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OMAP-L138 board LCD timing parameters

Other Parts Discussed in Thread: OMAP-L138, DA8XX

Hi,

I have 24-bit RGB LCD interface with OMAP-L138 board, Which is interfaced with Parallel DE mode RGB input timing Values:

Parameter                     Symbol    Min.     Typ.     Max.    Unit
CLK frequency                 fclk          7          9          12      MHz
DEV period time             Tv            277     288      400     H
DEV display area           Tvd         272                               H
DEV blanking                 Tvb           5          16       128      H
DEH period time             Th          520       525      800     CLK
DEH display area           Thd                    480                    CLK
DEH blanking                 Thb        40           45        320    CLK
CLK cycle time                 Tclk       83        110        200    ns
Clock width of high level Tcwh   40          50          60      %
Clock width of low level   Tcwl    40          50         60       %
Clock rising time               trck        -            9                      ns
Clock falling time             tfck          -            9                     ns
Data Setup Time             tdesu     10          -             -        ns
Data Hold Time               tdahd     10          -             -        ns
DE Setup Time                tdesu     10           -            -        ns
DE Hold Time                  tdehd     10           -            -        ns

da8xx_panel timing
    [1] = {
        .name = "LCD00000",
        .width = 480,
        .height = 272,
        .hfp = ???,
        .hbp = ???,
        .hsw = ???,
        .vfp = ???,
        .vbp = ???,
        .vsw = ???,
        .pxl_clk = ????,
        .invert_pxl_clk = ??,
    },

Can i have the timing parameters setting in linux driver. How to control using with DE signal. Please give me a driver modifications.

Thanks
Kumar

  • Hi Francis,

     Looking at your issue I stumble upon this patch in the Da-Vinci Linux Mailing list:

    http://linux.davincidsp.com/pipermail/davinci-linux-open-source/2009-November/017097.html

    It shows you in which files you should do the modifications to support your own LCD, you can not

    apply the patch directly since it is ment for VGA screens. In the datasheet for your LCD panel you

    should collect the following data:

    width = , Horizontal Pixel resolution of your LCD (Number of Pixels per Line)

    height =, Vertical Pixel resolution of your LCD (Number of lines)

    hfp = , Horizontal Front Porch (In CLK cycles)

    hbp = , Horizontal Back Porch (In CLK cycles)

    hsw = ,Horizontal SYNC Width (In CLK cycles)

    vfp = , Vertical Front Porch (In Horizontal Lines)

    vbp = ,Vertical Back Porch (In Horizontal Lines)

    vsw = ,Vertical SYNC Width (In Horizontal Lines)

    pxl_clk = , Pixel Clock Frequency in Hz

    invert_pxl_clk = ,Data Latching of the LCD: 1=Rising Edge , 0=Falling Edge

    For more reference you should check the OMAP-L138 Datasheet on page 226 for the timing of the raster controller.

     If you post the datasheet of your LCD maybe I could take a look at it