powercap_sys.c 18 KB

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  1. // SPDX-License-Identifier: GPL-2.0-only
  2. /*
  3. * Power capping class
  4. * Copyright (c) 2013, Intel Corporation.
  5. */
  6. #include <linux/module.h>
  7. #include <linux/device.h>
  8. #include <linux/err.h>
  9. #include <linux/slab.h>
  10. #include <linux/powercap.h>
  11. #define to_powercap_zone(n) container_of(n, struct powercap_zone, dev)
  12. #define to_powercap_control_type(n) \
  13. container_of(n, struct powercap_control_type, dev)
  14. /* Power zone show function */
  15. #define define_power_zone_show(_attr) \
  16. static ssize_t _attr##_show(struct device *dev, \
  17. struct device_attribute *dev_attr,\
  18. char *buf) \
  19. { \
  20. u64 value; \
  21. ssize_t len = -EINVAL; \
  22. struct powercap_zone *power_zone = to_powercap_zone(dev); \
  23. \
  24. if (power_zone->ops->get_##_attr) { \
  25. if (!power_zone->ops->get_##_attr(power_zone, &value)) \
  26. len = sprintf(buf, "%lld\n", value); \
  27. } \
  28. \
  29. return len; \
  30. }
  31. /* The only meaningful input is 0 (reset), others are silently ignored */
  32. #define define_power_zone_store(_attr) \
  33. static ssize_t _attr##_store(struct device *dev,\
  34. struct device_attribute *dev_attr, \
  35. const char *buf, size_t count) \
  36. { \
  37. int err; \
  38. struct powercap_zone *power_zone = to_powercap_zone(dev); \
  39. u64 value; \
  40. \
  41. err = kstrtoull(buf, 10, &value); \
  42. if (err) \
  43. return -EINVAL; \
  44. if (value) \
  45. return count; \
  46. if (power_zone->ops->reset_##_attr) { \
  47. if (!power_zone->ops->reset_##_attr(power_zone)) \
  48. return count; \
  49. } \
  50. \
  51. return -EINVAL; \
  52. }
  53. /* Power zone constraint show function */
  54. #define define_power_zone_constraint_show(_attr) \
  55. static ssize_t show_constraint_##_attr(struct device *dev, \
  56. struct device_attribute *dev_attr,\
  57. char *buf) \
  58. { \
  59. u64 value; \
  60. ssize_t len = -ENODATA; \
  61. struct powercap_zone *power_zone = to_powercap_zone(dev); \
  62. int id; \
  63. struct powercap_zone_constraint *pconst;\
  64. \
  65. if (!sscanf(dev_attr->attr.name, "constraint_%d_", &id)) \
  66. return -EINVAL; \
  67. if (id >= power_zone->const_id_cnt) \
  68. return -EINVAL; \
  69. pconst = &power_zone->constraints[id]; \
  70. if (pconst && pconst->ops && pconst->ops->get_##_attr) { \
  71. if (!pconst->ops->get_##_attr(power_zone, id, &value)) \
  72. len = sprintf(buf, "%lld\n", value); \
  73. } \
  74. \
  75. return len; \
  76. }
  77. /* Power zone constraint store function */
  78. #define define_power_zone_constraint_store(_attr) \
  79. static ssize_t store_constraint_##_attr(struct device *dev,\
  80. struct device_attribute *dev_attr, \
  81. const char *buf, size_t count) \
  82. { \
  83. int err; \
  84. u64 value; \
  85. struct powercap_zone *power_zone = to_powercap_zone(dev); \
  86. int id; \
  87. struct powercap_zone_constraint *pconst;\
  88. \
  89. if (!sscanf(dev_attr->attr.name, "constraint_%d_", &id)) \
  90. return -EINVAL; \
  91. if (id >= power_zone->const_id_cnt) \
  92. return -EINVAL; \
  93. pconst = &power_zone->constraints[id]; \
  94. err = kstrtoull(buf, 10, &value); \
  95. if (err) \
  96. return -EINVAL; \
  97. if (pconst && pconst->ops && pconst->ops->set_##_attr) { \
  98. if (!pconst->ops->set_##_attr(power_zone, id, value)) \
  99. return count; \
  100. } \
  101. \
  102. return -ENODATA; \
  103. }
  104. /* Power zone information callbacks */
  105. define_power_zone_show(power_uw);
