From: arun c <aru...@gm...> - 2008-04-04 09:02:26
|
Hi all, I am working on 2430SDP. SDP has omap2430 as the processor and it's display controller supports rotation of framebuffer in hardware. I will explain the hardware rotation in brief. 1) One Physical framebuffer is allocated in memory 2) This physical address ( as well as width and height) is programmed in the VRFB Module (the hardware rotation engine, it stands for virtual rotated frame buffer) 3)Then VRFB gives you 4 addresses ( virtual addresses which are transparent to applications) VBA0 --> Address for 0 degree rotation VBA90 --> Address for 90 degree rotation VBA180 --> Address for 180 degree rotation VBA270 --> Address for 270 degree rotation Rotation is achieved like this Assume you want 90 degree rotation Processor writes all picture data to VBA90 space and lcd reads all data from VBA0 space For this kind of implementation i need to change fb_fix_screeninfo members (smem_start ,smem_len) and fb_info member( screen_base) dynamically according to degree of rotation. Please anybody suggest me good ways to implement this kind of rotation in my driver or point me to some code so that i can refer and implement the same. Regards, Arun C |