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 <darrick.wong@oracle.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 <linux/acpi.h>
  34
  35#define ACPI_POWER_METER_NAME           "power_meter"
  36ACPI_MODULE_NAME(ACPI_POWER_METER_NAME);
  37#define ACPI_POWER_METER_DEVICE_NAME    "Power Meter"
  38#define ACPI_POWER_METER_CLASS          "pwr_meter_resource"
  39
  40#define NUM_SENSORS                     17
  41
  42#define POWER_METER_CAN_MEASURE (1 << 0)
  43#define POWER_METER_CAN_TRIP    (1 << 1)
  44#define POWER_METER_CAN_CAP     (1 << 2)
  45#define POWER_METER_CAN_NOTIFY  (1 << 3)
  46#define POWER_METER_IS_BATTERY  (1 << 8)
  47#define UNKNOWN_HYSTERESIS      0xFFFFFFFF
  48
  49#define METER_NOTIFY_CONFIG     0x80
  50#define METER_NOTIFY_TRIP       0x81
  51#define METER_NOTIFY_CAP        0x82
  52#define METER_NOTIFY_CAPPING    0x83
  53#define METER_NOTIFY_INTERVAL   0x84
  54
  55#define POWER_AVERAGE_NAME      "power1_average"
  56#define POWER_CAP_NAME          "power1_cap"
  57#define POWER_AVG_INTERVAL_NAME "power1_average_interval"
  58#define POWER_ALARM_NAME        "power1_alarm"
  59
  60static int cap_in_hardware;
  61static bool force_cap_on;
  62
  63static int can_cap_in_hardware(void)
  64{
  65        return force_cap_on || cap_in_hardware;
  66}
  67
  68static const struct acpi_device_id power_meter_ids[] = {
  69        {"ACPI000D", 0},
  70        {"", 0},
  71};
  72MODULE_DEVICE_TABLE(acpi, power_meter_ids);
  73
  74struct acpi_power_meter_capabilities {
  75        u64             flags;
  76        u64             units;
  77        u64             type;
  78        u64             accuracy;
  79        u64             sampling_time;
  80        u64             min_avg_interval;
  81        u64             max_avg_interval;
  82        u64             hysteresis;
  83        u64             configurable_cap;
  84        u64             min_cap;
  85        u64             max_cap;
  86};
  87
  88struct acpi_power_meter_resource {
  89        struct acpi_device      *acpi_dev;
  90        acpi_bus_id             name;
  91        struct mutex            lock;
  92        struct device           *hwmon_dev;
  93        struct acpi_power_meter_capabilities    caps;
  94        acpi_string             model_number;
  95        acpi_string             serial_number;
  96        acpi_string             oem_info;
  97        u64             power;
  98        u64             cap;
  99        u64             avg_interval;
 100        int                     sensors_valid;
 101        unsigned long           sensors_last_updated;
 102        struct sensor_device_attribute  sensors[NUM_SENSORS];
 103        int                     num_sensors;
 104        s64                     trip[2];
 105        int                     num_domain_devices;
 106        struct acpi_device      **domain_devices;
 107        struct kobject          *holders_dir;
 108};
 109
 110struct sensor_template {
 111        char *label;
 112        ssize_t (*show)(struct device *dev,
 113                        struct device_attribute *devattr,
 114                        char *buf);
 115        ssize_t (*set)(struct device *dev,
 116                       struct device_attribute *devattr,
 117                       const char *buf, size_t count);
 118        int index;
 119};
 120
 121/* Averaging interval */
 122static int update_avg_interval(struct acpi_power_meter_resource *resource)
 123{
 124        unsigned long long data;
 125        acpi_status status;
 126
 127        status = acpi_evaluate_integer(resource->acpi_dev->handle, "_GAI",
 128                                       NULL, &data);
 129        if (ACPI_FAILURE(status)) {
 130                ACPI_EXCEPTION((AE_INFO, status, "Evaluating _GAI"));
 131                return -ENODEV;
 132        }
 133
 134        resource->avg_interval = data;
 135        return 0;
 136}
 137
 138static ssize_t show_avg_interval(struct device *dev,
 139                                 struct device_attribute *devattr,
 140                                 char *buf)
 141{
 142        struct acpi_device *acpi_dev = to_acpi_device(dev);
 143        struct acpi_power_meter_resource *resource = acpi_dev->driver_data;
 144
 145        mutex_lock(&resource->lock);
 146        update_avg_interval(resource);
 147        mutex_unlock(&resource->lock);
