1776 	opp_table->regulators = NULL;
1777 	opp_table->regulator_count = -1;
1778 
1779 put_opp_table:
1780 	dev_pm_opp_put_opp_table(opp_table);
1781 }
1782 EXPORT_SYMBOL_GPL(dev_pm_opp_put_regulators);
1783 
1784 /**
1785  * dev_pm_opp_set_clkname() - Set clk name for the device
1786  * @dev: Device for which clk name is being set.
1787  * @name: Clk name.
1788  *
1789  * In order to support OPP switching, OPP layer needs to get pointer to the
1790  * clock for the device. Simple cases work fine without using this routine (i.e.
1791  * by passing connection-id as NULL), but for a device with multiple clocks
1792  * available, the OPP core needs to know the exact name of the clk to use.
1793  *
1794  * This must be called before any OPPs are initialized for the device.
1795  */
1796 struct opp_table *dev_pm_opp_set_clkname(struct device *dev, const char *name)
1797 {
1798 	struct opp_table *opp_table;
1799 	int ret;
1800 
1801 	opp_table = dev_pm_opp_get_opp_table(dev);
1802 	if (!opp_table)
1803 		return ERR_PTR(-ENOMEM);
1804 
1805 	/* This should be called before OPPs are initialized */
1806 	if (WARN_ON(!list_empty(&opp_table->opp_list))) {
1807 		ret = -EBUSY;
1808 		goto err;
1809 	}
1810 
1811 	/* Already have default clk set, free it */
1812 	if (!IS_ERR(opp_table->clk))
1813 		clk_put(opp_table->clk);
1814 
1815 	/* Find clk for the device */
1816 	opp_table->clk = clk_get(dev, name);
1817 	if (IS_ERR(opp_table->clk)) {
1818 		ret = PTR_ERR(opp_table->clk);
1819 		if (ret != -EPROBE_DEFER) {
1820 			dev_err(dev, "%s: Couldn't find clock: %d\n", __func__,
1821 				ret);
1822 		}
1823 		goto err;
1824 	}
1825 
1826 	return opp_table;
1827 
1828 err:
1829 	dev_pm_opp_put_opp_table(opp_table);
1830 
1831 	return ERR_PTR(ret);
1832 }
1833 EXPORT_SYMBOL_GPL(dev_pm_opp_set_clkname);
1834 
1835 /**
1836  * dev_pm_opp_put_clkname() - Releases resources blocked for clk.
1837  * @opp_table: OPP table returned from dev_pm_opp_set_clkname().
1838  */
1839 void dev_pm_opp_put_clkname(struct opp_table *opp_table)
1840 {
1841 	/* Make sure there are no concurrent readers while updating opp_table */
1842 	WARN_ON(!list_empty(&opp_table->opp_list));
1843 
1844 	clk_put(opp_table->clk);
1845 	opp_table->clk = ERR_PTR(-EINVAL);
1846 
1847 	dev_pm_opp_put_opp_table(opp_table);
1848 }
1849 EXPORT_SYMBOL_GPL(dev_pm_opp_put_clkname);
1850 
1851 /**
1852  * dev_pm_opp_register_set_opp_helper() - Register custom set OPP helper
1853  * @dev: Device for which the helper is getting registered.
1854  * @set_opp: Custom set OPP helper.
1855  *
1856  * This is useful to support complex platforms (like platforms with multiple
1857  * regulators per device), instead of the generic OPP set rate helper.
1858  *
1859  * This must be called before any OPPs are initialized for the device.
1860  */
1861 struct opp_table *dev_pm_opp_register_set_opp_helper(struct device *dev,
1862 			int (*set_opp)(struct dev_pm_set_opp_data *data))
1863 {
1864 	struct opp_table *opp_table;
1865 
1866 	if (!set_opp)
1867 		return ERR_PTR(-EINVAL);
1868 
1869 	opp_table = dev_pm_opp_get_opp_table(dev);
1870 	if (!opp_table)
1871 		return ERR_PTR(-ENOMEM);
1872 
1873 	/* This should be called before OPPs are initialized */
1874 	if (WARN_ON(!list_empty(&opp_table->opp_list))) {
1875 		dev_pm_opp_put_opp_table(opp_table);
1876 		return ERR_PTR(-EBUSY);
1877 	}
1878 
1879 	/* Another CPU that shares the OPP table has set the helper ? */
1880 	if (!opp_table->set_opp)
1881 		opp_table->set_opp = set_opp;
1882 
1883 	return opp_table;
1884 }
1885 EXPORT_SYMBOL_GPL(dev_pm_opp_register_set_opp_helper);
1886 
1887 /**
1888  * dev_pm_opp_unregister_set_opp_helper() - Releases resources blocked for
1889  *					   set_opp helper
1890  * @opp_table: OPP table returned from dev_pm_opp_register_set_opp_helper().
