/* * A hwmon driver for ACPI 4.0 power meters * Copyright (C) 2009 IBM * * Author: Darrick J. Wong <djwong@us.ibm.com> * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; either version 2 of the License, or * (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program; if not, write to the Free Software * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA */ #include <linux/module.h> #include <linux/hwmon.h> #include <linux/hwmon-sysfs.h> #include <linux/jiffies.h> #include <linux/mutex.h> #include <linux/dmi.h> #include <linux/kdev_t.h> #include <linux/sched.h> #include <linux/time.h> #include <acpi/acpi_drivers.h> #include <acpi/acpi_bus.h> #define ACPI_POWER_METER_NAME "power_meter" ACPI_MODULE_NAME(ACPI_POWER_METER_NAME); #define ACPI_POWER_METER_DEVICE_NAME "Power Meter" #define ACPI_POWER_METER_CLASS "power_meter_resource" #define NUM_SENSORS 17 #define POWER_METER_CAN_MEASURE (1 << 0) #define POWER_METER_CAN_TRIP (1 << 1) #define POWER_METER_CAN_CAP (1 << 2) #define POWER_METER_CAN_NOTIFY (1 << 3) #define POWER_METER_IS_BATTERY (1 << 8) #define UNKNOWN_HYSTERESIS 0xFFFFFFFF #define METER_NOTIFY_CONFIG 0x80 #define METER_NOTIFY_TRIP 0x81 #define METER_NOTIFY_CAP 0x82 #define METER_NOTIFY_CAPPING 0x83 #define METER_NOTIFY_INTERVAL 0x84 #define POWER_AVERAGE_NAME "power1_average" #define POWER_CAP_NAME "power1_cap" #define POWER_AVG_INTERVAL_NAME "power1_average_interval" #define POWER_ALARM_NAME "power1_alarm" static int cap_in_hardware; static int force_cap_on; static int can_cap_in_hardware(void) { return force_cap_on || cap_in_hardware; } static struct acpi_device_id power_meter_ids[] = { {"ACPI000D", 0}, {"", 0}, }; MODULE_DEVICE_TABLE(acpi, power_meter_ids); struct acpi_power_meter_capabilities { acpi_integer flags; acpi_integer units; acpi_integer type; acpi_integer accuracy; acpi_integer sampling_time; acpi_integer min_avg_interval; acpi_integer max_avg_interval; acpi_integer hysteresis; acpi_integer configurable_cap; acpi_integer min_cap; acpi_integer max_cap; }; struct acpi_power_meter_resource { struct acpi_device *acpi_dev; acpi_bus_id name; struct mutex lock; struct device *hwmon_dev; struct acpi_power_meter_capabilities caps; acpi_string model_number; acpi_string serial_number; acpi_string oem_info; acpi_integer power; acpi_integer cap; acpi_integer avg_interval; int sensors_valid; unsigned long sensors_last_updated; struct sensor_device_attribute sensors[NUM_SENSORS]; int num_sensors; int trip[2]; int num_domain_devices; struct acpi_device **domain_devices; struct kobject *holders_dir; }; struct ro_sensor_template { char *label; ssize_t (*show)(struct device *dev, struct device_attribute *devattr, char *buf); int index; }; struct rw_sensor_template { char *label; ssize_t (*show)(struct device *dev, struct device_attribute *devattr, char *buf); ssize_t (*set)(struct device *dev, struct device_attribute *devattr, const char *buf, size_t count); int index; }; /* Averaging interval */ static int update_avg_interval(struct acpi_power_meter_resource *resource) { unsigned long long data; acpi_status status; status = acpi_evaluate_integer(resource->acpi_dev->handle, "_GAI", NULL, &data); if (ACPI_FAILURE(status)) { ACPI_EXCEPTION((AE_INFO, status, "Evaluating _GAI")); return -ENODEV; } resource->avg_interval = data; return 0; } static ssize_t show_avg_interval(struct device *dev, struct device_attribute *devattr, char *buf) { struct acpi_device *acpi_dev = to_acpi_device(dev); struct acpi_power_meter_resource *resource = acpi_dev->driver_data; mutex_lock(&resource->lock); update_avg_interval(resource); mutex_unlock(&resource->lock); return sprintf(buf, "%llu\n", resource->avg_interval); } static ssize_t set_avg_interval(struct device *dev, struct device_attribute *devattr, const char *buf, size_t count) { struct acpi_device *acpi_dev = to_acpi_device(dev); struct acpi_power_meter_resource *resource = acpi_dev->driver_data; union acpi_object arg0 = { ACPI_TYPE_INTEGER }; struct acpi_object_list args = { 1, &arg0 }; int res; unsigned long temp; unsigned long long data; acpi_status status; res = strict_strtoul(buf, 10, &temp); if (res) return res; if (temp > resource->caps.max_avg_interval || temp < resource->caps.min_avg_interval) return -EINVAL; arg0.integer.value = temp; mutex_lock(&resource->lock); status = acpi_evaluate_integer(resource->acpi_dev->handle, "_PAI", &args, &data); if (!ACPI_FAILURE(status)) resource->avg_interval = temp; mutex_unlock(&resource->lock); if (ACPI_FAILURE(status)) { ACPI_EXCEPTION((AE_INFO, status, "Evaluating _PAI")); return -EINVAL; } /* _PAI returns 0 on success, nonzero otherwise */ if (data) return -EINVAL; return count; } /* Cap functions */ static int update_cap(struct acpi_power_meter_resource *resource) { unsigned long long data; acpi_status status; status = acpi_evaluate_integer(resource->acpi_dev->handle, "_GHL", NULL, &data); if (ACPI_FAILURE(status)) { ACPI_EXCEPTION((AE_INFO, status, "Evaluating _GHL")); return -ENODEV; } resource->cap = data; return 0; } static ssize_t show_cap(struct device *dev, struct device_attribute *devattr, char *buf) { struct acpi_device *acpi_dev = to_acpi_device(dev); struct acpi_power_meter_resource *resource = acpi_dev->driver_data; mutex_lock(&resource->lock); update_cap(resource); mutex_unlock(&resource->lock); return sprintf(buf, "%llu\n", resource->cap * 1000); } static ssize_t set_cap(struct device *dev, struct device_attribute *devattr, const char *buf, size_t count) { struct acpi_device *acpi_dev = to_acpi_device(dev); struct acpi_power_meter_resource *resource = acpi_dev->driver_data; union acpi_object arg0 = { ACPI_TYPE_INTEGER }; struct acpi_object_list args = { 1, &arg0 }; int res; unsigned long temp; unsigned long long data; acpi_status status; res = strict_strtoul(buf, 10, &temp); if (res) return res; temp /= 1000; if (temp > resource->caps.max_cap || temp < resource->caps.min_cap) return -EINVAL; arg0.integer.value = temp; mutex_lock(&resource->lock); status = acpi_evaluate_integer(resource->acpi_dev->handle, "_SHL", &args, &data); if (!ACPI_FAILURE(status)) resource->cap = temp; mutex_unlock(&resource->lock); if (ACPI_FAILURE(status)) { ACPI_EXCEPTION((AE_INFO, status, "Evaluating _SHL")); return -EINVAL; } /* _SHL returns 0 on success, nonzero otherwise */ if (data) return -EINVAL; return count; } /* Power meter trip points */ static int set_acpi_trip(struct acpi_power_meter_resource *resource) { union acpi_object arg_objs[] = { {ACPI_TYPE_INTEGER}, {ACPI_TYPE_INTEGER} }; struct acpi_object_list args = { 2, arg_objs }; unsigned long long data; acpi_status status; /* Both trip levels must be set */ if (resource->trip[0] < 0 || resource->trip[1] < 0) return 0; /* This driver stores min, max; ACPI wants max, min. */ arg_objs[0].integer.value = resource->trip[1]; arg_objs[1].integer.value = resource->trip[0]; status = acpi_evaluate_integer(resource->acpi_dev->handle, "_PTP", &args, &data); if (ACPI_FAILURE(status)) { ACPI_EXCEPTION((AE_INFO, status, "Evaluating _PTP")); return -EINVAL; } return data; } static ssize_t set_trip(struct device *dev, struct device_attribute *devattr, const char *buf, size_t count) { struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr); struct acpi_device *acpi_dev = to_acpi_device(dev); struct acpi_power_meter_resource *resource = acpi_dev->driver_data; int res; unsigned long temp; res = strict_strtoul(buf, 10, &temp); if (res) return res; temp /= 1000; if (temp < 0) return -EINVAL; mutex_lock(&resource->lock); resource->trip[attr->index - 7] = temp; res = set_acpi_trip(resource); mutex_unlock(&resource->lock); if (res) return res; return count; } /* Power meter */ static int update_meter(struct acpi_power_meter_resource *resource) { unsigned long long data; acpi_status status; unsigned long local_jiffies = jiffies; if (time_before(local_jiffies, resource->sensors_last_updated + msecs_to_jiffies(resource->caps.sampling_time)) && resource->sensors_valid) return 0; status = acpi_evaluate_integer(resource->acpi_dev->handle, "_PMM", NULL, &data); if (ACPI_FAILURE(status)) { ACPI_EXCEPTION((AE_INFO, status, "Evaluating _PMM")); return -ENODEV; } resource->power = data; resource->sensors_valid = 1; resource->sensors_last_updated = jiffies; return 0; } static ssize_t show_power(struct device *dev, struct device_attribute *devattr, char *buf) { struct acpi_device *acpi_dev = to_acpi_device(dev); struct acpi_power_meter_resource *resource = acpi_dev->driver_data; mutex_lock(&resource->lock); update_meter(resource); mutex_unlock(&resource->lock); return sprintf(buf, "%llu\n", resource->power * 1000); } /* Miscellaneous */ static ssize_t show_str(struct device *dev, struct device_attribute *devattr, char *buf) { struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr); struct acpi_device *acpi_dev = to_acpi_device(dev); struct acpi_power_meter_resource *resource = acpi_dev->driver_data; acpi_string val; switch (attr->index) { case 0: val = resource->model_number; break; case 1: val = resource->serial_number; break; case 2: val = resource->oem_info; break; default: BUG(); } return sprintf(buf, "%s\n", val); } static ssize_t show_val(struct device *dev, struct device_attribute *devattr, char *buf) { struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr); struct acpi_device *acpi_dev = to_acpi_device(dev); struct acpi_power_meter_resource *resource = acpi_dev->driver_data; acpi_integer val = 0; switch (attr->index) { case 0: val = resource->caps.min_avg_interval; break; case 1: val = resource->caps.max_avg_interval; break; case 2: val = resource->caps.min_cap * 1000; break; case 3: val = resource->caps.max_cap * 1000; break; case 4: if (resource->caps.hysteresis == UNKNOWN_HYSTERESIS) return sprintf(buf, "unknown\n"); val = resource->caps.hysteresis * 1000; break; case 5: if (resource->caps.flags & POWER_METER_IS_BATTERY) val = 1; else val = 0; break; case 6: if (resource->power > resource->cap) val = 1; else val = 0; break; case 7: case 8: if (resource->trip[attr->index - 7] < 0) return sprintf(buf, "unknown\n"); val = resource->trip[attr->index - 7] * 1000; break; default: BUG(); } return sprintf(buf, "%llu\n", val); } static ssize_t show_accuracy(struct device *dev, struct device_attribute *devattr, char *buf) { struct acpi_device *acpi_dev = to_acpi_device(dev); struct acpi_power_meter_resource *resource = acpi_dev->driver_data; unsigned int acc = resource->caps.accuracy; return sprintf(buf, "%u.%u%%\n", acc / 1000, acc % 1000); } static ssize_t show_name(struct device *dev, struct device_attribute *devattr, char *buf) { return sprintf(buf, "%s\n", ACPI_POWER_METER_NAME); } /* Sensor descriptions. If you add a sensor, update NUM_SENSORS above! */ static struct ro_sensor_template meter_ro_attrs[] = { {POWER_AVERAGE_NAME, show_power, 0}, {"power1_accuracy", show_accuracy, 0}, {"power1_average_interval_min", show_val, 0}, {"power1_average_interval_max", show_val, 1}, {"power1_is_battery", show_val, 5}, {NULL, NULL, 0}, }; static struct rw_sensor_template meter_rw_attrs[] = { {POWER_AVG_INTERVAL_NAME, show_avg_interval, set_avg_interval, 0}, {NULL, NULL, NULL, 0}, }; static struct ro_sensor_template misc_cap_attrs[] = { {"power1_cap_min", show_val, 2}, {"power1_cap_max", show_val, 3}, {"power1_cap_hyst", show_val, 