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treewide: remove redundant IS_ERR() before error code check
[linux/fpc-iii.git] / drivers / cpufreq / vexpress-spc-cpufreq.c
blob83c85d3d67e355495695b278b37586869e466f0c
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * Versatile Express SPC CPUFreq Interface driver
4 *
5 * Copyright (C) 2013 - 2019 ARM Ltd.
6 * Sudeep Holla <sudeep.holla@arm.com>
7 *
8 * Copyright (C) 2013 Linaro.
9 * Viresh Kumar <viresh.kumar@linaro.org>
10 */
11
12 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
13
14 #include <linux/clk.h>
15 #include <linux/cpu.h>
16 #include <linux/cpufreq.h>
17 #include <linux/cpumask.h>
18 #include <linux/cpu_cooling.h>
19 #include <linux/device.h>
20 #include <linux/module.h>
21 #include <linux/mutex.h>
22 #include <linux/of_platform.h>
23 #include <linux/platform_device.h>
24 #include <linux/pm_opp.h>
25 #include <linux/slab.h>
26 #include <linux/topology.h>
27 #include <linux/types.h>
28
29 /* Currently we support only two clusters */
30 #define A15_CLUSTER 0
31 #define A7_CLUSTER 1
32 #define MAX_CLUSTERS 2
33
34 #ifdef CONFIG_BL_SWITCHER
35 #include <asm/bL_switcher.h>
36 static bool bL_switching_enabled;
37 #define is_bL_switching_enabled() bL_switching_enabled
38 #define set_switching_enabled(x) (bL_switching_enabled = (x))
39 #else
40 #define is_bL_switching_enabled() false
41 #define set_switching_enabled(x) do { } while (0)
42 #define bL_switch_request(...) do { } while (0)
43 #define bL_switcher_put_enabled() do { } while (0)
44 #define bL_switcher_get_enabled() do { } while (0)
45 #endif
46
47 #define ACTUAL_FREQ(cluster, freq) ((cluster == A7_CLUSTER) ? freq << 1 : freq)
48 #define VIRT_FREQ(cluster, freq) ((cluster == A7_CLUSTER) ? freq >> 1 : freq)
49
50 static struct thermal_cooling_device *cdev[MAX_CLUSTERS];
51 static struct clk *clk[MAX_CLUSTERS];
52 static struct cpufreq_frequency_table *freq_table[MAX_CLUSTERS + 1];
53 static atomic_t cluster_usage[MAX_CLUSTERS + 1];
54
55 static unsigned int clk_big_min; /* (Big) clock frequencies */
56 static unsigned int clk_little_max; /* Maximum clock frequency (Little) */
57
58 static DEFINE_PER_CPU(unsigned int, physical_cluster);
59 static DEFINE_PER_CPU(unsigned int, cpu_last_req_freq);
60
61 static struct mutex cluster_lock[MAX_CLUSTERS];
62
63 static inline int raw_cpu_to_cluster(int cpu)
64 {
65 return topology_physical_package_id(cpu);
66 }
67
68 static inline int cpu_to_cluster(int cpu)
69 {
70 return is_bL_switching_enabled() ?
71 MAX_CLUSTERS : raw_cpu_to_cluster(cpu);
72 }
73
74 static unsigned int find_cluster_maxfreq(int cluster)
75 {
76 int j;
77 u32 max_freq = 0, cpu_freq;
78
79 for_each_online_cpu(j) {
80 cpu_freq = per_cpu(cpu_last_req_freq, j);
81
82 if (cluster == per_cpu(physical_cluster, j) &&
83 max_freq < cpu_freq)
84 max_freq = cpu_freq;
85 }
86
87 return max_freq;
88 }
89
90 static unsigned int clk_get_cpu_rate(unsigned int cpu)
91 {
92 u32 cur_cluster = per_cpu(physical_cluster, cpu);
93 u32 rate = clk_get_rate(clk[cur_cluster]) / 1000;
94
95 /* For switcher we use virtual A7 clock rates */
96 if (is_bL_switching_enabled())
97 rate = VIRT_FREQ(cur_cluster, rate);
98
99 return rate;
100 }
101
102 static unsigned int ve_spc_cpufreq_get_rate(unsigned int cpu)
103 {
104 if (is_bL_switching_enabled())
105 return per_cpu(cpu_last_req_freq, cpu);
106 else
107 return clk_get_cpu_rate(cpu);
108 }
109
110 static unsigned int
111 ve_spc_cpufreq_set_rate(u32 cpu, u32 old_cluster, u32 new_cluster, u32 rate)
112 {
113 u32 new_rate, prev_rate;
114 int ret;
115 bool bLs = is_bL_switching_enabled();
116
117 mutex_lock(&cluster_lock[new_cluster]);
118
119 if (bLs) {
120 prev_rate = per_cpu(cpu_last_req_freq, cpu);
121 per_cpu(cpu_last_req_freq, cpu) = rate;
122 per_cpu(physical_cluster, cpu) = new_cluster;
123
124 new_rate = find_cluster_maxfreq(new_cluster);
125 new_rate = ACTUAL_FREQ(new_cluster, new_rate);
126 } else {
127 new_rate = rate;
128 }
129
130 ret = clk_set_rate(clk[new_cluster], new_rate * 1000);
131 if (!ret) {
132 /*
133 * FIXME: clk_set_rate hasn't returned an error here however it
134 * may be that clk_change_rate failed due to hardware or
135 * firmware issues and wasn't able to report that due to the
136 * current design of the clk core layer. To work around this
137 * problem we will read back the clock rate and check it is
138 * correct. This needs to be removed once clk core is fixed.
