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 <[email protected]>
   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         bool            power_alarm;
  88         int                     sensors_valid;
  89         unsigned long           sensors_last_updated;
  90         struct sensor_device_attribute  sensors[NUM_SENSORS];
  91         int                     num_sensors;
  92         s64                     trip[2];
  93         int                     num_domain_devices;
  94         struct acpi_device      **domain_devices;
  95         struct kobject          *holders_dir;
  96 };
  97
  98 struct sensor_template {
  99         char *label;
 100         ssize_t (*show)(struct device *dev,
 101                         struct device_attribute *devattr,
 102                         char *buf);
 103         ssize_t (*set)(struct device *dev,
 104                        struct device_attribute *devattr,
 105                        const char *buf, size_t count);
 106         int index;
 107 };
 108
 109 /* Averaging interval */
 110 static int update_avg_interval(struct acpi_power_meter_resource *resource)
 111 {
 112         unsigned long long data;
 113         acpi_status status;
 114
 115         status = acpi_evaluate_integer(resource->acpi_dev->handle, "_GAI",
 116                                        NULL, &data);
 117         if (ACPI_FAILURE(status)) {
 118                 acpi_evaluation_failure_warn(resource->acpi_dev->handle, "_GAI",
 119                                              status);
 120                 return -ENODEV;
 121         }
 122
 123         resource->avg_interval = data;
 124         return 0;
 125 }
 126
 127 static ssize_t show_avg_interval(struct device *dev,
 128                                  struct device_attribute *devattr,
 129                                  char *buf)
 130 {
 131         struct acpi_device *acpi_dev = to_acpi_device(dev);
 132         struct acpi_power_meter_resource *resource = acpi_dev->driver_data;
 133
 134         mutex_lock(&resource->lock);
 135         update_avg_interval(resource);
 136         mutex_unlock(&resource->lock);
 137
 138         return sprintf(buf, "%llu\n", resource->avg_interval);
 139 }
 140
 141 static ssize_t set_avg_interval(struct device *dev,
 142                                 struct device_attribute *devattr,
 143                                 const char *buf, size_t count)
 144 {
 145         struct acpi_device *acpi_dev = to_acpi_device(dev);
 146         struct acpi_power_meter_resource *resource = acpi_dev->driver_data;
 147         union acpi_object arg0 = { ACPI_TYPE_INTEGER };
 148         struct acpi_object_list args = { 1, &arg0 };
 149         int res;
 150         unsigned long temp;
 151         unsigned long long data;
 152         acpi_status status;
 153
 154         res = kstrtoul(buf, 10, &temp);
 155         if (res)
 156                 return res;
 157
 158         if (temp > resource->caps.max_avg_interval ||
 159             temp < resource->caps.min_avg_interval)
 160                 return -EINVAL;
 161         arg0.integer.value = temp;
 162
 163         mutex_lock(&resource->lock);
 164         status = acpi_evaluate_integer(resource->acpi_dev->handle, "_PAI",
 165                                        &args, &data);
 166         if (ACPI_SUCCESS(status))
 167                 resource->avg_interval = temp;
 168         mutex_unlock(&resource->lock);
 169
 170         if (ACPI_FAILURE(status)) {
 171                 acpi_evaluation_failure_warn(resource->acpi_dev->handle, "_PAI",
 172                                              status);
 173                 return -EINVAL;
 174         }
 175
 176         /* _PAI returns 0 on success, nonzero otherwise */
 177         if (data)
 178                 return -EINVAL;
 179
 180         return count;
 181 }
 182
 183 /* Cap functions */
 184 static int update_cap(struct acpi_power_meter_resource *resource)
 185 {
 186         unsigned long long data;
 187         acpi_status status;
 188
 189         status = acpi_evaluate_integer(resource->acpi_dev->handle, "_GHL",
 190                                        NULL, &data);
 191         if (ACPI_FAILURE(status)) {
 192                 acpi_evaluation_failure_warn(resource->acpi_dev->handle, "_GHL",
 193                                              status);
 194                 return -ENODEV;
 195         }
 196
 197         resource->cap = data;
 198         return 0;
 199 }
 200
