src/battery.c

   1 /**
   2  * collectd - src/battery.c
   3  * Copyright (C) 2006-2014  Florian octo Forster
   4  * Copyright (C) 2008       Michał Mirosław
   5  * Copyright (C) 2014       Andy Parkins
   6  *
   7  * This program is free software; you can redistribute it and/or modify it
   8  * under the terms of the GNU General Public License as published by the
   9  * Free Software Foundation; only version 2 of the License is applicable.
  10  *
  11  * This program is distributed in the hope that it will be useful, but
  12  * WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14  * General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU General Public License along
  17  * with this program; if not, write to the Free Software Foundation, Inc.,
  18  * 51 Franklin St, Fifth Floor, Boston, MA  02110-1301 USA
  19  *
  20  * Authors:
  21  *   Florian octo Forster <octo at collectd.org>
  22  *   Michał Mirosław <mirq-linux at rere.qmqm.pl>
  23  *   Andy Parkins <andyp at fussylogic.co.uk>
  24  **/
  25
  26 #include "collectd.h"
  27 #include "common.h"
  28 #include "plugin.h"
  29
  30 #include "utils_complain.h"
  31
  32 #if HAVE_MACH_MACH_TYPES_H
  33 #  include <mach/mach_types.h>
  34 #endif
  35 #if HAVE_MACH_MACH_INIT_H
  36 #  include <mach/mach_init.h>
  37 #endif
  38 #if HAVE_MACH_MACH_ERROR_H
  39 #  include <mach/mach_error.h>
  40 #endif
  41 #if HAVE_COREFOUNDATION_COREFOUNDATION_H
  42 #  include <CoreFoundation/CoreFoundation.h>
  43 #endif
  44 #if HAVE_IOKIT_IOKITLIB_H
  45 #  include <IOKit/IOKitLib.h>
  46 #endif
  47 #if HAVE_IOKIT_IOTYPES_H
  48 #  include <IOKit/IOTypes.h>
  49 #endif
  50 #if HAVE_IOKIT_PS_IOPOWERSOURCES_H
  51 #  include <IOKit/ps/IOPowerSources.h>
  52 #endif
  53 #if HAVE_IOKIT_PS_IOPSKEYS_H
  54 #  include <IOKit/ps/IOPSKeys.h>
  55 #endif
  56
  57 #if !HAVE_IOKIT_IOKITLIB_H && !HAVE_IOKIT_PS_IOPOWERSOURCES_H && !KERNEL_LINUX
  58 # error "No applicable input method."
  59 #endif
  60
  61 #if HAVE_IOKIT_IOKITLIB_H || HAVE_IOKIT_PS_IOPOWERSOURCES_H
  62         /* No global variables */
  63 /* #endif HAVE_IOKIT_IOKITLIB_H || HAVE_IOKIT_PS_IOPOWERSOURCES_H */
  64
  65 #elif KERNEL_LINUX
  66 # define PROC_PMU_PATH_FORMAT "/proc/pmu/battery_%i"
  67 # define PROC_ACPI_PATH "/proc/acpi/battery"
  68 # define PROC_ACPI_FACTOR 0.001
  69 # define SYSFS_PATH "/sys/class/power_supply"
  70 # define SYSFS_FACTOR 0.000001
  71 #endif /* KERNEL_LINUX */
  72
  73 static _Bool report_percent = 0;
  74 static _Bool report_degraded = 0;
  75
  76 static void battery_submit2 (char const *plugin_instance, /* {{{ */
  77                 char const *type, char const *type_instance, gauge_t value)
  78 {
  79         value_t values[1];
  80         value_list_t vl = VALUE_LIST_INIT;
  81
  82         values[0].gauge = value;
  83
  84         vl.values = values;
  85         vl.values_len = 1;
  86         sstrncpy (vl.host, hostname_g, sizeof (vl.host));
  87         sstrncpy (vl.plugin, "battery", sizeof (vl.plugin));
  88         sstrncpy (vl.plugin_instance, plugin_instance, sizeof (vl.plugin_instance));
  89         sstrncpy (vl.type, type, sizeof (vl.type));
  90         if (type_instance != NULL)
  91                 sstrncpy (vl.type_instance, type_instance, sizeof (vl.type_instance));
  92
  93         plugin_dispatch_values (&vl);
  94 } /* }}} void battery_submit2 */
  95
  96 static void battery_submit (char const *plugin_instance, /* {{{ */
  97                 char const *type, gauge_t value)
  98 {
  99         battery_submit2 (plugin_instance, type, NULL, value);
 100 } /* }}} void battery_submit */
 101
 102 static void submit_capacity (char const *plugin_instance, /* {{{ */
 103                 gauge_t capacity_charged,
 104                 gauge_t capacity_full,
 105                 gauge_t capacity_design)
 106 {
 107         if (report_percent && (capacity_charged > capacity_full))
 108                 return;
 109         if (report_degraded && (capacity_full > capacity_design))
 110                 return;
 111
 112         if (report_percent)
 113         {
 114                 gauge_t capacity_max;
 115
 116                 if (report_degraded)
