linux/drivers/acpi/power_meter.c
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   1/*
   2 * A hwmon driver for ACPI 4.0 power meters
   3 * Copyright (C) 2009 IBM
   4 *
   5 * Author: Darrick J. Wong <djwong@us.ibm.com>
   6 *
   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.
  11 *
  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.
  16 *
  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
  20 */
  21
  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>
  33
  34#define ACPI_POWER_METER_NAME           "power_meter"
  35ACPI_MODULE_NAME(ACPI_POWER_METER_NAME);
  36#define ACPI_POWER_METER_DEVICE_NAME    "Power Meter"
  37#define ACPI_POWER_METER_CLASS          "power_meter_resource"
  38
  39#define NUM_SENSORS                     17
  40
  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
  47
  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
  53
  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"
  58
  59static int cap_in_hardware;
  60static int force_cap_on;
  61
  62static int can_cap_in_hardware(void)
  63{
  64        return force_cap_on || cap_in_hardware;
  65}
  66
  67static struct acpi_device_id power_meter_ids[] = {
  68        {"ACPI000D", 0},
  69        {"", 0},
  70};
  71MODULE_DEVICE_TABLE(acpi, power_meter_ids);
  72
  73struct acpi_power_meter_capabilities {
  74        acpi_integer            flags;
  75        acpi_integer            units;
  76        acpi_integer            type;
  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;
  83        acpi_integer            min_cap;
  84        acpi_integer            max_cap;
  85};
  86
  87struct acpi_power_meter_resource {
  88        struct acpi_device      *acpi_dev;
  89        acpi_bus_id             name;
  90        struct mutex            lock;
  91        struct device           *hwmon_dev;
  92        struct acpi_power_meter_capabilities    caps;
  93        acpi_string             model_number;
  94        acpi_string             serial_number;
  95        acpi_string             oem_info;
  96        acpi_integer            power;
  97        acpi_integer            cap;
  98        acpi_integer            avg_interval;
  99        int                     sensors_valid;
 100        unsigned long           sensors_last_updated;
 101        struct sensor_device_attribute  sensors[NUM_SENSORS];
 102        int                     num_sensors;
 103        int                     trip[2];
 104        int                     num_domain_devices;
 105        struct acpi_device      **domain_devices;
 106        struct kobject          *holders_dir;
 107};
 108
 109struct ro_sensor_template {
 110        char *label;
 111        ssize_t (*show)(struct device *dev,
 112                        struct device_attribute *devattr,
 113                        char *buf);
 114        int index;
 115};
 116
 117struct rw_sensor_template {
 118        char *label;
 119        ssize_t (*show)(struct device *dev,
 120                        struct device_attribute *devattr,
 121                        char *buf);
 122        ssize_t (*set)(struct device *dev,
 123                       struct device_attribute *devattr,
 124                       const char *buf, size_t count);
 125        int index;
 126};
 127
 128/* Averaging interval */
 129static int update_avg_interval(struct acpi_power_meter_resource *resource)
 130{
 131        unsigned long long data;
 132        acpi_status status;
 133
 134        status = acpi_evaluate_integer(resource->acpi_dev->handle, "_GAI",
 135                                       NULL, &data);
 136        if (ACPI_FAILURE(status)) {
 137                ACPI_EXCEPTION((AE_INFO, status, "Evaluating _GAI"));
 138                return -ENODEV;
 139        }
 140
 141        resource->avg_interval = data;
 142        return 0;
 143}
 144
 145static ssize_t show_avg_interval(struct device *dev,
 146                                 struct device_attribute *devattr,
 147                                 char *buf)
 148{
 149        struct acpi_device *acpi_dev = to_acpi_device(dev);
 150        struct acpi_power_meter_resource *resource = acpi_dev->driver_data;
 151
 152        mutex_lock(&resource->lock);
