Merge branch 'collectd-5.5' into collectd-5.6
[collectd.git] / src / battery.c
index d921484..0327d5d 100644 (file)
@@ -1,7 +1,8 @@
 /**
  * collectd - src/battery.c
- * Copyright (C) 2006,2007  Florian octo Forster
+ * Copyright (C) 2006-2014  Florian octo Forster
  * Copyright (C) 2008       Michał Mirosław
+ * Copyright (C) 2014       Andy Parkins
  *
  * This program is free software; you can redistribute it and/or modify it
  * under the terms of the GNU General Public License as published by the
  * 51 Franklin St, Fifth Floor, Boston, MA  02110-1301 USA
  *
  * Authors:
- *   Florian octo Forster <octo at verplant.org>
+ *   Florian octo Forster <octo at collectd.org>
  *   Michał Mirosław <mirq-linux at rere.qmqm.pl>
+ *   Andy Parkins <andyp at fussylogic.co.uk>
  **/
 
 #include "collectd.h"
+
 #include "common.h"
 #include "plugin.h"
 
-#include "utils_complain.h"
-
 #if HAVE_MACH_MACH_TYPES_H
 #  include <mach/mach_types.h>
 #endif
 # error "No applicable input method."
 #endif
 
-#define INVALID_VALUE 47841.29
-
 #if HAVE_IOKIT_IOKITLIB_H || HAVE_IOKIT_PS_IOPOWERSOURCES_H
        /* No global variables */
 /* #endif HAVE_IOKIT_IOKITLIB_H || HAVE_IOKIT_PS_IOPOWERSOURCES_H */
 
 #elif KERNEL_LINUX
-static int   battery_pmu_num = 0;
-static char *battery_pmu_file = "/proc/pmu/battery_%i";
-static const char *battery_acpi_dir = "/proc/acpi/battery";
+# define PROC_PMU_PATH_FORMAT "/proc/pmu/battery_%i"
+# define PROC_ACPI_PATH "/proc/acpi/battery"
+# define PROC_ACPI_FACTOR 0.001
+# define SYSFS_PATH "/sys/class/power_supply"
+# define SYSFS_FACTOR 0.000001
 #endif /* KERNEL_LINUX */
 
-static int battery_init (void)
-{
-#if HAVE_IOKIT_IOKITLIB_H || HAVE_IOKIT_PS_IOPOWERSOURCES_H
-       /* No init neccessary */
-/* #endif HAVE_IOKIT_IOKITLIB_H || HAVE_IOKIT_PS_IOPOWERSOURCES_H */
-
-#elif KERNEL_LINUX
-       int len;
-       char filename[128];
-
-       for (battery_pmu_num = 0; ; battery_pmu_num++)
-       {
-               len = ssnprintf (filename, sizeof (filename), battery_pmu_file, battery_pmu_num);
-
-               if ((len < 0) || ((unsigned int)len >= sizeof (filename)))
-                       break;
+static _Bool report_percent = 0;
+static _Bool report_degraded = 0;
 
-               if (access (filename, R_OK))
-                       break;
-       }
-#endif /* KERNEL_LINUX */
-
-       return (0);
-}
-
-static void battery_submit (const char *plugin_instance, const char *type, double value)
+static void battery_submit2 (char const *plugin_instance, /* {{{ */
+               char const *type, char const *type_instance, gauge_t value)
 {
        value_t values[1];
        value_list_t vl = VALUE_LIST_INIT;
@@ -106,12 +86,63 @@ static void battery_submit (const char *plugin_instance, const char *type, doubl
        sstrncpy (vl.plugin, "battery", sizeof (vl.plugin));
        sstrncpy (vl.plugin_instance, plugin_instance, sizeof (vl.plugin_instance));
        sstrncpy (vl.type, type, sizeof (vl.type));
+       if (type_instance != NULL)
+               sstrncpy (vl.type_instance, type_instance, sizeof (vl.type_instance));
 
