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* A hwmon driver for ACPI 4.0 power meters
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* Copyright (C) 2009 IBM
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* Author: Darrick J. Wong <djwong@us.ibm.com>
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
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#include <linux/module.h>
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#include <linux/hwmon.h>
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#include <linux/hwmon-sysfs.h>
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#include <linux/jiffies.h>
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#include <linux/mutex.h>
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#include <linux/dmi.h>
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#include <linux/slab.h>
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#include <linux/kdev_t.h>
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#include <linux/sched.h>
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#include <linux/time.h>
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#include <acpi/acpi_drivers.h>
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#include <acpi/acpi_bus.h>
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#define ACPI_POWER_METER_NAME "power_meter"
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ACPI_MODULE_NAME(ACPI_POWER_METER_NAME);
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#define ACPI_POWER_METER_DEVICE_NAME "Power Meter"
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#define ACPI_POWER_METER_CLASS "pwr_meter_resource"
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#define NUM_SENSORS 17
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#define POWER_METER_CAN_MEASURE (1 << 0)
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#define POWER_METER_CAN_TRIP (1 << 1)
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#define POWER_METER_CAN_CAP (1 << 2)
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#define POWER_METER_CAN_NOTIFY (1 << 3)
46
#define POWER_METER_IS_BATTERY (1 << 8)
47
#define UNKNOWN_HYSTERESIS 0xFFFFFFFF
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#define METER_NOTIFY_CONFIG 0x80
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#define METER_NOTIFY_TRIP 0x81
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#define METER_NOTIFY_CAP 0x82
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#define METER_NOTIFY_CAPPING 0x83
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#define METER_NOTIFY_INTERVAL 0x84
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#define POWER_AVERAGE_NAME "power1_average"
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#define POWER_CAP_NAME "power1_cap"
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#define POWER_AVG_INTERVAL_NAME "power1_average_interval"
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#define POWER_ALARM_NAME "power1_alarm"
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static int cap_in_hardware;
61
static int force_cap_on;
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static int can_cap_in_hardware(void)
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return force_cap_on || cap_in_hardware;
68
static const struct acpi_device_id power_meter_ids[] = {
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MODULE_DEVICE_TABLE(acpi, power_meter_ids);
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struct acpi_power_meter_capabilities {
88
struct acpi_power_meter_resource {
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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;
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struct kobject *holders_dir;
110
struct ro_sensor_template {
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ssize_t (*show)(struct device *dev,
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struct device_attribute *devattr,
118
struct rw_sensor_template {
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ssize_t (*show)(struct device *dev,
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struct device_attribute *devattr,
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ssize_t (*set)(struct device *dev,
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struct device_attribute *devattr,
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const char *buf, size_t count);
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/* Averaging interval */
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static int update_avg_interval(struct acpi_power_meter_resource *resource)
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unsigned long long data;
