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 #define UNKNOWN_POWER           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_evaluation_failure_warn(resource->acpi_dev->handle, "_GAI",
 118                                              status);
 119                 return -ENODEV;
 120         }
 121
 122         resource->avg_interval = data;
 123         return 0;
 124 }
 125
 126 static ssize_t show_avg_interval(struct device *dev,
 127                                  struct device_attribute *devattr,
 128                                  char *buf)
 129 {
 130         struct acpi_device *acpi_dev = to_acpi_device(dev);
 131         struct acpi_power_meter_resource *resource = acpi_dev->driver_data;
 132
 133         mutex_lock(&resource->lock);
 134         update_avg_interval(resource);
 135         mutex_unlock(&resource->lock);
 136
 137         return sprintf(buf, "%llu\n", resource->avg_interval);
 138 }
 139
 140 static ssize_t set_avg_interval(struct device *dev,
 141                                 struct device_attribute *devattr,
 142                                 const char *buf, size_t count)
 143 {
 144         struct acpi_device *acpi_dev = to_acpi_device(dev);
 145         struct acpi_power_meter_resource *resource = acpi_dev->driver_data;
 146         union acpi_object arg0 = { ACPI_TYPE_INTEGER };
 147         struct acpi_object_list args = { 1, &arg0 };
 148         int res;
 149         unsigned long temp;
 150         unsigned long long data;
 151         acpi_status status;
 152
 153         res = kstrtoul(buf, 10, &temp);
 154         if (res)
 155                 return res;
 156
 157         if (temp > resource->caps.max_avg_interval ||
 158             temp < resource->caps.min_avg_interval)
 159                 return -EINVAL;
 160         arg0.integer.value = temp;
 161
 162         mutex_lock(&resource->lock);
 163         status = acpi_evaluate_integer(resource->acpi_dev->handle, "_PAI",
 164                                        &args, &data);
 165         if (ACPI_SUCCESS(status))
 166                 resource->avg_interval = temp;
 167         mutex_unlock(&resource->lock);
 168
 169         if (ACPI_FAILURE(status)) {
 170                 acpi_evaluation_failure_warn(resource->acpi_dev->handle, "_PAI",
 171                                              status);
 172                 return -EINVAL;
 173         }
 174
 175         /* _PAI returns 0 on success, nonzero otherwise */
 176         if (data)
 177                 return -EINVAL;
 178
 179         return count;
 180 }
 181
 182 /* Cap functions */
 183 static int update_cap(struct acpi_power_meter_resource *resource)
 184 {
 185         unsigned long long data;
 186         acpi_status status;
 187
 188         status = acpi_evaluate_integer(resource->acpi_dev->handle, "_GHL",
 189                                        NULL, &data);
 190         if (ACPI_FAILURE(status)) {
 191                 acpi_evaluation_failure_warn(resource->acpi_dev->handle, "_GHL",
 192                                              status);
 193                 return -ENODEV;
 194         }
 195
 196         resource->cap = data;
 197         return 0;
 198 }
 199
 200 static ssize_t show_cap(struct device *dev,
 201                         struct device_attribute *devattr,
 202                         char *buf)
 203 {
 204         struct acpi_device *acpi_dev = to_acpi_device(dev);
 205         struct acpi_power_meter_resource *resource = acpi_dev->driver_data;
 206
 207         mutex_lock(&resource->lock);
 208         update_cap(resource);
 209         mutex_unlock(&resource->lock);
 210
 211         return sprintf(buf, "%llu\n", resource->cap * 1000);
 212 }
 213
 214 static ssize_t set_cap(struct device *dev, struct device_attribute *devattr,
 215                        const char *buf, size_t count)
 216 {
 217         struct acpi_device *acpi_dev = to_acpi_device(dev);
