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/kdev_t.h>
29 #include <linux/sched.h>
30 #include <linux/time.h>
31 #include <acpi/acpi_drivers.h>
32 #include <acpi/acpi_bus.h>
34 #define ACPI_POWER_METER_NAME "power_meter"
35 ACPI_MODULE_NAME(ACPI_POWER_METER_NAME);
36 #define ACPI_POWER_METER_DEVICE_NAME "Power Meter"
37 #define ACPI_POWER_METER_CLASS "power_meter_resource"
39 #define NUM_SENSORS 17
41 #define POWER_METER_CAN_MEASURE (1 << 0)
42 #define POWER_METER_CAN_TRIP (1 << 1)
43 #define POWER_METER_CAN_CAP (1 << 2)
44 #define POWER_METER_CAN_NOTIFY (1 << 3)
45 #define POWER_METER_IS_BATTERY (1 << 8)
46 #define UNKNOWN_HYSTERESIS 0xFFFFFFFF
48 #define METER_NOTIFY_CONFIG 0x80
49 #define METER_NOTIFY_TRIP 0x81
50 #define METER_NOTIFY_CAP 0x82
51 #define METER_NOTIFY_CAPPING 0x83
52 #define METER_NOTIFY_INTERVAL 0x84
54 #define POWER_AVERAGE_NAME "power1_average"
55 #define POWER_CAP_NAME "power1_cap"
56 #define POWER_AVG_INTERVAL_NAME "power1_average_interval"
57 #define POWER_ALARM_NAME "power1_alarm"
59 static int cap_in_hardware;
60 static int force_cap_on;
62 static int can_cap_in_hardware(void)
64 return force_cap_on || cap_in_hardware;
67 static struct acpi_device_id power_meter_ids[] = {
71 MODULE_DEVICE_TABLE(acpi, power_meter_ids);
73 struct acpi_power_meter_capabilities {
77 acpi_integer accuracy;
78 acpi_integer sampling_time;
79 acpi_integer min_avg_interval;
80 acpi_integer max_avg_interval;
81 acpi_integer hysteresis;
82 acpi_integer configurable_cap;
87 struct acpi_power_meter_resource {
88 struct acpi_device *acpi_dev;
91 struct device *hwmon_dev;
92 struct acpi_power_meter_capabilities caps;
93 acpi_string model_number;
94 acpi_string serial_number;
98 acpi_integer avg_interval;
100 unsigned long sensors_last_updated;
101 struct sensor_device_attribute sensors[NUM_SENSORS];
104 int num_domain_devices;
105 struct acpi_device **domain_devices;
106 struct kobject *holders_dir;
109 struct ro_sensor_template {
111 ssize_t (*show)(struct device *dev,
112 struct device_attribute *devattr,
117 struct rw_sensor_template {
119 ssize_t (*show)(struct device *dev,
120 struct device_attribute *devattr,
122 ssize_t (*set)(struct device *dev,
123 struct device_attribute *devattr,
124 const char *buf, size_t count);
128 /* Averaging interval */
129 static int update_avg_interval(struct acpi_power_meter_resource *resource)
131 unsigned long long data;
134 status = acpi_evaluate_integer(resource->acpi_dev->handle, "_GAI",
136 if (ACPI_FAILURE(status)) {
137 ACPI_EXCEPTION((AE_INFO, status, "Evaluating _GAI"));
141 resource->avg_interval = data;
145 static ssize_t show_avg_interval(struct device *dev,
146 struct device_attribute *devattr,
149 struct acpi_device *acpi_dev = to_acpi_device(dev);
150 struct acpi_power_meter_resource *resource = acpi_dev->driver_data;
152 mutex_lock(&resource->lock);
153 update_avg_interval(resource);
154 mutex_unlock(&resource->lock);
156 return sprintf(buf, "%llu\n", resource->avg_interval);
159 static ssize_t set_avg_interval(struct device *dev,
160 struct device_attribute *devattr,
161 const char *buf, size_t count)
163 struct acpi_device *acpi_dev = to_acpi_device(dev);
164 struct acpi_power_meter_resource *resource = acpi_dev->driver_data;
165 union acpi_object arg0 = { ACPI_TYPE_INTEGER };
166 struct acpi_object_list args = { 1, &arg0 };
169 unsigned long long data;
172 res = strict_strtoul(buf, 10, &temp);
