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1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  *  (C) 2004-2009  Dominik Brodowski <linux@dominikbrodowski.de>
4  */
5 
6 
7 #include <stdio.h>
8 #include <errno.h>
9 #include <stdlib.h>
10 #include <string.h>
11 #include <sys/types.h>
12 #include <sys/stat.h>
13 #include <fcntl.h>
14 #include <unistd.h>
15 
16 #include "cpufreq.h"
17 #include "cpupower_intern.h"
18 
19 /* CPUFREQ sysfs access **************************************************/
20 
21 /* helper function to read file from /sys into given buffer */
22 /* fname is a relative path under "cpuX/cpufreq" dir */
sysfs_cpufreq_read_file(unsigned int cpu,const char * fname,char * buf,size_t buflen)23 static unsigned int sysfs_cpufreq_read_file(unsigned int cpu, const char *fname,
24 					    char *buf, size_t buflen)
25 {
26 	char path[SYSFS_PATH_MAX];
27 
28 	snprintf(path, sizeof(path), PATH_TO_CPU "cpu%u/cpufreq/%s",
29 			 cpu, fname);
30 	return cpupower_read_sysfs(path, buf, buflen);
31 }
32 
33 /* helper function to write a new value to a /sys file */
34 /* fname is a relative path under "cpuX/cpufreq" dir */
sysfs_cpufreq_write_file(unsigned int cpu,const char * fname,const char * value,size_t len)35 static unsigned int sysfs_cpufreq_write_file(unsigned int cpu,
36 					     const char *fname,
37 					     const char *value, size_t len)
38 {
39 	char path[SYSFS_PATH_MAX];
40 	int fd;
41 	ssize_t numwrite;
42 
43 	snprintf(path, sizeof(path), PATH_TO_CPU "cpu%u/cpufreq/%s",
44 			 cpu, fname);
45 
46 	fd = open(path, O_WRONLY);
47 	if (fd == -1)
48 		return 0;
49 
50 	numwrite = write(fd, value, len);
51 	if (numwrite < 1) {
52 		close(fd);
53 		return 0;
54 	}
55 
56 	close(fd);
57 
58 	return (unsigned int) numwrite;
59 }
60 
61 /* read access to files which contain one numeric value */
62 
63 enum cpufreq_value {
64 	CPUINFO_CUR_FREQ,
65 	CPUINFO_MIN_FREQ,
66 	CPUINFO_MAX_FREQ,
67 	CPUINFO_LATENCY,
68 	SCALING_CUR_FREQ,
69 	SCALING_MIN_FREQ,
70 	SCALING_MAX_FREQ,
71 	STATS_NUM_TRANSITIONS,
72 	MAX_CPUFREQ_VALUE_READ_FILES
73 };
74 
75 static const char *cpufreq_value_files[MAX_CPUFREQ_VALUE_READ_FILES] = {
76 	[CPUINFO_CUR_FREQ] = "cpuinfo_cur_freq",
77 	[CPUINFO_MIN_FREQ] = "cpuinfo_min_freq",
78 	[CPUINFO_MAX_FREQ] = "cpuinfo_max_freq",
79 	[CPUINFO_LATENCY]  = "cpuinfo_transition_latency",
80 	[SCALING_CUR_FREQ] = "scaling_cur_freq",
81 	[SCALING_MIN_FREQ] = "scaling_min_freq",
82 	[SCALING_MAX_FREQ] = "scaling_max_freq",
83 	[STATS_NUM_TRANSITIONS] = "stats/total_trans"
84 };
85 
86 
sysfs_cpufreq_get_one_value(unsigned int cpu,enum cpufreq_value which)87 static unsigned long sysfs_cpufreq_get_one_value(unsigned int cpu,
88 						 enum cpufreq_value which)
89 {
90 	unsigned long value;
91 	unsigned int len;
92 	char linebuf[MAX_LINE_LEN];
93 	char *endp;
94 
95 	if (which >= MAX_CPUFREQ_VALUE_READ_FILES)
96 		return 0;
97 
98 	len = sysfs_cpufreq_read_file(cpu, cpufreq_value_files[which],
99 				linebuf, sizeof(linebuf));
100 
101 	if (len == 0)
102 		return 0;
103 
104 	value = strtoul(linebuf, &endp, 0);
