2 * A hwmon driver for ACPI 4.0 power meters
3 * Copyright (C) 2009 IBM
5 * Author: Darrick J. Wong <djwong@us.ibm.com>
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License as published by
9 * the Free Software Foundation; either version 2 of the License, or
10 * (at your option) any later version.
12 * This program is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 * GNU General Public License for more details.
17 * You should have received a copy of the GNU General Public License
18 * along with this program; if not, write to the Free Software
19 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
22 #include <linux/module.h>
23 #include <linux/hwmon.h>
24 #include <linux/hwmon-sysfs.h>
25 #include <linux/jiffies.h>
26 #include <linux/mutex.h>
27 #include <linux/dmi.h>
28 #include <linux/slab.h>
29 #include <linux/kdev_t.h>
30 #include <linux/sched.h>
31 #include <linux/time.h>
32 #include <acpi/acpi_drivers.h>
33 #include <acpi/acpi_bus.h>
35 #define ACPI_POWER_METER_NAME "power_meter"
36 ACPI_MODULE_NAME(ACPI_POWER_METER_NAME);
37 #define ACPI_POWER_METER_DEVICE_NAME "Power Meter"
38 #define ACPI_POWER_METER_CLASS "pwr_meter_resource"
40 #define NUM_SENSORS 17
42 #define POWER_METER_CAN_MEASURE (1 << 0)
43 #define POWER_METER_CAN_TRIP (1 << 1)
44 #define POWER_METER_CAN_CAP (1 << 2)
45 #define POWER_METER_CAN_NOTIFY (1 << 3)
46 #define POWER_METER_IS_BATTERY (1 << 8)
47 #define UNKNOWN_HYSTERESIS 0xFFFFFFFF
49 #define METER_NOTIFY_CONFIG 0x80
50 #define METER_NOTIFY_TRIP 0x81
51 #define METER_NOTIFY_CAP 0x82
52 #define METER_NOTIFY_CAPPING 0x83
53 #define METER_NOTIFY_INTERVAL 0x84
55 #define POWER_AVERAGE_NAME "power1_average"
56 #define POWER_CAP_NAME "power1_cap"
57 #define POWER_AVG_INTERVAL_NAME "power1_average_interval"
58 #define POWER_ALARM_NAME "power1_alarm"
60 static int cap_in_hardware;
61 static bool force_cap_on;
63 static int can_cap_in_hardware(void)
65 return force_cap_on || cap_in_hardware;
68 static const struct acpi_device_id power_meter_ids[] = {
72 MODULE_DEVICE_TABLE(acpi, power_meter_ids);
74 struct acpi_power_meter_capabilities {
88 struct acpi_power_meter_resource {
89 struct acpi_device *acpi_dev;
92 struct device *hwmon_dev;
93 struct acpi_power_meter_capabilities caps;
94 acpi_string model_number;
95 acpi_string serial_number;
101 unsigned long sensors_last_updated;
102 struct sensor_device_attribute sensors[NUM_SENSORS];
105 int num_domain_devices;
106 struct acpi_device **domain_devices;
107 struct kobject *holders_dir;
110 struct sensor_template {
112 ssize_t (*show)(struct device *dev,
113 struct device_attribute *devattr,
115 ssize_t (*set)(struct device *dev,
116 struct device_attribute *devattr,
117 const char *buf, size_t count);
121 /* Averaging interval */
122 static int update_avg_interval(struct acpi_power_meter_resource *resource)
124 unsigned long long data;
127 status = acpi_evaluate_integer(resource->acpi_dev->handle, "_GAI",
129 if (ACPI_FAILURE(status)) {
130 ACPI_EXCEPTION((AE_INFO, status, "Evaluating _GAI"));
134 resource->avg_interval = data;
138 static ssize_t show_avg_interval(struct device *dev,
139 struct device_attribute *devattr,
142 struct acpi_device *acpi_dev = to_acpi_device(dev);
143 struct acpi_power_meter_resource *resource = acpi_dev->driver_data;
145 mutex_lock(&resource->lock);
146 update_avg_interval(resource);
147 mutex_unlock(&resource->lock);
149 return sprintf(buf, "%llu\n", resource->avg_interval);