176 if (temp > resource->caps.max_avg_interval ||
177 temp < resource->caps.min_avg_interval)
179 arg0.integer.value = temp;
181 mutex_lock(&resource->lock);
182 status = acpi_evaluate_integer(resource->acpi_dev->handle, "_PAI",
184 if (!ACPI_FAILURE(status))
185 resource->avg_interval = temp;
186 mutex_unlock(&resource->lock);
188 if (ACPI_FAILURE(status)) {
189 ACPI_EXCEPTION((AE_INFO, status, "Evaluating _PAI"));
193 /* _PAI returns 0 on success, nonzero otherwise */
201 static int update_cap(struct acpi_power_meter_resource *resource)
203 unsigned long long data;
206 status = acpi_evaluate_integer(resource->acpi_dev->handle, "_GHL",
208 if (ACPI_FAILURE(status)) {
209 ACPI_EXCEPTION((AE_INFO, status, "Evaluating _GHL"));
213 resource->cap = data;
217 static ssize_t show_cap(struct device *dev,
218 struct device_attribute *devattr,
221 struct acpi_device *acpi_dev = to_acpi_device(dev);
222 struct acpi_power_meter_resource *resource = acpi_dev->driver_data;
224 mutex_lock(&resource->lock);
225 update_cap(resource);
226 mutex_unlock(&resource->lock);
228 return sprintf(buf, "%llu\n", resource->cap * 1000);
231 static ssize_t set_cap(struct device *dev, struct device_attribute *devattr,
232 const char *buf, size_t count)
234 struct acpi_device *acpi_dev = to_acpi_device(dev);
235 struct acpi_power_meter_resource *resource = acpi_dev->driver_data;
236 union acpi_object arg0 = { ACPI_TYPE_INTEGER };
237 struct acpi_object_list args = { 1, &arg0 };
240 unsigned long long data;
243 res = strict_strtoul(buf, 10, &temp);
248 if (temp > resource->caps.max_cap || temp < resource->caps.min_cap)
250 arg0.integer.value = temp;
252 mutex_lock(&resource->lock);
253 status = acpi_evaluate_integer(resource->acpi_dev->handle, "_SHL",
255 if (!ACPI_FAILURE(status))
256 resource->cap = temp;
257 mutex_unlock(&resource->lock);
259 if (ACPI_FAILURE(status)) {
260 ACPI_EXCEPTION((AE_INFO, status, "Evaluating _SHL"));
264 /* _SHL returns 0 on success, nonzero otherwise */
271 /* Power meter trip points */
272 static int set_acpi_trip(struct acpi_power_meter_resource *resource)
274 union acpi_object arg_objs[] = {
278 struct acpi_object_list args = { 2, arg_objs };
279 unsigned long long data;
282 /* Both trip levels must be set */
283 if (resource->trip[0] < 0 || resource->trip[1] < 0)
286 /* This driver stores min, max; ACPI wants max, min. */
287 arg_objs[0].integer.value = resource->trip[1];
288 arg_objs[1].integer.value = resource->trip[0];
290 status = acpi_evaluate_integer(resource->acpi_dev->handle, "_PTP",
292 if (ACPI_FAILURE(status)) {
293 ACPI_EXCEPTION((AE_INFO, status, "Evaluating _PTP"));
300 static ssize_t set_trip(struct device *dev, struct device_attribute *devattr,
301 const char *buf, size_t count)
303 struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
304 struct acpi_device *acpi_dev = to_acpi_device(dev);
305 struct acpi_power_meter_resource *resource = acpi_dev->driver_data;
309 res = strict_strtoul(buf, 10, &temp);
317 mutex_lock(&resource->lock);
318 resource->trip[attr->index - 7] = temp;
319 res = set_acpi_trip(resource);
320 mutex_unlock(&resource->lock);
329 static int update_meter(struct acpi_power_meter_resource *resource)
331 unsigned long long data;
333 unsigned long local_jiffies = jiffies;
335 if (time_before(local_jiffies, resource->sensors_last_updated +
336 msecs_to_jiffies(resource->caps.sampling_time)) &&
