drivers/hwmon/acpi_power_meter.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  * A hwmon driver for ACPI 4.0 power meters
   4  * Copyright (C) 2009 IBM
   5  *
   6  * Author: Darrick J. Wong <darrick.wong@oracle.com>
   7  */
   8
   9 #include <linux/module.h>
  10 #include <linux/hwmon.h>
  11 #include <linux/hwmon-sysfs.h>
  12 #include <linux/jiffies.h>
  13 #include <linux/mutex.h>
  14 #include <linux/dmi.h>
  15 #include <linux/slab.h>
  16 #include <linux/kdev_t.h>
  17 #include <linux/sched.h>
  18 #include <linux/time.h>
  19 #include <linux/err.h>
  20 #include <linux/acpi.h>
  21
  22 #define ACPI_POWER_METER_NAME           "power_meter"
  23 #define ACPI_POWER_METER_DEVICE_NAME    "Power Meter"
  24 #define ACPI_POWER_METER_CLASS          "pwr_meter_resource"
  25
  26 #define NUM_SENSORS                     17
  27
  28 #define POWER_METER_CAN_MEASURE (1 << 0)
  29 #define POWER_METER_CAN_TRIP    (1 << 1)
  30 #define POWER_METER_CAN_CAP     (1 << 2)
  31 #define POWER_METER_CAN_NOTIFY  (1 << 3)
  32 #define POWER_METER_IS_BATTERY  (1 << 8)
  33 #define UNKNOWN_HYSTERESIS      0xFFFFFFFF
  34
  35 #define METER_NOTIFY_CONFIG     0x80
  36 #define METER_NOTIFY_TRIP       0x81
  37 #define METER_NOTIFY_CAP        0x82
  38 #define METER_NOTIFY_CAPPING    0x83
  39 #define METER_NOTIFY_INTERVAL   0x84
  40
  41 #define POWER_AVERAGE_NAME      "power1_average"
  42 #define POWER_CAP_NAME          "power1_cap"
  43 #define POWER_AVG_INTERVAL_NAME "power1_average_interval"
  44 #define POWER_ALARM_NAME        "power1_alarm"
  45
  46 static int cap_in_hardware;
  47 static bool force_cap_on;
  48
  49 static int can_cap_in_hardware(void)
  50 {
  51         return force_cap_on || cap_in_hardware;
  52 }
  53
  54 static const struct acpi_device_id power_meter_ids[] = {
  55         {"ACPI000D", 0},
  56         {"", 0},
  57 };
  58 MODULE_DEVICE_TABLE(acpi, power_meter_ids);
  59
  60 struct acpi_power_meter_capabilities {
  61         u64             flags;
  62         u64             units;
  63         u64             type;
  64         u64             accuracy;
  65         u64             sampling_time;
  66         u64             min_avg_interval;
  67         u64             max_avg_interval;
  68         u64             hysteresis;
  69         u64             configurable_cap;
  70         u64             min_cap;
  71         u64             max_cap;
  72 };
  73
  74 struct acpi_power_meter_resource {
  75         struct acpi_device      *acpi_dev;
  76         acpi_bus_id             name;
  77         struct mutex            lock;
  78         struct device           *hwmon_dev;
  79         struct acpi_power_meter_capabilities    caps;
  80         acpi_string             model_number;
  81         acpi_string             serial_number;
  82         acpi_string             oem_info;
  83         u64             power;
  84         u64             cap;
  85         u64             avg_interval;
  86         int                     sensors_valid;
  87         unsigned long           sensors_last_updated;
  88         struct sensor_device_attribute  sensors[NUM_SENSORS];
  89         int                     num_sensors;
  90         s64                     trip[2];
  91         int                     num_domain_devices;
  92         struct acpi_device      **domain_devices;
  93         struct kobject          *holders_dir;
  94 };
  95
  96 struct sensor_template {
  97         char *label;
  98         ssize_t (*show)(struct device *dev,
  99                         struct device_attribute *devattr,
 100                         char *buf);
 101         ssize_t (*set)(struct device *dev,
 102                        struct device_attribute *devattr,
 103                        const char *buf, size_t count);
 104         int index;
 105 };
 106
 107 /* Averaging interval */
 108 static int update_avg_interval(struct acpi_power_meter_resource *resource)
 109 {
 110         unsigned long long data;
 111         acpi_status status;
 112
 113         status = acpi_evaluate_integer(resource->acpi_dev->handle, "_GAI",
 114                                        NULL, &data);
 115         if (ACPI_FAILURE(status)) {
 116                 acpi_evaluation_failure_warn(resource->acpi_dev->handle, "_GAI",
 117                                              status);
 118                 return -ENODEV;
 119         }
 120
 121         resource->avg_interval = data;
