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        int ret;
 359
 360        mutex_lock(&resource->lock);
 361        switch (attr->index) {
 362        case 0:
 363                val = resource->model_number;
 364                break;
 365        case 1:
 366                val = resource->serial_number;
 367                break;
 368        case 2:
 369                val = resource->oem_info;
 370                break;
 371        default:
 372                WARN(1, "Implementation error: unexpected attribute index %d\n",
 373                     attr->index);
 374                val = "";
 375                break;
 376        }
 377        ret = sprintf(buf, "%s\n", val);
 378        mutex_unlock(&resource->lock);
 379        return ret;
 380}
 381
 382static ssize_t show_val(struct device *dev,
 383                        struct device_attribute *devattr,
 384                        char *buf)
 385{
 386        struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
 387        struct acpi_device *acpi_dev = to_acpi_device(dev);
 388        struct acpi_power_meter_resource *resource = acpi_dev->driver_data;
 389        u64 val = 0;
 390
 391        switch (attr->index) {
 392        case 0:
 393                val = resource->caps.min_avg_interval;
 394                break;
 395        case 1:
 396                val = resource->caps.max_avg_interval;
 397                break;
 398        case 2:
 399                val = resource->caps.min_cap * 1000;
 400                break;
 401        case 3:
 402                val = resource->caps.max_cap * 1000;
 403                break;
 404        case 4:
 405                if (resource->caps.hysteresis == UNKNOWN_HYSTERESIS)
 406                        return sprintf(buf, "unknown\n");
 407
 408                val = resource->caps.hysteresis * 1000;
 409                break;
 410        case 5:
 411                if (resource->caps.flags & POWER_METER_IS_BATTERY)
 412                        val = 1;
 413                else
 414                        val = 0;
 415                break;
 416        case 6:
 417                if (resource->power > resource->cap)
 418                        val = 1;
 419                else
 420                        val = 0;
 421                break;
 422        case 7:
 423        case 8:
 424                if (resource->trip[attr->index - 7] < 0)
 425                        return sprintf(buf, "unknown\n");
 426
 427                val = resource->trip[attr->index - 7] * 1000;
 428                break;
 429        default:
 430                WARN(1, "Implementation error: unexpected attribute index %d\n",
 431                     attr->index);
 432                break;
 433        }
 434
 435        return sprintf(buf, "%llu\n", val);
 436}
 437
 438static ssize_t show_accuracy(struct device *dev,
 439                             struct device_attribute *devattr,
 440                             char *buf)
 441{
 442        struct acpi_device *acpi_dev = to_acpi_device(dev);
 443        struct acpi_power_meter_resource *resource = acpi_dev->driver_data;
 444        unsigned int acc = resource->caps.accuracy;
 445
 446        return sprintf(buf, "%u.%u%%\n", acc / 1000, acc % 1000);
 447}
 448
 449static ssize_t show_name(struct device *dev,
 450                         struct device_attribute *devattr,
 451                         char *buf)
 452{
 453        return sprintf(buf, "%s\n", ACPI_POWER_METER_NAME);
 454}
 455
 456#define RO_SENSOR_TEMPLATE(_label, _show, _index)       \
 457        {                                               \
 458                .label = _label,                        \
 459                .show  = _show,                         \
 460                .index = _index,                        \
 461        }
 462
 463#define RW_SENSOR_TEMPLATE(_label, _show, _set, _index) \
 464        {                                               \
 465                .label = _label,                        \
 466                .show  = _show,                         \
 467                .set   = _set,                          \
 468                .index = _index,                        \
 469        }
 470
 471/* Sensor descriptions.  If you add a sensor, update NUM_SENSORS above! */
 472static struct sensor_template meter_attrs[] = {
