isst_if_mbox_cmds
cb.offset = offsetof(struct isst_if_mbox_cmds, mbox_cmd);
cb.offset = offsetof(struct isst_if_mbox_cmds, mbox_cmd);
#define ISST_IF_MBOX_COMMAND _IOWR(ISST_IF_MAGIC, 3, struct isst_if_mbox_cmds *)
struct isst_if_mbox_cmds mbox_cmds = { 0 };