 122         return 0;
 123 }
 124
 125 static ssize_t show_avg_interval(struct device *dev,
 126                                  struct device_attribute *devattr,
 127                                  char *buf)
 128 {
 129         struct acpi_device *acpi_dev = to_acpi_device(dev);
 130         struct acpi_power_meter_resource *resource = acpi_dev->driver_data;
 131
 132         mutex_lock(&resource->lock);
 133         update_avg_interval(resource);
 134         mutex_unlock(&resource->lock);
 135
 136         return sprintf(buf, "%llu\n", resource->avg_interval);
 137 }
 138
 139 static ssize_t set_avg_interval(struct device *dev,
 140                                 struct device_attribute *devattr,
 141                                 const char *buf, size_t count)
 142 {
 143         struct acpi_device *acpi_dev = to_acpi_device(dev);
 144         struct acpi_power_meter_resource *resource = acpi_dev->driver_data;
 145         union acpi_object arg0 = { ACPI_TYPE_INTEGER };
 146         struct acpi_object_list args = { 1, &arg0 };
 147         int res;
 148         unsigned long temp;
 149         unsigned long long data;
 150         acpi_status status;
 151
 152         res = kstrtoul(buf, 10, &temp);
 153         if (res)
 154                 return res;
 155
 156         if (temp > resource->caps.max_avg_interval ||
 157             temp < resource->caps.min_avg_interval)
 158                 return -EINVAL;
 159         arg0.integer.value = temp;
 160
 161         mutex_lock(&resource->lock);
 162         status = acpi_evaluate_integer(resource->acpi_dev->handle, "_PAI",
 163                                        &args, &data);
 164         if (ACPI_SUCCESS(status))
 165                 resource->avg_interval = temp;
 166         mutex_unlock(&resource->lock);
 167
 168         if (ACPI_FAILURE(status)) {
 169                 acpi_evaluation_failure_warn(resource->acpi_dev->handle, "_PAI",
 170                                              status);
 171                 return -EINVAL;
 172         }
 173
 174         /* _PAI returns 0 on success, nonzero otherwise */
 175         if (data)
 176                 return -EINVAL;
 177
 178         return count;
 179 }
 180
 181 /* Cap functions */
 182 static int update_cap(struct acpi_power_meter_resource *resource)
 183 {
 184         unsigned long long data;
 185         acpi_status status;
 186
 187         status = acpi_evaluate_integer(resource->acpi_dev->handle, "_GHL",
 188                                        NULL, &data);
 189         if (ACPI_FAILURE(status)) {
 190                 acpi_evaluation_failure_warn(resource->acpi_dev->handle, "_GHL",
 191                                              status);
 192                 return -ENODEV;
 193         }
 194
 195         resource->cap = data;
 196         return 0;
 197 }
 198
 199 static ssize_t show_cap(struct device *dev,
 200                         struct device_attribute *devattr,
 201                         char *buf)
 202 {
 203         struct acpi_device *acpi_dev = to_acpi_device(dev);
 204         struct acpi_power_meter_resource *resource = acpi_dev->driver_data;
 205
 206         mutex_lock(&resource->lock);
 207         update_cap(resource);
 208         mutex_unlock(&resource->lock);
 209
 210         return sprintf(buf, "%llu\n", resource->cap * 1000);
 211 }
 212
 213 static ssize_t set_cap(struct device *dev, struct device_attribute *devattr,
 214                        const char *buf, size_t count)
 215 {
 216         struct acpi_device *acpi_dev = to_acpi_device(dev);
 217         struct acpi_power_meter_resource *resource = acpi_dev->driver_data;
 218         union acpi_object arg0 = { ACPI_TYPE_INTEGER };
 219         struct acpi_object_list args = { 1, &arg0 };
 220         int res;
 221         unsigned long temp;
 222         unsigned long long data;
 223         acpi_status status;
 224
 225         res = kstrtoul(buf, 10, &temp);
 226         if (res)
 227                 return res;
 228
 229         temp = DIV_ROUND_CLOSEST(temp, 1000);
 230         if (temp > resource->caps.max_cap || temp < resource->caps.min_cap)
 231                 return -EINVAL;
 232         arg0.integer.value = temp;
 233
 234         mutex_lock(&resource->lock);
 235         status = acpi_evaluate_integer(resource->acpi_dev->handle, "_SHL",
 236                                        &args, &data);
 237         if (ACPI_SUCCESS(status))