 117                         capacity_max = capacity_design;
 118                 else
 119                         capacity_max = capacity_full;
 120
 121                 battery_submit2 (plugin_instance, "percent", "charged",
 122                                 100.0 * capacity_charged / capacity_max);
 123                 battery_submit2 (plugin_instance, "percent", "discharged",
 124                                 100.0 * (capacity_full - capacity_charged) / capacity_max);
 125
 126                 if (report_degraded)
 127                         battery_submit2 (plugin_instance, "percent", "degraded",
 128                                         100.0 * (capacity_design - capacity_full) / capacity_max);
 129         }
 130         else if (report_degraded) /* && !report_percent */
 131         {
 132                 battery_submit2 (plugin_instance, "capacity", "charged",
 133                                 capacity_charged);
 134                 battery_submit2 (plugin_instance, "capacity", "discharged",
 135                                 (capacity_full - capacity_charged));
 136                 battery_submit2 (plugin_instance, "capacity", "degraded",
 137                                 (capacity_design - capacity_full));
 138         }
 139         else /* !report_percent && !report_degraded */
 140         {
 141                 battery_submit (plugin_instance, "capacity", capacity_charged);
 142         }
 143 } /* }}} void submit_capacity */
 144
 145 #if HAVE_IOKIT_PS_IOPOWERSOURCES_H || HAVE_IOKIT_IOKITLIB_H
 146 static double dict_get_double (CFDictionaryRef dict, const char *key_string) /* {{{ */
 147 {
 148         double      val_double;
 149         long long   val_int;
 150         CFNumberRef val_obj;
 151         CFStringRef key_obj;
 152
 153         key_obj = CFStringCreateWithCString (kCFAllocatorDefault, key_string,
 154                         kCFStringEncodingASCII);
 155         if (key_obj == NULL)
 156         {
 157                 DEBUG ("CFStringCreateWithCString (%s) failed.\n", key_string);
 158                 return (NAN);
 159         }
 160
 161         if ((val_obj = CFDictionaryGetValue (dict, key_obj)) == NULL)
 162         {
 163                 DEBUG ("CFDictionaryGetValue (%s) failed.", key_string);
 164                 CFRelease (key_obj);
 165                 return (NAN);
 166         }
 167         CFRelease (key_obj);
 168
 169         if (CFGetTypeID (val_obj) == CFNumberGetTypeID ())
 170         {
 171                 if (CFNumberIsFloatType (val_obj))
 172                 {
 173                         CFNumberGetValue (val_obj,
 174                                         kCFNumberDoubleType,
 175                                         &val_double);
 176                 }
 177                 else
 178                 {
 179                         CFNumberGetValue (val_obj,
 180                                         kCFNumberLongLongType,
 181                                         &val_int);
 182                         val_double = val_int;
 183                 }
 184         }
 185         else
 186         {
 187                 DEBUG ("CFGetTypeID (val_obj) = %i", (int) CFGetTypeID (val_obj));
 188                 return (NAN);
 189         }
 190
 191         return (val_double);
 192 } /* }}} double dict_get_double */
 193
 194 # if HAVE_IOKIT_PS_IOPOWERSOURCES_H
 195 static void get_via_io_power_sources (double *ret_charge, /* {{{ */
 196                 double *ret_current,
 197                 double *ret_voltage)
 198 {
 199         CFTypeRef       ps_raw;
 200         CFArrayRef      ps_array;
 201         int             ps_array_len;
 202         CFDictionaryRef ps_dict;
 203         CFTypeRef       ps_obj;
 204
 205         double temp_double;
 206         int i;
 207
 208         ps_raw       = IOPSCopyPowerSourcesInfo ();
 209         ps_array     = IOPSCopyPowerSourcesList (ps_raw);
 210         ps_array_len = CFArrayGetCount (ps_array);
 211
 212         DEBUG ("ps_array_len == %i", ps_array_len);
 213
 214         for (i = 0; i < ps_array_len; i++)
 215         {
 216                 ps_obj  = CFArrayGetValueAtIndex (ps_array, i);
