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         int                     trip[2];
 105         int                     num_domain_devices;
 106         struct acpi_device      **domain_devices;
 107         struct kobject          *holders_dir;
 108 };
 109
 110 struct ro_sensor_template {
 111         char *label;
 112         ssize_t (*show)(struct device *dev,
 113                         struct device_attribute *devattr,
 114                         char *buf);
 115         int index;
 116 };
 117
 118 struct rw_sensor_template {
 119         char *label;
 120         ssize_t (*show)(struct device *dev,
 121                         struct device_attribute *devattr,
 122                         char *buf);
 123         ssize_t (*set)(struct device *dev,
 124                        struct device_attribute *devattr,
 125                        const char *buf, size_t count);
 126         int index;
 127 };
 128
 129 /* Averaging interval */
 130 static int update_avg_interval(struct acpi_power_meter_resource *resource)
 131 {
 132         unsigned long long data;
 133         acpi_status status;
 134
 135         status = acpi_evaluate_integer(resource->acpi_dev->handle, "_GAI",
 136                                        NULL, &data);
 137         if (ACPI_FAILURE(status)) {
 138                 ACPI_EXCEPTION((AE_INFO, status, "Evaluating _GAI"));
 139                 return -ENODEV;
 140         }
 141
 142         resource->avg_interval = data;
 143         return 0;
 144 }
 145
 146 static ssize_t show_avg_interval(struct device *dev,
 147                                  struct device_attribute *devattr,
 148                                  char *buf)
 149 {
 150         struct acpi_device *acpi_dev = to_acpi_device(dev);
 151         struct acpi_power_meter_resource *resource = acpi_dev->driver_data;
 152
 153         mutex_lock(&resource->lock);
 154         update_avg_interval(resource);
 155         mutex_unlock(&resource->lock);
 156
 157         return sprintf(buf, "%llu\n", resource->avg_interval);
 158 }
 159
 160 static ssize_t set_avg_interval(struct device *dev,
 161                                 struct device_attribute *devattr,
 162                                 const char *buf, size_t count)
 163 {
 164         struct acpi_device *acpi_dev = to_acpi_device(dev);
 165         struct acpi_power_meter_resource *resource = acpi_dev->driver_data;
 166         union acpi_object arg0 = { ACPI_TYPE_INTEGER };
 167         struct acpi_object_list args = { 1, &arg0 };
 168         int res;
 169         unsigned long temp;
 170         unsigned long long data;
 171         acpi_status status;
 172
 173         res = kstrtoul(buf, 10, &temp);
 174         if (res)
 175                 return res;
 176
 177         if (temp > resource->caps.max_avg_interval ||
 178             temp < resource->caps.min_avg_interval)
 179                 return -EINVAL;
 180         arg0.integer.value = temp;
 181
 182         mutex_lock(&resource->lock);
 183         status = acpi_evaluate_integer(resource->acpi_dev->handle, "_PAI",
 184                                        &args, &data);
 185         if (!ACPI_FAILURE(status))
 186                 resource->avg_interval = temp;
 187         mutex_unlock(&resource->lock);
 188
 189         if (ACPI_FAILURE(status)) {
 190                 ACPI_EXCEPTION((AE_INFO, status, "Evaluating _PAI"));
 191                 return -EINVAL;
 192         }
 193
 194         /* _PAI returns 0 on success, nonzero otherwise */
 195         if (data)
 196                 return -EINVAL;
 197
 198         return count;
 199 }
 200
 201 /* Cap functions */
 202 static int update_cap(struct acpi_power_meter_resource *resource)
 203 {
 204         unsigned long long data;
 205         acpi_status status;
 206
 207         status = acpi_evaluate_integer(resource->acpi_dev->handle, "_GHL",
 208                                        NULL, &data);
 209         if (ACPI_FAILURE(status)) {
 210                 ACPI_EXCEPTION((AE_INFO, status, "Evaluating _GHL"));
 211                 return -ENODEV;
 212         }