 238                 resource->cap = temp;
 239         mutex_unlock(&resource->lock);
 240
 241         if (ACPI_FAILURE(status)) {
 242                 acpi_evaluation_failure_warn(resource->acpi_dev->handle, "_SHL",
 243                                              status);
 244                 return -EINVAL;
 245         }
 246
 247         /* _SHL returns 0 on success, nonzero otherwise */
 248         if (data)
 249                 return -EINVAL;
 250
 251         return count;
 252 }
 253
 254 /* Power meter trip points */
 255 static int set_acpi_trip(struct acpi_power_meter_resource *resource)
 256 {
 257         union acpi_object arg_objs[] = {
 258                 {ACPI_TYPE_INTEGER},
 259                 {ACPI_TYPE_INTEGER}
 260         };
 261         struct acpi_object_list args = { 2, arg_objs };
 262         unsigned long long data;
 263         acpi_status status;
 264
 265         /* Both trip levels must be set */
 266         if (resource->trip[0] < 0 || resource->trip[1] < 0)
 267                 return 0;
 268
 269         /* This driver stores min, max; ACPI wants max, min. */
 270         arg_objs[0].integer.value = resource->trip[1];
 271         arg_objs[1].integer.value = resource->trip[0];
 272
 273         status = acpi_evaluate_integer(resource->acpi_dev->handle, "_PTP",
 274                                        &args, &data);
 275         if (ACPI_FAILURE(status)) {
 276                 acpi_evaluation_failure_warn(resource->acpi_dev->handle, "_PTP",
 277                                              status);
 278                 return -EINVAL;
 279         }
 280
 281         /* _PTP returns 0 on success, nonzero otherwise */
 282         if (data)
 283                 return -EINVAL;
 284
 285         return 0;
 286 }
 287
 288 static ssize_t set_trip(struct device *dev, struct device_attribute *devattr,
 289                         const char *buf, size_t count)
 290 {
 291         struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
 292         struct acpi_device *acpi_dev = to_acpi_device(dev);
 293         struct acpi_power_meter_resource *resource = acpi_dev->driver_data;
 294         int res;
 295         unsigned long temp;
 296
 297         res = kstrtoul(buf, 10, &temp);
 298         if (res)
 299                 return res;
 300
 301         temp = DIV_ROUND_CLOSEST(temp, 1000);
 302
 303         mutex_lock(&resource->lock);
 304         resource->trip[attr->index - 7] = temp;
 305         res = set_acpi_trip(resource);
 306         mutex_unlock(&resource->lock);
 307
 308         if (res)
 309                 return res;
 310
 311         return count;
 312 }
 313
 314 /* Power meter */
 315 static int update_meter(struct acpi_power_meter_resource *resource)
 316 {
 317         unsigned long long data;
 318         acpi_status status;
 319         unsigned long local_jiffies = jiffies;
 320
 321         if (time_before(local_jiffies, resource->sensors_last_updated +
 322                         msecs_to_jiffies(resource->caps.sampling_time)) &&
 323                         resource->sensors_valid)
 324                 return 0;
 325
 326         status = acpi_evaluate_integer(resource->acpi_dev->handle, "_PMM",
 327                                        NULL, &data);
 328         if (ACPI_FAILURE(status)) {
 329                 acpi_evaluation_failure_warn(resource->acpi_dev->handle, "_PMM",
 330                                              status);
 331                 return -ENODEV;
 332         }
 333
 334         resource->power = data;
 335         resource->sensors_valid = 1;
 336         resource->sensors_last_updated = jiffies;
 337         return 0;
 338 }
 339
 340 static ssize_t show_power(struct device *dev,
 341                           struct device_attribute *devattr,
 342                           char *buf)
 343 {
 344         struct acpi_device *acpi_dev = to_acpi_device(dev);
 345         struct acpi_power_meter_resource *resource = acpi_dev->driver_data;
 346
 347         mutex_lock(&resource->lock);
 348         update_meter(resource);
 349         mutex_unlock(&resource->lock);
 350
 351         return sprintf(buf, "%llu\n", resource->power * 1000);
 352 }
 353
 354 /* Miscellaneous */
 355 static ssize_t show_str(struct device *dev,
 356                         struct device_attribute *devattr,
 357                         char *buf)
 358 {
 359         struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