 473        RO_SENSOR_TEMPLATE(POWER_AVERAGE_NAME, show_power, 0),
 474        RO_SENSOR_TEMPLATE("power1_accuracy", show_accuracy, 0),
 475        RO_SENSOR_TEMPLATE("power1_average_interval_min", show_val, 0),
 476        RO_SENSOR_TEMPLATE("power1_average_interval_max", show_val, 1),
 477        RO_SENSOR_TEMPLATE("power1_is_battery", show_val, 5),
 478        RW_SENSOR_TEMPLATE(POWER_AVG_INTERVAL_NAME, show_avg_interval,
 479                set_avg_interval, 0),
 480        {},
 481};
 482
 483static struct sensor_template misc_cap_attrs[] = {
 484        RO_SENSOR_TEMPLATE("power1_cap_min", show_val, 2),
 485        RO_SENSOR_TEMPLATE("power1_cap_max", show_val, 3),
 486        RO_SENSOR_TEMPLATE("power1_cap_hyst", show_val, 4),
 487        RO_SENSOR_TEMPLATE(POWER_ALARM_NAME, show_val, 6),
 488        {},
 489};
 490
 491static struct sensor_template ro_cap_attrs[] = {
 492        RO_SENSOR_TEMPLATE(POWER_CAP_NAME, show_cap, 0),
 493        {},
 494};
 495
 496static struct sensor_template rw_cap_attrs[] = {
 497        RW_SENSOR_TEMPLATE(POWER_CAP_NAME, show_cap, set_cap, 0),
 498        {},
 499};
 500
 501static struct sensor_template trip_attrs[] = {
 502        RW_SENSOR_TEMPLATE("power1_average_min", show_val, set_trip, 7),
 503        RW_SENSOR_TEMPLATE("power1_average_max", show_val, set_trip, 8),
 504        {},
 505};
 506
 507static struct sensor_template misc_attrs[] = {
 508        RO_SENSOR_TEMPLATE("name", show_name, 0),
 509        RO_SENSOR_TEMPLATE("power1_model_number", show_str, 0),
 510        RO_SENSOR_TEMPLATE("power1_oem_info", show_str, 2),
 511        RO_SENSOR_TEMPLATE("power1_serial_number", show_str, 1),
 512        {},
 513};
 514
 515#undef RO_SENSOR_TEMPLATE
 516#undef RW_SENSOR_TEMPLATE
 517
 518/* Read power domain data */
 519static void remove_domain_devices(struct acpi_power_meter_resource *resource)
 520{
 521        int i;
 522
 523        if (!resource->num_domain_devices)
 524                return;
 525
 526        for (i = 0; i < resource->num_domain_devices; i++) {
 527                struct acpi_device *obj = resource->domain_devices[i];
 528                if (!obj)
 529                        continue;
 530
 531                sysfs_remove_link(resource->holders_dir,
 532                                  kobject_name(&obj->dev.kobj));
 533                put_device(&obj->dev);
 534        }
 535
 536        kfree(resource->domain_devices);
 537        kobject_put(resource->holders_dir);
 538        resource->num_domain_devices = 0;
 539}
 540
 541static int read_domain_devices(struct acpi_power_meter_resource *resource)
 542{
 543        int res = 0;
 544        int i;
 545        struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
 546        union acpi_object *pss;
 547        acpi_status status;
 548
 549        status = acpi_evaluate_object(resource->acpi_dev->handle, "_PMD", NULL,
 550                                      &buffer);
 551        if (ACPI_FAILURE(status)) {
 552                ACPI_EXCEPTION((AE_INFO, status, "Evaluating _PMD"));
 553                return -ENODEV;
 554        }
 555
 556        pss = buffer.pointer;
 557        if (!pss ||
 558            pss->type != ACPI_TYPE_PACKAGE) {
 559                dev_err(&resource->acpi_dev->dev, ACPI_POWER_METER_NAME
 560                        "Invalid _PMD data\n");
 561                res = -EFAULT;
 562                goto end;
 563        }
 564
 565        if (!pss->package.count)
 566                goto end;
 567
 568        resource->domain_devices = kcalloc(pss->package.count,
 569                                           sizeof(struct acpi_device *),
 570                                           GFP_KERNEL);
 571        if (!resource->domain_devices) {
 572                res = -ENOMEM;
 573                goto end;
 574        }
 575
 576        resource->holders_dir = kobject_create_and_add("measures",
 577                                        &resource->acpi_dev->dev.kobj);
 578        if (!resource->holders_dir) {
 579                res = -ENOMEM;
 580                goto exit_free;
 581        }
 582
 583        resource->num_domain_devices = pss->package.count;
 584
 585        for (i = 0; i < pss->package.count; i++) {
 586                struct acpi_device *obj;
 587                union acpi_object *element = &(pss->package.elements[i]);
