1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * Power capping class
4 * Copyright (c) 2013, Intel Corporation.
5 */
6
7 #include <linux/module.h>
8 #include <linux/device.h>
9 #include <linux/err.h>
10 #include <linux/kstrtox.h>
11 #include <linux/slab.h>
12 #include <linux/powercap.h>
13
14 #define to_powercap_zone(n) container_of(n, struct powercap_zone, dev)
15 #define to_powercap_control_type(n) \
16 container_of(n, struct powercap_control_type, dev)
17
18 /* Power zone show function */
19 #define define_power_zone_show(_attr) \
20 static ssize_t _attr##_show(struct device *dev, \
21 struct device_attribute *dev_attr,\
22 char *buf) \
23 { \
24 u64 value; \
25 ssize_t len = -EINVAL; \
26 struct powercap_zone *power_zone = to_powercap_zone(dev); \
27 \
28 if (power_zone->ops->get_##_attr) { \
29 if (!power_zone->ops->get_##_attr(power_zone, &value)) \
30 len = sprintf(buf, "%lld\n", value); \
31 } \
32 \
33 return len; \
34 }
35
36 /* The only meaningful input is 0 (reset), others are silently ignored */
37 #define define_power_zone_store(_attr) \
38 static ssize_t _attr##_store(struct device *dev,\
39 struct device_attribute *dev_attr, \
40 const char *buf, size_t count) \
41 { \
42 int err; \
43 struct powercap_zone *power_zone = to_powercap_zone(dev); \
44 u64 value; \
45 \
46 err = kstrtoull(buf, 10, &value); \
47 if (err) \
48 return -EINVAL; \
49 if (value) \
50 return count; \
51 if (power_zone->ops->reset_##_attr) { \
52 if (!power_zone->ops->reset_##_attr(power_zone)) \
53 return count; \
54 } \
55 \
56 return -EINVAL; \
57 }
58
59 /* Power zone constraint show function */
60 #define define_power_zone_constraint_show(_attr) \
61 static ssize_t show_constraint_##_attr(struct device *dev, \
62 struct device_attribute *dev_attr,\
63 char *buf) \
64 { \
65 u64 value; \
66 ssize_t len = -ENODATA; \
67 struct powercap_zone *power_zone = to_powercap_zone(dev); \
68 int id; \
69 struct powercap_zone_constraint *pconst;\
70 \
71 if (!sscanf(dev_attr->attr.name, "constraint_%d_", &id)) \
72 return -EINVAL; \
73 if (id >= power_zone->const_id_cnt) \
74 return -EINVAL; \
75 pconst = &power_zone->constraints[id]; \
76 if (pconst && pconst->ops && pconst->ops->get_##_attr) { \
77 if (!pconst->ops->get_##_attr(power_zone, id, &value)) \
78 len = sprintf(buf, "%lld\n", value); \
79 } \
80 \
81 return len; \
82 }
83
84 /* Power zone constraint store function */
85 #define define_power_zone_constraint_store(_attr) \
86 static ssize_t store_constraint_##_attr(struct device *dev,\
87 struct device_attribute *dev_attr, \
88 const char *buf, size_t count) \
89 { \
90 int err; \
91 u64 value; \
92 struct powercap_zone *power_zone = to_powercap_zone(dev); \
93 int id; \
94 struct powercap_zone_constraint *pconst;\
95 \
96 if (!sscanf(dev_attr->attr.name, "constraint_%d_", &id)) \
97 return -EINVAL; \
98 if (id >= power_zone->const_id_cnt) \
99 return -EINVAL; \
100 pconst = &power_zone->constraints[id]; \
101 err = kstrtoull(buf, 10, &value); \
102 if (err) \
103 return -EINVAL; \
104 if (pconst && pconst->ops && pconst->ops->set_##_attr) { \
105 if (!pconst->ops->set_##_attr(power_zone, id, value)) \
106 return count; \
107 } \
108 \
109 return -ENODATA; \
110 }
111
112 /* Power zone information callbacks */
113 define_power_zone_show(power_uw);
114 define_power_zone_show(max_power_range_uw);
115 define_power_zone_show(energy_uj);
116 define_power_zone_store(energy_uj);
117 define_power_zone_show(max_energy_range_uj);
118
119 /* Power zone attributes */
120 static DEVICE_ATTR_RO(max_power_range_uw);
121 static DEVICE_ATTR_RO(power_uw);
122 static DEVICE_ATTR_RO(max_energy_range_uj);
