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