Provide an explicit configuration option to disable default "unlock all" of any flash chip which supports locking. It doesn't make sense to automatically unprotect the entire flash on each u-boot startup if the block protection bits are actually used.
Traditionally, the unlock was there to be able to write to flash devices which powered-up with the block protection bits set. Over time this feature creeped into all flash devices which support locking.
For a more detailed description and discussion see: https://lore.kernel.org/linux-mtd/20201203162959.29589-8-michael@walle.cc/
Keep things simple in u-boot and just provide a configration option to disable this behavior which can be set per board.
Signed-off-by: Michael Walle michael@walle.cc --- drivers/mtd/spi/Kconfig | 10 ++++++++++ drivers/mtd/spi/spi-nor-core.c | 9 +++++---- 2 files changed, 15 insertions(+), 4 deletions(-)
diff --git a/drivers/mtd/spi/Kconfig b/drivers/mtd/spi/Kconfig index 018e8c597e..bb8e8a9153 100644 --- a/drivers/mtd/spi/Kconfig +++ b/drivers/mtd/spi/Kconfig @@ -95,6 +95,16 @@ config SPI_FLASH_BAR Bank/Extended address registers are used to access the flash which has size > 16MiB in 3-byte addressing.
+config SPI_FLASH_UNLOCK_ALL + bool "Unlock the entire SPI flash on u-boot startup" + default y + help + Some flashes tend to power up with the software write protection + bits set. If this option is set, the whole flash will be unlocked. + + For legacy reasons, this option default to y. But if you intend to + actually use the software protection bits you should say n here. + config SF_DUAL_FLASH bool "SPI DUAL flash memory support" help diff --git a/drivers/mtd/spi/spi-nor-core.c b/drivers/mtd/spi/spi-nor-core.c index e16b0e1462..ef426dac02 100644 --- a/drivers/mtd/spi/spi-nor-core.c +++ b/drivers/mtd/spi/spi-nor-core.c @@ -2443,10 +2443,11 @@ static int spi_nor_init(struct spi_nor *nor) * Atmel, SST, Intel/Numonyx, and others serial NOR tend to power up * with the software protection bits set */ - if (JEDEC_MFR(nor->info) == SNOR_MFR_ATMEL || - JEDEC_MFR(nor->info) == SNOR_MFR_INTEL || - JEDEC_MFR(nor->info) == SNOR_MFR_SST || - nor->info->flags & SPI_NOR_HAS_LOCK) { + if (IS_ENABLED(CONFIG_SPI_FLASH_UNLOCK_ALL) && + (JEDEC_MFR(nor->info) == SNOR_MFR_ATMEL || + JEDEC_MFR(nor->info) == SNOR_MFR_INTEL || + JEDEC_MFR(nor->info) == SNOR_MFR_SST || + nor->info->flags & SPI_NOR_HAS_LOCK)) { write_enable(nor); write_sr(nor, 0); spi_nor_wait_till_ready(nor);