powerpc/64: Implement and use soft_enabled_set_return API
[linux/fpc-iii.git] / drivers / cpufreq / arm_big_little.c
blob65ec5f01aa8d7369517285188c1e4dc408dc4eb8
1 /*
2 * ARM big.LITTLE Platforms CPUFreq support
4 * Copyright (C) 2013 ARM Ltd.
5 * Sudeep KarkadaNagesha <sudeep.karkadanagesha@arm.com>
7 * Copyright (C) 2013 Linaro.
8 * Viresh Kumar <viresh.kumar@linaro.org>
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.
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.
20 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
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>
36 #include "arm_big_little.h"
38 /* Currently we support only two clusters */
39 #define A15_CLUSTER 0
40 #define A7_CLUSTER 1
41 #define MAX_CLUSTERS 2
43 #ifdef CONFIG_BL_SWITCHER
44 #include <asm/bL_switcher.h>
45 static 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
56 #define ACTUAL_FREQ(cluster, freq) ((cluster == A7_CLUSTER) ? freq << 1 : freq)
57 #define VIRT_FREQ(cluster, freq) ((cluster == A7_CLUSTER) ? freq >> 1 : freq)
59 static struct thermal_cooling_device *cdev[MAX_CLUSTERS];
60 static const struct cpufreq_arm_bL_ops *arm_bL_ops;
61 static struct clk *clk[MAX_CLUSTERS];
62 static struct cpufreq_frequency_table *freq_table[MAX_CLUSTERS + 1];
63 static atomic_t cluster_usage[MAX_CLUSTERS + 1];
65 static unsigned int clk_big_min; /* (Big) clock frequencies */
66 static unsigned int clk_little_max; /* Maximum clock frequency (Little) */
68 static DEFINE_PER_CPU(unsigned int, physical_cluster);
69 static DEFINE_PER_CPU(unsigned int, cpu_last_req_freq);
71 static struct mutex cluster_lock[MAX_CLUSTERS];
73 static inline int raw_cpu_to_cluster(int cpu)
75 return topology_physical_package_id(cpu);
78 static inline int cpu_to_cluster(int cpu)
80 return is_bL_switching_enabled() ?
81 MAX_CLUSTERS : raw_cpu_to_cluster(cpu);
84 static unsigned int find_cluster_maxfreq(int cluster)
86 int j;
87 u32 max_freq = 0, cpu_freq;
89 for_each_online_cpu(j) {
90 cpu_freq = per_cpu(cpu_last_req_freq, j);
92 if ((cluster == per_cpu(physical_cluster, j)) &&
93 (max_freq < cpu_freq))
94 max_freq = cpu_freq;
97 pr_debug("%s: cluster: %d, max freq: %d\n", __func__, cluster,
98 max_freq);
100 return max_freq;
103 static unsigned int clk_get_cpu_rate(unsigned int cpu)
105 u32 cur_cluster = per_cpu(physical_cluster, cpu);
106 u32 rate = clk_get_rate(clk[cur_cluster]) / 1000;
108 /* For switcher we use virtual A7 clock rates */
109 if (is_bL_switching_enabled())
110 rate = VIRT_FREQ(cur_cluster, rate);
112 pr_debug("%s: cpu: %d, cluster: %d, freq: %u\n", __func__, cpu,
113 cur_cluster, rate);
115 return rate;
118 static unsigned int bL_cpufreq_get_rate(unsigned int cpu)
120 if (is_bL_switching_enabled()) {
121 pr_debug("%s: freq: %d\n", __func__, per_cpu(cpu_last_req_freq,
122 cpu));
124 return per_cpu(cpu_last_req_freq, cpu);
125 } else {
126 return clk_get_cpu_rate(cpu);
130 static unsigned int
131 bL_cpufreq_set_rate(u32 cpu, u32 old_cluster, u32 new_cluster, u32 rate)
133 u32 new_rate, prev_rate;
134 int ret;
135 bool bLs = is_bL_switching_enabled();
137 mutex_lock(&cluster_lock[new_cluster]);
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;
144 new_rate = find_cluster_maxfreq(new_cluster);
145 new_rate = ACTUAL_FREQ(new_cluster, new_rate);
146 } else {
147 new_rate = rate;
150 pr_debug("%s: cpu: %d, old cluster: %d, new cluster: %d, freq: %d\n",
151 __func__, cpu, old_cluster, new_cluster, new_rate);
153 ret = clk_set_rate(clk[new_cluster], new_rate * 1000);
154 if (!ret) {
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.