        plugin_dispatch_values (&vl);
-} /* void battery_submit */
+} /* }}} void battery_submit2 */
+
+static void battery_submit (char const *plugin_instance, /* {{{ */
+               char const *type, gauge_t value)
+{
+       battery_submit2 (plugin_instance, type, NULL, value);
+} /* }}} void battery_submit */
+
+static void submit_capacity (char const *plugin_instance, /* {{{ */
+               gauge_t capacity_charged,
+               gauge_t capacity_full,
+               gauge_t capacity_design)
+{
+       if (report_percent && (capacity_charged > capacity_full))
+               return;
+       if (report_degraded && (capacity_full > capacity_design))
+               return;
+
+       if (report_percent)
+       {
+               gauge_t capacity_max;
+
+               if (report_degraded)
+                       capacity_max = capacity_design;
+               else
+                       capacity_max = capacity_full;
+
+               battery_submit2 (plugin_instance, "percent", "charged",
+                               100.0 * capacity_charged / capacity_max);
+               battery_submit2 (plugin_instance, "percent", "discharged",
+                               100.0 * (capacity_full - capacity_charged) / capacity_max);
+
+               if (report_degraded)
+                       battery_submit2 (plugin_instance, "percent", "degraded",
+                                       100.0 * (capacity_design - capacity_full) / capacity_max);
+       }
+       else if (report_degraded) /* && !report_percent */
+       {
+               battery_submit2 (plugin_instance, "capacity", "charged",
+                               capacity_charged);
+               battery_submit2 (plugin_instance, "capacity", "discharged",
+                               (capacity_full - capacity_charged));
+               battery_submit2 (plugin_instance, "capacity", "degraded",
+                               (capacity_design - capacity_full));
+       }
+       else /* !report_percent && !report_degraded */
+       {
+               battery_submit (plugin_instance, "capacity", capacity_charged);
+       }
+} /* }}} void submit_capacity */
 
 #if HAVE_IOKIT_PS_IOPOWERSOURCES_H || HAVE_IOKIT_IOKITLIB_H
-static double dict_get_double (CFDictionaryRef dict, char *key_string)
+static double dict_get_double (CFDictionaryRef dict, const char *key_string) /* {{{ */
 {
        double      val_double;
        long long   val_int;
@@ -119,18 +150,18 @@ static double dict_get_double (CFDictionaryRef dict, char *key_string)
        CFStringRef key_obj;
 
        key_obj = CFStringCreateWithCString (kCFAllocatorDefault, key_string,
-                       kCFStringEncodingASCII);
+                       kCFStringEncodingASCII);
        if (key_obj == NULL)
        {
                DEBUG ("CFStringCreateWithCString (%s) failed.\n", key_string);
-               return (INVALID_VALUE);
+               return (NAN);
        }
 
        if ((val_obj = CFDictionaryGetValue (dict, key_obj)) == NULL)
        {
                DEBUG ("CFDictionaryGetValue (%s) failed.", key_string);
                CFRelease (key_obj);
-               return (INVALID_VALUE);
+               return (NAN);
        }
        CFRelease (key_obj);
 
@@ -153,15 +184,14 @@ static double dict_get_double (CFDictionaryRef dict, char *key_string)
        else
        {
                DEBUG ("CFGetTypeID (val_obj) = %i", (int) CFGetTypeID (val_obj));
-               return (INVALID_VALUE);
+               return (NAN);
        }
 
        return (val_double);
-}
-#endif /* HAVE_IOKIT_PS_IOPOWERSOURCES_H || HAVE_IOKIT_IOKITLIB_H */
+} /* }}} double dict_get_double */
 
-#if HAVE_IOKIT_PS_IOPOWERSOURCES_H
-static void get_via_io_power_sources (double *ret_charge,
+# if HAVE_IOKIT_PS_IOPOWERSOURCES_H
+static void get_via_io_power_sources (double *ret_charge, /* {{{ */
                double *ret_current,
                double *ret_voltage)
 {
@@ -172,7 +202,6 @@ static void get_via_io_power_sources (double *ret_charge,
        CFTypeRef       ps_obj;
 
        double temp_double;
-       int i;
 
        ps_raw       = IOPSCopyPowerSourcesInfo ();
        ps_array     = IOPSCopyPowerSourcesList (ps_raw);
@@ -180,7 +209,7 @@ static void get_via_io_power_sources (double *ret_charge,
 
        DEBUG ("ps_array_len == %i", ps_array_len);
 
-       for (i = 0; i < ps_array_len; i++)
+       for (int i = 0; i < ps_array_len; i++)
        {
                ps_obj  = CFArrayGetValueAtIndex (ps_array, i);
                ps_dict = IOPSGetPowerSourceDescription (ps_raw, ps_obj);
@@ -199,41 +228,42 @@ static void get_via_io_power_sources (double *ret_charge,
 