 218         struct acpi_power_meter_resource *resource = acpi_dev->driver_data;
 219         union acpi_object arg0 = { ACPI_TYPE_INTEGER };
 220         struct acpi_object_list args = { 1, &arg0 };
 221         int res;
 222         unsigned long temp;
 223         unsigned long long data;
 224         acpi_status status;
 225
 226         res = kstrtoul(buf, 10, &temp);
 227         if (res)
 228                 return res;
 229
 230         temp = DIV_ROUND_CLOSEST(temp, 1000);
 231         if (temp > resource->caps.max_cap || temp < resource->caps.min_cap)
 232                 return -EINVAL;
 233         arg0.integer.value = temp;
 234
 235         mutex_lock(&resource->lock);
 236         status = acpi_evaluate_integer(resource->acpi_dev->handle, "_SHL",
 237                                        &args, &data);
 238         if (ACPI_SUCCESS(status))
 239                 resource->cap = temp;
 240         mutex_unlock(&resource->lock);
 241
 242         if (ACPI_FAILURE(status)) {
 243                 acpi_evaluation_failure_warn(resource->acpi_dev->handle, "_SHL",
 244                                              status);
 245                 return -EINVAL;
 246         }
 247
 248         /* _SHL returns 0 on success, nonzero otherwise */
 249         if (data)
 250                 return -EINVAL;
 251
 252         return count;
 253 }
 254
 255 /* Power meter trip points */
 256 static int set_acpi_trip(struct acpi_power_meter_resource *resource)
 257 {
 258         union acpi_object arg_objs[] = {
 259                 {ACPI_TYPE_INTEGER},
 260                 {ACPI_TYPE_INTEGER}
 261         };
 262         struct acpi_object_list args = { 2, arg_objs };
 263         unsigned long long data;
 264         acpi_status status;
 265
 266         /* Both trip levels must be set */
 267         if (resource->trip[0] < 0 || resource->trip[1] < 0)
 268                 return 0;
 269
 270         /* This driver stores min, max; ACPI wants max, min. */
 271         arg_objs[0].integer.value = resource->trip[1];
 272         arg_objs[1].integer.value = resource->trip[0];
 273
 274         status = acpi_evaluate_integer(resource->acpi_dev->handle, "_PTP",
 275                                        &args, &data);
 276         if (ACPI_FAILURE(status)) {
 277                 acpi_evaluation_failure_warn(resource->acpi_dev->handle, "_PTP",
 278                                              status);
 279                 return -EINVAL;
 280         }
 281
 282         /* _PTP returns 0 on success, nonzero otherwise */
 283         if (data)
 284                 return -EINVAL;
 285
 286         return 0;
 287 }
 288
 289 static ssize_t set_trip(struct device *dev, struct device_attribute *devattr,
 290                         const char *buf, size_t count)
 291 {
 292         struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
 293         struct acpi_device *acpi_dev = to_acpi_device(dev);
 294         struct acpi_power_meter_resource *resource = acpi_dev->driver_data;
 295         int res;
 296         unsigned long temp;
 297
 298         res = kstrtoul(buf, 10, &temp);
 299         if (res)
 300                 return res;
 301
 302         temp = DIV_ROUND_CLOSEST(temp, 1000);
 303
 304         mutex_lock(&resource->lock);
 305         resource->trip[attr->index - 7] = temp;
 306         res = set_acpi_trip(resource);
 307         mutex_unlock(&resource->lock);
 308
 309         if (res)
 310                 return res;
 311
 312         return count;
 313 }
 314
 315 /* Power meter */
 316 static int update_meter(struct acpi_power_meter_resource *resource)
 317 {
 318         unsigned long long data;
 319         acpi_status status;
 320         unsigned long local_jiffies = jiffies;
 321
 322         if (time_before(local_jiffies, resource->sensors_last_updated +
 323                         msecs_to_jiffies(resource->caps.sampling_time)) &&
 324                         resource->sensors_valid)
 325                 return 0;
 326
