linux/drivers/hwmon/acpi_power_meter.c
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   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"
  23ACPI_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
  47static int cap_in_hardware;
  48static bool force_cap_on;
  49
  50static int can_cap_in_hardware(void)
  51{
  52        return force_cap_on || cap_in_hardware;
  53}
  54
  55static const struct acpi_device_id power_meter_ids[] = {
  56        {"ACPI000D", 0},
  57        {"", 0},
  58};
  59MODULE_DEVICE_TABLE(acpi, power_meter_ids);
  60
  61struct 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
  75struct 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
  97struct 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 */
 109static 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
 125static 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
 139static 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 */
 181static 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
 197static 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
 211static 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 */
 252static 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
 284static 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 */
 311static 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
 335static 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 */
 350static 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
 379static 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
 435static 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
 446static 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! */
 469static 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
 480static 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
 488static struct sensor_template ro_cap_attrs[] = {
 489        RO_SENSOR_TEMPLATE(POWER_CAP_NAME, show_cap, 0),
 490        {},
 491};
 492
 493static struct sensor_template rw_cap_attrs[] = {
 494        RW_SENSOR_TEMPLATE(POWER_CAP_NAME, show_cap, set_cap, 0),
 495        {},
 496};
 497
 498static 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
 504static 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 */
 516static 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
 538static 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
 610exit_free:
 611        kfree(resource->domain_devices);
 612end:
 613        kfree(buffer.pointer);
 614        return res;
 615}
 616
 617/* Registration and deregistration */
 618static 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
 648error:
 649        return res;
 650}
 651
 652static 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
 668static 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
 702skip_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;
 714error:
 715        remove_attrs(resource);
 716        return res;
 717}
 718
 719static 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
 729static 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;
 800error:
 801        str = &resource->model_number;
 802        for (i = 0; i < 3; i++, str++)
 803                kfree(*str);
 804end:
 805        kfree(buffer.pointer);
 806        return res;
 807}
 808
 809/* Handle ACPI event notifications */
 810static 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
 857static 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
 897exit_remove:
 898        remove_attrs(resource);
 899exit_free:
 900        kfree(resource);
 901exit:
 902        return res;
 903}
 904
 905static 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
 924static 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
 943static SIMPLE_DEV_PM_OPS(acpi_power_meter_pm, NULL, acpi_power_meter_resume);
 944
 945static 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 */
 958static int __init enable_cap_knobs(const struct dmi_system_id *d)
 959{
 960        cap_in_hardware = 1;
 961        return 0;
 962}
 963
 964static 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
 974static 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
 990static void __exit acpi_power_meter_exit(void)
 991{
 992        acpi_bus_unregister_driver(&acpi_power_meter_driver);
 993}
 994
 995MODULE_AUTHOR("Darrick J. Wong <darrick.wong@oracle.com>");
 996MODULE_DESCRIPTION("ACPI 4.0 power meter driver");
 997MODULE_LICENSE("GPL");
 998
 999module_param(force_cap_on, bool, 0644);
1000MODULE_PARM_DESC(force_cap_on, "Enable power cap even it is unsafe to do so.");
1001
1002module_init(acpi_power_meter_init);
1003module_exit(acpi_power_meter_exit);
1004