 217                 ps_dict = IOPSGetPowerSourceDescription (ps_raw, ps_obj);
 218
 219                 if (ps_dict == NULL)
 220                 {
 221                         DEBUG ("IOPSGetPowerSourceDescription failed.");
 222                         continue;
 223                 }
 224
 225                 if (CFGetTypeID (ps_dict) != CFDictionaryGetTypeID ())
 226                 {
 227                         DEBUG ("IOPSGetPowerSourceDescription did not return a CFDictionaryRef");
 228                         continue;
 229                 }
 230
 231                 /* FIXME: Check if this is really an internal battery */
 232
 233                 if (isnan (*ret_charge))
 234                 {
 235                         /* This is the charge in percent. */
 236                         temp_double = dict_get_double (ps_dict,
 237                                         kIOPSCurrentCapacityKey);
 238                         if (!isnan ((temp_double))
 239                                         && (temp_double >= 0.0)
 240                                         && (temp_double <= 100.0))
 241                                 *ret_charge = temp_double;
 242                 }
 243
 244                 if (isnan (*ret_current))
 245                 {
 246                         temp_double = dict_get_double (ps_dict,
 247                                         kIOPSCurrentKey);
 248                         if (!isnan (temp_double))
 249                                 *ret_current = temp_double / 1000.0;
 250                 }
 251
 252                 if (isnan (*ret_voltage))
 253                 {
 254                         temp_double = dict_get_double (ps_dict,
 255                                         kIOPSVoltageKey);
 256                         if (!isnan (temp_double))
 257                                 *ret_voltage = temp_double / 1000.0;
 258                 }
 259         }
 260
 261         CFRelease(ps_array);
 262         CFRelease(ps_raw);
 263 } /* }}} void get_via_io_power_sources */
 264 # endif /* HAVE_IOKIT_PS_IOPOWERSOURCES_H */
 265
 266 # if HAVE_IOKIT_IOKITLIB_H
 267 static void get_via_generic_iokit (double *ret_capacity_full, /* {{{ */
 268                 double *ret_capacity_design,
 269                 double *ret_current,
 270                 double *ret_voltage)
 271 {
 272         kern_return_t   status;
 273         io_iterator_t   iterator;
 274         io_object_t     io_obj;
 275
 276         CFDictionaryRef bat_root_dict;
 277         CFArrayRef      bat_info_arry;
 278         CFIndex         bat_info_arry_len;
 279         CFIndex         bat_info_arry_pos;
 280         CFDictionaryRef bat_info_dict;
 281
 282         double temp_double;
 283
 284         status = IOServiceGetMatchingServices (kIOMasterPortDefault,
 285                         IOServiceNameMatching ("battery"),
 286                         &iterator);
 287         if (status != kIOReturnSuccess)
 288         {
 289                 DEBUG ("IOServiceGetMatchingServices failed.");
 290                 return;
 291         }
 292
 293         while ((io_obj = IOIteratorNext (iterator)))
 294         {
 295                 status = IORegistryEntryCreateCFProperties (io_obj,
 296                                 (CFMutableDictionaryRef *) &bat_root_dict,
 297                                 kCFAllocatorDefault,
 298                                 kNilOptions);
 299                 if (status != kIOReturnSuccess)
 300                 {
 301                         DEBUG ("IORegistryEntryCreateCFProperties failed.");
 302                         continue;
 303                 }
 304
 305                 bat_info_arry = (CFArrayRef) CFDictionaryGetValue (bat_root_dict,
 306                                 CFSTR ("IOBatteryInfo"));
 307                 if (bat_info_arry == NULL)
 308                 {
 309                         CFRelease (bat_root_dict);
 310                         continue;
 311                 }
 312                 bat_info_arry_len = CFArrayGetCount (bat_info_arry);
 313
 314                 for (bat_info_arry_pos = 0;
 315                                 bat_info_arry_pos < bat_info_arry_len;