 327         status = acpi_evaluate_integer(resource->acpi_dev->handle, "_PMM",
 328                                        NULL, &data);
 329         if (ACPI_FAILURE(status)) {
 330                 acpi_evaluation_failure_warn(resource->acpi_dev->handle, "_PMM",
 331                                              status);
 332                 return -ENODEV;
 333         }
 334
 335         resource->power = data;
 336         resource->sensors_valid = 1;
 337         resource->sensors_last_updated = jiffies;
 338         return 0;
 339 }
 340
 341 static ssize_t show_power(struct device *dev,
 342                           struct device_attribute *devattr,
 343                           char *buf)
 344 {
 345         struct acpi_device *acpi_dev = to_acpi_device(dev);
 346         struct acpi_power_meter_resource *resource = acpi_dev->driver_data;
 347
 348         mutex_lock(&resource->lock);
 349         update_meter(resource);
 350         mutex_unlock(&resource->lock);
 351
 352         if (resource->power == UNKNOWN_POWER)
 353                 return -ENODATA;
 354
 355         return sprintf(buf, "%llu\n", resource->power * 1000);
 356 }
 357
 358 /* Miscellaneous */
 359 static ssize_t show_str(struct device *dev,
 360                         struct device_attribute *devattr,
 361                         char *buf)
 362 {
 363         struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
 364         struct acpi_device *acpi_dev = to_acpi_device(dev);
 365         struct acpi_power_meter_resource *resource = acpi_dev->driver_data;
 366         acpi_string val;
 367         int ret;
 368
 369         mutex_lock(&resource->lock);
 370         switch (attr->index) {
 371         case 0:
 372                 val = resource->model_number;
 373                 break;
 374         case 1:
 375                 val = resource->serial_number;
 376                 break;
 377         case 2:
 378                 val = resource->oem_info;
 379                 break;
 380         default:
 381                 WARN(1, "Implementation error: unexpected attribute index %d\n",
 382                      attr->index);
 383                 val = "";
 384                 break;
 385         }
 386         ret = sprintf(buf, "%s\n", val);
 387         mutex_unlock(&resource->lock);
 388         return ret;
 389 }
 390
 391 static ssize_t show_val(struct device *dev,
 392                         struct device_attribute *devattr,
 393                         char *buf)
 394 {
 395         struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
 396         struct acpi_device *acpi_dev = to_acpi_device(dev);
 397         struct acpi_power_meter_resource *resource = acpi_dev->driver_data;
 398         u64 val = 0;
 399
 400         switch (attr->index) {
 401         case 0:
 402                 val = resource->caps.min_avg_interval;
 403                 break;
 404         case 1:
 405                 val = resource->caps.max_avg_interval;
 406                 break;
 407         case 2:
 408                 val = resource->caps.min_cap * 1000;
 409                 break;
 410         case 3:
 411                 val = resource->caps.max_cap * 1000;
 412                 break;
 413         case 4:
 414                 if (resource->caps.hysteresis == UNKNOWN_HYSTERESIS)
 415                         return sprintf(buf, "unknown\n");
 416
 417                 val = resource->caps.hysteresis * 1000;
 418                 break;
 419         case 5:
 420                 if (resource->caps.flags & POWER_METER_IS_BATTERY)
 421                         val = 1;
 422                 else
 423                         val = 0;
 424                 break;
 425         case 6:
 426                 if (resource->power > resource->cap)
 427                         val = 1;
 428                 else
 429                         val = 0;
 430                 break;
 431         case 7:
 432         case 8:
 433                 if (resource->trip[attr->index - 7] < 0)
