linux/drivers/hwmon/acpi_power_meter.c
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   1/*
   2 * A hwmon driver for ACPI 4.0 power meters
   3 * Copyright (C) 2009 IBM
   4 *
   5 * Author: Darrick J. Wong <djwong@us.ibm.com>
   6 *
   7 * This program is free software; you can redistribute it and/or modify
   8 * it under the terms of the GNU General Public License as published by
   9 * the Free Software Foundation; either version 2 of the License, or
  10 * (at your option) any later version.
  11 *
  12 * This program is distributed in the hope that it will be useful,
  13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15 * GNU General Public License for more details.
  16 *
  17 * You should have received a copy of the GNU General Public License
  18 * along with this program; if not, write to the Free Software
  19 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  20 */
  21
  22#include <linux/module.h>
  23#include <linux/hwmon.h>
  24#include <linux/hwmon-sysfs.h>
  25#include <linux/jiffies.h>
  26#include <linux/mutex.h>
  27#include <linux/dmi.h>
  28#include <linux/slab.h>
  29#include <linux/kdev_t.h>
  30#include <linux/sched.h>
  31#include <linux/time.h>
  32#include <linux/err.h>
  33#include <acpi/acpi_drivers.h>
  34#include <acpi/acpi_bus.h>
  35
  36#define ACPI_POWER_METER_NAME           "power_meter"
  37ACPI_MODULE_NAME(ACPI_POWER_METER_NAME);
  38#define ACPI_POWER_METER_DEVICE_NAME    "Power Meter"
  39#define ACPI_POWER_METER_CLASS          "pwr_meter_resource"
  40
  41#define NUM_SENSORS                     17
  42
  43#define POWER_METER_CAN_MEASURE (1 << 0)
  44#define POWER_METER_CAN_TRIP    (1 << 1)
  45#define POWER_METER_CAN_CAP     (1 << 2)
  46#define POWER_METER_CAN_NOTIFY  (1 << 3)
  47#define POWER_METER_IS_BATTERY  (1 << 8)
  48#define UNKNOWN_HYSTERESIS      0xFFFFFFFF
  49
  50#define METER_NOTIFY_CONFIG     0x80
  51#define METER_NOTIFY_TRIP       0x81
  52#define METER_NOTIFY_CAP        0x82
  53#define METER_NOTIFY_CAPPING    0x83
  54#define METER_NOTIFY_INTERVAL   0x84
  55
  56#define POWER_AVERAGE_NAME      "power1_average"
  57#define POWER_CAP_NAME          "power1_cap"
  58#define POWER_AVG_INTERVAL_NAME "power1_average_interval"
  59#define POWER_ALARM_NAME        "power1_alarm"
  60
  61static int cap_in_hardware;
  62static bool force_cap_on;
  63
  64static int can_cap_in_hardware(void)
  65{
  66        return force_cap_on || cap_in_hardware;
  67}
  68
  69static const struct acpi_device_id power_meter_ids[] = {
  70        {"ACPI000D", 0},
  71        {"", 0},
  72};
  73MODULE_DEVICE_TABLE(acpi, power_meter_ids);
  74
  75struct acpi_power_meter_capabilities {
  76        u64             flags;
  77        u64             units;
  78        u64             type;
  79        u64             accuracy;
  80        u64             sampling_time;
  81        u64             min_avg_interval;
  82        u64             max_avg_interval;
  83        u64             hysteresis;
  84        u64             configurable_cap;
  85        u64             min_cap;
  86        u64             max_cap;
  87};
  88
  89struct acpi_power_meter_resource {
  90        struct acpi_device      *acpi_dev;
  91        acpi_bus_id             name;
  92        struct mutex            lock;
  93        struct device           *hwmon_dev;
  94        struct acpi_power_meter_capabilities    caps;
  95        acpi_string             model_number;
  96        acpi_string             serial_number;
  97        acpi_string             oem_info;
  98        u64             power;
  99        u64             cap;
 100        u64             avg_interval;
 101        int                     sensors_valid;
 102        unsigned long           sensors_last_updated;
 103        struct sensor_device_attribute  sensors[NUM_SENSORS];
 104        int                     num_sensors;
 105        s64                     trip[2];
 106        int                     num_domain_devices;
 107        struct acpi_device      **domain_devices;
 108        struct kobject          *holders_dir;
 109};
 110
 111struct sensor_template {
 112        char *label;
 113        ssize_t (*show)(struct device *dev,
 114                        struct device_attribute *devattr,
 115                        char *buf);
 116        ssize_t (*set)(struct device *dev,
 117                       struct device_attribute *devattr,
 118                       const char *buf, size_t count);