 201 static ssize_t show_cap(struct device *dev,
 202                         struct device_attribute *devattr,
 203                         char *buf)
 204 {
 205         struct acpi_device *acpi_dev = to_acpi_device(dev);
 206         struct acpi_power_meter_resource *resource = acpi_dev->driver_data;
 207
 208         mutex_lock(&resource->lock);
 209         update_cap(resource);
 210         mutex_unlock(&resource->lock);
 211
 212         return sprintf(buf, "%llu\n", resource->cap * 1000);
 213 }
 214
 215 static ssize_t set_cap(struct device *dev, struct device_attribute *devattr,
 216                        const char *buf, size_t count)
 217 {
 218         struct acpi_device *acpi_dev = to_acpi_device(dev);
 219         struct acpi_power_meter_resource *resource = acpi_dev->driver_data;
 220         union acpi_object arg0 = { ACPI_TYPE_INTEGER };
 221         struct acpi_object_list args = { 1, &arg0 };
 222         int res;
 223         unsigned long temp;
 224         unsigned long long data;
 225         acpi_status status;
 226
 227         res = kstrtoul(buf, 10, &temp);
 228         if (res)
 229                 return res;
 230
 231         temp = DIV_ROUND_CLOSEST(temp, 1000);
 232         if (temp > resource->caps.max_cap || temp < resource->caps.min_cap)
 233                 return -EINVAL;
 234         arg0.integer.value = temp;
 235
 236         mutex_lock(&resource->lock);
 237         status = acpi_evaluate_integer(resource->acpi_dev->handle, "_SHL",
 238                                        &args, &data);
 239         if (ACPI_SUCCESS(status))
 240                 resource->cap = temp;
 241         mutex_unlock(&resource->lock);
 242
 243         if (ACPI_FAILURE(status)) {
 244                 acpi_evaluation_failure_warn(resource->acpi_dev->handle, "_SHL",
 245                                              status);
 246                 return -EINVAL;
 247         }
 248
 249         /* _SHL returns 0 on success, nonzero otherwise */
 250         if (data)
 251                 return -EINVAL;
 252
 253         return count;
 254 }
 255
 256 /* Power meter trip points */
 257 static int set_acpi_trip(struct acpi_power_meter_resource *resource)
 258 {
 259         union acpi_object arg_objs[] = {
 260                 {ACPI_TYPE_INTEGER},
 261                 {ACPI_TYPE_INTEGER}
 262         };
 263         struct acpi_object_list args = { 2, arg_objs };
 264         unsigned long long data;
 265         acpi_status status;
 266
 267         /* Both trip levels must be set */
 268         if (resource->trip[0] < 0 || resource->trip[1] < 0)
 269                 return 0;
 270
 271         /* This driver stores min, max; ACPI wants max, min. */
 272         arg_objs[0].integer.value = resource->trip[1];
 273         arg_objs[1].integer.value = resource->trip[0];
 274
 275         status = acpi_evaluate_integer(resource->acpi_dev->handle, "_PTP",
 276                                        &args, &data);
 277         if (ACPI_FAILURE(status)) {
 278                 acpi_evaluation_failure_warn(resource->acpi_dev->handle, "_PTP",
 279                                              status);
 280                 return -EINVAL;
 281         }
 282
 283         /* _PTP returns 0 on success, nonzero otherwise */
 284         if (data)
 285                 return -EINVAL;
 286
 287         return 0;
 288 }
 289
 290 static ssize_t set_trip(struct device *dev, struct device_attribute *devattr,
 291                         const char *buf, size_t count)
 292 {
 293         struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
 294         struct acpi_device *acpi_dev = to_acpi_device(dev);
 295         struct acpi_power_meter_resource *resource = acpi_dev->driver_data;
 296         unsigned long temp, trip_bk;
 297         int res;
 298
 299         res = kstrtoul(buf, 10, &temp);
 300         if (res)
 301                 return res;
 302
 303         temp = DIV_ROUND_CLOSEST(temp, 1000);
 304
 305         guard(mutex)(&resource->lock);
 306
 307         trip_bk = resource->trip[attr->index - 7];
 308         resource->trip[attr->index - 7] = temp;
 309         res = set_acpi_trip(resource);
 310         if (res) {
 311                 resource->trip[attr->index - 7] = trip_bk;
 312                 return res;
 313         }
 314
 315         return count;
 316 }
 317
 318 /* Power meter */
 319 static int update_meter(struct acpi_power_meter_resource *resource)
 320 {
 321         unsigned long long data;
 322         acpi_status status;