                /* FIXME: Check if this is really an internal battery */
 
-               if (*ret_charge == INVALID_VALUE)
+               if (isnan (*ret_charge))
                {
                        /* This is the charge in percent. */
                        temp_double = dict_get_double (ps_dict,
                                        kIOPSCurrentCapacityKey);
-                       if ((temp_double != INVALID_VALUE)
+                       if (!isnan ((temp_double))
                                        && (temp_double >= 0.0)
                                        && (temp_double <= 100.0))
                                *ret_charge = temp_double;
                }
 
-               if (*ret_current == INVALID_VALUE)
+               if (isnan (*ret_current))
                {
                        temp_double = dict_get_double (ps_dict,
                                        kIOPSCurrentKey);
-                       if (temp_double != INVALID_VALUE)
+                       if (!isnan (temp_double))
                                *ret_current = temp_double / 1000.0;
                }
 
-               if (*ret_voltage == INVALID_VALUE)
+               if (isnan (*ret_voltage))
                {
                        temp_double = dict_get_double (ps_dict,
                                        kIOPSVoltageKey);
-                       if (temp_double != INVALID_VALUE)
+                       if (!isnan (temp_double))
                                *ret_voltage = temp_double / 1000.0;
                }
        }
 
        CFRelease(ps_array);
        CFRelease(ps_raw);
-}
-#endif /* HAVE_IOKIT_PS_IOPOWERSOURCES_H */
+} /* }}} void get_via_io_power_sources */
+# endif /* HAVE_IOKIT_PS_IOPOWERSOURCES_H */
 
-#if HAVE_IOKIT_IOKITLIB_H
-static void get_via_generic_iokit (double *ret_charge,
+# if HAVE_IOKIT_IOKITLIB_H
+static void get_via_generic_iokit (double *ret_capacity_full, /* {{{ */
+               double *ret_capacity_design,
                double *ret_current,
                double *ret_voltage)
 {
@@ -244,7 +274,6 @@ static void get_via_generic_iokit (double *ret_charge,
        CFDictionaryRef bat_root_dict;
        CFArrayRef      bat_info_arry;
        CFIndex         bat_info_arry_len;
-       CFIndex         bat_info_arry_pos;
        CFDictionaryRef bat_info_dict;
 
        double temp_double;
@@ -279,73 +308,316 @@ static void get_via_generic_iokit (double *ret_charge,
                }
                bat_info_arry_len = CFArrayGetCount (bat_info_arry);
 
-               for (bat_info_arry_pos = 0;
-                               bat_info_arry_pos < bat_info_arry_len;
-                               bat_info_arry_pos++)
+               for (CFIndex bat_info_arry_pos = 0;
+                               bat_info_arry_pos < bat_info_arry_len;
+                               bat_info_arry_pos++)
                {
                        bat_info_dict = (CFDictionaryRef) CFArrayGetValueAtIndex (bat_info_arry, bat_info_arry_pos);
 
-                       if (*ret_charge == INVALID_VALUE)
+                       if (isnan (*ret_capacity_full))
                        {
-                               temp_double = dict_get_double (bat_info_dict,
-                                               "Capacity");
-                               if (temp_double != INVALID_VALUE)
-                                       *ret_charge = temp_double / 1000.0;
+                               temp_double = dict_get_double (bat_info_dict, "Capacity");
+                               *ret_capacity_full = temp_double / 1000.0;
                        }
 
-                       if (*ret_current == INVALID_VALUE)
+                       if (isnan (*ret_capacity_design))
                        {
-                               temp_double = dict_get_double (bat_info_dict,
-                                               "Current");
-                               if (temp_double != INVALID_VALUE)
-                                       *ret_current = temp_double / 1000.0;
+                               temp_double = dict_get_double (bat_info_dict, "AbsoluteMaxCapacity");
+                               *ret_capacity_design = temp_double / 1000.0;
                        }
 
-                       if (*ret_voltage == INVALID_VALUE)
+                       if (isnan (*ret_current))
                        {
-                               temp_double = dict_get_double (bat_info_dict,
-                                               "Voltage");
-                               if (temp_double != INVALID_VALUE)
-                                       *ret_voltage = temp_double / 1000.0;
+                               temp_double = dict_get_double (bat_info_dict, "Current");
+                               *ret_current = temp_double / 1000.0;
+                       }
+
+                       if (isnan (*ret_voltage))
+                       {
+                               temp_double = dict_get_double (bat_info_dict, "Voltage");
+                               *ret_voltage = temp_double / 1000.0;
                        }
                }
-               
+
                CFRelease (bat_root_dict);
        }
 
