drivers/hwmon/acpi_power_meter.c

   1 /*
   2  * A hwmon driver for ACPI 4.0 power meters
   3  * Copyright (C) 2009 IBM
   4  *
   5  * Author: Darrick J. Wong <darrick.wong@oracle.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/slab.h>
  29 #include <linux/kdev_t.h>
  30 #include <linux/sched.h>
  31 #include <linux/time.h>
  32 #include <linux/err.h>
  33 #include <acpi/acpi_drivers.h>
  34 #include <acpi/acpi_bus.h>
  35
  36 #define ACPI_POWER_METER_NAME           "power_meter"
  37 ACPI_MODULE_NAME(ACPI_POWER_METER_NAME);
  38 #define ACPI_POWER_METER_DEVICE_NAME    "Power Meter"
  39 #define ACPI_POWER_METER_CLASS          "pwr_meter_resource"
  40
  41 #define NUM_SENSORS                     17
  42
  43 #define POWER_METER_CAN_MEASURE (1 << 0)
  44 #define POWER_METER_CAN_TRIP    (1 << 1)
  45 #define POWER_METER_CAN_CAP     (1 << 2)
  46 #define POWER_METER_CAN_NOTIFY  (1 << 3)
  47 #define POWER_METER_IS_BATTERY  (1 << 8)
  48 #define UNKNOWN_HYSTERESIS      0xFFFFFFFF
  49
  50 #define METER_NOTIFY_CONFIG     0x80
  51 #define METER_NOTIFY_TRIP       0x81
  52 #define METER_NOTIFY_CAP        0x82
  53 #define METER_NOTIFY_CAPPING    0x83
  54 #define METER_NOTIFY_INTERVAL   0x84
  55
  56 #define POWER_AVERAGE_NAME      "power1_average"
  57 #define POWER_CAP_NAME          "power1_cap"
  58 #define POWER_AVG_INTERVAL_NAME "power1_average_interval"
  59 #define POWER_ALARM_NAME        "power1_alarm"
  60
  61 static int cap_in_hardware;
  62 static bool force_cap_on;
  63
  64 static int can_cap_in_hardware(void)
  65 {
  66         return force_cap_on || cap_in_hardware;
  67 }
  68
  69 static const struct acpi_device_id power_meter_ids[] = {
  70         {"ACPI000D", 0},
  71         {"", 0},
  72 };
  73 MODULE_DEVICE_TABLE(acpi, power_meter_ids);
  74
  75 struct acpi_power_meter_capabilities {
  76         u64             flags;
  77         u64             units;
  78         u64             type;
  79         u64             accuracy;
  80         u64             sampling_time;
  81         u64             min_avg_interval;
  82         u64             max_avg_interval;
  83         u64             hysteresis;
  84         u64             configurable_cap;
  85         u64             min_cap;
  86         u64             max_cap;
  87 };
  88
  89 struct acpi_power_meter_resource {
  90         struct acpi_device      *acpi_dev;
  91         acpi_bus_id             name;
  92         struct mutex            lock;
  93         struct device           *hwmon_dev;
  94         struct acpi_power_meter_capabilities    caps;
  95         acpi_string             model_number;
  96         acpi_string             serial_number;
  97         acpi_string             oem_info;
  98         u64             power;
  99         u64             cap;
 100         u64             avg_interval;
 101         int                     sensors_valid;
 102         unsigned long           sensors_last_updated;
 103         struct sensor_device_attribute  sensors[NUM_SENSORS];
 104         int                     num_sensors;
 105         s64                     trip[2];
 106         int                     num_domain_devices;
 107         struct acpi_device      **domain_devices;
 108         struct kobject          *holders_dir;
 109 };
 110
 111 struct sensor_template {
 112         char *label;
 113         ssize_t (*show)(struct device *dev,
 114                         struct device_attribute *devattr,
 115                         char *buf);
 116         ssize_t (*set)(struct device *dev,
 117                        struct device_attribute *devattr,
 118                        const char *buf, size_t count);
 119         int index;
 120 };
 121
 122 /* Averaging interval */
 123 static int update_avg_interval(struct acpi_power_meter_resource *resource)
 124 {
 125         unsigned long long data;
 126         acpi_status status;
 127
 128         status = acpi_evaluate_integer(resource->acpi_dev->handle, "_GAI",
 129                                        NULL, &data);
 130         if (ACPI_FAILURE(status)) {
 131                 ACPI_EXCEPTION((AE_INFO, status, "Evaluating _GAI"));
 132                 return -ENODEV;
 133         }
 134
 135         resource->avg_interval = data;
 136         return 0;
 137 }
 138
 139 static ssize_t show_avg_interval(struct device *dev,
 140                                  struct device_attribute *devattr,
 141                                  char *buf)
 142 {