163 if (clk_get_rate(clk[new_cluster]) != new_rate * 1000)
164 ret = -EIO;
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;
175 mutex_unlock(&cluster_lock[new_cluster]);
177 return ret;
180 mutex_unlock(&cluster_lock[new_cluster]);
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);
187 /* Switch cluster */
188 bL_switch_request(cpu, new_cluster);
190 mutex_lock(&cluster_lock[old_cluster]);
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);
196 if (new_rate) {
197 pr_debug("%s: Updating rate of old cluster: %d, to freq: %d\n",
198 __func__, old_cluster, new_rate);
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);
204 mutex_unlock(&cluster_lock[old_cluster]);
207 return 0;
210 /* Set clock frequency */
211 static int bL_cpufreq_set_target(struct cpufreq_policy *policy,
212 unsigned int index)
214 u32 cpu = policy->cpu, cur_cluster, new_cluster, actual_cluster;
215 unsigned int freqs_new;
216 int ret;
218 cur_cluster = cpu_to_cluster(cpu);
219 new_cluster = actual_cluster = per_cpu(physical_cluster, cpu);
221 freqs_new = freq_table[cur_cluster][index].frequency;
223 if (is_bL_switching_enabled()) {
224 if ((actual_cluster == A15_CLUSTER) &&
225 (freqs_new < clk_big_min)) {
226 new_cluster = A7_CLUSTER;
227 } else if ((actual_cluster == A7_CLUSTER) &&
228 (freqs_new > clk_little_max)) {
229 new_cluster = A15_CLUSTER;
233 ret = bL_cpufreq_set_rate(cpu, actual_cluster, new_cluster, freqs_new);
235 if (!ret) {
236 arch_set_freq_scale(policy->related_cpus, freqs_new,
237 policy->cpuinfo.max_freq);
240 return ret;
243 static inline u32 get_table_count(struct cpufreq_frequency_table *table)
245 int count;
247 for (count = 0; table[count].frequency != CPUFREQ_TABLE_END; count++)
250 return count;
253 /* get the minimum frequency in the cpufreq_frequency_table */
254 static inline u32 get_table_min(struct cpufreq_frequency_table *table)
256 struct cpufreq_frequency_table *pos;
257 uint32_t min_freq = ~0;
258 cpufreq_for_each_entry(pos, table)
259 if (pos->frequency < min_freq)
260 min_freq = pos->frequency;
261 return min_freq;
264 /* get the maximum frequency in the cpufreq_frequency_table */
265 static inline u32 get_table_max(struct cpufreq_frequency_table *table)
267 struct cpufreq_frequency_table *pos;
268 uint32_t max_freq = 0;
269 cpufreq_for_each_entry(pos, table)
270 if (pos->frequency > max_freq)
271 max_freq = pos->frequency;
272 return max_freq;
275 static int merge_cluster_tables(void)
277 int i, j, k = 0, count = 1;
278 struct cpufreq_frequency_table *table;
280 for (i = 0; i < MAX_CLUSTERS; i++)
281 count += get_table_count(freq_table[i]);
283 table = kzalloc(sizeof(*table) * count, GFP_KERNEL);
284 if (!table)
285 return -ENOMEM;
287 freq_table[MAX_CLUSTERS] = table;
289 /* Add in reverse order to get freqs in increasing order */
290 for (i = MAX_CLUSTERS - 1; i >= 0; i--) {
291 for (j = 0; freq_table[i][j].frequency != CPUFREQ_TABLE_END;
292 j++) {
293 table[k].frequency = VIRT_FREQ(i,
294 freq_table[i][j].frequency);
295 pr_debug("%s: index: %d, freq: %d\n", __func__, k,
296 table[k].frequency);
297 k++;
301 table[k].driver_data = k;
302 table[k].frequency = CPUFREQ_TABLE_END;
304 pr_debug("%s: End, table: %p, count: %d\n", __func__, table, k);
306 return 0;
