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1/*
2 * ARM big.LITTLE Platforms CPUFreq support
3 *
4 * Copyright (C) 2013 ARM Ltd.
5 * Sudeep KarkadaNagesha <sudeep.karkadanagesha@arm.com>
6 *
7 * Copyright (C) 2013 Linaro.
8 * Viresh Kumar <viresh.kumar@linaro.org>
9 *
10 * This program is free software; you can redistribute it and/or modify
11 * it under the terms of the GNU General Public License version 2 as
12 * published by the Free Software Foundation.
13 *
14 * This program is distributed "as is" WITHOUT ANY WARRANTY of any
15 * kind, whether express or implied; without even the implied warranty
16 * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
17 * GNU General Public License for more details.
18 */
19
20#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
21
22#include <linux/clk.h>
23#include <linux/cpu.h>
24#include <linux/cpufreq.h>
25#include <linux/cpumask.h>
26#include <linux/cpu_cooling.h>
27#include <linux/export.h>
28#include <linux/module.h>
29#include <linux/mutex.h>
30#include <linux/of_platform.h>
31#include <linux/pm_opp.h>
32#include <linux/slab.h>
33#include <linux/topology.h>
34#include <linux/types.h>
35
36#include "arm_big_little.h"
37
38/* Currently we support only two clusters */
39#define A15_CLUSTER 0
40#define A7_CLUSTER 1
41#define MAX_CLUSTERS 2
42
43#ifdef CONFIG_BL_SWITCHER
44#include <asm/bL_switcher.h>
45static bool bL_switching_enabled;
46#define is_bL_switching_enabled() bL_switching_enabled
47#define set_switching_enabled(x) (bL_switching_enabled = (x))
48#else
49#define is_bL_switching_enabled() false
50#define set_switching_enabled(x) do { } while (0)
51#define bL_switch_request(...) do { } while (0)
52#define bL_switcher_put_enabled() do { } while (0)
53#define bL_switcher_get_enabled() do { } while (0)
54#endif
55
56#define ACTUAL_FREQ(cluster, freq) ((cluster == A7_CLUSTER) ? freq << 1 : freq)
57#define VIRT_FREQ(cluster, freq) ((cluster == A7_CLUSTER) ? freq >> 1 : freq)
58
59static struct thermal_cooling_device *cdev[MAX_CLUSTERS];
60static struct cpufreq_arm_bL_ops *arm_bL_ops;
61static struct clk *clk[MAX_CLUSTERS];
62static struct cpufreq_frequency_table *freq_table[MAX_CLUSTERS + 1];
63static atomic_t cluster_usage[MAX_CLUSTERS + 1];
64
65static unsigned int clk_big_min; /* (Big) clock frequencies */
66static unsigned int clk_little_max; /* Maximum clock frequency (Little) */
67
68static DEFINE_PER_CPU(unsigned int, physical_cluster);
69static DEFINE_PER_CPU(unsigned int, cpu_last_req_freq);
70
71static struct mutex cluster_lock[MAX_CLUSTERS];
72
73static inline int raw_cpu_to_cluster(int cpu)
74{
75 return topology_physical_package_id(cpu);
76}
77
78static inline int cpu_to_cluster(int cpu)
79{
80 return is_bL_switching_enabled() ?