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status = acpi_evaluate_integer(resource->acpi_dev->handle, "_GAI",
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if (ACPI_FAILURE(status)) {
138
ACPI_EXCEPTION((AE_INFO, status, "Evaluating _GAI"));
142
resource->avg_interval = data;
146
static ssize_t show_avg_interval(struct device *dev,
147
struct device_attribute *devattr,
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struct acpi_device *acpi_dev = to_acpi_device(dev);
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struct acpi_power_meter_resource *resource = acpi_dev->driver_data;
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mutex_lock(&resource->lock);
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update_avg_interval(resource);
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mutex_unlock(&resource->lock);
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return sprintf(buf, "%llu\n", resource->avg_interval);
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static ssize_t set_avg_interval(struct device *dev,
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struct device_attribute *devattr,
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const char *buf, size_t count)
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struct acpi_device *acpi_dev = to_acpi_device(dev);
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struct acpi_power_meter_resource *resource = acpi_dev->driver_data;
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union acpi_object arg0 = { ACPI_TYPE_INTEGER };
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struct acpi_object_list args = { 1, &arg0 };
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unsigned long long data;
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res = strict_strtoul(buf, 10, &temp);
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if (temp > resource->caps.max_avg_interval ||
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temp < resource->caps.min_avg_interval)
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arg0.integer.value = temp;
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mutex_lock(&resource->lock);
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status = acpi_evaluate_integer(resource->acpi_dev->handle, "_PAI",
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if (!ACPI_FAILURE(status))
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resource->avg_interval = temp;
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mutex_unlock(&resource->lock);
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if (ACPI_FAILURE(status)) {
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ACPI_EXCEPTION((AE_INFO, status, "Evaluating _PAI"));
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/* _PAI returns 0 on success, nonzero otherwise */
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static int update_cap(struct acpi_power_meter_resource *resource)
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unsigned long long data;
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status = acpi_evaluate_integer(resource->acpi_dev->handle, "_GHL",
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if (ACPI_FAILURE(status)) {
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ACPI_EXCEPTION((AE_INFO, status, "Evaluating _GHL"));
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resource->cap = data;
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static ssize_t show_cap(struct device *dev,
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struct device_attribute *devattr,
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struct acpi_device *acpi_dev = to_acpi_device(dev);
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struct acpi_power_meter_resource *resource = acpi_dev->driver_data;
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mutex_lock(&resource->lock);
226
update_cap(resource);
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mutex_unlock(&resource->lock);
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return sprintf(buf, "%llu\n", resource->cap * 1000);
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static ssize_t set_cap(struct device *dev, struct device_attribute *devattr,
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const char *buf, size_t count)
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struct acpi_device *acpi_dev = to_acpi_device(dev);
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struct acpi_power_meter_resource *resource = acpi_dev->driver_data;
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union acpi_object arg0 = { ACPI_TYPE_INTEGER };