 588
 589                /* Refuse non-references */
 590                if (element->type != ACPI_TYPE_LOCAL_REFERENCE)
 591                        continue;
 592
 593                /* Create a symlink to domain objects */
 594                resource->domain_devices[i] = NULL;
 595                if (acpi_bus_get_device(element->reference.handle,
 596                                        &resource->domain_devices[i]))
 597                        continue;
 598
 599                obj = resource->domain_devices[i];
 600                get_device(&obj->dev);
 601
 602                res = sysfs_create_link(resource->holders_dir, &obj->dev.kobj,
 603                                      kobject_name(&obj->dev.kobj));
 604                if (res) {
 605                        put_device(&obj->dev);
 606                        resource->domain_devices[i] = NULL;
 607                }
 608        }
 609
 610        res = 0;
 611        goto end;
 612
 613exit_free:
 614        kfree(resource->domain_devices);
 615end:
 616        kfree(buffer.pointer);
 617        return res;
 618}
 619
 620/* Registration and deregistration */
 621static int register_attrs(struct acpi_power_meter_resource *resource,
 622                          struct sensor_template *attrs)
 623{
 624        struct device *dev = &resource->acpi_dev->dev;
 625        struct sensor_device_attribute *sensors =
 626                &resource->sensors[resource->num_sensors];
 627        int res = 0;
 628
 629        while (attrs->label) {
 630                sensors->dev_attr.attr.name = attrs->label;
 631                sensors->dev_attr.attr.mode = 0444;
 632                sensors->dev_attr.show = attrs->show;
 633                sensors->index = attrs->index;
 634
 635                if (attrs->set) {
 636                        sensors->dev_attr.attr.mode |= 0200;
 637                        sensors->dev_attr.store = attrs->set;
 638                }
 639
 640                sysfs_attr_init(&sensors->dev_attr.attr);
 641                res = device_create_file(dev, &sensors->dev_attr);
 642                if (res) {
 643                        sensors->dev_attr.attr.name = NULL;
 644                        goto error;
 645                }
 646                sensors++;
 647                resource->num_sensors++;
 648                attrs++;
 649        }
 650
 651error:
 652        return res;
 653}
 654
 655static void remove_attrs(struct acpi_power_meter_resource *resource)
 656{
 657        int i;
 658
 659        for (i = 0; i < resource->num_sensors; i++) {
 660                if (!resource->sensors[i].dev_attr.attr.name)
 661                        continue;
 662                device_remove_file(&resource->acpi_dev->dev,
 663                                   &resource->sensors[i].dev_attr);
 664        }
 665
 666        remove_domain_devices(resource);
 667
 668        resource->num_sensors = 0;
 669}
 670
 671static int setup_attrs(struct acpi_power_meter_resource *resource)
 672{
 673        int res = 0;
 674
 675        res = read_domain_devices(resource);
 676        if (res)
 677                return res;
 678
 679        if (resource->caps.flags & POWER_METER_CAN_MEASURE) {
 680                res = register_attrs(resource, meter_attrs);
 681                if (res)
 682                        goto error;
 683        }
 684
 685        if (resource->caps.flags & POWER_METER_CAN_CAP) {
 686                if (!can_cap_in_hardware()) {
 687                        dev_warn(&resource->acpi_dev->dev,
 688                                 "Ignoring unsafe software power cap!\n");
 689                        goto skip_unsafe_cap;
 690                }
 691
 692                if (resource->caps.configurable_cap)
 693                        res = register_attrs(resource, rw_cap_attrs);
 694                else
 695                        res = register_attrs(resource, ro_cap_attrs);
 696
 697                if (res)
 698                        goto error;
 699
 700                res = register_attrs(resource, misc_cap_attrs);
 701                if (res)
 702                        goto error;
 703        }
 704
 705skip_unsafe_cap:
 706        if (resource->caps.flags & POWER_METER_CAN_TRIP) {
 707                res = register_attrs(resource, trip_attrs);
 708                if (res)