105 
106 	if (endp == linebuf || errno == ERANGE)
107 		return 0;
108 
109 	return value;
110 }
111 
112 /* read access to files which contain one string */
113 
114 enum cpufreq_string {
115 	SCALING_DRIVER,
116 	SCALING_GOVERNOR,
117 	MAX_CPUFREQ_STRING_FILES
118 };
119 
120 static const char *cpufreq_string_files[MAX_CPUFREQ_STRING_FILES] = {
121 	[SCALING_DRIVER] = "scaling_driver",
122 	[SCALING_GOVERNOR] = "scaling_governor",
123 };
124 
125 
sysfs_cpufreq_get_one_string(unsigned int cpu,enum cpufreq_string which)126 static char *sysfs_cpufreq_get_one_string(unsigned int cpu,
127 					   enum cpufreq_string which)
128 {
129 	char linebuf[MAX_LINE_LEN];
130 	char *result;
131 	unsigned int len;
132 
133 	if (which >= MAX_CPUFREQ_STRING_FILES)
134 		return NULL;
135 
136 	len = sysfs_cpufreq_read_file(cpu, cpufreq_string_files[which],
137 				linebuf, sizeof(linebuf));
138 	if (len == 0)
139 		return NULL;
140 
141 	result = strdup(linebuf);
142 	if (result == NULL)
143 		return NULL;
144 
145 	if (result[strlen(result) - 1] == '\n')
146 		result[strlen(result) - 1] = '\0';
147 
148 	return result;
149 }
150 
151 /* write access */
152 
153 enum cpufreq_write {
154 	WRITE_SCALING_MIN_FREQ,
155 	WRITE_SCALING_MAX_FREQ,
156 	WRITE_SCALING_GOVERNOR,
157 	WRITE_SCALING_SET_SPEED,
158 	MAX_CPUFREQ_WRITE_FILES
159 };
160 
161 static const char *cpufreq_write_files[MAX_CPUFREQ_WRITE_FILES] = {
162 	[WRITE_SCALING_MIN_FREQ] = "scaling_min_freq",
163 	[WRITE_SCALING_MAX_FREQ] = "scaling_max_freq",
164 	[WRITE_SCALING_GOVERNOR] = "scaling_governor",
165 	[WRITE_SCALING_SET_SPEED] = "scaling_setspeed",
166 };
167 
sysfs_cpufreq_write_one_value(unsigned int cpu,enum cpufreq_write which,const char * new_value,size_t len)168 static int sysfs_cpufreq_write_one_value(unsigned int cpu,
169 					 enum cpufreq_write which,
170 					 const char *new_value, size_t len)
171 {
172 	if (which >= MAX_CPUFREQ_WRITE_FILES)
173 		return 0;
174 
175 	if (sysfs_cpufreq_write_file(cpu, cpufreq_write_files[which],
176 					new_value, len) != len)
177 		return -ENODEV;
178 
179 	return 0;
180 };
181 
cpufreq_get_freq_kernel(unsigned int cpu)182 unsigned long cpufreq_get_freq_kernel(unsigned int cpu)
183 {
184 	return sysfs_cpufreq_get_one_value(cpu, SCALING_CUR_FREQ);
185 }
186 
cpufreq_get_freq_hardware(unsigned int cpu)187 unsigned long cpufreq_get_freq_hardware(unsigned int cpu)
188 {
189 	return sysfs_cpufreq_get_one_value(cpu, CPUINFO_CUR_FREQ);
190 }
191 
cpufreq_get_transition_latency(unsigned int cpu)192 unsigned long cpufreq_get_transition_latency(unsigned int cpu)
193 {
194 	return sysfs_cpufreq_get_one_value(cpu, CPUINFO_LATENCY);
195 }
196 
cpufreq_get_hardware_limits(unsigned int cpu,unsigned long * min,unsigned long * max)197 int cpufreq_get_hardware_limits(unsigned int cpu,
198 				unsigned long *min,
199 				unsigned long *max)
200 {
201 	if ((!min) || (!max))
202 		return -EINVAL;
203 
204 	*min = sysfs_cpufreq_get_one_value(cpu, CPUINFO_MIN_FREQ);
205 	if (!*min)
206 		return -ENODEV;
207 
208 	*max = sysfs_cpufreq_get_one_value(cpu, CPUINFO_MAX_FREQ);