4}, {POWER_ALARM_NAME, show_val, 6}, {NULL, NULL, 0}, }; static struct ro_sensor_template ro_cap_attrs[] = { {POWER_CAP_NAME, show_cap, 0}, {NULL, NULL, 0}, }; static struct rw_sensor_template rw_cap_attrs[] = { {POWER_CAP_NAME, show_cap, set_cap, 0}, {NULL, NULL, NULL, 0}, }; static struct rw_sensor_template trip_attrs[] = { {"power1_average_min", show_val, set_trip, 7}, {"power1_average_max", show_val, set_trip, 8}, {NULL, NULL, NULL, 0}, }; static struct ro_sensor_template misc_attrs[] = { {"name", show_name, 0}, {"power1_model_number", show_str, 0}, {"power1_oem_info", show_str, 2}, {"power1_serial_number", show_str, 1}, {NULL, NULL, 0}, }; /* Read power domain data */ static void remove_domain_devices(struct acpi_power_meter_resource *resource) { int i; if (!resource->num_domain_devices) return; for (i = 0; i < resource->num_domain_devices; i++) { struct acpi_device *obj = resource->domain_devices[i]; if (!obj) continue; sysfs_remove_link(resource->holders_dir, kobject_name(&obj->dev.kobj)); put_device(&obj->dev); } kfree(resource->domain_devices); kobject_put(resource->holders_dir); } static int read_domain_devices(struct acpi_power_meter_resource *resource) { int res = 0; int i; struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL }; union acpi_object *pss; acpi_status status; status = acpi_evaluate_object(resource->acpi_dev->handle, "_PMD", NULL, &buffer); if (ACPI_FAILURE(status)) { ACPI_EXCEPTION((AE_INFO, status, "Evaluating _PMD")); return -ENODEV; } pss = buffer.pointer; if (!pss || pss->type != ACPI_TYPE_PACKAGE) { dev_err(&resource->acpi_dev->dev, ACPI_POWER_METER_NAME "Invalid _PMD data\n"); res = -EFAULT; goto end; } if (!pss->package.count) goto end; resource->domain_devices = kzalloc(sizeof(struct acpi_device *) * pss->package.count, GFP_KERNEL); if (!resource->domain_devices) { res = -ENOMEM; goto end; } resource->holders_dir = kobject_create_and_add("measures", &resource->acpi_dev->dev.kobj); if (!resource->holders_dir) { res = -ENOMEM; goto exit_free; } resource->num_domain_devices = pss->package.count; for (i = 0; i < pss->package.count; i++) { struct acpi_device *obj; union acpi_object *element = &(pss->package.elements[i]); /* Refuse non-references */ if (element->type != ACPI_TYPE_LOCAL_REFERENCE) continue; /* Create a symlink to domain objects */ resource->domain_devices[i] = NULL; status = acpi_bus_get_device(element->reference.handle, &resource->domain_devices[i]); if (ACPI_FAILURE(status)) continue; obj = resource->domain_devices[i]; get_device(&obj->dev); res = sysfs_create_link(resource->holders_dir, &obj->dev.kobj, kobject_name(&obj->dev.kobj)); if (res) { put_device(&obj->dev); resource->domain_devices[i] = NULL; } } res = 0; goto end; exit_free: kfree(resource->domain_devices); end: kfree(buffer.pointer); return res; } /* Registration and deregistration */ static int register_ro_attrs(struct acpi_power_meter_resource *resource, struct ro_sensor_template *ro) { struct device *dev = &resource->acpi_dev->dev; struct sensor_device_attribute *sensors = &resource->sensors[resource->num_sensors]; int res = 0; while (ro->label) { sensors->dev_attr.attr.name = ro->label; sensors->dev_attr.attr.mode = S_IRUGO; sensors->dev_attr.show = ro->show; sensors->index = ro->index; res = device_create_file(dev, &sensors->dev_attr); if (res) { sensors->dev_attr.attr.name = NULL; goto error; } sensors++; resource->num_sensors++; ro++; } error: return res; } static int register_rw_attrs(struct acpi_power_meter_resource *resource, struct rw_sensor_template *rw) { struct device *dev = &resource->acpi_dev->dev; struct sensor_device_attribute *sensors = &resource->sensors[resource->num_sensors]; int res = 0; while (rw->label) { sensors->dev_attr.attr.name = rw->label; sensors->dev_attr.attr.mode = S_IRUGO | S_IWUSR; sensors->dev_attr.show = rw->show; sensors->dev_attr.store = rw->set; sensors->index = rw->index; res = device_create_file(dev, &sensors->dev_attr); if (res) { sensors->dev_attr.attr.name = NULL; goto error; } sensors++; resource->num_sensors++; rw++; } error: return res; } static void remove_attrs(struct acpi_power_meter_resource *resource) { int i; for (i = 0; i < resource->num_sensors; i++) { if (!resource->sensors[i].dev_attr.attr.name) continue; device_remove_file(&resource->acpi_dev->dev, &resource->sensors[i].dev_attr); } remove_domain_devices(resource); resource->num_sensors = 0; } static int setup_attrs(struct acpi_power_meter_resource *resource) { int res = 0; res = read_domain_devices(resource); if (res) return res; if (resource->caps.flags & POWER_METER_CAN_MEASURE) { res = register_ro_attrs(resource, meter_ro_attrs); if (res) goto error; res = register_rw_attrs(resource, meter_rw_attrs); if (res) goto error; } if (resource->caps.flags & POWER_METER_CAN_CAP) { if (!can_cap_in_hardware()) { dev_err(&resource->acpi_dev->dev, "Ignoring unsafe software power cap!\n"); goto skip_unsafe_cap; } if (resource->caps.configurable_cap) { res = register_rw_attrs(resource, rw_cap_attrs); if (res) goto error; } else { res = register_ro_attrs(resource, ro_cap_attrs); if (res) goto error; } res = register_ro_attrs(resource, misc_cap_attrs); if (res) goto error; } skip_unsafe_cap: if (resource->caps.flags & POWER_METER_CAN_TRIP) { res = register_rw_attrs(resource, trip_attrs); if (res) goto error; } res = register_ro_attrs(resource, misc_attrs); if (res) goto error; return res; error: remove_domain_devices(resource); remove_attrs(resource); return res; } static void free_capabilities(struct acpi_power_meter_resource *resource) { acpi_string *str; int i; str = &resource->model_number; for (i = 0; i < 3; i++, str++) kfree(*str); } static int read_capabilities(struct acpi_power_meter_resource *resource) { int res = 0; int i; struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL }; struct acpi_buffer state = { 0, NULL }; struct acpi_buffer format = { sizeof("NNNNNNNNNNN"), "NNNNNNNNNNN" }; union acpi_object *pss; acpi_string *str; acpi_status status; status = acpi_evaluate_object(resource->acpi_dev->handle, "_PMC", NULL, &buffer); if (ACPI_FAILURE(status)) { ACPI_EXCEPTION((AE_INFO, status, "Evaluating _PMC")); return -ENODEV; } pss = buffer.pointer; if (!pss || pss->type != ACPI_TYPE_PACKAGE || pss->package.count != 14) { dev_err(&resource->acpi_dev->dev, ACPI_POWER_METER_NAME "Invalid _PMC data\n"); res = -EFAULT; goto end; } /* Grab all the integer data at once */ state.length = sizeof(struct acpi_power_meter_capabilities); state.pointer = &resource->caps; status = acpi_extract_package(pss, &format, &state); if (ACPI_FAILURE(status)) { ACPI_EXCEPTION((AE_INFO, status, "Invalid data")); res = -EFAULT; goto end; } if (resource->caps.units) { dev_err(&resource->acpi_dev->dev, ACPI_POWER_METER_NAME "Unknown units %llu.\n", resource->caps.units); res = -EINVAL; goto end; } /* Grab the string data */ str = &resource->model_number; for (i = 11; i < 14; i++) { union acpi_object *element = &(pss->package.elements[i]); if (element->type != ACPI_TYPE_STRING) { res = -EINVAL; goto error; } *str = kzalloc(sizeof(u8) * (element->string.length + 1), GFP_KERNEL); if (!*str) { res = -ENOMEM; goto error; } strncpy(*str, element->string.pointer, element->string.length); str++; } dev_info(&resource->acpi_dev->dev, "Found ACPI power meter.