LVDS (single) on kernel 3.10.53 [WBQ]

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LVDS (single) on kernel 3.10.53 [WBQ]

Postby kruszi » Fri Jan 27, 2017 4:45 pm

Hi,

I am trying to activate LVDS on kernel 3.10.53. (I could successfully activate it on kernel version 3.0.xx, works perfectly there by passing argument via the u-boot bootparameters).

I substituted the original videoargs

Code: Select all
=> print videoargs<\n><\r>
videoargs=setenv nextcon 0; if hdmidet; then setenv bootargs ${bootargs} video=mxcfb${nextcon}:dev=hdmi,1280x720M@60,if=RGB24; setenv fbmem fbmem=28M; setexpr nextcon ${nextcon} + 1; else echo - no HDMI monitor;fi; i2c dev 1; if i2c probe 0x10; then setenv bootargs ${bootargs} video=mxcfb${nextcon}:dev=lcd,800x480@60,if=RGB666,bpp=32; if test 0 -eq ${nextcon}; then setenv fbmem fbmem=10M; else setenv fbmem ${fbmem},10M; fi; setexpr nextcon ${nextcon} + 1; else echo '- no FWBADAPT-7WVGA-LCD-F07A-0102 display';fi; setenv bootargs ${bootargs} ${fbmem}


with my videoargs, I don't need HDMI, I need LVDS only

Code: Select all
=> print videoargs<\n><\r>
videoargs=setenv nextcon 1; setenv bootargs ${bootargs} video=mxcfb2:dev=ldb,1280x720M@60,if=RGB666; setenv fbmem fbmem=28M; echo - gesetzt; setenv bootargs ${bootargs} ${fbmem}<\n><\r>


The original devicetree looks fine according to my point of view.

(imx6qdl-wandboard.dtsi)
Code: Select all
        mxcfb2: fb@1 {
                compatible = "fsl,mxc_sdc_fb";
                disp_dev = "ldb";
                interface_pix_fmt = "RGB666";
                default_bpp = <24>;
                int_clk = <0>;
                late_init = <0>;
                status = "disabled";
        };

...
Code: Select all
&ldb {
   status = "okay";
   
   lvds-channel@0 {
      fsl,data-mapping = "spwg";
      fsl,data-width = <24>;
      primary;
      status = "okay";

      display-timings {
         native-mode = <&timing0>;
         timing0: hj070na {
            clock-frequency = <51000000>;
            hactive = <1024>;
            vactive = <600>;
            hback-porch = <90>;
            hfront-porch = <120>;
            vback-porch = <1>;
            vfront-porch = <1>;
            hsync-len = <100>;
            vsync-len = <33>;
         };
      };
   };
};


(imx6q-wandboard.dts)
Code: Select all
&ldb {
   lvds-channel@0 {
      crtc = "ipu1-di1";
   };
};

&mxcfb1 {
   status = "okay";
};

&mxcfb2 {
   status = "okay";
};

#if 0
&mxcfb3 {
   status = "okay";
};

&mxcfb4 {
   status = "okay";
};
#endif



Does anybody spot the error I made ?


Thank you for your help
kruszi
 
Posts: 12
Joined: Wed May 11, 2016 2:33 pm

Re: LVDS (single) on kernel 3.10.53 [WBQ]

Postby vpeter » Fri Jan 27, 2017 8:02 pm

You can compare how I have it done for Udoo Dual/Quad for 3.14 kernel: https://github.com/LibreELEC/LibreELEC. ... port.patch
Last edited by vpeter on Mon Jan 30, 2017 9:25 am, edited 1 time in total.
vpeter
 
Posts: 78
Joined: Wed Dec 24, 2014 7:44 am

Re: LVDS (single) on kernel 3.10.53 [WBQ]

Postby kruszi » Fri Jan 27, 2017 9:21 pm

Thanks for your Patch, i'll Check on that.

Could you post your U-Boot (video/bootargs), too?

Thank you so much for helping me out.
kruszi
 
Posts: 12
Joined: Wed May 11, 2016 2:33 pm

Re: LVDS (single) on kernel 3.10.53 [WBQ]

Postby vpeter » Fri Jan 27, 2017 9:27 pm

different boot args: https://github.com/LibreELEC/LibreELEC. ... v-udoo.txt

Code: Select all
udoo_quad:~ # cat /proc/cmdline
root=/dev/ram0 rdinit=/init noram usbcore.autosuspend=-1 coherent_pool=2M ip=dhcp boot=NFS=10.0.0.1:/mnt/sd/tftp/imx6 disk=NFS=10.0.0.1:/mnt/sd/tftp/imx6/nfs-le-storage ssh console=ttymxc0,115200 quiet morequiet video=mxcfb0:dev=ldb,1360x768M@60,if=RGB24,bpp=32 dmfc=3 consoleblank=0
vpeter
 
Posts: 78
Joined: Wed Dec 24, 2014 7:44 am

Re: LVDS (single) on kernel 3.10.53 [WBQ]

Postby kruszi » Sat Jan 28, 2017 8:58 pm

Hi,

thanks for your bootargs - I'll test them.

One simple (silly) question:

As you can see above I am using
Code: Select all
 mxcfb2: fb@1 {

So obviously I am using fb1. Is there a possibility that this the reason I see nothing on my LVDS-LCD? I mean could it be that everything is routed to fb0? Is fb0 the standard framebuffer? How could I make X11 (?) and everything else being routed to fb1 instead of fb0 (preferably via bootargs)?

Another thing I don't understand: your devicetree says: ldb@...mxfcb2:fb@1. How come you can use it in the bootargs with mxcfb0 and fb0?


Thanks again
kruszi
 
Posts: 12
Joined: Wed May 11, 2016 2:33 pm

Re: LVDS (single) on kernel 3.10.53 [WBQ]

Postby vpeter » Mon Jan 30, 2017 9:28 am

kruszi, it took some time until I got something on my display. And I had help. That's why I don't understand everything. And I will leave until it will fail :)
vpeter
 
Posts: 78
Joined: Wed Dec 24, 2014 7:44 am


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