209 	if (!*max)
210 		return -ENODEV;
211 
212 	return 0;
213 }
214 
cpufreq_get_driver(unsigned int cpu)215 char *cpufreq_get_driver(unsigned int cpu)
216 {
217 	return sysfs_cpufreq_get_one_string(cpu, SCALING_DRIVER);
218 }
219 
cpufreq_put_driver(char * ptr)220 void cpufreq_put_driver(char *ptr)
221 {
222 	if (!ptr)
223 		return;
224 	free(ptr);
225 }
226 
cpufreq_get_policy(unsigned int cpu)227 struct cpufreq_policy *cpufreq_get_policy(unsigned int cpu)
228 {
229 	struct cpufreq_policy *policy;
230 
231 	policy = malloc(sizeof(struct cpufreq_policy));
232 	if (!policy)
233 		return NULL;
234 
235 	policy->governor = sysfs_cpufreq_get_one_string(cpu, SCALING_GOVERNOR);
236 	if (!policy->governor) {
237 		free(policy);
238 		return NULL;
239 	}
240 	policy->min = sysfs_cpufreq_get_one_value(cpu, SCALING_MIN_FREQ);
241 	policy->max = sysfs_cpufreq_get_one_value(cpu, SCALING_MAX_FREQ);
242 	if ((!policy->min) || (!policy->max)) {
243 		free(policy->governor);
244 		free(policy);
245 		return NULL;
246 	}
247 
248 	return policy;
249 }
250 
cpufreq_put_policy(struct cpufreq_policy * policy)251 void cpufreq_put_policy(struct cpufreq_policy *policy)
252 {
253 	if ((!policy) || (!policy->governor))
254 		return;
255 
256 	free(policy->governor);
257 	policy->governor = NULL;
258 	free(policy);
259 }
260 
cpufreq_get_available_governors(unsigned int cpu)261 struct cpufreq_available_governors *cpufreq_get_available_governors(unsigned
262 								int cpu)
263 {
264 	struct cpufreq_available_governors *first = NULL;
265 	struct cpufreq_available_governors *current = NULL;
266 	char linebuf[MAX_LINE_LEN];
267 	unsigned int pos, i;
268 	unsigned int len;
269 
270 	len = sysfs_cpufreq_read_file(cpu, "scaling_available_governors",
271 				linebuf, sizeof(linebuf));
272 	if (len == 0)
273 		return NULL;
274 
275 	pos = 0;
276 	for (i = 0; i < len; i++) {
277 		if (linebuf[i] == ' ' || linebuf[i] == '\n') {
278 			if (i - pos < 2)
279 				continue;
280 			if (current) {
281 				current->next = malloc(sizeof(*current));
282 				if (!current->next)
283 					goto error_out;
284 				current = current->next;
285 			} else {
286 				first = malloc(sizeof(*first));
287 				if (!first)
288 					goto error_out;
289 				current = first;
290 			}
291 			current->first = first;
292 			current->next = NULL;
293 
294 			current->governor = malloc(i - pos + 1);
295 			if (!current->governor)
296 				goto error_out;
297 
298 			memcpy(current->governor, linebuf + pos, i - pos);
299 			current->governor[i - pos] = '\0';
300 			pos = i + 1;
301 		}
302 	}
303 
304 	return first;
305 
306  error_out:
307 	while (first) {
308 		current = first->next;
309 		if (first->governor)
310 			free(first->governor);
311 		free(first);
312 		first = current;
313 	}
314 	return NULL;
315 }
316 
cpufreq_put_available_governors(struct cpufreq_available_governors * any)317 void cpufreq_put_available_governors(struct cpufreq_available_governors *any)
318 {
319 	struct cpufreq_available_governors *tmp, *next;
320 
321 	if (!any)
322 		return;
323 