 143         struct acpi_device *acpi_dev = to_acpi_device(dev);
 144         struct acpi_power_meter_resource *resource = acpi_dev->driver_data;
 145
 146         mutex_lock(&resource->lock);
 147         update_avg_interval(resource);
 148         mutex_unlock(&resource->lock);
 149
 150         return sprintf(buf, "%llu\n", resource->avg_interval);
 151 }
 152
 153 static ssize_t set_avg_interval(struct device *dev,
 154                                 struct device_attribute *devattr,
 155                                 const char *buf, size_t count)
 156 {
 157         struct acpi_device *acpi_dev = to_acpi_device(dev);
 158         struct acpi_power_meter_resource *resource = acpi_dev->driver_data;
 159         union acpi_object arg0 = { ACPI_TYPE_INTEGER };
 160         struct acpi_object_list args = { 1, &arg0 };
 161         int res;
 162         unsigned long temp;
 163         unsigned long long data;
 164         acpi_status status;
 165
 166         res = kstrtoul(buf, 10, &temp);
 167         if (res)
 168                 return res;
 169
 170         if (temp > resource->caps.max_avg_interval ||
 171             temp < resource->caps.min_avg_interval)
 172                 return -EINVAL;
 173         arg0.integer.value = temp;
 174
 175         mutex_lock(&resource->lock);
 176         status = acpi_evaluate_integer(resource->acpi_dev->handle, "_PAI",
 177                                        &args, &data);
 178         if (!ACPI_FAILURE(status))
 179                 resource->avg_interval = temp;
 180         mutex_unlock(&resource->lock);
 181
 182         if (ACPI_FAILURE(status)) {
 183                 ACPI_EXCEPTION((AE_INFO, status, "Evaluating _PAI"));
 184                 return -EINVAL;
 185         }
 186
 187         /* _PAI returns 0 on success, nonzero otherwise */
 188         if (data)
 189                 return -EINVAL;
 190
 191         return count;
 192 }
 193
 194 /* Cap functions */
 195 static int update_cap(struct acpi_power_meter_resource *resource)
 196 {
 197         unsigned long long data;
 198         acpi_status status;
 199
 200         status = acpi_evaluate_integer(resource->acpi_dev->handle, "_GHL",
 201                                        NULL, &data);
 202         if (ACPI_FAILURE(status)) {
 203                 ACPI_EXCEPTION((AE_INFO, status, "Evaluating _GHL"));
 204                 return -ENODEV;
 205         }
 206
 207         resource->cap = data;
 208         return 0;
 209 }
 210
 211 static ssize_t show_cap(struct device *dev,
 212                         struct device_attribute *devattr,
 213                         char *buf)
 214 {
 215         struct acpi_device *acpi_dev = to_acpi_device(dev);
 216         struct acpi_power_meter_resource *resource = acpi_dev->driver_data;
 217
 218         mutex_lock(&resource->lock);
 219         update_cap(resource);
 220         mutex_unlock(&resource->lock);
 221
 222         return sprintf(buf, "%llu\n", resource->cap * 1000);
 223 }
 224
 225 static ssize_t set_cap(struct device *dev, struct device_attribute *devattr,
 226                        const char *buf, size_t count)
 227 {
 228         struct acpi_device *acpi_dev = to_acpi_device(dev);
 229         struct acpi_power_meter_resource *resource = acpi_dev->driver_data;
 230         union acpi_object arg0 = { ACPI_TYPE_INTEGER };
 231         struct acpi_object_list args = { 1, &arg0 };
 232         int res;
 233         unsigned long temp;
 234         unsigned long long data;
 235         acpi_status status;
 236
 237         res = kstrtoul(buf, 10, &temp);
 238         if (res)
 239                 return res;
 240
 241         temp = DIV_ROUND_CLOSEST(temp, 1000);
 242         if (temp > resource->caps.max_cap || temp < resource->caps.min_cap)
 243                 return -EINVAL;
 244         arg0.integer.value = temp;
 245
 246         mutex_lock(&resource->lock);
 247         status = acpi_evaluate_integer(resource->acpi_dev->handle, "_SHL",
 248                                        &args, &data);
 249         if (!ACPI_FAILURE(status))
 250                 resource->cap = temp;
 251         mutex_unlock(&resource->lock);
 252
 253         if (ACPI_FAILURE(status)) {
 254                 ACPI_EXCEPTION((AE_INFO, status, "Evaluating _SHL"));
 255                 return -EINVAL;
 256         }
 257
 258         /* _SHL returns 0 on success, nonzero otherwise */
 259         if (data)
 260                 return -EINVAL;
 261
 262         return count;
 263 }
 264
