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 ACPI_MODULE_NAME(ACPI_POWER_METER_NAME);
  24 #define ACPI_POWER_METER_DEVICE_NAME    "Power Meter"
  25 #define ACPI_POWER_METER_CLASS          "pwr_meter_resource"
  26
  27 #define NUM_SENSORS                     17
  28
  29 #define POWER_METER_CAN_MEASURE (1 << 0)
  30 #define POWER_METER_CAN_TRIP    (1 << 1)
  31 #define POWER_METER_CAN_CAP     (1 << 2)
  32 #define POWER_METER_CAN_NOTIFY  (1 << 3)
  33 #define POWER_METER_IS_BATTERY  (1 << 8)
  34 #define UNKNOWN_HYSTERESIS      0xFFFFFFFF
  35
  36 #define METER_NOTIFY_CONFIG     0x80
  37 #define METER_NOTIFY_TRIP       0x81
  38 #define METER_NOTIFY_CAP        0x82
  39 #define METER_NOTIFY_CAPPING    0x83
  40 #define METER_NOTIFY_INTERVAL   0x84
  41
  42 #define POWER_AVERAGE_NAME      "power1_average"
  43 #define POWER_CAP_NAME          "power1_cap"
  44 #define POWER_AVG_INTERVAL_NAME "power1_average_interval"
  45 #define POWER_ALARM_NAME        "power1_alarm"
  46
  47 static int cap_in_hardware;
  48 static bool force_cap_on;
  49
  50 static int can_cap_in_hardware(void)
  51 {
  52         return force_cap_on || cap_in_hardware;
  53 }
  54
  55 static const struct acpi_device_id power_meter_ids[] = {
  56         {"ACPI000D", 0},
  57         {"", 0},
  58 };
  59 MODULE_DEVICE_TABLE(acpi, power_meter_ids);
  60
  61 struct acpi_power_meter_capabilities {
  62         u64             flags;
  63         u64             units;
  64         u64             type;
  65         u64             accuracy;
  66         u64             sampling_time;
  67         u64             min_avg_interval;
  68         u64             max_avg_interval;
  69         u64             hysteresis;
  70         u64             configurable_cap;
  71         u64             min_cap;
  72         u64             max_cap;
  73 };
  74
  75 struct acpi_power_meter_resource {
  76         struct acpi_device      *acpi_dev;
  77         acpi_bus_id             name;
  78         struct mutex            lock;
  79         struct device           *hwmon_dev;
  80         struct acpi_power_meter_capabilities    caps;
  81         acpi_string             model_number;
  82         acpi_string             serial_number;
  83         acpi_string             oem_info;
  84         u64             power;
  85         u64             cap;
  86         u64             avg_interval;
  87         int                     sensors_valid;
  88         unsigned long           sensors_last_updated;
  89         struct sensor_device_attribute  sensors[NUM_SENSORS];
  90         int                     num_sensors;
  91         s64                     trip[2];
  92         int                     num_domain_devices;
  93         struct acpi_device      **domain_devices;
  94         struct kobject          *holders_dir;
  95 };
  96
  97 struct sensor_template {
  98         char *label;
  99         ssize_t (*show)(struct device *dev,
 100                         struct device_attribute *devattr,
 101                         char *buf);
 102         ssize_t (*set)(struct device *dev,
 103                        struct device_attribute *devattr,
 104                        const char *buf, size_t count);
 105         int index;
 106 };
 107
 108 /* Averaging interval */
 109 static int update_avg_interval(struct acpi_power_meter_resource *resource)
 110 {
 111         unsigned long long data;
 112         acpi_status status;
 113
 114         status = acpi_evaluate_integer(resource->acpi_dev->handle, "_GAI",
 115                                        NULL, &data);
 116         if (ACPI_FAILURE(status)) {
 117                 ACPI_EXCEPTION((AE_INFO, status, "Evaluating _GAI"));
 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_FAILURE(status))
 165                 resource->avg_interval = temp;
 166         mutex_unlock(&resource->lock);
 167
 168         if (ACPI_FAILURE(status)) {
 169                 ACPI_EXCEPTION((AE_INFO, status, "Evaluating _PAI"));
 170                 return -EINVAL;
 171         }
 172
 173         /* _PAI returns 0 on success, nonzero otherwise */
 174         if (data)
 175                 return -EINVAL;
 176
 177         return count;
 178 }
 179
