Merge tag 'safesetid-bugfix-5.4' of git://github.com/micah-morton/linux
[linux-2.6-microblaze.git] / drivers / opp / of.c
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         lockdep_assert_held(&opp_table_lock);
81
82         mutex_lock(&opp_table->lock);
83
84         list_for_each_entry(opp, &opp_table->opp_list, node) {
85                 if (opp->np == opp_np) {
86                         dev_pm_opp_get(opp);
87                         mutex_unlock(&opp_table->lock);
88                         return opp;
89                 }
90         }
91
92         mutex_unlock(&opp_table->lock);
93
94         return NULL;
95 }
96
97 static struct device_node *of_parse_required_opp(struct device_node *np,
98                                                  int index)
99 {
100         struct device_node *required_np;
101
102         required_np = of_parse_phandle(np, "required-opps", index);
103         if (unlikely(!required_np)) {
104                 pr_err("%s: Unable to parse required-opps: %pOF, index: %d\n",
105                        __func__, np, index);
106         }
107
108         return required_np;
109 }
110
111 /* The caller must call dev_pm_opp_put_opp_table() after the table is used */
112 static struct opp_table *_find_table_of_opp_np(struct device_node *opp_np)
113 {
114         struct opp_table *opp_table;
115         struct device_node *opp_table_np;
116
117         lockdep_assert_held(&opp_table_lock);
118
119         opp_table_np = of_get_parent(opp_np);
120         if (!opp_table_np)
121                 goto err;
122
123         /* It is safe to put the node now as all we need now is its address */
124         of_node_put(opp_table_np);
125
126         list_for_each_entry(opp_table, &opp_tables, node) {
127                 if (opp_table_np == opp_table->np) {
128                         _get_opp_table_kref(opp_table);
129                         return opp_table;
130                 }
131         }
132
133 err:
134         return ERR_PTR(-ENODEV);
135 }
136
137 /* Free resources previously acquired by _opp_table_alloc_required_tables() */
138 static void _opp_table_free_required_tables(struct opp_table *opp_table)
139 {
140         struct opp_table **required_opp_tables = opp_table->required_opp_tables;
141         int i;
142
143         if (!required_opp_tables)
144                 return;
145
146         for (i = 0; i < opp_table->required_opp_count; i++) {
147                 if (IS_ERR_OR_NULL(required_opp_tables[i]))
148                         break;
149
150                 dev_pm_opp_put_opp_table(required_opp_tables[i]);
151         }
152
153         kfree(required_opp_tables);
154
155         opp_table->required_opp_count = 0;
156         opp_table->required_opp_tables = NULL;
157 }
158
159 /*
160  * Populate all devices and opp tables which are part of "required-opps" list.
161  * Checking only the first OPP node should be enough.
162  */
163 static void _opp_table_alloc_required_tables(struct opp_table *opp_table,
164                                              struct device *dev,
165                                              struct device_node *opp_np)
166 {
167         struct opp_table **required_opp_tables;
168         struct device_node *required_np, *np;
169         int count, i;
170
171         /* Traversing the first OPP node is all we need */
172         np = of_get_next_available_child(opp_np, NULL);
173         if (!np) {
174                 dev_err(dev, "Empty OPP table\n");
175                 return;
176         }
177
178         count = of_count_phandle_with_args(np, "required-opps", NULL);
179         if (!count)
180                 goto put_np;
181
182         required_opp_tables = kcalloc(count, sizeof(*required_opp_tables),
183                                       GFP_KERNEL);
184         if (!required_opp_tables)
185                 goto put_np;
186
187         opp_table->required_opp_tables = required_opp_tables;
188         opp_table->required_opp_count = count;
189
190         for (i = 0; i < count; i++) {
191                 required_np = of_parse_required_opp(np, i);
192                 if (!required_np)
193                         goto free_required_tables;
194
195                 required_opp_tables[i] = _find_table_of_opp_np(required_np);
196                 of_node_put(required_np);
197
198                 if (IS_ERR(required_opp_tables[i]))
199                         goto free_required_tables;
200
201                 /*
202                  * We only support genpd's OPPs in the "required-opps" for now,
203                  * as we don't know how much about other cases. Error out if the
204                  * required OPP doesn't belong to a genpd.
205                  */
206                 if (!required_opp_tables[i]->is_genpd) {
207                         dev_err(dev, "required-opp doesn't belong to genpd: %pOF\n",
208                                 required_np);
209                         goto free_required_tables;
210                 }
211         }
212
213         goto put_np;
214
215 free_required_tables:
216         _opp_table_free_required_tables(opp_table);
217 put_np:
218         of_node_put(np);
219 }
220
221 void _of_init_opp_table(struct opp_table *opp_table, struct device *dev,
222                         int index)
223 {
224         struct device_node *np, *opp_np;
225         u32 val;
226
227         /*
228          * Only required for backward compatibility with v1 bindings, but isn't
229          * harmful for other cases. And so we do it unconditionally.