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struct acpi_object_list args = { 1, &arg0 };
241
unsigned long long data;
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res = strict_strtoul(buf, 10, &temp);
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if (temp > resource->caps.max_cap || temp < resource->caps.min_cap)
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arg0.integer.value = temp;
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mutex_lock(&resource->lock);
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status = acpi_evaluate_integer(resource->acpi_dev->handle, "_SHL",
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if (!ACPI_FAILURE(status))
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resource->cap = temp;
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mutex_unlock(&resource->lock);
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if (ACPI_FAILURE(status)) {
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ACPI_EXCEPTION((AE_INFO, status, "Evaluating _SHL"));
265
/* _SHL returns 0 on success, nonzero otherwise */
272
/* Power meter trip points */
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static int set_acpi_trip(struct acpi_power_meter_resource *resource)
275
union acpi_object arg_objs[] = {
279
struct acpi_object_list args = { 2, arg_objs };
280
unsigned long long data;
283
/* Both trip levels must be set */
284
if (resource->trip[0] < 0 || resource->trip[1] < 0)
287
/* This driver stores min, max; ACPI wants max, min. */
288
arg_objs[0].integer.value = resource->trip[1];
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arg_objs[1].integer.value = resource->trip[0];
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status = acpi_evaluate_integer(resource->acpi_dev->handle, "_PTP",
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if (ACPI_FAILURE(status)) {
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ACPI_EXCEPTION((AE_INFO, status, "Evaluating _PTP"));
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/* _PTP returns 0 on success, nonzero otherwise */
305
static ssize_t set_trip(struct device *dev, struct device_attribute *devattr,
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const char *buf, size_t count)
308
struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
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struct acpi_device *acpi_dev = to_acpi_device(dev);
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struct acpi_power_meter_resource *resource = acpi_dev->driver_data;
314
res = strict_strtoul(buf, 10, &temp);
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mutex_lock(&resource->lock);
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resource->trip[attr->index - 7] = temp;
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res = set_acpi_trip(resource);
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mutex_unlock(&resource->lock);
334
static int update_meter(struct acpi_power_meter_resource *resource)
336
unsigned long long data;
338
unsigned long local_jiffies = jiffies;
340
if (time_before(local_jiffies, resource->sensors_last_updated +
341
msecs_to_jiffies(resource->caps.sampling_time)) &&
342
resource->sensors_valid)
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status = acpi_evaluate_integer(resource->acpi_dev->handle, "_PMM",
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if (ACPI_FAILURE(status)) {
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ACPI_EXCEPTION((AE_INFO, status, "Evaluating _PMM"));
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resource->power = data;
353
resource->sensors_valid = 1;
354
resource->sensors_last_updated = jiffies;
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static ssize_t show_power(struct device *dev,
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struct device_attribute *devattr,
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struct acpi_device *acpi_dev = to_acpi_device(dev);
363
struct acpi_power_meter_resource *resource = acpi_dev->driver_data;
365
mutex_lock(&resource->lock);
366
update_meter(resource);
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mutex_unlock(&resource->lock);
369
return sprintf(buf, "%llu\n", resource->power * 1000);
373
static ssize_t show_str(struct device *dev,
374
struct device_attribute *devattr,
377
struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
378
struct acpi_device *acpi_dev = to_acpi_device(dev);
379
struct acpi_power_meter_resource *resource = acpi_dev->driver_data;
382
switch (attr->index) {
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val = resource->model_number;
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val = resource->serial_number;
390
val = resource->oem_info;