 119        int index;
 120};
 121
 122/* Averaging interval */
 123static int update_avg_interval(struct acpi_power_meter_resource *resource)
 124{
 125        unsigned long long data;
 126        acpi_status status;
 127
 128        status = acpi_evaluate_integer(resource->acpi_dev->handle, "_GAI",
 129                                       NULL, &data);
 130        if (ACPI_FAILURE(status)) {
 131                ACPI_EXCEPTION((AE_INFO, status, "Evaluating _GAI"));
 132                return -ENODEV;
 133        }
 134
 135        resource->avg_interval = data;
 136        return 0;
 137}
 138
 139static ssize_t show_avg_interval(struct device *dev,
 140                                 struct device_attribute *devattr,
 141                                 char *buf)
 142{
 143        struct acpi_device *acpi_dev = to_acpi_device(dev);
 144        struct acpi_power_meter_resource *resource = acpi_dev->driver_data;
 145
 146        mutex_lock(&resource->lock);
 147        update_avg_interval(resource);
 148        mutex_unlock(&resource->lock);
 149
 150        return sprintf(buf, "%llu\n", resource->avg_interval);
 151}
 152
 153static ssize_t set_avg_interval(struct device *dev,
 154                                struct device_attribute *devattr,
 155                                const char *buf, size_t count)
 156{
 157        struct acpi_device *acpi_dev = to_acpi_device(dev);
 158        struct acpi_power_meter_resource *resource = acpi_dev->driver_data;
 159        union acpi_object arg0 = { ACPI_TYPE_INTEGER };
 160        struct acpi_object_list args = { 1, &arg0 };
 161        int res;
 162        unsigned long temp;
 163        unsigned long long data;
 164        acpi_status status;
 165
 166        res = kstrtoul(buf, 10, &temp);
 167        if (res)
 168                return res;
 169
 170        if (temp > resource->caps.max_avg_interval ||
 171            temp < resource->caps.min_avg_interval)
 172                return -EINVAL;
 173        arg0.integer.value = temp;
 174
 175        mutex_lock(&resource->lock);
 176        status = acpi_evaluate_integer(resource->acpi_dev->handle, "_PAI",
 177                                       &args, &data);
 178        if (!ACPI_FAILURE(status))
 179                resource->avg_interval = temp;
 180        mutex_unlock(&resource->lock);
 181
 182        if (ACPI_FAILURE(status)) {
 183                ACPI_EXCEPTION((AE_INFO, status, "Evaluating _PAI"));
 184                return -EINVAL;
 185        }
 186
 187        /* _PAI returns 0 on success, nonzero otherwise */
 188        if (data)
 189                return -EINVAL;
 190
 191        return count;
 192}
 193
 194/* Cap functions */
 195static int update_cap(struct acpi_power_meter_resource *resource)
 196{
 197        unsigned long long data;
 198        acpi_status status;
 199
 200        status = acpi_evaluate_integer(resource->acpi_dev->handle, "_GHL",
 201                                       NULL, &data);
 202        if (ACPI_FAILURE(status)) {
 203                ACPI_EXCEPTION((AE_INFO, status, "Evaluating _GHL"));
 204                return -ENODEV;
 205        }
 206
 207        resource->cap = data;
 208        return 0;
 209}
 210
 211static ssize_t show_cap(struct device *dev,
 212                        struct device_attribute *devattr,
 213                        char *buf)
 214{
 215        struct acpi_device *acpi_dev = to_acpi_device(dev);
 216        struct acpi_power_meter_resource *resource = acpi_dev->driver_data;
 217
 218        mutex_lock(&resource->lock);
 219        update_cap(resource);
 220        mutex_unlock(&resource->lock);
 221
 222        return sprintf(buf, "%llu\n", resource->cap * 1000);
 223}
 224
 225static ssize_t set_cap(struct device *dev, struct device_attribute *devattr,
 226                       const char *buf, size_t count)
 227{
 228        struct acpi_device *acpi_dev = to_acpi_device(dev);
 229        struct acpi_power_meter_resource *resource = acpi_dev->driver_data;
 230        union acpi_object arg0 = { ACPI_TYPE_INTEGER };
 231        struct acpi_object_list args = { 1, &arg0 };
 232        int res;
 233        unsigned long temp;
 234        unsigned long long data;
 235        acpi_status status;
 236
 237        res = kstrtoul(buf, 10, &temp);
 238        if (res)
 239                return res;
 240
 241        temp = DIV_ROUND_CLOSEST(temp, 1000);
