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 <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/slab.h>
  29 #include <linux/kdev_t.h>
  30 #include <linux/sched.h>
  31 #include <linux/time.h>
  32 #include <acpi/acpi_drivers.h>
  33 #include <acpi/acpi_bus.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                 BUG();
 384                 val = "";
 385         }
 386
 387         return sprintf(buf, "%s\n", val);
 388 }
 389
 390 static ssize_t show_val(struct device *dev,
 391                         struct device_attribute *devattr,
 392                         char *buf)
 393 {
 394         struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
 395         struct acpi_device *acpi_dev = to_acpi_device(dev);
 396         struct acpi_power_meter_resource *resource = acpi_dev->driver_data;
 397         u64 val = 0;
 398
 399         switch (attr->index) {
 400         case 0:
 401                 val = resource->caps.min_avg_interval;
 402                 break;
 403         case 1:
 404                 val = resource->caps.max_avg_interval;
 405                 break;
 406         case 2:
 407                 val = resource->caps.min_cap * 1000;
 408                 break;
 409         case 3:
 410                 val = resource->caps.max_cap * 1000;
 411                 break;
 412         case 4:
 413                 if (resource->caps.hysteresis == UNKNOWN_HYSTERESIS)
 414                         return sprintf(buf, "unknown\n");
 415
 416                 val = resource->caps.hysteresis * 1000;
 417                 break;
 418         case 5:
 419                 if (resource->caps.flags & POWER_METER_IS_BATTERY)
 420                         val = 1;
 421                 else
 422                         val = 0;
 423                 break;
 424         case 6:
 425                 if (resource->power > resource->cap)
 426                         val = 1;
 427                 else
 428                         val = 0;
 429                 break;
 430         case 7:
 431         case 8:
 432                 if (resource->trip[attr->index - 7] < 0)
 433                         return sprintf(buf, "unknown\n");
 434
 435                 val = resource->trip[attr->index - 7] * 1000;
 436                 break;
 437         default:
 438                 BUG();
 439         }
 440
 441         return sprintf(buf, "%llu\n", val);
 442 }
 443
 444 static ssize_t show_accuracy(struct device *dev,
 445                              struct device_attribute *devattr,
 446                              char *buf)
 447 {
 448         struct acpi_device *acpi_dev = to_acpi_device(dev);
 449         struct acpi_power_meter_resource *resource = acpi_dev->driver_data;
 450         unsigned int acc = resource->caps.accuracy;
 451
 452         return sprintf(buf, "%u.%u%%\n", acc / 1000, acc % 1000);
 453 }
 454
 455 static ssize_t show_name(struct device *dev,
 456                          struct device_attribute *devattr,
 457                          char *buf)
 458 {
 459         return sprintf(buf, "%s\n", ACPI_POWER_METER_NAME);
 460 }
 461
 462 #define RO_SENSOR_TEMPLATE(_label, _show, _index)       \
 463         {                                               \
 464                 .label = _label,                        \
 465                 .show  = _show,                         \
 466                 .index = _index,                        \
 467         }
 468
 469 #define RW_SENSOR_TEMPLATE(_label, _show, _set, _index) \
 470         {                                               \
 471                 .label = _label,                        \
 472                 .show  = _show,                         \
 473                 .set   = _set,                          \
 474                 .index = _index,                        \
 475         }
 476
 477 /* Sensor descriptions.  If you add a sensor, update NUM_SENSORS above! */
 478 static struct sensor_template meter_attrs[] = {
 479         RO_SENSOR_TEMPLATE(POWER_AVERAGE_NAME, show_power, 0),
 480         RO_SENSOR_TEMPLATE("power1_accuracy", show_accuracy, 0),
 481         RO_SENSOR_TEMPLATE("power1_average_interval_min", show_val, 0),
 482         RO_SENSOR_TEMPLATE("power1_average_interval_max", show_val, 1),
 483         RO_SENSOR_TEMPLATE("power1_is_battery", show_val, 5),
 484         RW_SENSOR_TEMPLATE(POWER_AVG_INTERVAL_NAME, show_avg_interval,
 485                 set_avg_interval, 0),
 486         {},
 487 };
 488
 489 static struct sensor_template misc_cap_attrs[] = {