152 static ssize_t set_avg_interval(struct device *dev,
153 struct device_attribute *devattr,
154 const char *buf, size_t count)
156 struct acpi_device *acpi_dev = to_acpi_device(dev);
157 struct acpi_power_meter_resource *resource = acpi_dev->driver_data;
158 union acpi_object arg0 = { ACPI_TYPE_INTEGER };
159 struct acpi_object_list args = { 1, &arg0 };
162 unsigned long long data;
165 res = kstrtoul(buf, 10, &temp);
169 if (temp > resource->caps.max_avg_interval ||
170 temp < resource->caps.min_avg_interval)
172 arg0.integer.value = temp;
174 mutex_lock(&resource->lock);
175 status = acpi_evaluate_integer(resource->acpi_dev->handle, "_PAI",
177 if (!ACPI_FAILURE(status))
178 resource->avg_interval = temp;
179 mutex_unlock(&resource->lock);
181 if (ACPI_FAILURE(status)) {
182 ACPI_EXCEPTION((AE_INFO, status, "Evaluating _PAI"));
186 /* _PAI returns 0 on success, nonzero otherwise */
194 static int update_cap(struct acpi_power_meter_resource *resource)
196 unsigned long long data;
199 status = acpi_evaluate_integer(resource->acpi_dev->handle, "_GHL",
201 if (ACPI_FAILURE(status)) {
202 ACPI_EXCEPTION((AE_INFO, status, "Evaluating _GHL"));
206 resource->cap = data;
210 static ssize_t show_cap(struct device *dev,
211 struct device_attribute *devattr,
214 struct acpi_device *acpi_dev = to_acpi_device(dev);
215 struct acpi_power_meter_resource *resource = acpi_dev->driver_data;
217 mutex_lock(&resource->lock);
218 update_cap(resource);
219 mutex_unlock(&resource->lock);
221 return sprintf(buf, "%llu\n", resource->cap * 1000);
224 static ssize_t set_cap(struct device *dev, struct device_attribute *devattr,
225 const char *buf, size_t count)
227 struct acpi_device *acpi_dev = to_acpi_device(dev);
228 struct acpi_power_meter_resource *resource = acpi_dev->driver_data;
229 union acpi_object arg0 = { ACPI_TYPE_INTEGER };
230 struct acpi_object_list args = { 1, &arg0 };
233 unsigned long long data;
236 res = kstrtoul(buf, 10, &temp);
241 if (temp > resource->caps.max_cap || temp < resource->caps.min_cap)
243 arg0.integer.value = temp;
245 mutex_lock(&resource->lock);
246 status = acpi_evaluate_integer(resource->acpi_dev->handle, "_SHL",
248 if (!ACPI_FAILURE(status))
249 resource->cap = temp;
250 mutex_unlock(&resource->lock);
252 if (ACPI_FAILURE(status)) {
253 ACPI_EXCEPTION((AE_INFO, status, "Evaluating _SHL"));
257 /* _SHL returns 0 on success, nonzero otherwise */
264 /* Power meter trip points */
265 static int set_acpi_trip(struct acpi_power_meter_resource *resource)
267 union acpi_object arg_objs[] = {
271 struct acpi_object_list args = { 2, arg_objs };
272 unsigned long long data;
275 /* Both trip levels must be set */
276 if (resource->trip[0] < 0 || resource->trip[1] < 0)
279 /* This driver stores min, max; ACPI wants max, min. */
280 arg_objs[0].integer.value = resource->trip[1];
281 arg_objs[1].integer.value = resource->trip[0];
283 status = acpi_evaluate_integer(resource->acpi_dev->handle, "_PTP",
285 if (ACPI_FAILURE(status)) {
286 ACPI_EXCEPTION((AE_INFO, status, "Evaluating _PTP"));
290 /* _PTP returns 0 on success, nonzero otherwise */
297 static ssize_t set_trip(struct device *dev, struct device_attribute *devattr,
298 const char *buf, size_t count)
300 struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
301 struct acpi_device *acpi_dev = to_acpi_device(dev);
302 struct acpi_power_meter_resource *resource = acpi_dev->driver_data;
306 res = kstrtoul(buf, 10, &temp);
314 mutex_lock(&resource->lock);