        IOObjectRelease (iterator);
-}
-#endif /* HAVE_IOKIT_IOKITLIB_H */
+} /* }}} void get_via_generic_iokit */
+# endif /* HAVE_IOKIT_IOKITLIB_H */
 
-#if KERNEL_LINUX
-static int battery_read_acpi (const char __attribute__((unused)) *dir,
-               const char *name, void __attribute__((unused)) *user_data)
+static int battery_read (void) /* {{{ */
 {
-       double  current = INVALID_VALUE;
-       double  voltage = INVALID_VALUE;
-       double  charge  = INVALID_VALUE;
-       double *valptr = NULL;
-       int charging = 0;
+       gauge_t current = NAN; /* Current in A */
+       gauge_t voltage = NAN; /* Voltage in V */
 
-       char filename[256];
-       FILE *fh;
+       /* We only get the charged capacity as a percentage from
+        * IOPowerSources. IOKit, on the other hand, only reports the full
+        * capacity. We use the two to calculate the current charged capacity. */
+       gauge_t charge_rel = NAN; /* Current charge in percent */
+       gauge_t capacity_charged; /* Charged capacity */
+       gauge_t capacity_full = NAN; /* Total capacity */
+       gauge_t capacity_design = NAN; /* Full design capacity */
+
+#if HAVE_IOKIT_PS_IOPOWERSOURCES_H
+       get_via_io_power_sources (&charge_rel, &current, &voltage);
+#endif
+#if HAVE_IOKIT_IOKITLIB_H
+       get_via_generic_iokit (&capacity_full, &capacity_design, &current, &voltage);
+#endif
+
+       capacity_charged = charge_rel * capacity_full / 100.0;
+       submit_capacity ("0", capacity_charged, capacity_full, capacity_design);
+
+       if (!isnan (current))
+               battery_submit ("0", "current", current);
+       if (!isnan (voltage))
+               battery_submit ("0", "voltage", voltage);
+
+       return (0);
+} /* }}} int battery_read */
+/* #endif HAVE_IOKIT_IOKITLIB_H || HAVE_IOKIT_PS_IOPOWERSOURCES_H */
 