324 	tmp = any->first;
325 	while (tmp) {
326 		next = tmp->next;
327 		if (tmp->governor)
328 			free(tmp->governor);
329 		free(tmp);
330 		tmp = next;
331 	}
332 }
333 
334 
335 struct cpufreq_available_frequencies
cpufreq_get_available_frequencies(unsigned int cpu)336 *cpufreq_get_available_frequencies(unsigned int cpu)
337 {
338 	struct cpufreq_available_frequencies *first = NULL;
339 	struct cpufreq_available_frequencies *current = NULL;
340 	char one_value[SYSFS_PATH_MAX];
341 	char linebuf[MAX_LINE_LEN];
342 	unsigned int pos, i;
343 	unsigned int len;
344 
345 	len = sysfs_cpufreq_read_file(cpu, "scaling_available_frequencies",
346 				      linebuf, sizeof(linebuf));
347 	if (len == 0)
348 		return NULL;
349 
350 	pos = 0;
351 	for (i = 0; i < len; i++) {
352 		if (linebuf[i] == ' ' || linebuf[i] == '\n') {
353 			if (i - pos < 2)
354 				continue;
355 			if (i - pos >= SYSFS_PATH_MAX)
356 				goto error_out;
357 			if (current) {
358 				current->next = malloc(sizeof(*current));
359 				if (!current->next)
360 					goto error_out;
361 				current = current->next;
362 			} else {
363 				first = malloc(sizeof(*first));
364 				if (!first)
365 					goto error_out;
366 				current = first;
367 			}
368 			current->first = first;
369 			current->next = NULL;
370 
371 			memcpy(one_value, linebuf + pos, i - pos);
372 			one_value[i - pos] = '\0';
373 			if (sscanf(one_value, "%lu", &current->frequency) != 1)
374 				goto error_out;
375 
376 			pos = i + 1;
377 		}
378 	}
379 
380 	return first;
381 
382  error_out:
383 	while (first) {
384 		current = first->next;
385 		free(first);
386 		first = current;
387 	}
388 	return NULL;
389 }
390 
391 struct cpufreq_available_frequencies
cpufreq_get_boost_frequencies(unsigned int cpu)392 *cpufreq_get_boost_frequencies(unsigned int cpu)
393 {
394 	struct cpufreq_available_frequencies *first = NULL;
395 	struct cpufreq_available_frequencies *current = NULL;
396 	char one_value[SYSFS_PATH_MAX];
397 	char linebuf[MAX_LINE_LEN];
398 	unsigned int pos, i;
399 	unsigned int len;
400 
401 	len = sysfs_cpufreq_read_file(cpu, "scaling_boost_frequencies",
402 				      linebuf, sizeof(linebuf));
403 	if (len == 0)
404 		return NULL;
405 
406 	pos = 0;
407 	for (i = 0; i < len; i++) {
408 		if (linebuf[i] == ' ' || linebuf[i] == '\n') {
409 			if (i - pos < 2)
410 				continue;
411 			if (i - pos >= SYSFS_PATH_MAX)
412 				goto error_out;
413 			if (current) {
414 				current->next = malloc(sizeof(*current));
415 				if (!current->next)
416 					goto error_out;
417 				current = current->next;
418 			} else {
419 				first = malloc(sizeof(*first));
420 				if (!first)
421 					goto error_out;
422 				current = first;
423 			}
424 			current->first = first;
425 			current->next = NULL;
426 
427 			memcpy(one_value, linebuf + pos, i - pos);
428 			one_value[i - pos] = '\0';
429 			if (sscanf(one_value, "%lu", &current->frequency) != 1)
430 				goto error_out;
431 
432 			pos = i + 1;
433 		}
434 	}
435 
436 	return first;
437 
438  error_out:
439 	while (first) {
440 		current = first->next;