 323         unsigned long local_jiffies = jiffies;
 324
 325         if (time_before(local_jiffies, resource->sensors_last_updated +
 326                         msecs_to_jiffies(resource->caps.sampling_time)) &&
 327                         resource->sensors_valid)
 328                 return 0;
 329
 330         status = acpi_evaluate_integer(resource->acpi_dev->handle, "_PMM",
 331                                        NULL, &data);
 332         if (ACPI_FAILURE(status)) {
 333                 acpi_evaluation_failure_warn(resource->acpi_dev->handle, "_PMM",
 334                                              status);
 335                 return -ENODEV;
 336         }
 337
 338         resource->power = data;
 339         resource->sensors_valid = 1;
 340         resource->sensors_last_updated = jiffies;
 341         return 0;
 342 }
 343
 344 static ssize_t show_power(struct device *dev,
 345                           struct device_attribute *devattr,
 346                           char *buf)
 347 {
 348         struct acpi_device *acpi_dev = to_acpi_device(dev);
 349         struct acpi_power_meter_resource *resource = acpi_dev->driver_data;
 350
 351         mutex_lock(&resource->lock);
 352         update_meter(resource);
 353         mutex_unlock(&resource->lock);
 354
 355         if (resource->power == UNKNOWN_POWER)
 356                 return -ENODATA;
 357
 358         return sprintf(buf, "%llu\n", resource->power * 1000);
 359 }
 360
 361 /* Miscellaneous */
 362 static ssize_t show_str(struct device *dev,
 363                         struct device_attribute *devattr,
 364                         char *buf)
 365 {
 366         struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
 367         struct acpi_device *acpi_dev = to_acpi_device(dev);
 368         struct acpi_power_meter_resource *resource = acpi_dev->driver_data;
 369         acpi_string val;
 370         int ret;
 371
 372         mutex_lock(&resource->lock);
 373         switch (attr->index) {
 374         case 0:
 375                 val = resource->model_number;
 376                 break;
 377         case 1:
 378                 val = resource->serial_number;
 379                 break;
 380         case 2:
 381                 val = resource->oem_info;
 382                 break;
 383         default:
 384                 WARN(1, "Implementation error: unexpected attribute index %d\n",
 385                      attr->index);
 386                 val = "";
 387                 break;
 388         }
 389         ret = sprintf(buf, "%s\n", val);
 390         mutex_unlock(&resource->lock);
 391         return ret;
 392 }
 393
 394 static ssize_t show_val(struct device *dev,
 395                         struct device_attribute *devattr,
 396                         char *buf)
 397 {
 398         struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
 399         struct acpi_device *acpi_dev = to_acpi_device(dev);
 400         struct acpi_power_meter_resource *resource = acpi_dev->driver_data;
 401         u64 val = 0;
 402         int ret;
 403
 404         guard(mutex)(&resource->lock);
 405
 406         switch (attr->index) {
 407         case 0:
 408                 val = resource->caps.min_avg_interval;
 409                 break;
 410         case 1:
 411                 val = resource->caps.max_avg_interval;
 412                 break;
 413         case 2:
 414                 val = resource->caps.min_cap * 1000;
 415                 break;
 416         case 3:
 417                 val = resource->caps.max_cap * 1000;
 418                 break;
 419         case 4:
 420                 if (resource->caps.hysteresis == UNKNOWN_HYSTERESIS)
 421                         return sprintf(buf, "unknown\n");
 422
 423                 val = resource->caps.hysteresis * 1000;
 424                 break;
 425         case 5:
 426                 if (resource->caps.flags & POWER_METER_IS_BATTERY)
 427                         val = 1;
 428                 else
 429                         val = 0;
 430                 break;
 431         case 6:
 432                 ret = update_meter(resource);
 433                 if (ret)
 434                         return ret;
 435                 /* need to update cap if not to support the notification. */
 436                 if (!(resource->caps.flags & POWER_METER_CAN_NOTIFY)) {
 437                         ret = update_cap(resource);
 438                         if (ret)
 439                                 return ret;
 440                 }