 153        update_avg_interval(resource);
 154        mutex_unlock(&resource->lock);
 155
 156        return sprintf(buf, "%llu\n", resource->avg_interval);
 157}
 158
 159static ssize_t set_avg_interval(struct device *dev,
 160                                struct device_attribute *devattr,
 161                                const char *buf, size_t count)
 162{
 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 };
 167        int res;
 168        unsigned long temp;
 169        unsigned long long data;
 170        acpi_status status;
 171
 172        res = strict_strtoul(buf, 10, &temp);
 173        if (res)
 174                return res;
 175
 176        if (temp > resource->caps.max_avg_interval ||
 177            temp < resource->caps.min_avg_interval)
 178                return -EINVAL;
 179        arg0.integer.value = temp;
 180
 181        mutex_lock(&resource->lock);
 182        status = acpi_evaluate_integer(resource->acpi_dev->handle, "_PAI",
 183                                       &args, &data);
 184        if (!ACPI_FAILURE(status))
 185                resource->avg_interval = temp;
 186        mutex_unlock(&resource->lock);
 187
 188        if (ACPI_FAILURE(status)) {
 189                ACPI_EXCEPTION((AE_INFO, status, "Evaluating _PAI"));
 190                return -EINVAL;
 191        }
 192
 193        /* _PAI returns 0 on success, nonzero otherwise */
 194        if (data)
 195                return -EINVAL;
 196
 197        return count;
 198}
 199
 200/* Cap functions */
 201static int update_cap(struct acpi_power_meter_resource *resource)
 202{
 203        unsigned long long data;
 204        acpi_status status;
 205
 206        status = acpi_evaluate_integer(resource->acpi_dev->handle, "_GHL",
 207                                       NULL, &data);
 208        if (ACPI_FAILURE(status)) {
 209                ACPI_EXCEPTION((AE_INFO, status, "Evaluating _GHL"));
 210                return -ENODEV;
 211        }
 212
 213        resource->cap = data;
 214        return 0;
 215}
 216
 217static ssize_t show_cap(struct device *dev,
 218                        struct device_attribute *devattr,
 219                        char *buf)
 220{
 221        struct acpi_device *acpi_dev = to_acpi_device(dev);
 222        struct acpi_power_meter_resource *resource = acpi_dev->driver_data;
 223
 224        mutex_lock(&resource->lock);
 225        update_cap(resource);
 226        mutex_unlock(&resource->lock);
 227
 228        return sprintf(buf, "%llu\n", resource->cap * 1000);
 229}
 230
 231static ssize_t set_cap(struct device *dev, struct device_attribute *devattr,
 232                       const char *buf, size_t count)
 233{
 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 };
 238        int res;
 239        unsigned long temp;
 240        unsigned long long data;
 241        acpi_status status;
 242
 243        res = strict_strtoul(buf, 10, &temp);
 244        if (res)
 245                return res;
 246
 247        temp /= 1000;
 248        if (temp > resource->caps.max_cap || temp < resource->caps.min_cap)
 249                return -EINVAL;
 250        arg0.integer.value = temp;
 251
 252        mutex_lock(&resource->lock);
 253        status = acpi_evaluate_integer(resource->acpi_dev->handle, "_SHL",
 254                                       &args, &data);
 255        if (!ACPI_FAILURE(status))
 256                resource->cap = temp;
 257        mutex_unlock(&resource->lock);
 258
 259        if (ACPI_FAILURE(status)) {
 260                ACPI_EXCEPTION((AE_INFO, status, "Evaluating _SHL"));
 261                return -EINVAL;
 262        }
 263
 264        /* _SHL returns 0 on success, nonzero otherwise */
 265        if (data)
 266                return -EINVAL;
 267
 268        return count;
 269}
 270
 271/* Power meter trip points */
 272static int set_acpi_trip(struct acpi_power_meter_resource *resource)
 273{
 274        union acpi_object arg_objs[] = {
 275                {ACPI_TYPE_INTEGER},
 276                {ACPI_TYPE_INTEGER}
 277        };
 278        struct acpi_object_list args = { 2, arg_objs };
 279        unsigned long long data;
 280        acpi_status status;
 281
 282        /* Both trip levels must be set */