 242        if (temp > resource->caps.max_cap || temp < resource->caps.min_cap)
 243                return -EINVAL;
 244        arg0.integer.value = temp;
 245
 246        mutex_lock(&resource->lock);
 247        status = acpi_evaluate_integer(resource->acpi_dev->handle, "_SHL",
 248                                       &args, &data);
 249        if (!ACPI_FAILURE(status))
 250                resource->cap = temp;
 251        mutex_unlock(&resource->lock);
 252
 253        if (ACPI_FAILURE(status)) {
 254                ACPI_EXCEPTION((AE_INFO, status, "Evaluating _SHL"));
 255                return -EINVAL;
 256        }
 257
 258        /* _SHL returns 0 on success, nonzero otherwise */
 259        if (data)
 260                return -EINVAL;
 261
 262        return count;
 263}
 264
 265/* Power meter trip points */
 266static int set_acpi_trip(struct acpi_power_meter_resource *resource)
 267{
 268        union acpi_object arg_objs[] = {
 269                {ACPI_TYPE_INTEGER},
 270                {ACPI_TYPE_INTEGER}
 271        };
 272        struct acpi_object_list args = { 2, arg_objs };
 273        unsigned long long data;
 274        acpi_status status;
 275
 276        /* Both trip levels must be set */
 277        if (resource->trip[0] < 0 || resource->trip[1] < 0)
 278                return 0;
 279
 280        /* This driver stores min, max; ACPI wants max, min. */
 281        arg_objs[0].integer.value = resource->trip[1];
 282        arg_objs[1].integer.value = resource->trip[0];
 283
 284        status = acpi_evaluate_integer(resource->acpi_dev->handle, "_PTP",
 285                                       &args, &data);
 286        if (ACPI_FAILURE(status)) {
 287                ACPI_EXCEPTION((AE_INFO, status, "Evaluating _PTP"));
 288                return -EINVAL;
 289        }
 290
 291        /* _PTP returns 0 on success, nonzero otherwise */
 292        if (data)
 293                return -EINVAL;
 294
 295        return 0;
 296}
 297
 298static ssize_t set_trip(struct device *dev, struct device_attribute *devattr,
 299                        const char *buf, size_t count)
 300{
 301        struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
 302        struct acpi_device *acpi_dev = to_acpi_device(dev);
 303        struct acpi_power_meter_resource *resource = acpi_dev->driver_data;
 304        int res;
 305        unsigned long temp;
 306
 307        res = kstrtoul(buf, 10, &temp);
 308        if (res)
 309                return res;
 310
 311        temp = DIV_ROUND_CLOSEST(temp, 1000);
 312
 313        mutex_lock(&resource->lock);
 314        resource->trip[attr->index - 7] = temp;
 315        res = set_acpi_trip(resource);
 316        mutex_unlock(&resource->lock);
 317
 318        if (res)
 319                return res;
 320
 321        return count;
 322}
 323
 324/* Power meter */
 325static int update_meter(struct acpi_power_meter_resource *resource)
 326{
 327        unsigned long long data;
 328        acpi_status status;
 329        unsigned long local_jiffies = jiffies;
 330
 331        if (time_before(local_jiffies, resource->sensors_last_updated +
 332                        msecs_to_jiffies(resource->caps.sampling_time)) &&
 333                        resource->sensors_valid)
 334                return 0;
 335
 336        status = acpi_evaluate_integer(resource->acpi_dev->handle, "_PMM",
 337                                       NULL, &data);
 338        if (ACPI_FAILURE(status)) {
 339                ACPI_EXCEPTION((AE_INFO, status, "Evaluating _PMM"));
 340                return -ENODEV;
 341        }
 342
 343        resource->power = data;
 344        resource->sensors_valid = 1;
 345        resource->sensors_last_updated = jiffies;
 346        return 0;
 347}
 348
 349static ssize_t show_power(struct device *dev,
 350                          struct device_attribute *devattr,
 351                          char *buf)
 352{
 353        struct acpi_device *acpi_dev = to_acpi_device(dev);
 354        struct acpi_power_meter_resource *resource = acpi_dev->driver_data;
 355
 356        mutex_lock(&resource->lock);
 357        update_meter(resource);
 358        mutex_unlock(&resource->lock);
 359
 360        return sprintf(buf, "%llu\n", resource->power * 1000);
 361}
 362
 363/* Miscellaneous */
 364static ssize_t show_str(struct device *dev,
 365                        struct device_attribute *devattr,
 366                        char *buf)