 441                 val = resource->power_alarm || resource->power > resource->cap;
 442                 resource->power_alarm = resource->power > resource->cap;
 443                 break;
 444         case 7:
 445         case 8:
 446                 if (resource->trip[attr->index - 7] < 0)
 447                         return sprintf(buf, "unknown\n");
 448
 449                 val = resource->trip[attr->index - 7] * 1000;
 450                 break;
 451         default:
 452                 WARN(1, "Implementation error: unexpected attribute index %d\n",
 453                      attr->index);
 454                 break;
 455         }
 456
 457         return sprintf(buf, "%llu\n", val);
 458 }
 459
 460 static ssize_t show_accuracy(struct device *dev,
 461                              struct device_attribute *devattr,
 462                              char *buf)
 463 {
 464         struct acpi_device *acpi_dev = to_acpi_device(dev);
 465         struct acpi_power_meter_resource *resource = acpi_dev->driver_data;
 466         unsigned int acc = resource->caps.accuracy;
 467
 468         return sprintf(buf, "%u.%u%%\n", acc / 1000, acc % 1000);
 469 }
 470
 471 static ssize_t show_name(struct device *dev,
 472                          struct device_attribute *devattr,
 473                          char *buf)
 474 {
 475         return sprintf(buf, "%s\n", ACPI_POWER_METER_NAME);
 476 }
 477
 478 #define RO_SENSOR_TEMPLATE(_label, _show, _index)       \
 479         {                                               \
 480                 .label = _label,                        \
 481                 .show  = _show,                         \
 482                 .index = _index,                        \
 483         }
 484
 485 #define RW_SENSOR_TEMPLATE(_label, _show, _set, _index) \
 486         {                                               \
 487                 .label = _label,                        \
 488                 .show  = _show,                         \
 489                 .set   = _set,                          \
 490                 .index = _index,                        \
 491         }
 492
 493 /* Sensor descriptions.  If you add a sensor, update NUM_SENSORS above! */
 494 static struct sensor_template meter_attrs[] = {
 495         RO_SENSOR_TEMPLATE(POWER_AVERAGE_NAME, show_power, 0),
 496         RO_SENSOR_TEMPLATE("power1_accuracy", show_accuracy, 0),
 497         RO_SENSOR_TEMPLATE("power1_average_interval_min", show_val, 0),
 498         RO_SENSOR_TEMPLATE("power1_average_interval_max", show_val, 1),
 499         RO_SENSOR_TEMPLATE("power1_is_battery", show_val, 5),
 500         RW_SENSOR_TEMPLATE(POWER_AVG_INTERVAL_NAME, show_avg_interval,
 501                            set_avg_interval, 0),
 502         {},
 503 };
 504
 505 static struct sensor_template misc_cap_attrs[] = {
 506         RO_SENSOR_TEMPLATE("power1_cap_min", show_val, 2),
 507         RO_SENSOR_TEMPLATE("power1_cap_max", show_val, 3),
 508         RO_SENSOR_TEMPLATE("power1_cap_hyst", show_val, 4),
 509         RO_SENSOR_TEMPLATE(POWER_ALARM_NAME, show_val, 6),
 510         {},
 511 };
 512
 513 static struct sensor_template ro_cap_attrs[] = {
 514         RO_SENSOR_TEMPLATE(POWER_CAP_NAME, show_cap, 0),
 515         {},
 516 };
 517
 518 static struct sensor_template rw_cap_attrs[] = {
 519         RW_SENSOR_TEMPLATE(POWER_CAP_NAME, show_cap, set_cap, 0),
 520         {},
 521 };
 522
 523 static struct sensor_template trip_attrs[] = {
 524         RW_SENSOR_TEMPLATE("power1_average_min", show_val, set_trip, 7),
 525         RW_SENSOR_TEMPLATE("power1_average_max", show_val, set_trip, 8),
 526         {},
 527 };
 528
 529 static struct sensor_template misc_attrs[] = {
 530         RO_SENSOR_TEMPLATE("name", show_name, 0),
 531         RO_SENSOR_TEMPLATE("power1_model_number", show_str, 0),
 532         RO_SENSOR_TEMPLATE("power1_oem_info", show_str, 2),
 533         RO_SENSOR_TEMPLATE("power1_serial_number", show_str, 1),
 534         {},
 535 };
 536
 537 #undef RO_SENSOR_TEMPLATE
 538 #undef RW_SENSOR_TEMPLATE
 539
 540 /* Read power domain data */
 541 static void remove_domain_devices(struct acpi_power_meter_resource *resource)
 542 {
 543         int i;
 544
 545         if (!resource->num_domain_devices)
 546                 return;
 547
 548         for (i = 0; i < resource->num_domain_devices; i++) {
 549                 struct acpi_device *obj = resource->domain_devices[i];
 550
 551                 if (!obj)