 148
 149        return sprintf(buf, "%llu\n", resource->avg_interval);
 150}
 151
 152static ssize_t set_avg_interval(struct device *dev,
 153                                struct device_attribute *devattr,
 154                                const char *buf, size_t count)
 155{
 156        struct acpi_device *acpi_dev = to_acpi_device(dev);
 157        struct acpi_power_meter_resource *resource = acpi_dev->driver_data;
 158        union acpi_object arg0 = { ACPI_TYPE_INTEGER };
 159        struct acpi_object_list args = { 1, &arg0 };
 160        int res;
 161        unsigned long temp;
 162        unsigned long long data;
 163        acpi_status status;
 164
 165        res = kstrtoul(buf, 10, &temp);
 166        if (res)
 167                return res;
 168
 169        if (temp > resource->caps.max_avg_interval ||
 170            temp < resource->caps.min_avg_interval)
 171                return -EINVAL;
 172        arg0.integer.value = temp;
 173
 174        mutex_lock(&resource->lock);
 175        status = acpi_evaluate_integer(resource->acpi_dev->handle, "_PAI",
 176                                       &args, &data);
 177        if (!ACPI_FAILURE(status))
 178                resource->avg_interval = temp;
 179        mutex_unlock(&resource->lock);
 180
 181        if (ACPI_FAILURE(status)) {
 182                ACPI_EXCEPTION((AE_INFO, status, "Evaluating _PAI"));
 183                return -EINVAL;
 184        }
 185
 186        /* _PAI returns 0 on success, nonzero otherwise */
 187        if (data)
 188                return -EINVAL;
 189
 190        return count;
 191}
 192
 193/* Cap functions */
 194static int update_cap(struct acpi_power_meter_resource *resource)
 195{
 196        unsigned long long data;
 197        acpi_status status;
 198
 199        status = acpi_evaluate_integer(resource->acpi_dev->handle, "_GHL",
 200                                       NULL, &data);
 201        if (ACPI_FAILURE(status)) {
 202                ACPI_EXCEPTION((AE_INFO, status, "Evaluating _GHL"));
 203                return -ENODEV;
 204        }
 205
 206        resource->cap = data;
 207        return 0;
 208}
 209
 210static ssize_t show_cap(struct device *dev,
 211                        struct device_attribute *devattr,
 212                        char *buf)
 213{
 214        struct acpi_device *acpi_dev = to_acpi_device(dev);
 215        struct acpi_power_meter_resource *resource = acpi_dev->driver_data;
 216
 217        mutex_lock(&resource->lock);
 218        update_cap(resource);
 219        mutex_unlock(&resource->lock);
 220
 221        return sprintf(buf, "%llu\n", resource->cap * 1000);
 222}
 223
 224static ssize_t set_cap(struct device *dev, struct device_attribute *devattr,
 225                       const char *buf, size_t count)
 226{
 227        struct acpi_device *acpi_dev = to_acpi_device(dev);
 228        struct acpi_power_meter_resource *resource = acpi_dev->driver_data;
 229        union acpi_object arg0 = { ACPI_TYPE_INTEGER };
 230        struct acpi_object_list args = { 1, &arg0 };
 231        int res;
 232        unsigned long temp;
 233        unsigned long long data;
 234        acpi_status status;
 235
 236        res = kstrtoul(buf, 10, &temp);
 237        if (res)
 238                return res;
 239
 240        temp = DIV_ROUND_CLOSEST(temp, 1000);
 241        if (temp > resource->caps.max_cap || temp < resource->caps.min_cap)
 242                return -EINVAL;
 243        arg0.integer.value = temp;
 244
 245        mutex_lock(&resource->lock);
 246        status = acpi_evaluate_integer(resource->acpi_dev->handle, "_SHL",
 247                                       &args, &data);
 248        if (!ACPI_FAILURE(status))
 249                resource->cap = temp;
 250        mutex_unlock(&resource->lock);
 251
 252        if (ACPI_FAILURE(status)) {
 253                ACPI_EXCEPTION((AE_INFO, status, "Evaluating _SHL"));
 254                return -EINVAL;
 255        }
 256
 257        /* _SHL returns 0 on success, nonzero otherwise */
 258        if (data)
 259                return -EINVAL;
 260
 261        return count;
 262}
 263
 264/* Power meter trip points */
 265static int set_acpi_trip(struct acpi_power_meter_resource *resource)
 266{
 267        union acpi_object arg_objs[] = {
 268                {ACPI_TYPE_INTEGER},
