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 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 /= 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 /= 1000;
 311         if (temp < 0)
 312                 return -EINVAL;
 313
 314         mutex_lock(&resource->lock);
 315         resource->trip[attr->index - 7] = temp;
 316         res = set_acpi_trip(resource);
 317         mutex_unlock(&resource->lock);
 318
 319         if (res)
 320                 return res;
 321
 322         return count;
 323 }
 324
 325 /* Power meter */
 326 static int update_meter(struct acpi_power_meter_resource *resource)
 327 {
 328         unsigned long long data;
 329         acpi_status status;
 330         unsigned long local_jiffies = jiffies;
 331
 332         if (time_before(local_jiffies, resource->sensors_last_updated +
 333                         msecs_to_jiffies(resource->caps.sampling_time)) &&
 334                         resource->sensors_valid)
 335                 return 0;
 336
 337         status = acpi_evaluate_integer(resource->acpi_dev->handle, "_PMM",
 338                                        NULL, &data);
 339         if (ACPI_FAILURE(status)) {
 340                 ACPI_EXCEPTION((AE_INFO, status, "Evaluating _PMM"));
 341                 return -ENODEV;
 342         }
 343
 344         resource->power = data;
 345         resource->sensors_valid = 1;
 346         resource->sensors_last_updated = jiffies;
 347         return 0;
 348 }
 349
 350 static ssize_t show_power(struct device *dev,
 351                           struct device_attribute *devattr,
 352                           char *buf)
 353 {
 354         struct acpi_device *acpi_dev = to_acpi_device(dev);
 355         struct acpi_power_meter_resource *resource = acpi_dev->driver_data;
 356
 357         mutex_lock(&resource->lock);
 358         update_meter(resource);
 359         mutex_unlock(&resource->lock);
 360
 361         return sprintf(buf, "%llu\n", resource->power * 1000);
 362 }
 363
 364 /* Miscellaneous */
 365 static ssize_t show_str(struct device *dev,
 366                         struct device_attribute *devattr,
 367                         char *buf)
 368 {
 369         struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
 370         struct acpi_device *acpi_dev = to_acpi_device(dev);
 371         struct acpi_power_meter_resource *resource = acpi_dev->driver_data;
 372         acpi_string val;
 373
 374         switch (attr->index) {
 375         case 0:
 376                 val = resource->model_number;
 377                 break;
 378         case 1:
 379                 val = resource->serial_number;
 380                 break;
 381         case 2:
 382                 val = resource->oem_info;
 383                 break;
 384         default:
 385                 BUG();
 386                 val = "";
 387         }
 388
 389         return sprintf(buf, "%s\n", val);
 390 }
 391
 392 static ssize_t show_val(struct device *dev,
 393                         struct device_attribute *devattr,
 394                         char *buf)
 395 {
 396         struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
 397         struct acpi_device *acpi_dev = to_acpi_device(dev);
 398         struct acpi_power_meter_resource *resource = acpi_dev->driver_data;
 399         u64 val = 0;
 400
 401         switch (attr->index) {
 402         case 0:
 403                 val = resource->caps.min_avg_interval;
 404                 break;
 405         case 1:
 406                 val = resource->caps.max_avg_interval;
 407                 break;
 408         case 2:
 409                 val = resource->caps.min_cap * 1000;
 410                 break;
 411         case 3:
 412                 val = resource->caps.max_cap * 1000;
 413                 break;
 414         case 4:
 415                 if (resource->caps.hysteresis == UNKNOWN_HYSTERESIS)
 416                         return sprintf(buf, "unknown\n");
 417
 418                 val = resource->caps.hysteresis * 1000;
 419                 break;
 420         case 5:
 421                 if (resource->caps.flags & POWER_METER_IS_BATTERY)