123 static DEVICE_ATTR_RW(energy_uj);
124
125 /* Power zone constraint attributes callbacks */
126 define_power_zone_constraint_show(power_limit_uw);
127 define_power_zone_constraint_store(power_limit_uw);
128 define_power_zone_constraint_show(time_window_us);
129 define_power_zone_constraint_store(time_window_us);
130 define_power_zone_constraint_show(max_power_uw);
131 define_power_zone_constraint_show(min_power_uw);
132 define_power_zone_constraint_show(max_time_window_us);
133 define_power_zone_constraint_show(min_time_window_us);
134
135 /* For one time seeding of constraint device attributes */
136 struct powercap_constraint_attr {
137 struct device_attribute power_limit_attr;
138 struct device_attribute time_window_attr;
139 struct device_attribute max_power_attr;
140 struct device_attribute min_power_attr;
141 struct device_attribute max_time_window_attr;
142 struct device_attribute min_time_window_attr;
143 struct device_attribute name_attr;
144 };
145
146 static struct powercap_constraint_attr
147 constraint_attrs[MAX_CONSTRAINTS_PER_ZONE];
148
149 /* A list of powercap control_types */
150 static LIST_HEAD(powercap_cntrl_list);
151 /* Mutex to protect list of powercap control_types */
152 static DEFINE_MUTEX(powercap_cntrl_list_lock);
153
154 #define POWERCAP_CONSTRAINT_NAME_LEN 30 /* Some limit to avoid overflow */
show_constraint_name(struct device * dev,struct device_attribute * dev_attr,char * buf)155 static ssize_t show_constraint_name(struct device *dev,
156 struct device_attribute *dev_attr,
157 char *buf)
158 {
159 const char *name;
160 struct powercap_zone *power_zone = to_powercap_zone(dev);
161 int id;
162 ssize_t len = -ENODATA;
163 struct powercap_zone_constraint *pconst;
164
165 if (!sscanf(dev_attr->attr.name, "constraint_%d_", &id))
166 return -EINVAL;
167 if (id >= power_zone->const_id_cnt)
168 return -EINVAL;
169 pconst = &power_zone->constraints[id];
170
171 if (pconst && pconst->ops && pconst->ops->get_name) {
172 name = pconst->ops->get_name(power_zone, id);
173 if (name) {
174 sprintf(buf, "%.*s\n", POWERCAP_CONSTRAINT_NAME_LEN - 1,
175 name);
176 len = strlen(buf);
177 }
178 }
179
180 return len;
181 }
182
create_constraint_attribute(int id,const char * name,int mode,struct device_attribute * dev_attr,ssize_t (* show)(struct device *,struct device_attribute *,char *),ssize_t (* store)(struct device *,struct device_attribute *,const char *,size_t))183 static int create_constraint_attribute(int id, const char *name,
184 int mode,
185 struct device_attribute *dev_attr,
186 ssize_t (*show)(struct device *,
187 struct device_attribute *, char *),
188 ssize_t (*store)(struct device *,
189 struct device_attribute *,
190 const char *, size_t)
191 )
192 {
193
194 dev_attr->attr.name = kasprintf(GFP_KERNEL, "constraint_%d_%s",
195 id, name);
196 if (!dev_attr->attr.name)
197 return -ENOMEM;
198 dev_attr->attr.mode = mode;
199 dev_attr->show = show;
200 dev_attr->store = store;
201
202 return 0;
203 }
204
free_constraint_attributes(void)205 static void free_constraint_attributes(void)
206 {
207 int i;
208
209 for (i = 0; i < MAX_CONSTRAINTS_PER_ZONE; ++i) {
210 kfree(constraint_attrs[i].power_limit_attr.attr.name);
211 kfree(constraint_attrs[i].time_window_attr.attr.name);
212 kfree(constraint_attrs[i].name_attr.attr.name);
213 kfree(constraint_attrs[i].max_power_attr.attr.name);
214 kfree(constraint_attrs[i].min_power_attr.attr.name);
215 kfree(constraint_attrs[i].max_time_window_attr.attr.name);
216 kfree(constraint_attrs[i].min_time_window_attr.attr.name);
217 }
218 }
219
seed_constraint_attributes(void)220 static int seed_constraint_attributes(void)
221 {
222 int i;
223 int ret;
