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 int 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 = strict_strtoul(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 = strict_strtoul(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 = strict_strtoul(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         }
 395
 396         return sprintf(buf, "%s\n", val);
 397 }
 398
 399 static ssize_t show_val(struct device *dev,
 400                         struct device_attribute *devattr,
 401                         char *buf)
 402 {
 403         struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
 404         struct acpi_device *acpi_dev = to_acpi_device(dev);
 405         struct acpi_power_meter_resource *resource = acpi_dev->driver_data;
 406         u64 val = 0;
 407
 408         switch (attr->index) {
 409         case 0:
 410                 val = resource->caps.min_avg_interval;
 411                 break;
 412         case 1:
 413                 val = resource->caps.max_avg_interval;
 414                 break;
 415         case 2:
 416                 val = resource->caps.min_cap * 1000;
 417                 break;
 418         case 3:
 419                 val = resource->caps.max_cap * 1000;
 420                 break;
 421         case 4:
 422                 if (resource->caps.hysteresis == UNKNOWN_HYSTERESIS)
 423                         return sprintf(buf, "unknown\n");
 424
 425                 val = resource->caps.hysteresis * 1000;
 426                 break;
 427         case 5:
 428                 if (resource->caps.flags & POWER_METER_IS_BATTERY)
 429                         val = 1;
 430                 else
 431                         val = 0;
 432                 break;
 433         case 6:
 434                 if (resource->power > resource->cap)
 435                         val = 1;
 436                 else
 437                         val = 0;
 438                 break;
 439         case 7:
 440         case 8:
 441                 if (resource->trip[attr->index - 7] < 0)
 442                         return sprintf(buf, "unknown\n");
 443
 444                 val = resource->trip[attr->index - 7] * 1000;
 445                 break;
 446         default:
 447                 BUG();
 448         }
 449
 450         return sprintf(buf, "%llu\n", val);
 451 }
 452
 453 static ssize_t show_accuracy(struct device *dev,
 454                              struct device_attribute *devattr,
 455                              char *buf)
 456 {
 457         struct acpi_device *acpi_dev = to_acpi_device(dev);
 458         struct acpi_power_meter_resource *resource = acpi_dev->driver_data;
 459         unsigned int acc = resource->caps.accuracy;
 460
 461         return sprintf(buf, "%u.%u%%\n", acc / 1000, acc % 1000);
 462 }
 463
 464 static ssize_t show_name(struct device *dev,
 465                          struct device_attribute *devattr,
 466                          char *buf)
 467 {
 468         return sprintf(buf, "%s\n", ACPI_POWER_METER_NAME);
 469 }
 470
 471 /* Sensor descriptions.  If you add a sensor, update NUM_SENSORS above! */
 472 static struct ro_sensor_template meter_ro_attrs[] = {
 473 {POWER_AVERAGE_NAME, show_power, 0},
 474 {"power1_accuracy", show_accuracy, 0},
 475 {"power1_average_interval_min", show_val, 0},
 476 {"power1_average_interval_max", show_val, 1},
 477 {"power1_is_battery", show_val, 5},
 478 {NULL, NULL, 0},
 479 };
 480
 481 static struct rw_sensor_template meter_rw_attrs[] = {
 482 {POWER_AVG_INTERVAL_NAME, show_avg_interval, set_avg_interval, 0},
 483 {NULL, NULL, NULL, 0},
 484 };
 485
 486 static struct ro_sensor_template misc_cap_attrs[] = {
 487 {"power1_cap_min", show_val, 2},
 488 {"power1_cap_max", show_val, 3},
 489 {"power1_cap_hyst", show_val, 4},
 490 {POWER_ALARM_NAME, show_val, 6},
 491 {NULL, NULL, 0},
 492 };
 493
 494 static struct ro_sensor_template ro_cap_attrs[] = {
 495 {POWER_CAP_NAME, show_cap, 0},
 496 {NULL, NULL, 0},
 497 };
 498
 499 static struct rw_sensor_template rw_cap_attrs[] = {
 500 {POWER_CAP_NAME, show_cap, set_cap, 0},
 501 {NULL, NULL, NULL, 0},
 502 };
 503
 504 static struct rw_sensor_template trip_attrs[] = {
 505 {"power1_average_min", show_val, set_trip, 7},
 506 {"power1_average_max", show_val, set_trip, 8},
 507 {NULL, NULL, NULL, 0},
 508 };
 509
 510 static struct ro_sensor_template misc_attrs[] = {
 511 {"name", show_name, 0},
 512 {"power1_model_number", show_str, 0},