 367{
 368        struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
 369        struct acpi_device *acpi_dev = to_acpi_device(dev);
 370        struct acpi_power_meter_resource *resource = acpi_dev->driver_data;
 371        acpi_string val;
 372
 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                BUG();
 385                val = "";
 386        }
 387
 388        return sprintf(buf, "%s\n", val);
 389}
 390
 391static ssize_t show_val(struct device *dev,
 392                        struct device_attribute *devattr,
 393                        char *buf)
 394{
 395        struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
 396        struct acpi_device *acpi_dev = to_acpi_device(dev);
 397        struct acpi_power_meter_resource *resource = acpi_dev->driver_data;
 398        u64 val = 0;
 399
 400        switch (attr->index) {
 401        case 0:
 402                val = resource->caps.min_avg_interval;
 403                break;
 404        case 1:
 405                val = resource->caps.max_avg_interval;
 406                break;
 407        case 2:
 408                val = resource->caps.min_cap * 1000;
 409                break;
 410        case 3:
 411                val = resource->caps.max_cap * 1000;
 412                break;
 413        case 4:
 414                if (resource->caps.hysteresis == UNKNOWN_HYSTERESIS)
 415                        return sprintf(buf, "unknown\n");
 416
 417                val = resource->caps.hysteresis * 1000;
 418                break;
 419        case 5:
 420                if (resource->caps.flags & POWER_METER_IS_BATTERY)
 421                        val = 1;
 422                else
 423                        val = 0;
 424                break;
 425        case 6:
 426                if (resource->power > resource->cap)
 427                        val = 1;
 428                else
 429                        val = 0;
 430                break;
 431        case 7:
 432        case 8:
 433                if (resource->trip[attr->index - 7] < 0)
 434                        return sprintf(buf, "unknown\n");
 435
 436                val = resource->trip[attr->index - 7] * 1000;
 437                break;
 438        default:
 439                BUG();
 440        }
 441
 442        return sprintf(buf, "%llu\n", val);
 443}
 444
 445static ssize_t show_accuracy(struct device *dev,
 446                             struct device_attribute *devattr,
 447                             char *buf)
 448{
 449        struct acpi_device *acpi_dev = to_acpi_device(dev);
 450        struct acpi_power_meter_resource *resource = acpi_dev->driver_data;
 451        unsigned int acc = resource->caps.accuracy;
 452
 453        return sprintf(buf, "%u.%u%%\n", acc / 1000, acc % 1000);
 454}
 455
 456static ssize_t show_name(struct device *dev,
 457                         struct device_attribute *devattr,
 458                         char *buf)
 459{
 460        return sprintf(buf, "%s\n", ACPI_POWER_METER_NAME);
 461}
 462
 463#define RO_SENSOR_TEMPLATE(_label, _show, _index)       \
 464        {                                               \
 465                .label = _label,                        \
 466                .show  = _show,                         \
 467                .index = _index,                        \
 468        }
 469
 470#define RW_SENSOR_TEMPLATE(_label, _show, _set, _index) \
 471        {                                               \
 472                .label = _label,                        \
 473                .show  = _show,                         \
 474                .set   = _set,                          \
 475                .index = _index,                        \
 476        }
 477
 478/* Sensor descriptions.  If you add a sensor, update NUM_SENSORS above! */
 479static struct sensor_template meter_attrs[] = {
 480        RO_SENSOR_TEMPLATE(POWER_AVERAGE_NAME, show_power, 0),
 481        RO_SENSOR_TEMPLATE("power1_accuracy", show_accuracy, 0),
 482        RO_SENSOR_TEMPLATE("power1_average_interval_min", show_val, 0),
 483        RO_SENSOR_TEMPLATE("power1_average_interval_max", show_val, 1),
 484        RO_SENSOR_TEMPLATE("power1_is_battery", show_val, 5),
 485        RW_SENSOR_TEMPLATE(POWER_AVG_INTERVAL_NAME, show_avg_interval,
 486                set_avg_interval, 0),
 487        {},
 488};
 489
 490static struct sensor_template misc_cap_attrs[] = {