 360         struct acpi_device *acpi_dev = to_acpi_device(dev);
 361         struct acpi_power_meter_resource *resource = acpi_dev->driver_data;
 362         acpi_string val;
 363         int ret;
 364
 365         mutex_lock(&resource->lock);
 366         switch (attr->index) {
 367         case 0:
 368                 val = resource->model_number;
 369                 break;
 370         case 1:
 371                 val = resource->serial_number;
 372                 break;
 373         case 2:
 374                 val = resource->oem_info;
 375                 break;
 376         default:
 377                 WARN(1, "Implementation error: unexpected attribute index %d\n",
 378                      attr->index);
 379                 val = "";
 380                 break;
 381         }
 382         ret = sprintf(buf, "%s\n", val);
 383         mutex_unlock(&resource->lock);
 384         return ret;
 385 }
 386
 387 static ssize_t show_val(struct device *dev,
 388                         struct device_attribute *devattr,
 389                         char *buf)
 390 {
 391         struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
 392         struct acpi_device *acpi_dev = to_acpi_device(dev);
 393         struct acpi_power_meter_resource *resource = acpi_dev->driver_data;
 394         u64 val = 0;
 395
 396         switch (attr->index) {
 397         case 0:
 398                 val = resource->caps.min_avg_interval;
 399                 break;
 400         case 1:
 401                 val = resource->caps.max_avg_interval;
 402                 break;
 403         case 2:
 404                 val = resource->caps.min_cap * 1000;
 405                 break;
 406         case 3:
 407                 val = resource->caps.max_cap * 1000;
 408                 break;
 409         case 4:
 410                 if (resource->caps.hysteresis == UNKNOWN_HYSTERESIS)
 411                         return sprintf(buf, "unknown\n");
 412
 413                 val = resource->caps.hysteresis * 1000;
 414                 break;
 415         case 5:
 416                 if (resource->caps.flags & POWER_METER_IS_BATTERY)
 417                         val = 1;
 418                 else
 419                         val = 0;
 420                 break;
 421         case 6:
 422                 if (resource->power > resource->cap)
 423                         val = 1;
 424                 else
 425                         val = 0;
 426                 break;
 427         case 7:
 428         case 8:
 429                 if (resource->trip[attr->index - 7] < 0)
 430                         return sprintf(buf, "unknown\n");
 431
 432                 val = resource->trip[attr->index - 7] * 1000;
 433                 break;
 434         default:
 435                 WARN(1, "Implementation error: unexpected attribute index %d\n",
 436                      attr->index);
 437                 break;
 438         }
 439
 440         return sprintf(buf, "%llu\n", val);
 441 }
 442
 443 static ssize_t show_accuracy(struct device *dev,
 444                              struct device_attribute *devattr,
 445                              char *buf)
 446 {
 447         struct acpi_device *acpi_dev = to_acpi_device(dev);
 448         struct acpi_power_meter_resource *resource = acpi_dev->driver_data;
 449         unsigned int acc = resource->caps.accuracy;
 450
 451         return sprintf(buf, "%u.%u%%\n", acc / 1000, acc % 1000);
 452 }
 453
 454 static ssize_t show_name(struct device *dev,
 455                          struct device_attribute *devattr,
 456                          char *buf)
 457 {
 458         return sprintf(buf, "%s\n", ACPI_POWER_METER_NAME);
 459 }
 460
 461 #define RO_SENSOR_TEMPLATE(_label, _show, _index)       \
 462         {                                               \
 463                 .label = _label,                        \
 464                 .show  = _show,                         \
 465                 .index = _index,                        \
 466         }
 467
 468 #define RW_SENSOR_TEMPLATE(_label, _show, _set, _index) \
 469         {                                               \
 470                 .label = _label,                        \
 471                 .show  = _show,                         \
 472                 .set   = _set,                          \
 473                 .index = _index,                        \
