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