From: Takahiro Kuwano Takahiro.Kuwano@infineon.com
Some of Spansion/Cypress chips support volatile version of configuration registers and it is recommended to update volatile registers in the field application due to a risk of the non-volatile registers corruption by power interrupt. This patch adds a function to set Quad Enable bit in CFR1 volatile.
Signed-off-by: Takahiro Kuwano Takahiro.Kuwano@infineon.com --- Changes in v6: - No change
Changes in v5: - Fix register address calculation, 'base | offset' -> 'base + offset'
drivers/mtd/spi/spi-nor-core.c | 53 ++++++++++++++++++++++++++++++++++ include/linux/mtd/spi-nor.h | 1 + 2 files changed, 54 insertions(+)
diff --git a/drivers/mtd/spi/spi-nor-core.c b/drivers/mtd/spi/spi-nor-core.c index 36c1756576..d731df30a7 100644 --- a/drivers/mtd/spi/spi-nor-core.c +++ b/drivers/mtd/spi/spi-nor-core.c @@ -1644,6 +1644,59 @@ static int spansion_read_cr_quad_enable(struct spi_nor *nor) return 0; }
+/** + * spansion_quad_enable_volatile() - enable Quad I/O mode in volatile register. + * @nor: pointer to a 'struct spi_nor' + * @addr_base: base address of register (can be >0 in multi-die parts) + * @dummy: number of dummy cycles for register read + * + * It is recommended to update volatile registers in the field application due + * to a risk of the non-volatile registers corruption by power interrupt. This + * function sets Quad Enable bit in CFR1 volatile. + * + * Return: 0 on success, -errno otherwise. + */ +static int spansion_quad_enable_volatile(struct spi_nor *nor, u32 addr_base, + u8 dummy) +{ + u32 addr = addr_base + SPINOR_REG_ADDR_CFR1V; + + u8 cr; + int ret; + + /* Check current Quad Enable bit value. */ + ret = spansion_read_any_reg(nor, addr, dummy, &cr); + if (ret < 0) { + dev_dbg(nor->dev, + "error while reading configuration register\n"); + return -EINVAL; + } + + if (cr & CR_QUAD_EN_SPAN) + return 0; + + cr |= CR_QUAD_EN_SPAN; + + write_enable(nor); + + ret = spansion_write_any_reg(nor, addr, cr); + + if (ret < 0) { + dev_dbg(nor->dev, + "error while writing configuration register\n"); + return -EINVAL; + } + + /* Read back and check it. */ + ret = spansion_read_any_reg(nor, addr, dummy, &cr); + if (ret || !(cr & CR_QUAD_EN_SPAN)) { + dev_dbg(nor->dev, "Spansion Quad bit not set\n"); + return -EINVAL; + } + + return 0; +} + #if CONFIG_IS_ENABLED(SPI_FLASH_SFDP_SUPPORT) /** * spansion_no_read_cr_quad_enable() - set QE bit in Configuration Register. diff --git a/include/linux/mtd/spi-nor.h b/include/linux/mtd/spi-nor.h index a9b389f2af..de4472da5c 100644 --- a/include/linux/mtd/spi-nor.h +++ b/include/linux/mtd/spi-nor.h @@ -123,6 +123,7 @@ #define SPINOR_OP_CLSR 0x30 /* Clear status register 1 */ #define SPINOR_OP_RDAR 0x65 /* Read any register */ #define SPINOR_OP_WRAR 0x71 /* Write any register */ +#define SPINOR_REG_ADDR_CFR1V 0x00800002
/* Used for Micron flashes only. */ #define SPINOR_OP_RD_EVCR 0x65 /* Read EVCR register */