81 MAX_CLUSTERS : raw_cpu_to_cluster(cpu);
82}
83
84static unsigned int find_cluster_maxfreq(int cluster)
85{
86 int j;
87 u32 max_freq = 0, cpu_freq;
88
89 for_each_online_cpu(j) {
90 cpu_freq = per_cpu(cpu_last_req_freq, j);
91
92 if ((cluster == per_cpu(physical_cluster, j)) &&
93 (max_freq < cpu_freq))
94 max_freq = cpu_freq;
95 }
96
97 pr_debug("%s: cluster: %d, max freq: %d\n", __func__, cluster,
98 max_freq);
99
100 return max_freq;
101}
102
103static unsigned int clk_get_cpu_rate(unsigned int cpu)
104{
105 u32 cur_cluster = per_cpu(physical_cluster, cpu);
106 u32 rate = clk_get_rate(clk[cur_cluster]) / 1000;
107
108 /* For switcher we use virtual A7 clock rates */
109 if (is_bL_switching_enabled())
110 rate = VIRT_FREQ(cur_cluster, rate);
111
112 pr_debug("%s: cpu: %d, cluster: %d, freq: %u\n", __func__, cpu,
113 cur_cluster, rate);
114
115 return rate;
116}
117
118static unsigned int bL_cpufreq_get_rate(unsigned int cpu)
119{
120 if (is_bL_switching_enabled()) {
121 pr_debug("%s: freq: %d\n", __func__, per_cpu(cpu_last_req_freq,
122 cpu));
123
124 return per_cpu(cpu_last_req_freq, cpu);
125 } else {
126 return clk_get_cpu_rate(cpu);
127 }
128}
129
130static unsigned int
131bL_cpufreq_set_rate(u32 cpu, u32 old_cluster, u32 new_cluster, u32 rate)
132{
133 u32 new_rate, prev_rate;
134 int ret;
135 bool bLs = is_bL_switching_enabled();
136
137 mutex_lock(&cluster_lock[new_cluster]);
138
139 if (bLs) {
140 prev_rate = per_cpu(cpu_last_req_freq, cpu);
141 per_cpu(cpu_last_req_freq, cpu) = rate;
142 per_cpu(physical_cluster, cpu) = new_cluster;
143
144 new_rate = find_cluster_maxfreq(new_cluster);
145 new_rate = ACTUAL_FREQ(new_cluster, new_rate);
146 } else {
147 new_rate = rate;
148 }
149
150 pr_debug("%s: cpu: %d, old cluster: %d, new cluster: %d, freq: %d\n",
151 __func__, cpu, old_cluster, new_cluster, new_rate);
152
153 ret = clk_set_rate(clk[new_cluster], new_rate * 1000);
154 if (!ret) {
155 /*
156 * FIXME: clk_set_rate hasn't returned an error here however it
157 * may be that clk_change_rate failed due to hardware or
158 * firmware issues and wasn't able to report that due to the
159 * current design of the clk core layer. To work around this
160 * problem we will read back the clock rate and check it is
161 * correct. This needs to be removed once clk core is fixed.
162 */
163 if (clk_get_rate(clk[new_cluster]) != new_rate * 1000)
164 ret = -EIO;
165 }
166
167 if (WARN_ON(ret)) {
168 pr_err("clk_set_rate failed: %d, new cluster: %d\n", ret,
169 new_cluster);
170 if (bLs) {
171 per_cpu(cpu_last_req_freq, cpu) = prev_rate;
172 per_cpu(physical_cluster, cpu) = old_cluster;
173 }
174
175 mutex_unlock(&cluster_lock[new_cluster]);
176
177 return ret;
178 }
179
180 mutex_unlock(&cluster_lock[new_cluster]);
181
182 /* Recalc freq for old cluster when switching clusters */
183 if (old_cluster != new_cluster) {
184 pr_debug("%s: cpu: %d, old cluster: %d, new cluster: %d\n",
185 __func__, cpu, old_cluster, new_cluster);
186
187 /* Switch cluster */
188 bL_switch_request(cpu, new_cluster);
189
190 mutex_lock(&cluster_lock[old_cluster]);
191
192 /* Set freq of old cluster if there are cpus left on it */
193 new_rate = find_cluster_maxfreq(old_cluster);
194 new_rate = ACTUAL_FREQ(old_cluster, new_rate);
195
196 if (new_rate) {
