i.MX ProcessorsのトピックRe: Add new lvds with clock frequency 25.18mHz

Add new lvds with clock frequency 25.18mHz

giorgiofantin — Wed, 29 Apr 2015 07:29:37 GMT

Hi to everybody,

i coming crazy to add a new lvds to my embedded linux. I have an i.MX6 with kernel versoin 3.0.35 and FS ubuntu 12.02.

It works fine, but now i have to add a new lvds with a resolution as 640 x 480. Its clock frequency is about 25.18 with a maximum of 28.33. I added in ldc.c the new resolution, but with default valued i get a clock frequency of 38 MHz. Searching on google, i found to modifify clock.c file (arch/arm/mach-mx6/clock.c) and set

clk_set_parent(&ldb_di0_clk, &pll5_video_main_clk);

Defautl value is clk_set_parent(&ldb_di0_clk, &pll2_pfd_352M);

Chanching it, the clock frequency goes from 38kHz to 33, but not to 25.

Can anyone help me?

Thnaks

Re: Add new lvds with clock frequency 25.18mHz

giorgiofantin — Thu, 30 Apr 2015 07:08:56 GMT

i foget to add the declare in ldb.c

Here it is:

{

"LDB-VGA2B", 60, 640, 480, 30060, //, // Rif. 640x480 BIG DISPLAY LVDS

40, 40,

22, 23,

96, 1,

FB_VMODE_NONINTERLACED,

FB_MODE_IS_DETAILED,},

Any help?

Thanks

Re: Add new lvds with clock frequency 25.18mHz

gusarambula — Fri, 01 May 2015 20:34:40 GMT

Hello Giorgio,

Perhaps the following Community Thread may be of help

https://community.freescale.com/message/331739

Please keep in mind that the clock configuration may not allow for all desired values to be reached so perhaps you wont' be able to get to 25.18Mhz.

Re: Add new lvds with clock frequency 25.18mHz

giorgiofantin — Mon, 04 May 2015 07:39:56 GMT

Hi Gusarambula,

thanks for the answer, but i followed that guide and nothing goes on the right way.

in any case, the image on display is showed, but not centered perfectly on the screen....

I don't understand if this missmatch is a problem of frequency or a problem of horizontal sync

Re: Add new lvds with clock frequency 25.18mHz

gusarambula — Thu, 21 May 2015 19:41:09 GMT

Hello Giorgio,

If the image is shown correctly but not centered I would recommend looking at the horizontal sync first. Have you had success on your application?