• Ondrej Jirman's avatar
    bus: sunxi-rsb: Return correct data when mixing 16-bit and 8-bit reads · a43ab30d
    Ondrej Jirman authored
    When doing a 16-bit read that returns data in the MSB byte, the
    RSB_DATA register will keep the MSB byte unchanged when doing
    the following 8-bit read. sunxi_rsb_read() will then return
    a result that contains high byte from 16-bit read mixed with
    the 8-bit result.
    The consequence is that after this happens the PMIC's regmap will
    look like this: (0x33 is the high byte from the 16-bit read)
    % cat /sys/kernel/debug/regmap/sunxi-rsb-3a3/registers
    00: 33
    01: 33
    02: 33
    03: 33
    04: 33
    05: 33
    06: 33
    07: 33
    08: 33
    09: 33
    0a: 33
    0b: 33
    0c: 33
    0d: 33
    0e: 33
    Fix this by masking the result of the read with the correct mask
    based on the size of the read. There are no 16-bit users in the
    mainline kernel, so this doesn't need to get into the stable tree.
    Signed-off-by: default avatarOndrej Jirman <megous@megous.com>
    Acked-by: default avatarChen-Yu Tsai <wens@csie.org>
    Signed-off-by: default avatarMaxime Ripard <maxime@cerno.tech>
sunxi-rsb.c 19 KB