 513 {"power1_oem_info", show_str, 2},
 514 {"power1_serial_number", show_str, 1},
 515 {NULL, NULL, 0},
 516 };
 517
 518 /* Read power domain data */
 519 static void remove_domain_devices(struct acpi_power_meter_resource *resource)
 520 {
 521         int i;
 522
 523         if (!resource->num_domain_devices)
 524                 return;
 525
 526         for (i = 0; i < resource->num_domain_devices; i++) {
 527                 struct acpi_device *obj = resource->domain_devices[i];
 528                 if (!obj)
 529                         continue;
 530
 531                 sysfs_remove_link(resource->holders_dir,
 532                                   kobject_name(&obj->dev.kobj));
 533                 put_device(&obj->dev);
 534         }
 535
 536         kfree(resource->domain_devices);
 537         kobject_put(resource->holders_dir);
 538         resource->num_domain_devices = 0;
 539 }
 540
 541 static int read_domain_devices(struct acpi_power_meter_resource *resource)
 542 {
 543         int res = 0;
 544         int i;
 545         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
 546         union acpi_object *pss;
 547         acpi_status status;
 548
 549         status = acpi_evaluate_object(resource->acpi_dev->handle, "_PMD", NULL,
 550                                       &buffer);
 551         if (ACPI_FAILURE(status)) {
 552                 ACPI_EXCEPTION((AE_INFO, status, "Evaluating _PMD"));
 553                 return -ENODEV;
 554         }
 555
 556         pss = buffer.pointer;
 557         if (!pss ||
 558             pss->type != ACPI_TYPE_PACKAGE) {
 559                 dev_err(&resource->acpi_dev->dev, ACPI_POWER_METER_NAME
 560                         "Invalid _PMD data\n");
 561                 res = -EFAULT;
 562                 goto end;
 563         }
 564
 565         if (!pss->package.count)
 566                 goto end;
 567
 568         resource->domain_devices = kzalloc(sizeof(struct acpi_device *) *
 569                                            pss->package.count, GFP_KERNEL);
 570         if (!resource->domain_devices) {
 571                 res = -ENOMEM;
 572                 goto end;
 573         }
 574
 575         resource->holders_dir = kobject_create_and_add("measures",
 576                                         &resource->acpi_dev->dev.kobj);
 577         if (!resource->holders_dir) {
 578                 res = -ENOMEM;
 579                 goto exit_free;
 580         }
 581
 582         resource->num_domain_devices = pss->package.count;
 583
 584         for (i = 0; i < pss->package.count; i++) {
 585                 struct acpi_device *obj;
 586                 union acpi_object *element = &(pss->package.elements[i]);
 587
 588                 /* Refuse non-references */
 589                 if (element->type != ACPI_TYPE_LOCAL_REFERENCE)
 590                         continue;
 591
 592                 /* Create a symlink to domain objects */
 593                 resource->domain_devices[i] = NULL;
 594                 status = acpi_bus_get_device(element->reference.handle,
 595                                              &resource->domain_devices[i]);
 596                 if (ACPI_FAILURE(status))
 597                         continue;
 598
 599                 obj = resource->domain_devices[i];
 600                 get_device(&obj->dev);
 601
 602                 res = sysfs_create_link(resource->holders_dir, &obj->dev.kobj,
 603                                       kobject_name(&obj->dev.kobj));
 604                 if (res) {
 605                         put_device(&obj->dev);
 606                         resource->domain_devices[i] = NULL;
 607                 }
 608         }
 609
 610         res = 0;
 611         goto end;
 612
 613 exit_free:
 614         kfree(resource->domain_devices);
 615 end:
 616         kfree(buffer.pointer);
 617         return res;
 618 }
 619
 620 /* Registration and deregistration */
 621 static int register_ro_attrs(struct acpi_power_meter_resource *resource,
 622                              struct ro_sensor_template *ro)
 623 {
 624         struct device *dev = &resource->acpi_dev->dev;
 625         struct sensor_device_attribute *sensors =
 626                 &resource->sensors[resource->num_sensors];
 627         int res = 0;
 628
 629         while (ro->label) {
 630                 sensors->dev_attr.attr.name = ro->label;
 631                 sensors->dev_attr.attr.mode = S_IRUGO;
 632                 sensors->dev_attr.show = ro->show;
