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1/*
2 * Generic OPP OF helpers
3 *
4 * Copyright (C) 2009-2010 Texas Instruments Incorporated.
5 * Nishanth Menon
6 * Romit Dasgupta
7 * Kevin Hilman
8 *
9 * This program is free software; you can redistribute it and/or modify
10 * it under the terms of the GNU General Public License version 2 as
11 * published by the Free Software Foundation.
12 */
13
14#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
15
16#include <linux/cpu.h>
17#include <linux/errno.h>
18#include <linux/device.h>
19#include <linux/of_device.h>
20#include <linux/slab.h>
21#include <linux/export.h>
22
23#include "opp.h"
24
25static struct opp_table *_managed_opp(const struct device_node *np)
26{
27 struct opp_table *opp_table, *managed_table = NULL;
28
29 mutex_lock(&opp_table_lock);
30
31 list_for_each_entry(opp_table, &opp_tables, node) {
32 if (opp_table->np == np) {
33 /*
34 * Multiple devices can point to the same OPP table and
35 * so will have same node-pointer, np.
36 *
37 * But the OPPs will be considered as shared only if the
38 * OPP table contains a "opp-shared" property.
39 */
40 if (opp_table->shared_opp == OPP_TABLE_ACCESS_SHARED) {
41 _get_opp_table_kref(opp_table);
42 managed_table = opp_table;
43 }
44
45 break;
46 }
47 }
48
49 mutex_unlock(&opp_table_lock);
50
51 return managed_table;
52}
53
54void _of_init_opp_table(struct opp_table *opp_table, struct device *dev)
55{
56 struct device_node *np;
57
58 /*
59 * Only required for backward compatibility with v1 bindings, but isn't
60 * harmful for other cases. And so we do it unconditionally.
61 */
62 np = of_node_get(dev->of_node);
63 if (np) {
64 u32 val;
65
66 if (!of_property_read_u32(np, "clock-latency", &val))
67 opp_table->clock_latency_ns_max = val;
68 of_property_read_u32(np, "voltage-tolerance",
69 &opp_table->voltage_tolerance_v1);
70 of_node_put(np);
71 }
72}
73
74static bool _opp_is_supported(struct device *dev, struct opp_table *opp_table,
75 struct device_node *np)
76{
77 unsigned int count = opp_table->supported_hw_count;
78 u32 version;
79 int ret;
80
81 if (!opp_table->supported_hw) {
82 /*
83 * In the case that no supported_hw has been set by the
84 * platform but there is an opp-supported-hw value set for
85 * an OPP then the OPP should not be enabled as there is
86 * no way to see if the hardware supports it.
87 */
88 if (of_find_property(np, "opp-supported-hw", NULL))
89 return false;
90 else
91 return true;
92 }
93
94 while (count--) {
95 ret = of_property_read_u32_index(np, "opp-supported-hw", count,
96 &version);
97 if (ret) {
98 dev_warn(dev, "%s: failed to read opp-supported-hw property at index %d: %d\n",
99 __func__, count, ret);
100 return false;
101 }
102
103 /* Both of these are bitwise masks of the versions */
104 if (!(version & opp_table->supported_hw[count]))
105 return false;
106 }
107
108 return true;
109}
110
111static int opp_parse_supplies(struct dev_pm_opp *opp, struct device *dev,
112 struct opp_table *opp_table)
113{
114 u32 *microvolt, *microamp = NULL;
115 int supplies, vcount, icount, ret, i, j;
116 struct property *prop = NULL;
117 char name[NAME_MAX];
118
119 supplies = opp_table->regulator_count ? opp_table->regulator_count : 1;
120
121 /* Search for "opp-microvolt-<name>" */
122 if (opp_table->prop_name) {
123 snprintf(name, sizeof(name), "opp-microvolt-%s",
124 opp_table->prop_name);
125 prop = of_find_property(opp->np, name, NULL);
126 }
127
128 if (!prop) {
129 /* Search for "opp-microvolt" */
130 sprintf(name, "opp-microvolt");