 283        if (resource->trip[0] < 0 || resource->trip[1] < 0)
 284                return 0;
 285
 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];
 289
 290        status = acpi_evaluate_integer(resource->acpi_dev->handle, "_PTP",
 291                                       &args, &data);
 292        if (ACPI_FAILURE(status)) {
 293                ACPI_EXCEPTION((AE_INFO, status, "Evaluating _PTP"));
 294                return -EINVAL;
 295        }
 296
 297        /* _PTP returns 0 on success, nonzero otherwise */
 298        if (data)
 299                return -EINVAL;
 300
 301        return 0;
 302}
 303
 304static ssize_t set_trip(struct device *dev, struct device_attribute *devattr,
 305                        const char *buf, size_t count)
 306{
 307        struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
 308        struct acpi_device *acpi_dev = to_acpi_device(dev);
 309        struct acpi_power_meter_resource *resource = acpi_dev->driver_data;
 310        int res;
 311        unsigned long temp;
 312
 313        res = strict_strtoul(buf, 10, &temp);
 314        if (res)
 315                return res;
 316
 317        temp /= 1000;
 318        if (temp < 0)
 319                return -EINVAL;
 320
 321        mutex_lock(&resource->lock);
 322        resource->trip[attr->index - 7] = temp;
 323        res = set_acpi_trip(resource);
 324        mutex_unlock(&resource->lock);
 325
 326        if (res)
 327                return res;
 328
 329        return count;
 330}
 331
 332/* Power meter */
 333static int update_meter(struct acpi_power_meter_resource *resource)
 334{
 335        unsigned long long data;
 336        acpi_status status;
 337        unsigned long local_jiffies = jiffies;
 338
 339        if (time_before(local_jiffies, resource->sensors_last_updated +
 340                        msecs_to_jiffies(resource->caps.sampling_time)) &&
 341                        resource->sensors_valid)
 342                return 0;
 343
 344        status = acpi_evaluate_integer(resource->acpi_dev->handle, "_PMM",
 345                                       NULL, &data);
 346        if (ACPI_FAILURE(status)) {
 347                ACPI_EXCEPTION((AE_INFO, status, "Evaluating _PMM"));
 348                return -ENODEV;
 349        }
 350
 351        resource->power = data;
 352        resource->sensors_valid = 1;
 353        resource->sensors_last_updated = jiffies;
 354        return 0;
 355}
 356
 357static ssize_t show_power(struct device *dev,
 358                          struct device_attribute *devattr,
 359                          char *buf)
 360{
 361        struct acpi_device *acpi_dev = to_acpi_device(dev);
 362        struct acpi_power_meter_resource *resource = acpi_dev->driver_data;
 363
 364        mutex_lock(&resource->lock);
 365        update_meter(resource);
 366        mutex_unlock(&resource->lock);
 367
 368        return sprintf(buf, "%llu\n", resource->power * 1000);
 369}
 370
 371/* Miscellaneous */
 372static ssize_t show_str(struct device *dev,
 373                        struct device_attribute *devattr,
 374                        char *buf)
 375{
 376        struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
 377        struct acpi_device *acpi_dev = to_acpi_device(dev);
 378        struct acpi_power_meter_resource *resource = acpi_dev->driver_data;
 379        acpi_string val;
 380
 381        switch (attr->index) {
 382        case 0:
 383                val = resource->model_number;
 384                break;
 385        case 1:
 386                val = resource->serial_number;
 387                break;
 388        case 2:
 389                val = resource->oem_info;
 390                break;
 391        default:
 392                BUG();
 393        }
 394
 395        return sprintf(buf, "%s\n", val);
 396}
 397
 398static ssize_t show_val(struct device *dev,
 399                        struct device_attribute *devattr,
 400                        char *buf)
 401{
 402        struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
 403        struct acpi_device *acpi_dev = to_acpi_device(dev);
 404        struct acpi_power_meter_resource *resource = acpi_dev->driver_data;