+#elif KERNEL_LINUX
+/* Reads a file which contains only a number (and optionally a trailing
+ * newline) and parses that number. */
+static int sysfs_file_to_buffer(char const *dir, /* {{{ */
+               char const *power_supply,
+               char const *basename,
+               char *buffer, size_t buffer_size)
+{
+       int status;
+       FILE *fp;
+       char filename[PATH_MAX];
+
+       ssnprintf (filename, sizeof (filename), "%s/%s/%s",
+                       dir, power_supply, basename);
+
+       /* No file isn't the end of the world -- not every system will be
+        * reporting the same set of statistics */
+       if (access (filename, R_OK) != 0)
+               return ENOENT;
+
+       fp = fopen (filename, "r");
+       if (fp == NULL)
+       {
+               status = errno;
+               if (status != ENOENT)
+               {
+                       char errbuf[1024];
+                       WARNING ("battery plugin: fopen (%s) failed: %s", filename,
+                                       sstrerror (status, errbuf, sizeof (errbuf)));
+               }
+               return status;
+       }
+
+       if (fgets (buffer, buffer_size, fp) == NULL)
+       {
+               status = errno;
+               if (status != ENODEV)
+               {
+                       char errbuf[1024];
+                       WARNING ("battery plugin: fgets (%s) failed: %s", filename,
+                                       sstrerror (status, errbuf, sizeof (errbuf)));
+               }
+               fclose (fp);
+               return status;
+       }
+
+       strstripnewline (buffer);
+
+       fclose (fp);
+       return 0;
+} /* }}} int sysfs_file_to_buffer */
+
+/* Reads a file which contains only a number (and optionally a trailing
+ * newline) and parses that number. */
+static int sysfs_file_to_gauge(char const *dir, /* {{{ */
+               char const *power_supply,
+               char const *basename, gauge_t *ret_value)
+{
+       int status;
+       char buffer[32] = "";
+
+       status = sysfs_file_to_buffer (dir, power_supply, basename, buffer, sizeof (buffer));
+       if (status != 0)
+               return (status);
+
+       return (strtogauge (buffer, ret_value));
+} /* }}} sysfs_file_to_gauge */
+
+static int read_sysfs_capacity (char const *dir, /* {{{ */
+               char const *power_supply,
+               char const *plugin_instance)
+{
+       gauge_t capacity_charged = NAN;
+       gauge_t capacity_full = NAN;
+       gauge_t capacity_design = NAN;
+       int status;
+
+       status = sysfs_file_to_gauge (dir, power_supply, "energy_now", &capacity_charged);
+       if (status != 0)
+               return (status);
+
+       status = sysfs_file_to_gauge (dir, power_supply, "energy_full", &capacity_full);
+       if (status != 0)
+               return (status);
+
+       status = sysfs_file_to_gauge (dir, power_supply, "energy_full_design", &capacity_design);
+       if (status != 0)
+               return (status);
+
+       submit_capacity (plugin_instance,
+                       capacity_charged * SYSFS_FACTOR,
+                       capacity_full * SYSFS_FACTOR,
+                       capacity_design * SYSFS_FACTOR);
+       return (0);
+} /* }}} int read_sysfs_capacity */
+
+static int read_sysfs_callback (char const *dir, /* {{{ */
+               char const *power_supply,
+               void *user_data)
+{
+       int *battery_index = user_data;
+
+       char const *plugin_instance;
+       char buffer[32];
+       gauge_t v = NAN;
+       _Bool discharging = 0;
+       int status;
+
+       /* Ignore non-battery directories, such as AC power. */
+       status = sysfs_file_to_buffer (dir, power_supply, "type", buffer, sizeof (buffer));
+       if (status != 0)
+               return (0);
+       if (strcasecmp ("Battery", buffer) != 0)
+               return (0);
+
+       (void) sysfs_file_to_buffer (dir, power_supply, "status", buffer, sizeof (buffer));
+       if (strcasecmp ("Discharging", buffer) == 0)
+               discharging = 1;
+
+       /* FIXME: This is a dirty hack for backwards compatibility: The battery
+        * plugin, for a very long time, has had the plugin_instance
+        * hard-coded to "0". So, to keep backwards compatibility, we'll use
+        * "0" for the first battery we find and the power_supply name for all
+        * following. This should be reverted in a future major version. */
+       plugin_instance = (*battery_index == 0) ? "0" : power_supply;
+       (*battery_index)++;
+
+       read_sysfs_capacity (dir, power_supply, plugin_instance);
+
+       if (sysfs_file_to_gauge (dir, power_supply, "power_now", &v) == 0)
+       {
+               if (discharging)
+                       v *= -1.0;
+               battery_submit (plugin_instance, "power", v * SYSFS_FACTOR);
+       }
+       if (sysfs_file_to_gauge (dir, power_supply, "current_now", &v) == 0)
+       {
+               if (discharging)
+                       v *= -1.0;
+               battery_submit (plugin_instance, "current", v * SYSFS_FACTOR);
+       }
+
+       if (sysfs_file_to_gauge (dir, power_supply, "voltage_now", &v) == 0)
+               battery_submit (plugin_instance, "voltage", v * SYSFS_FACTOR);
+
+       return (0);
+} /* }}} int read_sysfs_callback */
+
+static int read_sysfs (void) /* {{{ */
+{
+       int status;
+       int battery_counter = 0;
+
+       if (access (SYSFS_PATH, R_OK) != 0)
+               return (ENOENT);
+
+       status = walk_directory (SYSFS_PATH, read_sysfs_callback,
+                       /* user_data = */ &battery_counter,
+                       /* include hidden */ 0);
+       return (status);
+} /* }}} int read_sysfs */
+
+static int read_acpi_full_capacity (char const *dir, /* {{{ */
+               char const *power_supply,
+               gauge_t *ret_capacity_full,
+               gauge_t *ret_capacity_design)
+
+{
+       char filename[PATH_MAX];
        char buffer[1024];
-       char *fields[8];
-       int numfields;
-       char *endptr;
-       int len;
 
-       len = ssnprintf (filename, sizeof (filename), "%s/%s/state", battery_acpi_dir, name);
+       FILE *fh;
+
+       ssnprintf (filename, sizeof (filename), "%s/%s/info", dir, power_supply);
+       fh = fopen (filename, "r");
+       if (fh == NULL)
+               return (errno);
 
-       if ((len < 0) || ((unsigned int)len >= sizeof (filename)))
-               return -1;
+       /* last full capacity:      40090 mWh */
+       while (fgets (buffer, sizeof (buffer), fh) != NULL)
+       {
+               gauge_t *value_ptr;
+               int fields_num;
+               char *fields[8];
+               int index;
 