131 prop = of_find_property(opp->np, name, NULL);
132
133 /* Missing property isn't a problem, but an invalid entry is */
134 if (!prop) {
135 if (!opp_table->regulator_count)
136 return 0;
137
138 dev_err(dev, "%s: opp-microvolt missing although OPP managing regulators\n",
139 __func__);
140 return -EINVAL;
141 }
142 }
143
144 vcount = of_property_count_u32_elems(opp->np, name);
145 if (vcount < 0) {
146 dev_err(dev, "%s: Invalid %s property (%d)\n",
147 __func__, name, vcount);
148 return vcount;
149 }
150
151 /* There can be one or three elements per supply */
152 if (vcount != supplies && vcount != supplies * 3) {
153 dev_err(dev, "%s: Invalid number of elements in %s property (%d) with supplies (%d)\n",
154 __func__, name, vcount, supplies);
155 return -EINVAL;
156 }
157
158 microvolt = kmalloc_array(vcount, sizeof(*microvolt), GFP_KERNEL);
159 if (!microvolt)
160 return -ENOMEM;
161
162 ret = of_property_read_u32_array(opp->np, name, microvolt, vcount);
163 if (ret) {
164 dev_err(dev, "%s: error parsing %s: %d\n", __func__, name, ret);
165 ret = -EINVAL;
166 goto free_microvolt;
167 }
168
169 /* Search for "opp-microamp-<name>" */
170 prop = NULL;
171 if (opp_table->prop_name) {
172 snprintf(name, sizeof(name), "opp-microamp-%s",
173 opp_table->prop_name);
174 prop = of_find_property(opp->np, name, NULL);
175 }
176
177 if (!prop) {
178 /* Search for "opp-microamp" */
179 sprintf(name, "opp-microamp");
180 prop = of_find_property(opp->np, name, NULL);
181 }
182
183 if (prop) {
184 icount = of_property_count_u32_elems(opp->np, name);
185 if (icount < 0) {
186 dev_err(dev, "%s: Invalid %s property (%d)\n", __func__,
187 name, icount);
188 ret = icount;
189 goto free_microvolt;
190 }
191
192 if (icount != supplies) {
193 dev_err(dev, "%s: Invalid number of elements in %s property (%d) with supplies (%d)\n",
194 __func__, name, icount, supplies);
195 ret = -EINVAL;
196 goto free_microvolt;
197 }
198
199 microamp = kmalloc_array(icount, sizeof(*microamp), GFP_KERNEL);
200 if (!microamp) {
201 ret = -EINVAL;
202 goto free_microvolt;
203 }
204
205 ret = of_property_read_u32_array(opp->np, name, microamp,
206 icount);
207 if (ret) {
208 dev_err(dev, "%s: error parsing %s: %d\n", __func__,
209 name, ret);
210 ret = -EINVAL;
211 goto free_microamp;
212 }
213 }
214
215 for (i = 0, j = 0; i < supplies; i++) {
216 opp->supplies[i].u_volt = microvolt[j++];
217
218 if (vcount == supplies) {
219 opp->supplies[i].u_volt_min = opp->supplies[i].u_volt;
220 opp->supplies[i].u_volt_max = opp->supplies[i].u_volt;
221 } else {
222 opp->supplies[i].u_volt_min = microvolt[j++];
223 opp->supplies[i].u_volt_max = microvolt[j++];
224 }
225
226 if (microamp)
227 opp->supplies[i].u_amp = microamp[i];
228 }
229
230free_microamp:
231 kfree(microamp);
232free_microvolt:
233 kfree(microvolt);
234
235 return ret;
236}
237
238/**
239 * dev_pm_opp_of_remove_table() - Free OPP table entries created from static DT
240 * entries
241 * @dev: device pointer used to lookup OPP table.
242 *
243 * Free OPPs created using static entries present in DT.
244 */
245void dev_pm_opp_of_remove_table(struct device *dev)
246{
247 _dev_pm_opp_find_and_remove_table(dev, false);
248}
249EXPORT_SYMBOL_GPL(dev_pm_opp_of_remove_table);
250
251/* Returns opp descriptor node for a device node, caller must
252 * do of_node_put() */
253static struct device_node *_opp_of_get_opp_desc_node(struct device_node *np)
254{
255 /*
256 * There should be only ONE phandle present in "operating-points-v2"
257 * property.