 180 /* Cap functions */
 181 static int update_cap(struct acpi_power_meter_resource *resource)
 182 {
 183         unsigned long long data;
 184         acpi_status status;
 185
 186         status = acpi_evaluate_integer(resource->acpi_dev->handle, "_GHL",
 187                                        NULL, &data);
 188         if (ACPI_FAILURE(status)) {
 189                 ACPI_EXCEPTION((AE_INFO, status, "Evaluating _GHL"));
 190                 return -ENODEV;
 191         }
 192
 193         resource->cap = data;
 194         return 0;
 195 }
 196
 197 static ssize_t show_cap(struct device *dev,
 198                         struct device_attribute *devattr,
 199                         char *buf)
 200 {
 201         struct acpi_device *acpi_dev = to_acpi_device(dev);
 202         struct acpi_power_meter_resource *resource = acpi_dev->driver_data;
 203
 204         mutex_lock(&resource->lock);
 205         update_cap(resource);
 206         mutex_unlock(&resource->lock);
 207
 208         return sprintf(buf, "%llu\n", resource->cap * 1000);
 209 }
 210
 211 static ssize_t set_cap(struct device *dev, struct device_attribute *devattr,
 212                        const char *buf, size_t count)
 213 {
 214         struct acpi_device *acpi_dev = to_acpi_device(dev);
 215         struct acpi_power_meter_resource *resource = acpi_dev->driver_data;
 216         union acpi_object arg0 = { ACPI_TYPE_INTEGER };
 217         struct acpi_object_list args = { 1, &arg0 };
 218         int res;
 219         unsigned long temp;
 220         unsigned long long data;
 221         acpi_status status;
 222
 223         res = kstrtoul(buf, 10, &temp);
 224         if (res)
 225                 return res;
 226
 227         temp = DIV_ROUND_CLOSEST(temp, 1000);
 228         if (temp > resource->caps.max_cap || temp < resource->caps.min_cap)
 229                 return -EINVAL;
 230         arg0.integer.value = temp;
 231
 232         mutex_lock(&resource->lock);
 233         status = acpi_evaluate_integer(resource->acpi_dev->handle, "_SHL",
 234                                        &args, &data);
 235         if (!ACPI_FAILURE(status))
 236                 resource->cap = temp;
 237         mutex_unlock(&resource->lock);
 238
 239         if (ACPI_FAILURE(status)) {
 240                 ACPI_EXCEPTION((AE_INFO, status, "Evaluating _SHL"));
 241                 return -EINVAL;
 242         }
 243
 244         /* _SHL returns 0 on success, nonzero otherwise */
 245         if (data)
 246                 return -EINVAL;
 247
 248         return count;
 249 }
 250
 251 /* Power meter trip points */
 252 static int set_acpi_trip(struct acpi_power_meter_resource *resource)
 253 {
 254         union acpi_object arg_objs[] = {
 255                 {ACPI_TYPE_INTEGER},
 256                 {ACPI_TYPE_INTEGER}
 257         };
 258         struct acpi_object_list args = { 2, arg_objs };
 259         unsigned long long data;
 260         acpi_status status;
 261
 262         /* Both trip levels must be set */
 263         if (resource->trip[0] < 0 || resource->trip[1] < 0)
 264                 return 0;
 265
 266         /* This driver stores min, max; ACPI wants max, min. */
 267         arg_objs[0].integer.value = resource->trip[1];
 268         arg_objs[1].integer.value = resource->trip[0];
 269
 270         status = acpi_evaluate_integer(resource->acpi_dev->handle, "_PTP",
 271                                        &args, &data);
 272         if (ACPI_FAILURE(status)) {
 273                 ACPI_EXCEPTION((AE_INFO, status, "Evaluating _PTP"));
 274                 return -EINVAL;
 275         }
 276
 277         /* _PTP returns 0 on success, nonzero otherwise */
 278         if (data)
 279                 return -EINVAL;
 280
 281         return 0;
 282 }
 283
 284 static ssize_t set_trip(struct device *dev, struct device_attribute *devattr,
 285                         const char *buf, size_t count)
 286 {
 287         struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
 288         struct acpi_device *acpi_dev = to_acpi_device(dev);
 289         struct acpi_power_meter_resource *resource = acpi_dev->driver_data;
 290         int res;
 291         unsigned long temp;
 292