-       if ((fh = fopen (filename, "r")) == NULL) {
-               char errbuf[1024];
-               ERROR ("Cannot open `%s': %s", filename,
-                       sstrerror (errno, errbuf, sizeof (errbuf)));
-               return -1;
+               if (strncmp ("last full capacity:", buffer, strlen ("last full capacity:")) == 0)
+               {
+                       value_ptr = ret_capacity_full;
+                       index = 3;
+               }
+               else if (strncmp ("design capacity:", buffer, strlen ("design capacity:")) == 0)
+               {
+                       value_ptr = ret_capacity_design;
+                       index = 2;
+               }
+               else
+               {
+                       continue;
+               }
+
+               fields_num = strsplit (buffer, fields, STATIC_ARRAY_SIZE (fields));
+               if (fields_num <= index)
+                       continue;
+
+               strtogauge (fields[index], value_ptr);
+       }
+
+       fclose (fh);
+       return (0);
+} /* }}} int read_acpi_full_capacity */
+
+static int read_acpi_callback (char const *dir, /* {{{ */
+               char const *power_supply,
+               void *user_data)
+{
+       int *battery_index = user_data;
+
+       gauge_t power = NAN;
+       gauge_t voltage = NAN;
+       gauge_t capacity_charged = NAN;
+       gauge_t capacity_full = NAN;
+       gauge_t capacity_design = NAN;
+       _Bool charging = 0;
+       _Bool is_current = 0;
+
+       char const *plugin_instance;
+       char filename[PATH_MAX];
+       char buffer[1024];
+
+       FILE *fh;
+
+       ssnprintf (filename, sizeof (filename), "%s/%s/state", dir, power_supply);
+       fh = fopen (filename, "r");
+       if (fh == NULL)
+       {
+               if ((errno == EAGAIN) || (errno == EINTR) || (errno == ENOENT))
+                       return (0);
+               else
+                       return (errno);
        }
 
        /*
@@ -359,8 +631,10 @@ static int battery_read_acpi (const char __attribute__((unused)) *dir,
         */
        while (fgets (buffer, sizeof (buffer), fh) != NULL)
        {
-               numfields = strsplit (buffer, fields, 8);
+               char *fields[8];
+               int numfields;
 
+               numfields = strsplit (buffer, fields, STATIC_ARRAY_SIZE (fields));
                if (numfields < 3)
                        continue;
 
@@ -374,164 +648,177 @@ static int battery_read_acpi (const char __attribute__((unused)) *dir,
                        continue;
                }
 
+               /* The unit of "present rate" depends on the battery. Modern
+                * batteries export power (watts), older batteries (used to)
+                * export current (amperes). We check the fourth column and try
+                * to find old batteries this way. */
                if ((strcmp (fields[0], "present") == 0)
                                && (strcmp (fields[1], "rate:") == 0))
-                       valptr = &current;
+               {
+                       strtogauge (fields[2], &power);
+
+                       if ((numfields >= 4) && (strcmp ("mA", fields[3]) == 0))
+                               is_current = 1;
+               }
                else if ((strcmp (fields[0], "remaining") == 0)
                                && (strcmp (fields[1], "capacity:") == 0))
-                       valptr = &charge;
+                       strtogauge (fields[2], &capacity_charged);
                else if ((strcmp (fields[0], "present") == 0)
                                && (strcmp (fields[1], "voltage:") == 0))
-                       valptr = &voltage;
-               else
-                       continue;
-
-               endptr = NULL;
-               errno  = 0;
-               *valptr = strtod (fields[2], &endptr) / 1000.0;
-
-               if ((fields[2] == endptr) || (errno != 0))
-                       *valptr = INVALID_VALUE;
+                       strtogauge (fields[2], &voltage);
        } /* while (fgets (buffer, sizeof (buffer), fh) != NULL) */
 
        fclose (fh);
 
-       if ((current != INVALID_VALUE) && (charging == 0))
-                       current *= -1;
+       if (!charging)
+               power *= -1.0;
 
-       if (charge != INVALID_VALUE)
-               battery_submit ("0", "charge", charge);
-       if (current != INVALID_VALUE)
-               battery_submit ("0", "current", current);
-       if (voltage != INVALID_VALUE)
-               battery_submit ("0", "voltage", voltage);
+       /* FIXME: This is a dirty hack for backwards compatibility: The battery
+        * plugin, for a very long time, has had the plugin_instance
+        * hard-coded to "0". So, to keep backwards compatibility, we'll use
+        * "0" for the first battery we find and the power_supply name for all
+        * following. This should be reverted in a future major version. */
+       plugin_instance = (*battery_index == 0) ? "0" : power_supply;
+       (*battery_index)++;
 