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return sprintf(buf, "%s\n", val);
399
static ssize_t show_val(struct device *dev,
400
struct device_attribute *devattr,
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struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
404
struct acpi_device *acpi_dev = to_acpi_device(dev);
405
struct acpi_power_meter_resource *resource = acpi_dev->driver_data;
408
switch (attr->index) {
410
val = resource->caps.min_avg_interval;
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val = resource->caps.max_avg_interval;
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val = resource->caps.min_cap * 1000;
419
val = resource->caps.max_cap * 1000;
422
if (resource->caps.hysteresis == UNKNOWN_HYSTERESIS)
423
return sprintf(buf, "unknown\n");
425
val = resource->caps.hysteresis * 1000;
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if (resource->caps.flags & POWER_METER_IS_BATTERY)
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if (resource->power > resource->cap)
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if (resource->trip[attr->index - 7] < 0)
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return sprintf(buf, "unknown\n");
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val = resource->trip[attr->index - 7] * 1000;
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return sprintf(buf, "%llu\n", val);
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static ssize_t show_accuracy(struct device *dev,
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struct device_attribute *devattr,
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struct acpi_device *acpi_dev = to_acpi_device(dev);
458
struct acpi_power_meter_resource *resource = acpi_dev->driver_data;
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unsigned int acc = resource->caps.accuracy;
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return sprintf(buf, "%u.%u%%\n", acc / 1000, acc % 1000);
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static ssize_t show_name(struct device *dev,
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struct device_attribute *devattr,
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return sprintf(buf, "%s\n", ACPI_POWER_METER_NAME);
471
/* Sensor descriptions. If you add a sensor, update NUM_SENSORS above! */
472
static struct ro_sensor_template meter_ro_attrs[] = {
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{POWER_AVERAGE_NAME, show_power, 0},
474
{"power1_accuracy", show_accuracy, 0},
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{"power1_average_interval_min", show_val, 0},
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{"power1_average_interval_max", show_val, 1},
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{"power1_is_battery", show_val, 5},
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static struct rw_sensor_template meter_rw_attrs[] = {
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{POWER_AVG_INTERVAL_NAME, show_avg_interval, set_avg_interval, 0},
483
{NULL, NULL, NULL, 0},
486
static struct ro_sensor_template misc_cap_attrs[] = {
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{"power1_cap_min", show_val, 2},
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{"power1_cap_max", show_val, 3},
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{"power1_cap_hyst", show_val, 4},
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{POWER_ALARM_NAME, show_val, 6},
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static struct ro_sensor_template ro_cap_attrs[] = {
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{POWER_CAP_NAME, show_cap, 0},
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static struct rw_sensor_template rw_cap_attrs[] = {
500
{POWER_CAP_NAME, show_cap, set_cap, 0},
501
{NULL, NULL, NULL, 0},
504
static struct rw_sensor_template trip_attrs[] = {
505
{"power1_average_min", show_val, set_trip, 7},
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{"power1_average_max", show_val, set_trip, 8},
507
{NULL, NULL, NULL, 0},
510
static struct ro_sensor_template misc_attrs[] = {
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{"name", show_name, 0},
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{"power1_model_number", show_str, 0},
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{"power1_oem_info", show_str, 2},
514
{"power1_serial_number", show_str, 1},
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/* Read power domain data */
519
static void remove_domain_devices(struct acpi_power_meter_resource *resource)
523
if (!resource->num_domain_devices)
526
for (i = 0; i < resource->num_domain_devices; i++) {
527
struct acpi_device *obj = resource->domain_devices[i];
531