441 		free(first);
442 		first = current;
443 	}
444 	return NULL;
445 }
446 
cpufreq_put_available_frequencies(struct cpufreq_available_frequencies * any)447 void cpufreq_put_available_frequencies(struct cpufreq_available_frequencies *any)
448 {
449 	struct cpufreq_available_frequencies *tmp, *next;
450 
451 	if (!any)
452 		return;
453 
454 	tmp = any->first;
455 	while (tmp) {
456 		next = tmp->next;
457 		free(tmp);
458 		tmp = next;
459 	}
460 }
461 
cpufreq_put_boost_frequencies(struct cpufreq_available_frequencies * any)462 void cpufreq_put_boost_frequencies(struct cpufreq_available_frequencies *any)
463 {
464 	cpufreq_put_available_frequencies(any);
465 }
466 
sysfs_get_cpu_list(unsigned int cpu,const char * file)467 static struct cpufreq_affected_cpus *sysfs_get_cpu_list(unsigned int cpu,
468 							const char *file)
469 {
470 	struct cpufreq_affected_cpus *first = NULL;
471 	struct cpufreq_affected_cpus *current = NULL;
472 	char one_value[SYSFS_PATH_MAX];
473 	char linebuf[MAX_LINE_LEN];
474 	unsigned int pos, i;
475 	unsigned int len;
476 
477 	len = sysfs_cpufreq_read_file(cpu, file, linebuf, sizeof(linebuf));
478 	if (len == 0)
479 		return NULL;
480 
481 	pos = 0;
482 	for (i = 0; i < len; i++) {
483 		if (i == len || linebuf[i] == ' ' || linebuf[i] == '\n') {
484 			if (i - pos  < 1)
485 				continue;
486 			if (i - pos >= SYSFS_PATH_MAX)
487 				goto error_out;
488 			if (current) {
489 				current->next = malloc(sizeof(*current));
490 				if (!current->next)
491 					goto error_out;
492 				current = current->next;
493 			} else {
494 				first = malloc(sizeof(*first));
495 				if (!first)
496 					goto error_out;
497 				current = first;
498 			}
499 			current->first = first;
500 			current->next = NULL;
501 
502 			memcpy(one_value, linebuf + pos, i - pos);
503 			one_value[i - pos] = '\0';
504 
505 			if (sscanf(one_value, "%u", &current->cpu) != 1)
506 				goto error_out;
507 
508 			pos = i + 1;
509 		}
510 	}
511 
512 	return first;
513 
514  error_out:
515 	while (first) {
516 		current = first->next;
517 		free(first);
518 		first = current;
519 	}
520 	return NULL;
521 }
522 
cpufreq_get_affected_cpus(unsigned int cpu)523 struct cpufreq_affected_cpus *cpufreq_get_affected_cpus(unsigned int cpu)
524 {
525 	return sysfs_get_cpu_list(cpu, "affected_cpus");
526 }
527 
cpufreq_put_affected_cpus(struct cpufreq_affected_cpus * any)528 void cpufreq_put_affected_cpus(struct cpufreq_affected_cpus *any)
529 {
530 	struct cpufreq_affected_cpus *tmp, *next;
531 
532 	if (!any)
533 		return;
534 
535 	tmp = any->first;
536 	while (tmp) {
537 		next = tmp->next;
538 		free(tmp);
539 		tmp = next;
540 	}
541 }
542 
543 
cpufreq_get_related_cpus(unsigned int cpu)544 struct cpufreq_affected_cpus *cpufreq_get_related_cpus(unsigned int cpu)
545 {
546 	return sysfs_get_cpu_list(cpu, "related_cpus");
547 }
548 
cpufreq_put_related_cpus(struct cpufreq_affected_cpus * any)549 void cpufreq_put_related_cpus(struct cpufreq_affected_cpus *any)
550 {
551 	cpufreq_put_affected_cpus(any);
552 }
553 