 434                         return sprintf(buf, "unknown\n");
 435
 436                 val = resource->trip[attr->index - 7] * 1000;
 437                 break;
 438         default:
 439                 WARN(1, "Implementation error: unexpected attribute index %d\n",
 440                      attr->index);
 441                 break;
 442         }
 443
 444         return sprintf(buf, "%llu\n", val);
 445 }
 446
 447 static ssize_t show_accuracy(struct device *dev,
 448                              struct device_attribute *devattr,
 449                              char *buf)
 450 {
 451         struct acpi_device *acpi_dev = to_acpi_device(dev);
 452         struct acpi_power_meter_resource *resource = acpi_dev->driver_data;
 453         unsigned int acc = resource->caps.accuracy;
 454
 455         return sprintf(buf, "%u.%u%%\n", acc / 1000, acc % 1000);
 456 }
 457
 458 static ssize_t show_name(struct device *dev,
 459                          struct device_attribute *devattr,
 460                          char *buf)
 461 {
 462         return sprintf(buf, "%s\n", ACPI_POWER_METER_NAME);
 463 }
 464
 465 #define RO_SENSOR_TEMPLATE(_label, _show, _index)       \
 466         {                                               \
 467                 .label = _label,                        \
 468                 .show  = _show,                         \
 469                 .index = _index,                        \
 470         }
 471
 472 #define RW_SENSOR_TEMPLATE(_label, _show, _set, _index) \
 473         {                                               \
 474                 .label = _label,                        \
 475                 .show  = _show,                         \
 476                 .set   = _set,                          \
 477                 .index = _index,                        \
 478         }
 479
 480 /* Sensor descriptions.  If you add a sensor, update NUM_SENSORS above! */
 481 static struct sensor_template meter_attrs[] = {
 482         RO_SENSOR_TEMPLATE(POWER_AVERAGE_NAME, show_power, 0),
 483         RO_SENSOR_TEMPLATE("power1_accuracy", show_accuracy, 0),
 484         RO_SENSOR_TEMPLATE("power1_average_interval_min", show_val, 0),
 485         RO_SENSOR_TEMPLATE("power1_average_interval_max", show_val, 1),
 486         RO_SENSOR_TEMPLATE("power1_is_battery", show_val, 5),
 487         RW_SENSOR_TEMPLATE(POWER_AVG_INTERVAL_NAME, show_avg_interval,
 488                            set_avg_interval, 0),
 489         {},
 490 };
 491
 492 static struct sensor_template misc_cap_attrs[] = {
 493         RO_SENSOR_TEMPLATE("power1_cap_min", show_val, 2),
 494         RO_SENSOR_TEMPLATE("power1_cap_max", show_val, 3),
 495         RO_SENSOR_TEMPLATE("power1_cap_hyst", show_val, 4),
 496         RO_SENSOR_TEMPLATE(POWER_ALARM_NAME, show_val, 6),
 497         {},
 498 };
 499
 500 static struct sensor_template ro_cap_attrs[] = {
 501         RO_SENSOR_TEMPLATE(POWER_CAP_NAME, show_cap, 0),
 502         {},
 503 };
 504
 505 static struct sensor_template rw_cap_attrs[] = {
 506         RW_SENSOR_TEMPLATE(POWER_CAP_NAME, show_cap, set_cap, 0),
 507         {},
 508 };
 509
 510 static struct sensor_template trip_attrs[] = {
 511         RW_SENSOR_TEMPLATE("power1_average_min", show_val, set_trip, 7),
 512         RW_SENSOR_TEMPLATE("power1_average_max", show_val, set_trip, 8),
 513         {},
 514 };
 515
 516 static struct sensor_template misc_attrs[] = {
 517         RO_SENSOR_TEMPLATE("name", show_name, 0),
 518         RO_SENSOR_TEMPLATE("power1_model_number", show_str, 0),
 519         RO_SENSOR_TEMPLATE("power1_oem_info", show_str, 2),
 520         RO_SENSOR_TEMPLATE("power1_serial_number", show_str, 1),
 521         {},
 522 };
 523
 524 #undef RO_SENSOR_TEMPLATE
 525 #undef RW_SENSOR_TEMPLATE
 526
 527 /* Read power domain data */
 528 static void remove_domain_devices(struct acpi_power_meter_resource *resource)
 529 {
 530         int i;
 531
