• Thomas Petazzoni's avatar
    mtd: pxa3xx_nand: make the driver work on big-endian systems · b7e46062
    Thomas Petazzoni authored
    The pxa3xx_nand driver currently uses __raw_writel() and __raw_readl()
    to access I/O registers. However, those functions do not do any
    endianness swapping, which means that they won't work when the CPU
    runs in big-endian but the I/O registers are little endian, which is
    the common situation for ARM systems running big endian.
    
    Since __raw_writel() and __raw_readl() do not include any memory
    barriers and the pxa3xx_nand driver can only be compiled for ARM
    platforms, the closest I/o accessors functions that do endianess
    swapping are writel_relaxed() and readl_relaxed().
    
    This patch has been verified to work on Armada XP GP: without the
    patch, the NAND is not detected when the kernel runs big endian while
    it is properly detected when the kernel runs little endian. With the
    patch applied, the NAND is properly detected in both situations
    (little and big endian).
    Signed-off-by: default avatarThomas Petazzoni <thomas.petazzoni@free-electrons.com>
    Cc: <stable@vger.kernel.org> # v3.13+
    Signed-off-by: default avatarBrian Norris <computersforpeace@gmail.com>
    b7e46062
pxa3xx_nand.c 48.3 KB