 552                         continue;
 553
 554                 sysfs_remove_link(resource->holders_dir,
 555                                   kobject_name(&obj->dev.kobj));
 556                 acpi_dev_put(obj);
 557         }
 558
 559         kfree(resource->domain_devices);
 560         kobject_put(resource->holders_dir);
 561         resource->num_domain_devices = 0;
 562 }
 563
 564 static int read_domain_devices(struct acpi_power_meter_resource *resource)
 565 {
 566         int res = 0;
 567         int i;
 568         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
 569         union acpi_object *pss;
 570         acpi_status status;
 571
 572         status = acpi_evaluate_object(resource->acpi_dev->handle, "_PMD", NULL,
 573                                       &buffer);
 574         if (ACPI_FAILURE(status)) {
 575                 acpi_evaluation_failure_warn(resource->acpi_dev->handle, "_PMD",
 576                                              status);
 577                 return -ENODEV;
 578         }
 579
 580         pss = buffer.pointer;
 581         if (!pss ||
 582             pss->type != ACPI_TYPE_PACKAGE) {
 583                 dev_err(&resource->acpi_dev->dev, ACPI_POWER_METER_NAME
 584                         "Invalid _PMD data\n");
 585                 res = -EFAULT;
 586                 goto end;
 587         }
 588
 589         if (!pss->package.count)
 590                 goto end;
 591
 592         resource->domain_devices = kcalloc(pss->package.count,
 593                                            sizeof(struct acpi_device *),
 594                                            GFP_KERNEL);
 595         if (!resource->domain_devices) {
 596                 res = -ENOMEM;
 597                 goto end;
 598         }
 599
 600         resource->holders_dir = kobject_create_and_add("measures",
 601                                                        &resource->acpi_dev->dev.kobj);
 602         if (!resource->holders_dir) {
 603                 res = -ENOMEM;
 604                 goto exit_free;
 605         }
 606
 607         resource->num_domain_devices = pss->package.count;
 608
 609         for (i = 0; i < pss->package.count; i++) {
 610                 struct acpi_device *obj;
 611                 union acpi_object *element = &pss->package.elements[i];
 612
 613                 /* Refuse non-references */
 614                 if (element->type != ACPI_TYPE_LOCAL_REFERENCE)
 615                         continue;
 616
 617                 /* Create a symlink to domain objects */
 618                 obj = acpi_get_acpi_dev(element->reference.handle);
 619                 resource->domain_devices[i] = obj;
 620                 if (!obj)
 621                         continue;
 622
 623                 res = sysfs_create_link(resource->holders_dir, &obj->dev.kobj,
 624                                         kobject_name(&obj->dev.kobj));
 625                 if (res) {
 626                         acpi_dev_put(obj);
 627                         resource->domain_devices[i] = NULL;
 628                 }
 629         }
 630
 631         res = 0;
 632         goto end;
 633
 634 exit_free:
 635         kfree(resource->domain_devices);
 636 end:
 637         kfree(buffer.pointer);
 638         return res;
 639 }
 640
 641 /* Registration and deregistration */
 642 static int register_attrs(struct acpi_power_meter_resource *resource,
 643                           struct sensor_template *attrs)
 644 {
 645         struct device *dev = &resource->acpi_dev->dev;
 646         struct sensor_device_attribute *sensors =
 647                 &resource->sensors[resource->num_sensors];
 648         int res = 0;
 649
 650         while (attrs->label) {
 651                 sensors->dev_attr.attr.name = attrs->label;
 652                 sensors->dev_attr.attr.mode = 0444;
 653                 sensors->dev_attr.show = attrs->show;
 654                 sensors->index = attrs->index;
 655
 656                 if (attrs->set) {
 657                         sensors->dev_attr.attr.mode |= 0200;
 658                         sensors->dev_attr.store = attrs->set;
 659                 }
 660
 661                 sysfs_attr_init(&sensors->dev_attr.attr);
 662                 res = device_create_file(dev, &sensors->dev_attr);
 663                 if (res) {
 664                         sensors->dev_attr.attr.name = NULL;
 665                         goto error;
 666                 }
 667                 sensors++;
 668                 resource->num_sensors++;