230          */
231         np = of_node_get(dev->of_node);
232         if (!np)
233                 return;
234
235         if (!of_property_read_u32(np, "clock-latency", &val))
236                 opp_table->clock_latency_ns_max = val;
237         of_property_read_u32(np, "voltage-tolerance",
238                              &opp_table->voltage_tolerance_v1);
239
240         if (of_find_property(np, "#power-domain-cells", NULL))
241                 opp_table->is_genpd = true;
242
243         /* Get OPP table node */
244         opp_np = _opp_of_get_opp_desc_node(np, index);
245         of_node_put(np);
246
247         if (!opp_np)
248                 return;
249
250         if (of_property_read_bool(opp_np, "opp-shared"))
251                 opp_table->shared_opp = OPP_TABLE_ACCESS_SHARED;
252         else
253                 opp_table->shared_opp = OPP_TABLE_ACCESS_EXCLUSIVE;
254
255         opp_table->np = opp_np;
256
257         _opp_table_alloc_required_tables(opp_table, dev, opp_np);
258         of_node_put(opp_np);
259 }
260
261 void _of_clear_opp_table(struct opp_table *opp_table)
262 {
263         _opp_table_free_required_tables(opp_table);
264 }
265
266 /*
267  * Release all resources previously acquired with a call to
268  * _of_opp_alloc_required_opps().
269  */
270 void _of_opp_free_required_opps(struct opp_table *opp_table,
271                                 struct dev_pm_opp *opp)
272 {
273         struct dev_pm_opp **required_opps = opp->required_opps;
274         int i;
275
276         if (!required_opps)
277                 return;
278
279         for (i = 0; i < opp_table->required_opp_count; i++) {
280                 if (!required_opps[i])
281                         break;
282
283                 /* Put the reference back */
284                 dev_pm_opp_put(required_opps[i]);
285         }
286
287         kfree(required_opps);
288         opp->required_opps = NULL;
289 }
290
291 /* Populate all required OPPs which are part of "required-opps" list */
292 static int _of_opp_alloc_required_opps(struct opp_table *opp_table,
293                                        struct dev_pm_opp *opp)
294 {
295         struct dev_pm_opp **required_opps;
296         struct opp_table *required_table;
297         struct device_node *np;
298         int i, ret, count = opp_table->required_opp_count;
299
300         if (!count)
301                 return 0;
302
303         required_opps = kcalloc(count, sizeof(*required_opps), GFP_KERNEL);
304         if (!required_opps)
305                 return -ENOMEM;
306
307         opp->required_opps = required_opps;
308
309         for (i = 0; i < count; i++) {
310                 required_table = opp_table->required_opp_tables[i];
311
312                 np = of_parse_required_opp(opp->np, i);
313                 if (unlikely(!np)) {
314                         ret = -ENODEV;
315                         goto free_required_opps;
316                 }
317
318                 required_opps[i] = _find_opp_of_np(required_table, np);
319                 of_node_put(np);
320
321                 if (!required_opps[i]) {
322                         pr_err("%s: Unable to find required OPP node: %pOF (%d)\n",
323                                __func__, opp->np, i);
324                         ret = -ENODEV;
325                         goto free_required_opps;
326                 }
327         }
328
329         return 0;
330
331 free_required_opps:
332         _of_opp_free_required_opps(opp_table, opp);
333
334         return ret;
335 }
336
337 static bool _opp_is_supported(struct device *dev, struct opp_table *opp_table,
338                               struct device_node *np)
339 {
340         unsigned int count = opp_table->supported_hw_count;
341         u32 version;
342         int ret;
343
344         if (!opp_table->supported_hw) {
345                 /*
346                  * In the case that no supported_hw has been set by the
347                  * platform but there is an opp-supported-hw value set for
348                  * an OPP then the OPP should not be enabled as there is
349                  * no way to see if the hardware supports it.