 633                 sensors->index = ro->index;
 634
 635                 res = device_create_file(dev, &sensors->dev_attr);
 636                 if (res) {
 637                         sensors->dev_attr.attr.name = NULL;
 638                         goto error;
 639                 }
 640                 sensors++;
 641                 resource->num_sensors++;
 642                 ro++;
 643         }
 644
 645 error:
 646         return res;
 647 }
 648
 649 static int register_rw_attrs(struct acpi_power_meter_resource *resource,
 650                              struct rw_sensor_template *rw)
 651 {
 652         struct device *dev = &resource->acpi_dev->dev;
 653         struct sensor_device_attribute *sensors =
 654                 &resource->sensors[resource->num_sensors];
 655         int res = 0;
 656
 657         while (rw->label) {
 658                 sensors->dev_attr.attr.name = rw->label;
 659                 sensors->dev_attr.attr.mode = S_IRUGO | S_IWUSR;
 660                 sensors->dev_attr.show = rw->show;
 661                 sensors->dev_attr.store = rw->set;
 662                 sensors->index = rw->index;
 663
 664                 res = device_create_file(dev, &sensors->dev_attr);
 665                 if (res) {
 666                         sensors->dev_attr.attr.name = NULL;
 667                         goto error;
 668                 }
 669                 sensors++;
 670                 resource->num_sensors++;
 671                 rw++;
 672         }
 673
 674 error:
 675         return res;
 676 }
 677
 678 static void remove_attrs(struct acpi_power_meter_resource *resource)
 679 {
 680         int i;
 681
 682         for (i = 0; i < resource->num_sensors; i++) {
 683                 if (!resource->sensors[i].dev_attr.attr.name)
 684                         continue;
 685                 device_remove_file(&resource->acpi_dev->dev,
 686                                    &resource->sensors[i].dev_attr);
 687         }
 688
 689         remove_domain_devices(resource);
 690
 691         resource->num_sensors = 0;
 692 }
 693
 694 static int setup_attrs(struct acpi_power_meter_resource *resource)
 695 {
 696         int res = 0;
 697
 698         res = read_domain_devices(resource);
 699         if (res)
 700                 return res;
 701
 702         if (resource->caps.flags & POWER_METER_CAN_MEASURE) {
 703                 res = register_ro_attrs(resource, meter_ro_attrs);
 704                 if (res)
 705                         goto error;
 706                 res = register_rw_attrs(resource, meter_rw_attrs);
 707                 if (res)
 708                         goto error;
 709         }
 710
 711         if (resource->caps.flags & POWER_METER_CAN_CAP) {
 712                 if (!can_cap_in_hardware()) {
 713                         dev_err(&resource->acpi_dev->dev,
 714                                 "Ignoring unsafe software power cap!\n");
 715                         goto skip_unsafe_cap;
 716                 }
 717
 718                 if (resource->caps.configurable_cap) {
 719                         res = register_rw_attrs(resource, rw_cap_attrs);
 720                         if (res)
 721                                 goto error;
 722                 } else {
 723                         res = register_ro_attrs(resource, ro_cap_attrs);
 724                         if (res)
 725                                 goto error;
 726                 }
 727                 res = register_ro_attrs(resource, misc_cap_attrs);
 728                 if (res)
 729                         goto error;
 730         }
 731 skip_unsafe_cap:
 732
 733         if (resource->caps.flags & POWER_METER_CAN_TRIP) {
 734                 res = register_rw_attrs(resource, trip_attrs);
 735                 if (res)
 736                         goto error;
 737         }
 738
 739         res = register_ro_attrs(resource, misc_attrs);
 740         if (res)
 741                 goto error;
 742
 743         return res;
 744 error:
 745         remove_attrs(resource);
 746         return res;
 747 }
 748
 749 static void free_capabilities(struct acpi_power_meter_resource *resource)
 750 {
 751         acpi_string *str;
 752         int i;
 753
 754         str = &resource->model_number;
 755         for (i = 0; i < 3; i++, str++)
 756                 kfree(*str);
 757 }
 758
 759 static int read_capabilities(struct acpi_power_meter_resource *resource)
 760 {