 490         RO_SENSOR_TEMPLATE("power1_cap_min", show_val, 2),
 491         RO_SENSOR_TEMPLATE("power1_cap_max", show_val, 3),
 492         RO_SENSOR_TEMPLATE("power1_cap_hyst", show_val, 4),
 493         RO_SENSOR_TEMPLATE(POWER_ALARM_NAME, show_val, 6),
 494         {},
 495 };
 496
 497 static struct sensor_template ro_cap_attrs[] = {
 498         RO_SENSOR_TEMPLATE(POWER_CAP_NAME, show_cap, 0),
 499         {},
 500 };
 501
 502 static struct sensor_template rw_cap_attrs[] = {
 503         RW_SENSOR_TEMPLATE(POWER_CAP_NAME, show_cap, set_cap, 0),
 504         {},
 505 };
 506
 507 static struct sensor_template trip_attrs[] = {
 508         RW_SENSOR_TEMPLATE("power1_average_min", show_val, set_trip, 7),
 509         RW_SENSOR_TEMPLATE("power1_average_max", show_val, set_trip, 8),
 510         {},
 511 };
 512
 513 static struct sensor_template misc_attrs[] = {
 514         RO_SENSOR_TEMPLATE("name", show_name, 0),
 515         RO_SENSOR_TEMPLATE("power1_model_number", show_str, 0),
 516         RO_SENSOR_TEMPLATE("power1_oem_info", show_str, 2),
 517         RO_SENSOR_TEMPLATE("power1_serial_number", show_str, 1),
 518         {},
 519 };
 520
 521 #undef RO_SENSOR_TEMPLATE
 522 #undef RW_SENSOR_TEMPLATE
 523
 524 /* Read power domain data */
 525 static void remove_domain_devices(struct acpi_power_meter_resource *resource)
 526 {
 527         int i;
 528
 529         if (!resource->num_domain_devices)
 530                 return;
 531
 532         for (i = 0; i < resource->num_domain_devices; i++) {
 533                 struct acpi_device *obj = resource->domain_devices[i];
 534                 if (!obj)
 535                         continue;
 536
 537                 sysfs_remove_link(resource->holders_dir,
 538                                   kobject_name(&obj->dev.kobj));
 539                 put_device(&obj->dev);
 540         }
 541
 542         kfree(resource->domain_devices);
 543         kobject_put(resource->holders_dir);
 544         resource->num_domain_devices = 0;
 545 }
 546
 547 static int read_domain_devices(struct acpi_power_meter_resource *resource)
 548 {
 549         int res = 0;
 550         int i;
 551         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
 552         union acpi_object *pss;
 553         acpi_status status;
 554
 555         status = acpi_evaluate_object(resource->acpi_dev->handle, "_PMD", NULL,
 556                                       &buffer);
 557         if (ACPI_FAILURE(status)) {
 558                 ACPI_EXCEPTION((AE_INFO, status, "Evaluating _PMD"));
 559                 return -ENODEV;
 560         }
 561
 562         pss = buffer.pointer;
 563         if (!pss ||
 564             pss->type != ACPI_TYPE_PACKAGE) {
 565                 dev_err(&resource->acpi_dev->dev, ACPI_POWER_METER_NAME
 566                         "Invalid _PMD data\n");
 567                 res = -EFAULT;
 568                 goto end;
 569         }
 570
 571         if (!pss->package.count)
 572                 goto end;
 573
 574         resource->domain_devices = kzalloc(sizeof(struct acpi_device *) *
 575                                            pss->package.count, GFP_KERNEL);
 576         if (!resource->domain_devices) {
 577                 res = -ENOMEM;
 578                 goto end;
 579         }
 580
 581         resource->holders_dir = kobject_create_and_add("measures",
 582                                         &resource->acpi_dev->dev.kobj);
 583         if (!resource->holders_dir) {
 584                 res = -ENOMEM;
 585                 goto exit_free;
 586         }
 587
 588         resource->num_domain_devices = pss->package.count;
 589
 590         for (i = 0; i < pss->package.count; i++) {
 591                 struct acpi_device *obj;
 592                 union acpi_object *element = &(pss->package.elements[i]);
 593
 594                 /* Refuse non-references */
 595                 if (element->type != ACPI_TYPE_LOCAL_REFERENCE)
 596                         continue;
 597
 598                 /* Create a symlink to domain objects */
 599                 resource->domain_devices[i] = NULL;
 600                 status = acpi_bus_get_device(element->reference.handle,
 601                                              &resource->domain_devices[i]);
 602                 if (ACPI_FAILURE(status))
 603                         continue;
 604
 605                 obj = resource->domain_devices[i];
 606                 get_device(&obj->dev);
 607