 213
 214         resource->cap = data;
 215         return 0;
 216 }
 217
 218 static ssize_t show_cap(struct device *dev,
 219                         struct device_attribute *devattr,
 220                         char *buf)
 221 {
 222         struct acpi_device *acpi_dev = to_acpi_device(dev);
 223         struct acpi_power_meter_resource *resource = acpi_dev->driver_data;
 224
 225         mutex_lock(&resource->lock);
 226         update_cap(resource);
 227         mutex_unlock(&resource->lock);
 228
 229         return sprintf(buf, "%llu\n", resource->cap * 1000);
 230 }
 231
 232 static ssize_t set_cap(struct device *dev, struct device_attribute *devattr,
 233                        const char *buf, size_t count)
 234 {
 235         struct acpi_device *acpi_dev = to_acpi_device(dev);
 236         struct acpi_power_meter_resource *resource = acpi_dev->driver_data;
 237         union acpi_object arg0 = { ACPI_TYPE_INTEGER };
 238         struct acpi_object_list args = { 1, &arg0 };
 239         int res;
 240         unsigned long temp;
 241         unsigned long long data;
 242         acpi_status status;
 243
 244         res = kstrtoul(buf, 10, &temp);
 245         if (res)
 246                 return res;
 247
 248         temp /= 1000;
 249         if (temp > resource->caps.max_cap || temp < resource->caps.min_cap)
 250                 return -EINVAL;
 251         arg0.integer.value = temp;
 252
 253         mutex_lock(&resource->lock);
 254         status = acpi_evaluate_integer(resource->acpi_dev->handle, "_SHL",
 255                                        &args, &data);
 256         if (!ACPI_FAILURE(status))
 257                 resource->cap = temp;
 258         mutex_unlock(&resource->lock);
 259
 260         if (ACPI_FAILURE(status)) {
 261                 ACPI_EXCEPTION((AE_INFO, status, "Evaluating _SHL"));
 262                 return -EINVAL;
 263         }
 264
 265         /* _SHL returns 0 on success, nonzero otherwise */
 266         if (data)
 267                 return -EINVAL;
 268
 269         return count;
 270 }
 271
 272 /* Power meter trip points */
 273 static int set_acpi_trip(struct acpi_power_meter_resource *resource)
 274 {
 275         union acpi_object arg_objs[] = {
 276                 {ACPI_TYPE_INTEGER},
 277                 {ACPI_TYPE_INTEGER}
 278         };
 279         struct acpi_object_list args = { 2, arg_objs };
 280         unsigned long long data;
 281         acpi_status status;
 282
 283         /* Both trip levels must be set */
 284         if (resource->trip[0] < 0 || resource->trip[1] < 0)
 285                 return 0;
 286
 287         /* This driver stores min, max; ACPI wants max, min. */
 288         arg_objs[0].integer.value = resource->trip[1];
 289         arg_objs[1].integer.value = resource->trip[0];
 290
 291         status = acpi_evaluate_integer(resource->acpi_dev->handle, "_PTP",
 292                                        &args, &data);
 293         if (ACPI_FAILURE(status)) {
 294                 ACPI_EXCEPTION((AE_INFO, status, "Evaluating _PTP"));
 295                 return -EINVAL;
 296         }
 297
 298         /* _PTP returns 0 on success, nonzero otherwise */
 299         if (data)
 300                 return -EINVAL;
 301
 302         return 0;
 303 }
 304
 305 static ssize_t set_trip(struct device *dev, struct device_attribute *devattr,
 306                         const char *buf, size_t count)
 307 {
 308         struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
 309         struct acpi_device *acpi_dev = to_acpi_device(dev);
 310         struct acpi_power_meter_resource *resource = acpi_dev->driver_data;
 311         int res;
 312         unsigned long temp;
 313
 314         res = kstrtoul(buf, 10, &temp);
 315         if (res)
 316                 return res;
 317
 318         temp /= 1000;
 319         if (temp < 0)
 320                 return -EINVAL;
 321
 322         mutex_lock(&resource->lock);
 323         resource->trip[attr->index - 7] = temp;
 324         res = set_acpi_trip(resource);
 325         mutex_unlock(&resource->lock);
