[U-Boot] iMX6 IPU configuration by EDID

[Luca Ellero <luca.ellero@brickedbrain.com>]

Hi all,
I'm trying to configure IPU on a iMX6 based platform by reading EDID 
from the external monitor.

Everything seem to work fine except for the pixelclock. In particular my 
monitor has a standard resolution of 1280x1024 at 60 (108 MHz pixelclock).

When the function ipu_init_sync_panel (file ipu_disp.c) is called it 
correctly receive 108 MHz as pixelclock. but during the execution of 
this function it gets rounded to 130 MHz.

I can see that the function calls clk_round_rate to round the clock to 
130 MHz but it's not clear for me how it works.

Can someone please tell me how to get the exact pixelclock I would like 
to achieve? I've carefully read the iMX6 manual but it's not very useful 
in this case.

Another doubt that I have regards the field "ext_clk" of parameter 
"ipu_di_signal_cfg_t sig". In this case, is it better to set it or not?

Thanks
Regards
Luca


-- 
Luca Ellero

E-mail: luca.ellero at brickedbrain.com
Internet: www.brickedbrain.com