337 resource->sensors_valid)
340 status = acpi_evaluate_integer(resource->acpi_dev->handle, "_PMM",
342 if (ACPI_FAILURE(status)) {
343 ACPI_EXCEPTION((AE_INFO, status, "Evaluating _PMM"));
347 resource->power = data;
348 resource->sensors_valid = 1;
349 resource->sensors_last_updated = jiffies;
353 static ssize_t show_power(struct device *dev,
354 struct device_attribute *devattr,
357 struct acpi_device *acpi_dev = to_acpi_device(dev);
358 struct acpi_power_meter_resource *resource = acpi_dev->driver_data;
360 mutex_lock(&resource->lock);
361 update_meter(resource);
362 mutex_unlock(&resource->lock);
364 return sprintf(buf, "%llu\n", resource->power * 1000);
368 static ssize_t show_str(struct device *dev,
369 struct device_attribute *devattr,
372 struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
373 struct acpi_device *acpi_dev = to_acpi_device(dev);
374 struct acpi_power_meter_resource *resource = acpi_dev->driver_data;
377 switch (attr->index) {
379 val = resource->model_number;
382 val = resource->serial_number;
385 val = resource->oem_info;
391 return sprintf(buf, "%s\n", val);
394 static ssize_t show_val(struct device *dev,
395 struct device_attribute *devattr,
398 struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
399 struct acpi_device *acpi_dev = to_acpi_device(dev);
400 struct acpi_power_meter_resource *resource = acpi_dev->driver_data;
401 acpi_integer val = 0;
403 switch (attr->index) {
405 val = resource->caps.min_avg_interval;
408 val = resource->caps.max_avg_interval;
411 val = resource->caps.min_cap * 1000;
414 val = resource->caps.max_cap * 1000;
417 if (resource->caps.hysteresis == UNKNOWN_HYSTERESIS)
418 return sprintf(buf, "unknown\n");
420 val = resource->caps.hysteresis * 1000;
423 if (resource->caps.flags & POWER_METER_IS_BATTERY)
429 if (resource->power > resource->cap)
436 if (resource->trip[attr->index - 7] < 0)
437 return sprintf(buf, "unknown\n");
439 val = resource->trip[attr->index - 7] * 1000;
445 return sprintf(buf, "%llu\n", val);
448 static ssize_t show_accuracy(struct device *dev,
449 struct device_attribute *devattr,
452 struct acpi_device *acpi_dev = to_acpi_device(dev);
453 struct acpi_power_meter_resource *resource = acpi_dev->driver_data;
454 unsigned int acc = resource->caps.accuracy;
456 return sprintf(buf, "%u.%u%%\n", acc / 1000, acc % 1000);
459 static ssize_t show_name(struct device *dev,
460 struct device_attribute *devattr,
463 return sprintf(buf, "%s\n", ACPI_POWER_METER_NAME);
466 /* Sensor descriptions. If you add a sensor, update NUM_SENSORS above! */
467 static struct ro_sensor_template meter_ro_attrs[] = {
468 {POWER_AVERAGE_NAME, show_power, 0},
469 {"power1_accuracy", show_accuracy, 0},
470 {"power1_average_interval_min", show_val, 0},
471 {"power1_average_interval_max", show_val, 1},
472 {"power1_is_battery", show_val, 5},
476 static struct rw_sensor_template meter_rw_attrs[] = {
477 {POWER_AVG_INTERVAL_NAME, show_avg_interval, set_avg_interval, 0},
478 {NULL, NULL, NULL, 0},
481 static struct ro_sensor_template misc_cap_attrs[] = {
482 {"power1_cap_min", show_val, 2},
483 {"power1_cap_max", show_val, 3},
484 {"power1_cap_hyst", show_val, 4},
485 {POWER_ALARM_NAME, show_val, 6},
489 static struct ro_sensor_template ro_cap_attrs[] = {
490 {POWER_CAP_NAME, show_cap, 0},
494 static struct rw_sensor_template rw_cap_attrs[] = {
495 {POWER_CAP_NAME, show_cap, set_cap, 0},
