User`s guide

Supporting the i.MX53 Reference Board DISP0 LCD
i.MX53 System Development User’s Guide, Rev. 1
Freescale Semiconductor 18-5
18.3 Modifying Boot Kernel Parameters to Support a New LCD
Users can use the video and di1_primary kernel parameters to change all timing and interface aspect ratios
without writing a single line of code by changing the settings through the default driver.
18.3.1 Setting the Video Kernel Parameter
The video kernel parameter is a multipurpose parameter used to configure display features in either display
port 0 or display port 1. It controls the following features:
• Display resolution
• Pixel color depth
• Refresh rate
• IPU display output interface format
See the modedb.txt file located at Documentation/fb/modedb.txt for specific parameter information.
To set the parameter information for the video argument, use the following format. Variables between
square brackets are optional.
<interface_id>:<ipu_out_fmt>,<xres>x<yres>[M][R][-<bpp>][@<refresh>][i][m]<name>[-<bpp>][@
<refresh>]
Table 18-3 defines the variables.
Active frame height VDISP — 480 — Line
Vertical refresh rate FV 55 60 65 Hz
Screen width or horizontal cycle HP 750 800 900 PIXCLK
HSYNC pulse width HSW 1 1 1 PIXCLK
Horizontal back porch HBP 46 46 46 PIXCLK
Horizontal front porch HFP 64 114 214 PIXCLK
Active frame width HDISP — 640 — PIXCLK
Table 18-3. Parameter Information
Argument Name Definition Units Values
interface_id Display interface id (DI0/DI1) NA mxcdi0fb, mxcdi1fb
interface_pix_fmt Display Interface output format NA RGB565, RGB666, RGB24, YUV444
name Video mode name NA String name
xres Horizontal resolution pixels Decimal value
yres Vertical resolution lines Decimal value
Table 18-2. Timing Parameters (continued)
Parameter Symbol Min Typ Max Unit