static int
 nvkm_volt_set(struct nvkm_volt *volt, u32 uv)
 {
+       struct nvkm_subdev *subdev = &volt->subdev;
        if (volt->vid_set) {
                int i, ret = -EINVAL;
                for (i = 0; i < volt->vid_nr; i++) {
                        if (volt->vid[i].uv == uv) {
                                ret = volt->vid_set(volt, volt->vid[i].vid);
-                               nv_debug(volt, "set %duv: %d\n", uv, ret);
+                               nvkm_debug(subdev, "set %duv: %d\n", uv, ret);
                                break;
                        }
                }
 _nvkm_volt_init(struct nvkm_object *object)
 {
        struct nvkm_volt *volt = (void *)object;
+       struct nvkm_subdev *subdev = &volt->subdev;
        int ret;
 
        ret = nvkm_subdev_init(&volt->subdev);
        ret = volt->get(volt);
        if (ret < 0) {
                if (ret != -ENODEV)
-                       nv_debug(volt, "current voltage unknown\n");
+                       nvkm_debug(subdev, "current voltage unknown\n");
                return 0;
        }
 
-       nv_info(volt, "GPU voltage: %duv\n", ret);
+       nvkm_debug(subdev, "current voltage: %duv\n", ret);
        return 0;
 }
 
 nvkm_volt_create_(struct nvkm_object *parent, struct nvkm_object *engine,
                  struct nvkm_oclass *oclass, int length, void **pobject)
 {
-       struct nvkm_bios *bios = nvkm_bios(parent);
+       struct nvkm_device *device = (void *)parent;
+       struct nvkm_bios *bios = device->bios;
        struct nvkm_volt *volt;
        int ret, i;
 
 
        if (volt->vid_nr) {
                for (i = 0; i < volt->vid_nr; i++) {
-                       nv_debug(volt, "VID %02x: %duv\n",
-                                volt->vid[i].vid, volt->vid[i].uv);
+                       nvkm_debug(&volt->subdev, "VID %02x: %duv\n",
+                                  volt->vid[i].vid, volt->vid[i].uv);
                }
 
                /*XXX: this is an assumption.. there probably exists boards
 
 gk20a_volt_vid_set(struct nvkm_volt *obj, u8 vid)
 {
        struct gk20a_volt *volt = container_of(obj, typeof(*volt), base);
+       struct nvkm_subdev *subdev = &volt->base.subdev;
 
-       nv_debug(volt, "set voltage as %duv\n", volt->base.vid[vid].uv);
+       nvkm_debug(subdev, "set voltage as %duv\n", volt->base.vid[vid].uv);
        return regulator_set_voltage(volt->vdd, volt->base.vid[vid].uv, 1200000);
 }
 
 gk20a_volt_set_id(struct nvkm_volt *obj, u8 id, int condition)
 {
        struct gk20a_volt *volt = container_of(obj, typeof(*volt), base);
+       struct nvkm_subdev *subdev = &volt->base.subdev;
        int prev_uv = regulator_get_voltage(volt->vdd);
        int target_uv = volt->base.vid[id].uv;
        int ret;
 
-       nv_debug(volt, "prev=%d, target=%d, condition=%d\n",
-                       prev_uv, target_uv, condition);
+       nvkm_debug(subdev, "prev=%d, target=%d, condition=%d\n",
+                  prev_uv, target_uv, condition);
        if (!condition ||
                (condition < 0 && target_uv < prev_uv) ||
                (condition > 0 && target_uv > prev_uv)) {
        plat = nv_device_to_platform(nv_device(parent));
 
        uv = regulator_get_voltage(plat->gpu->vdd);
-       nv_info(volt, "The default voltage is %duV\n", uv);
+       nvkm_info(&volt->base.subdev, "The default voltage is %duV\n", uv);
 
        volt->vdd = plat->gpu->vdd;
        volt->base.vid_get = gk20a_volt_vid_get;
        volt->base.set_id = gk20a_volt_set_id;
 
        volt->base.vid_nr = ARRAY_SIZE(gk20a_cvb_coef);
-       nv_debug(volt, "%s - vid_nr = %d\n", __func__, volt->base.vid_nr);
+       nvkm_debug(&volt->base.subdev, "%s - vid_nr = %d\n", __func__,
+                  volt->base.vid_nr);
        for (i = 0; i < volt->base.vid_nr; i++) {
                volt->base.vid[i].vid = i;
                volt->base.vid[i].uv =
                        gk20a_volt_calc_voltage(&gk20a_cvb_coef[i],
                                                plat->gpu_speedo);
-               nv_debug(volt, "%2d: vid=%d, uv=%d\n", i,
-                        volt->base.vid[i].vid, volt->base.vid[i].uv);
+               nvkm_debug(&volt->base.subdev, "%2d: vid=%d, uv=%d\n", i,
+                          volt->base.vid[i].vid, volt->base.vid[i].uv);
        }
 
        return 0;