 532         if (!resource->num_domain_devices)
 533                 return;
 534
 535         for (i = 0; i < resource->num_domain_devices; i++) {
 536                 struct acpi_device *obj = resource->domain_devices[i];
 537
 538                 if (!obj)
 539                         continue;
 540
 541                 sysfs_remove_link(resource->holders_dir,
 542                                   kobject_name(&obj->dev.kobj));
 543                 acpi_dev_put(obj);
 544         }
 545
 546         kfree(resource->domain_devices);
 547         kobject_put(resource->holders_dir);
 548         resource->num_domain_devices = 0;
 549 }
 550
 551 static int read_domain_devices(struct acpi_power_meter_resource *resource)
 552 {
 553         int res = 0;
 554         int i;
 555         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
 556         union acpi_object *pss;
 557         acpi_status status;
 558
 559         status = acpi_evaluate_object(resource->acpi_dev->handle, "_PMD", NULL,
 560                                       &buffer);
 561         if (ACPI_FAILURE(status)) {
 562                 acpi_evaluation_failure_warn(resource->acpi_dev->handle, "_PMD",
 563                                              status);
 564                 return -ENODEV;
 565         }
 566
 567         pss = buffer.pointer;
 568         if (!pss ||
 569             pss->type != ACPI_TYPE_PACKAGE) {
 570                 dev_err(&resource->acpi_dev->dev, ACPI_POWER_METER_NAME
 571                         "Invalid _PMD data\n");
 572                 res = -EFAULT;
 573                 goto end;
 574         }
 575
 576         if (!pss->package.count)
 577                 goto end;
 578
 579         resource->domain_devices = kcalloc(pss->package.count,
 580                                            sizeof(struct acpi_device *),
 581                                            GFP_KERNEL);
 582         if (!resource->domain_devices) {
 583                 res = -ENOMEM;
 584                 goto end;
 585         }
 586
 587         resource->holders_dir = kobject_create_and_add("measures",
 588                                                        &resource->acpi_dev->dev.kobj);
 589         if (!resource->holders_dir) {
 590                 res = -ENOMEM;
 591                 goto exit_free;
 592         }
 593
 594         resource->num_domain_devices = pss->package.count;
 595
 596         for (i = 0; i < pss->package.count; i++) {
 597                 struct acpi_device *obj;
 598                 union acpi_object *element = &pss->package.elements[i];
 599
 600                 /* Refuse non-references */
 601                 if (element->type != ACPI_TYPE_LOCAL_REFERENCE)
 602                         continue;
 603
 604                 /* Create a symlink to domain objects */
 605                 obj = acpi_get_acpi_dev(element->reference.handle);
 606                 resource->domain_devices[i] = obj;
 607                 if (!obj)
 608                         continue;
 609
 610                 res = sysfs_create_link(resource->holders_dir, &obj->dev.kobj,
 611                                         kobject_name(&obj->dev.kobj));
 612                 if (res) {
 613                         acpi_dev_put(obj);
 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 = 0444;
 640                 sensors->dev_attr.show = attrs->show;
 641                 sensors->index = attrs->index;
 642
 643                 if (attrs->set) {
 644                         sensors->dev_attr.attr.mode |= 0200;
 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_warn(&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                 *str = NULL;
 739         }
 740 }
 741
 742 static int read_capabilities(struct acpi_power_meter_resource *resource)
 743 {
 744         int res = 0;
 745         int i;
 746         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
 747         struct acpi_buffer state = { 0, NULL };
