Other NXP ProductsのトピックRe: 800x600 VGA Driver in IMX31-Linux

800x600 VGA Driver in IMX31-Linux

siva2fs — Fri, 12 Sep 2008 22:16:34 GMT

hi,
Iam working in IMX31 LInux platform, as we are working in VGA driver in the PDK version of the BSP, we facing a problem in 800x600 display VGA in our custom board. After i modified in the mxcfb.c and mxcfb_modedb.c file with VGA configuration, still the monitor flickering .But its working fine in 640x480 VGA display.Can anyone please suggest me to override this..

Thanks in advance
Best regards,
Sivakumar

Re: 800x600 VGA Driver in IMX31-Linux

GAV — Fri, 31 Oct 2008 08:22:28 GMT

Hello,

In the mxcfb_modedb.c file, what did you make the "Value in Picoseconds" for the DOTCLOCK? For the Epson, as an example, its the number in RED...... its "Epson-VGA", 60, 480, 640, 41701, 20, 111, 10, 15, 20, 10,

In the file "linux-2.6.19.2/drivers/mxc/ipu/ipu_sdc.c there is a hard code divide by 4 that is forced when the 1/picosecond value increases beyond 33MHz. (See code below)

Try forcing is number to an abnormally low value. Like, 2500. This will increase your DOTCLOCK to 33MHz. Still under whats typically recommended for a SVGA display, but on some displays it looks fine. (I have done this with an AOU SVGA display....and it looked good.)

Hope this helps!!!

Gerry

div = (clk_get_rate(g_ipu_clk) * 16) / pixel_clk;
if (div < 0x40) { /* Divider less than 4 */
  dev_dbg(g_ipu_dev,
   "InitPanel() - Pixel clock divider less than 1\n");
  div = 0x40;

Re: 800x600 VGA Driver in IMX31-Linux

fabio_estevam — Fri, 31 Oct 2008 20:18:46 GMT

There is also a nice demo of a 800x600 connected to a MX31 here: http://www.youtube.com/watch?v=gijvxOV14bE&feature=related

Regards,

Fabio Estevam