 422                         val = 1;
 423                 else
 424                         val = 0;
 425                 break;
 426         case 6:
 427                 if (resource->power > resource->cap)
 428                         val = 1;
 429                 else
 430                         val = 0;
 431                 break;
 432         case 7:
 433         case 8:
 434                 if (resource->trip[attr->index - 7] < 0)
 435                         return sprintf(buf, "unknown\n");
 436
 437                 val = resource->trip[attr->index - 7] * 1000;
 438                 break;
 439         default:
 440                 BUG();
 441         }
 442
 443         return sprintf(buf, "%llu\n", val);
 444 }
 445
 446 static ssize_t show_accuracy(struct device *dev,
 447                              struct device_attribute *devattr,
 448                              char *buf)
 449 {
 450         struct acpi_device *acpi_dev = to_acpi_device(dev);
 451         struct acpi_power_meter_resource *resource = acpi_dev->driver_data;
 452         unsigned int acc = resource->caps.accuracy;
 453
 454         return sprintf(buf, "%u.%u%%\n", acc / 1000, acc % 1000);
 455 }
 456
 457 static ssize_t show_name(struct device *dev,
 458                          struct device_attribute *devattr,
 459                          char *buf)
 460 {
 461         return sprintf(buf, "%s\n", ACPI_POWER_METER_NAME);
 462 }
 463
 464 #define RO_SENSOR_TEMPLATE(_label, _show, _index)       \
 465         {                                               \
 466                 .label = _label,                        \
 467                 .show  = _show,                         \
 468                 .index = _index,                        \
 469         }
 470
 471 #define RW_SENSOR_TEMPLATE(_label, _show, _set, _index) \
 472         {                                               \
 473                 .label = _label,                        \
 474                 .show  = _show,                         \
 475                 .set   = _set,                          \
 476                 .index = _index,                        \
 477         }
 478
 479 /* Sensor descriptions.  If you add a sensor, update NUM_SENSORS above! */
 480 static struct sensor_template meter_attrs[] = {
 481         RO_SENSOR_TEMPLATE(POWER_AVERAGE_NAME, show_power, 0),
 482         RO_SENSOR_TEMPLATE("power1_accuracy", show_accuracy, 0),
 483         RO_SENSOR_TEMPLATE("power1_average_interval_min", show_val, 0),
 484         RO_SENSOR_TEMPLATE("power1_average_interval_max", show_val, 1),
 485         RO_SENSOR_TEMPLATE("power1_is_battery", show_val, 5),
 486         RW_SENSOR_TEMPLATE(POWER_AVG_INTERVAL_NAME, show_avg_interval,
 487                 set_avg_interval, 0),
 488         {},
 489 };
 490
 491 static struct sensor_template misc_cap_attrs[] = {
 492         RO_SENSOR_TEMPLATE("power1_cap_min", show_val, 2),
 493         RO_SENSOR_TEMPLATE("power1_cap_max", show_val, 3),
 494         RO_SENSOR_TEMPLATE("power1_cap_hyst", show_val, 4),
 495         RO_SENSOR_TEMPLATE(POWER_ALARM_NAME, show_val, 6),
 496         {},
 497 };
 498
 499 static struct sensor_template ro_cap_attrs[] = {
 500         RO_SENSOR_TEMPLATE(POWER_CAP_NAME, show_cap, 0),
 501         {},
 502 };
 503
 504 static struct sensor_template rw_cap_attrs[] = {
 505         RW_SENSOR_TEMPLATE(POWER_CAP_NAME, show_cap, set_cap, 0),
 506         {},
 507 };
 508
 509 static struct sensor_template trip_attrs[] = {
 510         RW_SENSOR_TEMPLATE("power1_average_min", show_val, set_trip, 7),
 511         RW_SENSOR_TEMPLATE("power1_average_max", show_val, set_trip, 8),
 512         {},
 513 };
 514
 515 static struct sensor_template misc_attrs[] = {
 516         RO_SENSOR_TEMPLATE("name", show_name, 0),
 517         RO_SENSOR_TEMPLATE("power1_model_number", show_str, 0),
 518         RO_SENSOR_TEMPLATE("power1_oem_info", show_str, 2),
 519         RO_SENSOR_TEMPLATE("power1_serial_number", show_str, 1),
 520         {},
 521 };
 522
 523 #undef RO_SENSOR_TEMPLATE
 524 #undef RW_SENSOR_TEMPLATE
 525
 526 /* Read power domain data */