verify_gov(char * new_gov,char * passed_gov)554 static int verify_gov(char *new_gov, char *passed_gov)
555 {
556 	unsigned int i, j = 0;
557 
558 	if (!passed_gov || (strlen(passed_gov) > 19))
559 		return -EINVAL;
560 
561 	strncpy(new_gov, passed_gov, 20);
562 	for (i = 0; i < 20; i++) {
563 		if (j) {
564 			new_gov[i] = '\0';
565 			continue;
566 		}
567 		if ((new_gov[i] >= 'a') && (new_gov[i] <= 'z'))
568 			continue;
569 
570 		if ((new_gov[i] >= 'A') && (new_gov[i] <= 'Z'))
571 			continue;
572 
573 		if (new_gov[i] == '-')
574 			continue;
575 
576 		if (new_gov[i] == '_')
577 			continue;
578 
579 		if (new_gov[i] == '\0') {
580 			j = 1;
581 			continue;
582 		}
583 		return -EINVAL;
584 	}
585 	new_gov[19] = '\0';
586 	return 0;
587 }
588 
cpufreq_set_policy(unsigned int cpu,struct cpufreq_policy * policy)589 int cpufreq_set_policy(unsigned int cpu, struct cpufreq_policy *policy)
590 {
591 	char min[SYSFS_PATH_MAX];
592 	char max[SYSFS_PATH_MAX];
593 	char gov[SYSFS_PATH_MAX];
594 	int ret;
595 	unsigned long old_min;
596 	int write_max_first;
597 
598 	if (!policy || !(policy->governor))
599 		return -EINVAL;
600 
601 	if (policy->max < policy->min)
602 		return -EINVAL;
603 
604 	if (verify_gov(gov, policy->governor))
605 		return -EINVAL;
606 
607 	snprintf(min, SYSFS_PATH_MAX, "%lu", policy->min);
608 	snprintf(max, SYSFS_PATH_MAX, "%lu", policy->max);
609 
610 	old_min = sysfs_cpufreq_get_one_value(cpu, SCALING_MIN_FREQ);
611 	write_max_first = (old_min && (policy->max < old_min) ? 0 : 1);
612 
613 	if (write_max_first) {
614 		ret = sysfs_cpufreq_write_one_value(cpu, WRITE_SCALING_MAX_FREQ,
615 						    max, strlen(max));
616 		if (ret)
617 			return ret;
618 	}
619 
620 	ret = sysfs_cpufreq_write_one_value(cpu, WRITE_SCALING_MIN_FREQ, min,
621 					    strlen(min));
622 	if (ret)
623 		return ret;
624 
625 	if (!write_max_first) {
626 		ret = sysfs_cpufreq_write_one_value(cpu, WRITE_SCALING_MAX_FREQ,
627 						    max, strlen(max));
628 		if (ret)
629 			return ret;
630 	}
631 
632 	return sysfs_cpufreq_write_one_value(cpu, WRITE_SCALING_GOVERNOR,
633 					     gov, strlen(gov));
634 }
635 
636 
cpufreq_modify_policy_min(unsigned int cpu,unsigned long min_freq)637 int cpufreq_modify_policy_min(unsigned int cpu, unsigned long min_freq)
638 {
639 	char value[SYSFS_PATH_MAX];
640 
641 	snprintf(value, SYSFS_PATH_MAX, "%lu", min_freq);
642 
643 	return sysfs_cpufreq_write_one_value(cpu, WRITE_SCALING_MIN_FREQ,
644 					     value, strlen(value));
645 }
646 
647 
cpufreq_modify_policy_max(unsigned int cpu,unsigned long max_freq)648 int cpufreq_modify_policy_max(unsigned int cpu, unsigned long max_freq)
649 {
650 	char value[SYSFS_PATH_MAX];
651 
652 	snprintf(value, SYSFS_PATH_MAX, "%lu", max_freq);
653 
654 	return sysfs_cpufreq_write_one_value(cpu, WRITE_SCALING_MAX_FREQ,
655 					     value, strlen(value));
656 }
657 
cpufreq_modify_policy_governor(unsigned int cpu,char * governor)658 int cpufreq_modify_policy_governor(unsigned int cpu, char *governor)
659 {
660 	char new_gov[SYSFS_PATH_MAX];
661 
662 	if ((!governor) || (strlen(governor) > 19))