1891  *
1892  * Release resources blocked for platform specific set_opp helper.
1893  */
1894 void dev_pm_opp_unregister_set_opp_helper(struct opp_table *opp_table)
1895 {
1896 	/* Make sure there are no concurrent readers while updating opp_table */
1897 	WARN_ON(!list_empty(&opp_table->opp_list));
1898 
1899 	opp_table->set_opp = NULL;
1900 	dev_pm_opp_put_opp_table(opp_table);
1901 }
1902 EXPORT_SYMBOL_GPL(dev_pm_opp_unregister_set_opp_helper);
1903 
1904 static void _opp_detach_genpd(struct opp_table *opp_table)
1905 {
1906 	int index;
1907 
1908 	for (index = 0; index < opp_table->required_opp_count; index++) {
1909 		if (!opp_table->genpd_virt_devs[index])
1910 			continue;
1911 
1912 		dev_pm_domain_detach(opp_table->genpd_virt_devs[index], false);
1913 		opp_table->genpd_virt_devs[index] = NULL;
1914 	}
1915 
1916 	kfree(opp_table->genpd_virt_devs);
1917 	opp_table->genpd_virt_devs = NULL;
1918 }
1919 
1920 /**
1921  * dev_pm_opp_attach_genpd - Attach genpd(s) for the device and save virtual device pointer
1922  * @dev: Consumer device for which the genpd is getting attached.
1923  * @names: Null terminated array of pointers containing names of genpd to attach.
1924  * @virt_devs: Pointer to return the array of virtual devices.
1925  *
1926  * Multiple generic power domains for a device are supported with the help of
1927  * virtual genpd devices, which are created for each consumer device - genpd
1928  * pair. These are the device structures which are attached to the power domain
1929  * and are required by the OPP core to set the performance state of the genpd.
1930  * The same API also works for the case where single genpd is available and so
1931  * we don't need to support that separately.
1932  *
1933  * This helper will normally be called by the consumer driver of the device
1934  * "dev", as only that has details of the genpd names.
1935  *
1936  * This helper needs to be called once with a list of all genpd to attach.
1937  * Otherwise the original device structure will be used instead by the OPP core.
1938  *
1939  * The order of entries in the names array must match the order in which
1940  * "required-opps" are added in DT.
1941  */
1942 struct opp_table *dev_pm_opp_attach_genpd(struct device *dev,
1943 		const char **names, struct device ***virt_devs)
1944 {
1945 	struct opp_table *opp_table;
1946 	struct device *virt_dev;
1947 	int index = 0, ret = -EINVAL;
1948 	const char **name = names;
1949 
1950 	opp_table = dev_pm_opp_get_opp_table(dev);
1951 	if (!opp_table)
1952 		return ERR_PTR(-ENOMEM);
1953 
1954 	/*
1955 	 * If the genpd's OPP table isn't already initialized, parsing of the
1956 	 * required-opps fail for dev. We should retry this after genpd's OPP
1957 	 * table is added.