315 resource->trip[attr->index - 7] = temp;
316 res = set_acpi_trip(resource);
317 mutex_unlock(&resource->lock);
326 static int update_meter(struct acpi_power_meter_resource *resource)
328 unsigned long long data;
330 unsigned long local_jiffies = jiffies;
332 if (time_before(local_jiffies, resource->sensors_last_updated +
333 msecs_to_jiffies(resource->caps.sampling_time)) &&
334 resource->sensors_valid)
337 status = acpi_evaluate_integer(resource->acpi_dev->handle, "_PMM",
339 if (ACPI_FAILURE(status)) {
340 ACPI_EXCEPTION((AE_INFO, status, "Evaluating _PMM"));
344 resource->power = data;
345 resource->sensors_valid = 1;
346 resource->sensors_last_updated = jiffies;
350 static ssize_t show_power(struct device *dev,
351 struct device_attribute *devattr,
354 struct acpi_device *acpi_dev = to_acpi_device(dev);
355 struct acpi_power_meter_resource *resource = acpi_dev->driver_data;
357 mutex_lock(&resource->lock);
358 update_meter(resource);
359 mutex_unlock(&resource->lock);
361 return sprintf(buf, "%llu\n", resource->power * 1000);
365 static ssize_t show_str(struct device *dev,
366 struct device_attribute *devattr,
369 struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
370 struct acpi_device *acpi_dev = to_acpi_device(dev);
371 struct acpi_power_meter_resource *resource = acpi_dev->driver_data;
374 switch (attr->index) {
376 val = resource->model_number;
379 val = resource->serial_number;
382 val = resource->oem_info;
389 return sprintf(buf, "%s\n", val);
392 static ssize_t show_val(struct device *dev,
393 struct device_attribute *devattr,
396 struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
397 struct acpi_device *acpi_dev = to_acpi_device(dev);
398 struct acpi_power_meter_resource *resource = acpi_dev->driver_data;
401 switch (attr->index) {
403 val = resource->caps.min_avg_interval;
406 val = resource->caps.max_avg_interval;
409 val = resource->caps.min_cap * 1000;
412 val = resource->caps.max_cap * 1000;
415 if (resource->caps.hysteresis == UNKNOWN_HYSTERESIS)
416 return sprintf(buf, "unknown\n");
418 val = resource->caps.hysteresis * 1000;
421 if (resource->caps.flags & POWER_METER_IS_BATTERY)
427 if (resource->power > resource->cap)
434 if (resource->trip[attr->index - 7] < 0)
435 return sprintf(buf, "unknown\n");
437 val = resource->trip[attr->index - 7] * 1000;
443 return sprintf(buf, "%llu\n", val);
446 static ssize_t show_accuracy(struct device *dev,
447 struct device_attribute *devattr,
450 struct acpi_device *acpi_dev = to_acpi_device(dev);
451 struct acpi_power_meter_resource *resource = acpi_dev->driver_data;
452 unsigned int acc = resource->caps.accuracy;
454 return sprintf(buf, "%u.%u%%\n", acc / 1000, acc % 1000);
457 static ssize_t show_name(struct device *dev,
458 struct device_attribute *devattr,
461 return sprintf(buf, "%s\n", ACPI_POWER_METER_NAME);
464 #define RO_SENSOR_TEMPLATE(_label, _show, _index) \
471 #define RW_SENSOR_TEMPLATE(_label, _show, _set, _index) \
479 /* Sensor descriptions. If you add a sensor, update NUM_SENSORS above! */
480 static struct sensor_template meter_attrs[] = {
481 RO_SENSOR_TEMPLATE(POWER_AVERAGE_NAME, show_power, 0),
482 RO_SENSOR_TEMPLATE("power1_accuracy", show_accuracy, 0),
483 RO_SENSOR_TEMPLATE("power1_average_interval_min", show_val, 0),
484 RO_SENSOR_TEMPLATE("power1_average_interval_max", show_val, 1),
485 RO_SENSOR_TEMPLATE("power1_is_battery", show_val, 5),
486 RW_SENSOR_TEMPLATE(POWER_AVG_INTERVAL_NAME, show_avg_interval,