 316                                 bat_info_arry_pos++)
 317                 {
 318                         bat_info_dict = (CFDictionaryRef) CFArrayGetValueAtIndex (bat_info_arry, bat_info_arry_pos);
 319
 320                         if (isnan (*ret_capacity_full))
 321                         {
 322                                 temp_double = dict_get_double (bat_info_dict, "Capacity");
 323                                 *ret_capacity_full = temp_double / 1000.0;
 324                         }
 325
 326                         if (isnan (*ret_capacity_design))
 327                         {
 328                                 temp_double = dict_get_double (bat_info_dict, "AbsoluteMaxCapacity");
 329                                 *ret_capacity_design = temp_double / 1000.0;
 330                         }
 331
 332                         if (isnan (*ret_current))
 333                         {
 334                                 temp_double = dict_get_double (bat_info_dict, "Current");
 335                                 *ret_current = temp_double / 1000.0;
 336                         }
 337
 338                         if (isnan (*ret_voltage))
 339                         {
 340                                 temp_double = dict_get_double (bat_info_dict, "Voltage");
 341                                 *ret_voltage = temp_double / 1000.0;
 342                         }
 343                 }
 344
 345                 CFRelease (bat_root_dict);
 346         }
 347
 348         IOObjectRelease (iterator);
 349 } /* }}} void get_via_generic_iokit */
 350 # endif /* HAVE_IOKIT_IOKITLIB_H */
 351
 352 static int battery_read (void) /* {{{ */
 353 {
 354         gauge_t current = NAN; /* Current in A */
 355         gauge_t voltage = NAN; /* Voltage in V */
 356
 357         /* We only get the charged capacity as a percentage from
 358          * IOPowerSources. IOKit, on the other hand, only reports the full
 359          * capacity. We use the two to calculate the current charged capacity. */
 360         gauge_t charge_rel = NAN; /* Current charge in percent */
 361         gauge_t capacity_charged = NAN; /* Charged capacity */
 362         gauge_t capacity_full = NAN; /* Total capacity */
 363         gauge_t capacity_design = NAN; /* Full design capacity */
 364
 365 #if HAVE_IOKIT_PS_IOPOWERSOURCES_H
 366         get_via_io_power_sources (&charge_rel, &current, &voltage);
 367 #endif
 368 #if HAVE_IOKIT_IOKITLIB_H
 369         get_via_generic_iokit (&capacity_full, &capacity_design, &current, &voltage);
 370 #endif
 371
 372         capacity_charged = charge_rel * capacity_full / 100.0;
 373         submit_capacity ("0", capacity_charged, capacity_full, capacity_design);
 374
 375         if (!isnan (current))
 376                 battery_submit ("0", "current", current);
 377         if (!isnan (voltage))
 378                 battery_submit ("0", "voltage", voltage);
 379
 380         return (0);
 381 } /* }}} int battery_read */
 382 /* #endif HAVE_IOKIT_IOKITLIB_H || HAVE_IOKIT_PS_IOPOWERSOURCES_H */
 383
 384 #elif KERNEL_LINUX
 385 /* Reads a file which contains only a number (and optionally a trailing
 386  * newline) and parses that number. */
 387 static int sysfs_file_to_buffer(char const *dir, /* {{{ */
 388                 char const *power_supply,
 389                 char const *basename,
 390                 char *buffer, size_t buffer_size)
 391 {
 392         int status;
 393         FILE *fp;
 394         char filename[PATH_MAX];
 395
 396         ssnprintf (filename, sizeof (filename), "%s/%s/%s",
 397                         dir, power_supply, basename);
 398
 399         /* No file isn't the end of the world -- not every system will be
 400          * reporting the same set of statistics */
 401         if (access (filename, R_OK) != 0)
 402                 return ENOENT;
 403
 404         fp = fopen (filename, "r");
 405         if (fp == NULL)
 406         {
 407                 status = errno;
 408                 if (status != ENOENT)
 409                 {
 410                         char errbuf[1024];
 411                         WARNING ("battery plugin: fopen (%s) failed: %s", filename,