350                  */
351                 if (of_find_property(np, "opp-supported-hw", NULL))
352                         return false;
353                 else
354                         return true;
355         }
356
357         while (count--) {
358                 ret = of_property_read_u32_index(np, "opp-supported-hw", count,
359                                                  &version);
360                 if (ret) {
361                         dev_warn(dev, "%s: failed to read opp-supported-hw property at index %d: %d\n",
362                                  __func__, count, ret);
363                         return false;
364                 }
365
366                 /* Both of these are bitwise masks of the versions */
367                 if (!(version & opp_table->supported_hw[count]))
368                         return false;
369         }
370
371         return true;
372 }
373
374 static int opp_parse_supplies(struct dev_pm_opp *opp, struct device *dev,
375                               struct opp_table *opp_table)
376 {
377         u32 *microvolt, *microamp = NULL;
378         int supplies = opp_table->regulator_count, vcount, icount, ret, i, j;
379         struct property *prop = NULL;
380         char name[NAME_MAX];
381
382         /* Search for "opp-microvolt-<name>" */
383         if (opp_table->prop_name) {
384                 snprintf(name, sizeof(name), "opp-microvolt-%s",
385                          opp_table->prop_name);
386                 prop = of_find_property(opp->np, name, NULL);
387         }
388
389         if (!prop) {
390                 /* Search for "opp-microvolt" */
391                 sprintf(name, "opp-microvolt");
392                 prop = of_find_property(opp->np, name, NULL);
393
394                 /* Missing property isn't a problem, but an invalid entry is */
395                 if (!prop) {
396                         if (unlikely(supplies == -1)) {
397                                 /* Initialize regulator_count */
398                                 opp_table->regulator_count = 0;
399                                 return 0;
400                         }
401
402                         if (!supplies)
403                                 return 0;
404
405                         dev_err(dev, "%s: opp-microvolt missing although OPP managing regulators\n",
406                                 __func__);
407                         return -EINVAL;
408                 }
409         }
410
411         if (unlikely(supplies == -1)) {
412                 /* Initialize regulator_count */
413                 supplies = opp_table->regulator_count = 1;
414         } else if (unlikely(!supplies)) {
415                 dev_err(dev, "%s: opp-microvolt wasn't expected\n", __func__);
416                 return -EINVAL;
417         }
418
419         vcount = of_property_count_u32_elems(opp->np, name);
420         if (vcount < 0) {
421                 dev_err(dev, "%s: Invalid %s property (%d)\n",
422                         __func__, name, vcount);
423                 return vcount;
424         }
425
426         /* There can be one or three elements per supply */
427         if (vcount != supplies && vcount != supplies * 3) {
428                 dev_err(dev, "%s: Invalid number of elements in %s property (%d) with supplies (%d)\n",
429                         __func__, name, vcount, supplies);
430                 return -EINVAL;
431         }
432
433         microvolt = kmalloc_array(vcount, sizeof(*microvolt), GFP_KERNEL);
434         if (!microvolt)
435                 return -ENOMEM;
436
437         ret = of_property_read_u32_array(opp->np, name, microvolt, vcount);
438         if (ret) {
439                 dev_err(dev, "%s: error parsing %s: %d\n", __func__, name, ret);
440                 ret = -EINVAL;
441                 goto free_microvolt;
442         }
443
444         /* Search for "opp-microamp-<name>" */
445         prop = NULL;
446         if (opp_table->prop_name) {
447                 snprintf(name, sizeof(name), "opp-microamp-%s",
448                          opp_table->prop_name);
449                 prop = of_find_property(opp->np, name, NULL);
450         }
451
452         if (!prop) {
453                 /* Search for "opp-microamp" */
454                 sprintf(name, "opp-microamp");
455                 prop = of_find_property(opp->np, name, NULL);
456         }
457
458         if (prop) {
459                 icount = of_property_count_u32_elems(opp->np, name);
460                 if (icount < 0) {
461                         dev_err(dev, "%s: Invalid %s property (%d)\n", __func__,
462                                 name, icount);
463                         ret = icount;
464                         goto free_microvolt;
465                 }
466
467                 if (icount != supplies) {
468                         dev_err(dev, "%s: Invalid number of elements in %s property (%d) with supplies (%d)\n",
469                                 __func__, name, icount, supplies);
470                         ret = -EINVAL;
471                         goto free_microvolt;
472                 }
473
474                 microamp = kmalloc_array(icount, sizeof(*microamp), GFP_KERNEL);
475                 if (!microamp) {
476                         ret = -EINVAL;
477                         goto free_microvolt;
478                 }
479
480                 ret = of_property_read_u32_array(opp->np, name, microamp,
481                                                  icount);
482                 if (ret) {
483                         dev_err(dev, "%s: error parsing %s: %d\n", __func__,
484                                 name, ret);
485                         ret = -EINVAL;
486                         goto free_microamp;
487                 }
488         }
489
490         for (i = 0, j = 0; i < supplies; i++) {
491                 opp->supplies[i].u_volt = microvolt[j++];
492
493                 if (vcount == supplies) {
494                         opp->supplies[i].u_volt_min = opp->supplies[i].u_volt;
495                         opp->supplies[i].u_volt_max = opp->supplies[i].u_volt;
496                 } else {
497                         opp->supplies[i].u_volt_min = microvolt[j++];
498                         opp->supplies[i].u_volt_max = microvolt[j++];
499                 }
500
501                 if (microamp)
502                         opp->supplies[i].u_amp = microamp[i];
503         }
504
505 free_microamp:
506         kfree(microamp);
507 free_microvolt:
508         kfree(microvolt);
509
510         return ret;
511 }
512
513 /**
514  * dev_pm_opp_of_remove_table() - Free OPP table entries created from static DT
515  *                                entries
516  * @dev:        device pointer used to lookup OPP table.