197 pr_debug("%s: Updating rate of old cluster: %d, to freq: %d\n",
198 __func__, old_cluster, new_rate);
199
200 if (clk_set_rate(clk[old_cluster], new_rate * 1000))
201 pr_err("%s: clk_set_rate failed: %d, old cluster: %d\n",
202 __func__, ret, old_cluster);
203 }
204 mutex_unlock(&cluster_lock[old_cluster]);
205 }
206
207 return 0;
208}
209
210/* Set clock frequency */
211static int bL_cpufreq_set_target(struct cpufreq_policy *policy,
212 unsigned int index)
213{
214 u32 cpu = policy->cpu, cur_cluster, new_cluster, actual_cluster;
215 unsigned int freqs_new;
216
217 cur_cluster = cpu_to_cluster(cpu);
218 new_cluster = actual_cluster = per_cpu(physical_cluster, cpu);
219
220 freqs_new = freq_table[cur_cluster][index].frequency;
221
222 if (is_bL_switching_enabled()) {
223 if ((actual_cluster == A15_CLUSTER) &&
224 (freqs_new < clk_big_min)) {
225 new_cluster = A7_CLUSTER;
226 } else if ((actual_cluster == A7_CLUSTER) &&
227 (freqs_new > clk_little_max)) {
228 new_cluster = A15_CLUSTER;
229 }
230 }
231
232 return bL_cpufreq_set_rate(cpu, actual_cluster, new_cluster, freqs_new);
233}
234
235static inline u32 get_table_count(struct cpufreq_frequency_table *table)
236{
237 int count;
238
239 for (count = 0; table[count].frequency != CPUFREQ_TABLE_END; count++)
240 ;
241
242 return count;
243}
244
245/* get the minimum frequency in the cpufreq_frequency_table */
246static inline u32 get_table_min(struct cpufreq_frequency_table *table)
247{
248 struct cpufreq_frequency_table *pos;
249 uint32_t min_freq = ~0;
250 cpufreq_for_each_entry(pos, table)
251 if (pos->frequency < min_freq)
252 min_freq = pos->frequency;
253 return min_freq;
254}
255
256/* get the maximum frequency in the cpufreq_frequency_table */
257static inline u32 get_table_max(struct cpufreq_frequency_table *table)
258{
259 struct cpufreq_frequency_table *pos;
260 uint32_t max_freq = 0;
261 cpufreq_for_each_entry(pos, table)
262 if (pos->frequency > max_freq)
263 max_freq = pos->frequency;
264 return max_freq;
265}
266
267static int merge_cluster_tables(void)
268{
269 int i, j, k = 0, count = 1;
270 struct cpufreq_frequency_table *table;
271
272 for (i = 0; i < MAX_CLUSTERS; i++)
273 count += get_table_count(freq_table[i]);
274
275 table = kzalloc(sizeof(*table) * count, GFP_KERNEL);
276 if (!table)
277 return -ENOMEM;
278
279 freq_table[MAX_CLUSTERS] = table;
280
281 /* Add in reverse order to get freqs in increasing order */
282 for (i = MAX_CLUSTERS - 1; i >= 0; i--) {
283 for (j = 0; freq_table[i][j].frequency != CPUFREQ_TABLE_END;
284 j++) {
285 table[k].frequency = VIRT_FREQ(i,
286 freq_table[i][j].frequency);
287 pr_debug("%s: index: %d, freq: %d\n", __func__, k,
288 table[k].frequency);
289 k++;
290 }
291 }
292
293 table[k].driver_data = k;
294 table[k].frequency = CPUFREQ_TABLE_END;
295
296 pr_debug("%s: End, table: %p, count: %d\n", __func__, table, k);
297
298 return 0;
299}
300
301static void _put_cluster_clk_and_freq_table(struct device *cpu_dev,
302 const struct cpumask *cpumask)
303{
304 u32 cluster = raw_cpu_to_cluster(cpu_dev->id);
305
306 if (!freq_table[cluster])
307 return;
308
309 clk_put(clk[cluster]);
310 dev_pm_opp_free_cpufreq_table(cpu_dev, &freq_table[cluster]);
311 if (arm_bL_ops->free_opp_table)
312 arm_bL_ops->free_opp_table(cpumask);
313 dev_dbg(cpu_dev, "%s: cluster: %d\n", __func__, cluster);