 405        acpi_integer val = 0;
 406
 407        switch (attr->index) {
 408        case 0:
 409                val = resource->caps.min_avg_interval;
 410                break;
 411        case 1:
 412                val = resource->caps.max_avg_interval;
 413                break;
 414        case 2:
 415                val = resource->caps.min_cap * 1000;
 416                break;
 417        case 3:
 418                val = resource->caps.max_cap * 1000;
 419                break;
 420        case 4:
 421                if (resource->caps.hysteresis == UNKNOWN_HYSTERESIS)
 422                        return sprintf(buf, "unknown\n");
 423
 424                val = resource->caps.hysteresis * 1000;
 425                break;
 426        case 5:
 427                if (resource->caps.flags & POWER_METER_IS_BATTERY)
 428                        val = 1;
 429                else
 430                        val = 0;
 431                break;
 432        case 6:
 433                if (resource->power > resource->cap)
 434                        val = 1;
 435                else
 436                        val = 0;
 437                break;
 438        case 7:
 439        case 8:
 440                if (resource->trip[attr->index - 7] < 0)
 441                        return sprintf(buf, "unknown\n");
 442
 443                val = resource->trip[attr->index - 7] * 1000;
 444                break;
 445        default:
 446                BUG();
 447        }
 448
 449        return sprintf(buf, "%llu\n", val);
 450}
 451
 452static ssize_t show_accuracy(struct device *dev,
 453                             struct device_attribute *devattr,
 454                             char *buf)
 455{
 456        struct acpi_device *acpi_dev = to_acpi_device(dev);
 457        struct acpi_power_meter_resource *resource = acpi_dev->driver_data;
 458        unsigned int acc = resource->caps.accuracy;
 459
 460        return sprintf(buf, "%u.%u%%\n", acc / 1000, acc % 1000);
 461}
 462
 463static ssize_t show_name(struct device *dev,
 464                         struct device_attribute *devattr,
 465                         char *buf)
 466{
 467        return sprintf(buf, "%s\n", ACPI_POWER_METER_NAME);
 468}
 469
 470/* Sensor descriptions.  If you add a sensor, update NUM_SENSORS above! */
 471static struct ro_sensor_template meter_ro_attrs[] = {
 472{POWER_AVERAGE_NAME, show_power, 0},
 473{"power1_accuracy", show_accuracy, 0},
 474{"power1_average_interval_min", show_val, 0},
 475{"power1_average_interval_max", show_val, 1},
 476{"power1_is_battery", show_val, 5},
 477{NULL, NULL, 0},
 478};
 479
 480static struct rw_sensor_template meter_rw_attrs[] = {
 481{POWER_AVG_INTERVAL_NAME, show_avg_interval, set_avg_interval, 0},
 482{NULL, NULL, NULL, 0},
 483};
 484
 485static struct ro_sensor_template misc_cap_attrs[] = {
 486{"power1_cap_min", show_val, 2},
 487{"power1_cap_max", show_val, 3},
 488{"power1_cap_hyst", show_val, 4},
 489{POWER_ALARM_NAME, show_val, 6},
 490{NULL, NULL, 0},
 491};
 492
 493static struct ro_sensor_template ro_cap_attrs[] = {
 494{POWER_CAP_NAME, show_cap, 0},
 495{NULL, NULL, 0},
 496};
 497
 498static struct rw_sensor_template rw_cap_attrs[] = {
 499{POWER_CAP_NAME, show_cap, set_cap, 0},
 500{NULL, NULL, NULL, 0},
 501};
 502
 503static struct rw_sensor_template trip_attrs[] = {
 504{"power1_average_min", show_val, set_trip, 7},
 505{"power1_average_max", show_val, set_trip, 8},
 506{NULL, NULL, NULL, 0},
 507};
 508
 509static struct ro_sensor_template misc_attrs[] = {
 510{"name", show_name, 0},
 511{"power1_model_number", show_str, 0},
 512{"power1_oem_info", show_str, 2},
 513{"power1_serial_number", show_str, 1},
 514{NULL, NULL, 0},
 515};
 516
 517/* Read power domain data */
 518static void remove_domain_devices(struct acpi_power_meter_resource *resource)
 519{
 520        int i;
 521
 522        if (!resource->num_domain_devices)
 523                return;
 524
 525        for (i = 0; i < resource->num_domain_devices; i++) {
 526                struct acpi_device *obj = resource->domain_devices[i];
 527                if (!obj)
 528                        continue;
 529
 530                sysfs_remove_link(resource->holders_dir,
