+static int button_suitable(Button *b) {
+ unsigned long types[CONST_MAX(EV_KEY, EV_SW)/ULONG_BITS+1];
+
+ assert(b);
+ assert(b->fd);
+
+ if (ioctl(b->fd, EVIOCGBIT(EV_SYN, sizeof(types)), types) < 0)
+ return -errno;
+
+ if (bitset_get(types, EV_KEY)) {
+ unsigned long keys[CONST_MAX4(KEY_POWER, KEY_POWER2, KEY_SLEEP, KEY_SUSPEND)/ULONG_BITS+1];
+
+ if (ioctl(b->fd, EVIOCGBIT(EV_KEY, sizeof(keys)), keys) < 0)
+ return -errno;
+
+ if (bitset_get(keys, KEY_POWER) ||
+ bitset_get(keys, KEY_POWER2) ||
+ bitset_get(keys, KEY_SLEEP) ||
+ bitset_get(keys, KEY_SUSPEND))
+ return true;
+ }
+
+ if (bitset_get(types, EV_SW)) {
+ unsigned long switches[CONST_MAX(SW_LID, SW_DOCK)/ULONG_BITS+1];
+
+ if (ioctl(b->fd, EVIOCGBIT(EV_SW, sizeof(switches)), switches) < 0)
+ return -errno;
+
+ if (bitset_get(switches, SW_LID) ||
+ bitset_get(switches, SW_DOCK))
+ return true;
+ }
+
+ return false;
+}
+