wmacpi/libacpi.c

   1 #include <stdio.h>
   2 #include <string.h>
   3 #include <stdlib.h>
   4 #include <sys/types.h>
   5 #include <dirent.h>
   6
   7 #include "wmacpi.h"
   8
   9 #define MAXBATT 8
  10
  11 #ifdef ACPI
  12 #ifdef PRO
  13 extern char *state[];
  14 #endif
  15 extern APMInfo *apminfo;
  16 static char batteries[MAXBATT][128];
  17 static char battinfo[MAXBATT][128];
  18 int batt_count;
  19 /* temp buffer */
  20 char buf[512];
  21
  22 /* local proto */
  23 int acpi_get_design_cap(int battery);
  24
  25 /* see if we have ACPI support and check version */
  26 int power_init(void)
  27 {
  28     FILE *acpi;
  29     char buf[4096];
  30     DIR *battdir;
  31     struct dirent *batt;
  32     char *name;
  33     int acpi_ver = 0;
  34
  35     if (!(acpi = fopen("/proc/acpi/info", "r"))) {
  36         fprintf(stderr, "This system does not support ACPI\n");
  37         return 1;
  38     }
  39
  40     /* okay, now see if we got the right version */
  41     fread(buf, 4096, 1, acpi);
  42     acpi_ver = strtol(buf + 25, NULL, 10);
  43     eprint(1, "ACPI version detected: %d\n", acpi_ver);
  44     if (acpi_ver < 20020214) {
  45         fprintf(stderr, "This version requires ACPI subsystem version 20020214\n");
  46         fclose(acpi);
  47         return 1;
  48     }
  49
  50     /* yep, all good */
  51     fclose(acpi);
  52
  53     /* now enumerate batteries */
  54     batt_count = 0;
  55     battdir = opendir("/proc/acpi/battery");
  56     if (battdir == NULL) {
  57         fprintf(stderr, "No batteries or ACPI not supported\n");
  58         return 1;
  59     }
  60     while ((batt = readdir(battdir))) {
  61         name = batt->d_name;
  62
  63         /* skip . and .. */
  64         if (!strncmp(".", name, 1) || !strncmp("..", name, 2))
  65             continue;
  66
  67         sprintf(batteries[batt_count], "/proc/acpi/battery/%s/state", name);
  68         sprintf(battinfo[batt_count], "/proc/acpi/battery/%s/info", name);
  69         eprint(1, "battery detected at %s\n", batteries[batt_count]);
  70         batt_count++;
  71     }
  72     closedir(battdir);
  73
  74     /* tell user some info */
  75     eprint(1, "%d batteries detected\n", batt_count);
  76     fprintf(stderr, "wmacpi: found %d batter%s\n", batt_count,
  77             (batt_count == 1) ? "y" : "ies");
  78
  79     return 0;
  80 }
  81
  82 int acpi_get_design_cap(int battery)
  83 {
  84     FILE *acpi;
  85     char *ptr;
  86     int design_cap;
  87
  88     if (battery > MAXBATT)
  89         return -1;
  90
  91     if (!(acpi = fopen(battinfo[battery], "r")))
  92         return -1;
  93
  94     fread(buf, 512, 1, acpi);
  95     fclose(acpi);
  96
  97     if ((ptr = strstr(buf, "last full capacity"))) {
  98         ptr += 25;
  99         sscanf(ptr, "%d", &design_cap);
 100         eprint(1, "last full capacity: %d\n", design_cap);
 101     } else {
 102         /* hack.  if there isnt any info on last capacity, we are
 103          * screwed, but let's not come back here again */
 104         design_cap = -1;
 105         eprint(1, "Cannot retrieve design capacity!");
 106     }
 107
 108     return design_cap;
 109 }
 110
 111 void acquire_info(void)
 112 {
 113     FILE *acpi;
 114     char *ptr;
 115     char stat;
 116
 117     static int dcap = 0xdeadbeef;
 118
 119     int percent = 100;          /* battery percentage */
 120     int ptemp, rate, rtime = 0;
 121
 122     if (dcap == 0xdeadbeef) {
 123         /* get from first battery for now */
 124         dcap = acpi_get_design_cap(0);
 125     }
 126