139 */
140 if (clk_get_rate(clk[new_cluster]) != new_rate * 1000)
141 ret = -EIO;
142 }
143
144 if (WARN_ON(ret)) {
145 if (bLs) {
146 per_cpu(cpu_last_req_freq, cpu) = prev_rate;
147 per_cpu(physical_cluster, cpu) = old_cluster;
148 }
149
150 mutex_unlock(&cluster_lock[new_cluster]);
151
152 return ret;
153 }
154
155 mutex_unlock(&cluster_lock[new_cluster]);
156
157 /* Recalc freq for old cluster when switching clusters */
158 if (old_cluster != new_cluster) {
159 /* Switch cluster */
160 bL_switch_request(cpu, new_cluster);
161
162 mutex_lock(&cluster_lock[old_cluster]);
163
164 /* Set freq of old cluster if there are cpus left on it */
165 new_rate = find_cluster_maxfreq(old_cluster);
166 new_rate = ACTUAL_FREQ(old_cluster, new_rate);
167
168 if (new_rate &&
169 clk_set_rate(clk[old_cluster], new_rate * 1000)) {
170 pr_err("%s: clk_set_rate failed: %d, old cluster: %d\n",
171 __func__, ret, old_cluster);
172 }
173 mutex_unlock(&cluster_lock[old_cluster]);
174 }
175
176 return 0;
177 }
178
179 /* Set clock frequency */
180 static int ve_spc_cpufreq_set_target(struct cpufreq_policy *policy,
181 unsigned int index)
182 {
183 u32 cpu = policy->cpu, cur_cluster, new_cluster, actual_cluster;
184 unsigned int freqs_new;
185 int ret;
186
187 cur_cluster = cpu_to_cluster(cpu);
188 new_cluster = actual_cluster = per_cpu(physical_cluster, cpu);
189
190 freqs_new = freq_table[cur_cluster][index].frequency;
191
192 if (is_bL_switching_enabled()) {
193 if (actual_cluster == A15_CLUSTER && freqs_new < clk_big_min)
194 new_cluster = A7_CLUSTER;
195 else if (actual_cluster == A7_CLUSTER &&
196 freqs_new > clk_little_max)
197 new_cluster = A15_CLUSTER;
198 }
199
200 ret = ve_spc_cpufreq_set_rate(cpu, actual_cluster, new_cluster,
201 freqs_new);
202
203 if (!ret) {
204 arch_set_freq_scale(policy->related_cpus, freqs_new,
205 policy->cpuinfo.max_freq);
206 }
207
208 return ret;
209 }
210
211 static inline u32 get_table_count(struct cpufreq_frequency_table *table)
212 {
213 int count;
214
215 for (count = 0; table[count].frequency != CPUFREQ_TABLE_END; count++)
216 ;
217
218 return count;
219 }
220
221 /* get the minimum frequency in the cpufreq_frequency_table */
222 static inline u32 get_table_min(struct cpufreq_frequency_table *table)
223 {
224 struct cpufreq_frequency_table *pos;
225 u32 min_freq = ~0;
226
227 cpufreq_for_each_entry(pos, table)
228 if (pos->frequency < min_freq)
229 min_freq = pos->frequency;
230 return min_freq;
231 }
232
233 /* get the maximum frequency in the cpufreq_frequency_table */
234 static inline u32 get_table_max(struct cpufreq_frequency_table *table)
235 {
236 struct cpufreq_frequency_table *pos;
237 u32 max_freq = 0;
238
239 cpufreq_for_each_entry(pos, table)
240 if (pos->frequency > max_freq)
241 max_freq = pos->frequency;
242 return max_freq;
243 }
244
245 static bool search_frequency(struct cpufreq_frequency_table *table, int size,
246 unsigned int freq)
247 {
248 int count;
249
250 for (count = 0; count < size; count++) {
251 if (table[count].frequency == freq)
252 return true;
253 }
254
255 return false;
256 }
257
258 static int merge_cluster_tables(void)