 709                        goto error;
 710        }
 711
 712        res = register_attrs(resource, misc_attrs);
 713        if (res)
 714                goto error;
 715
 716        return res;
 717error:
 718        remove_attrs(resource);
 719        return res;
 720}
 721
 722static void free_capabilities(struct acpi_power_meter_resource *resource)
 723{
 724        acpi_string *str;
 725        int i;
 726
 727        str = &resource->model_number;
 728        for (i = 0; i < 3; i++, str++) {
 729                kfree(*str);
 730                *str = NULL;
 731        }
 732}
 733
 734static int read_capabilities(struct acpi_power_meter_resource *resource)
 735{
 736        int res = 0;
 737        int i;
 738        struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
 739        struct acpi_buffer state = { 0, NULL };
 740        struct acpi_buffer format = { sizeof("NNNNNNNNNNN"), "NNNNNNNNNNN" };
 741        union acpi_object *pss;
 742        acpi_string *str;
 743        acpi_status status;
 744
 745        status = acpi_evaluate_object(resource->acpi_dev->handle, "_PMC", NULL,
 746                                      &buffer);
 747        if (ACPI_FAILURE(status)) {
 748                ACPI_EXCEPTION((AE_INFO, status, "Evaluating _PMC"));
 749                return -ENODEV;
 750        }
 751
 752        pss = buffer.pointer;
 753        if (!pss ||
 754            pss->type != ACPI_TYPE_PACKAGE ||
 755            pss->package.count != 14) {
 756                dev_err(&resource->acpi_dev->dev, ACPI_POWER_METER_NAME
 757                        "Invalid _PMC data\n");
 758                res = -EFAULT;
 759                goto end;
 760        }
 761
 762        /* Grab all the integer data at once */
 763        state.length = sizeof(struct acpi_power_meter_capabilities);
 764        state.pointer = &resource->caps;
 765
 766        status = acpi_extract_package(pss, &format, &state);
 767        if (ACPI_FAILURE(status)) {
 768                ACPI_EXCEPTION((AE_INFO, status, "Invalid data"));
 769                res = -EFAULT;
 770                goto end;
 771        }
 772
 773        if (resource->caps.units) {
 774                dev_err(&resource->acpi_dev->dev, ACPI_POWER_METER_NAME
 775                        "Unknown units %llu.\n",
 776                        resource->caps.units);
 777                res = -EINVAL;
 778                goto end;
 779        }
 780
 781        /* Grab the string data */
 782        str = &resource->model_number;
 783
 784        for (i = 11; i < 14; i++) {
 785                union acpi_object *element = &(pss->package.elements[i]);
 786
 787                if (element->type != ACPI_TYPE_STRING) {
 788                        res = -EINVAL;
 789                        goto error;
 790                }
 791
 792                *str = kcalloc(element->string.length + 1, sizeof(u8),
 793                               GFP_KERNEL);
 794                if (!*str) {
 795                        res = -ENOMEM;
 796                        goto error;
 797                }
 798
 799                strncpy(*str, element->string.pointer, element->string.length);
 800                str++;
 801        }
 802
 803        dev_info(&resource->acpi_dev->dev, "Found ACPI power meter.\n");
 804        goto end;
 805error:
 806        free_capabilities(resource);
 807end:
 808        kfree(buffer.pointer);
 809        return res;
 810}
 811
 812/* Handle ACPI event notifications */
 813static void acpi_power_meter_notify(struct acpi_device *device, u32 event)
 814{
 815        struct acpi_power_meter_resource *resource;
 816        int res;
 817
 818        if (!device || !acpi_driver_data(device))
 819                return;
 820
 821        resource = acpi_driver_data(device);
 822
 823        switch (event) {
 824        case METER_NOTIFY_CONFIG:
 825                mutex_lock(&resource->lock);
 826                free_capabilities(resource);
 827                res = read_capabilities(resource);
 828                mutex_unlock(&resource->lock);
 829                if (res)
 830                        break;
 831
 832                remove_attrs(resource);
 833                setup_attrs(resource);
 834                break;
 835        case METER_NOTIFY_TRIP:
 836                sysfs_notify(&device->dev.kobj, NULL, POWER_AVERAGE_NAME);