 326
 327         if (res)
 328                 return res;
 329
 330         return count;
 331 }
 332
 333 /* Power meter */
 334 static int update_meter(struct acpi_power_meter_resource *resource)
 335 {
 336         unsigned long long data;
 337         acpi_status status;
 338         unsigned long local_jiffies = jiffies;
 339
 340         if (time_before(local_jiffies, resource->sensors_last_updated +
 341                         msecs_to_jiffies(resource->caps.sampling_time)) &&
 342                         resource->sensors_valid)
 343                 return 0;
 344
 345         status = acpi_evaluate_integer(resource->acpi_dev->handle, "_PMM",
 346                                        NULL, &data);
 347         if (ACPI_FAILURE(status)) {
 348                 ACPI_EXCEPTION((AE_INFO, status, "Evaluating _PMM"));
 349                 return -ENODEV;
 350         }
 351
 352         resource->power = data;
 353         resource->sensors_valid = 1;
 354         resource->sensors_last_updated = jiffies;
 355         return 0;
 356 }
 357
 358 static ssize_t show_power(struct device *dev,
 359                           struct device_attribute *devattr,
 360                           char *buf)
 361 {
 362         struct acpi_device *acpi_dev = to_acpi_device(dev);
 363         struct acpi_power_meter_resource *resource = acpi_dev->driver_data;
 364
 365         mutex_lock(&resource->lock);
 366         update_meter(resource);
 367         mutex_unlock(&resource->lock);
 368
 369         return sprintf(buf, "%llu\n", resource->power * 1000);
 370 }
 371
 372 /* Miscellaneous */
 373 static ssize_t show_str(struct device *dev,
 374                         struct device_attribute *devattr,
 375                         char *buf)
 376 {
 377         struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
 378         struct acpi_device *acpi_dev = to_acpi_device(dev);
 379         struct acpi_power_meter_resource *resource = acpi_dev->driver_data;
 380         acpi_string val;
 381
 382         switch (attr->index) {
 383         case 0:
 384                 val = resource->model_number;
 385                 break;
 386         case 1:
 387                 val = resource->serial_number;
 388                 break;
 389         case 2:
 390                 val = resource->oem_info;
 391                 break;
 392         default:
 393                 BUG();
 394                 val = "";
 395         }
 396
 397         return sprintf(buf, "%s\n", val);
 398 }
 399
 400 static ssize_t show_val(struct device *dev,
 401                         struct device_attribute *devattr,
 402                         char *buf)
 403 {
 404         struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
 405         struct acpi_device *acpi_dev = to_acpi_device(dev);
 406         struct acpi_power_meter_resource *resource = acpi_dev->driver_data;
 407         u64 val = 0;
 408
 409         switch (attr->index) {
 410         case 0:
 411                 val = resource->caps.min_avg_interval;
 412                 break;
 413         case 1:
 414                 val = resource->caps.max_avg_interval;
 415                 break;
 416         case 2:
 417                 val = resource->caps.min_cap * 1000;
 418                 break;
 419         case 3:
 420                 val = resource->caps.max_cap * 1000;
 421                 break;
 422         case 4:
 423                 if (resource->caps.hysteresis == UNKNOWN_HYSTERESIS)
 424                         return sprintf(buf, "unknown\n");
 425
 426                 val = resource->caps.hysteresis * 1000;
 427                 break;
 428         case 5:
 429                 if (resource->caps.flags & POWER_METER_IS_BATTERY)
 430                         val = 1;
 431                 else
 432                         val = 0;
 433                 break;
 434         case 6:
 435                 if (resource->power > resource->cap)
 436                         val = 1;
 437                 else
 438                         val = 0;
 439                 break;
 440         case 7:
 441         case 8:
 442                 if (resource->trip[attr->index - 7] < 0)
 443                         return sprintf(buf, "unknown\n");
 444
 445                 val = resource->trip[attr->index - 7] * 1000;
 446                 break;
 447         default:
 448                 BUG();
 449         }
 450
 451         return sprintf(buf, "%llu\n", val);
 452 }
 453
 454 static ssize_t show_accuracy(struct device *dev,
 455                              struct device_attribute *devattr,
 456                              char *buf)
 457 {
 458         struct acpi_device *acpi_dev = to_acpi_device(dev);
 459         struct acpi_power_meter_resource *resource = acpi_dev->driver_data;
 460         unsigned int acc = resource->caps.accuracy;
 461
 462         return sprintf(buf, "%u.%u%%\n", acc / 1000, acc % 1000);
 463 }
 464
 465 static ssize_t show_name(struct device *dev,
 466                          struct device_attribute *devattr,
 467                          char *buf)
 468 {
 469         return sprintf(buf, "%s\n", ACPI_POWER_METER_NAME);
 470 }
 471
 472 /* Sensor descriptions.  If you add a sensor, update NUM_SENSORS above! */
 473 static struct ro_sensor_template meter_ro_attrs[] = {
 474 {POWER_AVERAGE_NAME, show_power, 0},
 475 {"power1_accuracy", show_accuracy, 0},
 476 {"power1_average_interval_min", show_val, 0},
 477 {"power1_average_interval_max", show_val, 1},
 478 {"power1_is_battery", show_val, 5},
 479 {NULL, NULL, 0},
 480 };
 481
 482 static struct rw_sensor_template meter_rw_attrs[] = {
 483 {POWER_AVG_INTERVAL_NAME, show_avg_interval, set_avg_interval, 0},
 484 {NULL, NULL, NULL, 0},
 485 };
 486
 487 static struct ro_sensor_template misc_cap_attrs[] = {
 488 {"power1_cap_min", show_val, 2},
 489 {"power1_cap_max", show_val, 3},
 490 {"power1_cap_hyst", show_val, 4},
 491 {POWER_ALARM_NAME, show_val, 6},
 492 {NULL, NULL, 0},
 493 };
 494
 495 static struct ro_sensor_template ro_cap_attrs[] = {
 496 {POWER_CAP_NAME, show_cap, 0},
 497 {NULL, NULL, 0},
 498 };
 499
 500 static struct rw_sensor_template rw_cap_attrs[] = {
 501 {POWER_CAP_NAME, show_cap, set_cap, 0},
 502 {NULL, NULL, NULL, 0},
 503 };
 504
 505 static struct rw_sensor_template trip_attrs[] = {
 506 {"power1_average_min", show_val, set_trip, 7},
 507 {"power1_average_max", show_val, set_trip, 8},
 508 {NULL, NULL, NULL, 0},
 509 };
 510
 511 static struct ro_sensor_template misc_attrs[] = {
 512 {"name", show_name, 0},
 513 {"power1_model_number", show_str, 0},
 514 {"power1_oem_info", show_str, 2},
 515 {"power1_serial_number", show_str, 1},
 516 {NULL, NULL, 0},
 517 };
 518
 519 /* Read power domain data */
 520 static void remove_domain_devices(struct acpi_power_meter_resource *resource)
 521 {
 522         int i;
 523
 524         if (!resource->num_domain_devices)
 525                 return;
 526
 527         for (i = 0; i < resource->num_domain_devices; i++) {
 528                 struct acpi_device *obj = resource->domain_devices[i];
 529                 if (!obj)
 530                         continue;
 531
 532                 sysfs_remove_link(resource->holders_dir,
 533                                   kobject_name(&obj->dev.kobj));
 534                 put_device(&obj->dev);
 535         }
 536
 537         kfree(resource->domain_devices);
 538         kobject_put(resource->holders_dir);
 539         resource->num_domain_devices = 0;
 540 }
 541
 542 static int read_domain_devices(struct acpi_power_meter_resource *resource)
 543 {
 544         int res = 0;
 545         int i;
 546         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
 547         union acpi_object *pss;
 548         acpi_status status;
 549
 550         status = acpi_evaluate_object(resource->acpi_dev->handle, "_PMD", NULL,
 551                                       &buffer);
 552         if (ACPI_FAILURE(status)) {
 553                 ACPI_EXCEPTION((AE_INFO, status, "Evaluating _PMD"));
 554                 return -ENODEV;
 555         }
 556
 557         pss = buffer.pointer;
 558         if (!pss ||
 559             pss->type != ACPI_TYPE_PACKAGE) {