258 */
259
260 return of_parse_phandle(np, "operating-points-v2", 0);
261}
262
263/* Returns opp descriptor node for a device, caller must do of_node_put() */
264struct device_node *dev_pm_opp_of_get_opp_desc_node(struct device *dev)
265{
266 return _opp_of_get_opp_desc_node(dev->of_node);
267}
268EXPORT_SYMBOL_GPL(dev_pm_opp_of_get_opp_desc_node);
269
270/**
271 * _opp_add_static_v2() - Allocate static OPPs (As per 'v2' DT bindings)
272 * @opp_table: OPP table
273 * @dev: device for which we do this operation
274 * @np: device node
275 *
276 * This function adds an opp definition to the opp table and returns status. The
277 * opp can be controlled using dev_pm_opp_enable/disable functions and may be
278 * removed by dev_pm_opp_remove.
279 *
280 * Return:
281 * 0 On success OR
282 * Duplicate OPPs (both freq and volt are same) and opp->available
283 * -EEXIST Freq are same and volt are different OR
284 * Duplicate OPPs (both freq and volt are same) and !opp->available
285 * -ENOMEM Memory allocation failure
286 * -EINVAL Failed parsing the OPP node
287 */
288static int _opp_add_static_v2(struct opp_table *opp_table, struct device *dev,
289 struct device_node *np)
290{
291 struct dev_pm_opp *new_opp;
292 u64 rate;
293 u32 val;
294 int ret;
295
296 new_opp = _opp_allocate(opp_table);
297 if (!new_opp)
298 return -ENOMEM;
299
300 ret = of_property_read_u64(np, "opp-hz", &rate);
301 if (ret < 0) {
302 dev_err(dev, "%s: opp-hz not found\n", __func__);
303 goto free_opp;
304 }
305
306 /* Check if the OPP supports hardware's hierarchy of versions or not */
307 if (!_opp_is_supported(dev, opp_table, np)) {
308 dev_dbg(dev, "OPP not supported by hardware: %llu\n", rate);
309 goto free_opp;
310 }
311
312 /*
313 * Rate is defined as an unsigned long in clk API, and so casting
314 * explicitly to its type. Must be fixed once rate is 64 bit
315 * guaranteed in clk API.
316 */
317 new_opp->rate = (unsigned long)rate;
318 new_opp->turbo = of_property_read_bool(np, "turbo-mode");
319
320 new_opp->np = np;
321 new_opp->dynamic = false;
322 new_opp->available = true;
323
324 if (!of_property_read_u32(np, "clock-latency-ns", &val))
325 new_opp->clock_latency_ns = val;
326
327 ret = opp_parse_supplies(new_opp, dev, opp_table);
328 if (ret)
329 goto free_opp;
330
331 ret = _opp_add(dev, new_opp, opp_table);
332 if (ret) {
333 /* Don't return error for duplicate OPPs */
334 if (ret == -EBUSY)
335 ret = 0;
336 goto free_opp;
337 }
338
339 /* OPP to select on device suspend */
340 if (of_property_read_bool(np, "opp-suspend")) {
341 if (opp_table->suspend_opp) {
342 dev_warn(dev, "%s: Multiple suspend OPPs found (%lu %lu)\n",
343 __func__, opp_table->suspend_opp->rate,
344 new_opp->rate);
345 } else {
346 new_opp->suspend = true;
347 opp_table->suspend_opp = new_opp;
348 }
349 }
350
351 if (new_opp->clock_latency_ns > opp_table->clock_latency_ns_max)
352 opp_table->clock_latency_ns_max = new_opp->clock_latency_ns;
353
354 pr_debug("%s: turbo:%d rate:%lu uv:%lu uvmin:%lu uvmax:%lu latency:%lu\n",
355 __func__, new_opp->turbo, new_opp->rate,
356 new_opp->supplies[0].u_volt, new_opp->supplies[0].u_volt_min,
357 new_opp->supplies[0].u_volt_max, new_opp->clock_latency_ns);
358
359 /*
360 * Notify the changes in the availability of the operable
361 * frequency/voltage list.