 293         res = kstrtoul(buf, 10, &temp);
 294         if (res)
 295                 return res;
 296
 297         temp = DIV_ROUND_CLOSEST(temp, 1000);
 298
 299         mutex_lock(&resource->lock);
 300         resource->trip[attr->index - 7] = temp;
 301         res = set_acpi_trip(resource);
 302         mutex_unlock(&resource->lock);
 303
 304         if (res)
 305                 return res;
 306
 307         return count;
 308 }
 309
 310 /* Power meter */
 311 static int update_meter(struct acpi_power_meter_resource *resource)
 312 {
 313         unsigned long long data;
 314         acpi_status status;
 315         unsigned long local_jiffies = jiffies;
 316
 317         if (time_before(local_jiffies, resource->sensors_last_updated +
 318                         msecs_to_jiffies(resource->caps.sampling_time)) &&
 319                         resource->sensors_valid)
 320                 return 0;
 321
 322         status = acpi_evaluate_integer(resource->acpi_dev->handle, "_PMM",
 323                                        NULL, &data);
 324         if (ACPI_FAILURE(status)) {
 325                 ACPI_EXCEPTION((AE_INFO, status, "Evaluating _PMM"));
 326                 return -ENODEV;
 327         }
 328
 329         resource->power = data;
 330         resource->sensors_valid = 1;
 331         resource->sensors_last_updated = jiffies;
 332         return 0;
 333 }
 334
 335 static ssize_t show_power(struct device *dev,
 336                           struct device_attribute *devattr,
 337                           char *buf)
 338 {
 339         struct acpi_device *acpi_dev = to_acpi_device(dev);
 340         struct acpi_power_meter_resource *resource = acpi_dev->driver_data;
 341
 342         mutex_lock(&resource->lock);
 343         update_meter(resource);
 344         mutex_unlock(&resource->lock);
 345
 346         return sprintf(buf, "%llu\n", resource->power * 1000);
 347 }
 348
 349 /* Miscellaneous */
 350 static ssize_t show_str(struct device *dev,
 351                         struct device_attribute *devattr,
 352                         char *buf)
 353 {
 354         struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
 355         struct acpi_device *acpi_dev = to_acpi_device(dev);
 356         struct acpi_power_meter_resource *resource = acpi_dev->driver_data;
 357         acpi_string val;
 358
 359         switch (attr->index) {
 360         case 0:
 361                 val = resource->model_number;
 362                 break;
 363         case 1:
 364                 val = resource->serial_number;
 365                 break;
 366         case 2:
 367                 val = resource->oem_info;
 368                 break;
 369         default:
 370                 WARN(1, "Implementation error: unexpected attribute index %d\n",
 371                      attr->index);
 372                 val = "";
 373                 break;
 374         }
 375
 376         return sprintf(buf, "%s\n", val);
 377 }
 378
 379 static ssize_t show_val(struct device *dev,
 380                         struct device_attribute *devattr,
 381                         char *buf)
 382 {
 383         struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
 384         struct acpi_device *acpi_dev = to_acpi_device(dev);
 385         struct acpi_power_meter_resource *resource = acpi_dev->driver_data;
 386         u64 val = 0;
 387
 388         switch (attr->index) {
 389         case 0:
 390                 val = resource->caps.min_avg_interval;
 391                 break;
 392         case 1:
 393                 val = resource->caps.max_avg_interval;
 394                 break;
 395         case 2:
 396                 val = resource->caps.min_cap * 1000;
 397                 break;
 398         case 3:
 399                 val = resource->caps.max_cap * 1000;
 400                 break;
 401         case 4:
 402                 if (resource->caps.hysteresis == UNKNOWN_HYSTERESIS)
 403                         return sprintf(buf, "unknown\n");
 404
 405                 val = resource->caps.hysteresis * 1000;
 406                 break;
 407         case 5:
 408                 if (resource->caps.flags & POWER_METER_IS_BATTERY)
 409                         val = 1;