 269                {ACPI_TYPE_INTEGER}
 270        };
 271        struct acpi_object_list args = { 2, arg_objs };
 272        unsigned long long data;
 273        acpi_status status;
 274
 275        /* Both trip levels must be set */
 276        if (resource->trip[0] < 0 || resource->trip[1] < 0)
 277                return 0;
 278
 279        /* This driver stores min, max; ACPI wants max, min. */
 280        arg_objs[0].integer.value = resource->trip[1];
 281        arg_objs[1].integer.value = resource->trip[0];
 282
 283        status = acpi_evaluate_integer(resource->acpi_dev->handle, "_PTP",
 284                                       &args, &data);
 285        if (ACPI_FAILURE(status)) {
 286                ACPI_EXCEPTION((AE_INFO, status, "Evaluating _PTP"));
 287                return -EINVAL;
 288        }
 289
 290        /* _PTP returns 0 on success, nonzero otherwise */
 291        if (data)
 292                return -EINVAL;
 293
 294        return 0;
 295}
 296
 297static ssize_t set_trip(struct device *dev, struct device_attribute *devattr,
 298                        const char *buf, size_t count)
 299{
 300        struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
 301        struct acpi_device *acpi_dev = to_acpi_device(dev);
 302        struct acpi_power_meter_resource *resource = acpi_dev->driver_data;
 303        int res;
 304        unsigned long temp;
 305
 306        res = kstrtoul(buf, 10, &temp);
 307        if (res)
 308                return res;
 309
 310        temp = DIV_ROUND_CLOSEST(temp, 1000);
 311
 312        mutex_lock(&resource->lock);
 313        resource->trip[attr->index - 7] = temp;
 314        res = set_acpi_trip(resource);
 315        mutex_unlock(&resource->lock);
 316
 317        if (res)
 318                return res;
 319
 320        return count;
 321}
 322
 323/* Power meter */
 324static int update_meter(struct acpi_power_meter_resource *resource)
 325{
 326        unsigned long long data;
 327        acpi_status status;
 328        unsigned long local_jiffies = jiffies;
 329
 330        if (time_before(local_jiffies, resource->sensors_last_updated +
 331                        msecs_to_jiffies(resource->caps.sampling_time)) &&
 332                        resource->sensors_valid)
 333                return 0;
 334
 335        status = acpi_evaluate_integer(resource->acpi_dev->handle, "_PMM",
 336                                       NULL, &data);
 337        if (ACPI_FAILURE(status)) {
 338                ACPI_EXCEPTION((AE_INFO, status, "Evaluating _PMM"));
 339                return -ENODEV;
 340        }
 341
 342        resource->power = data;
 343        resource->sensors_valid = 1;
 344        resource->sensors_last_updated = jiffies;
 345        return 0;
 346}
 347
 348static ssize_t show_power(struct device *dev,
 349                          struct device_attribute *devattr,
 350                          char *buf)
 351{
 352        struct acpi_device *acpi_dev = to_acpi_device(dev);
 353        struct acpi_power_meter_resource *resource = acpi_dev->driver_data;
 354
 355        mutex_lock(&resource->lock);
 356        update_meter(resource);
 357        mutex_unlock(&resource->lock);
 358
 359        return sprintf(buf, "%llu\n", resource->power * 1000);
 360}
 361
 362/* Miscellaneous */
 363static ssize_t show_str(struct device *dev,
 364                        struct device_attribute *devattr,
 365                        char *buf)
 366{
 367        struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
 368        struct acpi_device *acpi_dev = to_acpi_device(dev);
 369        struct acpi_power_meter_resource *resource = acpi_dev->driver_data;
 370        acpi_string val;
 371
 372        switch (attr->index) {
 373        case 0:
 374                val = resource->model_number;
 375                break;
 376        case 1:
 377                val = resource->serial_number;
 378                break;
 379        case 2:
 380                val = resource->oem_info;
 381                break;
 382        default:
 383                WARN(1, "Implementation error: unexpected attribute index %d\n",
 384                     attr->index);
 385                val = "";
 386                break;
 387        }
 388
 389        return sprintf(buf, "%s\n", val);
 390}
 391
 392static ssize_t show_val(struct device *dev,