 608                 res = sysfs_create_link(resource->holders_dir, &obj->dev.kobj,
 609                                       kobject_name(&obj->dev.kobj));
 610                 if (res) {
 611                         put_device(&obj->dev);
 612                         resource->domain_devices[i] = NULL;
 613                 }
 614         }
 615
 616         res = 0;
 617         goto end;
 618
 619 exit_free:
 620         kfree(resource->domain_devices);
 621 end:
 622         kfree(buffer.pointer);
 623         return res;
 624 }
 625
 626 /* Registration and deregistration */
 627 static int register_attrs(struct acpi_power_meter_resource *resource,
 628                           struct sensor_template *attrs)
 629 {
 630         struct device *dev = &resource->acpi_dev->dev;
 631         struct sensor_device_attribute *sensors =
 632                 &resource->sensors[resource->num_sensors];
 633         int res = 0;
 634
 635         while (attrs->label) {
 636                 sensors->dev_attr.attr.name = attrs->label;
 637                 sensors->dev_attr.attr.mode = S_IRUGO;
 638                 sensors->dev_attr.show = attrs->show;
 639                 sensors->index = attrs->index;
 640
 641                 if (attrs->set) {
 642                         sensors->dev_attr.attr.mode |= S_IWUSR;
 643                         sensors->dev_attr.store = attrs->set;
 644                 }
 645
 646                 sysfs_attr_init(&sensors->dev_attr.attr);
 647                 res = device_create_file(dev, &sensors->dev_attr);
 648                 if (res) {
 649                         sensors->dev_attr.attr.name = NULL;
 650                         goto error;
 651                 }
 652                 sensors++;
 653                 resource->num_sensors++;
 654                 attrs++;
 655         }
 656
 657 error:
 658         return res;
 659 }
 660
 661 static void remove_attrs(struct acpi_power_meter_resource *resource)
 662 {
 663         int i;
 664
 665         for (i = 0; i < resource->num_sensors; i++) {
 666                 if (!resource->sensors[i].dev_attr.attr.name)
 667                         continue;
 668                 device_remove_file(&resource->acpi_dev->dev,
 669                                    &resource->sensors[i].dev_attr);
 670         }
 671
 672         remove_domain_devices(resource);
 673
 674         resource->num_sensors = 0;
 675 }
 676
 677 static int setup_attrs(struct acpi_power_meter_resource *resource)
 678 {
 679         int res = 0;
 680
 681         res = read_domain_devices(resource);
 682         if (res)
 683                 return res;
 684
 685         if (resource->caps.flags & POWER_METER_CAN_MEASURE) {
 686                 res = register_attrs(resource, meter_attrs);
 687                 if (res)
 688                         goto error;
 689         }
 690
 691         if (resource->caps.flags & POWER_METER_CAN_CAP) {
 692                 if (!can_cap_in_hardware()) {
 693                         dev_err(&resource->acpi_dev->dev,
 694                                 "Ignoring unsafe software power cap!\n");
 695                         goto skip_unsafe_cap;
 696                 }
 697
 698                 if (resource->caps.configurable_cap)
 699                         res = register_attrs(resource, rw_cap_attrs);
 700                 else
 701                         res = register_attrs(resource, ro_cap_attrs);
 702
 703                 if (res)
 704                         goto error;
 705
 706                 res = register_attrs(resource, misc_cap_attrs);
 707                 if (res)
 708                         goto error;
 709         }
 710
 711 skip_unsafe_cap:
 712         if (resource->caps.flags & POWER_METER_CAN_TRIP) {
 713                 res = register_attrs(resource, trip_attrs);
 714                 if (res)
 715                         goto error;
 716         }
 717
 718         res = register_attrs(resource, misc_attrs);
 719         if (res)
 720                 goto error;
 721
 722         return res;
 723 error:
 724         remove_attrs(resource);
 725         return res;
 726 }
 727
 728 static void free_capabilities(struct acpi_power_meter_resource *resource)
 729 {
 730         acpi_string *str;
 731         int i;
 732
 733         str = &resource->model_number;
 734         for (i = 0; i < 3; i++, str++)
 735                 kfree(*str);
 736 }
 737
 738 static int read_capabilities(struct acpi_power_meter_resource *resource)
 739 {
 740         int res = 0;
 741         int i;