 410                 else
 411                         val = 0;
 412                 break;
 413         case 6:
 414                 if (resource->power > resource->cap)
 415                         val = 1;
 416                 else
 417                         val = 0;
 418                 break;
 419         case 7:
 420         case 8:
 421                 if (resource->trip[attr->index - 7] < 0)
 422                         return sprintf(buf, "unknown\n");
 423
 424                 val = resource->trip[attr->index - 7] * 1000;
 425                 break;
 426         default:
 427                 WARN(1, "Implementation error: unexpected attribute index %d\n",
 428                      attr->index);
 429                 break;
 430         }
 431
 432         return sprintf(buf, "%llu\n", val);
 433 }
 434
 435 static ssize_t show_accuracy(struct device *dev,
 436                              struct device_attribute *devattr,
 437                              char *buf)
 438 {
 439         struct acpi_device *acpi_dev = to_acpi_device(dev);
 440         struct acpi_power_meter_resource *resource = acpi_dev->driver_data;
 441         unsigned int acc = resource->caps.accuracy;
 442
 443         return sprintf(buf, "%u.%u%%\n", acc / 1000, acc % 1000);
 444 }
 445
 446 static ssize_t show_name(struct device *dev,
 447                          struct device_attribute *devattr,
 448                          char *buf)
 449 {
 450         return sprintf(buf, "%s\n", ACPI_POWER_METER_NAME);
 451 }
 452
 453 #define RO_SENSOR_TEMPLATE(_label, _show, _index)       \
 454         {                                               \
 455                 .label = _label,                        \
 456                 .show  = _show,                         \
 457                 .index = _index,                        \
 458         }
 459
 460 #define RW_SENSOR_TEMPLATE(_label, _show, _set, _index) \
 461         {                                               \
 462                 .label = _label,                        \
 463                 .show  = _show,                         \
 464                 .set   = _set,                          \
 465                 .index = _index,                        \
 466         }
 467
 468 /* Sensor descriptions.  If you add a sensor, update NUM_SENSORS above! */
 469 static struct sensor_template meter_attrs[] = {
 470         RO_SENSOR_TEMPLATE(POWER_AVERAGE_NAME, show_power, 0),
 471         RO_SENSOR_TEMPLATE("power1_accuracy", show_accuracy, 0),
 472         RO_SENSOR_TEMPLATE("power1_average_interval_min", show_val, 0),
 473         RO_SENSOR_TEMPLATE("power1_average_interval_max", show_val, 1),
 474         RO_SENSOR_TEMPLATE("power1_is_battery", show_val, 5),
 475         RW_SENSOR_TEMPLATE(POWER_AVG_INTERVAL_NAME, show_avg_interval,
 476                 set_avg_interval, 0),
 477         {},
 478 };
 479
 480 static struct sensor_template misc_cap_attrs[] = {
 481         RO_SENSOR_TEMPLATE("power1_cap_min", show_val, 2),
 482         RO_SENSOR_TEMPLATE("power1_cap_max", show_val, 3),
 483         RO_SENSOR_TEMPLATE("power1_cap_hyst", show_val, 4),
 484         RO_SENSOR_TEMPLATE(POWER_ALARM_NAME, show_val, 6),
 485         {},
 486 };
 487
 488 static struct sensor_template ro_cap_attrs[] = {
 489         RO_SENSOR_TEMPLATE(POWER_CAP_NAME, show_cap, 0),
 490         {},
 491 };
 492
 493 static struct sensor_template rw_cap_attrs[] = {
 494         RW_SENSOR_TEMPLATE(POWER_CAP_NAME, show_cap, set_cap, 0),
 495         {},
 496 };
 497
 498 static struct sensor_template trip_attrs[] = {
 499         RW_SENSOR_TEMPLATE("power1_average_min", show_val, set_trip, 7),
 500         RW_SENSOR_TEMPLATE("power1_average_max", show_val, set_trip, 8),
 501         {},
 502 };
 503
 504 static struct sensor_template misc_attrs[] = {
 505         RO_SENSOR_TEMPLATE("name", show_name, 0),
 506         RO_SENSOR_TEMPLATE("power1_model_number", show_str, 0),
 507         RO_SENSOR_TEMPLATE("power1_oem_info", show_str, 2),
 508         RO_SENSOR_TEMPLATE("power1_serial_number", show_str, 1),
 509         {},
 510 };
 511
 512 #undef RO_SENSOR_TEMPLATE
 513 #undef RW_SENSOR_TEMPLATE
 514
 515 /* Read power domain data */
