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  1. 09 May, 2012 4 commits
  3. 03 May, 2012 3 commits
    • Chandrabhanu Mahapatra's avatar
      OMAPDSS: DISPC: Correct DISPC functional clock usage · 8b53d991
      Chandrabhanu Mahapatra authored 
      DISPC_FCLK is incorrectly used as functional clock of DISPC in scaling
calculations. So, DISPC_CORE_CLK replaces as functional clock of DISPC.
DISPC_CORE_CLK is derived from DISPC_FCLK divided by an independent DISPC
divisor LCD.
Signed-off-by: default avatarChandrabhanu Mahapatra <cmahapatra@ti.com>
Signed-off-by: default avatarTomi Valkeinen <tomi.valkeinen@ti.com>
      8b53d991
    • Chandrabhanu Mahapatra's avatar
      OMAPDSS: DISPC: Handle synclost errors in OMAP3 · 7faa9233
      Chandrabhanu Mahapatra authored 
      In OMAP3 DISPC video overlays suffer from some undocumented horizontal position
and timing related limitations leading to SYNCLOST errors. Whenever the image
window is moved towards the right of the screen SYNCLOST errors become
frequent. Checks have been implemented to see that DISPC driver rejects
configuration exceeding above limitations.

This code was successfully tested on OMAP3. This code is written based on code
written by Ville Syrjälä <ville.syrjala@nokia.com> in Linux OMAP kernel. Ville
Syrjälä <ville.syrjala@nokia.com> had added checks for video overlay horizontal
timing and DISPC horizontal blanking length limitations.
Signed-off-by: default avatarChandrabhanu Mahapatra <cmahapatra@ti.com>
Signed-off-by: default avatarTomi Valkeinen <tomi.valkeinen@ti.com>
      7faa9233
    • Chandrabhanu Mahapatra's avatar
      OMAPDSS: DISPC: Enable predecimation · aed74b55
      Chandrabhanu Mahapatra authored 
      In OMAP3 and OMAP4, the DISPC Scaler can downscale an image up to 4 times, and
up to 2 times in OMAP2. However, with predecimation, the image can be reduced
to 16 times by fetching only the necessary pixels in memory. Then this
predecimated image can be downscaled further by the DISPC scaler.

The pipeline is configured to use a burst of size 8 * 128 bits which consists
of 8 mini bursts of 16 bytes each. So, horizontal predecimation more than 16
can lead to complete discarding of such mini bursts. L3 interconnect may
handover the bus to some other initiator and inturn delay the fetching of
pixels leading to underflows. So, maximum predecimation limit is fixed at 16.

Based on the downscaling required, a prior calculation of predecimation values
for width and height of an image is done. Since, Predecimation reduces quality
of an image higher priorty is given to DISPC Scaler for downscaling.

This code was successfully tested on OMAP2, OMAP3 and OMAP4. Horizontal and
vertical predecimation worked fine except for some synclost errors due to
undocumented errata in OMAP3 which are fixed later and skewed images were seen
on OMAP2 and OMAP3 during horizontal predecimation which will be addressed in
the future patches.

This code is based on code written by Lajos Molnar <lajos@ti.com> who had added
predecimation support for NV12/YUV/rotated/SDMA buffers.
Signed-off-by: default avatarChandrabhanu Mahapatra <cmahapatra@ti.com>
Signed-off-by: default avatarTomi Valkeinen <tomi.valkeinen@ti.com>
      aed74b55
  5. 23 Apr, 2012 17 commits
  7. 21 Apr, 2012 16 commits
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