487 set_avg_interval, 0),
491 static struct sensor_template misc_cap_attrs[] = {
492 RO_SENSOR_TEMPLATE("power1_cap_min", show_val, 2),
493 RO_SENSOR_TEMPLATE("power1_cap_max", show_val, 3),
494 RO_SENSOR_TEMPLATE("power1_cap_hyst", show_val, 4),
495 RO_SENSOR_TEMPLATE(POWER_ALARM_NAME, show_val, 6),
499 static struct sensor_template ro_cap_attrs[] = {
500 RO_SENSOR_TEMPLATE(POWER_CAP_NAME, show_cap, 0),
504 static struct sensor_template rw_cap_attrs[] = {
505 RW_SENSOR_TEMPLATE(POWER_CAP_NAME, show_cap, set_cap, 0),
509 static struct sensor_template trip_attrs[] = {
510 RW_SENSOR_TEMPLATE("power1_average_min", show_val, set_trip, 7),
511 RW_SENSOR_TEMPLATE("power1_average_max", show_val, set_trip, 8),
515 static struct sensor_template misc_attrs[] = {
516 RO_SENSOR_TEMPLATE("name", show_name, 0),
517 RO_SENSOR_TEMPLATE("power1_model_number", show_str, 0),
518 RO_SENSOR_TEMPLATE("power1_oem_info", show_str, 2),
519 RO_SENSOR_TEMPLATE("power1_serial_number", show_str, 1),
523 #undef RO_SENSOR_TEMPLATE
524 #undef RW_SENSOR_TEMPLATE
526 /* Read power domain data */
527 static void remove_domain_devices(struct acpi_power_meter_resource *resource)
531 if (!resource->num_domain_devices)
534 for (i = 0; i < resource->num_domain_devices; i++) {
535 struct acpi_device *obj = resource->domain_devices[i];
539 sysfs_remove_link(resource->holders_dir,
540 kobject_name(&obj->dev.kobj));
541 put_device(&obj->dev);
544 kfree(resource->domain_devices);
545 kobject_put(resource->holders_dir);
546 resource->num_domain_devices = 0;
549 static int read_domain_devices(struct acpi_power_meter_resource *resource)
553 struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
554 union acpi_object *pss;
557 status = acpi_evaluate_object(resource->acpi_dev->handle, "_PMD", NULL,
559 if (ACPI_FAILURE(status)) {
560 ACPI_EXCEPTION((AE_INFO, status, "Evaluating _PMD"));
564 pss = buffer.pointer;
566 pss->type != ACPI_TYPE_PACKAGE) {
567 dev_err(&resource->acpi_dev->dev, ACPI_POWER_METER_NAME
568 "Invalid _PMD data\n");
573 if (!pss->package.count)
576 resource->domain_devices = kzalloc(sizeof(struct acpi_device *) *
577 pss->package.count, GFP_KERNEL);
578 if (!resource->domain_devices) {
583 resource->holders_dir = kobject_create_and_add("measures",
584 &resource->acpi_dev->dev.kobj);
585 if (!resource->holders_dir) {
590 resource->num_domain_devices = pss->package.count;
592 for (i = 0; i < pss->package.count; i++) {
593 struct acpi_device *obj;
594 union acpi_object *element = &(pss->package.elements[i]);
596 /* Refuse non-references */
597 if (element->type != ACPI_TYPE_LOCAL_REFERENCE)
600 /* Create a symlink to domain objects */
601 resource->domain_devices[i] = NULL;
602 status = acpi_bus_get_device(element->reference.handle,
603 &resource->domain_devices[i]);
604 if (ACPI_FAILURE(status))
607 obj = resource->domain_devices[i];
608 get_device(&obj->dev);
610 res = sysfs_create_link(resource->holders_dir, &obj->dev.kobj,
611 kobject_name(&obj->dev.kobj));
613 put_device(&obj->dev);
614 resource->domain_devices[i] = NULL;
622 kfree(resource->domain_devices);
624 kfree(buffer.pointer);
628 /* Registration and deregistration */
629 static int register_attrs(struct acpi_power_meter_resource *resource,
630 struct sensor_template *attrs)
632 struct device *dev = &resource->acpi_dev->dev;
633 struct sensor_device_attribute *sensors =
634 &resource->sensors[resource->num_sensors];
637 while (attrs->label) {