1958 	 */
1959 	if (!opp_table->required_opp_count) {
1960 		ret = -EPROBE_DEFER;
1961 		goto put_table;
1962 	}
1963 
1964 	mutex_lock(&opp_table->genpd_virt_dev_lock);
1965 
1966 	opp_table->genpd_virt_devs = kcalloc(opp_table->required_opp_count,
1967 					     sizeof(*opp_table->genpd_virt_devs),
1968 					     GFP_KERNEL);
1969 	if (!opp_table->genpd_virt_devs)
1970 		goto unlock;
1971 
1972 	while (*name) {
1973 		if (index >= opp_table->required_opp_count) {
1974 			dev_err(dev, "Index can't be greater than required-opp-count - 1, %s (%d : %d)\n",
1975 				*name, opp_table->required_opp_count, index);
1976 			goto err;
1977 		}
1978 
1979 		if (opp_table->genpd_virt_devs[index]) {
1980 			dev_err(dev, "Genpd virtual device already set %s\n",
1981 				*name);
1982 			goto err;
1983 		}
1984 
1985 		virt_dev = dev_pm_domain_attach_by_name(dev, *name);
1986 		if (IS_ERR(virt_dev)) {
1987 			ret = PTR_ERR(virt_dev);
1988 			dev_err(dev, "Couldn't attach to pm_domain: %d\n", ret);
1989 			goto err;
1990 		}
1991 
1992 		opp_table->genpd_virt_devs[index] = virt_dev;
1993 		index++;
1994 		name++;
1995 	}
1996 
1997 	if (virt_devs)
1998 		*virt_devs = opp_table->genpd_virt_devs;
1999 	mutex_unlock(&opp_table->genpd_virt_dev_lock);
2000 
2001 	return opp_table;
2002 
2003 err:
2004 	_opp_detach_genpd(opp_table);
2005 unlock:
2006 	mutex_unlock(&opp_table->genpd_virt_dev_lock);
2007 
2008 put_table:
2009 	dev_pm_opp_put_opp_table(opp_table);
2010 
2011 	return ERR_PTR(ret);
2012 }
2013 EXPORT_SYMBOL_GPL(dev_pm_opp_attach_genpd);
2014 
2015 /**
2016  * dev_pm_opp_detach_genpd() - Detach genpd(s) from the device.
2017  * @opp_table: OPP table returned by dev_pm_opp_attach_genpd().
2018  *
2019  * This detaches the genpd(s), resets the virtual device pointers, and puts the
2020  * OPP table.
2021  */
2022 void dev_pm_opp_detach_genpd(struct opp_table *opp_table)
2023 {
2024 	/*
2025 	 * Acquire genpd_virt_dev_lock to make sure virt_dev isn't getting
2026 	 * used in parallel.
2027 	 */
2028 	mutex_lock(&opp_table->genpd_virt_dev_lock);
2029 	_opp_detach_genpd(opp_table);
2030 	mutex_unlock(&opp_table->genpd_virt_dev_lock);
2031 
2032 	dev_pm_opp_put_opp_table(opp_table);
2033 }
2034 EXPORT_SYMBOL_GPL(dev_pm_opp_detach_genpd);
2035 
2036 /**
2037  * dev_pm_opp_xlate_performance_state() - Find required OPP's pstate for src_table.
2038  * @src_table: OPP table which has dst_table as one of its required OPP table.
2039  * @dst_table: Required OPP table of the src_table.
2040  * @pstate: Current performance state of the src_table.
2041  *
2042  * This Returns pstate of the OPP (present in @dst_table) pointed out by the
2043  * "required-opps" property of the OPP (present in @src_table) which has
2044  * performance state set to @pstate.
2045  *
2046  * Return: Zero or positive performance state on success, otherwise negative
2047  * value on errors.
2048  */
2049 int dev_pm_opp_xlate_performance_state(struct opp_table *src_table,
2050 				       struct opp_table *dst_table,
2051 				       unsigned int pstate)
2052 {
2053 	struct dev_pm_opp *opp;
2054 	int dest_pstate = -EINVAL;
2055 	int i;
2056 
2057 	if (!pstate)
2058 		return 0;
2059 
2060 	/*
2061 	 * Normally the src_table will have the "required_opps" property set to
2062 	 * point to one of the OPPs in the dst_table, but in some cases the
2063 	 * genpd and its master have one to one mapping of performance states
2064 	 * and so none of them have the "required-opps" property set. Return the
2065 	 * pstate of the src_table as it is in such cases.