 393                        struct device_attribute *devattr,
 394                        char *buf)
 395{
 396        struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
 397        struct acpi_device *acpi_dev = to_acpi_device(dev);
 398        struct acpi_power_meter_resource *resource = acpi_dev->driver_data;
 399        u64 val = 0;
 400
 401        switch (attr->index) {
 402        case 0:
 403                val = resource->caps.min_avg_interval;
 404                break;
 405        case 1:
 406                val = resource->caps.max_avg_interval;
 407                break;
 408        case 2:
 409                val = resource->caps.min_cap * 1000;
 410                break;
 411        case 3:
 412                val = resource->caps.max_cap * 1000;
 413                break;
 414        case 4:
 415                if (resource->caps.hysteresis == UNKNOWN_HYSTERESIS)
 416                        return sprintf(buf, "unknown\n");
 417
 418                val = resource->caps.hysteresis * 1000;
 419                break;
 420        case 5:
 421                if (resource->caps.flags & POWER_METER_IS_BATTERY)
 422                        val = 1;
 423                else
 424                        val = 0;
 425                break;
 426        case 6:
 427                if (resource->power > resource->cap)
 428                        val = 1;
 429                else
 430                        val = 0;
 431                break;
 432        case 7:
 433        case 8:
 434                if (resource->trip[attr->index - 7] < 0)
 435                        return sprintf(buf, "unknown\n");
 436
 437                val = resource->trip[attr->index - 7] * 1000;
 438                break;
 439        default:
 440                WARN(1, "Implementation error: unexpected attribute index %d\n",
 441                     attr->index);
 442                break;
 443        }
 444
 445        return sprintf(buf, "%llu\n", val);
 446}
 447
 448static ssize_t show_accuracy(struct device *dev,
 449                             struct device_attribute *devattr,
 450                             char *buf)
 451{
 452        struct acpi_device *acpi_dev = to_acpi_device(dev);
 453        struct acpi_power_meter_resource *resource = acpi_dev->driver_data;
 454        unsigned int acc = resource->caps.accuracy;
 455
 456        return sprintf(buf, "%u.%u%%\n", acc / 1000, acc % 1000);
 457}
 458
 459static ssize_t show_name(struct device *dev,
 460                         struct device_attribute *devattr,
 461                         char *buf)
 462{
 463        return sprintf(buf, "%s\n", ACPI_POWER_METER_NAME);
 464}
 465
 466#define RO_SENSOR_TEMPLATE(_label, _show, _index)       \
 467        {                                               \
 468                .label = _label,                        \
 469                .show  = _show,                         \
 470                .index = _index,                        \
 471        }
 472
 473#define RW_SENSOR_TEMPLATE(_label, _show, _set, _index) \
 474        {                                               \
 475                .label = _label,                        \
 476                .show  = _show,                         \
 477                .set   = _set,                          \
 478                .index = _index,                        \
 479        }
 480
 481/* Sensor descriptions.  If you add a sensor, update NUM_SENSORS above! */
 482static struct sensor_template meter_attrs[] = {
 483        RO_SENSOR_TEMPLATE(POWER_AVERAGE_NAME, show_power, 0),
 484        RO_SENSOR_TEMPLATE("power1_accuracy", show_accuracy, 0),
 485        RO_SENSOR_TEMPLATE("power1_average_interval_min", show_val, 0),
 486        RO_SENSOR_TEMPLATE("power1_average_interval_max", show_val, 1),
 487        RO_SENSOR_TEMPLATE("power1_is_battery", show_val, 5),
 488        RW_SENSOR_TEMPLATE(POWER_AVG_INTERVAL_NAME, show_avg_interval,
 489                set_avg_interval, 0),
 490        {},
 491};
 492
 493static struct sensor_template misc_cap_attrs[] = {
 494        RO_SENSOR_TEMPLATE("power1_cap_min", show_val, 2),
 495        RO_SENSOR_TEMPLATE("power1_cap_max", show_val, 3),
 496        RO_SENSOR_TEMPLATE("power1_cap_hyst", show_val, 4),
 497        RO_SENSOR_TEMPLATE(POWER_ALARM_NAME, show_val, 6),
 498        {},
 499};
 500
 501static struct sensor_template ro_cap_attrs[] = {