 531                                  kobject_name(&obj->dev.kobj));
 532                put_device(&obj->dev);
 533        }
 534
 535        kfree(resource->domain_devices);
 536        kobject_put(resource->holders_dir);
 537}
 538
 539static int read_domain_devices(struct acpi_power_meter_resource *resource)
 540{
 541        int res = 0;
 542        int i;
 543        struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
 544        union acpi_object *pss;
 545        acpi_status status;
 546
 547        status = acpi_evaluate_object(resource->acpi_dev->handle, "_PMD", NULL,
 548                                      &buffer);
 549        if (ACPI_FAILURE(status)) {
 550                ACPI_EXCEPTION((AE_INFO, status, "Evaluating _PMD"));
 551                return -ENODEV;
 552        }
 553
 554        pss = buffer.pointer;
 555        if (!pss ||
 556            pss->type != ACPI_TYPE_PACKAGE) {
 557                dev_err(&resource->acpi_dev->dev, ACPI_POWER_METER_NAME
 558                        "Invalid _PMD data\n");
 559                res = -EFAULT;
 560                goto end;
 561        }
 562
 563        if (!pss->package.count)
 564                goto end;
 565
 566        resource->domain_devices = kzalloc(sizeof(struct acpi_device *) *
 567                                           pss->package.count, GFP_KERNEL);
 568        if (!resource->domain_devices) {
 569                res = -ENOMEM;
 570                goto end;
 571        }
 572
 573        resource->holders_dir = kobject_create_and_add("measures",
 574                                        &resource->acpi_dev->dev.kobj);
 575        if (!resource->holders_dir) {
 576                res = -ENOMEM;
 577                goto exit_free;
 578        }
 579
 580        resource->num_domain_devices = pss->package.count;
 581
 582        for (i = 0; i < pss->package.count; i++) {
 583                struct acpi_device *obj;
 584                union acpi_object *element = &(pss->package.elements[i]);
 585
 586                /* Refuse non-references */
 587                if (element->type != ACPI_TYPE_LOCAL_REFERENCE)
 588                        continue;
 589
 590                /* Create a symlink to domain objects */
 591                resource->domain_devices[i] = NULL;
 592                status = acpi_bus_get_device(element->reference.handle,
 593                                             &resource->domain_devices[i]);
 594                if (ACPI_FAILURE(status))
 595                        continue;
 596
 597                obj = resource->domain_devices[i];
 598                get_device(&obj->dev);
 599
 600                res = sysfs_create_link(resource->holders_dir, &obj->dev.kobj,
 601                                      kobject_name(&obj->dev.kobj));
 602                if (res) {
 603                        put_device(&obj->dev);
 604                        resource->domain_devices[i] = NULL;
 605                }
 606        }
 607
 608        res = 0;
 609        goto end;
 610
 611exit_free:
 612        kfree(resource->domain_devices);
 613end:
 614        kfree(buffer.pointer);
 615        return res;
 616}
 617
 618/* Registration and deregistration */
 619static int register_ro_attrs(struct acpi_power_meter_resource *resource,
 620                             struct ro_sensor_template *ro)
 621{
 622        struct device *dev = &resource->acpi_dev->dev;
 623        struct sensor_device_attribute *sensors =
 624                &resource->sensors[resource->num_sensors];
 625        int res = 0;
 626
 627        while (ro->label) {
 628                sensors->dev_attr.attr.name = ro->label;
 629                sensors->dev_attr.attr.mode = S_IRUGO;
 630                sensors->dev_attr.show = ro->show;
 631                sensors->index = ro->index;
 632
 633                res = device_create_file(dev, &sensors->dev_attr);
 634                if (res) {
 635                        sensors->dev_attr.attr.name = NULL;
 636                        goto error;
 637                }
 638                sensors++;
 639                resource->num_sensors++;
 640                ro++;
 641        }
 642
 643error:
 644        return res;
 645}
 646