314}
315
316static void put_cluster_clk_and_freq_table(struct device *cpu_dev,
317 const struct cpumask *cpumask)
318{
319 u32 cluster = cpu_to_cluster(cpu_dev->id);
320 int i;
321
322 if (atomic_dec_return(&cluster_usage[cluster]))
323 return;
324
325 if (cluster < MAX_CLUSTERS)
326 return _put_cluster_clk_and_freq_table(cpu_dev, cpumask);
327
328 for_each_present_cpu(i) {
329 struct device *cdev = get_cpu_device(i);
330 if (!cdev) {
331 pr_err("%s: failed to get cpu%d device\n", __func__, i);
332 return;
333 }
334
335 _put_cluster_clk_and_freq_table(cdev, cpumask);
336 }
337
338 /* free virtual table */
339 kfree(freq_table[cluster]);
340}
341
342static int _get_cluster_clk_and_freq_table(struct device *cpu_dev,
343 const struct cpumask *cpumask)
344{
345 u32 cluster = raw_cpu_to_cluster(cpu_dev->id);
346 int ret;
347
348 if (freq_table[cluster])
349 return 0;
350
351 ret = arm_bL_ops->init_opp_table(cpumask);
352 if (ret) {
353 dev_err(cpu_dev, "%s: init_opp_table failed, cpu: %d, err: %d\n",
354 __func__, cpu_dev->id, ret);
355 goto out;
356 }
357
358 ret = dev_pm_opp_init_cpufreq_table(cpu_dev, &freq_table[cluster]);
359 if (ret) {
360 dev_err(cpu_dev, "%s: failed to init cpufreq table, cpu: %d, err: %d\n",
361 __func__, cpu_dev->id, ret);
362 goto free_opp_table;
363 }
364
365 clk[cluster] = clk_get(cpu_dev, NULL);
366 if (!IS_ERR(clk[cluster])) {
367 dev_dbg(cpu_dev, "%s: clk: %p & freq table: %p, cluster: %d\n",
368 __func__, clk[cluster], freq_table[cluster],
369 cluster);
370 return 0;
371 }
372
373 dev_err(cpu_dev, "%s: Failed to get clk for cpu: %d, cluster: %d\n",
374 __func__, cpu_dev->id, cluster);
375 ret = PTR_ERR(clk[cluster]);
376 dev_pm_opp_free_cpufreq_table(cpu_dev, &freq_table[cluster]);
377
378free_opp_table:
379 if (arm_bL_ops->free_opp_table)
380 arm_bL_ops->free_opp_table(cpumask);
381out:
382 dev_err(cpu_dev, "%s: Failed to get data for cluster: %d\n", __func__,
383 cluster);
384 return ret;
385}
386
387static int get_cluster_clk_and_freq_table(struct device *cpu_dev,
388 const struct cpumask *cpumask)
389{
390 u32 cluster = cpu_to_cluster(cpu_dev->id);
391 int i, ret;
392
393 if (atomic_inc_return(&cluster_usage[cluster]) != 1)
394 return 0;
395
396 if (cluster < MAX_CLUSTERS) {
397 ret = _get_cluster_clk_and_freq_table(cpu_dev, cpumask);
398 if (ret)
399 atomic_dec(&cluster_usage[cluster]);
400 return ret;
401 }
402
403 /*
404 * Get data for all clusters and fill virtual cluster with a merge of
405 * both
406 */
407 for_each_present_cpu(i) {
408 struct device *cdev = get_cpu_device(i);
409 if (!cdev) {
410 pr_err("%s: failed to get cpu%d device\n", __func__, i);
411 return -ENODEV;
412 }
413
414 ret = _get_cluster_clk_and_freq_table(cdev, cpumask);
415 if (ret)
416 goto put_clusters;
417 }
418
419 ret = merge_cluster_tables();
420 if (ret)
421 goto put_clusters;
422
423 /* Assuming 2 cluster, set clk_big_min and clk_little_max */
424 clk_big_min = get_table_min(freq_table[0]);
425 clk_little_max = VIRT_FREQ(1, get_table_max(freq_table[1]));
426
427 pr_debug("%s: cluster: %d, clk_big_min: %d, clk_little_max: %d\n",
428 __func__, cluster, clk_big_min, clk_little_max);
429
430 return 0;
431
432put_clusters:
433 for_each_present_cpu(i) {
434 struct device *cdev = get_cpu_device(i);
435 if (!cdev) {