 502        RO_SENSOR_TEMPLATE(POWER_CAP_NAME, show_cap, 0),
 503        {},
 504};
 505
 506static struct sensor_template rw_cap_attrs[] = {
 507        RW_SENSOR_TEMPLATE(POWER_CAP_NAME, show_cap, set_cap, 0),
 508        {},
 509};
 510
 511static struct sensor_template trip_attrs[] = {
 512        RW_SENSOR_TEMPLATE("power1_average_min", show_val, set_trip, 7),
 513        RW_SENSOR_TEMPLATE("power1_average_max", show_val, set_trip, 8),
 514        {},
 515};
 516
 517static struct sensor_template misc_attrs[] = {
 518        RO_SENSOR_TEMPLATE("name", show_name, 0),
 519        RO_SENSOR_TEMPLATE("power1_model_number", show_str, 0),
 520        RO_SENSOR_TEMPLATE("power1_oem_info", show_str, 2),
 521        RO_SENSOR_TEMPLATE("power1_serial_number", show_str, 1),
 522        {},
 523};
 524
 525#undef RO_SENSOR_TEMPLATE
 526#undef RW_SENSOR_TEMPLATE
 527
 528/* Read power domain data */
 529static void remove_domain_devices(struct acpi_power_meter_resource *resource)
 530{
 531        int i;
 532
 533        if (!resource->num_domain_devices)
 534                return;
 535
 536        for (i = 0; i < resource->num_domain_devices; i++) {
 537                struct acpi_device *obj = resource->domain_devices[i];
 538                if (!obj)
 539                        continue;
 540
 541                sysfs_remove_link(resource->holders_dir,
 542                                  kobject_name(&obj->dev.kobj));
 543                put_device(&obj->dev);
 544        }
 545
 546        kfree(resource->domain_devices);
 547        kobject_put(resource->holders_dir);
 548        resource->num_domain_devices = 0;
 549}
 550
 551static int read_domain_devices(struct acpi_power_meter_resource *resource)
 552{
 553        int res = 0;
 554        int i;
 555        struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
 556        union acpi_object *pss;
 557        acpi_status status;
 558
 559        status = acpi_evaluate_object(resource->acpi_dev->handle, "_PMD", NULL,
 560                                      &buffer);
 561        if (ACPI_FAILURE(status)) {
 562                ACPI_EXCEPTION((AE_INFO, status, "Evaluating _PMD"));
 563                return -ENODEV;
 564        }
 565
 566        pss = buffer.pointer;
 567        if (!pss ||
 568            pss->type != ACPI_TYPE_PACKAGE) {
 569                dev_err(&resource->acpi_dev->dev, ACPI_POWER_METER_NAME
 570                        "Invalid _PMD data\n");
 571                res = -EFAULT;
 572                goto end;
 573        }
 574
 575        if (!pss->package.count)
 576                goto end;
 577
 578        resource->domain_devices = kcalloc(pss->package.count,
 579                                           sizeof(struct acpi_device *),
 580                                           GFP_KERNEL);
 581        if (!resource->domain_devices) {
 582                res = -ENOMEM;
 583                goto end;
 584        }
 585
 586        resource->holders_dir = kobject_create_and_add("measures",
 587                                        &resource->acpi_dev->dev.kobj);
 588        if (!resource->holders_dir) {
 589                res = -ENOMEM;
 590                goto exit_free;
 591        }
 592
 593        resource->num_domain_devices = pss->package.count;
 594
 595        for (i = 0; i < pss->package.count; i++) {
 596                struct acpi_device *obj;
 597                union acpi_object *element = &(pss->package.elements[i]);
 598
 599                /* Refuse non-references */
 600                if (element->type != ACPI_TYPE_LOCAL_REFERENCE)
 601                        continue;
 602
 603                /* Create a symlink to domain objects */
 604                resource->domain_devices[i] = NULL;
 605                if (acpi_bus_get_device(element->reference.handle,
 606                                        &resource->domain_devices[i]))
 607                        continue;
 608
 609                obj = resource->domain_devices[i];
 610                get_device(&obj->dev);
 611
 612                res = sysfs_create_link(resource->holders_dir, &obj->dev.kobj,
 613                                      kobject_name(&obj->dev.kobj));
 614                if (res) {
 615                        put_device(&obj->dev);
 616                        resource->domain_devices[i] = NULL;