 669                 attrs++;
 670         }
 671
 672 error:
 673         return res;
 674 }
 675
 676 static void remove_attrs(struct acpi_power_meter_resource *resource)
 677 {
 678         int i;
 679
 680         for (i = 0; i < resource->num_sensors; i++) {
 681                 if (!resource->sensors[i].dev_attr.attr.name)
 682                         continue;
 683                 device_remove_file(&resource->acpi_dev->dev,
 684                                    &resource->sensors[i].dev_attr);
 685         }
 686
 687         remove_domain_devices(resource);
 688
 689         resource->num_sensors = 0;
 690 }
 691
 692 static int setup_attrs(struct acpi_power_meter_resource *resource)
 693 {
 694         int res = 0;
 695
 696         /* _PMD method is optional. */
 697         res = read_domain_devices(resource);
 698         if (res && res != -ENODEV)
 699                 return res;
 700
 701         if (resource->caps.flags & POWER_METER_CAN_MEASURE) {
 702                 res = register_attrs(resource, meter_attrs);
 703                 if (res)
 704                         goto error;
 705         }
 706
 707         if (resource->caps.flags & POWER_METER_CAN_CAP) {
 708                 if (!can_cap_in_hardware()) {
 709                         dev_warn(&resource->acpi_dev->dev,
 710                                  "Ignoring unsafe software power cap!\n");
 711                         goto skip_unsafe_cap;
 712                 }
 713
 714                 if (resource->caps.configurable_cap)
 715                         res = register_attrs(resource, rw_cap_attrs);
 716                 else
 717                         res = register_attrs(resource, ro_cap_attrs);
 718
 719                 if (res)
 720                         goto error;
 721
 722                 res = register_attrs(resource, misc_cap_attrs);
 723                 if (res)
 724                         goto error;
 725         }
 726
 727 skip_unsafe_cap:
 728         if (resource->caps.flags & POWER_METER_CAN_TRIP) {
 729                 res = register_attrs(resource, trip_attrs);
 730                 if (res)
 731                         goto error;
 732         }
 733
 734         res = register_attrs(resource, misc_attrs);
 735         if (res)
 736                 goto error;
 737
 738         return res;
 739 error:
 740         remove_attrs(resource);
 741         return res;
 742 }
 743
 744 static void free_capabilities(struct acpi_power_meter_resource *resource)
 745 {
 746         acpi_string *str;
 747         int i;
 748
 749         str = &resource->model_number;
 750         for (i = 0; i < 3; i++, str++) {
 751                 kfree(*str);
 752                 *str = NULL;
 753         }
 754 }
 755
 756 static int read_capabilities(struct acpi_power_meter_resource *resource)
 757 {
 758         int res = 0;
 759         int i;
 760         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
 761         struct acpi_buffer state = { 0, NULL };
 762         struct acpi_buffer format = { sizeof("NNNNNNNNNNN"), "NNNNNNNNNNN" };
 763         union acpi_object *pss;
 764         acpi_string *str;
 765         acpi_status status;
 766
 767         status = acpi_evaluate_object(resource->acpi_dev->handle, "_PMC", NULL,
 768                                       &buffer);
 769         if (ACPI_FAILURE(status)) {
 770                 acpi_evaluation_failure_warn(resource->acpi_dev->handle, "_PMC",
 771                                              status);
 772                 return -ENODEV;
 773         }
 774
 775         pss = buffer.pointer;
 776         if (!pss ||
 777             pss->type != ACPI_TYPE_PACKAGE ||
 778             pss->package.count != 14) {
 779                 dev_err(&resource->acpi_dev->dev, ACPI_POWER_METER_NAME
 780                         "Invalid _PMC data\n");
 781                 res = -EFAULT;
 782                 goto end;
 783         }
 784
 785         /* Grab all the integer data at once */
 786         state.length = sizeof(struct acpi_power_meter_capabilities);
 787         state.pointer = &resource->caps;
 788
 789         status = acpi_extract_package(pss, &format, &state);
 790         if (ACPI_FAILURE(status)) {
 791                 dev_err(&resource->acpi_dev->dev, ACPI_POWER_METER_NAME
 792                         "_PMC package parsing failed: %s\n",
 793                         acpi_format_exception(status));
 794                 res = -EFAULT;
 795                 goto end;
 796         }