 647static int register_rw_attrs(struct acpi_power_meter_resource *resource,
 648                             struct rw_sensor_template *rw)
 649{
 650        struct device *dev = &resource->acpi_dev->dev;
 651        struct sensor_device_attribute *sensors =
 652                &resource->sensors[resource->num_sensors];
 653        int res = 0;
 654
 655        while (rw->label) {
 656                sensors->dev_attr.attr.name = rw->label;
 657                sensors->dev_attr.attr.mode = S_IRUGO | S_IWUSR;
 658                sensors->dev_attr.show = rw->show;
 659                sensors->dev_attr.store = rw->set;
 660                sensors->index = rw->index;
 661
 662                res = device_create_file(dev, &sensors->dev_attr);
 663                if (res) {
 664                        sensors->dev_attr.attr.name = NULL;
 665                        goto error;
 666                }
 667                sensors++;
 668                resource->num_sensors++;
 669                rw++;
 670        }
 671
 672error:
 673        return res;
 674}
 675
 676static void remove_attrs(struct acpi_power_meter_resource *resource)
 677{
 678        int i;
 679
 680        for (i = 0; i < resource->num_sensors; i++) {
 681                if (!resource->sensors[i].dev_attr.attr.name)
 682                        continue;
 683                device_remove_file(&resource->acpi_dev->dev,
 684                                   &resource->sensors[i].dev_attr);
 685        }
 686
 687        remove_domain_devices(resource);
 688
 689        resource->num_sensors = 0;
 690}
 691
 692static int setup_attrs(struct acpi_power_meter_resource *resource)
 693{
 694        int res = 0;
 695
 696        res = read_domain_devices(resource);
 697        if (res)
 698                return res;
 699
 700        if (resource->caps.flags & POWER_METER_CAN_MEASURE) {
 701                res = register_ro_attrs(resource, meter_ro_attrs);
 702                if (res)
 703                        goto error;
 704                res = register_rw_attrs(resource, meter_rw_attrs);
 705                if (res)
 706                        goto error;
 707        }
 708
 709        if (resource->caps.flags & POWER_METER_CAN_CAP) {
 710                if (!can_cap_in_hardware()) {
 711                        dev_err(&resource->acpi_dev->dev,
 712                                "Ignoring unsafe software power cap!\n");
 713                        goto skip_unsafe_cap;
 714                }
 715
 716                if (resource->caps.configurable_cap) {
 717                        res = register_rw_attrs(resource, rw_cap_attrs);
 718                        if (res)
 719                                goto error;
 720                } else {
 721                        res = register_ro_attrs(resource, ro_cap_attrs);
 722                        if (res)
 723                                goto error;
 724                }
 725                res = register_ro_attrs(resource, misc_cap_attrs);
 726                if (res)
 727                        goto error;
 728        }
 729skip_unsafe_cap:
 730
 731        if (resource->caps.flags & POWER_METER_CAN_TRIP) {
 732                res = register_rw_attrs(resource, trip_attrs);
 733                if (res)
 734                        goto error;
 735        }
 736
 737        res = register_ro_attrs(resource, misc_attrs);
 738        if (res)
 739                goto error;
 740
 741        return res;
 742error:
 743        remove_domain_devices(resource);
 744        remove_attrs(resource);
 745        return res;
 746}
 747
 748static void free_capabilities(struct acpi_power_meter_resource *resource)
 749{
 750        acpi_string *str;
 751        int i;
 752
 753        str = &resource->model_number;
 754        for (i = 0; i < 3; i++, str++)
 755                kfree(*str);
 756}
 757
 758static int read_capabilities(struct acpi_power_meter_resource *resource)
 759{
 760        int res = 0;
 761        int i;
 762        struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
 763        struct acpi_buffer state = { 0, NULL };
 764        struct acpi_buffer format = { sizeof("NNNNNNNNNNN"), "NNNNNNNNNNN" };
 765        union acpi_object *pss;
 766        acpi_string *str;
