dev_ref
if (d->hold && !dev_ref(d))
if (!dev_ref(mtc->dev))
dev_ref(mtc->dev);
return dev_ref(c->u.hw.dev);
int dev_ref(struct dev *);
int dev_ref(struct dev *);
if (!dev_ref(ndev))
dev_ref(o->dev);
if (dev_ref(a->dev))