Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
[linux-2.6-microblaze.git] / drivers / powercap / powercap_sys.c
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/slab.h>
11 #include <linux/powercap.h>
12
13 #define to_powercap_zone(n) container_of(n, struct powercap_zone, dev)
14 #define to_powercap_control_type(n) \
15                         container_of(n, struct powercap_control_type, dev)
16
17 /* Power zone show function */
18 #define define_power_zone_show(_attr)           \
19 static ssize_t _attr##_show(struct device *dev, \
20                                         struct device_attribute *dev_attr,\
21                                         char *buf) \
22 { \
23         u64 value; \
24         ssize_t len = -EINVAL; \
25         struct powercap_zone *power_zone = to_powercap_zone(dev); \
26         \
27         if (power_zone->ops->get_##_attr) { \
28                 if (!power_zone->ops->get_##_attr(power_zone, &value)) \
29                         len = sprintf(buf, "%lld\n", value); \
30         } \
31         \
32         return len; \
33 }
34
35 /* The only meaningful input is 0 (reset), others are silently ignored */
36 #define define_power_zone_store(_attr)          \
37 static ssize_t _attr##_store(struct device *dev,\
38                                 struct device_attribute *dev_attr, \
39                                 const char *buf, size_t count) \
40 { \
41         int err; \
42         struct powercap_zone *power_zone = to_powercap_zone(dev); \
43         u64 value; \
44         \
45         err = kstrtoull(buf, 10, &value); \
46         if (err) \
47                 return -EINVAL; \
48         if (value) \
49                 return count; \
50         if (power_zone->ops->reset_##_attr) { \
51                 if (!power_zone->ops->reset_##_attr(power_zone)) \
52                         return count; \
53         } \
54         \
55         return -EINVAL; \
56 }
57
58 /* Power zone constraint show function */
59 #define define_power_zone_constraint_show(_attr) \
60 static ssize_t show_constraint_##_attr(struct device *dev, \
61                                 struct device_attribute *dev_attr,\
62                                 char *buf) \
63 { \
64         u64 value; \
65         ssize_t len = -ENODATA; \
66         struct powercap_zone *power_zone = to_powercap_zone(dev); \
67         int id; \
68         struct powercap_zone_constraint *pconst;\
69         \
70         if (!sscanf(dev_attr->attr.name, "constraint_%d_", &id)) \
71                 return -EINVAL; \
72         if (id >= power_zone->const_id_cnt)     \
73                 return -EINVAL; \
74         pconst = &power_zone->constraints[id]; \
75         if (pconst && pconst->ops && pconst->ops->get_##_attr) { \
76                 if (!pconst->ops->get_##_attr(power_zone, id, &value)) \
77                         len = sprintf(buf, "%lld\n", value); \
78         } \
79         \
80         return len; \
81 }
82
83 /* Power zone constraint store function */
84 #define define_power_zone_constraint_store(_attr) \
85 static ssize_t store_constraint_##_attr(struct device *dev,\
86                                 struct device_attribute *dev_attr, \
87                                 const char *buf, size_t count) \
88 { \
89         int err; \
90         u64 value; \
91         struct powercap_zone *power_zone = to_powercap_zone(dev); \
92         int id; \
93         struct powercap_zone_constraint *pconst;\
94         \
95         if (!sscanf(dev_attr->attr.name, "constraint_%d_", &id)) \
96                 return -EINVAL; \
97         if (id >= power_zone->const_id_cnt)     \
98                 return -EINVAL; \
99         pconst = &power_zone->constraints[id]; \
100         err = kstrtoull(buf, 10, &value); \
101         if (err) \
102                 return -EINVAL; \
103         if (pconst && pconst->ops && pconst->ops->set_##_attr) { \
104                 if (!pconst->ops->set_##_attr(power_zone, id, value)) \
105                         return count; \
106         } \
107         \
108         return -ENODATA; \
109 }
110
111 /* Power zone information callbacks */
112 define_power_zone_show(power_uw);
113 define_power_zone_show(max_power_range_uw);
114 define_power_zone_show(energy_uj);
115 define_power_zone_store(energy_uj);
116 define_power_zone_show(max_energy_range_uj);
117
118 /* Power zone attributes */
119 static DEVICE_ATTR_RO(max_power_range_uw);
120 static DEVICE_ATTR_RO(power_uw);
121 static DEVICE_ATTR_RO(max_energy_range_uj);