  106. define_power_zone_show(max_power_range_uw);
  107. define_power_zone_show(energy_uj);
  108. define_power_zone_store(energy_uj);
  109. define_power_zone_show(max_energy_range_uj);
  110. /* Power zone attributes */
  111. static DEVICE_ATTR_RO(max_power_range_uw);
  112. static DEVICE_ATTR_RO(power_uw);
  113. static DEVICE_ATTR_RO(max_energy_range_uj);
  114. static DEVICE_ATTR_RW(energy_uj);
  115. /* Power zone constraint attributes callbacks */
  116. define_power_zone_constraint_show(power_limit_uw);
  117. define_power_zone_constraint_store(power_limit_uw);
  118. define_power_zone_constraint_show(time_window_us);
  119. define_power_zone_constraint_store(time_window_us);
  120. define_power_zone_constraint_show(max_power_uw);
  121. define_power_zone_constraint_show(min_power_uw);
  122. define_power_zone_constraint_show(max_time_window_us);
  123. define_power_zone_constraint_show(min_time_window_us);
  124. /* For one time seeding of constraint device attributes */
  125. struct powercap_constraint_attr {
  126. struct device_attribute power_limit_attr;
  127. struct device_attribute time_window_attr;
  128. struct device_attribute max_power_attr;
  129. struct device_attribute min_power_attr;
  130. struct device_attribute max_time_window_attr;
  131. struct device_attribute min_time_window_attr;
  132. struct device_attribute name_attr;
  133. };
  134. static struct powercap_constraint_attr
  135. constraint_attrs[MAX_CONSTRAINTS_PER_ZONE];
  136. /* A list of powercap control_types */
  137. static LIST_HEAD(powercap_cntrl_list);
  138. /* Mutex to protect list of powercap control_types */
  139. static DEFINE_MUTEX(powercap_cntrl_list_lock);
  140. #define POWERCAP_CONSTRAINT_NAME_LEN 30 /* Some limit to avoid overflow */
  141. static ssize_t show_constraint_name(struct device *dev,
  142. struct device_attribute *dev_attr,
  143. char *buf)
  144. {
  145. const char *name;
  146. struct powercap_zone *power_zone = to_powercap_zone(dev);
  147. int id;
  148. ssize_t len = -ENODATA;
  149. struct powercap_zone_constraint *pconst;
  150. if (!sscanf(dev_attr->attr.name, "constraint_%d_", &id))
  151. return -EINVAL;
  152. if (id >= power_zone->const_id_cnt)
  153. return -EINVAL;
  154. pconst = &power_zone->constraints[id];
  155. if (pconst && pconst->ops && pconst->ops->get_name) {
  156. name = pconst->ops->get_name(power_zone, id);
  157. if (name) {
  158. snprintf(buf, POWERCAP_CONSTRAINT_NAME_LEN,
  159. "%s\n", name);
  160. buf[POWERCAP_CONSTRAINT_NAME_LEN] = '\0';
  161. len = strlen(buf);
  162. }
  163. }
  164. return len;
  165. }
  166. static int create_constraint_attribute(int id, const char *name,
  167. int mode,
  168. struct device_attribute *dev_attr,
  169. ssize_t (*show)(struct device *,
  170. struct device_attribute *, char *),
  171. ssize_t (*store)(struct device *,
  172. struct device_attribute *,
  173. const char *, size_t)
  174. )
  175. {
  176. dev_attr->attr.name = kasprintf(GFP_KERNEL, "constraint_%d_%s",
  177. id, name);
  178. if (!dev_attr->attr.name)
  179. return -ENOMEM;
  180. dev_attr->attr.mode = mode;
  181. dev_attr->show = show;
  182. dev_attr->store = store;
  183. return 0;
  184. }
  185. static void free_constraint_attributes(void)
  186. {
  187. int i;
  188. for (i = 0; i < MAX_CONSTRAINTS_PER_ZONE; ++i) {
  189. kfree(constraint_attrs[i].power_limit_attr.attr.name);
  190. kfree(constraint_attrs[i].time_window_attr.attr.name);
  191. kfree(constraint_attrs[i].name_attr.attr.name);
  192. kfree(constraint_attrs[i].max_power_attr.attr.name);
  193. kfree(constraint_attrs[i].min_power_attr.attr.name);
