how to set the resolution of the LCD

Hi Younger,

I have use the DPI to output 1920x1200@30 successfully.

You can refer to this link: https://gist.github.com/4116881

1.modify board-omap4panda.c, modedb.c, and panel-generic

2.if you get "GFX underflow" error, modify dispc.c and dispc.h

Regards,
Ping-Chu

Hi Ping-Chu,

      Your suggestion is really useful to me!

      Have you tried to set the DPI to 1920x1200@60Hz (pixel clock about 155Mhz)?

      Because I can't set the pixel clock over 85MHz.....

Thanks and regards,

Leo

Hi Leo,

According to document http://makelinux.net/lib/ti/OMAP4460/doc-2503, we can output SXGA@85Hz (http://tinyvga.com/vga-timing/1280x1024@85Hz).

I tried 1920x1200@60, but had the same problem as yours.

The formula of pixel clock is: LCD2_PCLK = LCD2_CLK / LCK / PCK

If you trace the source code, you can find LCK and PCK are set in dispc_find_clk_divs of dispc.c.

And the PCK value is set "u16 pcd_min = is_tft ? 2 : 3;"

Maybe you can change pcd_min value to 1 and try it again.

Regards,
Ping-Chu

Hi Ping-Chu,

    Thanks for your reply and suggestions! I will try to change the pcd_min value.

    I also read a Table 10-4. DSS Clock Frequencies in http://makelinux.net/lib/ti/OMAP4460/doc-2487.

    I think present setting is OPP50, therefore the pixel clock can only output about 85.5MHz ( 93 * 186/170).

Thanks and regards,

Leo

Hi, Leo

I also meet the same problem as yours, have u solve the problem?

BR

Younger

Hi, Ping-Chu

According to document http://makelinux.net/ti/docs/OMAP4460/doc-2482 Table 10-1 , may be we should set LCD2_TV_SEL = 1.

is it right? if right, how to set?

BR

younger