309 static void _put_cluster_clk_and_freq_table(struct device *cpu_dev,
310 const struct cpumask *cpumask)
312 u32 cluster = raw_cpu_to_cluster(cpu_dev->id);
314 if (!freq_table[cluster])
315 return;
317 clk_put(clk[cluster]);
318 dev_pm_opp_free_cpufreq_table(cpu_dev, &freq_table[cluster]);
319 if (arm_bL_ops->free_opp_table)
320 arm_bL_ops->free_opp_table(cpumask);
321 dev_dbg(cpu_dev, "%s: cluster: %d\n", __func__, cluster);
324 static void put_cluster_clk_and_freq_table(struct device *cpu_dev,
325 const struct cpumask *cpumask)
327 u32 cluster = cpu_to_cluster(cpu_dev->id);
328 int i;
330 if (atomic_dec_return(&cluster_usage[cluster]))
331 return;
333 if (cluster < MAX_CLUSTERS)
334 return _put_cluster_clk_and_freq_table(cpu_dev, cpumask);
336 for_each_present_cpu(i) {
337 struct device *cdev = get_cpu_device(i);
338 if (!cdev) {
339 pr_err("%s: failed to get cpu%d device\n", __func__, i);
340 return;
343 _put_cluster_clk_and_freq_table(cdev, cpumask);
346 /* free virtual table */
347 kfree(freq_table[cluster]);
350 static int _get_cluster_clk_and_freq_table(struct device *cpu_dev,
351 const struct cpumask *cpumask)
353 u32 cluster = raw_cpu_to_cluster(cpu_dev->id);
354 int ret;
356 if (freq_table[cluster])
357 return 0;
359 ret = arm_bL_ops->init_opp_table(cpumask);
360 if (ret) {
361 dev_err(cpu_dev, "%s: init_opp_table failed, cpu: %d, err: %d\n",
362 __func__, cpu_dev->id, ret);
363 goto out;
366 ret = dev_pm_opp_init_cpufreq_table(cpu_dev, &freq_table[cluster]);
367 if (ret) {
368 dev_err(cpu_dev, "%s: failed to init cpufreq table, cpu: %d, err: %d\n",
369 __func__, cpu_dev->id, ret);
370 goto free_opp_table;
373 clk[cluster] = clk_get(cpu_dev, NULL);
374 if (!IS_ERR(clk[cluster])) {
375 dev_dbg(cpu_dev, "%s: clk: %p & freq table: %p, cluster: %d\n",
376 __func__, clk[cluster], freq_table[cluster],
377 cluster);
378 return 0;
381 dev_err(cpu_dev, "%s: Failed to get clk for cpu: %d, cluster: %d\n",
382 __func__, cpu_dev->id, cluster);
383 ret = PTR_ERR(clk[cluster]);
384 dev_pm_opp_free_cpufreq_table(cpu_dev, &freq_table[cluster]);
386 free_opp_table:
387 if (arm_bL_ops->free_opp_table)
388 arm_bL_ops->free_opp_table(cpumask);
389 out:
390 dev_err(cpu_dev, "%s: Failed to get data for cluster: %d\n", __func__,
391 cluster);
392 return ret;
395 static int get_cluster_clk_and_freq_table(struct device *cpu_dev,
396 const struct cpumask *cpumask)
398 u32 cluster = cpu_to_cluster(cpu_dev->id);
399 int i, ret;
401 if (atomic_inc_return(&cluster_usage[cluster]) != 1)
402 return 0;
404 if (cluster < MAX_CLUSTERS) {
405 ret = _get_cluster_clk_and_freq_table(cpu_dev, cpumask);
406 if (ret)
407 atomic_dec(&cluster_usage[cluster]);
408 return ret;
412 * Get data for all clusters and fill virtual cluster with a merge of
413 * both
415 for_each_present_cpu(i) {
416 struct device *cdev = get_cpu_device(i);
417 if (!cdev) {
418 pr_err("%s: failed to get cpu%d device\n", __func__, i);
419 return -ENODEV;
422 ret = _get_cluster_clk_and_freq_table(cdev, cpumask);
423 if (ret)
424 goto put_clusters;
427 ret = merge_cluster_tables();
428 if (ret)
429 goto put_clusters;
431 /* Assuming 2 cluster, set clk_big_min and clk_little_max */
432 clk_big_min = get_table_min(freq_table[0]);
433 clk_little_max = VIRT_FREQ(1, get_table_max(freq_table[1]));