 412                                         sstrerror (status, errbuf, sizeof (errbuf)));
 413                 }
 414                 return status;
 415         }
 416
 417         if (fgets (buffer, buffer_size, fp) == NULL)
 418         {
 419                 status = errno;
 420                 if (status != ENODEV)
 421                 {
 422                         char errbuf[1024];
 423                         WARNING ("battery plugin: fgets (%s) failed: %s", filename,
 424                                         sstrerror (status, errbuf, sizeof (errbuf)));
 425                 }
 426                 fclose (fp);
 427                 return status;
 428         }
 429
 430         strstripnewline (buffer);
 431
 432         fclose (fp);
 433         return 0;
 434 } /* }}} int sysfs_file_to_buffer */
 435
 436 /* Reads a file which contains only a number (and optionally a trailing
 437  * newline) and parses that number. */
 438 static int sysfs_file_to_gauge(char const *dir, /* {{{ */
 439                 char const *power_supply,
 440                 char const *basename, gauge_t *ret_value)
 441 {
 442         int status;
 443         char buffer[32] = "";
 444
 445         status = sysfs_file_to_buffer (dir, power_supply, basename, buffer, sizeof (buffer));
 446         if (status != 0)
 447                 return (status);
 448
 449         return (strtogauge (buffer, ret_value));
 450 } /* }}} sysfs_file_to_gauge */
 451
 452 static int read_sysfs_capacity (char const *dir, /* {{{ */
 453                 char const *power_supply,
 454                 char const *plugin_instance)
 455 {
 456         gauge_t capacity_charged = NAN;
 457         gauge_t capacity_full = NAN;
 458         gauge_t capacity_design = NAN;
 459         int status;
 460
 461         status = sysfs_file_to_gauge (dir, power_supply, "energy_now", &capacity_charged);
 462         if (status != 0)
 463                 return (status);
 464
 465         status = sysfs_file_to_gauge (dir, power_supply, "energy_full", &capacity_full);
 466         if (status != 0)
 467                 return (status);
 468
 469         status = sysfs_file_to_gauge (dir, power_supply, "energy_full_design", &capacity_design);
 470         if (status != 0)
 471                 return (status);
 472
 473         submit_capacity (plugin_instance,
 474                         capacity_charged * SYSFS_FACTOR,
 475                         capacity_full * SYSFS_FACTOR,
 476                         capacity_design * SYSFS_FACTOR);
 477         return (0);
 478 } /* }}} int read_sysfs_capacity */
 479
 480 static int read_sysfs_callback (char const *dir, /* {{{ */
 481                 char const *power_supply,
 482                 void *user_data)
 483 {
 484         int *battery_index = user_data;
 485
 486         char const *plugin_instance;
 487         char buffer[32];
 488         gauge_t v = NAN;
 489         _Bool discharging = 0;
 490         int status;
 491
 492         /* Ignore non-battery directories, such as AC power. */
 493         status = sysfs_file_to_buffer (dir, power_supply, "type", buffer, sizeof (buffer));
 494         if (status != 0)
 495                 return (0);
 496         if (strcasecmp ("Battery", buffer) != 0)
 497                 return (0);
 498
 499         (void) sysfs_file_to_buffer (dir, power_supply, "status", buffer, sizeof (buffer));
 500         if (strcasecmp ("Discharging", buffer) == 0)
 501                 discharging = 1;
 502
 503         /* FIXME: This is a dirty hack for backwards compatibility: The battery
 504          * plugin, for a very long time, has had the plugin_instance
 505          * hard-coded to "0". So, to keep backwards compatibility, we'll use
 506          * "0" for the first battery we find and the power_supply name for all
 507          * following. This should be reverted in a future major version. */
 508         plugin_instance = (*battery_index == 0) ? "0" : power_supply;
 509         (*battery_index)++;
 510
 511         read_sysfs_capacity (dir, power_supply, plugin_instance);
 512
 513         if (sysfs_file_to_gauge (dir, power_supply, "power_now", &v) == 0)
 514         {