 797
 798         if (resource->caps.units) {
 799                 dev_err(&resource->acpi_dev->dev, ACPI_POWER_METER_NAME
 800                         "Unknown units %llu.\n",
 801                         resource->caps.units);
 802                 res = -EINVAL;
 803                 goto end;
 804         }
 805
 806         /* Grab the string data */
 807         str = &resource->model_number;
 808
 809         for (i = 11; i < 14; i++) {
 810                 union acpi_object *element = &pss->package.elements[i];
 811
 812                 if (element->type != ACPI_TYPE_STRING) {
 813                         res = -EINVAL;
 814                         goto error;
 815                 }
 816
 817                 *str = kmemdup_nul(element->string.pointer, element->string.length,
 818                                    GFP_KERNEL);
 819                 if (!*str) {
 820                         res = -ENOMEM;
 821                         goto error;
 822                 }
 823
 824                 str++;
 825         }
 826
 827         dev_info(&resource->acpi_dev->dev, "Found ACPI power meter.\n");
 828         goto end;
 829 error:
 830         free_capabilities(resource);
 831 end:
 832         kfree(buffer.pointer);
 833         return res;
 834 }
 835
 836 /* Handle ACPI event notifications */
 837 static void acpi_power_meter_notify(struct acpi_device *device, u32 event)
 838 {
 839         struct acpi_power_meter_resource *resource;
 840         int res;
 841
 842         if (!device || !acpi_driver_data(device))
 843                 return;
 844
 845         resource = acpi_driver_data(device);
 846
 847         switch (event) {
 848         case METER_NOTIFY_CONFIG:
 849                 mutex_lock(&resource->lock);
 850                 free_capabilities(resource);
 851                 res = read_capabilities(resource);
 852                 mutex_unlock(&resource->lock);
 853                 if (res)
 854                         break;
 855
 856                 remove_attrs(resource);
 857                 setup_attrs(resource);
 858                 break;
 859         case METER_NOTIFY_TRIP:
 860                 sysfs_notify(&device->dev.kobj, NULL, POWER_AVERAGE_NAME);
 861                 break;
 862         case METER_NOTIFY_CAP:
 863                 mutex_lock(&resource->lock);
 864                 res = update_cap(resource);
 865                 if (res)
 866                         dev_err_once(&device->dev, "update cap failed when capping value is changed.\n");
 867                 mutex_unlock(&resource->lock);
 868                 sysfs_notify(&device->dev.kobj, NULL, POWER_CAP_NAME);
 869                 break;
 870         case METER_NOTIFY_INTERVAL:
 871                 sysfs_notify(&device->dev.kobj, NULL, POWER_AVG_INTERVAL_NAME);
 872                 break;
 873         case METER_NOTIFY_CAPPING:
 874                 mutex_lock(&resource->lock);
 875                 resource->power_alarm = true;
 876                 mutex_unlock(&resource->lock);
 877                 sysfs_notify(&device->dev.kobj, NULL, POWER_ALARM_NAME);
 878                 dev_info(&device->dev, "Capping in progress.\n");
 879                 break;
 880         default:
 881                 WARN(1, "Unexpected event %d\n", event);
 882                 break;
 883         }
 884
 885         acpi_bus_generate_netlink_event(ACPI_POWER_METER_CLASS,
 886                                         dev_name(&device->dev), event, 0);
 887 }
 888
 889 static int acpi_power_meter_add(struct acpi_device *device)
 890 {
 891         int res;
 892         struct acpi_power_meter_resource *resource;
 893
 894         if (!device)
 895                 return -EINVAL;
 896
 897         resource = kzalloc(sizeof(*resource), GFP_KERNEL);
 898         if (!resource)
 899                 return -ENOMEM;
 900
 901         resource->sensors_valid = 0;
 902         resource->acpi_dev = device;
 903         mutex_init(&resource->lock);
 904         strcpy(acpi_device_name(device), ACPI_POWER_METER_DEVICE_NAME);
 905         strcpy(acpi_device_class(device), ACPI_POWER_METER_CLASS);
 906         device->driver_data = resource;
 907
 908 #if IS_REACHABLE(CONFIG_ACPI_IPMI)
 909         /*
 910          * On Dell systems several methods of acpi_power_meter access
 911          * variables in IPMI region, so wait until IPMI space handler is
 912          * installed by acpi_ipmi and also wait until SMI is selected to make
 913          * the space handler fully functional.
