vbox_encoder
#define to_vbox_encoder(x) container_of(x, struct vbox_encoder, base)
struct vbox_encoder *vbox_encoder;
vbox_encoder = kzalloc_obj(*vbox_encoder);
if (!vbox_encoder)
drm_encoder_init(dev, &vbox_encoder->base, &vbox_enc_funcs,
vbox_encoder->base.possible_crtcs = 1 << i;
return &vbox_encoder->base;