 527 static void remove_domain_devices(struct acpi_power_meter_resource *resource)
 528 {
 529         int i;
 530
 531         if (!resource->num_domain_devices)
 532                 return;
 533
 534         for (i = 0; i < resource->num_domain_devices; i++) {
 535                 struct acpi_device *obj = resource->domain_devices[i];
 536                 if (!obj)
 537                         continue;
 538
 539                 sysfs_remove_link(resource->holders_dir,
 540                                   kobject_name(&obj->dev.kobj));
 541                 put_device(&obj->dev);
 542         }
 543
 544         kfree(resource->domain_devices);
 545         kobject_put(resource->holders_dir);
 546         resource->num_domain_devices = 0;
 547 }
 548
 549 static int read_domain_devices(struct acpi_power_meter_resource *resource)
 550 {
 551         int res = 0;
 552         int i;
 553         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
 554         union acpi_object *pss;
 555         acpi_status status;
 556
 557         status = acpi_evaluate_object(resource->acpi_dev->handle, "_PMD", NULL,
 558                                       &buffer);
 559         if (ACPI_FAILURE(status)) {
 560                 ACPI_EXCEPTION((AE_INFO, status, "Evaluating _PMD"));
 561                 return -ENODEV;
 562         }
 563
 564         pss = buffer.pointer;
 565         if (!pss ||
 566             pss->type != ACPI_TYPE_PACKAGE) {
 567                 dev_err(&resource->acpi_dev->dev, ACPI_POWER_METER_NAME
 568                         "Invalid _PMD data\n");
 569                 res = -EFAULT;
 570                 goto end;
 571         }
 572
 573         if (!pss->package.count)
 574                 goto end;
 575
 576         resource->domain_devices = kzalloc(sizeof(struct acpi_device *) *
 577                                            pss->package.count, GFP_KERNEL);
 578         if (!resource->domain_devices) {
 579                 res = -ENOMEM;
 580                 goto end;
 581         }
 582
 583         resource->holders_dir = kobject_create_and_add("measures",
 584                                         &resource->acpi_dev->dev.kobj);
 585         if (!resource->holders_dir) {
 586                 res = -ENOMEM;
 587                 goto exit_free;
 588         }
 589
 590         resource->num_domain_devices = pss->package.count;
 591
 592         for (i = 0; i < pss->package.count; i++) {
 593                 struct acpi_device *obj;
 594                 union acpi_object *element = &(pss->package.elements[i]);
 595
 596                 /* Refuse non-references */
 597                 if (element->type != ACPI_TYPE_LOCAL_REFERENCE)
 598                         continue;
 599
 600                 /* Create a symlink to domain objects */
 601                 resource->domain_devices[i] = NULL;
 602                 status = acpi_bus_get_device(element->reference.handle,
 603                                              &resource->domain_devices[i]);
 604                 if (ACPI_FAILURE(status))
 605                         continue;
 606
 607                 obj = resource->domain_devices[i];
 608                 get_device(&obj->dev);
 609
 610                 res = sysfs_create_link(resource->holders_dir, &obj->dev.kobj,
 611                                       kobject_name(&obj->dev.kobj));
 612                 if (res) {
 613                         put_device(&obj->dev);
 614                         resource->domain_devices[i] = NULL;
 615                 }
 616         }
 617
 618         res = 0;
 619         goto end;
 620
 621 exit_free:
 622         kfree(resource->domain_devices);
 623 end:
 624         kfree(buffer.pointer);
 625         return res;
 626 }
 627
 628 /* Registration and deregistration */
 629 static int register_attrs(struct acpi_power_meter_resource *resource,
 630                           struct sensor_template *attrs)
 631 {
 632         struct device *dev = &resource->acpi_dev->dev;
 633         struct sensor_device_attribute *sensors =
 634                 &resource->sensors[resource->num_sensors];
 635         int res = 0;
 636
 637         while (attrs->label) {