496 {NULL, NULL, NULL, 0},
499 static struct rw_sensor_template trip_attrs[] = {
500 {"power1_average_min", show_val, set_trip, 7},
501 {"power1_average_max", show_val, set_trip, 8},
502 {NULL, NULL, NULL, 0},
505 static struct ro_sensor_template misc_attrs[] = {
506 {"name", show_name, 0},
507 {"power1_model_number", show_str, 0},
508 {"power1_oem_info", show_str, 2},
509 {"power1_serial_number", show_str, 1},
513 /* Read power domain data */
514 static void remove_domain_devices(struct acpi_power_meter_resource *resource)
518 if (!resource->num_domain_devices)
521 for (i = 0; i < resource->num_domain_devices; i++) {
522 struct acpi_device *obj = resource->domain_devices[i];
526 sysfs_remove_link(resource->holders_dir,
527 kobject_name(&obj->dev.kobj));
528 put_device(&obj->dev);
531 kfree(resource->domain_devices);
532 kobject_put(resource->holders_dir);
535 static int read_domain_devices(struct acpi_power_meter_resource *resource)
539 struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
540 union acpi_object *pss;
543 status = acpi_evaluate_object(resource->acpi_dev->handle, "_PMD", NULL,
545 if (ACPI_FAILURE(status)) {
546 ACPI_EXCEPTION((AE_INFO, status, "Evaluating _PMD"));
550 pss = buffer.pointer;
552 pss->type != ACPI_TYPE_PACKAGE) {
553 dev_err(&resource->acpi_dev->dev, ACPI_POWER_METER_NAME
554 "Invalid _PMD data\n");
559 if (!pss->package.count)
562 resource->domain_devices = kzalloc(sizeof(struct acpi_device *) *
563 pss->package.count, GFP_KERNEL);
564 if (!resource->domain_devices) {
569 resource->holders_dir = kobject_create_and_add("measures",
570 &resource->acpi_dev->dev.kobj);
571 if (!resource->holders_dir) {
576 resource->num_domain_devices = pss->package.count;
578 for (i = 0; i < pss->package.count; i++) {
579 struct acpi_device *obj;
580 union acpi_object *element = &(pss->package.elements[i]);
582 /* Refuse non-references */
583 if (element->type != ACPI_TYPE_LOCAL_REFERENCE)
586 /* Create a symlink to domain objects */
587 resource->domain_devices[i] = NULL;
588 status = acpi_bus_get_device(element->reference.handle,
589 &resource->domain_devices[i]);
590 if (ACPI_FAILURE(status))
593 obj = resource->domain_devices[i];
594 get_device(&obj->dev);
596 res = sysfs_create_link(resource->holders_dir, &obj->dev.kobj,
597 kobject_name(&obj->dev.kobj));
599 put_device(&obj->dev);
600 resource->domain_devices[i] = NULL;
608 kfree(resource->domain_devices);
610 kfree(buffer.pointer);
614 /* Registration and deregistration */
615 static int register_ro_attrs(struct acpi_power_meter_resource *resource,
616 struct ro_sensor_template *ro)
618 struct device *dev = &resource->acpi_dev->dev;
619 struct sensor_device_attribute *sensors =
620 &resource->sensors[resource->num_sensors];
624 sensors->dev_attr.attr.name = ro->label;
625 sensors->dev_attr.attr.mode = S_IRUGO;
626 sensors->dev_attr.show = ro->show;
627 sensors->index = ro->index;
629 res = device_create_file(dev, &sensors->dev_attr);
631 sensors->dev_attr.attr.name = NULL;
635 resource->num_sensors++;
643 static int register_rw_attrs(struct acpi_power_meter_resource *resource,
644 struct rw_sensor_template *rw)
646 struct device *dev = &resource->acpi_dev->dev;
647 struct sensor_device_attribute *sensors =
648 &resource->sensors[resource->num_sensors];
652 sensors->dev_attr.attr.name = rw->label;
653 sensors->dev_attr.attr.mode = S_IRUGO | S_IWUSR;