436 pr_err("%s: failed to get cpu%d device\n", __func__, i);
437 return -ENODEV;
438 }
439
440 _put_cluster_clk_and_freq_table(cdev, cpumask);
441 }
442
443 atomic_dec(&cluster_usage[cluster]);
444
445 return ret;
446}
447
448/* Per-CPU initialization */
449static int bL_cpufreq_init(struct cpufreq_policy *policy)
450{
451 u32 cur_cluster = cpu_to_cluster(policy->cpu);
452 struct device *cpu_dev;
453 int ret;
454
455 cpu_dev = get_cpu_device(policy->cpu);
456 if (!cpu_dev) {
457 pr_err("%s: failed to get cpu%d device\n", __func__,
458 policy->cpu);
459 return -ENODEV;
460 }
461
462 if (cur_cluster < MAX_CLUSTERS) {
463 int cpu;
464
465 cpumask_copy(policy->cpus, topology_core_cpumask(policy->cpu));
466
467 for_each_cpu(cpu, policy->cpus)
468 per_cpu(physical_cluster, cpu) = cur_cluster;
469 } else {
470 /* Assumption: during init, we are always running on A15 */
471 per_cpu(physical_cluster, policy->cpu) = A15_CLUSTER;
472 }
473
474 ret = get_cluster_clk_and_freq_table(cpu_dev, policy->cpus);
475 if (ret)
476 return ret;
477
478 ret = cpufreq_table_validate_and_show(policy, freq_table[cur_cluster]);
479 if (ret) {
480 dev_err(cpu_dev, "CPU %d, cluster: %d invalid freq table\n",
481 policy->cpu, cur_cluster);
482 put_cluster_clk_and_freq_table(cpu_dev, policy->cpus);
483 return ret;
484 }
485
486 if (arm_bL_ops->get_transition_latency)
487 policy->cpuinfo.transition_latency =
488 arm_bL_ops->get_transition_latency(cpu_dev);
489 else
490 policy->cpuinfo.transition_latency = CPUFREQ_ETERNAL;
491
492 if (is_bL_switching_enabled())
493 per_cpu(cpu_last_req_freq, policy->cpu) = clk_get_cpu_rate(policy->cpu);
494
495 dev_info(cpu_dev, "%s: CPU %d initialized\n", __func__, policy->cpu);
496 return 0;
497}
498
499static int bL_cpufreq_exit(struct cpufreq_policy *policy)
500{
501 struct device *cpu_dev;
502 int cur_cluster = cpu_to_cluster(policy->cpu);
503
504 if (cur_cluster < MAX_CLUSTERS) {
505 cpufreq_cooling_unregister(cdev[cur_cluster]);
506 cdev[cur_cluster] = NULL;
507 }
508
509 cpu_dev = get_cpu_device(policy->cpu);
510 if (!cpu_dev) {
511 pr_err("%s: failed to get cpu%d device\n", __func__,
512 policy->cpu);
513 return -ENODEV;
514 }
515
516 put_cluster_clk_and_freq_table(cpu_dev, policy->related_cpus);
517 dev_dbg(cpu_dev, "%s: Exited, cpu: %d\n", __func__, policy->cpu);
518
519 return 0;
520}
521
522static void bL_cpufreq_ready(struct cpufreq_policy *policy)
523{
524 struct device *cpu_dev = get_cpu_device(policy->cpu);
525 int cur_cluster = cpu_to_cluster(policy->cpu);
526 struct device_node *np;
527
528 /* Do not register a cpu_cooling device if we are in IKS mode */
529 if (cur_cluster >= MAX_CLUSTERS)
530 return;
531
532 np = of_node_get(cpu_dev->of_node);
533 if (WARN_ON(!np))
534 return;
535
536 if (of_find_property(np, "#cooling-cells", NULL)) {
537 u32 power_coefficient = 0;
538
539 of_property_read_u32(np, "dynamic-power-coefficient",
540 &power_coefficient);
541
542 cdev[cur_cluster] = of_cpufreq_power_cooling_register(np,
543 policy->related_cpus, power_coefficient, NULL);
544 if (IS_ERR(cdev[cur_cluster])) {
545 dev_err(cpu_dev,
546 "running cpufreq without cooling device: %ld\n",
547 PTR_ERR(cdev[cur_cluster]));
548 cdev[cur_cluster] = NULL;
549 }
550 }
551 of_node_put(np);
552}
553
554static struct cpufreq_driver bL_cpufreq_driver = {
555 .name = "arm-big-little",