 474         }
 475
 476 /* Sensor descriptions.  If you add a sensor, update NUM_SENSORS above! */
 477 static struct sensor_template meter_attrs[] = {
 478         RO_SENSOR_TEMPLATE(POWER_AVERAGE_NAME, show_power, 0),
 479         RO_SENSOR_TEMPLATE("power1_accuracy", show_accuracy, 0),
 480         RO_SENSOR_TEMPLATE("power1_average_interval_min", show_val, 0),
 481         RO_SENSOR_TEMPLATE("power1_average_interval_max", show_val, 1),
 482         RO_SENSOR_TEMPLATE("power1_is_battery", show_val, 5),
 483         RW_SENSOR_TEMPLATE(POWER_AVG_INTERVAL_NAME, show_avg_interval,
 484                            set_avg_interval, 0),
 485         {},
 486 };
 487
 488 static struct sensor_template misc_cap_attrs[] = {
 489         RO_SENSOR_TEMPLATE("power1_cap_min", show_val, 2),
 490         RO_SENSOR_TEMPLATE("power1_cap_max", show_val, 3),
 491         RO_SENSOR_TEMPLATE("power1_cap_hyst", show_val, 4),
 492         RO_SENSOR_TEMPLATE(POWER_ALARM_NAME, show_val, 6),
 493         {},
 494 };
 495
 496 static struct sensor_template ro_cap_attrs[] = {
 497         RO_SENSOR_TEMPLATE(POWER_CAP_NAME, show_cap, 0),
 498         {},
 499 };
 500
 501 static struct sensor_template rw_cap_attrs[] = {
 502         RW_SENSOR_TEMPLATE(POWER_CAP_NAME, show_cap, set_cap, 0),
 503         {},
 504 };
 505
 506 static struct sensor_template trip_attrs[] = {
 507         RW_SENSOR_TEMPLATE("power1_average_min", show_val, set_trip, 7),
 508         RW_SENSOR_TEMPLATE("power1_average_max", show_val, set_trip, 8),
 509         {},
 510 };
 511
 512 static struct sensor_template misc_attrs[] = {
 513         RO_SENSOR_TEMPLATE("name", show_name, 0),
 514         RO_SENSOR_TEMPLATE("power1_model_number", show_str, 0),
 515         RO_SENSOR_TEMPLATE("power1_oem_info", show_str, 2),
 516         RO_SENSOR_TEMPLATE("power1_serial_number", show_str, 1),
 517         {},
 518 };
 519
 520 #undef RO_SENSOR_TEMPLATE
 521 #undef RW_SENSOR_TEMPLATE
 522
 523 /* Read power domain data */
 524 static void remove_domain_devices(struct acpi_power_meter_resource *resource)
 525 {
 526         int i;
 527
 528         if (!resource->num_domain_devices)
 529                 return;
 530
 531         for (i = 0; i < resource->num_domain_devices; i++) {
 532                 struct acpi_device *obj = resource->domain_devices[i];
 533
 534                 if (!obj)
 535                         continue;
 536
 537                 sysfs_remove_link(resource->holders_dir,
 538                                   kobject_name(&obj->dev.kobj));
 539                 acpi_dev_put(obj);
 540         }
 541
 542         kfree(resource->domain_devices);
 543         kobject_put(resource->holders_dir);
 544         resource->num_domain_devices = 0;
 545 }
 546
 547 static int read_domain_devices(struct acpi_power_meter_resource *resource)
 548 {
 549         int res = 0;
 550         int i;
 551         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
 552         union acpi_object *pss;
 553         acpi_status status;
 554
 555         status = acpi_evaluate_object(resource->acpi_dev->handle, "_PMD", NULL,
 556                                       &buffer);
 557         if (ACPI_FAILURE(status)) {
 558                 acpi_evaluation_failure_warn(resource->acpi_dev->handle, "_PMD",
 559                                              status);
 560                 return -ENODEV;
 561         }
 562
 563         pss = buffer.pointer;
 564         if (!pss ||
 565             pss->type != ACPI_TYPE_PACKAGE) {
 566                 dev_err(&resource->acpi_dev->dev, ACPI_POWER_METER_NAME
 567                         "Invalid _PMD data\n");
 568                 res = -EFAULT;
 569                 goto end;
 570         }
 571
 572         if (!pss->package.count)
 573                 goto end;
 574
 575         resource->domain_devices = kcalloc(pss->package.count,
 576                                            sizeof(struct acpi_device *),
 577                                            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                 obj = acpi_bus_get_acpi_device(element->reference.handle);
 602                 resource->domain_devices[i] = obj;
 603                 if (!obj)
 604                         continue;
 605
 606                 res = sysfs_create_link(resource->holders_dir, &obj->dev.kobj,
 607                                         kobject_name(&obj->dev.kobj));
 608                 if (res) {
