From: Tudor Ambarus <[email protected]> Some spi-nor flashes come write protected by default after a power-on sequence to avoid destructing commands (erase, write) during power-up.
Backward compatibility imposes to disable the write protection at power-up by default. Add a Kconfig option to let the user benefit of the power-up write protection. Signed-off-by: Tudor Ambarus <[email protected]> --- v2: mark spi_nor_spansion_clear_sr_bp() and spi_nor_unlock_global_block_protection() definitions as __maybe_unused, to avoid -Wunused-function warnings when MTD_SPI_NOR_DISABLE_POWER_UP_WRITE_PROTECTION is not selected. drivers/mtd/spi-nor/Kconfig | 8 ++++++++ drivers/mtd/spi-nor/spi-nor.c | 7 +++++-- 2 files changed, 13 insertions(+), 2 deletions(-) diff --git a/drivers/mtd/spi-nor/Kconfig b/drivers/mtd/spi-nor/Kconfig index 6de83277ce8b..b550e10657f1 100644 --- a/drivers/mtd/spi-nor/Kconfig +++ b/drivers/mtd/spi-nor/Kconfig @@ -22,6 +22,14 @@ config MTD_SPI_NOR_USE_4K_SECTORS Please note that some tools/drivers/filesystems may not work with 4096 B erase size (e.g. UBIFS requires 15 KiB as a minimum). +config MTD_SPI_NOR_DISABLE_POWER_UP_WRITE_PROTECTION + bool "Disable write protection during power-up" + default y + help + Some spi-nor flashes are write protected by default after a power-on + reset cycle, in order to avoid inadvertend writes during power-up. + Disable the write protection during power-up. + config SPI_ASPEED_SMC tristate "Aspeed flash controllers in SPI mode" depends on ARCH_ASPEED || COMPILE_TEST diff --git a/drivers/mtd/spi-nor/spi-nor.c b/drivers/mtd/spi-nor/spi-nor.c index ffb53740031c..9b948295ef27 100644 --- a/drivers/mtd/spi-nor/spi-nor.c +++ b/drivers/mtd/spi-nor/spi-nor.c @@ -1684,7 +1684,7 @@ static int spi_nor_clear_sr_bp(struct spi_nor *nor) * * Return: 0 on success, -errno otherwise. */ -static int spi_nor_spansion_clear_sr_bp(struct spi_nor *nor) +static int __maybe_unused spi_nor_spansion_clear_sr_bp(struct spi_nor *nor) { int ret; u8 mask = SR_BP2 | SR_BP1 | SR_BP0; @@ -1726,7 +1726,8 @@ static int spi_nor_spansion_clear_sr_bp(struct spi_nor *nor) return spi_nor_clear_sr_bp(nor); } -static int spi_nor_unlock_global_block_protection(struct spi_nor *nor) +static int __maybe_unused +spi_nor_unlock_global_block_protection(struct spi_nor *nor) { int ret; @@ -4049,6 +4050,7 @@ static int spi_nor_init(struct spi_nor *nor) { int err; +#ifdef CONFIG_MTD_SPI_NOR_DISABLE_POWER_UP_WRITE_PROTECTION /* * Atmel, SST, Intel/Numonyx, and others serial NOR tend to power up * with the software protection bits set. @@ -4082,6 +4084,7 @@ static int spi_nor_init(struct spi_nor *nor) return err; } } +#endif if (nor->quad_enable) { err = nor->quad_enable(nor); -- 2.9.5