  194. kfree(constraint_attrs[i].max_time_window_attr.attr.name);
  195. kfree(constraint_attrs[i].min_time_window_attr.attr.name);
  196. }
  197. }
  198. static int seed_constraint_attributes(void)
  199. {
  200. int i;
  201. int ret;
  202. for (i = 0; i < MAX_CONSTRAINTS_PER_ZONE; ++i) {
  203. ret = create_constraint_attribute(i, "power_limit_uw",
  204. S_IWUSR | S_IRUGO,
  205. &constraint_attrs[i].power_limit_attr,
  206. show_constraint_power_limit_uw,
  207. store_constraint_power_limit_uw);
  208. if (ret)
  209. goto err_alloc;
  210. ret = create_constraint_attribute(i, "time_window_us",
  211. S_IWUSR | S_IRUGO,
  212. &constraint_attrs[i].time_window_attr,
  213. show_constraint_time_window_us,
  214. store_constraint_time_window_us);
  215. if (ret)
  216. goto err_alloc;
  217. ret = create_constraint_attribute(i, "name", S_IRUGO,
  218. &constraint_attrs[i].name_attr,
  219. show_constraint_name,
  220. NULL);
  221. if (ret)
  222. goto err_alloc;
  223. ret = create_constraint_attribute(i, "max_power_uw", S_IRUGO,
  224. &constraint_attrs[i].max_power_attr,
  225. show_constraint_max_power_uw,
  226. NULL);
  227. if (ret)
  228. goto err_alloc;
  229. ret = create_constraint_attribute(i, "min_power_uw", S_IRUGO,
  230. &constraint_attrs[i].min_power_attr,
  231. show_constraint_min_power_uw,
  232. NULL);
  233. if (ret)
  234. goto err_alloc;
  235. ret = create_constraint_attribute(i, "max_time_window_us",
  236. S_IRUGO,
  237. &constraint_attrs[i].max_time_window_attr,
  238. show_constraint_max_time_window_us,
  239. NULL);
  240. if (ret)
  241. goto err_alloc;
  242. ret = create_constraint_attribute(i, "min_time_window_us",
  243. S_IRUGO,
  244. &constraint_attrs[i].min_time_window_attr,
  245. show_constraint_min_time_window_us,
  246. NULL);
  247. if (ret)
  248. goto err_alloc;
  249. }
  250. return 0;
  251. err_alloc:
  252. free_constraint_attributes();
  253. return ret;
  254. }
  255. static int create_constraints(struct powercap_zone *power_zone,
  256. int nr_constraints,
  257. const struct powercap_zone_constraint_ops *const_ops)
  258. {
  259. int i;
  260. int ret = 0;
  261. int count;
  262. struct powercap_zone_constraint *pconst;
  263. if (!power_zone || !const_ops || !const_ops->get_power_limit_uw ||
  264. !const_ops->set_power_limit_uw ||
  265. !const_ops->get_time_window_us ||
  266. !const_ops->set_time_window_us)
  267. return -EINVAL;
  268. count = power_zone->zone_attr_count;
  269. for (i = 0; i < nr_constraints; ++i) {
  270. pconst = &power_zone->constraints[i];
  271. pconst->ops = const_ops;
  272. pconst->id = power_zone->const_id_cnt;
  273. power_zone->const_id_cnt++;
  274. power_zone->zone_dev_attrs[count++] =
  275. &constraint_attrs[i].power_limit_attr.attr;
  276. power_zone->zone_dev_attrs[count++] =
  277. &constraint_attrs[i].time_window_attr.attr;
  278. if (pconst->ops->get_name)
  279. power_zone->zone_dev_attrs[count++] =
  280. &constraint_attrs[i].name_attr.attr;
  281. if (pconst->ops->get_max_power_uw)
  282. power_zone->zone_dev_attrs[count++] =
  283. &constraint_attrs[i].max_power_attr.attr;
  284. if (pconst->ops->get_min_power_uw)
  285. power_zone->zone_dev_attrs[count++] =
  286. &constraint_attrs[i].min_power_attr.attr;
  287. if (pconst->ops->get_max_time_window_us)
  288. power_zone->zone_dev_attrs[count++] =
  289. &constraint_attrs[i].max_time_window_attr.attr;
  290. if (pconst->ops->get_min_time_window_us)
  291. power_zone->zone_dev_attrs[count++] =
  292. &constraint_attrs[i].min_time_window_attr.attr;
  293. }
  294. power_zone->zone_attr_count = count;
  295. return ret;
  296. }
  297. static bool control_type_valid(void *control_type)