259 {
260 int i, j, k = 0, count = 1;
261 struct cpufreq_frequency_table *table;
262
263 for (i = 0; i < MAX_CLUSTERS; i++)
264 count += get_table_count(freq_table[i]);
265
266 table = kcalloc(count, sizeof(*table), GFP_KERNEL);
267 if (!table)
268 return -ENOMEM;
269
270 freq_table[MAX_CLUSTERS] = table;
271
272 /* Add in reverse order to get freqs in increasing order */
273 for (i = MAX_CLUSTERS - 1; i >= 0; i--, count = k) {
274 for (j = 0; freq_table[i][j].frequency != CPUFREQ_TABLE_END;
275 j++) {
276 if (i == A15_CLUSTER &&
277 search_frequency(table, count, freq_table[i][j].frequency))
278 continue; /* skip duplicates */
279 table[k++].frequency =
280 VIRT_FREQ(i, freq_table[i][j].frequency);
281 }
282 }
283
284 table[k].driver_data = k;
285 table[k].frequency = CPUFREQ_TABLE_END;
286
287 return 0;
288 }
289
290 static void _put_cluster_clk_and_freq_table(struct device *cpu_dev,
291 const struct cpumask *cpumask)
292 {
293 u32 cluster = raw_cpu_to_cluster(cpu_dev->id);
294
295 if (!freq_table[cluster])
296 return;
297
298 clk_put(clk[cluster]);
299 dev_pm_opp_free_cpufreq_table(cpu_dev, &freq_table[cluster]);
300 }
301
302 static void put_cluster_clk_and_freq_table(struct device *cpu_dev,
303 const struct cpumask *cpumask)
304 {
305 u32 cluster = cpu_to_cluster(cpu_dev->id);
306 int i;
307
308 if (atomic_dec_return(&cluster_usage[cluster]))
309 return;
310
311 if (cluster < MAX_CLUSTERS)
312 return _put_cluster_clk_and_freq_table(cpu_dev, cpumask);
313
314 for_each_present_cpu(i) {
315 struct device *cdev = get_cpu_device(i);
316
317 if (!cdev)
318 return;
319
320 _put_cluster_clk_and_freq_table(cdev, cpumask);
321 }
322
323 /* free virtual table */
324 kfree(freq_table[cluster]);
325 }
326
327 static int _get_cluster_clk_and_freq_table(struct device *cpu_dev,
328 const struct cpumask *cpumask)
329 {
330 u32 cluster = raw_cpu_to_cluster(cpu_dev->id);
331 int ret;
332
333 if (freq_table[cluster])
334 return 0;
335
336 /*
337 * platform specific SPC code must initialise the opp table
338 * so just check if the OPP count is non-zero
339 */
340 ret = dev_pm_opp_get_opp_count(cpu_dev) <= 0;
341 if (ret)
342 goto out;
343
344 ret = dev_pm_opp_init_cpufreq_table(cpu_dev, &freq_table[cluster]);
345 if (ret)
346 goto out;
347
348 clk[cluster] = clk_get(cpu_dev, NULL);
349 if (!IS_ERR(clk[cluster]))
350 return 0;
351
352 dev_err(cpu_dev, "%s: Failed to get clk for cpu: %d, cluster: %d\n",
353 __func__, cpu_dev->id, cluster);
354 ret = PTR_ERR(clk[cluster]);
355 dev_pm_opp_free_cpufreq_table(cpu_dev, &freq_table[cluster]);
356
357 out:
358 dev_err(cpu_dev, "%s: Failed to get data for cluster: %d\n", __func__,
359 cluster);
360 return ret;
361 }
362
363 static int get_cluster_clk_and_freq_table(struct device *cpu_dev,
364 const struct cpumask *cpumask)
365 {
366 u32 cluster = cpu_to_cluster(cpu_dev->id);
367 int i, ret;
368
369 if (atomic_inc_return(&cluster_usage[cluster]) != 1)
370 return 0;
371
372 if (cluster < MAX_CLUSTERS) {
373 ret = _get_cluster_clk_and_freq_table(cpu_dev, cpumask);
374 if (ret)
375 atomic_dec(&cluster_usage[cluster]);
