int result;
 
        if (strlen(type) >= THERMAL_NAME_LENGTH)
-               return NULL;
+               return ERR_PTR(-EINVAL);
 
        if (!ops || !ops->get_max_state || !ops->get_cur_state ||
            !ops->set_cur_state)
-               return NULL;
+               return ERR_PTR(-EINVAL);
 
        cdev = kzalloc(sizeof(struct thermal_cooling_device), GFP_KERNEL);
        if (!cdev)
-               return NULL;
+               return ERR_PTR(-ENOMEM);
 
        result = get_idr(&thermal_cdev_idr, &thermal_idr_lock, &cdev->id);
        if (result) {
                kfree(cdev);
-               return NULL;
+               return ERR_PTR(result);
        }
 
        strcpy(cdev->type, type);
        if (result) {
                release_idr(&thermal_cdev_idr, &thermal_idr_lock, cdev->id);
                kfree(cdev);
-               return NULL;
+               return ERR_PTR(result);
        }
 
        /* sys I/F */
       unregister:
        release_idr(&thermal_cdev_idr, &thermal_idr_lock, cdev->id);
        device_unregister(&cdev->device);
-       return NULL;
+       return ERR_PTR(result);
 }
 
 EXPORT_SYMBOL(thermal_cooling_device_register);
        int count;
 
        if (strlen(type) >= THERMAL_NAME_LENGTH)
-               return NULL;
+               return ERR_PTR(-EINVAL);
 
        if (trips > THERMAL_MAX_TRIPS || trips < 0)
-               return NULL;
+               return ERR_PTR(-EINVAL);
 
        if (!ops || !ops->get_temp)
-               return NULL;
+               return ERR_PTR(-EINVAL);
 
        tz = kzalloc(sizeof(struct thermal_zone_device), GFP_KERNEL);
        if (!tz)
-               return NULL;
+               return ERR_PTR(-ENOMEM);
 
        INIT_LIST_HEAD(&tz->cooling_devices);
        idr_init(&tz->idr);
        result = get_idr(&thermal_tz_idr, &thermal_idr_lock, &tz->id);
        if (result) {
                kfree(tz);
-               return NULL;
+               return ERR_PTR(result);
        }
 
        strcpy(tz->type, type);
        if (result) {
                release_idr(&thermal_tz_idr, &thermal_idr_lock, tz->id);
                kfree(tz);
-               return NULL;
+               return ERR_PTR(result);
        }
 
        /* sys I/F */
       unregister:
        release_idr(&thermal_tz_idr, &thermal_idr_lock, tz->id);
        device_unregister(&tz->device);
-       return NULL;
+       return ERR_PTR(result);
 }
 
 EXPORT_SYMBOL(thermal_zone_device_register);