 609                         acpi_dev_put(obj);
 610                         resource->domain_devices[i] = NULL;
 611                 }
 612         }
 613
 614         res = 0;
 615         goto end;
 616
 617 exit_free:
 618         kfree(resource->domain_devices);
 619 end:
 620         kfree(buffer.pointer);
 621         return res;
 622 }
 623
 624 /* Registration and deregistration */
 625 static int register_attrs(struct acpi_power_meter_resource *resource,
 626                           struct sensor_template *attrs)
 627 {
 628         struct device *dev = &resource->acpi_dev->dev;
 629         struct sensor_device_attribute *sensors =
 630                 &resource->sensors[resource->num_sensors];
 631         int res = 0;
 632
 633         while (attrs->label) {
 634                 sensors->dev_attr.attr.name = attrs->label;
 635                 sensors->dev_attr.attr.mode = 0444;
 636                 sensors->dev_attr.show = attrs->show;
 637                 sensors->index = attrs->index;
 638
 639                 if (attrs->set) {
 640                         sensors->dev_attr.attr.mode |= 0200;
 641                         sensors->dev_attr.store = attrs->set;
 642                 }
 643
 644                 sysfs_attr_init(&sensors->dev_attr.attr);
 645                 res = device_create_file(dev, &sensors->dev_attr);
 646                 if (res) {
 647                         sensors->dev_attr.attr.name = NULL;
 648                         goto error;
 649                 }
 650                 sensors++;
 651                 resource->num_sensors++;
 652                 attrs++;
 653         }
 654
 655 error:
 656         return res;
 657 }
 658
 659 static void remove_attrs(struct acpi_power_meter_resource *resource)
 660 {
 661         int i;
 662
 663         for (i = 0; i < resource->num_sensors; i++) {
 664                 if (!resource->sensors[i].dev_attr.attr.name)
 665                         continue;
 666                 device_remove_file(&resource->acpi_dev->dev,
 667                                    &resource->sensors[i].dev_attr);
 668         }
 669
 670         remove_domain_devices(resource);
 671
 672         resource->num_sensors = 0;
 673 }
 674
 675 static int setup_attrs(struct acpi_power_meter_resource *resource)
 676 {
 677         int res = 0;
 678
 679         res = read_domain_devices(resource);
 680         if (res)
 681                 return res;
 682
 683         if (resource->caps.flags & POWER_METER_CAN_MEASURE) {
 684                 res = register_attrs(resource, meter_attrs);
 685                 if (res)
 686                         goto error;
 687         }
 688
 689         if (resource->caps.flags & POWER_METER_CAN_CAP) {
 690                 if (!can_cap_in_hardware()) {
 691                         dev_warn(&resource->acpi_dev->dev,
 692                                  "Ignoring unsafe software power cap!\n");
 693                         goto skip_unsafe_cap;
 694                 }
 695
 696                 if (resource->caps.configurable_cap)
 697                         res = register_attrs(resource, rw_cap_attrs);
 698                 else
 699                         res = register_attrs(resource, ro_cap_attrs);
 700
 701                 if (res)
 702                         goto error;
 703
 704                 res = register_attrs(resource, misc_cap_attrs);
 705                 if (res)
 706                         goto error;
 707         }
 708
 709 skip_unsafe_cap:
 710         if (resource->caps.flags & POWER_METER_CAN_TRIP) {
 711                 res = register_attrs(resource, trip_attrs);
 712                 if (res)
 713                         goto error;
 714         }
 715
 716         res = register_attrs(resource, misc_attrs);
 717         if (res)
 718                 goto error;
 719
 720         return res;
 721 error:
 722         remove_attrs(resource);
 723         return res;
 724 }
 725
 726 static void free_capabilities(struct acpi_power_meter_resource *resource)
 727 {
 728         acpi_string *str;
 729         int i;
 730
 731         str = &resource->model_number;
 732         for (i = 0; i < 3; i++, str++) {
 733                 kfree(*str);
 734                 *str = NULL;
 735         }
 736 }
 737
 738 static int read_capabilities(struct acpi_power_meter_resource *resource)
 739 {
 740         int res = 0;
 741         int i;