 914          */
 915         if (dmi_match(DMI_SYS_VENDOR, "Dell Inc.")) {
 916                 struct acpi_device *ipi_device = acpi_dev_get_first_match_dev("IPI0001", NULL, -1);
 917
 918                 if (ipi_device && acpi_wait_for_acpi_ipmi())
 919                                 dev_warn(&device->dev, "Waiting for ACPI IPMI timeout");
 920                 acpi_dev_put(ipi_device);
 921         }
 922 #endif
 923
 924         res = read_capabilities(resource);
 925         if (res)
 926                 goto exit_free;
 927
 928         resource->trip[0] = -1;
 929         resource->trip[1] = -1;
 930
 931         res = setup_attrs(resource);
 932         if (res)
 933                 goto exit_free_capability;
 934
 935         resource->hwmon_dev = hwmon_device_register(&device->dev);
 936         if (IS_ERR(resource->hwmon_dev)) {
 937                 res = PTR_ERR(resource->hwmon_dev);
 938                 goto exit_remove;
 939         }
 940
 941         res = 0;
 942         goto exit;
 943
 944 exit_remove:
 945         remove_attrs(resource);
 946 exit_free_capability:
 947         free_capabilities(resource);
 948 exit_free:
 949         kfree(resource);
 950 exit:
 951         return res;
 952 }
 953
 954 static void acpi_power_meter_remove(struct acpi_device *device)
 955 {
 956         struct acpi_power_meter_resource *resource;
 957
 958         if (!device || !acpi_driver_data(device))
 959                 return;
 960
 961         resource = acpi_driver_data(device);
 962         hwmon_device_unregister(resource->hwmon_dev);
 963
 964         remove_attrs(resource);
 965         free_capabilities(resource);
 966
 967         kfree(resource);
 968 }
 969
 970 static int acpi_power_meter_resume(struct device *dev)
 971 {
 972         struct acpi_power_meter_resource *resource;
 973
 974         if (!dev)
 975                 return -EINVAL;
 976
 977         resource = acpi_driver_data(to_acpi_device(dev));
 978         if (!resource)
 979                 return -EINVAL;
 980
 981         free_capabilities(resource);
 982         read_capabilities(resource);
 983
 984         return 0;
 985 }
 986
 987 static DEFINE_SIMPLE_DEV_PM_OPS(acpi_power_meter_pm, NULL,
 988                                 acpi_power_meter_resume);
 989
 990 static struct acpi_driver acpi_power_meter_driver = {
 991         .name = "power_meter",
 992         .class = ACPI_POWER_METER_CLASS,
 993         .ids = power_meter_ids,
 994         .ops = {
 995                 .add = acpi_power_meter_add,
 996                 .remove = acpi_power_meter_remove,
 997                 .notify = acpi_power_meter_notify,
 998                 },
 999         .drv.pm = pm_sleep_ptr(&acpi_power_meter_pm),
1000 };
1001
1002 /* Module init/exit routines */
1003 static int __init enable_cap_knobs(const struct dmi_system_id *d)
1004 {
1005         cap_in_hardware = 1;
1006         return 0;
1007 }
1008
1009 static const struct dmi_system_id pm_dmi_table[] __initconst = {
1010         {
1011                 enable_cap_knobs, "IBM Active Energy Manager",
1012                 {
1013                         DMI_MATCH(DMI_SYS_VENDOR, "IBM")
1014                 },
1015         },
1016         {}
1017 };
1018
1019 static int __init acpi_power_meter_init(void)
1020 {
1021         int result;
1022
1023         if (acpi_disabled)
1024                 return -ENODEV;
1025
1026         dmi_check_system(pm_dmi_table);
1027
1028         result = acpi_bus_register_driver(&acpi_power_meter_driver);
1029         if (result < 0)
1030                 return result;
1031
1032         return 0;
1033 }
1034
1035 static void __exit acpi_power_meter_exit(void)
1036 {
1037         acpi_bus_unregister_driver(&acpi_power_meter_driver);
1038 }
1039
1040 MODULE_AUTHOR("Darrick J. Wong <[email protected]>");
1041 MODULE_DESCRIPTION("ACPI 4.0 power meter driver");
1042 MODULE_LICENSE("GPL");
1043
1044 module_param(force_cap_on, bool, 0644);
1045 MODULE_PARM_DESC(force_cap_on, "Enable power cap even it is unsafe to do so.");
1046
1047 module_init(acpi_power_meter_init);
1048 module_exit(acpi_power_meter_exit);