 515                 if (discharging)
 516                         v *= -1.0;
 517                 battery_submit (plugin_instance, "power", v * SYSFS_FACTOR);
 518         }
 519         if (sysfs_file_to_gauge (dir, power_supply, "current_now", &v) == 0)
 520         {
 521                 if (discharging)
 522                         v *= -1.0;
 523                 battery_submit (plugin_instance, "current", v * SYSFS_FACTOR);
 524         }
 525
 526         if (sysfs_file_to_gauge (dir, power_supply, "voltage_now", &v) == 0)
 527                 battery_submit (plugin_instance, "voltage", v * SYSFS_FACTOR);
 528
 529         return (0);
 530 } /* }}} int read_sysfs_callback */
 531
 532 static int read_sysfs (void) /* {{{ */
 533 {
 534         int status;
 535         int battery_counter = 0;
 536
 537         if (access (SYSFS_PATH, R_OK) != 0)
 538                 return (ENOENT);
 539
 540         status = walk_directory (SYSFS_PATH, read_sysfs_callback,
 541                         /* user_data = */ &battery_counter,
 542                         /* include hidden */ 0);
 543         return (status);
 544 } /* }}} int read_sysfs */
 545
 546 static int read_acpi_full_capacity (char const *dir, /* {{{ */
 547                 char const *power_supply,
 548                 gauge_t *ret_capacity_full,
 549                 gauge_t *ret_capacity_design)
 550
 551 {
 552         char filename[PATH_MAX];
 553         char buffer[1024];
 554
 555         FILE *fh;
 556
 557         ssnprintf (filename, sizeof (filename), "%s/%s/info", dir, power_supply);
 558         fh = fopen (filename, "r");
 559         if (fh == NULL)
 560                 return (errno);
 561
 562         /* last full capacity:      40090 mWh */
 563         while (fgets (buffer, sizeof (buffer), fh) != NULL)
 564         {
 565                 gauge_t *value_ptr;
 566                 int fields_num;
 567                 char *fields[8];
 568                 int index;
 569
 570                 if (strncmp ("last full capacity:", buffer, strlen ("last full capacity:")) == 0)
 571                 {
 572                         value_ptr = ret_capacity_full;
 573                         index = 3;
 574                 }
 575                 else if (strncmp ("design capacity:", buffer, strlen ("design capacity:")) == 0)
 576                 {
 577                         value_ptr = ret_capacity_design;
 578                         index = 2;
 579                 }
 580                 else
 581                 {
 582                         continue;
 583                 }
 584
 585                 fields_num = strsplit (buffer, fields, STATIC_ARRAY_SIZE (fields));
 586                 if (fields_num <= index)
 587                         continue;
 588
 589                 strtogauge (fields[index], value_ptr);
 590         }
 591
 592         fclose (fh);
 593         return (0);
 594 } /* }}} int read_acpi_full_capacity */
 595
 596 static int read_acpi_callback (char const *dir, /* {{{ */
 597                 char const *power_supply,
 598                 void *user_data)
 599 {
 600         int *battery_index = user_data;
 601
 602         gauge_t power = NAN;
 603         gauge_t voltage = NAN;
 604         gauge_t capacity_charged = NAN;
 605         gauge_t capacity_full = NAN;
 606         gauge_t capacity_design = NAN;
 607         _Bool charging = 0;
 608         _Bool is_current = 0;
 609
 610         char const *plugin_instance;
 611         char filename[PATH_MAX];
 612         char buffer[1024];
 613
 614         FILE *fh;
 615
 616         ssnprintf (filename, sizeof (filename), "%s/%s/state", dir, power_supply);
 617         fh = fopen (filename, "r");
 618         if (fh == NULL)
 619         {
 620                 if ((errno == EAGAIN) || (errno == EINTR) || (errno == ENOENT))
 621                         return (0);
 622                 else
 623                         return (errno);
 624         }
 625
 626         /*
 627          * [11:00] <@tokkee> $ cat /proc/acpi/battery/BAT1/state
 628          * [11:00] <@tokkee> present:                 yes
 629          * [11:00] <@tokkee> capacity state:          ok
 630          * [11:00] <@tokkee> charging state:          charging