 516 static void remove_domain_devices(struct acpi_power_meter_resource *resource)
 517 {
 518         int i;
 519
 520         if (!resource->num_domain_devices)
 521                 return;
 522
 523         for (i = 0; i < resource->num_domain_devices; i++) {
 524                 struct acpi_device *obj = resource->domain_devices[i];
 525                 if (!obj)
 526                         continue;
 527
 528                 sysfs_remove_link(resource->holders_dir,
 529                                   kobject_name(&obj->dev.kobj));
 530                 put_device(&obj->dev);
 531         }
 532
 533         kfree(resource->domain_devices);
 534         kobject_put(resource->holders_dir);
 535         resource->num_domain_devices = 0;
 536 }
 537
 538 static int read_domain_devices(struct acpi_power_meter_resource *resource)
 539 {
 540         int res = 0;
 541         int i;
 542         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
 543         union acpi_object *pss;
 544         acpi_status status;
 545
 546         status = acpi_evaluate_object(resource->acpi_dev->handle, "_PMD", NULL,
 547                                       &buffer);
 548         if (ACPI_FAILURE(status)) {
 549                 ACPI_EXCEPTION((AE_INFO, status, "Evaluating _PMD"));
 550                 return -ENODEV;
 551         }
 552
 553         pss = buffer.pointer;
 554         if (!pss ||
 555             pss->type != ACPI_TYPE_PACKAGE) {
 556                 dev_err(&resource->acpi_dev->dev, ACPI_POWER_METER_NAME
 557                         "Invalid _PMD data\n");
 558                 res = -EFAULT;
 559                 goto end;
 560         }
 561
 562         if (!pss->package.count)
 563                 goto end;
 564
 565         resource->domain_devices = kcalloc(pss->package.count,
 566                                            sizeof(struct acpi_device *),
 567                                            GFP_KERNEL);
 568         if (!resource->domain_devices) {
 569                 res = -ENOMEM;
 570                 goto end;
 571         }
 572
 573         resource->holders_dir = kobject_create_and_add("measures",
 574                                         &resource->acpi_dev->dev.kobj);
 575         if (!resource->holders_dir) {
 576                 res = -ENOMEM;
 577                 goto exit_free;
 578         }
 579
 580         resource->num_domain_devices = pss->package.count;
 581
 582         for (i = 0; i < pss->package.count; i++) {
 583                 struct acpi_device *obj;
 584                 union acpi_object *element = &(pss->package.elements[i]);
 585
 586                 /* Refuse non-references */
 587                 if (element->type != ACPI_TYPE_LOCAL_REFERENCE)
 588                         continue;
 589
 590                 /* Create a symlink to domain objects */
 591                 resource->domain_devices[i] = NULL;
 592                 if (acpi_bus_get_device(element->reference.handle,
 593                                         &resource->domain_devices[i]))
 594                         continue;
 595
 596                 obj = resource->domain_devices[i];
 597                 get_device(&obj->dev);
 598
 599                 res = sysfs_create_link(resource->holders_dir, &obj->dev.kobj,
 600                                       kobject_name(&obj->dev.kobj));
 601                 if (res) {
 602                         put_device(&obj->dev);
 603                         resource->domain_devices[i] = NULL;
 604                 }
 605         }
 606
 607         res = 0;
 608         goto end;
 609
 610 exit_free:
 611         kfree(resource->domain_devices);
 612 end:
 613         kfree(buffer.pointer);
 614         return res;
 615 }
 616
 617 /* Registration and deregistration */
 618 static int register_attrs(struct acpi_power_meter_resource *resource,
 619                           struct sensor_template *attrs)
 620 {
 621         struct device *dev = &resource->acpi_dev->dev;
 622         struct sensor_device_attribute *sensors =
 623                 &resource->sensors[resource->num_sensors];
 624         int res = 0;
 625
 626         while (attrs->label) {
 627                 sensors->dev_attr.attr.name = attrs->label;