654 sensors->dev_attr.show = rw->show;
655 sensors->dev_attr.store = rw->set;
656 sensors->index = rw->index;
658 res = device_create_file(dev, &sensors->dev_attr);
660 sensors->dev_attr.attr.name = NULL;
664 resource->num_sensors++;
672 static void remove_attrs(struct acpi_power_meter_resource *resource)
676 for (i = 0; i < resource->num_sensors; i++) {
677 if (!resource->sensors[i].dev_attr.attr.name)
679 device_remove_file(&resource->acpi_dev->dev,
680 &resource->sensors[i].dev_attr);
683 remove_domain_devices(resource);
685 resource->num_sensors = 0;
688 static int setup_attrs(struct acpi_power_meter_resource *resource)
692 res = read_domain_devices(resource);
696 if (resource->caps.flags & POWER_METER_CAN_MEASURE) {
697 res = register_ro_attrs(resource, meter_ro_attrs);
700 res = register_rw_attrs(resource, meter_rw_attrs);
705 if (resource->caps.flags & POWER_METER_CAN_CAP) {
706 if (!can_cap_in_hardware()) {
707 dev_err(&resource->acpi_dev->dev,
708 "Ignoring unsafe software power cap!\n");
709 goto skip_unsafe_cap;
712 if (resource->caps.configurable_cap) {
713 res = register_rw_attrs(resource, rw_cap_attrs);
717 res = register_ro_attrs(resource, ro_cap_attrs);
721 res = register_ro_attrs(resource, misc_cap_attrs);
727 if (resource->caps.flags & POWER_METER_CAN_TRIP) {
728 res = register_rw_attrs(resource, trip_attrs);
733 res = register_ro_attrs(resource, misc_attrs);
739 remove_domain_devices(resource);
740 remove_attrs(resource);
744 static void free_capabilities(struct acpi_power_meter_resource *resource)
749 str = &resource->model_number;
750 for (i = 0; i < 3; i++, str++)
754 static int read_capabilities(struct acpi_power_meter_resource *resource)
758 struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
759 struct acpi_buffer state = { 0, NULL };
760 struct acpi_buffer format = { sizeof("NNNNNNNNNNN"), "NNNNNNNNNNN" };
761 union acpi_object *pss;
765 status = acpi_evaluate_object(resource->acpi_dev->handle, "_PMC", NULL,
767 if (ACPI_FAILURE(status)) {
768 ACPI_EXCEPTION((AE_INFO, status, "Evaluating _PMC"));
772 pss = buffer.pointer;
774 pss->type != ACPI_TYPE_PACKAGE ||
775 pss->package.count != 14) {
776 dev_err(&resource->acpi_dev->dev, ACPI_POWER_METER_NAME
777 "Invalid _PMC data\n");
782 /* Grab all the integer data at once */
783 state.length = sizeof(struct acpi_power_meter_capabilities);
784 state.pointer = &resource->caps;
786 status = acpi_extract_package(pss, &format, &state);
787 if (ACPI_FAILURE(status)) {
788 ACPI_EXCEPTION((AE_INFO, status, "Invalid data"));
793 if (resource->caps.units) {
794 dev_err(&resource->acpi_dev->dev, ACPI_POWER_METER_NAME
795 "Unknown units %llu.\n",
796 resource->caps.units);
801 /* Grab the string data */
802 str = &resource->model_number;
804 for (i = 11; i < 14; i++) {
805 union acpi_object *element = &(pss->package.elements[i]);
807 if (element->type != ACPI_TYPE_STRING) {
812 *str = kzalloc(sizeof(u8) * (element->string.length + 1),
819 strncpy(*str, element->string.pointer, element->string.length);
823 dev_info(&resource->acpi_dev->dev, "Found ACPI power meter.\n");
826 str = &resource->model_number;
827 for (i = 0; i < 3; i++, str++)
830 kfree(buffer.pointer);
834 /* Handle ACPI event notifications */
835 static void acpi_power_meter_notify(struct acpi_device *device, u32 event)
837 struct acpi_power_meter_resource *resource;
840 if (!device || !acpi_driver_data(device))