-       return 0;
-}
-#endif /* KERNEL_LINUX */
+       read_acpi_full_capacity (dir, power_supply, &capacity_full, &capacity_design);
 
+       submit_capacity (plugin_instance,
+                       capacity_charged * PROC_ACPI_FACTOR,
+                       capacity_full * PROC_ACPI_FACTOR,
+                       capacity_design * PROC_ACPI_FACTOR);
 
-static int battery_read (void)
-{
-#if HAVE_IOKIT_IOKITLIB_H || HAVE_IOKIT_PS_IOPOWERSOURCES_H
-       double charge  = INVALID_VALUE; /* Current charge in Ah */
-       double current = INVALID_VALUE; /* Current in A */
-       double voltage = INVALID_VALUE; /* Voltage in V */
+       battery_submit (plugin_instance,
+                       is_current ? "current" : "power",
+                       power * PROC_ACPI_FACTOR);
+       battery_submit (plugin_instance, "voltage", voltage * PROC_ACPI_FACTOR);
 
-       double charge_rel = INVALID_VALUE; /* Current charge in percent */
-       double charge_abs = INVALID_VALUE; /* Total capacity */
+       return 0;
+} /* }}} int read_acpi_callback */
 
-#if HAVE_IOKIT_PS_IOPOWERSOURCES_H
-       get_via_io_power_sources (&charge_rel, &current, &voltage);
-#endif
-#if HAVE_IOKIT_IOKITLIB_H
-       get_via_generic_iokit (&charge_abs, &current, &voltage);
-#endif
+static int read_acpi (void) /* {{{ */
+{
+       int status;
+       int battery_counter = 0;
 
-       if ((charge_rel != INVALID_VALUE) && (charge_abs != INVALID_VALUE))
-               charge = charge_abs * charge_rel / 100.0;
+       if (access (PROC_ACPI_PATH, R_OK) != 0)
+               return (ENOENT);
 
-       if (charge != INVALID_VALUE)
-               battery_submit ("0", "charge", charge);
-       if (current != INVALID_VALUE)
-               battery_submit ("0", "current", current);
-       if (voltage != INVALID_VALUE)
-               battery_submit ("0", "voltage", voltage);
-/* #endif HAVE_IOKIT_IOKITLIB_H || HAVE_IOKIT_PS_IOPOWERSOURCES_H */
+       status = walk_directory (PROC_ACPI_PATH, read_acpi_callback,
+                       /* user_data = */ &battery_counter,
+                       /* include hidden */ 0);
+       return (status);
+} /* }}} int read_acpi */
 
-#elif KERNEL_LINUX
-       static c_complain_t acpi_dir_complaint = C_COMPLAIN_INIT_STATIC;
+static int read_pmu (void) /* {{{ */
+{
+       int i = 0;
+       /* The upper limit here is just a safeguard. If there is a system with
+        * more than 100 batteries, this can easily be increased. */
+       for (; i < 100; i++)
+       {
+               FILE *fh;
 
-       FILE *fh;
-       char buffer[1024];
-       char filename[256];
-       
-       char *fields[8];
-       int numfields;
+               char buffer[1024];
+               char filename[PATH_MAX];
+               char plugin_instance[DATA_MAX_NAME_LEN];
 
-       int i;
-       int len;
+               gauge_t current = NAN;
+               gauge_t voltage = NAN;
+               gauge_t charge  = NAN;
 
-       for (i = 0; i < battery_pmu_num; i++)
-       {
-               char    batnum_str[256];
-               double  current = INVALID_VALUE;
-               double  voltage = INVALID_VALUE;
-               double  charge  = INVALID_VALUE;
-               double *valptr = NULL;
-
-               len = ssnprintf (filename, sizeof (filename), battery_pmu_file, i);
-               if ((len < 0) || ((unsigned int)len >= sizeof (filename)))
-                       continue;
+               ssnprintf (filename, sizeof (filename), PROC_PMU_PATH_FORMAT, i);
+               if (access (filename, R_OK) != 0)
+                       break;
 