 631          * [11:00] <@tokkee> present rate:            1724 mA
 632          * [11:00] <@tokkee> remaining capacity:      4136 mAh
 633          * [11:00] <@tokkee> present voltage:         12428 mV
 634          */
 635         while (fgets (buffer, sizeof (buffer), fh) != NULL)
 636         {
 637                 char *fields[8];
 638                 int numfields;
 639
 640                 numfields = strsplit (buffer, fields, STATIC_ARRAY_SIZE (fields));
 641                 if (numfields < 3)
 642                         continue;
 643
 644                 if ((strcmp (fields[0], "charging") == 0)
 645                                 && (strcmp (fields[1], "state:") == 0))
 646                 {
 647                         if (strcmp (fields[2], "charging") == 0)
 648                                 charging = 1;
 649                         else
 650                                 charging = 0;
 651                         continue;
 652                 }
 653
 654                 /* The unit of "present rate" depends on the battery. Modern
 655                  * batteries export power (watts), older batteries (used to)
 656                  * export current (amperes). We check the fourth column and try
 657                  * to find old batteries this way. */
 658                 if ((strcmp (fields[0], "present") == 0)
 659                                 && (strcmp (fields[1], "rate:") == 0))
 660                 {
 661                         strtogauge (fields[2], &power);
 662
 663                         if ((numfields >= 4) && (strcmp ("mA", fields[3]) == 0))
 664                                 is_current = 1;
 665                 }
 666                 else if ((strcmp (fields[0], "remaining") == 0)
 667                                 && (strcmp (fields[1], "capacity:") == 0))
 668                         strtogauge (fields[2], &capacity_charged);
 669                 else if ((strcmp (fields[0], "present") == 0)
 670                                 && (strcmp (fields[1], "voltage:") == 0))
 671                         strtogauge (fields[2], &voltage);
 672         } /* while (fgets (buffer, sizeof (buffer), fh) != NULL) */
 673
 674         fclose (fh);
 675
 676         if (!charging)
 677                 power *= -1.0;
 678
 679         /* FIXME: This is a dirty hack for backwards compatibility: The battery
 680          * plugin, for a very long time, has had the plugin_instance
 681          * hard-coded to "0". So, to keep backwards compatibility, we'll use
 682          * "0" for the first battery we find and the power_supply name for all
 683          * following. This should be reverted in a future major version. */
 684         plugin_instance = (*battery_index == 0) ? "0" : power_supply;
 685         (*battery_index)++;
 686
 687         read_acpi_full_capacity (dir, power_supply, &capacity_full, &capacity_design);
 688
 689         submit_capacity (plugin_instance,
 690                         capacity_charged * PROC_ACPI_FACTOR,
 691                         capacity_full * PROC_ACPI_FACTOR,
 692                         capacity_design * PROC_ACPI_FACTOR);
 693
 694         battery_submit (plugin_instance,
 695                         is_current ? "current" : "power",
 696                         power * PROC_ACPI_FACTOR);
 697         battery_submit (plugin_instance, "voltage", voltage * PROC_ACPI_FACTOR);
 698
 699         return 0;
 700 } /* }}} int read_acpi_callback */
 701
 702 static int read_acpi (void) /* {{{ */
 703 {
 704         int status;
 705         int battery_counter = 0;
 706
 707         if (access (PROC_ACPI_PATH, R_OK) != 0)
 708                 return (ENOENT);
 709
 710         status = walk_directory (PROC_ACPI_PATH, read_acpi_callback,
 711                         /* user_data = */ &battery_counter,
 712                         /* include hidden */ 0);
 713         return (status);
 714 } /* }}} int read_acpi */
 715
 716 static int read_pmu (void) /* {{{ */
 717 {
 718         int i;
 719
 720         /* The upper limit here is just a safeguard. If there is a system with
 721          * more than 100 batteries, this can easily be increased. */