 265 /* Power meter trip points */
 266 static int set_acpi_trip(struct acpi_power_meter_resource *resource)
 267 {
 268         union acpi_object arg_objs[] = {
 269                 {ACPI_TYPE_INTEGER},
 270                 {ACPI_TYPE_INTEGER}
 271         };
 272         struct acpi_object_list args = { 2, arg_objs };
 273         unsigned long long data;
 274         acpi_status status;
 275
 276         /* Both trip levels must be set */
 277         if (resource->trip[0] < 0 || resource->trip[1] < 0)
 278                 return 0;
 279
 280         /* This driver stores min, max; ACPI wants max, min. */
 281         arg_objs[0].integer.value = resource->trip[1];
 282         arg_objs[1].integer.value = resource->trip[0];
 283
 284         status = acpi_evaluate_integer(resource->acpi_dev->handle, "_PTP",
 285                                        &args, &data);
 286         if (ACPI_FAILURE(status)) {
 287                 ACPI_EXCEPTION((AE_INFO, status, "Evaluating _PTP"));
 288                 return -EINVAL;
 289         }
 290
 291         /* _PTP returns 0 on success, nonzero otherwise */
 292         if (data)
 293                 return -EINVAL;
 294
 295         return 0;
 296 }
 297
 298 static ssize_t set_trip(struct device *dev, struct device_attribute *devattr,
 299                         const char *buf, size_t count)
 300 {
 301         struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
 302         struct acpi_device *acpi_dev = to_acpi_device(dev);
 303         struct acpi_power_meter_resource *resource = acpi_dev->driver_data;
 304         int res;
 305         unsigned long temp;
 306
 307         res = kstrtoul(buf, 10, &temp);
 308         if (res)
 309                 return res;
 310
 311         temp = DIV_ROUND_CLOSEST(temp, 1000);
 312
 313         mutex_lock(&resource->lock);
 314         resource->trip[attr->index - 7] = temp;
 315         res = set_acpi_trip(resource);
 316         mutex_unlock(&resource->lock);
 317
 318         if (res)
 319                 return res;
 320
 321         return count;
 322 }
 323
 324 /* Power meter */
 325 static int update_meter(struct acpi_power_meter_resource *resource)
 326 {
 327         unsigned long long data;
 328         acpi_status status;
 329         unsigned long local_jiffies = jiffies;
 330
 331         if (time_before(local_jiffies, resource->sensors_last_updated +
 332                         msecs_to_jiffies(resource->caps.sampling_time)) &&
 333                         resource->sensors_valid)
 334                 return 0;
 335
 336         status = acpi_evaluate_integer(resource->acpi_dev->handle, "_PMM",
 337                                        NULL, &data);
 338         if (ACPI_FAILURE(status)) {
 339                 ACPI_EXCEPTION((AE_INFO, status, "Evaluating _PMM"));
 340                 return -ENODEV;
 341         }
 342
 343         resource->power = data;
 344         resource->sensors_valid = 1;
 345         resource->sensors_last_updated = jiffies;
 346         return 0;
 347 }
 348
 349 static ssize_t show_power(struct device *dev,
 350                           struct device_attribute *devattr,
 351                           char *buf)
 352 {
 353         struct acpi_device *acpi_dev = to_acpi_device(dev);
 354         struct acpi_power_meter_resource *resource = acpi_dev->driver_data;
 355
 356         mutex_lock(&resource->lock);
 357         update_meter(resource);
 358         mutex_unlock(&resource->lock);
 359
 360         return sprintf(buf, "%llu\n", resource->power * 1000);
 361 }
 362
 363 /* Miscellaneous */
 364 static ssize_t show_str(struct device *dev,
 365                         struct device_attribute *devattr,
 366                         char *buf)
 367 {
 368         struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
 369         struct acpi_device *acpi_dev = to_acpi_device(dev);
 370         struct acpi_power_meter_resource *resource = acpi_dev->driver_data;
 371         acpi_string val;
 372
 373         switch (attr->index) {
 374         case 0:
 375                 val = resource->model_number;
 376                 break;
 377         case 1:
 378                 val = resource->serial_number;
 379                 break;
 380         case 2:
 381                 val = resource->oem_info;
 382                 break;
 383         default:
 384                 WARN(1, "Implementation error: unexpected attribute index %d\n",
 385                      attr->index);
 386                 val = "";