 638                 sensors->dev_attr.attr.name = attrs->label;
 639                 sensors->dev_attr.attr.mode = S_IRUGO;
 640                 sensors->dev_attr.show = attrs->show;
 641                 sensors->index = attrs->index;
 642
 643                 if (attrs->set) {
 644                         sensors->dev_attr.attr.mode |= S_IWUSR;
 645                         sensors->dev_attr.store = attrs->set;
 646                 }
 647
 648                 sysfs_attr_init(&sensors->dev_attr.attr);
 649                 res = device_create_file(dev, &sensors->dev_attr);
 650                 if (res) {
 651                         sensors->dev_attr.attr.name = NULL;
 652                         goto error;
 653                 }
 654                 sensors++;
 655                 resource->num_sensors++;
 656                 attrs++;
 657         }
 658
 659 error:
 660         return res;
 661 }
 662
 663 static void remove_attrs(struct acpi_power_meter_resource *resource)
 664 {
 665         int i;
 666
 667         for (i = 0; i < resource->num_sensors; i++) {
 668                 if (!resource->sensors[i].dev_attr.attr.name)
 669                         continue;
 670                 device_remove_file(&resource->acpi_dev->dev,
 671                                    &resource->sensors[i].dev_attr);
 672         }
 673
 674         remove_domain_devices(resource);
 675
 676         resource->num_sensors = 0;
 677 }
 678
 679 static int setup_attrs(struct acpi_power_meter_resource *resource)
 680 {
 681         int res = 0;
 682
 683         res = read_domain_devices(resource);
 684         if (res)
 685                 return res;
 686
 687         if (resource->caps.flags & POWER_METER_CAN_MEASURE) {
 688                 res = register_attrs(resource, meter_attrs);
 689                 if (res)
 690                         goto error;
 691         }
 692
 693         if (resource->caps.flags & POWER_METER_CAN_CAP) {
 694                 if (!can_cap_in_hardware()) {
 695                         dev_err(&resource->acpi_dev->dev,
 696                                 "Ignoring unsafe software power cap!\n");
 697                         goto skip_unsafe_cap;
 698                 }
 699
 700                 if (resource->caps.configurable_cap)
 701                         res = register_attrs(resource, rw_cap_attrs);
 702                 else
 703                         res = register_attrs(resource, ro_cap_attrs);
 704
 705                 if (res)
 706                         goto error;
 707
 708                 res = register_attrs(resource, misc_cap_attrs);
 709                 if (res)
 710                         goto error;
 711         }
 712
 713 skip_unsafe_cap:
 714         if (resource->caps.flags & POWER_METER_CAN_TRIP) {
 715                 res = register_attrs(resource, trip_attrs);
 716                 if (res)
 717                         goto error;
 718         }
 719
 720         res = register_attrs(resource, misc_attrs);
 721         if (res)
 722                 goto error;
 723
 724         return res;
 725 error:
 726         remove_attrs(resource);
 727         return res;
 728 }
 729
 730 static void free_capabilities(struct acpi_power_meter_resource *resource)
 731 {
 732         acpi_string *str;
 733         int i;
 734
 735         str = &resource->model_number;
 736         for (i = 0; i < 3; i++, str++)
 737                 kfree(*str);
 738 }
 739
 740 static int read_capabilities(struct acpi_power_meter_resource *resource)
 741 {
 742         int res = 0;
 743         int i;
 744         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
 745         struct acpi_buffer state = { 0, NULL };
 746         struct acpi_buffer format = { sizeof("NNNNNNNNNNN"), "NNNNNNNNNNN" };
 747         union acpi_object *pss;
 748         acpi_string *str;
 749         acpi_status status;
 750
 751         status = acpi_evaluate_object(resource->acpi_dev->handle, "_PMC", NULL,
 752                                       &buffer);
 753         if (ACPI_FAILURE(status)) {
 754                 ACPI_EXCEPTION((AE_INFO, status, "Evaluating _PMC"));
 755                 return -ENODEV;