362 */
363 blocking_notifier_call_chain(&opp_table->head, OPP_EVENT_ADD, new_opp);
364 return 0;
365
366free_opp:
367 _opp_free(new_opp);
368
369 return ret;
370}
371
372/* Initializes OPP tables based on new bindings */
373static int _of_add_opp_table_v2(struct device *dev, struct device_node *opp_np)
374{
375 struct device_node *np;
376 struct opp_table *opp_table;
377 int ret = 0, count = 0;
378
379 opp_table = _managed_opp(opp_np);
380 if (opp_table) {
381 /* OPPs are already managed */
382 if (!_add_opp_dev(dev, opp_table))
383 ret = -ENOMEM;
384 goto put_opp_table;
385 }
386
387 opp_table = dev_pm_opp_get_opp_table(dev);
388 if (!opp_table)
389 return -ENOMEM;
390
391 /* We have opp-table node now, iterate over it and add OPPs */
392 for_each_available_child_of_node(opp_np, np) {
393 count++;
394
395 ret = _opp_add_static_v2(opp_table, dev, np);
396 if (ret) {
397 dev_err(dev, "%s: Failed to add OPP, %d\n", __func__,
398 ret);
399 _dev_pm_opp_remove_table(opp_table, dev, false);
400 of_node_put(np);
401 goto put_opp_table;
402 }
403 }
404
405 /* There should be one of more OPP defined */
406 if (WARN_ON(!count)) {
407 ret = -ENOENT;
408 goto put_opp_table;
409 }
410
411 opp_table->np = opp_np;
412 if (of_property_read_bool(opp_np, "opp-shared"))
413 opp_table->shared_opp = OPP_TABLE_ACCESS_SHARED;
414 else
415 opp_table->shared_opp = OPP_TABLE_ACCESS_EXCLUSIVE;
416
417put_opp_table:
418 dev_pm_opp_put_opp_table(opp_table);
419
420 return ret;
421}
422
423/* Initializes OPP tables based on old-deprecated bindings */
424static int _of_add_opp_table_v1(struct device *dev)
425{
426 struct opp_table *opp_table;
427 const struct property *prop;
428 const __be32 *val;
429 int nr, ret = 0;
430
431 prop = of_find_property(dev->of_node, "operating-points", NULL);
432 if (!prop)
433 return -ENODEV;
434 if (!prop->value)
435 return -ENODATA;
436
437 /*
438 * Each OPP is a set of tuples consisting of frequency and
439 * voltage like <freq-kHz vol-uV>.
440 */
441 nr = prop->length / sizeof(u32);
442 if (nr % 2) {
443 dev_err(dev, "%s: Invalid OPP table\n", __func__);
444 return -EINVAL;
445 }
446
447 opp_table = dev_pm_opp_get_opp_table(dev);
448 if (!opp_table)
449 return -ENOMEM;
450
451 val = prop->value;
452 while (nr) {
453 unsigned long freq = be32_to_cpup(val++) * 1000;
454 unsigned long volt = be32_to_cpup(val++);
455
456 ret = _opp_add_v1(opp_table, dev, freq, volt, false);
457 if (ret) {
458 dev_err(dev, "%s: Failed to add OPP %ld (%d)\n",
459 __func__, freq, ret);
460 _dev_pm_opp_remove_table(opp_table, dev, false);
461 break;
462 }
463 nr -= 2;
464 }
465
466 dev_pm_opp_put_opp_table(opp_table);
467 return ret;
468}
469
470/**
471 * dev_pm_opp_of_add_table() - Initialize opp table from device tree
472 * @dev: device pointer used to lookup OPP table.
473 *
474 * Register the initial OPP table with the OPP library for given device.
475 *
476 * Return:
477 * 0 On success OR
478 * Duplicate OPPs (both freq and volt are same) and opp->available
479 * -EEXIST Freq are same and volt are different OR
480 * Duplicate OPPs (both freq and volt are same) and !opp->available
481 * -ENOMEM Memory allocation failure
482 * -ENODEV when 'operating-points' property is not found or is invalid data
483 * in device node.
484 * -ENODATA when empty 'operating-points' property is found
485 * -EINVAL when invalid entries are found in opp-v2 table
486 */
487int dev_pm_opp_of_add_table(struct device *dev)
488{
489 struct device_node *opp_np;
490 int ret;
491
492 /*
493 * OPPs have two version of bindings now. The older one is deprecated,
494 * try for the new binding first.
495 */
496 opp_np = dev_pm_opp_of_get_opp_desc_node(dev);
497 if (!opp_np) {
498 /*
499 * Try old-deprecated bindings for backward compatibility with
500 * older dtbs.
501 */
502 return _of_add_opp_table_v1(dev);
503 }
504
505 ret = _of_add_opp_table_v2(dev, opp_np);
506 of_node_put(opp_np);
507
508 return ret;
509}
510EXPORT_SYMBOL_GPL(dev_pm_opp_of_add_table);
511
512/* CPU device specific helpers */
513
514/**
515 * dev_pm_opp_of_cpumask_remove_table() - Removes OPP table for @cpumask
516 * @cpumask: cpumask for which OPP table needs to be removed
517 *
518 * This removes the OPP tables for CPUs present in the @cpumask.