 387                 break;
 388         }
 389
 390         return sprintf(buf, "%s\n", val);
 391 }
 392
 393 static ssize_t show_val(struct device *dev,
 394                         struct device_attribute *devattr,
 395                         char *buf)
 396 {
 397         struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
 398         struct acpi_device *acpi_dev = to_acpi_device(dev);
 399         struct acpi_power_meter_resource *resource = acpi_dev->driver_data;
 400         u64 val = 0;
 401
 402         switch (attr->index) {
 403         case 0:
 404                 val = resource->caps.min_avg_interval;
 405                 break;
 406         case 1:
 407                 val = resource->caps.max_avg_interval;
 408                 break;
 409         case 2:
 410                 val = resource->caps.min_cap * 1000;
 411                 break;
 412         case 3:
 413                 val = resource->caps.max_cap * 1000;
 414                 break;
 415         case 4:
 416                 if (resource->caps.hysteresis == UNKNOWN_HYSTERESIS)
 417                         return sprintf(buf, "unknown\n");
 418
 419                 val = resource->caps.hysteresis * 1000;
 420                 break;
 421         case 5:
 422                 if (resource->caps.flags & POWER_METER_IS_BATTERY)
 423                         val = 1;
 424                 else
 425                         val = 0;
 426                 break;
 427         case 6:
 428                 if (resource->power > resource->cap)
 429                         val = 1;
 430                 else
 431                         val = 0;
 432                 break;
 433         case 7:
 434         case 8:
 435                 if (resource->trip[attr->index - 7] < 0)
 436                         return sprintf(buf, "unknown\n");
 437
 438                 val = resource->trip[attr->index - 7] * 1000;
 439                 break;
 440         default:
 441                 WARN(1, "Implementation error: unexpected attribute index %d\n",
 442                      attr->index);
 443                 break;
 444         }
 445
 446         return sprintf(buf, "%llu\n", val);
 447 }
 448
 449 static ssize_t show_accuracy(struct device *dev,
 450                              struct device_attribute *devattr,
 451                              char *buf)
 452 {
 453         struct acpi_device *acpi_dev = to_acpi_device(dev);
 454         struct acpi_power_meter_resource *resource = acpi_dev->driver_data;
 455         unsigned int acc = resource->caps.accuracy;
 456
 457         return sprintf(buf, "%u.%u%%\n", acc / 1000, acc % 1000);
 458 }
 459
 460 static ssize_t show_name(struct device *dev,
 461                          struct device_attribute *devattr,
 462                          char *buf)
 463 {
 464         return sprintf(buf, "%s\n", ACPI_POWER_METER_NAME);
 465 }
 466
 467 #define RO_SENSOR_TEMPLATE(_label, _show, _index)       \
 468         {                                               \
 469                 .label = _label,                        \
 470                 .show  = _show,                         \
 471                 .index = _index,                        \
 472         }
 473
 474 #define RW_SENSOR_TEMPLATE(_label, _show, _set, _index) \
 475         {                                               \
 476                 .label = _label,                        \
 477                 .show  = _show,                         \
 478                 .set   = _set,                          \
 479                 .index = _index,                        \
 480         }
 481
 482 /* Sensor descriptions.  If you add a sensor, update NUM_SENSORS above! */
 483 static struct sensor_template meter_attrs[] = {
 484         RO_SENSOR_TEMPLATE(POWER_AVERAGE_NAME, show_power, 0),
 485         RO_SENSOR_TEMPLATE("power1_accuracy", show_accuracy, 0),
 486         RO_SENSOR_TEMPLATE("power1_average_interval_min", show_val, 0),
 487         RO_SENSOR_TEMPLATE("power1_average_interval_max", show_val, 1),
 488         RO_SENSOR_TEMPLATE("power1_is_battery", show_val, 5),
 489         RW_SENSOR_TEMPLATE(POWER_AVG_INTERVAL_NAME, show_avg_interval,
 490                 set_avg_interval, 0),
 491         {},
 492 };
 493
 494 static struct sensor_template misc_cap_attrs[] = {
 495         RO_SENSOR_TEMPLATE("power1_cap_min", show_val, 2),
 496         RO_SENSOR_TEMPLATE("power1_cap_max", show_val, 3),
 497         RO_SENSOR_TEMPLATE("power1_cap_hyst", show_val, 4),