556 .flags = CPUFREQ_STICKY |
557 CPUFREQ_HAVE_GOVERNOR_PER_POLICY |
558 CPUFREQ_NEED_INITIAL_FREQ_CHECK,
559 .verify = cpufreq_generic_frequency_table_verify,
560 .target_index = bL_cpufreq_set_target,
561 .get = bL_cpufreq_get_rate,
562 .init = bL_cpufreq_init,
563 .exit = bL_cpufreq_exit,
564 .ready = bL_cpufreq_ready,
565 .attr = cpufreq_generic_attr,
566};
567
568#ifdef CONFIG_BL_SWITCHER
569static int bL_cpufreq_switcher_notifier(struct notifier_block *nfb,
570 unsigned long action, void *_arg)
571{
572 pr_debug("%s: action: %ld\n", __func__, action);
573
574 switch (action) {
575 case BL_NOTIFY_PRE_ENABLE:
576 case BL_NOTIFY_PRE_DISABLE:
577 cpufreq_unregister_driver(&bL_cpufreq_driver);
578 break;
579
580 case BL_NOTIFY_POST_ENABLE:
581 set_switching_enabled(true);
582 cpufreq_register_driver(&bL_cpufreq_driver);
583 break;
584
585 case BL_NOTIFY_POST_DISABLE:
586 set_switching_enabled(false);
587 cpufreq_register_driver(&bL_cpufreq_driver);
588 break;
589
590 default:
591 return NOTIFY_DONE;
592 }
593
594 return NOTIFY_OK;
595}
596
597static struct notifier_block bL_switcher_notifier = {
598 .notifier_call = bL_cpufreq_switcher_notifier,
599};
600
601static int __bLs_register_notifier(void)
602{
603 return bL_switcher_register_notifier(&bL_switcher_notifier);
604}
605
606static int __bLs_unregister_notifier(void)
607{
608 return bL_switcher_unregister_notifier(&bL_switcher_notifier);
609}
610#else
611static int __bLs_register_notifier(void) { return 0; }
612static int __bLs_unregister_notifier(void) { return 0; }
613#endif
614
615int bL_cpufreq_register(struct cpufreq_arm_bL_ops *ops)
616{
617 int ret, i;
618
619 if (arm_bL_ops) {
620 pr_debug("%s: Already registered: %s, exiting\n", __func__,
621 arm_bL_ops->name);
622 return -EBUSY;
623 }
624
625 if (!ops || !strlen(ops->name) || !ops->init_opp_table) {
626 pr_err("%s: Invalid arm_bL_ops, exiting\n", __func__);
627 return -ENODEV;
628 }
629
630 arm_bL_ops = ops;
631
632 set_switching_enabled(bL_switcher_get_enabled());
633
634 for (i = 0; i < MAX_CLUSTERS; i++)
635 mutex_init(&cluster_lock[i]);
636
637 ret = cpufreq_register_driver(&bL_cpufreq_driver);
638 if (ret) {
639 pr_info("%s: Failed registering platform driver: %s, err: %d\n",
640 __func__, ops->name, ret);
641 arm_bL_ops = NULL;
642 } else {
643 ret = __bLs_register_notifier();
644 if (ret) {
645 cpufreq_unregister_driver(&bL_cpufreq_driver);
646 arm_bL_ops = NULL;
647 } else {
648 pr_info("%s: Registered platform driver: %s\n",
649 __func__, ops->name);
650 }
651 }
652
653 bL_switcher_put_enabled();
654 return ret;
655}
656EXPORT_SYMBOL_GPL(bL_cpufreq_register);
657
658void bL_cpufreq_unregister(struct cpufreq_arm_bL_ops *ops)
659{
660 if (arm_bL_ops != ops) {
661 pr_err("%s: Registered with: %s, can't unregister, exiting\n",
662 __func__, arm_bL_ops->name);
663 return;
664 }
665
666 bL_switcher_get_enabled();
667 __bLs_unregister_notifier();
668 cpufreq_unregister_driver(&bL_cpufreq_driver);
669 bL_switcher_put_enabled();
670 pr_info("%s: Un-registered platform driver: %s\n", __func__,
671 arm_bL_ops->name);
672 arm_bL_ops = NULL;
673}
674EXPORT_SYMBOL_GPL(bL_cpufreq_unregister);
675
676MODULE_AUTHOR("Viresh Kumar <viresh.kumar@linaro.org>");
677MODULE_DESCRIPTION("Generic ARM big LITTLE cpufreq driver");
678MODULE_LICENSE("GPL v2");