663 		return -EINVAL;
664 
665 	if (verify_gov(new_gov, governor))
666 		return -EINVAL;
667 
668 	return sysfs_cpufreq_write_one_value(cpu, WRITE_SCALING_GOVERNOR,
669 					     new_gov, strlen(new_gov));
670 }
671 
cpufreq_set_frequency(unsigned int cpu,unsigned long target_frequency)672 int cpufreq_set_frequency(unsigned int cpu, unsigned long target_frequency)
673 {
674 	struct cpufreq_policy *pol = cpufreq_get_policy(cpu);
675 	char userspace_gov[] = "userspace";
676 	char freq[SYSFS_PATH_MAX];
677 	int ret;
678 
679 	if (!pol)
680 		return -ENODEV;
681 
682 	if (strncmp(pol->governor, userspace_gov, 9) != 0) {
683 		ret = cpufreq_modify_policy_governor(cpu, userspace_gov);
684 		if (ret) {
685 			cpufreq_put_policy(pol);
686 			return ret;
687 		}
688 	}
689 
690 	cpufreq_put_policy(pol);
691 
692 	snprintf(freq, SYSFS_PATH_MAX, "%lu", target_frequency);
693 
694 	return sysfs_cpufreq_write_one_value(cpu, WRITE_SCALING_SET_SPEED,
695 					     freq, strlen(freq));
696 }
697 
cpufreq_get_stats(unsigned int cpu,unsigned long long * total_time)698 struct cpufreq_stats *cpufreq_get_stats(unsigned int cpu,
699 					unsigned long long *total_time)
700 {
701 	struct cpufreq_stats *first = NULL;
702 	struct cpufreq_stats *current = NULL;
703 	char one_value[SYSFS_PATH_MAX];
704 	char linebuf[MAX_LINE_LEN];
705 	unsigned int pos, i;
706 	unsigned int len;
707 
708 	len = sysfs_cpufreq_read_file(cpu, "stats/time_in_state",
709 				linebuf, sizeof(linebuf));
710 	if (len == 0)
711 		return NULL;
712 
713 	*total_time = 0;
714 	pos = 0;
715 	for (i = 0; i < len; i++) {
716 		if (i == strlen(linebuf) || linebuf[i] == '\n')	{
717 			if (i - pos < 2)
718 				continue;
719 			if ((i - pos) >= SYSFS_PATH_MAX)
720 				goto error_out;
721 			if (current) {
722 				current->next = malloc(sizeof(*current));
723 				if (!current->next)
724 					goto error_out;
725 				current = current->next;
726 			} else {
727 				first = malloc(sizeof(*first));
728 				if (!first)
729 					goto error_out;
730 				current = first;
731 			}
732 			current->first = first;
733 			current->next = NULL;
734 
735 			memcpy(one_value, linebuf + pos, i - pos);
736 			one_value[i - pos] = '\0';
737 			if (sscanf(one_value, "%lu %llu",
738 					&current->frequency,
739 					&current->time_in_state) != 2)
740 				goto error_out;
741 
742 			*total_time = *total_time + current->time_in_state;
743 			pos = i + 1;
744 		}
745 	}
746 
747 	return first;
748 
749  error_out:
750 	while (first) {
751 		current = first->next;
752 		free(first);
753 		first = current;
754 	}
755 	return NULL;
756 }
757 
cpufreq_put_stats(struct cpufreq_stats * any)758 void cpufreq_put_stats(struct cpufreq_stats *any)
759 {
760 	struct cpufreq_stats *tmp, *next;
761 
762 	if (!any)
763 		return;
764 
765 	tmp = any->first;
766 	while (tmp) {
767 		next = tmp->next;
768 		free(tmp);
769 		tmp = next;
770 	}
771 }
772 
cpufreq_get_transitions(unsigned int cpu)773 unsigned long cpufreq_get_transitions(unsigned int cpu)
774 {
775 	return sysfs_cpufreq_get_one_value(cpu, STATS_NUM_TRANSITIONS);
776 }
777