517  *
518  * Free OPPs created using static entries present in DT.
519  */
520 void dev_pm_opp_of_remove_table(struct device *dev)
521 {
522         _dev_pm_opp_find_and_remove_table(dev);
523 }
524 EXPORT_SYMBOL_GPL(dev_pm_opp_of_remove_table);
525
526 /**
527  * _opp_add_static_v2() - Allocate static OPPs (As per 'v2' DT bindings)
528  * @opp_table:  OPP table
529  * @dev:        device for which we do this operation
530  * @np:         device node
531  *
532  * This function adds an opp definition to the opp table and returns status. The
533  * opp can be controlled using dev_pm_opp_enable/disable functions and may be
534  * removed by dev_pm_opp_remove.
535  *
536  * Return:
537  * Valid OPP pointer:
538  *              On success
539  * NULL:
540  *              Duplicate OPPs (both freq and volt are same) and opp->available
541  *              OR if the OPP is not supported by hardware.
542  * ERR_PTR(-EEXIST):
543  *              Freq are same and volt are different OR
544  *              Duplicate OPPs (both freq and volt are same) and !opp->available
545  * ERR_PTR(-ENOMEM):
546  *              Memory allocation failure
547  * ERR_PTR(-EINVAL):
548  *              Failed parsing the OPP node
549  */
550 static struct dev_pm_opp *_opp_add_static_v2(struct opp_table *opp_table,
551                 struct device *dev, struct device_node *np)
552 {
553         struct dev_pm_opp *new_opp;
554         u64 rate = 0;
555         u32 val;
556         int ret;
557         bool rate_not_available = false;
558
559         new_opp = _opp_allocate(opp_table);
560         if (!new_opp)
561                 return ERR_PTR(-ENOMEM);
562
563         ret = of_property_read_u64(np, "opp-hz", &rate);
564         if (ret < 0) {
565                 /* "opp-hz" is optional for devices like power domains. */
566                 if (!opp_table->is_genpd) {
567                         dev_err(dev, "%s: opp-hz not found\n", __func__);
568                         goto free_opp;
569                 }
570
571                 rate_not_available = true;
572         } else {
573                 /*
574                  * Rate is defined as an unsigned long in clk API, and so
575                  * casting explicitly to its type. Must be fixed once rate is 64
576                  * bit guaranteed in clk API.
577                  */
578                 new_opp->rate = (unsigned long)rate;
579         }
580
581         of_property_read_u32(np, "opp-level", &new_opp->level);
582
583         /* Check if the OPP supports hardware's hierarchy of versions or not */
584         if (!_opp_is_supported(dev, opp_table, np)) {
585                 dev_dbg(dev, "OPP not supported by hardware: %llu\n", rate);
586                 goto free_opp;
587         }
588
589         new_opp->turbo = of_property_read_bool(np, "turbo-mode");
590
591         new_opp->np = np;
592         new_opp->dynamic = false;
593         new_opp->available = true;
594
595         ret = _of_opp_alloc_required_opps(opp_table, new_opp);
596         if (ret)
597                 goto free_opp;
598
599         if (!of_property_read_u32(np, "clock-latency-ns", &val))
600                 new_opp->clock_latency_ns = val;
601
602         ret = opp_parse_supplies(new_opp, dev, opp_table);
603         if (ret)
604                 goto free_required_opps;
605
606         if (opp_table->is_genpd)
607                 new_opp->pstate = pm_genpd_opp_to_performance_state(dev, new_opp);
608
609         ret = _opp_add(dev, new_opp, opp_table, rate_not_available);
610         if (ret) {
611                 /* Don't return error for duplicate OPPs */
612                 if (ret == -EBUSY)
613                         ret = 0;
614                 goto free_required_opps;
615         }
616
617         /* OPP to select on device suspend */
618         if (of_property_read_bool(np, "opp-suspend")) {
619                 if (opp_table->suspend_opp) {
620                         /* Pick the OPP with higher rate as suspend OPP */
621                         if (new_opp->rate > opp_table->suspend_opp->rate) {
622                                 opp_table->suspend_opp->suspend = false;
623                                 new_opp->suspend = true;
624                                 opp_table->suspend_opp = new_opp;
625                         }
626                 } else {
627                         new_opp->suspend = true;
628                         opp_table->suspend_opp = new_opp;
629                 }
630         }
631
632         if (new_opp->clock_latency_ns > opp_table->clock_latency_ns_max)
633                 opp_table->clock_latency_ns_max = new_opp->clock_latency_ns;
634
635         pr_debug("%s: turbo:%d rate:%lu uv:%lu uvmin:%lu uvmax:%lu latency:%lu\n",
636                  __func__, new_opp->turbo, new_opp->rate,
637                  new_opp->supplies[0].u_volt, new_opp->supplies[0].u_volt_min,
638                  new_opp->supplies[0].u_volt_max, new_opp->clock_latency_ns);
639
640         /*
641          * Notify the changes in the availability of the operable
642          * frequency/voltage list.
