Merge tag 'chrome-platform-for-linus-4.13' of git://git.kernel.org/pub/scm/linux...
[linux/fpc-iii.git] / drivers / cpufreq / arm_big_little.c
blob418042201e6da9e501ac6fb161437b117491b3ff
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 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;
217 cur_cluster = cpu_to_cluster(cpu);
218 new_cluster = actual_cluster = per_cpu(physical_cluster, cpu);
220 freqs_new = freq_table[cur_cluster][index].frequency;
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;
232 return bL_cpufreq_set_rate(cpu, actual_cluster, new_cluster, freqs_new);
235 static inline u32 get_table_count(struct cpufreq_frequency_table *table)
237 int count;
239 for (count = 0; table[count].frequency != CPUFREQ_TABLE_END; count++)
242 return count;
245 /* get the minimum frequency in the cpufreq_frequency_table */
246 static inline u32 get_table_min(struct cpufreq_frequency_table *table)
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;
256 /* get the maximum frequency in the cpufreq_frequency_table */
257 static inline u32 get_table_max(struct cpufreq_frequency_table *table)
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;
267 static int merge_cluster_tables(void)
269 int i, j, k = 0, count = 1;
270 struct cpufreq_frequency_table *table;
272 for (i = 0; i < MAX_CLUSTERS; i++)
273 count += get_table_count(freq_table[i]);
275 table = kzalloc(sizeof(*table) * count, GFP_KERNEL);
276 if (!table)
277 return -ENOMEM;
279 freq_table[MAX_CLUSTERS] = table;
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++;
293 table[k].driver_data = k;
294 table[k].frequency = CPUFREQ_TABLE_END;
296 pr_debug("%s: End, table: %p, count: %d\n", __func__, table, k);
298 return 0;
301 static void _put_cluster_clk_and_freq_table(struct device *cpu_dev,
302 const struct cpumask *cpumask)
304 u32 cluster = raw_cpu_to_cluster(cpu_dev->id);
306 if (!freq_table[cluster])
307 return;
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);
316 static void put_cluster_clk_and_freq_table(struct device *cpu_dev,
317 const struct cpumask *cpumask)
319 u32 cluster = cpu_to_cluster(cpu_dev->id);
320 int i;
322 if (atomic_dec_return(&cluster_usage[cluster]))
323 return;
325 if (cluster < MAX_CLUSTERS)
326 return _put_cluster_clk_and_freq_table(cpu_dev, cpumask);
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;
335 _put_cluster_clk_and_freq_table(cdev, cpumask);
338 /* free virtual table */
339 kfree(freq_table[cluster]);
342 static int _get_cluster_clk_and_freq_table(struct device *cpu_dev,
343 const struct cpumask *cpumask)
345 u32 cluster = raw_cpu_to_cluster(cpu_dev->id);
346 int ret;
348 if (freq_table[cluster])
349 return 0;
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;
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;
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;
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]);
378 free_opp_table:
379 if (arm_bL_ops->free_opp_table)
380 arm_bL_ops->free_opp_table(cpumask);
381 out:
382 dev_err(cpu_dev, "%s: Failed to get data for cluster: %d\n", __func__,
383 cluster);
384 return ret;
387 static int get_cluster_clk_and_freq_table(struct device *cpu_dev,
388 const struct cpumask *cpumask)
390 u32 cluster = cpu_to_cluster(cpu_dev->id);
391 int i, ret;
393 if (atomic_inc_return(&cluster_usage[cluster]) != 1)
394 return 0;
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;
404 * Get data for all clusters and fill virtual cluster with a merge of
405 * both
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;
414 ret = _get_cluster_clk_and_freq_table(cdev, cpumask);
415 if (ret)
416 goto put_clusters;
419 ret = merge_cluster_tables();
420 if (ret)
421 goto put_clusters;
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]));
427 pr_debug("%s: cluster: %d, clk_big_min: %d, clk_little_max: %d\n",
428 __func__, cluster, clk_big_min, clk_little_max);
430 return 0;
432 put_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;
440 _put_cluster_clk_and_freq_table(cdev, cpumask);
443 atomic_dec(&cluster_usage[cluster]);