 742         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
 743         struct acpi_buffer state = { 0, NULL };
 744         struct acpi_buffer format = { sizeof("NNNNNNNNNNN"), "NNNNNNNNNNN" };
 745         union acpi_object *pss;
 746         acpi_string *str;
 747         acpi_status status;
 748
 749         status = acpi_evaluate_object(resource->acpi_dev->handle, "_PMC", NULL,
 750                                       &buffer);
 751         if (ACPI_FAILURE(status)) {
 752                 acpi_evaluation_failure_warn(resource->acpi_dev->handle, "_PMC",
 753                                              status);
 754                 return -ENODEV;
 755         }
 756
 757         pss = buffer.pointer;
 758         if (!pss ||
 759             pss->type != ACPI_TYPE_PACKAGE ||
 760             pss->package.count != 14) {
 761                 dev_err(&resource->acpi_dev->dev, ACPI_POWER_METER_NAME
 762                         "Invalid _PMC data\n");
 763                 res = -EFAULT;
 764                 goto end;
 765         }
 766
 767         /* Grab all the integer data at once */
 768         state.length = sizeof(struct acpi_power_meter_capabilities);
 769         state.pointer = &resource->caps;
 770
 771         status = acpi_extract_package(pss, &format, &state);
 772         if (ACPI_FAILURE(status)) {
 773                 dev_err(&resource->acpi_dev->dev, ACPI_POWER_METER_NAME
 774                         "_PMC package parsing failed: %s\n",
 775                         acpi_format_exception(status));
 776                 res = -EFAULT;
 777                 goto end;
 778         }
 779
 780         if (resource->caps.units) {
 781                 dev_err(&resource->acpi_dev->dev, ACPI_POWER_METER_NAME
 782                         "Unknown units %llu.\n",
 783                         resource->caps.units);
 784                 res = -EINVAL;
 785                 goto end;
 786         }
 787
 788         /* Grab the string data */
 789         str = &resource->model_number;
 790
 791         for (i = 11; i < 14; i++) {
 792                 union acpi_object *element = &pss->package.elements[i];
 793
 794                 if (element->type != ACPI_TYPE_STRING) {
 795                         res = -EINVAL;
 796                         goto error;
 797                 }
 798
 799                 *str = kcalloc(element->string.length + 1, sizeof(u8),
 800                                GFP_KERNEL);
 801                 if (!*str) {
 802                         res = -ENOMEM;
 803                         goto error;
 804                 }
 805
 806                 strncpy(*str, element->string.pointer, element->string.length);
 807                 str++;
 808         }
 809
 810         dev_info(&resource->acpi_dev->dev, "Found ACPI power meter.\n");
 811         goto end;
 812 error:
 813         free_capabilities(resource);
 814 end:
 815         kfree(buffer.pointer);
 816         return res;
 817 }
 818
 819 /* Handle ACPI event notifications */
 820 static void acpi_power_meter_notify(struct acpi_device *device, u32 event)
 821 {
 822         struct acpi_power_meter_resource *resource;
 823         int res;
 824
 825         if (!device || !acpi_driver_data(device))
 826                 return;
 827
 828         resource = acpi_driver_data(device);
 829
 830         switch (event) {
 831         case METER_NOTIFY_CONFIG:
 832                 mutex_lock(&resource->lock);
 833                 free_capabilities(resource);
 834                 res = read_capabilities(resource);
 835                 mutex_unlock(&resource->lock);
 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                 break;
 845         case METER_NOTIFY_CAP:
 846                 sysfs_notify(&device->dev.kobj, NULL, POWER_CAP_NAME);
 847                 break;
 848         case METER_NOTIFY_INTERVAL:
 849                 sysfs_notify(&device->dev.kobj, NULL, POWER_AVG_INTERVAL_NAME);
 850                 break;
 851         case METER_NOTIFY_CAPPING:
 852                 sysfs_notify(&device->dev.kobj, NULL, POWER_ALARM_NAME);
 853                 dev_info(&device->dev, "Capping in progress.\n");
 854                 break;
 855         default:
 856                 WARN(1, "Unexpected event %d\n", event);
 857                 break;
 858         }
 859
 860         acpi_bus_generate_netlink_event(ACPI_POWER_METER_CLASS,
 861                                         dev_name(&device->dev), event, 0);
