FF_CNT
static const char *force[FF_CNT] = {
for (i = 0; i < BITS_TO_LONGS(FF_CNT); i++)
[EV_FF] = FF_CNT,
for_each_set_bit(i, dev->ffbit, FF_CNT)
unsigned long ffbit[BITS_TO_LONGS(FF_CNT)];
unsigned long ffbit[BITS_TO_LONGS(FF_CNT)];