AM572x HDMI and LCD resolution

Amritpreet Singh93

Hi All

I would to ask some questions regarding resolutions support in Display modules. I am using ti-processor-sdk-linux-am57xx-evm-02.00.02.11 with GPEVM. We need 576i out from both HDMI and LCD out 1 and 3.

1. i can change HDMI resolution as follows:

setenv mmcargs 'setenv bootargs console=${console} ${optargs} root=${mmcroot} rootfstype=${mmcrootfstype} video=HDMI-A-1:800x600’

But when weston starts it changes the resolution back to the 1080p. How can i hard-code this resolution?

2. Does HDMI support interlaced output? What changes are required in software to enable that?
(Our requirement is 576i)

3. Can LCD out interface support interlaced output? How to enable that?

Regards

Amrit

over 9 years ago

0 Biser Gatchev-XID over 9 years ago

TI__Guru**** 393215 points

Hi,

I will ask the software team to comment.

0 Yordan Kovachev over 9 years ago

TI__Guru**** 161600 points

Hi,

Amritpreet Singh93 said:
1. i can change HDMI resolution as follows:
setenv mmcargs 'setenv bootargs console=${console} ${optargs} root=${mmcroot} rootfstype=${mmcrootfstype} video=HDMI-A-1:800x600’

But when weston starts it changes the resolution back to the 1080p. How can i hard-code this resolution?

Display resolution is usually set in dts, that is why when your kernel boots, it changes the resolution. You can try to hardcode the 800x600 resolution in etc/weston.ini & etc/fb.modes:
http://manpages.ubuntu.com/manpages/wily/man5/weston.ini.5.html

Amritpreet Singh93 said:
2. Does HDMI support interlaced output? What changes are required in software to enable that?
(Our requirement is 576i)

Yes, HDMI supports interlaced output, but currently it is disabled in linux sources, have a look at drivers/video/fbdev/omap2/displays-new/connector-hdmi.c:

static const struct omap_video_timings hdmic_default_timings = {

......................

.interlace = false,

};

Amritpreet Singh93 said:
3. Can LCD out interface support interlaced output? How to enable that?

Yes, have a look at drivers/video/fbdev/omap2/dss/disp.c. You have to set interlace=true.

Hope this helps.

Best Regards,

Yordan

0 Amritpreet Singh93 over 9 years ago in reply to Yordan Kovachev

Expert 1285 points

Hi Yordan
Thanks for replying and giving concise answers.
1. I didn't find any file like: drivers/video/fbdev/omap2/dss/disp.c
but dispc.c and dispc6.c are present. which one should i change?
2. Will this make all LCD outputs as interlaced? We want LCD1 as progressive and LCD3 as interlaced. Both at different resolutions.

Regards
Amrit

0 Yordan Kovachev over 9 years ago in reply to Amritpreet Singh93

TI__Guru**** 161600 points

Hi Armit,

Correct, dispc.c & dispc6.c are the drivers to use, what I wrote disp.c is a typo.

Amritpreet Singh93 said:
2. Will this make all LCD outputs as interlaced? We want LCD1 as progressive and LCD3 as interlaced. Both at different resolutions.

You could set different resolutions for lcd1 & lcd3 in the dts file. However for the output modes, IMO, you would need significant modifications in the dispc driver.

Best Regards,
Yordan

0 Amritpreet Singh93 over 9 years ago in reply to Yordan Kovachev

Expert 1285 points

HI Yordon

Thanks a lot. Actually our requirement is this:
LCD1(720x576) -> PAL-Encoder(ADV7343) -> PAL out
LCD3(720x576) -> FPGA -> SDI out(576i)

So should i make LCD3 as interlaced and keep LCD1 as progressive? or Should i make both as interlaced?

0 Amritpreet Singh93 over 9 years ago in reply to Yordan Kovachev

Expert 1285 points

Hi Yordon

I can see that i can set the resolution of LCD out in device tree, by using panel-dpi driver.
How the framerate will be set ?
for example 720x576p at 50fps

Regards
Amrit

Processors

Processors forum

AM572x HDMI and LCD resolution