 617                }
 618        }
 619
 620        res = 0;
 621        goto end;
 622
 623exit_free:
 624        kfree(resource->domain_devices);
 625end:
 626        kfree(buffer.pointer);
 627        return res;
 628}
 629
 630/* Registration and deregistration */
 631static int register_attrs(struct acpi_power_meter_resource *resource,
 632                          struct sensor_template *attrs)
 633{
 634        struct device *dev = &resource->acpi_dev->dev;
 635        struct sensor_device_attribute *sensors =
 636                &resource->sensors[resource->num_sensors];
 637        int res = 0;
 638
 639        while (attrs->label) {
 640                sensors->dev_attr.attr.name = attrs->label;
 641                sensors->dev_attr.attr.mode = S_IRUGO;
 642                sensors->dev_attr.show = attrs->show;
 643                sensors->index = attrs->index;
 644
 645                if (attrs->set) {
 646                        sensors->dev_attr.attr.mode |= S_IWUSR;
 647                        sensors->dev_attr.store = attrs->set;
 648                }
 649
 650                sysfs_attr_init(&sensors->dev_attr.attr);
 651                res = device_create_file(dev, &sensors->dev_attr);
 652                if (res) {
 653                        sensors->dev_attr.attr.name = NULL;
 654                        goto error;
 655                }
 656                sensors++;
 657                resource->num_sensors++;
 658                attrs++;
 659        }
 660
 661error:
 662        return res;
 663}
 664
 665static void remove_attrs(struct acpi_power_meter_resource *resource)
 666{
 667        int i;
 668
 669        for (i = 0; i < resource->num_sensors; i++) {
 670                if (!resource->sensors[i].dev_attr.attr.name)
 671                        continue;
 672                device_remove_file(&resource->acpi_dev->dev,
 673                                   &resource->sensors[i].dev_attr);
 674        }
 675
 676        remove_domain_devices(resource);
 677
 678        resource->num_sensors = 0;
 679}
 680
 681static int setup_attrs(struct acpi_power_meter_resource *resource)
 682{
 683        int res = 0;
 684
 685        res = read_domain_devices(resource);
 686        if (res)
 687                return res;
 688
 689        if (resource->caps.flags & POWER_METER_CAN_MEASURE) {
 690                res = register_attrs(resource, meter_attrs);
 691                if (res)
 692                        goto error;
 693        }
 694
 695        if (resource->caps.flags & POWER_METER_CAN_CAP) {
 696                if (!can_cap_in_hardware()) {
 697                        dev_err(&resource->acpi_dev->dev,
 698                                "Ignoring unsafe software power cap!\n");
 699                        goto skip_unsafe_cap;
 700                }
 701
 702                if (resource->caps.configurable_cap)
 703                        res = register_attrs(resource, rw_cap_attrs);
 704                else
 705                        res = register_attrs(resource, ro_cap_attrs);
 706
 707                if (res)
 708                        goto error;
 709
 710                res = register_attrs(resource, misc_cap_attrs);
 711                if (res)
 712                        goto error;
 713        }
 714
 715skip_unsafe_cap:
 716        if (resource->caps.flags & POWER_METER_CAN_TRIP) {
 717                res = register_attrs(resource, trip_attrs);
 718                if (res)
 719                        goto error;
 720        }
 721
 722        res = register_attrs(resource, misc_attrs);
 723        if (res)
 724                goto error;
 725
 726        return res;
 727error:
 728        remove_attrs(resource);
 729        return res;
 730}
 731
 732static void free_capabilities(struct acpi_power_meter_resource *resource)
 733{
 734        acpi_string *str;
 735        int i;
 736
 737        str = &resource->model_number;
 738        for (i = 0; i < 3; i++, str++)
 739                kfree(*str);
 740}
 741
 742static int read_capabilities(struct acpi_power_meter_resource *resource)
 743{
 744        int res = 0;
 745        int i;
 746        struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
 747        struct acpi_buffer state = { 0, NULL };
 748        struct acpi_buffer format = { sizeof("NNNNNNNNNNN"), "NNNNNNNNNNN" };
 749        union acpi_object *pss;