 560                 dev_err(&resource->acpi_dev->dev, ACPI_POWER_METER_NAME
 561                         "Invalid _PMD data\n");
 562                 res = -EFAULT;
 563                 goto end;
 564         }
 565
 566         if (!pss->package.count)
 567                 goto end;
 568
 569         resource->domain_devices = kzalloc(sizeof(struct acpi_device *) *
 570                                            pss->package.count, GFP_KERNEL);
 571         if (!resource->domain_devices) {
 572                 res = -ENOMEM;
 573                 goto end;
 574         }
 575
 576         resource->holders_dir = kobject_create_and_add("measures",
 577                                         &resource->acpi_dev->dev.kobj);
 578         if (!resource->holders_dir) {
 579                 res = -ENOMEM;
 580                 goto exit_free;
 581         }
 582
 583         resource->num_domain_devices = pss->package.count;
 584
 585         for (i = 0; i < pss->package.count; i++) {
 586                 struct acpi_device *obj;
 587                 union acpi_object *element = &(pss->package.elements[i]);
 588
 589                 /* Refuse non-references */
 590                 if (element->type != ACPI_TYPE_LOCAL_REFERENCE)
 591                         continue;
 592
 593                 /* Create a symlink to domain objects */
 594                 resource->domain_devices[i] = NULL;
 595                 status = acpi_bus_get_device(element->reference.handle,
 596                                              &resource->domain_devices[i]);
 597                 if (ACPI_FAILURE(status))
 598                         continue;
 599
 600                 obj = resource->domain_devices[i];
 601                 get_device(&obj->dev);
 602
 603                 res = sysfs_create_link(resource->holders_dir, &obj->dev.kobj,
 604                                       kobject_name(&obj->dev.kobj));
 605                 if (res) {
 606                         put_device(&obj->dev);
 607                         resource->domain_devices[i] = NULL;
 608                 }
 609         }
 610
 611         res = 0;
 612         goto end;
 613
 614 exit_free:
 615         kfree(resource->domain_devices);
 616 end:
 617         kfree(buffer.pointer);
 618         return res;
 619 }
 620
 621 /* Registration and deregistration */
 622 static int register_ro_attrs(struct acpi_power_meter_resource *resource,
 623                              struct ro_sensor_template *ro)
 624 {
 625         struct device *dev = &resource->acpi_dev->dev;
 626         struct sensor_device_attribute *sensors =
 627                 &resource->sensors[resource->num_sensors];
 628         int res = 0;
 629
 630         while (ro->label) {
 631                 sensors->dev_attr.attr.name = ro->label;
 632                 sensors->dev_attr.attr.mode = S_IRUGO;
 633                 sensors->dev_attr.show = ro->show;
 634                 sensors->index = ro->index;
 635
 636                 sysfs_attr_init(&sensors->dev_attr.attr);
 637                 res = device_create_file(dev, &sensors->dev_attr);
 638                 if (res) {
 639                         sensors->dev_attr.attr.name = NULL;
 640                         goto error;
 641                 }
 642                 sensors++;
 643                 resource->num_sensors++;
 644                 ro++;
 645         }
 646
 647 error:
 648         return res;
 649 }
 650
 651 static int register_rw_attrs(struct acpi_power_meter_resource *resource,
 652                              struct rw_sensor_template *rw)
 653 {
 654         struct device *dev = &resource->acpi_dev->dev;
 655         struct sensor_device_attribute *sensors =
 656                 &resource->sensors[resource->num_sensors];
 657         int res = 0;
 658
 659         while (rw->label) {
 660                 sensors->dev_attr.attr.name = rw->label;
 661                 sensors->dev_attr.attr.mode = S_IRUGO | S_IWUSR;
 662                 sensors->dev_attr.show = rw->show;
 663                 sensors->dev_attr.store = rw->set;
 664                 sensors->index = rw->index;
 665