2066 	 */
2067 	if (!src_table->required_opp_count)
2068 		return pstate;
2069 
2070 	for (i = 0; i < src_table->required_opp_count; i++) {
2071 		if (src_table->required_opp_tables[i]->np == dst_table->np)
2072 			break;
2073 	}
2074 
2075 	if (unlikely(i == src_table->required_opp_count)) {
2076 		pr_err("%s: Couldn't find matching OPP table (%p: %p)\n",
2077 		       __func__, src_table, dst_table);
2078 		return -EINVAL;
2079 	}
2080 
2081 	mutex_lock(&src_table->lock);
2082 
2083 	list_for_each_entry(opp, &src_table->opp_list, node) {
2084 		if (opp->pstate == pstate) {
2085 			dest_pstate = opp->required_opps[i]->pstate;
2086 			goto unlock;
2087 		}
2088 	}
2089 
2090 	pr_err("%s: Couldn't find matching OPP (%p: %p)\n", __func__, src_table,
2091 	       dst_table);
2092 
2093 unlock:
2094 	mutex_unlock(&src_table->lock);
2095 
2096 	return dest_pstate;
2097 }
2098 
2099 /**
2100  * dev_pm_opp_add()  - Add an OPP table from a table definitions
2101  * @dev:	device for which we do this operation
2102  * @freq:	Frequency in Hz for this OPP
2103  * @u_volt:	Voltage in uVolts for this OPP
2104  *
2105  * This function adds an opp definition to the opp table and returns status.
2106  * The opp is made available by default and it can be controlled using
2107  * dev_pm_opp_enable/disable functions.
2108  *
2109  * Return:
2110  * 0		On success OR
2111  *		Duplicate OPPs (both freq and volt are same) and opp->available
2112  * -EEXIST	Freq are same and volt are different OR
2113  *		Duplicate OPPs (both freq and volt are same) and !opp->available
2114  * -ENOMEM	Memory allocation failure
2115  */
2116 int dev_pm_opp_add(struct device *dev, unsigned long freq, unsigned long u_volt)
2117 {
2118 	struct opp_table *opp_table;
2119 	int ret;
2120 
2121 	opp_table = dev_pm_opp_get_opp_table(dev);
2122 	if (!opp_table)
2123 		return -ENOMEM;
2124 
2125 	/* Fix regulator count for dynamic OPPs */
2126 	opp_table->regulator_count = 1;
2127 
2128 	ret = _opp_add_v1(opp_table, dev, freq, u_volt, true);
2129 	if (ret)
2130 		dev_pm_opp_put_opp_table(opp_table);
2131 
2132 	return ret;
2133 }
2134 EXPORT_SYMBOL_GPL(dev_pm_opp_add);
2135 
2136 /**
2137  * _opp_set_availability() - helper to set the availability of an opp
2138  * @dev:		device for which we do this operation
2139  * @freq:		OPP frequency to modify availability
2140  * @availability_req:	availability status requested for this opp
2141  *
2142  * Set the availability of an OPP, opp_{enable,disable} share a common logic
2143  * which is isolated here.
2144  *
2145  * Return: -EINVAL for bad pointers, -ENOMEM if no memory available for the
2146  * copy operation, returns 0 if no modification was done OR modification was
2147  * successful.
2148  */
2149 static int _opp_set_availability(struct device *dev, unsigned long freq,
2150 				 bool availability_req)
2151 {
2152 	struct opp_table *opp_table;
2153 	struct dev_pm_opp *tmp_opp, *opp = ERR_PTR(-ENODEV);
2154 	int r = 0;
2155 
2156 	/* Find the opp_table */
2157 	opp_table = _find_opp_table(dev);
2158 	if (IS_ERR(opp_table)) {
2159 		r = PTR_ERR(opp_table);
2160 		dev_warn(dev, "%s: Device OPP not found (%d)\n", __func__, r);
2161 		return r;
2162 	}
2163 
2164 	mutex_lock(&opp_table->lock);
2165 
2166 	/* Do we have the frequency? */
2167 	list_for_each_entry(tmp_opp, &opp_table->opp_list, node) {
2168 		if (tmp_opp->rate == freq) {
2169 			opp = tmp_opp;
2170 			break;
2171 		}
2172 	}
2173 
2174 	if (IS_ERR(opp)) {
2175 		r = PTR_ERR(opp);
2176 		goto unlock;
2177 	}
2178 
2179 	/* Is update really needed? */
2180 	if (opp->available == availability_req)
2181 		goto unlock;
2182 
2183 	opp->available = availability_req;
2184 
2185 	dev_pm_opp_get(opp);
2186 	mutex_unlock(&opp_table->lock);
2187 
2188 	/* Notify the change of the OPP availability */
2189 	if (availability_req)
2190 		blocking_notifier_call_chain(&opp_table->head, OPP_EVENT_ENABLE,
2191 					     opp);
2192 	else
2193 		blocking_notifier_call_chain(&opp_table->head,
2194 					     OPP_EVENT_DISABLE, opp);
2195 
2196 	dev_pm_opp_put(opp);
2197 	goto put_table;
2198 
2199 unlock:
2200 	mutex_unlock(&opp_table->lock);
2201 put_table:
2202 	dev_pm_opp_put_opp_table(opp_table);
2203 	return r;
2204 }
2205 
2206 /**
2207  * dev_pm_opp_adjust_voltage() - helper to change the voltage of an OPP
2208  * @dev:		device for which we do this operation
2209  * @freq:		OPP frequency to adjust voltage of
2210  * @u_volt:		new OPP target voltage
2211  * @u_volt_min:		new OPP min voltage
2212  * @u_volt_max:		new OPP max voltage
2213  *
2214  * Return: -EINVAL for bad pointers, -ENOMEM if no memory available for the
2215  * copy operation, returns 0 if no modifcation was done OR modification was
2216  * successful.