 491        RO_SENSOR_TEMPLATE("power1_cap_min", show_val, 2),
 492        RO_SENSOR_TEMPLATE("power1_cap_max", show_val, 3),
 493        RO_SENSOR_TEMPLATE("power1_cap_hyst", show_val, 4),
 494        RO_SENSOR_TEMPLATE(POWER_ALARM_NAME, show_val, 6),
 495        {},
 496};
 497
 498static struct sensor_template ro_cap_attrs[] = {
 499        RO_SENSOR_TEMPLATE(POWER_CAP_NAME, show_cap, 0),
 500        {},
 501};
 502
 503static struct sensor_template rw_cap_attrs[] = {
 504        RW_SENSOR_TEMPLATE(POWER_CAP_NAME, show_cap, set_cap, 0),
 505        {},
 506};
 507
 508static struct sensor_template trip_attrs[] = {
 509        RW_SENSOR_TEMPLATE("power1_average_min", show_val, set_trip, 7),
 510        RW_SENSOR_TEMPLATE("power1_average_max", show_val, set_trip, 8),
 511        {},
 512};
 513
 514static struct sensor_template misc_attrs[] = {
 515        RO_SENSOR_TEMPLATE("name", show_name, 0),
 516        RO_SENSOR_TEMPLATE("power1_model_number", show_str, 0),
 517        RO_SENSOR_TEMPLATE("power1_oem_info", show_str, 2),
 518        RO_SENSOR_TEMPLATE("power1_serial_number", show_str, 1),
 519        {},
 520};
 521
 522#undef RO_SENSOR_TEMPLATE
 523#undef RW_SENSOR_TEMPLATE
 524
 525/* Read power domain data */
 526static void remove_domain_devices(struct acpi_power_meter_resource *resource)
 527{
 528        int i;
 529
 530        if (!resource->num_domain_devices)
 531                return;
 532
 533        for (i = 0; i < resource->num_domain_devices; i++) {
 534                struct acpi_device *obj = resource->domain_devices[i];
 535                if (!obj)
 536                        continue;
 537
 538                sysfs_remove_link(resource->holders_dir,
 539                                  kobject_name(&obj->dev.kobj));
 540                put_device(&obj->dev);
 541        }
 542
 543        kfree(resource->domain_devices);
 544        kobject_put(resource->holders_dir);
 545        resource->num_domain_devices = 0;
 546}
 547
 548static int read_domain_devices(struct acpi_power_meter_resource *resource)
 549{
 550        int res = 0;
 551        int i;
 552        struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
 553        union acpi_object *pss;
 554        acpi_status status;
 555
 556        status = acpi_evaluate_object(resource->acpi_dev->handle, "_PMD", NULL,
 557                                      &buffer);
 558        if (ACPI_FAILURE(status)) {
 559                ACPI_EXCEPTION((AE_INFO, status, "Evaluating _PMD"));
 560                return -ENODEV;
 561        }
 562
 563        pss = buffer.pointer;
 564        if (!pss ||
 565            pss->type != ACPI_TYPE_PACKAGE) {
 566                dev_err(&resource->acpi_dev->dev, ACPI_POWER_METER_NAME
 567                        "Invalid _PMD data\n");
 568                res = -EFAULT;
 569                goto end;
 570        }
 571
 572        if (!pss->package.count)
 573                goto end;
 574
 575        resource->domain_devices = kzalloc(sizeof(struct acpi_device *) *
 576                                           pss->package.count, GFP_KERNEL);
 577        if (!resource->domain_devices) {
 578                res = -ENOMEM;
 579                goto end;
 580        }
 581
 582        resource->holders_dir = kobject_create_and_add("measures",
 583                                        &resource->acpi_dev->dev.kobj);
 584        if (!resource->holders_dir) {
 585                res = -ENOMEM;
 586                goto exit_free;
 587        }
 588
 589        resource->num_domain_devices = pss->package.count;
 590
 591        for (i = 0; i < pss->package.count; i++) {
 592                struct acpi_device *obj;
 593                union acpi_object *element = &(pss->package.elements[i]);
 594
 595                /* Refuse non-references */
 596                if (element->type != ACPI_TYPE_LOCAL_REFERENCE)
 597                        continue;
 598
 599                /* Create a symlink to domain objects */
 600                resource->domain_devices[i] = NULL;
 601                status = acpi_bus_get_device(element->reference.handle,
 602                                             &resource->domain_devices[i]);
 603                if (ACPI_FAILURE(status))
 604                        continue;
 605
 606                obj = resource->domain_devices[i];
 607                get_device(&obj->dev);
 608
 609                res = sysfs_create_link(resource->holders_dir, &obj->dev.kobj,