224
225 for (i = 0; i < MAX_CONSTRAINTS_PER_ZONE; ++i) {
226 ret = create_constraint_attribute(i, "power_limit_uw",
227 S_IWUSR | S_IRUGO,
228 &constraint_attrs[i].power_limit_attr,
229 show_constraint_power_limit_uw,
230 store_constraint_power_limit_uw);
231 if (ret)
232 goto err_alloc;
233 ret = create_constraint_attribute(i, "time_window_us",
234 S_IWUSR | S_IRUGO,
235 &constraint_attrs[i].time_window_attr,
236 show_constraint_time_window_us,
237 store_constraint_time_window_us);
238 if (ret)
239 goto err_alloc;
240 ret = create_constraint_attribute(i, "name", S_IRUGO,
241 &constraint_attrs[i].name_attr,
242 show_constraint_name,
243 NULL);
244 if (ret)
245 goto err_alloc;
246 ret = create_constraint_attribute(i, "max_power_uw", S_IRUGO,
247 &constraint_attrs[i].max_power_attr,
248 show_constraint_max_power_uw,
249 NULL);
250 if (ret)
251 goto err_alloc;
252 ret = create_constraint_attribute(i, "min_power_uw", S_IRUGO,
253 &constraint_attrs[i].min_power_attr,
254 show_constraint_min_power_uw,
255 NULL);
256 if (ret)
257 goto err_alloc;
258 ret = create_constraint_attribute(i, "max_time_window_us",
259 S_IRUGO,
260 &constraint_attrs[i].max_time_window_attr,
261 show_constraint_max_time_window_us,
262 NULL);
263 if (ret)
264 goto err_alloc;
265 ret = create_constraint_attribute(i, "min_time_window_us",
266 S_IRUGO,
267 &constraint_attrs[i].min_time_window_attr,
268 show_constraint_min_time_window_us,
269 NULL);
270 if (ret)
271 goto err_alloc;
272
273 }
274
275 return 0;
276
277 err_alloc:
278 free_constraint_attributes();
279
280 return ret;
281 }
282
create_constraints(struct powercap_zone * power_zone,int nr_constraints,const struct powercap_zone_constraint_ops * const_ops)283 static int create_constraints(struct powercap_zone *power_zone,
284 int nr_constraints,
285 const struct powercap_zone_constraint_ops *const_ops)
286 {
287 int i;
288 int ret = 0;
289 int count;
290 struct powercap_zone_constraint *pconst;
291
292 if (!power_zone || !const_ops || !const_ops->get_power_limit_uw ||
293 !const_ops->set_power_limit_uw ||
294 !const_ops->get_time_window_us ||
295 !const_ops->set_time_window_us)
296 return -EINVAL;
297
298 count = power_zone->zone_attr_count;
299 for (i = 0; i < nr_constraints; ++i) {
300 pconst = &power_zone->constraints[i];
301 pconst->ops = const_ops;
302 pconst->id = power_zone->const_id_cnt;
303 power_zone->const_id_cnt++;
304 power_zone->zone_dev_attrs[count++] =
305 &constraint_attrs[i].power_limit_attr.attr;
306 power_zone->zone_dev_attrs[count++] =
307 &constraint_attrs[i].time_window_attr.attr;
308 if (pconst->ops->get_name)
309 power_zone->zone_dev_attrs[count++] =
310 &constraint_attrs[i].name_attr.attr;
311 if (pconst->ops->get_max_power_uw)
312 power_zone->zone_dev_attrs[count++] =
313 &constraint_attrs[i].max_power_attr.attr;
314 if (pconst->ops->get_min_power_uw)
315 power_zone->zone_dev_attrs[count++] =
316 &constraint_attrs[i].min_power_attr.attr;
317 if (pconst->ops->get_max_time_window_us)
318 power_zone->zone_dev_attrs[count++] =
319 &constraint_attrs[i].max_time_window_attr.attr;
320 if (pconst->ops->get_min_time_window_us)
321 power_zone->zone_dev_attrs[count++] =
322 &constraint_attrs[i].min_time_window_attr.attr;
323 }
324 power_zone->zone_attr_count = count;
325
326 return ret;
327 }
328
control_type_valid(void * control_type)329 static bool control_type_valid(void *control_type)
330 {
331 struct powercap_control_type *pos = NULL;
332 bool found = false;
333
334 mutex_lock(&powercap_cntrl_list_lock);
335
336 list_for_each_entry(pos, &powercap_cntrl_list, node) {
337 if (pos == control_type) {
338 found = true;
339 break;
340 }
341 }