 756         }
 757
 758         pss = buffer.pointer;
 759         if (!pss ||
 760             pss->type != ACPI_TYPE_PACKAGE ||
 761             pss->package.count != 14) {
 762                 dev_err(&resource->acpi_dev->dev, ACPI_POWER_METER_NAME
 763                         "Invalid _PMC data\n");
 764                 res = -EFAULT;
 765                 goto end;
 766         }
 767
 768         /* Grab all the integer data at once */
 769         state.length = sizeof(struct acpi_power_meter_capabilities);
 770         state.pointer = &resource->caps;
 771
 772         status = acpi_extract_package(pss, &format, &state);
 773         if (ACPI_FAILURE(status)) {
 774                 ACPI_EXCEPTION((AE_INFO, status, "Invalid data"));
 775                 res = -EFAULT;
 776                 goto end;
 777         }
 778
 779         if (resource->caps.units) {
 780                 dev_err(&resource->acpi_dev->dev, ACPI_POWER_METER_NAME
 781                         "Unknown units %llu.\n",
 782                         resource->caps.units);
 783                 res = -EINVAL;
 784                 goto end;
 785         }
 786
 787         /* Grab the string data */
 788         str = &resource->model_number;
 789
 790         for (i = 11; i < 14; i++) {
 791                 union acpi_object *element = &(pss->package.elements[i]);
 792
 793                 if (element->type != ACPI_TYPE_STRING) {
 794                         res = -EINVAL;
 795                         goto error;
 796                 }
 797
 798                 *str = kzalloc(sizeof(u8) * (element->string.length + 1),
 799                                GFP_KERNEL);
 800                 if (!*str) {
 801                         res = -ENOMEM;
 802                         goto error;
 803                 }
 804
 805                 strncpy(*str, element->string.pointer, element->string.length);
 806                 str++;
 807         }
 808
 809         dev_info(&resource->acpi_dev->dev, "Found ACPI power meter.\n");
 810         goto end;
 811 error:
 812         str = &resource->model_number;
 813         for (i = 0; i < 3; i++, str++)
 814                 kfree(*str);
 815 end:
 816         kfree(buffer.pointer);
 817         return res;
 818 }
 819
 820 /* Handle ACPI event notifications */
 821 static void acpi_power_meter_notify(struct acpi_device *device, u32 event)
 822 {
 823         struct acpi_power_meter_resource *resource;
 824         int res;
 825
 826         if (!device || !acpi_driver_data(device))
 827                 return;
 828
 829         resource = acpi_driver_data(device);
 830
 831         mutex_lock(&resource->lock);
 832         switch (event) {
 833         case METER_NOTIFY_CONFIG:
 834                 free_capabilities(resource);
 835                 res = read_capabilities(resource);
 836                 if (res)
 837                         break;
 838
 839                 remove_attrs(resource);
 840                 setup_attrs(resource);
 841                 break;
 842         case METER_NOTIFY_TRIP:
 843                 sysfs_notify(&device->dev.kobj, NULL, POWER_AVERAGE_NAME);
 844                 update_meter(resource);
 845                 break;
 846         case METER_NOTIFY_CAP:
 847                 sysfs_notify(&device->dev.kobj, NULL, POWER_CAP_NAME);
 848                 update_cap(resource);
 849                 break;
 850         case METER_NOTIFY_INTERVAL:
 851                 sysfs_notify(&device->dev.kobj, NULL, POWER_AVG_INTERVAL_NAME);
 852                 update_avg_interval(resource);
 853                 break;
 854         case METER_NOTIFY_CAPPING:
 855                 sysfs_notify(&device->dev.kobj, NULL, POWER_ALARM_NAME);
 856                 dev_info(&device->dev, "Capping in progress.\n");
 857                 break;
 858         default:
 859                 BUG();
 860         }
 861         mutex_unlock(&resource->lock);
 862
 863         acpi_bus_generate_netlink_event(ACPI_POWER_METER_CLASS,
 864                                         dev_name(&device->dev), event, 0);
 865 }
 866
 867 static int acpi_power_meter_add(struct acpi_device *device)
 868 {