 610                                      kobject_name(&obj->dev.kobj));
 611                if (res) {
 612                        put_device(&obj->dev);
 613                        resource->domain_devices[i] = NULL;
 614                }
 615        }
 616
 617        res = 0;
 618        goto end;
 619
 620exit_free:
 621        kfree(resource->domain_devices);
 622end:
 623        kfree(buffer.pointer);
 624        return res;
 625}
 626
 627/* Registration and deregistration */
 628static int register_attrs(struct acpi_power_meter_resource *resource,
 629                          struct sensor_template *attrs)
 630{
 631        struct device *dev = &resource->acpi_dev->dev;
 632        struct sensor_device_attribute *sensors =
 633                &resource->sensors[resource->num_sensors];
 634        int res = 0;
 635
 636        while (attrs->label) {
 637                sensors->dev_attr.attr.name = attrs->label;
 638                sensors->dev_attr.attr.mode = S_IRUGO;
 639                sensors->dev_attr.show = attrs->show;
 640                sensors->index = attrs->index;
 641
 642                if (attrs->set) {
 643                        sensors->dev_attr.attr.mode |= S_IWUSR;
 644                        sensors->dev_attr.store = attrs->set;
 645                }
 646
 647                sysfs_attr_init(&sensors->dev_attr.attr);
 648                res = device_create_file(dev, &sensors->dev_attr);
 649                if (res) {
 650                        sensors->dev_attr.attr.name = NULL;
 651                        goto error;
 652                }
 653                sensors++;
 654                resource->num_sensors++;
 655                attrs++;
 656        }
 657
 658error:
 659        return res;
 660}
 661
 662static void remove_attrs(struct acpi_power_meter_resource *resource)
 663{
 664        int i;
 665
 666        for (i = 0; i < resource->num_sensors; i++) {
 667                if (!resource->sensors[i].dev_attr.attr.name)
 668                        continue;
 669                device_remove_file(&resource->acpi_dev->dev,
 670                                   &resource->sensors[i].dev_attr);
 671        }
 672
 673        remove_domain_devices(resource);
 674
 675        resource->num_sensors = 0;
 676}
 677
 678static int setup_attrs(struct acpi_power_meter_resource *resource)
 679{
 680        int res = 0;
 681
 682        res = read_domain_devices(resource);
 683        if (res)
 684                return res;
 685
 686        if (resource->caps.flags & POWER_METER_CAN_MEASURE) {
 687                res = register_attrs(resource, meter_attrs);
 688                if (res)
 689                        goto error;
 690        }
 691
 692        if (resource->caps.flags & POWER_METER_CAN_CAP) {
 693                if (!can_cap_in_hardware()) {
 694                        dev_err(&resource->acpi_dev->dev,
 695                                "Ignoring unsafe software power cap!\n");
 696                        goto skip_unsafe_cap;
 697                }
 698
 699                if (resource->caps.configurable_cap)
 700                        res = register_attrs(resource, rw_cap_attrs);
 701                else
 702                        res = register_attrs(resource, ro_cap_attrs);
 703
 704                if (res)
 705                        goto error;
 706
 707                res = register_attrs(resource, misc_cap_attrs);
 708                if (res)
 709                        goto error;
 710        }
 711
 712skip_unsafe_cap:
 713        if (resource->caps.flags & POWER_METER_CAN_TRIP) {
 714                res = register_attrs(resource, trip_attrs);
 715                if (res)
 716                        goto error;
 717        }
 718
 719        res = register_attrs(resource, misc_attrs);
 720        if (res)
 721                goto error;
 722
 723        return res;
 724error:
 725        remove_attrs(resource);
 726        return res;
 727}
 728
 729static void free_capabilities(struct acpi_power_meter_resource *resource)
 730{
 731        acpi_string *str;
 732        int i;
 733
 734        str = &resource->model_number;
 735        for (i = 0; i < 3; i++, str++)
 736                kfree(*str);
 737}
 738
 739static int read_capabilities(struct acpi_power_meter_resource *resource)
 740{
 741        int res = 0;
 742        int i;
 743        struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
