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U-boot support for integrating new LVDS display from SHARP

Question asked by Lijo John C on Mar 2, 2018
Latest reply on Mar 2, 2018 by igorpadykov


I am integrating the LVDS display (SHARP-LQ150X1LX95) into the Advantech development board that has DMS-BA16 Q7 module.

As per the LVDS display data sheet, it has the following configurations.

Refresh rate=60 Hz, Resolution =1024X768, pixel clock=65MHz, Horizontal period=1344, Horizontal period=806, RGB that has 24 bit(8 bit X RGB), this display also supports 18 bit (6 bit X RGB) configuration.

The "u-boot-fslc-2017.07/board/advantech/dms-ba16/dms-bs16.c" file is modified to support the above LVDS display configuration.

struct display_info_t const displays[] = {


       .bus   = -1,

       .addr  = 0,

       .pixfmt      = IPU_PIX_FMT_RGB24,

       .detect      = detect_baseboard,

       .enable      = NULL,

       .mode  = {

              .name           = "SHARP-LQ150X1LX95",

              .refresh       = 60,

              .xres           = 1024,

              .yres           = 768,

              /*pixclock     = (10^12)/clk_freq*/

              .pixclock       = 37000, //15385=65MHz //37000=27MHz

              .left_margin   = 220,

              .right_margin   = 40,

              .upper_margin   = 21,

              .lower_margin   = 7,

              .hsync_len     = 60,

              .vsync_len     = 10,

              .sync           = FB_SYNC_EXT,

              .vmode         = FB_VMODE_NONINTERLACED

} },


So the issue that I am facing with this LVDS display is that, it’s not working when I configure it for 65MHz pixel clock and if I configure it for 27 MHz, the LVDS is displaying with the following issue.

  1.  Color pattern is very much different.
  2. When I use the image of 1024X768, then the right most part of the image is going out of the screen.

I did few changes in the above configuration, but could not fix the issue. If I change the pixfmt to IPU_PIX_FMT_RGB666, then the image color is very different than the original. Also, the same image is coming properly in HDMI display, if I change the configuration as HDMI display in u-boot.

Please let me know the right configuration is U-boot and the relevant SW changes, so that I can update the same and displayed the screen correctly on the new LVDS display.


The below images are displayed using the “bmp display” command (after converting into BMP format – using “MS paint”) in U-boot. See the corresponding attachments displayed in LVDS.