 748         struct acpi_buffer format = { sizeof("NNNNNNNNNNN"), "NNNNNNNNNNN" };
 749         union acpi_object *pss;
 750         acpi_string *str;
 751         acpi_status status;
 752
 753         status = acpi_evaluate_object(resource->acpi_dev->handle, "_PMC", NULL,
 754                                       &buffer);
 755         if (ACPI_FAILURE(status)) {
 756                 acpi_evaluation_failure_warn(resource->acpi_dev->handle, "_PMC",
 757                                              status);
 758                 return -ENODEV;
 759         }
 760
 761         pss = buffer.pointer;
 762         if (!pss ||
 763             pss->type != ACPI_TYPE_PACKAGE ||
 764             pss->package.count != 14) {
 765                 dev_err(&resource->acpi_dev->dev, ACPI_POWER_METER_NAME
 766                         "Invalid _PMC data\n");
 767                 res = -EFAULT;
 768                 goto end;
 769         }
 770
 771         /* Grab all the integer data at once */
 772         state.length = sizeof(struct acpi_power_meter_capabilities);
 773         state.pointer = &resource->caps;
 774
 775         status = acpi_extract_package(pss, &format, &state);
 776         if (ACPI_FAILURE(status)) {
 777                 dev_err(&resource->acpi_dev->dev, ACPI_POWER_METER_NAME
 778                         "_PMC package parsing failed: %s\n",
 779                         acpi_format_exception(status));
 780                 res = -EFAULT;
 781                 goto end;
 782         }
 783
 784         if (resource->caps.units) {
 785                 dev_err(&resource->acpi_dev->dev, ACPI_POWER_METER_NAME
 786                         "Unknown units %llu.\n",
 787                         resource->caps.units);
 788                 res = -EINVAL;
 789                 goto end;
 790         }
 791
 792         /* Grab the string data */
 793         str = &resource->model_number;
 794
 795         for (i = 11; i < 14; i++) {
 796                 union acpi_object *element = &pss->package.elements[i];
 797
 798                 if (element->type != ACPI_TYPE_STRING) {
 799                         res = -EINVAL;
 800                         goto error;
 801                 }
 802
 803                 *str = kmemdup_nul(element->string.pointer, element->string.length,
 804                                    GFP_KERNEL);
 805                 if (!*str) {
 806                         res = -ENOMEM;
 807                         goto error;
 808                 }
 809
 810                 str++;
 811         }
 812
 813         dev_info(&resource->acpi_dev->dev, "Found ACPI power meter.\n");
 814         goto end;
 815 error:
 816         free_capabilities(resource);
 817 end:
 818         kfree(buffer.pointer);
 819         return res;
 820 }
 821
 822 /* Handle ACPI event notifications */
 823 static void acpi_power_meter_notify(struct acpi_device *device, u32 event)
 824 {
 825         struct acpi_power_meter_resource *resource;
 826         int res;
 827
 828         if (!device || !acpi_driver_data(device))
 829                 return;
 830
 831         resource = acpi_driver_data(device);
 832
 833         switch (event) {
 834         case METER_NOTIFY_CONFIG:
 835                 mutex_lock(&resource->lock);
 836                 free_capabilities(resource);
 837                 res = read_capabilities(resource);
 838                 mutex_unlock(&resource->lock);
 839                 if (res)
 840                         break;
 841
 842                 remove_attrs(resource);
 843                 setup_attrs(resource);
 844                 break;
 845         case METER_NOTIFY_TRIP:
 846                 sysfs_notify(&device->dev.kobj, NULL, POWER_AVERAGE_NAME);
 847                 break;
 848         case METER_NOTIFY_CAP:
 849                 sysfs_notify(&device->dev.kobj, NULL, POWER_CAP_NAME);
 850                 break;
 851         case METER_NOTIFY_INTERVAL:
 852                 sysfs_notify(&device->dev.kobj, NULL, POWER_AVG_INTERVAL_NAME);
 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                 WARN(1, "Unexpected event %d\n", event);
 860                 break;
 861         }
 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(*resource), GFP_KERNEL);
 876         if (!resource)
 877                 return -ENOMEM;
 878
 879         resource->sensors_valid = 0;
 880         resource->acpi_dev = device;
 881         mutex_init(&resource->lock);
 882         strcpy(acpi_device_name(device), ACPI_POWER_METER_DEVICE_NAME);
 883         strcpy(acpi_device_class(device), ACPI_POWER_METER_CLASS);
 884         device->driver_data = resource;
 885
 886         res = read_capabilities(resource);
 887         if (res)
 888                 goto exit_free;
 889
 890         resource->trip[0] = -1;
 891         resource->trip[1] = -1;
 892
 893         res = setup_attrs(resource);
 894         if (res)
 895                 goto exit_free_capability;
 896
 897         resource->hwmon_dev = hwmon_device_register(&device->dev);
 898         if (IS_ERR(resource->hwmon_dev)) {
 899                 res = PTR_ERR(resource->hwmon_dev);
 900                 goto exit_remove;
 901         }
 902
 903         res = 0;
 904         goto exit;
 905
 906 exit_remove:
 907         remove_attrs(resource);
 908 exit_free_capability:
 909         free_capabilities(resource);
 910 exit_free:
 911         kfree(resource);
 912 exit:
 913         return res;
 914 }
 915
 916 static void acpi_power_meter_remove(struct acpi_device *device)
 917 {
 918         struct acpi_power_meter_resource *resource;
 919
 920         if (!device || !acpi_driver_data(device))
 921                 return;
 922
 923         resource = acpi_driver_data(device);
 924         hwmon_device_unregister(resource->hwmon_dev);
 925
 926         remove_attrs(resource);
 927         free_capabilities(resource);
 928
 929         kfree(resource);
 930 }
 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 static DEFINE_SIMPLE_DEV_PM_OPS(acpi_power_meter_pm, NULL,
 950                                 acpi_power_meter_resume);
 951
 952 static struct acpi_driver acpi_power_meter_driver = {
 953         .name = "power_meter",
 954         .class = ACPI_POWER_METER_CLASS,
 955         .ids = power_meter_ids,
 956         .ops = {
 957                 .add = acpi_power_meter_add,
 958                 .remove = acpi_power_meter_remove,
 959                 .notify = acpi_power_meter_notify,
 960                 },
 961         .drv.pm = pm_sleep_ptr(&acpi_power_meter_pm),
 962 };
 963
 964 /* Module init/exit routines */
 965 static int __init enable_cap_knobs(const struct dmi_system_id *d)
 966 {
 967         cap_in_hardware = 1;
 968         return 0;
 969 }
 970
 971 static const struct dmi_system_id pm_dmi_table[] __initconst = {
 972         {
 973                 enable_cap_knobs, "IBM Active Energy Manager",
 974                 {
 975                         DMI_MATCH(DMI_SYS_VENDOR, "IBM")
 976                 },
 977         },
 978         {}
 979 };
 980
 981 static int __init acpi_power_meter_init(void)
 982 {
 983         int result;
 984
 985         if (acpi_disabled)
 986                 return -ENODEV;
 987
 988         dmi_check_system(pm_dmi_table);
 989
 990         result = acpi_bus_register_driver(&acpi_power_meter_driver);
 991         if (result < 0)
 992                 return result;
 993
 994         return 0;
 995 }
 996
 997 static void __exit acpi_power_meter_exit(void)
 998 {
 999         acpi_bus_unregister_driver(&acpi_power_meter_driver);
1000 }
1001
1002 MODULE_AUTHOR("Darrick J. Wong <darrick.wong@oracle.com>");
1003 MODULE_DESCRIPTION("ACPI 4.0 power meter driver");
1004 MODULE_LICENSE("GPL");
1005
1006 module_param(force_cap_on, bool, 0644);
1007 MODULE_PARM_DESC(force_cap_on, "Enable power cap even it is unsafe to do so.");
1008
1009 module_init(acpi_power_meter_init);
1010 module_exit(acpi_power_meter_exit);