638 sensors->dev_attr.attr.name = attrs->label;
639 sensors->dev_attr.attr.mode = S_IRUGO;
640 sensors->dev_attr.show = attrs->show;
641 sensors->index = attrs->index;
644 sensors->dev_attr.attr.mode |= S_IWUSR;
645 sensors->dev_attr.store = attrs->set;
648 sysfs_attr_init(&sensors->dev_attr.attr);
649 res = device_create_file(dev, &sensors->dev_attr);
651 sensors->dev_attr.attr.name = NULL;
655 resource->num_sensors++;
663 static void remove_attrs(struct acpi_power_meter_resource *resource)
667 for (i = 0; i < resource->num_sensors; i++) {
668 if (!resource->sensors[i].dev_attr.attr.name)
670 device_remove_file(&resource->acpi_dev->dev,
671 &resource->sensors[i].dev_attr);
674 remove_domain_devices(resource);
676 resource->num_sensors = 0;
679 static int setup_attrs(struct acpi_power_meter_resource *resource)
683 res = read_domain_devices(resource);
687 if (resource->caps.flags & POWER_METER_CAN_MEASURE) {
688 res = register_attrs(resource, meter_attrs);
693 if (resource->caps.flags & POWER_METER_CAN_CAP) {
694 if (!can_cap_in_hardware()) {
695 dev_err(&resource->acpi_dev->dev,
696 "Ignoring unsafe software power cap!\n");
697 goto skip_unsafe_cap;
700 if (resource->caps.configurable_cap)
701 res = register_attrs(resource, rw_cap_attrs);
703 res = register_attrs(resource, ro_cap_attrs);
708 res = register_attrs(resource, misc_cap_attrs);
714 if (resource->caps.flags & POWER_METER_CAN_TRIP) {
715 res = register_attrs(resource, trip_attrs);
720 res = register_attrs(resource, misc_attrs);
726 remove_attrs(resource);
730 static void free_capabilities(struct acpi_power_meter_resource *resource)
735 str = &resource->model_number;
736 for (i = 0; i < 3; i++, str++)
740 static int read_capabilities(struct acpi_power_meter_resource *resource)
744 struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
745 struct acpi_buffer state = { 0, NULL };
746 struct acpi_buffer format = { sizeof("NNNNNNNNNNN"), "NNNNNNNNNNN" };
747 union acpi_object *pss;
751 status = acpi_evaluate_object(resource->acpi_dev->handle, "_PMC", NULL,
753 if (ACPI_FAILURE(status)) {
754 ACPI_EXCEPTION((AE_INFO, status, "Evaluating _PMC"));
758 pss = buffer.pointer;
760 pss->type != ACPI_TYPE_PACKAGE ||
761 pss->package.count != 14) {
762 dev_err(&resource->acpi_dev->dev, ACPI_POWER_METER_NAME
763 "Invalid _PMC data\n");
768 /* Grab all the integer data at once */
769 state.length = sizeof(struct acpi_power_meter_capabilities);
770 state.pointer = &resource->caps;
772 status = acpi_extract_package(pss, &format, &state);
773 if (ACPI_FAILURE(status)) {
774 ACPI_EXCEPTION((AE_INFO, status, "Invalid data"));
779 if (resource->caps.units) {
780 dev_err(&resource->acpi_dev->dev, ACPI_POWER_METER_NAME
781 "Unknown units %llu.\n",
782 resource->caps.units);
787 /* Grab the string data */
788 str = &resource->model_number;
790 for (i = 11; i < 14; i++) {
791 union acpi_object *element = &(pss->package.elements[i]);
793 if (element->type != ACPI_TYPE_STRING) {
798 *str = kzalloc(sizeof(u8) * (element->string.length + 1),
805 strncpy(*str, element->string.pointer, element->string.length);
809 dev_info(&resource->acpi_dev->dev, "Found ACPI power meter.\n");
812 str = &resource->model_number;
813 for (i = 0; i < 3; i++, str++)
816 kfree(buffer.pointer);
820 /* Handle ACPI event notifications */
821 static void acpi_power_meter_notify(struct acpi_device *device, u32 event)
823 struct acpi_power_meter_resource *resource;
826 if (!device || !acpi_driver_data(device))