435 pr_debug("%s: cluster: %d, clk_big_min: %d, clk_little_max: %d\n",
436 __func__, cluster, clk_big_min, clk_little_max);
438 return 0;
440 put_clusters:
441 for_each_present_cpu(i) {
442 struct device *cdev = get_cpu_device(i);
443 if (!cdev) {
444 pr_err("%s: failed to get cpu%d device\n", __func__, i);
445 return -ENODEV;
448 _put_cluster_clk_and_freq_table(cdev, cpumask);
451 atomic_dec(&cluster_usage[cluster]);
453 return ret;
456 /* Per-CPU initialization */
457 static int bL_cpufreq_init(struct cpufreq_policy *policy)
459 u32 cur_cluster = cpu_to_cluster(policy->cpu);
460 struct device *cpu_dev;
461 int ret;
463 cpu_dev = get_cpu_device(policy->cpu);
464 if (!cpu_dev) {
465 pr_err("%s: failed to get cpu%d device\n", __func__,
466 policy->cpu);
467 return -ENODEV;
470 if (cur_cluster < MAX_CLUSTERS) {
471 int cpu;
473 cpumask_copy(policy->cpus, topology_core_cpumask(policy->cpu));
475 for_each_cpu(cpu, policy->cpus)
476 per_cpu(physical_cluster, cpu) = cur_cluster;
477 } else {
478 /* Assumption: during init, we are always running on A15 */
479 per_cpu(physical_cluster, policy->cpu) = A15_CLUSTER;
482 ret = get_cluster_clk_and_freq_table(cpu_dev, policy->cpus);
483 if (ret)
484 return ret;
486 ret = cpufreq_table_validate_and_show(policy, freq_table[cur_cluster]);
487 if (ret) {
488 dev_err(cpu_dev, "CPU %d, cluster: %d invalid freq table\n",
489 policy->cpu, cur_cluster);
490 put_cluster_clk_and_freq_table(cpu_dev, policy->cpus);
491 return ret;
494 policy->cpuinfo.transition_latency =
495 arm_bL_ops->get_transition_latency(cpu_dev);
497 if (is_bL_switching_enabled())
498 per_cpu(cpu_last_req_freq, policy->cpu) = clk_get_cpu_rate(policy->cpu);
500 dev_info(cpu_dev, "%s: CPU %d initialized\n", __func__, policy->cpu);
501 return 0;
504 static int bL_cpufreq_exit(struct cpufreq_policy *policy)
506 struct device *cpu_dev;
507 int cur_cluster = cpu_to_cluster(policy->cpu);
509 if (cur_cluster < MAX_CLUSTERS) {
510 cpufreq_cooling_unregister(cdev[cur_cluster]);
511 cdev[cur_cluster] = NULL;
514 cpu_dev = get_cpu_device(policy->cpu);
515 if (!cpu_dev) {
516 pr_err("%s: failed to get cpu%d device\n", __func__,
517 policy->cpu);
518 return -ENODEV;
521 put_cluster_clk_and_freq_table(cpu_dev, policy->related_cpus);
522 dev_dbg(cpu_dev, "%s: Exited, cpu: %d\n", __func__, policy->cpu);
524 return 0;
527 static void bL_cpufreq_ready(struct cpufreq_policy *policy)
529 struct device *cpu_dev = get_cpu_device(policy->cpu);
530 int cur_cluster = cpu_to_cluster(policy->cpu);
531 struct device_node *np;
533 /* Do not register a cpu_cooling device if we are in IKS mode */
534 if (cur_cluster >= MAX_CLUSTERS)
535 return;
537 np = of_node_get(cpu_dev->of_node);
538 if (WARN_ON(!np))
539 return;
541 if (of_find_property(np, "#cooling-cells", NULL)) {
542 u32 power_coefficient = 0;
544 of_property_read_u32(np, "dynamic-power-coefficient",
545 &power_coefficient);
547 cdev[cur_cluster] = of_cpufreq_power_cooling_register(np,
548 policy, power_coefficient, NULL);
549 if (IS_ERR(cdev[cur_cluster])) {
550 dev_err(cpu_dev,
551 "running cpufreq without cooling device: %ld\n",
552 PTR_ERR(cdev[cur_cluster]));
553 cdev[cur_cluster] = NULL;
556 of_node_put(np);
559 static struct cpufreq_driver bL_cpufreq_driver = {
