• Pavel Pisa's avatar
    imxfb: fast read flag and nonstandard field configurable · 9da505d1
    Pavel Pisa authored
    The i.MX frame-buffer read operation should be faster for all configurations
    then drawing each individual character again in response to scroll events.
    
    The nonstandard fields allows to configure frame-buffer special options flags
    for different display configurations by board specific initialization code.
    
    One of such specific options is reversed order of pixels in each individual
    byte.  i.MX frame-buffer seems to be designed for big-endian use first.  The
    byte order is correctly configured for little-endian ordering, but if 1, 2 or
    4 bits per pixel are used, pixels ordering is incompatible to Linux generic
    frame-buffer drawing functions.
    
    The patch "Allow generic BitBLT functions to work with swapped pixel order in
    bytes" introduces required functionality into FBDEV core.  The pixels ordering
    selection has to be enabled at compile time CONFIG_FB_CFB_REV_PIXELS_IN_BYTE
    and for each display configuration which requires it by flag
    FB_NONSTD_REV_PIX_IN_B in "nonstd" field of info structure.
    
    This patch provides way for board specific code to select this option.
    Signed-off-by: default avatarPavel Pisa <pisa@cmp.felk.cvut.cz>
    Signed-off-by: default avatarAntonino Daplas <adaplas@gmail.com>
    Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
    Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
    9da505d1
imxfb.c 16.6 KB