342 mutex_unlock(&powercap_cntrl_list_lock);
343
344 return found;
345 }
346
name_show(struct device * dev,struct device_attribute * attr,char * buf)347 static ssize_t name_show(struct device *dev,
348 struct device_attribute *attr,
349 char *buf)
350 {
351 struct powercap_zone *power_zone = to_powercap_zone(dev);
352
353 return sprintf(buf, "%s\n", power_zone->name);
354 }
355
356 static DEVICE_ATTR_RO(name);
357
358 /* Create zone and attributes in sysfs */
create_power_zone_common_attributes(struct powercap_zone * power_zone)359 static void create_power_zone_common_attributes(
360 struct powercap_zone *power_zone)
361 {
362 int count = 0;
363
364 power_zone->zone_dev_attrs[count++] = &dev_attr_name.attr;
365 if (power_zone->ops->get_max_energy_range_uj)
366 power_zone->zone_dev_attrs[count++] =
367 &dev_attr_max_energy_range_uj.attr;
368 if (power_zone->ops->get_energy_uj) {
369 if (power_zone->ops->reset_energy_uj)
370 dev_attr_energy_uj.attr.mode = S_IWUSR | S_IRUSR;
371 else
372 dev_attr_energy_uj.attr.mode = S_IRUSR;
373 power_zone->zone_dev_attrs[count++] =
374 &dev_attr_energy_uj.attr;
375 }
376 if (power_zone->ops->get_power_uw)
377 power_zone->zone_dev_attrs[count++] =
378 &dev_attr_power_uw.attr;
379 if (power_zone->ops->get_max_power_range_uw)
380 power_zone->zone_dev_attrs[count++] =
381 &dev_attr_max_power_range_uw.attr;
382 power_zone->zone_dev_attrs[count] = NULL;
383 power_zone->zone_attr_count = count;
384 }
385
powercap_release(struct device * dev)386 static void powercap_release(struct device *dev)
387 {
388 bool allocated;
389
390 if (dev->parent) {
391 struct powercap_zone *power_zone = to_powercap_zone(dev);
392
393 /* Store flag as the release() may free memory */
394 allocated = power_zone->allocated;
395 /* Remove id from parent idr struct */
396 idr_remove(power_zone->parent_idr, power_zone->id);
397 /* Destroy idrs allocated for this zone */
398 idr_destroy(&power_zone->idr);
399 kfree(power_zone->name);
400 kfree(power_zone->zone_dev_attrs);
401 kfree(power_zone->constraints);
402 if (power_zone->ops->release)
403 power_zone->ops->release(power_zone);
404 if (allocated)
405 kfree(power_zone);
406 } else {
407 struct powercap_control_type *control_type =
408 to_powercap_control_type(dev);
409
410 /* Store flag as the release() may free memory */
411 allocated = control_type->allocated;
412 idr_destroy(&control_type->idr);
413 mutex_destroy(&control_type->lock);
414 if (control_type->ops && control_type->ops->release)
415 control_type->ops->release(control_type);
416 if (allocated)
417 kfree(control_type);
418 }
419 }
420
enabled_show(struct device * dev,struct device_attribute * attr,char * buf)421 static ssize_t enabled_show(struct device *dev,
422 struct device_attribute *attr,
423 char *buf)
424 {
425 bool mode = true;
426
427 /* Default is enabled */
428 if (dev->parent) {
429 struct powercap_zone *power_zone = to_powercap_zone(dev);
430 if (power_zone->ops->get_enable)
431 if (power_zone->ops->get_enable(power_zone, &mode))
432 mode = false;
433 } else {
434 struct powercap_control_type *control_type =
435 to_powercap_control_type(dev);
436 if (control_type->ops && control_type->ops->get_enable)
437 if (control_type->ops->get_enable(control_type, &mode))
438 mode = false;
439 }
440
441 return sprintf(buf, "%d\n", mode);
442 }
443
enabled_store(struct device * dev,struct device_attribute * attr,const char * buf,size_t len)444 static ssize_t enabled_store(struct device *dev,
445 struct device_attribute *attr,
446 const char *buf, size_t len)
447 {
448 bool mode;
449
450 if (kstrtobool(buf, &mode))
451 return -EINVAL;
452 if (dev->parent) {