 666                 sysfs_attr_init(&sensors->dev_attr.attr);
 667                 res = device_create_file(dev, &sensors->dev_attr);
 668                 if (res) {
 669                         sensors->dev_attr.attr.name = NULL;
 670                         goto error;
 671                 }
 672                 sensors++;
 673                 resource->num_sensors++;
 674                 rw++;
 675         }
 676
 677 error:
 678         return res;
 679 }
 680
 681 static void remove_attrs(struct acpi_power_meter_resource *resource)
 682 {
 683         int i;
 684
 685         for (i = 0; i < resource->num_sensors; i++) {
 686                 if (!resource->sensors[i].dev_attr.attr.name)
 687                         continue;
 688                 device_remove_file(&resource->acpi_dev->dev,
 689                                    &resource->sensors[i].dev_attr);
 690         }
 691
 692         remove_domain_devices(resource);
 693
 694         resource->num_sensors = 0;
 695 }
 696
 697 static int setup_attrs(struct acpi_power_meter_resource *resource)
 698 {
 699         int res = 0;
 700
 701         res = read_domain_devices(resource);
 702         if (res)
 703                 return res;
 704
 705         if (resource->caps.flags & POWER_METER_CAN_MEASURE) {
 706                 res = register_ro_attrs(resource, meter_ro_attrs);
 707                 if (res)
 708                         goto error;
 709                 res = register_rw_attrs(resource, meter_rw_attrs);
 710                 if (res)
 711                         goto error;
 712         }
 713
 714         if (resource->caps.flags & POWER_METER_CAN_CAP) {
 715                 if (!can_cap_in_hardware()) {
 716                         dev_err(&resource->acpi_dev->dev,
 717                                 "Ignoring unsafe software power cap!\n");
 718                         goto skip_unsafe_cap;
 719                 }
 720
 721                 if (resource->caps.configurable_cap) {
 722                         res = register_rw_attrs(resource, rw_cap_attrs);
 723                         if (res)
 724                                 goto error;
 725                 } else {
 726                         res = register_ro_attrs(resource, ro_cap_attrs);
 727                         if (res)
 728                                 goto error;
 729                 }
 730                 res = register_ro_attrs(resource, misc_cap_attrs);
 731                 if (res)
 732                         goto error;
 733         }
 734 skip_unsafe_cap:
 735
 736         if (resource->caps.flags & POWER_METER_CAN_TRIP) {
 737                 res = register_rw_attrs(resource, trip_attrs);
 738                 if (res)
 739                         goto error;
 740         }
 741
 742         res = register_ro_attrs(resource, misc_attrs);
 743         if (res)
 744                 goto error;
 745
 746         return res;
 747 error:
 748         remove_attrs(resource);
 749         return res;
 750 }
 751
 752 static void free_capabilities(struct acpi_power_meter_resource *resource)
 753 {
 754         acpi_string *str;
 755         int i;
 756
 757         str = &resource->model_number;
 758         for (i = 0; i < 3; i++, str++)
 759                 kfree(*str);
 760 }
 761
 762 static int read_capabilities(struct acpi_power_meter_resource *resource)
 763 {
 764         int res = 0;
 765         int i;
 766         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
 767         struct acpi_buffer state = { 0, NULL };
 768         struct acpi_buffer format = { sizeof("NNNNNNNNNNN"), "NNNNNNNNNNN" };
 769         union acpi_object *pss;
 770         acpi_string *str;
 771         acpi_status status;
 772
 773         status = acpi_evaluate_object(resource->acpi_dev->handle, "_PMC", NULL,
 774                                       &buffer);
 775         if (ACPI_FAILURE(status)) {
 776                 ACPI_EXCEPTION((AE_INFO, status, "Evaluating _PMC"));
 777                 return -ENODEV;
 778         }
 779
 780         pss = buffer.pointer;
 781         if (!pss ||
 782             pss->type != ACPI_TYPE_PACKAGE ||
