diff options
| -rw-r--r-- | drivers/mtd/spi-nor/micron-st.c | 22 |
1 files changed, 17 insertions, 5 deletions
diff --git a/drivers/mtd/spi-nor/micron-st.c b/drivers/mtd/spi-nor/micron-st.c index 97e82d4f9f1f..bb95b1aabf74 100644 --- a/drivers/mtd/spi-nor/micron-st.c +++ b/drivers/mtd/spi-nor/micron-st.c @@ -13,6 +13,7 @@ #define SPINOR_OP_MT_WR_ANY_REG 0x81 /* Write volatile register */ #define SPINOR_REG_MT_CFR0V 0x00 /* For setting octal DTR mode */ #define SPINOR_REG_MT_CFR1V 0x01 /* For setting dummy cycles */ +#define SPINOR_REG_MT_CFR1V_DEF 0x1f /* Default dummy cycles */ #define SPINOR_MT_OCT_DTR 0xe7 /* Enable Octal DTR. */ #define SPINOR_MT_EXSPI 0xff /* Enable Extended SPI (default) */ @@ -48,17 +49,28 @@ static int spi_nor_micron_octal_dtr_enable(struct spi_nor *nor, bool enable) if (ret) return ret; - if (enable) - *buf = SPINOR_MT_OCT_DTR; - else - *buf = SPINOR_MT_EXSPI; + if (enable) { + buf[0] = SPINOR_MT_OCT_DTR; + } else { + /* + * The register is 1-byte wide, but 1-byte transactions are not + * allowed in 8D-8D-8D mode. The next register is the dummy + * cycle configuration register. Since the transaction needs to + * be at least 2 bytes wide, set the next register to its + * default value. This also makes sense because the value was + * changed when enabling 8D-8D-8D mode, it should be reset when + * disabling. + */ + buf[0] = SPINOR_MT_EXSPI; + buf[1] = SPINOR_REG_MT_CFR1V_DEF; + } op = (struct spi_mem_op) SPI_MEM_OP(SPI_MEM_OP_CMD(SPINOR_OP_MT_WR_ANY_REG, 1), SPI_MEM_OP_ADDR(enable ? 3 : 4, SPINOR_REG_MT_CFR0V, 1), SPI_MEM_OP_NO_DUMMY, - SPI_MEM_OP_DATA_OUT(1, buf, 1)); + SPI_MEM_OP_DATA_OUT(enable ? 1 : 2, buf, 1)); if (!enable) spi_nor_spimem_setup_op(nor, &op, SNOR_PROTO_8_8_8_DTR); |