829 resource = acpi_driver_data(device);
831 mutex_lock(&resource->lock);
833 case METER_NOTIFY_CONFIG:
834 free_capabilities(resource);
835 res = read_capabilities(resource);
839 remove_attrs(resource);
840 setup_attrs(resource);
842 case METER_NOTIFY_TRIP:
843 sysfs_notify(&device->dev.kobj, NULL, POWER_AVERAGE_NAME);
844 update_meter(resource);
846 case METER_NOTIFY_CAP:
847 sysfs_notify(&device->dev.kobj, NULL, POWER_CAP_NAME);
848 update_cap(resource);
850 case METER_NOTIFY_INTERVAL:
851 sysfs_notify(&device->dev.kobj, NULL, POWER_AVG_INTERVAL_NAME);
852 update_avg_interval(resource);
854 case METER_NOTIFY_CAPPING:
855 sysfs_notify(&device->dev.kobj, NULL, POWER_ALARM_NAME);
856 dev_info(&device->dev, "Capping in progress.\n");
861 mutex_unlock(&resource->lock);
863 acpi_bus_generate_netlink_event(ACPI_POWER_METER_CLASS,
864 dev_name(&device->dev), event, 0);
867 static int acpi_power_meter_add(struct acpi_device *device)
870 struct acpi_power_meter_resource *resource;
875 resource = kzalloc(sizeof(struct acpi_power_meter_resource),
880 resource->sensors_valid = 0;
881 resource->acpi_dev = device;
882 mutex_init(&resource->lock);
883 strcpy(acpi_device_name(device), ACPI_POWER_METER_DEVICE_NAME);
884 strcpy(acpi_device_class(device), ACPI_POWER_METER_CLASS);
885 device->driver_data = resource;
887 free_capabilities(resource);
888 res = read_capabilities(resource);
892 resource->trip[0] = resource->trip[1] = -1;
894 res = setup_attrs(resource);
898 resource->hwmon_dev = hwmon_device_register(&device->dev);
899 if (IS_ERR(resource->hwmon_dev)) {
900 res = PTR_ERR(resource->hwmon_dev);
908 remove_attrs(resource);
915 static int acpi_power_meter_remove(struct acpi_device *device, int type)
917 struct acpi_power_meter_resource *resource;
919 if (!device || !acpi_driver_data(device))
922 resource = acpi_driver_data(device);
923 hwmon_device_unregister(resource->hwmon_dev);
925 free_capabilities(resource);
926 remove_attrs(resource);
932 static int acpi_power_meter_resume(struct device *dev)
934 struct acpi_power_meter_resource *resource;
939 resource = acpi_driver_data(to_acpi_device(dev));
943 free_capabilities(resource);
944 read_capabilities(resource);
949 static SIMPLE_DEV_PM_OPS(acpi_power_meter_pm, NULL, acpi_power_meter_resume);
951 static struct acpi_driver acpi_power_meter_driver = {
952 .name = "power_meter",
953 .class = ACPI_POWER_METER_CLASS,
954 .ids = power_meter_ids,
956 .add = acpi_power_meter_add,
957 .remove = acpi_power_meter_remove,
958 .notify = acpi_power_meter_notify,
960 .drv.pm = &acpi_power_meter_pm,
963 /* Module init/exit routines */
964 static int __init enable_cap_knobs(const struct dmi_system_id *d)
970 static struct dmi_system_id __initdata pm_dmi_table[] = {
972 enable_cap_knobs, "IBM Active Energy Manager",
974 DMI_MATCH(DMI_SYS_VENDOR, "IBM")
980 static int __init acpi_power_meter_init(void)
987 dmi_check_system(pm_dmi_table);
989 result = acpi_bus_register_driver(&acpi_power_meter_driver);
996 static void __exit acpi_power_meter_exit(void)
998 acpi_bus_unregister_driver(&acpi_power_meter_driver);
1001 MODULE_AUTHOR("Darrick J. Wong <djwong@us.ibm.com>");
1002 MODULE_DESCRIPTION("ACPI 4.0 power meter driver");
1003 MODULE_LICENSE("GPL");
1005 module_param(force_cap_on, bool, 0644);
1006 MODULE_PARM_DESC(force_cap_on, "Enable power cap even it is unsafe to do so.");
1008 module_init(acpi_power_meter_init);
1009 module_exit(acpi_power_meter_exit);