560 .name = "arm-big-little",
561 .flags = CPUFREQ_STICKY |
562 CPUFREQ_HAVE_GOVERNOR_PER_POLICY |
563 CPUFREQ_NEED_INITIAL_FREQ_CHECK,
564 .verify = cpufreq_generic_frequency_table_verify,
565 .target_index = bL_cpufreq_set_target,
566 .get = bL_cpufreq_get_rate,
567 .init = bL_cpufreq_init,
568 .exit = bL_cpufreq_exit,
569 .ready = bL_cpufreq_ready,
570 .attr = cpufreq_generic_attr,
573 #ifdef CONFIG_BL_SWITCHER
574 static int bL_cpufreq_switcher_notifier(struct notifier_block *nfb,
575 unsigned long action, void *_arg)
577 pr_debug("%s: action: %ld\n", __func__, action);
579 switch (action) {
580 case BL_NOTIFY_PRE_ENABLE:
581 case BL_NOTIFY_PRE_DISABLE:
582 cpufreq_unregister_driver(&bL_cpufreq_driver);
583 break;
585 case BL_NOTIFY_POST_ENABLE:
586 set_switching_enabled(true);
587 cpufreq_register_driver(&bL_cpufreq_driver);
588 break;
590 case BL_NOTIFY_POST_DISABLE:
591 set_switching_enabled(false);
592 cpufreq_register_driver(&bL_cpufreq_driver);
593 break;
595 default:
596 return NOTIFY_DONE;
599 return NOTIFY_OK;
602 static struct notifier_block bL_switcher_notifier = {
603 .notifier_call = bL_cpufreq_switcher_notifier,
606 static int __bLs_register_notifier(void)
608 return bL_switcher_register_notifier(&bL_switcher_notifier);
611 static int __bLs_unregister_notifier(void)
613 return bL_switcher_unregister_notifier(&bL_switcher_notifier);
615 #else
616 static int __bLs_register_notifier(void) { return 0; }
617 static int __bLs_unregister_notifier(void) { return 0; }
618 #endif
620 int bL_cpufreq_register(const struct cpufreq_arm_bL_ops *ops)
622 int ret, i;
624 if (arm_bL_ops) {
625 pr_debug("%s: Already registered: %s, exiting\n", __func__,
626 arm_bL_ops->name);
627 return -EBUSY;
630 if (!ops || !strlen(ops->name) || !ops->init_opp_table ||
631 !ops->get_transition_latency) {
632 pr_err("%s: Invalid arm_bL_ops, exiting\n", __func__);
633 return -ENODEV;
636 arm_bL_ops = ops;
638 set_switching_enabled(bL_switcher_get_enabled());
640 for (i = 0; i < MAX_CLUSTERS; i++)
641 mutex_init(&cluster_lock[i]);
643 ret = cpufreq_register_driver(&bL_cpufreq_driver);
644 if (ret) {
645 pr_info("%s: Failed registering platform driver: %s, err: %d\n",
646 __func__, ops->name, ret);
647 arm_bL_ops = NULL;
648 } else {
649 ret = __bLs_register_notifier();
650 if (ret) {
651 cpufreq_unregister_driver(&bL_cpufreq_driver);
652 arm_bL_ops = NULL;
653 } else {
654 pr_info("%s: Registered platform driver: %s\n",
655 __func__, ops->name);
659 bL_switcher_put_enabled();
660 return ret;
662 EXPORT_SYMBOL_GPL(bL_cpufreq_register);
664 void bL_cpufreq_unregister(const struct cpufreq_arm_bL_ops *ops)
666 if (arm_bL_ops != ops) {
667 pr_err("%s: Registered with: %s, can't unregister, exiting\n",
668 __func__, arm_bL_ops->name);
669 return;
672 bL_switcher_get_enabled();
673 __bLs_unregister_notifier();
674 cpufreq_unregister_driver(&bL_cpufreq_driver);
675 bL_switcher_put_enabled();
676 pr_info("%s: Un-registered platform driver: %s\n", __func__,
677 arm_bL_ops->name);
678 arm_bL_ops = NULL;
680 EXPORT_SYMBOL_GPL(bL_cpufreq_unregister);
682 MODULE_AUTHOR("Viresh Kumar <viresh.kumar@linaro.org>");
683 MODULE_DESCRIPTION("Generic ARM big LITTLE cpufreq driver");
684 MODULE_LICENSE("GPL v2");