 744        struct acpi_buffer state = { 0, NULL };
 745        struct acpi_buffer format = { sizeof("NNNNNNNNNNN"), "NNNNNNNNNNN" };
 746        union acpi_object *pss;
 747        acpi_string *str;
 748        acpi_status status;
 749
 750        status = acpi_evaluate_object(resource->acpi_dev->handle, "_PMC", NULL,
 751                                      &buffer);
 752        if (ACPI_FAILURE(status)) {
 753                ACPI_EXCEPTION((AE_INFO, status, "Evaluating _PMC"));
 754                return -ENODEV;
 755        }
 756
 757        pss = buffer.pointer;
 758        if (!pss ||
 759            pss->type != ACPI_TYPE_PACKAGE ||
 760            pss->package.count != 14) {
 761                dev_err(&resource->acpi_dev->dev, ACPI_POWER_METER_NAME
 762                        "Invalid _PMC data\n");
 763                res = -EFAULT;
 764                goto end;
 765        }
 766
 767        /* Grab all the integer data at once */
 768        state.length = sizeof(struct acpi_power_meter_capabilities);
 769        state.pointer = &resource->caps;
 770
 771        status = acpi_extract_package(pss, &format, &state);
 772        if (ACPI_FAILURE(status)) {
 773                ACPI_EXCEPTION((AE_INFO, status, "Invalid data"));
 774                res = -EFAULT;
 775                goto end;
 776        }
 777
 778        if (resource->caps.units) {
 779                dev_err(&resource->acpi_dev->dev, ACPI_POWER_METER_NAME
 780                        "Unknown units %llu.\n",
 781                        resource->caps.units);
 782                res = -EINVAL;
 783                goto end;
 784        }
 785
 786        /* Grab the string data */
 787        str = &resource->model_number;
 788
 789        for (i = 11; i < 14; i++) {
 790                union acpi_object *element = &(pss->package.elements[i]);
 791
 792                if (element->type != ACPI_TYPE_STRING) {
 793                        res = -EINVAL;
 794                        goto error;
 795                }
 796
 797                *str = kzalloc(sizeof(u8) * (element->string.length + 1),
 798                               GFP_KERNEL);
 799                if (!*str) {
 800                        res = -ENOMEM;
 801                        goto error;
 802                }
 803
 804                strncpy(*str, element->string.pointer, element->string.length);
 805                str++;
 806        }
 807
 808        dev_info(&resource->acpi_dev->dev, "Found ACPI power meter.\n");
 809        goto end;
 810error:
 811        str = &resource->model_number;
 812        for (i = 0; i < 3; i++, str++)
 813                kfree(*str);
 814end:
 815        kfree(buffer.pointer);
 816        return res;
 817}
 818
 819/* Handle ACPI event notifications */
 820static void acpi_power_meter_notify(struct acpi_device *device, u32 event)
 821{
 822        struct acpi_power_meter_resource *resource;
 823        int res;
 824
 825        if (!device || !acpi_driver_data(device))
 826                return;
 827
 828        resource = acpi_driver_data(device);
 829
 830        mutex_lock(&resource->lock);
 831        switch (event) {
 832        case METER_NOTIFY_CONFIG:
 833                free_capabilities(resource);
 834                res = read_capabilities(resource);
 835                if (res)
 836                        break;
 837
 838                remove_attrs(resource);
 839                setup_attrs(resource);
 840                break;
 841        case METER_NOTIFY_TRIP:
 842                sysfs_notify(&device->dev.kobj, NULL, POWER_AVERAGE_NAME);
 843                update_meter(resource);
 844                break;
 845        case METER_NOTIFY_CAP:
 846                sysfs_notify(&device->dev.kobj, NULL, POWER_CAP_NAME);
 847                update_cap(resource);
 848                break;
 849        case METER_NOTIFY_INTERVAL:
 850                sysfs_notify(&device->dev.kobj, NULL, POWER_AVG_INTERVAL_NAME);
 851                update_avg_interval(resource);
 852                break;
 853        case METER_NOTIFY_CAPPING:
 854                sysfs_notify(&device->dev.kobj, NULL, POWER_ALARM_NAME);
 855                dev_info(&device->dev, "Capping in progress.\n");
 856                break;
 857        default:
 858                BUG();
 859        }
 860        mutex_unlock(&resource->lock);
 861
 862        acpi_bus_generate_netlink_event(ACPI_POWER_METER_CLASS,
