[U-Boot] [PATCH] sf: Make 4K sector support configurable

[Marek Vasut]

On Wednesday, August 05, 2015 at 10:36:31 AM, Jagan Teki wrote:
> On 5 August 2015 at 13:50, Jagan Teki <jteki at openedev.com> wrote:
> > On 3 August 2015 at 04:58, Marek Vasut <marex at denx.de> wrote:
> >> 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 at denx.de>
> >> Cc: Jagan Teki <jteki at 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,
> >> 
> >> --
> >> 2.1.4
> > 
> > Reviewed-by: Jagan Teki <jteki at openedev.com>
> 
> Applied to u-boot-spi/master

Excellent, thanks!