453 struct powercap_zone *power_zone = to_powercap_zone(dev);
454 if (power_zone->ops->set_enable)
455 if (!power_zone->ops->set_enable(power_zone, mode))
456 return len;
457 } else {
458 struct powercap_control_type *control_type =
459 to_powercap_control_type(dev);
460 if (control_type->ops && control_type->ops->set_enable)
461 if (!control_type->ops->set_enable(control_type, mode))
462 return len;
463 }
464
465 return -ENOSYS;
466 }
467
468 static DEVICE_ATTR_RW(enabled);
469
470 static struct attribute *powercap_attrs[] = {
471 &dev_attr_enabled.attr,
472 NULL,
473 };
474 ATTRIBUTE_GROUPS(powercap);
475
476 static struct class powercap_class = {
477 .name = "powercap",
478 .dev_release = powercap_release,
479 .dev_groups = powercap_groups,
480 };
481
powercap_register_zone(struct powercap_zone * power_zone,struct powercap_control_type * control_type,const char * name,struct powercap_zone * parent,const struct powercap_zone_ops * ops,int nr_constraints,const struct powercap_zone_constraint_ops * const_ops)482 struct powercap_zone *powercap_register_zone(
483 struct powercap_zone *power_zone,
484 struct powercap_control_type *control_type,
485 const char *name,
486 struct powercap_zone *parent,
487 const struct powercap_zone_ops *ops,
488 int nr_constraints,
489 const struct powercap_zone_constraint_ops *const_ops)
490 {
491 int result;
492 int nr_attrs;
493
494 if (!name || !control_type || !ops ||
495 nr_constraints > MAX_CONSTRAINTS_PER_ZONE ||
496 (!ops->get_energy_uj && !ops->get_power_uw) ||
497 !control_type_valid(control_type))
498 return ERR_PTR(-EINVAL);
499
500 if (power_zone) {
501 if (!ops->release)
502 return ERR_PTR(-EINVAL);
503 memset(power_zone, 0, sizeof(*power_zone));
504 } else {
505 power_zone = kzalloc(sizeof(*power_zone), GFP_KERNEL);
506 if (!power_zone)
507 return ERR_PTR(-ENOMEM);
508 power_zone->allocated = true;
509 }
510 power_zone->ops = ops;
511 power_zone->control_type_inst = control_type;
512 if (!parent) {
513 power_zone->dev.parent = &control_type->dev;
514 power_zone->parent_idr = &control_type->idr;
515 } else {
516 power_zone->dev.parent = &parent->dev;
517 power_zone->parent_idr = &parent->idr;
518 }
519 power_zone->dev.class = &powercap_class;
520
521 mutex_lock(&control_type->lock);
522 /* Using idr to get the unique id */
523 result = idr_alloc(power_zone->parent_idr, NULL, 0, 0, GFP_KERNEL);
524 if (result < 0)
525 goto err_idr_alloc;
526
527 power_zone->id = result;
528 idr_init(&power_zone->idr);
529 result = -ENOMEM;
530 power_zone->name = kstrdup(name, GFP_KERNEL);
531 if (!power_zone->name)
532 goto err_name_alloc;
533 power_zone->constraints = kcalloc(nr_constraints,
534 sizeof(*power_zone->constraints),
535 GFP_KERNEL);
536 if (!power_zone->constraints)
537 goto err_const_alloc;
538
539 nr_attrs = nr_constraints * POWERCAP_CONSTRAINTS_ATTRS +
540 POWERCAP_ZONE_MAX_ATTRS + 1;
541 power_zone->zone_dev_attrs = kcalloc(nr_attrs, sizeof(void *),
542 GFP_KERNEL);
543 if (!power_zone->zone_dev_attrs)
544 goto err_attr_alloc;
545 create_power_zone_common_attributes(power_zone);
546 result = create_constraints(power_zone, nr_constraints, const_ops);
547 if (result)
548 goto err_dev_ret;
549
550 power_zone->zone_dev_attrs[power_zone->zone_attr_count] = NULL;
551 power_zone->dev_zone_attr_group.attrs = power_zone->zone_dev_attrs;
552 power_zone->dev_attr_groups[0] = &power_zone->dev_zone_attr_group;
553 power_zone->dev_attr_groups[1] = NULL;
554 power_zone->dev.groups = power_zone->dev_attr_groups;
555 dev_set_name(&power_zone->dev, "%s:%x",
556 dev_name(power_zone->dev.parent),
557 power_zone->id);
558 result = device_register(&power_zone->dev);
559 if (result) {
