ROM-5420 User Manual
34
220, 40,
21, 7,
60, 10,
0,
FB_VMODE_NONINTERLACED,
FB_MODE_IS_DETAILED,},
}
The definition of fb_videomode in linux-3.0.35/include/linux/fb.h:
The name field is optional. If you input this value, it can be used in U-Boot environ-
ment settings.
The refresh field is the screen refresh frame rate, such as 60Hz, 70Hz. The resolution
can be filled in the xres & yres fields.
The pixel clock (pixclock) is equaled to
10
12
/(Total horizontal line * Total vertical line *
DCLK
). For example, the total horizontal line is 1344 DCLK, and total vertical number
is 806 horizontal lines. The DCLK frequency is 60 MHz. Therefore, we can get 10
12
/
(1344*806*60) = 15385.
The
margin
values can be seen as front porch & back porch.
The
sync_len
means pulse width.
The
sync
value indicates the sync polarity (low or high).
struct fb_videomode {
const char *name; (optional)
u32 refresh; (optional)
u32 xres;
u32 yres;
u32 pixclock;
u32 left_margin;
u32 right_margin;
u32 upper_margin;
u32 lower_margin;
u32 hsync_len;
u32 vsync_len;
u32 sync;
u32 vmode;
u32 flag;
};
3.8.5.2
Single Display Settings
HDMI out, please set in u-boot as below:
setenv bootargs_mmc 'setenv bootargs ${bootargs} root=/dev/
mmcblk1p1 rootwait rw video=mxcfb0:dev=hdmi,1920x1080M@60,if=RGB24'
VGA out, please set in u-boot as below:
setenv bootargs_mmc 'setenv bootargs ${bootargs} root=/dev/
mmcblk1p1 rootwait rw video=mxcfb0:dev=lcd,1920x1080M@60,if=RGB24'