 628                 sensors->dev_attr.attr.mode = 0444;
 629                 sensors->dev_attr.show = attrs->show;
 630                 sensors->index = attrs->index;
 631
 632                 if (attrs->set) {
 633                         sensors->dev_attr.attr.mode |= 0200;
 634                         sensors->dev_attr.store = attrs->set;
 635                 }
 636
 637                 sysfs_attr_init(&sensors->dev_attr.attr);
 638                 res = device_create_file(dev, &sensors->dev_attr);
 639                 if (res) {
 640                         sensors->dev_attr.attr.name = NULL;
 641                         goto error;
 642                 }
 643                 sensors++;
 644                 resource->num_sensors++;
 645                 attrs++;
 646         }
 647
 648 error:
 649         return res;
 650 }
 651
 652 static void remove_attrs(struct acpi_power_meter_resource *resource)
 653 {
 654         int i;
 655
 656         for (i = 0; i < resource->num_sensors; i++) {
 657                 if (!resource->sensors[i].dev_attr.attr.name)
 658                         continue;
 659                 device_remove_file(&resource->acpi_dev->dev,
 660                                    &resource->sensors[i].dev_attr);
 661         }
 662
 663         remove_domain_devices(resource);
 664
 665         resource->num_sensors = 0;
 666 }
 667
 668 static int setup_attrs(struct acpi_power_meter_resource *resource)
 669 {
 670         int res = 0;
 671
 672         res = read_domain_devices(resource);
 673         if (res)
 674                 return res;
 675
 676         if (resource->caps.flags & POWER_METER_CAN_MEASURE) {
 677                 res = register_attrs(resource, meter_attrs);
 678                 if (res)
 679                         goto error;
 680         }
 681
 682         if (resource->caps.flags & POWER_METER_CAN_CAP) {
 683                 if (!can_cap_in_hardware()) {
 684                         dev_warn(&resource->acpi_dev->dev,
 685                                  "Ignoring unsafe software power cap!\n");
 686                         goto skip_unsafe_cap;
 687                 }
 688
 689                 if (resource->caps.configurable_cap)
 690                         res = register_attrs(resource, rw_cap_attrs);
 691                 else
 692                         res = register_attrs(resource, ro_cap_attrs);
 693
 694                 if (res)
 695                         goto error;
 696
 697                 res = register_attrs(resource, misc_cap_attrs);
 698                 if (res)
 699                         goto error;
 700         }
 701
 702 skip_unsafe_cap:
 703         if (resource->caps.flags & POWER_METER_CAN_TRIP) {
 704                 res = register_attrs(resource, trip_attrs);
 705                 if (res)
 706                         goto error;
 707         }
 708
 709         res = register_attrs(resource, misc_attrs);
 710         if (res)
 711                 goto error;
 712
 713         return res;
 714 error:
 715         remove_attrs(resource);
 716         return res;
 717 }
 718
 719 static void free_capabilities(struct acpi_power_meter_resource *resource)
 720 {
 721         acpi_string *str;
 722         int i;
 723
 724         str = &resource->model_number;
 725         for (i = 0; i < 3; i++, str++)
 726                 kfree(*str);
 727 }
 728
 729 static int read_capabilities(struct acpi_power_meter_resource *resource)
 730 {
 731         int res = 0;
 732         int i;
 733         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
 734         struct acpi_buffer state = { 0, NULL };
 735         struct acpi_buffer format = { sizeof("NNNNNNNNNNN"), "NNNNNNNNNNN" };
 736         union acpi_object *pss;
 737         acpi_string *str;
 738         acpi_status status;
 739
 740         status = acpi_evaluate_object(resource->acpi_dev->handle, "_PMC", NULL,
 741                                       &buffer);
 742         if (ACPI_FAILURE(status)) {
 743                 ACPI_EXCEPTION((AE_INFO, status, "Evaluating _PMC"));
 744                 return -ENODEV;
 745         }
 746
 747         pss = buffer.pointer;
 748         if (!pss ||
 749             pss->type != ACPI_TYPE_PACKAGE ||