 127     if (!(acpi = fopen(batteries[0], "r")))
 128         return;
 129
 130     eprint(1, "opened acpi file successfully");
 131     fread(buf, 512, 1, acpi);
 132     fclose(acpi);
 133
 134     /* This section of the code will calculate "percentage remaining"
 135      * using battery capacity, and the following formula (acpi spec 3.9.2):
 136      * percentage = (current_capacity / last_full_capacity) * 100; */
 137     if ((ptr = strstr(buf, "remaining capacity"))) {
 138         ptr += 25;
 139         sscanf(ptr, "%d", &ptemp);
 140         eprint(1, "capacity: %d\n", ptemp);
 141         percent = (float)((float)ptemp / (float)dcap) * 100;
 142         eprint(1, "percent: %d\n", percent);
 143     }
 144     apminfo->percentage = percent;
 145
 146     /* this section of code will calculate "time remaining"
 147      * using battery remaining capacity, and battery "rate" (3.9.3) */
 148     if ((ptr = strstr(buf, "present rate"))) {
 149         ptr += 25;
 150         sscanf(ptr, "%d", &rate);
 151         eprint(1, "rate: %d\n", rate);
 152         if (rate <= 0)
 153             rate = 0;
 154         /* time remaining in minutes */
 155         rtime = ((float)((float)ptemp / (float)rate)) * 60;
 156         if (rtime <= 0)
 157             rtime = 0;
 158         eprint(1, "time rem: %d\n", rtime);
 159     }
 160     apminfo->rtime = rtime;
 161
 162     if ((ptr = strstr(buf, "charging state"))) {
 163         /* found battery discharging.  This is used to determine if
 164          * we are on AC power or not. Notice check for "ch" later on */
 165         stat = *(ptr + 25);
 166         if (stat == 'o' || stat == 'u') /* "ok" | "unknown" : charged, on ac power */
 167             apminfo->power = POWER;
 168         else
 169             /* we set this, and later on use percentage
 170              * value to determine high/med/low */
 171             apminfo->power = HIGH;
 172
 173         /* but if we are on power, we might be charging too.  Check. */
 174         if ((ptr = strstr(buf, "charging state"))) {
 175             /* found battery charging line.  We will change power state
 176              * if we are on power, and charging. */
 177             stat = *(ptr + 25);
 178             /* this is seriously stupid - but we catch "critical" */
 179             if (stat == 'c' && (*(ptr + 26) == 'h'))
 180                 apminfo->power = CHARGING;
 181         }
 182     }
 183
 184     /* we are not on power, and not charging.  So, it would make sense
 185      * to check if battery is "critical low", and calculate interesting
 186      * things like battery HIGH/LOW, and maybe battery usage LOAD
 187      * This will be replaced with some code to allow setting user-specified
 188      * low / critical alarms */
 189     if ((apminfo->power != POWER) && (apminfo->power != CHARGING)) {
 190         eprint(1, "entering battery status check");
 191         if ((ptr = strstr(buf, "capacity state"))) {
 192             stat = *(ptr + 25);
 193             /* only check "c" here because we already caught "CHarging" earlier
 194              * and also look into crit_level */
 195             if (stat == 'c' || (apminfo->percentage <= apminfo->crit_level)) {
 196                 /* nothing else to do here - critical battery. get out */
 197                 eprint(1, "Received critical battery status");
 198                 apminfo->power = CRIT;
 199             }
 200         }
 201     }
 202     process_plugin_timer();
 203
 204     eprint(1, "current state: %s (%d)", state[apminfo->power], apminfo->power);
 205 }
 206 #endif /* ACPI */