643          */
644         blocking_notifier_call_chain(&opp_table->head, OPP_EVENT_ADD, new_opp);
645         return new_opp;
646
647 free_required_opps:
648         _of_opp_free_required_opps(opp_table, new_opp);
649 free_opp:
650         _opp_free(new_opp);
651
652         return ERR_PTR(ret);
653 }
654
655 /* Initializes OPP tables based on new bindings */
656 static int _of_add_opp_table_v2(struct device *dev, struct opp_table *opp_table)
657 {
658         struct device_node *np;
659         int ret, count = 0, pstate_count = 0;
660         struct dev_pm_opp *opp;
661
662         /* OPP table is already initialized for the device */
663         if (opp_table->parsed_static_opps) {
664                 kref_get(&opp_table->list_kref);
665                 return 0;
666         }
667
668         /* We have opp-table node now, iterate over it and add OPPs */
669         for_each_available_child_of_node(opp_table->np, np) {
670                 opp = _opp_add_static_v2(opp_table, dev, np);
671                 if (IS_ERR(opp)) {
672                         ret = PTR_ERR(opp);
673                         dev_err(dev, "%s: Failed to add OPP, %d\n", __func__,
674                                 ret);
675                         of_node_put(np);
676                         return ret;
677                 } else if (opp) {
678                         count++;
679                 }
680         }
681
682         /* There should be one of more OPP defined */
683         if (WARN_ON(!count))
684                 return -ENOENT;
685
686         list_for_each_entry(opp, &opp_table->opp_list, node)
687                 pstate_count += !!opp->pstate;
688
689         /* Either all or none of the nodes shall have performance state set */
690         if (pstate_count && pstate_count != count) {
691                 dev_err(dev, "Not all nodes have performance state set (%d: %d)\n",
692                         count, pstate_count);
693                 return -ENOENT;
694         }
695
696         if (pstate_count)
697                 opp_table->genpd_performance_state = true;
698
699         opp_table->parsed_static_opps = true;
700
701         return 0;
702 }
703
704 /* Initializes OPP tables based on old-deprecated bindings */
705 static int _of_add_opp_table_v1(struct device *dev, struct opp_table *opp_table)
706 {
707         const struct property *prop;
708         const __be32 *val;
709         int nr, ret = 0;
710
711         prop = of_find_property(dev->of_node, "operating-points", NULL);
712         if (!prop)
713                 return -ENODEV;
714         if (!prop->value)
715                 return -ENODATA;
716
717         /*
718          * Each OPP is a set of tuples consisting of frequency and
719          * voltage like <freq-kHz vol-uV>.
720          */
721         nr = prop->length / sizeof(u32);
722         if (nr % 2) {
723                 dev_err(dev, "%s: Invalid OPP table\n", __func__);
724                 return -EINVAL;
725         }
726
727         val = prop->value;
728         while (nr) {
729                 unsigned long freq = be32_to_cpup(val++) * 1000;
730                 unsigned long volt = be32_to_cpup(val++);
731
732                 ret = _opp_add_v1(opp_table, dev, freq, volt, false);
733                 if (ret) {
734                         dev_err(dev, "%s: Failed to add OPP %ld (%d)\n",
735                                 __func__, freq, ret);
736                         return ret;
737                 }
738                 nr -= 2;
739         }
740
741         return ret;
742 }
743
744 /**
745  * dev_pm_opp_of_add_table() - Initialize opp table from device tree
746  * @dev:        device pointer used to lookup OPP table.
747  *
748  * Register the initial OPP table with the OPP library for given device.