 750             pss->package.count != 14) {
 751                 dev_err(&resource->acpi_dev->dev, ACPI_POWER_METER_NAME
 752                         "Invalid _PMC data\n");
 753                 res = -EFAULT;
 754                 goto end;
 755         }
 756
 757         /* Grab all the integer data at once */
 758         state.length = sizeof(struct acpi_power_meter_capabilities);
 759         state.pointer = &resource->caps;
 760
 761         status = acpi_extract_package(pss, &format, &state);
 762         if (ACPI_FAILURE(status)) {
 763                 ACPI_EXCEPTION((AE_INFO, status, "Invalid data"));
 764                 res = -EFAULT;
 765                 goto end;
 766         }
 767
 768         if (resource->caps.units) {
 769                 dev_err(&resource->acpi_dev->dev, ACPI_POWER_METER_NAME
 770                         "Unknown units %llu.\n",
 771                         resource->caps.units);
 772                 res = -EINVAL;
 773                 goto end;
 774         }
 775
 776         /* Grab the string data */
 777         str = &resource->model_number;
 778
 779         for (i = 11; i < 14; i++) {
 780                 union acpi_object *element = &(pss->package.elements[i]);
 781
 782                 if (element->type != ACPI_TYPE_STRING) {
 783                         res = -EINVAL;
 784                         goto error;
 785                 }
 786
 787                 *str = kcalloc(element->string.length + 1, sizeof(u8),
 788                                GFP_KERNEL);
 789                 if (!*str) {
 790                         res = -ENOMEM;
 791                         goto error;
 792                 }
 793
 794                 strncpy(*str, element->string.pointer, element->string.length);
 795                 str++;
 796         }
 797
 798         dev_info(&resource->acpi_dev->dev, "Found ACPI power meter.\n");
 799         goto end;
 800 error:
 801         str = &resource->model_number;
 802         for (i = 0; i < 3; i++, str++)
 803                 kfree(*str);
 804 end:
 805         kfree(buffer.pointer);
 806         return res;
 807 }
 808
 809 /* Handle ACPI event notifications */
 810 static void acpi_power_meter_notify(struct acpi_device *device, u32 event)
 811 {
 812         struct acpi_power_meter_resource *resource;
 813         int res;
 814
 815         if (!device || !acpi_driver_data(device))
 816                 return;
 817
 818         resource = acpi_driver_data(device);
 819
 820         mutex_lock(&resource->lock);
 821         switch (event) {
 822         case METER_NOTIFY_CONFIG:
 823                 free_capabilities(resource);
 824                 res = read_capabilities(resource);
 825                 if (res)
 826                         break;
 827
 828                 remove_attrs(resource);
 829                 setup_attrs(resource);
 830                 break;
 831         case METER_NOTIFY_TRIP:
 832                 sysfs_notify(&device->dev.kobj, NULL, POWER_AVERAGE_NAME);
 833                 update_meter(resource);
 834                 break;
 835         case METER_NOTIFY_CAP:
 836                 sysfs_notify(&device->dev.kobj, NULL, POWER_CAP_NAME);
 837                 update_cap(resource);
 838                 break;
 839         case METER_NOTIFY_INTERVAL:
 840                 sysfs_notify(&device->dev.kobj, NULL, POWER_AVG_INTERVAL_NAME);
 841                 update_avg_interval(resource);
 842                 break;
 843         case METER_NOTIFY_CAPPING:
 844                 sysfs_notify(&device->dev.kobj, NULL, POWER_ALARM_NAME);
 845                 dev_info(&device->dev, "Capping in progress.\n");
 846                 break;
 847         default:
 848                 WARN(1, "Unexpected event %d\n", event);
 849                 break;
 850         }
 851         mutex_unlock(&resource->lock);
 852
 853         acpi_bus_generate_netlink_event(ACPI_POWER_METER_CLASS,
 854                                         dev_name(&device->dev), event, 0);
 855 }
 856
 857 static int acpi_power_meter_add(struct acpi_device *device)
 858 {
 859         int res;
 860         struct acpi_power_meter_resource *resource;
 861
 862         if (!device)