sysfs_remove_link(resource->holders_dir,
532
kobject_name(&obj->dev.kobj));
533
put_device(&obj->dev);
536
kfree(resource->domain_devices);
537
kobject_put(resource->holders_dir);
538
resource->num_domain_devices = 0;
541
static int read_domain_devices(struct acpi_power_meter_resource *resource)
545
struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
546
union acpi_object *pss;
549
status = acpi_evaluate_object(resource->acpi_dev->handle, "_PMD", NULL,
551
if (ACPI_FAILURE(status)) {
552
ACPI_EXCEPTION((AE_INFO, status, "Evaluating _PMD"));
556
pss = buffer.pointer;
558
pss->type != ACPI_TYPE_PACKAGE) {
559
dev_err(&resource->acpi_dev->dev, ACPI_POWER_METER_NAME
560
"Invalid _PMD data\n");
565
if (!pss->package.count)
568
resource->domain_devices = kzalloc(sizeof(struct acpi_device *) *
569
pss->package.count, GFP_KERNEL);
570
if (!resource->domain_devices) {
575
resource->holders_dir = kobject_create_and_add("measures",
576
&resource->acpi_dev->dev.kobj);
577
if (!resource->holders_dir) {
582
resource->num_domain_devices = pss->package.count;
584
for (i = 0; i < pss->package.count; i++) {
585
struct acpi_device *obj;
586
union acpi_object *element = &(pss->package.elements[i]);
588
/* Refuse non-references */
589
if (element->type != ACPI_TYPE_LOCAL_REFERENCE)
592
/* Create a symlink to domain objects */
593
resource->domain_devices[i] = NULL;
594
status = acpi_bus_get_device(element->reference.handle,
595
&resource->domain_devices[i]);
596
if (ACPI_FAILURE(status))
599
obj = resource->domain_devices[i];
600
get_device(&obj->dev);
602
res = sysfs_create_link(resource->holders_dir, &obj->dev.kobj,
603
kobject_name(&obj->dev.kobj));
605
put_device(&obj->dev);
606
resource->domain_devices[i] = NULL;
614
kfree(resource->domain_devices);
616
kfree(buffer.pointer);
620
/* Registration and deregistration */
621
static int register_ro_attrs(struct acpi_power_meter_resource *resource,
622
struct ro_sensor_template *ro)
624
struct device *dev = &resource->acpi_dev->dev;
625
struct sensor_device_attribute *sensors =
626
&resource->sensors[resource->num_sensors];
630
sensors->dev_attr.attr.name = ro->label;
631
sensors->dev_attr.attr.mode = S_IRUGO;
632
sensors->dev_attr.show = ro->show;
633
sensors->index = ro->index;
635
res = device_create_file(dev, &sensors->dev_attr);
637
sensors->dev_attr.attr.name = NULL;
641
resource->num_sensors++;
649
static int register_rw_attrs(struct acpi_power_meter_resource *resource,
650
struct rw_sensor_template *rw)
652
struct device *dev = &resource->acpi_dev->dev;
653
struct sensor_device_attribute *sensors =
654
&resource->sensors[resource->num_sensors];
658
sensors->dev_attr.attr.name = rw->label;
659
sensors->dev_attr.attr.mode = S_IRUGO | S_IWUSR;
660
sensors->dev_attr.show = rw->show;
661
sensors->dev_attr.store = rw->set;
662
sensors->index = rw->index;
664
res = device_create_file(dev, &sensors->dev_attr);
666
sensors->dev_attr.attr.name = NULL;
670
resource->num_sensors++;
678
static void remove_attrs(struct acpi_power_meter_resource *resource)
682
for (i = 0; i < resource->num_sensors; i++) {
683
if (!resource->sensors[i].dev_attr.attr.name)
685
device_remove_file(&resource->acpi_dev->dev,
686
&resource->sensors[i].dev_attr);
689
remove_domain_devices(resource);
691
resource->num_sensors = 0;
694
static int setup_attrs(struct acpi_power_meter_resource *resource)
698
res = read_domain_devices(resource);
702
if (resource->caps.flags & POWER_METER_CAN_MEASURE) {
703
res = register_ro_attrs(resource, meter_ro_attrs);
706
res = register_rw_attrs(resource, meter_rw_attrs);
711
if (resource->caps.flags & POWER_METER_CAN_CAP) {
712
if (!can_cap_in_hardware()) {
713
dev_err(&resource->acpi_dev->dev,
714
"Ignoring unsafe software power cap!\n");
715
goto skip_unsafe_cap;
718
if (resource->caps.configurable_cap) {
719
res = register_rw_attrs(resource, rw_cap_attrs);
723
res = register_ro_attrs(resource, ro_cap_attrs);
727
res = register_ro_attrs(resource, misc_cap_attrs);
733
if (resource->caps.flags & POWER_METER_CAN_TRIP) {
734
res = register_rw_attrs(resource, trip_attrs);
739
res = register_ro_attrs(resource, misc_attrs);
745
remove_attrs(resource);
749
static void free_capabilities(struct acpi_power_meter_resource *resource)
754
str = &resource->model_number;
755
for (i = 0; i < 3; i++, str++)
759
static int read_capabilities(struct acpi_power_meter_resource *resource)
763
struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
764
struct acpi_buffer state = { 0, NULL };
765
struct acpi_buffer format = { sizeof("NNNNNNNNNNN"), "NNNNNNNNNNN" };
766
union acpi_object *pss;
770
status = acpi_evaluate_object(resource->acpi_dev->handle, "_PMC", NULL,
772
if (ACPI_FAILURE(status)) {
773
ACPI_EXCEPTION((AE_INFO, status, "Evaluating _PMC"));
777