 863                                        dev_name(&device->dev), event, 0);
 864}
 865
 866static int acpi_power_meter_add(struct acpi_device *device)
 867{
 868        int res;
 869        struct acpi_power_meter_resource *resource;
 870
 871        if (!device)
 872                return -EINVAL;
 873
 874        resource = kzalloc(sizeof(struct acpi_power_meter_resource),
 875                           GFP_KERNEL);
 876        if (!resource)
 877                return -ENOMEM;
 878
 879        resource->sensors_valid = 0;
 880        resource->acpi_dev = device;
 881        mutex_init(&resource->lock);
 882        strcpy(acpi_device_name(device), ACPI_POWER_METER_DEVICE_NAME);
 883        strcpy(acpi_device_class(device), ACPI_POWER_METER_CLASS);
 884        device->driver_data = resource;
 885
 886        free_capabilities(resource);
 887        res = read_capabilities(resource);
 888        if (res)
 889                goto exit_free;
 890
 891        resource->trip[0] = resource->trip[1] = -1;
 892
 893        res = setup_attrs(resource);
 894        if (res)
 895                goto exit_free;
 896
 897        resource->hwmon_dev = hwmon_device_register(&device->dev);
 898        if (IS_ERR(resource->hwmon_dev)) {
 899                res = PTR_ERR(resource->hwmon_dev);
 900                goto exit_remove;
 901        }
 902
 903        res = 0;
 904        goto exit;
 905
 906exit_remove:
 907        remove_attrs(resource);
 908exit_free:
 909        kfree(resource);
 910exit:
 911        return res;
 912}
 913
 914static int acpi_power_meter_remove(struct acpi_device *device, int type)
 915{
 916        struct acpi_power_meter_resource *resource;
 917
 918        if (!device || !acpi_driver_data(device))
 919                return -EINVAL;
 920
 921        resource = acpi_driver_data(device);
 922        hwmon_device_unregister(resource->hwmon_dev);
 923
 924        free_capabilities(resource);
 925        remove_attrs(resource);
 926
 927        kfree(resource);
 928        return 0;
 929}
 930
 931#ifdef CONFIG_PM_SLEEP
 932
 933static int acpi_power_meter_resume(struct device *dev)
 934{
 935        struct acpi_power_meter_resource *resource;
 936
 937        if (!dev)
 938                return -EINVAL;
 939
 940        resource = acpi_driver_data(to_acpi_device(dev));
 941        if (!resource)
 942                return -EINVAL;
 943
 944        free_capabilities(resource);
 945        read_capabilities(resource);
 946
 947        return 0;
 948}
 949
 950#endif /* CONFIG_PM_SLEEP */
 951
 952static SIMPLE_DEV_PM_OPS(acpi_power_meter_pm, NULL, acpi_power_meter_resume);
 953
 954static struct acpi_driver acpi_power_meter_driver = {
 955        .name = "power_meter",
 956        .class = ACPI_POWER_METER_CLASS,
 957        .ids = power_meter_ids,
 958        .ops = {
 959                .add = acpi_power_meter_add,
 960                .remove = acpi_power_meter_remove,
 961                .notify = acpi_power_meter_notify,
 962                },
 963        .drv.pm = &acpi_power_meter_pm,
 964};
 965
 966/* Module init/exit routines */
 967static int __init enable_cap_knobs(const struct dmi_system_id *d)
 968{
 969        cap_in_hardware = 1;
 970        return 0;
 971}
 972
 973static struct dmi_system_id __initdata pm_dmi_table[] = {
 974        {
 975                enable_cap_knobs, "IBM Active Energy Manager",
 976                {
 977                        DMI_MATCH(DMI_SYS_VENDOR, "IBM")
 978                },
 979        },
 980        {}
 981};
 982
 983static int __init acpi_power_meter_init(void)
 984{
 985        int result;
 986
 987        if (acpi_disabled)
 988                return -ENODEV;
 989
 990        dmi_check_system(pm_dmi_table);
 991
 992        result = acpi_bus_register_driver(&acpi_power_meter_driver);
 993        if (result < 0)
 994                return -ENODEV;
 995
 996        return 0;
 997}
 998
 999static void __exit acpi_power_meter_exit(void)
1000{
1001        acpi_bus_unregister_driver(&acpi_power_meter_driver);
1002}
1003
1004MODULE_AUTHOR("Darrick J. Wong <djwong@us.ibm.com>");
1005MODULE_DESCRIPTION("ACPI 4.0 power meter driver");
1006MODULE_LICENSE("GPL");
1007
1008module_param(force_cap_on, bool, 0644);
1009MODULE_PARM_DESC(force_cap_on, "Enable power cap even it is unsafe to do so.");
1010
1011module_init(acpi_power_meter_init);
1012module_exit(acpi_power_meter_exit);
1013
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