smmu_write_ack
error = smmu_write_ack(sc, SMMU_CR0, SMMU_CR0ACK, reg);
error = smmu_write_ack(sc, SMMU_IRQ_CTRL, SMMU_IRQ_CTRLACK, 0);
error = smmu_write_ack(sc, SMMU_IRQ_CTRL, SMMU_IRQ_CTRLACK, reg);
error = smmu_write_ack(sc, SMMU_CR0, SMMU_CR0ACK, reg);
error = smmu_write_ack(sc, SMMU_CR0, SMMU_CR0ACK, reg);
error = smmu_write_ack(sc, SMMU_CR0, SMMU_CR0ACK, reg);
error = smmu_write_ack(sc, SMMU_CR0, SMMU_CR0ACK, reg);
error = smmu_write_ack(sc, SMMU_CR0, SMMU_CR0ACK, reg);