 498         RO_SENSOR_TEMPLATE(POWER_ALARM_NAME, show_val, 6),
 499         {},
 500 };
 501
 502 static struct sensor_template ro_cap_attrs[] = {
 503         RO_SENSOR_TEMPLATE(POWER_CAP_NAME, show_cap, 0),
 504         {},
 505 };
 506
 507 static struct sensor_template rw_cap_attrs[] = {
 508         RW_SENSOR_TEMPLATE(POWER_CAP_NAME, show_cap, set_cap, 0),
 509         {},
 510 };
 511
 512 static struct sensor_template trip_attrs[] = {
 513         RW_SENSOR_TEMPLATE("power1_average_min", show_val, set_trip, 7),
 514         RW_SENSOR_TEMPLATE("power1_average_max", show_val, set_trip, 8),
 515         {},
 516 };
 517
 518 static struct sensor_template misc_attrs[] = {
 519         RO_SENSOR_TEMPLATE("name", show_name, 0),
 520         RO_SENSOR_TEMPLATE("power1_model_number", show_str, 0),
 521         RO_SENSOR_TEMPLATE("power1_oem_info", show_str, 2),
 522         RO_SENSOR_TEMPLATE("power1_serial_number", show_str, 1),
 523         {},
 524 };
 525
 526 #undef RO_SENSOR_TEMPLATE
 527 #undef RW_SENSOR_TEMPLATE
 528
 529 /* Read power domain data */
 530 static void remove_domain_devices(struct acpi_power_meter_resource *resource)
 531 {
 532         int i;
 533
 534         if (!resource->num_domain_devices)
 535                 return;
 536
 537         for (i = 0; i < resource->num_domain_devices; i++) {
 538                 struct acpi_device *obj = resource->domain_devices[i];
 539                 if (!obj)
 540                         continue;
 541
 542                 sysfs_remove_link(resource->holders_dir,
 543                                   kobject_name(&obj->dev.kobj));
 544                 put_device(&obj->dev);
 545         }
 546
 547         kfree(resource->domain_devices);
 548         kobject_put(resource->holders_dir);
 549         resource->num_domain_devices = 0;
 550 }
 551
 552 static int read_domain_devices(struct acpi_power_meter_resource *resource)
 553 {
 554         int res = 0;
 555         int i;
 556         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
 557         union acpi_object *pss;
 558         acpi_status status;
 559
 560         status = acpi_evaluate_object(resource->acpi_dev->handle, "_PMD", NULL,
 561                                       &buffer);
 562         if (ACPI_FAILURE(status)) {
 563                 ACPI_EXCEPTION((AE_INFO, status, "Evaluating _PMD"));
 564                 return -ENODEV;
 565         }
 566
 567         pss = buffer.pointer;
 568         if (!pss ||
 569             pss->type != ACPI_TYPE_PACKAGE) {
 570                 dev_err(&resource->acpi_dev->dev, ACPI_POWER_METER_NAME
 571                         "Invalid _PMD data\n");
 572                 res = -EFAULT;
 573                 goto end;
 574         }
 575
 576         if (!pss->package.count)
 577                 goto end;
 578
 579         resource->domain_devices = kzalloc(sizeof(struct acpi_device *) *
 580                                            pss->package.count, GFP_KERNEL);
 581         if (!resource->domain_devices) {
 582                 res = -ENOMEM;
 583                 goto end;
 584         }
 585
 586         resource->holders_dir = kobject_create_and_add("measures",
 587                                         &resource->acpi_dev->dev.kobj);
 588         if (!resource->holders_dir) {
 589                 res = -ENOMEM;
 590                 goto exit_free;
 591         }
 592
 593         resource->num_domain_devices = pss->package.count;
 594
 595         for (i = 0; i < pss->package.count; i++) {
 596                 struct acpi_device *obj;
 597                 union acpi_object *element = &(pss->package.elements[i]);
 598
 599                 /* Refuse non-references */
 600                 if (element->type != ACPI_TYPE_LOCAL_REFERENCE)
 601                         continue;
 602
 603                 /* Create a symlink to domain objects */
 604                 resource->domain_devices[i] = NULL;
 605                 status = acpi_bus_get_device(element->reference.handle,
 606                                              &resource->domain_devices[i]);
 607                 if (ACPI_FAILURE(status))
 608                         continue;
 609
 610                 obj = resource->domain_devices[i];
 611                 get_device(&obj->dev);
 612
 613                 res = sysfs_create_link(resource->holders_dir, &obj->dev.kobj,
 614                                       kobject_name(&obj->dev.kobj));
 615                 if (res) {
