topic Re: Frame Buffer sharing between HDMI and LCD in i.MX Processors

Frame Buffer sharing between HDMI and LCD

Subodh_K — Mon, 10 Nov 2014 06:19:46 GMT

Hi all,

I am working on a project which is based on IMX6Q board.I have integrated LCD and HDMI module to it and enabled hot pluggable support in kernel .

My LCD is connected on parallel port and HDMI is based on I2C. I am using frame buffer mxcfb1 for HDMI and for LCD is mxcfb2. Individually working fine

both LCD and HDMI.But when i give the mxcfb2 frame buffer in U-BOOT arguments but it does not seem working.

$ editenv mmcargs

Added This line

video=mxcfb2:dev=lcd,480x272@60,if=RGB24 video=mxcfb2:dev=hdmi,1920x1080M@60,if=RGB24

$ saveenv

$boot

It does not come on any display (LCD and HDMI).

If i try with their individual frame buffer in that case only LCD work not an HDMI.

video=mxcfb2:dev=lcd,480x272@60,if=RGB24 video=mxcfb1:dev=hdmi,1920x1080M@60,if=RGB24

Please help me to debug this issue soon.

Re: Frame Buffer sharing between HDMI and LCD

joanxie — Wed, 19 Nov 2014 07:55:19 GMT

you said: "I am using frame buffer mxcfb1 for HDMI and for LCD is mxcfb2. Individually working fineboth LCD and HDMI." and "

If i try with their individual frame buffer in that case only LCD work not an HDMI.

video=mxcfb2:dev=lcd,480x272@60,if=RGB24 video=mxcfb1:dev=hdmi,1920x1080M@60,if=RGB24

any typo? when you set mxcfb1 to hdmi and mxcfb2 to lcd, ok or not?

Re: Frame Buffer sharing between HDMI and LCD

Subodh_K — Wed, 19 Nov 2014 08:36:12 GMT

Hi Guanqiong ,

There is no typo in bootargs i checked it many times .

Re: Frame Buffer sharing between HDMI and LCD

joanxie — Wed, 19 Nov 2014 08:54:53 GMT

do you mean when you can use this two commans 1)video=mxcfb2:dev=lcd,480x272@60,if=RGB24 2)video=mxcfb1:dev=hdmi,1920x1080M@60,if=RGB24 Individually, but when you use together, just lcd is ok, right?

1) pls ensure you use different IPU or different port of same IPU

2) try to use the command video=mxcfb0:dev=lcd,480x272@60,if=RGB24 bpp=32

video=mxcfb1:dev=hdmi, 1920x1080M@60, if=RGB24 bpp=32

video=mxcfb2:off fbmem=5M,28M

3) when the board bootup, use the command "echo "0" >/sys/class/graphics/fb2/blank"

Re: Frame Buffer sharing between HDMI and LCD

Subodh_K — Wed, 19 Nov 2014 10:17:39 GMT

Hi Guanqiong,

I am using kernel 3.10.17 which has device tree concept and i have changed according to my need .

In LCD I am using mxcfb2 framebuffer:

mxcfb3: fb@2 {

compatible = "fsl,mxc_sdc_fb";

disp_dev = "lcd";

interface_pix_fmt = "RGB24";

mode_str ="CLAA-WVGA";

default_bpp = <16>;

int_clk = <0>;

late_init = <0>;

status = "okay";

};

For HDMI i am using mxcfb1 :

mxcfb2: fb@1 {

compatible = "fsl,mxc_sdc_fb";

disp_dev = "hdmi";

interface_pix_fmt = "RGB24";

mode_str ="1920x1080M@60";

default_bpp = <24>;

int_clk = <0>;

late_init = <0>;

status = "okay";

};

For IPU and Device ID assignment in LCD case :

lcd@0 {

compatible = "fsl,lcd";

ipu_id = <0>;

disp_id = <0>;

default_ifmt = "RGB24";

pinctrl-names = "default";

pinctrl-0 = <&pinctrl_ipu1_1>;

status = "okay";

};

For IPU and Device ID assignment in case of HDMI:

&hdmi_core {

ipu_id = <0>;

disp_id = <1>;

status = "okay";

};

And for blanking if i use echo 1 > /sys/class/graphics/fb0/blank it controls both display.