2217  */
2218 int dev_pm_opp_adjust_voltage(struct device *dev, unsigned long freq,
2219 			      unsigned long u_volt, unsigned long u_volt_min,
2220 			      unsigned long u_volt_max)
2221 
2222 {
2223 	struct opp_table *opp_table;
2224 	struct dev_pm_opp *tmp_opp, *opp = ERR_PTR(-ENODEV);
2225 	int r = 0;
2226 
2227 	/* Find the opp_table */
2228 	opp_table = _find_opp_table(dev);
2229 	if (IS_ERR(opp_table)) {
2230 		r = PTR_ERR(opp_table);
2231 		dev_warn(dev, "%s: Device OPP not found (%d)\n", __func__, r);
2232 		return r;
2233 	}
2234 
2235 	mutex_lock(&opp_table->lock);
2236 
2237 	/* Do we have the frequency? */
2238 	list_for_each_entry(tmp_opp, &opp_table->opp_list, node) {
2239 		if (tmp_opp->rate == freq) {
2240 			opp = tmp_opp;
2241 			break;
2242 		}
2243 	}
2244 
2245 	if (IS_ERR(opp)) {
2246 		r = PTR_ERR(opp);
2247 		goto adjust_unlock;
2248 	}
2249 
2250 	/* Is update really needed? */
2251 	if (opp->supplies->u_volt == u_volt)
2252 		goto adjust_unlock;
2253 
2254 	opp->supplies->u_volt = u_volt;
2255 	opp->supplies->u_volt_min = u_volt_min;
2256 	opp->supplies->u_volt_max = u_volt_max;
2257 
2258 	dev_pm_opp_get(opp);
2259 	mutex_unlock(&opp_table->lock);
2260 
2261 	/* Notify the voltage change of the OPP */
2262 	blocking_notifier_call_chain(&opp_table->head, OPP_EVENT_ADJUST_VOLTAGE,
2263 				     opp);
2264 
2265 	dev_pm_opp_put(opp);
2266 	goto adjust_put_table;
2267 
2268 adjust_unlock:
2269 	mutex_unlock(&opp_table->lock);
2270 adjust_put_table:
2271 	dev_pm_opp_put_opp_table(opp_table);
2272 	return r;
2273 }
2274 
2275 /**
2276  * dev_pm_opp_enable() - Enable a specific OPP
2277  * @dev:	device for which we do this operation
2278  * @freq:	OPP frequency to enable
2279  *
2280  * Enables a provided opp. If the operation is valid, this returns 0, else the
2281  * corresponding error value. It is meant to be used for users an OPP available
2282  * after being temporarily made unavailable with dev_pm_opp_disable.
2283  *
2284  * Return: -EINVAL for bad pointers, -ENOMEM if no memory available for the
2285  * copy operation, returns 0 if no modification was done OR modification was
2286  * successful.
