drivers/hwmon/acpi_power_meter.c

   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"
  37 ACPI_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
  61 static int cap_in_hardware;
  62 static bool force_cap_on;
  63
  64 static int can_cap_in_hardware(void)
  65 {
  66         return force_cap_on || cap_in_hardware;
  67 }
  68
  69 static const struct acpi_device_id power_meter_ids[] = {
  70         {"ACPI000D", 0},
  71         {"", 0},
  72 };
  73 MODULE_DEVICE_TABLE(acpi, power_meter_ids);
  74
  75 struct 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
  89 struct 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
 111 struct 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 */
 123 static 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
 139 static 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
 153 static 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 */
 195 static 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
 211 static 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
 225 static 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 */
 266 static 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
 298 static 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 */
 325 static 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
 349 static 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 */
 364 static 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
 391 static 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
 445 static 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
 456 static 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! */
 479 static 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
 490 static 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
 498 static struct sensor_template ro_cap_attrs[] = {
 499         RO_SENSOR_TEMPLATE(POWER_CAP_NAME, show_cap, 0),
 500         {},
 501 };
 502
 503 static struct sensor_template rw_cap_attrs[] = {
 504         RW_SENSOR_TEMPLATE(POWER_CAP_NAME, show_cap, set_cap, 0),
 505         {},
 506 };
 507
 508 static 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
 514 static 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 */
 526 static 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
 548 static 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
 620 exit_free:
 621         kfree(resource->domain_devices);
 622 end:
 623         kfree(buffer.pointer);
 624         return res;
 625 }
 626
 627 /* Registration and deregistration */
 628 static 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
 658 error:
 659         return res;
 660 }
 661
 662 static 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
 678 static 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
 712 skip_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;
 724 error:
 725         remove_attrs(resource);
 726         return res;
 727 }
 728
 729 static 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
 739 static 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;
 810 error:
 811         str = &resource->model_number;
 812         for (i = 0; i < 3; i++, str++)
 813                 kfree(*str);
 814 end:
 815         kfree(buffer.pointer);
 816         return res;
 817 }
 818
 819 /* Handle ACPI event notifications */
 820 static 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
 866 static 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
 906 exit_remove:
 907         remove_attrs(resource);
 908 exit_free:
 909         kfree(resource);
 910 exit:
 911         return res;
 912 }
 913
 914 static int acpi_power_meter_remove(struct acpi_device *device)
 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
 933 static 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
 952 static SIMPLE_DEV_PM_OPS(acpi_power_meter_pm, NULL, acpi_power_meter_resume);
 953
 954 static 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 */
 967 static int __init enable_cap_knobs(const struct dmi_system_id *d)
 968 {
 969         cap_in_hardware = 1;
 970         return 0;
 971 }
 972
 973 static 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
 983 static 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
 999 static void __exit acpi_power_meter_exit(void)
1000 {
1001         acpi_bus_unregister_driver(&acpi_power_meter_driver);
1002 }
1003
1004 MODULE_AUTHOR("Darrick J. Wong <djwong@us.ibm.com>");
1005 MODULE_DESCRIPTION("ACPI 4.0 power meter driver");
1006 MODULE_LICENSE("GPL");
1007
1008 module_param(force_cap_on, bool, 0644);
1009 MODULE_PARM_DESC(force_cap_on, "Enable power cap even it is unsafe to do so.");
1010
1011 module_init(acpi_power_meter_init);
1012 module_exit(acpi_power_meter_exit);