 750        acpi_string *str;
 751        acpi_status status;
 752
 753        status = acpi_evaluate_object(resource->acpi_dev->handle, "_PMC", NULL,
 754                                      &buffer);
 755        if (ACPI_FAILURE(status)) {
 756                ACPI_EXCEPTION((AE_INFO, status, "Evaluating _PMC"));
 757                return -ENODEV;
 758        }
 759
 760        pss = buffer.pointer;
 761        if (!pss ||
 762            pss->type != ACPI_TYPE_PACKAGE ||
 763            pss->package.count != 14) {
 764                dev_err(&resource->acpi_dev->dev, ACPI_POWER_METER_NAME
 765                        "Invalid _PMC data\n");
 766                res = -EFAULT;
 767                goto end;
 768        }
 769
 770        /* Grab all the integer data at once */
 771        state.length = sizeof(struct acpi_power_meter_capabilities);
 772        state.pointer = &resource->caps;
 773
 774        status = acpi_extract_package(pss, &format, &state);
 775        if (ACPI_FAILURE(status)) {
 776                ACPI_EXCEPTION((AE_INFO, status, "Invalid data"));
 777                res = -EFAULT;
 778                goto end;
 779        }
 780
 781        if (resource->caps.units) {
 782                dev_err(&resource->acpi_dev->dev, ACPI_POWER_METER_NAME
 783                        "Unknown units %llu.\n",
 784                        resource->caps.units);
 785                res = -EINVAL;
 786                goto end;
 787        }
 788
 789        /* Grab the string data */
 790        str = &resource->model_number;
 791
 792        for (i = 11; i < 14; i++) {
 793                union acpi_object *element = &(pss->package.elements[i]);
 794
 795                if (element->type != ACPI_TYPE_STRING) {
 796                        res = -EINVAL;
 797                        goto error;
 798                }
 799
 800                *str = kcalloc(element->string.length + 1, sizeof(u8),
 801                               GFP_KERNEL);
 802                if (!*str) {
 803                        res = -ENOMEM;
 804                        goto error;
 805                }
 806
 807                strncpy(*str, element->string.pointer, element->string.length);
 808                str++;
 809        }
 810
 811        dev_info(&resource->acpi_dev->dev, "Found ACPI power meter.\n");
 812        goto end;
 813error:
 814        str = &resource->model_number;
 815        for (i = 0; i < 3; i++, str++)
 816                kfree(*str);
 817end:
 818        kfree(buffer.pointer);
 819        return res;
 820}
 821
 822/* Handle ACPI event notifications */
 823static void acpi_power_meter_notify(struct acpi_device *device, u32 event)
 824{
 825        struct acpi_power_meter_resource *resource;
 826        int res;
 827
 828        if (!device || !acpi_driver_data(device))
 829                return;
 830
 831        resource = acpi_driver_data(device);
 832
 833        mutex_lock(&resource->lock);
 834        switch (event) {
 835        case METER_NOTIFY_CONFIG:
 836                free_capabilities(resource);
 837                res = read_capabilities(resource);
 838                if (res)
 839                        break;
 840
 841                remove_attrs(resource);
 842                setup_attrs(resource);
 843                break;
 844        case METER_NOTIFY_TRIP:
 845                sysfs_notify(&device->dev.kobj, NULL, POWER_AVERAGE_NAME);
 846                update_meter(resource);
 847                break;
 848        case METER_NOTIFY_CAP:
 849                sysfs_notify(&device->dev.kobj, NULL, POWER_CAP_NAME);
 850                update_cap(resource);
 851                break;
 852        case METER_NOTIFY_INTERVAL:
 853                sysfs_notify(&device->dev.kobj, NULL, POWER_AVG_INTERVAL_NAME);
 854                update_avg_interval(resource);
 855                break;
 856        case METER_NOTIFY_CAPPING:
 857                sysfs_notify(&device->dev.kobj, NULL, POWER_ALARM_NAME);
 858                dev_info(&device->dev, "Capping in progress.\n");
 859                break;
 860        default:
 861                WARN(1, "Unexpected event %d\n", event);
 862                break;
 863        }
 864        mutex_unlock(&resource->lock);
 865
 866        acpi_bus_generate_netlink_event(ACPI_POWER_METER_CLASS,
 867                                        dev_name(&device->dev), event, 0);