2287  */
2288 int dev_pm_opp_enable(struct device *dev, unsigned long freq)
2289 {
2290 	return _opp_set_availability(dev, freq, true);
2291 }
2292 EXPORT_SYMBOL_GPL(dev_pm_opp_enable);
2293 
2294 /**
2295  * dev_pm_opp_disable() - Disable a specific OPP
2296  * @dev:	device for which we do this operation
2297  * @freq:	OPP frequency to disable
2298  *
2299  * Disables a provided opp. If the operation is valid, this returns
2300  * 0, else the corresponding error value. It is meant to be a temporary
2301  * control by users to make this OPP not available until the circumstances are
2302  * right to make it available again (with a call to dev_pm_opp_enable).
2303  *
2304  * Return: -EINVAL for bad pointers, -ENOMEM if no memory available for the
2305  * copy operation, returns 0 if no modification was done OR modification was
2306  * successful.
2307  */
2308 int dev_pm_opp_disable(struct device *dev, unsigned long freq)
2309 {
2310 	return _opp_set_availability(dev, freq, false);
2311 }
2312 EXPORT_SYMBOL_GPL(dev_pm_opp_disable);
2313 
2314 /**
2315  * dev_pm_opp_register_notifier() - Register OPP notifier for the device
2316  * @dev:	Device for which notifier needs to be registered
2317  * @nb:		Notifier block to be registered
2318  *
2319  * Return: 0 on success or a negative error value.
2320  */
2321 int dev_pm_opp_register_notifier(struct device *dev, struct notifier_block *nb)
2322 {
2323 	struct opp_table *opp_table;
2324 	int ret;
2325 
2326 	opp_table = _find_opp_table(dev);
2327 	if (IS_ERR(opp_table))
2328 		return PTR_ERR(opp_table);
2329 
2330 	ret = blocking_notifier_chain_register(&opp_table->head, nb);
2331 
2332 	dev_pm_opp_put_opp_table(opp_table);
2333 
2334 	return ret;
2335 }
2336 EXPORT_SYMBOL(dev_pm_opp_register_notifier);
2337 
2338 /**
2339  * dev_pm_opp_unregister_notifier() - Unregister OPP notifier for the device
2340  * @dev:	Device for which notifier needs to be unregistered
2341  * @nb:		Notifier block to be unregistered
2342  *
2343  * Return: 0 on success or a negative error value.
2344  */
2345 int dev_pm_opp_unregister_notifier(struct device *dev,
2346 				   struct notifier_block *nb)
2347 {
2348 	struct opp_table *opp_table;
2349 	int ret;
2350 
2351 	opp_table = _find_opp_table(dev);
2352 	if (IS_ERR(opp_table))
2353 		return PTR_ERR(opp_table);
2354 
2355 	ret = blocking_notifier_chain_unregister(&opp_table->head, nb);
2356 
2357 	dev_pm_opp_put_opp_table(opp_table);
2358 
2359 	return ret;
2360 }
2361 EXPORT_SYMBOL(dev_pm_opp_unregister_notifier);
2362 
2363 void _dev_pm_opp_find_and_remove_table(struct device *dev)
2364 {
2365 	struct opp_table *opp_table;
2366 
2367 	/* Check for existing table for 'dev' */
2368 	opp_table = _find_opp_table(dev);
2369 	if (IS_ERR(opp_table)) {
2370 		int error = PTR_ERR(opp_table);
2371 
2372 		if (error != -ENODEV)
2373 			WARN(1, "%s: opp_table: %d\n",
2374 			     IS_ERR_OR_NULL(dev) ?
2375 					"Invalid device" : dev_name(dev),
2376 			     error);
2377 		return;
2378 	}
2379 
2380 	_opp_remove_all_static(opp_table);
2381 
2382 	/* Drop reference taken by _find_opp_table() */
2383 	dev_pm_opp_put_opp_table(opp_table);
2384 
2385 	/* Drop reference taken while the OPP table was added */
2386 	dev_pm_opp_put_opp_table(opp_table);
2387 }
2388 
2389 /**
2390  * dev_pm_opp_remove_table() - Free all OPPs associated with the device
2391  * @dev:	device pointer used to lookup OPP table.
2392  *
2393  * Free both OPPs created using static entries present in DT and the
2394  * dynamically added entries.
2395  */
2396 void dev_pm_opp_remove_table(struct device *dev)
2397 {
2398 	_dev_pm_opp_find_and_remove_table(dev);
2399 }
2400 EXPORT_SYMBOL_GPL(dev_pm_opp_remove_table);
2401