376 return ret;
377 }
378
379 /*
380 * Get data for all clusters and fill virtual cluster with a merge of
381 * both
382 */
383 for_each_present_cpu(i) {
384 struct device *cdev = get_cpu_device(i);
385
386 if (!cdev)
387 return -ENODEV;
388
389 ret = _get_cluster_clk_and_freq_table(cdev, cpumask);
390 if (ret)
391 goto put_clusters;
392 }
393
394 ret = merge_cluster_tables();
395 if (ret)
396 goto put_clusters;
397
398 /* Assuming 2 cluster, set clk_big_min and clk_little_max */
399 clk_big_min = get_table_min(freq_table[A15_CLUSTER]);
400 clk_little_max = VIRT_FREQ(A7_CLUSTER,
401 get_table_max(freq_table[A7_CLUSTER]));
402
403 return 0;
404
405 put_clusters:
406 for_each_present_cpu(i) {
407 struct device *cdev = get_cpu_device(i);
408
409 if (!cdev)
410 return -ENODEV;
411
412 _put_cluster_clk_and_freq_table(cdev, cpumask);
413 }
414
415 atomic_dec(&cluster_usage[cluster]);
416
417 return ret;
418 }
419
420 /* Per-CPU initialization */
421 static int ve_spc_cpufreq_init(struct cpufreq_policy *policy)
422 {
423 u32 cur_cluster = cpu_to_cluster(policy->cpu);
424 struct device *cpu_dev;
425 int ret;
426
427 cpu_dev = get_cpu_device(policy->cpu);
428 if (!cpu_dev) {
429 pr_err("%s: failed to get cpu%d device\n", __func__,
430 policy->cpu);
431 return -ENODEV;
432 }
433
434 if (cur_cluster < MAX_CLUSTERS) {
435 int cpu;
436
437 dev_pm_opp_get_sharing_cpus(cpu_dev, policy->cpus);
438
439 for_each_cpu(cpu, policy->cpus)
440 per_cpu(physical_cluster, cpu) = cur_cluster;
441 } else {
442 /* Assumption: during init, we are always running on A15 */
443 per_cpu(physical_cluster, policy->cpu) = A15_CLUSTER;
444 }
445
446 ret = get_cluster_clk_and_freq_table(cpu_dev, policy->cpus);
447 if (ret)
448 return ret;
449
450 policy->freq_table = freq_table[cur_cluster];
451 policy->cpuinfo.transition_latency = 1000000; /* 1 ms */
452
453 dev_pm_opp_of_register_em(policy->cpus);
454
455 if (is_bL_switching_enabled())
456 per_cpu(cpu_last_req_freq, policy->cpu) =
457 clk_get_cpu_rate(policy->cpu);
458
459 dev_info(cpu_dev, "%s: CPU %d initialized\n", __func__, policy->cpu);
460 return 0;
461 }
462
463 static int ve_spc_cpufreq_exit(struct cpufreq_policy *policy)
464 {
465 struct device *cpu_dev;
466 int cur_cluster = cpu_to_cluster(policy->cpu);
467
468 if (cur_cluster < MAX_CLUSTERS) {
469 cpufreq_cooling_unregister(cdev[cur_cluster]);
470 cdev[cur_cluster] = NULL;
471 }
472
473 cpu_dev = get_cpu_device(policy->cpu);
474 if (!cpu_dev) {
475 pr_err("%s: failed to get cpu%d device\n", __func__,
476 policy->cpu);
477 return -ENODEV;
478 }
479
480 put_cluster_clk_and_freq_table(cpu_dev, policy->related_cpus);
481 return 0;
482 }
483
484 static void ve_spc_cpufreq_ready(struct cpufreq_policy *policy)
485 {
486 int cur_cluster = cpu_to_cluster(policy->cpu);
487
488 /* Do not register a cpu_cooling device if we are in IKS mode */
489 if (cur_cluster >= MAX_CLUSTERS)
490 return;
491
492 cdev[cur_cluster] = of_cpufreq_cooling_register(policy);
493 }
494
495 static struct cpufreq_driver ve_spc_cpufreq_driver = {
496 .name = "vexpress-spc",
497 .flags = CPUFREQ_STICKY |
498 CPUFREQ_HAVE_GOVERNOR_PER_POLICY |
