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