122 static DEVICE_ATTR_RW(energy_uj);
123
124 /* Power zone constraint attributes callbacks */
125 define_power_zone_constraint_show(power_limit_uw);
126 define_power_zone_constraint_store(power_limit_uw);
127 define_power_zone_constraint_show(time_window_us);
128 define_power_zone_constraint_store(time_window_us);
129 define_power_zone_constraint_show(max_power_uw);
130 define_power_zone_constraint_show(min_power_uw);
131 define_power_zone_constraint_show(max_time_window_us);
132 define_power_zone_constraint_show(min_time_window_us);
133
134 /* For one time seeding of constraint device attributes */
135 struct powercap_constraint_attr {
136         struct device_attribute power_limit_attr;
137         struct device_attribute time_window_attr;
138         struct device_attribute max_power_attr;
139         struct device_attribute min_power_attr;
140         struct device_attribute max_time_window_attr;
141         struct device_attribute min_time_window_attr;
142         struct device_attribute name_attr;
143 };
144
145 static struct powercap_constraint_attr
146                                 constraint_attrs[MAX_CONSTRAINTS_PER_ZONE];
147
148 /* A list of powercap control_types */
149 static LIST_HEAD(powercap_cntrl_list);
150 /* Mutex to protect list of powercap control_types */
151 static DEFINE_MUTEX(powercap_cntrl_list_lock);
152
153 #define POWERCAP_CONSTRAINT_NAME_LEN    30 /* Some limit to avoid overflow */
154 static ssize_t show_constraint_name(struct device *dev,
155                                 struct device_attribute *dev_attr,
156                                 char *buf)
157 {
158         const char *name;
159         struct powercap_zone *power_zone = to_powercap_zone(dev);
160         int id;
161         ssize_t len = -ENODATA;
162         struct powercap_zone_constraint *pconst;
163
164         if (!sscanf(dev_attr->attr.name, "constraint_%d_", &id))
165                 return -EINVAL;
166         if (id >= power_zone->const_id_cnt)
167                 return -EINVAL;
168         pconst = &power_zone->constraints[id];
169
170         if (pconst && pconst->ops && pconst->ops->get_name) {
171                 name = pconst->ops->get_name(power_zone, id);
172                 if (name) {
173                         snprintf(buf, POWERCAP_CONSTRAINT_NAME_LEN,
174                                                                 "%s\n", name);
175                         buf[POWERCAP_CONSTRAINT_NAME_LEN] = '\0';
176                         len = strlen(buf);
177                 }
178         }
179
180         return len;
181 }
182
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
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
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
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
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
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 */
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_IRUGO;
371                 else
372                         dev_attr_energy_uj.attr.mode = S_IRUGO;
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
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
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
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 (strtobool(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
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         dev_set_name(&power_zone->dev, "%s:%x",
534                                         dev_name(power_zone->dev.parent),
535                                         power_zone->id);
536         power_zone->constraints = kcalloc(nr_constraints,
537                                           sizeof(*power_zone->constraints),
538                                           GFP_KERNEL);
539         if (!power_zone->constraints)
540                 goto err_const_alloc;
541
542         nr_attrs = nr_constraints * POWERCAP_CONSTRAINTS_ATTRS +
543                                                 POWERCAP_ZONE_MAX_ATTRS + 1;
544         power_zone->zone_dev_attrs = kcalloc(nr_attrs, sizeof(void *),
545                                              GFP_KERNEL);
546         if (!power_zone->zone_dev_attrs)
547                 goto err_attr_alloc;
548         create_power_zone_common_attributes(power_zone);
549         result = create_constraints(power_zone, nr_constraints, const_ops);
550         if (result)
551                 goto err_dev_ret;
552
553         power_zone->zone_dev_attrs[power_zone->zone_attr_count] = NULL;