749  *
750  * Return:
751  * 0            On success OR
752  *              Duplicate OPPs (both freq and volt are same) and opp->available
753  * -EEXIST      Freq are same and volt are different OR
754  *              Duplicate OPPs (both freq and volt are same) and !opp->available
755  * -ENOMEM      Memory allocation failure
756  * -ENODEV      when 'operating-points' property is not found or is invalid data
757  *              in device node.
758  * -ENODATA     when empty 'operating-points' property is found
759  * -EINVAL      when invalid entries are found in opp-v2 table
760  */
761 int dev_pm_opp_of_add_table(struct device *dev)
762 {
763         struct opp_table *opp_table;
764         int ret;
765
766         opp_table = dev_pm_opp_get_opp_table_indexed(dev, 0);
767         if (!opp_table)
768                 return -ENOMEM;
769
770         /*
771          * OPPs have two version of bindings now. Also try the old (v1)
772          * bindings for backward compatibility with older dtbs.
773          */
774         if (opp_table->np)
775                 ret = _of_add_opp_table_v2(dev, opp_table);
776         else
777                 ret = _of_add_opp_table_v1(dev, opp_table);
778
779         if (ret)
780                 dev_pm_opp_put_opp_table(opp_table);
781
782         return ret;
783 }
784 EXPORT_SYMBOL_GPL(dev_pm_opp_of_add_table);
785
786 /**
787  * dev_pm_opp_of_add_table_indexed() - Initialize indexed opp table from device tree
788  * @dev:        device pointer used to lookup OPP table.
789  * @index:      Index number.
790  *
791  * Register the initial OPP table with the OPP library for given device only
792  * using the "operating-points-v2" property.
793  *
794  * Return:
795  * 0            On success OR
796  *              Duplicate OPPs (both freq and volt are same) and opp->available
797  * -EEXIST      Freq are same and volt are different OR
798  *              Duplicate OPPs (both freq and volt are same) and !opp->available
799  * -ENOMEM      Memory allocation failure
800  * -ENODEV      when 'operating-points' property is not found or is invalid data
801  *              in device node.
802  * -ENODATA     when empty 'operating-points' property is found
803  * -EINVAL      when invalid entries are found in opp-v2 table
804  */
805 int dev_pm_opp_of_add_table_indexed(struct device *dev, int index)
806 {
807         struct opp_table *opp_table;
808         int ret, count;
809
810         if (index) {
811                 /*
812                  * If only one phandle is present, then the same OPP table
813                  * applies for all index requests.
814                  */
815                 count = of_count_phandle_with_args(dev->of_node,
816                                                    "operating-points-v2", NULL);
817                 if (count == 1)
818                         index = 0;
819         }
820
821         opp_table = dev_pm_opp_get_opp_table_indexed(dev, index);
822         if (!opp_table)
823                 return -ENOMEM;
824
825         ret = _of_add_opp_table_v2(dev, opp_table);
826         if (ret)
827                 dev_pm_opp_put_opp_table(opp_table);
828
829         return ret;
830 }
831 EXPORT_SYMBOL_GPL(dev_pm_opp_of_add_table_indexed);
832
833 /* CPU device specific helpers */
834
835 /**
836  * dev_pm_opp_of_cpumask_remove_table() - Removes OPP table for @cpumask
837  * @cpumask:    cpumask for which OPP table needs to be removed
838  *
839  * This removes the OPP tables for CPUs present in the @cpumask.
840  * This should be used only to remove static entries created from DT.
841  */
842 void dev_pm_opp_of_cpumask_remove_table(const struct cpumask *cpumask)
843 {
844         _dev_pm_opp_cpumask_remove_table(cpumask, -1);
845 }
846 EXPORT_SYMBOL_GPL(dev_pm_opp_of_cpumask_remove_table);
847
848 /**
849  * dev_pm_opp_of_cpumask_add_table() - Adds OPP table for @cpumask
850  * @cpumask:    cpumask for which OPP table needs to be added.
851  *
852  * This adds the OPP tables for CPUs present in the @cpumask.
853  */
854 int dev_pm_opp_of_cpumask_add_table(const struct cpumask *cpumask)
855 {
856         struct device *cpu_dev;
857         int cpu, ret;
858
859         if (WARN_ON(cpumask_empty(cpumask)))
860                 return -ENODEV;
861
862         for_each_cpu(cpu, cpumask) {
863                 cpu_dev = get_cpu_device(cpu);
864                 if (!cpu_dev) {
865                         pr_err("%s: failed to get cpu%d device\n", __func__,
866                                cpu);
867                         ret = -ENODEV;
868                         goto remove_table;
869                 }
870
871                 ret = dev_pm_opp_of_add_table(cpu_dev);
872                 if (ret) {
873                         /*
874                          * OPP may get registered dynamically, don't print error
875                          * message here.