499 CPUFREQ_NEED_INITIAL_FREQ_CHECK,
500 .verify = cpufreq_generic_frequency_table_verify,
501 .target_index = ve_spc_cpufreq_set_target,
502 .get = ve_spc_cpufreq_get_rate,
503 .init = ve_spc_cpufreq_init,
504 .exit = ve_spc_cpufreq_exit,
505 .ready = ve_spc_cpufreq_ready,
506 .attr = cpufreq_generic_attr,
507 };
508
509 #ifdef CONFIG_BL_SWITCHER
510 static int bL_cpufreq_switcher_notifier(struct notifier_block *nfb,
511 unsigned long action, void *_arg)
512 {
513 pr_debug("%s: action: %ld\n", __func__, action);
514
515 switch (action) {
516 case BL_NOTIFY_PRE_ENABLE:
517 case BL_NOTIFY_PRE_DISABLE:
518 cpufreq_unregister_driver(&ve_spc_cpufreq_driver);
519 break;
520
521 case BL_NOTIFY_POST_ENABLE:
522 set_switching_enabled(true);
523 cpufreq_register_driver(&ve_spc_cpufreq_driver);
524 break;
525
526 case BL_NOTIFY_POST_DISABLE:
527 set_switching_enabled(false);
528 cpufreq_register_driver(&ve_spc_cpufreq_driver);
529 break;
530
531 default:
532 return NOTIFY_DONE;
533 }
534
535 return NOTIFY_OK;
536 }
537
538 static struct notifier_block bL_switcher_notifier = {
539 .notifier_call = bL_cpufreq_switcher_notifier,
540 };
541
542 static int __bLs_register_notifier(void)
543 {
544 return bL_switcher_register_notifier(&bL_switcher_notifier);
545 }
546
547 static int __bLs_unregister_notifier(void)
548 {
549 return bL_switcher_unregister_notifier(&bL_switcher_notifier);
550 }
551 #else
552 static int __bLs_register_notifier(void) { return 0; }
553 static int __bLs_unregister_notifier(void) { return 0; }
554 #endif
555
556 static int ve_spc_cpufreq_probe(struct platform_device *pdev)
557 {
558 int ret, i;
559
560 set_switching_enabled(bL_switcher_get_enabled());
561
562 for (i = 0; i < MAX_CLUSTERS; i++)
563 mutex_init(&cluster_lock[i]);
564
565 ret = cpufreq_register_driver(&ve_spc_cpufreq_driver);
566 if (ret) {
567 pr_info("%s: Failed registering platform driver: %s, err: %d\n",
568 __func__, ve_spc_cpufreq_driver.name, ret);
569 } else {
570 ret = __bLs_register_notifier();
571 if (ret)
572 cpufreq_unregister_driver(&ve_spc_cpufreq_driver);
573 else
574 pr_info("%s: Registered platform driver: %s\n",
575 __func__, ve_spc_cpufreq_driver.name);
576 }
577
578 bL_switcher_put_enabled();
579 return ret;
580 }
581
582 static int ve_spc_cpufreq_remove(struct platform_device *pdev)
583 {
584 bL_switcher_get_enabled();
585 __bLs_unregister_notifier();
586 cpufreq_unregister_driver(&ve_spc_cpufreq_driver);
587 bL_switcher_put_enabled();
588 pr_info("%s: Un-registered platform driver: %s\n", __func__,
589 ve_spc_cpufreq_driver.name);
590 return 0;
591 }
592
593 static struct platform_driver ve_spc_cpufreq_platdrv = {
594 .driver = {
595 .name = "vexpress-spc-cpufreq",
596 },
597 .probe = ve_spc_cpufreq_probe,
598 .remove = ve_spc_cpufreq_remove,
599 };
600 module_platform_driver(ve_spc_cpufreq_platdrv);
601
602 MODULE_AUTHOR("Viresh Kumar <viresh.kumar@linaro.org>");
603 MODULE_AUTHOR("Sudeep Holla <sudeep.holla@arm.com>");
604 MODULE_DESCRIPTION("Vexpress SPC ARM big LITTLE cpufreq driver");
605 MODULE_LICENSE("GPL v2");
Linux with added FPC-III support