554         power_zone->dev_zone_attr_group.attrs = power_zone->zone_dev_attrs;
555         power_zone->dev_attr_groups[0] = &power_zone->dev_zone_attr_group;
556         power_zone->dev_attr_groups[1] = NULL;
557         power_zone->dev.groups = power_zone->dev_attr_groups;
558         result = device_register(&power_zone->dev);
559         if (result)
560                 goto err_dev_ret;
561
562         control_type->nr_zones++;
563         mutex_unlock(&control_type->lock);
564
565         return power_zone;
566
567 err_dev_ret:
568         kfree(power_zone->zone_dev_attrs);
569 err_attr_alloc:
570         kfree(power_zone->constraints);
571 err_const_alloc:
572         kfree(power_zone->name);
573 err_name_alloc:
574         idr_remove(power_zone->parent_idr, power_zone->id);
575 err_idr_alloc:
576         if (power_zone->allocated)
577                 kfree(power_zone);
578         mutex_unlock(&control_type->lock);
579
580         return ERR_PTR(result);
581 }
582 EXPORT_SYMBOL_GPL(powercap_register_zone);
583
584 int powercap_unregister_zone(struct powercap_control_type *control_type,
585                                 struct powercap_zone *power_zone)
586 {
587         if (!power_zone || !control_type)
588                 return -EINVAL;
589
590         mutex_lock(&control_type->lock);
591         control_type->nr_zones--;
592         mutex_unlock(&control_type->lock);
593
594         device_unregister(&power_zone->dev);
595
596         return 0;
597 }
598 EXPORT_SYMBOL_GPL(powercap_unregister_zone);
599
600 struct powercap_control_type *powercap_register_control_type(
601                                 struct powercap_control_type *control_type,
602                                 const char *name,
603                                 const struct powercap_control_type_ops *ops)
604 {
605         int result;
606
607         if (!name)
608                 return ERR_PTR(-EINVAL);
609         if (control_type) {
610                 if (!ops || !ops->release)
611                         return ERR_PTR(-EINVAL);
612                 memset(control_type, 0, sizeof(*control_type));
613         } else {
614                 control_type = kzalloc(sizeof(*control_type), GFP_KERNEL);
615                 if (!control_type)
616                         return ERR_PTR(-ENOMEM);
617                 control_type->allocated = true;
618         }
619         mutex_init(&control_type->lock);
620         control_type->ops = ops;
621         INIT_LIST_HEAD(&control_type->node);
622         control_type->dev.class = &powercap_class;
623         dev_set_name(&control_type->dev, "%s", name);
624         result = device_register(&control_type->dev);
625         if (result) {
626                 if (control_type->allocated)
627                         kfree(control_type);
628                 return ERR_PTR(result);
629         }
630         idr_init(&control_type->idr);
631
632         mutex_lock(&powercap_cntrl_list_lock);
633         list_add_tail(&control_type->node, &powercap_cntrl_list);
634         mutex_unlock(&powercap_cntrl_list_lock);
635
636         return control_type;
637 }
638 EXPORT_SYMBOL_GPL(powercap_register_control_type);
639
640 int powercap_unregister_control_type(struct powercap_control_type *control_type)
641 {
642         struct powercap_control_type *pos = NULL;
643
644         if (control_type->nr_zones) {
645                 dev_err(&control_type->dev, "Zones of this type still not freed\n");
646                 return -EINVAL;
647         }
648         mutex_lock(&powercap_cntrl_list_lock);
649         list_for_each_entry(pos, &powercap_cntrl_list, node) {
650                 if (pos == control_type) {
651                         list_del(&control_type->node);
652                         mutex_unlock(&powercap_cntrl_list_lock);
653                         device_unregister(&control_type->dev);
654                         return 0;
655                 }
656         }
657         mutex_unlock(&powercap_cntrl_list_lock);
658
659         return -ENODEV;
660 }
661 EXPORT_SYMBOL_GPL(powercap_unregister_control_type);
662
663 static int __init powercap_init(void)
664 {
665         int result;
666
667         result = seed_constraint_attributes();
668         if (result)
669                 return result;
670
671         return class_register(&powercap_class);
672 }
673
674 fs_initcall(powercap_init);
675
676 MODULE_DESCRIPTION("PowerCap sysfs Driver");
677 MODULE_AUTHOR("Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>");
678 MODULE_LICENSE("GPL v2");