519 * This should be used only to remove static entries created from DT.
520 */
521void dev_pm_opp_of_cpumask_remove_table(const struct cpumask *cpumask)
522{
523 _dev_pm_opp_cpumask_remove_table(cpumask, true);
524}
525EXPORT_SYMBOL_GPL(dev_pm_opp_of_cpumask_remove_table);
526
527/**
528 * dev_pm_opp_of_cpumask_add_table() - Adds OPP table for @cpumask
529 * @cpumask: cpumask for which OPP table needs to be added.
530 *
531 * This adds the OPP tables for CPUs present in the @cpumask.
532 */
533int dev_pm_opp_of_cpumask_add_table(const struct cpumask *cpumask)
534{
535 struct device *cpu_dev;
536 int cpu, ret = 0;
537
538 WARN_ON(cpumask_empty(cpumask));
539
540 for_each_cpu(cpu, cpumask) {
541 cpu_dev = get_cpu_device(cpu);
542 if (!cpu_dev) {
543 pr_err("%s: failed to get cpu%d device\n", __func__,
544 cpu);
545 continue;
546 }
547
548 ret = dev_pm_opp_of_add_table(cpu_dev);
549 if (ret) {
550 /*
551 * OPP may get registered dynamically, don't print error
552 * message here.
553 */
554 pr_debug("%s: couldn't find opp table for cpu:%d, %d\n",
555 __func__, cpu, ret);
556
557 /* Free all other OPPs */
558 dev_pm_opp_of_cpumask_remove_table(cpumask);
559 break;
560 }
561 }
562
563 return ret;
564}
565EXPORT_SYMBOL_GPL(dev_pm_opp_of_cpumask_add_table);
566
567/*
568 * Works only for OPP v2 bindings.
569 *
570 * Returns -ENOENT if operating-points-v2 bindings aren't supported.
571 */
572/**
573 * dev_pm_opp_of_get_sharing_cpus() - Get cpumask of CPUs sharing OPPs with
574 * @cpu_dev using operating-points-v2
575 * bindings.
576 *
577 * @cpu_dev: CPU device for which we do this operation
578 * @cpumask: cpumask to update with information of sharing CPUs
579 *
580 * This updates the @cpumask with CPUs that are sharing OPPs with @cpu_dev.
581 *
582 * Returns -ENOENT if operating-points-v2 isn't present for @cpu_dev.
583 */
584int dev_pm_opp_of_get_sharing_cpus(struct device *cpu_dev,
585 struct cpumask *cpumask)
586{
587 struct device_node *np, *tmp_np, *cpu_np;
588 int cpu, ret = 0;
589
590 /* Get OPP descriptor node */
591 np = dev_pm_opp_of_get_opp_desc_node(cpu_dev);
592 if (!np) {
593 dev_dbg(cpu_dev, "%s: Couldn't find opp node.\n", __func__);
594 return -ENOENT;
595 }
596
597 cpumask_set_cpu(cpu_dev->id, cpumask);
598
599 /* OPPs are shared ? */
600 if (!of_property_read_bool(np, "opp-shared"))
601 goto put_cpu_node;
602
603 for_each_possible_cpu(cpu) {
604 if (cpu == cpu_dev->id)
605 continue;
606
607 cpu_np = of_cpu_device_node_get(cpu);
608 if (!cpu_np) {
609 dev_err(cpu_dev, "%s: failed to get cpu%d node\n",
610 __func__, cpu);
611 ret = -ENOENT;
612 goto put_cpu_node;
613 }
614
615 /* Get OPP descriptor node */
616 tmp_np = _opp_of_get_opp_desc_node(cpu_np);
617 of_node_put(cpu_np);
618 if (!tmp_np) {
619 pr_err("%pOF: Couldn't find opp node\n", cpu_np);
620 ret = -ENOENT;
621 goto put_cpu_node;
622 }
623
624 /* CPUs are sharing opp node */
625 if (np == tmp_np)
626 cpumask_set_cpu(cpu, cpumask);
627
628 of_node_put(tmp_np);
629 }
630
631put_cpu_node:
632 of_node_put(np);
633 return ret;
634}
635EXPORT_SYMBOL_GPL(dev_pm_opp_of_get_sharing_cpus);