 616                         put_device(&obj->dev);
 617                         resource->domain_devices[i] = NULL;
 618                 }
 619         }
 620
 621         res = 0;
 622         goto end;
 623
 624 exit_free:
 625         kfree(resource->domain_devices);
 626 end:
 627         kfree(buffer.pointer);
 628         return res;
 629 }
 630
 631 /* Registration and deregistration */
 632 static int register_attrs(struct acpi_power_meter_resource *resource,
 633                           struct sensor_template *attrs)
 634 {
 635         struct device *dev = &resource->acpi_dev->dev;
 636         struct sensor_device_attribute *sensors =
 637                 &resource->sensors[resource->num_sensors];
 638         int res = 0;
 639
 640         while (attrs->label) {
 641                 sensors->dev_attr.attr.name = attrs->label;
 642                 sensors->dev_attr.attr.mode = S_IRUGO;
 643                 sensors->dev_attr.show = attrs->show;
 644                 sensors->index = attrs->index;
 645
 646                 if (attrs->set) {
 647                         sensors->dev_attr.attr.mode |= S_IWUSR;
 648                         sensors->dev_attr.store = attrs->set;
 649                 }
 650
 651                 sysfs_attr_init(&sensors->dev_attr.attr);
 652                 res = device_create_file(dev, &sensors->dev_attr);
 653                 if (res) {
 654                         sensors->dev_attr.attr.name = NULL;
 655                         goto error;
 656                 }
 657                 sensors++;
 658                 resource->num_sensors++;
 659                 attrs++;
 660         }
 661
 662 error:
 663         return res;
 664 }
 665
 666 static void remove_attrs(struct acpi_power_meter_resource *resource)
 667 {
 668         int i;
 669
 670         for (i = 0; i < resource->num_sensors; i++) {
 671                 if (!resource->sensors[i].dev_attr.attr.name)
 672                         continue;
 673                 device_remove_file(&resource->acpi_dev->dev,
 674                                    &resource->sensors[i].dev_attr);
 675         }
 676
 677         remove_domain_devices(resource);
 678
 679         resource->num_sensors = 0;
 680 }
 681
 682 static int setup_attrs(struct acpi_power_meter_resource *resource)
 683 {
 684         int res = 0;
 685
 686         res = read_domain_devices(resource);
 687         if (res)
 688                 return res;
 689
 690         if (resource->caps.flags & POWER_METER_CAN_MEASURE) {
 691                 res = register_attrs(resource, meter_attrs);
 692                 if (res)
 693                         goto error;
 694         }
 695
 696         if (resource->caps.flags & POWER_METER_CAN_CAP) {
 697                 if (!can_cap_in_hardware()) {
 698                         dev_err(&resource->acpi_dev->dev,
 699                                 "Ignoring unsafe software power cap!\n");
 700                         goto skip_unsafe_cap;
 701                 }
 702
 703                 if (resource->caps.configurable_cap)
 704                         res = register_attrs(resource, rw_cap_attrs);
 705                 else
 706                         res = register_attrs(resource, ro_cap_attrs);
 707
 708                 if (res)
 709                         goto error;
 710
 711                 res = register_attrs(resource, misc_cap_attrs);
 712                 if (res)
 713                         goto error;
 714         }
 715
 716 skip_unsafe_cap:
 717         if (resource->caps.flags & POWER_METER_CAN_TRIP) {
 718                 res = register_attrs(resource, trip_attrs);
 719                 if (res)
 720                         goto error;
 721         }
 722
 723         res = register_attrs(resource, misc_attrs);
 724         if (res)
 725                 goto error;
 726
 727         return res;
 728 error:
 729         remove_attrs(resource);
 730         return res;
 731 }
 732
 733 static void free_capabilities(struct acpi_power_meter_resource *resource)
 734 {
 735         acpi_string *str;
 736         int i;
 737
 738         str = &resource->model_number;
 739         for (i = 0; i < 3; i++, str++)
 740                 kfree(*str);
 741 }
 742
 743 static int read_capabilities(struct acpi_power_meter_resource *resource)
 744 {
 745         int res = 0;
 746         int i;
 747         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
 748         struct acpi_buffer state = { 0, NULL };
 749         struct acpi_buffer format = { sizeof("NNNNNNNNNNN"), "NNNNNNNNNNN" };
