Display Configuration with DRM in Linux 3.18

This forum is for users of Microchip MPUs and who are interested in using Linux OS.

Moderator: nferre

sds5096
Posts: 7
Joined: Sun Oct 05, 2014 4:01 pm

Display Configuration with DRM in Linux 3.18

Thu Jun 18, 2015 5:47 am

Hello,

I recently cloned the linux-at91 repo and attempted to load to a SAMA5D36-EK. I had previously been running on 3.10 Kernel which largely used board files as opposed to Device Trees.

With the shift to DRM for fb access, I'm unsure of how to properly configure the settings for my screen.

With 3.10, I was able to configure porch widths and pixel clock in the board file under mach-at91. This configuration is no longer in the board file. Can someone assist in identifying the location in which this configuration is controlled?

Thank you,
Scott
sds5096
Posts: 7
Joined: Sun Oct 05, 2014 4:01 pm

Re: Display Configuration with DRM in Linux 3.18

Wed Jun 24, 2015 2:48 am

Does anybody have any information on DRM and how to configure for LCD timing parameters?

Thank you
marcelgl2
Posts: 2
Joined: Thu Jul 02, 2015 8:33 am

Re: Display Configuration with DRM in Linux 3.18

Thu Jul 02, 2015 8:44 am

I just started with DRM and kernel 4.1. added a panel definition in the device tree:

ahb {
apb {


panel {
compatible = "atmel,panel";
invert-hsync;
invert-vsync;
status = "okay";
display-timings {
800x480p60 {
clock-frequency = <33260000>;
hactive = <800>;
vactive = <480>;
hfront-porch = <168>;
hback-porch = <88>;
hsync-len = <64>;
vback-porch = <8>;
vfront-porch = <37>;
vsync-len = <2>;
hsync-active = <1>;
vsync-active = <1>;
};
};
};
};
nferre
Site Admin
Posts: 166
Joined: Wed Feb 14, 2007 11:17 am

Re: Display Configuration with DRM in Linux 3.18

Tue Aug 25, 2015 6:30 pm

Panel definitions are stored in C code and called from DT by the simple-panel.

So, you can store your panel definition here: drivers/gpu/drm/panel/panel-simple.c

Best regards,

Return to “Linux”

Who is online

Users browsing this forum: No registered users and 3 guests