-               len = ssnprintf (batnum_str, sizeof (batnum_str), "%i", i);
-               if ((len < 0) || ((unsigned int)len >= sizeof (batnum_str)))
-                       continue;
+               ssnprintf (plugin_instance, sizeof (plugin_instance), "%i", i);
 
-               if ((fh = fopen (filename, "r")) == NULL)
-                       continue;
+               fh = fopen (filename, "r");
+               if (fh == NULL)
+               {
+                       if (errno == ENOENT)
+                               break;
+                       else if ((errno == EAGAIN) || (errno == EINTR))
+                               continue;
+                       else
+                               return (errno);
+               }
 
                while (fgets (buffer, sizeof (buffer), fh) != NULL)
                {
-                       numfields = strsplit (buffer, fields, 8);
+                       char *fields[8];
+                       int numfields;
 
+                       numfields = strsplit (buffer, fields, STATIC_ARRAY_SIZE (fields));
                        if (numfields < 3)
                                continue;
 
                        if (strcmp ("current", fields[0]) == 0)
-                               valptr = &current;
+                               strtogauge (fields[2], &current);
                        else if (strcmp ("voltage", fields[0]) == 0)
-                               valptr = &voltage;
+                               strtogauge (fields[2], &voltage);
                        else if (strcmp ("charge", fields[0]) == 0)
-                               valptr = &charge;
-                       else
-                               valptr = NULL;
-
-                       if (valptr != NULL)
-                       {
-                               char *endptr;
-
-                               endptr = NULL;
-                               errno  = 0;
-
-                               *valptr = strtod (fields[2], &endptr) / 1000.0;
-
-                               if ((fields[2] == endptr) || (errno != 0))
-                                       *valptr = INVALID_VALUE;
-                       }
+                               strtogauge (fields[2], &charge);
                }
 
                fclose (fh);
                fh = NULL;
 
-               if (charge != INVALID_VALUE)
-                       battery_submit ("0", "charge", charge);
-               if (current != INVALID_VALUE)
-                       battery_submit ("0", "current", current);
-               if (voltage != INVALID_VALUE)
-                       battery_submit ("0", "voltage", voltage);
+               battery_submit (plugin_instance, "charge", charge / 1000.0);
+               battery_submit (plugin_instance, "current", current / 1000.0);
+               battery_submit (plugin_instance, "voltage", voltage / 1000.0);
        }
 
-       if (0 == access (battery_acpi_dir, R_OK))
-               walk_directory (battery_acpi_dir, battery_read_acpi,
-                               /* user_data = */ NULL,
-                               /* include hidden */ 0);
-       else
-       {
-               char errbuf[1024];
-               c_complain_once (LOG_WARNING, &acpi_dir_complaint,
-                               "battery plugin: Failed to access `%s': %s",
-                               battery_acpi_dir,
-                               sstrerror (errno, errbuf, sizeof (errbuf)));
-       }
+       if (i == 0)
+               return (ENOENT);
+       return (0);
+} /* }}} int read_pmu */
 
+static int battery_read (void) /* {{{ */
+{
+       int status;
+
+       DEBUG ("battery plugin: Trying sysfs ...");
+       status = read_sysfs ();
+       if (status == 0)
+               return (0);
+
+       DEBUG ("battery plugin: Trying acpi ...");
+       status = read_acpi ();
+       if (status == 0)
+               return (0);
+
+       DEBUG ("battery plugin: Trying pmu ...");
+       status = read_pmu ();
+       if (status == 0)
+               return (0);
+
+       ERROR ("battery plugin: All available input methods failed.");
+       return (-1);
+} /* }}} int battery_read */
 #endif /* KERNEL_LINUX */
 
+static int battery_config (oconfig_item_t *ci)
+{
+       for (int i = 0; i < ci->children_num; i++)
+       {
+               oconfig_item_t *child = ci->children + i;
+
+               if (strcasecmp ("ValuesPercentage", child->key) == 0)
+                       cf_util_get_boolean (child, &report_percent);
+               else if (strcasecmp ("ReportDegraded", child->key) == 0)
+                       cf_util_get_boolean (child, &report_degraded);
+               else
+                       WARNING ("battery plugin: Ignoring unknown "
+                                       "configuration option \"%s\".",
+                                       child->key);
+       }
+
        return (0);
-}
+} /* }}} int battery_config */
 
 void module_register (void)
 {
-       plugin_register_init ("battery", battery_init);
+       plugin_register_complex_config ("battery", battery_config);
        plugin_register_read ("battery", battery_read);
 } /* void module_register */