[PATCH linux-next v4 5/5] mtd: atmel-quadspi: add driver for Atmel QSPI controller
From: Bean Huo 霍斌斌 beanhuo <hidden>
Date: 2015-08-25 01:46:41
Also in:
linux-devicetree, linux-spi, lkml
+ 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;
quoted hunk ↗ jump to hunk
@@ -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 <redacted>