  298. {
  299. struct powercap_control_type *pos = NULL;
  300. bool found = false;
  301. mutex_lock(&powercap_cntrl_list_lock);
  302. list_for_each_entry(pos, &powercap_cntrl_list, node) {
  303. if (pos == control_type) {
  304. found = true;
  305. break;
  306. }
  307. }
  308. mutex_unlock(&powercap_cntrl_list_lock);
  309. return found;
  310. }
  311. static ssize_t name_show(struct device *dev,
  312. struct device_attribute *attr,
  313. char *buf)
  314. {
  315. struct powercap_zone *power_zone = to_powercap_zone(dev);
  316. return sprintf(buf, "%s\n", power_zone->name);
  317. }
  318. static DEVICE_ATTR_RO(name);
  319. /* Create zone and attributes in sysfs */
  320. static void create_power_zone_common_attributes(
  321. struct powercap_zone *power_zone)
  322. {
  323. int count = 0;
  324. power_zone->zone_dev_attrs[count++] = &dev_attr_name.attr;
  325. if (power_zone->ops->get_max_energy_range_uj)
  326. power_zone->zone_dev_attrs[count++] =
  327. &dev_attr_max_energy_range_uj.attr;
  328. if (power_zone->ops->get_energy_uj) {
  329. if (power_zone->ops->reset_energy_uj)
  330. dev_attr_energy_uj.attr.mode = S_IWUSR | S_IRUSR;
  331. else
  332. dev_attr_energy_uj.attr.mode = S_IRUSR;
  333. power_zone->zone_dev_attrs[count++] =
  334. &dev_attr_energy_uj.attr;
  335. }
  336. if (power_zone->ops->get_power_uw)
  337. power_zone->zone_dev_attrs[count++] =
  338. &dev_attr_power_uw.attr;
  339. if (power_zone->ops->get_max_power_range_uw)
  340. power_zone->zone_dev_attrs[count++] =
  341. &dev_attr_max_power_range_uw.attr;
  342. power_zone->zone_dev_attrs[count] = NULL;
  343. power_zone->zone_attr_count = count;
  344. }
  345. static void powercap_release(struct device *dev)
  346. {
  347. bool allocated;
  348. if (dev->parent) {
  349. struct powercap_zone *power_zone = to_powercap_zone(dev);
  350. /* Store flag as the release() may free memory */
  351. allocated = power_zone->allocated;
  352. /* Remove id from parent idr struct */
  353. idr_remove(power_zone->parent_idr, power_zone->id);
  354. /* Destroy idrs allocated for this zone */
  355. idr_destroy(&power_zone->idr);
  356. kfree(power_zone->name);
  357. kfree(power_zone->zone_dev_attrs);
  358. kfree(power_zone->constraints);
  359. if (power_zone->ops->release)
  360. power_zone->ops->release(power_zone);
  361. if (allocated)
  362. kfree(power_zone);
  363. } else {
  364. struct powercap_control_type *control_type =
  365. to_powercap_control_type(dev);
  366. /* Store flag as the release() may free memory */
  367. allocated = control_type->allocated;
  368. idr_destroy(&control_type->idr);
  369. mutex_destroy(&control_type->lock);
  370. if (control_type->ops && control_type->ops->release)
  371. control_type->ops->release(control_type);
  372. if (allocated)
  373. kfree(control_type);
  374. }
  375. }
  376. static ssize_t enabled_show(struct device *dev,
  377. struct device_attribute *attr,
  378. char *buf)
  379. {
  380. bool mode = true;
  381. /* Default is enabled */
  382. if (dev->parent) {
  383. struct powercap_zone *power_zone = to_powercap_zone(dev);
  384. if (power_zone->ops->get_enable)
  385. if (power_zone->ops->get_enable(power_zone, &mode))
  386. mode = false;
  387. } else {
  388. struct powercap_control_type *control_type =
  389. to_powercap_control_type(dev);
  390. if (control_type->ops && control_type->ops->get_enable)
  391. if (control_type->ops->get_enable(control_type, &mode))
  392. mode = false;
  393. }
  394. return sprintf(buf, "%d\n", mode);
  395. }
  396. static ssize_t enabled_store(struct device *dev,