876                          */
877                         pr_debug("%s: couldn't find opp table for cpu:%d, %d\n",
878                                  __func__, cpu, ret);
879
880                         goto remove_table;
881                 }
882         }
883
884         return 0;
885
886 remove_table:
887         /* Free all other OPPs */
888         _dev_pm_opp_cpumask_remove_table(cpumask, cpu);
889
890         return ret;
891 }
892 EXPORT_SYMBOL_GPL(dev_pm_opp_of_cpumask_add_table);
893
894 /*
895  * Works only for OPP v2 bindings.
896  *
897  * Returns -ENOENT if operating-points-v2 bindings aren't supported.
898  */
899 /**
900  * dev_pm_opp_of_get_sharing_cpus() - Get cpumask of CPUs sharing OPPs with
901  *                                    @cpu_dev using operating-points-v2
902  *                                    bindings.
903  *
904  * @cpu_dev:    CPU device for which we do this operation
905  * @cpumask:    cpumask to update with information of sharing CPUs
906  *
907  * This updates the @cpumask with CPUs that are sharing OPPs with @cpu_dev.
908  *
909  * Returns -ENOENT if operating-points-v2 isn't present for @cpu_dev.
910  */
911 int dev_pm_opp_of_get_sharing_cpus(struct device *cpu_dev,
912                                    struct cpumask *cpumask)
913 {
914         struct device_node *np, *tmp_np, *cpu_np;
915         int cpu, ret = 0;
916
917         /* Get OPP descriptor node */
918         np = dev_pm_opp_of_get_opp_desc_node(cpu_dev);
919         if (!np) {
920                 dev_dbg(cpu_dev, "%s: Couldn't find opp node.\n", __func__);
921                 return -ENOENT;
922         }
923
924         cpumask_set_cpu(cpu_dev->id, cpumask);
925
926         /* OPPs are shared ? */
927         if (!of_property_read_bool(np, "opp-shared"))
928                 goto put_cpu_node;
929
930         for_each_possible_cpu(cpu) {
931                 if (cpu == cpu_dev->id)
932                         continue;
933
934                 cpu_np = of_cpu_device_node_get(cpu);
935                 if (!cpu_np) {
936                         dev_err(cpu_dev, "%s: failed to get cpu%d node\n",
937                                 __func__, cpu);
938                         ret = -ENOENT;
939                         goto put_cpu_node;
940                 }
941
942                 /* Get OPP descriptor node */
943                 tmp_np = _opp_of_get_opp_desc_node(cpu_np, 0);
944                 of_node_put(cpu_np);
945                 if (!tmp_np) {
946                         pr_err("%pOF: Couldn't find opp node\n", cpu_np);
947                         ret = -ENOENT;
948                         goto put_cpu_node;
949                 }
950
951                 /* CPUs are sharing opp node */
952                 if (np == tmp_np)
953                         cpumask_set_cpu(cpu, cpumask);
954
955                 of_node_put(tmp_np);
956         }
957
958 put_cpu_node:
959         of_node_put(np);
960         return ret;
961 }
962 EXPORT_SYMBOL_GPL(dev_pm_opp_of_get_sharing_cpus);
963
964 /**
965  * of_get_required_opp_performance_state() - Search for required OPP and return its performance state.
966  * @np: Node that contains the "required-opps" property.
967  * @index: Index of the phandle to parse.
968  *
969  * Returns the performance state of the OPP pointed out by the "required-opps"
970  * property at @index in @np.
971  *
972  * Return: Zero or positive performance state on success, otherwise negative
973  * value on errors.
974  */
975 int of_get_required_opp_performance_state(struct device_node *np, int index)
976 {
977         struct dev_pm_opp *opp;
978         struct device_node *required_np;
979         struct opp_table *opp_table;
980         int pstate = -EINVAL;
981
982         required_np = of_parse_required_opp(np, index);
983         if (!required_np)
984                 return -EINVAL;
985
986         opp_table = _find_table_of_opp_np(required_np);
987         if (IS_ERR(opp_table)) {
988                 pr_err("%s: Failed to find required OPP table %pOF: %ld\n",
989                        __func__, np, PTR_ERR(opp_table));
990                 goto put_required_np;
991         }
992
993         opp = _find_opp_of_np(opp_table, required_np);
994         if (opp) {
995                 pstate = opp->pstate;
996                 dev_pm_opp_put(opp);
997         }
998
999         dev_pm_opp_put_opp_table(opp_table);
1000
1001 put_required_np:
1002         of_node_put(required_np);
1003
1004         return pstate;
1005 }
1006 EXPORT_SYMBOL_GPL(of_get_required_opp_performance_state);
1007
1008 /**
1009  * dev_pm_opp_get_of_node() - Gets the DT node corresponding to an opp
1010  * @opp:        opp for which DT node has to be returned for
1011  *
1012  * Return: DT node corresponding to the opp, else 0 on success.