 761         int res = 0;
 762         int i;
 763         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
 764         struct acpi_buffer state = { 0, NULL };
 765         struct acpi_buffer format = { sizeof("NNNNNNNNNNN"), "NNNNNNNNNNN" };
 766         union acpi_object *pss;
 767         acpi_string *str;
 768         acpi_status status;
 769
 770         status = acpi_evaluate_object(resource->acpi_dev->handle, "_PMC", NULL,
 771                                       &buffer);
 772         if (ACPI_FAILURE(status)) {
 773                 ACPI_EXCEPTION((AE_INFO, status, "Evaluating _PMC"));
 774                 return -ENODEV;
 775         }
 776
 777         pss = buffer.pointer;
 778         if (!pss ||
 779             pss->type != ACPI_TYPE_PACKAGE ||
 780             pss->package.count != 14) {
 781                 dev_err(&resource->acpi_dev->dev, ACPI_POWER_METER_NAME
 782                         "Invalid _PMC data\n");
 783                 res = -EFAULT;
 784                 goto end;
 785         }
 786
 787         /* Grab all the integer data at once */
 788         state.length = sizeof(struct acpi_power_meter_capabilities);
 789         state.pointer = &resource->caps;
 790
 791         status = acpi_extract_package(pss, &format, &state);
 792         if (ACPI_FAILURE(status)) {
 793                 ACPI_EXCEPTION((AE_INFO, status, "Invalid data"));
 794                 res = -EFAULT;
 795                 goto end;
 796         }
 797
 798         if (resource->caps.units) {
 799                 dev_err(&resource->acpi_dev->dev, ACPI_POWER_METER_NAME
 800                         "Unknown units %llu.\n",
 801                         resource->caps.units);
 802                 res = -EINVAL;
 803                 goto end;
 804         }
 805
 806         /* Grab the string data */
 807         str = &resource->model_number;
 808
 809         for (i = 11; i < 14; i++) {
 810                 union acpi_object *element = &(pss->package.elements[i]);
 811
 812                 if (element->type != ACPI_TYPE_STRING) {
 813                         res = -EINVAL;
 814                         goto error;
 815                 }
 816
 817                 *str = kzalloc(sizeof(u8) * (element->string.length + 1),
 818                                GFP_KERNEL);
 819                 if (!*str) {
 820                         res = -ENOMEM;
 821                         goto error;
 822                 }
 823
 824                 strncpy(*str, element->string.pointer, element->string.length);
 825                 str++;
 826         }
 827
 828         dev_info(&resource->acpi_dev->dev, "Found ACPI power meter.\n");
 829         goto end;
 830 error:
 831         str = &resource->model_number;
 832         for (i = 0; i < 3; i++, str++)
 833                 kfree(*str);
 834 end:
 835         kfree(buffer.pointer);
 836         return res;
 837 }
 838
 839 /* Handle ACPI event notifications */
 840 static void acpi_power_meter_notify(struct acpi_device *device, u32 event)
 841 {
 842         struct acpi_power_meter_resource *resource;
 843         int res;
 844
 845         if (!device || !acpi_driver_data(device))
 846                 return;
 847
 848         resource = acpi_driver_data(device);
 849
 850         mutex_lock(&resource->lock);
 851         switch (event) {
 852         case METER_NOTIFY_CONFIG:
 853                 free_capabilities(resource);
 854                 res = read_capabilities(resource);
 855                 if (res)
 856                         break;
 857
 858                 remove_attrs(resource);
 859                 setup_attrs(resource);
 860                 break;
 861         case METER_NOTIFY_TRIP:
 862                 sysfs_notify(&device->dev.kobj, NULL, POWER_AVERAGE_NAME);
 863                 update_meter(resource);
 864                 break;
 865         case METER_NOTIFY_CAP:
 866                 sysfs_notify(&device->dev.kobj, NULL, POWER_CAP_NAME);
 867                 update_cap(resource);
 868                 break;
 869         case METER_NOTIFY_INTERVAL:
 870                 sysfs_notify(&device->dev.kobj, NULL, POWER_AVG_INTERVAL_NAME);
 871                 update_avg_interval(resource);
 872                 break;
 873         case METER_NOTIFY_CAPPING:
 874                 sysfs_notify(&device->dev.kobj, NULL, POWER_ALARM_NAME);
 875                 dev_info(&device->dev, "Capping in progress.\n");
 876                 break;
 877         default:
 878                 BUG();
 879         }
 880         mutex_unlock(&resource->lock);
 881
 882         acpi_bus_generate_netlink_event(ACPI_POWER_METER_CLASS,
 883                                         dev_name(&device->dev), event, 0);
 884 }
 885
 886 static int acpi_power_meter_add(struct acpi_device *device)
 887 {
 888         int res;
 889         struct acpi_power_meter_resource *resource;
 890
 891         if (!device)
 892                 return -EINVAL;
 893
 894         resource = kzalloc(sizeof(struct acpi_power_meter_resource),
 895                            GFP_KERNEL);
 896         if (!resource)
 897                 return -ENOMEM;
 898
 899         resource->sensors_valid = 0;
 900         resource->acpi_dev = device;
 901         mutex_init(&resource->lock);
 902         strcpy(acpi_device_name(device), ACPI_POWER_METER_DEVICE_NAME);
 903         strcpy(acpi_device_class(device), ACPI_POWER_METER_CLASS);
 904         device->driver_data = resource;
 905
 906         free_capabilities(resource);
 907         res = read_capabilities(resource);
 908         if (res)
 909                 goto exit_free;
 910
 911         resource->trip[0] = resource->trip[1] = -1;
 912
 913         res = setup_attrs(resource);
 914         if (res)
 915                 goto exit_free;
 916
 917         resource->hwmon_dev = hwmon_device_register(&device->dev);
 918         if (IS_ERR(resource->hwmon_dev)) {
 919                 res = PTR_ERR(resource->hwmon_dev);
 920                 goto exit_remove;
 921         }
 922
 923         res = 0;
 924         goto exit;
 925
 926 exit_remove:
 927         remove_attrs(resource);
 928 exit_free:
 929         kfree(resource);
 930 exit:
 931         return res;
 932 }
 933
 934 static int acpi_power_meter_remove(struct acpi_device *device, int type)
 935 {
 936         struct acpi_power_meter_resource *resource;
 937
 938         if (!device || !acpi_driver_data(device))
 939                 return -EINVAL;
 940
 941         resource = acpi_driver_data(device);
 942         hwmon_device_unregister(resource->hwmon_dev);
 943
 944         free_capabilities(resource);
 945         remove_attrs(resource);
 946
 947         kfree(resource);
 948         return 0;
 949 }
 950
 951 static int acpi_power_meter_resume(struct acpi_device *device)
 952 {
 953         struct acpi_power_meter_resource *resource;
 954
 955         if (!device || !acpi_driver_data(device))
 956                 return -EINVAL;
 957
 958         resource = acpi_driver_data(device);
 959         free_capabilities(resource);
 960         read_capabilities(resource);
 961
 962         return 0;
 963 }
 964
 965 static struct acpi_driver acpi_power_meter_driver = {
 966         .name = "power_meter",
 967         .class = ACPI_POWER_METER_CLASS,
 968         .ids = power_meter_ids,
 969         .ops = {
 970                 .add = acpi_power_meter_add,
 971                 .remove = acpi_power_meter_remove,
 972                 .resume = acpi_power_meter_resume,
 973                 .notify = acpi_power_meter_notify,
 974                 },
 975 };
 976
 977 /* Module init/exit routines */
 978 static int __init enable_cap_knobs(const struct dmi_system_id *d)
 979 {
 980         cap_in_hardware = 1;
 981         return 0;
 982 }
 983
 984 static struct dmi_system_id __initdata pm_dmi_table[] = {
 985         {
 986                 enable_cap_knobs, "IBM Active Energy Manager",
 987                 {
 988                         DMI_MATCH(DMI_SYS_VENDOR, "IBM")
 989                 },
 990         },
 991         {}
 992 };
 993
 994 static int __init acpi_power_meter_init(void)
 995 {
 996         int result;
 997
 998         if (acpi_disabled)
 999                 return -ENODEV;
1000
1001         dmi_check_system(pm_dmi_table);
1002
1003         result = acpi_bus_register_driver(&acpi_power_meter_driver);
1004         if (result < 0)
1005                 return -ENODEV;
1006
1007         return 0;
1008 }
1009
1010 static void __exit acpi_power_meter_exit(void)
1011 {
1012         acpi_bus_unregister_driver(&acpi_power_meter_driver);
1013 }
1014
1015 MODULE_AUTHOR("Darrick J. Wong <djwong@us.ibm.com>");
1016 MODULE_DESCRIPTION("ACPI 4.0 power meter driver");
1017 MODULE_LICENSE("GPL");
1018
1019 module_param(force_cap_on, bool, 0644);
1020 MODULE_PARM_DESC(force_cap_on, "Enable power cap even it is unsafe to do so.");
1021
1022 module_init(acpi_power_meter_init);
1023 module_exit(acpi_power_meter_exit);