 750         union acpi_object *pss;
 751         acpi_string *str;
 752         acpi_status status;
 753
 754         status = acpi_evaluate_object(resource->acpi_dev->handle, "_PMC", NULL,
 755                                       &buffer);
 756         if (ACPI_FAILURE(status)) {
 757                 ACPI_EXCEPTION((AE_INFO, status, "Evaluating _PMC"));
 758                 return -ENODEV;
 759         }
 760
 761         pss = buffer.pointer;
 762         if (!pss ||
 763             pss->type != ACPI_TYPE_PACKAGE ||
 764             pss->package.count != 14) {
 765                 dev_err(&resource->acpi_dev->dev, ACPI_POWER_METER_NAME
 766                         "Invalid _PMC data\n");
 767                 res = -EFAULT;
 768                 goto end;
 769         }
 770
 771         /* Grab all the integer data at once */
 772         state.length = sizeof(struct acpi_power_meter_capabilities);
 773         state.pointer = &resource->caps;
 774
 775         status = acpi_extract_package(pss, &format, &state);
 776         if (ACPI_FAILURE(status)) {
 777                 ACPI_EXCEPTION((AE_INFO, status, "Invalid data"));
 778                 res = -EFAULT;
 779                 goto end;
 780         }
 781
 782         if (resource->caps.units) {
 783                 dev_err(&resource->acpi_dev->dev, ACPI_POWER_METER_NAME
 784                         "Unknown units %llu.\n",
 785                         resource->caps.units);
 786                 res = -EINVAL;
 787                 goto end;
 788         }
 789
 790         /* Grab the string data */
 791         str = &resource->model_number;
 792
 793         for (i = 11; i < 14; i++) {
 794                 union acpi_object *element = &(pss->package.elements[i]);
 795
 796                 if (element->type != ACPI_TYPE_STRING) {
 797                         res = -EINVAL;
 798                         goto error;
 799                 }
 800
 801                 *str = kzalloc(sizeof(u8) * (element->string.length + 1),
 802                                GFP_KERNEL);
 803                 if (!*str) {
 804                         res = -ENOMEM;
 805                         goto error;
 806                 }
 807
 808                 strncpy(*str, element->string.pointer, element->string.length);
 809                 str++;
 810         }
 811
 812         dev_info(&resource->acpi_dev->dev, "Found ACPI power meter.\n");
 813         goto end;
 814 error:
 815         str = &resource->model_number;
 816         for (i = 0; i < 3; i++, str++)
 817                 kfree(*str);
 818 end:
 819         kfree(buffer.pointer);
 820         return res;
 821 }
 822
 823 /* Handle ACPI event notifications */
 824 static void acpi_power_meter_notify(struct acpi_device *device, u32 event)
 825 {
 826         struct acpi_power_meter_resource *resource;
 827         int res;
 828
 829         if (!device || !acpi_driver_data(device))
 830                 return;
 831
 832         resource = acpi_driver_data(device);
 833
 834         mutex_lock(&resource->lock);
 835         switch (event) {
 836         case METER_NOTIFY_CONFIG:
 837                 free_capabilities(resource);
 838                 res = read_capabilities(resource);
 839                 if (res)
 840                         break;
 841
 842                 remove_attrs(resource);
 843                 setup_attrs(resource);
 844                 break;
 845         case METER_NOTIFY_TRIP:
 846                 sysfs_notify(&device->dev.kobj, NULL, POWER_AVERAGE_NAME);
 847                 update_meter(resource);
 848                 break;
 849         case METER_NOTIFY_CAP:
 850                 sysfs_notify(&device->dev.kobj, NULL, POWER_CAP_NAME);
 851                 update_cap(resource);
 852                 break;
 853         case METER_NOTIFY_INTERVAL:
 854                 sysfs_notify(&device->dev.kobj, NULL, POWER_AVG_INTERVAL_NAME);
 855                 update_avg_interval(resource);
 856                 break;
 857         case METER_NOTIFY_CAPPING:
 858                 sysfs_notify(&device->dev.kobj, NULL, POWER_ALARM_NAME);
 859                 dev_info(&device->dev, "Capping in progress.\n");
 860                 break;
 861         default:
 862                 WARN(1, "Unexpected event %d\n", event);
 863                 break;
 864         }
 865         mutex_unlock(&resource->lock);
 866
 867         acpi_bus_generate_netlink_event(ACPI_POWER_METER_CLASS,