1013  *
1014  * The caller needs to put the node with of_node_put() after using it.
1015  */
1016 struct device_node *dev_pm_opp_get_of_node(struct dev_pm_opp *opp)
1017 {
1018         if (IS_ERR_OR_NULL(opp)) {
1019                 pr_err("%s: Invalid parameters\n", __func__);
1020                 return NULL;
1021         }
1022
1023         return of_node_get(opp->np);
1024 }
1025 EXPORT_SYMBOL_GPL(dev_pm_opp_get_of_node);
1026
1027 /*
1028  * Callback function provided to the Energy Model framework upon registration.
1029  * This computes the power estimated by @CPU at @kHz if it is the frequency
1030  * of an existing OPP, or at the frequency of the first OPP above @kHz otherwise
1031  * (see dev_pm_opp_find_freq_ceil()). This function updates @kHz to the ceiled
1032  * frequency and @mW to the associated power. The power is estimated as
1033  * P = C * V^2 * f with C being the CPU's capacitance and V and f respectively
1034  * the voltage and frequency of the OPP.
1035  *
1036  * Returns -ENODEV if the CPU device cannot be found, -EINVAL if the power
1037  * calculation failed because of missing parameters, 0 otherwise.
1038  */
1039 static int __maybe_unused _get_cpu_power(unsigned long *mW, unsigned long *kHz,
1040                                          int cpu)
1041 {
1042         struct device *cpu_dev;
1043         struct dev_pm_opp *opp;
1044         struct device_node *np;
1045         unsigned long mV, Hz;
1046         u32 cap;
1047         u64 tmp;
1048         int ret;
1049
1050         cpu_dev = get_cpu_device(cpu);
1051         if (!cpu_dev)
1052                 return -ENODEV;
1053
1054         np = of_node_get(cpu_dev->of_node);
1055         if (!np)
1056                 return -EINVAL;
1057
1058         ret = of_property_read_u32(np, "dynamic-power-coefficient", &cap);
1059         of_node_put(np);
1060         if (ret)
1061                 return -EINVAL;
1062
1063         Hz = *kHz * 1000;
1064         opp = dev_pm_opp_find_freq_ceil(cpu_dev, &Hz);
1065         if (IS_ERR(opp))
1066                 return -EINVAL;
1067
1068         mV = dev_pm_opp_get_voltage(opp) / 1000;
1069         dev_pm_opp_put(opp);
1070         if (!mV)
1071                 return -EINVAL;
1072
1073         tmp = (u64)cap * mV * mV * (Hz / 1000000);
1074         do_div(tmp, 1000000000);
1075
1076         *mW = (unsigned long)tmp;
1077         *kHz = Hz / 1000;
1078
1079         return 0;
1080 }
1081
1082 /**
1083  * dev_pm_opp_of_register_em() - Attempt to register an Energy Model
1084  * @cpus        : CPUs for which an Energy Model has to be registered
1085  *
1086  * This checks whether the "dynamic-power-coefficient" devicetree property has
1087  * been specified, and tries to register an Energy Model with it if it has.
1088  */
1089 void dev_pm_opp_of_register_em(struct cpumask *cpus)
1090 {
1091         struct em_data_callback em_cb = EM_DATA_CB(_get_cpu_power);
1092         int ret, nr_opp, cpu = cpumask_first(cpus);
1093         struct device *cpu_dev;
1094         struct device_node *np;
1095         u32 cap;
1096
1097         cpu_dev = get_cpu_device(cpu);
1098         if (!cpu_dev)
1099                 return;
1100
1101         nr_opp = dev_pm_opp_get_opp_count(cpu_dev);
1102         if (nr_opp <= 0)
1103                 return;
1104
1105         np = of_node_get(cpu_dev->of_node);
1106         if (!np)
1107                 return;
1108
1109         /*
1110          * Register an EM only if the 'dynamic-power-coefficient' property is
1111          * set in devicetree. It is assumed the voltage values are known if that
1112          * property is set since it is useless otherwise. If voltages are not
1113          * known, just let the EM registration fail with an error to alert the
1114          * user about the inconsistent configuration.
1115          */
1116         ret = of_property_read_u32(np, "dynamic-power-coefficient", &cap);
1117         of_node_put(np);
1118         if (ret || !cap)
1119                 return;
1120
1121         em_register_perf_domain(cpus, nr_opp, &em_cb);
1122 }
1123 EXPORT_SYMBOL_GPL(dev_pm_opp_of_register_em);