843 resource = acpi_driver_data(device);
845 mutex_lock(&resource->lock);
847 case METER_NOTIFY_CONFIG:
848 free_capabilities(resource);
849 res = read_capabilities(resource);
853 remove_attrs(resource);
854 setup_attrs(resource);
856 case METER_NOTIFY_TRIP:
857 sysfs_notify(&device->dev.kobj, NULL, POWER_AVERAGE_NAME);
858 update_meter(resource);
860 case METER_NOTIFY_CAP:
861 sysfs_notify(&device->dev.kobj, NULL, POWER_CAP_NAME);
862 update_cap(resource);
864 case METER_NOTIFY_INTERVAL:
865 sysfs_notify(&device->dev.kobj, NULL, POWER_AVG_INTERVAL_NAME);
866 update_avg_interval(resource);
868 case METER_NOTIFY_CAPPING:
869 sysfs_notify(&device->dev.kobj, NULL, POWER_ALARM_NAME);
870 dev_info(&device->dev, "Capping in progress.\n");
875 mutex_unlock(&resource->lock);
877 acpi_bus_generate_netlink_event(ACPI_POWER_METER_CLASS,
878 dev_name(&device->dev), event, 0);
881 static int acpi_power_meter_add(struct acpi_device *device)
884 struct acpi_power_meter_resource *resource;
889 resource = kzalloc(sizeof(struct acpi_power_meter_resource),
894 resource->sensors_valid = 0;
895 resource->acpi_dev = device;
896 mutex_init(&resource->lock);
897 strcpy(acpi_device_name(device), ACPI_POWER_METER_DEVICE_NAME);
898 strcpy(acpi_device_class(device), ACPI_POWER_METER_CLASS);
899 device->driver_data = resource;
901 free_capabilities(resource);
902 res = read_capabilities(resource);
906 resource->trip[0] = resource->trip[1] = -1;
908 res = setup_attrs(resource);
912 resource->hwmon_dev = hwmon_device_register(&device->dev);
913 if (IS_ERR(resource->hwmon_dev)) {
914 res = PTR_ERR(resource->hwmon_dev);
922 remove_attrs(resource);
929 static int acpi_power_meter_remove(struct acpi_device *device, int type)
931 struct acpi_power_meter_resource *resource;
933 if (!device || !acpi_driver_data(device))
936 resource = acpi_driver_data(device);
937 hwmon_device_unregister(resource->hwmon_dev);
939 free_capabilities(resource);
940 remove_attrs(resource);
946 static int acpi_power_meter_resume(struct acpi_device *device)
948 struct acpi_power_meter_resource *resource;
950 if (!device || !acpi_driver_data(device))
953 resource = acpi_driver_data(device);
954 free_capabilities(resource);
955 read_capabilities(resource);
960 static struct acpi_driver acpi_power_meter_driver = {
961 .name = "power_meter",
962 .class = ACPI_POWER_METER_CLASS,
963 .ids = power_meter_ids,
965 .add = acpi_power_meter_add,
966 .remove = acpi_power_meter_remove,
967 .resume = acpi_power_meter_resume,
968 .notify = acpi_power_meter_notify,
972 /* Module init/exit routines */
973 static int __init enable_cap_knobs(const struct dmi_system_id *d)
979 static struct dmi_system_id __initdata pm_dmi_table[] = {
981 enable_cap_knobs, "IBM Active Energy Manager",
983 DMI_MATCH(DMI_SYS_VENDOR, "IBM")
989 static int __init acpi_power_meter_init(void)
996 dmi_check_system(pm_dmi_table);
998 result = acpi_bus_register_driver(&acpi_power_meter_driver);
1005 static void __exit acpi_power_meter_exit(void)
1007 acpi_bus_unregister_driver(&acpi_power_meter_driver);
1010 MODULE_AUTHOR("Darrick J. Wong <djwong@us.ibm.com>");
1011 MODULE_DESCRIPTION("ACPI 4.0 power meter driver");
1012 MODULE_LICENSE("GPL");
1014 module_param(force_cap_on, bool, 0644);
1015 MODULE_PARM_DESC(force_cap_on, "Enable power cap even it is unsafe to do so.");
1017 module_init(acpi_power_meter_init);
1018 module_exit(acpi_power_meter_exit);