 868}
 869
 870static int acpi_power_meter_add(struct acpi_device *device)
 871{
 872        int res;
 873        struct acpi_power_meter_resource *resource;
 874
 875        if (!device)
 876                return -EINVAL;
 877
 878        resource = kzalloc(sizeof(struct acpi_power_meter_resource),
 879                           GFP_KERNEL);
 880        if (!resource)
 881                return -ENOMEM;
 882
 883        resource->sensors_valid = 0;
 884        resource->acpi_dev = device;
 885        mutex_init(&resource->lock);
 886        strcpy(acpi_device_name(device), ACPI_POWER_METER_DEVICE_NAME);
 887        strcpy(acpi_device_class(device), ACPI_POWER_METER_CLASS);
 888        device->driver_data = resource;
 889
 890        free_capabilities(resource);
 891        res = read_capabilities(resource);
 892        if (res)
 893                goto exit_free;
 894
 895        resource->trip[0] = resource->trip[1] = -1;
 896
 897        res = setup_attrs(resource);
 898        if (res)
 899                goto exit_free;
 900
 901        resource->hwmon_dev = hwmon_device_register(&device->dev);
 902        if (IS_ERR(resource->hwmon_dev)) {
 903                res = PTR_ERR(resource->hwmon_dev);
 904                goto exit_remove;
 905        }
 906
 907        res = 0;
 908        goto exit;
 909
 910exit_remove:
 911        remove_attrs(resource);
 912exit_free:
 913        kfree(resource);
 914exit:
 915        return res;
 916}
 917
 918static int acpi_power_meter_remove(struct acpi_device *device)
 919{
 920        struct acpi_power_meter_resource *resource;
 921
 922        if (!device || !acpi_driver_data(device))
 923                return -EINVAL;
 924
 925        resource = acpi_driver_data(device);
 926        hwmon_device_unregister(resource->hwmon_dev);
 927
 928        free_capabilities(resource);
 929        remove_attrs(resource);
 930
 931        kfree(resource);
 932        return 0;
 933}
 934
 935#ifdef CONFIG_PM_SLEEP
 936
 937static int acpi_power_meter_resume(struct device *dev)
 938{
 939        struct acpi_power_meter_resource *resource;
 940
 941        if (!dev)
 942                return -EINVAL;
 943
 944        resource = acpi_driver_data(to_acpi_device(dev));
 945        if (!resource)
 946                return -EINVAL;
 947
 948        free_capabilities(resource);
 949        read_capabilities(resource);
 950
 951        return 0;
 952}
 953
 954#endif /* CONFIG_PM_SLEEP */
 955
 956static SIMPLE_DEV_PM_OPS(acpi_power_meter_pm, NULL, acpi_power_meter_resume);
 957
 958static struct acpi_driver acpi_power_meter_driver = {
 959        .name = "power_meter",
 960        .class = ACPI_POWER_METER_CLASS,
 961        .ids = power_meter_ids,
 962        .ops = {
 963                .add = acpi_power_meter_add,
 964                .remove = acpi_power_meter_remove,
 965                .notify = acpi_power_meter_notify,
 966                },
 967        .drv.pm = &acpi_power_meter_pm,
 968};
 969
 970/* Module init/exit routines */
 971static int __init enable_cap_knobs(const struct dmi_system_id *d)
 972{
 973        cap_in_hardware = 1;
 974        return 0;
 975}
 976
 977static const struct dmi_system_id pm_dmi_table[] __initconst = {
 978        {
 979                enable_cap_knobs, "IBM Active Energy Manager",
 980                {
 981                        DMI_MATCH(DMI_SYS_VENDOR, "IBM")
 982                },
 983        },
 984        {}
 985};
 986
 987static int __init acpi_power_meter_init(void)
 988{
 989        int result;
 990
 991        if (acpi_disabled)
 992                return -ENODEV;
 993
 994        dmi_check_system(pm_dmi_table);
 995
 996        result = acpi_bus_register_driver(&acpi_power_meter_driver);
 997        if (result < 0)
 998                return result;
 999
1000        return 0;
1001}
1002
1003static void __exit acpi_power_meter_exit(void)
1004{
1005        acpi_bus_unregister_driver(&acpi_power_meter_driver);
1006}
1007
1008MODULE_AUTHOR("Darrick J. Wong <darrick.wong@oracle.com>");
1009MODULE_DESCRIPTION("ACPI 4.0 power meter driver");
1010MODULE_LICENSE("GPL");
1011
1012module_param(force_cap_on, bool, 0644);
1013MODULE_PARM_DESC(force_cap_on, "Enable power cap even it is unsafe to do so.");
1014
1015module_init(acpi_power_meter_init);
1016module_exit(acpi_power_meter_exit);
1017