  397. struct device_attribute *attr,
  398. const char *buf, size_t len)
  399. {
  400. bool mode;
  401. if (strtobool(buf, &mode))
  402. return -EINVAL;
  403. if (dev->parent) {
  404. struct powercap_zone *power_zone = to_powercap_zone(dev);
  405. if (power_zone->ops->set_enable)
  406. if (!power_zone->ops->set_enable(power_zone, mode))
  407. return len;
  408. } else {
  409. struct powercap_control_type *control_type =
  410. to_powercap_control_type(dev);
  411. if (control_type->ops && control_type->ops->set_enable)
  412. if (!control_type->ops->set_enable(control_type, mode))
  413. return len;
  414. }
  415. return -ENOSYS;
  416. }
  417. static DEVICE_ATTR_RW(enabled);
  418. static struct attribute *powercap_attrs[] = {
  419. &dev_attr_enabled.attr,
  420. NULL,
  421. };
  422. ATTRIBUTE_GROUPS(powercap);
  423. static struct class powercap_class = {
  424. .name = "powercap",
  425. .dev_release = powercap_release,
  426. .dev_groups = powercap_groups,
  427. };
  428. struct powercap_zone *powercap_register_zone(
  429. struct powercap_zone *power_zone,
  430. struct powercap_control_type *control_type,
  431. const char *name,
  432. struct powercap_zone *parent,
  433. const struct powercap_zone_ops *ops,
  434. int nr_constraints,
  435. const struct powercap_zone_constraint_ops *const_ops)
  436. {
  437. int result;
  438. int nr_attrs;
  439. if (!name || !control_type || !ops ||
  440. nr_constraints > MAX_CONSTRAINTS_PER_ZONE ||
  441. (!ops->get_energy_uj && !ops->get_power_uw) ||
  442. !control_type_valid(control_type))
  443. return ERR_PTR(-EINVAL);
  444. if (power_zone) {
  445. if (!ops->release)
  446. return ERR_PTR(-EINVAL);
  447. memset(power_zone, 0, sizeof(*power_zone));
  448. } else {
  449. power_zone = kzalloc(sizeof(*power_zone), GFP_KERNEL);
  450. if (!power_zone)
  451. return ERR_PTR(-ENOMEM);
  452. power_zone->allocated = true;
  453. }
  454. power_zone->ops = ops;
  455. power_zone->control_type_inst = control_type;
  456. if (!parent) {
  457. power_zone->dev.parent = &control_type->dev;
  458. power_zone->parent_idr = &control_type->idr;
  459. } else {
  460. power_zone->dev.parent = &parent->dev;
  461. power_zone->parent_idr = &parent->idr;
  462. }
  463. power_zone->dev.class = &powercap_class;
  464. mutex_lock(&control_type->lock);
  465. /* Using idr to get the unique id */
  466. result = idr_alloc(power_zone->parent_idr, NULL, 0, 0, GFP_KERNEL);
  467. if (result < 0)
  468. goto err_idr_alloc;
  469. power_zone->id = result;
  470. idr_init(&power_zone->idr);
  471. result = -ENOMEM;
  472. power_zone->name = kstrdup(name, GFP_KERNEL);
  473. if (!power_zone->name)
  474. goto err_name_alloc;
  475. dev_set_name(&power_zone->dev, "%s:%x",
  476. dev_name(power_zone->dev.parent),
  477. power_zone->id);
  478. power_zone->constraints = kcalloc(nr_constraints,
  479. sizeof(*power_zone->constraints),
  480. GFP_KERNEL);
  481. if (!power_zone->constraints)
  482. goto err_const_alloc;
  483. nr_attrs = nr_constraints * POWERCAP_CONSTRAINTS_ATTRS +
  484. POWERCAP_ZONE_MAX_ATTRS + 1;
  485. power_zone->zone_dev_attrs = kcalloc(nr_attrs, sizeof(void *),
  486. GFP_KERNEL);
  487. if (!power_zone->zone_dev_attrs)
  488. goto err_attr_alloc;
  489. create_power_zone_common_attributes(power_zone);
  490. result = create_constraints(power_zone, nr_constraints, const_ops);
  491. if (result)
  492. goto err_dev_ret;
  493. power_zone->zone_dev_attrs[power_zone->zone_attr_count] = NULL;
  494. power_zone->dev_zone_attr_group.attrs = power_zone->zone_dev_attrs;
  495. power_zone->dev_attr_groups[0] = &power_zone->dev_zone_attr_group;
