drm_version
struct drm_version __user *version;
#define DRM_IOCTL_VERSION DRM_IOWR(0x00, struct drm_version)
typedef struct drm_version drm_version_t;
int drm_version(struct drm_device *dev, void *data,
struct drm_version *version = data;
DRM_IOCTL_DEF(DRM_IOCTL_VERSION, drm_version, DRM_UNLOCKED),
struct drm_version version;
err = drm_version(dev, (void *)&version, file_priv);