 862 }
 863
 864 static int acpi_power_meter_add(struct acpi_device *device)
 865 {
 866         int res;
 867         struct acpi_power_meter_resource *resource;
 868
 869         if (!device)
 870                 return -EINVAL;
 871
 872         resource = kzalloc(sizeof(*resource), GFP_KERNEL);
 873         if (!resource)
 874                 return -ENOMEM;
 875
 876         resource->sensors_valid = 0;
 877         resource->acpi_dev = device;
 878         mutex_init(&resource->lock);
 879         strcpy(acpi_device_name(device), ACPI_POWER_METER_DEVICE_NAME);
 880         strcpy(acpi_device_class(device), ACPI_POWER_METER_CLASS);
 881         device->driver_data = resource;
 882
 883         res = read_capabilities(resource);
 884         if (res)
 885                 goto exit_free;
 886
 887         resource->trip[0] = -1;
 888         resource->trip[1] = -1;
 889
 890         res = setup_attrs(resource);
 891         if (res)
 892                 goto exit_free_capability;
 893
 894         resource->hwmon_dev = hwmon_device_register(&device->dev);
 895         if (IS_ERR(resource->hwmon_dev)) {
 896                 res = PTR_ERR(resource->hwmon_dev);
 897                 goto exit_remove;
 898         }
 899
 900         res = 0;
 901         goto exit;
 902
 903 exit_remove:
 904         remove_attrs(resource);
 905 exit_free_capability:
 906         free_capabilities(resource);
 907 exit_free:
 908         kfree(resource);
 909 exit:
 910         return res;
 911 }
 912
 913 static int acpi_power_meter_remove(struct acpi_device *device)
 914 {
 915         struct acpi_power_meter_resource *resource;
 916
 917         if (!device || !acpi_driver_data(device))
 918                 return -EINVAL;
 919
 920         resource = acpi_driver_data(device);
 921         hwmon_device_unregister(resource->hwmon_dev);
 922
 923         remove_attrs(resource);
 924         free_capabilities(resource);
 925
 926         kfree(resource);
 927         return 0;
 928 }
 929
 930 #ifdef CONFIG_PM_SLEEP
 931
 932 static int acpi_power_meter_resume(struct device *dev)
 933 {
 934         struct acpi_power_meter_resource *resource;
 935
 936         if (!dev)
 937                 return -EINVAL;
 938
 939         resource = acpi_driver_data(to_acpi_device(dev));
 940         if (!resource)
 941                 return -EINVAL;
 942
 943         free_capabilities(resource);
 944         read_capabilities(resource);
 945
 946         return 0;
 947 }
 948
 949 #endif /* CONFIG_PM_SLEEP */
 950
 951 static SIMPLE_DEV_PM_OPS(acpi_power_meter_pm, NULL, acpi_power_meter_resume);
 952
 953 static struct acpi_driver acpi_power_meter_driver = {
 954         .name = "power_meter",
 955         .class = ACPI_POWER_METER_CLASS,
 956         .ids = power_meter_ids,
 957         .ops = {
 958                 .add = acpi_power_meter_add,
 959                 .remove = acpi_power_meter_remove,
 960                 .notify = acpi_power_meter_notify,
 961                 },
 962         .drv.pm = &acpi_power_meter_pm,
 963 };
 964
 965 /* Module init/exit routines */
 966 static int __init enable_cap_knobs(const struct dmi_system_id *d)
 967 {
 968         cap_in_hardware = 1;
 969         return 0;
 970 }
 971
 972 static const struct dmi_system_id pm_dmi_table[] __initconst = {
 973         {
 974                 enable_cap_knobs, "IBM Active Energy Manager",
 975                 {
 976                         DMI_MATCH(DMI_SYS_VENDOR, "IBM")
 977                 },
 978         },
 979         {}
 980 };
 981
 982 static int __init acpi_power_meter_init(void)
 983 {
 984         int result;
 985
 986         if (acpi_disabled)
 987                 return -ENODEV;
 988
 989         dmi_check_system(pm_dmi_table);
 990
 991         result = acpi_bus_register_driver(&acpi_power_meter_driver);
 992         if (result < 0)
 993                 return result;
 994
 995         return 0;
 996 }
 997
 998 static void __exit acpi_power_meter_exit(void)
 999 {
1000         acpi_bus_unregister_driver(&acpi_power_meter_driver);
1001 }
1002
1003 MODULE_AUTHOR("Darrick J. Wong <darrick.wong@oracle.com>");
1004 MODULE_DESCRIPTION("ACPI 4.0 power meter driver");
1005 MODULE_LICENSE("GPL");
1006
1007 module_param(force_cap_on, bool, 0644);
1008 MODULE_PARM_DESC(force_cap_on, "Enable power cap even it is unsafe to do so.");
1009
1010 module_init(acpi_power_meter_init);
1011 module_exit(acpi_power_meter_exit);