  496. power_zone->dev_attr_groups[1] = NULL;
  497. power_zone->dev.groups = power_zone->dev_attr_groups;
  498. result = device_register(&power_zone->dev);
  499. if (result)
  500. goto err_dev_ret;
  501. control_type->nr_zones++;
  502. mutex_unlock(&control_type->lock);
  503. return power_zone;
  504. err_dev_ret:
  505. kfree(power_zone->zone_dev_attrs);
  506. err_attr_alloc:
  507. kfree(power_zone->constraints);
  508. err_const_alloc:
  509. kfree(power_zone->name);
  510. err_name_alloc:
  511. idr_remove(power_zone->parent_idr, power_zone->id);
  512. err_idr_alloc:
  513. if (power_zone->allocated)
  514. kfree(power_zone);
  515. mutex_unlock(&control_type->lock);
  516. return ERR_PTR(result);
  517. }
  518. EXPORT_SYMBOL_GPL(powercap_register_zone);
  519. int powercap_unregister_zone(struct powercap_control_type *control_type,
  520. struct powercap_zone *power_zone)
  521. {
  522. if (!power_zone || !control_type)
  523. return -EINVAL;
  524. mutex_lock(&control_type->lock);
  525. control_type->nr_zones--;
  526. mutex_unlock(&control_type->lock);
  527. device_unregister(&power_zone->dev);
  528. return 0;
  529. }
  530. EXPORT_SYMBOL_GPL(powercap_unregister_zone);
  531. struct powercap_control_type *powercap_register_control_type(
  532. struct powercap_control_type *control_type,
  533. const char *name,
  534. const struct powercap_control_type_ops *ops)
  535. {
  536. int result;
  537. if (!name)
  538. return ERR_PTR(-EINVAL);
  539. if (control_type) {
  540. if (!ops || !ops->release)
  541. return ERR_PTR(-EINVAL);
  542. memset(control_type, 0, sizeof(*control_type));
  543. } else {
  544. control_type = kzalloc(sizeof(*control_type), GFP_KERNEL);
  545. if (!control_type)
  546. return ERR_PTR(-ENOMEM);
  547. control_type->allocated = true;
  548. }
  549. mutex_init(&control_type->lock);
  550. control_type->ops = ops;
  551. INIT_LIST_HEAD(&control_type->node);
  552. control_type->dev.class = &powercap_class;
  553. dev_set_name(&control_type->dev, "%s", name);
  554. result = device_register(&control_type->dev);
  555. if (result) {
  556. if (control_type->allocated)
  557. kfree(control_type);
  558. return ERR_PTR(result);
  559. }
  560. idr_init(&control_type->idr);
  561. mutex_lock(&powercap_cntrl_list_lock);
  562. list_add_tail(&control_type->node, &powercap_cntrl_list);
  563. mutex_unlock(&powercap_cntrl_list_lock);
  564. return control_type;
  565. }
  566. EXPORT_SYMBOL_GPL(powercap_register_control_type);
  567. int powercap_unregister_control_type(struct powercap_control_type *control_type)
  568. {
  569. struct powercap_control_type *pos = NULL;
  570. if (control_type->nr_zones) {
  571. dev_err(&control_type->dev, "Zones of this type still not freed\n");
  572. return -EINVAL;
  573. }
  574. mutex_lock(&powercap_cntrl_list_lock);
  575. list_for_each_entry(pos, &powercap_cntrl_list, node) {
  576. if (pos == control_type) {
  577. list_del(&control_type->node);
  578. mutex_unlock(&powercap_cntrl_list_lock);
  579. device_unregister(&control_type->dev);
  580. return 0;
  581. }
  582. }
  583. mutex_unlock(&powercap_cntrl_list_lock);
  584. return -ENODEV;
  585. }
  586. EXPORT_SYMBOL_GPL(powercap_unregister_control_type);
  587. static int __init powercap_init(void)
  588. {
  589. int result;
  590. result = seed_constraint_attributes();
  591. if (result)
  592. return result;
  593. return class_register(&powercap_class);
  594. }
  595. fs_initcall(powercap_init);
  596. MODULE_DESCRIPTION("PowerCap sysfs Driver");
  597. MODULE_AUTHOR("Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>");
  598. MODULE_LICENSE("GPL v2");