in a project a had to output analog video (pal/ntsc) and i decided to use the adv7393 from analog devices that is connected to lcd (rgb) interface of the apalis module. my implementation is mainly based on the approach:
i also implemented the kernel patches to support interlaced video output.
My kernelparameter in u-boot for vidargs is:
vidargs=video=mxcfb0:dev=lcd,LCD-576I50,if=RGB24 video=mxcfb1:off video=mxcfb2:off video=mxcfb3:off fbmem=32M
i also attached my device tree file for my implemantation
so far everything looks good. i can start my system i have my framebuffer/video-devices, the setup on the i2c part of the encoder is correct and i can see some av video output. i have some timing issues on the av and not all of my monitors are happy with the video signal but this is another problem and might come from wrong mode settings.
but what confuses me is that not all of the 16 data bits that are fed into the adv7393 from the the lcd interface show data. i tested it with an oscilloscope and realized that i only have data output on even data bits (viewed from 24bit lcd interface side). all odd data bits stuck on gnd. this seems to be the case for all 24 data bits of the lcd interface. i tested only with the 16 data bits im using and a few more that i had access to, but im sure it is the same for all 24 bits.
hsync, vsync and pckl looks good.
Did i misconfigured something or did i forgot something?