 783             pss->package.count != 14) {
 784                 dev_err(&resource->acpi_dev->dev, ACPI_POWER_METER_NAME
 785                         "Invalid _PMC data\n");
 786                 res = -EFAULT;
 787                 goto end;
 788         }
 789
 790         /* Grab all the integer data at once */
 791         state.length = sizeof(struct acpi_power_meter_capabilities);
 792         state.pointer = &resource->caps;
 793
 794         status = acpi_extract_package(pss, &format, &state);
 795         if (ACPI_FAILURE(status)) {
 796                 ACPI_EXCEPTION((AE_INFO, status, "Invalid data"));
 797                 res = -EFAULT;
 798                 goto end;
 799         }
 800
 801         if (resource->caps.units) {
 802                 dev_err(&resource->acpi_dev->dev, ACPI_POWER_METER_NAME
 803                         "Unknown units %llu.\n",
 804                         resource->caps.units);
 805                 res = -EINVAL;
 806                 goto end;
 807         }
 808
 809         /* Grab the string data */
 810         str = &resource->model_number;
 811
 812         for (i = 11; i < 14; i++) {
 813                 union acpi_object *element = &(pss->package.elements[i]);
 814
 815                 if (element->type != ACPI_TYPE_STRING) {
 816                         res = -EINVAL;
 817                         goto error;
 818                 }
 819
 820                 *str = kzalloc(sizeof(u8) * (element->string.length + 1),
 821                                GFP_KERNEL);
 822                 if (!*str) {
 823                         res = -ENOMEM;
 824                         goto error;
 825                 }
 826
 827                 strncpy(*str, element->string.pointer, element->string.length);
 828                 str++;
 829         }
 830
 831         dev_info(&resource->acpi_dev->dev, "Found ACPI power meter.\n");
 832         goto end;
 833 error:
 834         str = &resource->model_number;
 835         for (i = 0; i < 3; i++, str++)
 836                 kfree(*str);
 837 end:
 838         kfree(buffer.pointer);
 839         return res;
 840 }
 841
 842 /* Handle ACPI event notifications */
 843 static void acpi_power_meter_notify(struct acpi_device *device, u32 event)
 844 {
 845         struct acpi_power_meter_resource *resource;
 846         int res;
 847
 848         if (!device || !acpi_driver_data(device))
 849                 return;
 850
 851         resource = acpi_driver_data(device);
 852
 853         mutex_lock(&resource->lock);
 854         switch (event) {
 855         case METER_NOTIFY_CONFIG:
 856                 free_capabilities(resource);
 857                 res = read_capabilities(resource);
 858                 if (res)
 859                         break;
 860
 861                 remove_attrs(resource);
 862                 setup_attrs(resource);
 863                 break;
 864         case METER_NOTIFY_TRIP:
 865                 sysfs_notify(&device->dev.kobj, NULL, POWER_AVERAGE_NAME);
 866                 update_meter(resource);
 867                 break;
 868         case METER_NOTIFY_CAP:
 869                 sysfs_notify(&device->dev.kobj, NULL, POWER_CAP_NAME);
 870                 update_cap(resource);
 871                 break;
 872         case METER_NOTIFY_INTERVAL:
 873                 sysfs_notify(&device->dev.kobj, NULL, POWER_AVG_INTERVAL_NAME);
 874                 update_avg_interval(resource);
 875                 break;
 876         case METER_NOTIFY_CAPPING:
 877                 sysfs_notify(&device->dev.kobj, NULL, POWER_ALARM_NAME);
 878                 dev_info(&device->dev, "Capping in progress.\n");
 879                 break;
 880         default:
 881                 BUG();
 882         }
 883         mutex_unlock(&resource->lock);
 884
 885         acpi_bus_generate_netlink_event(ACPI_POWER_METER_CLASS,
 886                                         dev_name(&device->dev), event, 0);
 887 }
 888
 889 static int acpi_power_meter_add(struct acpi_device *device)
 890 {
 891         int res;
 892         struct acpi_power_meter_resource *resource;