 722         for (i = 0; i < 100; i++)
 723         {
 724                 FILE *fh;
 725
 726                 char buffer[1024];
 727                 char filename[PATH_MAX];
 728                 char plugin_instance[DATA_MAX_NAME_LEN];
 729
 730                 gauge_t current = NAN;
 731                 gauge_t voltage = NAN;
 732                 gauge_t charge  = NAN;
 733
 734                 ssnprintf (filename, sizeof (filename), PROC_PMU_PATH_FORMAT, i);
 735                 if (access (filename, R_OK) != 0)
 736                         break;
 737
 738                 ssnprintf (plugin_instance, sizeof (plugin_instance), "%i", i);
 739
 740                 fh = fopen (filename, "r");
 741                 if (fh == NULL)
 742                 {
 743                         if (errno == ENOENT)
 744                                 break;
 745                         else if ((errno == EAGAIN) || (errno == EINTR))
 746                                 continue;
 747                         else
 748                                 return (errno);
 749                 }
 750
 751                 while (fgets (buffer, sizeof (buffer), fh) != NULL)
 752                 {
 753                         char *fields[8];
 754                         int numfields;
 755
 756                         numfields = strsplit (buffer, fields, STATIC_ARRAY_SIZE (fields));
 757                         if (numfields < 3)
 758                                 continue;
 759
 760                         if (strcmp ("current", fields[0]) == 0)
 761                                 strtogauge (fields[2], &current);
 762                         else if (strcmp ("voltage", fields[0]) == 0)
 763                                 strtogauge (fields[2], &voltage);
 764                         else if (strcmp ("charge", fields[0]) == 0)
 765                                 strtogauge (fields[2], &charge);
 766                 }
 767
 768                 fclose (fh);
 769                 fh = NULL;
 770
 771                 battery_submit (plugin_instance, "charge", charge / 1000.0);
 772                 battery_submit (plugin_instance, "current", current / 1000.0);
 773                 battery_submit (plugin_instance, "voltage", voltage / 1000.0);
 774         }
 775
 776         if (i == 0)
 777                 return (ENOENT);
 778         return (0);
 779 } /* }}} int read_pmu */
 780
 781 static int battery_read (void) /* {{{ */
 782 {
 783         int status;
 784
 785         DEBUG ("battery plugin: Trying sysfs ...");
 786         status = read_sysfs ();
 787         if (status == 0)
 788                 return (0);
 789
 790         DEBUG ("battery plugin: Trying acpi ...");
 791         status = read_acpi ();
 792         if (status == 0)
 793                 return (0);
 794
 795         DEBUG ("battery plugin: Trying pmu ...");
 796         status = read_pmu ();
 797         if (status == 0)
 798                 return (0);
 799
 800         ERROR ("battery plugin: Add available input methods failed.");
 801         return (-1);
 802 } /* }}} int battery_read */
 803 #endif /* KERNEL_LINUX */
 804
 805 static int battery_config (oconfig_item_t *ci)
 806 {
 807         int i;
 808
 809         for (i = 0; i < ci->children_num; i++)
 810         {
 811                 oconfig_item_t *child = ci->children + i;
 812
 813                 if (strcasecmp ("ValuesPercentage", child->key) == 0)
 814                         cf_util_get_boolean (child, &report_percent);
 815                 else if (strcasecmp ("ReportDegraded", child->key) == 0)
 816                         cf_util_get_boolean (child, &report_degraded);
 817                 else
 818                         WARNING ("battery plugin: Ignoring unknown "
 819                                         "configuration option \"%s\".",
 820                                         child->key);
 821         }
 822
 823         return (0);
 824 } /* }}} int battery_config */
 825
 826 void module_register (void)
 827 {
 828         plugin_register_complex_config ("battery", battery_config);
 829         plugin_register_read ("battery", battery_read);
 830 } /* void module_register */