 837                break;
 838        case METER_NOTIFY_CAP:
 839                sysfs_notify(&device->dev.kobj, NULL, POWER_CAP_NAME);
 840                break;
 841        case METER_NOTIFY_INTERVAL:
 842                sysfs_notify(&device->dev.kobj, NULL, POWER_AVG_INTERVAL_NAME);
 843                break;
 844        case METER_NOTIFY_CAPPING:
 845                sysfs_notify(&device->dev.kobj, NULL, POWER_ALARM_NAME);
 846                dev_info(&device->dev, "Capping in progress.\n");
 847                break;
 848        default:
 849                WARN(1, "Unexpected event %d\n", event);
 850                break;
 851        }
 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        res = read_capabilities(resource);
 878        if (res)
 879                goto exit_free;
 880
 881        resource->trip[0] = resource->trip[1] = -1;
 882
 883        res = setup_attrs(resource);
 884        if (res)
 885                goto exit_free_capability;
 886
 887        resource->hwmon_dev = hwmon_device_register(&device->dev);
 888        if (IS_ERR(resource->hwmon_dev)) {
 889                res = PTR_ERR(resource->hwmon_dev);
 890                goto exit_remove;
 891        }
 892
 893        res = 0;
 894        goto exit;
 895
 896exit_remove:
 897        remove_attrs(resource);
 898exit_free_capability:
 899        free_capabilities(resource);
 900exit_free:
 901        kfree(resource);
 902exit:
 903        return res;
 904}
 905
 906static int acpi_power_meter_remove(struct acpi_device *device)
 907{
 908        struct acpi_power_meter_resource *resource;
 909
 910        if (!device || !acpi_driver_data(device))
 911                return -EINVAL;
 912
 913        resource = acpi_driver_data(device);
 914        hwmon_device_unregister(resource->hwmon_dev);
 915
 916        remove_attrs(resource);
 917        free_capabilities(resource);
 918
 919        kfree(resource);
 920        return 0;
 921}
 922
 923#ifdef CONFIG_PM_SLEEP
 924
 925static int acpi_power_meter_resume(struct device *dev)
 926{
 927        struct acpi_power_meter_resource *resource;
 928
 929        if (!dev)
 930                return -EINVAL;
 931
 932        resource = acpi_driver_data(to_acpi_device(dev));
 933        if (!resource)
 934                return -EINVAL;
 935
 936        free_capabilities(resource);
 937        read_capabilities(resource);
 938
 939        return 0;
 940}
 941
 942#endif /* CONFIG_PM_SLEEP */
 943
 944static SIMPLE_DEV_PM_OPS(acpi_power_meter_pm, NULL, acpi_power_meter_resume);
 945
 946static struct acpi_driver acpi_power_meter_driver = {
 947        .name = "power_meter",
 948        .class = ACPI_POWER_METER_CLASS,
 949        .ids = power_meter_ids,
 950        .ops = {
 951                .add = acpi_power_meter_add,
 952                .remove = acpi_power_meter_remove,
 953                .notify = acpi_power_meter_notify,
 954                },
 955        .drv.pm = &acpi_power_meter_pm,
 956};
 957
 958/* Module init/exit routines */
 959static int __init enable_cap_knobs(const struct dmi_system_id *d)
 960{
 961        cap_in_hardware = 1;
 962        return 0;
 963}
 964
 965static const struct dmi_system_id pm_dmi_table[] __initconst = {
 966        {
 967                enable_cap_knobs, "IBM Active Energy Manager",
 968                {
 969                        DMI_MATCH(DMI_SYS_VENDOR, "IBM")
 970                },
 971        },
 972        {}
 973};
 974
 975static int __init acpi_power_meter_init(void)
 976{
 977        int result;
 978
 979        if (acpi_disabled)
 980                return -ENODEV;
 981
 982        dmi_check_system(pm_dmi_table);
 983
 984        result = acpi_bus_register_driver(&acpi_power_meter_driver);
 985        if (result < 0)
 986                return result;
 987
 988        return 0;
 989}
 990
 991static void __exit acpi_power_meter_exit(void)
 992{
 993        acpi_bus_unregister_driver(&acpi_power_meter_driver);
 994}
 995
 996MODULE_AUTHOR("Darrick J. Wong <darrick.wong@oracle.com>");
 997MODULE_DESCRIPTION("ACPI 4.0 power meter driver");
 998MODULE_LICENSE("GPL");
 999
1000module_param(force_cap_on, bool, 0644);
1001MODULE_PARM_DESC(force_cap_on, "Enable power cap even it is unsafe to do so.");
1002
1003module_init(acpi_power_meter_init);
1004module_exit(acpi_power_meter_exit);
1005