 893
 894         if (!device)
 895                 return -EINVAL;
 896
 897         resource = kzalloc(sizeof(struct acpi_power_meter_resource),
 898                            GFP_KERNEL);
 899         if (!resource)
 900                 return -ENOMEM;
 901
 902         resource->sensors_valid = 0;
 903         resource->acpi_dev = device;
 904         mutex_init(&resource->lock);
 905         strcpy(acpi_device_name(device), ACPI_POWER_METER_DEVICE_NAME);
 906         strcpy(acpi_device_class(device), ACPI_POWER_METER_CLASS);
 907         device->driver_data = resource;
 908
 909         free_capabilities(resource);
 910         res = read_capabilities(resource);
 911         if (res)
 912                 goto exit_free;
 913
 914         resource->trip[0] = resource->trip[1] = -1;
 915
 916         res = setup_attrs(resource);
 917         if (res)
 918                 goto exit_free;
 919
 920         resource->hwmon_dev = hwmon_device_register(&device->dev);
 921         if (IS_ERR(resource->hwmon_dev)) {
 922                 res = PTR_ERR(resource->hwmon_dev);
 923                 goto exit_remove;
 924         }
 925
 926         res = 0;
 927         goto exit;
 928
 929 exit_remove:
 930         remove_attrs(resource);
 931 exit_free:
 932         kfree(resource);
 933 exit:
 934         return res;
 935 }
 936
 937 static int acpi_power_meter_remove(struct acpi_device *device, int type)
 938 {
 939         struct acpi_power_meter_resource *resource;
 940
 941         if (!device || !acpi_driver_data(device))
 942                 return -EINVAL;
 943
 944         resource = acpi_driver_data(device);
 945         hwmon_device_unregister(resource->hwmon_dev);
 946
 947         free_capabilities(resource);
 948         remove_attrs(resource);
 949
 950         kfree(resource);
 951         return 0;
 952 }
 953
 954 static int acpi_power_meter_resume(struct acpi_device *device)
 955 {
 956         struct acpi_power_meter_resource *resource;
 957
 958         if (!device || !acpi_driver_data(device))
 959                 return -EINVAL;
 960
 961         resource = acpi_driver_data(device);
 962         free_capabilities(resource);
 963         read_capabilities(resource);
 964
 965         return 0;
 966 }
 967
 968 static struct acpi_driver acpi_power_meter_driver = {
 969         .name = "power_meter",
 970         .class = ACPI_POWER_METER_CLASS,
 971         .ids = power_meter_ids,
 972         .ops = {
 973                 .add = acpi_power_meter_add,
 974                 .remove = acpi_power_meter_remove,
 975                 .resume = acpi_power_meter_resume,
 976                 .notify = acpi_power_meter_notify,
 977                 },
 978 };
 979
 980 /* Module init/exit routines */
 981 static int __init enable_cap_knobs(const struct dmi_system_id *d)
 982 {
 983         cap_in_hardware = 1;
 984         return 0;
 985 }
 986
 987 static struct dmi_system_id __initdata pm_dmi_table[] = {
 988         {
 989                 enable_cap_knobs, "IBM Active Energy Manager",
 990                 {
 991                         DMI_MATCH(DMI_SYS_VENDOR, "IBM")
 992                 },
 993         },
 994         {}
 995 };
 996
 997 static int __init acpi_power_meter_init(void)
 998 {
 999         int result;
1000
1001         if (acpi_disabled)
1002                 return -ENODEV;
1003
1004         dmi_check_system(pm_dmi_table);
1005
1006         result = acpi_bus_register_driver(&acpi_power_meter_driver);
1007         if (result < 0)
1008                 return -ENODEV;
1009
1010         return 0;
1011 }
1012
1013 static void __exit acpi_power_meter_exit(void)
1014 {
1015         acpi_bus_unregister_driver(&acpi_power_meter_driver);
1016 }
1017
1018 MODULE_AUTHOR("Darrick J. Wong <djwong@us.ibm.com>");
1019 MODULE_DESCRIPTION("ACPI 4.0 power meter driver");
1020 MODULE_LICENSE("GPL");
1021
1022 module_param(force_cap_on, bool, 0644);
1023 MODULE_PARM_DESC(force_cap_on, "Enable power cap even it is unsafe to do so.");
1024
1025 module_init(acpi_power_meter_init);
1026 module_exit(acpi_power_meter_exit);