 767        acpi_status status;
 768
 769        status = acpi_evaluate_object(resource->acpi_dev->handle, "_PMC", NULL,
 770                                      &buffer);
 771        if (ACPI_FAILURE(status)) {
 772                ACPI_EXCEPTION((AE_INFO, status, "Evaluating _PMC"));
 773                return -ENODEV;
 774        }
 775
 776        pss = buffer.pointer;
 777        if (!pss ||
 778            pss->type != ACPI_TYPE_PACKAGE ||
 779            pss->package.count != 14) {
 780                dev_err(&resource->acpi_dev->dev, ACPI_POWER_METER_NAME
 781                        "Invalid _PMC data\n");
 782                res = -EFAULT;
 783                goto end;
 784        }
 785
 786        /* Grab all the integer data at once */
 787        state.length = sizeof(struct acpi_power_meter_capabilities);
 788        state.pointer = &resource->caps;
 789
 790        status = acpi_extract_package(pss, &format, &state);
 791        if (ACPI_FAILURE(status)) {
 792                ACPI_EXCEPTION((AE_INFO, status, "Invalid data"));
 793                res = -EFAULT;
 794                goto end;
 795        }
 796
 797        if (resource->caps.units) {
 798                dev_err(&resource->acpi_dev->dev, ACPI_POWER_METER_NAME
 799                        "Unknown units %llu.\n",
 800                        resource->caps.units);
 801                res = -EINVAL;
 802                goto end;
 803        }
 804
 805        /* Grab the string data */
 806        str = &resource->model_number;
 807
 808        for (i = 11; i < 14; i++) {
 809                union acpi_object *element = &(pss->package.elements[i]);
 810
 811                if (element->type != ACPI_TYPE_STRING) {
 812                        res = -EINVAL;
 813                        goto error;
 814                }
 815
 816                *str = kzalloc(sizeof(u8) * (element->string.length + 1),
 817                               GFP_KERNEL);
 818                if (!*str) {
 819                        res = -ENOMEM;
 820                        goto error;
 821                }
 822
 823                strncpy(*str, element->string.pointer, element->string.length);
 824                str++;
 825        }
 826
 827        dev_info(&resource->acpi_dev->dev, "Found ACPI power meter.\n");
 828        goto end;
 829error:
 830        str = &resource->model_number;
 831        for (i = 0; i < 3; i++, str++)
 832                kfree(*str);
 833end:
 834        kfree(buffer.pointer);
 835        return res;
 836}
 837
 838/* Handle ACPI event notifications */
 839static void acpi_power_meter_notify(struct acpi_device *device, u32 event)
 840{
 841        struct acpi_power_meter_resource *resource;
 842        int res;
 843
 844        if (!device || !acpi_driver_data(device))
 845                return;
 846
 847        resource = acpi_driver_data(device);
 848
 849        mutex_lock(&resource->lock);
 850        switch (event) {
 851        case METER_NOTIFY_CONFIG:
 852                free_capabilities(resource);
 853                res = read_capabilities(resource);
 854                if (res)
 855                        break;
 856
 857                remove_attrs(resource);
 858                setup_attrs(resource);
 859                break;
 860        case METER_NOTIFY_TRIP:
 861                sysfs_notify(&device->dev.kobj, NULL, POWER_AVERAGE_NAME);
 862                update_meter(resource);
 863                break;
 864        case METER_NOTIFY_CAP:
 865                sysfs_notify(&device->dev.kobj, NULL, POWER_CAP_NAME);
 866                update_cap(resource);
 867                break;
 868        case METER_NOTIFY_INTERVAL:
 869                sysfs_notify(&device->dev.kobj, NULL, POWER_AVG_INTERVAL_NAME);
 870                update_avg_interval(resource);
 871                break;
 872        case METER_NOTIFY_CAPPING:
 873                sysfs_notify(&device->dev.kobj, NULL, POWER_ALARM_NAME);
 874                dev_info(&device->dev, "Capping in progress.\n");
 875                break;
 876        default:
 877                BUG();
 878        }
 879        mutex_unlock(&resource->lock);
 880
 881        acpi_bus_generate_netlink_event(ACPI_POWER_METER_CLASS,