 742         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
 743         struct acpi_buffer state = { 0, NULL };
 744         struct acpi_buffer format = { sizeof("NNNNNNNNNNN"), "NNNNNNNNNNN" };
 745         union acpi_object *pss;
 746         acpi_string *str;
 747         acpi_status status;
 748
 749         status = acpi_evaluate_object(resource->acpi_dev->handle, "_PMC", NULL,
 750                                       &buffer);
 751         if (ACPI_FAILURE(status)) {
 752                 ACPI_EXCEPTION((AE_INFO, status, "Evaluating _PMC"));
 753                 return -ENODEV;
 754         }
 755
 756         pss = buffer.pointer;
 757         if (!pss ||
 758             pss->type != ACPI_TYPE_PACKAGE ||
 759             pss->package.count != 14) {
 760                 dev_err(&resource->acpi_dev->dev, ACPI_POWER_METER_NAME
 761                         "Invalid _PMC data\n");
 762                 res = -EFAULT;
 763                 goto end;
 764         }
 765
 766         /* Grab all the integer data at once */
 767         state.length = sizeof(struct acpi_power_meter_capabilities);
 768         state.pointer = &resource->caps;
 769
 770         status = acpi_extract_package(pss, &format, &state);
 771         if (ACPI_FAILURE(status)) {
 772                 ACPI_EXCEPTION((AE_INFO, status, "Invalid data"));
 773                 res = -EFAULT;
 774                 goto end;
 775         }
 776
 777         if (resource->caps.units) {
 778                 dev_err(&resource->acpi_dev->dev, ACPI_POWER_METER_NAME
 779                         "Unknown units %llu.\n",
 780                         resource->caps.units);
 781                 res = -EINVAL;
 782                 goto end;
 783         }
 784
 785         /* Grab the string data */
 786         str = &resource->model_number;
 787
 788         for (i = 11; i < 14; i++) {
 789                 union acpi_object *element = &(pss->package.elements[i]);
 790
 791                 if (element->type != ACPI_TYPE_STRING) {
 792                         res = -EINVAL;
 793                         goto error;
 794                 }
 795
 796                 *str = kzalloc(sizeof(u8) * (element->string.length + 1),
 797                                GFP_KERNEL);
 798                 if (!*str) {
 799                         res = -ENOMEM;
 800                         goto error;
 801                 }
 802
 803                 strncpy(*str, element->string.pointer, element->string.length);
 804                 str++;
 805         }
 806
 807         dev_info(&resource->acpi_dev->dev, "Found ACPI power meter.\n");
 808         goto end;
 809 error:
 810         str = &resource->model_number;
 811         for (i = 0; i < 3; i++, str++)
 812                 kfree(*str);
 813 end:
 814         kfree(buffer.pointer);
 815         return res;
 816 }
 817
 818 /* Handle ACPI event notifications */
 819 static void acpi_power_meter_notify(struct acpi_device *device, u32 event)
 820 {
 821         struct acpi_power_meter_resource *resource;
 822         int res;
 823
 824         if (!device || !acpi_driver_data(device))
 825                 return;
 826
 827         resource = acpi_driver_data(device);
 828
 829         mutex_lock(&resource->lock);
 830         switch (event) {
 831         case METER_NOTIFY_CONFIG:
 832                 free_capabilities(resource);
 833                 res = read_capabilities(resource);
 834                 if (res)
 835                         break;
 836
 837                 remove_attrs(resource);
 838                 setup_attrs(resource);
 839                 break;
 840         case METER_NOTIFY_TRIP:
 841                 sysfs_notify(&device->dev.kobj, NULL, POWER_AVERAGE_NAME);
 842                 update_meter(resource);
 843                 break;
 844         case METER_NOTIFY_CAP:
 845                 sysfs_notify(&device->dev.kobj, NULL, POWER_CAP_NAME);
 846                 update_cap(resource);
 847                 break;
 848         case METER_NOTIFY_INTERVAL:
 849                 sysfs_notify(&device->dev.kobj, NULL, POWER_AVG_INTERVAL_NAME);
 850                 update_avg_interval(resource);
 851                 break;
 852         case METER_NOTIFY_CAPPING:
 853                 sysfs_notify(&device->dev.kobj, NULL, POWER_ALARM_NAME);
 854                 dev_info(&device->dev, "Capping in progress.\n");
 855                 break;
 856         default:
 857                 BUG();
 858         }
 859         mutex_unlock(&resource->lock);