 868                                         dev_name(&device->dev), event, 0);
 869 }
 870
 871 static int acpi_power_meter_add(struct acpi_device *device)
 872 {
 873         int res;
 874         struct acpi_power_meter_resource *resource;
 875
 876         if (!device)
 877                 return -EINVAL;
 878
 879         resource = kzalloc(sizeof(struct acpi_power_meter_resource),
 880                            GFP_KERNEL);
 881         if (!resource)
 882                 return -ENOMEM;
 883
 884         resource->sensors_valid = 0;
 885         resource->acpi_dev = device;
 886         mutex_init(&resource->lock);
 887         strcpy(acpi_device_name(device), ACPI_POWER_METER_DEVICE_NAME);
 888         strcpy(acpi_device_class(device), ACPI_POWER_METER_CLASS);
 889         device->driver_data = resource;
 890
 891         free_capabilities(resource);
 892         res = read_capabilities(resource);
 893         if (res)
 894                 goto exit_free;
 895
 896         resource->trip[0] = resource->trip[1] = -1;
 897
 898         res = setup_attrs(resource);
 899         if (res)
 900                 goto exit_free;
 901
 902         resource->hwmon_dev = hwmon_device_register(&device->dev);
 903         if (IS_ERR(resource->hwmon_dev)) {
 904                 res = PTR_ERR(resource->hwmon_dev);
 905                 goto exit_remove;
 906         }
 907
 908         res = 0;
 909         goto exit;
 910
 911 exit_remove:
 912         remove_attrs(resource);
 913 exit_free:
 914         kfree(resource);
 915 exit:
 916         return res;
 917 }
 918
 919 static int acpi_power_meter_remove(struct acpi_device *device)
 920 {
 921         struct acpi_power_meter_resource *resource;
 922
 923         if (!device || !acpi_driver_data(device))
 924                 return -EINVAL;
 925
 926         resource = acpi_driver_data(device);
 927         hwmon_device_unregister(resource->hwmon_dev);
 928
 929         free_capabilities(resource);
 930         remove_attrs(resource);
 931
 932         kfree(resource);
 933         return 0;
 934 }
 935
 936 #ifdef CONFIG_PM_SLEEP
 937
 938 static int acpi_power_meter_resume(struct device *dev)
 939 {
 940         struct acpi_power_meter_resource *resource;
 941
 942         if (!dev)
 943                 return -EINVAL;
 944
 945         resource = acpi_driver_data(to_acpi_device(dev));
 946         if (!resource)
 947                 return -EINVAL;
 948
 949         free_capabilities(resource);
 950         read_capabilities(resource);
 951
 952         return 0;
 953 }
 954
 955 #endif /* CONFIG_PM_SLEEP */
 956
 957 static SIMPLE_DEV_PM_OPS(acpi_power_meter_pm, NULL, acpi_power_meter_resume);
 958
 959 static struct acpi_driver acpi_power_meter_driver = {
 960         .name = "power_meter",
 961         .class = ACPI_POWER_METER_CLASS,
 962         .ids = power_meter_ids,
 963         .ops = {
 964                 .add = acpi_power_meter_add,
 965                 .remove = acpi_power_meter_remove,
 966                 .notify = acpi_power_meter_notify,
 967                 },
 968         .drv.pm = &acpi_power_meter_pm,
 969 };
 970
 971 /* Module init/exit routines */
 972 static int __init enable_cap_knobs(const struct dmi_system_id *d)
 973 {
 974         cap_in_hardware = 1;
 975         return 0;
 976 }
 977
 978 static struct dmi_system_id __initdata pm_dmi_table[] = {
 979         {
 980                 enable_cap_knobs, "IBM Active Energy Manager",
 981                 {
 982                         DMI_MATCH(DMI_SYS_VENDOR, "IBM")
 983                 },
 984         },
 985         {}
 986 };
 987
 988 static int __init acpi_power_meter_init(void)
 989 {
 990         int result;
 991
 992         if (acpi_disabled)
 993                 return -ENODEV;
 994
 995         dmi_check_system(pm_dmi_table);
 996
 997         result = acpi_bus_register_driver(&acpi_power_meter_driver);
 998         if (result < 0)
 999                 return result;
1000
1001         return 0;
1002 }
1003
1004 static void __exit acpi_power_meter_exit(void)
1005 {
1006         acpi_bus_unregister_driver(&acpi_power_meter_driver);
1007 }
1008
1009 MODULE_AUTHOR("Darrick J. Wong <darrick.wong@oracle.com>");
1010 MODULE_DESCRIPTION("ACPI 4.0 power meter driver");
1011 MODULE_LICENSE("GPL");
1012
1013 module_param(force_cap_on, bool, 0644);
1014 MODULE_PARM_DESC(force_cap_on, "Enable power cap even it is unsafe to do so.");
1015
1016 module_init(acpi_power_meter_init);
1017 module_exit(acpi_power_meter_exit);