 863                 return -EINVAL;
 864
 865         resource = kzalloc(sizeof(struct acpi_power_meter_resource),
 866                            GFP_KERNEL);
 867         if (!resource)
 868                 return -ENOMEM;
 869
 870         resource->sensors_valid = 0;
 871         resource->acpi_dev = device;
 872         mutex_init(&resource->lock);
 873         strcpy(acpi_device_name(device), ACPI_POWER_METER_DEVICE_NAME);
 874         strcpy(acpi_device_class(device), ACPI_POWER_METER_CLASS);
 875         device->driver_data = resource;
 876
 877         free_capabilities(resource);
 878         res = read_capabilities(resource);
 879         if (res)
 880                 goto exit_free;
 881
 882         resource->trip[0] = resource->trip[1] = -1;
 883
 884         res = setup_attrs(resource);
 885         if (res)
 886                 goto exit_free;
 887
 888         resource->hwmon_dev = hwmon_device_register(&device->dev);
 889         if (IS_ERR(resource->hwmon_dev)) {
 890                 res = PTR_ERR(resource->hwmon_dev);
 891                 goto exit_remove;
 892         }
 893
 894         res = 0;
 895         goto exit;
 896
 897 exit_remove:
 898         remove_attrs(resource);
 899 exit_free:
 900         kfree(resource);
 901 exit:
 902         return res;
 903 }
 904
 905 static int acpi_power_meter_remove(struct acpi_device *device)
 906 {
 907         struct acpi_power_meter_resource *resource;
 908
 909         if (!device || !acpi_driver_data(device))
 910                 return -EINVAL;
 911
 912         resource = acpi_driver_data(device);
 913         hwmon_device_unregister(resource->hwmon_dev);
 914
 915         free_capabilities(resource);
 916         remove_attrs(resource);
 917
 918         kfree(resource);
 919         return 0;
 920 }
 921
 922 #ifdef CONFIG_PM_SLEEP
 923
 924 static int acpi_power_meter_resume(struct device *dev)
 925 {
 926         struct acpi_power_meter_resource *resource;
 927
 928         if (!dev)
 929                 return -EINVAL;
 930
 931         resource = acpi_driver_data(to_acpi_device(dev));
 932         if (!resource)
 933                 return -EINVAL;
 934
 935         free_capabilities(resource);
 936         read_capabilities(resource);
 937
 938         return 0;
 939 }
 940
 941 #endif /* CONFIG_PM_SLEEP */
 942
 943 static SIMPLE_DEV_PM_OPS(acpi_power_meter_pm, NULL, acpi_power_meter_resume);
 944
 945 static struct acpi_driver acpi_power_meter_driver = {
 946         .name = "power_meter",
 947         .class = ACPI_POWER_METER_CLASS,
 948         .ids = power_meter_ids,
 949         .ops = {
 950                 .add = acpi_power_meter_add,
 951                 .remove = acpi_power_meter_remove,
 952                 .notify = acpi_power_meter_notify,
 953                 },
 954         .drv.pm = &acpi_power_meter_pm,
 955 };
 956
 957 /* Module init/exit routines */
 958 static int __init enable_cap_knobs(const struct dmi_system_id *d)
 959 {
 960         cap_in_hardware = 1;
 961         return 0;
 962 }
 963
 964 static const struct dmi_system_id pm_dmi_table[] __initconst = {
 965         {
 966                 enable_cap_knobs, "IBM Active Energy Manager",
 967                 {
 968                         DMI_MATCH(DMI_SYS_VENDOR, "IBM")
 969                 },
 970         },
 971         {}
 972 };
 973
 974 static int __init acpi_power_meter_init(void)
 975 {
 976         int result;
 977
 978         if (acpi_disabled)
 979                 return -ENODEV;
 980
 981         dmi_check_system(pm_dmi_table);
 982
 983         result = acpi_bus_register_driver(&acpi_power_meter_driver);
 984         if (result < 0)
 985                 return result;
 986
 987         return 0;
 988 }
 989
 990 static void __exit acpi_power_meter_exit(void)
 991 {
 992         acpi_bus_unregister_driver(&acpi_power_meter_driver);
 993 }
 994
 995 MODULE_AUTHOR("Darrick J. Wong <darrick.wong@oracle.com>");
 996 MODULE_DESCRIPTION("ACPI 4.0 power meter driver");
 997 MODULE_LICENSE("GPL");
 998
 999 module_param(force_cap_on, bool, 0644);
1000 MODULE_PARM_DESC(force_cap_on, "Enable power cap even it is unsafe to do so.");
1001
1002 module_init(acpi_power_meter_init);
1003 module_exit(acpi_power_meter_exit);