 882                                        dev_name(&device->dev), event, 0);
 883}
 884
 885static int acpi_power_meter_add(struct acpi_device *device)
 886{
 887        int res;
 888        struct acpi_power_meter_resource *resource;
 889
 890        if (!device)
 891                return -EINVAL;
 892
 893        resource = kzalloc(sizeof(struct acpi_power_meter_resource),
 894                           GFP_KERNEL);
 895        if (!resource)
 896                return -ENOMEM;
 897
 898        resource->sensors_valid = 0;
 899        resource->acpi_dev = device;
 900        mutex_init(&resource->lock);
 901        strcpy(acpi_device_name(device), ACPI_POWER_METER_DEVICE_NAME);
 902        strcpy(acpi_device_class(device), ACPI_POWER_METER_CLASS);
 903        device->driver_data = resource;
 904
 905        free_capabilities(resource);
 906        res = read_capabilities(resource);
 907        if (res)
 908                goto exit_free;
 909
 910        resource->trip[0] = resource->trip[1] = -1;
 911
 912        res = setup_attrs(resource);
 913        if (res)
 914                goto exit_free;
 915
 916        resource->hwmon_dev = hwmon_device_register(&device->dev);
 917        if (IS_ERR(resource->hwmon_dev)) {
 918                res = PTR_ERR(resource->hwmon_dev);
 919                goto exit_remove;
 920        }
 921
 922        res = 0;
 923        goto exit;
 924
 925exit_remove:
 926        remove_attrs(resource);
 927exit_free:
 928        kfree(resource);
 929exit:
 930        return res;
 931}
 932
 933static int acpi_power_meter_remove(struct acpi_device *device, int type)
 934{
 935        struct acpi_power_meter_resource *resource;
 936
 937        if (!device || !acpi_driver_data(device))
 938                return -EINVAL;
 939
 940        resource = acpi_driver_data(device);
 941        hwmon_device_unregister(resource->hwmon_dev);
 942
 943        free_capabilities(resource);
 944        remove_attrs(resource);
 945
 946        kfree(resource);
 947        return 0;
 948}
 949
 950static int acpi_power_meter_resume(struct acpi_device *device)
 951{
 952        struct acpi_power_meter_resource *resource;
 953
 954        if (!device || !acpi_driver_data(device))
 955                return -EINVAL;
 956
 957        resource = acpi_driver_data(device);
 958        free_capabilities(resource);
 959        read_capabilities(resource);
 960
 961        return 0;
 962}
 963
 964static struct acpi_driver acpi_power_meter_driver = {
 965        .name = "power_meter",
 966        .class = ACPI_POWER_METER_CLASS,
 967        .ids = power_meter_ids,
 968        .ops = {
 969                .add = acpi_power_meter_add,
 970                .remove = acpi_power_meter_remove,
 971                .resume = acpi_power_meter_resume,
 972                .notify = acpi_power_meter_notify,
 973                },
 974};
 975
 976/* Module init/exit routines */
 977static int __init enable_cap_knobs(const struct dmi_system_id *d)
 978{
 979        cap_in_hardware = 1;
 980        return 0;
 981}
 982
 983static struct dmi_system_id __initdata pm_dmi_table[] = {
 984        {
 985                enable_cap_knobs, "IBM Active Energy Manager",
 986                {
 987                        DMI_MATCH(DMI_SYS_VENDOR, "IBM")
 988                },
 989        },
 990        {}
 991};
 992
 993static int __init acpi_power_meter_init(void)
 994{
 995        int result;
 996
 997        if (acpi_disabled)
 998                return -ENODEV;
 999
1000        dmi_check_system(pm_dmi_table);
1001
1002        result = acpi_bus_register_driver(&acpi_power_meter_driver);
1003        if (result < 0)
1004                return -ENODEV;
1005
1006        return 0;
1007}
1008
1009static void __exit acpi_power_meter_exit(void)
1010{
1011        acpi_bus_unregister_driver(&acpi_power_meter_driver);
1012}
1013
1014MODULE_AUTHOR("Darrick J. Wong <djwong@us.ibm.com>");
1015MODULE_DESCRIPTION("ACPI 4.0 power meter driver");
1016MODULE_LICENSE("GPL");
1017
1018module_param(force_cap_on, bool, 0644);
1019MODULE_PARM_DESC(force_cap_on, "Enable power cap even it is unsafe to do so.");
1020
1021module_init(acpi_power_meter_init);
1022module_exit(acpi_power_meter_exit);
1023