>+ nor->read_reg = atmel_qspi_read_reg; >+ nor->write_reg = atmel_qspi_write_reg; >+ nor->read = atmel_qspi_read; >+ nor->write = atmel_qspi_write; >+ nor->erase = atmel_qspi_erase; >+ nor->set_protocol = atmel_qspi_set_protocol; This is very good, the structure of spi_nor should add a hook function to notify spi controller That spi nor transfer protocol already changed. >+ >+ if (of_modalias_node(child, modalias, sizeof(modalias)) < 0) { >+ err = -ENODEV; >+ goto release_channel; >+ } >+ >+ err = of_property_read_u32(child, "spi-max-frequency", &aq->clk_rate); >+ if (err < 0) >+ goto release_channel; >+ >+ err = atmel_qspi_init(aq); >+ if (err) >+ goto release_channel; >+ >+ nor->dev->of_node = child; >+ err = spi_nor_scan(nor, modalias, SPI_NOR_QUAD); > goto release_channel; >+ ....... >static inline struct spi_nor *mtd_to_spi_nor(struct mtd_info *mtd) { return mtd->priv; >@@ -944,6 +960,11 @@ static int micron_quad_enable(struct spi_nor *nor) > return ret; > } > >+ /* switch protocol to Quad CMD 4-4-4 */ >+ ret = spi_nor_set_protocol(nor, SPI_PROTO_4_4_4); >+ if (ret) >+ return ret; >+ This make sense,from spi nor side,once its protocol being changed, Mtd layer must notify this status to spi nor controller immediately, And spi nor controller also should re-adjust its protocol. Otherwise, following reading SR operation will fail. > > ret = spi_nor_wait_till_ready(nor); > if (ret) > return ret; If my ack has any value in here, feel free to add it. Acked-by: Bean Huo <beanhuo@xxxxxxxxxx> -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html