 869         int res;
 870         struct acpi_power_meter_resource *resource;
 871
 872         if (!device)
 873                 return -EINVAL;
 874
 875         resource = kzalloc(sizeof(struct acpi_power_meter_resource),
 876                            GFP_KERNEL);
 877         if (!resource)
 878                 return -ENOMEM;
 879
 880         resource->sensors_valid = 0;
 881         resource->acpi_dev = device;
 882         mutex_init(&resource->lock);
 883         strcpy(acpi_device_name(device), ACPI_POWER_METER_DEVICE_NAME);
 884         strcpy(acpi_device_class(device), ACPI_POWER_METER_CLASS);
 885         device->driver_data = resource;
 886
 887         free_capabilities(resource);
 888         res = read_capabilities(resource);
 889         if (res)
 890                 goto exit_free;
 891
 892         resource->trip[0] = resource->trip[1] = -1;
 893
 894         res = setup_attrs(resource);
 895         if (res)
 896                 goto exit_free;
 897
 898         resource->hwmon_dev = hwmon_device_register(&device->dev);
 899         if (IS_ERR(resource->hwmon_dev)) {
 900                 res = PTR_ERR(resource->hwmon_dev);
 901                 goto exit_remove;
 902         }
 903
 904         res = 0;
 905         goto exit;
 906
 907 exit_remove:
 908         remove_attrs(resource);
 909 exit_free:
 910         kfree(resource);
 911 exit:
 912         return res;
 913 }
 914
 915 static int acpi_power_meter_remove(struct acpi_device *device, int type)
 916 {
 917         struct acpi_power_meter_resource *resource;
 918
 919         if (!device || !acpi_driver_data(device))
 920                 return -EINVAL;
 921
 922         resource = acpi_driver_data(device);
 923         hwmon_device_unregister(resource->hwmon_dev);
 924
 925         free_capabilities(resource);
 926         remove_attrs(resource);
 927
 928         kfree(resource);
 929         return 0;
 930 }
 931
 932 static int acpi_power_meter_resume(struct acpi_device *device)
 933 {
 934         struct acpi_power_meter_resource *resource;
 935
 936         if (!device || !acpi_driver_data(device))
 937                 return -EINVAL;
 938
 939         resource = acpi_driver_data(device);
 940         free_capabilities(resource);
 941         read_capabilities(resource);
 942
 943         return 0;
 944 }
 945
 946 static struct acpi_driver acpi_power_meter_driver = {
 947         .name = "power_meter",
 948         .class = ACPI_POWER_METER_CLASS,
 949         .ids = power_meter_ids,
 950         .ops = {
 951                 .add = acpi_power_meter_add,
 952                 .remove = acpi_power_meter_remove,
 953                 .resume = acpi_power_meter_resume,
 954                 .notify = acpi_power_meter_notify,
 955                 },
 956 };
 957
 958 /* Module init/exit routines */
 959 static int __init enable_cap_knobs(const struct dmi_system_id *d)
 960 {
 961         cap_in_hardware = 1;
 962         return 0;
 963 }
 964
 965 static struct dmi_system_id __initdata pm_dmi_table[] = {
 966         {
 967                 enable_cap_knobs, "IBM Active Energy Manager",
 968                 {
 969                         DMI_MATCH(DMI_SYS_VENDOR, "IBM")
 970                 },
 971         },
 972         {}
 973 };
 974
 975 static int __init acpi_power_meter_init(void)
 976 {
 977         int result;
 978
 979         if (acpi_disabled)
 980                 return -ENODEV;
 981
 982         dmi_check_system(pm_dmi_table);
 983
 984         result = acpi_bus_register_driver(&acpi_power_meter_driver);
 985         if (result < 0)
 986                 return -ENODEV;
 987
 988         return 0;
 989 }
 990
 991 static void __exit acpi_power_meter_exit(void)
 992 {
 993         acpi_bus_unregister_driver(&acpi_power_meter_driver);
 994 }
 995
 996 MODULE_AUTHOR("Darrick J. Wong <djwong@us.ibm.com>");
 997 MODULE_DESCRIPTION("ACPI 4.0 power meter driver");
 998 MODULE_LICENSE("GPL");
 999
1000 module_param(force_cap_on, bool, 0644);
1001 MODULE_PARM_DESC(force_cap_on, "Enable power cap even it is unsafe to do so.");
1002
1003 module_init(acpi_power_meter_init);
1004 module_exit(acpi_power_meter_exit);