1 files changed, 111 insertions, 0 deletions
diff --git a/battery.c b/battery.c
new file mode 100644
index 0000000..a4a35e0
--- /dev/null
+++ b/battery.c
@@ -0,0 +1,111 @@
+/*
+ * battery.c interface to APM and (TODO:) ACPI
+ * 
+ */
+
+/* exported functions:
+ *
+ * int Battery (double *perc, int *status, double *lasting);
+ *   returns:
+ *     perc ... percentage of battery (0..100)
+ *     status .. 0 (online), 1 (charging), 2 (discharging)
+ *     lasting ... seconds, how long battery will last
+ * 
+ */
+#include <stdlib.h>
+#include <stdio.h>
+#include <fcntl.h>
+#include <ctype.h>
+#include <string.h>
+#include <unistd.h>
+#include <errno.h>
+#include <sys/time.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+
+#include "debug.h"
+
+
+int Battery (int *perc, int *status, double *dur) 
+{
+  static int fd = -2;
+  static int apm = 0;
+
+  if (fd==-1) return -1;
+
+  if (fd==-2) {
+    fd = open("/proc/apm", O_RDONLY | O_NDELAY);
+    if (fd==-1) {
+      error ("open(/proc/apm) failed: %s", strerror(errno));
+      fd = open("/proc/acpi", O_RDONLY | O_NDELAY); /* FIXME */
+      if (fd==-1) {
+        error ("open(/proc/acpi) failed: %s", strerror(errno));
+        return -1;
+      }
+      debug ("open(/proc/acpi)=%d", fd);
+    }
+    else {
+      debug ("open(/proc/apm)=%d", fd);
+      apm = 1;
+    }
+  }
+  if (lseek(fd, 0L, SEEK_SET)!=0) {
+    error ("lseek(/proc/apm|acpi) failed: %s", strerror(errno));
+    fd=-1;
+    return -1;
+  }
+  if (apm) {
+    int f3, f4;
+    char eh[4];
+    char buffer[128];
+    /* /usr/src/linux/arch/i386/kernel/apm.c :
+      	p += sprintf(p, "%s %d.%d 0x%02x 0x%02x 0x%02x 0x%02x %d%% %d %s\n",
+		     driver_version,
+		     (apm_bios_info.version >> 8) & 0xff,
+		     apm_bios_info.version & 0xff,
+		     apm_bios_info.flags,
+		     ac_line_status,
+		     battery_status,
+		     battery_flag,
+		     percentage,
+		     time_units,
+		     units);
+	   3) AC line status
+	      0x00: Off-line
+	      0x01: On-line
+	      0x02: On backup power (BIOS >= 1.1 only)
+	      0xff: Unknown
+	   4) Battery status
+	      0x00: High
+	      0x01: Low
+	      0x02: Critical
+	      0x03: Charging
+	      0x04: Selected battery not present (BIOS >= 1.2 only)
+	      0xff: Unknown
+    */
+    
+    if (read (fd, &buffer, sizeof(buffer)-1)==-1) {
+      error ("read(/proc/apm) failed: %s", strerror(errno));
+      fd=-1;
+      return -1;
+    }
+    /*              Ver v.v fl  as bs bf perc tu u*/
+    sscanf(buffer, "%*s %*s %*s %x %x %*s %d%% %lf %3s", &f3, &f4, perc, dur, eh);
+    if (f3 == 0x1) 
+      *status = 0; /* Online */
+    else
+      *status = 2; /* Offline = discharging */
+    if (f4 == 0x3)
+      *status = 1; /* charging */
+    eh[1] = '\0'; /* m | s */
+    if (*eh == 'm')
+      *dur *= 60;
+#ifdef DEBUG_BATT    
+    info("perc=%d, f3=%x, f4=%x, stat=%d, dur=%lf", *perc,f3,f4, *status, *dur);
+#endif    
+  }
+  else {
+    /* FIXME: parse ACPI */
+  }
+  return 0;
+}