pss = buffer.pointer;
779
pss->type != ACPI_TYPE_PACKAGE ||
780
pss->package.count != 14) {
781
dev_err(&resource->acpi_dev->dev, ACPI_POWER_METER_NAME
782
"Invalid _PMC data\n");
787
/* Grab all the integer data at once */
788
state.length = sizeof(struct acpi_power_meter_capabilities);
789
state.pointer = &resource->caps;
791
status = acpi_extract_package(pss, &format, &state);
792
if (ACPI_FAILURE(status)) {
793
ACPI_EXCEPTION((AE_INFO, status, "Invalid data"));
798
if (resource->caps.units) {
799
dev_err(&resource->acpi_dev->dev, ACPI_POWER_METER_NAME
800
"Unknown units %llu.\n",
801
resource->caps.units);
806
/* Grab the string data */
807
str = &resource->model_number;
809
for (i = 11; i < 14; i++) {
810
union acpi_object *element = &(pss->package.elements[i]);
812
if (element->type != ACPI_TYPE_STRING) {
817
*str = kzalloc(sizeof(u8) * (element->string.length + 1),
824
strncpy(*str, element->string.pointer, element->string.length);
828
dev_info(&resource->acpi_dev->dev, "Found ACPI power meter.\n");
831
str = &resource->model_number;
832
for (i = 0; i < 3; i++, str++)
835
kfree(buffer.pointer);
839
/* Handle ACPI event notifications */
840
static void acpi_power_meter_notify(struct acpi_device *device, u32 event)
842
struct acpi_power_meter_resource *resource;
845
if (!device || !acpi_driver_data(device))
848
resource = acpi_driver_data(device);
850
mutex_lock(&resource->lock);
852
case METER_NOTIFY_CONFIG:
853
free_capabilities(resource);
854
res = read_capabilities(resource);
858
remove_attrs(resource);
859
setup_attrs(resource);
861
case METER_NOTIFY_TRIP:
862
sysfs_notify(&device->dev.kobj, NULL, POWER_AVERAGE_NAME);
863
update_meter(resource);
865
case METER_NOTIFY_CAP:
866
sysfs_notify(&device->dev.kobj, NULL, POWER_CAP_NAME);
867
update_cap(resource);
869
case METER_NOTIFY_INTERVAL:
870
sysfs_notify(&device->dev.kobj, NULL, POWER_AVG_INTERVAL_NAME);
871
update_avg_interval(resource);
873
case METER_NOTIFY_CAPPING:
874
sysfs_notify(&device->dev.kobj, NULL, POWER_ALARM_NAME);
875
dev_info(&device->dev, "Capping in progress.\n");
880
mutex_unlock(&resource->lock);
882
acpi_bus_generate_netlink_event(ACPI_POWER_METER_CLASS,
883
dev_name(&device->dev), event, 0);
886
static int acpi_power_meter_add(struct acpi_device *device)
889
struct acpi_power_meter_resource *resource;
894
resource = kzalloc(sizeof(struct acpi_power_meter_resource),
899
resource->sensors_valid = 0;
900
resource->acpi_dev = device;
901
mutex_init(&resource->lock);
902
strcpy(acpi_device_name(device), ACPI_POWER_METER_DEVICE_NAME);
903
strcpy(acpi_device_class(device), ACPI_POWER_METER_CLASS);
904
device->driver_data = resource;
906
free_capabilities(resource);
907
res = read_capabilities(resource);
911
resource->trip[0] = resource->trip[1] = -1;
913
res = setup_attrs(resource);
917
resource->hwmon_dev = hwmon_device_register(&device->dev);
918
if (IS_ERR(resource->hwmon_dev)) {
919
res = PTR_ERR(resource->hwmon_dev);
927
remove_attrs(resource);
934
static int acpi_power_meter_remove(struct acpi_device *device, int type)
936
struct acpi_power_meter_resource *resource;
938
if (!device || !acpi_driver_data(device))
941
resource = acpi_driver_data(device);
942
hwmon_device_unregister(resource->hwmon_dev);
944
free_capabilities(resource);
945
remove_attrs(resource);
951
static int acpi_power_meter_resume(struct acpi_device *device)
953
struct acpi_power_meter_resource *resource;
955
if (!device || !acpi_driver_data(device))
958
resource = acpi_driver_data(device);
959
free_capabilities(resource);
960
read_capabilities(resource);
965
static struct acpi_driver acpi_power_meter_driver = {
966
.name = "power_meter",
967
.class = ACPI_POWER_METER_CLASS,
968
.ids = power_meter_ids,
970
.add = acpi_power_meter_add,
971
.remove = acpi_power_meter_remove,
972
.resume = acpi_power_meter_resume,
973
.notify = acpi_power_meter_notify,
977
/* Module init/exit routines */
978
static int __init enable_cap_knobs(const struct dmi_system_id *d)
984
static struct dmi_system_id __initdata pm_dmi_table[] = {
986
enable_cap_knobs, "IBM Active Energy Manager",
988
DMI_MATCH(DMI_SYS_VENDOR, "IBM")
994
static int __init acpi_power_meter_init(void)
1001
dmi_check_system(pm_dmi_table);
1003
result = acpi_bus_register_driver(&acpi_power_meter_driver);
1010
static void __exit acpi_power_meter_exit(void)
1012
acpi_bus_unregister_driver(&acpi_power_meter_driver);
1015
MODULE_AUTHOR("Darrick J. Wong <djwong@us.ibm.com>");
1016
MODULE_DESCRIPTION("ACPI 4.0 power meter driver");
1017
MODULE_LICENSE("GPL");
1019
module_param(force_cap_on, bool, 0644);
1020
MODULE_PARM_DESC(force_cap_on, "Enable power cap even it is unsafe to do so.");
1022
module_init(acpi_power_meter_init);
1023
module_exit(acpi_power_meter_exit);