 860
 861         acpi_bus_generate_netlink_event(ACPI_POWER_METER_CLASS,
 862                                         dev_name(&device->dev), event, 0);
 863 }
 864
 865 static int acpi_power_meter_add(struct acpi_device *device)
 866 {
 867         int res;
 868         struct acpi_power_meter_resource *resource;
 869
 870         if (!device)
 871                 return -EINVAL;
 872
 873         resource = kzalloc(sizeof(struct acpi_power_meter_resource),
 874                            GFP_KERNEL);
 875         if (!resource)
 876                 return -ENOMEM;
 877
 878         resource->sensors_valid = 0;
 879         resource->acpi_dev = device;
 880         mutex_init(&resource->lock);
 881         strcpy(acpi_device_name(device), ACPI_POWER_METER_DEVICE_NAME);
 882         strcpy(acpi_device_class(device), ACPI_POWER_METER_CLASS);
 883         device->driver_data = resource;
 884
 885         free_capabilities(resource);
 886         res = read_capabilities(resource);
 887         if (res)
 888                 goto exit_free;
 889
 890         resource->trip[0] = resource->trip[1] = -1;
 891
 892         res = setup_attrs(resource);
 893         if (res)
 894                 goto exit_free;
 895
 896         resource->hwmon_dev = hwmon_device_register(&device->dev);
 897         if (IS_ERR(resource->hwmon_dev)) {
 898                 res = PTR_ERR(resource->hwmon_dev);
 899                 goto exit_remove;
 900         }
 901
 902         res = 0;
 903         goto exit;
 904
 905 exit_remove:
 906         remove_attrs(resource);
 907 exit_free:
 908         kfree(resource);
 909 exit:
 910         return res;
 911 }
 912
 913 static int acpi_power_meter_remove(struct acpi_device *device, int type)
 914 {
 915         struct acpi_power_meter_resource *resource;
 916
 917         if (!device || !acpi_driver_data(device))
 918                 return -EINVAL;
 919
 920         resource = acpi_driver_data(device);
 921         hwmon_device_unregister(resource->hwmon_dev);
 922
 923         free_capabilities(resource);
 924         remove_attrs(resource);
 925
 926         kfree(resource);
 927         return 0;
 928 }
 929
 930 static int acpi_power_meter_resume(struct device *dev)
 931 {
 932         struct acpi_power_meter_resource *resource;
 933
 934         if (!dev)
 935                 return -EINVAL;
 936
 937         resource = acpi_driver_data(to_acpi_device(dev));
 938         if (!resource)
 939                 return -EINVAL;
 940
 941         free_capabilities(resource);
 942         read_capabilities(resource);
 943
 944         return 0;
 945 }
 946
 947 static SIMPLE_DEV_PM_OPS(acpi_power_meter_pm, NULL, acpi_power_meter_resume);
 948
 949 static struct acpi_driver acpi_power_meter_driver = {
 950         .name = "power_meter",
 951         .class = ACPI_POWER_METER_CLASS,
 952         .ids = power_meter_ids,
 953         .ops = {
 954                 .add = acpi_power_meter_add,
 955                 .remove = acpi_power_meter_remove,
 956                 .notify = acpi_power_meter_notify,
 957                 },
 958         .drv.pm = &acpi_power_meter_pm,
 959 };
 960
 961 /* Module init/exit routines */
 962 static int __init enable_cap_knobs(const struct dmi_system_id *d)
 963 {
 964         cap_in_hardware = 1;
 965         return 0;
 966 }
 967
 968 static struct dmi_system_id __initdata pm_dmi_table[] = {
 969         {
 970                 enable_cap_knobs, "IBM Active Energy Manager",
 971                 {
 972                         DMI_MATCH(DMI_SYS_VENDOR, "IBM")
 973                 },
 974         },
 975         {}
 976 };
 977
 978 static int __init acpi_power_meter_init(void)
 979 {
 980         int result;
 981
 982         if (acpi_disabled)
 983                 return -ENODEV;
 984
 985         dmi_check_system(pm_dmi_table);
 986
 987         result = acpi_bus_register_driver(&acpi_power_meter_driver);
 988         if (result < 0)
 989                 return -ENODEV;
 990
 991         return 0;
 992 }
 993
 994 static void __exit acpi_power_meter_exit(void)
 995 {
 996         acpi_bus_unregister_driver(&acpi_power_meter_driver);
 997 }
 998
 999 MODULE_AUTHOR("Darrick J. Wong <djwong@us.ibm.com>");
1000 MODULE_DESCRIPTION("ACPI 4.0 power meter driver");
1001 MODULE_LICENSE("GPL");
1002
1003 module_param(force_cap_on, bool, 0644);
1004 MODULE_PARM_DESC(force_cap_on, "Enable power cap even it is unsafe to do so.");
1005
1006 module_init(acpi_power_meter_init);
1007 module_exit(acpi_power_meter_exit);