• Thor Thayer's avatar
    spi: dw-spi: Convert 16bit accesses to 32bit accesses · dd114443
    Thor Thayer authored
    Altera's Arria10 SoC interconnect requires a 32-bit write for APB
    peripherals. The current spi-dw driver uses 16-bit accesses in
    some locations. This patch converts all the 16-bit reads and
    writes to 32-bit reads and writes.
    Additional Documentation to Support this Change:
    The DW_apb_ssi databook states:
    "All registers in the DW_apb_ssi are addressed at 32-bit boundaries
    to remain consistent with the AHB bus. Where the physical size of
    any register is less than 32-bits wide, the upper unused bits of
    the 32-bit boundary are reserved. Writing to these bits has no
    effect; reading from these bits returns 0." [1]
    [1] Section 6.1 of dw_apb_ssi.pdf (version 3.22a)
    Request for test with platforms using the DesignWare SPI IP.
    Tested On:
    Altera CycloneV development kit
    Altera Arria10 development kit
    Compile tested for build errors on x86_64 (allyesconfigs)
    Signed-off-by: default avatarThor Thayer <tthayer@opensource.altera.com>
    Reviewed-and-tested-by: default avatarAndy Shevchenko <andriy.shevchenko@linux.intel.com>
    Signed-off-by: default avatarMark Brown <broonie@kernel.org>
spi-dw.h 5.29 KB