445 return ret;
448 /* Per-CPU initialization */
449 static int bL_cpufreq_init(struct cpufreq_policy *policy)
451 u32 cur_cluster = cpu_to_cluster(policy->cpu);
452 struct device *cpu_dev;
453 int ret;
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;
462 if (cur_cluster < MAX_CLUSTERS) {
463 int cpu;
465 cpumask_copy(policy->cpus, topology_core_cpumask(policy->cpu));
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;
474 ret = get_cluster_clk_and_freq_table(cpu_dev, policy->cpus);
475 if (ret)
476 return ret;
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;
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;
492 if (is_bL_switching_enabled())
493 per_cpu(cpu_last_req_freq, policy->cpu) = clk_get_cpu_rate(policy->cpu);
495 dev_info(cpu_dev, "%s: CPU %d initialized\n", __func__, policy->cpu);
496 return 0;
499 static int bL_cpufreq_exit(struct cpufreq_policy *policy)
501 struct device *cpu_dev;
502 int cur_cluster = cpu_to_cluster(policy->cpu);
504 if (cur_cluster < MAX_CLUSTERS) {
505 cpufreq_cooling_unregister(cdev[cur_cluster]);
506 cdev[cur_cluster] = NULL;
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;
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);
519 return 0;
522 static void bL_cpufreq_ready(struct cpufreq_policy *policy)
524 struct device *cpu_dev = get_cpu_device(policy->cpu);
525 int cur_cluster = cpu_to_cluster(policy->cpu);
526 struct device_node *np;
528 /* Do not register a cpu_cooling device if we are in IKS mode */
529 if (cur_cluster >= MAX_CLUSTERS)
530 return;
532 np = of_node_get(cpu_dev->of_node);
533 if (WARN_ON(!np))
534 return;
536 if (of_find_property(np, "#cooling-cells", NULL)) {
537 u32 power_coefficient = 0;
539 of_property_read_u32(np, "dynamic-power-coefficient",
540 &power_coefficient);
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;
551 of_node_put(np);
554 static 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,
568 #ifdef CONFIG_BL_SWITCHER
569 static int bL_cpufreq_switcher_notifier(struct notifier_block *nfb,
570 unsigned long action, void *_arg)
572 pr_debug("%s: action: %ld\n", __func__, action);
574 switch (action) {
575 case BL_NOTIFY_PRE_ENABLE:
576 case BL_NOTIFY_PRE_DISABLE:
577 cpufreq_unregister_driver(&bL_cpufreq_driver);
578 break;
580 case BL_NOTIFY_POST_ENABLE:
581 set_switching_enabled(true);
582 cpufreq_register_driver(&bL_cpufreq_driver);
583 break;
585 case BL_NOTIFY_POST_DISABLE:
586 set_switching_enabled(false);
587 cpufreq_register_driver(&bL_cpufreq_driver);
588 break;
590 default:
591 return NOTIFY_DONE;
594 return NOTIFY_OK;
597 static struct notifier_block bL_switcher_notifier = {
598 .notifier_call = bL_cpufreq_switcher_notifier,
601 static int __bLs_register_notifier(void)
603 return bL_switcher_register_notifier(&bL_switcher_notifier);
606 static int __bLs_unregister_notifier(void)
608 return bL_switcher_unregister_notifier(&bL_switcher_notifier);
610 #else
611 static int __bLs_register_notifier(void) { return 0; }
612 static int __bLs_unregister_notifier(void) { return 0; }
613 #endif
615 int bL_cpufreq_register(struct cpufreq_arm_bL_ops *ops)
617 int ret, i;
619 if (arm_bL_ops) {
620 pr_debug("%s: Already registered: %s, exiting\n", __func__,
621 arm_bL_ops->name);
622 return -EBUSY;
625 if (!ops || !strlen(ops->name) || !ops->init_opp_table) {
626 pr_err("%s: Invalid arm_bL_ops, exiting\n", __func__);
627 return -ENODEV;
630 arm_bL_ops = ops;
632 set_switching_enabled(bL_switcher_get_enabled());
634 for (i = 0; i < MAX_CLUSTERS; i++)
635 mutex_init(&cluster_lock[i]);
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);
653 bL_switcher_put_enabled();
654 return ret;
656 EXPORT_SYMBOL_GPL(bL_cpufreq_register);
658 void bL_cpufreq_unregister(struct cpufreq_arm_bL_ops *ops)
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;
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;
674 EXPORT_SYMBOL_GPL(bL_cpufreq_unregister);
676 MODULE_AUTHOR("Viresh Kumar <viresh.kumar@linaro.org>");
677 MODULE_DESCRIPTION("Generic ARM big LITTLE cpufreq driver");
678 MODULE_LICENSE("GPL v2");