update_devices
g_timeout_add(BATTERY_POLL_TIMER, update_devices, ctx);
gboolean update_devices(gpointer data);
(void) update_devices(ap_id, DEV_ADD);
(void) update_devices(ap_id, DEV_REMOVE);
(void) update_devices(OBP_CPU, DEV_ADD);
(void) update_devices(OBP_CPU, DEV_REMOVE);
extern int update_devices(char *dev, int op);