\n"); goto end; error: str = &resource->model_number; for (i = 0; i < 3; i++, str++) kfree(*str); end: kfree(buffer.pointer); return res; } /* Handle ACPI event notifications */ static void acpi_power_meter_notify(struct acpi_device *device, u32 event) { struct acpi_power_meter_resource *resource; int res; if (!device || !acpi_driver_data(device)) return; resource = acpi_driver_data(device); mutex_lock(&resource->lock); switch (event) { case METER_NOTIFY_CONFIG: free_capabilities(resource); res = read_capabilities(resource); if (res) break; remove_attrs(resource); setup_attrs(resource); break; case METER_NOTIFY_TRIP: sysfs_notify(&device->dev.kobj, NULL, POWER_AVERAGE_NAME); update_meter(resource); break; case METER_NOTIFY_CAP: sysfs_notify(&device->dev.kobj, NULL, POWER_CAP_NAME); update_cap(resource); break; case METER_NOTIFY_INTERVAL: sysfs_notify(&device->dev.kobj, NULL, POWER_AVG_INTERVAL_NAME); update_avg_interval(resource); break; case METER_NOTIFY_CAPPING: sysfs_notify(&device->dev.kobj, NULL, POWER_ALARM_NAME); dev_info(&device->dev, "Capping in progress.\n"); break; default: BUG(); } mutex_unlock(&resource->lock); acpi_bus_generate_netlink_event(ACPI_POWER_METER_CLASS, dev_name(&device->dev), event, 0); } static int acpi_power_meter_add(struct acpi_device *device) { int res; struct acpi_power_meter_resource *resource; if (!device) return -EINVAL; resource = kzalloc(sizeof(struct acpi_power_meter_resource), GFP_KERNEL); if (!resource) return -ENOMEM; resource->sensors_valid = 0; resource->acpi_dev = device; mutex_init(&resource->lock); strcpy(acpi_device_name(device), ACPI_POWER_METER_DEVICE_NAME); strcpy(acpi_device_class(device), ACPI_POWER_METER_CLASS); device->driver_data = resource; free_capabilities(resource); res = read_capabilities(resource); if (res) goto exit_free; resource->trip[0] = resource->trip[1] = -1; res = setup_attrs(resource); if (res) goto exit_free; resource->hwmon_dev = hwmon_device_register(&device->dev); if (IS_ERR(resource->hwmon_dev)) { res = PTR_ERR(resource->hwmon_dev); goto exit_remove; } res = 0; goto exit; exit_remove: remove_attrs(resource); exit_free: kfree(resource); exit: return res; } static int acpi_power_meter_remove(struct acpi_device *device, int type) { struct acpi_power_meter_resource *resource; if (!device || !acpi_driver_data(device)) return -EINVAL; resource = acpi_driver_data(device); hwmon_device_unregister(resource->hwmon_dev); free_capabilities(resource); remove_attrs(resource); kfree(resource); return 0; } static int acpi_power_meter_resume(struct acpi_device *device) { struct acpi_power_meter_resource *resource; if (!device || !acpi_driver_data(device)) return -EINVAL; resource = acpi_driver_data(device); free_capabilities(resource); read_capabilities(resource); return 0; } static struct acpi_driver acpi_power_meter_driver = { .name = "power_meter", .class = ACPI_POWER_METER_CLASS, .ids = power_meter_ids, .ops = { .add = acpi_power_meter_add, .remove = acpi_power_meter_remove, .resume = acpi_power_meter_resume, .notify = acpi_power_meter_notify, }, }; /* Module init/exit routines */ static int __init enable_cap_knobs(const struct dmi_system_id *d) { cap_in_hardware = 1; return 0; } static struct dmi_system_id __initdata pm_dmi_table[] = { { enable_cap_knobs, "IBM Active Energy Manager", { DMI_MATCH(DMI_SYS_VENDOR, "IBM") }, }, {} }; static int __init acpi_power_meter_init(void) { int result; if (acpi_disabled) return -ENODEV; dmi_check_system(pm_dmi_table); result = acpi_bus_register_driver(&acpi_power_meter_driver); if (result < 0) return -ENODEV; return 0; } static void __exit acpi_power_meter_exit(void) { acpi_bus_unregister_driver(&acpi_power_meter_driver); } MODULE_AUTHOR("Darrick J. Wong <djwong@us.ibm.com>"); MODULE_DESCRIPTION("ACPI 4.0 power meter driver"); MODULE_LICENSE("GPL"); module_param(force_cap_on, bool, 0644); MODULE_PARM_DESC(force_cap_on, "Enable power cap even it is unsafe to do so."); module_init(acpi_power_meter_init); module_exit(acpi_power_meter_exit);