i.MX ProcessorsのトピックRe: i.MX6Q LVDS split mode outputs LVDS1 only

i.MX6Q LVDS split mode outputs LVDS1 only

torus1000 — Mon, 13 Apr 2015 05:06:47 GMT

Hi,

I have 1920x1080 LVDS panel and modified device tree source (dtsi) of i.mx6q yocto L.3.10.53.
Then I tried ldb split mode (ldb=spl0) as following.

U-Boot> setenv displayinfo video=mxcfb1:dev=ldb,if=RGB24 ldb=spl0 fbmem=24M
...
U-Boot> boot
...

Kernel command line: console=ttymxc0,115200 root=/dev/mmcblk1p2 rootwait rw
video=mxcfb1:dev=ldb,if=RGB24 ldb=spl0 fbmem=24M
...

LVDS1 looked OK but LVDS0 (neither clock nor data) output nothing.

Can anyone help me to output both LVDS ports in split mode(2 ports for 1 panel)?

Actual fbset was as following...

> fbset
mode "960x1080-52"
      # D: 74.250 MHz, H: 60.861 kHz, V: 52.018 Hz
      geometry 960 1080 960 1088 16
      timings 13468 60 60 23 22 140 45
      rgba 5/11,6/5,5/0,0/0
endmode

Thanks.

Re: i.MX6Q LVDS split mode outputs LVDS1 only

saurabh206 — Mon, 13 Apr 2015 06:15:50 GMT

Torus

You need to add display information to struct fb_videomode ldb_modedb according to your resolution.

Can you try to verify ldb driver and dtb file initialization?

Why you have selected video=mxcfb1 ? You can use video=mxcfb0 with dtb setting.

Thanks

Saurabh

Re: i.MX6Q LVDS split mode outputs LVDS1 only

joanxie — Thu, 16 Apr 2015 10:14:26 GMT

did you add your lvds to the ldb.c? pls refer to the link as below:

Re: i.MX6 Dual LVDS Support

Re: i.MX6Q LVDS split mode outputs LVDS1 only

torus1000 — Fri, 24 Apr 2015 00:47:50 GMT

Dear Saurabh and Guanqiong,

Freescale local FAE kindly sent us a patch as following.
After applying this patch, it worked.
It seems additional "split-mode;" line required to resolve my issue.

Hava a nice day!

//patch//
--- a/arch/arm/boot/dts/imx6qdl-sabresd.dtsi
+++ b/arch/arm/boot/dts/imx6qdl-sabresd.dtsi
@@ -505,46 +505,47 @@

&ldb {
status = "okay";
+ split-mode;

lvds-channel@0 {
fsl,data-mapping = "spwg";
...

Re: i.MX6Q LVDS split mode outputs LVDS1 only

saurabh206 — Fri, 24 Apr 2015 03:47:15 GMT

Hi Torus

Thanks for posting the solution.

Saurabh

Re: i.MX6Q LVDS split mode outputs LVDS1 only

osmarfrisonjun1 — Thu, 16 Jul 2015 19:49:21 GMT

Hello,

How do I do to apply this changes to a new .sdcard?

Thanks.