560 put_device(&power_zone->dev);
561 mutex_unlock(&control_type->lock);
562
563 return ERR_PTR(result);
564 }
565
566 control_type->nr_zones++;
567 mutex_unlock(&control_type->lock);
568
569 return power_zone;
570
571 err_dev_ret:
572 kfree(power_zone->zone_dev_attrs);
573 err_attr_alloc:
574 kfree(power_zone->constraints);
575 err_const_alloc:
576 kfree(power_zone->name);
577 err_name_alloc:
578 idr_remove(power_zone->parent_idr, power_zone->id);
579 err_idr_alloc:
580 if (power_zone->allocated)
581 kfree(power_zone);
582 mutex_unlock(&control_type->lock);
583
584 return ERR_PTR(result);
585 }
586 EXPORT_SYMBOL_GPL(powercap_register_zone);
587
powercap_unregister_zone(struct powercap_control_type * control_type,struct powercap_zone * power_zone)588 int powercap_unregister_zone(struct powercap_control_type *control_type,
589 struct powercap_zone *power_zone)
590 {
591 if (!power_zone || !control_type)
592 return -EINVAL;
593
594 mutex_lock(&control_type->lock);
595 control_type->nr_zones--;
596 mutex_unlock(&control_type->lock);
597
598 device_unregister(&power_zone->dev);
599
600 return 0;
601 }
602 EXPORT_SYMBOL_GPL(powercap_unregister_zone);
603
powercap_register_control_type(struct powercap_control_type * control_type,const char * name,const struct powercap_control_type_ops * ops)604 struct powercap_control_type *powercap_register_control_type(
605 struct powercap_control_type *control_type,
606 const char *name,
607 const struct powercap_control_type_ops *ops)
608 {
609 int result;
610
611 if (!name)
612 return ERR_PTR(-EINVAL);
613 if (control_type) {
614 if (!ops || !ops->release)
615 return ERR_PTR(-EINVAL);
616 memset(control_type, 0, sizeof(*control_type));
617 } else {
618 control_type = kzalloc(sizeof(*control_type), GFP_KERNEL);
619 if (!control_type)
620 return ERR_PTR(-ENOMEM);
621 control_type->allocated = true;
622 }
623 mutex_init(&control_type->lock);
624 control_type->ops = ops;
625 INIT_LIST_HEAD(&control_type->node);
626 control_type->dev.class = &powercap_class;
627 dev_set_name(&control_type->dev, "%s", name);
628 result = device_register(&control_type->dev);
629 if (result) {
630 if (control_type->allocated)
631 kfree(control_type);
632 return ERR_PTR(result);
633 }
634 idr_init(&control_type->idr);
635
636 mutex_lock(&powercap_cntrl_list_lock);
637 list_add_tail(&control_type->node, &powercap_cntrl_list);
638 mutex_unlock(&powercap_cntrl_list_lock);
639
640 return control_type;
641 }
642 EXPORT_SYMBOL_GPL(powercap_register_control_type);
643
powercap_unregister_control_type(struct powercap_control_type * control_type)644 int powercap_unregister_control_type(struct powercap_control_type *control_type)
645 {
646 struct powercap_control_type *pos = NULL;
647
648 if (control_type->nr_zones) {
649 dev_err(&control_type->dev, "Zones of this type still not freed\n");
650 return -EINVAL;
651 }
652 mutex_lock(&powercap_cntrl_list_lock);
653 list_for_each_entry(pos, &powercap_cntrl_list, node) {
654 if (pos == control_type) {
655 list_del(&control_type->node);
656 mutex_unlock(&powercap_cntrl_list_lock);
657 device_unregister(&control_type->dev);
658 return 0;
659 }
660 }
661 mutex_unlock(&powercap_cntrl_list_lock);
662
663 return -ENODEV;
664 }
665 EXPORT_SYMBOL_GPL(powercap_unregister_control_type);
666
powercap_init(void)667 static int __init powercap_init(void)
668 {
669 int result;
670
671 result = seed_constraint_attributes();
672 if (result)
673 return result;
674
675 return class_register(&powercap_class);
676 }
677
678 fs_initcall(powercap_init);
679
680 MODULE_DESCRIPTION("PowerCap sysfs Driver");
681 MODULE_AUTHOR("Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>");
682