Make the support for 4K subpage I/O on a SPI NOR flash configurable. A board which requires the SPI NOR to be accessed in larger 32KiB or 64KiB pages can disable the 4K subpage support, but by default, the support for 4K subpage I/O is enabled. The functionality of this option is the same as CONFIG_MTD_SPI_NOR_USE_4K_SECTORS in Linux.
This is extremely useful in case one uses UBI on a SPI NOR flash. UBI needs at least 15k EBs and can not work on a flash which uses 4k ones, so disabling the support for 4k subpages lets UBI work on such flash.
Signed-off-by: Marek Vasut marex@denx.de Cc: Jagan Teki jteki@openedev.com --- drivers/mtd/spi/Kconfig | 15 +++++++++++++++ drivers/mtd/spi/sf_internal.h | 4 ++++ 2 files changed, 19 insertions(+)
diff --git a/drivers/mtd/spi/Kconfig b/drivers/mtd/spi/Kconfig index 8b730ff..3f7433c 100644 --- a/drivers/mtd/spi/Kconfig +++ b/drivers/mtd/spi/Kconfig @@ -86,6 +86,21 @@ config SPI_FLASH_WINBOND
endif
+config SPI_FLASH_USE_4K_SECTORS + bool "Use small 4096 B erase sectors" + depends on SPI_FLASH + default y + help + Many flash memories support erasing small (4096 B) sectors. Depending + on the usage this feature may provide performance gain in comparison + to erasing whole blocks (32/64 KiB). + Changing a small part of the flash's contents is usually faster with + small sectors. On the other hand erasing should be faster when using + 64 KiB block instead of 16 × 4 KiB 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 SPI_FLASH_DATAFLASH bool "AT45xxx DataFlash support" depends on SPI_FLASH && DM_SPI_FLASH diff --git a/drivers/mtd/spi/sf_internal.h b/drivers/mtd/spi/sf_internal.h index 9fb5557..9c95d56 100644 --- a/drivers/mtd/spi/sf_internal.h +++ b/drivers/mtd/spi/sf_internal.h @@ -37,7 +37,11 @@ enum spi_read_cmds {
/* sf param flags */ enum { +#ifdef CONFIG_SPI_FLASH_USE_4K_SECTORS SECT_4K = 1 << 0, +#else + SECT_4K = 0 << 0, +#endif SECT_32K = 1 << 1, E_FSR = 1 << 2, SST_BP = 1 << 3,